JP2004317020A - Heat pump water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of losing reliability of a compressor since the compressor frequently repeats starting-stopping when frequently repeating hot water supply and stopping of the hot water supply in a short time at a little flow rate such as face-washing and hand-washing. <P>SOLUTION: When starting the hot water supply in a hot water supply terminal 10 from a hot water supply circuit 11, hot water is supplied by heating city water 32 by using accumulation heat of a heat accumulator 14. When heat accumulation quantity of the heat accumulator 14 detected by a heat accumulation quantity detecting means 15 becomes a prescribed value or less, by using a heat pump water heater having a refrigerant circuit operation means 16 for operating a refrigerant circuit 6, frequenct starting-stopping of the compressor can be restrained; an abnormal pressure increase in the refrigerant circuit can be restrained; and the reliability of the compressor can be secured. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a heat pump water heater.
[0002]
[Prior art]
As shown in FIG. 5, a conventional heat pump water heater has a refrigerant circuit 6 in which a compressor 2, a radiator 3, a decompression means 4, and a heat absorber 5 are connected in a refrigerant flow path 1 formed in a closed circuit, and a radiator. A heat exchanger 8 having a water flow path 7 for exchanging heat with the heat exchanger 3, a water supply pipe 9 for supplying city water 32 to the water flow path 7, and a connection between the water flow path 7 and a hot water supply terminal 10 such as a shower or a faucet. A hot water supply circuit 11, a temperature sensor 12 provided in the hot water supply circuit 11 for detecting a hot water supply temperature, and an inverter 13 for controlling the number of revolutions of the compressor 2. The output frequency of the inverter 13 is converted according to the difference. In the conventional heat pump water heater, the rotation speed of the compressor 2 is increased when the hot water temperature is lower than the set temperature, and the rotation speed is higher when the hot water temperature is higher. To control to lower the number Which was (see Patent Document 1).
[0003]
That is, when the hot water supply is started and the hot water supply temperature is lower than the set temperature, the compressor 2 is operated, the hot water supply is stopped, and when the hot water supply temperature becomes higher than the set temperature, the operating frequency of the compressor 2 is reduced and the final operation is continued. Stop.
[0004]
[Patent Document 1]
JP-A-2-223767 (FIG. 5)
[0005]
[Problems to be solved by the invention]
However, in the configuration of the above-described conventional water heater, the hot water supply load at the time of hot water supply is not constant, and particularly, since the user varies the flow rate variously depending on the purpose of hot water supply, the hot water supply load greatly changes. For example, in the case of hot water for home use, a large flow rate of 10 to 20 L / min is required when hot water is supplied to a shower or bath, but 3 to 5 L / min when washing dishes in a kitchen or supplying hot water to a wash surface. Low flow rate. The hot water supply load also changes greatly due to seasonal changes in the water supply temperature.
[0006]
In particular, when hot water supply and frequent hot water supply stoppage are repeated in a short time at a small flow rate such as face washing and hand washing, the compressor 2 is always started when the hot water supply temperature is lower than the set temperature, and when the hot water supply is stopped, the compressor 2 is started. In order to stop the compressor 2, the compressor 2 repeatedly starts and stops.
[0007]
Further, even if the hot water supply is stopped, the compressor 2 is not stopped immediately, but the operating frequency of the compressor 2 is reduced to a specific frequency, and finally the compressor 2 is stopped. Since the hot water supply is stopped, the radiator 3 cannot release heat and the excess heat increases the pressure in the refrigerant circuit 6 until the compressor 2 lowers the operating frequency until the compressor 2 stops operating. There is a problem that the reliability of the compressor 2 cannot be ensured because the allowable operating range is exceeded.
[0008]
The present invention has been made to solve the above-mentioned conventional problems, and has as its object to provide a heat pump water heater that can ensure the reliability of the compressor 2.
