System and method for compressed air energy storage based on idle hydraulic tunnel

Abstract

The invention discloses a system and method for compressed air energy storage based on an idle hydraulic tunnel, and relates to the technical field of air energy storage, the system comprises an air storage subsystem, the air storage subsystem comprises a tunnel body and a standby bin connected with the tunnel body through a safety valve; the air compression subsystem is connected with the air storage subsystem; the power generation subsystem is connected with the other side of the gas storage subsystem and comprises a second heat exchanger, a second storage bin connected with the output end of the second heat exchanger, an air expansion machine connected with the second heat exchanger and a power generator connected with the air expansion machine; and a power grid subsystem. Due to the use of the standby bin, redundant pressure in the hole body can be released in time, the pressure in the hole body can be monitored in real time, waste caused by excessive pressure release is prevented, more accurate numerical values can be guaranteed through systematic calculation, and judgment through manual experience in the past is not needed.

Description

Technical Field

[0001] The present invention relates to the technical field of air energy storage, and in particular to a system and method for compressed air energy storage based on an idle hydraulic tunnel. Background Art

[0002] Compressed Air Energy Storage (CAES) is a technology that converts electrical energy into compressed air and stores it, releasing it to generate electricity when needed. The principle of the technology is to use electricity during low electricity price periods (such as nighttime electricity) to drive a compressor to compress and store air; during high electricity price periods (such as peak daytime electricity consumption), the compressed air is released and the generator is driven by an expander to generate electricity, thereby achieving peak and valley regulation and balancing of electricity.

[0003] Safety is an important consideration in compressed air energy storage systems. During system operation, in order to prevent the internal pressure from being too high, the pressure will be released. However, when to release and when to stop the release are determined by the staff's experience, which places high technical requirements on the staff. Summary of the invention

[0004] In view of the problems existing in the existing compressed air energy storage system based on idle hydraulic tunnels, the present invention is proposed.

[0005] Therefore, the problem to be solved by the present invention is that the time for releasing the pressure and stopping the pressure release cannot be determined.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a system for storing compressed air energy based on an idle hydraulic tunnel, which comprises:

[0008] The gas storage subsystem comprises a cavern and a spare tank connected to the cavern via a safety valve;

[0009] an air compression subsystem connected to the air storage subsystem, comprising a motor, a compressor connected to the motor, a first heat exchanger connected to the compressor, and a first storage bin connected to an output end of the first heat exchanger;

[0010] a power generation subsystem connected to the other side of the gas storage subsystem, comprising a second heat exchanger, a second storage bin connected to the output end of the second heat exchanger, an air expander connected to the second heat exchanger, and a generator connected to the air expander; and,

[0011] A power grid subsystem, wherein the output end of the power grid subsystem is connected to the air compression subsystem, and the input end of the power grid subsystem is connected to the power generation subsystem.

[0012] As a preferred solution of the system for compressed air energy storage based on idle hydraulic tunnels described in the present invention, multiple groups of sensors are arranged inside the cave body and the spare bin to detect the pressure inside the cave body and the spare bin.

[0013] As a preferred solution of the system for compressed air energy storage based on idle hydraulic tunnels described in the present invention, multiple groups of temperature sensors are arranged inside the first storage bin and the second storage bin to detect the internal temperature of the first storage bin and the second storage bin.

[0014] As a preferred solution of the system for compressed air energy storage based on idle hydraulic tunnels of the present invention, wherein: the output end of the power grid subsystem is also connected to the city circuit;

[0015] The gas storage subsystem, air compression subsystem, power generation subsystem and power grid subsystem are controlled through the central control terminal.

[0016] In a second aspect, an embodiment of the present invention provides a method for storing compressed air energy based on an idle hydraulic tunnel, which comprises the following steps:

[0017] During off-peak hours, the excess electricity in the grid subsystem is transmitted to the motor, which drives the compressor to compress the air.

[0018] The compressed air is transferred to the interior of the cavern for storage;

[0019] During peak electricity usage, the cavern releases the compressed air;

[0020] The released air enters the air expander, which drives the generator to run and transmit the generated electricity to the grid subsystem.

