JP6515859B2 - Hot water storage system - Google Patents

Description

  The present invention relates to a hot water storage type hot water supply system.

  The following hot water storage type hot water supply system is disclosed by the following patent document 1. A first mixing valve (22) and a second mixing valve (29) are provided. The first mixing valve (22) mixes the hot water from the hot water outlet pipe (7) connected to the upper part of the hot water storage tank (2) with the hot water from the water supply bypass pipe (23). The second mixing valve (29) is provided in the middle of the water supply bypass pipe (23). The second mixing valve (29) mixes the hot water from the intermediate outlet pipe (27) with the hot water flowing through the water supply bypass pipe (23).

  When the detected temperature of the intermediate temperature sensor (28) is higher than the temperature which is higher by a fixed temperature (for example 5 ° C.) than the hot water supply set temperature, the second mixing valve (29) causes the hot water from the intermediate outlet pipe (27) and the water supply bypass pipe The water from (23) is mixed to the set temperature and hot water is supplied. At this time, the outlet pipe (7) side of the first mixing valve (22) is fully closed.

  When the temperature detected by the intermediate temperature sensor (28) is lower than a temperature lower by a fixed temperature (for example, 5 ° C.) than the hot water supply set temperature, the intermediate discharge pipe (27) side of the second mixing valve (29) is fully opened. The hot water from the hot water discharge pipe (7) is mixed with the mixing valve (22) to supply hot water of the hot water setting temperature.

  When the detected temperature of the intermediate temperature sensor (28) is lower than the fixed temperature higher than the hot water supply set temperature and not lower than the fixed temperature lower than the hot water supply set temperature, the intermediate mixing pipe (27) with the second mixing valve (29) The hot water from the water and the water from the water supply bypass pipe (23) are mixed so that the temperature is lower by a predetermined temperature (for example, 5 ° C.) than the hot water supply setting temperature, and the mixed hot water and the hot water from the hot water pipe (7) are mixed Then, the first mixing valve (22) is controlled to supply the hot water of the hot water supply set temperature.

JP, 2004-197958, A

  The middle part of the hot water storage tank has a large temperature fluctuation due to the heat radiation of hot water and the thermal diffusion between the high temperature part and the low temperature part in the hot water storage tank. For this reason, the temperature of the medium-temperature water taken out from the middle part of the hot water storage tank may cause a rapid fluctuation, for example, a fluctuation of 5 ° C. or more per second.

  In the technology of Patent Document 1 described above, the hot water supply temperature is likely to fluctuate greatly in the following cases. If the temperature of middle warm water detected by the intermediate temperature sensor (28) is higher than a temperature higher by a fixed temperature (for example, 5 ° C.) than the hot water supply set temperature, low temperature water from the middle warm water and water source by the second mixing valve (29) And hot water by mixing to the set temperature. At this time, the side of the hot water discharge pipe (7) of the first mixing valve (22) is fully closed. When the temperature of the middle warm water from the intermediate tapping pipe (27) drops sharply, the hot water supply temperature drops sharply. When such a rapid drop in the temperature of the hot water supply is detected, the first mixing valve (22) operates largely to open the hot water outlet pipe (7) side. As a result, the hot water supply temperature may rise rapidly and may overshoot.

  The present invention has been made to solve the problems as described above, and provides a hot water storage type hot water supply system capable of achieving both effective utilization of middle warm water of a hot water storage tank and reduction of fluctuation of hot water supply temperature. The purpose is

The storage type hot water supply system according to the present invention is supplied from a storage hot water tank, high temperature piping connected to the top of the hot water storage tank, intermediate temperature piping connected to the hot water storage tank at a position lower than the connection position of the high temperature piping, and high temperature piping At least one mixing means for controlling the temperature of the hot water supplied to the hot water supply destination by mixing the high-temperature water with the low-temperature water supplied from the water source or the medium-temperature water supplied from the medium-temperature piping; Flow passage switching means for switching between the use condition of middle warm water which is a flow passage condition supplied to one mixing means and the use condition of middle warm water which is a flow passage condition of low temperature water being supplied to at least one mixing means; A means for detecting the temperature of the medium-temperature water and a means for controlling the at least one mixing means and the passage switching means, wherein the temperature of the medium-temperature water is lower than the first reference temperature which is a temperature lower than the hot water supply set temperature. If the temperature of middle warm water is higher than the second reference temperature which is lower than the hot water supply set temperature and higher than the first reference temperature, the flow passage switching means is switched to the middle warm water utilization state. Switch the switching means to the medium water non-use state, allow switching of the flow path switching means when the hot water supply to the hot water supply destination is stopped, and switch the flow path switching means when the hot water supply to the hot water supply destination is in progress It is not a thing.
In the storage type hot water supply system according to the present invention, the storage hot water tank, the high temperature piping connected to the upper portion of the hot water storage tank, the medium temperature piping connected to the hot water storage tank at a position lower than the connection position of the high temperature piping, and the high temperature piping At least one mixing means for controlling the temperature of the hot water supplied to the hot water supply destination by mixing the supplied high temperature water and the low temperature water supplied from the water source or the medium warm water supplied from the medium temperature piping, and the medium warm water A channel switching means for switching between the use condition of middle warm water, which is a flow passage condition supplied to at least one mixing unit, and the use condition of middle warm water, which is a flow passage condition where low temperature water is supplied to at least one mixing unit And means for detecting the temperature of the medium-temperature water and means for controlling the at least one mixing means and the passage switching means, and the medium-temperature water has a temperature lower than the hot water supply set temperature compared to the first reference temperature. If the degree is low, the flow path switching means is switched to the use condition of middle warm water, and if the temperature of middle warm water is higher than the second reference temperature which is lower than the hot water supply set temperature and higher than the first reference temperature, The at least one mixing means when the flow path switching means is switched to the middle warm water non-use state and the hot water supply to the hot water supply destination is stopped while the flow path switching means is the middle warm water use state is at the first standby position. At least one mixing means when the switching means is in the non-use condition and the hot water supply to the hot water supply destination is stopped is in the second standby position, and the second standby position is higher in temperature than the first standby position. And the at least one mixing means is operated from the first standby position to the second standby position after the flow path switching means is switched from the middle warm water utilization state to the middle warm water nonuse state. .
In the storage type hot water supply system according to the present invention, the storage hot water tank, the high temperature piping connected to the upper portion of the hot water storage tank, the medium temperature piping connected to the hot water storage tank at a position lower than the connection position of the high temperature piping, and the high temperature piping At least one mixing means for controlling the temperature of the hot water supplied to the hot water supply destination by mixing the supplied high temperature water and the low temperature water supplied from the water source or the medium warm water supplied from the medium temperature piping, and the medium warm water A channel switching means for switching between the use condition of middle warm water, which is a flow passage condition supplied to at least one mixing unit, and the use condition of middle warm water, which is a flow passage condition where low temperature water is supplied to at least one mixing unit And means for detecting the temperature of middle warm water, means for controlling at least one mixing means and flow path switching means, and an operation mode giving priority to improvement of energy efficiency as compared to the first operation mode. Means for enabling the user to set the second operation mode, and when the temperature of the medium temperature water is lower than the first reference temperature which is a temperature lower than the hot water supply set temperature, the passage switching means is used as the medium temperature water When the temperature of middle warm water is higher than the second reference temperature which is lower than the hot water supply set temperature and higher than the first reference temperature, the flow path switching unit is switched to the middle warm water non-use state. When the operation mode is set, the values of the first reference temperature and the second reference temperature are increased as compared with the case where the operation mode is not set.
In the storage type hot water supply system according to the present invention, the storage hot water tank, the high temperature piping connected to the upper portion of the hot water storage tank, the medium temperature piping connected to the hot water storage tank at a position lower than the connection position of the high temperature piping, and the high temperature piping At least one mixing means for controlling the temperature of the hot water supplied to the hot water supply destination by mixing the supplied high temperature water and the low temperature water supplied from the water source or the medium warm water supplied from the medium temperature piping, and the medium warm water A channel switching means for switching between the use condition of middle warm water, which is a flow passage condition supplied to at least one mixing unit, and the use condition of middle warm water, which is a flow passage condition where low temperature water is supplied to at least one mixing unit And means for detecting the temperature of the medium-temperature water and means for controlling the at least one mixing means and the passage switching means, and the medium-temperature water has a temperature lower than the hot water supply set temperature compared to the first reference temperature. If the degree is low, the flow path switching means is switched to the use condition of middle warm water, and if the temperature of middle warm water is higher than the second reference temperature which is lower than the hot water supply set temperature and higher than the first reference temperature, When the flow switching means is switched to the middle warm water non-use state, and the circuit of circulating the water of the circuit which returns water from inside the hot water storage tank and returns it to the hot water storage tank is executed, the flow path switching means to the middle warm water non-use state It is what changes.

