Water supply system and method for supplying water

Abstract

To improve energy efficiency in supplying water to a water-supply object of a multi-layered building.SOLUTION: A water supply system 1 includes: a compressor 2a for compressing air; an ordinary temperature water tank 3N for storing ordinary temperature water; a first heat exchanger 8a for exchanging heat between the compressed air compressed by the compressor 2a and the ordinary temperature water; a hot water tank 3H for storing hot water of which temperature is raised by the heat exchanged by the first heat exchanger 8a; and an ordinary temperature water supply line 9N for supplying the ordinary temperature water to a water-supply object from the ordinary temperature water tank 3N with the compressed air that is supplied to the ordinary temperature water tank 3N.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a water supply system and a water supply method. [Background technology]

[0002] Patent Document 1 discloses a water supply system for a high-rise building, in which an electric pump is used to pump water to the upper floors. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-035974 A Summary of the Invention [Problem to be solved by the invention]

[0004] It is difficult to recover the electrical energy consumed by the pump. Conventional water supply systems have room for improvement in terms of energy conservation.

[0005] The present invention aims to improve the energy efficiency of water supply to multi-story buildings. [Means for solving the problem]

[0006] One form of the present invention provides a water supply system that supplies water to a water supply target in a multi-story building, the water supply system comprising: a compressor that compresses air to generate compressed air; a room temperature water tank that stores water supplied from a water source as room temperature water and to which the compressed air is supplied; a first heat exchanger that generates hot water by exchanging heat between the compressed air and the water supplied from the water source; a hot water tank that stores the hot water; and a room temperature water supply line that supplies the room temperature water from the room temperature water tank to the first water supply target using the compressed air supplied to the room temperature water tank.

[0007] According to the above configuration, the compressed air generated by the compressor is high temperature and high pressure. Instead of using a pump, the high pressure of the compressed air can be used to supply room temperature water to a multi-story building. The heat of the compressed air can be recovered by the first heat exchanger, thereby generating hot water. In this way, the energy consumed in the operation of the compressor can be recovered, improving energy efficiency compared to pumping water with a pump.

[0008] The first water supply target may be an elevated water tank installed on an upper floor of the multi-story building, or a water supply header installed on each floor of the multi-story building.

[0009] According to the above configuration, depending on the situation, it is possible to temporarily store room temperature water in the elevated water tank and then supply it to the water supply target, or to supply room temperature water directly to the water supply target without passing through the elevated water tank. Water leakage from the shaft seal, which could occur with conventional water pumps, can be prevented.

[0010] The water supply system may further include a water tank located below the elevated water tank as the first water supply target, and a hydroelectric generator that generates electricity using hydraulic power moving from the elevated water tank to the water tank.

[0011] According to the above configuration, the potential energy of the room temperature water stored in the elevated water tank is recovered as electrical energy, thereby further improving energy efficiency.

[0012] The water supply system may further include a hot water tank supply line that supplies the compressed air to the hot water tank, and a hot water supply line that supplies the hot water from the hot water tank to a second water supply target using the compressed air supplied to the hot water tank.

[0013] According to the above configuration, the generated hot water is also supplied to the water supply target of the multi-story building by utilizing the high pressure of the compressed air, thereby improving convenience.

[0014] The water supply system may further include a room temperature water tank pressure sensor that detects the internal pressure of the room temperature water tank, a room temperature water tank water level sensor that detects the water level in the room temperature water tank, a room temperature water tank air supply on / off valve that switches whether or not the compressed air is supplied to the room temperature water tank, a room temperature water filling on / off valve that switches whether or not the room temperature water is supplied to the room temperature water tank, a room temperature water supply on / off valve that switches whether or not the room temperature water is supplied from the room temperature water tank to the first water supply target, and a controller that controls the room temperature water tank air supply on / off valve, the room temperature water filling on / off valve, and the room temperature water supply on / off valve based on the detection results of the room temperature water tank pressure sensor and the room temperature water tank water level sensor.

[0015] According to the above configuration, an operating cycle consisting of a series of operations of using the pressure of compressed air to supply room temperature water from the room temperature water tank to the water supply target and filling the room temperature water tank with the room temperature water can be automated by the controller.

[0016] The water supply system may further include a pressure accumulator tank for storing the compressed air, an expander driven by the compressed air supplied from the pressure accumulator tank, and a generator mechanically connected to the expander and driven by the expander.

[0017] According to the above configuration, the energy of the compressed air is recovered as electrical energy, thereby further improving energy efficiency.

[0018] The water supply system may further include a second heat exchanger that generates cold water by exchanging heat between the expanded air expanded and cooled by the expander and the water supplied from the water source, a cold water tank that stores the cold water, and a cold water supply line that supplies the cold water from the cold water tank to a third water supply target using the compressed air supplied to the cold water tank.

[0019] According to the above configuration, cold water is generated by the cold energy of the air expanded by the expander, and is supplied to the water supply target of the multi-story building by utilizing the high pressure of the compressed air, thereby further improving energy efficiency.

[0020] The water supply system may further include a cold air supply line that supplies the expanded air to an object to be air-conditioned in the multi-story building.

[0021] According to the above configuration, the water supply system can also be used to generate cool air, further improving energy efficiency.

[0022] One form of the present invention provides a water supply method for supplying water to a water supply target in a multi-story building, the water supply method comprising: compressing air with a compressor to generate compressed air; storing water supplied from a water source as room temperature water in a room temperature water tank; exchanging heat between the compressed air and the water supplied from the water source in a first heat exchanger to generate hot water; storing the hot water in a hot water tank; and supplying the compressed air to the room temperature water tank, thereby supplying the room temperature water from the room temperature water tank via a room temperature water supply line to a first water supply target.

[0023] According to the above configuration, instead of using a pump, high pressure compressed air can be used to supply room temperature water to a multi-story building. The heat of the compressed air can be recovered by the first heat exchanger, and hot water is generated. In this way, the energy consumed by the operation of the compressor can be recovered, which improves energy efficiency compared to pumping water with a pump.

[0024] The water supply method may further include supplying the compressed air to the hot water tank, thereby supplying the hot water from the hot water tank to a second water supply target via a hot water supply line.

