Drainage system and method for compressed air energy storage underground artificial gas storage

Abstract

The application discloses a drainage system and method of compressed air energy storage artificial underground gas storage, and belongs to the technical field of compressed air energy storage; the drainage system comprises a water collecting structure, a water collecting well and a pressure regulating structure; the water collecting structure is arranged at the bottom of the gas storage, and is used for collecting condensed water formed in the gas storage; the bottom of the water collecting structure is communicated with the bottom of the water collecting well through a drainage pipeline; the pressure regulating structure is arranged on the water collecting well; the gas storage comprises a first working state and a second working state; the pressure regulating structure is used for regulating the gas pressure in the water collecting well to be smaller than the gas pressure in the gas storage in the second working state, so that the condensed water in the water collecting structure flows into the water collecting well along the drainage pipeline; the application can guarantee efficient drainage without causing compressed air loss, improves energy utilization, and prolongs the service life of the gas storage.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compressed air energy storage, in particular to a drainage system and method for a compressed air energy storage artificial underground gas storage. BACKGROUND

[0002] The operation process of a compressed air energy storage power station includes an energy storage process (air charging process), a high-pressure gas storage stage, an energy release process (air discharging process) and a low-pressure pressure maintaining stage. Since water vapor is contained in air, when air is compressed, the pressure of water vapor will also increase; when compressed air is released, the pressure decreases, and water vapor will condense into liquid water, which cannot be discharged from the gas storage along with the gas, resulting in water accumulation in the gas storage. If the water accumulated in the gas storage cannot be discharged for a long time, it may cause corrosion to the sealing layer inside the gas storage, greatly reducing the service life of the sealing layer of the gas storage.

[0003] The existing drainage method for the gas storage usually sets a pressure equalizing pipe between the high-pressure gas storage and a water collecting well, so as to connect the inside of the high-pressure gas storage and the water collecting well through the pressure equalizing pipe, achieve the purpose of pressure equalization, and finally realize drainage. However, the use of this method for drainage will cause loss of compressed air in the gas storage, reducing the efficiency of the power station. SUMMARY

[0004] The present application provides a drainage system and method for a compressed air energy storage artificial underground gas storage, aiming to solve the problem of compressed air loss in the drainage process in the prior art.

[0005] The first aspect of the present application provides a drainage system for a compressed air energy storage artificial underground gas storage, comprising:

[0006] a water collecting structure, a water collecting well and a pressure regulating structure; the water collecting structure is arranged at the bottom of the gas storage, and is used for collecting condensed water formed inside the gas storage; the bottom of the water collecting structure is communicated with the bottom of the water collecting well through a drainage pipeline; and the pressure regulating structure is arranged on the water collecting well;

[0007] the gas storage comprises a first working state and a second working state; in the first working state, the gas pressure inside the gas storage is at a first operating pressure; in the second working state, the gas pressure inside the gas storage is at a second operating pressure, which is less than the first operating pressure;

[0008] the pressure regulating structure is used for adjusting the gas pressure in the water collecting well to be less than the gas pressure in the gas storage in the second working state, so that the condensed water in the water collecting structure flows into the water collecting well along the drainage pipeline.

[0009] Further, the water collecting well has an initial height of accumulated water pre-stored inside.

[0010] Further, the drainage system further comprises a flow guide structure, the flow guide structure is arranged at the bottom of the gas storage; a first connecting end of the flow guide structure is connected with the inner side wall of the gas storage, and a second connecting end of the flow guide structure is connected with the water collecting structure, and the flow guide structure is used for receiving the condensed water formed in the gas storage and guiding the condensed water into the water collecting structure.

[0011] Optionally, a side of the flow guide structure towards the inside of the gas storage is arranged as an inclined surface; the water collecting structure comprises a water collecting groove, and the water collecting groove is arranged at a lower end of the inclined surface.

[0012] Further, the slope of the inclined surface is greater than or equal to 3%.

