JP2023082959A - Compressed air energy storage system - Google Patents

Abstract

To provide a compressed air storage system capable of improving energy efficiency of a system by reusing heat absorbed in a compression stroke.SOLUTION: A system 100 includes: an air tank 40; a first heat exchanger 30A disposed downstream of a first compressor 10A; a second heat exchanger 30B disposed downstream of a second compressor 10B; a medium source 60 and a medium tank 50 that are connected in parallel with the first and second heat exchangers 30A, 30B; first flow control devices P1, V1 controlling a flow rate of a heating medium flowing to the first heat exchanger 30A; second flow control devices P1, V2 controlling a flow rate of the heating medium flowing to the second heat exchanger 30B; a first thermometer M1 measuring a first temperature of the heating medium flowing from the first heat exchanger 30A; a second thermometer M2 measuring a second temperature of the heating medium flowing from the second heat exchanger 30B; and a control device 90 controlling the first and second flow control devices P1, V1, V2 so that a difference between the first temperature and the second temperature falls within a predetermined range.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to compressed air energy storage systems.

Compressed air energy storage systems (CAES) are known in the prior art. CAES, for example, generates compressed air with a compressor and stores the compressed air during a time period when the selling price of electricity is low or there is surplus electricity. Conversely, CAES drives an expander with stored compressed air to supply power, for example, during times of high power demand.

For example, each of Patent Documents 1 to 6 discloses a CAES with multiple compressors. A heat exchanger is arranged downstream of each compressor, and the compressed air is cooled by the heat exchanger. The heat transfer medium that has absorbed heat in the compression process is used to heat the compressed air in the expansion process. With such a configuration, the heat absorbed in the compression process can be reused, and the energy efficiency of the system can be improved.

Japanese Patent Application Publication No. 2013-509530 JP 2017-160863 A JP 2018-182996 A JP 2019-173608 A JP 2020-84913 A Japanese Patent Publication No. 2020-528509

Further improvements in energy efficiency are desired in compressed air energy storage systems.

The present disclosure aims to provide a compressed air energy storage system that can improve energy efficiency.

A compressed air energy storage system according to one aspect of the present disclosure includes a plurality of compressors including at least a first compressor and a second compressor positioned downstream of the first compressor, and a compressor downstream of the plurality of compressors. An air tank that stores compressed air, a first heat exchanger that is arranged downstream of the first compressor and cools the compressed air from the first compressor, and a second compressor that is arranged downstream of the , a second heat exchanger for cooling the compressed air from the second compressor; a medium source that supplies a heat medium; a medium tank that is connected in parallel to the first heat exchanger and the second heat exchanger and recovers the heat medium from each of the first heat exchanger and the second heat exchanger; a first flow regulating device for regulating a first flow rate of heat medium flowing from the source to the first heat exchanger; and a second flow regulating device for regulating a second flow rate of heat medium flowing from the medium source to the second heat exchanger. a first thermometer for measuring a first temperature of the heat medium flowing from the first heat exchanger to the medium tank; and a second thermometer for measuring a second temperature of the heat medium flowing from the second heat exchanger to the medium tank. , a first flow rate adjustment to adjust the first flow rate and the second flow rate such that the difference between the first temperature from the first thermometer and the second temperature from the second thermometer is within a predetermined range; a controller for controlling the device and the second flow regulator.

Each of the first and second flow regulators may include at least one of a valve or a pump.

The compressed air energy storage system comprises a plurality of expanders including at least a first expander connected to an air tank and a second expander located downstream of the first expander; a third heat exchanger positioned to heat the compressed air to the first expander, the third heat exchanger being connected to the medium tank; a fourth heat exchanger for heating the compressed air to the machine, the fourth heat exchanger being connected to the medium tank in parallel to the third heat exchanger; and from the medium tank to the third heat exchanger. A third flow rate adjusting device for adjusting a third flow rate of the flowing heat medium; a fourth flow rate adjusting device for adjusting a fourth flow rate of the heat medium flowing from the medium tank to the fourth heat exchanger; a third thermometer that measures a third temperature of the heat medium;
a fourth thermometer for measuring a fourth temperature of the heat medium flowing from the fourth heat exchanger, the controller further comprising: a third temperature from the third thermometer; The third flow rate adjusting device and the fourth flow rate adjusting device may be controlled to adjust the third flow rate and the fourth flow rate so that the difference from the fourth temperature of is within a predetermined range.

