JP2003139392A - Water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water heater A which can prevent freezing of water for hot-water supply in a hot-water supply circuit without temperature drop of hot water in a hot-water tank or change in the distribution state of a hot-water temperature. SOLUTION: In this water heater A, when a water-supply temperature sensor 18 detects a temperature below a predetermined one during operation stop of a heat pump, a controller 16 activates a circulating pump 13 and a compressor 1, opens an expansion valve 4 to a predetermined opening and controls three-way valves 20 and 21 in the β direction for freezing prevention operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump type hot water supply apparatus which prevents hot water supply water in a pipe from freezing during cold weather.

[0002]

2. Description of the Related Art Conventionally, hot water passing through the refrigerant water heat exchanger and hot water for hot water passing through the inner tube of the refrigerant water heat exchanger are heat-exchanged with each other to supply hot water for hot water supply to a hot water storage tank. A hot water supply device for storing hot water is known. In this water heater
When the water temperature is equal to or lower than a predetermined temperature, the heat pump hot water supply operation is performed, the circulation pump is operated, or the electric heater in the hot water storage tank is energized to prevent the freezing of the hot water in the hot water supply tank unit.

[0003]

The above-described conventional hot water supply apparatus has the following problems. To raise the temperature of the cold water at the bottom of the hot water storage tank, it is necessary to perform freeze prevention operation for a long time (when performing heat pump hot water supply operation). Since the cold water in the lower part of the hot water storage tank is supplied as it is to the upper part of the hot water storage tank, it is necessary to operate the circulation pump for a long time to raise the temperature of the cold water in the lower part of the hot water storage tank (when operating the circulation pump). It is necessary to newly install an electric heater in the circulation pipes of the heat pump and the hot water storage tank, and it takes a long time for the antifreezing operation (in the case of the electric heater).

A first object of the present invention is to provide a heat pump type of hot water which can prevent freezing of hot water in the hot water supply circuit without lowering the temperature of the hot water in the hot water storage tank or changing the distribution state of the hot water temperature. It is in the provision of a water heater. A second object of the present invention is to reduce the energy consumed in the antifreezing operation and to prevent freezing of the hot water for hot water supply in the hot water supply circuit only by performing the antifreezing operation for a short time. Is provided.

[0005]

[Means for Solving the Problems] [Claim 1] A refrigerant circuit comprises a refrigerant compressor, a refrigerant passage of a refrigerant water heat exchanger, a pressure reducing means, and a refrigerant evaporator, which are annularly connected by a refrigerant pipe. In the hot water supply circuit, a hot water storage tank for storing hot water for hot water supply and a hot water supply water passage of the refrigerant water heat exchanger are annularly connected by a hot water supply water pipe, and a circulation pump is provided in the hot water supply water pipe. Bypass means is provided which bypasses the hot water storage tank and allows hot water to circulate between the hot water supply passage and the circulation pump via the hot water supply pipe.

During the heat pump operation (the bypass means is in a deactivated state), the controller operates the refrigerant compressor and the circulation pump so that the high-temperature refrigerant passing through the refrigerant passage and the hot-water supply water passing through the hot-water supply passage are provided. Heat is exchanged to heat the hot water to prepare hot water, which is stored in the hot water storage tank. Water is supplied from the water supply source to the water supply side by the amount of hot water supplied.

When the heat pump is not operating and the hot water in the hot water supply pipe may freeze,
The controller operates the refrigerant compressor and the bypass means to perform the antifreezing operation, and the produced hot water is flowed into the hot water supply water pipe of the hot water supply circuit. As a result, the temperature of the hot water supply water in the hot water supply circuit can be raised by the freeze prevention operation for a short time, so that the water can be prevented from freezing in the hot water supply circuit and damage to the hot water supply water pipe or the like can be prevented. It is not necessary to newly provide an auxiliary heat source such as an electric heater.

Further, during the antifreezing operation, the hot water storage tank is separated from the hot water supply circuit, so that the hot water supply water does not flow into the hot water storage tank, so that the temperature drop of the hot water in the hot water storage tank does not occur and the hot water temperature distribution state. Does not change. For this reason,
When the freeze prevention operation is finished and the heat pump operation is restarted, the hot water can be immediately and stably supplied to the bathtub, the shower or the like.

