JP4358832B2 - Refrigeration air conditioner - Google Patents

Description

  The present invention relates to a refrigeration air conditioner, and more particularly to a refrigeration air conditioner using an ejector.

In the conventional refrigeration air conditioner, an ejector is used, a gas-liquid separator is provided at the ejector outlet, the liquid refrigerant separated by the gas-liquid separator is supplied to the evaporator, and the refrigerant at the outlet of the evaporator is suctioned and boosted to the ejector. The gas refrigerant separated by the gas-liquid separator is supplied to the heater, and the refrigerant heated greatly by the heater is sucked into the compressor so that the discharge temperature at the compressor outlet becomes a predetermined value or more (for example, , See Patent Document 1).
In addition, as another conventional refrigeration air conditioner, an ejector is used to supply the liquid-phase refrigerant separated by the gas-liquid separator to the main evaporator and sub-evaporator, and the temperature of the gas-phase refrigerant separated by the gas-liquid separator is It is supplied to the compressor suction through an actuated variable throttle valve, and when the efficiency of the ejector deteriorates, the variable throttle opening of the temperature actuated variable throttle valve is narrowed so that the refrigerant also flows through the sub-evaporator. Yes (see, for example, Patent Document 2).

Japanese Patent Laying-Open No. 2004-3804 (page 5-8, FIG. 1) Japanese Patent Laid-Open No. 2000-283577 (page 1-7, FIG. 1)

  However, in the case of the conventional refrigeration air conditioner (Patent Document 1), the gas-liquid separator is used before the refrigerant is distributed to the evaporator and the heater, and thus there are the following problems. First, since the refrigerant supplied to the heater becomes a gas refrigerant, the amount of heat exchange in the heater is maximum until the refrigerant changes from a saturated gas state to a gas having the same temperature as the load heat medium cooled by the evaporator. However, there was a problem that the heat exchange amount was limited. Therefore, even if an attempt is made to increase the amount of heat exchange according to the operating conditions of the apparatus in the heater, there is a problem that the amount of heat exchange of the heater is insufficient, and the capability according to the request of the apparatus operator cannot be exhibited (note that If the evaporator is the first evaporator, the heater can be said to be the second evaporator).

  Another problem with conventional refrigeration and air-conditioning systems is that the refrigerant state of the heater cannot be controlled, so the intake temperature of the compressor rises significantly and the discharge temperature of the compressor rises excessively. There was a problem that reliability decreased. Since the refrigerant state at the heater inlet is fixed to the saturated gas state, the refrigerant state at the heater outlet is a gas refrigerant whose temperature has increased according to the amount of heat exchange. For this reason, when the temperature of the load heat medium cooled by the heater becomes high and the heat exchange amount greatly increases, the refrigerant temperature at the outlet of the heater, that is, the compressor intake temperature increases greatly accordingly. Thus, the discharge temperature was excessively increased.

  Further, another problem of the conventional refrigeration air conditioner is that the refrigeration oil circulating in the refrigeration cycle is difficult to return to the compressor, the amount of oil in the compressor is lowered, and the reliability of the compressor operation is lowered. The refrigerating machine oil that flows into the gas-liquid separator dissolves in the liquid refrigerant and flows out to the liquid refrigerant side, or is liquid even if it does not dissolve. Since it is separated, there is almost no refrigerating machine oil flowing out to the gas refrigerant side together with the gas refrigerant of the gas-liquid separator. Accordingly, it is difficult for oil to return to the compressor, causing a reduction in the reliability of compressor operation.

  Further, in the case of another conventional refrigeration air conditioner (Patent Document 2), there are the following problems. When the ejector efficiency deteriorates, the suction flow rate at the ejector decreases, and the flow rate that can flow to the main evaporator decreases. Accordingly, since the amount of liquid refrigerant that can be evaporated by the main evaporator is reduced, the dryness of the refrigerant that exits the ejector and flows into the gas-liquid separator is reduced. Here, in the conventional apparatus, when the refrigerant superheat degree at the outlet of the sub-evaporator increases, it is assumed that the ejector efficiency deterioration is detected. Therefore, the refrigerant dryness flowing into the gas-liquid separator when the efficiency deteriorates becomes too low, The refrigerant overflows and flows into the gas-phase-side channel, and the refrigerant flow rate in the gas-phase-side channel increases, thereby increasing the amount of pressure reduction at the temperature-actuated variable throttle valve, and the compressor suction pressure (= sub-evaporator) The pressure is decreased, the amount of heat exchange in the sub-evaporator is increased, and the degree of refrigerant superheat is increased.

  When this state is reached, the temperature-actuated variable throttle valve opening is reduced and the refrigerant superheat degree at the outlet of the sub-evaporator is reduced. The amount of liquid refrigerant is supplied to the sub-evaporator and the amount of liquid refrigerant supplied with respect to the amount of heat exchange is increased to reduce the degree of refrigerant superheating at the outlet of the sub-evaporator. Accordingly, the conventional apparatus can control the degree of superheat of the refrigerant at the outlet of the sub-evaporator, but does not have a function of controlling the amount of liquid refrigerant flowing out from the gas phase side flow path. Therefore, the compressor suction state where the gas-phase side flow path and the sub-evaporator outlet join cannot be controlled, and depending on the situation, the liquid refrigerant is sucked into the compressor, and the operation reliability of the compressor is increased. There was a problem of lowering the performance.

  The present invention has been made to solve the above-described problems. In a refrigeration air conditioner using an ejector, the amount of heat exchange in the second evaporator can be controlled, so that the second evaporation can be performed as necessary. The cooling capacity of the compressor is secured, the reliability of the operation of the equipment is ensured, the excessive rise in the compressor suction temperature and the liquid back to the suction are suppressed, and the oil return to the compressor is secured, the compressor An object of the present invention is to provide a refrigeration air conditioner that can ensure the reliability of operation.

The refrigerating air-conditioning apparatus according to the present invention is a refrigerating air-conditioning apparatus having a refrigerating cycle in which a compressor, a condenser or a radiator, an ejector, and an evaporator are connected in an annular shape. The evaporator includes a first evaporator and a second evaporation And a distributor for distributing the refrigerant from the ejector to the first evaporator and the second evaporator, between the ejector and the first and second evaporators, the ejector The refrigerant from the first evaporator is sucked and pressurized, the distributor separates the refrigerant flowing out from the ejector into a gas-liquid two-phase refrigerant and a liquid refrigerant, and the outlet of the first evaporator is a suction part of the ejector The inlet of the first evaporator is connected to the liquid refrigerant outlet of the distributor, the outlet of the second evaporator is connected to the compressor, and the inlet of the second evaporator is connected to the gas-liquid two-phase of the distributor. Connect to the refrigerant outlet, The so that the area of the second evaporator and the first evaporator is the same if the value converted to the evaporation temperature rise of the coolant is 1/2 of the temperature decline of air at the evaporator pressure amount And the converted evaporation temperature increase width of the refrigerant is larger than ½ of the air temperature decrease width in the evaporator, the heat transfer area of the second evaporator is set to be the same as that of the first evaporator. When the converted evaporation temperature increase width of the refrigerant is smaller than ½ of the air temperature decrease width in the evaporator, the heat transfer area of the first evaporator is set to the second heat transfer area. It should be smaller than the heat transfer area of the evaporator.

The present invention relates to a refrigeration air conditioner having a refrigeration cycle in which a compressor, a condenser or a radiator, an ejector, and an evaporator are connected in an annular shape, and the evaporator includes a first evaporator and a second evaporator. In addition, a distributor for distributing the refrigerant from the ejector to the first evaporator and the second evaporator is provided between the ejector and the first and second evaporators, and the ejector is provided in the first evaporator. The refrigerant from the ejector is separated into the gas-liquid two-phase refrigerant and the liquid refrigerant, and the outlet of the first evaporator is connected to the suction part of the ejector. An evaporator inlet is connected to the liquid refrigerant outlet of the distributor, an outlet of the second evaporator is connected to the compressor, and an inlet of the second evaporator is connected to a gas-liquid two-phase refrigerant outlet of the distributor. , Evaporating refrigerant by increasing pressure in the ejector If the value in terms of degrees of increase is 1/2 of the temperature decline of air at the evaporator is set such that the area of the second evaporator and the first evaporator is the same, the conversion If the increase in the evaporation temperature of the refrigerant is greater than half the temperature decrease in the evaporator, the heat transfer area of the second evaporator is made smaller than the heat transfer area of the first evaporator. If the converted evaporation temperature increase width of the refrigerant is smaller than ½ of the air temperature decrease width in the evaporator, the heat transfer area of the first evaporator is set as the heat transfer area of the second evaporator. Since the heat exchange amount in the second evaporator can be controlled, the capacity in the second evaporator can be secured as necessary to ensure the reliability of the operation of the apparatus, and the compressor intake temperature. The reliability of the compressor operation can be ensured by suppressing the excessive rise and the liquid back. Further, by allowing the refrigeration oil together with the liquid refrigerant to return to the compressor via the second evaporator, the amount of compressor oil can be ensured and the reliability of the compressor operation can be ensured. Furthermore, the temperature difference between the air and the refrigerant in the first evaporator and the second evaporator can be made relatively uniform, and the heat exchange efficiency between the first evaporator and the second evaporator can be improved.