  According to the storage type hot water supply system of the present invention, it is possible to make effective use of middle warm water of the hot water storage tank and to reduce fluctuation of the hot water supply temperature.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the hot water storage type hot-water supply system of Embodiment 1. FIG. 5 is a flowchart of a routine executed in the first embodiment.

Embodiment 1
FIG. 1 is a diagram showing a hot water storage type hot water supply system according to a first embodiment. The hot water storage type hot water supply system 35 according to the first embodiment shown in FIG. 1 includes a tank unit 33, an HP (heat pump) unit 7, and a remote control 44. The HP unit 7 and the tank unit 33 are connected via the HP forward piping 14, the HP return piping 15, and an electrical wiring (not shown). The tank unit 33 incorporates a control device 36. The operations of the various valves, pumps, and the like included in the tank unit 33 and the HP unit 7 are controlled by a controller 36 electrically connected to them.

  The remote controller 44 has a function of receiving the operation of the user regarding the change of the driving operation command and the setting value. The remote control 44 is an example of an operation terminal or a user interface device. The control device 36 and the remote controller 44 are connected so as to be capable of bidirectional data communication by wire or wirelessly. Although not shown, the remote controller 44 is equipped with a display unit for displaying information such as the state of the hot water storage type hot water supply system 35, an operation unit such as a switch operated by a user, a speaker, a microphone and the like. The remote control 44 may be installed in the kitchen. The remote control 44 may be installed in the bathroom. The hot water storage type hot water supply system 35 may be provided with a plurality of remote controls 44.

  The HP unit 7 is an example of heating means for heating water. The HP unit 7 includes a refrigerant circuit in which the compressor 1, the water refrigerant heat exchanger 3, the expansion valve 4, and the air heat exchanger 6 are annularly connected by the refrigerant pipe 5. The HP unit 7 operates the heat pump cycle by this refrigerant circuit. In the water-refrigerant heat exchanger 3, the water is heated by exchanging heat between the refrigerant compressed by the compressor 1 and the water led from the tank unit 33. The refrigerant compressed by the compressor 1 and the water directly supplied from a water source such as a water supply may be heat-exchanged by the water refrigerant heat exchanger 3.

  The tank unit 33 incorporates the following various components and piping. The hot water storage tank 8 stores hot and cold water. A third water supply pipe 9 c is connected to the water inlet 8 a provided at the lower part of the hot water storage tank 8. Water supplied from a water source such as water (hereinafter referred to as "low temperature water") is adjusted to a predetermined pressure by the pressure reducing valve 31, and then flows into the hot water storage tank 8 through the third water supply pipe 9c. . A hot water inlet / outlet 8 d and a hot water outlet 8 e are provided in the upper part of the hot water storage tank 8. One end of the hot water supply pipe 13 and one end of the high temperature pipe 21 are connected to the hot water inlet / outlet 8 d. The high temperature pipe 21 is used when the hot water stored in the hot water storage tank 8 is supplied to the outside of the hot water storage type hot water supply system 35. The first warm water inlet pipe 20a is connected to the warm water outlet 8e.

  In the hot water storage tank 8, high temperature water heated using the HP unit 7 flows in from the hot water introduction outlet 8d, and low temperature water supplied from the water source through the third water supply pipe 9c flows in from the water inlet 8a. . In the hot water storage tank 8, a temperature stratification is formed in which the upper side is high temperature and the lower side is low temperature, and hot and cold water is stored. On the surface of the hot water storage tank 8, a plurality of hot water storage temperature sensors 42, 43, 52 are attached at different heights. The control device 36 can grasp the amount of stored hot water and the amount of stored heat in the hot water storage tank 8 by detecting the temperature distribution of the hot and cold water in the hot water storage tank 8 with the hot water storage temperature sensors 42, 43 and 52.

  In the tank unit 33, the circulation pump 12 and the use side heat exchanger 20 are built in. The circulation pump 12 is a pump for circulating hot and cold water through various pipes in the tank unit 33 described later. The circulation pump 12 is connected in the middle of the HP forward piping 14. The usage-side heat exchanger 20 heats the fluid to be heated by exchanging heat between the high temperature water supplied from the HP unit 7 or the hot water storage tank 8 and the fluid to be heated on the secondary side. The fluid to be heated in the present embodiment is bath water led from the bath 30. The fluid to be heated is not limited to bath water, and may be, for example, a heating heat medium.

  In the present embodiment, as the configuration on the secondary side of the use-side heat exchanger 20, a description will be given by exemplifying a go-through pipe 27 and a return pipe 28 for circulating the bath water of the bath 30. The use-side heat exchanger 20 is installed in the middle of the blowout pipe 27 and the return pipe 28. In the middle of the blowout piping 27, a blowout temperature sensor 37 for detecting the temperature of the bath water after heat exchange, which has come out of the use side heat exchanger 20, is installed. In the middle of the bath return pipe 28, a bath circulation pump 29 for circulating bath water and a bath return temperature sensor 38 for detecting the temperature of the bath water discharged from the bath 30 are provided.

  The first four-way valve 18 is a flow path switching unit including a b port and a c port, which are inlets to which hot water flows, and an a port and a d port, which are outlets from which the hot water flows. The first four-way valve 18 is configured to be capable of switching between four paths, that is, ab, ac, bd, and cd.

  The second four-way valve 11 is a flow path switching unit including an a port and a d port, which are inlets through which the hot water flows, and b and c ports, which are outlets through which the hot water flows. The second four-way valve 11 is configured to be able to switch the flow path among four paths, that is, ab, ac, bd, and cd.

  The HP forward piping 14 connects between the primary side outlet of the use side heat exchanger 20 and the inlet of the HP unit 7. The HP return pipe 15 connects between the outlet of the HP unit 7 and the c port of the first four-way valve 18. The first water outlet pipe 10 a connects the water outlet 8 b provided in the lower part of the hot water storage tank 8 and the a port of the second four-way valve 11. The second water outlet pipe 10 b is located between the branch portion of the HP forward pipe 14 between the circulation pump 12 and the primary side outlet of the use side heat exchanger 20 and the c port of the second four-way valve 11. connect. The hot water supply pipe 13 connects between the d port of the first four-way valve 18 and the hot water introduction outlet 8 d at the top of the hot water storage tank 8. The first bypass pipe 16 connects between the a port of the first four-way valve 18 and the hot water inlet 8 c of the hot water storage tank 8. The hot water inlet 8 c is between the central portion and the lower portion in the height direction of the hot water storage tank 8. The second bypass pipe 17 connects between a branch portion of the HP forward pipe 14 between the circulation pump 12 and the inlet of the HP unit 7 and the b port of the first four-way valve 18. The first hot water inlet pipe 20 a connects between the hot water outlet 8 e at the top of the hot water storage tank 8 and the d port of the second four-way valve 11. The second hot water inlet pipe 20 b connects between the b port of the second four-way valve 11 and the primary inlet of the use side heat exchanger 20.

