CN102748900B - Heat pump, heat pump air conditioner and heat pump water heating unit sequentially using single/double stage compression - Google Patents

Abstract

The invention relates to a heat pump, a heat pump air conditioner and a heat pump water heating unit sequentially using single/double stage compression. The heat pump comprises a condenser, a throttling device, an evaporator and a compressor unit which are sequentially connected through refrigerating agent pipelines, wherein a heat absorption device of the evaporator is positioned in a low-temperature heat source, the condenser is positioned in a heated medium, the compressor unit is connected with a control device, and the control device is used for controlling the compressor unit to carry out single-stage parallel compression or recombining the compressor unit to carry out two-stage series compression. According to the invention, a classification recombination method is adopted by the compressor, the single/double compression is sequentially used, the 'three-high and one-low' technical problems that the air suction and exhaust differential pressure of the compressor is increased, the compression ratio is increased, the air exhaust temperature of the compressor is increased, and the heating efficiency is reduced are improved and solved under the conditions of lower environment temperature and higher heated medium temperature, and the energy in the air can be efficiently absorbed.

Description

Heat pump, heat pump air conditioner and heat-pump hot-water unit that single Two-stage Compression uses in order

Technical field

The present invention relates to a kind of heat pump, particularly the heat pump, heat pump air conditioner and the heat-pump hot-water unit that use in order of a kind of single Two-stage Compression.

Background technology

Heat pump is a kind of evaporation by working medium and condensation, by the thermal apparatus of the heat energy transfer of low-temperature heat source to high temperature heat source.The low-temperature heat source being generally used for heat pump assembly is medium---air, river, seawater around us, municipal sewage, surface water, underground water, middle water, fire cistern, or the medium of discharging from the equipment of industrial product.At present, heat pump can be used for the heating to water, wet goods medium.But, in existing heat pump, main employing single stage compress mode, if low-temperature heat source temperature is low, heated medium temperature is high, then the evaporating pressure of heat pump evaporimeter is low, the condensing pressure of condenser is high, cause suction pressure of compressor and pressure at expulsion " pressure reduction " between the two to expand, compression ratio increases, and compressor exhaust temperature raises, working conditions of compressor worsens, and heating capacity declines.Therefore, single stage compress heat pump, cannot meet the Production requirement of high temperature drying, air heat and health hot water at low temperature season.

As in air source heat pump hot water production device, main employing single stage compress system at present, its groundwork process is, cold-producing medium absorbs air heat energy and becomes low-pressure steam in evaporimeter, shortened into the steam of HTHP by compressor suction pressure, enter condenser and be condensed into refrigerant liquid after heat released by running water, reduce pressure through throttling arrangement again, again flow into evaporimeter, thus enter new round circulation, so move in circles, constantly the air heat energy of low-temperature space is pumped into the health hot water of high-temperature region.The single-stage compression heat-pump hot-water process units of operation like this, its heating efficiency (Energy Efficiency Ratio) determines primarily of the condensing pressure of heat pump and evaporating pressure.For heat-pump hot-water unit, if environment temperature high (such as 15 DEG C), hot water temperature's low (such as 25 DEG C), evaporating pressure then in heat pump evaporimeter higher (can more than 6atm be reached), condensing pressure in condenser lower (about 12atm), suction pressure of compressor and pressure at expulsion " pressure reduction " are between the two less, compression ratio is little, compressor exhaust temperature is lower, working conditions of compressor is good, heating capacity is extremely strong, and heating efficiency (heating the ratio of power and institute's power consumption) can reach more than 10 times.If but environment temperature is low, hot water temperature is high, then the evaporating pressure of heat pump evaporimeter is low, the condensing pressure of condenser is high, suction pressure of compressor and pressure at expulsion " pressure reduction " is between the two caused to increase, compression ratio increases, compressor exhaust temperature raises, " three high and one low " phenomenon that heating capacity declines, and working conditions of compressor worsens.

Because the evaporating temperature of heat pump must lower than the temperature of surrounding air, the liquid refrigerant in evaporimeter could absorb heat, carburation by evaporation from the air evaporimeter; So the evaporating pressure of heat pump is mainly determined by the temperature of surrounding air, the low then evaporating pressure of environment temperature is low, and the density of the refrigerant gas that compressor sucks is low, and circulating mass of refrigerant is little, and heating capacity is poor.And the condensation temperature of heat pump hot-water system must higher than hot water temperature, heat could be put to the hot water outside condenser by the refrigerant gas in condenser, condensation liquefaction; So the condensing pressure of heat-pump hot-water unit is mainly determined by the temperature of hot water in water tank, hot water temperature raises then condensing pressure and raises.Therefore, the heat pump hot-water system of band water-storing tank is an ever-increasing varying duty system of compressor electric motor load.

The air source heat pump hot water production device of current operation, the single stage compress that adopts heats mode more.Out of doors time environment temperature lower (less than 0 DEG C), initial period, because the tap water temperature in water tank is lower, heating efficiency is also higher; But when running water in water tank enters middle high-temperature region, then between the condensing pressure of this system and evaporating pressure " pressure reduction " obviously expands, compression ratio significantly improves, compressor exhaust temperature increases fast, working conditions of compressor obviously worsens, and heating efficiency declines fast.

Please refer to table 1, according to the data of American blend compressor " paddy wheel " manufacturer's up-to-date issue in 2011, different evaporating temperature, condensation temperature and the motor of a ZW108KS three-phase screw compressor suck power P and heat the relation between power (heating capacity) H, wherein, this compressor adopts R22 cold-producing medium.

Different evaporating temperature, condensation temperature and the motor of table 1:ZW108KS three-phase screw compressor suck power P and heat the relation between power (heating capacity) H

As can be seen from Table 1, under evaporating temperature 15 DEG C of condensation temperatures 25 DEG C of conditions, suck electrical power 4435W, heating capacity 47595W, its heating efficiency is up to 10.7; But this ZW108KS compressor, under the condition of evaporating temperature-25 DEG C, condensation temperature+65 DEG C, suck electrical power 9825W, heating capacity 15858W, its heating efficiency is down to 1.61; Compare with previous operating mode, compressor sucks electrical power increases by 121%, heating capacity reduces by 66.7%, has occurred the phenomenon of " three high and one low " that condensing pressure rising, compression ratio rising, compressor exhaust temperature rising, heating efficiency reduce, working conditions of compressor severe exacerbation.And, this or laboratory data, in the heating of reality, because repeatedly carry out power consumption etc. the factor of the reversion defrost on evaporimeter, water Pumps & Fans in the on-way resistance of evaporimeter, condenser " two devices ", system operation, the heating efficiency of system is by < 1.5, close to the direct-fired efficiency of resistance, high energy efficiency ratio and the economy of " heat pump " exhaust.This is the corollary of high compression ratio single stage compress heat pump process.

Same problem is also present in existing Household hot pump type air-conditioning.

Outdoor environment temperature-10 DEG C, under indoor air temperature 30 DEG C of conditions, consider that cross-ventilation heat transfer coefficient is lower, and the heat transfer area of outdoor unit heat exchanger is larger, the off-premises station evaporator heat transfer temperature difference of its reality is 10 DEG C, the indoor set condenser thermal transfer temperature difference is 15 DEG C, when air-conditioning carries out heating operation, indoor set leaving air temp 50 DEG C, i.e. evaporating temperature-20 DEG C, condensation temperature 65 DEG C, the heating efficiency of the heat pump air conditioner unit of ZW108KS three-phase screw compressor is adopted to only have 1.88, only be equivalent to outside air temperature 20 DEG C, evaporating temperature 10 DEG C, indoor air temperature 30 DEG C, about 48% of this heat pump air conditioner unit heating efficiency 3.86 under condensation temperature 65 DEG C of operating modes, this or laboratory data.

If environment temperature declines further, such as outdoor temperature drops to less than-20 DEG C, add heat pump in actual motion to the defrosting repeatedly to evaporimeter in off-premises station, and the factor such as the on-way resistance of evaporator-condenser " two devices " causes evaporating pressure to reduce further, condensing pressure raises further, no matter be fixed frequency air conditioner or convertible frequency air-conditioner, its heating efficiency and economy all will decay totally.In order to make up the shortcoming of heat pump air conditioner cold operation poor performance, current common practice can only be increase the auxiliary heater such as PTC or electrothermal tube, does not so both improve heat pump compressor bad working environments, the more overall energy consumption of air-conditioner is increased, economy is lower.

Therefore, current single stage compress air source heat pump system, cannot meet the high temperature health hot water Production requirement of Cold Winter, also cannot solve the shortcoming of Cold Winter heat pump air conditioner heating operation poor performance at all.

Summary of the invention

The object of the present invention is to provide the heat pump that a kind of single Two-stage Compression uses in order, to solve the technical problem heating high-temperature medium under cryogenic that single stage compress air source heat pump system cannot meet;

The present invention also aims to the heat pump air conditioner providing a kind of single Two-stage Compression to use in order, to solve the technical problem that single stage compress air source heat pump system in prior art cannot solve suction and discharge pressure reduction raises, compression ratio raises, compressor exhaust temperature raises, heating efficiency reduces " three high and one low " when Cold Winter air-conditioning heating runs;

The present invention also aims to the heat-pump hot-water unit providing a kind of single Two-stage Compression to use in order, to solve " three high and one low " technical problem that suction and discharge pressure reduction raises when Cold Winter heating operation, compression ratio raises, compressor exhaust temperature raises, heating efficiency reduces of single stage compress air source heat pump system in prior art, to meet the production of the high temperature health hot water of Cold Winter.

In order to solve the problem, the invention provides the heat pump that a kind of single Two-stage Compression uses in order, comprise the condenser, throttling arrangement, evaporimeter and the compressor bank that sequentially pass through refrigerant line and connect, the heat sink at described evaporimeter place is placed in low-temperature heat source, described condenser is placed in heated medium, described compressor bank is connected with a control device, and described control device controls compressor bank to carry out single-stage parallel connection compression or recombinate carrying out two-stage series connection compression;

Described compressor bank comprises some compressors, some compressors control to carry out single-stage parallel connection compression or be reassembled as first order compression and second level compression series connection compression by described control device, the compression of the described first order comprises one or at least two compressors in parallel, and the compression of the described second level comprises one or at least two compressors in parallel;

Be reassembled as first order compression and second level compression series connection compression when described control device controls described compressor bank, the inspiratory capacity of wherein said first order compressor is 4 to 8 times of the inspiratory capacity of second level compression.

According to the heat pump that the single Two-stage Compression described in the application's preferred embodiment uses in order, described compressor bank comprises a multicylinder compressor, some cylinders are comprised in this multicylinder compressor, some cylinders carry out single-stage parallel connection compression by control device or are reassembled as first order compression and second level compression series connection compression, the compression of the described first order comprises one or at least two cylinders in parallel, and the compression of the described second level comprises one or at least two cylinders in parallel.

According to the heat pump that the single Two-stage Compression described in the application's preferred embodiment uses in order, described compressor bank is when two-stage series connection compresses, the refrigerant gas discharge rate that refrigerant gas soakage and the previous stage of the compression of described rear stage compresss matches, and defers to that " the work done during compression w of the certain volume gas to suction is compressed in the second level ₂the work done during compression w to the equivalent volumes gas sucked is compressed with the first order ₁substantially equal; I.e. second level compression pressure reduction p ₂be less than first order compression pressure reduction p ₁, p ₂≈ (0.3 ~ 0.8) p ₁; Also be second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁" principle.