[0021] As a preferred solution of the method for storing compressed air energy based on an idle hydraulic tunnel according to the present invention, when the cavern stores compressed air, the internal pressure is detected by a set sensor, and whether to transmit the air to the spare tank through a safety valve is selected according to the monitoring result, which specifically includes the following steps:

[0022] Set a pressure threshold K. When the pressure is detected to be no greater than the threshold K, the safety valve is in a closed state.

[0023] When the pressure detected is greater than the threshold value K, the safety valve is in the open state, and the air inside the cave enters the spare compartment through the safety valve;

[0024] Set a protection threshold L. When the pressure detected is less than the threshold L, the safety valve is closed to interrupt the air transmission from the cave to the spare compartment.

[0025] The steps for setting the protection threshold L are as follows:

[0026] When electricity is used during valley hours, the pressure difference before and after the air compression subsystem outputs compressed air to the cave is collected, and the protection threshold L is obtained according to the calculation formula. The calculation formula is:

[0027] L=[α·(λ)]·φ

[0028] In the formula, L represents the protection threshold, α represents the weight value, λ represents the pressure difference, and φ represents the safety value, which is 0 or 1.

[0029] As a preferred solution of the method for compressed air energy storage based on idle hydraulic tunnels described in the present invention, when the pressure value inside the cave is obtained by multiple sets of sensors, the difference between the maximum pressure value and the minimum pressure value is calculated, and it is determined whether the difference is greater than a preset value. When the difference is not greater than the preset value, all pressure values ​​are marked as qualified. When the difference is greater than the preset value, the screening value is calculated. The specific calculation method is:

[0030]

[0031] Where P smax Expressed as the maximum screening value, P smin Expressed as the minimum screening value, P max Expressed as the maximum pressure value, P max-n Expressed as the second largest pressure value, P min Expressed as the minimum pressure value, P min-n Expressed as the second smallest pressure value;

[0032] Determine the difference between the screening value and the average value, and the calculation formula is:

[0033]

[0034] Where P n It means the pressure value detected by the nth sensor, n is the number of sensors, P AVG Expressed as the average pressure, P Amax It is expressed as the difference between the maximum screening value and the average value, P Amin It is expressed as the difference between the minimum screening value and the average value;

[0035] When P Amax >P Amin , the maximum pressure value is deleted and a new maximum pressure value is obtained;

[0036] When PAmax <P Amin , the minimum pressure value is deleted and a new minimum pressure value is obtained;

[0037] When P Amax =P Amin , the maximum pressure value and the minimum pressure value are deleted, and new maximum pressure value and minimum pressure value are obtained again;

[0038] The difference between the new maximum pressure value and the new minimum pressure value is re-determined until the difference is less than the preset value.

[0039] As a preferred solution of the method for compressed air energy storage based on idle hydraulic tunnels according to the present invention, the operation steps of the air compression subsystem include:

[0040] The motor receives power from the grid subsystem and drives the compressor to run. The air enters the compressor, and the compressor completes the compression and output of the air, causing the air to heat up. The air is then cooled by the first heat exchanger, and the heat is stored in the first storage bin. The cooled air then enters the cavern.

[0041] When the air enters the compressor, it will be filtered by the filter mechanism at the inlet of the compressor. The filter mechanism is a filter with a pore size of 3 to 6 mm.

[0042] As a preferred solution of the method for storing compressed air energy based on idle hydraulic tunnels according to the present invention, the operation steps of the power generation subsystem include:

[0043] The air released from the cave flows through the pipeline into the second heat exchanger. The second storage bin injects heat into the second heat exchanger to heat up the air flowing through it. The air then enters the air expander, which drives the generator to run, so that the electricity generated by the generator is transmitted to the power grid subsystem.

