JP6834494B2 - Hot water storage type water heater - Google Patents

Description

The present invention relates to a hot water storage type water heater.

Conventionally, a technique relating to a heat recovery operation for recovering heat by exchanging heat with hot water in a bathtub using water in a hot water storage tank as a heat medium has been disclosed. For example, the hot water supply system of Patent Document 1 has a configuration for introducing water taken out from a water outlet provided in the lower part of a tank into a heat exchanger. In the heat exchanger, the hot water in the bathtub is circulated to heat the water taken out from the outlet. The water heated by the heat exchanger is returned into the tank from the water inlet provided at the bottom of the tank.

Japanese Unexamined Patent Publication No. 2010-276220

In the heat recovery operation of the apparatus of Patent Document 1, the water taken out from the lower part of the tank is returned from the lower part of the tank after heat exchange. In such a configuration, the temperature of the water stored in the lower part of the tank becomes high due to the heat recovery operation. In this case, there is a problem that the heat exchange efficiency is lowered because the temperature of the water flowing into the heat exchanger becomes high in the heat recovery operation.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a hot water storage type water heater capable of performing heat recovery operation with high energy efficiency.

The hot water storage type water supply machine according to the present invention has a tank connecting pipe connecting the first hot water storage tank, the second hot water storage tank, the lower part of the first hot water storage tank and the upper part of the second hot water storage tank, and the lower part of the second hot water storage tank. A water supply pipe for supplying city water, a water inlet pipe for supplying the water stored in the lower part of the second hot water storage tank to the heating means, and a water supply pipe for supplying the water heated by the heating means to the upper part of the first hot water storage tank. A heat exchanger that is connected to the tub via a hot water outlet pipe and a tub water circulation circuit and exchanges heat between the tub water guided from the tub and a heat medium, and tub water to the tub water circulation circuit and the heat exchanger. The tub water pump that circulates and the water stored in the lower part of the second hot water storage tank are supplied to the heat exchanger as a heat medium, and the heat medium that has passed through the heat exchanger is moved to a position above the lower part of the second hot water storage tank. The heat recovery circuit is provided with a heat recovery circuit for returning the water, a circulation pump for circulating the heat medium to the heat recovery circuit and the heat exchanger, a bath water pump, and a control device for controlling the circulation pump. The heat recovery circuit is a second hot water storage tank. It is configured to include a recovery circulation flow path that connects the lower part of the pipe and a connection point in the middle of the tank connection pipe, and a tank connection pipe from the connection point to the upper part of the second hot water storage tank.
Further, the hot water storage type water supply machine according to the present invention includes a tank connecting pipe connecting the first hot water storage tank, the second hot water storage tank, the lower part of the first hot water storage tank and the upper part of the second hot water storage tank, and the second hot water storage tank. Water supply pipe for supplying city water to the lower part of the water supply pipe, water inlet pipe for supplying the water stored in the lower part of the second hot water storage tank to the heating means, and water heated by the heating means to the upper part of the first hot water storage tank. A heat exchanger that is connected to the bathtub via a hot water supply pipe and a bath water circulation circuit and exchanges heat between the bath water guided from the bathtub and a heat medium, and a bathtub to the bathtub water circulation circuit and the heat exchanger. The bath water pump that circulates water and the water stored in the lower part of the second hot water storage tank are supplied to the heat exchanger as a heat medium, and the heat medium that has passed through the heat exchanger is above the lower part of the second hot water storage tank. A heat recovery circuit for returning to a position, a circulation pump for circulating a heat medium in the heat recovery circuit and a heat exchanger, a bath water pump, and a control device for controlling the circulation pump are provided, and the control device is a bath water pump. It is configured to perform a heat recovery operation that drives the circulation pump while driving, and is equipped with a hot water supply pipe connected to the upper part of the first hot water storage tank and a flow sensor that detects the flow of hot water in the hot water supply pipe, and is controlled. The device is configured to prohibit the execution of the heat recovery operation when the flow sensor detects the flow of hot water.