According to the heat pump that the single Two-stage Compression described in the application's preferred embodiment uses in order, described compressor bank comprises 5 ~ 9 compressors, and described first order compression comprises 4 ~ 8 compressors in parallel.

According to the heat pump that the single Two-stage Compression described in the application's preferred embodiment uses in order, described compressor bank comprises at least one large compressor and at least one little compressor, and the inspiratory capacity of described large compressor is 4 to 8 times of the inspiratory capacity of little compressor; Described large compressor and little compressor are when double stage tandem compression work, and described large compressor is placed in first order compression, and described little compressor is placed in second level compression.

According to the heat pump that the single Two-stage Compression described in the application's preferred embodiment uses in order, the compression of the described second level is or/and the compressor of first order compression is frequency-changeable compressor.

According to the heat pump that the single Two-stage Compression described in the application's preferred embodiment uses in order, described control device comprises some magnetic valves, controls compressor bank carry out single-stage parallel connection compression or recombinate carrying out two-stage series connection compression by the break-make of each magnetic valve.

According to the heat pump that the single Two-stage Compression described in the application's preferred embodiment uses in order, described low-temperature heat source comprises air or underground water or seawater, and described heated medium comprises water or air or oil.

The heat pump air conditioner that the present invention also provides a kind of single Two-stage Compression to use in order, comprise indoor set, off-premises station, also comprise the condenser, throttling arrangement, evaporimeter and the compressor bank that sequentially pass through refrigerant line and connect, described condenser is arranged in described indoor set, described indoor set is placed in air, the off-premises station at described evaporimeter place is placed in air or seawater or underground water, described compressor bank is connected with a control device, and described control device controls compressor bank to carry out single-stage parallel connection compression or recombinate carrying out two-stage series connection compression;

Described compressor bank comprises some compressors, some compressors control to carry out single-stage parallel connection compression or be reassembled as first order compression and second level compression series connection compression by described control device, the compression of the described first order comprises one or at least two compressors in parallel, and the compression of the described second level comprises one or at least two compressors in parallel;

Be reassembled as first order compression and second level compression series connection compression when described control device controls described compressor bank, the inspiratory capacity of wherein said first order compressor is 4 to 8 times of the inspiratory capacity of second level compression.

According to the heat pump air conditioner that the single Two-stage Compression described in the application's preferred embodiment uses in order, described compressor bank comprises a multicylinder compressor, some cylinders are comprised in this multicylinder compressor, some cylinders carry out single-stage parallel connection compression by control device or are reassembled as first order compression and second level compression series connection compression, the compression of the described first order comprises one or at least two cylinders in parallel, and the compression of the described second level comprises one or at least two cylinders in parallel.

According to the heat pump air conditioner that the single Two-stage Compression described in the application's preferred embodiment uses in order, described compressor bank is when two-stage series connection compresses, the refrigerant gas discharge rate that refrigerant gas soakage and the previous stage of the compression of described rear stage compresss matches, and defers to that " the work done during compression w of the certain volume gas to suction is compressed in the second level ₂the work done during compression w to the equivalent volumes gas sucked is compressed with the first order ₁substantially equal; I.e. second level compression pressure reduction p ₂be less than first order compression pressure reduction p ₁, p ₂≈ (0.3 ~ 0.8) p ₁; Also be second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁" principle.

According to the heat pump air conditioner that the single Two-stage Compression described in the application's preferred embodiment uses in order, described compressor bank comprises 5 ~ 9 compressors, and described first order compression comprises 4 ~ 8 compressors in parallel.

According to the heat pump air conditioner that the single Two-stage Compression described in the application's preferred embodiment uses in order, described compressor bank comprises at least one large compressor and at least one little compressor, and the inspiratory capacity of described large compressor is 4 to 8 times of the inspiratory capacity of little compressor; Described large compressor and little compressor are when double stage tandem compression work, and described large compressor is placed in first order compression, and described little compressor is placed in second level compression.

According to the heat pump air conditioner that the single Two-stage Compression described in the application's preferred embodiment uses in order, the compression of the described second level is or/and the compressor of first order compression is frequency-changeable compressor.

According to the heat pump air conditioner that the single Two-stage Compression described in the application's preferred embodiment uses in order, described control device comprises some magnetic valves, controls compressor bank carry out single-stage parallel connection compression or recombinate carrying out two-stage series connection compression by the break-make of each magnetic valve.

The heat-pump hot-water unit that the present invention also provides a kind of single Two-stage Compression to use in order, comprise water tank, also comprise the condenser, throttling arrangement, evaporimeter and the compressor bank that sequentially pass through refrigerant line and connect, described condenser is arranged in described water tank, the heat sink at described evaporimeter place is placed in air or seawater or underground water, described compressor bank is connected with a control device, and described control device controls compressor bank to carry out single-stage parallel connection compression or recombinate carrying out two-stage series connection compression;

Described compressor bank comprises some compressors, some compressors control to carry out single-stage parallel connection compression or be reassembled as first order compression and second level compression series connection compression by described control device, the compression of the described first order comprises one or at least two compressors in parallel, and the compression of the described second level comprises one or at least two compressors in parallel;

Be reassembled as first order compression and second level compression series connection compression when described control device controls described compressor bank, the inspiratory capacity of wherein said first order compressor is 4 to 8 times of the inspiratory capacity of second level compression.

According to the heat-pump hot-water unit that the single Two-stage Compression described in the application's preferred embodiment uses in order, described compressor bank comprises a multicylinder compressor, some cylinders are comprised in this multicylinder compressor, some cylinders carry out single-stage parallel connection compression by control device or are reassembled as first order compression and second level compression series connection compression, the compression of the described first order comprises one or at least two cylinders in parallel, and the compression of the described second level comprises one or at least two cylinders in parallel.

According to the heat-pump hot-water unit that the single Two-stage Compression described in the application's preferred embodiment uses in order, described compressor bank is when two-stage series connection compresses, the refrigerant gas discharge rate that refrigerant gas soakage and the previous stage of the compression of described rear stage compresss matches, and defers to that " the work done during compression w of the certain volume gas to suction is compressed in the second level ₂the work done during compression w to the equivalent volumes gas sucked is compressed with the first order ₁substantially equal; I.e. second level compression pressure reduction p ₂be less than first order compression pressure reduction p ₁, p ₂≈ (0.3 ~ 0.8) p ₁; Also be second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁" principle.

According to the heat-pump hot-water unit that the single Two-stage Compression described in the application's preferred embodiment uses in order, described compressor bank comprises 5 ~ 9 compressors, and described first order compression comprises 4 ~ 8 compressors in parallel.

According to the heat-pump hot-water unit that the single Two-stage Compression described in the application's preferred embodiment uses in order, described compressor bank comprises at least one large compressor and at least one little compressor, and the inspiratory capacity of described large compressor is 4 to 8 times of the inspiratory capacity of little compressor; Described large compressor and little compressor are when double stage tandem compression work, and described large compressor is placed in first order compression, and described little compressor is placed in second level compression.

According to the heat-pump hot-water unit that the single Two-stage Compression described in the application's preferred embodiment uses in order, the compression of the described second level is or/and the compressor of first order compression is frequency-changeable compressor.

According to the heat-pump hot-water unit that the single Two-stage Compression described in the application's preferred embodiment uses in order, described control device comprises some magnetic valves, controls compressor bank carry out single-stage parallel connection compression or recombinate carrying out two-stage series connection compression by the break-make of each magnetic valve.

Compared with prior art, there is following technique effect in the present invention:

The heat pump that a kind of single Two-stage Compression provided by the invention uses in order, compressor adopts classification recombination method, the single/double stage that uses in order compresses, can under, condition that heated medium temperature is higher lower in environment temperature, improve and solve the technical problem of compressor suction and discharge pressure reduction raises, compression ratio raises, compressor exhaust temperature raises, heating efficiency reduces " three high and one low ", high efficiency absorbs the energy in air.

The heat pump air conditioner that the present invention also provides a kind of single Two-stage Compression to use in order, adopt compressor classification recombination method provided by the invention, lower than in the environment of-10 DEG C, adopt two stages of compression, high efficiency absorbs the energy in air, with the air heat release to about 30 DEG C, indoor.As winter outside air temperature higher (general > 0 DEG C), then adopt 2 compressor parallel connections to produce for the heat pump air conditioner be made up of small one and large one two compressor, namely single stage compress mode heats.And when outside air temperature lower (general < 0 DEG C), large compressor is then adopted to compress as the first order for the heat pump air conditioner be made up of small one and large one two compressor, little compressor compresses as the second level, first, Two-stage Compression is formed after two-stage compression series connection, with the air heat release to about 30 DEG C, indoor, now two-stage compression heat pump system can improve working conditions of compressor, improve entire system heating efficiency, solve single stage compress heat pump in prior art and cannot meet the technical problem that the heating of Cold Winter room air realizes heating, and solve the suction and discharge pressure reduction that existing single stage compress air source heat pump system occurs when room temperature more than 30 DEG C and raise, compression ratio raises, compressor exhaust temperature raises, the technical problem of " three high and one low " that heating efficiency reduces.

The heat-pump hot-water unit that the present invention also provides a kind of single Two-stage Compression to use in order, adopt compressor classification recombination method provided by the invention, the heat pump of the single/double stage that uses in order compression, high efficiency can absorb energy in air, to produce the health hot water of about 60 DEG C.As the water temperature of heat pump type hot water machine water tank lower (general < 40 DEG C), then adopt multiple compressors parallel connection to produce for the heat-pump water heater be made up of multiple compressors, namely single stage compress mode heats and carries out hot water production.And when water tank water temperature higher (general > 40 DEG C), about about 6/7 quantity compressor parallel is then adopted to compress as the first order for the heat-pump water heater be made up of multiple compressors, about 1/7 remaining compressor compresses as the second level, first, Two-stage Compression is formed after two-stage compression series connection, that carries out hot water high temperature section heats production, the heat pump that this kind of single Two-stage Compression uses in order can improve working conditions of compressor, improve entire system heating efficiency, solve the technical problem that single stage compress air source heat pump system in prior art cannot meet the high temperature health hot water Production requirement of Cold Winter, and solve the suction and discharge pressure reduction that existing single stage compress air source heat pump system occurs during high-temperature region in water tank water temperature is in and raise, compression ratio raises, compressor exhaust temperature raises, the technical problem of " three high and one low " that heating efficiency reduces.

Accompanying drawing explanation

Fig. 1 is the structural representation of the heat pump air conditioner that a kind of single Two-stage Compression of the present invention uses in order;

Fig. 2 is the structural representation of the heat pump air conditioner that the present invention adopts single stage compress to use;

Fig. 3 is the structural representation of the heat pump air conditioner that the present invention adopts Two-stage Compression to use;

Fig. 4 be the present invention's heat pump air conditioner of adopting Two-stage Compression to use P-V figure

Fig. 5 is the structural representation of the heat-pump hot-water unit that a kind of single Two-stage Compression of the present invention uses in order;

Fig. 6 is the structural representation of the heat-pump hot-water unit that the present invention adopts single stage compress to use;

Fig. 7 is the structural representation of the heat-pump hot-water unit that the present invention adopts Two-stage Compression to use;

Fig. 8 be the present invention's heat-pump hot-water unit of adopting Two-stage Compression to use P-V figure.