Each of the third and fourth flow regulators may include at least one of a valve or a pump.

According to the present disclosure, energy efficiency can be improved.

1 is a schematic diagram illustrating a compressed air energy storage system according to an embodiment; FIG. FIG. 2 is a table showing an example of computer simulation conditions and results. FIG. 3 is a flow chart showing the operation of the control device in the compression process. FIG. 4 is a flow chart showing the operation of the control device in the expansion process.

Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Specific dimensions, materials, numerical values, and the like shown in such embodiments are merely examples for facilitating understanding, and do not limit the present disclosure unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are given the same reference numerals to omit redundant description, and elements that are not directly related to the present disclosure are omitted from the drawings. do.

FIG. 1 is a schematic diagram of a compressed air energy storage system 100 according to an embodiment. In FIG. 1, the solid line arrows indicate the flow of the heat medium, and the dashed line arrows indicate the air flow. In this disclosure, the compressed air energy storage system (CAES) 100 may also be referred to simply as the "system."

System 100 comprises compression system 101 and expansion system 102 . Specifically, the system 100 includes a plurality of compressors 10, a plurality of expanders 20, a plurality of heat exchangers 30, an air tank 40, a first medium tank 50, a second medium tank (medium source ) 60 and a control device 90 . System 100 may further comprise other components.

The system 100 generates compressed air with the compressor 10 in the compression system 101 and stores the compressed air in the air tank 40, for example, during a time period when the selling price of electricity is low or there is surplus electricity. For example, these may include daytime hours for solar power generation and nighttime hours for conventional power generation such as thermal power generation. The period of time for generating and storing compressed air is not limited to these.

Conversely, the system 100 drives the expander 20 with stored compressed air in the expansion system 102 to generate electricity, for example, during periods of high power demand or during emergencies. The period of time during which power is generated using compressed air is not limited to these. According to such a configuration, surplus power can be effectively used.

The multiple compressors 10 include at least a first compressor 10A and a second compressor 10B. In other embodiments, system 100 may include more than two compressors 10 . Each compressor 10 is driven by electric power and compresses the sucked air. A plurality of compressors 10 are connected in series and compress air in stages. The second compressor 10B is arranged downstream of the first compressor 10A in the air flow indicated by the dashed arrows. For example, the first compressor 10A sucks ambient air. In this embodiment, the second compressor 10B is connected to the air tank 40 via a second heat exchanger 30B, which will be described later. Air compressed by the second compressor 10B is stored in the air tank 40 .

The multiple expanders 20 include at least a first expander 20A and a second expander 20B. In other embodiments, the system 100 may comprise more than two expanders 20. Each expander 20 is driven by compressed air from an air tank 40 to generate electric power. The plurality of expanders 20 are connected in series and expand the compressed air from the air tank 40 step by step. The first expander 20A is connected to the air tank 40 via a third heat exchanger 30C, which will be described later. The second expander 20B is arranged downstream of the first expander 20A in the air flow indicated by the dashed arrows. The air expanded by the second expander 20B may be released to the outside environment, for example.

In this embodiment, the plurality of heat exchangers 30 are a first heat exchanger 30A and a second heat exchanger 30B of the compression system 101 and a third heat exchanger 30C and a fourth heat exchanger 30D of the expansion system 102. including. In other embodiments, the compression system 101 may include three or more heat exchangers 30, depending on the number of compressors 10, and the expansion system 102 may include three or more, depending on the number of expanders 20. of heat exchangers 30 may be included. In the heat exchanger 30, for example, oil may be used as a heat medium.

