Compressed air energy storage device

Abstract

To provide a technique that can adjust electric power demand and supply.SOLUTION: A compressed air energy storage device 100 comprises air compressors 6 and 7 for generating compressed air, heat exchangers 24 and 25 for exchanging heat between the compressed air and a heat accumulation medium, a pressure accumulation tank 8 for storing the compressed air heat-exchanged by the heat exchangers 24 and 25, a heat accumulation tank 21 for storing the heat accumulation medium heat-exchanged by the heat exchangers 24 and 25, a heat exchanger 32 for generating low-pressure steam by heating water by exchanging heat with the heat accumulation medium, a steam compressor 41 for generating high-temperature steam by compressing the low-pressure steam, power generators 12 and 13 for generating electric power, and expanders 10 and 11 for driving the power generators 12 and 13 by the compressed air or the high-temperature steam, and supplies one or more of the compressed air, the high-temperature steam, and the electric power.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a compressed air energy storage device. [Background technology]

[0002] Renewable energy power generation such as wind power generation and solar power generation depends on weather conditions, so the amount of power generated can fluctuate and be unstable. Compressed Air Energy Storage (CAES) systems are known as a system that can level out power generation output to deal with such fluctuations.

[0003] A compressed air energy storage device (CAES device) that utilizes this CAES system, for example, when generating electricity from a solar power generation system, operates the compressor during daytime hours when surplus electricity is generated, and stores electrical energy as compressed air in an accumulator tank, and when electricity is needed, uses the compressed air to drive an expander to operate a generator, thereby generating electrical energy and leveling out output.

[0004] In such a CAES device, for example, Patent Document 1 discloses a compressed air energy storage device that stores compressed air in tanks of different sizes according to the period of power fluctuation.

[0005] On the other hand, equipment such as pneumatic systems (air compressors) and boilers that are commonly used as power sources in factories use a large proportion of energy, such as electricity and fossil fuels, have a large energy loss in the form of exhaust heat, and emit large amounts of carbon dioxide.

[0006] As an example of an apparatus that utilizes waste heat from other equipment in a boiler, Patent Document 2 discloses an apparatus that utilizes waste heat from a ship's engine to heat boiler water and use the steam as a heating source inside the ship. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6368577 [Patent Document 2] JP 2015-17771 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, Patent Documents 1 and 2 do not disclose adjusting the power supply and demand by combining an air compressor with a boiler.

[0009] Therefore, an object of the present invention is to provide a technique capable of adjusting power supply and demand. [Means for solving the problem]

[0010] In order to solve the above problems, one representative compressed air energy storage device of the present invention includes an air compressor that generates compressed air, a first heat exchanger that exchanges heat between the compressed air and a heat storage medium, a pressure storage tank that stores the compressed air that has been heat exchanged in the first heat exchanger, a heat storage tank that stores the heat storage medium that has been heat exchanged in the first heat exchanger, a low-pressure steam generating device that heats water by heat exchange with the heat storage medium to generate low-pressure steam, a steam compressor that compresses the low-pressure steam to generate high-temperature steam, a generator that generates electricity, and an expander that drives the generator with compressed air or high-temperature steam, and supplies one or more of compressed air, high-temperature steam, and electricity. Effect of the Invention

[0011] According to the present invention, power supply and demand can be adjusted.

[0012] Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0013] [Figure 1] 1 is a diagram showing an example of a schematic configuration of a compressed air energy storage device according to a first embodiment. FIG. [Diagram 2]FIG. 11 is a diagram showing an example of a schematic configuration of a compressed air energy storage device according to a second embodiment. [Diagram 3] FIG. 11 is a diagram showing an example of a schematic configuration of a compressed air energy storage device according to a third embodiment. [Figure 4] FIG. 11 is a diagram showing an example of a schematic configuration of a compressed air energy storage device according to a fourth embodiment. [Diagram 5] FIG. 13 is a diagram showing an example of a schematic configuration of a compressed air energy storage device according to a fifth embodiment. [Figure 6] FIG. 13 is a diagram showing an example of a schematic configuration of a compressed air energy storage device according to a sixth embodiment. [Figure 7] 4 is a flowchart of an operation control process executed by a control device of the compressed air energy storage device of the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Like elements are given like reference numerals and similar descriptions will not be repeated. EXAMPLES

[0015] FIG. 1 is a diagram showing an example of a schematic configuration of a compressed air energy storage device according to a first embodiment.

[0016] The compressed air energy storage device 100 includes an air pressure unit 1, a heat storage unit 2, a boiler unit 40, and a power generation unit 3.

[0017] The air pressure unit 1 includes motors (electric motors) 4 and 5, air compressors 6 and 7, and an accumulator tank 8. The heat storage unit 2 includes a high-temperature side heat storage tank 21 and a low-temperature side heat storage tank 22 containing a heat storage medium such as water, and heat exchangers 24 and 25. The boiler unit 40 mainly includes a steam compressor 41. The power generation unit 3 includes expanders 10 and 11, and generators 12 and 13.

[0018] The motors 4 and 5 are connected to grid power 20 that utilizes renewable energy or the like via an inverter 9. In addition, the power generation unit 3 is connected to the grid power 20 via a power conditioner 14. The grid power 20 is connected to a solar power generation device 18 and a wind power generation device 19.

[0019] The motor 4 is mechanically connected to an air compressor 6 which is responsible for the low-stage compression stroke, and the motor 5 is mechanically connected to an air compressor 7 which is responsible for the high-stage compression stroke. The air pressure unit 1 performs two-stage compression by the low-stage compression stroke and the high-stage compression stroke.

[0020] The intake port of air compressor 6 is open to the atmosphere, and the discharge port of air compressor 6 is connected to heat exchanger 24 and then to the intake port of air compressor 7. The discharge port of air compressor 7 is connected to heat exchanger 25 and then to accumulator tank 8.

[0021] The suction port of the expander 10 is connected to the heat exchanger 26, and the discharge port of the expander 10 is connected to a pipe 92 connected to the heat exchanger 27 and a pipe 93 connected to the first air pressure pipe 71. The pipe 92 has a valve 53, and the pipe 93 has a valve 54. The suction port of the expander 11 is connected to the heat exchanger 27, and the discharge port of the expander 11 is open to the atmosphere.

[0022] The heat exchanger 26 has a pipe 91 that connects to the accumulator tank 8, and the pipe 91 has a valve 52. Compressed air from the accumulator tank 8 flows into the heat exchanger 26.

