Storage tank type hot water supply device

Abstract

To provide a hot water storage type water heater which suppresses air which has flowed in a hot water storage tank by discharge of hot water in the hot water storage tank during the water supply stop surpassing an assumed upper limit temperature.SOLUTION: A hot water storage type water heater 10 which supplies hot water in a hot water storage tank 12 to a first water faucet 13 includes: a circulation circuit 44 which comes into a circulation state where the hot water acquired from a lower part of the hot water storage tank 12 is returned to an upper part of the hot water storage tank 12 by a circulation pump 45 actuating; a second water faucet 48 opened during the water supply stop and for discharging the hot water at the lower part of the hot water storage tank 12; air acquisition means 50 for taking in the outside air that flows inside the hot water storage tank 12 according to the discharge of the hot water of the hot water storage tank 12 from the second water faucet 48; and control means for detecting that the air which has flowed in the hot water storage tank 12 and has accumulated at the upper part of the hot water storage tank 12 has become the temperature higher than a predetermined set temperature, on the basis of, a measurement temperature of a temperature sensor 14 provided at the upper part of the hot water storage tank 12, and bringing the circulation circuit 44 into a circulation state by actuating the circulation pump 45.SELECTED DRAWING: Figure 7

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, which is 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, hot water can be dispensed from the faucet by opening the faucet. As hot water dispenses from the hot water storage tank, water is poured into the hot water storage tank from the water pipe. However, when a natural disaster or other incident causes the water supply infrastructure to fail, the flow of water in the water pipes stops, and there is no water pressure in the pipes, so no hot or cold water comes out of the tap even when it is turned on. [Prior art documents] [Patent documents]

[0003] [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]

[0004] Regarding this issue, by connecting a water supply pipe to the hot water storage tank and providing a dedicated faucet on the water supply pipe, it becomes possible to dispense hot water from the hot water storage tank from the dedicated faucet even when the water supply is stopped. Here, when the water supply is stopped, even if hot water dispenses from the hot water storage tank, water is not injected into the hot water storage tank from the water pipe. Since a conventional hot water storage type hot water supply device is provided with a negative pressure operated valve, air outside the hot water storage tank flows into the hot water storage tank via the negative pressure operated valve as hot water dispenses from the hot water storage tank, and air accumulates in the hot water storage tank from the top. The temperature of the air accumulated in the hot water storage tank is lower than the temperature of the hot water stored in the upper part of the hot water storage tank. For this reason, the temperature of the air accumulated in the hot water storage tank has not been considered a problem in the past.

[0005] However, it was discovered that the temperature of the air accumulated at the top of the hot water storage tank could exceed the upper limit temperature (for example, 100°C) assumed for the hot water storage tank. This is because the negative pressure operated valve does not have the function of discharging the air inside the hot water storage tank to the outside, and when water is injected from the water pipes into the hot water storage tank with air accumulated therein after the water supply infrastructure is restored, the air inside the hot water storage tank is compressed, causing the air temperature to rise. The present invention has been made in consideration of such circumstances, and aims to provide a storage-type hot water supply device that prevents the air flowing into the hot water storage tank when hot water flows out of the tank when the water supply is stopped from exceeding the expected upper limit temperature. [Means for solving the problem]

[0006] The hot water storage type hot water supply device of the present invention, which meets the above-mentioned objective, is a hot water storage type hot water supply device that supplies hot water in the 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, and is equipped with a temperature sensor provided on the top of the hot water storage tank, a circulation circuit having a circulation pump that operates to circulate hot water obtained from the bottom of the hot water storage tank back to the top of the hot water storage tank, a second water faucet that is opened when the water supply is stopped and water from the water pipe is not supplied to the bottom of the hot water storage tank to dispense hot water from the bottom of the hot water storage tank, air acquisition means that takes in outside air that flows into the hot water storage tank as hot water from the hot water storage tank is discharged from the second water faucet, and control means that detects based on the temperature measured by the temperature sensor that the air that has flowed into the hot water storage tank and accumulated at the top of the hot water storage tank has become hotter than a predetermined set temperature, and operates the circulation pump to put the circulation circuit into the circulation state. Effect of the Invention