In compression system 101 , heat exchanger 30 is positioned downstream of each compressor 10 in the air flow to cool the air compressed by each compressor 10 . Specifically, the first heat exchanger 30A is arranged downstream of the first compressor 10A, and the second heat exchanger 30B is arranged downstream of the second compressor 10B. More specifically, the first heat exchanger 30A is arranged between the first compressor 10A and the second compressor 10B, and the second heat exchanger 30B is arranged between the second compressor 10B and the air tank 40. is placed between

As indicated by solid line arrows, the first heat exchanger 30A and the second heat exchanger 30B are connected in parallel to the second medium tank 60 . In this embodiment, the pipe L1 from the second medium tank 60 is branched, and the branched pipes L2 and L3 are connected to the first heat exchanger 30A and the second heat exchanger 30B, respectively. In another embodiment, each of the pipes L2 and L3 may extend directly from the second medium tank 60 instead of the pipe L1. The second medium tank 60 supplies the heat medium cooled by the expansion system 102 to each of the first heat exchanger 30A and the second heat exchanger 30B.

A pump P1 is provided in the pipe L1. Further, valves V1 and V2 are provided on the pipes L2 and L3, respectively. Pump P1 and valves V1 and V2 are communicably connected to controller 90 by wire or wirelessly, and controlled by controller 90 . The control device 90 adjusts the flow rate of the heat medium supplied from the second medium tank 60 to the pipe L1 by controlling the output of the pump P1. The controller 90 also adjusts the flow rates of the heat medium flowing through the pipes L2 and L3 by adjusting the opening degrees of the valves V1 and V2.

The control device 90 adjusts the first flow rate of the heat medium flowing from the second medium tank 60 to the first heat exchanger 30A by adjusting the output of the pump P1 and the opening of the valve V1. Therefore, in this embodiment, the pump P1 and the valve V1 function as a first flow control device.

The control device 90 adjusts the second flow rate of the heat medium flowing from the second medium tank 60 to the second heat exchanger 30B by adjusting the output of the pump P1 and the degree of opening of the valve V2. Therefore, in this embodiment, the pump P1 and the valve V2 function as a second flow control device.

The first flow rate adjusting device and the second flow rate adjusting device are not limited to the configurations described above. For example, in other embodiments, the first flow regulator and the second flow regulator may further include additional components. For example, in other embodiments, each of the first flow regulator and the second flow regulator may include separate and independent pumps.

As indicated by solid line arrows, the first heat exchanger 30A and the second heat exchanger 30B are connected in parallel to the first medium tank 50 . In this embodiment, the pipe L4 extending from the first heat exchanger 30A and the pipe L5 extending from the second heat exchanger 30B merge into the pipe L6 connected to the first medium tank 50 . In another embodiment, each of the pipes L4 and L5 may be directly connected to the first medium tank 50 instead of the pipe L6. The first medium tank 50 stores the heat medium heated by the compression system 101 .

A first thermometer M1 and a second thermometer M2 are provided on the pipes L4 and L5, respectively. A first thermometer M1 measures a first temperature of the heat medium flowing from the first heat exchanger 30A to the first medium tank 50 . A second thermometer M2 measures a second temperature of the heat medium flowing from the second heat exchanger 30B to the first medium tank 50 . The first thermometer M<b>1 and the second thermometer M<b>2 are communicably connected to the control device 90 by wire or wirelessly, and transmit measurement data to the control device 90 .

In expansion system 102 , heat exchanger 30 is positioned upstream of each expander 20 in the airflow to heat the compressed air supplied to each expander 20 . Specifically, the third heat exchanger 30C is arranged upstream of the first expander 20A, and the fourth heat exchanger 30D is arranged upstream of the second expander 20B. More specifically, the third heat exchanger 30C is arranged between the air tank 40 and the first expander 20A, and the second heat exchanger 30B is arranged between the first expander 20A and the second expander 20B. is placed between By heating the compressed air supplied to each expander 20, power generation efficiency in the expander 20 can be improved.

As indicated by solid line arrows, the third heat exchanger 30C and the fourth heat exchanger 30D are connected in parallel to the first medium tank 50 . In this embodiment, the pipe L7 from the first medium tank 50 is branched, and the branched pipes L8 and L9 are connected to the third heat exchanger 30C and the fourth heat exchanger 30D, respectively. In another embodiment, each of the pipes L8 and L9 may extend directly from the first medium tank 50 instead of the pipe L7. The first medium tank 50 supplies the heat medium heated by the compression system 101 to each of the third heat exchanger 30C and the fourth heat exchanger 30D.

