KR101482845B1 - Storage type hot water supply system - Google Patents

Abstract

[PROBLEMS] To provide a low-temperature type hot water supply system capable of reducing a running cost at the time of hot water supply operation.
(Solution) The water in the storage tank 11 is heated to the predetermined boiling temperature by the heat pump 51 under the ambient temperature surrounding the ambient temperature and then supplied to the hot water supply pipe 13 from the storage tank 11 Boiling water at boiling temperature is heated to the set temperature by the hot water heater 87 to assume the hot water supply operation for tapping the hot water supply pipe 13 so that the running cost of the heat pump 51 in the hot water supply operation and the hot water heater 87 Of the running cost of the running cost of the running cost is the lowest boiling temperature at which the lowest running cost temperature is lowest.

Description

{STORAGE TYPE HOT WATER SUPPLY SYSTEM}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a hot water system having a hot water tank for heating hot water in a hot water tank by a heat pump and an auxiliary heat source.

BACKGROUND ART Conventionally, an instantaneous heating type hot water heater (auxiliary heat source) is connected to a downstream side of a storage tank of a storage tank for heating boiled water in a storage tank by a heat pump, and the hot water in the storage tank is lowered A hot water type hot water supply system is known in which an instantaneous hot water heater is operated to raise the temperature of hot water from a storage tank (see, for example, Patent Document 1).

In the low-temperature type hot water supply system described in Patent Document 1, when the amount of primary energy required for obtaining the same amount of heat for hot water supply becomes larger when the heat pump is operated than when the hot water heater is operated, The heat pump is not operated even if the amount of heat in the space is reduced, thereby reducing the primary energy consumption.

Patent Document 1: JP-A-2009-275958

In the low-temperature type hot water supply system described in Patent Document 1, whether the heat pump is operated or not is determined by comparing the primary energy amounts of the heat pump and the heat pump, which are necessary for obtaining the same heat quantity for hot water supply. However, there is a case in which the user is interested in the reduction of the running cost (the usage charge of electricity, gas, etc. accompanying the operation of the low-temperature type hot water supply system) rather than the reduction of the primary energy consumption amount.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a low-temperature type hot water supply system capable of reducing the running cost during hot water supply operation.

The present invention has been made in order to achieve the above object,

A storage tank in which a water supply pipe is connected to a lower portion thereof, a hot water supply pipe is connected to an upper portion thereof, and water supplied from the water supply pipe is stored;

A tank circulation path connecting the lower part and the upper part of the storage tank; a tank circulation pump circulating the water stored in the lower part of the storage tank to the upper part of the storage tank through the tank circulation path; A heat pump unit having a heat pump for heating water flowing in the tank circulation path,

And an auxiliary heat source installed in the middle of the hot water supply pipe for heating the hot water supplied from the storage tank to the hot water supply pipe,

A water supply temperature sensor for detecting a water supply temperature from the water supply pipe to the storage tank,

An ambient temperature sensor for detecting an ambient temperature of the heat pump,

The water at the water supply temperature in the storage tank is heated by the heat pump unit to the boiling temperature not higher than the target hot water temperature set at a predetermined temperature higher than the set temperature of the low temperature water heating system under the ambient temperature, The hot water supplied to the hot water supply pipe is heated to the set temperature by the auxiliary heat source to assume the hot water supply operation for tapping the hot water supply pipe and the running cost of the heat pump in the assumed hot water supply operation and the auxiliary A lowest running cost temperature determining unit that determines a lowest running cost temperature that is the boiling temperature at which the total cost of the running cost of the heat source unit is lowest,

Wherein the boiling water in the storage tank is heated to the lowest running cost temperature by the heat pump unit when the hot water cutoff of the storage tank is detected and then the hot water supplied from the storage tank to the hot water tank is supplied by the auxiliary heat source And a hot water control unit for heating the hot water to the set temperature and supplying the hot water to the hot water supply pipe (first invention).

According to the first aspect of the present invention, the minimum running cost determining unit determines the lowest running cost based on the supply water temperature from the water supply pipe to the storage tank detected by the water supply temperature sensor and the ambient temperature of the heat pump detected by the ambient temperature sensor And determines the lowest running cost temperature which is the boiling assumed temperature of the boiled water in the storage tank at which the total running cost of the heat pump and the auxiliary heat source is lowest when hot water is supplied to the set temperature.

The hot water supply control unit controls the hot water supplied from the hot water tank to the hot water supply pipe to the set temperature of the hot water supply unit by the auxiliary heat source after heating the hot water in the storage tank to the lowest running cost temperature by the heat pump unit, And the first hot water supply operation for supplying the hot water to the hot water supply pipe is executed. This makes it possible to operate the heat pump and the auxiliary heat source by the operating conditions assumed to be the lowest total running cost, thereby executing the hot water supply operation in which the running cost is reduced.

The running cost refers to a charge (electric charge, gas charge, etc.) necessary for operating the heat pump and the auxiliary heat source. The lowest running cost temperature at which the total running cost of the heat pump and the auxiliary heat source is the lowest is a temperature at which the running cost is the lowest in absolute terms and the running cost is the lowest in any examination range It also includes losing temperature.

Further, in the first invention,

Wherein the lowest running cost temperature determination section determines the minimum running cost temperature by changing the boiling supposition temperature of the boiled water in the storage tank within a first temperature range below the target hot water temperature, Which is an estimated value of the running cost of the heat pump under the ambient temperature required for raising the temperature of the water in the hot water tank to the assumed temperature, And the second running cost, which is an assumed value of the running cost of the auxiliary heat source necessary for raising the temperature of the first running cost and the second running cost, is calculated, and the estimated temperature, at which the total cost of the first running cost and the second running cost is lowest, And determining the lowest running cost temperature (the second invention).

According to the second aspect of the present invention, the first running cost and the second running cost for each assumed temperature are calculated by changing the assumed boiling temperature of water in the storage tank within the first temperature range, The cost temperature can be easily determined.

In the first invention or the second invention,

Wherein the hot water supply control unit is configured to raise the water of the water supply temperature in the storage tank step by step when the water of the water supply temperature in the storage tank is heated by the heat pump unit to the lowest running cost temperature, And the heat is heated by the heat pump unit up to the temperature (the third invention).

According to the third aspect of the present invention, as described later in detail, since the primary energy efficiency increases as the boiling temperature width of the heat pump unit becomes smaller, the water of the water supply temperature in the storage tank is gradually increased to the lowest running cost temperature By heating, the efficiency of the heat pump can be increased.

In the third invention,

And a hot water temperature holding unit for holding hot water temperature history data indicating a history of past hot water supply operation,

The hot water supply control unit performs heating from the hot water supply history data to the lowest running cost temperature of the water in the storage tank at a time when the hot water supply operation is not expected to be executed.

According to the fourth invention, hot water supply is started during the stepwise heating of water in the storage tank by the hot water supply control unit, and the heating amount in the auxiliary heat source is increased, so that the running cost of the auxiliary heat source increases Can be prevented.

