Storage tank type hot water supply device

Abstract

To provide a storage type water heater which enables hot water in a hot water storage tank to be taken out and can prevent the hot water storage tank from getting empty when water service is stopped.SOLUTION: A storage type water heater 10 supplies hot water in a hot water storage tank 12 to a first cock 13 during normal time in which water of a water pipe 11 is supplied to the hot water storage tank 12. The storage type water heater 10 includes: a circulation circuit 44 in which a circulation pump 45 is operated to take out hot water from the hot water storage tank 12 and return the hot water to the hot water storage tank 12; a heat pump 53 which is operated to heat the hot water flowing in the circulation circuit 44; and control means having a function which causes the circulation pump 45 and the heat pump 53 to operate to conduct a boiling operation of the hot water storage tank 12 and a function which causes the circulation pump 45 to operate and bring the storage type water heater 10 into an emergency water supply state, in which hot water in the hot water storage tank 12 is discharged from a second cock 57 via a water line 58, when water service is stopped and water of the water pipe 11 is not supplied to the hot water storage tank 12. The control means performs controlling for preventing the hot water storage tank 12 from getting empty in the emergency water supply state.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a storage type hot water supply device that supplies hot water in a hot water storage tank to the outside. [Background technology]

[0002] A hot water storage type water heater uses the water pressure of the water pipe to supply hot water obtained by mixing hot water from a hot water storage tank with water from a water pipe or water from the water pipe (hereinafter, hot water or water will be referred to as "hot water") to a water faucet installed in a kitchen or bathroom (see Patent Documents 1 and 2). Therefore, under normal circumstances, when the faucet is opened, hot water can be dispensed from the faucet, and as hot water dispenses from the hot water storage tank, water is poured into the hot water storage tank from the water pipe.

[0003] However, when a natural disaster or other event causes the water supply infrastructure to fail, the flow of water in the water pipes stops, and water pressure is no longer applied to the water pipes, causing a water outage. In such a case, hot water will not come out of the tap even if you open it. To address this issue, by installing a drain hose at the bottom of the hot water storage tank, it will be possible to drain hot water from the hot water storage tank through the drain hose even when the water supply is out. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-196887 A [Patent Document 2] JP 2017-129328 A Summary of the Invention [Problem to be solved by the invention]

[0005] Meanwhile, in a storage-type hot water supply device 104 provided with a circulation circuit 103 as shown in FIG. 8, in which hot water is taken from the bottom of a hot water storage tank 101 by the operation of a pump 100, heated by a heat pump 102, and returned to the hot water storage tank 101 to boil the hot water storage tank 101, when the outside air temperature or the like falls below a predetermined temperature, a freeze prevention operation is performed to circulate the hot water from the hot water storage tank 101 through the circulation circuit 103 to prevent the circulation circuit 103 from freezing. However, since tap water is not supplied to hot water storage tank 101 when the water supply is stopped, if hot water continues to be discharged from the drain hose of hot water storage tank 101 when the water supply is stopped, hot water storage tank 101 will become empty and anti-freeze operation will no longer be possible. If hot water storage tank 101 becomes empty, restrictions will arise other than anti-freeze operation, which is not preferable.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a storage type hot water supply device that can remove hot water from the hot water storage tank when the water supply is stopped, and can prevent the hot water storage tank from becoming empty. [Means for solving the problem]

[0007] A storage type hot water supply device according to a first aspect of the present invention that meets the above-mentioned object is a storage type hot water supply device that supplies hot water in a hot water storage tank to a first water faucet during normal times when water from a water pipe is supplied to the hot water storage tank, the storage type hot water supply device comprising: The system comprises a circulation circuit having a circulation pump that operates to extract hot water from the hot water storage tank and return it to the hot water storage tank; a heat pump that operates to heat the hot water flowing through the circulation circuit; a second faucet connected to the downstream end of a water supply pipe whose upstream end is connected to the circulation circuit; and control means having a function of operating the circulation pump and the heat pump to heat the hot water storage tank, and a function of operating the circulation pump to establish an emergency water supply state in which the hot water in the hot water storage tank flows out of the second faucet via the water supply pipe when the water supply is stopped and water from the water pipe is not supplied to the hot water storage tank, and in the emergency water supply state, the control means performs control to prevent the hot water storage tank from becoming empty.