Detailed description of the invention

The invention provides the heat pump that a kind of single Two-stage Compression uses in order, comprise the condenser, throttling arrangement, evaporimeter and the compressor bank that sequentially pass through refrigerant line and connect, the heat sink at evaporimeter place is placed in low-temperature heat source, condenser is placed in heated medium, compressor bank is connected with a control device, and control device controls compressor bank to carry out single-stage parallel connection compression or recombinate carrying out two-stage series connection compression.In the present invention, low-temperature heat source can comprise air or seawater or underground water, and heated medium can comprise water or air or wet goods, and the type of the present invention to low-temperature heat source and heated medium is not limited.

In the present invention, compressor bank has following several possible structure:

The first, compressor bank comprises some identical compressors, and some compressors carry out single-stage parallel connection compression by control device, or some compressors carry out two-stage series connection compression by control device restructuring.As adopted multiple compressor parallel to carry out single stage compress at low-temperature space, adopt multiple weight of compressor to form two-stage series connection compression in middle high-temperature region, two-stage series connection compression can improve working conditions of compressor, improve the overall heating efficiency of system.

In the present invention, some compressors control to carry out single-stage parallel connection compression or be reassembled as first order compression and second level compression series connection compression by control device, first order compression comprises one or at least two compressors in parallel, and second level compression comprises one or at least two compressors in parallel.The present invention does not limit the compressor number in first order compression and second level compression, but in order to improve compression efficiency, compressor bank is when two-stage series connection compresses, the refrigerant gas discharge rate that refrigerant gas soakage and the previous stage of rear stage compression compresss matches, and defers to that " the work done during compression w of the certain volume gas to suction is compressed in the second level ₂the work done during compression w to the equivalent volumes gas sucked is compressed with the first order ₁substantially equal; I.e. second level compression pressure reduction p ₂be less than first order compression pressure reduction p ₁, p ₂≈ (0.3 ~ 0.8) p ₁; Also be second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁" principle.

First order compression can be the identical single cylinder compressor of structure with each compressor in the compression of the second level, as compressor bank comprises the multiple compressor of 5 ~ 9 or 5 ~ 9, the first order compresses the compressor of the multiple platform parallel connection comprising 4 ~ 8 or 4 ~ 8, preferably, compressor bank comprises 5 ~ 9 compressors, first order compression comprises 4 ~ 8 compressors in parallel, but the present invention is not limited thereto.In the present invention, the first order compression and the second level compress in each compressor also can be multicylinder compressor, as long as meet compressor bank when two-stage series connection compresses, the refrigerant gas discharge rate that the refrigerant gas soakage of rear stage compression and previous stage are compressed matches, the second level is compressed pressure reduction and is less than the principle that the first order compresses pressure reduction, and the present invention does not limit this.In this enforcement embodiment, second level compression is or/and each compressor in first order compression can adopt frequency-changeable compressor, according to actual conditions by changing incoming frequency thus changing compressor speed power, to reach energy-conservation effect, but the present invention does not do concrete restriction to this.

The second, compressor bank comprises a multicylinder compressor, comprises some cylinders in this multicylinder compressor, and some cylinders carry out single-stage parallel connection compression by control device, or some cylinders carry out two-stage series connection compression by control device restructuring.As adopted multiple cylinder parallel connection to carry out single stage compress at low-temperature space, adopt multi-cylinder to reassemble into two-stage series connection compression in middle high-temperature region, two-stage series connection compression can improve working conditions of compressor, improve overall heating efficiency of the present invention.

In the present invention, some cylinders control to carry out single-stage parallel connection compression or be reassembled as first order compression and second level compression series connection compression by control device, first order compression comprises one or at least two cylinders in parallel, and second level compression comprises one or at least two cylinders in parallel.The present invention does not limit the cylinder number in first order compression and second level compression, but in order to improve compression efficiency, compressor bank is when two-stage series connection compresses, the refrigerant gas discharge rate that refrigerant gas soakage and the previous stage of rear stage compression compresss matches, and defers to that " the work done during compression w of the certain volume gas to suction is compressed in the second level ₂the work done during compression w to the equivalent volumes gas sucked is compressed with the first order ₁substantially equal; I.e. second level compression pressure reduction p ₂be less than first order compression pressure reduction p ₁, p ₂≈ (0.3 ~ 0.8) p ₁; Also be second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁" principle multiple cylinder is recombinated.In the present invention, first order compression adopts more number of cylinders.As in six cylinder compressors, when carrying out two-stage series connection compression, the cylinder that first order compression employing 5 is in parallel, second level boil down to 1 cylinder, first order compression is compressed with the second level and is connected, and this is one of them specific embodiment of present embodiment, but the present invention is not limited thereto.

The third, compressor bank comprises at least one large compressor and at least one little compressor, and the inspiratory capacity of large compressor is greater than the inspiratory capacity of little compressor, and the inspiratory capacity of concrete large compressor is that several times of the present invention of little compressor air suction amount do not limit.Preferably, large compressor and little compressor are when double stage tandem works, the inspiratory capacity of large compressor is 4 to 8 times of the inspiratory capacity of little compressor, preferably, the inspiratory capacity of large compressor is 6 times of the inspiratory capacity of little compressor, large compressor and little compressor are when double stage tandem works, and large compressor is placed in first order compression, and little compressor is placed in second level compression.Namely the compressor bank of heat-pump-type Hot water units is made up of small one and large one two compressor (or compressor of their integral multiples), and the inspiratory capacity of this small one and large one two compressors differs about 6 times.

Compressor bank can adopt any one of above-mentioned several situation, and the present invention does not limit.

In the present invention, control device comprises some magnetic valves, controls compressor bank carry out single-stage parallel connection compression or recombinate carrying out two-stage series connection compression by the break-make of each magnetic valve.The principle of carrying out plural serial stage compression to compressor bank restructuring by control device is identical with the principle that two-stage series connection compression is carried out in restructuring, therefore, carries out plural serial stage compression also belong to protection scope of the present invention by control device to compressor bank restructuring.

In the present invention, the heat pump that this single Two-stage Compression uses in order can be used for heating water, air, wet goods heated medium, its principle of heating is identical, in order to hot pump structure of the present invention and operation principle can be clearly stated, be used for air-conditioner for heat pump add hot-air and for hot water production, described in detail.

The present invention also provides a kind of heat pump air conditioner of single Two-stage Compression, comprise indoor set and off-premises station, also comprise the condenser, throttling arrangement, evaporimeter and the compressor bank that sequentially pass through refrigerant line and connect, the number of the present invention to evaporimeter does not limit, as comprised the evaporimeter of some parallel connections.Condenser i.e. indoor set disposed in the interior, indoor set is placed in air, the heat sink at evaporimeter place and off-premises station are placed in outdoor air or seawater or underground water, and the present invention is not limited this, is placed in air is described in detail at the present embodiment for off-premises station.Compressor bank is connected with a control device, and control device controls compressor bank to carry out single-stage parallel connection compression or recombinate carrying out two-stage series connection compression.Control device is connected with compressor bank, controls compressor bank and carries out single-stage compression pyrogenic in parallel when outdoor environment temperature is in middle and high warm area (general >0 DEG C) in the winter time.When outdoor environment temperature is in low-temperature space (general <0 DEG C) in the winter time, first carry out single-stage compression pyrogenic in parallel; When indoor air temperature reaches more than 20 temperature, then by the most of compressor in compressor bank or cylinder parallel connection, compress as the first order; Remaining minority compressor parallel or cylinder (if also having more than 2), compress as the second level; And then by first and second level compression series connection, form Two-stage Compression, effectively can improve indoor environment temperature, solve and improve the problem of compressor suction and discharge pressure reduction raises, compression ratio raises, compressor exhaust temperature raises, heating efficiency reduces " three high and one low " that existing single stage compress air source heat pump system occurs when severe cold season environment temperature is low.Below enumerate some preferably embodiment described in detail.

The first, compressor bank comprises some identical compressors, and some compressors carry out single-stage parallel connection compression by control device, or some compressors carry out two-stage series connection compression by control device restructuring.Multiple compressor parallel is adopted to carry out single stage compress as outdoor environment temperature is in the winter time in 0 DEG C with upper high-temperature region; When environment temperature is in the low-temperature space lower than 0 DEG C, first carry out single-stage compression pyrogenic in parallel; When indoor air temperature reaches more than 20 temperature, then adopt multiple weight of compressor to form two-stage series connection compression, two-stage series connection compression can improve working conditions of compressor, improve the overall heating efficiency of system.

During in order to room air effectively be heated (> 30 DEG C) in low temperature environment (< 0 DEG C) in the winter time, the refrigerant discharge capacity that cold-producing medium soakage and the first order of the second level compression compresss matches, the present invention and defer to that " the work done during compression w of the certain volume gas to suction is compressed in the second level ₂the work done during compression w to the equivalent volumes gas sucked is compressed with the first order ₁substantially equal; I.e. second level compression pressure reduction p ₂be less than first order compression pressure reduction p ₁, p ₂≈ (0.3 ~ 0.8) p ₁; Also be second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁" principle carry out the restructuring of multiple compressors.First order compression can be the identical single cylinder compressor of structure with each compressor in the compression of the second level, as compressor bank comprises the multiple compressor of 5 ~ 9 or 5 ~ 9, the first order compresses the compressor of the multiple platform parallel connection comprising 4 ~ 8 or 4 ~ 8, preferably, compressor bank comprises 5 ~ 9 compressors, first order compression comprises 4 ~ 8 compressors in parallel, but the present invention is not limited thereto.The present embodiment preferably recombination method is, first order compression comprises 6 compressors in parallel, and second level compression comprises 1 compressor.During 7 compressor parallel connections simultaneously, compressor bank does single-stage parallel connection compression.When 1 compressor compressed with the second level again after 6 compressor parallels of first order compression is connected, compressor bank forms Two-stage Compression.The number of the present invention to compressor does not limit, and, does not also limit the restructuring situation of multiple compressor meanwhile, can select number and the restructuring progression of compressor according to concrete service condition.

The second, compressor bank comprises a multicylinder compressor, comprises some cylinders in this multicylinder compressor, and some cylinders carry out single-stage parallel connection compression by control device, or some cylinders carry out two-stage series connection compression by control device restructuring.Multiple cylinder parallel connection is adopted to carry out single stage compress as environment temperature is in the winter time in high-temperature region in more than 0 DEG C; Be in the low-temperature space lower than 0 DEG C in environment temperature, first carry out single-stage compression pyrogenic in parallel; When indoor air temperature reaches more than 20 temperature, then adopt multi-cylinder to reassemble into two-stage series connection compression, two-stage series connection compression can improve working conditions of compressor, improve overall heating efficiency of the present invention.