[0013] Further, a drainage groove is arranged on the inclined surface, an extension direction of the drainage groove is consistent with the inclination direction of the inclined surface, and the inside of the drainage groove is communicated with the inside of the water collecting groove.

[0014] Further, a drainage valve is arranged on the drainage pipeline, and the drainage system further comprises a controller connected with the drainage valve and used for controlling the opening or closing of the drainage valve.

[0015] Further, a liquid level detection element is arranged in the water collecting structure, the liquid level detection element is used for detecting the current liquid level in the water collecting structure, the controller is connected with the liquid level detection element, and the controller is used for controlling the drainage valve to be opened according to that the detected current liquid level reaches a first preset height, or the controller is used for controlling the drainage valve to be closed according to that the detected current liquid level reaches a second preset height.

[0016] Optionally, the liquid level detection element comprises a first liquid level sensor and a second liquid level sensor; the first liquid level sensor is arranged at a first height position in the water collecting structure and is used for detecting whether the current liquid level reaches the first preset height; and the second liquid level sensor is arranged at a second height position in the water collecting structure and is used for detecting whether the current liquid level reaches the second preset height.

[0017] Optionally, a first gas conveying pipeline and an exhaust pipeline are connected with the gas storage; an input end of the first gas conveying pipeline is connected with a gas source, the gas source is used for providing compressed air in the gas storage; an air inlet valve is arranged on the first gas conveying pipeline, and an air outlet valve is arranged on the exhaust pipeline.

[0018] Optionally, a second gas conveying pipeline is connected with the water collecting well, an input end of the second gas conveying pipeline is connected with the gas source, the gas source is further used for providing compressed air in the water collecting well, and the pressure regulating structure comprises a pressure regulating valve arranged on the second gas conveying pipeline.

[0019] Optionally, a pressure detection element is arranged in the gas storage, and the pressure detection element is used to detect the gas pressure in the gas storage.

[0020] The second aspect of the embodiment of the present application provides a drainage method using the drainage system of the compressed energy storage artificial underground gas storage as described above, and the drainage method comprises the following steps:

[0021] compressed air is filled into the gas storage, the gas pressure in the gas storage is increased, the air filling is stopped when the gas pressure in the gas storage reaches the first operating pressure, and the gas storage is in a first working state;

[0022] the gas storage is drained, the gas pressure in the gas storage is decreased, the gas draining is stopped when the gas pressure in the gas storage reaches the second operating pressure, and the gas storage is in a second working state;

[0023] in the second working state, the gas pressure in the water collecting well is adjusted by the pressure regulating structure, the gas pressure in the water collecting well is less than the gas pressure in the gas storage, the drainage pipeline is opened, and the condensed water in the water collecting structure flows into the water collecting well along the drainage pipeline.

[0024] Beneficial effects:

[0025] The present application provides a drainage system of a compressed energy storage artificial underground gas storage, which comprises a water collecting structure, a water collecting well and a pressure regulating structure; the water collecting structure is arranged at the bottom of the gas storage, and is used to collect condensed water formed in the gas storage; the bottom of the water collecting structure is communicated with the bottom of the water collecting well through a drainage pipeline; and the pressure regulating structure is arranged on the water collecting well. In the second working state, i.e. the low-pressure pressure maintaining state after energy release of the gas storage, the gas pressure in the water collecting well is adjusted by the pressure regulating structure, the gas pressure in the water collecting well is less than the gas pressure in the gas storage, the condensed water in the water collecting structure is driven to flow along the drainage pipeline to the water collecting well by the gas pressure difference, the condensed water in the gas storage is efficiently drained, the service life of the gas storage is increased, the maintenance cost is reduced, the problem of compressed air loss in the gas storage during the drainage process is effectively avoided, energy is saved, and the working efficiency of the power station is ensured.

[0026] The present application also provides a drainage method using the drainage system of the compressed energy storage artificial underground gas storage as described above, and the beneficial effects of the drainage method relative to the prior art are the same as those of the drainage system, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0028] Figure 1 is a structural schematic diagram of a drainage system of a compressed air energy storage artificial underground gas storage proposed by an embodiment of the present application;

[0029] Figure 2 is a sectional schematic diagram of a gas storage in the drainage system of the compressed air energy storage artificial underground gas storage proposed by an embodiment of the present application.