Embodiment 1 FIG.
A first embodiment of the present invention is shown in FIG. FIG. 1 is a circuit diagram of a refrigerating and air-conditioning apparatus according to the present invention. In an outdoor unit 1, there are a compressor 3 and a condenser (radiator), an outdoor heat exchanger 4 acting as a heat source side heat exchanger, and an ejector 5. A liquid distributor 6 serving as a distributor, an expansion valve 7 serving as a second pressure reducing device, a first evaporator 8 and a second evaporator 9 acting as a load side heat exchanger are mounted as shown in the figure. To form a refrigerant circuit.
That is, the refrigeration cycle is configured in the order of the compressor 3, the outdoor heat exchanger 4, the ejector 5, the liquid distributor 6, and the second evaporator 9, and the refrigerant that has exited the second evaporator 9 enters the compressor 3 suction side. Returned. A part of the refrigerant distributed by the liquid distributor 6 is returned to the suction portion of the ejector 5 through the expansion valve 7 and the first evaporator 8.
The compressor 3 is a type in which the rotation speed is controlled by an inverter and the capacity is controlled. The outdoor heat exchanger 4 exchanges heat with the air around the outdoor unit 1 conveyed by a blower. The ejector 5 has a structure in which the throttle opening at the expansion portion is variable. The expansion valve 7 is an electronic expansion valve whose opening degree is variably controlled. The first evaporator 8 and the second evaporator 9 are plate heat exchangers, and perform heat exchange between the load side heat medium such as water and brine to be conveyed and the refrigerant. For example, R410A is used as the refrigerant of the refrigeration air conditioner.
In the indoor unit 2, the load-side heat medium of water and brine cooled by the first evaporator 8 and the second evaporator 9 is conveyed, and the load-side heat medium and air are transferred by the indoor heat exchanger 20 in the indoor unit 2. Cooling operation is performed by heat exchange.

In the outdoor unit 1, the temperature sensor 11 a is on the suction side of the compressor 3, the temperature sensor 11 b is on the discharge side of the compressor 3, the temperature sensor 11 c is on the second evaporator 9 inlet, the temperature sensor 11 d is on the first evaporator 8 inlet, and the temperature sensor 11e is provided at the outlet of the first evaporator 8 and measures the refrigerant temperature at the installation location. Moreover, the temperature sensor 11f is provided in the load side heat-medium flow path of the 1st evaporator 8 exit, and measures the temperature of the load-side heat medium here. Moreover, the temperature sensor 11g is provided in order to measure the outdoor temperature around the outdoor unit 1.
Moreover, the pressure sensor 12a is provided in the compressor 3 suction | inhalation side, and the pressure sensor 12b is provided in the compressor 3 discharge | emission side, and each measures the refrigerant | coolant pressure of an installation place.

  In addition, a measurement control device 10 is provided in the outdoor unit 1, and the compressor 3 is based on measurement information such as the temperature sensor 11 and the pressure sensor 12 and the operation content instructed by the user of the refrigeration air conditioner. The operation method, the air flow rate of the outdoor heat exchanger 4, the throttle opening of the ejector 5, the opening of the expansion valve 7, and the like are controlled.

  Next, the structure of the ejector 5 in this refrigeration air conditioner will be described. 2 is a diagram showing the relationship between the structure of the ejector used in the refrigerating and air-conditioning apparatus according to Embodiment 1 of the present invention and the pressure change. FIG. 2 (a) shows the structure of the ejector 5. FIG. 2 (b) shows the pressure distribution corresponding to the refrigerant flow direction position of the ejector 5 in FIG. 2 (a). 2B, the horizontal axis represents the refrigerant flow direction position of the ejector 5 in FIG. 2A, and the vertical axis represents the pressure change at each position of the ejector 5. In the figure, the ejector 5 is composed of a needle part 42, an electromagnetic coil part 41 for driving the needle part 42, a nozzle part 43, a mixing part 44, and a diffuser part 45. The nozzle part 43 further includes a decompression part 43a and a nozzle throat part 43c. And the divergent portion 43b. Therefore, the ejector 5 of the present embodiment has a structure in which the needle portion 42 is driven (moved) in the axial direction by the electromagnetic coil portion 41 so that the flow passage area of the nozzle throat portion 43c can be varied. It is an ejector provided with a variable degree diaphragm mechanism.

  The ejector 5 decompresses and expands the liquid refrigerant E1 having a pressure P1, which is a driving flow, at the pressure reducing portion 43a (X1 to X2) to obtain a sound velocity at the pressure P2 at the nozzle throat portion 43c (X2), and further, the widening portion 43b (X2 to X3) To reduce the pressure to supersonic speed to pressure P3. At this time, the gas refrigerant E4 is sucked from the suction part inlet 5a of the surrounding gas refrigerant, and the sucked gas refrigerant flows out of the divergent part 43b in the suction mixing part (X3 to X4) and becomes supersonic. Is mixed into the gas-liquid two-phase refrigerant E2, and the mixed gas-liquid two-phase refrigerant E2 recovers the pressure at the mixing unit 44 (X4 to X5) to the pressure P4, and further, the diffuser unit 45 (X5 to X5). In X6), the pressure rises to the pressure P5 and flows out.

  Next, the liquid distributor 6 will be described. FIG. 3 is a sectional view of the liquid distributor of the refrigerating and air-conditioning apparatus showing Embodiment 1 of the present invention. In the figure, the liquid distributor 6 includes an inflow path 6 a from the ejector 5, a first branch path 6 b that branches from the inflow path 6 a to the first evaporator side 8, and a second branch that branches from the inflow path 6 a to the second evaporator 9. The first and second branch paths 6b and 6c are U-shaped. And the 1st branch path 6b is arrange | positioned below the 2nd branch path 6c, and the refrigerant flow path which flows into the 1st evaporator 8 becomes below rather than the refrigerant flow path which flows into the 2nd evaporator 9 in a branch part. Are arranged as follows. At this time, the liquid refrigerant flows to the lower first evaporator 8 side due to gravity, and the remaining liquid refrigerant that cannot flow completely flows to the upper second evaporator 9 side.

  Next, the operation | movement operation | movement in this refrigeration air conditioner is demonstrated based on FIGS. 1-4. FIG. 4 is a diagram showing the relationship between the pressure and enthalpy of the refrigerating and air-conditioning apparatus according to Embodiment 1 of the present invention, where the horizontal axis represents enthalpy and the vertical axis represents pressure. Here, the refrigerating and air-conditioning apparatus according to the present embodiment, for example, transports a load side heat medium while exchanging heat from an outdoor unit 1 installed outdoors to an indoor unit 2 provided indoors to cool the room. The high-temperature and high-pressure gas refrigerant R1 (I1, Pc1) discharged from the compressor 3 dissipates heat to the air in the outdoor heat exchanger 4, condenses and liquefies, and the high-pressure liquid refrigerant R2 (I2, Pc1) (E1) flows into the ejector 5.

  The refrigerant that has flowed into the ejector 5 enters the state R3 (I3, Pe2) at the outlet of the nozzle portion 43 (position X3 in FIG. 2) and flows into the mixing portion 44. After mixing with the refrigerant gas of R4 (I8, Pe2) (E4) flowing in from the gas refrigerant suction part inlet 5a of the ejector 5 in the mixing unit 44, the refrigerant in the state of R5 (I5, Pe2) is caused by the diffuser 45. The pressure is restored from Pe2 to Pe1, and a state R6 (I6, Pe1) is obtained. The refrigerant decompressed by the ejector 5 flows into the liquid distributor 6. In the liquid distributor 6, a part of the liquid refrigerant in the two-phase refrigerant that has exited the ejector 5 is distributed to the first evaporator 8 side, and the liquid refrigerant in the state R9 (I9, Pe1) is decompressed by the expansion valve 7, The refrigerant flows into the first evaporator 8, evaporates while cooling the load-side heat medium, becomes a gas refrigerant in the state R4 (I8, Pe2), and is sucked into the gas refrigerant suction portion inlet 5a of the ejector 5. On the other hand, the two-phase refrigerant in the state R7 (I7, Pe1) in which the remaining liquid refrigerant and gas refrigerant that have not been separated to the first evaporator 8 side by the liquid distributor 6 are mixed flows into the second evaporator 9, While cooling the load-side heat medium, it evaporates to become a gas refrigerant in the state R8 (I8, Pe1) and is sucked into the compressor 3. In the present embodiment, Pc1> Pc2> Pe1> Pe2 and I1> I8> I7> I6> I5> I2> I2> I3> I9.

  Here, the driving force of the ejector 5 is an enthalpy difference ΔH (= I2−I3) between the enthalpy I3 at the time of isentropic expansion and the enthalpy I2 at the time of isentropic expansion. The greater the enthalpy difference ΔH, the greater the effect of introducing the ejector. Generally, the enthalpy difference ΔH increases as the pressure difference ΔPc (= Pc1−Pe2) between the high pressure Pc1 and the low pressure Pe2 increases.

Next, the flow and temperature change of the load-side heat medium in the cooling operation in this refrigeration air conditioner will be described. Here, the load side heat medium will be described as water. In the indoor unit 2, low-temperature water, for example, water at 7 ° C. is supplied from the outdoor unit, and while the indoor unit space is cooled, the water temperature rises to become high-temperature water, for example, 12 ° C. water, and exits the indoor unit 2. It flows into the outdoor unit 1. In the outdoor unit 1, water first flows into the second evaporator 9, where it is cooled by the refrigerant and the temperature is lowered, for example, 9 ° C. water is discharged from the second evaporator 9. The water exiting the second evaporator 9 continues to flow into the first evaporator 8, where it is further cooled by the refrigerant to lower the temperature, for example, becomes 7 ° C. water and flows out of the first evaporator 8, and the outdoor unit Exit 1 and flow into indoor unit 2.
In this refrigeration air conditioner, first, the high temperature water is cooled by the second evaporator 9, and then the relatively low temperature water is cooled by the first evaporator 8.

  Next, the control operation in this refrigeration air conditioner will be described with reference to FIG. First, the operation is performed with the rotation speed of the compressor 3, the outdoor heat exchanger 4 blown air volume, the ejector 5 opening, and the expansion valve 7 opening set to initial values (S1). Here, the initial setting value of the air flow rate of the outdoor heat exchanger 4 is determined by the outside air temperature detected by the temperature sensor 11g, and is set to a high air volume when the outside air temperature is high and to a low air volume when it is low (S1).

  And after driving | running in this state, each actuator is controlled according to an apparatus operating state. First, the rotational speed of the compressor 3 is set so that the outlet water temperature, which is the load-side heat medium temperature (S2) at the outlet of the first evaporator 8 detected by the temperature sensor 11f, becomes a preset target value, for example, 7 ° C. Be controlled. When the rotation speed of the compressor 3 is high, the refrigerant flow rate increases, the cooling capacity of the apparatus increases, and the water is further cooled, so the water temperature at the outlet of the first evaporator 8 decreases. Conversely, when the rotation speed of the compressor 3 is low, the water temperature at the outlet of the first evaporator 8 rises. Therefore, the water temperature at the outlet of the first evaporator 8 is compared with the target value (S3). When the water temperature is high, the rotational speed of the compressor 3 is increased, and when the water temperature is low, the rotational speed of the compressor 3 is decreased ( S4).