[0025] According to the above configuration, the generated hot water is also supplied to the water supply target of the multi-story building by utilizing the high pressure of the compressed air, thereby improving convenience. Effect of the Invention

[0026] According to the present invention, it is possible to improve the energy efficiency in supplying water to a multi-story building. [Brief description of the drawings]

[0027] [Figure 1]1 is a conceptual diagram of a water supply system according to a first embodiment. [Diagram 2] FIG. 2 is a block diagram showing a control system of the water supply system according to the first embodiment. [Figure 3A] FIG. 2 is an operational diagram of the water supply system according to the first embodiment. [Figure 3B] FIG. 2 is an operational diagram of the water supply system according to the first embodiment. [Figure 3C] FIG. 2 is an operational diagram of the water supply system according to the first embodiment. [Figure 3D] FIG. 2 is an operational diagram of the water supply system according to the first embodiment. [Figure 4] FIG. 11 is a conceptual diagram of a water supply system according to a second embodiment. [Diagram 5] FIG. 11 is a conceptual diagram of a water supply system according to a third embodiment. [Figure 6] FIG. 11 is a conceptual diagram of a water supply system according to a fourth embodiment. [Figure 7A] FIG. 13 is an operational diagram of the water supply system according to the fifth embodiment. [Figure 7B] FIG. 13 is an operational diagram of the water supply system according to the fifth embodiment. [Figure 7C] FIG. 13 is an operational diagram of the water supply system according to the fifth embodiment. [Figure 7D] FIG. 13 is an operational diagram of the water supply system according to the fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, an embodiment will be described with reference to the drawings. Note that the same or corresponding elements are designated by the same reference numerals throughout the drawings, and detailed description thereof will be omitted.

[0029] Referring to FIG. 1, a water supply system 1 supplies water to a water supply target. The water supply target is provided in a building B. The water supply target is, for example, an elevated water tank 3E provided on an upper floor, a tank provided on each floor, a water supply header or a faucet, etc. FIG. 1 shows a six-story building B in schematic form, but the number of floors of the building B is not particularly limited. The water supply system 1 according to this embodiment is also applicable to a high-rise building of 70 m class (for example, 20 floors). The use of the building B is not particularly limited, and it may be a house, an office, or a school.

[0030] The water supplied to the water supply target by the water supply system 1 is room temperature water, hot water, and cold water. When distinguishing between these three types of water supply targets, the room temperature water supply target may be referred to as a first water supply target, the hot water supply target may be referred to as a second water supply target, and the cold water supply target may be referred to as a third water supply target. The room temperature water is, for example, tap water, well water, or groundwater, and is taken from a water source W (a typical example is a waterworks facility). In this embodiment, the room temperature water and the water source W are the same for both hot water and cold water. The hot water is generated by increasing the temperature of the room temperature water supplied from the water source W. The cold water is generated by decreasing the temperature of the room temperature water supplied from the water source W. As a mere example, the room temperature water is 20 to 30°C, the hot water is 50 to 70°C, and the cold water is 5 to 15°C.

[0031] The water supply system 1 includes a compressor unit 2, a group of tanks, an air supply line 4, a water filling line 5, a generator unit 6, an expander line 7, a group of heat exchangers, a water supply line 9, a group of pumps, and a group of valves.

[0032] The compressor unit 2 includes a compressor 2a, a motor 2b, and an inverter 2c. The motor 2b is a drive source for the compressor 2a and is a three-phase AC motor. The motor 2b rotates and drives the rotor of the compressor 2a. As a result, the compressor 2a sucks in air, compresses the air, and discharges the compressed air. The inverter 2c is connected to a power source such as a commercial power source or a solar cell, and controls the AC supplied to the motor 2b. As a result, the rotation speed of the motor 2b and thus the compressor 2a can be adjusted, and the discharge pressure of the compressor 2a can also be adjusted.

[0033] It is preferable that the compressor 2a is an oil-free compressor. The oil-free compressor includes an oil-free screw compressor. In the case of an oil-free compressor, the compressed air and, in turn, the water stored in each tank are not mixed with lubricating oil. Therefore, the quality of the water supplied to the water supply target can be maintained high while omitting or miniaturizing the filter or separator. Furthermore, it is more preferable that the compressor 2a is an oil-free screw compressor. The discharge temperature of the oil-free screw compressor is high, so that exhaust heat recovery is easy.

[0034] The tank group includes a normal temperature water tank 3N, a hot water tank 3H, a cold water tank 3C, and a pressure tank 3A. The normal temperature water tank 3N, the hot water tank 3H, and the cold water tank 3C are capable of storing water. In addition, compressed air generated by the compressor 2a is supplied to the normal temperature water tank 3N, the hot water tank 3H, and the cold water tank 3C. The pressure tank 3A is an air tank and is capable of storing compressed air. The tank group further includes an elevated water tank 3E. The normal temperature water tank 3N, the hot water tank 3H, the cold water tank 3C, and the pressure tank 3A are installed at the same level as the first floor of the building B, while the elevated water tank 3E is installed on an upper floor of the building B, for example, on the rooftop. The elevated water tank 3E is also capable of storing water.

[0035] The air supply line 4 connects the discharge port of the compressor 2a to the normal temperature water tank 3N, the hot water tank 3H, the cold water tank 3C, and the pressure accumulator tank 3A. The air supply line 4 is connected to the top of each tank. The air supply line 4 includes a main air supply line 4M extending from the discharge port of the compressor 2a, and a normal temperature water tank air supply line 4N, a hot water tank air supply line 4H, a cold water tank air supply line 4C, and a pressure accumulator tank air supply line 4A that branch off from the main air supply line 4M and are connected to the normal temperature water tank 3N, the hot water tank 3H, the cold water tank 3C, and the pressure accumulator tank 3A, respectively.

[0036] The water filling line 5 connects the water source W to the room temperature water tank 3N, the hot water tank 3H, and the cold water tank 3C. As an example, the water filling line 5 is connected to the bottom of each tank. The water filling line 5 includes a room temperature water filling line 5N that connects the water source W to the room temperature water tank 3N, a hot water filling line 5H that branches off from the room temperature water filling line 5N and connects to the hot water tank 3H, and a cold water filling line 5C that branches off from the room temperature water filling line 5N and connects to the cold water tank 3C. Hereinafter, the room temperature water flowing through the water filling line 5 may be referred to as water source water.