A pump P2 is provided in the pipe L7. Further, valves V3 and V4 are provided on the pipes L8 and L9, respectively. Pump P2 and valves V3 and V4 are communicably connected to controller 90 by wire or wirelessly, and controlled by controller 90 . The control device 90 adjusts the flow rate of the heat medium supplied from the first medium tank 50 to the pipe L7 by controlling the output of the pump P2. The controller 90 also adjusts the flow rates of the heat medium flowing through the pipes L8 and L9 by adjusting the opening degrees of the valves V3 and V4.

The control device 90 adjusts the third flow rate of the heat medium flowing from the first medium tank 50 to the third heat exchanger 30C by adjusting the output of the pump P2 and the opening of the valve V3. Therefore, in this embodiment, the pump P2 and the valve V3 function as a third flow control device.

The control device 90 adjusts the fourth flow rate of the heat medium flowing from the first medium tank 50 to the fourth heat exchanger 30D by adjusting the output of the pump P2 and the opening of the valve V4. Therefore, in this embodiment, the pump P2 and the valve V4 function as a fourth flow control device.

The third flow rate adjusting device and the fourth flow rate adjusting device are not limited to the configurations described above. For example, in other embodiments, the third flow regulator and the fourth flow regulator may further include additional components. For example, in other embodiments, each of the third flow regulator and the fourth flow regulator may include separate and independent pumps.

As indicated by solid line arrows, the third heat exchanger 30C and the fourth heat exchanger 30D are connected in parallel to the second medium tank 60 . In the present embodiment, a pipe L10 extending from the third heat exchanger 30C and a pipe L11 extending from the fourth heat exchanger 30D merge into a pipe L12 connected to the second medium tank 60. In another embodiment, each of the pipes L10 and L11 may be directly connected to the second medium tank 60 instead of the pipe L12. The second medium tank 60 stores the heat medium cooled by the expansion system 102 .

A third thermometer M3 and a fourth thermometer M4 are provided on the pipes L10 and L11, respectively. A third thermometer M3 measures a third temperature of the heat medium flowing from the third heat exchanger 30C to the second medium tank 60 . A fourth thermometer M4 measures a fourth temperature of the heat medium flowing from the fourth heat exchanger 30D to the second medium tank 60. FIG. The third thermometer M3 and the fourth thermometer M4 are communicably connected to the control device 90 by wire or wirelessly, and transmit measurement data to the control device 90 .

Controller 90 controls all or part of system 100 . The control device 90 includes components such as a processor 90a, a storage device 90b and a connector 90c, and these components are connected to each other via a bus. For example, the processor 90a includes a CPU (Central Processing Unit) and the like. For example, the storage device 90b includes a hard disk, a ROM storing programs and the like, and a RAM as a work area. Controller 90 communicates with each component of system 100 via connector 90c. For example, the control device 90 may further include other components such as a display device such as a liquid crystal display or touch panel, and an input device such as a keyboard, buttons or touch panel. For example, the operations of controller 90 described below may be implemented by having processor 90a execute a program stored in storage device 90b.

The inventors have found that in each of the compression system 101 and expansion system 102 as described above, a plurality of heat exchangers 30 are supplied such that the outlet temperatures of these heat exchangers 30 are equal or approximately equal to each other. It has been found that the energy efficiency of the system 100 can be improved by adjusting the flow rate of the heat transfer medium.

FIG. 2 is a table showing an example of computer simulation conditions and results. Specifically, the inventors performed a computer simulation of the system 100 shown in FIG. 1 using the conditions shown in FIG. Conditions were varied in the expansion system 102 in this simulation.

In the comparative example, the pump P2 and the valves V3 and V4 were controlled so that the heat medium was supplied from the first medium tank 50 to the pipes L8 and L9 at the same rate (50%). That is, the heat medium was supplied at the same flow rate to the third heat exchanger 30C and the fourth heat exchanger 30D.

