JP2002372326A - Heat pump type hot water spply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the turbulence of a temperature stratification formed in a hot water storage tank upon defrosting operation. SOLUTION: A hot water circulation amount adjusting means 13 adjusts the circulation quantity of hot water in the hot water storage tank 1 which is circulated by a hot water circulating means 4. An operation control means H performs an ordinary operation for switching a refrigerant circuit T to a heating state and the hot water circulating means 4 to a hot water storage state and the defrosting operation for switching the refrigerant circuit T to a defrosting state and the hot water circulating means 4 to a heat supply state. The hot water circulation quantity adjusting means 13 is operated so that the circulation quantity of hot water in the hot water storage tank 1 circulated by the hot water circulating means 4 is smaller in the defrosting operation than that in the ordinary operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water storage tank for storing hot water in a state where a thermal stratification is formed, and a heating state in which a hot water supply heat exchanger functions as a condenser and an air heat exchanger functions as an evaporator. A compression-type refrigerant circuit that can be switched to a defrosting state in which the hot water supply heat exchanger functions as an evaporator and the air heat exchanger functions as a condenser,
After the hot water taken out from the bottom of the hot water storage tank is subjected to heat exchange in the hot water supply heat exchanger, the hot water supply state supplied to the top of the hot water storage tank and the hot water taken out from the top of the hot water storage tank are subjected to the heat exchange for hot water supply. A hot water circulation means that can be switched to a heat transfer state to be supplied to the bottom of the hot water storage tank after heat exchange by a heat exchanger, and an operation control means that controls operation of the refrigerant circuit and the hot water circulation means. The operation control means switches the refrigerant circuit to the heating state and the hot water circulation means to the hot water storage state, and the operation control means switches the refrigerant circuit to the defrosting state and supplies the hot water circulation means to the hot water circulation means. The present invention relates to a heat pump water heater configured to execute a defrosting operation for switching to a heat state.

[0002]

2. Description of the Related Art A heat pump type hot water supply apparatus as described above switches the refrigerant circuit between a heating state and a defrosting state by reversing the flow direction of the refrigerant in the refrigerant circuit.
By reversing the flow direction of the hot water in the hot water circulation means, the hot water circulation means is switched between the hot water storage state and the heat transfer state.In normal operation, the hot water supply heat exchanger takes out refrigerant from the refrigerant circuit from the bottom of the hot water storage tank. The hot water is heated to a hot water storage set temperature, the heated hot water is supplied to an upper portion of the hot water storage tank, and the hot water is stored in a state where a temperature stratification is formed in the hot water storage tank. Heat is supplied to the refrigerant by the refrigerant circuit with hot water taken out from the upper portion of the hot water storage tank, and the refrigerant is supplied to the air heat exchanger to melt frost attached to the air heat exchanger (for example, 2-25106). In this type of heat pump hot water supply apparatus, in normal operation, the rotation speed of the circulation pump is adjusted so that hot water at the set hot water storage temperature is obtained when the hot water is supplied by the hot water supply heat exchanger. In the defrosting operation, the circulation speed of the circulation pump is set to a constant speed such as an intermediate speed, and the circulation amount of the hot water in the range of the circulation amount of the hot water in the normal operation is adjusted. The amount of hot water circulated in the hot water storage tank circulated by the means is made a certain amount.

[0003]

In the heat pump type hot water supply apparatus described above, in a normal operation, if the amount of hot water circulated in the hot water storage tank circulated by the hot water circulating means is increased,
Since the time required for the amount of hot water stored in the hot water storage tank to reach the set amount is reduced, it is desired to increase the amount of hot water circulation, and the configuration is such that the amount of hot water circulation during normal operation increases. .

However, in the above-mentioned conventional heat pump type hot water supply apparatus, by setting the rotation speed of the circulation pump to a constant speed such as an intermediate speed, the circulation of the hot water in the defrosting operation is performed within the range of the circulation amount of the hot water in the normal operation. Since the amount is set to a certain amount, the circulation amount of hot water in the defrosting operation also increases, the flow of hot water returning from the bottom of the hot water storage tank to the hot water storage tank becomes stronger, and the temperature stratification formed in the hot water storage tank Was disturbed.

The present invention has been made in view of such a point, and an object thereof is to provide a heat pump type hot water supply apparatus capable of preventing disturbance of a temperature stratification formed in a hot water storage tank. It is in.