[0037] The generator unit 6 includes an expander 6a and a generator 6b. The expander line 7 includes an expander supply line 7a that connects the pressure storage tank 3A to the suction port of the expander 6a, and an expander discharge line 7b that extends from the discharge port of the expander 6a. The expander 6a is driven by compressed air stored in the pressure storage tank 3A, expands the compressed air, and discharges the expanded air that has been expanded and cooled. The generator 6b is mechanically connected to the rotor of the expander 6a and driven by the expander 6a to generate AC power. The power generated by the generator 6b may be used to drive the motor 2b of the compressor 2a.

[0038] The main air supply line 4M and the hot water filling line 5H pass through the first heat exchanger 8a. In the first heat exchanger 8a, the compressed air discharged from the compressor 2a exchanges heat with room temperature water (water source water) flowing through the hot water filling line 5H. As a result, the compressed air is cooled, while the room temperature water (water source water) is heated. As a result, hot water is generated in the first heat exchanger 8a and supplied to the hot water tank 3H.

[0039] The expander discharge line 7b and the cold water filling line 5C pass through the second heat exchanger 8b. In the second heat exchanger 8b, the expanded air discharged from the expander 6a exchanges heat with room temperature water (water source water) flowing through the cold water filling line 5C. As a result, the expanded air is heated, while the room temperature water (water source water) is cooled by the cold energy of the expanded air. As a result, cold water is generated in the second heat exchanger 8b and supplied to the cold water tank 3C.

[0040] The water supply line 9 connects the normal temperature water tank 3N, the hot water tank 3H, and the cold water tank 3C to the water supply targets. The water supply line 9 is connected to the bottom of each tank. The water supply line 9 includes a normal temperature water supply line 9N, a hot water supply line 9H, and a cold water supply line 9C. The normal temperature water supply line 9N connects the normal temperature water tank 3N to the first water supply target. In this embodiment, the first water supply target is the elevated water tank 3E. The hot water supply line 9H connects the hot water tank 3H to the second water supply target. The cold water supply line 9C connects the cold water tank 3C to the third water supply target. In this embodiment, the second water supply target and the third water supply target are tanks, water supply headers, or faucets provided on each floor. Naturally, even if the second water supply target and the third water supply target are the same type of element (for example, both are water supply headers), they are separated into hot water and cold water. The normal temperature water tank 3N, the hot water tank 3H, the cold water tank 3C, and the pressure storage tank 3A are installed at the same level as the first floor of building B.

[0041] The normal temperature water supply line 9N directly connects the normal temperature water tank 3N to the elevated water tank 3E. The hot water supply line 9H and the cold water supply line 9C include an upper and lower extension section that extends vertically upward, and a plurality of branch sections that branch off from the upper and lower extension sections for each floor. In each of these lines, water is pumped upward by compressed air supplied to the tank, and is supplied to the corresponding water supply target. The elevated water tank 3E is connected to the water supply target (e.g., a tank, a water supply header, or a faucet) provided for each floor via the falling water line 30. The falling water line 30 includes an upper and lower extension section that extends vertically downward from the elevated water tank 3E, and a plurality of branch sections that branch off from the upper and lower extension sections and are connected to the water supply target. In the falling water line 30, water flows downward due to the head pressure of the elevated water tank 3E.

[0042] The pump group includes a hot water pump 10H provided on the hot water filling line 5H and a cold water pump 10C provided on the cold water filling line 5C. The hot water pump 10H and the cold water pump 10C are electrically powered. The power source may be a commercial power source or a generator 6b. The hot water pump 10H draws room temperature water (water source water) from the room temperature water filling line 5N into the hot water filling line 5H, supplies the room temperature water (water source water) to the first heat exchanger 8a, and supplies hot water to the hot water tank 3H. The cold water pump 10C draws room temperature water (water source water) from the room temperature water filling line 5N into the cold water filling line 5C, supplies the room temperature water (water source water) to the second heat exchanger 8b, and supplies cold water to the cold water tank 3C.

[0043] The group of valves includes a main air supply on-off valve 14M that opens and closes the main air supply line 4M, a normal temperature water tank air supply on-off valve 14N that opens and closes the normal temperature water tank air supply line 4N, a hot water tank air supply on-off valve 14H that opens and closes the hot water tank air supply line 4H, a cold water tank air supply on-off valve 14C that opens and closes the cold water tank air supply line 4C, a pressure accumulator tank air supply on-off valve 14A that opens and closes the pressure accumulator tank air supply line 4A, a normal temperature water filling on-off valve 15N that opens and closes the normal temperature water filling line 5N, a hot water filling on-off valve 15H that opens and closes the hot water filling line 5H, a cold water filling on-off valve 15C that opens and closes the cold water filling line 5C, an expander on-off valve 17 that opens and closes the expander supply line 7a, a normal temperature water supply on-off valve 19N that opens and closes the normal temperature water supply line 9N, a hot water supply on-off valve 19H that opens and closes the hot water supply line 9H, and a cold water supply on-off valve 19C that opens and closes the cold water supply line 9C.

[0044] Although not shown in FIG. 1, the valve group further includes a room temperature water tank atmosphere release valve 13N that opens the room temperature water tank 3N to the atmosphere, a hot water tank atmosphere release valve 13H that opens the hot water tank 3H to the atmosphere, a cold water tank atmosphere release valve 13C that opens the cold water tank 3C to the atmosphere, and a pressure accumulator tank atmosphere release valve 13A that opens the pressure accumulator tank 3A to the atmosphere.

[0045] All of the above valves are electromagnetic on-off valves, whose valve positions are switched between an open position and a closed position in response to a signal supplied from a controller 20 (see FIG. 2).

[0046] 2, water supply system 1 includes a pressure sensor group that detects the internal pressure of the tank group, and a water level sensor group that detects the water level of the tank group. The pressure sensor group includes normal temperature water tank pressure sensor 21N, hot water tank pressure sensor 21H, cold water tank pressure sensor 21C, and accumulator tank pressure sensor 21A. The water level sensor group includes normal temperature water tank water level sensor 22N, hot water tank water level sensor 22H, and cold water tank water level sensor 22C.

[0047] The normal temperature water tank pressure sensor 21N detects the internal pressure of the normal temperature water tank 3N. The hot water tank pressure sensor 21H detects the internal pressure of the hot water tank 3H. The cold water tank pressure sensor 21C detects the internal pressure of the cold water tank 3C. The pressure accumulator tank pressure sensor 21A detects the internal pressure of the pressure accumulator tank 3A. The normal temperature water tank water level sensor 22N detects the water level in the normal temperature water tank 3N. The hot water tank water level sensor 22H detects the water level in the hot water tank 3H. The cold water tank water level sensor 22C detects the water level in the cold water tank 3C.