[0030] Explanation of reference signs:

[0031] 1, gas storage; 2, water collecting well; 21, pressure regulating valve; 3, water collecting tank; 4, drainage tank; 5, drainage pipeline; 51, drainage valve; 61, first liquid level sensor; 62, second liquid level sensor; 7, air compressor; 8, first gas conveying pipeline; 81, air inlet valve; 9, second gas conveying pipeline; 10, concrete plug. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described clearly and completely in the following with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort belong to the scope of protection of the present application.

[0033] In the related art, the drainage of the gas storage is usually performed in the following way: the gas storage is arranged at a high position, and the bottom elevation of the gas storage is higher than the top elevation of the water collecting well; a pressure equalizing pipeline is arranged between the high-pressure gas storage and the water collecting well, the inside of the high-pressure gas storage and the water collecting well is communicated through the pressure equalizing pipeline, the purpose of pressure equalization is achieved, and finally the drainage is realized. However, the compressed air in the gas storage is lost and the efficiency of the power station is reduced by using this way to drain.

[0034] Therefore, the present application proposes a drainage system of a compressed air energy storage artificial underground gas storage.

[0035] Referring to Figure 1 , a drainage system of a compressed air energy storage artificial underground gas storage, comprising: a water collecting structure, a water collecting well 2 and a pressure regulating structure; the water collecting structure is arranged at the bottom of the gas storage 1, and is used for collecting the condensed water formed in the inside of the gas storage 1; the bottom of the water collecting structure is communicated with the bottom of the water collecting well 2 through a drainage pipeline 5; and the pressure regulating structure is arranged on the water collecting well 2.

[0036] The gas storage 1 comprises a first working state and a second working state; in the first working state, the gas pressure inside the gas storage 1 is at a first operating pressure; in the second working state, the gas pressure inside the gas storage 1 is at a second operating pressure, which is less than the first operating pressure.

[0037] The pressure regulating structure is used to adjust the gas pressure in the water collecting well 2 to be less than the gas pressure in the gas storage 1 in the second working state, so that the condensed water in the water collecting structure flows into the water collecting well 2 along the drain pipe 5.

[0038] Specifically, referring to Figure 1 In the embodiment, the gas storage 1 is a horizontally inclined cylindrical structure, and the inner cavity of the gas storage 1 is used to store compressed air. A concrete plug 10 is arranged at one end of the gas storage 1 to close the inner cavity. The concrete plug 10 is provided with an inspection valve for facilitating inspection. In the embodiment, the water collecting structure is a water collecting groove 3 arranged at the bottom of the gas storage 1, which can collect the condensed water formed in the gas storage 1.

[0039] The water collecting well 2 is arranged outside the gas storage 1, and the bottom of the water collecting well 2 is connected to the bottom of the water collecting structure through the drain pipe 5. In this way, when draining, the condensed water in the water collecting structure can enter the water collecting well 2 along the drain pipe 5. The water collecting well 2 is provided with a pressure regulating structure, which can adjust the gas pressure in the water collecting well 2.

[0040] The gas storage 1 comprises a first working state and a second working state. Specifically, in the charging process, the gas storage 1 is filled with compressed gas, and the gas pressure in the gas storage 1 continuously rises until it reaches the upper limit of the operating pressure, i.e., the first operating pressure, and the charging process ends. At this time, the gas pressure in the gas storage 1 is maintained at the first operating pressure, and the gas storage 1 is in the first working state, i.e., the high-pressure gas storage state. In the discharging process, the high-pressure air in the gas storage 1 is released, and the gas pressure in the gas storage 1 continuously decreases. The water vapor in the air condenses to form liquid water, which accumulates in the water collecting structure at the bottom of the gas storage 1. When the gas pressure in the gas storage 1 reaches the lower limit of the operating pressure, i.e., the second operating pressure, the discharging process ends. At this time, the gas pressure in the gas storage 1 is maintained at the second operating pressure, and the gas storage 1 is in the second working state, i.e., the low-pressure pressure-maintaining state.