In the present invention, some cylinders control to carry out single-stage parallel connection compression or be reassembled as first order compression and second level compression series connection compression by control device, first order compression comprises one or at least two cylinders in parallel, and second level compression comprises one or at least two cylinders in parallel.The present invention does not limit the cylinder number in first order compression and second level compression, but in order to improve compression efficiency, compressor bank is when two-stage series connection compresses, the refrigerant gas discharge rate that the refrigerant gas soakage of rear stage compression and previous stage are compressed matches, and the present invention defers to, and " second level compression is to the work done during compression w of the certain volume gas sucked ₂the work done during compression w to the equivalent volumes gas sucked is compressed with the first order ₁substantially equal; I.e. second level compression pressure reduction p ₂be less than first order compression pressure reduction p ₁, p ₂≈ (0.3 ~ 0.8) p ₁; Also be second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁" principle multiple cylinder is recombinated.In the present invention, first order compression adopts more number of cylinders.The restructuring situation of the present invention to multiple cylinder does not also limit, and can select number and the restructuring progression of cylinder according to concrete service condition.As for eight cylinder compressors, the cylinder that first order compression employing seven is in parallel, second level compression employing cylinder.

The third, compressor bank comprises at least one large compressor and at least one little compressor, the inspiratory capacity of large compressor is 4 to 8 times of the inspiratory capacity of little compressor, preferably, the inspiratory capacity of large compressor is 6 times of the inspiratory capacity of little compressor, large compressor and little compressor are when double stage tandem works, and large compressor is placed in first order compression, and little compressor is placed in second level compression.Namely the compressor bank of heat pump air conditioner is made up of small one and large one two compressor (or compressor of their integral multiples), and the inspiratory capacity of this small one and large one two compressors differs about 6 times, the present invention is with reference to the Principles and ways of a two-stage compression module restructuring of above-mentioned compressor group, in the winter time time environment temperature higher (general >0 DEG C), this small one and large one two compressor parallel connections are carried out heating work, namely adopts single stage compress mode to heat air; And when environment temperature lower (general <0 DEG C), first carry out single-stage compression pyrogenic in parallel; When indoor air temperature reaches more than 20 temperature, then compressed as the first order by large inspiratory capacity compressor, inspiratory capacity only has the little compressor of large compressor about 1/6 to compress as the second level; And then by first and second level compression series connection, form Two-stage Compression, heat, the good result improved working conditions of compressor, improve the overall heating efficiency of unit can be reached equally.

In the present invention, multicylinder compressor and multiple single cylinder compressor and multicylinder compressor are identical with the operation principle of the compress mode that single cylinder compressor combines, and the present invention is illustrated no longer one by one.

Below in conjunction with accompanying drawing, for the heat pump air conditioner unit be made up of small one and large one two compressors, the heat pump air conditioner that single Two-stage Compression uses in order is described in detail.

Please refer to Fig. 1, the heat pump air conditioner that a kind of single Two-stage Compression uses in order, comprise indoor set 10, off-premises station and heat pump assembly, heat pump assembly comprises the condenser 2, throttling arrangement, evaporimeter 5 and the compressor bank 6 that sequentially pass through refrigerant line and connect, in the present embodiment, heat pump assembly comprises three condensers 2 in parallel, but the number of the present invention to condenser does not limit.In condenser 2 machine 10 disposed in the interior, indoor set 10 is placed in air, and the off-premises station at evaporimeter 5 place is placed in air, and compressor bank is connected with a control device, and control device controls compressor bank to carry out single-stage parallel connection compression or recombinate carrying out two-stage series connection compression.In the present embodiment, the lower end of indoor set 11 is provided with air outlet, air inlet and outlet pipe, control device comprises some magnetic valves, control compressor bank 6 by the break-make of each magnetic valve to carry out single-stage parallel connection compression or recombinate carrying out double stage tandem compression, wherein, compressor bank 6 comprises large compressor and a little compressor, the inspiratory capacity of large compressor is about 5.5 times of little compressor, large compressor 68 and little compressor 69 carry out single-stage parallel connection compression by control device, or two-stage series connection compression is carried out in restructuring.In heat pump assembly, the pipeline connecting little compressor 69 has two, i.e. the first pipeline and the second pipeline, first pipeline is provided with on magnetic valve 1 and magnetic valve 39, second pipeline and magnetic valve 28 is set: please refer to Fig. 2, when magnetic valve 1 and magnetic valve 39 open, magnetic valve 28 close time, first pipeline is connected, second pipeline is closed, and little compressor 69 is in parallel with large compressor 68, is called single-stage parallel connection compression; Please refer to Fig. 3, when magnetic valve 1 and magnetic valve 39 closedown, magnetic valve 28 are opened, first pipeline is closed, second pipeline is connected, little compressor 69 is connected with large compressor 68, namely by the folding of magnetic valve, compressor restructuring is formed double stage tandem compression, large compressor 68 is placed in first order compression, and little compressor 69 is placed in second level compression.

In the winter time time environment temperature higher (general >0 DEG C), the present invention is then in parallel by this two compressor for the heat pump assembly be made up of small one and large one two compressor, carries out air heat, namely adopts single stage compress mode to heat.And in the winter time environment temperature lower (general <0 DEG C) time, first adopt the single stage compress of size compressor parallel to heat; When room air reaches more than 20 DEG C, the compressor bank between evaporator outlet and condenser inlet is recombinated: large inspiratory capacity compressor is wherein compressed as the first order; Little inspiratory capacity compressor is compressed as the second level; And then by first and second level compression series connection, form Two-stage Compression, carry out the effective heating to room air under low ambient temperature.

Because refrigerant gas is different from refrigerant liquid, there is compressibility and significantly compressed by compressor, so on each flow area in heat pump, refrigerant mass fluxes is identical and volume flow is widely different, must ensure that when weight of compressor component level soakage that rear stage compresses and previous stage are compressed mating of discharge rate and balanced, Here it is using in system " large inspiratory capacity is compressed as the first order; And little inspiratory capacity compressor is compressed as the second level " basis.

When environment temperature is in low-temperature space (general <0 DEG C) enforcement multiple compressors restructuring in the winter time, the present invention defers to, and " second level compression is to the work done during compression w of the certain volume gas sucked ₂the work done during compression w to the equivalent volumes gas sucked is compressed with the first order ₁substantially equal; I.e. second level compression pressure reduction p ₂be less than first order compression pressure reduction p ₁, p ₂≈ (0.3 ~ 0.8) p ₁; Also be second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁" principle carry out the restructuring of multiple compressors.

Why the present invention adopts the Ya Suo Gong ⊿ w of high stage compressor ₂with the Ya Suo Gong ⊿ w of first order compressor ₁substantially equal method is recombinated to multiple compressors, large inspiratory capacity compressor is wherein compressed as the first order, and little inspiratory capacity compressor is compressed as the second level, and then by first, the Two-stage Compression pattern that compressor configuration is carried out in two-stage compression series connection carries out the effective heating to room air under low ambient temperature, when being to produce high temperature air in low temperature (< 0 DEG C) environment, the refrigerant discharge capacity that the cold-producing medium soakage of second level compression and the first order are compressed matches, the first order is compressed and to compress the live load of each compressor substantially even in the second level, thus electric machine iron core and coil heating when each compressor is run, electrical machine insulation and cylinder lubricating system etc. are all in the stable kilter of basis equalization, with preventing portion dividing potential drop contracting machine particularly high stage compressor occur that heavy overload runs.

As winter environment temperature < 0 DEG C, during indoor air temperature < 20 DEG C, first by parallel for small one and large one two compressor of air source heat pump air-conditioner, weave into single stage compress module and carry out heating production; As indoor air temperature > 20 DEG C, again large inspiratory capacity compressor (inspiratory capacity is about 5.5 times of little compressor) is wherein weaved into first order compression module, second level compression module born by another 1 little inspiratory capacity compressor, and two block coupled in series operations are with high-temperature hot air in production.

Winter heating, source pump list Two-stage Compression uses in order, but shorter for the single stage compress process of atmosphere temperature rising; The body of work time of heat pump air conditioner unit and heating task, be to compensate the leakage of room air to body of wall and atmospheric environment hot, maintain room air and be in higher temperatures district as 30 DEG C.Maintain the temperature of room air main body 30 DEG C, the leaving air temp of source pump indoor set must reach more than 45 DEG C, and condensation temperature must reach more than 50 DEG C.

Now operate to example explanations with the heat pump heating under ambient air temperature-10 DEG C of conditions. ambient air temperature-10 DEG C, heat pump air conditioner unit main body adopts two stages of compression mode running time, defers to that " second level compression is to the work done during compression w of certain volume gas of suction ₂the work done during compression w to the equivalent volumes gas sucked is compressed with the first order ₁substantially equal; I.e. second level compression pressure reduction p ₂be less than first order compression pressure reduction p ₁, p ₂≈ (0.3 ~ 0.8) p ₁; Also be second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁" principle carry out the spirit of multiple compressors restructuring; two stages of compression operating mode is: the pressure of inspiration(Pi) of first order compression module and large inspiratory capacity compressor and evaporating pressure are 2.44atm (corresponding evaporating temperature-20 DEG C; lower than ambient air temperature 10 DEG C); the pressure at expulsion of second level compression module and little inspiratory capacity compressor and condensing pressure are 19.43atm (corresponding condensation temperature 50 DEG C; higher than indoor set air draught temperature 20 DEG C; higher than indoor machine wind-discharging temperature 5 DEG C), and overall compression ratio reaches 8.Intermediate pressure (i.e. the pressure at expulsion of first order compression, the pressure of inspiration(Pi) of also i.e. second level compression) is 13.42atm, and first order compression ratio is 5.5, and pressure reduction is 10.98atm; Second level compression ratio is 1.45, and pressure reduction is 6.0atm.If continue the mode of production adopting single stage compress, heating efficiency drops to less than 2 in reality by by theoretic more than 4, because the factor such as clearance and leakage of compressor has become very serious under High Pressure Difference high compression ratio condition, cause the actual exhaust air temperature in this stage can reach more than 130 DEG C, heating efficiency drops to less than 1.5, and high energy efficiency ratio and the economy of " heat pump " exhaust.

And in this stage, the present invention adopts two stages of compression, the overall compression ratio 8 of heat pump air conditioner unit carries out decomposing, configuring between two stages of compression module, the operating mode of whole system can be ensured, heating efficiency is in rational period, the overall operating mode of heat pump air conditioner unit, efficiency, compared with single stage compress, obviously improve.

Please refer to Fig. 4, the actual compression process of compressor is a polytropic proces between isotherm compression process and adiabatic compression process (adiabatic exponent of R22 is 1.18) on P-V figure.Intermediate pressure between first two-stage compression, by the inspiratory capacity of all compressors in the second level on P-V figure, the intersection point of the line of compression process in many ways gathered with all compressors of the first order determines.When indoor air temperature reaches 20 DEG C, control system automatically switches, pipeline by large inspiratory capacity compressor in the single stage compress stage towards condenser is closed, and intercooler is transported in the exhaust of this large inspiratory capacity compressor, release after most of sensible heat significantly lowers the temperature, send into the suction inlet of second level compression module (i.e. little inspiratory capacity compressor) again, second-compressed enters condenser after becoming high steam.

Now for heat pump air conditioner unit, the first order in combining two stages of compression and the work done during compression of the second level, carry out mathematical modeling analysis.