[0008] A second invention in line with the above-mentioned object is a hot water storage type hot water supply device that supplies hot water in a hot water storage tank to a first faucet during normal times when water from a water pipe is supplied to the hot water storage tank, and is equipped with a circulation pump, a circulation circuit that operates to extract hot water from the hot water storage tank and return it to the hot water storage tank, a heat pump that operates to heat the hot water flowing through the circulation circuit, a second faucet whose upstream end is connected to the hot water storage tank and whose downstream end is connected to a water supply pipe on which a water supply pump is provided, and control means that has a function of operating the circulation pump and the heat pump to heat the hot water storage tank, and a function of operating the water supply pump to enter an emergency water supply state in which hot water in the hot water storage tank flows out of the second faucet via the water supply pipe during a water supply outage when water from the water pipe is not supplied to the hot water storage tank, and in the emergency water supply state, the control means performs control to prevent the hot water storage tank from becoming empty. Effect of the Invention

[0009] In the storage type hot water supply devices of the first and second inventions, when the water supply is stopped and water from the water pipe is not supplied to the hot water storage tank, the control means operates the circulation pump (or water supply pump) to enter an emergency water supply state in which hot water in the hot water storage tank flows out of the second water faucet via the water supply pipe, and in the emergency water supply state, control is performed to prevent the hot water storage tank from running empty, so that hot water can be removed from the hot water storage tank when the water supply is stopped and the hot water storage tank can be prevented from running empty. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is an explanatory diagram of a storage type hot water supply device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a block diagram showing connections of a control means. [Diagram 3] FIG. 2 is an explanatory diagram showing the process of boiling water in a hot water storage tank. [Figure 4] FIG. 2 is an explanatory diagram showing the process of boiling water in a hot water storage tank. [Diagram 5] FIG. 11 is an explanatory diagram showing the freeze prevention operation. [Figure 6]FIG. 11 is an explanatory diagram showing the emergency water supply state. [Figure 7] FIG. 4 is an explanatory diagram of a storage type hot water supply device according to a second embodiment of the present invention. [Figure 8] FIG. 1 is an explanatory diagram of a conventional hot water storage type hot water supply device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Next, with reference to the attached drawings, an embodiment of the present invention will be described for understanding the present invention. As shown in Figure 1, the storage type hot water supply device 10 of the first embodiment of the present invention is a device that supplies hot water in the hot water storage tank 12 to a first faucet 13 during normal times when water from a water pipe 11 is supplied to the hot water storage tank 12.

[0012] 1, a plurality of (six in this embodiment) temperature sensors 14, 14a, 14b, 14c, 14d, and 14e are attached to the hot water storage tank 12. Of the temperature sensors 14, 14a, 14b, 14c, 14d, and 14e, the temperature sensor 14 is disposed at the highest position, followed by the temperature sensors 14, 14a, 14b, 14c, 14d, and 14e in descending order. One end of a water pipe 11 is connected to the lower part of the hot water storage tank 12. The water pipe 11 is provided with a pressure reducing valve 15, a temperature sensor 16, and check valves 17, 18, and 19.

[0013] The upper end of a hot water supply pipe 20, whose downstream end is connected to a first water faucet 13, is connected to the top of the hot water storage tank 12. A check valve 21, a mixing valve 24, a water volume sensor 22, and a temperature sensor 23 are provided in the hot water supply pipe 20 from the upstream end to the downstream end, and another end of the water pipe 11 is connected to the mixing valve 24. As shown in Fig. 2, the mixing valve 24 is connected to a control means 25 constituted by an IC chip or the like, together with the temperature sensors 14, 14a, 14b, 14c, 14d, 14e, 16, 23, and the water volume sensor 22.

[0014] The control means 25 is connected to an operation terminal 26 through which various input operations, including an operation for inputting the temperature of hot and cold water to be supplied to the first water faucet 13, are performed. The control means 25 detects the measurement values ​​of the temperature sensors 14, 16, 23 and the water volume sensor 22, and based on these measurement values, adjusts the mixing ratio of the hot water supplied from the top of the hot water storage tank 12 and the water from the water pipe 11 through the mixing valve 24, thereby controlling the temperature of the hot water sent from the mixing valve 24 to the first faucet 13 to be the temperature set on the operation terminal 26.