In the embodiment, the pump P2 adjusts the ratio of the heat medium flowing from the first medium tank 50 to the pipes L8 and L9 so that the outlet temperatures of the third heat exchanger 30C and the fourth heat exchanger 30D are equal to each other. and valves V3 and V4. That is, the flow rate of the heat medium supplied to the third heat exchanger 30C and the fourth heat exchanger 30D was adjusted so that the temperatures of the third thermometer M3 and the fourth thermometer M4 were equal to each other. At this time, the ratio of the heat medium flowing to the pipe L8 was 45.5%, and the ratio of the heat medium flowing to the pipe L9 was 54.5%. Other conditions, including the conditions not shown in FIG. 2, are generally the same in the comparative example and the example, although the initial temperature of the heat medium is slightly different. The initial temperature of the heat medium indicates the temperature of the heat medium stored in the first medium tank 50 . The initial air temperature indicates the temperature of the compressed air stored in the air tank 40 . The first-stage input temperature of air indicates the temperature of the compressed air that flows to the first expander 20A after being heated by the third heat exchanger 30C. The first stage output temperature of air indicates the temperature of the compressed air flowing from the first expander 20A. The second-stage input temperature of air indicates the temperature of the compressed air that flows to the second expander 20B after being heated by the fourth heat exchanger 30D. Output indicates the total power generated by the first expander 20A and the second expander 20B.

In the comparative example, the temperatures of the third thermometer M3 and the fourth thermometer M4 were 122.8° C. and 119.5° C. respectively, whereas in the example they were the same as each other because , the flow rates of the heat medium supplied to the third heat exchanger 30C and the fourth heat exchanger 30D are adjusted so that the temperatures of the third thermometer M3 and the fourth thermometer M4 are equal to each other.

As shown in FIG. 2, the output of the example is 0.7% higher than the output of the comparative example. Therefore, by adjusting the flow rate of the heat medium supplied to the third heat exchanger 30C and the fourth heat exchanger 30D, the system It can be seen that the energy efficiency of 100 can be improved. As can be seen from the comparison of the first-stage input temperature and the first-stage output temperature of air, the compressed air is cooled after being expanded by the first expander 20A. In the embodiment, by adjusting the flow rate of the heat medium supplied to the third heat exchanger 30C and the fourth heat exchanger 30D so that the temperatures of the third thermometer M3 and the fourth thermometer M4 are equal to each other , the heat medium supplied to the fourth heat exchanger 30D relatively increases. Therefore, as can be seen from the comparison of the second stage input temperature of the air in the comparative example and the example, in the example, the compressed air cooled by the first expander 20A is more efficiently cooled in the fourth heat exchanger 30D. It can be reheated, which is presumed to lead to improved energy efficiency.

In the example of FIG. 2, the conditions were varied only in the expansion system 102 . In theory, however, the same applies to compression system 101 . Therefore, by adjusting the flow rate of the heat medium supplied to the first heat exchanger 30A and the second heat exchanger 30B so that the temperatures of the first thermometer M1 and the second thermometer M2 are equal to each other, the same can increase the output by 0.7%. Therefore, the overall system 100 can increase power output by 1.4%.

Also, in the embodiment of FIG. 2, in the expansion system 102, heat is supplied to the third heat exchanger 30C and the fourth heat exchanger 30D such that the temperatures of the third thermometer M3 and the fourth thermometer M4 are equal to each other. The flow rate of the heat transfer medium was adjusted. However, the temperatures of the third thermometer M3 and the fourth thermometer M4 may not be exactly equal to each other, and the temperature difference between the third thermometer M3 and the fourth thermometer M4 is within a predetermined range. You may adjust the flow volume of the heat medium supplied to the 3rd heat exchanger 30C and the 4th heat exchanger 30D. Similarly, in the compression system 101, the temperatures of the first thermometer M1 and the second thermometer M2 may not be exactly equal to each other, and the difference between the temperatures of the first thermometer M1 and the second thermometer M2 is within a predetermined range. You may adjust the flow volume of the heat medium supplied to the 1st heat exchanger 30A and the 2nd heat exchanger 30B so that it may be settled in. For example, the "predetermined range" can be a tolerance, for example 5°C, or 1°C for greater effect.

Based on the new knowledge as described above, the control device 90 determines that, in the compression system 101, the difference between the first temperature from the first thermometer M1 and the second temperature from the second thermometer M2 is within a predetermined range. In order to adjust the first flow rate of the heat medium to the first compressor 10A and the second flow rate of the heat medium to the second compressor 10B, the output of the pump P1 and the opening degrees of the valves V1 and V2 to control. Specifically, the controller 90 controls the output of the pump P1 and the opening of the valves V1 and V2 so that the first temperature from the first thermometer M1 and the second temperature from the second thermometer M2 are equal to each other. control the degree.