[0006]

According to the first aspect of the present invention, there is provided a hot water storage tank for storing hot water in a state where a thermal stratification is formed, and a hot water supply heat exchanger including a condenser. And a defrosting state in which the air heat exchanger functions as an evaporator and the hot water supply heat exchanger functions as an evaporator and the air heat exchanger functions as a condenser. A compression-type refrigerant circuit,
After the hot water taken out from the bottom of the hot water storage tank is subjected to heat exchange in the hot water supply heat exchanger, the hot water supply state supplied to the top of the hot water storage tank and the hot water taken out from the top of the hot water storage tank are subjected to the heat exchange for hot water supply. A hot water circulation means that can be switched to a heat transfer state to be supplied to the bottom of the hot water storage tank after heat exchange by a heat exchanger, and an operation control means that controls operation of the refrigerant circuit and the hot water circulation means. The operation control means switches the refrigerant circuit to the heating state and the hot water circulation means to the hot water storage state, and the operation control means switches the refrigerant circuit to the defrosting state and supplies the hot water circulation means to the hot water circulation means. In a heat pump type hot water supply apparatus configured to execute a defrosting operation for switching to a heat state, the hot water storage tank circulated by the hot water circulation means is provided. Hot water circulation amount adjusting means for adjusting the amount of water circulation is provided, and the operation control means circulates the hot water storage tank in the hot water circulation means during the defrosting operation than during the normal operation. In order to reduce the amount of hot water circulated in the inside, the hot water circulating amount adjusting means is operated.

That is, in the normal operation, the operation control means operates the hot water circulation amount adjusting means such that the circulation amount of the hot water in the hot water storage tank circulated by the hot water circulation means becomes the circulation amount for the normal operation. Then, in the defrosting operation, the hot water circulation amount adjusting means can be operated such that the circulation amount of the hot water in the hot water storage tank circulated by the hot water circulation means is smaller than the circulation amount for the normal operation. Therefore, the circulation amount of hot water in the hot water storage tank circulated by the hot water circulation means
It is possible to reduce the amount of defrosting operation in the normal operation, while increasing the amount in the normal operation. Therefore, in the normal operation, the circulation amount of the hot water is increased in the defrosting operation as compared with the normal operation, while increasing the circulation amount of the hot water to shorten the time until the set amount of hot water is stored in the hot water storage tank. As a result, it is possible to provide a heat pump type hot water supply apparatus that can prevent disturbance of the temperature stratification formed in the hot water storage tank and can prevent disturbance of the temperature stratification formed in the hot water storage tank. Reached.

According to the second aspect of the present invention, during the normal operation, there is provided temperature detecting means for detecting the temperature of the refrigerant supplied to the air heat exchanger, and the operation control means comprises: When the temperature detected by the temperature detecting means becomes equal to or lower than the set temperature, the defrosting operation is executed.

That is, the operation control means is configured to execute the defrosting operation when the temperature detected by the temperature detecting means becomes equal to or lower than the set temperature. If there is frost on the
The operation control means can execute the defrosting operation to melt the frost on the air heat exchanger. Therefore,
When the defrosting operation is required, the defrosting operation can be automatically performed, which is convenient.

According to the third aspect of the present invention, the refrigerant circuit is configured to be a supercritical heat pump cycle in which the refrigerant pressure on the high pressure side is equal to or higher than the critical pressure of the refrigerant. That is, since the refrigerant circuit is configured to be a supercritical heat pump cycle in which the refrigerant pressure on the high pressure side is equal to or higher than the critical pressure of the refrigerant, the temperature of hot water heated by the refrigerant is increased to approximately 100 ° C. Thus, even if the set temperature of hot water storage when storing hot water in the hot water storage tank is high, it is possible to cope with only the refrigerant circuit without providing an auxiliary heating means or the like.

According to the fourth aspect of the present invention, the hot water supply heat exchanger includes a hot water supply heat transfer tube through which hot water in the hot water storage tank flows and a refrigerant heat transfer tube through which the refrigerant flows. The air heat exchanger has a double-tube structure with one inside and the other outside, and the air heat exchanger has a structure in which a plurality of heat transfer fins pass through the heat transfer tube through which the refrigerant passes. It is configured.

