JP2019219156A - Storage water heater - Google Patents

Abstract

To provide a storage water heater advantageous for preventing an increase in a difference between a hot water supply temperature and a target value.SOLUTION: A storage water heater includes: a hot water delivery selector valve 26 for switching a boiling-up circuit and a bypass circuit; a general hot water supply side electric mixing valve 7 for controlling a hot water supply temperature; and a control section 24 for controlling a boiling-up operation for causing hot water heated by a heat pump unit 2 to flow into an upper part of a hot water storage tank 1 by the boiling-up circuit and a bypass operation for circulating water in the bypass circuit prior to the boiling-up operation. The control section 24 can execute bypass operation time change control for executing the bypass operation only for a first bypass operation time when the boiling-up operation is started while a hot water supply operation from the general hot water supply side electric mixing valve 7 to a hot water supply destination is being executed and for executing the bypass operation only for a second bypass operation time longer than the first bypass operation time when the boiling-up operation is started while the hot water supply operation is not being executed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hot water supply type hot water supply apparatus.

  Hot water storage type hot water supply devices that supply hot water using hot water stored in a hot water storage tank are widely used. The hot water storage device has a function of supplying hot water to a faucet, a shower, a bathtub, or the like at a temperature set by a user using a remote controller, for example.

  The hot water storage type hot water supply apparatus disclosed in Patent Literature 1 directly or directly connects the heapon return pipe and the heapon return pipe that return high-temperature water heated by the water-refrigerant heat exchanger of the heat pump unit to the top of the hot water storage tank. A bypass pipe is provided for bypassing, and when the boiling operation is started, when the outlet temperature sensor for detecting the outlet hot water temperature of the water-refrigerant heat exchanger detects a predetermined temperature, the flow from the bypass pipe side to the heapon return pipe side The flow path switching means is controlled so as to flow to the flow path.

JP 2009-264617 A

  If the temperature of the hot water flowing out of the heating means such as the heat pump unit during the boiling operation is lower or higher than the temperature of the hot water in the upper part of the hot water storage tank, the next hot water supply operation was performed. Sometimes, the difference between the hot water supply temperature and the target value may increase.

  The present invention has been made in order to solve the above-described problems, and has an object to provide a hot water storage type hot water supply apparatus that is advantageous in preventing a difference between a hot water supply temperature and a target value from increasing. .

Hot water storage type hot water supply device according to the present invention, a hot water storage tank, heating means for heating water, water taken out from the lower part of the hot water storage tank, a boiling circuit for flowing into the upper part of the hot water storage tank via the heating means, A bypass circuit for allowing water taken out from the lower part of the hot water storage tank to flow into the lower part of the hot water storage tank via the heating means, a switching valve for switching between a boiling circuit and a bypass circuit, and a first valve supplied from the upper part of the hot water storage tank A mixing valve for adjusting the hot water supply temperature by mixing hot water and second hot water having a lower temperature than the first hot water, and boiling for flowing hot water heated by the heating means into an upper portion of the hot water storage tank by a boiling circuit. A control unit that controls the operation and a bypass operation that circulates water to the bypass circuit before the boiling operation.The control unit is configured to perform the boiling operation when the hot water supply operation from the mixing valve to the hot water supply destination is being performed. Open up operation When performing the bypass operation only for the first bypass operation time, and when starting the boiling operation when the hot water supply operation is not being performed, the second bypass operation longer than the first bypass operation time The bypass operation time change control that executes the bypass operation only for the time can be performed.
Further, the hot water storage type hot water supply apparatus according to the present invention includes a hot water storage tank, a heating means for heating water, and a boiling circuit for flowing water taken out from a lower part of the hot water storage tank into an upper part of the hot water storage tank via the heating means. A mixing valve for adjusting the hot water supply temperature by mixing the first hot water supplied from the upper portion of the hot water storage tank with the second hot water having a lower temperature than the first hot water, and boiling the hot water heated by the heating means. A control unit that controls a boiling operation in which the upper circuit flows into the upper part of the hot water storage tank and a standby opening degree that is an opening degree of the mixing valve when hot water is not being supplied from the mixing valve to the hot water supply destination; Tank upper temperature detecting means for detecting a tank upper temperature which is a temperature of hot water at an upper part, tapping temperature detecting means for detecting a tapping temperature which is a temperature of hot water flowing out of the heating means, and detecting a temperature of the second hot water Second hot water temperature detection hand The control unit adjusts the standby opening degree based on the tank upper temperature and the temperature of the second hot water when the boiling operation is being performed and the tapping temperature is lower than the tank upper temperature, and When the operation is being performed and the tapping temperature is equal to or higher than the tank upper temperature, the mixing valve opening change control for adjusting the standby opening based on the tapping temperature and the temperature of the second hot water can be performed.

  Advantageous Effects of Invention According to the present invention, it is possible to provide a hot water supply type hot water supply apparatus that is advantageous in preventing a difference between a hot water supply temperature and a target value from increasing.

It is a figure which shows the hot-water storage type hot-water supply apparatus by Embodiment 1. It is a flowchart which shows the control operation of the bypass operation time change control of the hot water storage type hot water supply apparatus according to Embodiment 1. It is a flowchart which shows the control operation | movement of the mixing valve opening degree change control of the hot-water storage type hot water supply apparatus by Embodiment 1.

  Hereinafter, embodiments will be described with reference to the drawings. In the drawings, common or corresponding elements are denoted by the same reference numerals, and redundant description will be simplified or omitted. The present disclosure may include any combination of configurations that can be combined among the configurations described in the following embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a hot water supply type hot water supply apparatus according to Embodiment 1. As shown in FIG. 1, the hot water supply type hot water supply apparatus of the present embodiment includes a heat pump unit 2 which is a heating unit for heating water, and a hot water storage unit 40 having a hot water storage tank 1. The heat pump unit 2 and the hot water storage unit 40 are connected via an HP going pipe 48, an HP returning pipe 49, and electric wiring (not shown). The heat pump unit 2 includes a heat pump circuit in which a compressor, a hot water supply heat exchanger, an expansion valve, and an air heat exchanger are sequentially connected by refrigerant piping.

  Hot water storage tank 1 stores hot water. Inside the hot water storage tank 1, a temperature stratification in which the upper side has a high temperature and the lower side has a low temperature can be formed due to the difference in water density depending on the temperature. For convenience of description, the upper, middle, and lower portions of the hot water storage tank 1 are defined. The intermediate portion of hot water storage tank 1 is a portion having a height between an upper portion of hot water storage tank 1 and a lower portion of hot water storage tank 1. Portions corresponding to １ ／ of the capacity of the hot water storage tank 1 may be regarded as upper, middle, and lower portions, respectively, or upper, middle, and lower portions may be defined at different positions. It is sufficient that the hot water storage tank 1 has an upper part, an intermediate part, and a lower part in order from the upper side. In the case where the hot water storage tank 1 includes a plurality of tanks connected in series via pipes, the upper part, the middle part, and the lower part of the entire tank from the highest tank to the lowest tank The lower part may be determined.