Similarly, the control device 90 controls the expansion system 102 so that the difference between the third temperature from the third thermometer M3 and the fourth temperature from the fourth thermometer M4 is within a predetermined range. The output of the pump P2 and the opening degrees of the valves V3 and V4 are controlled so as to adjust the third flow rate of the heat medium to the expander 20A and the fourth flow rate of the heat medium to the second expander 20B. Specifically, the controller 90 controls the output of the pump P2 and the opening of the valves V3 and V4 so that the third temperature from the third thermometer M3 and the fourth temperature from the fourth thermometer M4 are equal to each other. control the degree.

Next, the operation of system 100 will be described.

FIG. 3 is a flow chart showing the operation of the control device 90 in the compression system 101. As shown in FIG. For example, the operations shown in FIG. 3 are repeated at predetermined intervals, such as hundreds to hundreds of milliseconds, one to several seconds, ten to several tens of seconds, or one to several minutes, while the compression system 101 is in operation. may

The processor 90a acquires the first temperature of the heat medium flowing from the first heat exchanger 30A to the first medium tank 50 from the first thermometer M1 (step S100).

Subsequently, the processor 90a acquires the second temperature of the heat medium flowing from the second heat exchanger 30B to the first medium tank 50 from the second thermometer M2 (step S102).

Subsequently, the processor 90a calculates the difference between the first temperature and the second temperature (step S104).

Subsequently, the processor 90a determines whether the difference calculated in step S104 is within a predetermined range (step S106).

In step S106, if the difference is within the predetermined range (YES), the processor 90a terminates the series of operations.

In step S106, if the difference is not within the predetermined range (NO), the processor 90a controls the first flow rate of the heat medium to the first heat exchanger 30A and the second heat exchange rate so that the difference is within the predetermined range. The second flow rate of the heat medium to the vessel 30B is adjusted (step S108), and the series of operations is completed. Specifically, the processor 90a changes at least one of the output of the pump P1 and the opening of the valves V1 and V2.

FIG. 4 is a flow chart illustrating the operation of controller 90 in inflation system 102 . For example, the operations shown in FIG. 4 are repeated at predetermined intervals, such as hundreds to hundreds of milliseconds, seconds to seconds, seconds to tens of seconds, or minutes to minutes, during operation of the inflation system 102. may

The processor 90a acquires the third temperature of the heat medium flowing from the third heat exchanger 30C to the second medium tank 60 from the third thermometer M3 (step S200).

Subsequently, the processor 90a acquires the fourth temperature of the heat medium flowing from the fourth heat exchanger 30D to the second medium tank 60 from the fourth thermometer M4 (step S202).

Subsequently, the processor 90a calculates the difference between the third temperature and the fourth temperature (step S204).

Subsequently, the processor 90a determines whether the difference calculated in step S204 is within a predetermined range (step S206).

In step S206, if the difference is within the predetermined range (YES), the processor 90a terminates the series of operations.

In step S206, if the difference is not within the predetermined range (NO), the processor 90a controls the third flow rate of the heat medium to the third heat exchanger 30C and the fourth heat exchange rate so that the difference is within the predetermined range. The fourth flow rate of the heat medium to the vessel 30D is adjusted (step S208), and the series of operations is completed. Specifically, processor 90a changes at least one of the output of pump P2 and the opening of valves V3 and V4.