  The hot water mixing valve 22 includes a high temperature side inlet, a low temperature side inlet, and an outlet. The bath mixing valve 23 includes a high temperature side inlet, a low temperature side inlet, and an outlet. The other end of the high temperature pipe 21 whose one end is connected to the hot water inlet / outlet 8d at the top of the hot water storage tank 8 is branched into two, and the high temperature side inlet of the hot water mixing valve 22 and the high temperature side of the bath mixing valve 23 Connected to the entrance.

  The three-way valve 78 is a flow path switching unit including an a port and a b port, which are inlets to which hot water flows, and a c port, from which the hot water flows out. The three-way valve 78 is configured to be able to switch the flow path between two paths, that is, a-c and b-c. One end of the first water supply pipe 9a is connected to a water source such as a water supply. The other end of the first water supply pipe 9 a is connected to the second water supply pipe 9 b and the third water supply pipe 9 c via the pressure reducing valve 31. In the middle of the first water supply pipe 9a, a water supply temperature sensor 50 for detecting the temperature of water passing through the first water supply pipe 9a is attached. The second water supply pipe 9 b connects between the secondary side of the pressure reducing valve 31 and the a port of the three-way valve 78. The third water supply pipe 9 c branches from the middle of the second water supply pipe 9 b and is connected to the water inlet 8 a at the lower part of the hot water storage tank 8. One end of the water pipe 19 is connected to the c port of the three-way valve 78. The other end of the water pipe 19 is branched into two and connected to the low temperature side inlet of the hot water supply mixing valve 22 and the low temperature side inlet of the bath mixing valve 23. The middle-temperature pipe 79 connects the middle-temperature outlet 8 f provided at the middle in the height direction of the hot water storage tank 8 and the b port of the three-way valve 78. The medium temperature outlet 8f is at a lower position than the hot water inlet 8d.

  The three-way valve 78 can be switched to a flow path state in which the intermediate temperature pipe 79 communicates with the water pipe 19 and the second water supply pipe 9 b is shut off. This flow path state is hereinafter referred to as "middle warm water utilization state". When the hot water is supplied to the hot water destination in the medium hot water utilization state, the medium hot water flowing out from the medium temperature outlet 8f of the hot water storage tank 8 to the medium temperature pipe 79 passes through the water pipe 19 and is used for the hot water mixing valve 22 and the bath. It is supplied to the low temperature side inlet of the mixing valve 23. The hot water storage temperature sensor 52 is attached to the surface of the hot water storage tank 8 near the medium temperature outlet 8 f. The temperature of the warm water can be detected by the stored-water temperature sensor 52.

  The three-way valve 78 can be switched to a flow path state in which the second water supply pipe 9 b communicates with the water pipe 19 and the intermediate temperature pipe 79 is shut off. Hereinafter, this channel state is referred to as "a state where middle warm water is not used". When hot water is supplied to the hot water supply destination in the middle warm water non-use state, low temperature water supplied from the water source via the first water supply pipe 9a and the second water supply pipe 9b passes through the water pipe 19 for hot water supply It is supplied to the low temperature side inlet of the mixing valve 22 and the mixing valve 23 for bath.

  The first hot water supply pipe 24 connects between the outlet of the hot water supply mixing valve 22 and the hot water supply valve 34 installed in the housing of the tank unit 33. A hot water supply flow rate sensor 48 for detecting the flow rate of hot water passing through the first hot water supply pipe 24 and a hot water supply temperature sensor 51 for detecting the temperature of hot water passing through the first hot water supply pipe 24 are provided in the middle of the first hot water supply pipe 24. It is done. The second hot water supply pipe 25 connects between the outlet of the mixing valve 23 for the bath and the branch portion in the middle of the fork pipe 27. In the middle of the second hot water supply pipe 25, a solenoid valve 26 for bath for opening and closing the second hot water supply pipe 25 and a flow rate sensor 45 for bath for detecting the flow rate of hot water passing through the second hot water supply pipe 25 are provided.

  The hot water supply mixing valve 22 is supplied to the hot water supply destination by mixing the high temperature water supplied from the upper part of the hot water storage tank 8 through the high temperature pipe 21 and the medium warm water or low temperature water supplied from the water pipe 19. It is an example of the 1st mixing means which temperature-controls the hot water. An external hot water supply pipe (not shown) is connected to the hot water supply valve 34 from the outside of the tank unit 33. Hot water whose temperature is controlled by the hot water supply mixing valve 22 is supplied to a hot water supply destination such as a shower or a faucet such as a caran used by the user via the first hot water supply pipe 24, the hot water supply valve 34, and the external hot water supply pipe. Ru.

  The user can change the hot water supply set temperature for the hot water supply destination of the hot water supply mixing valve 22, that is, the faucet, to a desired value by operating the remote control 44. When the hot water supply destination of the hot water supply mixing valve 22 is heated, the control device 36 controls the hot water supply mixing valve 22 so that the hot water supply temperature detected by the hot water supply temperature sensor 51 becomes equal to the hot water supply set temperature.

  The bath mixing valve 23 mixes hot water supplied from the upper portion of the hot water storage tank 8 through the high temperature pipe 21 with middle warm water or low temperature water supplied from the water pipe 19 to provide a hot water supply destination, ie, the bath 30. It is an example of the 2nd mixing means which temperature-controls the hot water supplied to it. In the case of supplying hot water to the bathtub 30, the following is performed. The bath solenoid valve 26 is opened. The hot water whose temperature has been adjusted by the mixing valve 23 for bath flows into the bath 30 through at least one of the second hot water supply pipe 25, the inflowing pipe 27 and the return pipe 28.

  By operating the remote control 44, the user can change the hot water supply temperature for the bath mixing valve 23, that is, the hot water setting temperature for the bath 30, to a desired value. When supplying water to the bath tub 30, the control device 36 controls the mixing valve 23 for the bath so that the hot water supply temperature detected by the going-out temperature sensor 37 or the back-off temperature sensor 38 becomes equal to the hot water supply set temperature. .

  The first four-way valve 18 has a form in which the HP return pipe 15 communicates with the hot water supply pipe 13, a form in which the HP return pipe 15 communicates with the first bypass pipe 16, a first bypass pipe 16 and a second bypass pipe 17 Can be switched to the four flow path forms of the form in which the hot water supply pipe 13 and the second bypass pipe 17 are in communication. The second four-way valve 11 has a form in which the first water outlet pipe 10a and the second water outlet pipe 10b communicate with each other, a form in which the first water outlet pipe 10a and the second hot water inlet pipe 20b communicate with each other, It is possible to switch to three flow path configurations in which the first hot water inlet pipe 20a and the second hot water inlet pipe 20b communicate with each other.

  Hereinafter, the operation of the hot water storage type hot water supply system 35 of the first embodiment will be further described. The low temperature water supplied from the water source through the first water supply pipe 9a is depressurized to a predetermined pressure by the pressure reducing valve 31, and flows into the lower portion of the hot water storage tank 8 through the third water supply pipe 9c. The hot water storage tank 8 is always kept full. In the case of a heat storage operation which is an operation of accumulating high temperature water heated by the HP unit 7 in the hot water storage tank 8, the following occurs. The HP unit 7 and the circulation pump 12 are operated. The water in the lower part of the hot water storage tank 8 passes through the first water outlet pipe 10a, the second four-way valve 11, the second water outlet pipe 10b, and the HP forward pipe 14 to heat the water refrigerant in the HP unit 7 It is sent to the switch 3. Hot water, ie, high-temperature water heated while passing through the water refrigerant heat exchanger 3, passes from the hot water introduction outlet 8d to the hot water storage tank 8 via the HP return pipe 15, the first four-way valve 18, and the hot water pipe 13. To flow. At this time, port a and port c are electrically connected in the second four-way valve 11, and port c and port d are electrically connected in the first four-way valve.