That is, the hot water supply heat exchanger for exchanging heat between hot water and a refrigerant has a double-pipe structure in which one of a hot water supply heat transfer tube and a refrigerant heat transfer tube is inside and the other is outside. Therefore, it is possible to increase the heat transfer area between the hot water and the refrigerant by using the double tube structure, and the air heat exchanger for exchanging heat between the refrigerant and the air has a plurality of heat transfer tubes in the longitudinal direction. Since the structure is such that the heat fins are penetrated, the heat transfer area between the refrigerant and the air can be increased by using the heat transfer tube structure with the heat transfer fins.
Therefore, in the heat exchanger for hot water supply and the air heat exchanger, it is possible to perform the effective heat exchange while simplifying the structure by using the double tube structure and the heat transfer tube structure with the heat transfer fins. Becomes

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A heat pump hot water supply apparatus according to the present invention will be described with reference to the drawings. As shown in FIG. 1, this heat pump type hot water supply apparatus is a compression type refrigerant including a hot water storage tank 1, a hot water supply heat exchanger 2, and an air heat exchanger 3 which store hot water in a state where a temperature stratification is formed. A circuit T, a hot water circulation means 4 for circulating hot water in the hot water storage tank 1 while passing through the hot water supply heat exchanger 2, an operation control unit H as an operation control means for controlling the operation of the refrigerant circuit T and the hot water circulation means 4. , And a remote controller R for instructing the operation control unit H with control information.

The hot water storage tank 1 is connected from the bottom to a water supply channel 5 for supplying water to the hot water storage tank 1 using tap water pressure, and a hot water supply channel 6 for supplying hot water to a hot water tap 9 from the upper portion thereof. Supply water 5 by the amount used by the stopper 9
The water is supplied to the hot water storage tank 1 from above. In the hot water storage tank 1, the upper thermistor S1 detects whether the amount of hot water is small or more by detecting the temperature of the hot water, and detects the temperature of hot water whether the amount of hot water is medium or more. And a lower thermistor S3 for detecting whether or not the amount of hot water stored therein is greater than or equal to the temperature by detecting the temperature of the hot water. The hot water supply path 6 has a water supply branch path 7 branched from the water supply path 5.
A mixing valve 8 is provided at the connection point of the mixing valve 8 so that the mixing ratio between hot water from the hot water supply path 6 and water from the water supply branch path 7 can be adjusted.

The hot water circulation means 4 has one end connected to the bottom of the hot water storage tank 1 and the other end connected to the upper part of the hot water storage tank 1 with the other end being supplied to a part of the hot water supply path 6. A hot water four-way valve 11 for reversing the flow direction of hot water in the hot water circulation path 10, a circulation pump 12, a water control valve 13 as hot water circulation amount adjusting means, and a hot water supply heat exchanger 2 are provided. In the hot water circulation circuit 10, a four-way hot water valve 11, a circulation pump 12, a water control valve 13, and a hot water supply heat exchanger 2 are provided in this order from the bottom side of the hot water storage tank 1, and are heated by the hot water supply heat exchanger 2. A heating temperature thermistor 14 for detecting the temperature of the hot and cold water is provided.

The hot water circulation means 4 reverses the flow direction of the hot water by the hot water four-way valve 11 so that the hot water taken out from the bottom of the hot water storage tank 1 is heat-exchanged by the hot water supply heat exchanger 2. Switching between a hot water storage state supplied to the upper portion of the hot water storage tank 1 and a heat transfer state supplied to the bottom of the hot water storage tank 1 after the hot water taken out from the upper portion of the hot water storage tank 1 undergoes heat exchange in the hot water supply heat exchanger 2. It is freely configured.

The refrigerant circuit T is constituted by connecting a compressor 15, a refrigerant four-way valve 16, a hot water supply heat exchanger 2, an electronic expansion valve 17, an air heat exchanger 3, and an accumulator 18 in an annular manner. It is used as a refrigerant.
Then, an outside air ventilation means 19 for ventilating outside air to the air heat exchanger 3, and a temperature sensor 20 as a temperature detection means for detecting a temperature of the refrigerant supplied to the air heat exchanger 3 during a normal operation described later. Is provided.