  Next, although it is the amount of ventilation of the outdoor heat exchanger 4, the operation is basically performed at the initial set value. However, if the high pressure (pressure of the refrigerant discharged from the compressor 3) detected by the pressure sensor 12b rises excessively depending on the operating conditions, control is performed to increase the air volume to protect the compressor 3. When the high pressure is excessively reduced, the low pressure (pressure of the refrigerant sucked by the compressor 3) is greatly reduced even when the ejector 5 opening degree and the expansion valve 7 opening degree control are performed, and water is used as the load-side transport medium. In some cases, the refrigerant evaporation temperature is too low, and there is a risk of freezing. Therefore, control is performed to reduce the air volume so as to suppress an excessive decrease in high pressure (S5).

Next, the opening degree of the ejector 5 is controlled so that the refrigerant superheat degree SH2 at the outlet of the second evaporator 9 (the compressor 3 suction port) becomes a preset target value, for example, 5 ° C. Here, the refrigerant superheat degree SH2 at the outlet of the second evaporator 9 is calculated by the temperature sensor 11a detected temperature (second evaporator 9 outlet temperature) -temperature sensor 11c detected temperature (refrigerant evaporation temperature at the second evaporator 9). Or a value calculated from the refrigerant saturated gas temperature converted from the temperature sensor 11a detected temperature-pressure sensor 12a detected pressure (S6). As described above, the compressor suction side superheat degree detection means includes the temperature sensors 11a and 11c, and calculates the superheat degree from this temperature difference.
When the opening degree of the ejector 5 is reduced, the flow rate of the refrigerant passing through the ejector 5 is reduced, so that the conveyance flow rate by the compressor 3 is reduced and the flow rate of the refrigerant flowing through the second evaporator 9 is also reduced.

  Therefore, the increase / decrease in the flow rate of the refrigerant flowing with respect to the predetermined heat exchange amount is controlled, which is the same change as when the so-called opening control of the expansion valve 7 is performed. The refrigerant superheat degree SH2 at the outlet of the second evaporator 9 increases, and when the opening degree of the ejector 5 is increased, the refrigerant superheat degree SH2 at the outlet of the second evaporator 9 decreases. Therefore, the refrigerant superheat degree SH2 at the outlet of the second evaporator 9 is compared with the target value (S7). If the refrigerant superheat degree SH2 is larger than the target value, the opening degree of the ejector 5 is controlled to be large, and the refrigerant superheat degree is determined. When SH2 is smaller than the target value, the opening degree of the ejector 5 is controlled to be small (S8).

Next, the opening degree of the expansion valve 7 is controlled so that the refrigerant superheat degree SH1 at the outlet of the first evaporator 8 becomes a preset target value, for example, 5 ° C. Here, the refrigerant superheat degree SH1 at the outlet of the first evaporator 8 is the detected temperature of the temperature sensor 11e (first evaporator 8 outlet temperature) −the detected temperature of the temperature sensor 11d (refrigerant evaporation temperature in the first evaporator 8). The calculated value is used (S9). Thus, the first evaporator outlet superheat degree detection means comprises the temperature sensors 11e and 11d, and calculates the superheat degree from this temperature difference.
When the opening degree of the expansion valve 7 decreases, the flow rate of the refrigerant flowing through the first evaporator 8 decreases, the refrigerant superheat degree SH1 at the outlet of the first evaporator 8 increases, and conversely, when the opening degree of the expansion valve 7 increases, The refrigerant superheat degree SH1 at the outlet of one evaporator 8 becomes small. Therefore, the refrigerant superheat degree SH1 at the outlet of the first evaporator 8 is compared with the target value (S10), and when the refrigerant superheat degree SH1 is larger than the target value, the opening degree of the expansion valve 7 is controlled to be large, When the degree SH1 is smaller than the target value, the opening degree of the expansion valve 7 is controlled to be small (S11).

  In the rotation speed control of the compressor 3 and the opening control of the ejector 5 and the expansion valve 7, the control amount is determined by a PID control method based on a deviation from the target value.

  Next, the effect obtained by the configuration and control of this refrigeration air conditioner will be described. First, high-efficiency operation is realized by the boosting effect of the ejector 5. In the case of a refrigeration air conditioner that does not use an ejector, it is necessary to reduce the pressure to the pressure (Pe2) in the first evaporator 8 in order to cool the load-side heat medium. As a result, the suction pressure of the compressor 3 is increased from Pe2 to Pe1, which is the pressure in the second evaporator 9. Accordingly, the input required for driving the compressor 3 is reduced, and high-efficiency operation is realized.

  Further, the distribution of the liquid distributor 6 enables the liquid refrigerant to be supplied to the second evaporator 9 as well, and the following effects are obtained. First, when the cooling load increases and an overload operation is performed and the load-side heat medium temperature flowing into the second evaporator 9 rises, the amount of heat exchange in the second evaporator 9 increases, and the second evaporator 9 Since the refrigerant superheat degree SH2 at the outlet increases, the opening degree of the ejector 5 is largely controlled. If the opening degree of the expansion valve 7 is the same at this time, the flow rate of the two-phase refrigerant that passes through the ejector 5 and flows into the liquid distributor 6, that is, the liquid and gas flow rates both increase, while the first through the expansion valve 7. Since the liquid refrigerant flow rate flowing out to the evaporator 8 does not change, the refrigerant flow rate flowing out to the second evaporator 9 side increases, and the liquid refrigerant flow rate flowing out also increases. Therefore, the amount of refrigerant evaporated in the second evaporator 9 increases, and a larger amount of heat exchange can be obtained. Therefore, even if it becomes an overload driving | operation, the driving | operation which increases a cooling capability can be performed and the reliability of an apparatus driving | operation can be ensured.

  Further, by supplying liquid refrigerant so that the amount of heat exchanged in the second evaporator 9 increases according to the load, an increase in the superheated gas region in the second evaporator 9 is suppressed, and the heat transfer coefficient is increased. Since a large two-phase refrigerant area can be secured, high heat exchange performance can be maintained even during overload operation, and the evaporator performance as seen in the entire system is maintained high, and high efficiency is achieved even in overload operation. Can be operated.

  Even in the overload operation, since the liquid refrigerant is supplied to the second evaporator 9, only the gas refrigerant after the gas-liquid separator is not heated as in the conventional example, and the second evaporator 9 An excessive increase in the outlet refrigerant temperature can be suppressed, an increase in the discharge temperature of the compressor 3 can be suppressed, and a highly reliable operation of the compressor 3 can be realized.

  In addition, since the liquid refrigerant can be supplied to the second evaporator 9 by the distribution in the liquid distributor 6, the refrigeration oil can be supplied to the second evaporator 9 together with the liquid refrigerant. Accordingly, after passing through the second evaporator 9, the refrigeration oil can be returned to the compressor 3, and only the gas refrigerant after the gas-liquid separator is supplied to the compressor 3 as in the conventional example. In comparison, the amount of oil in the compressor 3 can be ensured, and the reliability of compressor operation can be ensured.

  In addition, when using a gas-liquid separator as in the conventional example, a method of separating by gravity using the gas-liquid density difference is generally taken, but it is necessary to make the refrigerant flow rate as slow as possible to ensure the separation. There is a problem that a large-diameter container is used and the cost is high. In the refrigerating and air-conditioning apparatus according to the present invention, it is only necessary to perform liquid distribution. Therefore, the liquid distributor 6 has U-shaped branch shapes as shown in FIG. 3 arranged vertically, and the refrigerant flows to the second evaporator 9 at the branch portion. It can be a simple branching structure in which the refrigerant flow path that flows to the first evaporator 8 is lower than the flow path, and the liquid refrigerant flows to the first evaporator 8 side below by gravity and the remaining flow that cannot flow The liquid refrigerant flows to the upper second evaporator 9 side. Thus, since it can be set as the distribution structure which considered only the liquid refrigerant, the distributor of a simple structure can be applied and low cost can be realized.

Regarding the power that can be applied to the suction pressure increase by the ejector 5,
Since the correlation between power suction flow rate x pressure increase range applicable to suction pressure increase is established, if the refrigerant flow rate distributed to the first evaporator 8 is large, the pressure increase range at the ejector 5 becomes small, and the efficiency increase range due to the low pressure increase Becomes smaller. Therefore, it is desirable that the flow rate of the refrigerant distributed to the first evaporator 8 is not more than necessary. In the refrigerating and air-conditioning apparatus of the present invention, the expansion valve 7 is provided at the inlet of the first evaporator 8, and the refrigerant superheat degree at the outlet of the first evaporator 8 can be controlled appropriately. Therefore, in order to obtain the same heat exchange amount, it is possible to avoid a state in which an excessive flow rate flows into the first evaporator 8 and the outlet of the first evaporator 8 is sucked into the ejector 5 while being in a gas-liquid two-phase state. The minimum refrigerant flow rate that secures the heat exchange amount in one evaporator 8 can be supplied, the maximum efficiency increase due to the pressure increase in the ejector 5 can be operated, and a highly efficient refrigeration air conditioner can be obtained. .

  Further, since it is desirable that the refrigerant flow rate distributed to the first evaporator 8 is small, it is desirable that the gas refrigerant that does not contribute to the exchange of evaporation heat is not distributed to the first evaporator 8 as much as possible. It is desirable to distribute as much of the inflowing gas refrigerant as possible to the second evaporator 9 side. In the case of the liquid distributor 6 structure as shown in FIG. 3, since the gas refrigerant flows biased upward, the distributor branching portion is arranged up and down, and the flow path branched upward is on the second evaporator 9 side. The flow path branched downward is arranged on the first evaporator 8 side (expansion valve 7 side). With this arrangement, there is almost no gas flow rate distributed to the first evaporator 8 side, and a large gas flow rate can be distributed to the second evaporator 9 side. Can be operated at the maximum, and a highly efficient refrigeration air conditioner can be obtained.