[0044] When the second storage bin injects heat into the second heat exchanger, the temperature inside the second storage bin is obtained, and the opening and closing state of the second storage bin outlet valve is selected according to the judgment conditions:

[0045] The judgment condition is: preset the judgment temperature value Q and the minimum limit W, compare the temperature inside the second storage bin with the judgment temperature value Q and the minimum limit W, when the temperature inside the second storage bin is not less than the judgment temperature value Q, the outlet valve opening and closing state is half-open, when the temperature inside the second storage bin is less than the judgment temperature value Q and greater than the minimum limit W, the outlet valve opening and closing state is fully open, when the temperature inside the second storage bin is not greater than the minimum limit W, the outlet valve opening and closing state is closed;

[0046] Among them, the opening and closing states of the outlet valve include a closed state, a half-open state and a fully open state.

[0047] As a preferred solution of the method for compressed air energy storage based on idle hydraulic tunnels of the present invention, when the power grid subsystem outputs power to the air compression subsystem or when the power grid subsystem receives power from the power generation subsystem, the current is set to the minimum flow rate, and after X time, it is determined whether the system is abnormal:

[0048] When no abnormality occurs, the setting of the minimum flow rate is cancelled;

[0049] When an abnormality occurs, an alarm is issued to the staff.

[0050] The beneficial effects of the present invention are as follows: due to the use of the spare bin, the excess pressure inside the cave can be released in time, and the pressure in the cave can be monitored in real time to prevent waste caused by excessive pressure release, and the systematic calculation can ensure that the numerical value is more accurate, and there is no need to make judgments based on manual experience in the past. Secondly, by using the second storage bin, the released air can be heated, and by adjusting the opening and closing state of the outlet valve, the flow rate of heat transfer can be adjusted to ensure that the air temperature meets the optimal standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0052] Figure 1 This is a scenario diagram of a system for compressed air energy storage based on idle hydraulic tunnels. DETAILED DESCRIPTION

[0053] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0054] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0055] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0056] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0057] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0058] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] Example 1

[0060] Reference Figure 1 , which is the first embodiment of the present invention, provides a system for storing compressed air energy based on an idle hydraulic tunnel, comprising:

[0061] The gas storage subsystem 100 includes a cavern 101 and a spare tank 102 connected to the cavern 101 via a safety valve;

[0062] The air compression subsystem 200 connected to the air storage subsystem 100 includes a motor 201, a compressor 202 connected to the motor 201, a first heat exchanger 203 connected to the compressor 202, and a first storage bin 204 connected to an output end of the first heat exchanger 203;

[0063] A power generation subsystem 300 connected to the other side of the gas storage subsystem 100, comprising a second heat exchanger 301, a second storage bin 302 connected to the output end of the second heat exchanger 301, an air expander 303 connected to the second heat exchanger 301, and a generator 304 connected to the air expander 303; and,

[0064] The power grid subsystem 400 has an output end connected to the air compression subsystem 200 , and an input end connected to the power generation subsystem 300 .

[0065] Furthermore, multiple sets of sensors are provided inside the cavity 101 and the spare chamber 102 for detecting the pressure inside the cavity 101 and the spare chamber 102 , and the pressure inside the cavity 101 and the spare chamber 102 can be effectively detected.

[0066] Furthermore, multiple groups of temperature sensors are set inside the first storage bin 204 and the second storage bin 302 to detect the internal temperature of the first storage bin 204 and the second storage bin 302. The internal temperature of the first storage bin 204 and the second storage bin 302 is detected by the temperature sensors.

[0067] Preferably, the output end of the power grid subsystem 400 is also connected to the city circuit;

[0068] The gas storage subsystem 100, the air compression subsystem 200, the power generation subsystem 300 and the power grid subsystem 400 are controlled through the central control terminal, and the detection and control of the entire system are achieved through the central control terminal.

[0069] In summary, due to the use of the spare warehouse 102, the excess pressure inside the cave body 101 can be released in time, and the pressure inside the cave body 101 can be monitored in real time to prevent waste caused by excessive pressure release, and the systematic calculation can ensure that the numerical value is more accurate, and there is no need for judgment based on manual experience. Secondly, by using the second storage warehouse 302, the released air can be heated, and by adjusting the opening and closing state of the outlet valve, the flow rate of heat transfer can be adjusted to ensure that the air temperature meets the optimal standard.