In any one of the first to fourth inventions,

A maximum primary energy efficiency temperature determination unit for determining a maximum primary energy efficiency temperature which is a boiling temperature at which the total primary energy efficiency of the heat pump and the auxiliary heat source in the supposed hot water supply operation becomes the highest,

And a reference indicator selecting unit for selecting a running cost or a primary energy efficiency according to a user operation,

Wherein the hot water supply control unit executes the first hot water supply operation when the running cost is selected by the reference indicator selection unit and when the primary energy efficiency is selected by the reference indicator selection unit, The boiled water in the storage tank is heated to the maximum primary energy efficiency temperature by the heat pump unit and then the boiled water supplied from the storage tank to the hot water supply pipe is heated to the set temperature by the auxiliary heat source , And a second hot water supply operation for supplying the hot water to the hot water supply pipe (fifth invention).

According to the fifth aspect of the present invention, the maximum primary energy efficiency temperature determination unit determines the maximum primary energy efficiency of the water in the storage tank, which is the boiling temperature of the water in the storage tank at which the total primary energy efficiency of the heat pump and the auxiliary heat source becomes highest, Determine the energy efficiency temperature. Further, the user of the low-temperature type hot water supply system can select the running cost or the primary energy efficiency as an index of interest by operating the reference indicator selection unit. Therefore, convenience for the user can be improved.

When the running cost is selected by the reference indicator selection unit, the hot water supply control unit can perform the hot water supply operation in which the running cost is reduced by performing the first hot water supply operation in which the total running cost is the lowest. In addition, when the primary energy efficiency is selected by the reference indicator selection unit, the hot water supply control unit can perform the hot water supply operation in which the primary energy efficiency is the highest and the primary energy consumption is suppressed .

In addition, primary energy refers to energy obtained directly from nature such as fossil fuels such as petroleum, coal and natural gas, uranium as nuclear fuel, and natural energy such as hydroelectric power, solar energy, and geothermal energy. The primary energy efficiency refers to the ratio of the primary energy consumed (= required energy / primary energy consumption) to obtain the required energy, and the primary energy efficiency increases as the primary energy consumption decreases.

The maximum primary energy efficiency temperature at which the total primary energy efficiency of the heat pump and the auxiliary heat source is maximized is not only the temperature at which the primary energy efficiency is the highest in an absolute sense but also the relative primary energy efficiency It also includes the highest temperature.

Here, the boiling temperature of the water in the storage tank may be set to the same temperature as the set temperature of the low-temperature type hot water supply system. Further, the boiling temperature may be higher than the set temperature by an error or the like. In this case, the hot water supplied from the storage tank is mixed with the water supplied from the water supply pipe to obtain the hot water at the set temperature, so that the primary energy efficiency becomes equal to the case where the boiling temperature is equal to the set temperature.

In the fifth invention,

Wherein the maximum primary energy efficiency temperature determination section determines the maximum primary energy efficiency temperature in the storage tank by changing the boiling supposition temperature of the boiled water in the storage tank within a second temperature range lower than the target hot water temperature, A first primary energy consumption amount that is an assumed value of a primary energy consumption amount of the heat pump under the ambient temperature necessary for raising a temperature of the water to an assumed temperature, Based on a total consumed amount of the first primary energy consumption and the second primary energy consumption, and calculating a second primary energy consumption, which is a primary energy consumption of the auxiliary heat source, To the highest temperature, Characterized in that the temperature determined by the energy efficiency (the sixth invention).

According to the sixth aspect of the present invention, the first primary energy consumption amount and the second primary energy consumption amount for each assumed temperature are calculated by changing the assumed boiling temperature of water in the storage tank within the second temperature range, The highest primary energy efficiency temperature can be easily determined.

In the fifth invention or the sixth invention,

And a remote controller for remotely operating the heat pump unit and the auxiliary heat source,

The reference index selection unit selects a running cost or a primary energy consumption amount according to an operation of the remote controller by the user (seventh invention).

According to the seventh aspect of the present invention, the user of the low-temperature type hot water supply system can easily select an indicator of interest among the running cost and the primary energy efficiency by the operation of the remote control to suppress the running cost or the primary energy efficiency Hot water can be used.

1 is a schematic view of a low-
2 is a flowchart of a process for determining the lowest running cost temperature
Fig. 3 is a flowchart of a process of determining the highest primary energy efficiency temperature
4 is an explanatory diagram of the relationship between the efficiency of the heat pump and the thermal efficiency of the hot water heater
5 is a graph showing the relationship between the efficiency of the heat pump and the boiling temperature of water in the storage tank

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to Figs. 1, the low-temperature type hot water supply system of the present embodiment includes a low-temperature unit 10, a heat pump unit 50, a gas heat source unit 80, and a controller 120 for controlling the overall operation of the low- As shown in Fig.

1 shows a single controller 120 as a controller of the low-temperature type hot water supply system, the controller of the low temperature unit 10, the controller of the heat pump unit 50, the controller of the gas heat source unit 80, And the overall operation of the low-temperature type hot water supply system may be controlled by communication between the controllers.

The low temperature unit (10) has a storage tank (11), a water supply pipe (12), a hot water supply pipe (13), and the like. The storage tank 11 stores hot water therein, and tank temperature sensors 14 to 17 are provided at substantially equal intervals in the height direction. At the bottom of the holding tank 11, there is provided a drain valve 18 which is opened by manual operation of the operator.

The other end of the water supply pipe 12 is connected to the lower portion of the storage tank 11 and supplies water to the lower portion of the storage tank 11. [ The water supply pipe 12 is provided with a pressure reducing valve 19 for preventing the internal pressure of the storage tank 11 from becoming excessive and a check valve 19 for preventing the water from flowing from the storage tank 11 to the water supply pipe 12 20 are installed.

The water supply pipe 12 is connected to the hot water supply pipe 13 through the tank mixing valve 21 and is connected to the hot water supplied from the storage tank 11 to the hot water supply pipe 13 and the water supply pipe 12 to the water supply pipe is changed. The water supply pipe 12 is provided with a water supply temperature sensor 22 for detecting the temperature of water supplied to the water supply pipe 12, a water flow rate sensor 23 for detecting the flow rate of water flowing through the water supply pipe 12, Backward flow prevention valve 24 for preventing the flow of the hot water from the water supply pipe 12 to the water supply pipe 12 is provided.

The hot water supply pipe 13 has one end connected to the hot water supply port 31 and the other end connected to the upper portion of the storage tank 11. [ The hot water stored in the upper portion of the storage tank 11 is supplied to a hot water tap (a kitchen, a toilet, a bathroom faucet, a shower, or the like) not shown via a hot water supply port 31. The hot water supply pipe 13 is provided with a backflow prevention valve 25 for preventing inflow of hot water from the hot water supply pipe 13 to the storage tank 11 and a hot water temperature sensor 26 for detecting the temperature of the hot water in the hot water supply pipe 13 And a hot water flow rate sensor 27 for detecting the flow rate of the hot water flowing through the hot water supply pipe 13 are provided.

The hot water supply pipe 13 is connected to the gas heat source unit 80 via a bypass pipe 33 (bypass supply pipe 33a, bypass return pipe 33b). A hot water temperature sensor 28 is provided between the connection portion of the hot water supply pipe 13 with the bypass supply pipe 33a and the tank mixing valve 21 and is connected to the bypass return pipe 33b of the hot water supply pipe 13 A hot water temperature sensor 32 is provided between the connecting portion of the hot water supply port 31 and the hot water supply port 31.

Between the connection portion of the hot water supply pipe 13 with the bypass supply pipe 33a and the connection portion between the bypass return pipe 33b and the bypass supply pipe 33a, A control valve 29 is provided.