The system 100 as described above includes a plurality of compressors 10 including at least a first compressor 10A and a second compressor 10B arranged downstream of the first compressor 10A, and a plurality of compressors 10 downstream of the compressors 10. An air tank 40 arranged to store compressed air, a first heat exchanger 30A arranged downstream of the first compressor 10A and cooling the compressed air from the first compressor 10A, and the second compressor 10B A second heat exchanger 30B arranged downstream to cool the compressed air from the second compressor 10B, and connected in parallel to the first heat exchanger 30A and the second heat exchanger 30B, the first heat exchanger 30A and the second heat exchanger 30B, and the first heat exchanger 30A and the second heat exchanger 30B. A first medium tank 50 for recovering the heat medium from each of the heat exchangers 30B, and first flow control devices P1 and V1 for adjusting a first flow rate of the heat medium flowing from the second medium tank 60 to the first heat exchanger 30A. and second flow rate adjusting devices P1 and V2 for adjusting the second flow rate of the heat medium flowing from the second medium tank 60 to the second heat exchanger 30B, and the heat flowing from the first heat exchanger 30A to the first medium tank 50 A first thermometer M1 for measuring a first temperature of the medium, a second thermometer M2 for measuring a second temperature of the heat medium flowing from the second heat exchanger 30B to the first medium tank 50, and a first thermometer M1 The first and second flow regulators adjust the first flow rate and the second flow rate such that the difference between the first temperature from the second thermometer M2 and the second temperature from the second thermometer M2 is within a predetermined range. and a control device 90 that controls P1, V1 and V2. As noted above, the inventors have found that in each of the compression system 101 and the expansion system 102, the heat exchangers 30 are supplied with the same or nearly equal outlet temperatures to each other. It has been found that the energy efficiency of the system 100 can be improved by adjusting the flow rate of the heat transfer medium. Therefore, according to the above configuration, the outlet temperatures of the first heat exchanger 30A and the second heat exchanger 30B can be made equal or approximately equal, and the energy efficiency of the system 100 can be improved.

Also in system 100, the first and second flow regulators include valves V1, V2 and pump P1. However, each of the first and second flow regulators may be implemented by various configurations, including at least one of valves and pumps. Also, in other embodiments, each of the first and second flow control devices may be realized by still other configurations.

Further, the system 100 includes a plurality of expanders 20 including at least a first expander 20A connected to the air tank 40 and a second expander 20B arranged downstream of the first expander 20A; a third heat exchanger 30C arranged upstream of the machine 20A and heating the compressed air to the first expander 20A, the third heat exchanger 30C being connected to the first medium tank 50; A fourth heat exchanger 30D that is arranged upstream of the expander 20B and heats the compressed air to the second expander 20B, and is connected to the first medium tank 50 in parallel with the third heat exchanger 30C. a fourth heat exchanger 30D; third flow rate adjusting devices P2 and V3 for adjusting a third flow rate of the heat medium flowing from the first medium tank 50 to the third heat exchanger 30C; Fourth flow rate adjusting devices P2 and V4 for adjusting a fourth flow rate of the heat medium flowing to the heat exchanger 30D, a third thermometer M3 for measuring a third temperature of the heat medium flowing from the third heat exchanger 30C, and a fourth thermometer M4 for measuring a fourth temperature of the heat medium flowing from the fourth heat exchanger 30D. The third and fourth flow control devices P2, V3, V4 are controlled to adjust the third flow rate and the fourth flow rate so that the difference from the fourth temperature from M4 is within a predetermined range. As described above, in the expansion system 102, by adjusting the flow rate of the heat medium supplied to the heat exchangers 30 so that the outlet temperatures of the heat exchangers 30 are equal or substantially equal to each other, The energy efficiency of system 100 can be improved. Therefore, according to the above configuration, the outlet temperatures of the third heat exchanger 30C and the fourth heat exchanger 30D can be made equal or approximately equal, and the energy efficiency of the system 100 can be improved.

Also in system 100, the third and fourth flow regulators include valves V3, V4 and pump P2. However, each of the third and fourth flow regulators may be implemented by various configurations, including at least one of valves and pumps. Also, in other embodiments, each of the third and fourth flow regulators may be realized by still other configurations.

Although the embodiments have been described above with reference to the accompanying drawings, the present disclosure is not limited to the above embodiments. It is clear that a person skilled in the art can conceive of various modifications or modifications within the scope of the claims, and it is understood that these also belong to the technical scope of the present disclosure. be done.