Further, the opening degree control of the ejector 5 may be controlled with the discharge temperature of the compressor 3 or the superheat degree of the discharged refrigerant as a target instead of the refrigerant superheat degree control at the outlet of the second evaporator 9.
So far, this refrigeration and air-conditioning apparatus has been described as performing cooling operation, but with the same refrigerant circuit configuration, the first evaporator 8 and the second evaporator 9 are configured as heat source side heat exchangers to collect heat from the outside air, Instead of the heat exchanger 4, a heat exchanger that heats hot water can be provided as a condenser to provide a heat pump water heater. In the water heater, since the operation of raising the temperature to the boiling temperature is performed by utilizing the sensible heat amount of the discharge gas of the compressor 3, the discharge temperature or the discharge refrigerant indicating the magnitude of the sensible heat amount of the discharge gas is performed. How to set the degree of superheat is important for securing heating capacity and improving operating efficiency.

Therefore, the discharge target or the control target value of the superheat degree of the discharged refrigerant is set according to the boiling temperature so that the optimum operation with high efficiency and high efficiency can be performed, and the temperature that is the compressor discharge temperature detection means The superheat degree of the discharge refrigerant calculated by the condensation temperature calculated from the discharge temperature detected by the sensor 11b or the pressure-high pressure detected by the discharge temperature-pressure sensor 12b detected by the temperature sensor 11b becomes the target value. Then, the opening degree of the ejector 5 is controlled. As described above, the compressor discharge superheat degree detection means includes the temperature sensor 11b and the pressure sensor 12b, and calculates the superheat degree based on the difference between the detected temperature and the condensation temperature obtained from the detected pressure.
As described above, the opening degree control of the ejector 5 shows the same tendency as the normal expansion valve opening degree control. Therefore, when the discharge temperature or the superheat degree of the discharged refrigerant is higher than the target value, the opening degree of the ejector 5 is controlled. When the discharge temperature or the superheat degree of the discharged refrigerant is lower than the target value, the opening degree of the ejector 5 is controlled to be small.
By performing such an operation, it is possible to obtain a refrigerating and air-conditioning apparatus capable of ensuring a heating capability and performing a highly efficient operation.

In addition, when the first evaporator 8 and the second evaporator 9 are used for cooling, the second evaporator 9 cools the medium to be cooled as shown in the configuration of FIG. The first evaporator 8 is preferably cooled.
This is because the pressure of the first evaporator 8 (Pe2 in FIG. 4) <
Since the pressure of the second evaporator 9 (Pe 1 in FIG. 4) is reached, the evaporation temperature of the refrigerant is the first evaporator 8 <the second evaporator 9, so the temperature of the medium to be cooled is also the first evaporator 8. <When the second evaporator 9 is used, the temperature difference between the refrigerant evaporation temperature and the medium to be cooled in the evaporation heat exchange can be made uniform, the heat exchange efficiency in the evaporator can be increased, and the operation efficiency of the apparatus is increased. can do.

Note that the medium cooled by the first evaporator 8 and the second evaporator 9 is not limited to water or brine, and air may be used, and the first evaporator 8 and the second evaporator 9 are placed in the space to be cooled. A direct expansion operation for cooling the air may be performed.
In this case, as shown in FIG. 6, an air heat exchanger structure in which the first evaporator 8 and the second evaporator 9 are arranged in the same air passage, and the air that has just been introduced into the heat exchanger and is at a high temperature is used. The second evaporator 9 is disposed on the upper side, and the first evaporator 8 is disposed on the leeward side where the air temperature is lowered by cooling with the second evaporator 9. In this case as well, the temperature difference between the refrigerant evaporation temperature and the medium to be cooled can be made uniform, the heat exchange efficiency in the first evaporator 8 and the second evaporator 9 can be increased, and the operation efficiency of the apparatus can be increased. it can.

  Moreover, it is not necessary to cool the same medium with the 1st evaporator 8 and the 2nd evaporator 9, and you may cool separately. For example, since the first evaporator 8 can be operated at a lower evaporation temperature, it is a dehumidifying heat exchanger that operates at an evaporation temperature lower than the dew point temperature of the indoor space to perform dehumidification, and the second evaporator 9 is operated at a high evaporation temperature. Therefore, the heat exchanger for sensible heat cooling that cools the sensible heat in the indoor space higher than the dew point temperature may be used. Also in this case, compared with the case where dehumidification and sensible heat cooling are performed in the same heat exchanger, the temperature difference between the refrigerant evaporation temperature in the evaporation heat exchange and the medium to be cooled can be made more uniform. The heat exchange efficiency in the two evaporators 9 can be increased, and the operation efficiency of the apparatus can be increased. Further, the evaporation temperature corresponding to the suction pressure of the compressor 3 can be set to a temperature corresponding to sensible heat cooling, air conditioning that can perform dehumidification with a high suction pressure can be performed, and highly efficient and comfortable operation can be performed. it can.

  In addition, the first evaporator 8 and the second evaporator 9 may be cooled although the temperatures to be cooled are different. For example, it is possible to perform interpersonal air conditioning that requires a lower temperature in the first evaporator 8 and to perform mechanical air conditioning in which the cooling temperature may be higher in the second evaporator 9. Moreover, it uses for cooling for low temperature, such as a showcase system, for example, the 1st evaporator 8 cools fresh products, such as meat fish which require a low temperature, and the 2nd evaporator 9 may have high cooling temperature. You may make it cool fruits and vegetables and daily goods.

Embodiment 2. FIG.
In the first embodiment, the liquid distributor is U-shaped, but this embodiment has a cylindrical structure. 7 and 8 are cross-sectional views showing the structure of the liquid distributor of the refrigerating and air-conditioning apparatus showing Embodiment 2 of the present invention.
In FIG. 7, the cylindrical structure of the liquid distributor 6 is arranged vertically, the first and second branch paths 6b and 6c are made vertical, the liquid refrigerant is retained in the lower part of the cylindrical portion, and the liquid refrigerant is generated therefrom. Is extracted and supplied to the first evaporator 8 side (expansion valve 7 side). In the case of this structure, the distributor inlet portion is arranged above the distributor so that the gas refrigerant does not reach the lower part of the cylindrical portion, and the first branch path 6b is longer than the second branch path 6c. It is desirable to do.
FIG. 8 shows a horizontal arrangement of the cylindrical structure, the inflow path 6a and the second branch path 6c are horizontal, the first branch path 6b is vertical, and the two-phase refrigerant is in the gas phase on the upper side and the lower side. The liquid refrigerant is extracted from the bottom of the cylindrical shape and is supplied to the first evaporator 8 side (expansion valve 7 side) by utilizing the characteristics separated from the liquid phase. In any case, in the refrigerant flow path at the branch portion, the flow path branched to the first evaporator 8 side (expansion valve 7 side) is lower than the flow path branched to the second evaporator 9 side. Placed in.

  7 and FIG. 8, it is not necessary to ensure gas-liquid separation, and gas refrigerant and liquid refrigerant may be mixed and flow out on the second evaporator 9 side. Therefore, unlike the generally used gas-liquid separator, it is not necessary to slow down the refrigerant flow rate, and the diameter of the cylindrical portion may be an appropriate size for the liquid refrigerant to stay. Therefore, it can be configured with a copper pipe throttle structure, and in this case as well, it is less expensive than a conventional gas-liquid separator, and a low-cost refrigeration air conditioner can be obtained.

Embodiment 3 FIG.
In the first embodiment, the ejector 5 has a structure with a variable throttle opening, but in this embodiment, the opening of the ejector 5 is fixed and an expansion valve is added.
9 and 10 are diagrams showing circuit configurations of the ejector and the expansion valve of the refrigerating and air-conditioning apparatus according to Embodiment 3 of the present invention.
FIG. 9 is a combination of an ejector 5 and a variable opening electronic expansion valve 13 which is a first decompression device in parallel, and FIG. 10 is a serial decompression device configured by connecting them in series. The flow rate of the liquid refrigerant distributed to the second evaporator 9 is controlled by the opening degree control of 13.
The control by this structure performs superheat degree control of the 2nd evaporator 9 exit similarly to the opening degree control of the ejector 5. FIG.

The control by this configuration can obtain the same effect as the opening degree control by the ejector 5, the structure of the ejector 5 is simple and inexpensive, and a low-cost refrigeration air conditioner can be obtained.
Instead of the electronic expansion valve 13, a plurality of circuits in which a capillary tube and an electromagnetic valve are connected in series may be connected as the first pressure reducing device. In this case, each capillary tube has a different flow resistance, and the flow resistance as the decompression device can be made variable by opening and closing the electromagnetic valve, and the same function as the electronic expansion valve 13 can be realized.

Embodiment 4 FIG.
In the present embodiment, an internal heat exchanger is used instead of the second evaporator 9 shown in FIG. 1 of the first embodiment.
FIG. 11 is a circuit diagram of a refrigerating and air-conditioning apparatus showing Embodiment 4 of the present invention. In the figure, the same or corresponding parts as in FIG. Instead of the second evaporator 9, an internal heat exchanger 19 for exchanging heat between the high-pressure side refrigerant at the outlet of the outdoor heat exchanger 4 that is a condenser and the low-pressure side refrigerant sucked into the compressor 3 is provided. ing.

In this configuration, liquid refrigerant is supplied to the internal heat exchanger 19 as in the first embodiment, and similar effects such as adjustment of heat exchange amount, suppression of increase in discharge temperature, and securing of oil return amount can be obtained. .
In addition, when using CO ₂ as a refrigerant or for low-temperature applications such as refrigeration, the refrigerant enthalpy difference in the evaporator is generally small and the efficiency tends to decrease. However, if the internal heat exchanger 19 is used, condensation occurs. By cooling the refrigerant at the outlet of the vessel 4, the refrigerant enthalpy difference as an evaporator can be expanded and more efficient operation can be performed.