  During the heat storage operation, the controller 36 controls at least one of the HP unit 7 and the circulation pump 12 so that the temperature of the hot water flowing out of the HP unit 7 (hereinafter referred to as “temperature after heating”) becomes equal to the target value. The operation may be controlled. The target value of the post-heating temperature may be, for example, a temperature in the range of 65 ° C to 90 ° C. The HP outlet water temperature sensor 39 attached to the HP return pipe 15 can detect the temperature after heating.

  The HP incoming water temperature sensor 40 attached to the HP forward pipe 14 can detect the temperature of water flowing into the HP unit 7 (hereinafter referred to as “the temperature before heating”). The control device 36 determines that the entire amount of the hot water storage tank 8 is filled with hot water when the pre-heating temperature detected by the HP incoming water temperature sensor 40 exceeds the reference (for example, 60 ° C.), and ends the heat storage operation. You may The control device 36 may end the heat storage operation before the entire amount of the hot water storage tank 8 is filled with the hot water according to the required heat storage amount.

  In the operation of heating water by a heat pump system such as the HP unit 7, generally, the heating efficiency is high when the temperature before heating is low, and the heating efficiency is low when the temperature before heating is high.

  The hot water stored in the hot water storage tank 8 causes a temperature drop due to various factors, and the warm water is gradually generated in the hot water storage tank 8. For example, as the stored time lengthens, the heat in the hot water storage tank 8 causes a temperature decrease due to natural heat release. In addition, middle-class hot water is generated in the hot-water storage tank 8 by performing post-heating operation or floor heating using the use-side heat exchanger 20. Further, by performing the bath exhaust heat recovery operation, the water in the hot water storage tank 8 is heated by heat exchange with the hot water in the bath 30, so that the inside warm water is generated. In the following, as an example, the operation in the case of performing the chase-up operation and the chute exhaust heat recovery operation and the generation of the medium-temperature water will be described.

  The following is the case when performing furo chase operation. When the control device 36 receives an instruction to start the chute operation by the remote control 44 or the operation of the chute circulation pump 29, the temperature of the bath water in the tub 30 is detected by the chute temperature sensor 38, and the tub is kept below a predetermined temperature. When there is a temperature drop of 30, chase operation is started. When the chase operation is started, the circulation circulation pump 29 is operated, and the bath water in the tub 30 is passed through the back pipe 28, the heat exchanger 20 on the user side, and the forward pipe 27 into the tub 30. It circulates back. On the other hand, the circulating pump 12 also operates, and the hot water stored at a higher temperature than the upper portion of the hot water storage tank 8 passes through the first hot water inlet pipe 20a, the second four-way valve 11, and the second hot water inlet pipe 20b. It is sent to the switch 20. The temperature of the high-temperature hot water drops from the bath water while passing through the use-side heat exchanger 20, so that the temperature drops and it becomes middle warm water. The temperature of the middle warm water is, for example, about 50.degree. The middle warm water flows from the hot water inlet 8 c into the hot water storage tank 8 from the use side heat exchanger 20 via the HP forward piping 14, the second bypass piping 17, the first four-way valve 18, and the first bypass piping 16. Do. At this time, the d-port and the b-port of the second four-way valve 11 are electrically connected, and the b-port and the a-port of the first four-way valve 18 are electrically connected.

  The hot water storage in the hot water storage tank 8 decreases and the medium hot water increases as the furo repurposing continues. If the heat storage operation is performed in a state where a large amount of middle warm water generated by the chase is in the hot water storage tank 8, the middle warm water is heated by the HP unit 7 instead of low temperature water. It becomes high and the heating efficiency of HP unit 7 becomes low.

  In the case of performing the bath exhaust heat recovery operation, it is as follows. When the controller 36 receives an instruction to start the waste heat recovery from the remote controller 44, the waste heat recovery operation is started. When the bath exhaust heat recovery operation is started, first, whether or not the state of the hot water storage tank 8 is capable of performing the bath exhaust heat recovery operation is confirmed as follows. The bath circulation pump 29 is operated, and the temperature of the bath water in the bath 30 is detected by the bath return temperature sensor 38. The temperature of the lower part of the hot water storage tank 8 is detected by a hot water storage temperature sensor 43. If the temperature of the lower part of the hot water storage tank 8 detected by the hot water storage temperature sensor 43 is lower than the temperature of the bath water in the bathtub 30 detected by the backflow temperature sensor 38, it is determined that the bath exhaust heat recovery operation can be performed. Do. If it is determined that the bath exhaust heat recovery operation can be performed, the circulation pump 12 is also operated. Low temperature hot water from the lower part of the hot water storage tank 8 is sent to the use-side heat exchanger 20 via the first water outlet pipe 10a, the second four-way valve 11, and the second hot water inlet pipe 20b. By passing heat from the bath water while passing through the use-side heat exchanger 20, the low-temperature hot water rises in temperature and becomes warm water. The temperature of the medium temperature water is, for example, about 30 ° C. The middle warm water flows from the hot water inlet 8 c into the hot water storage tank 8 from the use side heat exchanger 20 via the HP forward piping 14, the second bypass piping 17, the first four-way valve 18, and the first bypass piping 16. Do. At this time, port a and port b are electrically connected in the second four-way valve 11, and port b and port a are electrically connected in the first four-way valve.

  When the temperature of the lower part of the hot water storage tank 8 detected by the hot water storage temperature sensor 43 becomes close to the temperature of the bath water detected by the bath return temperature sensor 38, the exhaust heat is further recovered. Heat transfer will not occur. When the difference between the temperature detected by the hot water storage temperature sensor 43 and the temperature detected by the backflow temperature sensor 38 becomes smaller than the reference, the control device 36 ends the bath exhaust heat recovery operation.

  When such a bath exhaust heat recovery operation is performed, the low temperature water in the hot water storage tank 8 decreases, and the middle warm water increases. If the heat storage operation is performed with a large amount of middle warm water generated in the bath exhaust heat recovery operation in the hot water storage tank 8, the middle warm water will be heated by the HP unit 7 instead of low temperature water. The temperature rises and the heating efficiency of the HP unit 7 decreases.

  In the case of the present embodiment, when hot water is supplied to the hot water supply destination when the three-way valve 78 is in the use of medium hot water, the middle warm water supplied from the medium temperature pipe 79 mixes the hot water mixing valve 22 and the bath. The valve 23 is supplied. When the middle warm water in the hot water storage tank 8 flows out to the middle temperature pipe 79, low temperature water flows from the third water supply pipe 9c to the lower part of the hot water storage tank 8. In the present embodiment, since the middle warm water in the hot water storage tank 8 can be used for hot water supply, the amount of heat possessed by the middle warm water can be effectively used. In addition, by consuming the warm water in the hot water storage tank 8, the warm water in the hot water storage tank 8 can be replaced with the low temperature water flowing in from the third water supply pipe 9c. Therefore, when the heat storage operation is performed, the temperature before heating can be lowered, and the heating efficiency of the HP unit 7 becomes high.

  Next, control regarding hot water supply using the hot water supply mixing valve 22 will be described with reference to FIG. FIG. 2 is a flowchart of the routine executed in the first embodiment. FIG. 2 is a flowchart relating to control of switching of the three-way valve 78. In the present embodiment, control device 36 executes the processing of this flowchart. The control device 36 periodically and repeatedly executes the routine of this flowchart regardless of the state of the hot water storage type hot water supply system 35. When it is assumed that the user uses the hot water supply using the hot water supply mixing valve 22, the control device 36 repeatedly executes the routine of this flowchart at all times.