[0041] The pressure regulating structure is used to adjust the gas pressure in the water collecting well 2 in the second working state, so that the gas pressure in the water collecting well 2 is less than the gas pressure in the gas storage 1, i.e., the pressure difference between the gas storage 1 and the water collecting well 2 is positive. The pressure difference is used as the driving force for drainage, so that the condensed water in the water collecting structure can automatically flow from the relatively high-pressure gas storage 1 to the relatively low-pressure water collecting well 2, ensuring the efficiency of drainage, and by reasonably controlling the range of the pressure difference, the water hammer pressure can be reduced.

[0042] Through the above arrangement, drainage only occurs in the second working state of the gas storage 1, i.e. the low-pressure pressure-maintaining state, thus avoiding the problem of loss of compressed air in the gas storage 1 caused by drainage during the inflation process and the high-pressure energy storage phase, avoiding energy loss and ensuring the working efficiency of the power station.

[0043] Further, the inside of the water collecting well 2 is pre-stored with accumulated water of an initial height.

[0044] Since the drainage pipeline 5 between the water collecting well 2 and the water collecting structure has a small diameter, at the moment when the drainage pipeline 5 is opened for drainage, the pressure of the water flow flowing out through the drainage pipeline 5 is high, which is likely to cause a large impact on the water collecting well 2. Therefore, in order to further reduce the water hammer pressure and avoid damage to the water collecting well 2 caused by water flow impact, a certain amount of accumulated water is pre-stored in the inside of the water collecting well 2, and the part of accumulated water has a certain initial liquid surface height in the inside of the water collecting well 2, which can play a buffering role during drainage, reduce the water flow impact force, ensure the safety of the drainage process, and prolong the service life of the water collecting well 2.

[0045] Further, the drainage system further comprises a flow guide structure, the flow guide structure is arranged at the bottom of the gas storage 1; a first connecting end of the flow guide structure is connected with the inner side wall of the gas storage 1, and a second connecting end of the flow guide structure is connected with the water collecting structure; the flow guide structure is used for receiving the condensed water formed in the gas storage 1 and guiding the condensed water into the water collecting structure.

[0046] By arranging the flow guide structure, the received condensed water can be guided to flow into the water collecting structure along the flow guide structure, preventing liquid water from being deposited in the gas storage 1 for a long time to cause corrosion to the sealing layer in the inside of the gas storage 1.

[0047] Optionally, one side of the flow guide structure facing the inside of the gas storage 1 is arranged as an inclined surface; the water collecting structure comprises a water collecting tank 3, and the water collecting tank 3 is arranged at the end of the inclined surface with a lower height.

[0048] Specifically, in the embodiment, the flow guide structure is the bottom wall of the gas storage 1, as shown in Figure 1 , the inner cavity of the gas storage 1 is arranged in a cylindrical shape, the axis of the inner cavity is arranged obliquely, the bottom surface of the inner cavity, i.e. the inner wall surface of the flow guide structure, is formed as an inclined surface, the inclination angle of the inclined surface is consistent with the inclination angle of the axis of the inner cavity, the right end of the inclined surface has a higher height, and the left end has a lower height, and the water collecting tank 3 is arranged at the left end of the inclined surface. In this way, after the condensed water formed in the gas storage 1 falls on the flow guide structure, the condensed water will flow along the inclined surface from high to low to the water collecting tank 3, and finally be collected in the water collecting tank 3.

[0049] Preferably, the slope of the inclined surface is greater than or equal to 3%.

