JP5192406B2 - Method for determining boiling target temperature of heat pump water heater - Google Patents

Description

  The present invention relates to a method for determining a boiling target temperature of a heat pump water heater that boils and stores hot water by a heat pump heating means.

  Conventionally, in this type of heat pump type hot water heater, as shown in Patent Document 1 and Patent Document 2, the boiling target is set so that the necessary amount of heat is boiled on the next day with midnight power at a low unit price during the midnight hours. When the temperature is set and the water in the hot water tank is heated to the target temperature by the heat pump type heating means of the air heat source, and the remaining hot water in the hot water tank is insufficient during the daytime, It was designed to increase the shortage with daytime electricity with a high unit price.

JP 2004-218873 A Japanese Patent Laid-Open No. 2004-233002

  In general, the heat efficiency of the heat pump heating means decreases at low outside air temperature, so the heat efficiency of the heat pump is higher in the daytime period when the outside air temperature is high. However, in the conventional system, in order to boil the amount of heat required for the next day during midnight hours, the boiling target temperature is set to a higher temperature, lowering the heating efficiency and lowering the outside air temperature at midnight hours In some cases, the heating efficiency is further reduced due to the boiling of the water, resulting in a high electricity bill.

  In order to solve the above-mentioned problems, the present invention has a hot water storage tank for storing hot water, a compressor, a refrigerant water heat exchanger, a decompressor, and an air heat exchanger, and a heat pump type for heating the water in the hot water storage tank. A heating target temperature determination method for a heat pump water heater comprising a heating means and an outside air temperature sensor for detecting an outside air temperature, wherein the daytime outside air temperature and nighttime outside air for each of a plurality of temporary boiling target temperatures A plurality of provisional boiling targets using the step of determining the heating efficiency of the heat pump according to each of the temperatures from a pre-stored relationship and the prestored daytime power rate unit price and nighttime power rate unit price The step of calculating the electricity charge necessary to boil the target hot water storage amount for each temperature, and the boiling target temperature is determined based on the electricity charge calculated for each of the plurality of temporary boiling target temperatures. Was one having a step.

  Further, in claim 2, there is provided a hot water storage tank for storing hot water, a heat pump heating means for heating the water in the hot water storage tank, comprising a compressor, a refrigerant water heat exchanger, a decompressor and an air heat exchanger. A method for determining a boiling target temperature of a heat pump water heater, comprising: an outside air temperature sensor for detecting an outside air temperature; and a feed water temperature sensor for detecting a temperature of feed water supplied to the hot water storage tank. The amount of heat used to calculate the amount of heat used from the hot water storage tank, including the amount of heat used, and the target amount of heat stored in the hot water for the next day based on the amount of heat used for the past several days calculated in the step of calculating the amount of heat used A setting step, a feed water temperature storing step for storing a feed water temperature based on a detection value of the feed water temperature sensor, a daytime time zone and a night time based on a detection value of the outside air temperature sensor Steps for storing outside air temperature for each time zone for storing each outside air temperature of the belt, and boiling for each time zone for calculating the amount of heat for night boiling and the amount of heat for daytime heating for each of a plurality of temporary boiling target temperature based on the target hot water storage heat amount Night heating efficiency based on the heating heat amount calculation step, the feed water temperature stored in the feed water temperature storage step for each of a plurality of provisional boiling target temperatures, and the night outside air temperature stored in the outside air temperature storage step for each time zone The night heating efficiency determination step for determining the value of the heating temperature based on the relationship between the heating efficiency based on the pre-stored feed water temperature, the outside air temperature, and the boiling target temperature, and the feed water temperature storage step for each of a plurality of temporary boiling target temperatures Daytime heating based on the water supply temperature stored in the water supply temperature storage step stored in step 1 and the daytime outdoor air temperature stored in the time-dependent outdoor air temperature storage step A daytime heating efficiency determination step for determining a rate value from a relationship of heating efficiency based on the previously stored feed water temperature, outside air temperature, and boiling target temperature, and the time for each of a plurality of temporary boiling target temperatures Night power usage calculation step for calculating the night power usage from the night heating heat amount calculated in the zone-specific heating heat amount calculation step and the night heating efficiency determined in the night heating efficiency setting step, and a plurality of temporary boiling A night power charge calculating step for calculating a night power charge from the night power consumption calculated in the night power consumption calculating step for each temperature and a night power charge unit price stored in advance, and a plurality of temporary boiling targets For each temperature, the daytime electric power is calculated from the daytime boiling heat amount calculated in the hourly heating amount calculation step and the daytime heating efficiency determined in the daytime heating efficiency setting step. A daytime power usage calculation step for calculating a power usage amount, a daytime power usage amount calculated in the daytime power usage amount calculation step for each of a plurality of provisional boiling target temperatures, and a daytime power rate unit price stored in advance. A daytime power rate calculation step for calculating a daytime power rate from the nighttime power rate calculated in the nighttime power rate calculation step for each of a plurality of temporary boiling target temperatures, and a daytime power rate calculated in the daytime power rate calculation step And a heating temperature determination step for determining a heating target temperature by comparing the total power charges for each temporary heating target temperature calculated in the total power charging calculation step. It was supposed to be.

