JP7788064B2 - Hot water storage system - Google Patents

Description

The present invention relates to a hot water storage and supply system, particularly one that allows hot water to be extracted from a hot water storage tank in emergencies such as water outages, and particularly one that allows extraction to desired locations inside or outside the home.

Conventional hot water storage systems are equipped with a hot water storage tank, and when it is necessary to draw hot water from the tank in an emergency such as a water outage, the air charge valve, which allows air to be introduced into the hot water storage tank, is opened, and the drain valve located outside the home is opened to draw hot water from the tank and use it for domestic use.

The hot water storage type electric water heater described in Patent Document 1 is configured so that a pump is installed in a bypass pipe that connects the bottom of the hot water storage tank to the hot water outlet pipe, and the pump can be operated in the event of a water outage to draw hot water from the hot water storage tank to the hot water tap.

Patent No. 6066452

In conventional hot water storage and supply systems, it is possible to open the drain valve to remove hot water from the hot water storage tank in an emergency such as a water outage, but because the drain valve is designed for drainage, it is not always possible to fill hot water into containers such as plastic tanks, and in many cases a separate hose must be connected, making it difficult to use.

Furthermore, because the drain valve is located outside the home, the hot water from the hot water storage tank cannot be taken inside the home, making it difficult to take out hot water outside the home during cold seasons such as winter.

On the other hand, as described in Patent Document 1, the method of extracting hot water from a hot water storage tank through a water tap inside the home has the problem that the hot water cannot be extracted and used from the hot water storage tank when it is not possible to enter the home, such as during an earthquake, or when it is dangerous to be inside the home.

The object of the present invention is to provide a hot water supply system that allows hot water in a hot water storage tank to be drawn off to a hot water tap, and to provide a hot water supply system that allows hot water in a hot water storage tank to be drawn off to a hot water tap inside the home or to an outside extraction passage.

The hot water storage and water supply system of claim 1 is a hot water storage and water supply system comprising a hot water storage tank for storing hot water, a heating device for heating the hot water in the hot water storage tank, and an outer case for housing the hot water storage tank and the heating device, characterized in that it has a drainage passage connected to the bottom of the hot water storage tank and having a drain plug at its downstream end, a bypass passage branching off from a portion of the drainage passage closer to the hot water storage tank than the drain plug and connected to a portion of the hot water supply passage outside the outer case, an outside-house removal passage branching off from the bypass passage and provided at a portion outside the outer case, and a three-way valve provided at the branching point where the outside-house removal passage branches off from the bypass passage, the three-way valve being switchable between a first position that connects the bypass passage to the bypass passage, a second position that connects the bypass passage to the outside-house removal passage, and a closed position that blocks both the bypass passage and the outside-house removal passage .

According to the above configuration, the hot water storage and supply system includes a drain passage having a drain plug, a bypass passage branching from the drain passage and connected to a portion of the hot water supply passage outside the exterior case , an outside outlet passage branching from the bypass passage, and a three-way valve provided at a branch point where the outside outlet passage branches from the bypass passage . The three-way valve is switchable between a first position that connects the bypass passage to the outside outlet passage, a second position that connects the bypass passage to the outside outlet passage, and a closed position that blocks both the bypass passage and the outside outlet passage. Therefore, by setting the three-way valve to the closed position during normal times, setting the three-way valve to the first position when hot water in the hot water storage tank is to be drawn from a hot water tap in the house in an emergency such as a water outage, and setting the three-way valve to the second position when hot water in the hot water storage tank is to be drawn to the outside outlet passage in an emergency such as a water outage, hot water in the hot water storage tank can be drawn from a hot water tap in the house connected to the hot water supply passage or outside the house in an emergency such as a water outage.
Furthermore, since most of the bypass passage can be arranged outside the outer case, it is possible to retrofit an existing hot water storage and heating device with a bypass passage, or to install a bypass passage as an option according to the user's preference.