According to the hot water storage type water heater of the present invention, the heat medium that has passed through the heat exchanger in the heat recovery operation is returned to a position above the lower part of the second hot water storage tank. As a result, it is possible to prevent the temperature of the water stored in the lower part of the second hot water storage tank from rising, so that the heat recovery operation with high energy efficiency can be performed.

It is a block diagram which shows the main part of the hot water storage type heat pump water heater in Embodiment 1. FIG. It is a figure which shows the structure of the heat pump heating means. It is a circuit block diagram at the time of heat recovery operation of the hot water storage type heat pump water heater of Embodiment 1. FIG. It is a figure which shows the application example of the hot water storage type heat pump water heater of Embodiment 1. FIG. It is a circuit block diagram at the time of hot water filling operation of the system shown in FIG. It is a circuit block diagram at the time of the reheating operation of the system shown in FIG. It is a circuit block diagram at the time of heat recovery operation of the system shown in FIG.

Hereinafter, embodiments will be described with reference to the drawings. The elements common to each figure are designated by the same reference numerals, and duplicate description will be omitted.

Embodiment 1.
[Structure of Embodiment 1]
FIG. 1 is a configuration diagram showing a main part of a hot water storage type heat pump water heater according to the first embodiment. The hot water storage type heat pump water heater 1 shown in FIG. 1 is configured as a hot water storage type water heater including a hot water storage tank unit 10 and a heat pump heating means 31. The heat pump heating means 31 is a unit configured to utilize a heat pump cycle. The hot water storage tank unit 10 and the heat pump heating means 31 are connected by a heat pump water inlet pipe 4 and a heat pump hot water outlet pipe 5. Further, the hot water storage tank unit 10 has a built-in control device 100. The operation of various valves, pumps, etc. included in the hot water storage tank unit 10 and the heat pump heating means 31 is controlled by the control device 100 connected to them via wiring. Hereinafter, each component of the hot water storage type heat pump water heater 1 will be described.

The hot water storage tank unit 10 includes a first hot water storage tank 2a and a second hot water storage tank 2b. In the following description, when the first hot water storage tank 2a and the second hot water storage tank 2b are not particularly distinguished, they are simply referred to as "hot water storage tank 2". The lower part of the first hot water storage tank 2a and the upper part of the second hot water storage tank 2b are connected by a tank connecting pipe 3. The upper portion of the second hot water storage tank 2b referred to here is not limited to the upper end portion of the second hot water storage tank 2b as shown in FIG. That is, the tank connecting pipe 3 may be connected at a position higher than the lower part of the second hot water storage tank 2b to which the heat pump water inlet pipe 4 or the water supply pipe 6 described later is connected.

The lower portion of the second hot water storage tank 2b is connected to the heat pump heating means 31 via the heat pump water inlet pipe 4. Further, the upper portion of the first hot water storage tank 2a is connected to the heat pump heating means 31 via the heat pump hot water discharge pipe 5. A water supply pipe 6 for supplying city water is connected to the lower part of the second hot water storage tank 2b. High-temperature water heated by the heat pump heating means 31 flows into the first hot water storage tank 2a from the upper part of the tank via the heat pump hot water outlet pipe 5.

FIG. 2 is a diagram showing a configuration of a heat pump heating means. The heat pump heating means 31 is an example of a heating means for heating the low-temperature water led from the hot water storage tank unit 10. The heat pump heating means 31 includes a compressor 32, a gas cooler 33, an internal heat exchanger 34, an expansion valve 35, and an air heat exchanger 36. The heat pump heating means 31 includes a refrigerant circuit 37 in which these parts are sequentially connected in an annular shape, and operates a refrigeration cycle, that is, a heat pump cycle. The compressor 32 compresses the low-pressure refrigerant gas. The refrigerant may be, for example, carbon dioxide. The gas cooler 33 exchanges heat between the high-temperature and high-pressure refrigerant discharged from the compressor 32 and the low-temperature water led from the hot water storage tank unit 10.