[0070] Example 2

[0071] On the basis of the first embodiment, this embodiment further provides a method for storing compressed air energy based on an idle hydraulic tunnel, comprising the following steps:

[0072] When electricity is used during off-peak hours, the excess electricity of the power grid subsystem 400 is transmitted to the motor 201, which drives the compressor 202 to operate and complete the air compression;

[0073] The compressed air is transmitted to the interior of the cavity 101 for storage.

[0074] When the cavern 101 stores compressed air, the internal pressure is detected by a sensor, and whether to transmit the air to the spare chamber 102 through the safety valve is selected according to the monitoring result, which specifically includes the following steps:

[0075] Set a pressure threshold K. When the pressure is detected to be no greater than the threshold K, the safety valve is in a closed state.

[0076] When the pressure detected is greater than the threshold value K, the safety valve is in an open state, and the air inside the cavity 101 enters the spare chamber 102 through the safety valve;

[0077] A protection threshold L is set. When the pressure detected is less than the threshold L, the safety valve is closed to interrupt the air transmission from the cavity 101 to the spare compartment 102.

[0078] The steps for setting the protection threshold L are as follows:

[0079] When electricity is used during valley hours, the pressure difference before and after the air compression subsystem 200 outputs compressed air to the cave 101 is collected, and the protection threshold L is obtained according to the calculation formula. The calculation formula is:

[0080] L=[α·(λ)]·φ

[0081] In the formula, L represents the protection threshold, α represents the weight value, λ represents the pressure difference, and φ represents the safety value, which is 0 or 1;

[0082] For example, the pressure threshold K is set to 5MPa, and the average value of the pressure values ​​detected by the multiple groups of sensors installed inside the cave 101 is calculated, and the average value is compared with the pressure threshold K. When the pressure is not greater than the pressure threshold K, it means that the inside of the cave 101 is still in a stable state and there is no need to open the safety valve. When the pressure is greater than the pressure threshold K, it means that the pressure inside the cave 101 is relatively high, so the safety valve is opened to release the pressure. When the pressure is released, the sensor will detect the pressure inside the cave 101 in real time.

[0083] Regarding the setting of the protection threshold L, the protection threshold L is calculated by obtaining the pressure difference before and after the air compression subsystem 200 outputs compressed air to the cave 101 for the last time. During the calculation, the weight value α decreases as the length of time the air compression subsystem 200 outputs compressed air to the cave 101 for the last time increases, and α∈[0.5,2].

[0084] When the pressure value inside the cave 101 is obtained by multiple sets of sensors, the difference between the maximum pressure value and the minimum pressure value is calculated, and it is determined whether the difference is greater than a preset value. When the difference is not greater than the preset value, all pressure values ​​are marked as qualified. When the difference is greater than the preset value, the screening value is calculated. The specific calculation method is:

[0085]

[0086] Where P smax Expressed as the maximum screening value, P smin Expressed as the minimum screening value, P max Expressed as the maximum pressure value, P max-n Expressed as the second largest pressure value, P min Expressed as the minimum pressure value, P min-n Expressed as the second smallest pressure value;

[0087] For example, the pressure values ​​inside the cave 101 obtained by multiple sets of sensors are 3.5MPa, 3.8MPa, 4MPa, 4.4MPa, 4.6MPa and 4.8MPa, among which the difference between the maximum pressure value and the minimum pressure value is 1.3MPa, and when the preset value is set to 1.5, all are marked as qualified. When the preset value is set to 1.2, the screening value is calculated, and the calculation method is: the absolute value of 4.8-4.6 and the absolute value of 3.5-3.8, that is, the maximum screening value P is obtained. smax is 0.2, the minimum screening value P smin is 0.3;

[0088] Determine the difference between the screening value and the average value, and the calculation formula is:

[0089]

[0090] Where P n It means the pressure value detected by the nth sensor, n is the number of sensors, P AVG Expressed as the average pressure, P Amax It is expressed as the difference between the maximum screening value and the average value, P Amin It is expressed as the difference between the minimum screening value and the average value;