[0050] The slope of the inclined surface refers to the ratio of the vertical height of the inclined surface to the horizontal distance, that is, the tangent value of the inclination angle. The slope of the inclined surface can be set according to the requirements of the slope drainage slope in the specification for slope design of water conservancy and hydropower engineering, and as an optimization, the slope of the inclined surface is set to be greater than or equal to 3%, which is beneficial to ensure the speed of the water flow, reduce the retention of the water flow on the diversion structure, and ensure the drainage efficiency. Specifically, in the embodiment, the inner cavity of the gas storage 1 is set to be cylindrical, the axis of the inner cavity is inclined, and the bottom surface of the inner cavity forms the inclined surface of the diversion structure, Figure 1 The angle α between the axis of the inner cavity of the gas storage 1 and the horizontal direction shown in the figure is the inclination angle of the inclined surface, and according to the slope of the inclined surface being greater than or equal to 3%, it can be calculated that α≥arctan(0.03)≈1.7°.

[0051] Further, the inclined surface is provided with a drainage groove 4, the extension direction of the drainage groove 4 is consistent with the inclination direction of the inclined surface, and the inside of the drainage groove 4 is communicated with the inside of the water collecting groove 3.

[0052] Specifically, to further improve the collection efficiency of the condensed water, the drainage groove 4 is provided on the inclined surface, the length direction of the drainage groove 4 is consistent with the axis direction of the inner cavity of the gas storage 1, referring to Figure 2 On the A-A section of the gas storage 1, the inner cavity wall of the gas storage 1 is in the form of a circular arc, the drainage groove 4 is located at the lowest part of the inner cavity bottom, and the water droplets condensed on the inner cavity wall of the gas storage 1 can be gathered into the drainage groove 4 at the lowest part along the circular arc-shaped wall. Since the extension direction of the drainage groove 4 is consistent with the inclination direction of the inclined surface, the water flow gathered in the drainage groove 4 will flow from the end with a higher height to the end with a lower height under the action of gravity, and finally flow into the water collecting groove 3, so as to realize the accumulation in the water collecting groove 3.

[0053] Further, the drainage pipeline 5 is provided with a drainage valve 51, and the drainage system further comprises a controller connected with the drainage valve 51 for controlling the opening or closing of the drainage valve 51.

[0054] Specifically, the drainage valve 51 can be arranged on the drainage pipeline 5 close to one end of the water collecting groove 3. By arranging the drainage valve 51 and using the controller to control the opening or closing of the drainage valve 51, the on-off state of the drainage pipeline 5 can be switched, so as to control the drainage process.

[0055] Furthermore, the water collection structure is provided with a liquid level detection element, which is used to detect the current liquid level in the water collection structure; the controller is connected to the liquid level detection element and is used to control the drain valve 51 to open when the detected current liquid level reaches a first preset height, or to control the drain valve 51 to close when the detected current liquid level reaches a second preset height.

[0056] By setting a controller and cooperating with a liquid level detection element, the opening and closing status of the drain valve 51 can be automatically controlled according to the liquid level in the water collection tank 3, making the drainage process more intelligent. Specifically, in the second working state of the gas storage tank 1, that is, the low-pressure holding state, when the water in the water collection tank 3 accumulates to a high level, the drain valve can automatically open to drain the water in a timely manner; as the condensate in the water collection tank 3 is drained, when only a shallow water level remains in the water collection tank 3, the drain valve can automatically close to stop drainage and continue the next round of water collection.

[0057] Optionally, the liquid level detection element includes a first liquid level sensor 61 and a second liquid level sensor 62; the first liquid level sensor 61 is disposed at a first height position within the water collection structure and is used to detect whether the current liquid level has reached a first preset height; the second liquid level sensor 62 is disposed at a second height position within the water collection structure and is used to detect whether the current liquid level has reached a second preset height.

[0058] like Figure 1 As shown, in this embodiment, the liquid level detection element includes two liquid level sensors. The first liquid level sensor 61 is positioned at a high position in the water collection tank 3 to detect whether the liquid level has reached a preset maximum point, i.e., a first preset height. The second liquid level sensor 62 is positioned at a low position in the water collection tank 3 to detect whether the liquid level has reached a preset minimum point, i.e., a second preset height. By setting the first liquid level sensor 61 and the second liquid level sensor 62, the controller can adjust the opening and closing state of the drain valve 51 in a timely manner according to the amount of water in the water collection tank 3, ensuring efficient drainage.