P-V figure can clearly find out: during heating operation, the actual compression process of compressor is a polytropic proces between isotherm compression process and adiabatic compression process, and the cold-producing medium that the present embodiment adopts is R22:

In many ways compression process equation is: pv ⁿ=c, (1 < n < 1.18)

The first order compression of heat pump air conditioner unit is first discussed.

First use the method for definite integral, calculate and adopt large compressor to carry out first order compression, by 136.95m per hour ³, 2.44atm low-pressure steam, be compressed to intermediate pressure 13.42atm and consume electric work.The volume of low-pressure steam is compressed to about 1/5.5 by first order compression, is namely compressed to gross exhaust gas (the 1/5.5) × 136.95m of the large compressor of the first order ³with the inspiratory capacity 24.9m of the little compressor in the second level ³substantially equal, the intermediate pressure now between the first order second level is about 5.5 × 2.44=13.42atm.

In many ways will compress and be considered as adiabatic compression:

Pv ⁿ＝c，n＝1.18

The pressure of compression starting point and volume are brought into

C＝P·v ⁿ

＝p ₁·v ₁ ⁿ

＝2.44×1.013×100000×136.95 ^1.18

Work done during compression can be tried to achieve by the definite integral of volume versus pressure between 2.44atm to 13.42atm

$\begin{array}{c}S={\&Integral;}_{2.44}^{13.42}p\&CenterDot;\mathrm{dv}\\ =v_1/(1-1/n)\&CenterDot;({p_1}^{1/n}\&CenterDot;{p_2}^{1-1/n}-p_1)\\ =6.591\&times;{10}^{7}J\\ =18.31\mathrm{kwh}\end{array}$

As with 24.9m ³inspiratory capacity be reference, then equivalent horsepower is 3.3kw.If also namely little inspiratory capacity compressor operating is in the first order, then its compression horsepower is 3.3kw, is in " underloading " state.The work done during compression of the first order large inspiratory capacity compressor 18.31kwh, during with this compressor single stage compress, directly from-10 DEG C of surrounding airs, absorb the room air that heat pumps into 30 DEG C, corresponding to pressure of inspiration(Pi) 2.44atm, pressure at expulsion 19.43atm, work done during compression 22.95kwh per hour compares, and this compressor is in " underloading " state.As with " pressure of inspiration(Pi) 2.44atm, pressure at expulsion 19.43atm " for compressor 100% full load condition, then under the duty of " pressure of inspiration(Pi) 2.44atm, pressure at expulsion 13.42atm ", rate of load condensate is 79.8%.

See the second level compression of heat pump air-conditioner set again.

The method of present use definite integral, calculates second level compression by 24.9m ³the both vapor compression that/h, intermediate pressure are 13.42atm is consumed electric work to the final states of 19.43atm:

C＝Pv ⁿ

＝13.42×1.013×100000×24.9 ^1.18

The second level effective compression horsepower of little inspiratory capacity compressor is 3.58kw, belongs to light running; 24.9m is equivalent to the first order ³the compression equivalent horsepower 3.3kw of inspiratory capacity, very close, " substantially equal ".

On P-V figure, compressor carries out the work done during compression that first compression does, and is exactly the area that the bent limit that encloses of compression process curve, suction pressure of compressor line, Compressor Discharge Pressure line and P axle is trapezoidal in many ways.Because the compression curve in many ways of hiigh pressure stage is more precipitous than the compression curve in many ways of low-pressure stage, only have and adopt second level compression Ya Cha ⊿ p ₂be less than first order compression Ya Cha ⊿ p ₁, be also second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁method, " the Ya Suo Gong ⊿ w of little inspiratory capacity compressor of second level compression could be realized ₂the equivalent suction body of the large inspiratory capacity compressor compressed with the first order amasss work done during compression ⊿ w ₁substantially equal ".

Under environment temperature below-10 DEG C, heat pump air conditioner is used to absorb the hot-air of the energy production 40 DEG C in air, in room air high-temperature region (> 30 DEG C), the present invention defers to, and " second level compression is to the work done during compression w of the certain volume gas sucked ₂the work done during compression w to the equivalent volumes gas sucked is compressed with the first order ₁substantially equal; I.e. second level compression pressure reduction p ₂be less than first order compression pressure reduction p ₁, p ₂≈ (0.3 ~ 0.8) p ₁; Also be second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁" principle, carry out the restructuring of compressor bank, improve the operating mode of compressor at all, and improve the Energy Efficiency Ratio heated.After single stage compress becomes two stages of compression, total thermal discharge of heat pump air conditioner unit condenser reduces to some extent, and when minimizing ratio and single stage compress, to account for the ratio of size two compressor air suction total amounts in system identical for the inspiratory capacity of little compressor, and about 1/6; The heating efficiency (Energy Efficiency Ratio) of this stage heat pump air conditioner is greater than 3, only little by about 17% (1/6) than the heating efficiency of single stage compress during indoor air temperature 20 DEG C, single stage compress heat pump air conditioner unit Energy Efficiency Ratio more than 1/3 when exceeding indoor temperature 30 DEG C.

The heat-pump hot-water unit that the present invention also provides a kind of single Two-stage Compression to use in order, at this heat-pump hot-water unit, the compressor bank in the heat pump air conditioner that the structure of compressor bank and recombination form and single Two-stage Compression use in order is similar, repeats no more herein.Below in conjunction with accompanying drawing, lift the air heat pump Hot water units that a compressor bank adopts many single cylinder compressors, the method for single Two-stage Compression that uses in order under cryogenic conditions in the winter time, the process of high efficiency production high temperature health hot water, is described in detail.

The heat-pump hot-water unit that a kind of single Two-stage Compression uses in order, comprise water tank, also comprise the condenser, throttling arrangement, evaporimeter and the compressor bank that sequentially pass through refrigerant line and connect, the heat sink at evaporimeter place is placed in air or seawater or underground water, and condenser is arranged in water tank.In the present invention, the operation principle that the heat sink at evaporimeter place is placed in air or seawater or underground water is identical, the present invention is placed in where to heat sink and does not do concrete restriction, is placed in air is below described in detail for the heat sink at evaporimeter place.In the present invention, compressor bank comprises several compressors and control device, and some compressors are compressor, and some compressors carry out single-stage parallel connection compression by control device, or some compressors carry out two-stage series connection compression by control device restructuring.The present invention also lists within protection scope of the present invention the situation that some compressors can be divided into multi-stage compression by control device.

In the present invention, when the water temperature of heat pump type hot water machine water tank lower (general < 40 DEG C), then by all compressor parallels, hot water production is carried out for the heat pump assembly be made up of multiple compressors, namely adopts single stage compress mode to heat and carry out hot water production.And when water tank water temperature higher (general > 40 DEG C), then the compressor bank between evaporator outlet and condenser inlet is recombinated: for the hot water apparatus be made up of multiple compressors, by most of compressor parallels wherein, compress as the first order; Remaining minority compressor parallel (if also having more than 2), compresses as the second level; And then by first and second level compression series connection, form Two-stage Compression, that carries out hot water high temperature section heats production.

Because refrigerant gas is different from refrigerant liquid, there is compressibility and significantly compressed by compressor, so on each flow area in heat pump, refrigerant mass fluxes is identical and volume flow is widely different, must ensure that when weight of compressor component level soakage that rear stage compresses and previous stage are compressed mating of discharge rate and balanced, Here it is by system " most of compressor parallel, compresses as the first order; And the minority compressor parallel of remainder (if also have more than 2), as second level compression " basis.

When the water tank water temperature section of reaching a high temperature (general > 40 DEG C) implements multiple compressors restructuring, the present invention defers to, and " second level compression is to the work done during compression w of the certain volume gas sucked ₂the work done during compression w to the equivalent volumes gas sucked is compressed with the first order ₁substantially equal; I.e. second level compression pressure reduction p ₂be less than first order compression pressure reduction p ₁, p ₂≈ (0.3 ~ 0.8) p ₁; Also be second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁" principle carry out the restructuring of multiple compressors.

Why the present invention adopts the Ya Suo Gong ⊿ w of high stage compressor ₂with the Ya Suo Gong ⊿ w of first order compressor ₁substantially equal method is recombinated to multiple compressors, most of compressors (about 6/7) parallel connection is wherein compressed as the first order, and (if also having more than 2) in parallel for the minority compressor (about 1/7) of remainder is compressed as the second level, and then by first, what the Two-stage Compression pattern that compressor configuration is carried out in two-stage compression series connection carried out hot water high temperature section heats production, when being to produce high temperature (> 60 DEG C) hot water in low temperature (< ﹣ 10 DEG C) environment, the refrigerant discharge capacity that the cold-producing medium soakage of second level compression and the first order are compressed matches, the first order is compressed and to compress the live load of each compressor substantially even in the second level, thus electric machine iron core and coil heating when each compressor is run, electrical machine insulation and cylinder lubricating system etc. are all in the stable kilter of basis equalization, with preventing portion dividing potential drop contracting machine particularly high stage compressor occur that heavy overload runs.

Now for heat-pump hot-water unit, the first order in combining two stages of compression and the work done during compression of the second level, carry out mathematical modeling analysis.

P-V figure can clearly find out: during heating operation, the actual compression process of compressor is a polytropic proces between isotherm compression process and adiabatic compression process, and the cold-producing medium that the present embodiment adopts is R22:

In many ways compression process equation is: pv ⁿ=c, (1 < n < 1.18)

First order compression is first discussed.

First use the method for definite integral, calculate and adopt paddy wheel compression machine Zw108ks to carry out first order compression, by 24.9m per hour ³, 2.44atm low-pressure steam, be compressed to intermediate pressure 14.64atm and consume electric work.The volume of low-pressure steam is compressed to about 1/6 by first order compression, is namely compressed to gross exhaust gas 6 × (the 1/6) × 24.9m of the first order 6 compressors ³with the inspiratory capacity 24.9m of high stage compressor ³substantially equal, the intermediate pressure now between the first order second level is about 6 × 2.44=14.64atm.

In many ways will compress and be considered as adiabatic compression:

Pv ⁿ＝c，n＝1.18

The pressure of compression starting point and volume are brought into

C＝Pv ⁿ

＝p ₁·v ₁ ⁿ

＝2.44×1.013×100000×24.9 ^1.18

Work done during compression can be tried to achieve by the definite integral of volume versus pressure between 2.44atm to 14.64atm

$\begin{array}{c}S={\&Integral;}_{2.44}^{14.64}\mathrm{vdp}\\ =v_1/(1-1/n)\&CenterDot;({p_1}^{1/n}\&CenterDot;{p_2}^{1-1/n}-p_1)\\ =12672000J\\ =3.52\mathrm{kwh}\end{array}$

Effective compression horsepower is the power that 3.52kw, Zw108ks compressor works between evaporating temperature-20 DEG C, condensation temperature+35 DEG C is 5267W, and electric efficiency=3520w/5267W=66.8%, belongs to light running.

See that the second level is compressed again.

When two stages of compression operational mode starts, first order pressure of inspiration(Pi) is 2.44atm, and intermediate pressure is 14.64atm, and second level pressure at expulsion is 17.3atm; System overall compression ratio 7.1, wherein first order compression ratio is 6, and second level compression ratio is 1.18.