Note that when the internal heat exchanger 19 is made large in size to increase the heat exchange amount and to further increase the refrigerant enthalpy difference as an evaporator, the gas refrigerant separated by the gas-liquid separator as in the conventional example If is supplied to the internal heat exchanger, the suction temperature of the compressor 3 increases too much, and the operation efficiency may decrease. In this case, when the liquid refrigerant is supplied to the internal heat exchanger 19 as in the configuration of the present invention, the refrigerant enthalpy difference is enlarged, and an excessive increase in the intake temperature of the compressor 3 is suppressed. More efficient operation can be performed.
In addition, the heat exchange area in the internal heat exchanger 19 can be used more effectively than in the case of having a circuit structure that reduces the amount of heat exchange in the internal heat exchanger 19 for the purpose of suppressing the rise in suction temperature, and the internal heat exchange The effect of the vessel 19 can be sufficiently obtained.
In the figure, the internal heat exchanger 19 is not configured to cool the load heat medium from the indoor unit 2, but as the second evaporator 9, the internal heat exchanger 19 and the load-side heat medium are cooled. The same effect can be obtained even if a heat exchanger is used.

  In FIG. 1, both the first evaporator 8 and the second evaporator 9 are shown as one heat exchanger, but the same effect can be obtained even when there are a plurality of them. For example, as a direct expansion system in which the indoor unit 2 including the first evaporator 8 and the expansion valve 7 is composed of two or more units and directly cools the air in each indoor unit 2 as shown in the circuit diagram of FIG. The first evaporator 8a, the indoor unit 2a incorporating the expansion valve 7a, the first evaporator 8b, the indoor unit 2b incorporating the expansion valve 7b, and the like may be employed. In this case, the refrigerant distributed by the liquid distributor 6 is drawn into the ejector 5 through the expansion valves 7a and 7b and the first evaporators 8a and 8b in the indoor units 2a and 2b.

Embodiment 5 FIG.
In the first and fourth embodiments, the refrigerating and air-conditioning apparatus of the present invention has been described as performing a cooling operation (cooling operation). However, the present embodiment is a heat pump that performs both cooling (cooling) and heating (heating). Applicable.
FIG. 13 is a circuit diagram of a refrigerating and air-conditioning apparatus showing Embodiment 5 of the present invention.
In the figure, the same or corresponding parts as in FIG. 1 of the first embodiment and FIG. 12 of the fourth embodiment are denoted by the same reference numerals, and description thereof is omitted.
The outdoor unit 1 has a four-way valve 14 and a check valve 15 which are switching means for switching a flow path for performing a cooling operation or a heating operation, and serves as a condenser during the cooling operation, and serves as a first evaporator during the heating operation. An outdoor heat exchanger 17 acting as a side heat exchanger and an expansion valve 7c are provided. The indoor units 2a and 2b are provided with an outdoor heat exchanger 17 that serves as a condenser during the cooling operation and serves as a first evaporator during the heating operation.
The indoor units 2a and 2b are provided with indoor heat exchangers 16a and 16b, respectively, which serve as a first evaporator during the cooling operation and serve as a condenser during the heating operation and function as a load-side heat exchanger.

  Next, a driving | operation operation | movement is demonstrated based on FIG. First, when cooling operation is performed by switching the flow path of the four-way valve 14 and the check valve 15, the compressor 3, the four-way valve 14, the outdoor heat exchanger 17, the expansion valve 7c, the check valve 15a, the ejector 5, the liquid distribution The refrigerant is distributed in the liquid distributor 6 through the check valve 15b and each of the indoor units 2a and 2b. It becomes a circuit returned to the suction part inlet 5a of the ejector 5 gas refrigerant through the expansion valves 7a and 7b, the indoor heat exchangers 16a and 16b, and the four-way valve 14. The refrigerant flow is a solid line in the figure, and the indoor heat exchangers 16a and 16b in the indoor units 2a and 2b serve as the first evaporator and the outdoor heat exchanger 17 serves as a condenser to perform the cooling operation.

  When performing the heating operation, the compressor 3, the four-way valve 14, the indoor heat exchangers 16a and 13b in the indoor units 2a and 2b, the expansion valves 7a and 7b, the check valve 15c, the ejector 5, and the liquid distributor 6 are used. The circuit configuration is connected to the suction portion of the compressor 3 through the internal heat exchanger 19, and a part of the refrigerant distributed by the liquid distributor 6 is a check valve 15d, an expansion valve 7c, and an outdoor heat exchanger 17. The circuit is returned to the suction portion inlet 5a of the ejector 5 gas refrigerant through the four-way valve 14. The refrigerant flow path is a dotted line in the figure, and the indoor heat exchangers 16a and 16b in the indoor units 2a and 2b are condensers, and the outdoor heat exchanger 17 is a first evaporator, and heating operation is performed.

With this circuit configuration, the four-way valve 14 switches the flow path so that the refrigerant discharged from the compressor 3 flows to the heat exchanger that becomes the condenser during each cooling and heating operation, and the heat exchanger that becomes the first evaporator The flow path is switched so that the refrigerant that has flowed out is sucked into the ejector 5. The check valve 15 switches the flow path so that the high-pressure refrigerant that has flowed out of the heat exchanger serving as a condenser flows into the flow path that exhibits suction power in the ejector 5, and the first flow from the liquid distributor 6. The flow path is switched so that the liquid cooling distributed to flow into the evaporator flows into the heat exchanger serving as the first evaporator.
By adopting such a circuit configuration, it is possible to obtain the same effect as in the case of the circuit of FIG. Further, even when a multi-system that connects a plurality of indoor units 2 is configured, the same effect as in the case of the circuit of FIG. 1 can be obtained.

In this case, the opening degree control of the ejector 5 is performed so that the refrigerant superheat degree SH2 at the outlet of the internal heat exchanger 19 (intake of the compressor 3) becomes a preset target value during both the cooling operation and the heating operation. Is called. Further, regarding the control of the expansion valve 7c, during the cooling operation, the expansion valve 7c at the outlet of the outdoor heat exchanger 17 is controlled so as not to be depressurized with the opening fully opened, and the expansion valves 7a and 7b correspond to the first evaporator 8. Control is performed so that the outlet refrigerant superheat degree of the indoor heat exchangers 16a and 16b becomes a preset target value. The refrigerant superheat degree at the outlet of the indoor heat exchanger 16a is calculated by the temperature sensor 11e detection temperature-temperature sensor 11d detection temperature, and the refrigerant superheat degree at the indoor heat exchanger 16b outlet is calculated by the temperature sensor 11i detection temperature-temperature sensor 11h detection temperature. Calculated with
During the heating operation, the expansion valves 7a and 7b at the outlets of the indoor heat exchangers 16a and 16b are controlled so as not to be depressurized by fully opening, and the expansion valve 7c is a refrigerant at the outlet of the outdoor heat exchanger 17 corresponding to the first evaporator 8. Control is performed so that the degree of superheat becomes a preset target value. The refrigerant superheat degree at the outlet of the outdoor heat exchanger 17 is calculated by the temperature sensor 11k detection temperature-temperature sensor 11j detection temperature.

  The compressor 3 may be of any type such as scroll, rotary, reciprocating, etc., and the capacity control method is not limited to the number of revolutions controlled by an inverter, but the number of units when there are a plurality of compressors. Various methods may be used such as control, injection, refrigerant bypass between high and low pressures, and changing the stroke volume for variable stroke volume types.

Also, the refrigerant to be applied is not limited to R410A, and can be applied to other HFC refrigerants, natural refrigerants such as HC refrigerant, CO ₂ , and NH 3. In the case of CO ₂ refrigerant, since the high / low pressure differential pressure is large, the recovery power in the ejector 5 is large and the pressure increase amount in the ejector 5 is large, which is more effective when applied to the present invention. When a CO ₂ refrigerant is applied and the high pressure is operated at a critical pressure or higher, the condenser acts as a radiator.

Embodiment 6 (Embodiment of the Invention)
In the first and fourth embodiments, the refrigerating and air-conditioning apparatus according to the present invention has been described as performing a cooling operation. However, the present embodiment is applied to a refrigerating apparatus that supplies cold heat to refrigeration and freezing applications such as food.
FIG. 14 is a circuit diagram of a refrigerating and air-conditioning apparatus showing Embodiment 6 of the present invention. In this embodiment, the outdoor unit 1 is a condensing unit, the indoor unit 2 is a unit cooler, and cools the air around the unit cooler. The condensing unit 1 and the unit cooler 2 are connected by a gas pipe 21 and a liquid pipe 22.
The measurement control device 10a is a control device for the condensing unit 1 and compresses the condensing unit 1 based on measurement information such as the temperature sensor 11 and the pressure sensor 12 and the operation content instructed by the user of the refrigeration air conditioner. The operation method of the machine 3 and the blower air volume of the outdoor heat exchanger 4 are controlled. The measurement control device 10b is a control device for the unit cooler 2, and based on the measurement information such as the temperature sensor 11 and the pressure sensor 12 and the operation content instructed by the user of the refrigeration air conditioner, the ejector 5 in the unit cooler 2, The opening degree of the expansion valve 7 is controlled.

In the unit cooler 2, the first evaporator 8 and the second evaporator 9 are configured by an integrally structured plate fin heat exchanger 18. FIG. 14 also shows a cross-sectional structure of a plate fin heat exchanger 18 that is an air heat exchanger and an arrangement structure of the heat transfer tubes 23, and the heat transfer tubes 23 are arranged in parallel at predetermined intervals. After passing through a through hole (not shown) provided in the fin plate 24, it is folded back at both the front and back ends in the direction perpendicular to the plane of the paper, and arranged so as to return to the fin plate 24 again. Has been.
In the plate fin heat exchanger 18, the air flows from the right to the left in FIG. The heat transfer tubes 23 are arranged in five rows perpendicular to the air flow path, and the first evaporator 8 is constituted by the four rows of heat transfer tubes 23 on the leeward side of the flow channel, and one row of heat transfer tubes on the upper side of the flow channel. The second evaporator 9 is configured at 23. In FIG. 14, the rows indicated by dotted lines are rows in which the fin plate 24 has through holes through which the heat transfer tubes 23 pass, but the heat transfer tubes 23 are not arranged.

  The temperature sensor 11l is installed at the outlet of the second evaporator 9, and measures the refrigerant temperature at the installation location. The reference numerals of the devices in FIG. 14 other than those described above are the same as those in the first embodiment, and a description thereof is omitted.