[0023] An air-using device 200 that is driven by air pressure in a factory is connected to the accumulator tank 8 by a first air pressure pipe 71, and the first air pressure pipe 71 has a valve 51. Compressed air is supplied to the air-using device 200 from the accumulator tank 8 via the first air pressure pipe 71.

[0024] The heat storage unit 2 has a fluid circuit connecting the heat exchangers 24, 25, the heat storage tank 21, the heat exchanger 32, and the heat storage tank 22. The heat storage medium exchanges heat with compressed air in the heat exchangers 24, 25 to recover the heat of compression, and the high-temperature heat storage medium is stored in the heat storage tank 21. Thereafter, the heat storage medium exchanges heat with low-temperature water in the heat exchanger 32 to generate low-pressure steam, and the low-temperature heat storage medium is stored in the heat storage tank 22. These fluid circuits are provided with pumps 28, 29 for transporting the heat storage medium.

[0025] The boiler unit 40 includes a low-pressure steam generator 43, a gas-liquid separator 42, a low-temperature water circulation pump 44, a steam compressor 41, a pressure reducing valve 45, and a medium-temperature water heat recovery heat exchanger 47. The low-pressure steam generator 43 heats water flowing in from the gas-liquid separator 42 through a water supply pipe to generate low-pressure steam, and the generated low-pressure steam is compressed by the steam compressor 41 to generate high-temperature steam. The water supply pipe is provided with a pressure reducing valve 45.

[0026] In the low-pressure steam generator 43, a portion of the low-temperature water is vaporized to become low-pressure steam below atmospheric pressure. The low-pressure steam and the low-temperature water are separated, and the low-pressure steam is guided to the steam compressor 41, while the low-temperature water is sent to the heat exchanger 32 by the low-temperature water circulation pump 44.

[0027] The steam compressor 41 is driven by a motor connected to the grid power 20 via an inverter 9, and compresses low-pressure steam to high temperature and pressure to generate high-temperature steam. The high-temperature steam is supplied as a heat source for process heating and the like to steam-using equipment 300 in the factory.

[0028] The steam-using equipment 300 in the factory is connected to the steam compressor 41 by a first steam pipe 72, and the first steam pipe 72 has a valve 59. High-temperature steam is supplied to the steam-using equipment 300 from the steam compressor 41 via the first steam pipe 72.

[0029] The first steam pipe 72 is connected to pipes 94, 95 connected to the heat exchangers 26, 27, respectively, and to pipes 96, 97 connected to the expanders 10, 11, respectively. The pipes 94, 95 have valves 55, 56, respectively, and the pipes 94, 95 have valves 57, 58, respectively.

[0030] The power generation unit 3 includes expanders 10, 11 driven by compressed air, generators 12, 13 driven by the expanders 10, 11 to generate electricity, a power conditioner 14 that converts the voltage of the generated electricity, and heat exchangers 26, 27 that heat the compressed air at the inlets of the expanders 10, 11.

[0031] The expander 10 is responsible for the high-stage expansion stroke, and the expander 11 is responsible for the low-stage expansion stroke. The power generation unit 3 performs two-stage expansion by the high-stage expansion stroke and the low-stage expansion stroke.

[0032] The generator 12 is mechanically connected to the expander 10, and the generator 13 is mechanically connected to the expander 11. The generators 12, 13 generate power (power regeneration) by being driven by the expanders 10, 11. The generators 12, 13 are connected to grid power 20 via a power conditioner 14, and return the regenerated power to the grid power 20.

[0033] The compressed air energy storage device 100 also includes a control device 80. The control device 80 controls the operation of the air compressors 6, 7 and the steam compressor 41, and controls the opening and closing of valves 51, 52, 53, 54, 55, 56, 57, 58, and 59 in accordance with the demand for compressed air, the demand for high-temperature steam, and the demand for electricity in the factory.

[0034] The operation of the compressed air energy storage device 100 will now be described.

[0035] First, the operation of generating and storing compressed air will be described.

[0036] Motors 4 and 5 connected to grid power 20 utilizing renewable energy or the like are driven by input power from the grid power 20. Two-stage compression is performed by air compressor 6 driven by motor 4 and air compressor 7 driven by motor 5.

[0037] The air compressor 6 draws in the atmosphere from the intake port and performs the first stage adiabatic compression. The compressed air discharged from the discharge port of the air compressor 6 is heat exchanged with the heat storage medium in the heat exchanger 24, and then drawn into the air compressor 7.

[0038] The compressed air sucked into the air compressor 7 is further adiabatically compressed in a second stage by the air compressor 7, and becomes high-pressure, high-temperature state. This compressed air is heat exchanged with the heat storage medium in the heat exchanger 25.

[0039] The heat exchangers 24 and 25 exchange heat between the high-temperature compressed air and the heat storage medium that is branched off and supplied from the low-temperature side heat storage tank 22. This heat exchange causes the low-temperature heat storage medium to become hot, and is stored in the high-temperature side heat storage tank 21. On the other hand, the temperature of the compressed air that has exchanged heat with the heat storage medium in the heat exchanger 25 decreases, and the compressed air flows into the pressure storage tank 8 and is stored therein.

[0040] With the above operation, the compressed air energy of the compressed air and the compressed heat generated when the compressed air is generated in the pneumatic unit is stored in the pressure storage tank 8 for the compressed air and in the heat storage tank 21 for the compressed heat.

[0041] Next, the operation of supplying compressed air will be described.

[0042] The compressed air stored in the accumulator tank 8 is sequentially supplied from the accumulator tank 8 to the air-using devices 200 .

[0043] In addition, as described later, the compressed air stored in the accumulator tank 8 is also used for power generation by expansion machines 10 and 11. Therefore, a pressure higher than the pressure used in the air-using equipment 200 in the factory is stored in the accumulator tank 8. When the pressure in the accumulator tank 8 is significantly different from the pressure used in the air-using equipment 200 in the factory and the pressure used is low, the valve 51 of the first air pressure pipe 71 that supplies the air from the accumulator tank 8 to the air-using equipment 200 is closed, and the valve 52 of the pipe 91 that supplies the air to the heat exchanger 26 is opened, and the compressed air flows into the expander 10 through the heat exchanger 26, and is decompressed and expanded by the expander 10 to the pressure used in the air-using equipment 200. Then, the valve 54 of the pipe 93 is opened to return the compressed air to the first air pressure pipe 71 and supply it to the air-using equipment 200. At this time, the generator 12 is driven by the expander 10, and the generator 12 performs a power generation operation.