  On the outer surface of the hot water storage tank 1, the volume from the top of the hot water storage tank 1 is, for example, at each of 0L, 50L, 100L, 150L, 170L, and 220L, the first temperature sensor 5a, the second temperature sensor 5b, A third temperature sensor 5c, a fourth temperature sensor 5d, a fifth temperature sensor 5e, and a sixth temperature sensor 5f are provided, and each position detects a water temperature. The first temperature sensor 5a, the second temperature sensor 5b, the third temperature sensor 5c, the fourth temperature sensor 5d, the fifth temperature sensor 5e, and the sixth temperature sensor 5f It functions as a remaining hot-water calorie detecting means for detecting the amount of hot-water. The HP going pipe 48 is provided with a seventh temperature sensor 5g for detecting the temperature of water entering the heat pump unit 2.

  In the hot water storage unit 40, a circulation pump 4, a general hot water supply side electric mixing valve 7, a high temperature pipe 8, a water supply pipe 9, a bath hot water supply side electric mixing valve 11, a solenoid valve for bath 13, a bath circulation pump 14, a water inlet switching valve 17. , Hot water supply flow sensor 19, hot water supply temperature sensor 20, bath flow sensor 21, bath temperature sensor 22, water supply temperature sensor 23, hot water switching valve 26, medium temperature return switching valve 27, medium temperature extraction switching valve 28, medium temperature pipe 30 And so on.

  The upstream of the water supply pipe 9 is connected to a water source such as a water pipe. The downstream side of the water supply pipe 9 is branched into a water supply pipe 9a and a water supply pipe 9b. The water supply pipe 9 a is connected to a lower part of the hot water storage tank 1. When the low-temperature water supplied from the water source flows into the lower part of the hot water storage tank 1 from the water supply pipe 9a, the inside of the hot water storage tank 1 is maintained in a full state.

  The medium temperature extraction switching valve 28 has a medium temperature inlet 28a, a low temperature inlet 28b, and a water outlet 28c. The water supply pipe 9b is connected to the low-temperature inlet 28b. One end of a medium temperature pipe 30 is connected to the medium temperature inlet 28a. The upstream portion of the high-temperature pipe 8 communicates with the hot water storage tank 1 at a first position 1 a above the hot water storage tank 1. The other end of the intermediate temperature pipe 30 communicates with the inside of the hot water storage tank 1 at a second position 1b lower than the first position 1a. The second position 1b is higher than the lower part of the hot water storage tank 1 to which the water supply pipe 9a is connected. That is, the second position 1b is located at an intermediate portion between the upper and lower portions of the hot water storage tank 1.

  Medium-temperature water supplied from the hot-water storage tank 1 through the medium-temperature pipe 30 flows into the medium-temperature inlet 28a. Low-temperature water having a lower temperature than the medium-temperature water flows into the low-temperature inlet 28b. In the present embodiment, low-temperature water supplied from the water source through the water supply pipe 9b flows into the low-temperature inlet 28b. The medium temperature extraction switching valve 28 can switch the flow path between a “medium temperature position” and a “low temperature position”. At the "medium temperature position", the medium temperature inlet 28a communicates with the water outlet 28c, and the low temperature inlet 28b is shut off. At the “medium temperature position”, the medium temperature water from the medium temperature pipe 30 flows to the water outlet 28c. In the "low temperature position", the low temperature inlet 28b communicates with the water outlet 28c, and the medium temperature inlet 28a is shut off. At the "low temperature position", the low temperature water from the water supply pipe 9b flows to the water outlet 28c.

  The general hot water supply side electric mixing valve 7 includes a hot water side inlet 7a, a water side inlet 7b, and a hot water outlet 7c. The bath water supply side electric mixing valve 11 includes a hot water side inlet 11a, a water side inlet 11b, and a hot water outlet 11c. The downstream portion of the high-temperature pipe 8 communicates with each of the hot-water inlet 7a and the hot-water inlet 11a. The water outlet 28c of the intermediate temperature extraction switching valve 28 communicates with each of the water-side inlet 7b and the water-side inlet 11b.

  One end of the first hot water supply pipe 10 is connected to the hot water outlet 7c. The general hot water supply side electric mixing valve 7 mixes the first hot water supplied from the hot water storage tank 1 through the high temperature pipe 8 and the second hot water from the water outlet 28 c of the medium temperature extraction switching valve 28. The second hot water has a lower temperature than the first hot water. Therefore, the hot water supply temperature can be adjusted by the general hot water supply side electric mixing valve 7 adjusting the mixing ratio of the first hot water and the second hot water. The hot water whose temperature has been adjusted by the general hot water supply side electric mixing valve 7 flows into the first hot water supply pipe 10. Hot water passing through the first hot water supply pipe 10 is supplied to a hot water supply destination such as a faucet or a shower.

  One end of the second hot water supply pipe 18 is connected to the hot water outlet 11c. The bath hot water supply side electric mixing valve 11 mixes the first hot water supplied from the hot water storage tank 1 through the high temperature pipe 8 with the second hot water from the water outlet 28c of the medium temperature extraction switching valve 28 to adjust the temperature. The hot water whose temperature has been adjusted flows into the second hot water supply pipe 18.

  The water supply pipe 9 is provided with a water supply temperature sensor 23. The feedwater temperature sensor 23 detects a feedwater temperature that is the temperature of the water flowing through the feedwater pipe 9. The first hot water supply pipe 10 is provided with a hot water supply flow rate sensor 19 and a hot water supply temperature sensor 20. Hot water supply flow sensor 19 detects the flow rate of hot water flowing through first hot water supply pipe 10. Hot water supply temperature sensor 20 detects the temperature of hot water flowing through first hot water supply pipe 10. The second hot water supply pipe 18 is provided with a bath solenoid valve 13, a bath flow sensor 21, and a bath temperature sensor 22. The bath solenoid valve 13 corresponds to an on-off valve that opens and closes the second hot water supply pipe 18. Bath flow sensor 21 detects the flow rate of hot water flowing through second hot water supply pipe 18. Bath temperature sensor 22 detects the temperature of hot water flowing through second hot water supply pipe 18.

  The second hot water supply pipe 18 is connected to the bath-side circulation circuit 12. The heat exchanger 15 is arranged in the hot water storage unit 40. The bath-side circulation circuit 12 is a path through which bath water can be drawn from a bath tub (not shown) in a bathroom outside the hot water supply type hot water supply device, and the bath water passed through the heat exchanger 15 can be returned into the bath tub. When the bath circulation pump 14 connected in the middle of the bath-side circulation circuit 12 is operated, bath water is circulated from the bathtub so as to pass through the bath-side circulation circuit 12 and return to the bathtub. The heat exchanger 15 exchanges heat between the bath water and the heat medium. The heat medium is, for example, hot water supplied from the hot water storage tank 1.