[Claim 2] The refrigerant circuit comprises a refrigerant compressor, a refrigerant passage of a refrigerant water heat exchanger, a pressure reducing means, and a refrigerant evaporator, which are annularly connected by a refrigerant pipe. The hot water supply circuit connects the hot water storage side of the hot water storage tank for storing hot water and the outlet side of the hot water supply water passage of the refrigerant water heat exchanger with hot water supply piping,
The water supply side of the hot water storage tank and the inlet side of the hot water supply passage of the refrigerant water heat exchanger are annularly connected by a water pipe, and a circulation pump is provided in the water intake pipe.

There is provided a reverse circulation means capable of circulating the hot water for hot water supply in the hot water supply circuit in the reverse direction, and the controller is used during cold weather when the heat pump operation is stopped and the hot water for hot water supply may freeze. Activates the reverse circulation means.

The high-temperature hot water stored on the hot water storage side of the hot water storage tank is supplied to the outlet side of the hot water supply water passage of the refrigerant water heat exchanger through the hot water supply pipe, and the hot water is stored from the inlet side of the hot water supply water passage through the intake pipe. Return to the water supply side of the tank. As a result, the temperature of the hot water for hot water supply in the hot water supply circuit rises in a short time antifreezing operation, so that it is possible to prevent water from freezing in the hot water supply circuit and prevent damage to pipes and the like. In addition, since the refrigerant compressor is not operated during the freeze prevention operation, power consumption can be suppressed to a low level. Furthermore, it is not necessary to newly provide an auxiliary heat source such as an electric heater.

[Claim 3] The refrigerant circuit comprises a refrigerant compressor, a refrigerant passage of a refrigerant water heat exchanger, a pressure reducing means, and a refrigerant evaporator which are annularly connected by a refrigerant pipe.

The hot water supply circuit has a flow path switching means, and a hot water storage tank for storing hot water for hot water supply and a hot water supply water passage of the refrigerant water heat exchanger are connected in an annular shape by a hot water supply water pipe provided with a circulation pump. There is.

When the heat pump is in operation (the flow path switching means is in a stopped state), the controllers of the refrigerant compressor and the circulation pump are operated to heat the hot water for hot water passing through the hot water supply passage of the refrigerant water heat exchanger, The prepared hot water is supplied to the hot water storage side of the hot water storage tank, and the hot water supply water on the water supply side of the hot water storage tank is returned to the inlet side of the hot water supply water passage of the refrigerant water heat exchanger. Water is supplied from the water supply source to the water supply side by the amount of hot water supplied.

During cold weather when there is a risk that the hot water for hot water supply in the hot water supply circuit may freeze while the heat pump is not operating, the controller operates the flow path switching means and the circulation pump to cool the hot water for hot water storage on the hot water storage side of the hot water storage tank as a refrigerant. An anti-freezing operation is performed in which water is supplied to the inlet side of the hot water supply passage of the water heat exchanger and hot water is returned from the outlet side of the hot water supply passage to the hot water supply side of the hot water storage tank.

As a result, the temperature of the hot water for hot water supply in the hot water supply circuit can be raised by a short time anti-freezing operation, so that the water can be prevented from freezing in the hot water supply circuit and damage to the hot water supply water pipe and the like can be prevented. it can. It is not necessary to newly provide an auxiliary heat source such as an electric heater. Further, the flow path switching means can be easily provided by a four-way valve or the like.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention (corresponding to claim 1) will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, in a hot water supply device A, a compressor 1 for compressing a refrigerant, a refrigerant passage 3 of a refrigerant water heat exchanger 2, an expansion valve 4, a refrigerant evaporator 5, and an accumulator 6 are annularly connected by a refrigerant pipe 7. The refrigerant circuit 8 formed by the above, the hot water storage tank 9, and the hot water supply water passage 10 of the refrigerant water heat exchanger 2 are connected to the hot water supply water pipes 11, 1
2 is connected in a ring shape, and the circulation pump 1 is installed in the hot water supply pipe 11.
3, a hot water supply circuit 14 provided therebetween, a bypass means 15 for bypassing hot water supply water, and a controller 16.

The compressor 1 is driven by a drive device (not shown) such as an electric motor and compresses and discharges the sucked gas refrigerant (CO ₂ having a low critical pressure in this embodiment). The refrigerant discharge amount of the compressor 1 can be changed according to the rotation speed of the compressor (driving device).