The heat exchanger 2 for hot water supply is for exchanging heat between the hot water in the hot water storage tank 1 and the refrigerant, and has the heat transfer pipe 2a for the refrigerant flowing therethrough and the hot water in the hot water storage tank 1 flowing therethrough. It has a double tube structure with the heat transfer tube 2b for hot water supply on the outside, and the double tube is spirally wound. The air heat exchanger 3 is for exchanging heat between the refrigerant and the outside air, and has a structure in which a plurality of heat transfer fins 3b penetrate a heat transfer tube 3a through which the refrigerant passes in a longitudinal direction thereof. The heat pipes 3a are connected in a rosary with U-shaped pipes.

The compressor 15 is of a hermetically sealed rolling piston type which compresses and discharges a gaseous refrigerant sucked from an accumulator 18 to a pressure higher than a critical pressure. A supercritical heat pump cycle in which the pressure is equal to or higher than the critical pressure is configured.

The refrigerant circuit T heats the hot water supply heat exchanger 2 to function as a condenser and the air heat exchanger 3 to function as an evaporator by reversing the flow direction of the refrigerant by a refrigerant four-way valve 16. It is configured to be freely switchable between a state and a defrosting state in which the hot water supply heat exchanger 2 functions as an evaporator and the air heat exchanger functions as a condenser.

The operation control unit H includes a hot water supply operation for supplying hot water stored in the hot water storage tank 1 to the hot water tap 9, a normal operation for switching the hot water circulation means 4 to a hot water storage state and switching the refrigerant circuit T to a heating state, In addition, it is configured to execute a defrosting operation of switching the hot and cold water circulating means 4 to the heat transfer state and switching the refrigerant circuit T to the defrosting state.

The operation control section H starts the hot water supply operation with the operation of opening the hot water tap 9, stops the hot water supply operation with the operation of closing the hot water tap 9, and starts the normal operation from the remote controller R. When a command is issued, normal operation starts, and when the amount of hot water stored in the hot water storage tank 1 reaches the set hot water storage amount based on the detection information of the central thermistor S2 and the lower thermistor S3, the normal operation is stopped. In addition, the operation control unit H starts the defrosting operation when the temperature detected by the temperature sensor 20 becomes equal to or lower than the set temperature during the normal operation, and the set time elapses after the start of the defrosting operation or the temperature sensor 20
Is configured to stop the defrosting operation when the temperature detected by the controller becomes equal to or higher than the stop set temperature.

The hot water supply operation, the normal operation, and the defrosting operation will be described below. In the hot water supply operation, the hot water stored in the hot water storage tank 1 is taken out from the upper part of the hot water storage tank 1 to the hot water supply path 6, and the temperature of the mixed hot water mixed with the water from the hot water supply branch 7 is controlled by the remote control R. The mixing valve 8 is adjusted so as to reach the target temperature, and hot water of the hot water supply target temperature is supplied to the hot water tap 9.

In the normal operation, as shown in FIG. 1, hot water taken out from the bottom of the hot water storage tank 1 is supplied to a hot water supply heat exchanger 2.
To supply it to the upper portion of the hot water storage tank 1 and supply the refrigerant in the refrigerant circuit T to the compressor 15 → the hot water supply heat exchanger 2 → the electronic expansion valve 17 → the air heat exchanger 3 → the accumulator 18 → the compressor 15 , The hot water supply heat exchanger 2 functions as a condenser and the air heat exchanger 3 functions as an evaporator. And
In the hot water supply heat exchanger 2, the hot water discharged from the bottom of the hot water storage tank 1 is heated by the high-temperature refrigerant (hot gas) discharged from the compressor 15, and the heated hot water flows to the upper part of the hot water storage tank 1. The hot water is supplied and stored in the hot water storage tank 1. Further, the rotation speed of the circulation pump 12 and the opening of the water control valve 13 are adjusted so that the temperature of the hot water heated by the hot water supply heat exchanger 2 becomes the set hot water storage temperature (for example, 80 ° C.). The amount of hot water circulated in the hot water storage tank 1 circulated by the hot water circulating means 4 is adjusted.
The hot water is stored in a state where a temperature stratification is formed in the hot water.