[0007] The hot water storage type hot water supply device of the present invention comprises a circulation circuit in which the circulation pump is operated to circulate hot water obtained from the bottom of the hot water storage tank and returned to the top of the hot water storage tank, a second faucet that is opened when the water supply is stopped to dispense hot water from the bottom of the hot water storage tank, an air acquisition means for taking in outside air that flows into the hot water storage tank as hot water from the hot water storage tank is discharged from the second faucet, and a control means for detecting based on the temperature measured by a temperature sensor that the air that has flowed into the hot water storage tank and accumulated at the top of the hot water storage tank has become hotter than a predetermined set temperature, and for operating the circulation pump to put the circulation circuit into a circulation state, thereby making it possible to prevent the air that flows into the hot water storage tank due to the discharge of hot water from the hot water storage tank when the water supply is stopped from exceeding the upper limit temperature assumed under normal circumstances. [Brief description of the drawings]

[0008] [Figure 1] 1 is a circuit 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. 13 is an explanatory diagram of an emergency water supply state. [Figure 6] FIG. 4 is an explanatory diagram showing how air in a hot water storage tank is compressed. [Figure 7] FIG. 10 is an explanatory diagram showing how air in a hot water storage tank is cooled. [Figure 8] FIG. 11 is an explanatory diagram showing how air in a hot water storage tank is cooled in a hot water storage type hot water supply device according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Next, with reference to the attached drawings, an embodiment of the present invention will be described for better understanding of 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.

[0010] 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. The temperature sensors 14, 14a, 14b, 14c, 14d, and 14e are arranged in the highest position, with the temperature sensor 14 provided at the top of the hot water storage tank 12 being arranged in the highest position, followed by the temperature sensors 14, 14a, 14b, 14c, 14d, and 14e in descending order. To the lower part of the hot water storage tank 12, one end of a water pipe 11 is connected, on which a pressure reducing valve 15, a temperature sensor 16, and check valves 17 and 18 are provided.

[0011] 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.

[0012] 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.

[0013] 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.

[0014] 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, which are mixed in 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.

[0015] 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.

[0016] 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 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.

[0017] 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.

[0018] In contrast, when the infrastructure for supplying tap water stops functioning, the water pressure in water pipe 11 drops and the water in water pipe 11 is no longer supplied to the lower part of hot water storage tank 12. When the water supply is stopped and the water in water pipe 11 is not supplied to the lower part of hot water storage tank 12, even if first water faucet 13 or solenoid valve 32 is opened, the hot water in hot water storage tank 12 does not flow from the upper part of hot water storage tank 12 to hot water supply pipe 20, and hot water is not sent to first water faucet 13 or bathtub B.

[0019] Also, the upstream end of a boiling circuit (one example of a circulation circuit) 44, the downstream end of which is connected to the upper and lower parts of the hot water storage tank 12, is connected to the lower part of the hot water storage tank 12. As shown in Figs. 1 and 2, the boiling circuit 44 has a circulation pump 45, a heating means 46, and a switching means 47, each of which is connected to the control means 25, and the circulation pump 45 is operated by the control means 25 (operating the circulation pump 45), and the hot water obtained from the lower part of the hot water storage tank 12 is circulated and returned to the upper or lower part of the hot water storage tank 12, as shown in Figs. 3 and 4. Hereinafter, the state of the boiling circuit 44 in which the hot water obtained from the lower part of the hot water storage tank 12 is circulated and returned to the upper part of the hot water storage tank 12 is referred to as a circulation state.

[0020] The circulation pump 45, the heating means 46, and the switching means 47 are arranged in order along the flow of hot water through the boiling circuit 44. The boiling circuit 44 branches into two downstream of the switching means 47, one of which is connected to the top of the hot water storage tank 12, and the other is connected to the bottom of the hot water storage tank 12. The heating means 46 is operated by the control means 25 to heat the hot water circulating through the boiling circuit 44.

[0021] The switching means 47 can switch the destination of the hot water that has passed through the heating means 46 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 (amount of boiling water) in the hot water storage tank 12 has decreased based on the measured temperatures of each of the temperature sensors 14, 14a, 14b, 14c, 14d, and 14e, it operates the circulation pump 45 and the heating means 46 to circulate the hot water in the lower part of the hot water storage tank 12 to the boiling circuit 44, and boils the hot water storage tank 12.