As explained above, the present invention offers a variety of advantages.

1 is a configuration diagram of a hot water storage and supply system according to an embodiment of the present invention. FIG. 1 is a diagram illustrating the configuration of a heat pump type heat source machine.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the accompanying drawings.
First, the overall configuration of the hot water storage and supply system 1 of the present invention will be described.
As shown in Figure 1, the hot water storage system 1 is composed of a hot water storage and water heater 2 that stores hot water, a heat pump type heat source unit 3 (equivalent to a heating device), and a circulation circuit 15 that circulates hot water between the hot water storage and water heater 2 and the heat pump type heat source unit 3.

Next, the hot water storage and heating apparatus 2 will be briefly described.
The hot water storage and heating device 2 has functions such as storing hot water, supplying hot water, supplying hot water to a bathtub, reheating the bathtub, and supplying hot water to hot water heating devices such as floor heating panels, and is equipped with a hot water storage tank 4, an auxiliary heat source unit 5, a bath heat exchanger 6, a heating heat exchanger 7, a water supply system passage 8, a hot water supply system passage 9, a hot water outlet passage 11, a bath reheating circuit 12, a hot water heating circuit 13, a heat utilization circulation circuit 14, a hot water storage circulation circuit 15, a control unit 10, and an operation remote control 20 for setting various aspects of the hot water storage and heating device 2, most of which are housed together in an exterior case 16. The exterior case 16 is equipped with an outside air temperature detection sensor 16a that can detect the outside air temperature.

Next, the hot water tank 4 will be described.
The hot water storage tank 4 is composed of a sealed tank capable of storing high-temperature hot water (for example, 60 to 70°C) heated by the heat pump heat source unit 3, and the tank is surrounded by a heat insulating material to prevent the stored hot water from losing heat. A plurality of hot water temperature detection sensors 4a to 4d are provided in order at equal intervals from the bottom to the top around the outer periphery of the hot water storage tank 4, and these multiple hot water temperature detection sensors 4a to 4d detect the hot water temperatures of the multiple temperature stratifications inside the hot water storage tank 4.

Next, the auxiliary heat source unit 5 will be described.
The auxiliary heat source unit 5 is configured as a known gas water heater incorporating a burner, heat exchanger, etc. The auxiliary heat source unit 5 is activated to burn and heat the water only in special cases, such as when the temperature of the hot water in the hot water storage tank 4 drops or when the supply of hot water from the hot water storage tank is stopped, in response to a command sent from the control unit 10.

Next, the water supply passage 8 will be described.
The water supply system passage 8 supplies low-temperature clean water from a clean water source to the hot water storage tank 4 and the like, and has an upstream water supply passage 8a, an intermediate water supply passage 8b, and a downstream water supply passage 8c, with the upstream end of the upstream water supply passage 8a connected to the clean water source and the downstream end of the downstream water supply passage 8c connected to the bottom of the hot water storage tank 4. A pressure reducing valve 8d is installed in the upstream water supply passage 8a, and a check valve 8e is installed in the intermediate water supply passage 8b.

A bypass passage 17, which connects to the hot water supply system passage 9, branches off between the upstream water supply passage 8a and the intermediate water supply passage 8b. A check valve 17a is installed in the bypass passage 17. A bypass passage 18, which connects to the heat utilization circulation circuit 14, branches off between the intermediate water supply passage 8b and the downstream water supply passage 8c. A heat storage switching valve 19 is installed at this branch. This bypass passage 18 allows low-temperature clean water to be supplied to the heat utilization circulation circuit 14, and conversely, allows hot water to be returned from the heat utilization circulation circuit 14 to the hot water storage tank 4.