[0009]
[Means for Solving the Problems]
In order to achieve this object, the heat pump water heater according to the present invention is configured such that when hot water is supplied to a hot water supply terminal from a hot water supply circuit, city water is heated by using heat storage of a heat storage body to perform hot water supply, and a heat storage amount detection unit. And a refrigerant circuit operating means for operating the refrigerant circuit when the heat storage amount of the heat storage body detected by the method becomes equal to or less than a predetermined value.
[0010]
Thus, for frequent hot water supply with a small flow rate, the city water is heated and hot water is supplied using the heat storage of the heat storage body without operating the compressor, so that frequent start / stop of the compressor can be suppressed. Further, since the compressor is not operated, the pressure increase in the refrigerant circuit can be suppressed.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
The invention according to claim 1 of the present invention is directed to a heat exchanger including a refrigerant circuit including a compressor, a radiator, a decompression unit, and a heat sink, a heat exchanger including a water flow path for performing heat exchange with the radiator, and A water supply pipe for supplying city water to the road, a hot water supply circuit connected so as to pass water from the water flow path to the hot water supply terminal, a heat storage element for storing heat of the refrigerant circuit, and a heat storage amount of the heat storage element is detected. When the hot water supply to the hot water supply terminal is started from the hot water supply circuit, the hot water is heated by using the heat storage of the heat storage body to perform hot water supply, and the heat storage amount detected by the heat storage amount detection means. When the heat storage amount of the heat storage body becomes equal to or less than a predetermined value, a refrigerant circuit operating means for operating the refrigerant circuit is provided.
[0012]
According to the present invention, for frequent hot water supply with a small flow rate, the city water is heated by using the heat storage of the heat storage body without operating the compressor, and hot water is supplied. it can. Further, since the compressor is not operated, the pressure increase in the refrigerant circuit can be suppressed, and the reliability of the compressor can be ensured.
[0013]
According to a second aspect of the present invention, in the configuration of the heat pump hot water supply apparatus according to the first aspect, when the refrigerant circuit is operated and hot water supply from the hot water supply terminal is stopped, the heat storage element is operated by the heat storage operation means. And a stop heat storage means for storing heat of the refrigerant circuit.
[0014]
According to the present invention, when the hot water supply is stopped during the operation of the compressor, the surplus heat until the compressor stops by the stop heat storage means can be used for storing heat in the heat storage body. That is, since the excess heat in the refrigerant circuit can be radiated to the heat storage body, the pressure increase in the refrigerant circuit can be suppressed and controlled, so that the reliability of the compressor can be ensured.
[0015]
According to a third aspect of the present invention, in the configuration of the heat pump hot water supply apparatus according to the second aspect, the hot water supply terminal further includes frost detection means for detecting frost formation of the heat absorber, and the refrigerant circuit is operated to operate the refrigerant circuit. And a stop-time defrosting means for performing a defrosting operation of the heat absorber when the frost detection is detected by the frost detection means.
[0016]
According to the present invention, when the hot water supply is stopped during the operation of the compressor, the surplus heat until the compressor stops by the stop-time defrosting means can be used for defrosting. That is, since excess heat in the refrigerant circuit is radiated to frost adhering to the heat absorber to melt the frost, a pressure increase in the refrigerant circuit can be suppressed and controlled, so that the reliability of the compressor can be secured.
[0017]
According to a fourth aspect of the present invention, in the configuration of the heat pump hot water supply apparatus according to the third aspect, a water temperature detecting means for detecting a temperature of the city water, and the refrigerant circuit based on the detected temperature of the city water. And a water temperature heat storage amount calculating means for calculating the heat storage amount of the heat storage body to be stored by operating the heat storage device.
[0018]
According to the present invention, the amount of heat stored to operate the refrigerant circuit changes according to the temperature change of the city water. That is, when the city water temperature increases, the water temperature heat storage calculating means calculates a smaller amount of heat stored in the heat storage to start the operation of the refrigerant circuit, so that the time of hot water supply using the heat of the heat storage is longer. In other words, the number of operations of the refrigerant circuit is reduced, so that the number of times of starting and stopping of the compressor is also reduced, and frequent starting and stopping of the compressor can be further suppressed, so that the reliability of the compressor can be ensured.
