Compressed air energy storage underground cavern automatic drainage system and method

Abstract

The invention relates to the field of gas storage cavern drainage, and provides a compressed air energy storage underground cavern automatic drainage system and a compressed air energy storage underground cavern automatic drainage system in order to not affect working efficiency. A water collection pit is arranged at the bottom of a gas storage cavern, a drainage gallery is arranged on the lateral upper portion of the gas storage cavern and connected with the water collection pit through a drainage pipe, and a valve is arranged on the drainage pipe; the intelligent control system controls opening and closing of the valve according to the internal condition of the gas storage cavern. The internal circulating pressure of the high-pressure gas storage cavern is used for discharging internal accumulated water, and an extra power source is not needed; the compressed air energy storage underground cavern is used for draining water in the cycle inflation and deflation period, normal operation of the high-pressure air storage cavern is not affected, and the efficiency is higher; the intelligent control system is used for controlling the water level of the cavern and opening and closing of the valves, accurate control can be achieved, and manpower resource allocation is reduced; the device has an internal and external water discharge function, can ensure maintenance drainage or emergency drainage of the gas storage cavern, is energy-saving and efficient, and is convenient to maintain.

Description

Technical Field

[0001] The invention relates to the field of gas storage cavern drainage, and in particular to an automatic drainage system and method for a compressed air energy storage underground cavern. Background Art

[0002] As an important branch of new energy storage technology, compressed air energy storage has a low initial investment. The use of hydropower underground caverns to build energy storage projects can better coordinate hydropower to participate in deep peak and frequency regulation, promote the consumption of new energy, promote the integrated development of water, wind, solar and storage, and realize the reuse of idle underground caverns in hydropower stations.

[0003] During the operation of the compressed air power station, the air is first compressed by a compressor. The general operating pressure reaches 10MPa, the air temperature rises, and then the high-pressure gas is discharged to generate electricity using an expander. At this time, the temperature drops. Due to the huge change in air pressure, a large amount of water will accumulate in the gas storage cavern. Under the action of high internal pressure, the accumulated pressurized water will damage the structure. At the same time, a large amount of water will also occupy the cross-section of the cavern, reducing the efficiency of gas storage power generation. The internal water of conventional water diversion tunnels or traffic tunnels is basically pumped out by water pumps, which affects the operating efficiency of the cavern and is also limited by power supply. During the operation of the compressed air energy storage underground cavern, due to its high internal pressure, the external water has little effect on the structure. However, when the gas storage cavern is in a maintenance state, excessive external water pressure may cause buckling damage to the lining structure. The existing gas storage cavern drainage structure fails to make full use of the high-pressure gas in the gas storage cavern, and the functions are relatively single, and the drainage effect is limited. For this reason, there is an urgent need for an intelligent drainage system and method that can use the high internal pressure of the gas storage cavern to discharge internal and external water without affecting work efficiency. Summary of the invention

[0004] In order to solve the above problems, the present application provides a compressed air energy storage underground cavern automatic drainage system and method.

[0005] The technical solution adopted by the present invention to solve the above problems is:

[0006] The automatic drainage system of a compressed air energy storage underground cavern comprises: a gas storage cavern, and also comprises at least one sump, a drainage pipe, a drainage gallery and an intelligent control system, wherein the intelligent control system comprises a water level sensor, a pressure sensor and a control unit respectively connected to the water level sensor and the pressure sensor, wherein the pressure sensor is arranged in the gas storage cavern, the water level sensor is arranged in the sump, the sump is arranged at the bottom of the gas storage cavern, a drainage outlet is arranged at the bottom of the sump, the drainage gallery is located above the side of the gas storage cavern and is connected to the drainage outlet through the drainage pipe; a sump control valve and a gallery control valve are respectively arranged at both ends of the drainage pipe, and the control unit controls the opening and closing of the sump control valve and the gallery control valve according to the detection results of the water level sensor and the pressure sensor.

[0007] Furthermore, when there are multiple sump pits, the effective volume of a single sump pit must satisfy the following relationship:

[0008]

[0009] V0 ≥ V2

[0010] V0≤0.1%V3

[0011] Among them, n is the number of sump pits; V0 is the effective volume of a single sump pit, V1 is the volume of condensed water generated during one filling and deflation process; V2 is the volume of a single drainage pipe; V3 is the volume of the gas storage cavern.

[0012] Furthermore, a filter grid is provided on the sump.

[0013] Furthermore, the bottom of the gas storage cavern, the sump and / or the drainage gallery are provided with a slope.

[0014] Furthermore, the drainage gallery is arranged above the side of the gas storage cavern and parallel to the axial direction of the cavern.

[0015] Furthermore, a water pump is also provided in the drainage gallery.