[0015] In addition, as shown in Figure 1, the upstream end of a hot water filling pipe 27 that supplies hot water to bathtub B and the upstream end of a heat exchange circulation circuit 28 that heats the hot water in bathtub B are connected to the hot water supply pipe 20. A check valve 29, a mixing valve 30, a water volume sensor 31, a solenoid valve 32, a check valve 33 and a temperature sensor 34 are provided in this order on the filling pipe 27 from its upstream end to its downstream end connected to the bathtub B, and another end of the water pipe 11 is connected to the mixing valve 30. The mixing valve 30, the water volume sensor 31, the solenoid valve 32 and the temperature sensor 34 are connected to the control means 25 as shown in FIG.

[0016] When the operation to fill bathtub B is performed using the operation terminal 26, the control means 25 opens the solenoid valve 32 so that the hot water from the top of the hot water storage tank 12 and the water from the water pipe 11, mixed by the mixing valve 30, are sent to bathtub B, and based on the detection values ​​of the temperature sensors 14, 16, 34 and the water volume sensor 31, the control means 25 adjusts the mixing ratio of the hot water from the top of the hot water storage tank 12 and the water from the water pipe 11, and controls the temperature of the hot water sent to bathtub B to the temperature set on the operation terminal 26.

[0017] 1, the heat exchange circulation circuit 28 has a check valve 36 and a pump 37, and its downstream end is connected to the hot water storage tank 12. A water level sensor 38, a water flow switch 39, a temperature sensor 40, and a pump 41 are provided in the bathtub B, and the upstream end of a bath circulation circuit 42 is connected to the bathtub B, whose downstream end is connected to the hot water filling pipe 27. A heat exchanger 43 is attached to the heat exchange circulation circuit 28 and the bath circulation circuit 42, and the pumps 37, 41, the water level sensor 38, the water flow switch 39, and the temperature sensor 40 are connected to the control means 25, as shown in FIG.

[0018] When the reheating operation is performed on the operation terminal 26, the control means 25 operates the pumps 37, 41 to return the hot water in the upper part of the hot water storage tank 12 to the hot water storage tank 12 through part of the hot water supply pipe 20 and the heat exchange circulation circuit 28, and to return the hot water in the bathtub B to the bathtub B through the bath circulation circuit 42 and part of the hot water filling pipe 27. As a result, heat is exchanged between the hot water flowing through the heat exchange circulation circuit 28 and the hot water flowing through the bath circulation circuit 42 by the heat exchanger 43, the hot water flowing through the bath circulation circuit 42 is heated, and the temperature of the hot water in the bathtub B rises.

[0019] Normally, a certain water pressure is generated in water pipe 11, and when first water faucet 13 is opened (or bathtub B is filled with water), the water pressure in water pipe 11 causes hot water to come out of first water faucet 13 (hot water flows into bathtub B), and the same amount of water as that sent out from the top of hot water storage tank 12 flows from water pipe 11 into the bottom of hot water storage tank 12. Therefore, under normal circumstances, hot water storage tank 12 is filled with hot water. In contrast, when the water supply is stopped and there is no specified water pressure in the water pipe 11, even if the first water faucet 13 or the solenoid valve 32 is opened, the hot water in the hot water storage tank 12 does not flow out from the top of the hot water storage tank 12 to the hot water supply pipe 20, and the hot water is not sent to the first water faucet 13 or the bathtub B.

[0020] In addition, the upstream end of a circulation circuit 44 is connected to the lower part of the hot water storage tank 12, and the two downstream ends are connected to the upper and lower parts of the hot water storage tank 12, respectively. As shown in Figs. 1 and 2, the circulation circuit 44 has a circulation pump 45 and a switching means 47, each connected to the control means 25. The circulation pump 45 is operated by the control means 25 to take out hot water from the lower part of the hot water storage tank 12, circulate it, and return it to the upper or lower part of the hot water storage tank 12, as shown in Figs. 3 and 4. The command signal sent from the control means 25 to the circulation pump 45 for operating the circulation pump 45 includes an output indication value that determines the operation level (output level) of the circulation pump 45. The control means 25 can detect the rotation speed of the circulation pump 45 during operation.