The detection signals of the respective sensors provided in the hot water unit (10) are input to the controller (120). The operation of the tank mixing valve 21 and the bypass control valve 29 is controlled by a control signal output from the controller 120. [

Next, the heat pump unit 50 circulates the hot water in the storage tank 11 through the tank circulation path 41 to heat it, and is installed outdoors. The heat pump unit 50 includes a heat pump 55 constituted by an evaporator 53, a compressor 54, a heat pump heat exchanger 55 (condenser), and an expansion valve 56 connected by a heat pump circulation path 52, (51).

The evaporator 53 is disposed between the air (outdoor air) supplied by the rotation of the fan 60 and the heating medium (alternative freon such as hydrofluorocarbon (HFC), carbon dioxide, etc.) flowing through the heat pump circulation path 52 As shown in FIG. The compressor 54 compresses the heating medium discharged from the evaporator 53 to a high pressure and a high temperature and sends it to the heat pump heat exchanger 55. The expansion valve (56) opens the pressure of the heating medium pressed by the compressor (54).

The defrosting valve 61 is installed by bypassing the expansion valve 56 and defrosts the evaporator 53 by the heating medium sent out from the compressor 54. [ A heat medium temperature sensor (not shown) for detecting the temperature of the heat medium circulating in the heat pump circulation path 52 is provided on the upstream side and the downstream side of the expansion valve 56 of the heat pump circulation path 52 and on the upstream side and the downstream side of the compressor 54 62, 63, 64, and 65, respectively. The evaporator 53 is provided with an ambient temperature sensor 67 for detecting the temperature of the air sucked into the evaporator 53 (corresponding to the ambient temperature and the ambient temperature of the present invention).

The heat pump heat exchanger 55 is connected to the tank circulation path 41 and is connected to the tank circulation path 41 by the heat exchange between the heat medium which has been brought to high pressure and high temperature by the compressor 54 and the hot water circulating in the tank circulation path 41 ) Is heated. The tank circulation path 41 is provided with a tank circulation pump 66 for circulating the tap water in the storage tank 11 through the tank circulation path 41.

The hot water stored in the lower portion of the storage tank 11 is led to the tank circulation path 41 by the tank circulation pump 66 and heated to the boiling temperature in the heat pump heat exchanger 55, Lt; / RTI > As a result, the boiling water at the boiling temperature is sequentially stacked from the upper part of the storage tank 11 and stored.

On the upstream side and the downstream side of the heat pump heat exchanger 55 of the tank circulation path 41 are provided hot water temperature sensors 68 and 69 for detecting the temperature of the hot water flowing in the tank circulation path 41. The heat pump heat exchanger 55 is provided with an atmospheric temperature sensor 57 for detecting the atmospheric temperature therein.

The detection signals of the respective sensors provided in the heat pump unit 50 are input to the controller 120. [ The operation of the compressor 54, the tank circulation pump 66, and the fan 60 is controlled by the control signal output from the controller 120. [

The gas heat source unit 80 heats boiled water supplied to the bypass pipe 33 and hot water flowing in the bathtub circulation path 102 connected to the bathtub 101. The hot water burner 81, A hot water heat exchanger 82, an additional heating burner 83, an additional heating heat exchanger 84, a water supply pipe 85, a hot water supply pipe 86, and the like. The water supply pipe 85 and the hot water supply pipe 86 correspond to the hot water supply pipe of the present invention connected to the storage tank 11.

Fuel gas is supplied from a gas supply pipe (not shown) to the hot water burner 81 and the additional heating burner 83, and combustion air is supplied by a combustion fan (not shown). The controller 120 controls the flow rates of the fuel gas and the combustion air to be supplied to the hot water burner 81 and the additional heating burner 83 to control the amount of combustion of the hot water burner 81 and the additional heating burner 83 .

The hot water heat exchanger 82 is connected to the water supply pipe 85 and the hot water supply pipe 86 and heats the water supplied from the water supply pipe 85 by the heat of combustion of the hot water burner 81, It makes a boil. One end of the water supply pipe 85 is connected to the bypass supply pipe 33a of the hot water unit 10 and the hot water is supplied through the bypass supply pipe 33a. One end of the hot water supply pipe 86 is connected to the bypass return pipe 33b of the hot water unit 10 and supplies hot water from the hot water supply port 31 through the bypass return pipe 33b.

The water supply pipe 85 is provided with a water stop valve 93 and a water quantity sensor 88 in order from the upstream side. The water supply pipe 85 and the hot water supply pipe 86 are connected to each other by a bypass pipe 89. A quantity control valve 90 for controlling the opening degree of the bypass pipe 89 is connected to the bypass pipe 89, Respectively. A hot water temperature sensor (not shown) for detecting the temperature of the hot water flowing through the hot water supply pipe 86 is disposed downstream of the hot water heat exchanger 82 of the hot water supply pipe 86 and downstream of the connection portion with the bypass pipe 89 91, and 92, respectively.

The water supplied to the water supply pipe 85 through the bypass supply pipe 33a is heated by the hot water heat exchanger 82 so that the hot water is supplied to the hot water supply pipe 33a, And is mixed with water from the bypass pipe 89 and supplied from the hot water supply port 31 through the hot water supply pipe 86 and the bypass return pipe 33b.

The hot water heat exchanger 82 is connected to the water supply pipe 85 and the hot water supply pipe 86 and the hot water burner 81 for heating the hot water heat exchanger 82 to supply water from the water supply pipe 85 to the hot water heat exchanger 82 for heating the hot water flowing through the hot water supply pipe 86 corresponds to the auxiliary heat source of the present invention and is shown as a hot water heater 87 in FIG.

The hot water supply pipe 86 is connected to the bathtub circulation path 102 connected to the bathtub 101 by the hot water filling pipe 100. The hot water filling pipe 100 is provided with a hot water filling valve 103 for opening and closing the hot water filling pipe 100 and a hot water filling flow rate sensor 104 for detecting the flow rate of the hot water flowing through the hot water pipe 86 .

The controller 120 opens the hot water filling valve 103 to supply the hot water from the hot water supply pipe 86 to the bath 101 through the hot water filling pipe 100 and the tub circulation path 102, The hot water filling operation for accumulating the amount of hot water supplied to the bath 101 by the flow rate detected by the flow rate sensor 104 and supplying the hot water of the target hot water filling amount to the bath 101 is executed.

The bath circulation path 102 includes a bathtub supply pipe 102a and a bathtub return pipe 102b to which the bath 101 and the additional heating heat exchanger 84 are connected. The bath returning pipe 102b is provided with a bath circulation pump 105 for circulating the hot water in the bath 101 through the bath circulation path 102 and a water flow switch 108 for detecting the water flow in the bath circulation path 102, And a bath return temperature sensor 107 for detecting the temperature of the hot water flowing in the bath return pipe 102b. The bathtub supply pipe 102a is provided with a bathtub temperature sensor 106 for detecting the temperature of the hot water flowing through the bathtub pipe 102a.

The controller 120 operates the bath circulation pump 105 to burn the additional heating burner 83 while circulating the hot water in the bathtub 101 through the bath circulation path 102. The controller 120 then controls the bathtub circulation pump 102 Quot; additional heating operation "

The detection signals of the sensors and the water flow switch 108 provided in the gas heat source unit 80 are input to the controller 120. [ The hot water burner 81, the additional heating burner 83, the water quantity control valve 90, the exponent valve 93, the hot water filling valve 103, the bath circulation pump 90, (105) is controlled.