[0044] When the pressure in the accumulator tank 8 drops and approaches the pressure used in the air-using equipment 200, the valve 52 of the piping 91 supplying air to the heat exchanger 26 is closed, and the valve 51 of the first air pressure piping 71 supplying air from the accumulator tank 8 to the air-using equipment 200 is opened, and the pressure in the accumulator tank 8 is reduced and adjusted to supply air directly to the air-using equipment 200.

[0045] Next, the operation of supplying high-temperature steam will be described.

[0046] High-temperature steam is generated in a boiler unit 40. In a low-pressure steam generator 43, low-temperature water flowing in from a gas-liquid separator 42 via a water supply pipe is separated into gas and liquid, and the liquid low-temperature water is sent to the heat exchanger 32 by a low-temperature water circulating pump 44.

[0047] The heat storage medium stored in the heat storage tank 21 is supplied to the heat exchanger 32 by the pump 28, where it exchanges heat with low-temperature water flowing in from the low-pressure steam generator 43, heating the low-temperature water. A part of the heated low-temperature water vaporizes to become low-pressure steam below atmospheric pressure, which is separated into gas and liquid and then sucked into the steam compressor 41. The low-pressure steam is compressed by the steam compressor 41 to a high-temperature and high-pressure state, passes through the gas-liquid separator 42, and is supplied from a steam pipe as a heat source for process heating in a factory or the like.

[0048] The condensed water separated in the gas-liquid separator 42 heats and exchanges heat with the supply water to the low-pressure steam generator 43 in the medium-temperature water heat recovery heat exchanger 47, and then is reduced in pressure to a low level by the pressure reducing valve 45 and returned to the low-pressure steam generator 43.

[0049] As described later, the high-temperature steam generated in the boiler unit 40 is also used for expansion power generation by the expanders 10 and 11. For expansion power generation, valves 55, 56, 57, and 58 that supply high-temperature steam to pipes 94, 95, 96, and 97 connected to the heat exchangers 26 and 27 and the suction ports of the expanders 10 and 11 are opened to supply high-temperature steam to the power generation unit 3.

[0050] Next, a power generating operation in which the generator is driven by compressed air to generate power will be described.

[0051] The compressed air stored in the accumulator tank 8 is supplied to the heat exchanger 26 by opening the valve 52 of the pipe 91. In the heat exchanger 26, the compressed air is heated to a high temperature by heat exchange with high-temperature steam supplied from the boiler unit 40, and the high-temperature compressed air is drawn into the expander 10 and undergoes the first stage of adiabatic expansion. This drives the expander 10.

[0052] The air adiabatically expanded by the expander 10 is supplied to the heat exchanger 27. In the heat exchanger 27, the compressed air is heated to a high temperature by exchanging heat with high-temperature steam supplied from the boiler unit 40, and the compressed air is then drawn into the expander 11, where it undergoes a second stage of adiabatic expansion. This drives the expander 11. The compressed air adiabatically expanded by the expander 11 is again in a low-temperature, low-pressure state, and is released to the atmosphere from the discharge port of the expander 11.

[0053] By driving the expanders 10 and 11, which perform two-stage expansion, electricity is generated by the generator 12 driven by the expander 10 and the generator 13 driven by the expander 11, and the generated electricity is supplied to grid power 20 via a power conditioner 14.

[0054] Through the above operations, the compressed air energy stored as compressed air and heat of compression can be used to supply compressed air, high-temperature steam, and generate / supply electricity.

[0055] The operating modes of the compressed air energy storage device 100 will now be described.

[0056] In the operation mode 1, only compressed air storage is performed. The compressed air energy storage device 100 performs an operation of generating compressed air, storing the compressed air in the pressure storage tank 8, and storing the heat of compression in the heat storage tank 21.

[0057] In the operation mode 2, only compressed air is supplied. The compressed air energy storage device 100 performs the operation of supplying compressed air.

[0058] Here, when compressed air close to the pressure used by the air pressure-using device 200 is stored in the accumulator tank 8, the pressure is reduced and adjusted by the valve 51 of the first air pressure pipe 71 to supply compressed air (operation mode 2-1).

[0059] On the other hand, when a pressure sufficiently high relative to the operating pressure of the air-using equipment 200 has been accumulated, the valves 52 and 54 are opened, and the air is decompressed by adiabatic expansion in the expander 10, and then compressed air is supplied through the first air pressure piping 71 (operation mode 2-2). When adiabatic expansion is performed in the expander 10, electricity is also generated at the same time, so electricity is supplied together with the compressed air.

[0060] Furthermore, by providing a plurality of pressure accumulator tanks 8, it is possible to generate electricity according to the demand for electricity.

[0061] When power supply is required, compressed air is supplied from the accumulator tank 8, in which high-pressure compressed air is stored, and expanded adiabatically by the expander 10, thereby supplying compressed air and power simultaneously. When the pressure in the accumulator tank 8 approaches the operating pressure of the air-using device 200, the supply is switched to another accumulator tank 8 in which high-pressure compressed air is stored, and the supply of compressed air and power is continued.

[0062] When power supply is not required, compressed air is supplied from the pressure accumulator tank 8 storing a pressure close to the operating pressure of the air-using device 200 through the valve 51, and when the pressure falls below the operating pressure of the air-using device 200, the pressure is switched to another pressure accumulator tank 8 storing a lower pressure, and compressed air is supplied through the valve 51.

[0063] In the operation mode 3, compressed air storage and compressed air supply are performed simultaneously. The compressed air energy storage device 100 simultaneously performs a charging operation of generating and storing compressed air, and an operation of supplying compressed air.

[0064] The air compressors 6, 7 operate in a storage mode in which the compressed air is compressed to a high pressure, and the compressed air in the accumulator tank 8 is supplied by adiabatic expansion in the expander 10 (operation mode 3-1) or by pressure reduction adjustment in the valve 51 (operation mode 3-2).

[0065] In this case, when a plurality of accumulator tanks 8 are prepared, the accumulator tank used for the compressed air storage operation and the accumulator tank used for the compressed air supply may be different tanks.

[0066] In addition, since a high-temperature heat storage medium is also stored in the heat storage tank 22 by operating the air compressors 6 and 7, the boiler unit 40 is driven to generate high-temperature steam, and the compressed air to be adiabatically expanded is heated in the heat exchanger 26, or the compressed air is directly mixed with the high-temperature steam to heat the compressed air and then sent to the expander 10, thereby increasing the amount of power generation. When heating in the heat exchanger 26, the valve 56 is opened and the high-temperature steam is supplied to the heat exchanger 26 (operation mode 3-1-1). When directly mixing, the valve 58 is opened and the high-temperature steam is supplied to the expander 10 together with the compressed air (operation mode 3-1-2).