  When performing the filling operation of pouring hot water from the hot water storage unit 40 into the bathtub, the following is performed. The bath solenoid valve 13 is opened. The hot water whose temperature has been adjusted by the bath water supply side electric mixing valve 11 flows into the bathtub through the second hot water supply pipe 18 and the bath side circulation circuit 12. When the bath solenoid valve 13 closes, the filling operation ends.

  The water input switching valve 17 is a flow path switching unit having an a port and a b port serving as inlets and a c port serving as an outlet. The water inlet switching valve 17 is configured to be able to switch between two paths, ac and bc.

  The hot water switching valve 26 is a flow path switching unit having an a port and a b port serving as inlets and a c port and a d port serving as outlets. The hot water switching valve 26 is configured to be capable of switching flow paths among four paths of ac, ad, bc, and bd.

  The intermediate temperature return switching valve 27 is a flow path switching unit having an a port serving as an inlet, and b, c, and d ports serving as outlets. The intermediate temperature return switching valve 27 is configured to be capable of switching a flow path among three paths of ab, ac, and ad.

  Hot water storage unit 40 further includes bypass pipe 32, pipe 41, pipe 42, pipe 43, pipe 45, pipe 46, and pipe 47. The bypass pipe 32 connects between the port c of the hot water switching valve 26 and the lower part of the hot water storage tank 1. The pipe 41 connects between the lower part of the hot water storage tank 1 and the port a of the water input switching valve 17. The pipe 42 connects between the port c of the water inlet switching valve 17 and the inlet of the circulation pump 4. The HP going pipe 48 connects between the outlet of the circulation pump 4 and the inlet of the heat pump unit 2. The HP return pipe 49 connects between the outlet of the heat pump unit 2 and the b port of the hot water switching valve 26. The pipe 43 connects between the d port of the hot water switching valve 26 and the a port of the intermediate temperature return switching valve 27. The pipe 45 connects between the b port of the intermediate temperature return switching valve 27 and the hot water inlet / outlet 1 c at the upper part of the hot water storage tank 1. The pipe 46 connects between the d port of the intermediate temperature return switching valve 27 and a position in the middle of the high temperature pipe 8. The pipe 47 connects between the port c of the intermediate temperature return switching valve 27 and a hot water inlet 1 d provided in an intermediate portion of the hot water storage tank 1.

  In the following description, the temperature of the hot water flowing out of the heat pump unit 2 will be referred to as “hot water temperature”. A tap water temperature sensor 6 is provided near the hot water inlet / outlet 1c. Hot water temperature sensor 6 corresponds to hot water temperature detecting means for detecting hot water temperature. Hot water temperature sensor 6 in the present embodiment detects the temperature of hot water heated by heat pump unit 2 and returned to the upper portion of hot water storage tank 1. Instead of the illustrated configuration, the tapping temperature sensor 6 may be arranged in, for example, the pipe 43, the pipe 45, or the HP return pipe 49.

  The first tank circulation pipe 16 connects between a position in the middle of the pipe 45 and the inlet of the heat medium of the heat exchanger 15. The second tank circulation pipe 50 connects between the outlet of the heat medium of the heat exchanger 15 and the b port of the water input switching valve 17. The pipe 51 branches from the HP pumping pipe 48 between the circulation pump 4 and the inlet of the heat pump unit 2 and is connected to the port a of the hot water switching valve 26. The bath heat recovery pipe 31 branches off from a position in the middle of the second tank circulation pipe 50 and is connected to a position in the middle temperature pipe 30.

  The hot water supply type hot water supply apparatus of the present embodiment includes a control unit 24 as control means. The control unit 24 is electrically connected to each actuator and each sensor described above. Various operations of the hot water supply type hot water supply apparatus including a boiling operation and a bypass operation described later are controlled by the control unit 24. The control unit 24 may include, for example, a processing circuit having at least one processor and at least one memory.

  Communication between the control unit 24 and the remote controller 25 can be performed bidirectionally by wired communication or wireless communication. The control unit 24 and the remote controller 25 may be able to communicate via a network. The remote controller 25 is an example of a user interface. The remote controller 25 has an operation unit operated by a user and a display unit 25a for displaying information. The remote controller 25 may include a touch screen having both functions of the operation unit and the display unit 25a. By operating the remote controller 25, the user can remotely control the hot water supply type hot water supply apparatus and perform various settings. The display unit 25a of the remote controller 25 has a function as a notification unit that notifies the user of information. The remote controller 25 in the present embodiment includes the display unit 25a as a notification unit, but may include another notification unit such as a voice guidance device as a modification.

  In the present embodiment, the remote controller 25 may be installed on a wall such as a kitchen, a living room, or a bathroom. Alternatively, for example, a portable information terminal such as a smartphone may be configured to have a function as a user interface such as the remote controller 25. A plurality of remote controllers 25 may be able to communicate with the control unit 24.

  By operating the remote controller 25, the user can change the set temperature of the general hot water supply side electric mixing valve 7 and the set temperature of the bath hot water supply side electric mixing valve 11, respectively. In the following description, the set temperature of the general hot water supply side electric mixing valve 7 is referred to as “hot water supply set temperature”, and the set temperature of the bath hot water supply side electric mixing valve 11 is referred to as “hot water setting temperature”.

  The hot water storage type hot water supply apparatus of the present embodiment can perform a boiling operation in which hot water heated by heat pump unit 2 flows into an upper portion of hot water storage tank 1. In the boiling operation, it becomes as follows. The heat pump unit 2 and the circulation pump 4 are operated. The water taken out from the lower part of the hot water storage tank 1 is guided into the heat pump unit 2 through the pipe 41, the water input switching valve 17, the pipe 42, the circulation pump 4, and the HP going pipe 48. The hot water heated in the heat pump unit 2 flows into the hot water storage tank 1 from the hot water inlet / outlet 1c through the HP return pipe 49, the hot water switching valve 26, the pipe 43, the medium temperature return switching valve 27, and the pipe 45. The circuit in which water circulates in this way corresponds to a boiling circuit in which water taken out from the lower part of the hot water storage tank 1 flows into the upper part of the hot water storage tank 1 via the heat pump unit 2. The boiling operation is typically performed around the midnight power hours, and hot water used for the next day is stored in the hot water storage tank 1.

  The hot water supply type hot water supply apparatus of the present embodiment executes the bypass operation before the boiling operation. In the bypass operation, the following is performed. The heat pump unit 2 and the circulation pump 4 are operated. The water taken out from the lower part of the hot water storage tank 1 is guided into the heat pump unit 2 through the pipe 41, the water input switching valve 17, the pipe 42, the circulation pump 4, and the HP going pipe 48. The hot water heated in the heat pump unit 2 flows into the lower part of the hot water storage tank 1 through the HP return pipe 49, the hot water switching valve 26, and the bypass pipe 32. The circuit in which the water circulates in this way corresponds to a bypass circuit that causes the water taken out from the lower part of the hot water storage tank 1 to flow into the lower part of the hot water storage tank 1 via the heat pump unit 2. In the present embodiment, the hot water switching valve 26 can switch between the boiling circuit and the bypass circuit.