The refrigerant water heat exchanger 2 exchanges heat between the high-temperature and high-pressure gas refrigerant compressed by the compressor 1 and the hot water supply water, and the refrigerant passage 3 through which the refrigerant passes and the hot water supply water through which the hot water supply water passes. The passage 10 is provided adjacent to the passage 10, and is configured such that the flow direction of the refrigerant and the flow direction of the hot water supply water are opposed to each other.

The expansion valve 4 is provided in a refrigerant pipe 7 between the refrigerant passage 3 of the refrigerant water heat exchanger 2 and the refrigerant evaporator 5. When the refrigerant that has passed through the refrigerant passage 3 and cooled passes through the expansion valve 4, it is depressurized and sent to the refrigerant evaporator 5. The valve opening of the expansion valve 4 is operated by the controller 16. The refrigerant evaporator 5 receives the air blown by the outdoor fan 17, and receives the expansion valve 4
The refrigerant decompressed in step 1 and the outside air are heat-exchanged to evaporate the refrigerant.

The circulation pump 13 is provided in the hot water supply water pipe 12, and the hot water supply water in the hot water storage tank 9 in the hot water supply circuit 14 is supplied from the bottom outlet to the hot water supply water passage 10 of the refrigerant water heat exchanger 2.
The water flow returning from the upper inlet into the hot water storage tank 9 via the inlet of the hot water supply water passage 10 → the outlet of the hot water supply water passage 10 (during heat pump operation). The amount of water flowing through the circulation pump 13 increases or decreases according to the amount of electricity supplied to the pump motor controlled by the controller 16.

A hot water supply temperature sensor 18 and a hot water supply water intermediate temperature sensor 19 for detecting a hot water supply temperature are provided at an inlet and an intermediate portion of the hot water supply water passage 10 of the refrigerant water heat exchanger 2, respectively.

The hot water storage tank 9 is made of a metal (stainless steel or the like) having excellent corrosion resistance and has a heat insulating structure.
By this, hot water for hot water supply can be kept warm for a long time. The hot water in the hot water storage tank 9 is used for kitchen, bath, floor heating, indoor heating, bathroom drying and the like.

The bypass means 15 is a hot water supply water pipe 11,
Three-way valves 20 and 21 installed in the 12 and the bypass pipe 2
2 and is installed in the tank case 23. Controller 1 during heat pump operation (normal operation)
According to the instruction of 6, the energization of the three-way valves 20 and 21 is stopped, and the three-way valves 20 and 21 communicate with each other in the α direction.

In this case, the hot water for hot water supply in the hot water supply circuit 14 circulates as follows. Hot water supply water passage 10 of the refrigerant water heat exchanger 2
→ Exit of hot water supply water passage 10 → Hot water supply water pipe 11 → Three-way valve 20 → Hot water storage tank 9 → Hot water supply water pipe 12 → Three-way valve 21 →
Hot water supply water pipe 12 → Circulation pump 13 → Hot water supply water pipe 12
→ Inlet of hot water supply water passage 10 → Hot water supply water passage 10 of the refrigerant water heat exchanger 2.

During the antifreezing operation, the three-way valves 20 and 21 are energized according to an instruction from the controller 16, and the three-way valves 20 and 21 are turned on.
21 communicates in the β direction. In this case, the hot water for hot water supply in the hot water supply circuit 14 circulates as follows. Hot water supply water passage 10 of the refrigerant water heat exchanger 2 → outlet of the hot water supply water passage 10 → hot water supply water pipe 11 → three-way valve 20 → bypass pipe 22 → three-way valve 21 → hot water supply water pipe 12 → circulation pump 13 → hot water supply water pipe 12 → Inlet of hot water supply water passage 10-> hot water supply water passage 10 of the refrigerant water heat exchanger 2.

Next, the operation of the hot water supply device A will be described with reference to the flowchart shown in FIG. In step s1, the water heater A is in the heat pump operation stop state. In step s2, it is determined whether or not the temperature of the hot water supply water (freezing prevention operation start temperature) detected by the water supply temperature sensor 18 is 3 ° C. or lower, and if it exceeds 3 ° C. (NO), the process returns to step s1. If the heat pump operation is stopped and the temperature is 3 ° C. or lower (YES), the process proceeds to step s3.