[0048] Each water level sensor is configured to be able to detect two water levels: a full water level and an empty water level. For example, the room temperature water tank water level sensor 22N may be configured with two sensors: a full water level sensor that detects the full water level, and an empty water level sensor that detects the empty water level. The two sensors are attached to the inner surface side of the room temperature water tank 3N and are spaced apart in the vertical direction. The same applies to the hot water tank water level sensor 22H and the cold water tank water level sensor 22C.

[0049] The water supply system 1 includes a controller 20. The controller 20 is connected to the above-mentioned sensor group. The controller 20 is connected to the inverter 2c, the pump group, and the valve group. The controller 20 is, for example, a computer having a CPU, a memory, and an input / output interface. The controller 20 executes a water supply method for supplying water to a water supply target through information processing according to instructions of a program pre-stored in the memory. In the following description, the operations of the inverter 2c, the pump group, and the valve group occur as a result of control by the controller 20.

[0050] 3A to 3D are explanatory diagrams of the supply of room temperature water. Referring to FIG. 3A, when the water level in the room temperature water tank 3N reaches the empty water level, room temperature water is stored in the room temperature water tank 3N. For this purpose, the room temperature water tank air supply on-off valve 14N and the room temperature water supply on-off valve 19N are closed, while the room temperature water filling on-off valve 15N and the room temperature water tank atmosphere release valve 13N are opened. As a result, the internal pressure of the room temperature water tank 3N (pressure of the air layer in the tank) becomes atmospheric pressure. When the water source W is a waterworks facility, the room temperature water (tap water in this case) has a water pressure (for example, 0.2 MPa) that exceeds atmospheric pressure. For this reason, the room temperature water from the water source W is filled into the room temperature water tank 3N.

[0051] When the water level reaches the full water level, the room temperature water filling opening / closing valve 15N and the room temperature water tank atmosphere release valve 13N are closed.

[0052] Next, room temperature water is supplied from the room temperature water tank 3N to the elevated water tank 3E through the room temperature water supply line 9N. To this end, the room temperature water filling on-off valve 15N and the room temperature water tank atmospheric release valve 13N are closed, while the main air supply on-off valve 14M, the room temperature water tank air supply on-off valve 14N, and the room temperature water supply on-off valve 19N are opened. As a result, compressed air is supplied to the room temperature water tank 3N from the compressor 2a through the main air supply line 4M and the room temperature water tank air supply line 4N. The internal pressure of the room temperature water tank 3N rises to the pressure of the compressed air. Pushed by the compressed air, the room temperature water in the room temperature water tank 3N is discharged from the room temperature water tank 3N and pumped up. The pressure of the compressed air is, for example, about 0.7 MPa. In this case, when the room temperature water tank 3N is installed at the same level as the first floor of the building B, the room temperature water is pumped up to about 70 m. In other words, room temperature water can be pumped up to the rooftop floor of building B, which is 20 stories high, without any problems.

[0053] The supply of compressed air to the room temperature water tank 3N, and therefore the supply of room temperature water to the elevated water tank 3E, continues until the water level in the room temperature water tank 3N reaches the empty water level. The volume of the elevated water tank 3E is larger than the volume of the room temperature water tank 3N. Therefore, even if the room temperature water changes continuously and at high speed from the full water level to the empty water level of the room temperature water tank 3N, the elevated water tank 3E can receive the supplied room temperature water.

[0054] Referring to FIG. 3C, when the water level reaches the empty water level, the room temperature water tank air supply on-off valve 14N and the room temperature water supply on-off valve 19N are temporarily closed.

[0055] Referring to FIG. 3D, the compressed air stored in the normal temperature water tank 3N is recovered in the pressure accumulator tank 3A. To this end, the main air supply valve 14M and the normal temperature water supply valve 19N are closed, while the normal temperature water tank air supply valve 14N and the pressure accumulator tank air supply valve 14A are opened. It is preferable that the expander open / close valve 17 is closed. As a result, the compressed air in the normal temperature water tank 3N is supplied to the pressure accumulator tank 3A via the normal temperature water tank air supply line 4N and the pressure accumulator tank air supply line 4A. When the internal pressure of the pressure accumulator tank 3A is balanced with the internal pressure of the normal temperature water tank 3N, the transfer of the compressed air stops. By forming a state in which the compressor 2a is isolated from the normal temperature water tank 3N and the pressure accumulator tank 3A and the normal temperature water tank 3N is connected to the pressure accumulator tank 3A, such energy recovery of the compressed air can be realized.

[0056] When the transfer of compressed air stops, the pressure accumulator tank air supply opening / closing valve 14A is closed. After that, the process returns to Fig. 3A, and the above operations are repeated starting from filling with room temperature water.

[0057] The room temperature water in the elevated water tank 3E flows vertically downward through the downflow line 30 by utilizing the head pressure, and is supplied to the water supply targets on each floor. The elevated water tank 3E may be provided with a pump for draining the water in the elevated water tank 3E.

[0058] Although detailed operational diagrams are omitted, the hot water tank 3H and cold water tank 3C are similar to the normal temperature water tank 3N. In the hot water tank 3H, a series of operations is repeated, including storing hot water in the hot water tank 3H, supplying hot water from the hot water tank 3H to the water supply target, and recovering energy from the compressed air in the hot water tank 3H. In the cold water tank 3C, a series of operations is repeated, including storing cold water in the cold water tank 3C, supplying cold water from the cold water tank 3C to the water supply target, and recovering energy from the compressed air in the cold water tank 3C.

[0059] During hot water storage, the on-off valve associated with the hot water tank 3H operates in the same manner as the on-off valve associated with the normal temperature water tank 3N. As a result, hot water is supplied to the hot water tank 3H through the hot water filling line 5H while the hot water tank 3H is open to the atmosphere and is isolated from the compressor 2a and other tanks. At this time, as a difference from the normal temperature water storage, the hot water pump 10H operates, and normal temperature water from the water source W is drawn from the normal temperature water filling line 5N to the hot water filling line 5H. During this hot water storage, compressed air is not supplied to the hot water tank 3H, but is supplied to the normal temperature water tank 3N, cold water tank 3C, or pressure storage tank 3A, and in the process, the compressed air passes through the first heat exchanger 8a. The temperature of the compressed air is 150 to 180°C immediately after being discharged from the compressor 2a. On the other hand, the temperature of the normal temperature water is 20 to 30°C. While flowing through the hot water filling line 5H, the room temperature water exchanges heat with compressed air in the first heat exchanger 8a and is heated to 50 to 70° C., becoming hot water. The hot water pump 10H is stopped except when hot water is stored.