Next, the hot water supply passage 9 will be described.
The hot water supply system passage 9 supplies hot water stored in the hot water storage tank 4 to the hot water tap 34, a bath, or other desired hot water destination, and includes a hot water supply passage 21 connected to the hot water tap 34, a tank hot water outlet passage 22 connected from the top of the hot water storage tank 4 to the hot water supply passage 21, an auxiliary heating passage 23 branching off from the tank hot water outlet passage 22 and connected to a combustion-type auxiliary heat source unit 5, and an auxiliary heat source unit hot water outlet passage 24 connected from the auxiliary heat source unit 5 to the hot water supply passage 21.

The hot water supply passage 21 has an upstream hot water supply passage 21a through which high-temperature hot water flows, an intermediate hot water supply passage 21b through which mixed hot water flows, and a downstream hot water supply passage 21c. The upstream end of the upstream hot water supply passage 21a is connected to the tank hot water outlet passage 22, and the downstream end of the downstream hot water supply passage 21c is connected to the hot water tap 34.

A mixing valve 25 is installed between the upstream hot water supply passage 21a and the intermediate hot water supply passage 21b. A bypass passage 17 branching off from the water supply system passage 8 is connected to this mixing valve 25. The mixing valve 25 controls the mixing ratio of low-temperature clean water and high-temperature hot water so that the hot water outlet temperature becomes the command temperature. A flow sensor 21d and a hot water outlet proportioning valve 26 are installed in the intermediate hot water supply passage 21b. A branch passage 27 branching off from the bypass passage 17 is connected to the intermediate hot water supply passage 21b, and a high-temperature hot water outlet avoidance solenoid valve 28 is installed in the branch passage 27.

The tank hot water outlet passage 22 has an upper hot water outlet passage 22a and a lower hot water outlet passage 22b, with the upstream end of the upper hot water outlet passage 22a connected to the top of the hot water storage tank 4 and the downstream end of the lower hot water outlet passage 22b connected to the hot water supply passage 21. An auxiliary heating passage 23 branches off between the upper hot water outlet passage 22a and the lower hot water outlet passage 22b.

The auxiliary heating passage 23 has an upstream heating passage 23a and a downstream heating passage 23b. The upstream end of the upstream heating passage 23a is connected to the tank hot water outlet passage 22, and the downstream end of the downstream heating passage 23b is connected to the inlet of the auxiliary heat source unit 5. A check valve 23c is installed in the upstream heating passage 23a, and a pressure pump 29 and a flow rate sensor 23d are installed in the downstream heating passage 23b.

A three-way valve 31 is installed between the upstream heating passage 23a and the downstream heating passage 23b, which can switch between the tank hot water outlet passage 22 and the auxiliary heating passage 23. The three-way valve 31 is also connected to the hot water return passage 14d of the heat utilization circulation circuit 14. This three-way valve 31 can switch between connecting and disconnecting between the upstream heating passage 23a and the downstream heating passage 23b, and between the downstream heating passage 23b and the hot water return passage 14d, and can connect all of the passages: the upstream heating passage 23a, the downstream heating passage 23b, and the hot water return passage 14d.

The auxiliary heat source unit hot water outlet passage 24 has an upstream auxiliary hot water outlet passage 24a and a downstream auxiliary hot water outlet passage 24b. The upstream end of the upstream auxiliary hot water outlet passage 24a is connected to the outlet of the auxiliary heat source unit 5, and the downstream end of the downstream auxiliary hot water outlet passage 24b is connected to the upstream end of the hot water supply passage 21. The hot water supply passage 14a of the heat utilization circulation circuit 14 branches off between the upstream auxiliary hot water outlet passage 24a and the downstream auxiliary hot water outlet passage 24b. A tank water proportional valve 32 is installed in the downstream auxiliary hot water outlet passage 24b.

Next, the control unit 10 will be described.
The hot water storage and hot water supply device 2 is controlled by a control unit 10. Detection signals from various sensors are sent to the control unit 10, which controls the operation of the hot water storage and hot water supply device 2, the start and stop of various pumps, the switching of the open/closed state of various valves and the adjustment of their opening degrees, and performs various operations (hot water supply operation, hot water filling operation, reheating operation, high-temperature hot water supply operation, heating operation, anti-freeze operation, etc.).