  In step S10 of FIG. 2, it is determined whether hot water supply to the hot water supply destination of the hot water supply mixing valve 22 is in progress or being stopped. In the present embodiment, based on the output of the hot water supply flow rate sensor 48 of the first hot water supply pipe 24, it can be determined whether hot water supply to the hot water supply destination of the hot water supply mixing valve 22 is in progress or stopped. If hot water supply to the hot water supply destination of the mixing valve 22 for hot water supply is in progress, the routine is ended without switching the three-way valve 78.

  Temporarily, if the three-way valve 78 is switched when hot water supply to the hot water supply destination of the hot water supply mixing valve 22 is being performed, the water flowing into the low temperature side inlet of the hot water supply mixing valve 22 changes from middle warm water to low temperature water, Alternatively, the hot water supply temperature is likely to fluctuate by switching from low temperature water to medium temperature water. According to the temperature detected by the hot water supply temperature sensor 51, the hot water supply mixing valve 22 is controlled, but at least the temperature of hot water corresponding to the flow path volume from the hot water supply mixing valve 22 to the hot water supply temperature sensor 51 can not be controlled For this reason, it can not be completely prevented that fluctuations in the temperature of water flowing into the low temperature side inlet of the hot water supply mixing valve 22 cause fluctuations in the hot water supply temperature. In the present embodiment, on the other hand, the hot water supply temperature fluctuates by not switching the three-way valve 78 when hot water supply to the hot water supply destination of the hot water supply mixing valve 22 is in progress. It can be suppressed reliably.

  When the hot water supply to the hot water supply destination of the hot water supply mixing valve 22 is stopped, the process proceeds from step S10 to step S11. In step S11, the temperature of the warm water is detected by the hot water storage temperature sensor 52. In the present embodiment, the temperature of the medium-temperature water can be accurately detected by the stored-water temperature sensor 52 even when the medium-temperature water does not flow through the medium-temperature pipe 79. The process proceeds from step S11 to step S12.

  In step S12, it is determined whether or not the three-way valve 78 is in a state of conducting between the a port and the c port, that is, whether or not the middle warm water is not used. If the three-way valve 78 is in the middle water non-use state, the process proceeds from step S12 to step S13. If the three-way valve 78 is not in the middle-water use state, that is, if the three-way valve 78 is in the middle-water use state, the process proceeds from step S12 to step S16.

  In step S13 in which the current three-way valve 78 is in the middle water non-use state, it is determined whether or not the temperature of the middle water detected in step S11 is lower than the first reference temperature. The first reference temperature is a temperature lower than the hot water supply set temperature for the hot water supply destination of the hot water supply mixing valve 22. The first reference temperature may be a temperature lower than the hot water supply set temperature by a predetermined first temperature difference. The first temperature difference may be, for example, 8 ° C. If the temperature of the middle warm water is less than or equal to the first reference temperature, it may be determined that the temperature of the middle warm water is lower than the first reference temperature.

  If the temperature of the middle warm water is not lower than the first reference temperature, the routine is ended after step S13 without switching the three-way valve 78 from the middle warm water non-use state to the middle warm water use state. If the temperature of the medium-temperature water is lower than the first reference temperature, the process proceeds from step S13 to step S14. In step S14, the hot water supply mixing valve 22 is operated such that the standby position of the hot water supply mixing valve 22 changes from the second standby position to the first standby position. The process proceeds from step S14 to step S15. In step S15, the three-way valve 78 is switched from the middle warm water non-use state to the middle warm water use state. That is, the three-way valve 78 is switched from the state in which the port a and the port c are electrically connected to the state in which the port b and the port c are electrically connected. After step S15, the routine ends.

  Here, the standby position of the hot water supply mixing valve 22 will be described. The standby position of the hot water supply mixing valve 22 is a position where the hot water supply mixing valve 22 is on standby when hot water supply to the hot water supply destination of the hot water supply mixing valve 22 is stopped. The first standby position is a standby position of the hot water supply mixing valve 22 when the three-way valve 78 is in the middle warm water utilization state. The controller 36 can calculate the first standby position as follows. The control device 36 is configured to satisfy the hot water supply set temperature based on the temperature of the high temperature water detected by the hot water storage temperature sensor 42 and the temperature of the middle warm water detected by the hot water storage temperature sensor 52 The mixing ratio of can be calculated. The controller 36 can calculate the ratio of the opening area communicating with the high temperature side inlet and the opening area communicating with the low temperature side inlet so that the mixing ratio for hot water supply can be satisfied. The controller 36 can calculate the standby position of the valve body of the hot water mixing valve 22 so as to satisfy such mixing ratio or opening area ratio. The standby position of such a valve body corresponds to the first standby position.

  The hot water supply is started by setting the hot water supply mixing valve 22 in the first standby position when the hot water supply to the hot water supply destination of the hot water supply mixing valve 22 is stopped and the three-way valve 78 is in the middle hot water utilization state In this case, it is possible to quickly bring the hot water supply temperature close to the hot water supply set temperature.

  The second standby position is a standby position of the hot water supply mixing valve 22 when the three-way valve 78 is in the non-use state of the medium temperature water. The controller 36 can calculate the second standby position as follows. The controller 36 controls the high-temperature water and the low-temperature water to satisfy the hot water supply set temperature based on the temperature of the high-temperature water detected by the stored-water temperature sensor 42 and the temperature of the low-temperature water detected by the feed water temperature sensor 50. The mixing ratio of can be calculated. The controller 36 can calculate the ratio of the opening area communicating with the high temperature side inlet and the opening area communicating with the low temperature side inlet so that the mixing ratio for hot water supply can be satisfied. The controller 36 can calculate the standby position of the valve body of the hot water mixing valve 22 so as to satisfy such mixing ratio or opening area ratio. The standby position of such a valve body corresponds to the second standby position.

  The hot water supply is started by setting the hot water supply mixing valve 22 in the second standby position when the hot water supply to the hot water supply destination of the hot water supply mixing valve 22 is stopped and the three-way valve 78 is not in use. In this case, it is possible to quickly bring the hot water supply temperature close to the hot water supply set temperature.

  The middle part of the hot water storage tank 8 is the heat radiation of hot water, the heat diffusion between the high temperature part and the low temperature part in the hot water storage tank 8, the hot water introduction port 8c from the hot water introduction port 8c at the time of furo chase operation or bath exhaust heat recovery operation. Temperature fluctuation is large due to the influence of middle warm water and so on. For this reason, the temperature of the medium-temperature water flowing out from the hot water storage tank 8 to the medium-temperature pipe 79 may cause a rapid change, for example, a change of 5 ° C. or more in 1 second.

  Assuming that the three-way valve 78 is switched from the non-use condition of middle warm water to the use condition of middle warm water after the temperature of the middle warm water detected by the hot water storage temperature sensor 52 falls below the hot water supply set temperature, Due to temperature fluctuations, the temperature of the medium temperature water may exceed the hot water supply set temperature. In such a case, the temperature of the hot water supplied from the hot water supply mixing valve 22 to the hot water destination becomes higher than the hot water supply set temperature. On the other hand, in the present embodiment, the three-way valve 78 is switched from the non-use condition of middle warm water to the use condition of middle warm water until the temperature of the middle warm water becomes lower than the first reference temperature lower than the hot water supply set temperature. Do not switch. Therefore, even when the temperature of the middle portion of the hot water storage tank 8 tends to fluctuate, the temperature of the hot water supplied from the hot water supply mixing valve 22 to the hot water supply destination can be reliably prevented from becoming higher than the hot water supply set temperature. .