For example, in the above embodiment, system 100 includes both compressor 10 and expander 20 separately. In other embodiments, for example, the system 100 may include only the compressor 10 and flow compressed air in a reverse direction from the air tank 40 and from the first medium tank 50 to the second medium tank 60. Compression system 101 may be used as expansion system 102 by counterflowing the heat transfer medium. In this case, system 100 may not include expander 20 and heat exchangers 30C and 30D. Similarly, for example, the system 100 may include only the expander 20 and draws air in a reverse direction from the second expander 20B and reverses from the second medium tank 60 to the first medium tank 50. Expansion system 102 may be used as compression system 101 by directing heat transfer medium flow. In this case, system 100 may not include compressor 10 and heat exchangers 30A and 30B.

The present disclosure can improve energy efficiency, thereby achieving Sustainable Development Goals (SDGs) Goal 7 "Ensure access to affordable, reliable, sustainable and modern energy" and Goal 13. We can contribute to “taking urgent action to combat climate change and its impacts”.

10 compressor 10A first compressor 10B second compressor 20 expander 20A first expander 20B second expander 30A first heat exchanger 30B second heat exchanger 30C third heat exchanger 30D fourth heat exchanger 40 air tank 50 first medium tank (medium tank)
60 second medium tank (medium source)
90 Control device 100 Compressed air energy storage system M1 First thermometer M2 Second thermometer M3 Third thermometer M4 Fourth thermometer P1 Pump (first flow rate regulator, second flow rate regulator)
P2 pump (third flow rate regulator, fourth flow rate regulator)
V1 valve (first flow control device)
V2 valve (second flow control device)
V3 valve (third flow control device)
V4 valve (fourth flow control device)

Claims (4)

a plurality of compressors including at least a first compressor and a second compressor arranged downstream of the first compressor;
an air tank arranged downstream of the plurality of compressors and storing compressed air;
a first heat exchanger arranged downstream of the first compressor for cooling compressed air from the first compressor;
a second heat exchanger arranged downstream of the second compressor for cooling compressed air from the second compressor;
a medium source connected in parallel to the first heat exchanger and the second heat exchanger and supplying a heat medium to each of the first heat exchanger and the second heat exchanger;
a medium tank connected in parallel to the first heat exchanger and the second heat exchanger and recovering the heat medium from each of the first heat exchanger and the second heat exchanger;
a first flow rate adjusting device that adjusts a first flow rate of the heat medium flowing from the medium source to the first heat exchanger;
a second flow rate adjusting device that adjusts a second flow rate of the heat medium flowing from the medium source to the second heat exchanger;
a first thermometer that measures a first temperature of the heat medium flowing from the first heat exchanger to the medium tank;
a second thermometer that measures a second temperature of the heat medium flowing from the second heat exchanger to the medium tank;
The first flow rate and the second flow rate are adjusted such that the difference between the first temperature from the first thermometer and the second temperature from the second thermometer falls within a predetermined range. a control device that controls the first flow rate regulator and the second flow rate regulator;
A compressed air energy storage system comprising: 2. The compressed air energy storage system of claim 1, wherein each of said first flow regulator and said second flow regulator includes at least one of a valve or a pump. a plurality of expanders including at least a first expander connected to the air tank and a second expander arranged downstream of the first expander;
a third heat exchanger arranged upstream of the first expander for heating compressed air to the first expander, the third heat exchanger connected to the medium tank;
A fourth heat exchanger arranged upstream of the second expander for heating compressed air to the second expander, the fourth heat exchanger being connected to the medium tank in parallel with the third heat exchanger , a fourth heat exchanger;
a third flow rate adjusting device that adjusts a third flow rate of the heat medium flowing from the medium tank to the third heat exchanger;
a fourth flow rate adjusting device that adjusts a fourth flow rate of the heat medium flowing from the medium tank to the fourth heat exchanger;
a third thermometer that measures a third temperature of the heat medium flowing from the third heat exchanger;
a fourth thermometer that measures a fourth temperature of the heat medium flowing from the fourth heat exchanger;
further comprising
The control device further
The third flow rate and the fourth flow rate are adjusted such that the difference between the third temperature from the third thermometer and the fourth temperature from the fourth thermometer falls within a predetermined range. controlling the third flow regulator and the fourth flow regulator;
Compressed air energy storage system according to claim 1 or 2. 4. The compressed air energy storage system of claim 3, wherein each of said third flow regulator and said fourth flow regulator includes at least one of a valve or a pump.

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