  Since the heat pump unit 2 cannot sufficiently heat water for a while after the heat pump unit 2 is started, hot water not reaching a sufficient temperature flows out of the heat pump unit 2. By performing the bypass operation before the boiling operation, it is possible to prevent such insufficiently heated hot water from flowing into the upper portion of the hot water storage tank 1, so that the high-temperature water stored in the upper portion of the hot water storage tank 1 can be prevented. It is possible to prevent the temperature from lowering.

  In the following description, the operation of supplying hot water from the general hot water supply side electric mixing valve 7 to the hot water supply destination is simply referred to as “hot water supply operation”. The control unit 24 can detect the start and stop of the hot water supply operation by the hot water supply flow rate sensor 19. During the execution of the hot water supply operation, the control unit 24 adjusts the mixing ratio of the general hot water supply side electric mixing valve 7 so that the hot water supply temperature detected by the hot water supply temperature sensor 20 becomes equal to the target hot water supply set temperature. can do. That is, during execution of the hot water supply operation, control unit 24 can perform feedback control of the hot water supply temperature.

  The general hot water supply side electric mixing valve 7 includes, for example, a valve body that is rotated by a stepping motor, and changes the ratio between the opening area of the hot water side inlet 7a and the opening area of the water side inlet 7b by rotation of the valve body. The mixing ratio of the first warm water flowing from the hot water inlet 7a and the second warm water flowing from the hot water inlet 7b can be adjusted. This mixing ratio changes according to “the opening degree of the general hot water supply side electric mixing valve 7”. The “opening degree of the general hot water supply side electric mixing valve 7” is represented, for example, by a numerical value corresponding to the rotation position of the stepping motor. The control unit 24 can hold information on the opening degree of the general hot water supply side electric mixing valve 7. Since the mixing ratio of the first hot water and the second hot water changes according to the opening of the general hot water supply side electric mixing valve 7, the control unit 24 can hold information on the mixing ratio. The configuration of the bath water supply side electric mixing valve 11 is the same as the configuration of the general hot water supply side electric mixing valve 7 described above.

  In the following description, the opening of the general hot water supply side electric mixing valve 7 when the hot water supply operation is not being executed is referred to as “mixing valve standby opening”. The control unit 24 in the present embodiment has a function of controlling the mixing valve standby opening.

  The control unit 24 sets the opening of the general hot water supply side electric mixing valve 7 when the hot water supply temperature detected by the hot water supply temperature sensor 20 becomes equal to the target value during the execution of the hot water supply operation to “a stable opening at hot water supply”. Can be stored as The control unit 24 can control the mixing valve standby opening such that the mixing valve standby opening is equal to the hot water supply stable opening during the previous hot water supply operation. In the next hot water supply operation, if the temperatures of the first hot water and the second hot water supplied to the general hot water supply side electric mixing valve 7 and the hot water supply set temperature are the same as those in the previous hot water supply operation, the mixing valve standby opening degree is changed. By making the opening degree equal to the hot water supply stable opening degree, the hot water supply temperature can be made equal to the target value immediately after the start of the hot water supply operation.

  The first temperature sensor 5a in the present embodiment corresponds to a tank upper temperature detecting unit that detects a tank upper temperature that is the temperature of hot water in the upper part of the hot water storage tank 1. When the temperature stratification in the hot water storage tank 1 is stable, the tank upper temperature detected by the first temperature sensor 5a is supplied to the general hot water supply side electric mixing valve 7 from the upper part of the hot water storage tank 1 through the high temperature pipe 8. Can be considered to be equal to the temperature of the first hot water.

  When the middle temperature extraction switching valve 28 is at the low temperature position, low temperature water from the water supply pipe 9 flows into the general hot water supply side electric mixing valve 7 as second hot water, and is mixed with the first hot water from the upper part of the hot water storage tank 1, It is supplied to the hot water supply destination. In this case, the temperature of the second hot water can be detected by the feedwater temperature sensor 23. That is, the feed water temperature sensor 23 corresponds to a second hot water temperature detecting unit that detects the temperature of the second hot water.

  The fourth temperature sensor 5d in the present embodiment is located at the same height or almost the same height as the second position 1b. For this reason, the temperature detected by the fourth temperature sensor 5d can be considered to be equal to the temperature of the medium-temperature water supplied from the hot-water storage tank 1 to the medium-temperature pipe 30. When the intermediate-temperature extraction switching valve 28 is at the intermediate-temperature position, the intermediate-temperature water flowing out of the hot-water storage tank 1 to the intermediate-temperature pipe 30 flows into the general hot-water-supply-side electric mixing valve 7 as second hot water, and the first hot water And supplied to the hot water supply destination. In this case, the temperature of the second hot water can be detected by the fourth temperature sensor 5d. That is, the fourth temperature sensor 5d corresponds to a second hot water temperature detecting unit that detects the temperature of the second hot water.

  In general, the longer the bypass operation time, the higher the tapping temperature when shifting from the bypass operation to the boiling operation. For this reason, from the viewpoint of preventing low-temperature hot water from flowing into the upper portion of the hot water storage tank 1, it is preferable that the bypass operation time is long. On the other hand, the longer the bypass operation time, the larger the amount of hot water flowing into the lower part of the hot water storage tank 1 during the bypass operation, and thus the greater the loss of heat generated by the heat pump unit 2 during the bypass operation. Therefore, from the viewpoint of energy saving, it is preferable that the bypass operation time is short.

  When both the hot water supply operation and the boiling operation are performed, hot water having a lower temperature than the hot water in the upper part of the hot water storage tank 1 (hereinafter, referred to as “low-temperature inflow water”) flows from the hot water introduction outlet 1c to the hot water storage tank 1c. Consider the case of flowing into the upper part of 1. In this case, the low-temperature inflow water gradually mixes with the hot water in the upper part of the hot water storage tank 1, and the hot water in the upper part of the hot water storage tank 1 flows out of the first position 1 a to the high-temperature pipe 8. For this reason, the temperature of the first hot water supplied from the upper part of the hot water storage tank 1 to the general hot water supply side electric mixing valve 7 through the high temperature pipe 8 is relatively unlikely to decrease. As a result, the hot water supply temperature is hardly reduced, and the difference between the hot water supply temperature and the target value is hardly large.

  On the other hand, when the low-temperature inflowing water flows into the upper part of the hot-water storage tank 1 from the hot-water inlet / outlet 1c by the boiling operation when the hot-water supply operation is not being performed, the following occurs. In this case, since the hot water in the upper part of the hot water storage tank 1 does not flow out to the high-temperature pipe 8, low-temperature inflow water accumulates in the upper part of the hot water storage tank 1, and the temperature in the upper part of the hot water storage tank 1 is liable to decrease significantly. . When the hot water supply operation is started at a timing when the temperature in the upper part of the hot water storage tank 1 is greatly reduced, the first hot water having a lower temperature than that of the previous hot water supply operation is supplied from the upper part of the hot water storage tank 1 to the general hot water supply side electric mixing valve 7. Supplied to As a result, the hot water supply temperature tends to decrease, and the difference between the hot water supply temperature and the target value tends to increase.