  The second standby position assuming the inflow of the low temperature water is a position where the mixing ratio of the high temperature water is higher than the first standby position assuming the inflow of the middle warm water. That is, in the second standby position, the opening area communicating with the high temperature side inlet of the hot water supply mixing valve 22 is larger than that in the first standby position.

  In the present embodiment, as in step S14 and step S15 described above, before switching the three-way valve 78 from the middle warm water non-use state to the middle warm water use state, the hot water supply mixing valve 22 is first standby from the second standby position. Actuate to position. Conversely, assuming that the hot water supply mixing valve 22 is operated from the second standby position to the first standby position after switching the three-way valve 78 from the middle warm water non-use state to the middle warm water use state, it is as follows: There is a possibility. When hot water supply is started while the three-way valve 78 is switched, middle warm water may flow into the low temperature side inlet of the hot water supply mixing valve 22 at the second standby position where the mixing ratio of high temperature water is high. In such a case, the hot water supply temperature from the hot water supply mixing valve 22 temporarily becomes higher than the hot water supply set temperature. Assuming an application where the human body is directly exposed to hot water, such as a shower, it is desirable to avoid the occurrence of a state in which the hot water supply temperature is higher than the hot water supply set temperature as much as possible. On the other hand, in the case of the present embodiment, after switching the hot water supply mixing valve 22 to the first standby position where the mixing ratio of the high temperature water is low, the three way valve 78 is switched to the middle warm water utilization state. Even when the hot water supply is started while switching, the hot water supply temperature from the hot water supply mixing valve 22 can be reliably prevented from becoming higher than the hot water supply set temperature.

  In step S16 in which the current three-way valve 78 is in the middle water use state, it is determined whether the temperature of the middle water detected in step S11 is higher than the second reference temperature. The second reference temperature is lower than the hot water supply set temperature for the hot water supply destination of the hot water supply mixing valve 22 and higher than the first reference temperature. The second reference temperature may be a temperature lower by a predetermined second temperature difference smaller than the first temperature difference, as compared to the hot water supply set temperature. The second temperature difference may be, for example, 6 ° C. When the temperature of the middle warm water is equal to or exceeds the second reference temperature, it may be determined that the temperature of the middle warm water is higher than the second reference temperature.

  If the temperature of the medium temperature water is not higher than the second reference temperature, the routine is ended after step S16 without switching the three-way valve 78 from the medium temperature water utilization state to the medium water temperature nonuse state. If the temperature of the medium-temperature water is higher than the second reference temperature, the process proceeds from step S16 to step S17. In step S17, the three-way valve 78 is switched from the middle warm water utilization state to the middle warm water nonuse state. That is, the three-way valve 78 is switched from the state where the b port and the c port are electrically connected to the state where the a port and the c port are electrically connected. The process proceeds from step S17 to step S18. In step S18, the hot water supply mixing valve 22 is operated so that the standby position of the hot water supply mixing valve 22 changes from the first standby position to the second standby position. After step S18, the routine ends.

  Assuming that the second reference temperature is equal to the first reference temperature, the following occurs. When the resolution of the hot water storage temperature sensor 52 is small or when the temperature of the hot water storage tank 8 is large with the temperature fluctuation of the middle part of the hot water storage tank 8, the temperature of the middle warm water detected by the hot water storage temperature sensor 52 fluctuates, Frequent switching of the three-way valve 78 may occur, resulting in large fluctuations in the hot water supply temperature. On the other hand, in the case of the present embodiment, after switching of the three-way valve 78 in step S15 or step S18 is performed by setting the second reference temperature higher than the first reference temperature, Switching conditions are less likely to be met. Therefore, the occurrence of frequent switching of the three-way valve 78 can be prevented, and fluctuations in the temperature of the hot water supply can be reliably suppressed.

  In the present embodiment, when the temperature of the medium temperature water is higher than the second reference temperature lower than the hot water supply setting temperature, the three-way valve 78 is switched from the medium temperature use condition to the medium temperature nonuse condition. It will not be used for hot water supply. If the temperature of the medium temperature water is higher than the second reference temperature and the temperature of the medium temperature water is slightly lower than the hot water supply set temperature, if the hot water obtained by mixing the medium temperature water and the high temperature water is supplied to the hot water supply destination, There are the following problems. When the temperature of the middle warm water is a temperature slightly lower than the hot water supply set temperature, the middle warm water is mixed with a small amount of high temperature water and supplied to the hot water supply destination. In such a case, when the temperature of the middle warm water fluctuates rapidly, a temperature fluctuation of almost the same magnitude as the temperature fluctuation of the middle warm water occurs in the hot water supply temperature, and a large fluctuation occurs in the hot water supply temperature. Even if it is assumed that the middle warm water is mixed with a small amount of low temperature water and supplied to the hot water supply destination when the middle warm water temperature is slightly higher than the hot water supply set temperature, a large fluctuation in the hot water supply temperature may occur similarly is there. On the other hand, in the present embodiment, when the temperature of the middle warm water is higher than the second reference temperature lower than the hot water supply set temperature, the middle hot water is not used for the hot water supply, thereby changing the hot water supply temperature. Can be reliably suppressed.

  In the present embodiment, as in step S17 and step S18 described above, after the three-way valve 78 is switched from the use condition of middle warm water to the use condition of middle warm water, the hot water supply mixing valve 22 is switched from the first standby position to the second standby state. Actuate to position. Contrary to this, assuming that the three-way valve 78 is switched from the use of the medium warm water to the use of the medium warm water after the hot water supply mixing valve 22 is operated from the first standby position to the second standby position, There is a possibility. If the hot water supply is started before the three-way valve 78 switches after the hot water supply mixing valve 22 is switched to the second standby position, the hot water mixing valve 22 in the second standby position where the mixing ratio of high temperature water is high. Middle warm water may flow into the low temperature side inlet. In such a case, the hot water supply temperature from the hot water supply mixing valve 22 temporarily becomes higher than the hot water supply set temperature. On the other hand, in the case of the present embodiment, by switching the three-way valve 78 earlier than the hot water supply mixing valve 22, the low temperature side inlet of the hot water supply mixing valve 22 in the second standby position where the mixing ratio of high temperature water is high. It is possible to reliably prevent the inflow of medium-temperature water. Therefore, it can be reliably prevented that the hot water supply temperature from the hot water supply mixing valve 22 becomes higher than the hot water supply set temperature.

  When the first reference temperature and the second reference temperature are increased, the opportunity to use middle warm water for hot water supply increases, so the energy efficiency of the hot water storage type hot water supply system 35 is further improved. For example, by reducing the values of the first temperature difference (for example, 8 ° C.) and the second temperature difference (for example, 6 ° C.) described above, the first reference temperature and the second reference temperature become higher. On the other hand, when the first reference temperature and the second reference temperature are increased, the fluctuation of the hot water supply temperature tends to increase somewhat.

  The hot water storage type hot water supply system 35 includes means for enabling the user to select and set the first operation mode and the second operation mode which is an operation mode in which the improvement of energy efficiency is given priority over the first operation mode. It is also good. The first operation mode may be, for example, a normal operation mode. The name of the second operation mode may be any name, such as an energy saving mode or a power saving mode. The user may operate the remote control 44 to select and set the first operation mode and the second operation mode. The controller 36 may increase the values of the first reference temperature and the second reference temperature when the second operation mode is set as compared to when the second operation mode is not set. By raising the values of the first reference temperature and the second reference temperature, the energy efficiency of the hot water storage type hot water supply system 35 is further improved, so that the intention of the user who has selected the second operation mode can be met.