[0022] When the temperature measured by a temperature sensor (not shown) provided in heating means 46 that measures the temperature of hot water passing through heating means 46 is below a predetermined value, control means 25 causes switching means 47 to send the hot water to the lower part of hot water storage tank 12, as shown in Fig. 3. This causes boiling circuit 44 to obtain water from the lower part of hot water storage tank 12 and return it to the lower part of hot water storage tank 12, preventing low-temperature hot water from flowing into the upper part of hot water storage tank 12.

[0023] 4, when the control means 25 detects that the temperature of the hot water passing through the heating means 46 has reached a predetermined value or higher, 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 a result, the boiling circuit 44 enters a circulation state, obtaining water from the lower part of the hot water storage tank 12 and returning it to the upper part of the hot water storage tank 12, so that the hot water heated by the heating means 46 is supplied to the upper part of the hot water storage tank 12.

[0024] Here, the expected maximum temperature of the hot water stored in the hot water storage tank 12 is U°C, and with α>β, the temperature of the hot water stored in the upper part of the hot water storage tank 12 by boiling the hot water storage tank 12 is U-α°C in summer and U-β°C in winter. The control means 25 adjusts the operation level of the heating means 46 so that the temperature of the hot water heated by the heating means 46 and sent to the upper part of the hot water storage tank 12 is U-α°C in summer and U-β°C in winter. In this embodiment, U°C=100°C, α°C=35°C, and β°C=15°C, but this is not limited to this.

[0025] After the hot water storage tank 12 has been completely heated, the switching means 47 changes the destination to the upper part of the hot water storage tank 12, and when the hot water storage tank 12 is heated again, if the temperature of the hot water passing through the heating means 46 is below a predetermined value, the control means 25 switches the destination to the lower part of the hot water storage tank 12.

[0026] In this embodiment, a heat pump unit is used for the heating means 46, and a three-way valve is used for the switching means 47, but the present invention is not limited to these. For example, a heating means that uses exhaust heat generated during power generation by the private generator to heat the hot water flowing through the boiling circuit, or a switching means configured with two solenoid valves can be used. When a heating means that uses exhaust heat during power generation is used, the boiling circuit does not need to have a switching means, and a boiling circuit is used in which the hot water heated by the heating means is sent only to the top of the hot water storage tank.

[0027] Furthermore, the upstream end of water supply pipe 49 is connected to the area between circulation pump 45 and heating means 46 of boiling circuit 44, and a second water faucet 48 is connected to the downstream end of water supply pipe 49. When the water supply is stopped, control means 25 operates circulation pump 45 in response to a predetermined input operation being performed on operation terminal 26, and places storage type hot water supply device 10 in a state in which hot water in storage tank 12 flows out of second water faucet 48 via water supply pipe 49 (hereinafter, this state will be referred to as "emergency water supply state"), as shown in Fig. 5. In other words, operation of circulation pump 45 allows second water faucet 48 to supply hot water from the lower part of storage tank 12.

[0028] In the emergency water supply state, hot water from the bottom of the hot water storage tank 12 is sent to the second faucet 48 via a water supply pipe 49, and a user can release the hot water in the hot water storage tank 12 from the second faucet 48 by opening the second faucet 48. In the present embodiment, when hot and cold water in the hot water storage tank 12 is discharged from the second faucet 48 using a circulation pump 45, the distance from the hot water storage tank 12 to the second faucet 48 can be made longer, and there is greater freedom in the placement of the second faucet 48, compared to when hot and cold water in the hot water storage tank 12 is discharged from the second faucet 48 using gravity alone.

[0029] The control means 25 can set the switching means 47 to a state in which hot water in the boiling circuit 44 is not intentionally sent to either the upper or lower part of the hot water storage tank 12, whereby the boiling circuit 44 is in a state in which the return of hot water to the hot water storage tank 12 is stopped (hereinafter, this state is referred to as a water stop state). Depending on the design of the switching means 47, for example, a small amount of hot water (for example, one-tenth the amount when the switching means 47 is fully open) is sent to the upper or lower part of the hot water storage tank 12. In this embodiment, when the storage type hot water supply device 10 is put into an emergency water supply state, the switching means 47 is put into a water stopping state and the heating means 46 is put into a non-operating state.