The expansion valve 35 is an example of a pressure reducing device that reduces the pressure of the high pressure refrigerant into the low pressure refrigerant. The decompressed low-pressure refrigerant is in a gas-liquid two-phase state. The air heat exchanger 36 is a heat exchanger that exchanges heat between the low-pressure refrigerant and the atmosphere. In the air heat exchanger 36, the low pressure refrigerant evaporates by absorbing the heat of the atmosphere. The internal heat exchanger 34 includes a high pressure flow path and a low pressure flow path. The internal heat exchanger 34 exchanges heat between the high-pressure refrigerant flowing through the high-pressure flow path and the low-pressure refrigerant flowing through the low-pressure flow path. The low-pressure refrigerant gas evaporated in the air heat exchanger 36 is sucked into the compressor 32 via the low-pressure flow path of the internal heat exchanger 34.

As shown in FIG. 1, a heat source pump 7 is provided in the middle of the heat pump water inlet pipe 4. When the heat source pump 7 is driven, the water stored in the lower part of the second hot water storage tank 2b is sent to the gas cooler 33 of the heat pump heating means 31. In the heat pump heating means 31, the water introduced by the heat exchange in the gas cooler 33 is heated. The high-temperature water after heating is stored in the tank from the upper part of the first hot water storage tank 2a via the heat pump hot water discharge pipe 5. By such a boiling operation is performed, from the top to the bottom of the first hot water tank 2a, and in turn the hot water is accumulated and via the tank connection pipe 3 from the top to the bottom of the second hot-water storage tank 2 b.

A high temperature pipe 8 for taking out the high temperature water stored in the upper part of the first hot water storage tank 2a is connected to the upper part of the first hot water storage tank 2a. The high temperature pipe 8 is connected to the hot water supply mixing valve 11 together with the low temperature pipe 9 branched from the water supply pipe 6. The hot water supply mixing valve 11 mixes the high temperature water flowing through the high temperature pipe 8 and the low temperature water flowing through the low temperature pipe 9. The hot water whose temperature is adjusted by the hot water supply mixing valve 11 is supplied from the hot water supply pipe 12 to a hot water supply load such as a faucet in the kitchen or a shower in the bathroom in response to a hot water supply request from the user. Hereinafter, such a hot water supply operation is referred to as a hot water supply operation. Further, a hot water supply flow rate sensor 13 for detecting the flow rate of hot water flowing through the hot water supply pipe 12 is arranged in the hot water supply pipe 12.

Next, the characteristic configuration of the hot water storage type heat pump water heater 1 of the first embodiment will be described. The hot water storage tank unit 10 of the hot water storage type heat pump water heater 1 includes a recovery circulation flow path 15 that connects the lower portion of the second hot water storage tank 2b and the tank connecting pipe 3. As a result, a heat recovery circuit is formed that returns from the lower part of the second hot water storage tank 2b to the upper part of the second hot water storage tank 2b via the recovery circulation flow path 15 and the tank connecting pipe 3. A bath heat exchanger 16 is provided in the middle of the recovery circulation flow path 15. The bath heat exchanger 16 is a heat exchange for exchanging heat with the bathtub water in the bathtub using the water flowing through the heat recovery circuit as a heat medium. The bath heat exchanger 16 is provided in the middle of the bathtub water circulation circuit 20 that circulates the bathtub water. Further, in the middle of the bathtub water circulation circuit 20, a bath heat primary pump 21 as a bathtub water pump for circulating bathtub water is installed.

A bath heat secondary pump 17 as a circulation pump is provided in the recovery circulation flow path 15 between the lower portion of the second hot water storage tank 2b and the bath heat exchanger 16. The bath heat secondary pump 17 takes out the water stored in the lower part of the second hot water storage tank 2b and sends it to the bath heat exchanger 16. A check valve 18 is provided on the downstream side of the bath heat exchanger 16 in the recovery circulation flow path 15. The check valve 18 regulates the backflow of the recovery circulation flow path 15, that is, the water flow in the direction opposite to the direction A in the drawing.

A first baffle 22 is provided at a connection portion of the first hot water storage tank 2a with the tank connecting pipe 3. Further, a second baffle 23 is provided at a connection portion of the second hot water storage tank 2b with the tank connecting pipe 3. The first baffle 22 and the second baffle 23 are for preventing the water in the tank from being agitated by the water flow flowing from the tank connecting pipe 3 into the first hot water storage tank 2a and the second hot water storage tank 2b.