Thereafter, the pressure at expulsion of second level compression and the overall compression ratio row on the way of system, reach 27.0,11.1 respectively, first order compression ratio is stabilized near 6, and second level compression ratio is progressively up reaches 1.8; The work done during compression of high stage compressor, by the work done during compression being less than the first order single compressor, rises to and maintains an equal level with it, then rises to the work done during compression being greater than the first order single compressor, realizes " the Ya Suo Gong ⊿ w of single compressor of second level compression on the whole ₂the Ya Suo Gong ⊿ w of single the compressor compressed with the first order ₁substantially equal ".

The method of present use definite integral, the starting stage is compressed by 24.9m in the second level calculated in Two-stage Compression ³the both vapor compression that/h, intermediate pressure are 14.64atm is consumed electric work to 17.3atm:

C＝p ₁·v ₁ ⁿ

＝14.64×1.013×100000×24.9 ^1.18

$\begin{array}{c}S={\&Integral;}_{14.64}^{17.3}v\&CenterDot;\mathrm{dp}\\ =v_1/(1-1/n)\&CenterDot;({p_1}^{1/n}\&CenterDot;{p_2}^{1-1/n}-p_1)\\ =6249600J\\ =1.74\mathrm{kwh}\end{array}$

Effective compression horsepower is 1.74kw, belongs to the light(-duty) service at two stages of compression initial stage.

And in the latter stage that heat-pump hot-water unit high temperature heats, there is heavy service in short-term in the second level compression in Two-stage Compression.The method of present use definite integral, calculates second level compression by 24.9m ³the both vapor compression that/h, intermediate pressure are 14.64atm is consumed electric work to the final states of 27.0atm:

Work done during compression

$\begin{array}{c}S={\&Integral;}_{14.64}^{27}\mathrm{vdp}\\ =v_1/(1-1/n)\&CenterDot;({p_1}^{1/n}\&CenterDot;{p_2}^{1-1/n}-p_1)\\ =23748800.8J\\ =6.6\mathrm{kwh}\end{array}$

Effective compression horsepower is 6.6kw, belongs to the heavy service in hot water production latter stage.

On an average, the mean power of the second level compression in Two-stage Compression is about 4.17kw, is a bit larger tham the power 3.52kw of the first order compression in Two-stage Compression, roughly the same.

On P-V figure, compressor carries out the work done during compression that first compression does, and is exactly the area that the bent limit that encloses of compression process curve, suction pressure of compressor line, Compressor Discharge Pressure line and P axle is trapezoidal in many ways.Because the compression curve in many ways of hiigh pressure stage is more precipitous than the compression curve in many ways of low-pressure stage, and the cylinder of compressor holds identical, only has and adopts second level compression Ya Cha ⊿ p ₂be less than first order compression Ya Cha ⊿ p ₁, be also second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁method, " the Ya Suo Gong ⊿ w of single compressor of second level compression could be realized ₂the Ya Suo Gong ⊿ w of single the compressor compressed with the first order ₁substantially equal ".

Intermediate pressure between first order compression and two-stage compression, by the inspiratory capacity of all compressors in the second level on P-V figure, the intersection point of the line of compression process in many ways gathered with all compressors of the first order determines.Under the evaporating pressure determined and condensing pressure, participate in the increasing number of the compressor of first order compression, the upwards lifting of the capacity gathered and pressure at expulsion, intermediate pressure also moves up; The quantity participating in the compressor of first order compression reduces, and the capacity gathered and pressure at expulsion reduce downwards, and intermediate pressure also moves down thereupon.Same, under the evaporating pressure determined and condensing pressure, participate in the increasing number of the compressor of second level compression, the second level inspiratory capacity gathered increases, and intermediate pressure also moves down; The quantity participating in the compressor of second level compression reduces, and the inspiratory capacity gathered reduces, and intermediate pressure also moves up thereupon.Therefore, heat pump type hot water machine is when hot water high temperature section adopts two stages of compression mode to carry out heating production, and its evaporating pressure is determined by ambient air temperature, and its condensing pressure is determined by hot water temperature, and its intermediate pressure is configured by the quantity of the first split-compressor and determines.

Time now with environment temperature ﹣ 10 DEG C, the net for air-source heat pump units adopting configuration 7 compressor is example explanation by water tank, 5 DEG C of running water are produced into 60 DEG C of health hot waters.

Please refer to Fig. 5, the heat-pump hot-water unit that a kind of single Two-stage Compression uses in order, comprise water tank 1 and heat pump assembly, heat pump assembly comprises the condenser 2, throttling arrangement, evaporimeter 5 and the compressor bank 6 that sequentially pass through refrigerant line and connect, wherein, the heater at evaporimeter 5 place is placed in air, condenser 2 to be arranged in water tank 1 and to be positioned at the bottom of water tank 1, throttling arrangement is choke valve 4, between condenser 2 and evaporimeter 5, be also provided with the device such as intercooler, filter 3, the present embodiment does not do concrete restriction.The upper end of water tank 1 is provided with exhaust outlet, water inlet, and lower end is provided with delivery port, and is also provided with water circulating pump in the lower end of water tank 1.Control device comprises some magnetic valves, control compressor bank 6 by the break-make of each magnetic valve to carry out single-stage parallel connection compression or recombinate carrying out double stage tandem compression, wherein, compressor bank 6 comprises the first compressor 61, second compressor 62, 3rd compressor 63, 4th compressor 64, 5th compressor 65, 6th compressor 66 and the 7th compressor 67, first compressor 61, second compressor 62, 3rd compressor 63, 4th compressor 64, 5th compressor 65, 6th compressor 66 is parallel with one another, in heat pump assembly, the pipeline connecting the 7th compressor 67 has two, i.e. the first pipeline and the second pipeline, first pipeline is provided with magnetic valve 1 and magnetic valve 39, second pipeline is arranged magnetic valve 28: please refer to Fig. 6, when magnetic valve 1 and magnetic valve 39 are opened, when magnetic valve 28 cuts out, first pipeline is connected, second pipeline is closed, 7th compressor 67 and other six compressor parallels, be called single-stage parallel connection compression, please refer to Fig. 7, when magnetic valve 1 and magnetic valve 39 closedown, magnetic valve 28 are opened, the first pipeline is closed, and the second pipeline is connected, 7th compressor 67 and other six compressors are connected, and namely by the folding of magnetic valve, compressor restructuring are formed double stage tandem compression.

Heat pump type hot water machine evaporimeter absorbs heat from surrounding air, and the convective heat-transfer coefficient of air is less, greatly about 25 ~ 120W/ (m ²dEG C), reach heat transfer temperature difference needed for certain Endothermic power comparatively large, generally at 6 ~ 12 DEG C, desirable 10 DEG C; Heat-pump hot-water unit condenser is to the running water heat release in water tank, and the convective heat-transfer coefficient of water is very high, greatly about 3500 ~ 9500W/ (m ²dEG C), reach heat transfer temperature difference needed for certain heat release power less, generally at 4 ~ 8 DEG C, desirable 5 DEG C.Ignore the resistance of the connecting line between inner tube of heat exchanger road and heat exchanger, compressor, choke valve, ignore in refrigerant gas compression process and piston, heat exchange between cylinder sleeve, the real process of complexity is abstracted into simple cyclic process.

1, the single stage compress stage

Time during water tank water temperature is in lower temperature, adopt 7 compressor concurrent job patterns, implement single stage compress, water temperature rises to+40 DEG C from ﹢ 5 DEG C of circulations.Under 2.44atm evaporating pressure (saturation temperature corresponded to is-20 DEG C, and the environment temperature than-10 DEG C is low 10 DEG C), the refrigerant vapor that source pump is suitably overheated after sucking evaporation, is discharged into condenser heat rejection after compression.The condensing pressure of source pump, constantly high in the process of water circulation heating, from 6.8atm (corresponding to the saturation temperature of 10 DEG C, 5 DEG C are exceeded) than the initial temperature 5 DEG C of running water in water tank, progressively rise to 17.3atm (corresponding saturation temperature is 45 DEG C), compression ratio progressively rises to 7.1 by 2.8, the theoretical delivery temperature of compressor progressively rises to 84 DEG C by 35 DEG C, in fact due to factors such as the compressor air suction degree of superheat, compressor redundant gap coefficients, delivery temperature is at about 120 DEG C; Unit heating efficiency (theory) is corresponding progressively drops to 3.4 by 7.2, and actual decline is more more.

As known from the above, rise in the process of+40 DEG C in water tank water temperature from ﹢ 5 DEG C of circulations, the corresponding phenomenon having occurred " three high and one low " that condensing pressure rising, compression ratio rising, compressor exhaust temperature rising, heating efficiency reduce of air source heat pump system.This is the corollary of single stage compress heat pump process, is also acceptable when tank hot water temperature < 40 DEG C.

2, the Two-stage Compression stage

When water tank water temperature reaches 40 DEG C, by parallel for 6 compressors of air friction drag, weave into one stage of compression module, another 1 compressor bears two-stage compression module, and two block coupled in series operations are with high temperature health hot water in production.

In first stage and the single stage compress stage of hot water production, when 7 compressor parallel runnings reach 40 DEG C to Water in Water Tanks temperature, control system automatically switches, pipeline by 6 compressors in the single stage compress stage towards condenser is closed, and the gas exhaust piping of this 6 compressor is merged, exhaust transports to intercooler behind interflow, with the liquid refrigerant heat exchange introduced from throttling arrangement in intercooler, release after most of sensible heat significantly lowers the temperature, send into the suction inlet of second level compression module (i.e. the 7th compressor) again, condenser is entered after being become high steam by second-compressed, heat release post liquefaction expenditure and pressure, enter the evaporimeter before first order compression module (6 compressors in parallel) again.

In this stage, the evaporating pressure of first order compression module is still 2.44atm, the condensing pressure of second level compression module rises in the process of 60 DEG C constantly high at Water in Water Tank temperature from 40 DEG C, progressively 27.0atm is risen to from 17.3atm, intermediate pressure also progressively rises thereupon, the corresponding rising of delivery temperature, overall compression ratio reaches 11.1.

If the mode of production adopting single stage compress is continued in high-temperature region in hot water, then rise in the process of+60 DEG C at Water in Water Tank temperature from+40 DEG C, condensing pressure rises to 27.0atm by 17.3 equally, the theoretical delivery temperature of unit will rise to 105 DEG C by 84 DEG C, heating efficiency will by 3.4 dropping to less than 2 in theory, because the factor such as clearance and leakage of compressor has become more serious under High Pressure Difference high compression ratio condition, cause the actual exhaust air temperature in this stage can reach more than 150 DEG C, heating efficiency drops to less than 1.5, high energy efficiency ratio and the economy of " heat pump " exhaust.

But in this stage, the present invention adopts two stages of compression, the overall compression ratio 11.1 of hot water machine carries out decomposing, configuring between two stages of compression module, the operating mode of whole system can be ensured, heating efficiency is in rational period, the overall operating mode of hot-water heating system, efficiency, compared with single stage compress, obviously improve.