[0091] When P Amax >P Amin , the maximum pressure value is deleted and a new maximum pressure value is obtained;

[0092] When P Amax <P Amin , the minimum pressure value is deleted and a new minimum pressure value is obtained;

[0093] When P Amax =PAmin , the maximum pressure value and the minimum pressure value are deleted, and new maximum pressure value and minimum pressure value are obtained again;

[0094] Re-determine the difference between the new maximum pressure value and the new minimum pressure value until the difference is less than the preset value;

[0095] When the calculated average value is 4.18MPa, the difference between the maximum screening value and the average value and the difference between the minimum screening value and the average value are calculated to be 3.98 and 3.88 respectively. At this time, the judgment condition is met. Amax <P Amin , then delete the minimum pressure value, obtain a new minimum pressure value, and repeat the calculation.

[0096] The operation steps of the air compression subsystem 200 include:

[0097] The motor 201 receives power from the power grid subsystem 400 and drives the compressor 202 to operate. The air enters the compressor 202, and is compressed and output by the compressor 202, so that the air is heated. The air is cooled by the first heat exchanger 203, and the heat is stored in the first storage bin 204. The cooled air then enters the cave 101.

[0098] When the air enters the compressor 202, it will be filtered by the filter mechanism at the entrance of the compressor 202. The filter mechanism is a filter with a pore size of 3 to 6 mm. Through the setting of the filter mechanism, the compressed air can be purified.

[0099] During peak electricity usage, the cavern 101 releases the compressed air;

[0100] The released air enters the air expander 303 , drives the generator 304 to operate through the air expander 303 , and transmits the generated electricity to the power grid subsystem 400 .

[0101] The operation steps of the power generation subsystem 300 include:

[0102] The air released from the cave 101 flows through the pipeline into the second heat exchanger 301. The second storage bin 302 injects heat into the second heat exchanger 301 to heat the air flowing through it. The air then enters the air expander 303, and the air expander 303 drives the generator 304 to operate, so that the generator 304 generates electricity and transmits it to the power grid subsystem 400.

[0103] When the second storage bin 302 injects heat into the second heat exchanger 301, the temperature inside the second storage bin 302 is obtained, and the opening and closing state of the outlet valve of the second storage bin 302 is selected according to the judgment condition:

[0104] The judgment condition is: preset the judgment temperature value Q and the minimum limit W, compare the temperature inside the second storage bin 302 with the judgment temperature value Q and the minimum limit W, when the temperature inside the second storage bin 302 is not less than the judgment temperature value Q, the outlet valve opening and closing state is half-open, when the temperature inside the second storage bin 302 is less than the judgment temperature value Q and greater than the minimum limit W, the outlet valve opening and closing state is fully open, when the temperature inside the second storage bin 302 is not greater than the minimum limit W, the outlet valve opening and closing state is closed;

[0105] Among them, the opening and closing states of the outlet valve include a closed state, a half-open state and a fully open state;

[0106] During implementation, the preset judgment temperature value Q is 80°C and the minimum limit W is 50°C. When the temperature inside the second storage bin 302 is 70°C, the outlet valve for the second storage bin 302 to output heat to the second heat exchanger 301 is fully open. According to the same judgment method, when the temperature inside the second storage bin 302 is 90°C, the outlet valve for the second storage bin 302 to output heat to the second heat exchanger 301 is half open. When the temperature inside the second storage bin 302 is 40°C, the outlet valve is closed. At this time, the air is heated according to other methods.

[0107] When the power grid subsystem 400 outputs power to the air compression subsystem 200 or receives power from the power generation subsystem 300, the power grid subsystem 400 sets the current to the lowest flow rate and determines whether the system is abnormal after X time:

[0108] When no abnormality occurs, the setting of the minimum flow rate is cancelled;

[0109] When an abnormality occurs, an alarm is issued to the staff;

[0110] For example, when the power grid subsystem 400 outputs electricity to the air compression subsystem 200, the current in normal use is 20A. Within X time, the current is set to the minimum flow rate, that is, the output current is 5A, to detect whether the system is running correctly. When it is running normally, the minimum flow rate setting is canceled and the system runs in a normal manner.