[Operation of the first embodiment]
Next, the characteristic operation of the hot water storage type heat pump water heater 1 of the first embodiment will be described. The hot water storage type heat pump water heater 1 of the first embodiment performs a heat recovery operation for recovering heat from the bathtub water. FIG. 3 is a circuit configuration diagram during heat recovery operation of the hot water storage type heat pump water heater of the first embodiment. The heat recovery operation referred to here is an operation of recovering the heat in the bathtub and storing it in the hot water storage tank 2 while the bathtub is filled with hot water. During this heat recovery operation, the control device 100 drives the bath heat primary pump 21 and the bath heat secondary pump 17. When the bath heat primary pump 21 is driven, the bath water in the bathtub circulates in the bathtub water circulation circuit 20. Further, when the bath heat secondary pump 17 is driven, the low temperature water stored in the lower part of the second hot water storage tank 2b circulates in the heat recovery circuit. The low-temperature water flowing into the bath heat exchanger 16 is heated by heat exchange with the bathtub water, and then flows into the tank from the upper part of the second hot water storage tank 2b.

According to such a heat recovery operation, the following actions and effects can be obtained. In the heat recovery operation, the low-temperature water stored in the lower part of the second hot water storage tank 2b is heated in the bath heat exchanger 16 and then returned to the upper part of the second hot water storage tank 2b. According to such a heat recovery operation, it is possible to prevent the temperature of the low temperature water stored in the lower part of the second hot water storage tank 2b from becoming high. As a result, it is possible to suppress the temperature difference between the low temperature water and the bath water in the bath heat exchanger 16 from becoming small, so that the heat recovery operation with high energy efficiency can be performed. Further, in the heat recovery operation of the first embodiment, water does not flow in and out of the first hot water storage tank 2a. As a result, it is possible to recover heat from the bath water while preventing a decrease in the effective heat amount in the first hot water storage tank 2a.

According to the heat recovery operation of the first embodiment, a part of the tank connecting pipe 3 also serves as a heat recovery circuit. Therefore, it is possible to achieve so-called VE (Value Engineering) that realizes the same function at a lower cost.

In the piping configuration as described above, when the heat recovery operation is performed, the connection point P1 between the recovery circulation flow path 15 and the tank connecting pipe 3 reaches the second hot water storage tank 2b via the tank connecting pipe 3. The second heat from the first heat recovery path and the connection point P1 to the second hot water storage tank 2b via the tank connecting pipe 3, the first hot water storage tank 2a, the heat pump hot water outlet pipe 5, the heat pump heating means 31 and the heat pump water inlet pipe 4. A recovery route is formed. Therefore, in the configuration in which the recovery circulation flow path 15 is connected to the tank connecting pipe 3, the pipe length, the pipe diameter, and the like so that the pressure loss of the first heat recovery path is smaller than the pressure loss of the second heat recovery path. It is preferable to set the arrangement parts and the like. As a result, when the heat recovery operation is performed, it is possible to prevent the water after the heat recovery from flowing into the first hot water storage tank 2a.

Further, in the above piping configuration, when the hot water supply operation is performed, the first hot water supply route from the second hot water storage tank 2b to the connection point P1 via the tank connecting pipe 3 and the second hot water storage tank 2b A second hot water supply path to the connection point P1 is formed via the recovery circulation flow path 15. Therefore, in the configuration in which the recovery circulation flow path 15 is connected to the tank connecting pipe 3, the pipe length, pipe diameter, and arrangement are arranged so that the pressure loss in the first hot water supply path is smaller than the pressure loss in the second hot water supply path. It is preferable to set parts and the like. As a result, when the hot water supply operation is performed, it is possible to prevent the low temperature water taken out from the lower part of the second hot water storage tank 2b from flowing into the first hot water storage tank 2a.