In step s3, the controller 16 puts the circulation pump 13 and the compressor 1 into an operating state (ON), sets the expansion valve 4 to a predetermined opening degree, and energizes the three-way valves 20 and 21 (in the β direction). (Communication) Start antifreeze operation.

At step s4, the temperature of the hot water for hot water detection (freezing prevention operation end temperature) detected by the hot water temperature sensor 18 is 10
It is determined whether or not the temperature is equal to or higher than 10 ° C. If the temperature is lower than 10 ° C. (NO), the process returns to step s3 to continue the antifreezing operation, and if the temperature is higher than 10 ° C. (YES), the process proceeds to step s5.

In step s5, the controller 16 deactivates the circulation pump 13 and the compressor 1 to stop the energization of the three-way valves 20 and 21 (communicate in the α direction) to end the freeze prevention operation.

The hot water supply apparatus A of this embodiment has the following advantages. [A] In the hot water supply apparatus A, when the heat pump operation is stopped, the temperature of the hot water supply water detected by the water supply temperature sensor 18 (freezing prevention operation start temperature) is 3 ° C. or less, and the hot water supply water in the hot water supply circuit 14 may be frozen. At a certain cold temperature, the controller 16 operates the circulation pump 13 and the compressor 1 in the operating state (O
N), the expansion valve 4 is set to a predetermined opening, and the three-way valve 20,
21 is energized (communication in the β direction) to perform antifreezing operation.

As a result, the temperature of the hot water supply water in the hot water supply circuit 14 can be raised by a short-time anti-freezing operation, so that the freezing of the water in the hot water supply circuit 14 can be prevented, and the hot water supply water pipes 11, 12 etc. It can prevent damage. It is not necessary to newly provide an auxiliary heat source such as an electric heater.

[B] By-pass means 15 constituted by three-way valves 20 and 21 provided in hot water supply water pipes 11 and 12 and a bypass pipe 22 is installed in a tank case 23. For this reason, the tank case 2 will not be exposed to cold temperatures when the hot water temperature sensor 18 detects a hot water temperature of 3 ° C. or lower.
3, hot water supply water pipes 11 and 12, three-way valve 2
The hot water for hot water supply in 0, 21, and the bypass pipe 22 does not easily freeze.

[C] During the anti-freezing operation, the hot water storage tank 9 is disconnected from the hot water supply circuit 14, so that low-temperature hot water for hot water supply does not flow into the hot water storage tank 9, so that the temperature of the hot water in the hot water storage tank 9 decreases. In addition, the distribution state of the hot water temperature in the hot water storage tank 9 does not change. Therefore, when the antifreezing operation is finished and the heat pump operation is restarted, the hot water can be immediately and stably supplied to the bathtub, the shower or the like.

Next, a second embodiment of the present invention (corresponding to claim 2) will be described with reference to FIGS. 3 and 4. As shown in FIG. 3, in the hot water supply device B, a compressor 1 for compressing a refrigerant, a refrigerant passage 3 of a refrigerant water heat exchanger 2, an expansion valve 4, a refrigerant evaporator 5, and an accumulator 6 are connected by a refrigerant pipe 7 in an annular shape. The refrigerant circuit 8 and the hot water storage tank 9 and the hot water supply water passage 10 of the refrigerant water heat exchanger 2 are annularly connected by the hot water supply pipe 111 and the intake pipe 121, and the circulation pump 13 is provided in the intake pipe 121. The hot water supply circuit 14 includes a hot water supply circuit 14, a reverse circulation means 25 capable of circulating hot water for hot water supply in the reverse direction, and a controller 16.

The reverse circulation means 25 is composed of an electromagnetic valve 24 provided in a water intake pipe 121 near the circulation pump 13 and a hot water supply water pipe 27 provided with a circulation pump 26 for reverse circulation.

During each operation, the hot water for hot water supply in the hot water supply circuit 14 circulates as follows. (During heat pump operation; solid line) Hot water supply water passage 10 of the refrigerant water heat exchanger 2 → Exit of hot water supply water passage 10 → Hot water supply pipe 11
1-> hot water storage tank 9-> intake pipe 121-> solenoid valve 24-> intake pipe 121-> circulation pump 13-> intake pipe 121-> inlet of hot water supply water passage 10-> hot water supply passage 1 of refrigerant water heat exchanger 2
0.