The controller 120 is an electronic circuit unit configured by a CPU, a memory, and the like, not shown, and executes a control program for the low-temperature hot water supply system stored in the memory in the CPU to select the reference indicator selection unit 121, And functions as a temperature determination unit 122, a maximum primary energy efficiency temperature determination unit 123, a hot water supply control unit 124, an additional heating control unit 125, a hot water filling control unit 126 and a hot water supply holding unit 127.

The controller 120 is connected to the remote controller 140 through a communication cable 130. The remote controller 140 is provided with a display 141 for displaying the operation status and operation conditions of the low-temperature type hot water supply system, and a switch unit 142 provided with various switches.

The user of the low-temperature type hot water supply system operates the remote controller 140 to control the boiling water boiling instruction in the storage tank 11, the hot water supply temperature from the hot water supply port 31 (the set hot water temperature, Setting of the hot water supply temperature (the set hot water filling temperature, the set temperature of the present invention) to the bath 101, the execution instruction of the "hot water filling operation", the execution instruction of the "additional heating operation" · Setting of the gas rate, selection of the reference index (running cost, primary energy efficiency) to be described later, and the like can be performed.

The reference index selection unit 121 selects the running cost or the primary energy efficiency as a reference index that the user is interested in, in accordance with the operation of the switch unit 142 of the remote controller 140 by the user.

The lowest running cost temperature determination unit 122 determines the lowest running cost of the hot water tank 51 and the running cost of the hot water tank 87 when the hot water tank 51 and the hot water tank 87 are running at the lowest cost, Which is the boiling temperature of water in the boiler 11.

The maximum primary energy efficiency temperature determination unit 123 determines that the sum of the primary energy consumption amount of the heat pump 51 and the primary energy consumption amount of the hot water heater 87 becomes minimum when the hot water supply operation or the hot water filling operation is performed , And determines the maximum primary energy efficiency temperature which is the boiling temperature of water in the warming tank 11 where the total primary energy efficiency of the heat pump 51 and the hot water heater 87 becomes highest.

The hot water supply control unit 124 detects that the hot water tap (not shown) connected through the hot water supply port 31 is opened and water having a predetermined minimum flow rate flows in the water supply pipe 85, Hot water supply operation "for supplying hot water of the set temperature (the set hot water temperature or the set hot water filled temperature set by the remote controller 140) from the hot water supply opening 31 is executed.

In the " hot water supply operation ", the hot water supply control unit 124 warms the hot water in the storage tank 11 to the boiling temperature by the heat pump 51, The combustion amount of the hot water burner 81, the mixing ratio of the tank mixing valve 21, the opening degree of the bypass control valve 29, the opening degree of the water quantity control valve 90, and the like.

The additional heating control unit 125 performs the above-described "additional heating operation" when the remote control unit 140 instructs the start of the "additional heating operation" to heat the hot water in the bath 101. [

The hot water filling control unit 126 performs the above described "hot water filling operation" when the remote controller 140 instructs the start of the "hot water filling operation" and sets the hot water of the set hot water filling temperature to the bathtub 101, Fill in the amount. In the " hot water filling operation ", the hot water supply control unit 124 performs " hot water supply operation " with the set hot water filling temperature as the set temperature.

The hot water keeping unit 127 holds the hot water temperature history data including the information of the time at which the "hot water supply operation" (including the "hot water supply operation" in the "hot water filling operation") was executed. The hot water supply control unit 124 refers to the hot water supply history data and recognizes the time zone in which the " hot water supply operation "

Next, the determination processing of the minimum running cost temperature and the maximum primary energy efficiency temperature by the controller 120 will be described according to the flowcharts shown in Figs. 2 to 3. Fig.

The controller 120 executes the processing of STEP 1 and subsequent steps in FIG. 2 when detecting the hot water breakdown in which the hot water of the set temperature (the set hot water temperature or the set hot water filling temperature) is absent in the storage tank 11. The detection of the hot water breakage is based on the fact that (1) the hot water heater 87 of the gas heat source unit 80 is operated, (2) the detection temperature of the tank temperature sensors 14 to 17 of the warming tank 11 reaches the set temperature (3) the detection temperature of the hot water from the storage tank 11 by the hot water temperature sensor 26 is lower than the set temperature, or the like.

The controller 120 acquires the data of the outdoor air temperature Tout which is the outdoor temperature at which the heat pump unit 50 is installed from the temperature detection signal of the ambient temperature sensor 67 in STEP 1, The data of the water supply temperature Tw from the temperature detection signal of the water supply pipe 12 to the water supply pipe 12 is obtained. Subsequently, in STEP3, data of the set temperature (Tcm) set by the operation of the switch unit 142 of the remote controller 140 and held in the memory is acquired.

In the next step 4, the controller 120 determines whether or not the running cost is selected by the reference index selection unit 121. [ When the running cost is selected, the flow proceeds to STEP 5. When the running cost is not selected (when the primary energy efficiency is selected), the flow branches to STEP 20 in FIG.

STEP5 to STEP10 are processing by the lowest running cost temperature determination unit 122. [ The lowest running cost temperature determination section 122 determines whether or not the water supplied into the storage tank 11 from the water supply pipe 12 is discharged at four preset temperatures of 25 DEG C, 35 DEG C, 45 DEG C, 55 DEG C (Set at a predetermined temperature higher than the set temperature Tcm), which is a boiling temperature determined according to the set temperature Tcm (45 占 폚 in the present embodiment) in the first temperature range of the present invention (Corresponding to Th_e = 25 deg. C, 35 deg. C and 45 deg. C) selected in the storage tank 11 under the ambient temperature Tout (Corresponding to the first running cost of the present invention) of the heat pump 51 necessary for boiling up to the assumed temperature Th_e.

In STEP7, when the temperature of the hot water in the storage tank 11 is equal to the three estimated temperatures Th_e (Th_e = 25 DEG C, 35 DEG C, and 45 DEG C), the lowest running cost temperature determination unit 122 determines, The running cost of the hot water heater 87 required for heating the hot water supplied from the hot water supply pipe 11 to the hot water supply pipe 13 to the set temperature Tcm by the hot water heater 87 (corresponding to the second running cost of the present invention) ).

The lowest running cost temperature determination unit 122 calculates the total running cost of the heat pump 51 and the hot water heater 87 for each boiling assumed temperature in STEP8 and stores the total running cost in the memory. In STEP 10, the lowest running cost temperature determining unit 122 determines the boiling assumed temperature at which the total running cost of the heat pump 51 and the hot water heater 87 is lowest, as the lowest running cost temperature Trc_min.

4A is a graph showing the relationship between the water temperature of the water supply tank (Tw = 5 DEG C) in the storage tank 11 and the water temperature The relationship between the efficiency of the heat pump 51 and the outdoor air temperature when the heat pump 51 is boiled to the assumed temperature Th_e (Th_e = 25 ° C, 35 ° C, 45 ° C, 55 ° C) Heat pump-efficiency map "indicated by a2 (Th_e = 25 ° C), a2 (Th_e = 35 ° C), a3 (Th_e = 45 ° C), and a4 (Th_e = 55 ° C)

The memory of the controller 120 also holds the data of the " outdoor air temperature-heat pump efficiency map " for the water supply temperature Tw other than 5 deg. The lowest running cost temperature determination unit 122 selects the "outside air temperature-heat pump efficiency map" to be used according to the water supply temperature Tw.