The hot water storage type heat pump water heater 1 of the first embodiment includes a check valve 18 in the middle of the recovery circulation flow path 15. As a result, even when the temperature distribution of the water in the second hot water storage tank 2b changes, it is possible to prevent the water in the recovery circulation flow path 15 from flowing back due to convection. As a result, heat dissipation due to the high temperature water in the second hot water storage tank 2b or the tank connecting pipe 3 flowing into the recovery circulation flow path 15 can be suppressed, and energy efficiency can be improved.

In the hot water storage type heat pump water heater 1 of the first embodiment, the bath heat secondary pump 17 is provided in the recovery circulation flow path 15 from the lower part of the second hot water storage tank 2b to the bath heat exchanger 16. According to such a configuration, since the suction side of the bath heat secondary pump 17 is surely filled with water, it is possible to prevent the water from being unable to be sent due to the mixing of air into the pump.

The hot water storage type heat pump water heater 1 of the first embodiment includes a first baffle 22. As a result, for example, even if a heat recovery operation is performed during hot water supply and water flows into the first hot water storage tank 2a from the tank connecting pipe 3, it is possible to avoid unnecessarily disturbing the temperature distribution in the first hot water storage tank 2a. To. As a result, it is possible to reduce the decrease in the amount of effective heat in the first hot water storage tank 2a.

The hot water storage type heat pump water heater 1 of the first embodiment includes a second baffle 23. As a result, for example, even when the amount of hot water flowing into the tank from the upper part of the second hot water storage tank 2b via the heat recovery circuit is large in the heat recovery operation, the water in the second hot water storage tank 2b is rapidly agitated. It is possible to prevent the temperature of the water stored in the lower part from becoming high.

By the way, in the hot water storage type heat pump water heater 1 of the first embodiment, if the hot water supply operation is started during the execution of the heat recovery operation, it is preferable to interrupt the heat recovery operation. Such control may be configured to prohibit the execution of the heat recovery operation during the period when the control device 100 detects that the hot water supply operation is being performed by the hot water supply flow rate sensor 13. According to such control, it is possible to suppress the disturbance of the temperature distribution in the tank due to the relatively low temperature water after the heat recovery entering the tank from the lower part of the first hot water storage tank 2a.

Further, in the hot water storage type heat pump water heater 1 of the first embodiment, the recovery circulation flow path 15 is connected in the middle of the tank connecting pipe 3. However, the recovery circulation flow path 15 may be configured to be directly connected to the upper part of the second hot water storage tank 2b.

[Application Example of Embodiment 1]
FIG. 4 is a diagram showing an application example of the hot water storage type heat pump water heater of the first embodiment. In FIG. 4, the description of the elements common to those in FIG. 1 will be omitted or simplified.

The hot water storage type heat pump water heater 1 of the first embodiment can be applied to, for example, the system shown in FIG. The hot water storage type heat pump water heater 1 shown in FIG. 4 has a first three-way valve 40, a second three-way valve 41, and a four-way valve 42. The first three-way valve 40 has two ports b and c, which are two inlets for water, and a port, which is one outlet for hot water to flow out. The first three-way valve 40 is configured so that the water path can be switched so that water flows in from either the b port or the c port. The second three-way valve 41 has two ports a and b, which are two inlets for water to flow in, and a c port, which is one outlet for hot water to flow out. The second three-way valve 41 is configured so that the water path can be switched so that water flows in from either the a port or the b port. The four-way valve 42 has two inlets, a port and b port, for water to flow in, and a c port and d port, which are two outlets for water to flow out. The four-way valve 42 is configured so that the flow path form can be switched between the three paths, that is, the a-c path, the bc path, and the b-d path.