  In the hot water supply after switching the three-way valve 78 from the middle warm water nonuse state to the middle warm water use state or from the middle warm water use state to the middle warm water nonuse state, the temperature of the water pipe 19 is from the low temperature water temperature to the middle The temperature of the warm water rises rapidly, or the temperature of the middle warm water drops to the temperature of the low temperature water. Until the temperature of the water pipe 19 stabilizes, the temperature of the hot water supply may fluctuate somewhat. In order to more reliably suppress the fluctuation of the hot water supply temperature in such a situation, the following may be performed.

  At the initial stage of hot water supply after switching the three-way valve 78 from the middle warm water non-use state to the middle warm water use state or from the middle warm water use state to the middle warm water non-use state, the control device 36 compares the subsequent stages. Alternatively, the control time interval for the hot water supply mixing valve 22 may be shortened. For example, at an initial stage of supplying water after the three-way valve 78 is switched, the control device 36 may shorten the control time interval for the hot water supply mixing valve 22 compared to the normal time. The initial stage of supplying water after switching of the three-way valve 78 is a stage where some fluctuations in the temperature of the hot water supply are likely to occur, for the reasons described above. By shortening the control time interval for the hot water supply mixing valve 22 at this stage, fluctuations in the hot water supply temperature can be more reliably suppressed.

  Here, with the control time interval, the change of the opening area communicating with the high temperature side inlet of the mixing valve 22 for hot water supply and the opening area communicating with the low temperature side inlet is completed in the state where the hot water supply is performed. It refers to the time interval before the next change of area starts. In the following description, the opening area communicating with the high temperature side inlet of the mixing valve for hot water supply 22 and the opening area communicating with the low temperature side inlet are collectively referred to simply as “opening area”. When there is a difference between the hot water supply temperature detected by the hot water supply temperature sensor 51 and the hot water supply set temperature, the control device 36 calculates the optimum opening area of the hot water supply mixing valve 22 from the difference and supplies the hot water so as to be the opening area. Control the mixing valve 22. After the change of the opening area of the hot water supply mixing valve 22 is completed and the control device 36 stands by for the control time interval, the control device 36 again calculates the optimum open area of the hot water supply mixing valve 22 and controls the hot water supply mixing valve 22. By providing the control time interval, it is possible to reliably detect the change of the hot water supply temperature due to the change of the opening area of the hot water supply mixing valve 22, and control of the unnecessary hot water supply mixing valve 22 and the hot water supply temperature Hunting can be suppressed.

  With regard to this control time interval, the optimum control time interval differs depending on the volume from the outlet of the hot water supply mixing valve 22 to the hot water supply temperature sensor 51 or parameters such as the hot water supply flow rate. The hot-water supply flow rate depends on the user and changes depending on the use scene, and can be regarded as a noise factor. By designing so that the volume from the outlet of the mixing valve 22 for hot water supply to the hot water supply temperature sensor 51 becomes smaller, it is possible to further reduce the fluctuation of the hot water supply temperature. If the volume from the outlet of the mixing valve 22 for hot water supply to the hot water supply temperature sensor 51 is small, the influence of the noise factor of the hot water supply flow rate on the fluctuation of the hot water supply temperature becomes small. In such a case, the optimal control time interval may be, for example, about 0.1 second.

  On the other hand, if the variation of the hot water supply temperature is small, particularly if the resolution of the hot water supply temperature sensor 51 is large, hunting may be caused if the control time interval is too short. In such a case, the optimal control time interval may be, for example, about 1.0 second.

  In FIG. 2, the control relating to the hot water supply using the hot water supply mixing valve 22 has been described. In the present embodiment, hot water supply using the mixing valve 23 for bath may be controlled in the same manner as in FIG. Further, in the present embodiment, both of the hot water supply mixing valve 22 and the bottom mixing valve 23 may be controlled in the same manner as in FIG. In that case, the following may be performed. If the value of the hot water supply setting temperature for the hot water supply destination of the hot water supply mixing valve 22 and the value of the hot water supply setting temperature for the hot water supply destination of the bath mixing valve 23 are different from each other, the control device 36 in steps S13 and S16 of FIG. The first reference temperature and the second reference temperature are based on the lower one of the hot water supply set temperature for the hot water supply destination of the hot water supply mixing valve 22 and the hot water supply set temperature for the hot water supply destination of the bath mixing valve 23. May be set. By doing so, hot water supply using middle warm water becomes possible for any of the hot water supply destination of the hot water supply mixing valve 22 and the hot water supply destination of the bath mixing valve 23.

  When the hot water supply setting temperature for the hot water supply destination of the mixing valve 23 for the bath is lower than the hot water supply setting temperature for the hot water supply destination of the mixing valve 22 for hot water supply, the first temperature difference and the first temperature difference described above in step S13 and step S16 of FIG. The value of the two temperature differences may be reduced. By reducing the values of the first temperature difference and the second temperature difference, more middle-class hot water can be used, and energy efficiency is further improved. The hot water supplied to the hot water supply destination of the bath mixing valve 23, that is, the hot water supplied to the bath 30, is not directly exposed to the human body. Therefore, in steps S13 and S16 of FIG. 2, when the first reference temperature and the second reference temperature approach the hot water supply set temperature for the hot water supply destination of the bath mixing valve 23, the hot water supply from the bath mixing valve 23 Even if the temperature tends to fluctuate a little, the effect is small.

  As described above, during execution of the chase refueling operation or the chute exhaust heat recovery operation, the middle warm water flows from the warm water inlet 8 c to the hot water storage tank 8, thereby disturbing the temperature distribution of the hot water in the hot water storage tank 8. Ru. For this reason, the temperature of the medium-temperature water flowing out to the medium-temperature pipe 79 is likely to fluctuate. The control device 36 may switch the three-way valve 78 to the non-use condition of the warm water and fix it when performing the chase operation or the chock exhaust heat recovery operation. During the execution of the chute-heating operation or the chute exhaust heat recovery operation, in which the temperature of the middle-warm water tends to fluctuate, it is possible to more reliably suppress the fluctuation of the hot-water supply temperature by using hot water not using the middle-warm water. The furo follow-up operation and the furo exhaust heat recovery operation in the present embodiment are examples of an operation of circulating water of a circuit which is led out of the hot water storage tank 8 and returned into the hot water storage tank 8.

  Each of the control device 36 of the hot water storage type water heater 35 and the control device included in the remote control 44 may be configured as follows. Each function of the control device may be realized by a processing circuit. The processing circuitry of the controller may comprise at least one processor and at least one memory. When the processing circuit includes at least one processor and at least one memory, each function of the control device may be realized by software, firmware, or a combination of software and firmware. Software and / or firmware may be described as a program. The software and / or firmware may be stored in at least one memory. At least one processor may implement each function of the control device by reading and executing a program stored in at least one memory. At least one memory may include non-volatile or volatile semiconductor memory, magnetic disk, and the like.

  The processing circuitry of the controller may comprise at least one dedicated hardware. When the processing circuit comprises at least one dedicated hardware, the processing circuit may, for example, be a single circuit, a complex circuit, a programmed processor, a parallel programmed processor, an application specific integrated circuit (ASIC), an FPGA (field- It may be a programmable gate array) or a combination thereof. The function of each part of the control device may be realized by the processing circuit. In addition, the functions of the respective units of the control device may be realized collectively by the processing circuit. For each function of the control device, a part may be realized by dedicated hardware, and another part may be realized by software or firmware. The processing circuit may implement each function of the control device by hardware, software, firmware, or a combination thereof.

  The configuration is not limited to a configuration in which the operation is controlled by a single control device, and a configuration in which a plurality of control devices cooperate to control the operation may be employed.