[0016] The automatic drainage method of the compressed air energy storage underground cavern is applied to the automatic drainage system of the compressed air energy storage underground cavern, including:

[0017] Before storing gas in the gas storage cavern, make sure all valves are in the closed state;

[0018] Pressurized gas is injected into the gas storage cavern, and the pressure in the cavern gradually increases. Under the action of pressure, the accumulated water in the cavern flows into the sump. When the water level sensor detects that the water level in the sump has reached the critical water level, the sump control valve and the gallery control valve are controlled to open.

[0019] After the valve is opened, the internal pressure of the gas storage cavern is used to push the accumulated water in the sump upward through the drainage pipe into the drainage gallery, and then the water is discharged to the outside of the cavern after being collected in the gallery.

[0020] When the pressure inside the cave increases to When the water level in the sump drops to a safe level, close the sump control valve and gallery control valve. min is the lowest pressure inside the gas storage cave, P max The maximum air pressure.

[0021] Further, the gallery control valve is opened first, and then the sump control valve is opened; the sump control valve is closed first, and then the gallery control valve is closed.

[0022] Compared with the prior art, the present invention has the following beneficial effects: utilizing the internal circulation pressure of the high-pressure gas storage cavern to discharge internal accumulated water without the need for an additional power source; utilizing the compressed air energy storage underground cavern to drain water during the cyclic charging and discharging period without affecting the normal operation of the high-pressure gas storage cavern, which is more efficient; using an intelligent control system to control the water level in the cavern and the opening and closing of valves, which can achieve precise control and reduce human resource allocation; having both internal and external water discharge functions, which can ensure maintenance drainage or emergency drainage of the gas storage cavern, is energy-saving and efficient, and is convenient for maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the structure of the automatic drainage system for compressed air energy storage underground caverns;

[0024] Figure 2 is a schematic diagram of the filter grid;

[0025] Figure numerals: 1 is a gas storage cavern, 2 is a drainage gallery, 3 is a drainage pipe, 4 is a sump, 5 is a filter grid, 6 is an intelligent control system, 7 is a sump control valve, 8 is a gallery control valve, and 9 is a water pump. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] like Figure 1 As shown, the automatic drainage system of the compressed air energy storage underground cavern comprises: an air storage cavern 1, and also comprises at least one sump 4, a drainage pipe 3, a drainage gallery 2 and an intelligent control system 6, wherein the intelligent control system comprises a water level sensor, a pressure sensor and a control unit respectively connected to the water level sensor and the pressure sensor, wherein the pressure sensor is arranged in the air storage cavern 1, and is used to detect the internal pressure of the air storage cavern; the water level sensor is arranged in the sump 4, and is used to detect the water level in the sump 4; the sump 4 is arranged at the bottom of the air storage cavern 1, and a drainage outlet is arranged at the bottom of the sump 4, and the drainage gallery 2 is located above the side of the air storage cavern and is connected to the drainage outlet through the drainage pipe 3; a sump control valve 7 and a gallery control valve 8 are respectively arranged at both ends of the drainage pipe 3, and the control unit controls the opening and closing of the sump control valve 7 and the gallery control valve 8 according to the detection results of the water level sensor and the pressure sensor.

[0028] It should be noted that the drainage gallery described in the present application is a drainage and water collection channel that is arranged at a certain distance above the side of the gas storage cavern and can prevent groundwater from entering the gas storage cavern. That is, the present application realizes the combination of the discharge of internal condensate water and external groundwater, thereby reducing the setting of the external discharge structure of internal condensate water. In order to effectively prevent groundwater from entering the gas storage cavern, the drainage gallery 2 is arranged parallel to the axial direction of the cavern. In order to facilitate the discharge of condensate, the bottom of the gas storage cavern, the sump and / or the drainage gallery are arranged with a certain slope.

[0029] The sump is set inside the cavern and the interval between sump can be set according to the length of the cavern. Condensate can be discharged quickly in a longer cavern. When multiple sump are set inside the gas storage cavern, the effective volume of a single sump must meet the following relationship:

[0030]

[0031] V0 ≥ V2

[0032] V0≤0.1%V3

[0033] Among them, n is the number of sump pits; V0 is the effective volume of a single sump pit, V1 is the volume of condensed water generated during one filling and deflation process; V2 is the volume of a single drainage pipe; V3 is the volume of the gas storage cavern.

[0034] Since the sump is directly set at the bottom of the gas storage cavern, in order to prevent the debris in the gas storage cavern from falling into the sump and causing the drainage pipe to be blocked, a filter grid 5 can be set on the sump. The filter grid structure is as follows: Figure 2 shown.

[0035] In order to realize maintenance drainage or emergency drainage of the gas storage cavern, a water pump 9 is also provided in the drainage gallery.