[0021] The switching means 47 is provided downstream of the circulation pump 45 in the circulation circuit 44, and the circulation circuit 44 branches into two downstream of the switching means 47, one of which is connected to the upper part of the hot water storage tank 12 and the other is connected to the lower part of the hot water storage tank 12. A heat pump 53 including an expansion valve 49, a heat exchanger 50, a compressor 51, and a heat exchanger 52, which are connected by a circulation flow path 48, is attached to the circulation circuit 44 between the circulation pump 45 and the switching means 47. The hot water circulating through the circulation circuit 44 passes through the heat exchanger 52 and is sent to the switching means 47.

[0022] A refrigerant is filled in the circulation flow path 48. The refrigerant circulates through the circulation flow path 48 by the operation of the compressor 51 (heat pump 53), is reduced in pressure as it passes through the expansion valve 49, picks up heat from the atmosphere as it passes through the heat exchanger 50, is compressed as it passes through the compressor 51, and gives heat to the hot water flowing through the circulation circuit 44 as it passes through the heat exchanger 52. Thus, the heat pump 53 operates to heat the hot water flowing through the circulation circuit 44.

[0023] The heat pump 53 further includes a temperature sensor 54 that measures the outside air temperature, and temperature sensors 55, 56 that measure the temperature of the hot and cold water in the circulation circuit 44 are attached to the upstream and downstream sides of the heat exchanger 52, respectively. The expansion valve 49, the compressor 51, and the temperature sensors 54, 55, 56 are connected to a control means 74 that is connected to the control means 25, as shown in FIG.

[0024] The switching means 47 can switch the destination of the hot water that has passed through the heat exchanger 52 from one of the upper and lower parts of the hot water storage tank 12 to the other. When the control means 25 detects that the amount of hot water boiling in the hot water storage tank 12 has decreased based on the measured temperatures of the temperature sensors 14, 14a, 14b, 14c, 14d, and 14e, it operates the circulation pump 45 and the compressor 51 (heat pump 53) to perform a boiling operation of the hot water storage tank 12.

[0025] When the boiling operation of the hot water storage tank 12 is started, the control means 25 adjusts the operating level of the compressor 51 and the opening degree (pressure reduction level) of the expansion valve 49 based on the temperatures measured by the temperature sensors 55, 56. When the temperature measured by the temperature sensor 56 is below a predetermined value, the control means 25 causes the switching means 47 to send hot water to the lower part of the hot water storage tank 12, as shown in Figure 3, and the circulation circuit 44 returns the water in the lower part of the hot water storage tank 12 to the lower part of the hot water storage tank 12, preventing low-temperature hot water from flowing into the upper part of the hot water storage tank 12.

[0026] Then, when the control means 25 detects that the temperature measured by the temperature sensor 56 has reached or exceeded a predetermined value, it switches the destination of the hot water sent by the switching means 47 to the upper part of the hot water storage tank 12, as shown in Fig. 4. This causes the circulation circuit 44 to acquire water from the lower part of the hot water storage tank 12 and return it to the upper part of the hot water storage tank 12, and supplies hot water heated by the heat pump 53 to the upper part of the hot water storage tank 12.

[0027] In addition, when the measured temperatures of temperature sensors 54, 55, 56 fall below a predetermined temperature (for example, when the measured temperature of temperature sensor 54 is below 3°C and at least one of temperature sensors 55, 56 is below 3°C) so that the hot water in the circulation circuit 44 does not freeze during low temperature periods such as winter, the control means 25 causes the circulation circuit 44 to perform anti-freeze operation by changing the destination of the hot water from the switching means 47 to the lower part of the hot water storage tank 12 while keeping the compressor 51 (heat pump 53) stopped, as shown in Figure 5, and operating the circulation pump 45 to circulate the hot water from the hot water storage tank 12 through the circulation circuit 44.