[0059] Optionally, the gas storage tank 1 is connected to a first gas supply pipe 8 and an exhaust pipe; the input end of the first gas supply pipe 8 is connected to a gas source, which is used to provide compressed air to the gas storage tank 1; an inlet valve 81 is provided on the first gas supply pipe 8, and an outlet valve is provided on the exhaust pipe.

[0060] Specifically, in this embodiment, the air source is an air compressor 7, which can provide compressed air for the air reservoir 1. A first air conveying pipeline 8 is arranged between the air compressor 7 and the air reservoir 1. During the air charging process, the compressed air output by the air compressor 7 can enter the air reservoir 1 through the first air conveying pipeline 8. An air inlet valve 81 is arranged on the first air conveying pipeline 8. By controlling the opening and closing state of the air inlet valve 81, the on-off state of the first air conveying pipeline 8 can be switched, so as to control the air charging process.

[0061] The air reservoir 1 is also connected with an air discharging pipeline (not shown in the figure). The output end of the air discharging pipeline is connected to the high-pressure gas input end of the power generation system. When it is needed to generate power by using the high-pressure gas in the air reservoir 1, the high-pressure gas in the air reservoir 1 can be discharged and supplied to the power generation system of the power station through the air discharging pipeline. An air outlet valve (not shown in the figure) is arranged on the air discharging pipeline. By controlling the opening and closing state of the air outlet valve, the on-off state of the air discharging pipeline can be switched, so as to control the air discharging process.

[0062] Optionally, a second air conveying pipeline 9 is connected to the water collecting well 2. The input end of the second air conveying pipeline 9 is connected with the air source. The air source is also used to provide compressed air for the water collecting well 2. The pressure regulating structure comprises a pressure regulating valve 21 arranged on the second air conveying pipeline 9.

[0063] Specifically, in this embodiment, the air pressure in the water collecting well 2 also comes from the air compressor 7. A second air conveying pipeline 9 is arranged between the water collecting well 2 and the air compressor 7. The compressed air output by the air compressor 7 can enter the water collecting well 2 along the second air conveying pipeline 9, so as to form an air cushion above the liquid surface of the water collecting well 2. The pressure regulating valve 21 is arranged on the second air conveying pipeline 9. The pressure regulating valve 21 can identify the current air pressure in the water collecting well 2 and adjust the opening degree according to the need, so as to regulate and control the air pressure in the water collecting well 2, ensure that the air pressure difference between the air reservoir 1 and the water collecting well 2 is positive, and ensure the smooth progress of the water discharging process.

[0064] Optionally, a pressure detecting element is arranged in the air reservoir 1. The pressure detecting element is used to detect the air pressure in the air reservoir 1.

[0065] In this embodiment, a pressure detecting element is also arranged in the air reservoir 1, which can detect the current air pressure in the air reservoir 1 in real time. The pressure detecting element, the air inlet valve 81 and the air outlet valve are respectively connected with a controller. The controller can control the closing of the air inlet valve 81 during the air charging process and the closing of the air outlet valve during the air discharging process according to the current air pressure in the air reservoir 1.

[0066] Specifically, in the process of charging, when the pressure detecting element detects that the current gas pressure in the gas storage 1 reaches the preset upper limit of the operating pressure, i.e., the first operating pressure, the controller can control the air inlet valve 81 to automatically close and stop charging; in the process of discharging, when the pressure detecting element detects that the current gas pressure in the gas storage 1 reaches the preset lower limit of the operating pressure, i.e., the second operating pressure, the controller can control the air outlet valve to automatically close and stop discharging.