[0019]
According to a fifth aspect of the present invention, in the configuration of the heat pump hot water supply apparatus according to the third aspect, an outside air temperature detecting means for detecting an outside air temperature, and operating the refrigerant circuit based on the detected outside air temperature. An external temperature heat storage amount calculating means for calculating a heat storage amount of the heat storage body to be stored.
[0020]
In other words, when the outside air temperature increases, the outside air temperature heat storage calculating means calculates the amount of heat stored in the heat storage that starts the operation of the refrigerant circuit, so that the time of hot water supply performed using the heat of the heat storage is long. In other words, the number of operations of the refrigerant circuit is reduced, so that the number of times of starting and stopping of the compressor is also reduced, and frequent starting and stopping of the compressor can be further suppressed, so that the reliability of the compressor can be ensured.
[0021]
According to a sixth aspect of the present invention, in the first to fifth aspects, the refrigerant circuit uses a refrigerant whose pressure is equal to or higher than a critical pressure.
[0022]
According to the present invention, the refrigerant flowing through the radiator of the heat exchanger is pressurized to a critical pressure or higher by the compressor. Does not condense. Therefore, it becomes easy to form a temperature difference between the refrigerant and the water in the entire region of the heat exchanger, so that high-temperature hot water can be obtained and the heat exchange efficiency can be increased.
[0023]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the conventional example and each embodiment, the same reference numerals are given to portions having the same configuration and the same operation, and detailed description will be omitted.
[0024]
(Example 1)
FIG. 1 is a schematic diagram showing a configuration of an instantaneous heating type heat pump water heater according to a first embodiment of the present invention. In FIG. 1, reference numeral 14 denotes a heat storage unit that stores heat generated by the refrigerant circuit 6. The heat storage material may be a solid substance such as magnesia clinker. In that case, water is passed through the heat storage unit 14. Then, heat exchange is performed to add heat of the heat storage material to the water. Further, water itself may be used as a heat storage material. In the present embodiment, description will be made on the assumption that the heat storage material is water.
[0025]
Numeral 15 is a heat storage amount detecting means for detecting the heat storage amount of the heat storage unit 14, which detects the temperature of the surface of the heat storage unit 14 by a temperature detecting device such as a thermistor, and calculates the heat storage unit 14 from the temperature and the capacity calculated from the thermistor mounting position. Detects the amount of heat stored inside. Reference numeral 16 denotes a refrigerant circuit operating unit that operates the refrigerant circuit 6. Reference numeral 30 denotes a pump for sending water to the water supply pipe 9, reference numeral 31 denotes a decompressor for adjusting the pressure of city water 32, and reference numeral 33 denotes a three-way valve for switching the water flow path 7, the hot water supply circuit 11, and the water path of the heat storage unit 14. Reference numeral 34 denotes a mixing valve which mixes with the city water 32 and adjusts the temperature to a set temperature when the temperature of the hot water mixed by the three-way valve 33 is higher than the set temperature. These components form a tapping circuit 35.
[0026]
The refrigerant circuit 6 uses, for example, a supercritical heat pump cycle in which carbon dioxide gas (CO2) is used as a refrigerant and the refrigerant pressure on the high pressure side is equal to or higher than the critical pressure of the refrigerant.
[0027]
The compressor 2 is driven by an electric motor (not shown) incorporated therein, and compresses the sucked refrigerant to a critical pressure and discharges the compressed refrigerant. The pressure reducing means 4 is a throttle valve driven by a stepping motor (not shown), and controls the refrigerant flow path resistance.
[0028]
A water supply pipe 9 for directly supplying city water 32 to the water flow path 7 and a hot water supply circuit 11 for passing hot water from the water flow path 7 to a hot water supply terminal 10 such as a shower or a faucet are connected.