[0028] Therefore, the control means 25 has a function of preventing freezing of the circulation circuit 44 by operating the circulation pump 45 with the heat pump 53 stopped. The freeze prevention operation ends when the temperature measured by the temperature sensors 54, 55, 56 reaches a predetermined temperature or higher (for example, the temperature measured by the temperature sensor 54 reaches 6°C or higher, or the temperature measured by at least one of the temperature sensors 55, 56 reaches 6°C or higher). Note that if the temperature measured by the temperature sensors 54, 55, 56 does not reach a temperature at which the freeze prevention operation ends even after the freeze prevention operation has been performed for a predetermined time (for example, 5 minutes), a boiling operation is performed.

[0029] In addition, as shown in Figure 1, the storage type hot water heater 10 has a water supply pipe 58 whose upstream end is connected to the area between the circulation pump 45 and the heat exchanger 52 of the circulation circuit 44, and a second faucet 57 connected to the downstream end of the water supply pipe 58. When the water supply is stopped and water from the water pipe 11 is not being supplied to the hot water storage tank 12, the control means 25 has the function of activating the circulation pump 45 by performing a specified input operation on the operation terminal 26, and putting the hot water storage type hot water supply device 10 into a state in which hot water in the hot water storage tank 12 comes out of the second water faucet 57 via the water supply pipe 58, as shown in Figure 6 (hereinafter, this state will be referred to as the ``emergency water supply state'').

[0030] In the emergency water supply state, a user can open the second water faucet 57 to supply hot and cold water from the hot water storage tank 12 through the second water faucet 57. In the present embodiment, when hot and cold water in the hot water storage tank 12 is discharged from the second faucet 57 using the circulation pump 45, the distance from the hot water storage tank 12 to the second faucet 57 can be made longer, and there is greater freedom in the placement of the second faucet 57, compared to when hot and cold water in the hot water storage tank 12 is discharged from the second faucet 57 using gravity alone.

[0031] As the hot water in the hot water storage tank 12 flows out from the second faucet 57, air taken in through the negative pressure operated valve 59 flows into the hot water storage tank 12, and air accumulates from the top inside the hot water storage tank 12. Note that under normal circumstances, the second faucet 57 is closed so that hot water does not come out from the second faucet 57 even when the circulation pump 45 is operated.

[0032] The control means 25 can set the switching means 47 to a state in which hot water in the circulation circuit 44 is not sent to either the upper or lower part of the hot water storage tank 12. In this embodiment, in an emergency water supply state, the control means 25 sets the switching means 47 to either a state in which hot water is not sent to either the upper or lower part of the hot water storage tank 12, or a state in which hot water is sent to the lower part of the hot water storage tank 12. Note that Fig. 6 shows a state in which the switching means 47 is set to a state in which hot water in the circulation circuit 44 is not sent to either the upper or lower part of the hot water storage tank 12.

[0033] Depending on the structure of the switching means 47, even if the switching means 47 is set to a state in which hot water is not sent to either the upper or lower part of the hot water storage tank 12, a small amount of hot water may be sent to at least one of the upper and lower parts of the hot water storage tank 12. Therefore, a state in which hot water in the circulation circuit 44 is not sent to either the upper or lower part of the hot water storage tank 12 means a state in which the switching means 47 is not actively (intentionally) sending hot water to either the upper or lower part of the hot water storage tank 12.

[0034] Here, when hot water storage tank 12 becomes empty, freeze prevention operation cannot be performed. Also, when a function is provided to return water from the bottom of hot water storage tank 12 to the top of hot water storage tank 12 via circulation circuit 44 in order to cool the temperature of the air that has flowed into hot water storage tank 12, this function cannot be performed when hot water storage tank 12 becomes empty. Therefore, in an emergency water supply state, the control means 25 detects when the remaining amount of hot water in the hot water storage tank 12 falls below a predetermined set remaining amount P, stops the circulation pump 45, prevents the amount of hot water in the hot water storage tank 12 from decreasing, and performs control to maintain a state where anti-freeze operation is possible (a state in which anti-freeze operation can be performed when necessary), i.e., controls to prevent the hot water storage tank 12 from becoming empty. In this embodiment, the set remaining amount P is a value between 30 L and 100 L, and the control means 25 derives the remaining amount of hot water in the hot water storage tank 12 from the operating time of the circulation pump 45 in the emergency water supply state.