Further, the hot water storage type heat pump water supply machine 1 has a pipe 43, a pipe 44, a pipe 45, a pipe 46, a pipe 47, a pipe 48, a pipe 49, a pipe 50 and a pipe 51. The pipe 43 is a flow path connecting the lower portion of the second hot water storage tank 2b and the b port of the first three-way valve 40. Further, the pipe 49 is a flow path connecting the a port of the first three-way valve 40 and the inlet side of the heat pump heating means 31. Further, the pipe 48 is a flow path connecting the outlet side of the heat pump heating means 31 and the a port of the four-way valve 42. Further, the pipe 44 is a flow path connecting the c port of the four-way valve 42 and the a port of the second three-way valve 41. The pipe 45 is a flow path connecting the d port of the four-way valve 42 and the lower portion of the second hot water storage tank 2b. The pipe 51 is a flow path that connects the middle of the tank connecting pipe 3 and the c port of the second three-way valve 41. The pipe 47 is a flow path connecting a portion of the pipe 51 on the outlet side of the bath heat exchanger 16 and the c port of the first three-way valve 40. Further, the pipe 46 is a flow path connecting the portion of the pipe 49 on the outlet side of the heat source pump 7 and the b port of the four-way valve 42. The pipe 50 is a flow path connecting the b port of the second three-way valve 41 and the upper part of the first hot water storage tank 2a.

Further, the hot water storage type heat pump water heater 1 is provided with a bath mixing valve 60. The two inlets of the bath mixing valve 60 are connected to the high temperature pipe 8 and the low temperature pipe 9, respectively. The pipe 61 connects one outlet of the bath mixing valve 60 to the middle of the bathtub water circulation circuit 20. A solenoid valve 62 is provided in the middle of the pipe 61. The bath mixing valve 60 mixes the high temperature water flowing through the high temperature pipe 8 and the low temperature water flowing through the low temperature pipe 9. The solenoid valve 62 switches between an open state and a closed state of the pipe 61.

In the system configured in this way, each element of the hot water storage type heat pump water heater 1 is realized by the following configuration. The heat pump water inlet pipe 4 is realized by the pipe 43 and the pipe 49. The heat pump hot water discharge pipe 5 is realized by the pipe 48, the pipe 44, and the pipe 50. The recovery circulation flow path 15 is realized by a pipe 43, a pipe 49, a pipe 46, a pipe 44, and a pipe 51. Further, the bath heat secondary pump 17 is realized by the heat source pump 7.

In the system shown in FIG. 4, the first three-way valve 40, the second three-way valve 41, and the four-way valve 42 are controlled according to the operating conditions shown in FIGS. 5 to 7 below to control the flow of water in the hot water storage tank unit 10. It is designed to be used by switching routes. FIG. 5 is a circuit configuration diagram of the system shown in FIG. 4 during hot water filling operation. The hot water filling operation referred to here is an operation of supplying hot water stored in the hot water storage tank 2 to the bathtub. During this hot water filling operation, the solenoid valve 62 is opened to form a flow path communicating from the pipe 61 to the bathtub via the bathtub water circulation circuit 20. The control device 100 adjusts the bath mixing valve 60 so that the hot water supply temperature to the bathtub becomes the target temperature. When the hot water filling operation is performed, the high temperature water in the first hot water storage tank 2a decreases. Therefore, in the hot water filling operation, hot water is supplied from the upper part of the second hot water storage tank 2b to the lower part of the first hot water storage tank 2a via the tank connecting pipe 3.

Next, FIG. 6 is a circuit configuration diagram during the reheating operation of the system shown in FIG. The reheating operation referred to here is an operation in which the bath heat exchanger 16 heats the bathtub water by exchanging heat between the hot water stored in the hot water storage tank 2 and the bathtub water. During this reheating operation, the first three-way valve 40 is controlled so that the c port and the a port communicate with each other and the b port is closed. As a result, the pipe 47 and the pipe 49 are communicated with each other, and the pipe 43 side is closed. Further, the four-way valve 42 is controlled so that the b port and the d port communicate with each other and the c port and the a port are closed. As a result, the pipe 46 and the pipe 45 are communicated with each other, and the pipe 48 side and the pipe 44 side are closed.

The reheating operation is executed by starting the operation of the heat source pump 7 and the bath heat primary pump 21 in a state where the first three-way valve 40 and the four-way valve 42 are controlled as described above. In this reheating operation state, the operation of the heat pump heating means 31 is stopped. As a result, the high-temperature water flowing out from the upper part of the first hot water storage tank 2a is guided to the bath heat exchanger 16 via the pipe 51, and heat exchange is performed with the bath water. The low-temperature water that has become cold due to heat exchange passes through the second hot water storage tank 2b via the pipe 51, the pipe 47, the first three-way valve 40, the pipe 49, the heat source pump 7, the pipe 46, the four-way valve 42, and the pipe 45. It is returned to the tank from the bottom. When the reheating operation is performed, the high temperature water in the first hot water storage tank 2a decreases. Therefore, in the reheating operation, hot water is supplied from the upper part of the second hot water storage tank 2b to the lower part of the first hot water storage tank 2a via the tank connecting pipe 3.