[0029]
The radiator 3 is configured such that the flow direction of the coolant flow path and the flow direction of the water flow path 7 are opposed to each other, and are closely adhered between the flow paths so that heat transfer is facilitated. With this configuration, the heat transfer between the coolant channel and the water channel 7 is made uniform, and the heat exchange efficiency is improved. In addition, hot water can be supplied. Reference numeral 36 denotes a blower provided in the heat absorber 5, which blows air so as to supply atmospheric heat to the heat absorber 5.
[0030]
Reference numeral 24 denotes a hot water supply temperature sensor for detecting the temperature of hot water passing through the water circuit 7 heated by the refrigerant circuit 6. Reference numeral 25 denotes a temperature detection sensor such as a thermistor for detecting the end of heat storage in the heat storage unit 14, which is set on the surface of the heat storage unit 14 by determining an installation position in consideration of a time from a frequency drop of the compressor 2 to a stop. It is a heat stop sensor.
[0031]
In the embodiment shown in FIG. 1, when the use of the hot water supply terminal 10 is detected, the heat storage amount detection unit 15 detects the heat storage amount of the heat storage body 14. If the detected heat storage amount is larger than the predetermined amount, the hot water in the heat storage unit 14 is sent to the mixing valve 34 through the three-way valve 33 and mixed with the city water 32 reduced to an appropriate pressure by the decompressor 31 to set the temperature. Hot water is supplied from the hot water supply terminal 10. At this time, the refrigerant circuit 6 is not operated.
[0032]
Further, when the heat storage amount detecting means 15 detects that the heat storage amount is smaller than the predetermined heat storage amount during the hot water supply from the hot water supply terminal 10, the refrigerant circuit operating means 16 starts the operation of the refrigerant circuit 6.
[0033]
In the refrigerant circuit 6 and the tapping circuit 35, the pressure reducing means 4 is in a throttle state, and the pump 9 is stopped. In this state, the blower 36 rotates, and the compressor 2 operates. In the refrigerant circuit 6, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 3.
[0034]
In the radiator 3, the city water 32 decompressed by the decompressor 31 is supplied to the water circuit 7 through the water supply pipe 9, and the city water 32 is heated by exchanging heat with a high-temperature gas refrigerant to become hot water. It becomes a low temperature gas state. After that, the refrigerant flows into the pressure reducing valve 4. When the refrigerant passes through the decompression means 4, the refrigerant enters a two-phase state of a low-temperature and low-pressure liquid and gas and flows into the heat absorber 5.
[0035]
In the heat absorber 5, the refrigerant absorbs heat from the outside air sucked by the blower 36. The refrigerant that has absorbed the outside air heat is vaporized and gasified and flows into the compressor 2. This cycle is repeated.
[0036]
At this time, the mixing valve 34 stops the supply from the city water 32, and the three-way valve 33 adjusts the temperature of the hot water of the water circuit 7 heated by the refrigerant circuit 6 and the hot water supplied from the heat storage unit 14 to an appropriate temperature. The water is mixed and supplied from the hot water supply terminal 10.
[0037]
In the refrigerant circuit 6, if the difference between the set temperature and the hot water temperature detected by the hot water temperature sensor 24 is large, the compressor speed is increased to increase the output of the refrigerant circuit 6, and the three-way valve 33 is connected to the hot water circuit from the heat storage unit 14. Is closed, and an attempt is made to supply hot water from the hot water supply terminal 10 using the refrigerant circuit 6 alone.
[0038]
When the hot water supply load from the hot water supply terminal 10 is larger than the output range of the refrigerant circuit 6 alone, the hot water is mixed with the hot water of the heat storage unit 14 through the three-way valve 33 and, if necessary, with the city water 32 through the mixing valve 34. Hot water from the hot water supply terminal 10. In this way, hot water is supplied using the refrigerant circuit 6 and the tapping circuit 35.
[0039]
On the other hand, a case where it is detected that the use of hot water from hot water supply terminal 10 has been completed is described below. First, when it is detected that the use of hot water from hot water supply terminal 10 has been completed, heat storage amount detecting means 15 detects the heat storage amount of heat storage body 14. When the detected amount of heat storage is larger than the predetermined amount, the refrigerant circuit 6 and the tapping circuit 35 are not operated and are maintained as they are when the use of the hot water supply terminal 10 is completed.