[0067] In the operation mode 4, only high temperature steam is supplied. The compressed air energy storage device 100 operates to supply high temperature steam.

[0068] At this time, if a high-temperature heat storage medium is stored in the heat storage tank 21, the air compressors 6 and 7 are not operated and the boiler unit 40 is operated.

[0069] In operation mode 5, compressed air storage and high-temperature steam supply are performed simultaneously. When there is a demand for steam in the steam-using equipment 300 and the high-temperature heat storage medium stored in the heat storage tank 21 is insufficient, the air compressors 6 and 7 are operated to exchange the heat of compression with the heat storage medium in the heat exchangers 24 and 25, and the heat is supplied to the boiler unit 40. At that time, the compressed air is stored in the pressure storage tank 8.

[0070] In operation mode 6, compressed air and high-temperature steam are supplied simultaneously. Compressed air is supplied from the pressure accumulator tank 8, and high-temperature steam supplies heat from the heat storage medium in the heat storage tank 21 to the boiler unit 40. High-temperature steam is generated in the steam compressor 41 and supplied through the valve 59.

[0071] Here, when either the compressed air or the heat of compression stored in the pressure accumulator tank 8 or the heat accumulator tank 21 runs short, the air compressors 6, 7 are operated to supply compressed air and heat to the pressure accumulator tank 8 and the heat accumulator tank 21. The supply is based on the amount of compressed air and high-temperature steam used (demand) in the factory, but the same amounts are not necessarily required at the same time. The air compressors 6, 7 are operated according to the demand for either compressed air or compressed heat, whichever is insufficient, and the surplus is stored in the pressure accumulator tank 8 or the heat accumulator tank 21 and used for the next supply. In other words, the supply of compressed air and high-temperature steam is leveled out in the pressure accumulator tank 8 and the heat accumulator tank 21.

[0072] In the operation mode 7, only power generation is performed. The compressed air energy storage device 100 operates to drive the expanders 10 and 11 with compressed air, and to drive the generators 12 and 13 to generate power.

[0073] At the same time, the boiler unit 40 is driven to supply high-temperature steam to the heat exchangers 26 and 27 to heat the compressed air, thereby increasing the amount of electricity generated (operation mode 7-1). In addition, high-temperature steam can be directly mixed into the compressed air through valves 57 and 58 to heat it (operation mode 7-2).

[0074] Immediately after the expansion machines 10, 11 start operating, heating is performed by direct mixing, which can raise the temperature more quickly, and when the temperatures of the heat exchangers 26, 27 have risen sufficiently, heating is switched to using the heat exchangers 26, 27. That is, immediately after the start of operation, valves 55, 56, 57, 58 are opened to supply high-temperature steam to the heat exchangers 26, 27 and directly mix it with the compressed air, and after the outlet air temperature of the heat exchangers 26, 27 has risen sufficiently, the valves 57, 58 are closed to end the direct mixing.

[0075] It is also possible to operate the system to generate power by supplying only compressed air to the expanders 10 and 11 without operating the boiler unit 40 (operation mode 7-3). In this case, the amount of power generated is lower than when high-temperature compressed air flows into the expanders 10 and 11.

[0076] In the operation mode 8, power generation and compressed air supply are performed simultaneously. The compressed air energy storage device 100 simultaneously performs an operation of driving a generator with compressed air to generate power, and an operation of supplying compressed air.

[0077] In this case, there are three operation modes: the first is a mode in which adiabatic expansion power is generated by the expander 10 and compressed air is supplied through valves 52 and 54 (operation mode 8-1), the second is a mode in which compressed air is reduced in pressure and adjusted by valve 51 and compressed air is supplied while valves 52 and 53 are also opened to simultaneously perform expansion power generation by the expanders 10 and 11 (operation mode 8-2), and the third is a mode in which the boiler unit 40 is also operated at the same time, compressed air is heated by high-pressure steam, and then expansion power generation is performed (operation mode 8-3). These modes switch operation according to the amount of power generation required along with the supply of compressed air, and when more power generation is required, the operation mode switches from 8-1 to 8-2, and from 8-2 to 8-3.

[0078] Furthermore, when a plurality of accumulator tanks 8 are used, the accumulator tank 8 used to drive the expander and the accumulator tank 8 used to supply compressed air are different tanks.

[0079] In the operation mode 9, high-temperature steam supply and power generation supply are performed simultaneously. The compressed air energy storage device 100 performs the operation of supplying high-temperature steam and the operation of generating power simultaneously.

[0080] The boiler unit 40 generates high-temperature steam and supplies the high-temperature steam through a valve 59, and also heats compressed air, thereby heating the compressed air to be sucked into the expanders 10 and 11 at a high temperature.

[0081] At this time, if compressed air is stored in the accumulator tank 8, valves 52, 53, 55, 56, 57, and 58 are opened, the compressed air in the accumulator tank 8 is heated by the heat exchangers 26 and 27 and the above-mentioned direct mixing, the expanders 10 and 11 are driven, and electricity is generated by the generators 12 and 13 (operation mode 9-1).

[0082] When there is not enough compressed air stored in the storage tank 8 for expansion power generation, there are two operation modes: one is a mode in which the air compressors 6 and 7 are operated to supply compressed air (operation mode 9-2-1), and the other is a mode in which the valves 52, 55, and 56 are closed and the expanders 10 and 11 are driven only by high-temperature steam without using compressed air (operation mode 9-2-2). This mode is switched according to the requirements for power supply and demand adjustment, which will be described later.

[0083] The switching of the operation modes of the compressed air energy storage device 100 and the adjustment of power supply and demand will be described.

[0084] When a solar power generation device 18 and a wind power generation device 19 are connected to grid power 20 and electricity derived from renewable energy generation is used, if the amount of electricity generated from renewable energy exceeds the amount of electricity used and surplus electricity is generated, the compressed air energy storage device 100 operates in operation mode 1 for storing compressed air, and stores the surplus electricity as compressed air and compressed heat.

[0085] At this time, when the demand for compressed air in the air-using equipment 200 is high and the amount of air used is large, the compressed air energy storage device 100 operates in operation mode 3 in which compressed air is stored and compressed air is supplied at the same time. At this time, the air used by the air-using equipment 200 uses the compressed air stored in the accumulator tank 8.

[0086] In addition, when the demand for high-temperature steam in the steam-using equipment 300 is high and the amount of steam used is large, the compressed air energy storage device 100 operates in operation mode 5, which simultaneously stores compressed air and supplies high-temperature steam. At this time, the high-temperature steam used by the steam-using equipment 300 recovers the compression heat stored in the heat storage tank 21 in the boiler unit 40, and generates high-temperature steam in the steam compressor 41.