Next, FIG. 7 is a circuit configuration diagram during the heat recovery operation of the system shown in FIG. During this heat recovery operation, the first three-way valve 40 is controlled so that the b port and the a port communicate with each other and the c port is closed. As a result, the pipe 43 and the pipe 49 communicate with each other, and the pipe 47 side is closed. Further, the four-way valve 42 is controlled so that the b port and the c port communicate with each other and the a port and the d port are closed. As a result, the pipe 46 and the pipe 44 are communicated with each other, and the pipe 48 side and the pipe 45 side are closed. Further, the second three-way valve 41 is controlled so that the a port and the c port communicate with each other and the b port is closed. As a result, the pipe 44 and the pipe 51 communicate with each other, and the pipe 50 side is closed.

The heat recovery operation is executed by starting the operation of the heat source pump 7 and the bath heat primary pump 21 in a state where the first three-way valve 40, the second three-way valve 41, and the four-way valve 42 are controlled as described above. .. In this heat recovery operation state, the operation of the heat pump heating means 31 is stopped. As a result, the low-temperature water flowing out from the lower part of the second hot water storage tank 2b is the pipe 43, the first three-way valve 40, the pipe 49, the heat source pump 7, the pipe 46, the four-way valve 42, the pipe 44, the second three-way valve 41 and the pipe. It is guided to the bath heat exchanger 16 via 51, and heat exchange is performed with the bath water. The water that has recovered the heat of the bathtub water by heat exchange is returned to the tank from the upper part of the second hot water storage tank 2b via the pipe 51 and the tank connecting pipe 3. During the heat recovery operation, water does not flow in or out of the first hot water storage tank 2a.

As described above, according to the hot water storage type heat pump water heater 1 shown in FIG. 4, the first three-way valve 40, the second three-way valve 41 and the four-way valve 42 are controlled to perform hot water filling operation, reheating operation and heat recovery operation. It can be realized.

1 Hot water storage type heat pump water supply machine, 2a 1st hot water storage tank, 2b 2nd hot water storage tank, 3 tank connection pipe, 4 heat pump water inlet pipe, 5 heat pump hot water outlet pipe, 6 water supply pipe, 7 heat source pump, 8 high temperature pipe, 9 low temperature pipe, 10 Hot water storage tank unit, 11 Hot water supply mixing valve, 12 Hot water supply piping, 13 Hot water supply flow sensor, 15 Recovery circulation flow path, 16 Bath heat exchanger, 17 Bath heat secondary pump, 18 Check valve, 20 Bath water circulation circuit, 21 Bath Primary heat pump, 22 1st baffle, 23 2nd baffle, 31 Heat pump heating means, 32 Compressor, 33 Gas cooler, 34 Internal heat exchanger, 35 Expansion valve, 36 Air heat exchanger, 37 Coolant circuit, 40 1st 3rd way Valve, 41 2nd 3-way valve, 42 4-way valve, 43, 44, 45, 46, 47, 48, 49, 50, 51 piping, 60 mixing valve, 61 piping, 62 electromagnetic valve, 100 control device

Claims (9)