[0111] This embodiment also provides a computer device, which is suitable for the method of performing compressed air energy storage based on idle hydraulic tunnels, and includes a memory and a processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement the method of performing compressed air energy storage based on idle hydraulic tunnels as proposed in the above embodiment.

[0112] The computer device may be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0113] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the method for realizing compressed air energy storage based on an idle hydraulic tunnel as proposed in the above embodiment is implemented.

[0114] The storage medium proposed in this embodiment and the data storage method proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be found in the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0115] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A system for compressed air energy storage based on idle hydraulic tunnels, characterized by: include, A gas storage subsystem (100) comprises a cavern (101) and a spare tank (102) connected to the cavern (101) via a safety valve; An air compression subsystem (200) connected to the air storage subsystem (100), comprising a motor (201), a compressor (202) connected to the motor (201), a first heat exchanger (203) connected to the compressor (202), and a first storage bin (204) connected to an output end of the first heat exchanger (203); a power generation subsystem (300) connected to the other side of the gas storage subsystem (100), comprising a second heat exchanger (301), a second storage bin (302) connected to the output end of the second heat exchanger (301), an air expander (303) connected to the second heat exchanger (301), and a generator (304) connected to the air expander (303); and, A power grid subsystem (400), wherein the output end of the power grid subsystem (400) is connected to the air compression subsystem (200), and the input end of the power grid subsystem (400) is connected to the power generation subsystem (300).

2. The system for storing compressed air energy based on idle hydraulic tunnels according to claim 1, characterized in that: Multiple groups of sensors are arranged inside the cavity (101) and the spare chamber (102) for detecting the pressure inside the cavity (101) and the spare chamber (102).

3. The system for storing compressed air energy based on idle hydraulic tunnels according to claim 2, characterized in that: A plurality of groups of temperature sensors are arranged inside the first storage bin (204) and the second storage bin (302) to detect the internal temperature of the first storage bin (204) and the second storage bin (302).

4. The system for storing compressed air energy based on idle hydraulic tunnels according to claim 3, characterized in that: The output end of the power grid subsystem (400) is also connected to the city circuit; The gas storage subsystem (100), the air compression subsystem (200), the power generation subsystem (300) and the power grid subsystem (400) are controlled through the central control terminal.

5. A method for compressed air energy storage based on an idle hydraulic tunnel, based on the system for compressed air energy storage based on an idle hydraulic tunnel according to any one of claims 1 to 4, characterized in that: The following steps are included: When electricity is used during off-peak hours, the excess electricity of the power grid subsystem (400) is transmitted to the motor (201), and the motor (201) drives the compressor (202) to operate, thereby completing the compression of air; The compressed air is transmitted to the interior of the cavity (101) for storage; During peak electricity usage, the cavern (101) releases the compressed air; The released air enters the air expander (303), drives the generator (304) to operate through the air expander (303), and transmits the generated electricity to the power grid subsystem (400).

6. The method for storing compressed air energy based on an idle hydraulic tunnel according to claim 5, characterized in that: When the cavern (101) stores compressed air, the internal pressure is detected by a sensor, and according to the monitoring result, it is selected whether to transmit the air to the spare chamber (102) through the safety valve, which specifically includes the following steps: Set a pressure threshold K. When the pressure is detected to be no greater than the threshold K, the safety valve is in a closed state. When the pressure detected is greater than the threshold value K, the safety valve is in an open state, and the air inside the cavity (101) enters the spare chamber (102) through the safety valve; A protection threshold L is set, and when the pressure is detected to be less than the threshold L, the safety valve is closed to interrupt the air transmission from the cavity (101) to the spare chamber (102); The steps for setting the protection threshold L are as follows: The pressure difference before and after the air compression subsystem (200) outputs compressed air to the cave (101) is collected when electricity is used during off-peak hours, and the protection threshold L is obtained according to a calculation formula. The calculation formula is: L=[α·(λ)]·φ In the formula, L represents the protection threshold, α represents the weight value, λ represents the pressure difference, and φ represents the safety value, which is 0 or 1.