[0087] When there is no demand for operation of the air pressure using equipment 200 and the steam using equipment 300, for example when the production equipment in the factory is stopped, the equipment is operated in operation mode 1 in which only compressed air is stored.

[0088] The stored compressed air and heat of compression are also used as a heat source for supplying compressed air and generating high-temperature steam, so it is desirable to store a sufficient amount of compressed air during times when electricity demand is low.

[0089] In cases where a large amount of renewable energy is generated during the day, resulting in surplus power, operating the vehicle in charging mode at night can help to level out power usage between day and night, and can also reduce power costs by reducing grid power usage at night. Next, when the amount of renewable energy power generation is less than the amount of power used, the compressed air energy storage device 100 operates in operation mode 6, which supplies compressed air and high-temperature steam. The compressed air in the pressure storage tank 8 is supplied to the air-using equipment 200, the compression heat stored in the heat storage tank 21 is recovered by the boiler unit 40, high-temperature steam is generated by the steam compressor 41 and supplied to the steam-using equipment 300, and the operation of the air compressors 6 and 7 is stopped.

[0090] Since no electricity is required to create compressed air, electricity demand can be reduced by 10 to 20% of the factory electricity. Also, the energy to generate high-temperature steam is used to operate the steam compressor 41, which reduces the use of fossil fuels such as kerosene and gas in combustion boilers, and significantly reduces carbon dioxide emissions.

[0091] Also, when the amount of renewable energy power generation is small and there is no operation request from the air pressure using equipment 200, the supply of compressed air from the pressure accumulator tank 8 is stopped and the compressed air from the pressure accumulator tank 8 is used to drive the expanders 10, 11 to generate power using the expanders. At this time, if there is an operation request from the steam using equipment 300 and the boiler unit 40 is operating, it is operated in operation mode 9-1. However, high pressure steam is supplied preferentially to the steam using equipment 300 and is not supplied to the heat exchangers 26, 27, and a small amount of it is heated by directly mixing it with the compressed air through valves 57, 58, or only expansion power generation is performed without heating the air.

[0092] When the compressed air in the accumulator tank 8 becomes low, the operation mode is switched to 9-2-2. When there is a surplus in the amount of steam generated in the boiler unit 40 compared to the amount of high-temperature steam supplied to the steam-using equipment 300, it is possible to reduce power consumption by reducing power demand while still generating power using only high-temperature steam. When there is no surplus in the amount of steam generated in the boiler unit 40, priority is given to the supply of high-temperature steam to the steam-using equipment 300, and power generation is stopped.

[0093] Furthermore, when there is no operation request from the steam-using equipment 300, operation is performed in operation mode 7, and high-temperature steam is not supplied to the steam-using equipment 300 but is used to heat the compressed air. This makes it possible to make up for any shortfall in the amount of power generated by expansion power generation, thereby reducing the power demand for the grid power. When there is no operation request from the steam-using equipment 300, operation is switched to operation mode 7-3, operation of the boiler unit 40 is stopped, and expansion power generation is performed without heating the compressed air, making it possible to further reduce the amount of power used.

[0094] An operation control process executed by the control device 80 of the compressed air energy storage device 100 will be described.

[0095] FIG. 7 is a flowchart of an operation control process executed by the control device 80 of the compressed air energy storage device 100 of the first embodiment.

[0096] The control device 80 determines whether or not there is a demand for compressed air from the air pressure using equipment 200 (step S101). If there is no demand for compressed air from the air pressure using equipment 200 in step S101, the process proceeds to step S107.

[0097] On the other hand, if there is a demand for compressed air from the air-using equipment 200 in step S101, it is determined whether compressed air is stored in the accumulator tank 8 (step S102). If compressed air is not stored in the accumulator tank 8 in step S102, the control device 80 operates the air compressors 6, 7 to generate compressed air and compressed heat, stores the generated compressed air and compressed heat in the accumulator tank 8 and the heat storage tank 21 (step S103), controls the valve 51 to reduce the pressure of the compressed air, and supplies the compressed air to the air-using equipment 200 (step S104), and proceeds to step S107.

[0098] On the other hand, if compressed air is stored in the accumulator tank 8 in step S102, it is determined whether or not the pressure of the compressed air stored in the accumulator tank 8 is higher than the operating pressure of the air-using device 200 (step S105). If the pressure of the compressed air stored in the accumulator tank 8 is approximately the same as the operating pressure of the air-using device 200 (NO in step S105), the process proceeds to step S104, where the valve 51 is controlled to reduce the pressure of the compressed air and supply the compressed air to the air-using device 200.

[0099] On the other hand, if the pressure of the compressed air stored in the accumulator tank 8 in step S105 is higher than the operating pressure of the air-using equipment 200, the valves 52, 54 are opened, and the compressed air is reduced in pressure by adiabatic expansion in the expander 10 and then supplied through the first air pressure piping 71 (step S106), and the process proceeds to step S107.

[0100] In step S107, the control device 80 determines whether or not there is a demand for high-temperature steam from the steam-using equipment 300. If there is no demand for high-temperature steam from the steam-using equipment 300 in step S107, the process proceeds to step S111.

[0101] On the other hand, if there is a demand for high-temperature steam from the steam-using equipment 300 in step S107, it is determined whether or not compression heat has been stored in the heat storage tank 21 (step S108). If compression heat has not been stored in the heat storage tank 21 in step S108, the control device 80 operates the air compressors 6, 7 to generate compressed air and compression heat, and stores the generated compressed air and compression heat in the pressure storage tank 8 and the heat storage tank 21 (step S109).

[0102] Next, the control device 80 operates the steam compressor 41 to generate high-temperature steam, controls the valve 59 to supply the high-temperature steam to the steam-using equipment 300 (step S110), and proceeds to step S111.

[0103] On the other hand, if the heat of compression has been stored in the heat storage tank 21 in step S108, the control device 80 skips step S109 and proceeds to step S110.

[0104] In step S111, the control device 80 determines whether or not the power usage in the factory is high and there is a demand for power. If there is no demand for power in step S111, the process proceeds to step S118.

[0105] On the other hand, if there is a demand for electricity in step S111, it is determined whether or not compressed air is stored in the accumulator tank 8 (step S112). If compressed air is stored in the accumulator tank 8 in step S110, the control device 80 determines whether or not the steam compressor 41 is operating (step S113).