4 (b), the ordinate axis is set to the thermal efficiency of the hot water heater 87 and the abscissa axis is set to the temperature of the hot water (hot water heater inlet temperature) supplied from the holding tank 11 to the hot water heat exchanger 82, Shows the relationship between the boiling temperature and the thermal efficiency of the hot water heater 87 (b). The hot water inlet temperature becomes the boiling temperature (Th) of the hot water in the warming tank 11.

The calculation of the running cost of the heat pump 51 in STEP6, the calculation of the running cost of the hot water heater 87 in STEP7, the calculation of the total running cost in STEP8, and the calculation of the running cost in STEP10 (Tw = 5 占 폚), outdoor air temperature (Tout = -5 占 폚), and set temperature (Tcm = 45 占 폚) will be described with reference to the processing for determining the lowest running cost temperature.

The lowest running cost temperature determination section 122 selects the "outside air temperature-heat pump efficiency map" for the water supply temperature (Tw = 5 ° C.) in FIG. 4 (a). In the "outside air temperature-heat pump efficiency map" in Fig. 4 (a), the water at the water supply temperature (Tw = 5 캜) in the storage tank 11 is heated to the boiling assumed temperature Th_e (Th_e = , 45 占 폚), the efficiency Eh of the heat pump 51 is as shown in Table 1 below. As the boiling temperature becomes lower, the efficiency of the heat pump 51 increases.

The assumed temperature (Th_e) 25 ℃ 35 ℃ 45 ° C Heat pump efficiency (Eh) 500% 350% 200%

The thermal efficiency Eb of the hot water heater 87 when heating the boiling supposition temperature Th_e (Th_e = 25 ° C, 35 ° C) to the set temperature (Tcm = 45 ° C) . Further, if the target hot water temperature is set to the set temperature (Tcm) or more, heating by the hot water heater 87 is not performed.

The assumed temperature (Th_e) 25 ℃ 35 ℃ Thermal efficiency (Eb) 86% 84%

The water at 25 ° C supplied from the storage tank 11 to the hot water supply pipe 13 is supplied to the hot water tank 13 after the water having the water supply temperature (Tw = 5 ° C) in the storage tank 11 is boiled up to 25 ° C by the heat pump 51, The running cost of the heat pump 51 and the running cost of the hot water heater 87 in the hot water supply operation in which the hot water heater 87 is assumed to heat up to the set temperature (Tcm = 45 deg. C) To (9). The capacity of the storage tank 11 is 100 liters.

[Case of assumed boiling temperature (Th_e = 25 DEG C)] [

· Calories required for boiling of the storage tank

(25 DEG C - 5 DEG C) x 100 liters x d x Cv = 2000 (kcal) ... ... (One)

Where d: density of water (kg / liter), Cv: specific heat of water (kcal / kg 占 폚).

· Caloric value considering efficiency (Eh) of heat pump

2000 ÷ 5 (Eh) = 400 (kcal) ... ... (2)

· Power consumption of heat pump (1kwh = 860kcal)

400 ÷ 860 = 0.465 (kWh) ... ... (3)

· Running cost of heat pump (set electricity rate at 22 yen / kWh)

0.465 × 22 (yen) = 10.23 (yen) ... ... (4)

· Heat quantity required for heating by 25 ℃ ~ 45 ℃ by hot water heater

(45 占 폚 - 25 占 폚) × 100 liters × d × Cv = 2000 (kcal) ... ... (5)

Where d: density of water (kg / liter), Cv: specific heat of water (kcal / kg 占 폚).

· Calorific value considering heat efficiency (Eb) of hot water heater

2000 ÷ 0.86 (Eb) = 2326 (kcal) ... ... (6)

· Consumption amount of fuel gas of hot water heater (calorific value: 11000kcal / ㎥)

2326 (kcal) ÷ 11000 = 0.211 (m3) ... ... (7)

· Running cost of the hot water heater (fuel gas rate set at 110 yen / ㎥)

0.211 x 110 (yen) = 23.21 (yen) ... ... (8)

· Total running cost

10.23 (yen) +23.21 (yen) = 33.44 (yen) ... ... (9)

Next, after the water of the water supply temperature (Tw = 5 占 폚) in the storage tank 11 is boiled to 35 占 폚 by the heat pump 51, the water of 35 占 폚 supplied to the hot water supply pipe 13 from the storage tank 11 The total running cost of the heat pump 51 and the hot water heater 87 in the hot water supply operation in which water is heated by the hot water heater 87 to the set temperature (Tcm = 45 deg. C) ) To (18).

[Case of assumed boiling temperature (Th_e = 35 deg. C)] [

· Calories required for boiling of the storage tank

(35 DEG C - 5 DEG C) x 100 liters x d x Cv = 3000 (kcal) ... ... (10)

Where d: density of water (kg / liter), Cv: specific heat of water (kcal / kg 占 폚).

· Caloric value considering efficiency (Eh) of heat pump

3000 ÷ 3.5 (Eh) = 857 (kcal) ... ... (11)

· Power consumption of heat pump (1kwh = 860kcal)

857 ÷ 860 = 0.997 (kWh) ... ... (12)

· Running cost of heat pump (set electricity rate at 22 yen / kWh)

HP_c = 0.997 占 22 (yen) = 21.93 (yen) ... ... (13)

· Heat quantity required for temperature rise (35 ℃ -> 45 ℃) by hot water heater

(45 占 폚 - 35 占 폚) × 100 liters × d × Cv = 1000 (kcal) ... ... (14)

Where d: density of water (kg / liter), Cv: specific heat of water (kcal / kg 占 폚).

· Calorific value considering heat efficiency (Eb) of hot water heater

1000 ÷ 0.84 (Eb) = 1190 (kcal) ... ... (15)

· Consumption amount of fuel gas of hot water heater (calorific value: calculated at 11000kcal / ㎥)

1190 (kcal) ÷ 11000 = 0.108 (m3) ... ... (16)

· Running cost of the hot water heater (fuel gas rate set at 110 yen / ㎥)

0.108 占 110 (yen) = 11.88 (yen) ... ... (17)

· Total running cost

21.93 (yen) +11.88 (yen) = 33.81 (yen) ... ... (18)

Next, when the water of the water supply temperature (Tw = 5 占 폚) in the holding tank 11 is boiled up to 45 占 폚 by the heat pump 51 and the heating by the hot water heater 87 is not performed, , The total running cost of the heat pump 51 and the hot water heater 87 is obtained by the following equations (19) to (23).

[Case of assumed boiling temperature (Th_e = 45 DEG C)] [

· Calories required for boiling of the storage tank

(45 ° C - 5 ° C) × 100 liters × d × Cv = 4000 (kcal) ... ... (19)

Where d: density of water (kg / liter), Cv: specific heat of water (kcal / kg 占 폚).

· Caloric value considering efficiency (Eh) of heat pump

4000 ÷ 2 (Eh) = 2000 (kcal) ... ... (20)

· Power consumption of heat pump (1kwh = 860kcal)

2000 ÷ 860 = 2.33 (kWh) ... ... (21)

· Running cost of heat pump (set electricity rate at 22 yen / kWh)

HP_c = 2.33 占 22 (yen) = 51.26 (yen) ... ... (22)

· Total running cost

51.26 (yen) +0 (yen, no heating of hot water heater) = 51.26 (yen) ... ... (23)

Next, as a reference, water of the water supply temperature (Tw = 5 deg. C) is heated to the set temperature (Tcm = 45 deg. C) by the water heater 87 without boiling water in the storage tank 11 by the heat pump 51 The total running cost of the heat pump 51 and the hot water heater 87 in the hot water supply operation assuming the case of heating is obtained by the following equations (24) to (27).