[0030] 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 heating means 46, the filling of bathtub B with hot water, and the reheating 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 using a common button.

[0031] When the button is pressed continuously (long pressed) for a certain period of time (e.g., 3 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 an 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.

[0032] Normally, the second faucet 48 is closed so that hot or cold water does not come out from the second faucet 48 even when the circulation pump 45 is operated. Also, since there is a possibility that high-temperature hot water may come out from the second faucet 48, in this embodiment, a notice is provided near the second faucet 48 that describes how to use the second faucet 48 as well as a warning about the possibility of hot water coming out.

[0033] In addition, a connection pipe 51 equipped with a negative pressure operated relief valve (one example of an air acquisition means) 50 is connected to the hot water supply pipe 20. The negative pressure operated relief valve 50 has a function of discharging the hot water in the hot water storage tank 12 that expands as the hot water storage tank 12 is heated to the outside via the hot water supply pipe 20 and the connection pipe 51, and a function of taking in air from the outside when the hot water storage tank 12 becomes negative pressure, and causing the air to flow into the hot water storage tank 12 via the connection pipe 51 and the hot water supply pipe 20.

[0034] As hot water flows out of the hot water storage tank 12 from the second faucet 48, negative pressure is created inside the hot water storage tank 12, and outside air is taken into the negative pressure operated relief valve 50 and flows into the top of the hot water storage tank 12 via the connecting pipe 51 and the hot water supply pipe 20, causing air to accumulate inside the hot water storage tank 12 from the top. Therefore, the negative pressure operated relief valve 50 takes in the outside air that flows into the hot water storage tank 12 as hot water flows out of the hot water storage tank 12 from the second faucet 48.

[0035] When the water supply is stopped, the temperature of the air accumulating at the top of the hot water storage tank 12 is γ°C (in this embodiment, 5°C≦γ°C≦15°C) lower than the temperature of the hot water stored at the top of the hot water storage tank 12, and the maximum temperature of the air in this embodiment is U-α-γ°C (e.g., 55°C) in summer and U-β-γ°C (e.g., 75°C) in winter (i.e., less than U°C).

[0036] When normal operation resumes after a water outage and the supply of water from water pipe 11 to hot water storage tank 12 resumes, water flows from water pipe 11 into the lower part of hot water storage tank 12, as shown in Fig. 6. Because negative pressure operated relief valve 50 is designed not to release the air in hot water storage tank 12 to the outside, the air in hot water storage tank 12 is compressed by the inflow of water from water pipe 11 into hot water storage tank 12, and the temperature rises, becoming higher than 55°C in summer and higher than 75°C in winter. If no treatment is given to lower the temperature of the air in hot water storage tank 12, the temperature of the air accumulated in hot water storage tank 12 may exceed U°C.

[0037] Therefore, the control means 25 detects, based on the temperature measured by the temperature sensor 14, that the air accumulating at the top of the hot water storage tank 12 (air that has flowed into and accumulated at the top of the hot water storage tank 12 as hot water and water from the hot water storage tank 12 is discharged from the second faucet 48) has returned to normal and is higher than a predetermined set temperature T°C (T°C is a temperature that is lower than U°C and exceeds U-β-γ°C, for example 85°C), and deactivates the heating means 46, as shown in Fig. 7, changes the destination of the hot water from the switching means 47 to the top of the hot water storage tank 12, and activates the circulation pump 45 to put the boiling circuit 44 into a circulation state. As a result, the hot water at the bottom of the hot water storage tank 12 flows into the top of the hot water storage tank 12 via the boiling circuit 44 without being heated by the heating means 46.