[0106] If the steam compressor 41 is operating in step S113, the control device 80 opens valves 52, 53, and 54 to send compressed air from the accumulator tank 8 to the expanders 10 and 11, opens valves 55 and 56 or valves 57 and 58 to heat the compressed air with high-pressure steam, and drives the generators 12 and 13 with the expanders 10 and 11 to generate electricity (step S114), and then proceeds to step S118.

[0107] If the steam compressor 41 is not operating in step S113, the control device 80 opens valves 52, 53, and 54 to send compressed air from the accumulator tank 8 to the expanders 10 and 11, and supplies only compressed air to the expanders 10 and 11 to generate electricity (step S115), and then proceeds to step S118.

[0108] If compressed air is not stored in the accumulator tank 8 in step S116, the control device 80 determines whether the steam compressor 41 is operating (step S116).

[0109] If the steam compressor 41 is operating in step S116, the controller 80 opens the valves 57, 58 to send high-pressure steam to the expanders 10, 11 and supplies only high-temperature steam to the expanders 10, 11 to generate electricity (step S117), and then proceeds to step S118.

[0110] If it is determined in step S116 that the steam compressor 41 is not operating, no power generation is performed and the process proceeds to step S118.

[0111] In step S118, the control device 80 determines whether or not the amount of power generated from renewable energy exceeds the amount of power used, resulting in the generation of surplus power.

[0112] If surplus electricity is generated in step S118, the control device 80 operates the air compressors 6, 7 to generate compressed air and compressed heat, and stores the generated compressed air and compressed heat in the pressure storage tank 8 and the heat storage tank 21 (step S119), and then ends the processing.

[0113] On the other hand, if surplus power is not generated in step S118, the control device 80 ends the process.

[0114] As described above, in this embodiment, the compressed air and compression heat generated by the air compressors 6, 7 are stored in the pressure storage tank 8 and the heat storage tank 21, the compressed air is used both for compressed air supply and for generating electricity by driving the expanders 10, 11 and the generators 12, 13 directly connected thereto, and the compression heat is used both for high-temperature steam supply and for heating the expander inlet air to drive the generators.Furthermore, the pressure storage tank 8 and the heat storage tank 21 make it possible to shift the time from generation to use, making it possible to adjust the power supply and demand within the factory, and it is possible to provide a compressed air energy storage device that integrates an air compressor and a steam boiler, which can be used as the main power source for renewable energy generation and reduce grid power consumption. EXAMPLES

[0115] 2 is a diagram showing an example of a schematic configuration of a compressed air energy storage device according to Example 2. In the following, the same components as those in Example 1 are given the same reference numerals, and duplicated explanations will be omitted.

[0116] In the second embodiment, the heat storage medium flows through a circuit that branches off from the heat storage tank 21 to the heat exchanger 32, and the heat storage medium flows through circuits that connect to the heat exchangers 34 and 35. The fluid circuits that connect to the heat exchangers 34 and 35 can be opened and closed by valves 61, 62, 63, and 64, respectively. These fluid circuits are provided with pumps 28 and 29 for transporting the heat storage medium.

[0117] Next, a power generating operation in which the generator is driven by compressed air to generate power will be described.

[0118] The compressed air stored in the pressure accumulator tank 8 is supplied to the heat exchangers 34 and 35 by opening the valve 52. In the heat storage unit 2, the high-temperature heat storage medium in the heat storage tank 21 is supplied to the heat exchangers 34 and 35 by opening the valves 61, 63, and 64, and the compressed air is heated to the heat storage medium temperature. The compressed air heated in the heat exchanger 35 passes through the heat exchanger 26 and is then supplied to the expander 10 to drive the expander 10.

[0119] The first stage expansion operation is carried out in the expander 10, and the discharged compressed air is decompressed and expanded, passed through valve 53 and supplied to the heat exchanger 34, where it is heated again to the heat storage medium temperature, and then passed through the heat exchanger 27 and sucked into the expander 11, driving the expander 11.

[0120] The expander 11 performs a second-stage expansion operation, and then the refrigerant is released into the atmosphere. The expanders 10 and 11 are directly connected to generators 12 and 13, respectively, and generate electricity. The generated electricity is voltage-converted by a power conditioner 14 and supplied to the grid power 20.

[0121] On the other hand, when the valves 61, 63, and 64 are closed and the valve 62 is opened, the heat storage medium flows into the heat exchanger 32 and heats the low-pressure steam in the heat exchanger 32. In this case, the stored heat is used as a heat source for high-temperature steam generated in the boiler unit 40.

[0122] The compressed air is heated to a high temperature by heat exchange with high-temperature steam supplied from the boiler unit 40, and the compressed air is sucked into the expander 10 and undergoes the first stage of adiabatic expansion. This drives the expander 10.

[0123] The air adiabatically expanded by the expander 10 is supplied to the heat exchanger 27. The compressed air is heated to a high temperature by exchanging heat with high-temperature steam supplied from the boiler unit 40, and the compressed air is sucked into the expander 11 and undergoes a second stage of adiabatic expansion. This drives the expander 11. The air adiabatically expanded by the expander 11 is again in a low-temperature, low-pressure state, and is released to the atmosphere from the discharge port of the expander 11.

[0124] By driving the expanders 10 and 11, which perform two-stage expansion, electricity is generated by the generator 12 driven by the expander 10 and the generator 13 driven by the expander 11, and the electricity is supplied to the grid power 20 via the power conditioner 14.

[0125] The switching of operation modes and the adjustment of power supply and demand of the compressed air energy storage device 100 will be described.

[0126] When the amount of renewable energy power generation is less than the amount of power used and there is no operation request from the air pressure using equipment 200 or the steam using equipment 300, the system is operated in operation mode 7. When the system is operated in operation mode 7-3 to reduce the amount of power used, the operation of the boiler unit 40 is stopped and compressed air heating using the heat exchangers 26, 27 is not performed.

[0127] Therefore, in order to prevent the amount of power generation from decreasing due to the low temperature of the compressed air drawn into the expanders 10 and 11, the valves 61, 63, and 64 are opened to heat the compressed air using the heat storage medium. This allows the temperature of the compressed air at the inlet of the expander to be restored to the temperature of the heat storage medium, making it possible to prevent a decrease in the amount of power generation.

[0128] As described above, in this embodiment, the heat of compression stored in the heat storage tank 21 can be used for both heating the compressed air for power generation and supplying high-temperature steam, thereby preventing a decrease in the amount of power generation during power supply and demand adjustments and providing a compressed air energy storage device that can achieve high system efficiency. EXAMPLES

[0129] 3 is a diagram showing an example of a schematic configuration of a compressed air energy storage device according to Example 3. In the following, the same components as those in Examples 1 and 2 are given the same reference numerals, and duplicated explanations are omitted.