[No boiling (the temperature of the water in the holding tank 11 = the water temperature 5 [deg.] C)]]

· Calories required for heating by a hot water heater (5 ℃ → 45 ℃)

(45 ° C - 5 ° C) × 100 liters × d × Cv = 4000 (kcal) ... ... (24)

Where d: density of water (kg / liter), Cv: specific heat of water (kcal / kg 占 폚).

· Calorific value considering heat efficiency (Eb) of hot water heater

4000 ÷ 0.92 (Eb) = 4348 (kcal) ... ... (25)

· Consumption amount of fuel gas of hot water heater (calorific value: 11000kcal / ㎥)

4348 (kcal) ÷ 11000 = 0.395 (m3) ... ... (26)

· Running cost of the hot water heater (fuel gas rate set at 110 yen / ㎥)

0.395 x 110 (yen) = 43.45 (yen) ... ... (27)

From the above calculated results, the total running cost of the heat pump 51 and the hot water heater 87 at each assumed temperature Th_e of boiling is as shown in Table 3 below.

Boiling temperature 5 ℃ 25 ℃ 35 ℃ 45 ° C Heat pump running cost - 10.23 (JPY) 21.93 (JPY) 51.26 (JPY) Hot running water running cost 43.45 (JPY) 23.21 (yen) 11.88 (yen) - Total running cost 43.45 (JPY) 33.44 (JPY) 33.81 (yen) 51.26 (JPY)

From Table 3, it is assumed that the total running cost of the heat pump 51 and the hot water heater 87 is lowest at a boiling temperature of 25 占 폚. Therefore, the lowest running cost temperature determination section 122 determines the lowest running cost temperature Trc_min at 25 占 폚 in STEP10.

STEP 11 is a process performed by the hot water supply control unit 124. The hot water supply control unit 124 sets the minimum running cost temperature Trc_min to the boiling temperature Th of the water in the storage tank 11 by the heat pump 51. [ Then, the process proceeds to STEP 12, and the controller 120 ends the process.

Next, STEP20 to STEP25 in FIG. 3 are processes by the maximum primary energy efficiency temperature determination unit 123. FIG. The maximum primary energy efficiency temperature determination unit 123 determines whether or not the water supplied from the water supply pipe 12 into the storage tank 11 at four preset temperatures of 25 DEG C, 35 DEG C, 45 DEG C, (Corresponding to the second temperature range of the present invention) in the range of 55 ° C to the target hot water temperature (set at a predetermined temperature higher than the set temperature), which is the boiling temperature determined according to the set temperature (Tcm) (45 ° C) When the water at the temperature Tw in the storage tank is boiled up to the assumed temperature Th_e under the ambient temperature Tout in STEP 21 with respect to the three assumed temperatures Th_e (Th_e = 25 ° C, 35 ° C and 45 ° C) (Corresponding to the first primary energy consumption amount of the present invention) of the heat pump 51 as required.

In STEP 22, the maximum primary energy efficiency temperature determination unit 123 determines the temperature of the hot water in the storage tank 11 (Th_e) (Th_e = 25 DEG C, 35 DEG C, 45 DEG C) (The second primary energy consumption amount of the present invention) required for heating the hot water supplied from the hot water supply pipe 13 to the hot water supply pipe 13 to the set temperature Tcm by the hot water supply device 87 ).

The maximum primary energy efficiency temperature determination unit 123 calculates the total primary energy efficiency of the heat pump 51 and the hot water heater 87 for each boiling assumed temperature in STEP 23 and holds it in the memory. In STEP25, the maximum primary energy efficiency temperature determination section 123 determines the boiling supposition temperature at which the total primary energy efficiency of the heat pump 51 and the hot water heater 87 becomes highest as the highest primary energy efficiency temperature Tre_max do.

The calculation of the primary energy consumption amount of the heat pump 51 in STEP21 by the highest primary energy efficiency temperature determination unit 123 and the calculation of the primary energy consumption amount in the hot water heater 87 in STEP 22 and the calculation of the total primary energy efficiency (Tw = 5 占 폚), outdoor air temperature (Tout = -5 占 폚), and outdoor air temperature (Tout = 5 占 폚) And the set temperature (Tcm = 45 deg. C) will be described as an example.

The maximum primary energy efficiency temperature determination unit 123 selects the "outside air temperature-heat pump efficiency map" for the water supply temperature (Tw = 5 ° C.) in FIG. 4 (a). The efficiency Eh of the heat pump 51 in this case is as shown in Table 1 above. The hot water heater 87 at the time of heating the boiling supposition temperature Th_e (Th_e = 25 ° C, 35 ° C and 45 ° C, corresponding to the second temperature range of the present invention) to the set temperature (Tcm) The thermal efficiency Eb of the fuel cell is as shown in Table 2 above.

Therefore, the water of the water supply temperature (Tw = 5 占 폚) in the storage tank 11 is boiled to 25 占 폚 by the heat pump 51 and the water of 25 占 폚 supplied from the storage tank 11 to the hot water supply pipe 13 The primary energy efficiency of the heat pump 51 and the primary energy efficiency of the hot water heater 87 at the time of heating to the set temperature (Tcm = 45 deg. C) by the hot water heater 87 are expressed by the following equations (28) (34).

[Case of assumed boiling temperature (Th_e = 25 DEG C)] [

· Calories required for boiling of the storage tank

(25 DEG C - 5 DEG C) x 100 liters x d x Cv = 2000 (kcal) ... ... (28)

Where d: density of water (kg / liter), Cv: specific heat of water (kcal / kg 占 폚).

· Caloric value considering efficiency (Eh) of heat pump

2000 ÷ 5 (Eh) = 400 (kcal) ... ... (29)

· The primary energy consumption of the heat pump (the power generation efficiency of the heat pump is set to 0.37)

400 ÷ 0.37 = 1081 (kcal) ... ... (30)

· Heat quantity required for heating by 25 ℃ ~ 45 ℃ by hot water heater

(45 占 폚 - 25 占 폚) × 100 liters × d × Cv = 2000 (kcal) ... ... (31)

Where d: density of water (kg / liter), Cv: specific heat of water (kcal / kg 占 폚).

· Heat amount (= primary energy consumption) considering thermal efficiency (Eb) of the hot water heater

2000 ÷ 0.86 (Eb) = 2326 (kcal) ... ... (32)

· Total primary energy consumption

1081 + 2326 = 3407 (kcal) ... ... (33)

· Total primary energy efficiency

4000 ÷ 3407 = 1.17 ... ... (34)

However, the amount of heat (= (45 ° C - 5 ° C) × 100 liters × d × Cv) required to boil water at 15 ° C of 4000: 100 liters up to 45 ° C.

Next, after the water of the water supply temperature (Tw = 5 占 폚) in the storage tank 11 is boiled to 35 占 폚 by the heat pump 51, the water of 35 占 폚 supplied to the hot water supply pipe 13 from the storage tank 11 The total primary energy efficiency of the heat pump 51 and the hot water heater 87 in the hot water supply operation in which the water is heated by the hot water heater 87 to the set temperature (Tcm = 45 deg. C) 35) to (41).