[0038] The hot water in the lower part of hot water storage tank 12 is at a lower temperature than the hot water in the upper part of hot water storage tank 12 due to the inflow of water from water pipe 11. Therefore, the hot water in the lower part of hot water storage tank 12 flows into the upper part of hot water storage tank 12, causing the temperature of the air in hot water storage tank 12 to drop. Setting t°C to a temperature between 5°C and 10°C, when control means 25 detects that the temperature of the air in hot water storage tank 12 has dropped and the measured temperature of temperature sensor 14 has fallen below Tt°C (e.g., 80°C), it stops circulation pump 45 and releases the circulation state of boiling circuit 44.

[0039] The boiling circuit 44 may be put into a circulating state to lower the temperature of the air in the hot water storage tank 12 in a non-normal state. For example, when the air that has accumulated in the hot water storage tank while the water supply is stopped becomes hotter than the set temperature T°C under normal conditions and then the water supply is stopped again, the boiling circuit 44 is put into a circulating state while the water supply is stopped to lower the temperature of the air in the hot water storage tank 12.

[0040] Here, in storage type hot water supply device 10, the upstream end of water supply pipe 49 is connected to boiling circuit 44, but is not limited to this. With reference to Fig. 8, 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 8, 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 the water supply pipe 71 has a water supply pump 73 connected to a control means.

[0041] When the water supply is stopped, the control means operates the water supply pump 73 to set up 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. The control means also detects, based on the temperature measured by the temperature sensor 14, that the air that has flowed into and accumulated in the upper part of the hot water storage tank 12 as hot water flows out of the hot water storage tank 12 from the second water faucet 72 has become higher than a predetermined set temperature T°C, deactivates the heating means 46, changes the destination of the hot water from the switching means 47 to the upper part of the hot water storage tank 12, operates the circulation pump 45, and sets the boiling circuit 44 in a circulation state.

[0042] 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 circulation circuit may be any circuit that has a circulation pump and can circulate the hot water taken from the bottom of the hot water storage tank and return it to the top of the hot water storage tank, and it goes without saying that the circulation circuit does not need to be a boiling circuit or have a heating means. Furthermore, a circulation circuit without a switching means may also be used. Furthermore, there is no need to use a pump to cause the hot water in the hot water storage tank to flow from the second faucet. For example, the hot water in the hot water storage tank may be allowed to flow by gravity when the second faucet is opened. Furthermore, if the first faucet is located below the hot water storage tank and the hot water in the hot water storage tank flows out from the first faucet by opening the first faucet when the water supply is stopped, the air acquisition means will take in outside air even when hot water in the hot water storage tank flows out from the first faucet. [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: 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: boiling circuit, 45: circulation pump, 46: heating means, 47: switching means, 48: second faucet, 49: water supply pipe, 50: relief valve with negative pressure actuated valve, 51: connecting pipe, 70: hot water storage type hot water supply device, 71: water supply pipe, 72: second faucet, 73: water supply pump, 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 temperature sensor provided on an upper portion of the hot water storage tank; A circulation circuit having a circulation pump, the circulation pump being operated to circulate the hot water taken from the lower part of the hot water storage tank back to the upper part of the hot water storage tank; a second faucet that is opened when the water supply is stopped and water from the water pipe is not supplied to the lower part of the hot water storage tank, to discharge hot water from the lower part of the hot water storage tank; an air acquisition means for taking in outside air that flows into the hot water storage tank as hot water is discharged from the second water faucet; A storage type hot water supply device characterized by being equipped with a control means that detects, based on the temperature measured by the temperature sensor, that the air that flows into the hot water storage tank and accumulates at the top of the hot water storage tank has become hotter than a predetermined set temperature, and operates the circulation pump to put the circulation circuit into the circulation state.

2. In the storage type hot water supply device described in claim 1, the circulation circuit further has a heating means that operates to heat the hot water circulating through the circulation circuit, and the control means detects that the air accumulated at the top of the hot water storage tank has a temperature higher than the set temperature, deactivates the heating means, and puts the circulation circuit into the circulation state.

3. In a storage type hot water supply device as described in claim 1 or 2, the second faucet is connected to the downstream end of a water supply pipe whose upstream end is connected to the circulation circuit downstream of the installation position of the circulation pump, and when the water supply is stopped, the circulation pump is operated to enable hot water to be dispensed from the lower part of the storage tank.

Images