[0036] The automatic drainage method of the compressed air energy storage underground cavern comprises:

[0037] Before storing gas in the gas storage cavern, make sure all valves are in the closed state;

[0038] Pressurized gas is injected into the gas storage cavern, and the pressure in the cavern gradually increases. Under the action of pressure, the accumulated water in the cavern flows into the sump. When the water level sensor detects that the water level in the sump has reached the critical water level, the sump control valve and the gallery control valve are controlled to open.

[0039] After the valve is opened, the internal pressure of the gas storage cavern is used to push the accumulated water in the sump upward through the drainage pipe into the drainage gallery, and then the water is discharged to the outside of the cavern after being collected in the gallery.

[0040] When the pressure inside the cave increases to When the water level in the sump drops to a safe level, close the sump control valve and gallery control valve.min is the lowest pressure inside the gas storage cave, P max The maximum air pressure.

[0041] That is, the valve opening condition is: H≥H c and Valve closing condition: H≤H s or Where H is the water level of the sump, in meters; H c is the critical water level, in m; H s is the safe water level, in m; P is the internal pressure of the cave, in kPa; the minimum pressure inside the gas storage cave P min , maximum air pressure P max , unit: kPa.

[0042] To prevent water backflow, before the water level in the sump reaches the critical water level and starts to drain, first open the gallery control valve to ensure that the air pressure in the drainage pipe is equal to the atmospheric pressure, and then open the sump control valve to start drainage; before the water level in the sump reaches the safety level to stop drainage, first close the sump control valve, wait until the air pressure in the drainage pipe is equal to the atmospheric pressure, and then close the gallery control valve. All valve inspections must be carried out under standard atmospheric pressure.

Claims

1. Compressed air energy storage underground cavern automatic drainage system, including: The gas storage cavern is characterized in that it also includes at least one sump, a drainage pipe, a drainage gallery and an intelligent control system, wherein the intelligent control system includes a water level sensor, a pressure sensor and a control unit respectively connected to the water level sensor and the pressure sensor, wherein the pressure sensor is arranged in the gas storage cavern, the water level sensor is arranged in the sump, the sump is arranged at the bottom of the gas storage cavern, a drainage outlet is arranged at the bottom of the sump, the drainage gallery is located above the side of the gas storage cavern and is connected to the drainage outlet through the drainage pipe; a sump control valve and a gallery control valve are respectively arranged at both ends of the drainage pipe, and the control unit controls the opening and closing of the sump control valve and the gallery control valve according to the detection results of the water level sensor and the pressure sensor.

2. The compressed air energy storage underground cavern automatic drainage system according to claim 1 is characterized in that: When there are multiple sump pits, the effective volume of a single sump pit must satisfy the following relationship: V0 ≥ V2 V0≤0.1%V3 Among them, n is the number of sump pits; V0 is the effective volume of a single sump pit, V1 is the volume of condensed water generated during one filling and deflation process; V2 is the volume of a single drainage pipe; V3 is the volume of the gas storage cavern.

3. The automatic drainage system for underground caverns with compressed air energy storage according to claim 1 is characterized in that: A filtering grid is arranged on the sump.

4. The automatic drainage system for underground caverns with compressed air energy storage according to claim 1 is characterized in that: The bottom of the gas storage cavern, the sump and / or the drainage gallery are provided with a slope.

5. The compressed air energy storage underground cavern automatic drainage system according to claim 1 is characterized in that: The drainage gallery is arranged above the side of the gas storage cavern and parallel to the axial direction of the cavern.

6. The automatic drainage system for underground caverns with compressed air energy storage according to any one of claims 1 to 5, characterized in that: A water pump is also provided in the drainage gallery.

7. A method for automatic drainage of an underground cavern with compressed air energy storage, applied to the automatic drainage system for an underground cavern with compressed air energy storage according to any one of claims 1 to 6, characterized in that: include: Before storing gas in the gas storage cavern, make sure all valves are in the closed state; Pressurized gas is injected into the gas storage cavern, and the pressure in the cavern gradually increases. Under the action of pressure, the accumulated water in the cavern flows into the sump. When the water level sensor detects that the water level in the sump has reached the critical water level, the sump control valve and the gallery control valve are controlled to open. After the valve is opened, the internal pressure of the gas storage cavern is used to push the accumulated water in the sump upward through the drainage pipe into the drainage gallery, and then the water is discharged to the outside of the cavern after being collected in the gallery. When the pressure inside the cave increases to When the water level in the sump drops to a safe level, close the sump control valve and gallery control valve. min is the lowest pressure inside the gas storage cave, P max The maximum air pressure.

8. The automatic drainage method for compressed air energy storage underground cavern according to claim 7, characterized in that: Open the gallery control valve first, then open the sump control valve; close the sump control valve first, then close the gallery control valve.

Images