[0130] In the third embodiment, the low-temperature water separated in the low-pressure steam generator 43 is sent to a radiator 49 by a low-temperature water circulation pump 44. The radiator 49 forms a refrigeration cycle together with a compressor 48, a heat absorber 46, a heat exchanger 32, and an expansion valve 50, and the low-temperature water is heated in the radiator 49 by the refrigerant compressed by the compressor 48.

[0131] In the refrigeration cycle, after passing through the radiator 49, the refrigerant is decompressed through the expansion valve 50, and then the refrigerant absorbs heat in the heat absorber 46 and the heat exchanger 32, and returns to the compressor 48. In the heat absorber 46, heat is exchanged with waste heat such as hot water heat in the factory, and waste heat from other equipment is recovered, and in the heat exchanger 32, heat is exchanged between the heat storage medium and the refrigerant in the refrigeration cycle. Carbon dioxide, hydrocarbons, fluorocarbon-based refrigerants, etc. are used as the refrigerant.

[0132] The steam compressor 41 sucks in low-pressure steam from the low-pressure steam generator 43, compresses it to high temperature and pressure, and supplies the high-temperature steam as a heat source for process heating in factories and the like.

[0133] Next, the operation of supplying high-temperature steam will be described.

[0134] High-temperature steam is generated in a boiler unit 40. In a low-pressure steam generator 43, low-temperature water flowing in from a gas-liquid separator 42 via a water supply pipe is separated into gas and liquid, and the liquid low-temperature water is sent to a radiator 49 by a low-temperature water circulating pump 44.

[0135] In the radiator 49, the refrigerant that has absorbed heat from the heat absorber 46 and the heat exchanger 32 exchanges heat with the low-temperature water flowing in from the low-pressure steam generator 43, heating the low-temperature water. A part of the heated low-temperature water vaporizes to become low-pressure steam below atmospheric pressure, which is separated into gas and liquid and then sucked into the steam compressor 41. The low-pressure steam is compressed by the steam compressor 41 to a high temperature and high pressure, passes through the gas-liquid separator 42, and is supplied from a steam pipe as a heat source for process heating in a factory or the like.

[0136] The condensed water separated in the gas-liquid separator 42 heats and exchanges heat with the feed water to the low-pressure steam generator 43 in the medium-temperature water heat recovery heat exchanger 47, and then is reduced in pressure to a low level by the pressure reducing valve 45 and returned to the low-pressure steam generator 43.

[0137] The high-temperature steam generated in the boiler unit 40 is also used for expansion power generation by the expander. For expansion power generation, the valves supplying the heat exchangers 26, 27 and the suction pipes of the expanders 10, 11 are opened to supply high-temperature steam to the power generation unit 3.

[0138] The switching of operation modes and the adjustment of power supply and demand of the compressed air energy storage device 100 will be described.

[0139] When the amount of renewable energy power generation is less than the amount of power used, there is no operation request from the air pressure using equipment 200, and there is an operation request from the steam using equipment 300, the system is operated in operation mode 9-1. High pressure steam is supplied to the steam using equipment 300 with priority, and is supplied to the heat exchangers 26, 27 only when there is a surplus in the high temperature steam supply.

[0140] In addition, since the boiler unit 40 uses the hot water exhaust heat from outside the system as a heat source in addition to the heat storage medium stored in the heat storage tank 21, the capacity of the boiler unit 40 can be increased and high-temperature steam supply and compressed air heating can be performed simultaneously.

[0141] As described above, in this embodiment, in addition to the heat of compression stored in the heat storage tank 21, other exhaust heat can be used as a heat source for supplying high-temperature steam, so that a compressed air energy storage device can be provided that can increase the amount of power generated during power supply and demand adjustment and achieve high system efficiency. EXAMPLES

[0142] 4 is a diagram showing an example of a schematic configuration of a compressed air energy storage device according to Example 4. In the following, the same components as those in Examples 1 to 3 are given the same reference numerals, and duplicated explanations will be omitted.

[0143] In the fourth embodiment, the refrigeration cycle of the boiler unit 40 reduces the pressure of the refrigerant in the expansion valve 50 after passing through the radiator 49, and then absorbs heat in the heat exchanger 32 and the heat absorber 46, and returns to the compressor 48. In the heat exchanger 32, heat is exchanged between the heat storage medium and the refrigerant in the refrigeration cycle, and in the heat absorber 46, heat is exchanged with waste heat such as hot water waste heat in the factory, and waste heat recovery is performed for other equipment. Carbon dioxide, hydrocarbons, fluorocarbon-based refrigerants, etc. are used as the refrigerant.

[0144] The difference from the third embodiment is the order of the heat absorber 46 and the heat exchanger 32 in the refrigeration cycle. In the third embodiment, the heat exchanger 32 is disposed downstream of the heat absorber 46, but in this embodiment, the heat absorber 46 is disposed downstream of the heat exchanger 32.

[0145] As described above, in this embodiment, the heat absorber 46 is disposed downstream of the heat exchanger 32, so that even if the temperature of the heat storage medium after heat exchange in the heat exchangers 34, 35 is lower than the hot water exhaust heat temperature, heat can be effectively absorbed, and the supply capacity of high-temperature steam can be increased. EXAMPLES

[0146] 5 is a diagram showing an example of a schematic configuration of a compressed air energy storage device according to Example 5. In the following, the same components as those in Examples 1 to 4 are given the same reference numerals, and duplicated explanations will be omitted.

[0147] In the fifth embodiment, the refrigeration cycle of the boiler unit 40 is made up of a compressor 48, a radiator 49, an expansion valve 50, and a heat absorber 46.

[0148] Both heat absorber 46 and heat exchanger 32 use hot water and exchange heat between the refrigerant and the heat storage medium. Hot water exhaust heat from other devices is supplied to heat exchanger 32 and heat absorber 46, where heat exchanger 32 absorbs heat from the heat storage medium after heat exchange in heat exchangers 26 and 27, and dissipates heat to the refrigerant in heat absorber 46. Carbon dioxide, hydrocarbons, fluorocarbon-based refrigerants, etc. are used as the refrigerant.

[0149] The order in which the hot water is supplied to the heat absorber 46 and the heat exchanger 32 can be changed. In FIG. 5, the hot water is circulated through the heat absorber 46 and then the heat exchanger 32, but the direction of circulation may be changed depending on the temperatures of the waste heat hot water from other devices and the low-temperature heat storage medium.