[0060] When supplying hot water, the on-off valve associated with the hot water tank 3H operates in the same manner as the on-off valve associated with the normal temperature water tank 3N. As a result, hot water is pumped through the hot water supply line 9H and supplied to the water supply target. When collecting compressed air from the hot water tank 3H, the on-off valve associated with the hot water tank 3H operates in the same manner as the on-off valve associated with the normal temperature water tank 3N. As a result, the compressed air from the hot water tank 3H is supplied to the accumulator tank 3A via the hot water tank air supply line 4H and the accumulator tank air supply line 4A. When the internal pressure of the accumulator tank 3A becomes equilibrium with the internal pressure of the hot water tank 3H, the transfer of compressed air stops.

[0061] During cold water storage, the on-off valve associated with the cold water tank 3C operates in the same manner as the on-off valve associated with the normal temperature water tank 3N. As a result, cold water is supplied to the cold water tank 3C through the cold water filling line 5C while the cold water tank 3C is open to the atmosphere and is isolated from the compressor 2a and other tanks. At this time, as a difference from the normal temperature water storage, the cold water pump 10C operates, and normal temperature water from the water source W is drawn from the normal temperature water filling line 5N to the cold water filling line 5C. During this cold water storage, the expander 6a operates with compressed air stored in the pressure accumulator 3A, and the expanded air discharged from the expander 6a passes through the second heat exchanger 8b. In the process of flowing through the cold water filling line 5C, the normal temperature water exchanges heat with the expanded air discharged from the expander 6a in the second heat exchanger 8b, and is cooled to 5 to 15°C, becoming cold water. The cold water pump 10C is stopped except when cold water is stored.

[0062] When supplying cold water, the on-off valve associated with the cold water tank 3C operates in the same manner as the on-off valve associated with the normal temperature water tank 3N. As a result, cold water is pumped through the cold water supply line 9C and supplied to the water supply target. When collecting compressed air from the cold water tank 3C, the on-off valve associated with the cold water tank 3C operates in the same manner as the on-off valve associated with the normal temperature water tank 3N. As a result, the compressed air from the cold water tank 3C is supplied to the pressure accumulator tank 3A through the cold water tank air supply line 4C and the pressure accumulator tank air supply line 4A. When the internal pressure of the pressure accumulator tank 3A is balanced with the internal pressure of the cold water tank 3C, the transfer of compressed air stops.

[0063] The water supply system 1 according to this embodiment supplies water to a water supply target provided on each floor of a multi-story building B. The water supply system 1 includes a compressor 2a that compresses air, a room temperature water tank 3N that stores room temperature water (water source water), a first heat exchanger 8a that exchanges heat between the compressed air compressed by the compressor 2a and the room temperature water (water source water), a hot water tank 3H that stores hot water heated by the heat exchange in the first heat exchanger 8a, a room temperature water supply line 9N that supplies room temperature water from the room temperature water tank 3N to the water supply target by the compressed air supplied to the room temperature water tank 3N, and a hot water supply line 9H that supplies hot water from the hot water tank 3H to the water supply target by the compressed air supplied to the hot water tank 3H.

[0064] In other words, the water supply method according to this embodiment is a method for supplying water to a water supply target provided on each floor of a multi-story building B. The water supply method includes compressing air with a compressor 2a, storing room temperature water in a room temperature water tank 3N, exchanging heat between the compressed air compressed by the compressor 2a and the room temperature water in a first heat exchanger 8a, storing hot water heated by the heat exchange in the first heat exchanger 8a in a hot water tank 3H, supplying the room temperature water from the room temperature water tank 3N to the water supply target via a room temperature water supply line 9N by supplying compressed air to the hot water tank 3H, and supplying the hot water from the hot water tank 3H to the water supply target via a hot water supply line 9H by supplying compressed air to the hot water tank 3H.

[0065] The compressed air generated by the compressor 2a is high temperature and high pressure. Instead of using a pump, the high pressure of the compressed air can be used to supply room temperature water to each floor of the building B. The heat of the compressed air can be recovered by the first heat exchanger 8a, thereby generating hot water. This hot water is also supplied to each floor of the building B by using the high pressure of the compressed air. In this way, the energy consumed in the operation of the compressor 2a is recovered as hot water that can be used by the water supply target. Energy efficiency is improved compared to when water is pumped up by a pump.

[0066] The water supply system 1 includes an elevated water tank 3E installed on the upper floor of a building B. A room temperature water supply line 9N pumps room temperature water from the room temperature water tank 3N to the elevated water tank 3E. The room temperature water is once stored in the elevated water tank 3E and then supplied to the water supply target. This prevents water leakage from the shaft seal, which could occur with conventional water pumps.

[0067] The water supply system 1 further includes a room temperature water tank pressure sensor 21N that detects the internal pressure of the room temperature water tank 3N, a room temperature water tank water level sensor 22N that detects the water level in the room temperature water tank 3N, a room temperature water tank air supply on / off valve 14N that switches whether or not compressed air is supplied to the room temperature water tank 3N, a room temperature water filling on / off valve 15N that switches whether or not room temperature water is supplied to the room temperature water tank 3N, a room temperature water supply on / off valve 19N that switches whether or not room temperature water is supplied from the room temperature water tank 3N to a water supply target, and a controller 20 that controls the room temperature water tank air supply on / off valve 14N, the room temperature water filling on / off valve 15N, and the room temperature water supply on / off valve 19N based on the detection results of the room temperature water tank pressure sensor 21N and the room temperature water tank water level sensor 22N. In this way, the controller 20 automates an operation cycle consisting of a series of operations in which room temperature water is supplied from the room temperature water tank 3N to a supply target by utilizing the pressure of the compressed air and the room temperature water is filled into the room temperature water tank 3N.