The refrigerant circuit T in the normal operation will be described with reference to a Mollier diagram in FIG. The Mollier diagram of FIG. 3 shows a case where the hot water storage set temperature is set to 80 ° C. The high-temperature refrigerant discharged from the compressor 15 is supplied to the hot water supply heat exchanger 2 so that the hot water supply heat exchanger 2 functions as a condenser (A → B in the figure).
Since the refrigerant in the hot water supply heat exchanger 2 is pressurized to a critical pressure or higher by the compressor 15, the refrigerant does not condense even if it radiates heat to the hot water passing through the hot water supply heat exchanger 2. Therefore, the condenser may be referred to as a gas cooler.

Then, the refrigerant that has passed through the hot water supply heat exchanger 2 is decompressed by the electronic expansion valve 17 (B → C in the figure), and the decompressed refrigerant is supplied to the air heat exchanger 3 so that the air is exchanged. The heat exchanger 3 is made to function as an evaporator, and is evaporated by heat exchange with the outside air ventilated by the outside air ventilation means 19 (C → D in the figure). The refrigerant that has passed through the air heat exchanger 3 is separated into gas and liquid by the accumulator 18, and only the gas-phase refrigerant is supplied to the compressor 15 and compressed to a critical pressure or higher (D → A in the figure).

In the defrosting operation, as shown in FIG. 2, hot water taken out from the upper part of the hot water storage tank 1 is supplied to the hot water supply heat exchanger 2.
To return to the bottom of the hot water storage tank 1 and to transfer the refrigerant in the refrigerant circuit T from the compressor 15 to the air heat exchanger 3.
→ The electronic expansion valve 17 → the hot water supply heat exchanger 2 → the accumulator 18 → the compressor 15 are circulated in this order, so that the hot water supply heat exchanger 2 functions as an evaporator and the air heat exchanger 3 functions as a condenser. It is configured. Then, in the hot water supply heat exchanger 2, heat is transferred to the refrigerant from the hot water taken out from the upper part of the hot water storage tank 1, and the high-temperature refrigerant (hot gas) discharged from the compressor 15 is supplied to the air heat exchanger 3, where The heat exchanger 3 functions as a condenser to dissipate heat and melt frost on the air heat exchanger 3.

In this defrosting operation, the circulation pump 12
Is adjusted to the minimum speed and the opening of the water control valve 13 is adjusted, so that the amount of hot water circulated in the hot water storage tank 1 circulated by the hot water circulating means 4 becomes smaller than in the normal operation. Has been adjusted as follows. In this manner, the amount of hot water circulating in the hot water storage tank 1 circulated by the hot water circulating means 4 is reduced during the defrosting operation compared with the normal operation, so that during the defrosting operation, The amount of hot water returned to the bottom of the hot water storage tank 1 is minimized so that the water flow does not disturb the temperature stratification formed in the hot water storage tank 1.

[Another Embodiment] (1) In the above embodiment, by adjusting the opening of the water control valve 13, the hot water circulation means 4 performs the defrosting operation more than the normal operation. Although the amount of hot water circulated in the hot water storage tank 1 to be circulated is reduced, the amount of hot water in the hot water storage tank 1 circulated by the hot water circulating means 4 is greater in the defrosting operation than in the normal operation. The configuration is not limited to the configuration of the above-described embodiment as long as the configuration is such that the circulation amount of hot and cold water is small.

For example, as shown in FIG.
A throttle mechanism is provided in the hot water circulation path 10 so that the flow rate of hot water flowing from the top to the bottom of the hot water storage tank 1 is smaller than the flow rate of hot water flowing from the bottom to the top of the hot water storage tank 1. Is also possible. Adding explanation, hot water circulation circuit 1
0, a throttle mechanism 10a is provided in a portion between the circulation pump 12 and the hot water supply heat exchanger 2, and a bypass 10b is provided to bypass the throttle mechanism 10a. The flow from the bottom to the top of the hot water storage tank 1 is reduced by providing a check valve 10c that allows the flow from the bottom to the top of the hot water storage tank 1 and allows the flow from the top to the bottom of the hot water storage tank 1. The configuration is such that the flow rate of hot water flowing from the top to the bottom of the hot water storage tank 1 is smaller. Incidentally, the throttle mechanism 10a shown in FIG. 4 is specifically composed of a capillary, an orifice, or the like.