[0150] As described above, in this embodiment, by changing the direction of hot water circulation while maintaining the same configuration, it is possible to accommodate the temperature difference between the exhaust heat hot water and the low-temperature heat storage medium, thereby enabling efficient steam generation. EXAMPLES

[0151] 6 is a diagram showing an example of a schematic configuration of a compressed air energy storage device according to Example 6. In the following, the same components as those in Examples 1 to 5 are given the same reference numerals, and duplicated explanations will be omitted.

[0152] In the sixth embodiment, the refrigeration cycle of the boiler unit 40 is formed by a radiator 49, a compressor 48, a heat absorber 46, and an expansion valve 50. The heat absorber 46 absorbs heat from the atmosphere, and the radiator 49 heats low-temperature water with the refrigerant compressed by the compressor 48. Carbon dioxide, hydrocarbons, fluorocarbon-based refrigerants, etc. are used as the refrigerant.

[0153] The steam compressor 41 sucks in low-pressure steam from the low-pressure steam generator 43, compresses it to high temperature and pressure, and supplies the high-temperature steam as a heat source for process heating or the like in a factory or the like.

[0154] As described above, in this embodiment, the heat of compression stored in the heat storage tank 21 is used only to heat the compressed air during power generation, and heat is pumped from the atmosphere and used as a heat source for supplying high-temperature steam. It is possible to provide a compressed air energy storage device that can supply compressed air, high-temperature steam, and electricity by utilizing heat other than the heat of compression and the hot water exhaust heat of other equipment.

[0155] In each of the above embodiments, the renewable energy power generation device may be any device that utilizes energy that is constantly (or repeatedly) replenished by natural forces and that fluctuates irregularly, such as wind power, sunlight, solar heat, wave or tidal power, running water or tides, and geothermal heat. The compressed air energy storage device of each embodiment may also be applied to a case where the power demand of a factory fluctuates greatly depending on the operating state of equipment that consumes large amounts of power in the factory. The power transmission and distribution system is not limited to the general power transmission and distribution system of a power company, and may be a microgrid power system for a region or within a factory.

[0156] In addition, the air compressors 6, 7 and the expanders 10, 11 in each embodiment may be of a screw type, but the type of these rotary machines is not limited. The air compressors 6, 7 and the expanders 10, 11 may be of a scroll type, a turbo type, a reciprocating type, or the like.

[0157] In addition, in each embodiment, the air compressors 6, 7 and the expanders 10, 11 are each a two-stage compression / two-stage expansion type, but the air compressors and expanders may be a single-stage compression / single-stage expansion type, or a three or more stage compression / expansion type, or the number of stages may be different between compression and expansion. Furthermore, the compressed air energy storage device may be provided with a plurality of air compressors and expanders. Also, there may be configurations in which the number of motors and compressors is different (for example, when one motor drives multiple compressors), and configurations in which the number of generators and expanders is different (for example, when multiple expanders drive one generator). [Explanation of symbols]

[0158] 1 Pneumatic unit 2. Heat storage unit 3 Power Generation Unit 4,5 Motor 6,7 Air compressor 8. Accumulator tank 9. Inverter 10,11 Expander 12,13 Generator 14 Power conditioner 18. Solar power generation equipment 19 Wind power generation equipment 20 Grid Power 21 High temperature side heat storage tank 22 Low temperature heat storage tank 24,25 Heat exchanger 26,27 heat exchanger 28,29Pump 32 Heat exchanger 34,35 heat exchanger 40 Boiler unit 41 Steam Compressor 42 Gas-liquid separator 43 Low pressure steam generator 44 Low temperature water circulation pump 45 Pressure reducing valve 46 Heat sink 47 Medium temperature water heat recovery heat exchanger 48 Compressor 49 Heat sink 50 Expansion valve 51~64 Valve 71 First air pressure pipe 72 No. 1 steam pipe 100 Compressed air energy storage device

Claims

1. an air compressor for generating compressed air; a first heat exchanger for exchanging heat between the compressed air and a heat storage medium; an accumulator tank that stores the compressed air that has been heat exchanged in the first heat exchanger; a heat storage tank that stores the heat storage medium that has been heat exchanged in the first heat exchanger; a low-pressure steam generating device for generating low-pressure steam by heating water through heat exchange with the heat storage medium; a steam compressor for compressing the low pressure steam to generate high temperature steam; A generator for generating electrical power; an expander that drives the generator by the compressed air or the high-temperature steam, A compressed air energy storage device that supplies any one or more of the compressed air, the high temperature steam, and the electricity.

2. 2. The compressed air energy storage device according to claim 1, Further comprising a plurality of valves for opening and closing a pipe through which the compressed air or the high-temperature steam passes, The compressed air energy storage device further includes a control device that controls operation of the air compressor, operation of the steam compressor, and opening and closing of each of the plurality of valves in response to demand for the compressed air, the high-temperature steam, and the electricity.

3. 3. The compressed air energy storage device according to claim 2, The air conditioner further includes a heating means for heating the compressed air by the high-temperature steam or the heat storage medium, The expander is a compressed air energy storage device that drives the generator with the compressed air heated by the heating means.

4. 4. The compressed air energy storage device according to claim 3, The heating means is a compressed air energy storage device that heats the compressed air by heat exchange with the high-temperature steam.

5. 4. The compressed air energy storage device according to claim 3, The heating means is a compressed air energy storage device that heats the compressed air by mixing the high-temperature steam.

6. 4. The compressed air energy storage device according to claim 3, The heating means is a compressed air energy storage device that heats the compressed air by heat exchange with the heat storage medium.

7. 3. The compressed air energy storage device according to claim 2, The low-pressure steam generating device is a compressed air energy storage device that generates the low-pressure steam by heating the water through heat exchange with the heat storage medium.

8. 3. The compressed air energy storage device according to claim 2, a refrigerant compressor that compresses and heats a refrigerant; An expansion valve that reduces the pressure of the refrigerant, The low-pressure steam generating device is a compressed air energy storage device that heats the water by heat exchange with the refrigerant to generate the low-pressure steam.

9. 9. The compressed air energy storage device according to claim 8, The compressed air energy storage device further comprises a second heat exchanger that heats the refrigerant by heat exchange with the heat storage medium.

10. 9. The compressed air energy storage device according to claim 8, The compressed air energy storage device further comprises a heat sink for heating the refrigerant by heat exchange with hot water from another device.

11. 11. The compressed air energy storage device of claim 10, The compressed air energy storage device further includes a third heat exchanger that heats the hot water from the other equipment by heat exchange with the heat storage medium.

12. 9. The compressed air energy storage device according to claim 8, The compressed air energy storage device further comprising a second heat sink for heating the refrigerant by heat exchange with ambient air.

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