7. The method for storing compressed air energy based on an idle hydraulic tunnel according to claim 6, characterized in that: When the pressure value inside the cavity (101) is obtained by multiple sets of sensors, the difference between the maximum pressure value and the minimum pressure value is calculated, and it is determined whether the difference is greater than a preset value. When the difference is not greater than the preset value, all pressure values ​​are marked as qualified. When the difference is greater than the preset value, the screening value is calculated. The specific calculation method is: Where P smax Expressed as the maximum screening value, P smin Expressed as the minimum screening value, P max Expressed as the maximum pressure value, P max-n Expressed as the second largest pressure value, P min Expressed as the minimum pressure value, P min-n Expressed as the second smallest pressure value; Determine the difference between the screening value and the average value, and the calculation formula is: Where P n It means the pressure value detected by the nth sensor, n is the number of sensors, P AVG Expressed as the average pressure, P Amax It is expressed as the difference between the maximum screening value and the average value, P Amin It is expressed as the difference between the minimum screening value and the average value; When P Amax >P Amin , the maximum pressure value is deleted and a new maximum pressure value is obtained; When P Amax <P Amin , the minimum pressure value is deleted and a new minimum pressure value is obtained; When P Amax =P Amin , the maximum pressure value and the minimum pressure value are deleted, and new maximum pressure value and minimum pressure value are obtained again; The difference between the new maximum pressure value and the new minimum pressure value is re-determined until the difference is less than the preset value.

8. The method for storing compressed air energy based on an idle hydraulic tunnel according to claim 7, characterized in that: The operation steps of the air compression subsystem (200) include: The motor (201) receives power from the power grid subsystem (400) and drives the compressor (202) to operate. Air enters the compressor (202), and is compressed and output by the compressor (202), causing the air to heat up. The air is then cooled by the first heat exchanger (203), and the heat is stored in the first storage bin (204). The cooled air then enters the cave (101). When the air enters the compressor (202), it is filtered by a filter mechanism at the inlet of the compressor (202), and the filter mechanism is a filter with a pore size of 3 to 6 mm.

9. The method for storing compressed air energy based on an idle hydraulic tunnel according to claim 8, characterized in that: The operation steps of the power generation subsystem (300) include: The air released from the cavity (101) flows through the pipeline into the second heat exchanger (301), and the second storage bin (302) injects heat into the second heat exchanger (301) to increase the temperature of the air flowing through the cavity (101). The air then enters the air expander (303), and the air expander (303) drives the generator (304) to operate, so that the generator (304) generates electricity and transmits it to the power grid subsystem (400). When the second storage bin (302) injects heat into the second heat exchanger (301), the temperature inside the second storage bin (302) is obtained, and the opening and closing state of the outlet valve of the second storage bin (302) is selected according to the judgment condition: The judgment condition is: a preset judgment temperature value Q and a minimum limit W, comparing the temperature inside the second storage bin (302) with the judgment temperature value Q and the minimum limit W, when the temperature inside the second storage bin (302) is not less than the judgment temperature value Q, the outlet valve opening and closing state is a half-open state, when the temperature inside the second storage bin (302) is less than the judgment temperature value Q and greater than the minimum limit W, the outlet valve opening and closing state is a fully open state, when the temperature inside the second storage bin (302) is not greater than the minimum limit W, the outlet valve opening and closing state is a closed state; Among them, the opening and closing states of the outlet valve include a closed state, a half-open state and a fully open state.

10. The method for storing compressed air energy based on an idle hydraulic tunnel according to claim 9, characterized in that: When the power grid subsystem (400) outputs power to the air compression subsystem (200) or when the power grid subsystem (400) receives power from the power generation subsystem (300), the current is set to the lowest flow rate, and after a period of X, it is determined whether an abnormality occurs in the system: When no abnormality occurs, the setting of the minimum flow rate is cancelled; When an abnormality occurs, an alarm is issued to the staff.

Images