(During antifreezing operation; broken line) Hot water supply water passage 10 of the refrigerant water heat exchanger 2 → Inlet of the hot water supply water passage 10 → Water intake pipe 121 → Hot water supply water pipe 27 → Circulation pump 26 → Hot water supply water pipe 27 → Water intake pipe 121 → hot water storage tank 9 → hot water supply pipe 111 → outlet of hot water supply water passage 10 → refrigerant water heat exchanger 2
Hot water supply water passage 10.

Next, the operation of the water heater B will be described with reference to the flow chart shown in FIG. In step S1, hot water supply device B is in a heat pump operation stopped state. In step S2, it is determined whether or not the temperature of the hot water supply water (freezing prevention operation start temperature) detected by the water supply temperature sensor 18 is 3 ° C. or lower, and if it exceeds 3 ° C. (NO), the process returns to step S1. If the heat pump operation is stopped and the temperature is 3 ° C. or lower (YES), the process proceeds to step S3.

In step S3, the controller 16 causes the solenoid valve 24
Is energized to close the valve, and the circulation pump 26 is activated (ON) to start the antifreezing operation.

In step S4, the temperature of the water for hot water supply detected by the water supply temperature sensor 18 (freezing prevention operation end temperature) is 10
It is determined whether or not the temperature is equal to or higher than 10 ° C. If the temperature is lower than 10 ° C. (NO), the process returns to step S3 to continue the antifreezing operation, and if the temperature is higher than 10 ° C. (YES), the process proceeds to step S5.

In step S5, the controller 16 deactivates the circulation pump 26 to stop the energization of the solenoid valve 24 and open it, thereby ending the freeze prevention operation.

The hot water supply device B of this embodiment has the following advantages. [D] In the hot water supply apparatus B, while the heat pump operation is stopped, the temperature of the hot water supply water detected by the water supply temperature sensor 18 (freezing prevention operation start temperature) is 3 ° C. or less, and the hot water supply water in the hot water supply circuit 14 may be frozen. In a certain cold condition, the controller 16 energizes the solenoid valve 24 to bring it into a closed state, and the circulation pump 26 is put into an operating state (ON) to perform the antifreezing operation.

As a result, the temperature of the hot water for hot water supply in the hot water supply circuit 14 can be raised by a short time antifreezing operation, so that the water in the hot water supply circuit 14 can be prevented from freezing and damage to the intake pipe 121 and the like can be prevented. be able to. Since the antifreezing operation is performed for a short time, the amount of heat of the hot water in the hot water storage tank 9 is not significantly lost. Furthermore, it is not necessary to newly provide an auxiliary heat source such as an electric heater.

[E] Since the compressor 1 is not operated and the hot water in the hot water storage tank 9 is used, the power consumption during the antifreezing operation can be kept low.

Next, a third embodiment of the present invention (corresponding to claim 3) will be described with reference to FIGS. 5 and 6. As shown in FIG. 5, in the hot water supply device C, a compressor 1 for compressing a refrigerant, a refrigerant passage 3 of a refrigerant water heat exchanger 2, an expansion valve 4, a refrigerant evaporator 5, and an accumulator 6 are annularly connected by a refrigerant pipe 7. The refrigerant circuit 8 and the hot water storage tank 9 and the hot water supply water passage 10 of the refrigerant water heat exchanger 2 are connected to the hot water supply water pipes 28 to 3.
The circulation pump 1 is connected in an annular shape at 1 and is installed in the hot water supply water pipe 31.
A hot water supply circuit 14 having a three-way valve 3 and a four-way valve 32 are provided.

During each operation, the hot water for hot water supply in the hot water supply circuit 14 circulates as follows. (During heat pump operation; solid line) Hot water supply water passage 10 of the refrigerant water heat exchanger 2 → Exit of hot water supply water passage 10 → Hot water supply water pipe 28 → Four-way valve 32 → Hot water supply water pipe 30 → Hot water storage tank 9 →
Hot water supply water pipe 29 → four-way valve 32 → hot water supply water pipe 31 → circulation pump 13 → hot water supply water pipe 31 → inlet of hot water supply water passage 10 → hot water supply water passage 10 of the refrigerant water heat exchanger 2.