[0068] The water supply system 1 further includes a pressure storage tank 3A for storing compressed air, an expander 6a driven by the compressed air supplied from the pressure storage tank 3A, and a generator 6b mechanically connected to the expander 6a and driven by the expander 6a. The energy of the compressed air supplied to the normal temperature water tank 3N and the hot water tank 3H is recovered as electrical energy. This further improves the energy efficiency of the water supply system 1. In the above description, the compressed air used to pump normal temperature water, hot water, and cold water is transferred to the pressure storage tank 3H, and the energy of the transferred compressed air is recovered as electrical energy in the generator unit 6, thereby achieving high energy efficiency. However, the compressed air discharged from the compressor 2a may be directly supplied to the pressure storage tank 3A, and even in this case, the electrical energy used to drive the compressor 2a can be recovered in the generator 6b.

[0069] The water supply system 1 further includes a second heat exchanger 8b that exchanges heat between the expanded air expanded by the expander 6a and room temperature water, a cold water tank 3C that stores cold water whose temperature has been reduced by heat exchange in the second heat exchanger 8b, and a cold water supply line 9C that supplies cold water from the cold water tank 3C to a water supply target using compressed air supplied to the cold water tank 3C. Cold water is generated by the cold energy of the expanded air expanded by the expander 6a, and is supplied to each floor of the building B using the high pressure of the compressed air. This further improves the energy efficiency of the water supply system 1.

[0070] Next, with reference to FIG. 4, a water supply system 1 according to a second embodiment will be described, focusing on the differences from the above embodiment.

[0071] The water supply system 1 according to this embodiment includes a water receiving tank 31, a downwater line 32, and a hydroelectric generator 33. The water receiving tank 31 is installed vertically below the elevated water tank 3E. As an example, the water receiving tank 31 is installed on the first floor or basement floor of a building B. The downwater line 32 is independent of the downwater line 30 connected to the water supply target, and allows room temperature water in the elevated water tank 3E to fall to the water receiving tank 31. A pump may be provided on the downwater line 32 to draw water from the elevated water tank 3E into the downwater line 32.

[0072] The hydroelectric generator 33 is a water current generator and is disposed on the downfall line 32. The hydroelectric generator 33 is driven by the water flow passing through the downfall line 32 to generate alternating current. The hydroelectric generator 33 may be configured with a water wheel that is rotationally driven by water power, or may be configured with a pump that is rotationally driven by water power. The other configurations are the same as those of the first embodiment.

[0073] According to this embodiment, the potential energy of the room temperature water supplied to the elevated water tank 3E can be recovered as electrical energy, thereby further improving the energy efficiency of the water supply system 1.

[0074] Next, with reference to FIG. 5, a water supply system 1 according to a third embodiment will be described, focusing on differences from the above embodiment.

[0075] In this embodiment, the expander discharge line 7b in the first embodiment is replaced with a cold air supply line 34. The cold air supply line 34 connects the discharge port of the expander 6a to the object to be air-conditioned. The object to be air-conditioned, like the object to be supplied with water, is provided on each floor of a multi-story building B. The object to be air-conditioned is, for example, a duct provided on each floor or a ventilation opening provided in each room.

[0076] With this configuration, cold air can be supplied to the object to be air-conditioned by using the cold energy generated by the expansion machine 6a. The water supply system 1 can also be utilized to generate cold air, and the energy efficiency of the water supply system 1 is further improved.

[0077] The water supply system 1 may include both the hydroelectric generator 33 (see FIG. 4) shown in the second embodiment and the cold air supply line 34 (see FIG. 5) shown in the third embodiment.

[0078] Next, with reference to FIG. 6, a water supply system 1 according to a fourth embodiment will be described, focusing on differences from the above-described embodiment.

[0079] In this embodiment, the elevated water tank 3E and the downwater line 30 (see FIG. 1) are not provided. Instead, the first water supply target is a tank, a water supply header, or a faucet provided on each floor, similar to the second water supply target and the third water supply target. The room temperature water supply line 9N directly connects the room temperature water tank 3N to such a first water supply target. The room temperature water supply line 9N includes an upper and lower extension portion extending vertically upward from the room temperature water tank 3N, similar to the hot water supply line 9H and the cold water supply line 9C, and a plurality of branch portions branching from the upper and lower extension portions for each floor and connected to the water supply target. In this way, the elevated water tank 3E can be omitted, and even in this case, the effect of improving the energy efficiency of the water supply system 1 can be obtained in the same manner as in the above embodiment.

[0080] The water supply system 1 may include both the cold air supply line 34 (see FIG. 5) shown in the third embodiment and the room temperature water supply line 9N shown in the fourth embodiment.

[0081] 7A to 7D, a water supply system 1 according to a fifth embodiment will be described, focusing on differences from the above-described embodiments. An illustration of the entire system will be omitted.

[0082] As shown in FIG. 7A, in this embodiment, the room temperature water bath 3N is of a double type and includes a first room temperature water bath 3Na and a second room temperature water bath 3Nb.

[0083] The downstream end of the normal temperature water tank air supply line 4N is branched to be connected to the first normal temperature water tank 3Na and the second normal temperature water tank 3Nb. The normal temperature water tank air supply line 4N includes a first normal temperature water tank air supply line 4Na connected to the first normal temperature water tank 3Na, and a second normal temperature water tank air supply line 4Nb branched from the main air supply line 4M and connected to the second normal temperature water tank 3Nb.

[0084] The downstream end of the room temperature water filling line 5N is branched so as to be connected to the first room temperature water tank 3Na and the second room temperature water tank 3Nb, respectively. The room temperature water filling line 5N includes a first room temperature water filling line 5Na connected to the first room temperature water tank 3Na and a second room temperature water filling line 5Nb connected to the second room temperature water tank 3Nb.

[0085] The upstream end of the room temperature water supply line 9N is branched to be connected to the first room temperature water tank 3Na and the second room temperature water tank 3Nb, respectively. The room temperature water supply line 9N includes a first room temperature water supply line 9Na connected to the first room temperature water tank 3Na and a second room temperature water supply line 9Nb connected to the second room temperature water tank 3Nb.

[0086] The normal temperature water tank air supply on-off valve 14N includes a first normal temperature water tank air supply on-off valve 14Na that opens and closes the first normal temperature water tank air supply line 4Na, and a second normal temperature water tank air supply on-off valve 14Nb that opens and closes the second normal temperature water tank air supply line 4Nb. The normal temperature water filling on-off valve 15N includes a first normal temperature water filling on-off valve 15Na that opens and closes the first normal temperature water filling line 5Na, and a second normal temperature water filling on-off valve 15Nb that opens and closes the second normal temperature water filling line 5Nb. The normal temperature water supply on-off valve 19N includes a first normal temperature water supply on-off valve 19Na that opens and closes the first normal temperature water supply line 9Na, and a second normal temperature water supply on-off valve 19Nb that opens and closes the second normal temperature water supply line 9Nb. The first room temperature water tank 3Na is provided with a first room temperature water tank atmosphere release valve 13Na, and the second room temperature water tank 3Nb is provided with a second room temperature water tank atmosphere release valve 13Nb.