  Further, according to claim 3, in the method of claim 2, in the heating heat amount calculation step according to time zone, a night heat value is calculated at a temporary boiling target temperature, and the night heat value is calculated from the target hot water storage amount. The step of increasing the amount of heat during the day by reducing the amount of heat to be raised and calculating the amount of heat was performed for each of a plurality of temporary boiling target temperatures.

  Further, according to claim 4, in the case of claim 3, when the daytime boiling heat amount is equal to or less than a certain minimum boiling heat amount, the daytime boiling heat amount is reduced to a certain minimum amount. It had a step of making the amount of heat increased.

  Moreover, in Claim 5, in the thing of the said Claim 4, when utilizing the hot water in the said hot water storage tank as a heat source of an external thermal load, it is the lowest temporary among several temporary boiling target temperature. The boiling target temperature was set to a higher temperature than when not used as a heat source.

  As described above, according to the present invention, the heating efficiency of the overall heat pump can be improved and energy can be saved in consideration of reducing the running cost, and the boiling target temperature Tbt is set lower. Therefore, heat dissipation loss can be reduced.

The schematic block diagram of one Embodiment of this invention. The flowchart explaining the action | operation of the same embodiment.

An embodiment of the present invention will be described with reference to the drawings.
1 is a hot water storage tank unit having a hot water storage tank 2 for storing hot water, 3 is a heat pump heating means for heating hot water in the hot water storage tank 2, 4 is a heat pump forward pipe 5 connected to the lower part of the hot water storage tank 2, and A heat pump circulation circuit comprising a heat pump return pipe 6 connected to the upper part of the hot water storage tank 2, 7 is connected to the lower part of the hot water storage tank 2, a water supply pipe for supplying water to the hot water storage tank 2, and 8 is connected to the upper part of the hot water storage tank 2. This is a hot water supply pipe that supplies hot water that is connected and stored.

  9 is a water supply bypass pipe branched from the water supply pipe 7, 10 is a mixing valve that mixes hot water from the hot water outlet pipe 8 and water from the water supply bypass pipe 9 to make hot water at a hot water supply set temperature Tht, and 11 is a mixing valve 10. A hot water supply pipe for supplying the mixed hot water to a hot water supply terminal (not shown), 12 is provided in the hot water supply pipe 11 to detect a hot water supply temperature Th after mixing, and 13 is provided in the hot water supply pipe 11 to supply a hot water flow rate F. A plurality of flow rate sensors 14 are provided across the upper and lower sides of the hot water storage tank 2, and a hot water storage temperature sensor 15 for detecting the temperature of the hot water in the hot water storage tank 2, 15 is provided in the water supply pipe 7 to keep the water supply pressure constant. A pressure reducing valve 16 for reducing the pressure is an overpressure relief valve for releasing the overpressure in the hot water storage tank 2. Here, the hot water storage temperature sensor 14 is referred to as 14a to 14e from top to bottom.

  17 is a bathtub, 18 is an indirect heat exchanger disposed in the upper part of the hot water storage tank 2 for heating the bath water, 19 is a flow circulation circuit that connects the bathtub 17 and the indirect heat exchanger 18 so that the bath water can circulate, 20 is a flow circulation pump provided in the middle of the flow circulation circuit 19 for circulating the bath water, 21 is a hot water supply pipe branched from the hot water supply pipe 11 and connected to the flow circulation circuit 19, and 22 is provided in the middle of the hot water supply pipe 21. A hot water on / off valve for starting and stopping the supply of hot water to the bathtub 17 is a remote controller having a plurality of operation switches (23a, 23b) for changing the hot water temperature setting and starting the hot water operation. is there.