Please refer to Fig. 8, the actual compression process of compressor is a polytropic proces between isotherm compression process and adiabatic compression process (adiabatic exponent of R22 is 1.18) on P-V figure.Intermediate pressure between first two-stage compression, by the inspiratory capacity of all compressors in the second level on P-V figure, the intersection point of the line of compression process in many ways gathered with all compressors of the first order determines.When Water in Water Tanks temperature reaches 40 DEG C, control system automatically switches, the pipeline of in 7 compressors 6 in the single stage compress stage towards condenser is closed, and the gas exhaust piping of this 6 compressor is merged, exhaust transports to intercooler behind interflow, release after most of sensible heat significantly lowers the temperature, then send into the suction inlet of second level compression module (i.e. the 7th compressor), second-compressed enters condenser after becoming high steam.The state parameter of (saturated) steam that first order compressor sucks is-20 DEG C, 2.44atm, 92.8l/kg, according to the requirement of " intersection point of the line of compression process in many ways that the inspiratory capacity of high stage compressor and all compressors of the first order gather determines intermediate pressure ", the specific volume of refrigerant gas must be compressed to 1/6 of inspiratory volume 92.8l/kg, i.e. 15.47l/kg, the capacity of 6 first order compressors could be mated substantially with the inspiratory capacity of high stage compressor.Specific volume is that the saturated vapour pressure of 15.47l/kg is about 14.64atm.Namely the intermediate pressure of the first two-stage compression is 14.64atm.

When two stages of compression operational mode starts, first order pressure of inspiration(Pi) is 2.44atm, and intermediate pressure is 14.64atm, and second level pressure at expulsion is 17.3atm; System overall compression ratio 7.1, wherein first order compression ratio is 6, and second level compression ratio is 1.18.Thereafter, the pressure at expulsion of second level compression and the overall compression ratio row on the way of system, reach 27.0,11.1 respectively, first order compression ratio is stabilized near 6, and second level compression ratio is also thereupon up reaches 1.8; The work done during compression of high stage compressor, by the work done during compression being less than the first order single compressor, it is fair to rise to, then rises to the work done during compression being greater than the first order single compressor, realizes " the Ya Suo Gong ⊿ w of single compressor of second level compression on the whole ₂the Ya Suo Gong ⊿ w of single the compressor compressed with the first order ₁substantially equal ".

Under environment temperature below-10 DEG C, heat pump is used to absorb the health hot water of the energy production 60 DEG C in air, at running water low-temperature space (< 40 DEG C), system energy efficiency higher (> 4).High-temperature region in hot water, the present invention defers to, and " second level compression is to the work done during compression w of the certain volume gas sucked ₂the work done during compression w to the equivalent volumes gas sucked is compressed with the first order ₁substantially equal; I.e. second level compression pressure reduction p ₂be less than first order compression pressure reduction p ₁, p ₂≈ (0.3 ~ 0.8) p ₁; Also be second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁" principle carry out the restructuring of multiple compressors, improve the operating mode of compressor at all, and improve the Energy Efficiency Ratio heated.At 40 ~ 60 DEG C of warm areas, adopt the two stages of compression mode of the present invention's restructuring to carry out high-temperature-hot-water production, the first split-compressor total power consumption is compared with total power consumption during single stage compress, and start slightly to reduce, remaining basically stable in centre, finally slightly rises; Total thermal discharge of hot water machine condenser reduces to some extent, and minimizing ratio is identical with the ratio that high stage compressor quantity accounts for compressor total amount in system, and about 1/7; The heating efficiency (Energy Efficiency Ratio) of this stage heat pump hot-water system is greater than 2.5, only little by about 14% (1/7) than the heating efficiency of single stage compress during tank hot water 40 DEG C, exceed identical warm area single stage compress heat-pump hot-water unit Energy Efficiency Ratio more than 2/3; Low temperature and two stages of middle high temperature integrate, heating efficiency (Energy Efficiency Ratio) > 3.

If heat pump hot-water system adopts inspiratory capacity to differ the size compressor combination of about 6 times, the present invention is according to the Principles and ways of a two-stage compression module restructuring of above-mentioned compressor group, size compression is recombinated, size compressor is adopted to walk abreast single stage compress at the low-temperature space of health hot water, adopt in middle high-temperature region that large inspiratory capacity compressor is placed in the first order, little inspiratory capacity compressor is placed in the second level, reassembles into two stages of compression, the good result improved working conditions of compressor, improve the overall heating efficiency of unit can be reached equally.

If heat pump adopts medium-sized or large scale multi-cylinder compressor, the present invention is according to the Principles and ways of a two-stage compression module restructuring of above-mentioned compressor group, the cylinder of multicylinder compressor is recombinated, multi-cylinder is adopted to walk abreast single stage compress at the low-temperature space of health hot water, adopt multi-cylinder restructuring two stages of compression in middle high-temperature region, the good result improved working conditions of compressor, improve the overall heating efficiency of unit can be reached equally.

If heat pump hot-water system adopts frequency-changeable compressor, particularly in high stage compressor, use converter technique, after implementing compressor bank of the present invention restructuring, the inspiratory capacity of low-pressure stage particularly hiigh pressure stage can be improved further, thus the exerting oneself and running quality of raising system further.

If in the season that temperature is higher, heat pump hot-water system is used to produce the high-temperature-hot-water of higher temperature (such as 80 DEG C), implement the present invention to recombinate to compressor bank, in the high-temperature region of hot water, the compression ratio that can reach the first order and high stage compressor group equally declines, delivery temperature declines, and operating mode is improved, the positive effect that the overall Energy Efficiency Ratio of hot-water heating system improves.

If heat pump is used to the heat temperature raising to heat conduction wet goods fluid media (medium), implement the present invention to recombinate to compressor bank, high-temperature region in fluid media (medium), the compression ratio of the first order and high stage compressor group is had to decline equally, delivery temperature declines, operating mode is improved, the positive effect that Energy Efficiency Ratio improves.

Main innovate point of the present invention is:

The first, subregion is carried out to the temperature of source pump, " because of district's suiting measures to different conditions ".

Winter, when heating to room air, environment temperature and indoor air temperature were carried out subregion by the present invention, during environment temperature > 0 DEG C, heated employing single stage compress; During environment temperature < 0 DEG C, heat the heat pump method adopting single Two-stage Compression to use in order: indoor air temperature is divided into low-temperature space (less than+5 DEG C-+20 DEG C) and middle warm area (+20 DEG C more than-+30 DEG C), the operational mode of corresponding heat pump, relative set is single stage compress and Two-stage Compression.

During winter production health hot water, produced health hot water temperature is carried out subregion by the present invention, be divided into middle low-temperature space (+5 DEG C-+40 DEG C) and middle high-temperature region (+40 DEG C-+60 DEG C), the operational mode of corresponding heat pump, relative set is single stage compress and Two-stage Compression.

So " because of district's suiting measures to different conditions ", specific aim and the flexibility of operation of heat pump is improved.

The second, founded comprise many with the compressor configuration method of " very the 6+1 " of single compressor hierarchical composition

The present invention defers to, and " second level compression is to the work done during compression w of the certain volume gas sucked ₂the work done during compression w to the equivalent volumes gas sucked is compressed with the first order ₁substantially equal; I.e. second level compression pressure reduction p ₂be less than first order compression pressure reduction p ₁, p ₂≈ (0.3 ~ 0.8) p ₁; Also be second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁" principle, carry out the restructuring of multiple compressors.

The Principles and ways of this restructuring, in the process heated to room air under outdoor environment temperature below-10 DEG C, when indoor air temperature reaches 20 DEG C, large inspiratory capacity compressor (volume inspiratory capacity is about 5.5 times of little compressor) in system is compressed as the first order, and little inspiratory capacity compressor is compressed as the second level, and then by first and second level compression series connection.This recombination method similar with " very 6+1 ", found the compressor configuration pattern of size compressor hierarchical composition, improve possibility and the operability of practical application, the suction and discharge pressure reduction at all solving single stage compress air source heat pump air-conditioner in winter increase, compression ratio is too high, compressor exhaust temperature is too high, " three high and one low " phenomenon that heating efficiency seriously reduces.The Principles and ways of this restructuring, produce in the process of the health hot water of 60 DEG C under outdoor environment temperature below-10 DEG C, when hot water temperature reaches 40 DEG C, most of compressors (about 6/7) parallel connection in the system be made up of many compressors is compressed as the first order, and using (if also having more than 2) in parallel for the minority compressor (about 1/7) of remainder as second level compression, and then by first and second level compression series connection.The recombination method of this " very 6+1 ", found the compressor configuration pattern of many compressors and single compressor hierarchical composition, improve possibility and the operability of practical application, " three high and one low " phenomenon that the suction and discharge pressure reduction at all solving single stage compress air source heat pump hot water system increases, compression ratio is too high, compressor exhaust temperature is too high, heating efficiency seriously reduces, makes " twin-stage high temperature heat pump " come true from concept.

3rd, the two-stage compression heat pump unit eer under winter-10 DEG C of conditions, exceeds identical warm area single stage compress pattern more than 1/3

Owing to have employed Two-stage Compression, the compression ratio of every one-level and compressor exhaust temperature all have larger decline, the overall operating mode of heat pump air conditioner unit, heat-pump hot-water unit significantly improves, in room air, in warm area, hot water, the heating efficiency (Energy Efficiency Ratio) of high-temperature region is greater than 2.5, exceeds identical warm area single stage compress heat-pump hot-water unit Energy Efficiency Ratio more than 1/3.

4th, improve the usage factor of original unit.

In the winter time under low temperature severe cold condition, when using heat pump air conditioner unit and heat-pump hot-water unit to heat, when room air or health hot water temperature reach the median (room air 20 DEG C, health hot water 40 DEG C) of setting, the single stage compress unit of last stage is recombinated, is transformed into the pattern of two stages of compression.In regrouping process, do not increase new special high stage compressor group, do not increase new heat exchanger, water pump, blower fan, only original compressor bank and corollary equipment are recombinated, improve the usage factor of original unit.

In the present invention, in the winter time under low temperature severe cold condition, heat pump heating efficiency exceeds identical warm area single stage compress heat-pump hot-water unit Energy Efficiency Ratio more than 1/3, can reach more than 3.0.In the present invention, the improvement of two stages of compression stage compression unit operating mode and the raising of heating efficiency, basic reason is:

1, change is separated into intensive

During the single stage compress of the large compression ratio of large for multiple compressor pressure reduction is run, not mate with design of electrical motor and the higher-pressure region that operational efficiency has significantly reduced merges, the unified high stage compressor only having the first order to compress total inspiratory capacity about 1/6 by new inspiratory capacity performs, change is separated into intensive, the compression condition that former single stage compress end is degrading and compression efficiency, improve and promote;

2, the width of leakage path and power (pressure reduction) all greatly reduce

During single stage compress, the leakage between compressor high-low pressure, occur in multiple compressor there is relative mechanical motion interface between, and the power (compressor suction and discharge pressure reduction) promoting to leak is very large, causes the leakage rate between high-low pressure very large.After the two stages of compression that compressor bank is reassembled as " very 6+1 ", between high-low pressure, the width of refrigerant gas leakage path and the power (pressure reduction) of leakage all greatly reduce, and leakage rate greatly reduces.Not only leakage rate greatly reduces, to leak into the refrigerant gas enthalpy of intermediate pressure region relatively high, decrease again the power consumption of second compression.