(2) In the above embodiment, by providing the water control valve 13 and adjusting the opening of the water control valve 13,
The amount of hot water circulating in the hot water storage tank 1 circulated by the hot water circulating means 4 is smaller in the defrosting operation than in the normal operation, but without providing the water control valve 13. In the normal operation, the rotation speed of the circulation pump 12 is adjusted in a range of a speed larger than the minimum speed, and in the defrosting operation, the rotation speed of the circulation pump 12 is adjusted to the minimum speed, so that the normal operation is performed. In the defrosting operation, the amount of hot water circulated in the hot water storage tank 1 circulated by the hot water circulating means 4 can be configured to be smaller than in the defrosting operation.

(3) In the above embodiment, the operation control unit H
Is configured to start the defrosting operation when the temperature detected by the temperature sensor 20 becomes equal to or lower than the set temperature. However, the defrosting operation start condition that is satisfied when the outside air temperature becomes equal to or lower than the set temperature is set, and the operation is started. The control unit H may be configured to execute the defrosting operation when the defrosting operation start condition is satisfied.

(4) In the above embodiment, the refrigerant circuit T
Although it is configured to be a supercritical heat pump cycle in which the refrigerant pressure on the high pressure side is equal to or higher than the critical pressure of the refrigerant,
The refrigerant circuit T is not limited to a supercritical heat pump cycle, but may be a normal heat pump cycle.
Also, the refrigerant is not limited to carbon dioxide, and other refrigerants can be used.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a heat pump water heater in a normal operation.

FIG. 2 is a schematic configuration diagram of a heat pump water heater in a defrosting operation.

FIG. 3 is a Mollier diagram in a normal operation.

FIG. 4 is a schematic configuration diagram of a heat pump water heater according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hot water storage tank 2 Heat exchanger for hot water supply 3 Air heat exchanger 4 Hot water circulation means 20 Temperature detection means H Operation control means

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3L092 BA17 FA34 TA06 UA01 UA21 VA07 WA22 WA25 YA18

Claims (4)

[Claims] 1. A hot water storage tank for storing hot water in a state where a temperature stratification is formed; a heating state in which a hot water supply heat exchanger functions as a condenser and an air heat exchanger functions as an evaporator; A compression-type refrigerant circuit that can be switched to a defrosting state in which the device functions as an evaporator and the air heat exchanger functions as a condenser, and hot water taken out from the bottom of the hot water storage tank is supplied to the hot water supply heat exchanger. Hot water is supplied to the top of the hot water storage tank, and hot water taken out from the top of the hot water storage tank is heat-exchanged by the hot water supply heat exchanger and then supplied to the bottom of the hot water storage tank. Water circulation means that can be switched to a heat transfer state, and operation control means that controls the operation of the refrigerant circuit and the water circulation means, wherein the operation control means A normal operation for switching to a hot state and switching the hot and cold water circulation means to the hot water storage state, and a defrosting operation for switching the refrigerant circuit to the defrosting state and switching the hot and cold water circulation means to the heat transfer state are performed. In the heat pump hot water supply device configured, hot water circulation amount adjusting means for adjusting a circulation amount of hot water in the hot water storage tank circulated by the hot water circulation means is provided; It is configured to operate the hot water circulation amount adjusting means during the defrosting operation to reduce the circulation amount of hot water in the hot water storage tank circulated by the hot water circulation means than during the operation. Heat pump water heater. 2. A temperature detecting means for detecting a temperature of the refrigerant supplied to the air heat exchanger during the normal operation, wherein the operation control means sets a temperature detected by the temperature detecting means to a set temperature. The heat pump hot water supply device according to claim 1, wherein the heat pump type hot water supply device is configured to execute the defrosting operation when the following conditions are satisfied. 3. The heat pump type hot water supply apparatus according to claim 1, wherein the refrigerant circuit is configured to be a supercritical heat pump cycle in which a refrigerant pressure on a high pressure side is equal to or higher than a critical pressure of the refrigerant. 4. The heat exchanger for hot water supply, wherein one of a heat transfer tube for hot water supply through which hot water in the hot water storage tank flows and a heat transfer tube for refrigerant through which the refrigerant flows, and the other is outside. The air heat exchanger is configured with a double tube structure, and the heat transfer tube through which the refrigerant passes,
The heat pump type hot water supply apparatus according to any one of claims 1 to 3, wherein the heat pump type hot water supply apparatus is configured to have a structure in which a plurality of heat transfer fins penetrate in the longitudinal direction.