  The heat pump type heating means 3 includes a compressor 24 for compressing refrigerant, a water heat exchanger 25 for exchanging heat between the high-temperature and high-pressure refrigerant and hot water in the hot water storage tank 2, and the refrigerant after passing through the water heat exchanger 25. A heat pump cycle 28 in which an expansion valve 26 as a pressure reducer for reducing the pressure and an air heat exchanger 27 as an evaporator for evaporating the low-temperature and low-pressure refrigerant from the expansion valve 26 are connected in an annular shape by a refrigerant pipe, and air heat exchange From a blower fan 29 for supplying outside air to the water heater 27, a heat pump circulation pump 30 provided in the middle of the water heat exchanger circuit 4 on the water side of the water heat exchanger 25 and circulating hot water in the hot water storage tank 2, and a compressor 24 The refrigerant temperature sensor 31 for detecting the discharged refrigerant temperature Tr, the outside air temperature sensor 32 for detecting the temperature of the air supplied to the air heat exchanger 27 (outside air temperature Ta), and the water heat exchanger 25 are supplied. The incoming water temperature sensor 33 for detecting the temperature (incoming water temperature Twh) of water, and the temperature sensor 34 boiling for detecting the temperature of the hot water heated by the water heat exchanger 25 is provided. The heat pump cycle 28 is filled with carbon dioxide refrigerant so as to be in a supercritical state on the high pressure side.

  35 is a heat pump side control means for controlling the heat pump type heating means 3, and the detection values of the refrigerant temperature sensor 31, the outside air temperature sensor 32, the incoming water temperature sensor 33, and the boiling temperature sensor 34 are inputted, the compressor 24, the expansion valve 26, the heating temperature Tb detected by the boiling temperature sensor 34 by heating the water taken out from the hot water storage tank 2 and controlling the operation of the blower fan 29 and the heat pump circulation pump 30 is set to a plurality of levels in advance. The heat pump heating means 3 is controlled so as to be any one of the temperatures selected and determined from the target temperature Tbt (for example, 6 levels in increments of 5 ° C. from 65 ° C. to 90 ° C.).

  36 is inputted with detection values of the hot water temperature sensor 12, the flow rate sensor 13, and the hot water storage temperature sensors 14 a to 14 e, and the mixing valve 10, the flow circulation pump 20, the hot water on / off valve 22, the flow circulation pump 15, and the hot water on / off valve 17. The hot water storage side control means is connected to the remote controller 23 and the heat-pump side control means 35 so as to be communicable with each other. The hot water storage side control means 36 has a program for controlling the operation of the hot water supply device and constants necessary for calculation in advance, and has calculation, comparison, storage function, and clock function. The relationship of the heating efficiency η (heating output / power consumption) based on the feed water temperature Tw, the outside air temperature Ta, and the boiling temperature Tb is stored in advance, and the power rate for each time zone of the power rate system for each time zone Unit prices Cd and Cn are stored. The relationship of the heating efficiency η based on the feed water temperature Tw, the outside air temperature Ta, and the boiling temperature Tb is stored as a formula or a data map that is obtained in advance by a test for operating the heat pump heating means 3. It is what.

Next, the operation of the present embodiment will be described based on the flowchart shown in FIG.
When there is hot water from the hot water supply terminal, water flows into the hot water storage tank 2 from the water supply pipe 7 and hot water in the hot water storage tank 2 flows out from the hot water discharge pipe 8. Then, the hot water storage side control means 36 controls the opening degree of the mixing valve 10 so that the hot water supply temperature Th detected by the hot water supply temperature sensor 12 becomes the hot water supply set temperature Tht set by the remote controller 23. Hot water and water from the water supply bypass pipe 9 are mixed to supply hot water.

  At this time, the hot water storage side control means 36 uses the hot water storage heat amount Qt in the hot water storage tank 2 for the amount of heat (used heat amount Qe) supplied to the hot water supply (and the hot water filling to the bathtub 17), the hot water supply set temperature Tht, the water supply temperature Tw, and the flow rate. It is calculated from the hot water supply flow rate F detected by the sensor 13, and this is integrated in units of one day (step S1). The hot water storage side control means 36 stores the temperature detected by the lowest hot water storage temperature sensor 14e (water supply temperature sensor) when the integrated value of the hot water supply flow rate F reaches a certain level or more as the water supply temperature Tw. (Step S2). The amount of heat supplied to the bathtub water (external heat load) of the bathtub 17 via the indirect heat exchanger 18 may be added to the use heat amount Qe.