On the other hand, when the detected amount of heat storage is smaller than the predetermined amount, the heat storage unit 14 stores heat in the heat storage unit 14 by the stop-time heat storage unit 17. The three-way valve 33 is set so that the water circuit 7 communicates with the heat storage unit 14, the pump 30 is operated, and the refrigerant circuit 6 is operated by the above-described operation.
[0040]
Low-temperature water in the heat storage unit 14 is sucked by the pump 30 and sent to the water circuit 7 through the water supply pipe 9. In the water circuit 7, the hot water heated by the refrigerant circuit 6 is sent to the heat storage unit 14 through the three-way valve 33. Hot water is stored in the heat storage unit 14 by repeating this circulation. When the temperature detected by the heat storage stop sensor 25 exceeds a predetermined temperature, the compressor 2 gradually lowers the frequency and stops.
[0041]
As described above, for frequent hot water supply with a small flow rate, the city water is heated by using the heat storage of the heat storage body 14 without operating the compressor 2 to supply hot water. Can be suppressed. Further, since the compressor 2 is not operated, an increase in pressure in the refrigerant circuit 6 can be suppressed.
[0042]
Further, when the hot water supply is stopped during the operation of the compressor 2, the surplus heat until the compressor 2 stops by the stop heat storage means 17 can be used for the heat storage in the heat storage body 14. That is, since excess heat in the refrigerant circuit 6 can be radiated to the heat storage body 14, a pressure increase in the refrigerant circuit 6 can be suppressed and controlled, so that the reliability of the compressor 2 can be ensured.
[0043]
The predetermined value of the “predetermined amount” of the heat storage amount is variable, and can be set to 10% to 50% of the maximum heat storage amount that can be stored in the heat storage body 14. That is, when a predetermined value is set to 30% of the maximum heat storage amount, when the heat storage amount is 30% or more, the refrigerant circuit 6 and the tapping circuit 35 do not operate and maintain the state. When it becomes smaller than 30%, the operation is performed such that the heat storage unit 17 stores heat in the heat storage unit 14 by the stop-time heat storage unit 17.
[0044]
Although the supercritical heat pump cycle in which the pressure is equal to or higher than the critical pressure is used in the first embodiment, a heat pump cycle in which the pressure is equal to or lower than a general critical pressure may be used. In this case, the refrigerant may be a fluorocarbon gas, ammonia, a hydrocarbon-based refrigerant (HC refrigerant), or the like.
[0045]
(Example 2)
2 is a configuration diagram of a heat pump water heater in Embodiment 2 of the present invention. The same components as those of the water heater of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
[0046]
Reference numeral 18 denotes a frost detection sensor for detecting frost formation on the heat absorber 5. Reference numeral 19 denotes a stoppage of hot water from the hot water supply terminal 10 when the refrigerant circuit 6 is operated, and the frost detection means 18 controls the heat absorber 5. This is a stop-time defrosting unit that performs a defrosting operation of the heat absorber 5 when frost formation is detected.
[0047]
The operation and operation of the above configuration will be described. Here, a case will be described in which the refrigerant circuit 6, which is a feature of the present invention, is operated and it is detected that the use of hot water from the hot water terminal 10 has been completed.
[0048]
When it is detected that the use of hot water from the hot water supply terminal 10 has been completed, first, the frost detection means 18 detects whether or not the heat absorber 5 has frost.
[0049]
Here, the detection of frost is performed by measuring the temperature of the heat absorber 5 and detecting the frost formation when the temperature becomes equal to or lower than the predetermined temperature for a predetermined time.
[0050]
When the frost formation is detected, the stop time defrosting means 19 stops the refrigerant circuit 6 after completing the defrosting of the heat absorber 5.
[0051]
That is, by making the pressure reducing means 4 larger than the set opening degree at the time of hot water supply while operating the compressor 2 and the blowing device 36, the temperature of the refrigerant passing through the pressure reducing means 4 increases, and the frosted frost is formed. Is passed through the heat absorber 5, the frost absorbs heat from the refrigerant and is melted and defrosted. After performing the defrosting operation for a predetermined time, the defrosting is ended.