In sum, implement usefulness of the present invention to be:

The present invention defers to, and " second level compression is to the work done during compression w of the certain volume gas sucked ₂the work done during compression w to the equivalent volumes gas sucked is compressed with the first order ₁substantially equal, i.e. second level compression pressure reduction p ₂be less than first order compression pressure reduction p ₁, p ₂≈ (0.3 ~ 0.8) p ₁, also be second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁" principle, carry out the restructuring of multiple compressors, by heat pump air conditioner unit, heat-pump hot-water unit is by single stage compress pattern, in room temperature, after water temperature reaches the median of setting, be reassembled as two stages of compression pattern, series operation, the compression ratio of the first order and high stage compressor can be made to decline, delivery temperature declines, operating mode is improved, Energy Efficiency Ratio improves, reach more than 3, exceed identical warm area single stage compress heat pump air conditioner unit, heat-pump hot-water unit Energy Efficiency Ratio more than 1/3, thus heat pump techniques is widely applied in the temperature range that heats of broader ambient temperature range and Geng Gao.

Be only a specific embodiment of the application above, but the application is not limited thereto, the changes that any person skilled in the art can think of, all should drops in the protection domain of the application.

Claims (22)

1. the heat pump that uses in order of a single Two-stage Compression, it is characterized in that, comprise the condenser, throttling arrangement, evaporimeter and the compressor bank that sequentially pass through refrigerant line and connect, the heat sink at described evaporimeter place is placed in low-temperature heat source, described condenser is placed in heated medium, described compressor bank is connected with a control device, and described control device controls compressor bank to carry out single-stage parallel connection compression or recombinate carrying out two-stage series connection compression;

Described compressor bank comprises some compressors, some compressors control to carry out single-stage parallel connection compression or be reassembled as first order compression and second level compression series connection compression by described control device, the compression of the described first order comprises one or at least two compressors in parallel, and the compression of the described second level comprises one or at least two compressors in parallel;

Be reassembled as first order compression and second level compression series connection compression when described control device controls described compressor bank, the inspiratory capacity of wherein said first order compressor is 4 to 8 times of the inspiratory capacity of second level compression.

2. the heat pump that uses in order of single Two-stage Compression as claimed in claim 1, it is characterized in that, described compressor bank comprises a multicylinder compressor, some cylinders are comprised in this multicylinder compressor, some cylinders carry out single-stage parallel connection compression by control device or are reassembled as first order compression and second level compression series connection compression, the compression of the described first order comprises one or at least two cylinders in parallel, and the compression of the described second level comprises one or at least two cylinders in parallel.

3. the heat pump that uses in order of single Two-stage Compression as claimed in claim 2, it is characterized in that, described compressor bank is when two-stage series connection compresses, the refrigerant gas discharge rate that refrigerant gas soakage and the previous stage of rear stage compression compresss matches, and defers to that " the Ya Suo Gong ⊿ w of the certain volume gas to suction is compressed in the second level ₂the Ya Suo Gong ⊿ w to the equivalent volumes gas sucked is compressed with the first order ₁substantially equal; I.e. second level compression Ya Cha ⊿ p ₂be less than first order compression Ya Cha ⊿ p ₁， ⊿ p ₂≈ (0.3 ~ 0.8) ⊿ p _1;also be second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁" principle.

4. the heat pump that uses in order of single Two-stage Compression as claimed in claim 3, it is characterized in that, described compressor bank comprises 5 ~ 9 compressors, and described first order compression comprises 4 ~ 8 compressors in parallel.

5. the heat pump that uses in order of single Two-stage Compression as claimed in claim 3, it is characterized in that, described compressor bank comprises at least one large compressor and at least one little compressor, and the inspiratory capacity of described large compressor is 4 to 8 times of the inspiratory capacity of little compressor; Described large compressor and little compressor are when double stage tandem compression work, and described large compressor is placed in first order compression, and described little compressor is placed in second level compression.

6. the heat pump that uses in order of single Two-stage Compression as claimed in claim 1, is characterized in that, the compression of the described second level is or/and the compressor of first order compression is frequency-changeable compressor.

7. the heat pump that uses in order of single Two-stage Compression as claimed in claim 1, it is characterized in that, described control device comprises some magnetic valves, controls compressor bank carry out single-stage parallel connection compression or two-stage series connection compression is carried out in restructuring by the break-make of each magnetic valve.

8. the heat pump that uses in order of single Two-stage Compression as claimed in claim 1, is characterized in that, described low-temperature heat source comprises air or underground water or seawater, and described heated medium comprises water or air or oil.

9. the heat pump air conditioner that uses in order of a single Two-stage Compression, comprise indoor set, off-premises station, it is characterized in that, also comprise the condenser, throttling arrangement, evaporimeter and the compressor bank that sequentially pass through refrigerant line and connect, described condenser is arranged in described indoor set, described indoor set is placed in air, the off-premises station at described evaporimeter place is placed in air or seawater or underground water, described compressor bank is connected with a control device, and described control device controls compressor bank to carry out single-stage parallel connection compression or recombinate carrying out two-stage series connection compression;

Described compressor bank comprises some compressors, some compressors control to carry out single-stage parallel connection compression or be reassembled as first order compression and second level compression series connection compression by described control device, the compression of the described first order comprises one or at least two compressors in parallel, and the compression of the described second level comprises one or at least two compressors in parallel;

Be reassembled as first order compression and second level compression series connection compression when described control device controls described compressor bank, the inspiratory capacity of wherein said first order compressor is 4 to 8 times of the inspiratory capacity of second level compression.

10. the heat pump air conditioner that uses in order of single Two-stage Compression as claimed in claim 9, it is characterized in that, described compressor bank comprises a multicylinder compressor, some cylinders are comprised in this multicylinder compressor, some cylinders carry out single-stage parallel connection compression by control device or are reassembled as first order compression and second level compression series connection compression, the compression of the described first order comprises one or at least two cylinders in parallel, and the compression of the described second level comprises one or at least two cylinders in parallel.

The heat pump air conditioner that 11. single Two-stage Compressions as claimed in claim 10 use in order, it is characterized in that, described compressor bank is when two-stage series connection compresses, the refrigerant gas discharge rate that refrigerant gas soakage and the previous stage of rear stage compression compresss matches, and defers to that " the Ya Suo Gong ⊿ w of the certain volume gas to suction is compressed in the second level ₂the Ya Suo Gong ⊿ w to the equivalent volumes gas sucked is compressed with the first order ₁substantially equal; I.e. second level compression Ya Cha ⊿ p ₂be less than first order compression Ya Cha ⊿ p ₁， ⊿ p ₂≈ (0.3 ~ 0.8) ⊿ p _1;also be second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁" principle.

The heat pump air conditioner that 12. single Two-stage Compressions as claimed in claim 11 use in order, it is characterized in that, described compressor bank comprises 5 ~ 9 compressors, and described first order compression comprises 4 ~ 8 compressors in parallel.

The heat pump air conditioner that 13. single Two-stage Compressions as claimed in claim 11 use in order, it is characterized in that, described compressor bank comprises at least one large compressor and at least one little compressor, the inspiratory capacity of described large compressor is 4 to 8 times of the inspiratory capacity of little compressor; Described large compressor and little compressor are when double stage tandem compression work, and described large compressor is placed in first order compression, and described little compressor is placed in second level compression.

The heat pump air conditioner that 14. single Two-stage Compressions as claimed in claim 9 use in order, is characterized in that, the compression of the described second level is or/and the compressor of first order compression is frequency-changeable compressor.

The heat pump air conditioner that 15. single Two-stage Compressions as claimed in claim 9 use in order, it is characterized in that, described control device comprises some magnetic valves, controls compressor bank carry out single-stage parallel connection compression or recombinate carrying out two-stage series connection compression by the break-make of each magnetic valve.

The heat-pump hot-water unit that 16. 1 kinds of single Two-stage Compressions use in order, comprise water tank, it is characterized in that, also comprise the condenser, throttling arrangement, evaporimeter and the compressor bank that sequentially pass through refrigerant line and connect, described condenser is arranged in described water tank, the heat sink at described evaporimeter place is placed in air or seawater or underground water, and described compressor bank is connected with a control device, and described control device controls compressor bank and carries out single-stage parallel connection compression or two-stage series connection compression is carried out in restructuring;

Described compressor bank comprises some compressors, some compressors control to carry out single-stage parallel connection compression or be reassembled as first order compression and second level compression series connection compression by described control device, the compression of the described first order comprises one or at least two compressors in parallel, and the compression of the described second level comprises one or at least two compressors in parallel;

Be reassembled as first order compression and second level compression series connection compression when described control device controls described compressor bank, the inspiratory capacity of wherein said first order compressor is 4 to 8 times of the inspiratory capacity of second level compression.

The heat-pump hot-water unit that 17. single Two-stage Compressions as claimed in claim 16 use in order, it is characterized in that, described compressor bank comprises a multicylinder compressor, some cylinders are comprised in this multicylinder compressor, some cylinders carry out single-stage parallel connection compression by control device or are reassembled as first order compression and second level compression series connection compression, the compression of the described first order comprises one or at least two cylinders in parallel, and the compression of the described second level comprises one or at least two cylinders in parallel.

The heat-pump hot-water unit that 18. single Two-stage Compressions as claimed in claim 17 use in order, it is characterized in that, described compressor bank is when two-stage series connection compresses, the refrigerant gas discharge rate that refrigerant gas soakage and the previous stage of rear stage compression compresss matches, and defers to that " the Ya Suo Gong ⊿ w of the certain volume gas to suction is compressed in the second level ₂the Ya Suo Gong ⊿ w to the equivalent volumes gas sucked is compressed with the first order ₁substantially equal; I.e. second level compression Ya Cha ⊿ p ₂be less than first order compression Ya Cha ⊿ p ₁， ⊿ p ₂≈ (0.3 ~ 0.8) ⊿ p _1;also be second level compression ratio ε ₂be significantly less than first order compression ratio ε ₁" principle.

The heat-pump hot-water unit that 19. single Two-stage Compressions as claimed in claim 18 use in order, it is characterized in that, described compressor bank comprises 5 ~ 9 compressors, and described first order compression comprises 4 ~ 8 compressors in parallel.

The heat-pump hot-water unit that 20. single Two-stage Compressions as claimed in claim 18 use in order, it is characterized in that, described compressor bank comprises at least one large compressor and at least one little compressor, the inspiratory capacity of described large compressor is 4 to 8 times of the inspiratory capacity of little compressor; Described large compressor and little compressor are when double stage tandem compression work, and described large compressor is placed in first order compression, and described little compressor is placed in second level compression.

The heat-pump hot-water unit that 21. single Two-stage Compressions as claimed in claim 16 use in order, is characterized in that, the compression of the described second level is or/and the compressor of first order compression is frequency-changeable compressor.

The heat-pump hot-water unit that 22. single Two-stage Compressions as claimed in claim 16 use in order, it is characterized in that, described control device comprises some magnetic valves, controls compressor bank carry out single-stage parallel connection compression or recombinate carrying out two-stage series connection compression by the break-make of each magnetic valve.