  Next, the hot water storage side control means 36 determines whether or not there is a daytime boiling-up heat quantity Qd described later (step S3). Now, the explanation will be made assuming that there is no heat quantity Qd due to boiling in the daytime. If it is determined that there is no daytime boiling-up heat quantity Qd, the process proceeds to step S9, and it is determined whether or not the start time of the night time zone (PM 11:00 to AM 7:00) at which the power unit price is low is reached. When PM11: 00 is reached, a target hot water storage heat amount Qtt that is predicted to be used on the next day is set based on the daily heat usage amount Qe for a plurality of days stored in the hot water storage side control means 36 (step S10). ).

  Here, an example of a method of calculating the target hot water storage heat amount Qtt is shown. The average value Qeav of daily use heat amount Qe for a plurality of days and the deviation Qρ are added together, and the heat dissipation loss during boiling in the heat pump heating means 3 It is calculated by dividing by a predetermined efficiency (for example, 0.8) in consideration of heat loss from the hot water storage tank 2 and the like.

Then, the hot water storage side control means 36, based on the target hot water storage heat quantity Qtt, boil in the nighttime heat quantity Qn and the daytime time period when the heat pump type heating means 3 boils up in the night time zone for each of a plurality of temporary boiling target temperatures Tbt. The daytime boiling-up heat quantity Qd is calculated by the following formulas 1 and 2 (step S11).
Heating amount Qn = (boiling target temperature Tbt−feed water temperature Tw) × hot water storage capacity L (Equation 1)
Daytime boiling heat amount Qd = target hot water storage heat amount Qtt−night boiling heat amount Qn (Equation 2)
Here, the hot water storage capacity L is a value stored in advance by the hot water storage side control means 36 based on the total capacity of the hot water storage tank 2. Further, if the amount of heat at night boiling Qn> the amount of heat stored in hot water Qtt, the amount of heat Bd increased during the day is set to zero.

  Since the heat pump heating means 3 is not suitable for boiling in a very short time, the amount of heat that can be boiled when the heat pump heating means 3 is operated at the rated heating capacity P for the minimum operating time (here 30 minutes) ( If the daytime boiling heat quantity Qd is smaller than the minimum boiling heat quantity Qdmin), the daytime boiling heat quantity Qd is set to the minimum boiling heat quantity Qdmin.

  Next, the hot water storage side control means 36 has a heating efficiency η (heating capacity) of the heat pump type heating means 3 based on the feed water temperature Tw, the outside air temperature Ta and the boiling target temperature Tbt stored in advance in the hot water storage side control means 36. / Electric power consumption), the night heating efficiency ηn and the daytime heating efficiency ηd based on the water supply temperature Tw and the nighttime outside air temperature Tan or daytime outside air temperature Tad described later at each of the plurality of temporary boiling target temperatures Tbt. Determine (step S12).

Further, the hot water storage side control means 36 calculates the night boiling heat amount Qn and the daytime boiling heat amount Qd for each of the plurality of temporary boiling target temperatures Tbt calculated in Step S11, and the plurality of temporary boiling determined in Step S12. From the nighttime heating efficiency ηn and the daytime heating efficiency ηd for each target heating temperature Tbt, the nighttime power consumption Wn and the daytime power consumption Wd for each of a plurality of temporary boiling target temperatures Tbt are expressed by the following equations 3 and 4. Calculate (step S13).
Night energy consumption Wn = Night heating energy Qn / Night heating efficiency ηn (Equation 3)
Daytime power consumption Wd = Daytime heating amount Qd / Daytime heating efficiency ηd (Equation 4)

  The hot water storage side control means 36 stores the nighttime power rate unit price Cn, the daytime power rate unit price Cd, the nighttime used power amount Wn for each of the plurality of temporary boiling target temperatures Tbt calculated in step S13, and The nighttime power charge Yn and the daytime power charge Yd for each of a plurality of temporary boiling target temperatures Tbt are calculated from the daytime power consumption Wd (step S14).