  The control unit 24 in the present embodiment includes bypass operation time changing means 24a for performing bypass operation time change control, and mixing valve opening degree changing means 24b for executing mixing valve opening degree change control. The hot water storage type hot water supply device of the present disclosure may be capable of performing only one of the bypass operation time change control and the mixing valve opening degree change control. That is, the control unit 24 may include only one of the bypass operation time changing unit 24a and the mixing valve opening changing unit 24b.

  In the bypass operation time change control according to the present embodiment, when starting the boiling operation while the hot water supply operation is being performed, the control unit 24 performs the boiling operation after performing the bypass operation for the first bypass operation time. Shift to upper operation. Further, in the bypass operation time change control, when starting the boiling operation when the hot water supply operation is not being performed, the control unit 24 performs the bypass operation for the second bypass operation time longer than the first bypass operation time. Then, the operation shifts to the boiling operation. According to such bypass operation time change control, the following effects can be obtained. When the hot water supply operation is being performed, as described above, even when the low-temperature inflow water flows into the upper part of the hot water storage tank 1, the hot water supply temperature does not easily decrease, and the difference between the hot water supply temperature and the target value does not easily increase. . For this reason, when the hot water supply operation is being performed, there is little need to lengthen the bypass operation time, so that the bypass operation is performed only for the relatively short first bypass operation time. Thereby, energy saving can be achieved. On the other hand, if the low-temperature inflow water flows into the upper portion of the hot water storage tank 1 when the hot water supply operation is not being performed, the hot water supply temperature tends to decrease when the hot water supply operation is started thereafter, and the difference between the hot water supply temperature and the target value is determined. The difference tends to be large. In order to prevent such a situation, when the hot water supply operation is not being performed, the bypass operation is performed for the relatively long second bypass operation time. Thereby, since the low-temperature inflow water can be reliably prevented from flowing into the upper portion of the hot water storage tank 1, even when the hot water supply operation is started thereafter, a decrease in the hot water supply temperature can be reliably suppressed.

  When the hot water supply operation is stopped and the boiling operation is being performed, hot water having a higher temperature than the hot water in the upper part of the hot water storage tank 1 (hereinafter, referred to as “high-temperature inflow water”) is supplied from the hot water inlet 1c. Consider a case where the water flows into the upper part of the hot water storage tank 1. In this case, when the hot water supply operation is started, hot water having a higher temperature than the hot water in the upper part of the hot water storage tank 1 before the boiling operation is supplied to the general hot water supply side electric mixing valve 7 through the high temperature pipe 8. Therefore, the hot water supply temperature may be higher than the target value.

  In the mixing valve opening degree change control of the present embodiment, the control unit 24 determines that the tapping temperature detected by the tapping temperature sensor 6 is detected by the first temperature sensor 5a while the boiling operation is being performed. If the temperature is lower than the temperature, the mixing valve standby opening is adjusted based on the tank upper temperature and the temperature of the second hot water detected by the feedwater temperature sensor 23 or the fourth temperature sensor 5d. That is, the control unit 24 opens and stops the mixing valve so that the hot water supply temperature becomes equal to the target value when it is assumed that the first hot water having the temperature equal to the tank upper temperature and the second hot water are mixed. Adjust the degree. The mixing valve standby opening thus adjusted is hereinafter referred to as “first standby opening”.

  In addition, in the mixing valve opening degree change control, the control unit 24 is performing the boiling operation, and the tapping temperature detected by the tapping temperature sensor 6 is equal to or higher than the tank upper temperature detected by the first temperature sensor 5a. In this case, the mixing valve standby opening is adjusted based on the tap water temperature and the temperature of the second hot water detected by the feed water temperature sensor 23 or the fourth temperature sensor 5d. That is, the control unit 24 sets the mixing valve standby opening degree so that the hot water supply temperature becomes equal to the target value when the first hot water having the temperature equal to the tap water temperature and the second hot water are mixed. To adjust. The mixing valve standby opening thus adjusted is hereinafter referred to as “second standby opening”.

  Consider a case where the hot water supply operation is started while the high-temperature inflow water is flowing into the upper portion of hot water storage tank 1 during the execution of the boiling operation. Assuming that the mixing valve standby opening at this time is the first standby opening, hot water having a temperature higher than the tank upper temperature detected by the first temperature sensor 5a passes through the high-temperature pipe 8 and is supplied to the general hot water supply side motor. Since there is a possibility that the hot water is supplied to the mixing valve 7, the hot water supply temperature may be higher than the target value. On the other hand, according to the above-described mixing valve opening change control, when the high-temperature inflow water flows into the upper part of the hot water storage tank 1 during the boiling operation, the mixing valve standby opening becomes the second standby opening. It is adjusted to. When the hot water supply operation is started in a state where the mixing valve standby opening is adjusted to the second standby opening, hot water having a temperature equal to the high temperature inflow water is supplied to the general hot water supply side electric mixing valve 7 through the high temperature pipe 8. Even so, the hot water supply temperature does not exceed the target value. For this reason, it can be surely suppressed that the hot water supply temperature becomes higher than the target value.

  FIG. 2 is a flowchart showing a control operation of the bypass operation time change control of the hot water supply type hot water supply apparatus according to Embodiment 1. The control unit 24 starts the process of this flowchart when it is necessary to perform the boiling operation. In step S1 of FIG. 2, the bypass operation time changing unit 24a determines whether the hot water supply operation is being performed. When the hot water supply operation is being performed, the process proceeds to step S3, and the bypass operation time changing unit 24a sets the scheduled time for continuing the bypass operation to the first bypass operation time, and performs the bypass operation.

  On the other hand, if the hot water supply operation is not being performed in step S1, the process proceeds to step S2, and it is determined whether a predetermined time has elapsed since the end of the previous hot water supply operation. If the predetermined time has not yet elapsed since the end of the previous hot water supply operation, the process proceeds to step S4, where the bypass operation time changing means 24a sets the scheduled time for continuing the bypass operation to the second bypass operation time. , Carry out bypass operation. On the other hand, if the predetermined time has already elapsed from the end of the previous hot water supply operation, the process proceeds to step S3, and the bypass operation time changing unit 24a sets the scheduled time for continuing the bypass operation to the first bypass operation. Set the time and perform the bypass operation.

  The “predetermined time” in step S2 described above corresponds to, for example, a reference time until the hot water staying in the first hot water supply pipe 10 cools down while the hot water supply operation is stopped. In the present embodiment, the bypass operation time changing means 24a starts the boiling operation when the hot water supply operation is not being performed, and the time elapsed from the end of the previous hot water supply operation has reached the reference time. If so, the process in steps S2 and S3 executes the bypass operation for the first bypass operation time, and then shifts to the boiling operation. Thereby, the following effects can be obtained. If the predetermined time has already elapsed from the end of the previous hot water supply operation, even if the bypass operation is executed only for the second bypass operation time, when the hot water supply operation starts, the inside of the first hot water supply pipe 10 is cooled. Since the low-temperature water is first sent to the hot water supply destination, it is inevitable that the hot water supply temperature at the hot water supply destination decreases. Therefore, it can be said that the benefit obtained by performing the bypass operation for a long time is relatively small. Therefore, in this case, energy can be saved by executing the bypass operation only for the relatively short first bypass operation time.