[0035] Circulation pump 45 is designed to increase its rotation speed (operation level) when the amount of hot water or water coming out of second faucet 57 (amount of hot water or water per unit time, the same applies below) is large, and decrease its rotation speed when the amount of hot water or water coming out is small. Therefore, control means 25 calculates the amount of hot water or water coming out of second faucet 57 based on the operation time of circulation pump 45 and the rotation speed of circulation pump 45 in the emergency water supply state, and finds the remaining amount of hot water or water in hot water storage tank 12.

[0036] The control means 25 may calculate the amount of hot water coming out of the second faucet 57 based on the operation time of the circulation pump 45 and the operation level of the circulation pump 45 in the emergency water supply state, to determine the remaining amount of hot water in the hot water storage tank 12. The control means 25 obtains information on the operation level of the circulation pump 45 from the output instruction value sent from the control means 25 to the circulation pump 45 in the emergency water supply state. In addition, since there is a possibility that hot water may come out of the second faucet 57, in this embodiment, a notice is provided near the second faucet 57 that warns users about the risk of hot water coming out, in addition to instructions on how to use the second faucet 57.

[0037] Furthermore, the control means 25 can, by a predetermined input operation on the operation terminal 26, put the hot water storage type hot water supply apparatus 10 into an emergency restriction state which prohibits the operation of the heat pump 53, the filling of bathtub B with hot water, and the re-heating of hot water in bathtub B. In this embodiment, on the operation terminal 26, the input operation for putting the hot water storage type hot water supply apparatus 10 into the emergency restriction state and the input operation for putting the hot water storage type hot water supply apparatus 10 into the emergency water supply state are performed with a common button.

[0038] When the button is pressed continuously (long pressed) for a certain period of time (e.g., 5 seconds), control means 25 puts storage type hot water supply device 10 into the emergency restriction state, and when the button is pressed and held again, control means 25 releases the emergency restriction state of storage type hot water supply device 10. When the button is pressed normally rather than long pressed, storage type hot water supply device 10 in the emergency restriction state is placed into the emergency water supply state by control means 25 while maintaining the emergency restriction state, and when the button is pressed normally again, only the emergency water supply state is released.

[0039] Here, in storage type hot water supply device 10, the upstream end of water supply pipe 58 is connected to circulation circuit 44, but is not limited to this. With reference to Fig. 7, a storage type hot water supply device 70 in which the upstream end of water supply pipe 71 is connected to hot water storage tank 12 will be described. Note that in storage type hot water supply device 70, components similar to those in storage type hot water supply device 10 are given the same reference numerals and detailed description thereof will be omitted. As shown in Figure 7, in a storage type hot water supply device 70 according to a second embodiment of the present invention, a second faucet 72 is connected to the downstream end of a water supply pipe 71 whose upstream end is connected to the lower part of the hot water storage tank 12, and a water supply pump 73 connected to a control means is provided in the water supply pipe 71.

[0040] When the water supply is stopped, the control means operates the water supply pump 73 to create an emergency water supply state in which hot water in the hot water storage tank 12 flows out of the second water faucet 72 via the water supply pipe 71, and when it detects that the remaining amount of hot water in the hot water storage tank 12 in the emergency water supply state has fallen below a predetermined set remaining amount P, it stops the water supply pump 73. The control means derives the remaining amount of hot water in the hot water storage tank 12 from the operation time and rotation speed of the water supply pump 73 in the emergency water supply state, or from the operation time and operation level of the water supply pump 73 in the emergency water supply state.

[0041] Although the embodiment of the present invention has been described above, the present invention is not limited to the above-mentioned embodiment, and all changes in conditions that do not depart from the gist of the present invention are within the scope of application of the present invention. For example, the control means may control the hot water storage tank to prevent it from becoming empty by detecting that the cumulative amount of air flowing into the hot water storage tank from the negative pressure operated valve has reached a predetermined value, and then stopping the circulation pump.