  Next, the hot water storage-side control means 36 adds the nighttime power rate Yn and the daytime power rate Yd for each of the plurality of temporary boiling target temperatures Tbt calculated in step S14, and adds each of the plurality of temporary boiling target temperatures Tbt. A total power charge Ya is calculated (step S15).

  Then, the hot water storage side control means 36 compares the total power charges Ya for each of the plurality of temporary boiling target temperatures Tbt calculated in step S15, and determines the cheapest temperature as the boiling target temperature Tbt (step S16). ).

  Here, the boiling target temperature Tbt with the lowest total power charge Ya is selected and determined by comparing all levels of the boiling target temperature Tbt, but the boiling target temperature Tbt of the previous day and the levels above and below it are selected. Of the boiling target temperature Tbt, the temperature at which the total power rate Ya is the cheapest may be selected and determined as the boiling target temperature Tbt. By doing so, it is possible to prevent excessive fluctuation of the boiling target temperature Tbt due to daily fluctuations in the target hot water storage heat amount Qtt, and to calculate the boiling target temperature Tbt and the upper and lower boiling target temperature Tbt on the previous day. Only 3 levels need to be done, and the calculation load can be reduced.

Next, the hot water storage side control means 36 sets the night heating heat amount Qn at the boiling target temperature Tbt determined in the step S16 to the rated heating capacity of the heat pump heating means 3 immediately before the start of the daytime time zone (for example, AM 6:30). The boiling start time (peak shift time) is calculated based on the following formula 5 so that the boiling at P is completed (step S17).
Peak shift time = AM6: 30− (Night boiling heat quantity Qn / rated heating capacity P) (Formula 5)

  When the current time becomes the peak shift time, the hot water storage side control means 36 outputs an instruction to start boiling at the boiling target temperature Tbt determined in step S16 to the heat pump side control means 35. The heat pump side control means 35 operates the compressor 24, the expansion valve 26, the blower fan 29, and the heat pump circulation pump 30 so that the boiling temperature Tb detected by the boiling temperature sensor 34 becomes the designated boiling target temperature Tbt. Is controlled to start boiling operation (step S18).

  During the heating operation, the heat-pump side control means 35 outputs the outside air temperature Ta detected by the outside air temperature sensor 32 after a predetermined time has elapsed from the start of the operation of the blower fan 29 to the hot water storage side control means 36. The side control means 36 averages the values of the nighttime outside air temperature Ta for several days (for example, three days) and stores them as the nighttime outside air temperature Tan (step S20).

  Next, when the amount of heat heated up becomes the amount of heat heated up at night Qn (step S21) or when the end time of the night time zone (here AM7: 00) is reached (step S22), the heating operation is stopped (step S21). S23).

  Then, the process returns to the first step again to monitor the daily usage heat quantity Qe (step S1) and the feed water temperature Tw (step S2), and the step S11 at the boiling target temperature Tbt determined in the step S16. It is determined whether or not there is an amount of heat Qd increased in the daytime calculated in (Step S3).

  When the daytime boiling heat quantity Qd is a value equal to or greater than 0, it is determined whether a predetermined time (PM 5:00 in this case) at which the power rate unit price is relatively low in the daytime period has been reached (step S4).

  When the predetermined time is reached, the hot water storage side control means 36 checks the current hot water storage heat amount Qt in the hot water storage tank 2 and if it is in a state where it can be heated up during the day and the heat amount Qd can be increased, the boiling determined in step S16 is performed. An instruction to start boiling at the target temperature Tbt is output to the heat pump side control means 36. The heat pump side control means 35 operates the compressor 24, the expansion valve 26, the blower fan 29, and the heat pump circulation pump 30 so that the boiling temperature Tb detected by the boiling temperature sensor 34 becomes the designated boiling target temperature Tbt. Is controlled to start boiling operation (step S5).

  During this heating operation, the heat-pump side control means 35 outputs the outside air temperature Ta detected by the outside air temperature sensor 32 after a certain time has elapsed from the start of the operation of the blower fan 29 to the hot water storage side control means 36. The side control means 36 averages the values of the daytime outside air temperature Ta for several days (for example, three days) and stores them as the daytime outside air temperature Tad (step S6). Here, on the day when there is no daytime boiling-up heat quantity Qd and the heating-up operation is not performed, the heat pump side control means 35 operates the blower fan 29 for a certain period of time when the predetermined time comes, and the outdoor temperature Ta at that time is changed to the daytime outside air. You may make it output to the hot water storage side control means 36 as temperature Tad.