The control unit 10 is capable of data communication with the operation remote control 20, which can be operated by the user. When various operations are set by operating the switches on the operation remote control 20, command signals are sent from the operation remote control 20 to the control unit 10.

Next, the heat pump type heat source unit 3 will be briefly described.
As shown in FIG. 2, the heat pump type heat source unit 3 has a heat pump circuit inside an outer case 3a, in which a compressor 36, a condensing heat exchanger 37, an expansion valve 38 (expansion means), and an evaporative heat exchanger 39 are connected by a refrigerant passage 40 (refrigerant circuit).

The heat pump heat source unit 3 controls heating operation and other operations using an auxiliary control unit 41 electrically connected to the control unit 10. During heating operation, the compressor 36 and the blower 39b that blows air to the evaporative heat exchanger 39 are driven, and the opening of the expansion valve 38 is adjusted to circulate the refrigerant sealed in the refrigerant passage 40. An outside air temperature sensor 39a that detects the outside air temperature is attached to the case of the blower 39b, and a compressor inlet temperature sensor (not shown) that detects the refrigerant temperature at the outlet of the evaporative heat exchanger 39 is attached. Detection signals from the sensors are supplied to the control unit 10 and the auxiliary control unit 41.

The high-temperature refrigerant compressed and heated in the compressor 36 during heating operation is introduced into the condensing heat exchanger 37. In the condensing heat exchanger 37, heat is exchanged between the high-temperature refrigerant and the hot water flowing through the heat exchange passage 37a connected to the hot water storage circulation passage 15, heating the hot water. The refrigerant, which has been cooled and partially liquefied by the heat exchange, expands in the expansion valve 38, further cooling it, and is introduced into the evaporating heat exchanger 39. In the evaporating heat exchanger 39, the refrigerant absorbs heat from the outside air and vaporizes, before being introduced back into the compressor 36.

Next, the hot water tank 4 and its peripheral equipment will be described.
The hot water storage circulation circuit 15 is provided with a circulation forward passage 15a extending from the bottom of the hot water storage tank 4 to the heat pump type heat source unit 3, a circulation return passage 15b returning from the heat pump type heat source unit 3 to the top of the hot water storage tank 4, and a bypass passage 15c connecting the circulation forward passage 15a and the circulation return passage 15b.
A circulation pump 34 is installed in the circulation forward passage 15a, and a three-way valve 33 is installed at the connection between the bypass passage 15c and the circulation return passage 15b. When the temperature of the cooling water returning from the heat pump type heat source unit 3 to the circulation return passage 15b is low, hot water is circulated in the order of the circulation forward passage 15a, the heat pump type heat source unit 3, the circulation return passage 15b, and the bypass passage 15c.

A drain passage 43 is connected to the downstream water supply passage 8c, and a drain plug 43a is provided at the tip of this drain passage 43. Water can be drained from the hot water storage tank 4 via the drain passage 43 and the drain plug 43a.
In the event of an emergency such as a water outage, the following bypass passage 44, an outdoor water extraction passage 45, and an air charge section 46 are provided so that the hot water in the hot water storage tank 4 can be extracted and used for domestic use.

The bypass passage 44 branches off from the drain passage 43 at a location closer to the hot water storage tank 4 than the drain plug 43a and connects to a location on the downstream hot water supply passage 21c outside the outer case 2. A pump 44a, which is driven when hot water is drawn from the hot water storage tank 4, is installed inside the outer case 16 in this bypass passage 44.