[0052]
After the completion of the defrosting, the heat storage amount detecting means 15 detects the heat storage amount of the heat storage body 14, and when the detected heat storage amount is smaller than the predetermined amount, the heat storage in the heat storage body 14 is performed by the stop-time heat storage means 17. .
[0053]
If the detected amount of stored heat is larger than the predetermined amount, the compressor 2 gradually reduces the frequency while defrosting and stops.
[0054]
As described above, when the hot water supply is stopped while the compressor 2 is operating, the surplus heat until the compressor 2 is stopped by the stop time defrosting means 19 can be used for defrosting. That is, the excess heat in the refrigerant circuit 6 is radiated to the frost adhering to the heat absorber 5 to melt the frost, so that the pressure increase in the refrigerant circuit 6 can be suppressed and controlled, so that the reliability of the compressor 2 can be secured. .
[0055]
(Example 3)
Third Embodiment FIG. 3 is a configuration diagram of a heat pump hot water supply apparatus according to a third embodiment of the present invention. The same components as those of the hot water supply device according to the second embodiment are denoted by the same reference numerals, and description thereof will be omitted.
[0056]
Reference numeral 20 denotes a water temperature detecting means for detecting the temperature of the city water 32. Reference numeral 21 denotes a water temperature for calculating the heat storage amount of the heat storage unit 14 according to the water temperature detected by the water temperature detection means 20 when the city water 32 temperature is high, the heat storage amount is small, and when the city water 32 temperature is low, the heat storage amount is large. This is a heat storage amount calculation unit.
[0057]
The operation and operation of the above configuration will be described. When hot water supply from hot water supply terminal 10 is started, heat storage amount detecting means 15 detects the heat storage amount of heat storage body 14. When the heat storage amount obtained by the water temperature heat storage amount calculating means 21 is smaller than the heat storage amount detected by the heat storage amount detecting means 15 from the city water 32 temperature detected by the water temperature detecting means 20, the refrigerant circuit 6 is not operated and is large. The refrigerant circuit 6 is operated by the refrigerant circuit operating means 16.
[0058]
As described above, the amount of heat storage for operating the refrigerant circuit 6 changes according to the temperature change of the city water 32. In other words, when the temperature of the city water 32 rises, the water temperature heat storage calculating means 21 calculates the amount of heat stored in the heat storage 14 that starts the operation of the refrigerant circuit 6 smaller, so that the operation is performed using the heat of the heat storage 14. Since the time of hot water supply becomes longer and the number of operations of the refrigerant circuit 6 decreases, the number of times of starting and stopping of the compressor 2 also decreases, and the frequent starting and stopping of the compressor 2 can be further suppressed, so that the reliability of the compressor 2 is secured. it can.
[0059]
(Example 4)
FIG. 4 is a configuration diagram of a heat pump hot water supply apparatus according to Embodiment 4 of the present invention. The same components as those of the hot water supply device according to the second embodiment are denoted by the same reference numerals, and description thereof will be omitted.
[0060]
22 is an outside air temperature detecting means for detecting the outside air temperature. Reference numeral 23 denotes an outside air heat storage for calculating the amount of heat stored in the heat storage unit 14 in accordance with the outside air temperature detected by the outside air temperature detecting means 22 when the outside air temperature is high and decreasing the amount of heat storage when the outside air temperature is low. It is an amount calculating means.
[0061]
The operation and operation of the above configuration will be described. When hot water supply from hot water supply terminal 10 is started, heat storage amount detecting means 15 detects the heat storage amount of heat storage body 14. If the amount of heat stored by the outside air heat storage amount calculation unit 23 is smaller than the amount of heat storage detected by the outside air temperature detection unit 15 from the outside air temperature detected by the outside air temperature detection unit 22, the refrigerant circuit 6 is not operated and is large. The refrigerant circuit 6 is operated by the refrigerant circuit operating means 16.