  Next, when the amount of heat increased by boiling reaches the amount of heat heated Qd at night (step S7), the heating operation is stopped (step S23).

  And it progresses to step S9 and it is judged whether the start time of the night time zone (here PM11: 00 to AM7: 00) where the electricity bill unit price is cheap was reached. When PM11: 00 is reached, the operation after step S10 is repeated again.

  In this way, the electric power unit price Ya is calculated for each boiling target temperature Tbt to determine the boiling target temperature Tbt, so that the overall heating efficiency of the heat pump can be improved with consideration given to reducing the running cost. In addition to being able to save energy, the heating target temperature Tbt is set lower, so that heat dissipation loss can be reduced.

  In addition, when performing the operation | movement which supplies the hot water storage amount Qt in the hot water storage tank 2 to the bathtub water (external heat load) in the bathtub 17 more than a fixed amount, when not using the lowest temporary boiling target temperature Tbt as a heat source By setting the temperature to a higher temperature (for example, 75 ° C.), it is possible to prevent the heating efficiency of the external heat load from being lowered more than necessary. The external heat load is not limited to bathtub water, and may be circulating water for heating. Moreover, it is good also as a form which circulates and supplies the hot water in the hot water storage tank 2 to an external heat exchanger as a heating form of an external heat load.

  In addition, this invention is not limited to this one Embodiment, It does not prevent changing in the range which does not change a summary. For example, the daytime reheating operation is performed after PM 5:00, but when used under a power rate system in which the daytime power rate unit price is constant throughout the daytime time zone, the daytime heating rate Qd is simply increased. It is good also as a structure which starts a boiling increase operation when it will be in the state which can be heated again. Further, the unit price of electric power charges for each time zone stored in advance by the hot water storage side control means 36 may be configured to be changeable by the user from the remote controller 23, and at this time, the configuration in which the fuel adjustment cost of the power company can be input And even better.

Next, a calculation example of the method for determining the boiling target temperature Tbt of the present invention will be described.
Table 1 below shows the preconditions.

  Table 2 below shows the results of calculation from step S11 to step S15 for each boiling target temperature Tbt under the preconditions in Table 1. Here, the nighttime heating efficiency ηn and the daytime heating efficiency ηd are the heating efficiency η of the heat pump type heating means 3 based on the feed water temperature Tw, the outside air temperature Ta and the boiling target temperature Tbt stored in advance in the hot water storage side control means 36. These values are referred to according to the preconditions in Table 1 and each boiling target temperature Tbt from the relationship of (heating capacity / power consumption).

  From the results shown in Table 2, when the boiling target temperature Tbt is 75 ° C., the total electricity rate Ya is the cheapest. Therefore, when the boiling target temperature Tbt is determined to be 75 ° C., the running cost is considered to be reduced. As a result, the heating efficiency of the overall heat pump can be improved and energy can be saved, and the heat loss can be reduced because the boiling target temperature Tbt is set lower than when the total amount of heat stored in the target hot water Qtt is boiled at night. .

2 Hot water storage tank 3 Heat pump type heating means 14a to e Hot water storage temperature sensor 24 Compressor 25 Water heat exchanger 26 Expansion valve 27 Air heat exchanger 32 Outside air temperature sensor 35 Heaton side control means 36 Hot water side control means Tbt Boiling target temperature Qe Use heat amount Qtt Target hot water storage amount Qd Daytime boiling heat amount Qn Night boiling heat amount Qdmin Minimum boiling heat amount Tw Water supply temperature

Tan Night outside air temperature Tad Daytime outside air temperature ηd Daytime heating efficiency ηn Nighttime heating efficiency Wd Daytime electricity consumption Wn Nighttime electricity consumption Cd Daytime electricity rate unit price Cn Nighttime electricity rate unit price Yd Daytime electricity rate unit price Yn Nighttime electricity rate Ya Total power rate

Claims (5)