The first hot water storage tank and
The second hot water storage tank and
A tank connecting pipe connecting the lower part of the first hot water storage tank and the upper part of the second hot water storage tank, and
A water supply pipe for supplying city water to the lower part of the second hot water storage tank,
A water inlet pipe that supplies the water stored in the lower part of the second hot water storage tank to the heating means, and
A hot water outlet pipe that supplies water heated by the heating means to the upper part of the first hot water storage tank, and
A heat exchanger that is connected to the bathtub via a bathtub water circulation circuit and exchanges heat between the bathtub water guided from the bathtub and a heat medium.
A bathtub water pump that circulates bathtub water to the bathtub water circulation circuit and the heat exchanger,
The water stored in the lower part of the second hot water storage tank is supplied to the heat exchanger as the heat medium, and the heat medium that has passed through the heat exchanger is moved to a position above the lower part of the second hot water storage tank. With a heat recovery circuit to return
A circulation pump that circulates the heat medium through the heat recovery circuit and the heat exchanger,
The bathtub water pump, a control device for controlling the circulation pump, and the like.
With
The heat recovery circuit
A recovery circulation flow path that connects the lower part of the second hot water storage tank and a connection point in the middle of the tank connecting pipe,
The tank connecting pipe from the connection point to the upper part of the second hot water storage tank, and
A hot water storage type water heater characterized by being configured to include. The pressure loss of the first heat recovery path from the connection point to the second hot water storage tank via the tank connecting pipe is the tank connecting pipe, the first hot water storage tank, the hot water discharge pipe, and the heating means. The hot water storage type water heater according to claim 1 , further comprising a pressure loss of a second heat recovery path leading to the second hot water storage tank via the water inlet pipe. The pressure loss of the first hot water supply path from the second hot water storage tank to the connection point via the tank connecting pipe reaches the connection point from the second hot water storage tank via the recovery circulation flow path. The hot water storage type water heater according to claim 1 or 2 , wherein the water heater is configured to be smaller than the pressure loss in the hot water supply path. The control device according to any one of claims 1 to 3 , wherein the control device is configured to perform a heat recovery operation for driving the circulation pump while driving the bathtub water pump. Hot water storage type water heater. The hot water supply pipe connected to the upper part of the first hot water storage tank and
It is equipped with a flow rate sensor that detects the flow of hot water in the hot water supply pipe.
The hot water storage type water heater according to claim 4 , wherein the control device is configured to prohibit execution of the heat recovery operation when the flow rate sensor detects the flow of hot water. From claim 1, the first baffle provided at a connection portion of the first hot water storage tank with the tank connecting pipe and for suppressing the water flow from the tank connecting pipe to the first hot water storage tank is further provided. The hot water storage type water heater according to any one of claims 5. According to claim 1, a second baffle provided at a connection portion of the second hot water storage tank with the tank connecting pipe and for suppressing a water flow from the tank connecting pipe to the second hot water storage tank is further provided. The hot water storage type water heater according to any one of claims 6. Claims 1 to 7 further include a check valve provided in the middle of the heat recovery circuit and for regulating the flow of the heat medium from the heat exchanger to the lower part of the second hot water storage tank. The hot water storage type water heater according to any one of the above. The first hot water storage tank and
The second hot water storage tank and
A tank connecting pipe connecting the lower part of the first hot water storage tank and the upper part of the second hot water storage tank, and
A water supply pipe for supplying city water to the lower part of the second hot water storage tank,
A water inlet pipe that supplies the water stored in the lower part of the second hot water storage tank to the heating means, and
A hot water outlet pipe that supplies water heated by the heating means to the upper part of the first hot water storage tank, and
A heat exchanger that is connected to the bathtub via a bathtub water circulation circuit and exchanges heat between the bathtub water guided from the bathtub and a heat medium.
A bathtub water pump that circulates bathtub water to the bathtub water circulation circuit and the heat exchanger,
The water stored in the lower part of the second hot water storage tank is supplied to the heat exchanger as the heat medium, and the heat medium that has passed through the heat exchanger is moved to a position above the lower part of the second hot water storage tank. With a heat recovery circuit to return
A circulation pump that circulates the heat medium through the heat recovery circuit and the heat exchanger,
The bathtub water pump, a control device for controlling the circulation pump, and the like.
With
The control device is configured to perform a heat recovery operation for driving the circulation pump while driving the bathtub water pump.
The hot water supply pipe connected to the upper part of the first hot water storage tank and
It is equipped with a flow rate sensor that detects the flow of hot water in the hot water supply pipe.
The control device is a hot water storage type water heater, which is configured to prohibit execution of the heat recovery operation when the flow rate sensor detects the flow of hot water.

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