  Not limited to the above control, the bypass operation time changing means 24a performs the bypass operation for the second bypass operation time when the hot water supply operation is not being performed, regardless of the elapsed time from the end of the previous hot water supply operation. May be performed. This is advantageous in reducing the time required for the hot water supply temperature to become equal to the target value when the hot water supply operation is started.

  The first bypass operation time is at least a time required for the water remaining inside the heat pump unit 2, the HP return pipe 49, and the hot water switching valve 26 to flow into the lower part of the hot water storage tank 1 through the bypass pipe 32. It is preferable that The first bypass operation time may be, for example, 90 seconds.

  The second bypass operation time is, for example, a time required for flowing water retained inside the heat pump unit 2, the HP return pipe 49, and the hot water switching valve 26 into the lower part of the hot water storage tank 1 through the bypass pipe 32. Preferably, the time is a time obtained by adding a time required for the temperature of the hot water flowing out of the heat pump unit 2 to rise to a predetermined temperature. The second bypass operation time may be, for example, 400 seconds.

  The process proceeds from step S3 or step S4 to step S5. In step S5, the bypass operation time changing unit 24a determines that the elapsed time from the start of the bypass operation has reached the first bypass operation time set in step S3 or the second bypass operation time set in step S4. Determine whether or not. When the elapsed time from the start of the bypass operation has not yet reached the set bypass operation time, the process proceeds to step S7, and the bypass operation time changing unit 24a sets the hot water switching valve 26 to the bypass side, that is, the bc port. The bypass operation is continued by maintaining the state in which the communication is established. On the other hand, when the elapsed time from the start of the bypass operation has reached the set bypass operation time, the process proceeds to step S6, and the bypass operation time changing means 24a sets the hot water switching valve 26 to the tank upper side, that is, b -Switch to a state that allows communication between d ports. This causes a transition from the bypass operation to the boiling operation.

  The process proceeds from step S6 or step S7 to step S8. In step S8, the bypass operation time changing unit 24a determines whether the elapsed time from the start of the bypass operation has reached the hot water supply stop monitoring time. The hot water supply stop monitoring time is, for example, a value equal to the second bypass operation time. If the elapsed time from the start of the bypass operation has reached the hot water supply stop monitoring time, the bypass operation time changing unit 24a ends the processing of this flowchart.

  On the other hand, if the elapsed time from the start of the bypass operation has not yet reached the hot water supply stop monitoring time, the process proceeds to step S9, and the bypass operation time changing unit 24a determines whether the stop of the hot water supply operation is detected. Judge. If it is not detected that the hot water supply operation has stopped, the process returns to step S5. On the other hand, when it is detected in step S9 that the hot water supply operation has stopped, the process proceeds to step S10, and the bypass operation time changing unit 24a sets the time for continuing the bypass operation to the third bypass operation time. The third bypass operation time is set as a time obtained by subtracting the time from the start of the bypass operation to the stop of the hot water supply operation detected in step S9 from the second bypass operation time. Proceeding from step S10 to step S11, the bypass operation time changing means 24a performs the bypass operation by setting the hot water switching valve 26 to a state in which the bypass side, that is, the bc port is communicated with. According to the processing in step S11, if the bypass operation is being performed, the bypass operation is continued. If the boiling operation is being performed, the boiling operation is interrupted and the bypass operation is performed. Will be resumed. The process returns from step S11 to step S5.

  If the third bypass operation time is set in step S10, and when returning to step S5, the bypass operation time changing means 24a sets the third elapsed time from the stop of the hot water supply operation detected in step S9. It is determined whether the bypass operation time has been reached.

  In the case where the hot water supply operation is stopped during the bypass operation started while the hot water supply operation is being performed, assuming that the operation has shifted from the bypass operation to the boiling operation when the first bypass operation time has elapsed, Low-temperature inflow water may accumulate in the upper part of the hot water storage tank 1. For this reason, when the hot water supply operation is restarted thereafter, the hot water supply temperature tends to decrease, and the difference between the hot water supply temperature and the target value may increase. On the other hand, according to the present embodiment, when the hot water supply operation is stopped during the bypass operation started while the hot water supply operation is being performed, the third processing is performed by the processing of steps S9 to S11. By setting the bypass operation time, the bypass operation is performed for a time equal to the second bypass operation time. As a result, the low-temperature inflow water can be reliably prevented from flowing into the upper part of the hot water storage tank 1, so that when the hot water supply operation is restarted thereafter, the hot water supply temperature is less likely to decrease, and the difference between the hot water supply temperature and the target value is reduced. Can be reliably prevented from increasing.

  In addition, during the boiling operation after the bypass operation is performed for the first bypass operation time, and before the time elapsed from the start of the bypass operation reaches the second bypass operation time, the hot water supply operation is performed. Assuming that it has stopped, low-temperature inflow water may accumulate in the upper part of the hot water storage tank 1. For this reason, when the hot water supply operation is restarted thereafter, the hot water supply temperature tends to decrease, and the difference between the hot water supply temperature and the target value may increase. On the other hand, according to the present embodiment, during the boiling operation after the bypass operation started when the hot water supply operation is being executed, and the time elapsed since the start of the bypass operation, If the hot water supply operation is stopped before reaching the stop monitoring time (= second bypass operation time), the bypass operation is restarted by the processing from step S8 to step S11. As a result, the low-temperature inflow water can be reliably prevented from flowing into the upper part of the hot water storage tank 1, so that when the hot water supply operation is restarted thereafter, the hot water supply temperature is less likely to decrease, and the difference between the hot water supply temperature and the target value Can be reliably prevented from increasing.

  The control unit 24 may include means for determining the model configuration of the hot water supply type hot water supply device. In that case, the following may be performed. For example, an inflow port for flowing hot water from the heat pump unit 2 into the upper portion of the hot water storage tank 1 and an outlet for taking out hot water from the upper portion of the hot water storage tank 1 for hot water supply are separated from each other. If it is determined that the bypass operation time change control by the bypass operation time changing means 24a is not necessary as in the model configuration in which the hot water supply operation is not being performed, the control unit 24 determines whether or not the hot water supply operation is being performed. Instead, the bypass operation time may be set to the first bypass operation time and the bypass operation may be performed.