[0062]
As described above, the amount of heat storage for operating the refrigerant circuit 6 changes according to the change in the outside air temperature. That is, when the outside air temperature increases, the outside air heat storage calculating means 23 calculates the amount of heat stored in the heat storage 14 that starts the operation of the refrigerant circuit 6 smaller, so that hot water supply using the heat of the heat storage 14 is performed. , The number of operations of the refrigerant circuit 6 is reduced, so that the number of times the compressor 2 is started and stopped is also reduced, and the frequent start and stop of the compressor 2 can be further suppressed, so that the reliability of the compressor 2 can be secured. .
[0063]
【The invention's effect】
As described above, according to the present invention, frequent start / stop of the compressor can be suppressed, and abnormal pressure rise in the refrigerant circuit can be suppressed, and reliability of the compressor can be ensured.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of a heat pump water heater according to a first embodiment of the present invention. FIG. 2 is a circuit diagram of a heat pump water heater according to a second embodiment of the present invention. FIG. FIG. 4 is a circuit diagram of a heat pump water heater according to a fourth embodiment of the present invention. FIG. 5 is a configuration diagram of a conventional heat pump water heater.
DESCRIPTION OF SYMBOLS 1 Refrigerant flow path 2 Compressor 3 Radiator 4 Decompression means 5 Heat sink 6 Refrigerant circuit 7 Water flow path 8 Heat exchanger 9 Water supply pipe 10 Hot water supply terminal 11 Hot water supply circuit 14 Heat storage unit 15 Heat storage amount detection means 16 Refrigerant circuit operation means 17 Stop Heat storage means 18 frost detection means 19 defrosting means at stop 20 water temperature detection means 21 water temperature heat storage amount calculation means 22 outside air temperature detection means 23 outside air heat storage amount calculation means

Claims (6)

A refrigerant circuit including a compressor, a radiator, a decompression unit, and a heat absorber; a heat exchanger including a water flow path that performs heat exchange with the radiator; a water supply pipe that supplies water to the water flow path; A hot water supply circuit connected so as to pass water from a road to a hot water supply terminal, a heat storage unit that stores heat of the refrigerant circuit, a heat storage amount detection unit that detects a heat storage amount of the heat storage unit, and the hot water supply unit that receives the hot water from the hot water supply circuit. When hot water supply to the terminal is started, the hot water is supplied by heating the water using the heat storage of the heat storage body, and when the heat storage amount of the heat storage body detected by the heat storage amount detection unit is equal to or less than a predetermined value, A heat pump water heater comprising a refrigerant circuit operating means for operating a refrigerant circuit. 2. The heat pump water heater according to claim 1, wherein when the refrigerant circuit is operated and hot water supply from the hot water supply terminal is stopped, the heat storage operation means includes stop heat storage means for storing heat of the refrigerant circuit in a heat storage body. 3. A frost detection means for detecting frost formation on the heat absorber, wherein when the refrigerant circuit is operated to stop hot water from the hot water supply terminal, frost formation is detected on the heat absorber by the frost detection means; The heat pump water heater according to claim 1 or 2, further comprising a stop-time defrosting means for performing a defrosting operation of the water heater. Water temperature detection means for detecting the temperature of city water, and water temperature heat quantity calculation means for operating a refrigerant circuit based on the detected temperature of the city water to calculate the heat storage quantity of the heat storage element to be stored. The heat pump water heater according to any one of claims 1 to 3. An outside air temperature detecting means for detecting an outside air temperature, and an outside air heat storage amount calculating means for operating a refrigerant circuit based on the detected outside air temperature to calculate a heat storage amount of a heat storage body to be stored. The heat pump water heater according to claim 1. The refrigerant circuit is a supercritical heat pump cycle in which the pressure of the refrigerant is equal to or higher than the critical pressure, and heats the flowing water in the water flow path of the heat exchanger with the refrigerant pressurized to the critical pressure or higher. 5. The heat pump water heater according to any one of 5.

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