(During antifreezing operation; broken line) Hot water supply water passage 10 of the refrigerant water heat exchanger 2 → Exit of the hot water supply water passage 10 → Hot water supply water pipe 28 → Four-way valve 32 → Hot water supply water pipe 29 → Hot water storage tank 9 → Hot water supply water Pipe 30 → four-way valve 32 → hot water supply water pipe 31 → circulation pump 13 → hot water supply water pipe 31 → inlet of hot water supply water passage 10 → hot water supply water passage 10 of the refrigerant water heat exchanger 2.

Next, the operation of the water heater C will be described with reference to the flow chart shown in FIG. In step st1,
The water heater C is in a heat pump operation stop state. In step st2, it is determined whether or not the temperature of the hot water supply water (freezing prevention operation start temperature) detected by the water supply temperature sensor 18 is 3 ° C. or lower, and if it exceeds 3 ° C. (NO), step st
Returning to 1, the heat pump operation stop state is continued, and if the temperature is 3 ° C. or lower (YES), the process proceeds to step st3.

At step st3, the controller 16 sets the four-way valve 3
2 is energized to switch the flow direction from the γ direction to the δ direction,
The circulation pump 13 is activated (ON) to start the antifreezing operation.

In step st4, the temperature of the hot water supply water detected by the water supply temperature sensor 18 (freezing prevention operation end temperature) is 1
Whether the temperature is 0 ° C. or higher is determined. If the temperature is lower than 10 ° C. (NO), the process returns to step st3 to continue the antifreezing operation, and if the temperature is higher than 10 ° C. (YES), step st5.
Proceed to.

At step st5, the controller 16 deactivates the circulation pump 13, energizes the four-way valve 32, returns the flow direction of the hot water for hot water supply to the original direction (γ direction), and finishes the antifreezing operation.

The hot water supply apparatus C of this embodiment has the following advantages. [F] In the hot water supply apparatus C, the temperature of the hot water supply water (freezing prevention operation start temperature) detected by the water supply temperature sensor 18 is 3 ° C. or less while the heat pump operation is stopped, and the hot water supply water in the hot water supply circuit 14 may be frozen. In a certain cold state, the controller 16 energizes the four-way valve 32 to switch the flow passage direction from the γ direction to the δ direction, and the circulation pump 26 is operated (ON) to perform the antifreezing operation.

As a result, the temperature of the hot water supply water in the hot water supply circuit 14 can be raised by a short-time anti-freezing operation, so that the freezing of the water in the hot water supply circuit 14 can be prevented and the hot water supply water pipes 28-31 and the like can be It can prevent damage. Since the antifreezing operation is performed for a short time, the amount of heat of the hot water in the hot water storage tank 9 is not significantly lost. Furthermore, it is not necessary to newly provide an auxiliary heat source such as an electric heater.

[G] Since the compressor 1 is not operated and the hot water in the hot water storage tank 9 is used, the power consumption during the antifreezing operation can be kept low. Further, since only one circulation pump is required, the manufacturing cost is lower than that of the water heater B.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a hot water supply device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of the hot water supply device.

FIG. 3 is a configuration diagram of a hot water supply device according to a second embodiment of the present invention.

FIG. 4 is a flowchart showing an operation of the hot water supply device.

FIG. 5 is a configuration diagram of a hot water supply device according to a third embodiment of the present invention.

FIG. 6 is a flowchart showing an operation of the hot water supply device.

[Explanation of symbols]

A, B, C water heater 1 compressor (refrigerant compressor) 2 Refrigerant water heat exchanger 3 Refrigerant passage 4 Expansion valve (pressure reducing means) 5 Refrigerant evaporator 7 Refrigerant piping 8 Refrigerant circuit 9 Hot water storage tank 10 Hot water supply passage 11, 12 Hot water supply water piping 13 Circulation pump 14 Hot water supply circuit 15 Bypass means 16 Controller 25 Reverse circulation means 28-31 Hot water supply water piping 32 flow path switching means 111 Hot water supply piping 121 Water intake piping