  The control unit 24 may be capable of switching the operation mode of the hot water supply type hot water supply device between a first operation mode and a second operation mode in which energy saving is prioritized over the first operation mode. For example, by operating the remote controller 25, the user may be able to switch between setting the first operation mode and setting the second operation mode. The second operation mode is hereinafter referred to as “energy saving mode”. When the energy saving mode is set, the control unit 24 does not perform the bypass operation time change control, and sets the bypass operation time to the first bypass operation regardless of whether the hot water supply operation is being performed. The time may be set and the bypass operation may be performed. By doing so, there is a possibility that the temperature of the hot water supply may fluctuate, but it is possible to reliably prevent the time of the bypass operation from being prolonged, thereby achieving energy saving.

  The hot water supply type hot water supply apparatus of the present embodiment may include a selection unit that allows a user to select whether or not to execute bypass operation time change control. For example, a configuration may be adopted in which the user can set whether or not to execute the bypass operation time change control by operating the remote controller 25. Thereby, the user can set so as not to execute the bypass operation time change control when the user wants to give priority to energy saving rather than suppressing the fluctuation of the hot water supply temperature.

  FIG. 3 is a flowchart showing a control operation of the mixing valve opening degree change control of the hot water storage type hot water supply apparatus according to Embodiment 1. Control unit 24 performs the processing of this flowchart when the hot water supply operation is stopped. In step S12 in FIG. 3, the mixing valve opening degree changing unit 24b determines whether the boiling operation is not being performed. If the boiling operation is not being performed, the process proceeds to step S15, and the mixing valve opening degree changing unit 24b determines whether the information of the hot water supply stable opening degree in the previous hot water supply operation is stored in the memory. to decide. If the information of the hot water supply stable opening is stored in the memory, the process proceeds to step S16, and the mixing valve opening changing means 24b determines whether the mixing valve standby opening is equal to the hot water supply stable opening. A command is issued to the side electric mixing valve 7. After step S16, the processing of this flowchart ends.

On the other hand, when the information of the hot water supply stable opening is not stored in the memory in step S15, the process proceeds to step S17, and the mixing valve opening changing means 24b determines that the mixing valve standby opening is calculated by the following equation (1). ) Is issued to the general hot water supply side electric mixing valve 7 so as to be equal to the first standby opening calculated by the above (1). After step S17, the processing of this flowchart ends.
First standby opening = {850 / (TH−Twm)} × {| required hot water temperature−Twm |} Equation (1)

  Here, TH is the tank upper temperature detected by the first temperature sensor 5a. Twm is the temperature of the water flowing into the water-side inlet 7b, that is, the temperature of the second hot water detected by the feedwater temperature sensor 23 or the fourth temperature sensor 5d. The “required hot water temperature” is a temperature obtained by adding a margin considering heat radiation to the hot water supply set temperature set by the remote controller 25, and corresponds to a target value of the hot water supply temperature.

  On the other hand, when the boiling operation is not being executed in step S12, the mixing valve opening degree changing unit 24b proceeds to step S13, and the hot water switching valve 26 is in a state of connecting the bypass side, that is, the bc port. Determine whether or not. When the hot water switching valve 26 is on the bypass side, the process proceeds to step S15. The processing after step S15 is as described above.

  If the hot water switching valve 26 is not on the bypass side in step S13, that is, if the hot water switching valve 26 is in the state of communicating with the tank upper side, that is, between the b and d ports, this corresponds to the case where the boiling operation is being executed. In this case, the process proceeds to step S14, and the mixing valve opening degree changing means 24b compares the tapping temperature Two detected by the tapping temperature sensor 6 with the tank upper temperature TH. When tapping temperature Two is lower than tank upper part temperature TH, the process proceeds to step S15. The processing after step S15 is as described above. On the other hand, when the tapping temperature Two is equal to or higher than the tank upper temperature TH, the process proceeds to Step S18, and the mixing valve opening changing unit 24b calculates the mixing valve standby opening using the following equation (2). A command is issued to the general hot water supply side electric mixing valve 7 so as to be equal to the second standby opening.

  Second standby opening = {850 / (Two−ΔTb−Twm)} × {| required hot water temperature−Twm |} Expression (2)

  Here, ΔTb is a pipe heat dissipation margin set in consideration of the fact that the temperature of the hot water from the heat pump unit 2 will decrease due to the heat dissipation of the pipe before flowing into the upper part of the hot water storage tank 1. ΔTb may be set to, for example, 5 ° C.

  Proceeding from step S18 to step S19, the mixing valve opening changing means 24b deletes the information on the hot water supply stable opening from the memory when the information on the hot water supply stable opening is stored in the memory. After step S19, the processing of this flowchart ends.

  According to the process of the flowchart of FIG. 3 described above, when high-temperature inflow water having a temperature higher than the tank upper temperature TH flows into the upper portion of the hot water storage tank 1 during the boiling operation, the mixing valve is processed by the process of step S18. The standby opening is adjusted to the second standby opening. As a result, when the hot water supply operation is started, it is possible to reliably prevent the hot water supply temperature from becoming higher than the target value.

  Further, in the present embodiment, in step S18, based on tap water temperature Two detected by tap water temperature sensor 6 and temperature Twm of the second hot water detected by feed water temperature sensor 23 or fourth temperature sensor 5d. If the mixing valve standby opening has been adjusted, that is, if the mixing valve standby opening has been adjusted to the second standby opening, in step S19, the mixing valve opening changing means 24b determines whether the hot water supply in the previous hot water supply operation was performed. The time stable opening information is erased from the memory. Thereby, the following effects can be obtained. During the boiling operation, the high-temperature inflow water having a higher temperature than the tank upper temperature TH flows into the upper portion of the hot water storage tank 1, so that the temperature of the hot water in the upper portion of the hot water storage tank 1 becomes higher than in the previous hot water supply operation. Could be. Therefore, if the hot water supply operation is started in a state where the mixing valve standby opening is equal to the hot water supply stable opening, the hot water supply temperature may become higher than the target value. On the other hand, according to the present embodiment, in the above case, since the information of the hot water supply stable opening at the time of the previous hot water supply operation is deleted, the mixing valve standby opening becomes the hot water supply stable opening. Can be reliably prevented from being started in a state equal to. As a result, it is possible to reliably prevent the hot water supply temperature from becoming higher than the target value.

  When the control unit 24 includes means for determining the model configuration of the hot water supply type hot water supply device, the following may be performed. For example, as in a model configuration having a circuit having a circuit in which tap water from the heat pump unit 2 flows directly into the upper portion of the hot water storage tank 1 without passing through the tap switch valve 26 and the intermediate temperature return switch valve 27 and the like. If it is determined that the model configuration does not require the mixing valve opening change control by the opening changing means 24b, the control unit 24 calculates the mixing valve standby opening by equation (1) regardless of the tapping temperature Two. The general hot water supply side electric mixing valve 7 may be controlled so as to be equal to the first standby opening degree or the hot water supply stable opening degree stored during the hot water supply operation.