1 compressor, 3 water refrigerant heat exchangers, 4 expansion valves, 5 refrigerant pipes, 6 air heat exchangers, 7 HP units, 8 hot water storage tanks, 8a water inlet, 8b water outlet, 8c hot water inlet, 8d hot water Introduction outlet, 8e hot water outlet, 8f medium temperature outlet, 9a first water supply piping, 9b second water supply piping, 9c third water supply piping, 10a first water outlet piping, 10b second water outlet piping, 11 second Four-way valve, 12 circulation pumps, 13 hot water delivery piping, 14 HP forward piping, 15 HP return piping, 16 first bypass piping, 17 second bypass piping, 18 first four-way valve, 19 water piping, 20 user side heat exchanger , 20a 1st hot water introduction piping, 20b 2nd hot water introduction piping, 21 high temperature piping, 22 mixing valves for hot water supply, 23 mixing valves for bath, 24 first hot water supply Pipe, 25 second hot water supply pipe, 26 solenoid valve for bath, 27 flow forward pipe, 28 flow return pipe, 29 bath circulation pump, 30 bath, 31 pressure reducing valve, 33 tank unit, 34 hot water supply valve, 35 hot water storage hot water supply system, 36 control unit, 37 flow temperature sensor, 38 flow return temperature sensor, 39 HP discharge temperature sensor, 40 HP incoming water temperature sensor, 42, 43, 52 hot water storage temperature sensor, 44 remote control, 45 flow sensor for flow, 48 flow rate for hot water supply Sensor, 50 water supply temperature sensor, 51 hot water supply temperature sensor, 78 three-way valve, 79 medium temperature piping

Claims (7)

With a hot water storage tank,
High temperature piping connected to the upper part of the hot water storage tank,
Intermediate temperature piping connected to the hot water storage tank at a position lower than the connection position of the high temperature piping,
At least one of mixing the temperature of the hot water supplied to the hot water supply destination by mixing the high temperature water supplied from the high temperature pipe and the low temperature water supplied from the water source or the medium warm water supplied from the medium temperature pipe Means,
The medium warm water utilization state, which is a flow path state in which the middle warm water is supplied to the at least one mixing means, and the middle warm water nonuse state, which is a flow path state in which the low temperature water is supplied to the at least one mixing means Flow path switching means for switching the
A means for detecting the temperature of the middle warm water;
Means for controlling the at least one mixing means and the flow path switching means;
Equipped with
When the temperature of the middle warm water is lower than the first reference temperature which is lower than the hot water supply set temperature, the flow path switching unit is switched to the middle warm water utilization state, and the first standard lower than the hot water supply set temperature. When the temperature of the middle warm water is higher than a second reference temperature higher than the temperature, the flow path switching unit is switched to the middle warm water non-use state ,
A hot water storage type hot water supply system which permits switching of the flow path switching means when the hot water supply to the hot water supply destination is stopped, and does not switch the flow path switching means when the hot water supply to the hot water supply destination is in progress . With a hot water storage tank,
High temperature piping connected to the upper part of the hot water storage tank,
Intermediate temperature piping connected to the hot water storage tank at a position lower than the connection position of the high temperature piping,
At least one of mixing the temperature of the hot water supplied to the hot water supply destination by mixing the high temperature water supplied from the high temperature pipe and the low temperature water supplied from the water source or the medium warm water supplied from the medium temperature pipe Means,
The medium warm water utilization state, which is a flow path state in which the middle warm water is supplied to the at least one mixing means, and the middle warm water nonuse state, which is a flow path state in which the low temperature water is supplied to the at least one mixing means Flow path switching means for switching the
A means for detecting the temperature of the middle warm water;
Means for controlling the at least one mixing means and the flow path switching means;
Equipped with
When the temperature of the middle warm water is lower than the first reference temperature which is lower than the hot water supply set temperature, the flow path switching unit is switched to the middle warm water utilization state, and the first standard lower than the hot water supply set temperature. When the temperature of the middle warm water is higher than a second reference temperature higher than the temperature, the flow path switching unit is switched to the middle warm water non-use state ,
The at least one mixing means is in a first standby position when the flow path switching means is in the middle warm water utilization state and the hot water supply to the hot water supply destination is stopped.
The at least one mixing means is in the second standby position when the flow path switching means is in the non-use condition of the middle warm water and the hot water supply to the hot water supply destination is stopped.
The second standby position is a position at which the mixing ratio of the high-temperature water is higher than that of the first standby position.
The hot water storage type hot-water supply system Ru is at least operated with one of the mixing means from the first standby position into the second standby position after switching the flow path switching unit from the warm water available state to the warm water non use state. The hot water storage according to claim 2 , wherein the at least one mixing means is operated from the second standby position to the first standby position before switching the flow path switching unit from the intermediate warm water non-use state to the intermediate warm water use state. Hot water supply system. With a hot water storage tank,
High temperature piping connected to the upper part of the hot water storage tank,
Intermediate temperature piping connected to the hot water storage tank at a position lower than the connection position of the high temperature piping,
At least one of mixing the temperature of the hot water supplied to the hot water supply destination by mixing the high temperature water supplied from the high temperature pipe and the low temperature water supplied from the water source or the medium warm water supplied from the medium temperature pipe Means,
The medium hot water utilization state, which is a flow path state where the middle warm water is supplied to the at least one mixing means, and the middle warm water nonuse state, which is a flow path state where the low temperature water is supplied to the at least one mixing means Flow path switching means for switching the
A means for detecting the temperature of the middle warm water;
Means for controlling the at least one mixing means and the flow path switching means;
A means for enabling the user to set a second operation mode, which is an operation mode in which priority is given to improvement of energy efficiency as compared with the first operation mode;
Equipped with
When the temperature of the middle warm water is lower than the first reference temperature which is lower than the hot water supply set temperature, the flow path switching unit is switched to the middle warm water utilization state, and the first standard lower than the hot water supply set temperature. When the temperature of the middle warm water is higher than a second reference temperature higher than the temperature, the flow path switching unit is switched to the middle warm water non-use state ,
When said second operation mode is set than otherwise, the hot-water storage type hot-water supply system that increases the value of the first reference temperature and the second reference temperature. With a hot water storage tank,
High temperature piping connected to the upper part of the hot water storage tank,
Intermediate temperature piping connected to the hot water storage tank at a position lower than the connection position of the high temperature piping,
At least one of mixing the temperature of the hot water supplied to the hot water supply destination by mixing the high temperature water supplied from the high temperature pipe and the low temperature water supplied from the water source or the medium warm water supplied from the medium temperature pipe Means,
The medium hot water utilization state, which is a flow path state where the middle warm water is supplied to the at least one mixing means, and the middle warm water nonuse state, which is a flow path state where the low temperature water is supplied to the at least one mixing means Flow path switching means for switching the
A means for detecting the temperature of the middle warm water;
Means for controlling the at least one mixing means and the flow path switching means;
Equipped with
When the temperature of the middle warm water is lower than the first reference temperature which is lower than the hot water supply set temperature, the flow path switching unit is switched to the middle warm water utilization state, and the first standard lower than the hot water supply set temperature. When the temperature of the middle warm water is higher than a second reference temperature higher than the temperature, the flow path switching unit is switched to the middle warm water non-use state ,
The hot water storage derives water from the tank when performing the operation for circulating the water in the circuit back into the hot water storage tank is toggle its hot water storage type hot-water supply system the channel switching means to the warm water non use state. In the early stages of the hot water to the hot water supply destination after switching the flow path switching unit, compared to a later stage, one of claims 1 to 5 to reduce the control time interval for the at least one mixing means A hot water storage type hot water supply system according to one item. The at least one mixing means comprises a first mixing means and a second mixing means,
The first reference temperature and the second reference based on the lower one of the hot water supply set temperature for the hot water supply destination of the first mixing means and the hot water supply set temperature for the hot water supply destination of the second mixing means The hot water storage type hot water supply system according to any one of claims 1 to 6, wherein a temperature is set.

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