[0087] 7A to 7D are explanatory diagrams of the supply of room temperature water in this embodiment configured as described above. Referring to FIG. 7A, when the water level in the first room temperature water tank 3Na becomes the empty water level, room temperature water is stored in the first room temperature water tank 3Na. For this purpose, the first room temperature water tank air supply valve 14Na and the first room temperature water supply valve 19Na are closed, while the first room temperature water filling valve 15Na and the first room temperature water tank atmosphere release valve 13Na are opened. The valve position of the main air supply valve 14M does not matter as long as it is located closer to the compressor 2a in the room temperature water tank air supply line 4N than the first room temperature water tank air supply valve 14Na. As a result, the internal pressure of the first room temperature water tank 3Na becomes atmospheric pressure. Room temperature water from the water source W is filled into the first room temperature water tank 3Na. The operation of the second room temperature water tank 3Nb at this time will be described later for convenience of explanation.

[0088] When the water level in the first room temperature water tank 3Na reaches the full water level, the first room temperature water supply opening / closing valve 19Na and the first room temperature water tank atmosphere release valve 13Na are temporarily closed. All other valves associated with the first room temperature water tank 3Na and the second room temperature water tank 3Nb are also closed.

[0089] Next, referring to FIG. 7B, room temperature water is supplied from the first room temperature water tank 3Na to the elevated water tank 3E through the room temperature water supply line 9N. To this end, the first room temperature water filling on-off valve 15Na and the first room temperature water tank atmospheric release valve 13Na are closed, while the main air supply on-off valve 14M, the first room temperature water tank air supply on-off valve 14Na, and the first room temperature water supply on-off valve 19Na are opened. As a result, compressed air is supplied from the compressor 2a to the first room temperature water tank 3Na through the main air supply line 4M and the first room temperature water tank air supply line 4Na. The internal pressure of the first room temperature water tank 3Na rises from atmospheric pressure to the pressure of the compressed air. Pushed by the compressed air, the room temperature water in the first room temperature water tank 3Na is discharged from the first room temperature water tank 3Na and is pumped up to the elevated water tank 3E through the upstream part 9NU.

[0090] At the same time, room temperature water is supplied to the second room temperature water tank 3Nb. To this end, the second room temperature water tank air supply valve 14Nb and the second room temperature water supply valve 19Nb are closed, while the second room temperature water filling valve 15Nb and the second room temperature water tank atmosphere release valve 13Nb are opened. To supply room temperature water from the first room temperature water tank 3Na to the water supply target (or the elevated water tank 3E), the main air supply valve 14M is open, but the second room temperature water tank 3Nb is cut off from the compressor 2a, and the internal pressure of the second room temperature water tank 3Nb becomes atmospheric pressure. Room temperature water from the water source W is filled into the second room temperature water tank 3Nb.

[0091] In this way, while room temperature water is being supplied from the first room temperature water tank 3Na to the water supply target, the second room temperature water tank 3Nb is being filled with room temperature water. Referring to Fig. 7C, when the water level in the first room temperature water tank 3Na reaches the empty water level, the first room temperature water tank air supply valve 14Na, the first room temperature water supply valve 19Na, the first room temperature water filling valve 15Na, and the first room temperature water tank atmosphere release valve 13Na are temporarily closed.

[0092] Referring to FIG. 7D, the compressed air stored in the first normal temperature water tank 3Na is collected in the pressure accumulator tank 3A. To achieve this, the main air supply valve 14M, the first normal temperature water tank atmosphere release valve 13Na, the first normal temperature water filling valve 15Na, and the first normal temperature water supply valve 19Na are closed. Meanwhile, the first normal temperature water tank air supply valve 14Na and the pressure accumulator tank air supply valve 14A are closed. It is preferable that the expander open / close valve 17 is closed. As a result, when the internal pressure of the pressure accumulator tank 3A is balanced with the internal pressure of the first normal temperature water tank 3Na, the transfer of the compressed air is stopped. The pressure balance is determined based on the detection result output from the pressure sensor.

[0093] When the transfer of compressed air stops, the pressure accumulator air supply opening / closing valve 14A is closed. After that, returning to Fig. 7A, normal temperature water is supplied again to the first normal temperature water tank 3Na.

[0094] As shown in FIG. 7A, while the first normal temperature water tank 3Na is being filled with normal temperature water, normal temperature water is supplied from the second normal temperature water tank 3Nb to the water supply target. To this end, the second normal temperature water filling on-off valve 15Nb and the second normal temperature water tank air release valve 13Nb are closed, while the main air supply on-off valve 14M, the second normal temperature water tank air supply on-off valve 14Nb, and the second normal temperature water supply on-off valve 19Nb are opened. As a result, compressed air is supplied from the compressor 2a to the second normal temperature water tank 3Nb via the main air supply line 4M and the second normal temperature water tank air supply line 4Nb. The internal pressure of the second normal temperature water tank 3Nb rises from atmospheric pressure to the pressure of the compressed air. Pushed by the compressed air, the normal temperature water in the second normal temperature water tank 3Nb is discharged from the second normal temperature water tank 3Nb and is pumped up to the elevated water tank 3E.

[0095] By using a dual room temperature water tank in this way, when one room temperature water tank is being filled, room temperature water can be supplied from the other room temperature water tank to the water supply target or the elevated water tank 3E. Water is supplied continuously, and a stable supply of room temperature water to the water supply target can be achieved.

[0096] Although detailed illustration is omitted, the compressed air stored in the second normal temperature water tank 3Nb can be collected in the pressure accumulator tank 3A in the same manner as the first normal temperature water tank 3Na. The hot water tank 3H or the cold water tank 3C may be configured as a double tank. This allows hot water or cold water to be stably supplied to the water supply target in the same manner as normal temperature water.

[0097] Although the embodiment has been described above, the above configuration can be appropriately added to, modified, or deleted within the scope of the present invention.