[Case of assumed boiling temperature (Th_e = 25 DEG C)] [

· Calories required for boiling of the storage tank

(35 DEG C - 5 DEG C) x 100 liters x d x Cv = 3000 (kcal) ... ... (35)

Where d: density of water (kg / liter), Cv: specific heat of water (kcal / kg 占 폚).

· Heat quantity considering efficiency of heat pump

3000 ÷ 3.5 (Eh) = 857 (kcal) ... ... (36)

· Primary energy consumption of the heat pump (power generation efficiency set to 0.37)

857 ÷ 0.37 = 2316 (kcal) ... ... (37)

· Heat quantity required for temperature rise (35 ℃ -> 45 ℃) by hot water heater

(45 占 폚 - 35 占 폚) × 100 liters × d × Cv = 1000 (kcal) ... ... (38)

Where d: density of water (kg / liter), Cv: specific heat of water (kcal / kg 占 폚).

· Calorie considering efficiency of hot water heater

1000 ÷ 0.84 (Eb) = 1190 (kcal) ... ... (39)

· Total primary energy consumption

2316 + 1190 = 3506 (kcal) ... ... (40)

· Total primary energy efficiency

4000 ÷ 3506 = 1.14 ... ... (41)

Next, when the water of the water supply temperature (Tw = 5 占 폚) in the holding tank 11 is boiled up to 45 占 폚 by the heat pump 51 and the heating by the hot water heater 87 is not performed, , The total primary energy efficiency of the heat pump 51 and the hot water heater 87 is obtained by the following equations (42) to (45).

[Case of assumed boiling temperature (Th_e = 45 DEG C)] [

· Calories required for boiling of the storage tank

(45 ° C - 5 ° C) × 100 liters × d × Cv = 4000 (kcal) ... ... (42)

Where d: density of water (kg / liter), Cv: specific heat of water (kcal / kg 占 폚).

. Heat efficiency considering heat pump

4000 ÷ 2 (Eh) = 2000 (kcal) ... ... (43)

· Primary energy consumption of heat pump (power generation efficiency is set to 0.37)

2000 ÷ 0.37 = 5405 (kcal) ... ... (44)

· Total primary energy efficiency (no hot water heater is used)

4000 ÷ 5405 = 0.74 ... ... (45)

The total primary energy efficiency of the heat pump 51 and the hot water heater 87 in the hot water supply operation assuming that the heating by the heat pump is not performed is obtained by the following equation (46).

[No boiling (temperature of the water in the storage tank = water temperature 5 [deg.] C)]

· Total primary energy efficiency

Primary energy efficiency = thermal efficiency of the hot water heater = 0.92 ... ... (46)

Thus, the total primary energy efficiency in the case of boiling water (Th_e = 25 deg. C, 35 deg. C, 45 deg. C) and no boiling water in the storage tank 11 are as shown in Table 4 below.

Boiling temperature 5 ℃ 25 ℃ 35 ℃ 45 ° C Heat pump primary energy consumption - 1081 (kcal) 2316 (kcal) 5405 (kcal) Primary energy consumption of hot water heater 4348 (kcal) 2326 (kcal) 1190 (kcal) - Total primary energy consumption 4348 (kcal) 3407 (kcal) 3506 (kcal) 5405 (kcal) Total primary energy efficiency 0.92 1.17 1.14 0.74

It can be seen from Table 4 that the total primary energy efficiency of the heat pump 51 and the water heater 87 is lowest when the assumed temperature of boiling water in the storage tank 11 is 25 占 폚. Therefore, the maximum primary energy efficiency temperature determination unit 123 determines, at STEP 25, the maximum primary energy efficiency temperature Tre_max, which is the boiling assumed temperature at which the total primary energy efficiency becomes the highest, at 25 占 폚.

The hot water supply control unit 124 sets the maximum primary energy efficiency temperature Tre_max to the boiling temperature Th of the water in the storage tank 11 by the heat pump 51 . Then, the process proceeds to STEP 12 in FIG. 2, and the controller 120 ends the process.

The hot water supply control unit 124 activates the heat pump 51 and the tank circulation pump 66 so that the boiling temperature Th set in STEP 10 or STEP 25 (the lowest running cost temperature Trc_min or the highest primary energy efficiency temperature Tre_max ) (The boiling operation of water in the storage tank 11).

When the temperature of the hot water supplied from the storage tank 11 to the hot water supply pipe 13 is lower than the set temperature Tcm, the hot water supply control unit 124 performs heating by the hot water supply unit 87, 31 is controlled to be the set temperature, and the " hot water supply operation " is executed.

The "hot water supply operation" in which the water in the storage tank 11 is boiled up to the lowest running cost temperature Trc_min corresponds to the first hot water supply operation of the present invention. The "hot water supply operation" in which the water in the storage tank 11 is boiled up to the maximum primary energy efficiency temperature Tre_max corresponds to the second hot water supply operation of the present invention.

In addition, when the water in the storage tank 11 is boiled, the hot water supply control unit 124 does not heat the boiling temperature to the boiling temperature at a time but gradually. For example, when the water supply temperature Tw is 5 ° C and the water in the storage tank 11 is finally heated to 45 ° C, it is preferable to heat the water in the storage tank 11 continuously from 5 ° C to 45 ° C by the heat pump 51 , The temperature of the heat pump is increased by heating stepwise from 5 ° C to 25 ° C (corresponding to the intermediate temperature of the present invention) to 45 ° C.

5 is a graph showing the relationship between the water supply temperature (Tw = 5 deg. C) when the vertical axis is set to the efficiency of the heat pump 51 and the horizontal axis is set to the boiling temperature Th of the hot water in the storage tank 11. [ (C2 in the figure) between the efficiency of the heat pump 51 and the boiling temperature at the time of the water supply temperature (Tw = 25 deg. C) and the relationship between the efficiency of the heat pump 51 and the boiling temperature .

When the temperature of the water in the holding tank 11 is 5 占 폚, the efficiency at the time of heating to 25 占 폚 as the first step and heating to 45 占 폚 as the final boiling point as the next second step, Is 700% (P1 in the figure) and the efficiency of the second step is 300% (P3 in the figure), the average is 500%.

On the other hand, when the temperature of the water in the holding tank 11 is 5 占 폚, the efficiency when the heat pump 51 is continuously operated and once boiled up to the final boiling temperature 45 占 폚 is 420% (P2 in the figure) do. Therefore, it is possible to increase the efficiency of the heat pump 51 by heating the water in the storage tank 11 stepwise from 5 ° C to 25 ° C to 45 ° C, as compared with the case where the water is continuously heated from 5 ° C to 45 ° C have. The water in the holding tank 11 may be heated to a final boiling temperature stepwise in three or more stages.

When the hot water is used in the first stage of heating at 5 캜 to 25 캜, water at a temperature lower than 25 캜, which is supplied to the hot water supply pipe 13 from within the warming tank 11, It is necessary to generate hot water of a set temperature (Tcm) (45 캜) by heating by the hot water heater 87, but the primary energy efficiency is lowered by the operation of the hot water heater 87.

Therefore, the hot water supply control unit 124 refers to the hot water supply history data held by the hot water supply history holding unit 127, recognizes the time zone in which the hot water supply is not expected to be used, And boiling water in the tank 11 is performed. Thereby, it is possible to avoid the use of the hot water during the boiling of the water in the stepwise reservoir tank (11).