  As shown in FIG. 14, the refrigerant circuit is configured in an annular shape, and is refrigerated in the order of the compressor 3, the outdoor heat exchanger 4, the liquid pipe 22, the ejector 5, the liquid distributor 6, the second evaporator 9, and the gas pipe 21. A cycle is configured, and the refrigerant that has exited the gas pipe 21 is returned to the compressor 3 suction side. A part of the refrigerant distributed by the liquid distributor 6 is returned to the suction portion of the ejector 5 through the expansion valve 7 and the first evaporator 8.

Next, the operation of this refrigeration air conditioner will be described. The high-temperature and high-pressure gas refrigerant discharged from the compressor 3 dissipates heat to the air in the outdoor heat exchanger 4 to condense and liquefy it to become a high-pressure liquid refrigerant and flows into the ejector 5 through the liquid pipe 22.
The refrigerant that has flowed into the ejector 5 is reduced in pressure at the nozzle portion to become a two-phase refrigerant, and then sucks the gas refrigerant in the suction portion in the mixing portion and recovers the pressure in the diffuser. The refrigerant decompressed by the ejector 5 flows into the liquid distributor 6. In the liquid distributor 6, a part of the liquid refrigerant in the two-phase refrigerant that has exited the ejector 5 is distributed to the first evaporator 8 side, and the liquid refrigerant is decompressed by the expansion valve 7 and flows into the first evaporator 8. The air flowing into the unit cooler 2 evaporates while cooling to become a gas refrigerant, and is sucked into the gas refrigerant suction portion inlet 5 a of the ejector 5. On the other hand, the two-phase refrigerant in a state where the remaining liquid refrigerant and gas refrigerant that have not been separated to the first evaporator 8 side by the liquid distributor 6 are mixed flows into the second evaporator 9 and flows into the unit cooler 2. While cooling the air, it evaporates to become a gas refrigerant and is sucked into the compressor 3 through the gas pipe 21.
The operation state of the refrigeration cycle is substantially the same as that in FIG. 4 in the first embodiment.

  Next, the control operation in this refrigeration air conditioner will be described. First, the operation is performed by setting the rotation speed of the compressor 3, the outdoor heat exchanger 4 air flow, the ejector 5 opening, and the expansion valve 7 opening to initial values. And after driving | running in this state, each actuator is controlled according to an apparatus operating state. First, the rotation speed of the compressor 3 is controlled such that the compressor suction pressure detected by the pressure sensor 12a becomes a preset target value, for example, 0.3 MPa. When the suction pressure is higher than the target value, the rotational speed of the compressor 3 is increased, and when the suction pressure is lower, the rotational speed of the compressor 3 is decreased.

  Next, although it is the air flow rate of the outdoor heat exchanger 4, this air flow rate is basically operated at an initial set value. However, if the high pressure (pressure of the refrigerant discharged from the compressor 3) detected by the pressure sensor 12b rises excessively depending on the operating conditions, control is performed to increase the air volume to protect the compressor 3.

  Next, the opening degree of the ejector 5 is controlled so that the refrigerant superheat degree SH2 at the outlet of the second evaporator 9 becomes a preset target value, for example, 2 ° C. Here, the refrigerant superheat degree SH2 at the outlet of the second evaporator 9 is calculated by the temperature sensor 11l detected temperature (second evaporator 9 outlet temperature) -temperature sensor 11c detected temperature (refrigerant evaporation temperature at the second evaporator 9). The value to be used is used. The refrigerant superheat degree SH2 at the outlet of the second evaporator 9 is compared with the target value. If the refrigerant superheat degree SH2 is larger than the target value, the opening degree of the ejector 5 is controlled to be large, and the refrigerant superheat degree SH2 is less than the target value. When it is small, the opening degree of the ejector 5 is controlled to be small.

  Next, the opening degree of the expansion valve 7 is controlled so that the refrigerant superheat degree SH1 at the outlet of the first evaporator 8 becomes a preset target value, for example, 2 ° C. Here, the refrigerant superheat degree SH1 at the outlet of the first evaporator 8 is the detected temperature of the temperature sensor 11e (first evaporator 8 outlet temperature) −the detected temperature of the temperature sensor 11d (refrigerant evaporation temperature in the first evaporator 8). Use the computed value. The refrigerant superheat degree SH1 at the outlet of the first evaporator 8 is compared with the target value. If the refrigerant superheat degree SH1 is larger than the target value, the opening degree of the expansion valve 7 is controlled to be large, and the refrigerant superheat degree SH1 is set to the target value. If smaller, the opening degree of the expansion valve 7 is controlled to be small.

  Next, the heat exchange operation and effects in the plate fin heat exchanger 18 in the present embodiment will be described. FIG. 15 is a diagram showing changes in the temperature of air and refrigerant in the plate fin heat exchanger 18, where the horizontal axis represents the heat transfer tube row position in the air flow direction, and the vertical axis represents the air and refrigerant temperatures. Represents. The refrigerant evaporation temperature is lower in the first evaporator 8 because the refrigerant is depressurized by the expansion valve 7. In the heat exchange between the air and the refrigerant, the refrigerant and the air in the second evaporator 9 exchange heat in the windward column (column number 1) that has just flowed in and is hot, and is cooled by the second evaporator 9 and is cooled to the air temperature. The refrigerant of the first evaporator 8 and the air exchange heat in the leeward side row (column numbers 2 to 5) in which the temperature decreases. Therefore, the temperature difference between the air and the refrigerant in the first evaporator 8 and the second evaporator 9 becomes relatively uniform. For this reason, the temperature difference between the air and the refrigerant is non-uniform, and there is no structure where the temperature difference is small. Therefore, the heat exchange efficiency in the first evaporator 8 and the second evaporator 9 can be increased, and the evaporation is increased accordingly. Since it can be operated at a temperature, the operating efficiency of the apparatus can be increased.

  Further, since the temperature difference between the air and the refrigerant becomes uniform in each part, the heat exchange amount can also be made uniform, and the amount of frost formation on the first evaporator 8 and the second evaporator 9 when used in a low temperature application is also uniform. Can be When used in refrigerated refrigeration applications, cooling is performed by operating the refrigerant evaporation temperature in the first evaporator 8 and the second evaporator 9 at 0 ° C. or lower, so that the cooling to the first evaporator 8 and the second evaporator 9 is performed. Frosting occurs and the amount of frosting increases as the operating time becomes longer. If the amount of frost formation exceeds a certain level, the ventilation resistance of the plate fin heat exchanger 18 increases, the air flow rate decreases, and the cooling capacity decreases, so the defrosting operation is carried out at regular intervals. In the case of the configuration of the present embodiment, the frost amount distribution can be made uniform, so that compared with the case where frost formation is uneven, the frost formation increases the airflow resistance and the air flow rate, and the cooling capacity is reduced. Since the time until this can be extended, the time interval for performing defrosting can be increased. Accordingly, the supply of cold heat is stopped during defrosting, and the frequency with which the load-side air temperature rises can be reduced, so that a more reliable device can be obtained.

  In FIG. 14, the first evaporator 8 is composed of four rows and the second evaporator 9 is composed of one row, and the number of the first evaporators 8 is large, and accordingly, the heat transfer area of the heat transfer tube and the surroundings of the heat transfer tube The heat transfer area of the fin plate 24 is large. The heat transfer area ratio between the first evaporator 8 and the second evaporator 9 is set according to the correlation between the pressure increase amount at the ejector 5 and the temperature drop width ΔTair of the air at the plate fin heat exchanger 18. . When the amount of pressure increase at the ejector 5 is converted into the refrigerant evaporation temperature increase width, and this increase width is ½ of the air temperature decrease width ΔTair at the plate fin heat exchanger 18, the first evaporator 8 is exactly the same. And the second evaporator 9 are set to have the same area. The temperature change of the refrigerant and air at this time is shown in FIG. 16, and the temperature drop of the air in the second evaporator 9 is ½ of the temperature drop ΔTair of the air in the plate fin heat exchanger 18 ( 1/2 · ΔTair), which equalizes the difference in evaporation temperature (ΔTref) between the first evaporator 8 and the second evaporator 9. At this time, the temperature difference between the air and the refrigerant in the first evaporator 8 and the second evaporator 9 can be secured with the same width, and the temperature difference is not uniform and the temperature difference is small in each heat exchanger. Therefore, the heat exchange efficiency in the first evaporator 8 and the second evaporator 9 can be increased.

  When the pressure increase amount at the ejector 5 is larger than ½ of the temperature drop ΔTair of the air at the plate fin heat exchanger 18, the air in the first evaporator 8 is changed from the state of FIG. 16 to the state shown in FIG. 17. The temperature difference between the refrigerant evaporation temperature (ΔTref) increases and the temperature difference between the air and the refrigerant evaporation temperature in the second evaporator 9 changes in a narrowing direction. Therefore, the temperature between the refrigerant and the air in the second evaporator 9 By reducing the difference, the heat exchange efficiency of the evaporator is reduced. Therefore, in such a case, the heat transfer area of the second evaporator 9 is reduced so that heat exchange is performed only with relatively hot air. For example, the first evaporator 8 has four rows and the second evaporator 9 has two rows, and the second evaporator 9 is arranged on the upstream side of the flow path. With such a configuration, the temperature difference between the air and the refrigerant in the first evaporator 8 and the second evaporator 9 is made relatively uniform, and heat exchange in the first evaporator 8 and the second evaporator 9 is performed. Efficiency can be improved.

  On the contrary, when the amount of pressure increase in the ejector 5 is smaller than 1/2 of the temperature drop ΔTair of the air in the plate fin heat exchanger 18, the air and refrigerant evaporation temperature in the first evaporator 8 from the state of FIG. And the temperature difference between the air and the refrigerant evaporating temperature in the second evaporator 9 changes in a widening direction, so that the temperature difference between the refrigerant and the air in the second evaporator 9 is large. As a result, the heat exchange efficiency of the evaporator is increased. Therefore, the heat transfer area of the first evaporator 8 is set smaller than the heat transfer area of the second evaporator 9.