[0098] In this embodiment, the normal temperature water tank 3N, the hot water tank 3H, the cold water tank 3C, and the pressure storage tank 3A are installed at the same level as the first floor of the building B, but may be installed at the same level as the basement.

[0099] Also, a heater for adjusting (for example, keeping warm) the temperature of the hot water stored in the hot water tank 3H or a cooler for adjusting (for example, keeping cold) the temperature of the water stored in the cold water tank 3C may be provided. Moreover, the electric power for the heater or cooler may be generated by the generator 6b or the hydroelectric generator 33 or may be supplied from the power supply facility. [Explanation of symbols]

[0100] 1. Water Supply System 2 Compressor unit 2a Compressor 2b Motor 2c inverter 3A pressure storage tank 3C cold water tank 3E Elevated water tank 3H hot water tank 3N normal temperature water tank 3Na First room temperature water tank 3Nb Second normal temperature water tank 4 Air supply line 4A Accumulator air supply line 4C Cold water tank air supply line 4H Hot water tank air supply line 4M main air supply line 4N Normal temperature water tank air supply line 4Na No. 1 normal temperature water tank air supply line 4Nb Second normal temperature water tank air supply line 5 Water filling line 5C Cold water filling line 5H Hot water filling line 5N normal temperature water filling line 5Na No.1 Ambient Water Filling Line 5Nb No. 2 normal temperature water filling line 6 Generator Unit 6a Expander 6b Generator 7 Expander Line 7a Expander supply line 7b Expander discharge line 8a 1st heat exchanger 8b Second heat exchanger 9. Water Supply Line 9C Chilled water supply line 9H Hot water supply line 9N Room temperature water supply line 9Na No. 1 normal temperature water supply line 9Nb Second normal temperature water supply line 10C Chilled water pump 10H Hot water pump 13A Pressure tank atmospheric release valve 13C Cold water tank atmospheric release valve 13H Hot water tank atmospheric release valve 13N Normal temperature water tank atmospheric release valve 13Na No. 1 normal temperature water tank air release valve 13Nb Second normal temperature water tank atmospheric release valve 14A Pressure tank air supply valve 14C Cold water tank air supply valve 14H Hot water tank air supply valve 14M Main air supply valve 14N Normal temperature water tank air supply valve 14Na First normal temperature water tank air supply valve 14Nb Second normal temperature water tank air supply opening and closing valve 15C Cold water filling shutoff valve 15H Hot water filling valve 15N Normal temperature water filling on-off valve 15Na No. 1 normal temperature water filling on-off valve 15Nb Second normal temperature water filling on-off valve 17 Expansion machine on-off valve 19C Chilled water supply valve 19H Hot water supply valve 19N Normal temperature water supply valve 19Na No. 1 normal temperature water supply on-off valve 19Nb Second normal temperature water supply on-off valve 20 Controller 21A Accumulator Pressure Sensor 21C Cold Water Tank Pressure Sensor 21H Hot water tank pressure sensor 21N Normal temperature water tank pressure sensor 22C Cold water tank level sensor 22H Hot water tank water level sensor 22N Normal temperature water tank level sensor 30 Falling Water Line 31 Water tank 32 Falling Water Line 33 Hydroelectric Generator 34 Cold air supply line B Building W water source

Claims

1. A water supply system for supplying water to a water supply target of a multi-story building, A compressor that compresses air to generate compressed air; a room temperature water tank for storing water supplied from a water source as room temperature water and for receiving the compressed air; a first heat exchanger that exchanges heat between the compressed air and water supplied from the water source to generate hot water; A hot water tank for storing the hot water; a room temperature water supply line that supplies the room temperature water from the room temperature water tank to a first water supply target by the compressed air supplied to the room temperature water tank; A water supply system comprising:

2. The first water supply target is an elevated water tank installed on an upper floor of the multi-story building, or a water supply header installed on each floor of the multi-story building. The water supply system according to claim 1 .

3. A water tank arranged below the elevated water tank as the first water supply target; A hydroelectric generator that generates electricity using hydraulic power moving from the elevated water tank to the water receiving tank; The water supply system of claim 2 further comprising:

4. a hot water tank air supply line for supplying the compressed air to the hot water tank; a hot water supply line that supplies hot water from the hot water tank to a second water supply target by the compressed air supplied to the hot water tank; The water supply system of claim 1 .

5. a normal temperature water tank pressure sensor for detecting an internal pressure of the normal temperature water tank; a room temperature water tank water level sensor for detecting a water level in the room temperature water tank; a room temperature water tank air supply opening / closing valve for switching whether or not the compressed air is supplied to the room temperature water tank; a room temperature water filling on-off valve for switching whether or not the room temperature water is supplied to the room temperature water tank; a room temperature water supply opening / closing valve that switches whether or not the room temperature water is supplied from the room temperature water tank to the first water supply target; a controller that controls the room temperature water tank air supply valve, the room temperature water filling valve, and the room temperature water supply valve based on detection results of the room temperature water tank pressure sensor and the room temperature water tank water level sensor; The water supply system according to claim 1 , further comprising:

6. a pressure accumulator tank for storing the compressed air; an expander driven by the compressed air supplied from the pressure accumulator; a generator mechanically connected to the expander and driven by the expander; The water supply system according to claim 1 , further comprising:

7. a second heat exchanger that exchanges heat between the expanded air expanded by the expander and cooled and the water supplied from the water source to generate cold water; a cold water tank for storing the cold water and for receiving the compressed air; a cold water supply line that supplies the cold water from the cold water tank to a third water supply target by the compressed air supplied to the cold water tank; The water supply system of claim 6 further comprising:

8. Further comprising a cold air supply line for supplying the expanded air to an air-conditioning target of the multi-story building. The water supply system according to claim 6.

9. A water supply method for supplying water to a water supply target of a multi-story building, comprising: Compressing air with a compressor to generate compressed air; Storing water supplied from a water source in a room temperature water tank as room temperature water; exchanging heat between the compressed air and the water supplied from the water source in a first heat exchanger to generate hot water; Storing the hot water in a hot water tank; Supplying the room temperature water from the room temperature water tank to a first water supply target via a room temperature water supply line by supplying the compressed air to the room temperature water tank; A water supply method comprising:

10. The method further includes supplying the compressed air to the hot water tank, and supplying the hot water from the hot water tank to a second water supply target through a hot water supply line. The water supply method according to claim 9.

Images