A hot water storage tank for storing hot water, a compressor, a refrigerant water heat exchanger, a decompressor, and an air heat exchanger, heat pump heating means for heating the water in the hot water storage tank, and outside air for detecting the outside air temperature A method for determining a boiling target temperature of a heat pump type water heater provided with a temperature sensor,
A step of determining the heating efficiency of the heat pump according to each of the daytime outside air temperature and the nighttime outside air temperature for each of a plurality of provisional boiling target temperatures from a prestored relationship, and a prestored daytime power rate Calculating a power rate required to boil the target hot water storage amount for each of a plurality of temporary boiling target temperatures using a unit price and a nightly power rate unit price, and calculating for each of the plurality of temporary boiling target temperatures. And a step of determining a boiling target temperature based on the electric power price. A method for determining a boiling target temperature of a heat pump type hot water heater. A hot water storage tank for storing hot water, a compressor, a refrigerant water heat exchanger, a decompressor, and an air heat exchanger, heat pump heating means for heating the water in the hot water storage tank, and outside air for detecting the outside air temperature A heating water temperature sensor for detecting a temperature of water supplied to the hot water storage tank, and a heating target temperature determination method for a heat pump type hot water heater comprising:
A heat consumption calculation step for calculating the amount of heat used from the hot water storage tank including at least hot water supply, and a target heat storage heat amount required for the next day is set based on the heat consumption for the past several days calculated in the heat consumption calculation step. A target hot water storage heat amount setting step, a water supply temperature storage step for storing a water supply temperature based on a detection value of the water supply temperature sensor, and an outside air temperature in a daytime time zone and a night time zone based on a detection value of the outside air temperature sensor An outdoor air temperature storage step for each time zone, a night-time boiling heat amount for each of a plurality of provisional boiling target temperatures and a day-time heating heat amount calculation step based on the target hot water storage heat amount, and a heating heat amount calculation step for each time zone, Water supply temperature stored in the water supply temperature storage step for each temporary boiling target temperature and nighttime stored in the outdoor air temperature storage step according to the time period Night heating efficiency determination step for determining a night heating efficiency value based on the air temperature based on the relationship between the heating efficiency based on the pre-stored feed water temperature, the outside air temperature, and the boiling target temperature, and a plurality of temporary boiling The value of the daytime heating efficiency based on the water supply temperature stored in the water supply temperature storage step stored in the water supply temperature storage step for each target temperature and the daytime outdoor air temperature stored in the outdoor air temperature storage step for each time zone is described above. Daytime heating efficiency determination step determined from the relationship of heating efficiency based on the pre-stored feed water temperature, outside air temperature and boiling target temperature, and the heating heat amount per time zone for each of a plurality of temporary boiling target temperatures Night power consumption calculation that calculates the night power consumption from the night heating heat amount calculated in the calculation step and the night heating efficiency determined in the night heating efficiency setting step. Night power charge calculation step for calculating the night power charge from the step and the night power consumption calculated in the night power consumption calculation step for each of a plurality of temporary boiling temperatures and the night power charge unit price stored in advance And daytime power consumption from the daytime heating heat amount calculated in the hourly heating heat amount calculation step and the daytime heating efficiency setting step in the daytime heating efficiency setting step for each of a plurality of temporary boiling target temperatures. Calculate the daytime power usage from the daytime power usage calculation step and the daytime power usage calculated in the daytime power usage calculation step for each of a plurality of temporary boiling target temperatures and the daytime power unit price stored in advance. A daytime power rate calculation step, a nighttime power rate calculated in the nighttime power rate calculation step for each of a plurality of temporary boiling target temperatures, and the daytime power rate The heating target temperature is determined by comparing the total power rate calculation step for adding the daytime power rate calculated in the calculation step with the total power rate for each temporary heating target temperature calculated in the total power rate calculation step. A boiling temperature determination method for a heat pump type water heater, comprising: a boiling temperature determination step.   In the heating heat amount calculation step by time zone, there are a plurality of steps of calculating a night heating heat amount at a temporary boiling target temperature, and subtracting the night boiling heat amount from the target hot water storage amount to calculate a daytime boiling heat amount. The method according to claim 2, wherein the heating target temperature is determined for each temporary boiling target temperature.   A step of setting the daytime boiling heat amount to a certain minimum boiling heat amount when the daytime boiling heat amount is equal to or less than a certain minimum boiling heat amount. Item 4. A method for determining a boiling target temperature of a heat pump water heater according to item 3.   When the hot water stored in the hot water storage tank is used as a heat source for an external heat load, among the plurality of temporary boiling target temperatures, the lowest temporary boiling target temperature is higher than when not used as a heat source. The heating target temperature determination method for a heat pump type hot water heater according to claim 4, wherein the heating target temperature is determined.

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