[0042] In addition, when detecting the remaining amount of hot water in the hot water storage tank, the remaining amount of hot water in the hot water storage tank, which decreases when water flows out from the second faucet, can be derived based on the measurement value of a water volume sensor installed in the water supply pipe. However, in this case, the number of parts increases compared to when the remaining amount of hot water in the hot water storage tank is derived from the operating time of the circulation pump. The circulation circuit does not need to have a switching means. For example, if the hot water in the circulation circuit is heated by using the exhaust heat generated by the private generator during power generation to heat the hot water in the hot water storage tank, the circulation circuit does not need to have a switching means. In this case, the destination of the hot water heated by the heating means is the upper part of the hot water storage tank. [Explanation of symbols]

[0043] 10: storage type hot water supply device, 11: water pipe, 12: hot water tank, 13: first water faucet, 14, 14a, 14b, 14c, 14d, 14e: temperature sensor, 15: pressure reducing valve, 16: temperature sensor, 17, 18, 19: check valve, 20: hot water supply pipe, 21: check valve, 22: water volume sensor, 23: temperature sensor, 24: mixing valve, 25: control means, 26: operation terminal, 27: hot water filling pipe, 28: heat exchange circulation circuit, 29: check valve, 30: mixing valve, 31: water volume sensor, 32: solenoid valve, 33: check valve, 34: temperature sensor, 36: check valve, 37: pump, 38: water level sensor, 39: water flow switch, 40: temperature sensor, 41: pump, 42: bath circulation circuit, 43: heat exchanger, 44: circulation circuit, 45: circulation pump, 47: switching means, 48, circulation flow path, 49: expansion valve, 50: heat exchanger, 51: compressor, 52: heat exchanger, 53: heat pump, 54, 55, 56: temperature sensor, 57: second faucet, 58: water supply pipe, 59: negative pressure actuated valve, 70: hot water storage type hot water supply device, 71: water supply pipe, 72: second faucet, 73: water supply pump, 74: control means, B: bathtub

Claims

1. In a storage-type hot water supply device, when water from a water pipe is normally supplied to the hot water storage tank, hot water in the hot water storage tank is supplied to a first water faucet, A circulation circuit having a circulation pump, the circulation pump being operated to take hot water from the hot water storage tank and return it to the hot water storage tank; A heat pump that operates to heat the hot and cold water flowing through the circulation circuit; A second faucet connected to a downstream end of a water supply pipe whose upstream end is connected to the circulation circuit; a control means having a function of operating the circulation pump and the heat pump to perform a heating operation for the hot water storage tank, and a function of operating the circulation pump to establish an emergency water supply state in which hot water in the hot water storage tank flows out of the second water faucet via the water supply pipe when the water supply is stopped and water from the water pipe is not supplied to the hot water storage tank; In the emergency water supply state, the control means performs control to prevent the hot water storage tank from becoming empty by detecting when the remaining amount of hot water in the hot water storage tank falls below a predetermined set remaining amount P and stopping the circulation pump, and further derives the remaining amount of hot water in the hot water storage tank from the operating time of the circulation pump and the rotation speed of the circulation pump in the emergency water supply state, or from the operating time of the circulation pump and the operating level of the circulation pump in the emergency water supply state.

2. In a storage-type hot water supply device, when water from a water pipe is normally supplied to the hot water storage tank, hot water in the hot water storage tank is supplied to a first water faucet, A circulation circuit having a circulation pump, the circulation pump being operated to take hot water from the hot water storage tank and return it to the hot water storage tank; A heat pump that operates to heat the hot and cold water flowing through the circulation circuit; A second faucet connected to a downstream end of a water supply pipe having an upstream end connected to the hot water tank and a water supply pump provided therein; a control means having a function of operating the circulation pump and the heat pump to perform a heating operation for the hot water storage tank, and a function of operating the water supply pump to set up an emergency water supply state in which hot water in the hot water storage tank flows out of the second water faucet via the water supply pipe during a water supply outage in which water from the water pipe is not supplied to the hot water storage tank, In the emergency water supply state, the control means performs control to prevent the hot water storage tank from becoming empty by detecting when the remaining amount of hot water in the hot water storage tank falls below a predetermined set remaining amount P and stopping the water supply pump, and further derives the remaining amount of hot water in the hot water storage tank from the operating time and rotation speed of the water supply pump in the emergency water supply state, or from the operating time and operating level of the water supply pump in the emergency water supply state.

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