  In general, when used in refrigerated refrigeration applications, the air temperature change width in the evaporator is set to about 5 to 10 ° C. from the viewpoint of suppressing fluctuations in the cooling temperature. On the other hand, since the ejector 5 is used at a lower pressure than the air-conditioning operation, the decompression width is large, the recovery power is increased correspondingly, and the ascending width is also increased. The temperature rises. Accordingly, when used in refrigerated refrigeration, the value obtained by converting the pressure increase amount in the ejector 5 into the evaporation temperature increase width of the refrigerant is larger than ½ of the air temperature decrease width. If the heat transfer area is larger than that of the second evaporator 9, a highly efficient evaporator can be obtained.

  If the refrigerant pressure loss in the first evaporator 8 is large, the pressure of the refrigerant sucked by the ejector 5 is lowered, and the pressure of the refrigerant flowing out from the ejector 5 is lowered by that amount. Accordingly, the suction pressure of the compressor 3 is lowered, the efficiency of the refrigeration cycle is lowered, and the operation efficiency of the apparatus is lowered. Therefore, in order to prevent the refrigerant pressure loss in the first evaporator 8 from becoming excessive, the number of refrigerant branches (flow paths) in the first evaporator 8 is made plural, and the refrigerant that flows per one heat transfer tube 23. It is good also as a structure which reduces a flow volume and reduces a refrigerant | coolant pressure loss. In the configuration of FIG. 14, the number of refrigerant branches is 1, but the number of refrigerant branches may be 2 as in the configuration shown in FIG.

19, the number of branches on the inlet side of the first evaporator 8 may be 1, and the number of branches on the outlet side may be 2. When a plurality of refrigerant channels are used and the refrigerant flow rate per one of the heat transfer tubes 23 is reduced, the pressure loss is reduced while the refrigerant-side heat transfer coefficient is also reduced. On the inlet side of the first evaporator 8, even if it is a two-phase refrigerant, the flow is relatively rich in liquid refrigerant, so the refrigerant flow rate is slow and the pressure loss value is small. Therefore, in this region, rather than reducing the pressure loss, increasing the refrigerant flow rate to improve the refrigerant side heat transfer rate contributes to improving the operation efficiency of the apparatus. On the other hand, on the evaporator outlet side, even if it is a two-phase refrigerant, the flow is relatively rich in gas refrigerant, the refrigerant flow rate is fast, and the value of pressure loss is also large. Therefore, in this region, reducing the pressure loss contributes to improving the operating efficiency of the device.
Therefore, as in the configuration of FIG. 19, the number of branches on the outlet side of the first evaporator 8 is configured to be larger than the number of branches on the inlet side. By doing in this way, the effect of a pressure loss reduction and a heat-transfer rate improvement can be acquired optimally, and an apparatus with high operating efficiency can be obtained.

  As described above, the refrigerant evaporation temperature in the first evaporator 8 is lower than the refrigerant evaporation temperature in the second evaporator 9. For example, in operation for refrigeration, the refrigerant evaporation temperature of the first evaporator 8 is −10 ° C. The refrigerant evaporation temperature in the second evaporator 9 is −5 ° C., and in the operation for refrigeration, the refrigerant evaporation temperature in the first evaporator 8 is −40 ° C., and the refrigerant evaporation temperature in the second evaporator 9 is −32 ° C. Since the refrigerant evaporation temperature in the second evaporator 9 is high in this way, heat is transferred from the refrigerant in the second evaporator 9 to the first evaporator 8 via the fin plate 24, and the air in the first evaporator 8. There is a possibility that the amount of heat absorbed from will decrease. Therefore, it is desirable to adopt a heat transfer suppression structure that suppresses heat transfer from the refrigerant of the second evaporator 9 to the first evaporator 8.

For example, in the plate fin heat exchanger 18 of FIG. 14, a row in which the heat transfer tubes 23 are not arranged is provided between the first evaporator 8 and the second evaporator 9, and the first evaporator 8 and the second evaporator 9 is arranged with a larger distance than the inter-row distance (row pitch) in FIG. With this arrangement, the thermal resistance of the fin plate 24 between the first evaporator 8 and the second evaporator 9 is increased, and the refrigerant of the second evaporator 9 is changed to the refrigerant of the first evaporator 8. Suppresses heat transfer. Therefore, it is possible to avoid a reduction in the amount of heat absorbed from the air in the first evaporator 8, increase the heat exchange efficiency as the evaporator, and increase the operation efficiency of the apparatus.
Even if the row pitch interval is locally changed, the same structure can be obtained, but in that case, fin types corresponding to various row patterns are required, and fin type design is required for each model, which is difficult. Cost. A configuration in which the pitch is equally spaced and the heat transfer tubes 23 are not arranged in some rows, and the heat transfer is easily suppressed with the same fin type regardless of the form and capacity of the heat exchanger. Can be manufactured, and a heat exchanger can be configured for general purpose and at low cost.

In addition, you may provide a slit and a notch in the fin plate 24 as a structure which suppresses the heat transfer from the refrigerant | coolant of the 2nd evaporator 9 to the 1st evaporator 8. FIG. The place where the slit is provided may be the entire fin plate 24 or may be provided locally at the boundary between the first evaporator 8 and the second evaporator 9. By providing the fin plate 24 as a whole, the heat transfer rate on the air side can be increased while suppressing heat transfer between the first evaporator 8 and the second evaporator 9, and a higher performance heat exchanger can be obtained. Can do.
A slit may be locally provided only at the boundary between the first evaporator 8 and the second evaporator 9. When a slit is provided in the fin plate 24, frosting on the slit portion proceeds quickly, so that the increase in ventilation resistance due to frosting is accelerated and the time interval required for defrosting is shortened. Therefore, by providing a slit locally at the boundary between the first evaporator 8 and the second evaporator 9, the slit can be locally disposed in an indispensable part. The first evaporator 8 and the second evaporator 9 In addition to suppressing the heat transfer between them, the time interval required for defrosting can be made long, and a highly efficient and reliable device can be obtained.
The same effect can be obtained by cutting the fin plate 24 at the boundary between the first evaporator 8 and the second evaporator 9.

In addition, when determining the refrigerant | coolant flow direction of the 1st evaporator 8, the heat exchanger tube 23 of an exit part is arrange | positioned in the air flow path side windward side, as FIG. 14 shows. In the heat transfer tube 23 at the outlet of the evaporator, since the refrigerant becomes a superheated gas, the temperature rises from other parts, and the temperatures of the air and the refrigerant are likely to approach each other. In order to make the temperature difference between the refrigerant and the air in the evaporator uniform and improve the efficiency, it is desirable that the superheated gas is in contact with the hot air as much as possible to ensure the temperature difference. Therefore, as in the configuration shown in FIG. 14, the heat transfer tube 23 at the outlet portion is arranged on the furthest upstream side of the air flow path so that the superheated gas portion and the high-temperature air exchange heat.
By setting it as such a structure, the temperature difference of the refrigerant | coolant and air in the 1st evaporator 8 and the 2nd evaporator 9 can be equalize | homogenized, and it can be set as a higher performance heat exchanger.

  When the refrigerant pressure loss in the first evaporator 8 is large, the refrigerant evaporation temperature decreases from the inlet to the outlet. In this case, as shown in FIG. 20, the heat transfer tube 23 at the outlet of the evaporator is disposed on the leeward side of the air flow path. In this case, the temperature change between the air and the refrigerant is shown in FIG. 21. When the air leeward side row is reached, the air temperature is lowered and the refrigerant temperature is lowered. Therefore, the temperature difference between the refrigerant and the air in the first evaporator 8 and the second evaporator 9 can be made uniform, and a higher performance heat exchanger can be obtained.

  In the refrigerant circuit of FIG. 14, the case where the unit cooler 2 is constituted by one unit is shown, but the same effect can be obtained even when two or more unit coolers 2 are connected in parallel. Further, the form is not limited to the unit cooler 2, and the same effect can be obtained even when applied to other low-temperature equipment such as a showcase.

1 is a circuit diagram of a refrigerating and air-conditioning apparatus showing Embodiment 1 of the present invention. It is the figure which showed the structure and pressure change of the ejector of the refrigerating and air-conditioning apparatus which shows Embodiment 1 of this invention. It is sectional drawing which shows the structure of the liquid distributor of the refrigerating and air-conditioning apparatus which shows Embodiment 1 of this invention. It is a figure which shows the correlation of the pressure and enthalpy of the refrigerating air-conditioning apparatus which shows Embodiment 1 of this invention. It is a flowchart which shows the control action of the refrigerating air conditioner which shows Embodiment 1 of this invention. It is a figure which shows the structure of the evaporator of the refrigerating air conditioning apparatus which shows Embodiment 1 of this invention. It is sectional drawing which shows the structure of the liquid distributor of the refrigerating air-conditioning apparatus which shows Embodiment 2 of this invention. It is sectional drawing which shows the other structure of the liquid distributor of the refrigerating air-conditioning apparatus which shows Embodiment 2 of this invention. It is a figure which shows the circuit structure of the ejector and expansion valve of the refrigerating and air-conditioning apparatus which shows Embodiment 3 of this invention. It is a figure which shows the circuit structure of the ejector and expansion valve of the refrigerating and air-conditioning apparatus which shows Embodiment 3 of this invention. It is a circuit diagram of the refrigerating and air-conditioning apparatus which shows Embodiment 4 of this invention. It is a circuit diagram of the refrigerating and air-conditioning apparatus which shows Embodiment 4 of this invention. It is a circuit diagram of the refrigerating and air-conditioning apparatus which shows Embodiment 5 of this invention. It is a circuit diagram of the refrigerating and air-conditioning apparatus which shows Embodiment 6 of this invention. It is the figure which showed the temperature change of the air and the refrigerant | coolant in the plate fin heat exchanger of the refrigerating air conditioner which shows Embodiment 6 of this invention. It is the figure which showed the temperature change of the air and the refrigerant | coolant in the plate fin heat exchanger of the refrigerating air conditioner which shows Embodiment 6 of this invention. It is the figure which showed the temperature change of the air and the refrigerant | coolant in the plate fin heat exchanger of the refrigerating air conditioner which shows Embodiment 6 of this invention. It is the figure which showed the 2nd structure of the plate fin heat exchanger of the refrigerating and air-conditioning apparatus which shows Embodiment 6 of this invention. It is the figure which showed the 3rd structure of the plate fin heat exchanger of the refrigerating and air-conditioning apparatus which shows Embodiment 6 of this invention. It is the figure which showed the 4th structure of the plate fin heat exchanger of the refrigerating and air-conditioning apparatus which shows Embodiment 6 of this invention. It is the figure which showed the temperature change of the air and the refrigerant | coolant in the plate fin heat exchanger of the refrigerating air conditioner which shows Embodiment 6 of this invention.