In the present embodiment, the reference index selection unit 121 and the highest primary energy efficiency temperature determination unit 123 are provided to determine the highest primary energy efficiency temperature Tre_max, The effect of the present invention can be obtained by providing at least the lowest running cost temperature determination unit 122 to determine the lowest running cost temperature Trc_min to perform the hot water supply operation .

In the present embodiment, the minimum running cost temperature Trc_min and the maximum primary energy efficiency temperature Tre_max are determined by the above equations (1) to (46), but the set temperature Tcm and the water supply temperature Tw For the input of the ambient temperature Tout and the ambient temperature Tout, data of the map for determining the lowest running cost temperature Trc_min and the map for determining the highest primary energy efficiency temperature Tre_max are held in the memory, The minimum running cost temperature Trc_min and the maximum primary energy efficiency temperature Tre_max may be determined.

In the present embodiment, the unit price of the electricity bill and the gas bill is inputted by the remote controller 140, but the unit price may be input by a switch provided on the board in the controller 120, May be written. Alternatively, the portable terminal may be connected to the controller 120, and this unit price may be inputted by the portable terminal.

When the setting of the electricity rate varies depending on the time zone or the usage amount, the setting of the electricity rate corresponding to the change may be input by a remote controller or the like.

In the present embodiment, the hot water supply control unit 124 performs the stepwise boiling of the hot water in the storage tank 11 as described above, but even if the boiling water is not stepwise boiled, the effect of the present invention is obtained .

In the present embodiment, the hot water supply control unit 124 is provided with the hot water supply holding unit 127, and the hot water supply control unit 124 determines the time zone in which the hot water supply is not expected to be used from the past hot water supply history, The effect of the present invention can be obtained.

In the present embodiment, the hot water heater 87 using gas as fuel as the auxiliary heat source of the present invention is shown, but other kinds of auxiliary heat sources such as a hot water heater using electric power such as petroleum or other electric heaters may be used .

The minimum running cost temperature Trc_min and the maximum primary energy efficiency temperature Tre_max may be compared and displayed on the display 141 of the remote controller 140 by operating the switch unit 142 of the remote controller 140 .

10 - Low temperature unit 11 - Storage tank
12 - Water supply pipe 13 - Water supply pipe
22 - Water temperature sensor 67 - Ambient temperature sensor
50 - Heat pump unit 51 - Heat pump
80 - Gas heat source unit 87 - Water heater
120 - controller 121 - reference indicator selection unit
122 - lowest running cost temperature determination unit
123 - The highest primary energy efficiency temperature determination unit
124 - Hot water supply control unit 127 - Hot water supply temperature maintenance unit

Claims (7)

A storage tank in which a water supply pipe is connected to a lower portion thereof, a hot water supply pipe is connected to an upper portion thereof, and water supplied from the water supply pipe is stored;
A tank circulation path connecting the lower part and the upper part of the storage tank; a tank circulation pump circulating the water stored in the lower part of the storage tank to the upper part of the storage tank through the tank circulation path; A heat pump unit having a heat pump for heating water flowing in the tank circulation path,
And an auxiliary heat source installed in the middle of the hot water supply pipe for heating hot water supplied from the storage tank to the hot water supply pipe,
A water supply temperature sensor for detecting a water supply temperature from the water supply pipe to the storage tank;
An ambient temperature sensor for detecting an ambient temperature of the heat pump,
The water at the water supply temperature in the storage tank is heated by the heat pump unit to the boiling temperature not higher than the target hot water temperature set at a predetermined temperature higher than the set temperature of the low temperature water heating system under the ambient temperature, The hot water supplied to the hot water supply pipe is heated to the set temperature by the auxiliary heat source to assume the hot water supply operation for tapping the hot water supply pipe and the running cost of the heat pump in the assumed hot water supply operation and the auxiliary A lowest running cost temperature determining unit that determines a lowest running cost temperature that is the boiling temperature at which the total cost of the running cost of the heat source unit is lowest,
Wherein the boiling water in the storage tank is heated to the lowest running cost temperature by the heat pump unit when the hot water cutoff of the storage tank is detected and then the hot water supplied from the storage tank to the hot water tank is supplied by the auxiliary heat source And a hot water supply control unit for performing a first hot water supply operation for heating the hot water to the set temperature and supplying the hot water to the hot water supply pipe.
The method according to claim 1,
Wherein the lowest running cost temperature determination section determines the minimum running cost temperature by changing the boiling supposition temperature of the boiled water in the storage tank within a first temperature range below the target hot water temperature, Which is an estimated value of the running cost of the heat pump under the ambient temperature, necessary for raising the temperature of the water in the auxiliary heat source to the predetermined temperature, and a second running cost, And the second running cost, which is an assumed value of the running cost of the auxiliary heat source necessary for raising the temperature of the first running cost and the second running cost, is calculated, and the estimated temperature, at which the total cost of the first running cost and the second running cost is lowest, And the lowest running cost temperature is determined as the lowest running cost temperature. The method according to claim 1,
Wherein the hot water supply control unit is configured to raise the water of the water supply temperature in the storage tank step by step when the water of the water supply temperature in the storage tank is heated by the heat pump unit to the lowest running cost temperature, Wherein the heat pump unit is heated by the heat pump unit to a predetermined temperature.
The method of claim 3,
And a hot water temperature holding unit for holding hot water temperature history data indicating a history of past hot water supply operation,
Wherein the hot water supply control unit performs heating from the hot water supply history data to the lowest running cost temperature of the water in the storage tank at a time when the hot water supply operation is not expected to be executed.
The method of claim 1, 3, or 4,
A maximum primary energy efficiency temperature determination unit for determining a maximum primary energy efficiency temperature which is a boiling temperature at which the total primary energy efficiency of the heat pump and the auxiliary heat source in the supposed hot water supply operation becomes the highest,
And a reference indicator selecting unit for selecting a running cost or a primary energy efficiency according to a user operation,
Wherein the hot water supply control unit executes the first hot water supply operation when the running cost is selected by the reference indicator selection unit and when the primary energy efficiency is selected by the reference indicator selection unit, The boiled water in the storage tank is heated to the maximum primary energy efficiency temperature by the heat pump unit and then the boiled water supplied from the storage tank to the hot water supply pipe is heated to the set temperature by the auxiliary heat source And a second hot water supply operation for supplying the hot water to the hot water supply pipe.
The method of claim 5,
Wherein the maximum primary energy efficiency temperature determination section determines the maximum primary energy efficiency temperature in the storage tank by changing the boiling supposition temperature of the boiled water in the storage tank within a second temperature range lower than the target hot water temperature, A first primary energy consumption amount that is an assumed value of a primary energy consumption amount of the heat pump under the ambient temperature necessary for raising a temperature of the water to an assumed temperature, Based on a total consumed amount of the first primary energy consumption and the second primary energy consumption, and calculating a second primary energy consumption, which is a primary energy consumption of the auxiliary heat source, To the highest temperature, Me tangsik hot water supply system, characterized in that for determining temperature in energy efficiency.
The method of claim 5,
And a remote controller for remotely operating the heat pump unit and the auxiliary heat source,
Wherein the reference index selection unit selects a running cost or a primary energy consumption amount according to an operation of the remote control by a user.

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