  When the energy saving mode is set, the control unit 24 calculates the mixing valve standby opening by the equation (1) regardless of the tapping temperature Two without executing the mixing valve opening change control. The general hot water supply side electric mixing valve 7 may be controlled so as to be equal to the first standby opening degree or the hot water supply stable opening degree stored during the hot water supply operation. By doing so, the operation frequency of the general hot water supply side electric mixing valve 7 can be reduced, so that the power consumption of the general hot water supply side electric mixing valve 7 can be suppressed, and energy saving can be achieved.

  The hot water supply type hot water supply apparatus of the present embodiment may include a selection unit that allows a user to select whether to execute the mixing valve opening degree change control or not. For example, the user may operate the remote controller 25 so that the user can set whether to execute the mixing valve opening degree change control or not. Thereby, the user can set so as not to execute the mixing valve opening change control when the user wants to give priority to energy saving rather than suppressing fluctuation of the hot water supply temperature.

Reference Signs List 1 hot water storage tank, 1a first position, 1b second position, 1c hot water inlet / outlet, 1d hot water inlet, 2 heat pump unit, 4 circulation pump, 5a first temperature sensor, 5b second temperature sensor, 5c third Temperature sensor, 5d fourth temperature sensor, 5e fifth temperature sensor, 5f sixth temperature sensor, 5g seventh temperature sensor, 6 tapping temperature sensor, 7 general hot water supply side electric mixing valve, 7a hot water side inlet, 7b Water side inlet, 7c hot water outlet, 8 high temperature pipe, 9 water supply pipe, 9a water supply pipe, 9b water supply pipe, 10 first hot water supply pipe, 11 bath hot water supply side electric mixing valve, 11a hot water side inlet, 11b water side inlet, 11c hot water Outlet, 12 bath side circulation circuit, 13 bath solenoid valve, 14 bath circulation pump, 15 heat exchanger, 16 first tank circulation piping, 17 water supply switching valve, 18 second hot water supply pipe, 19 hot water supply flow sensor, 20 hot water supply temperature sensor, 21 bath flow sensor, 22 bath temperature sensor, 23 water supply temperature sensor, 24 control unit, 24a bypass operation time changing means , 24b mixing valve opening changing means, 25 remote controller, 25a display unit, 26 hot water switching valve, 27 medium temperature return switching valve, 28 medium temperature extraction switching valve, 28a medium temperature inlet, 28b low temperature inlet, 28c water outlet, 30 medium temperature pipe, 31 Bath heat recovery piping, 32 bypass piping, 40 hot water storage units, 41 piping, 42 piping, 43 piping, 45 piping, 46 piping, 47 piping, 48 HP going piping, 49 HP returning piping, 50 second tank circulation piping, 51 piping

Claims (10)

Hot water storage tank,
Heating means for heating water;
A boiling circuit for flowing water taken out from the lower part of the hot water storage tank into the upper part of the hot water storage tank via the heating means,
A bypass circuit for flowing water taken out from the lower part of the hot water storage tank into the lower part of the hot water storage tank via the heating means;
A switching valve for switching between the boiling circuit and the bypass circuit,
A mixing valve for adjusting the hot water supply temperature by mixing first hot water supplied from the upper portion of the hot water storage tank and second hot water having a lower temperature than the first hot water,
A control unit that controls a boiling operation in which hot water heated by the heating means flows into an upper portion of the hot water storage tank by the boiling circuit, and a bypass operation in which water is circulated to the bypass circuit before the boiling operation. When,
With
When starting the boiling operation while the hot water supply operation from the mixing valve to the hot water supply destination is being performed, the control unit performs the bypass operation for a first bypass operation time, and performs the hot water supply operation. When the boiling operation is started when is not being executed, bypass operation time change control for executing the bypass operation for a second bypass operation time longer than the first bypass operation time can be performed. Hot water storage device. Hot water storage tank,
Heating means for heating water;
A boiling circuit for flowing water taken out from the lower part of the hot water storage tank into the upper part of the hot water storage tank via the heating means,
A mixing valve for adjusting the hot water supply temperature by mixing first hot water supplied from the upper portion of the hot water storage tank and second hot water having a lower temperature than the first hot water,
A boiling operation in which hot water heated by the heating means flows into the upper portion of the hot water storage tank by the boiling circuit, and an opening degree of the mixing valve when hot water is not being supplied from the mixing valve to a hot water supply destination. A control unit for controlling the standby opening degree;
Tank upper temperature detecting means for detecting a tank upper temperature that is a temperature of hot water at an upper portion of the hot water storage tank,
Tap water temperature detection means for detecting a tap water temperature that is the temperature of the hot water flowing out of the heating means,
Second hot water temperature detecting means for detecting the temperature of the second hot water,
With
The controller is configured to adjust the standby opening degree based on the tank upper temperature and the second hot water temperature when the boiling operation is being performed and the tapping temperature is lower than the tank upper temperature, Mixing valve opening change control for adjusting the standby opening based on the tapping temperature and the temperature of the second hot water when the boiling operation is being performed and the tapping temperature is equal to or higher than the tank upper temperature. Hot water storage type hot water supply device that can be implemented.   The control unit is configured to start the boiling operation when the hot water supply operation is not being performed, and when the time elapsed from the end of the previous hot water supply operation has reached a reference, The hot-water storage type hot water supply device according to claim 1, wherein the bypass operation is performed for one bypass operation time.   The control unit, when the hot water supply operation is stopped during the bypass operation started when the hot water supply operation is being performed, executes the bypass operation for the second bypass operation time. The hot-water storage type hot-water supply device according to claim 1 or 3.   The control unit is in the middle of the boiling operation after the bypass operation started when the hot water supply operation is being performed, and the time elapsed from the start of the bypass operation is the second bypass operation. 5. The hot water supply apparatus according to claim 1, wherein the bypass operation is restarted when the hot water supply operation is stopped before the operation time is reached. 6. The controller can store the opening degree of the mixing valve when the hot water temperature becomes equal to a target value during execution of the hot water supply operation from the mixing valve to the hot water supply destination as a hot water supply stable opening degree,
3. The control unit according to claim 2, wherein when the standby opening is adjusted based on the tapping temperature and the temperature of the second hot water, the control unit deletes the stored information on the hot water supply stable opening. Hot water storage device.   The hot water storage according to any one of claims 1, 3, 3, and 4, further comprising a selection unit that allows a user to select whether to perform the bypass operation time change control. Water heater.   The hot water supply type hot water supply apparatus according to claim 2 or 6, further comprising a selection unit configured to allow a user to select whether to perform the mixing valve opening degree change control. It is possible to switch between a first operation mode and a second operation mode that prioritizes energy saving over the first operation mode,
When the second operation mode is set, the control unit does not perform the bypass operation time change control, and the control unit does not perform the bypass operation time change control according to any one of claims 1, 3, 4, 5, and 7. The hot-water storage type hot-water supply device according to any one of the preceding claims. It is possible to switch between a first operation mode and a second operation mode that prioritizes energy saving over the first operation mode,
The said control part does not perform the said mixing valve opening degree change control, when the said 2nd operation mode is set, The Claims any one of Claim 2, Claim 6, and Claim 8 characterized by the above-mentioned. Hot water storage device.

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