The outside removal passage 45 branches off from the bypass passage 44 and is provided outside the exterior case 16. A three-way valve 47 is provided at the branching point where the outside removal passage 45 branches off from the bypass passage 44. The three-way valve 47 is configured to be switchable between a first position that connects the bypass passage 44, a second position that connects the bypass passage 44 (the upstream portion of the bypass passage 44) and the outside removal passage 45, and a closed position that blocks both the bypass passage 44 and the outside removal passage 45.
Although the three-way valve 47 is a manually operated type, it may be an electromagnetic three-way valve.

The air charge section 46 is composed of an air charge pipe 46a and an air charge valve 46b.
The upper end of the air charge pipe 46a is connected to the tank hot water outlet passage 22 near the top of the hot water storage tank 4, and the air charge pipe 46a extends sideways and then bends and extends downward for a predetermined length. A manually openable air charge valve 46b is installed at the lower end of the air charge pipe 46a.

Next, the operation and effects of the hot water storage system 1 will be described.
As with a normal hot water storage and supply system, the hot water in the hot water storage tank 4 is heated and stored while circulating through the heat pump heat source unit 3, and the hot water can be supplied to a bath or hot water tap 34, used to reheat the bath, or used for heating. In addition, if the temperature of the hot water in the hot water storage tank 4 is low, the auxiliary heat source unit 5 can be operated to supply hot water of a higher temperature.

Here, in the event of an emergency such as a water outage, if the hot water in the hot water storage tank 4 needs to be extracted and used, and if that hot water needs to be supplied to the hot water tap 34, the air charge valve 46b is opened, the three-way valve 47 is switched to the first position which connects to the bypass passage 44, and the pump 44a is driven, allowing the hot water in the hot water storage tank 4 to be extracted to the hot water tap 34.

In addition, when hot water in the hot water storage tank 4 is to be removed outside the home, the air charge valve 46b is opened, the three-way valve 47 is switched to its second position, and the pump 44a is driven, which supplies the hot water in the hot water storage tank 4 to the outside removal passage 45 and allows it to be removed. Furthermore, when removal of the hot water is complete, the three-way valve 47 is switched to the closed position.

In addition, since most of the bypass passage 44 can be arranged outside the exterior case 16, the bypass passage 44 can be retrofitted to an existing hot water storage and heating device 2, or the bypass passage 44 can be installed as an option according to the user's preferences.

A modification of the above embodiment will now be described.
1) The pump 44a provided in the bypass passage 44 is not essential, and if the hot water in the hot water storage tank 4 can be supplied to the hot water tap 34 by hydraulic head pressure, the pump 44a can be omitted.

2) The present invention can also be applied to a hot water storage and supply system in which a fuel cell power generation device is provided instead of a heat pump type heat exchanger, in the same manner as described above.
3) In addition, those skilled in the art will be able to implement the present invention in various forms by adding various modifications to the above-described embodiments without departing from the spirit of the present invention, and the present invention also includes such modifications.

1: Hot water storage and hot water supply system 2: Hot water storage and hot water supply device 3: Heat pump type heat source device 4: Hot water storage tank 16: Outer case 21: Hot water supply passage 21c: Downstream hot water supply passage 43: Drain passage 44: Bypass passage 45: Outside-house take-out passage 47: Three-way valve

Claims (1)

A hot water storage and hot water supply system including a hot water storage tank for storing hot water, a heating device for heating the hot water in the hot water storage tank, and an exterior case for accommodating the hot water storage tank and the heating device,
A hot water storage and hot water supply system characterized by having: a drain passage connected to the bottom of the hot water storage tank and having a drain plug at its downstream end; a bypass passage branching off from the drain passage at a position closer to the hot water storage tank than the drain plug and connected to a portion of the hot water supply passage outside the outer case; an outside-house removal passage branching off from the bypass passage and provided at a position outside the outer case; and a three-way valve provided at the branching point where the outside-house removal passage branches off from the bypass passage, the three-way valve being switchable between a first position that connects the bypass passage to the outside-house removal passage, a second position that connects the bypass passage to the outside-house removal passage, and a closed position that blocks both the bypass passage and the outside-house removal passage.