Explanation of symbols

1 outdoor unit (condensing unit), 2, 2a, 2b indoor unit (unit cooler), 3 compressor, 4 outdoor heat exchanger (condenser, radiator), 5 ejector, 5a suction part inlet, 6 liquid distributor 6a Inflow passage, 6b First branch passage, 6c Second branch passage, 7, 7a, 7b, 7c Expansion valve, 8 First evaporator, 9 Second evaporator, 10, 10a, 10b Measurement control device, 11a, 11b, 11c, 11d, 11e, 11f, 11g, 11h, 11i, 11j, 11k, 11l Temperature sensor, 12a, 12b Pressure sensor, 13 Expansion valve, 14 Four-way valve, 15 Check valve, 16a, 16b Indoor heat exchanger , 17 outdoor heat exchanger, 18 plate fin heat exchanger, 19 internal heat exchanger, 20 indoor heat exchanger, 21 gas pipe, 22 liquid pipe, 23 heat transfer pipe, 24 fin plate.

Claims (26)

In a refrigeration air conditioner having a refrigeration cycle in which a compressor, a condenser or a radiator, an ejector, and an evaporator are connected in an annular shape,
The evaporator includes a first evaporator,
A second evaporator;
With
A distributor for distributing the refrigerant from the ejector to the first evaporator and the second evaporator; and between the ejector and the first and second evaporators,
The ejector sucks and boosts the refrigerant from the first evaporator,
The distributor separates the refrigerant flowing out of the ejector into a gas-liquid two-phase refrigerant and a liquid refrigerant,
Connecting the outlet of the first evaporator to the suction part of the ejector, and connecting the inlet of the first evaporator to the liquid refrigerant outlet of the distributor;
Connecting the outlet of the second evaporator to the compressor and connecting the inlet of the second evaporator to the gas-liquid two-phase refrigerant outlet of the distributor;
When the value obtained by converting the pressure increase amount at the ejector into the evaporation temperature increase width of the refrigerant is ½ of the air temperature decrease width at the evaporator, the areas of the first evaporator and the second evaporator are Set to be the same,
If the converted evaporation temperature increase width of the refrigerant is larger than ½ of the air temperature decrease width in the evaporator, the heat transfer area of the second evaporator is made larger than the heat transfer area of the first evaporator. If the reduced evaporation temperature increase width of the refrigerant is smaller than half of the air temperature decrease width in the evaporator, the heat transfer area of the first evaporator is set to the heat transfer area of the second evaporator. A refrigeration air conditioner characterized by being smaller than the heat area.   The refrigerating and air-conditioning apparatus according to claim 1, further comprising control means for controlling a flow resistance of the ejector according to an operating state of the refrigerating and air-conditioning apparatus. In a refrigeration air conditioner having a refrigeration cycle in which a compressor, a condenser or a radiator, an ejector, and an evaporator are connected in an annular shape,
The evaporator includes a first evaporator,
A second evaporator;
With
A distributor for distributing the refrigerant from the ejector to the first evaporator and the second evaporator; and between the ejector and the first and second evaporators,
The ejector sucks and boosts the refrigerant from the first evaporator,
Connecting the outlet of the first evaporator to the suction part of the ejector, and connecting the inlet of the first evaporator to the liquid refrigerant outlet of the distributor;
Connecting the outlet of the second evaporator to the compressor and connecting the inlet of the second evaporator to the gas-liquid two-phase refrigerant outlet of the distributor;
Furthermore, according to the operating state of the refrigeration air conditioner, a control means for controlling the flow resistance of the ejector,
A compressor suction side superheat degree detecting means for detecting the superheat degree of the refrigerant sucked into the compressor;
Have
The control means controls the flow resistance of the ejector so that the degree of superheat detected by the compressor suction side superheat degree detection means becomes a predetermined value,
When the value obtained by converting the pressure increase amount at the ejector into the evaporation temperature increase width of the refrigerant is ½ of the air temperature decrease width at the evaporator, the areas of the first evaporator and the second evaporator are Set to be the same,
If the converted evaporation temperature increase width of the refrigerant is larger than ½ of the air temperature decrease width in the evaporator, the heat transfer area of the second evaporator is made larger than the heat transfer area of the first evaporator. If the reduced evaporation temperature increase width of the refrigerant is smaller than half of the air temperature decrease width in the evaporator, the heat transfer area of the first evaporator is set to the heat transfer area of the second evaporator. A refrigeration air conditioner characterized by being smaller than the heat area.   The refrigerating and air-conditioning apparatus according to claim 2 or 3, wherein the control means includes an opening area variable means for changing the flow resistance by changing the opening area of the nozzle portion of the ejector. A first pressure reducing device connected in series or in parallel with the ejector;
4. The refrigerating and air-conditioning apparatus according to claim 1, further comprising a control unit that changes a flow resistance of the first decompression device in accordance with an operating state of the refrigerating and air-conditioning apparatus. A compressor suction side superheat degree detecting means for detecting the superheat degree of refrigerant sucked into the compressor;
The control means controls the flow resistance of the ejector or the first pressure reducing device so that the degree of superheat detected by the compressor suction side superheat degree detection means becomes a predetermined value. Item 6. The refrigeration air conditioner according to any one of Items 2, 4, and 5.   The refrigerating and air-conditioning apparatus according to claim 1, further comprising a second decompression device between the distributor and the inlet of the first evaporator. First evaporator outlet superheat degree detecting means for detecting the superheat degree of the refrigerant at the outlet of the first evaporator;
The control means for changing the flow resistance of the second decompression device so that the degree of superheat detected by the first evaporator outlet superheat degree detection means becomes a predetermined value. Refrigeration air conditioner.   The temperature of the load side heat medium cooled by the first evaporator is lower than the temperature of the load side heat medium cooled by the second evaporator. The refrigeration air conditioner described in 1.   10. The distributor according to claim 1, wherein a flow rate of gas refrigerant distributed to the first evaporator is smaller than a flow rate of gas refrigerant distributed to the second evaporator. A refrigeration air conditioner according to claim 1. The distributor includes an inflow path from the ejector;
A first branch path that branches from the inflow path toward the first evaporator;
A second branch path branched from the inflow path to the second evaporator side;
With
The refrigerating and air-conditioning apparatus according to any one of claims 1 to 10, wherein the first branch path is disposed below the second branch path.   The refrigerating and air-conditioning apparatus according to claim 11, wherein the first and second branch paths are U-shaped.   The refrigerating and air-conditioning apparatus according to claim 11, wherein the first and second branch paths are vertical, and the first branch path is longer than the second branch path.   The refrigerating and air-conditioning apparatus according to claim 11, wherein the inflow path and the second branch path are horizontal, and the first branch path is vertical.   In place of the second evaporator, an internal heat exchanger for exchanging heat between the high-pressure side refrigerant at the outlet of the condenser or the radiator and the low-pressure side refrigerant sucked into the compressor is provided. The refrigeration air conditioner according to any one of claims 1 to 14.   The said 1st evaporator and the said 2nd pressure reduction apparatus are incorporated in the indoor unit, The heat exchange with indoor air and a refrigerant | coolant is carried out by the said 1st evaporator, The refrigerant | coolant of Claim 15 characterized by the above-mentioned. Refrigeration air conditioner. Switching means for switching the flow of the refrigerant by cooling and heating operation,
When performing the cooling operation, the switching means connects the compressor, the switching means, the heat source side heat exchanger acting as a condenser, the ejector the distributor, the internal heat exchanger in an annular shape, The liquid distributor, the load side heat exchanger acting as the first evaporator, and the suction part of the ejector are connected,
When performing the heating operation, the load side heat exchanger acting as the compressor, the condenser or the radiator, the ejector, the distributor, the internal heat exchanger are connected in a ring shape, and the distributor, the first The refrigerating and air-conditioning apparatus according to claim 16, wherein a heat source side heat exchanger acting as an evaporator and a suction part of the ejector are connected.   By arranging the first and second evaporators in the same air flow path, an air heat exchanger that cools the air is configured, and the second evaporator is located closer to the air flow path than the first evaporator. The refrigerating and air-conditioning apparatus according to any one of claims 1 to 14, wherein the refrigerating and air-conditioning apparatus is disposed on the windward side.   Each of the first and second evaporators includes at least one row of multistage first evaporator side heat transfer tubes and second evaporator side heat transfer tubes, and the first evaporator side heat transfer tubes and the The refrigerating and air-conditioning apparatus according to claim 18, wherein the heat exchanger tube on the second evaporator side is integrally formed through a plurality of fin plates to constitute the air heat exchanger.   The refrigerating and air-conditioning apparatus according to claim 18 or 19, wherein a heat transfer area of the first evaporator is configured to be larger than a heat transfer area of the second evaporator. The heat transfer tubes at the inlet side and the outlet side of the heat transfer tube of the first evaporator are each branched into at least one, and the number of branches on the outlet side is larger than the number of branches on the inlet side. refrigerating and air-conditioning apparatus according to claim 19, wherein. Wherein between the first evaporator and the second evaporator, the refrigeration air conditioning system according to claim 19 characterized in that a said heat transfer tube 1 row equivalent or more intervals. Whole of the fin plate, or the first, the refrigerating and air-conditioning apparatus according to claim 19 characterized in that a lack slits or cut at the boundary portion of the second evaporator. The row of the heat transfer tubes on the inlet side of the first evaporator is arranged on the windward side of the air flow path with respect to the row of the heat transfer tubes on the outlet side of the first evaporator. Refrigeration air conditioner of description . The row of the heat transfer tubes on the outlet side of the first evaporator is arranged on the windward side of the air flow path with respect to the row of the heat transfer tubes on the inlet side of the first evaporator. Refrigeration air conditioner of description .   26. The refrigerating and air-conditioning apparatus according to claim 1, wherein carbon dioxide is used as the refrigerant.

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