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Jouji Kuroki             1-1, Showa-cho, Kariya city, Aichi stock market             Inside the company DENSO (72) Inventor, Kousuke Sakakibara             1-1, Showa-cho, Kariya city, Aichi stock market             Inside the company DENSO (72) Inventor Tomoaki Kobayakawa             1-3-1, Uchisaiwaicho, Chiyoda-ku, Tokyo East             Inside Kyoden Electric Co., Ltd. (72) Inventor Kazutoshi Kusakari             1-3-1, Uchisaiwaicho, Chiyoda-ku, Tokyo East             Inside Kyoden Electric Co., Ltd. (72) Inventor Michiyuki Saikawa             2-6-1, Nagasaka, Yokosuka City, Kanagawa Prefecture             Central Research Institute of Electric Power Industry Yokosuka Research Center

Claims (3)

[Claims] 1. A refrigerant circuit formed by annularly connecting a refrigerant compressor, a refrigerant passage of a refrigerant water heat exchanger, a pressure reducing means, and a refrigerant evaporator, a hot water storage tank for storing hot water for hot water supply, and the refrigerant. A hot water supply circuit in which a hot water supply water passage of a water heat exchanger is annularly connected by a hot water supply water pipe, and a circulation pump is provided in the hot water supply water pipe, and the refrigerant compressor, the decompression means, and the circulation pump are controlled. With a controller to operate the heat pump,
In the hot water supply device for heating the hot water supply water passing through the hot water supply water passage of the refrigerant water heat exchanger by activating the refrigerant compressor and the circulation pump, the hot water supply water is bypassed and the hot water supply water is bypassed. Bypass means for circulating the hot water supply water between the passage and the circulation pump via the hot water supply water pipe is provided, and when the heat pump is stopped, the hot water supply water in the hot water supply pipe may freeze during cold weather. The hot water supply apparatus wherein the controller operates the refrigerant compressor and the bypass means to perform freeze prevention operation. 2. A refrigerant circuit in which a refrigerant compressor, a refrigerant passage of a refrigerant water heat exchanger, a pressure reducing means, and a refrigerant evaporator are annularly connected by a refrigerant pipe, and a hot water storage side of a hot water storage tank for storing hot water for hot water supply. And the outlet side of the hot water supply water passage of the refrigerant water heat exchanger is connected by a hot water supply pipe,
A hot water supply circuit in which a water supply side of the hot water storage tank and an inlet side of a hot water supply water passage of the refrigerant water heat exchanger are annularly connected by a water pipe, and a circulation pump is provided in the water intake pipe, the refrigerant compressor, and A pressure reducing means and a controller for controlling the circulation pump are provided, and during heat pump operation,
In a hot water supply device that heats the hot water supply water passing through the hot water supply water passage of the refrigerant water heat exchanger by operating the refrigerant compressor and the circulation pump, the hot water supply water in the hot water supply circuit is reversed. Provided with a reverse circulation means capable of circulating the heat pump, the hot water for hot water supply in the hot water supply circuit may freeze during cold weather,
The hot water supply apparatus wherein the controller operates the reverse circulation means to perform freeze prevention operation. 3. A refrigerant circuit, which comprises a refrigerant compressor, a refrigerant passage of a refrigerant water heat exchanger, a pressure reducing means, and a refrigerant evaporator, which are annularly connected by a refrigerant pipe, and a flow path switching means. A hot water supply circuit in which a hot water storage tank for storing hot water and a hot water supply water passage of the refrigerant water heat exchanger are annularly connected by a hot water supply water pipe having a circulation pump, the refrigerant compressor, the pressure reducing means, the circulation pump, and A controller for controlling the flow path switching means, and in heat pump operation, hot water supply that passes through the hot water supply water passage of the refrigerant water heat exchanger with the controller operating the refrigerant compressor and the circulation pump. Heat the water,
The prepared hot water is supplied to the hot water storage side of the hot water storage tank, the hot water supply water on the water supply side of the hot water storage tank is returned to the inlet side of the hot water supply water passage of the refrigerant water heat exchanger, and the heat pump operation is stopped. During cold weather when the hot water for hot water supply may freeze, the controller operates the flow path switching means and the circulation pump to supply the hot water for hot water stored in the hot water storage side of the hot water storage tank to the hot water for the refrigerant water heat exchanger. A hot water supply apparatus, characterized in that a freezing prevention operation is performed in which hot water supply water is supplied to the inlet side of a passage and hot water supply water is returned from the outlet side of the hot water supply passage to the water supply side of the hot water storage tank.