[0067] The working process of the drainage system of the compressed air energy storage artificial underground gas storage provided by the embodiments of the present application is as follows:

[0068] In the process of charging, the air inlet valve 81 is opened, the air outlet valve is closed, compressed air is injected into the gas storage 1 by the air compressor 7 to store energy, and the gas pressure in the gas storage 1 continuously rises; when the gas pressure in the gas storage 1 reaches the preset upper limit of the operating pressure, the air inlet valve 81 is closed to stop charging; at this time, the gas pressure in the gas storage 1 is maintained at the first operating pressure, and the gas storage 1 is in the first working state, i.e., the high-pressure gas storage state.

[0069] When it is needed to generate electricity by using the high-pressure gas in the gas storage 1, the process of discharging is performed, the air outlet valve is opened, the air inlet valve 81 is closed, the high-pressure air in the gas storage 1 is released, and the gas pressure in the gas storage 1 continuously decreases; the water vapor in the air condenses to form liquid water, and the liquid water forms accumulated water at the bottom of the gas storage 1 due to gravity and flows into the water collecting tank 3 along the drainage groove 4; when the gas pressure in the gas storage 1 reaches the preset lower limit of the operating pressure, the air outlet valve is closed to stop discharging; at this time, the gas pressure in the gas storage 1 is maintained at the second operating pressure, and the gas storage 1 is in the second working state, i.e., the low-pressure pressure-maintaining state.

[0070] With the circulation of multiple charging and discharging processes, the condensed water formed in the gas storage 1 continuously accumulates in the water collecting tank 3; in the second working state of the gas storage 1, i.e., the low-pressure pressure-maintaining state, when the liquid level in the water collecting tank 3 reaches the preset highest point, the pressure in the water collecting well 2 is adjusted by the pressure regulating structure so that the pressure difference between the gas storage 1 and the water collecting well 2 is positive, and at the same time, the drainage valve 51 is opened to perform drainage, and the accumulated water in the water collecting tank 3 flows into the water collecting well 2 through the drainage pipeline 5 under the driving of the pressure difference; with the discharge of the accumulated water, when the liquid level in the water collecting tank 3 drops to the preset lowest point, the drainage valve 51 is closed, and the drainage is completed.

[0071] The drainage system of the compressed air energy storage artificial underground gas storage provided by the embodiments of the present application drives the accumulated water to be discharged by using the pressure difference between the gas storage 1 and the water collecting well 2 through the setting of the pressure regulating structure, ensures the efficient drainage, and the drainage process only occurs in the low-pressure pressure maintaining stage after the energy releasing process of the gas storage 1, and does not cause the loss of compressed air in the gas storage 1, which is beneficial to improve the energy utilization rate; the accumulated water is guided into the water collecting groove 3 by using the gravity through the setting of the flow guiding structure with the inclined surface and the drainage groove 4, which effectively reduces the long-term retention of the accumulated water in the gas storage 1, avoids the long-term high water content in the gas storage 1 from causing the corrosion of the sealing material and the sealing failure, helps to increase the service life of the gas storage 1 and reduce the maintenance cost; the drainage process can be reasonably controlled according to the amount of the accumulated water in the water collecting groove 3 through the cooperation of the controller, the drainage valve 51 and the first liquid level sensor 61 and the second liquid level sensor 62, which improves the intelligentization and automation level of the drainage process and is easy to operate.

[0072] The second aspect of the embodiments of the present application provides a drainage method using the drainage system of the compressed air energy storage artificial underground gas storage as described above, and the drainage method comprises the following steps.

[0073] The compressed air is filled into the gas storage 1, the air pressure in the gas storage 1 is increased, and the air filling is stopped when the air pressure in the gas storage 1 reaches the first operating pressure, and the gas storage 1 is in the first working state;

[0074] The gas storage 1 discharges air outward, the air pressure in the gas storage 1 is decreased, and the air discharge is stopped when the air pressure in the gas storage 1 reaches the second operating pressure, and the gas storage 1 is in the second working state;

[0075] In the second working state, the air pressure in the water collecting well 2 is adjusted by the pressure regulating structure, so that the air pressure in the water collecting well 2 is less than the air pressure in the gas storage 1, the drainage pipeline 5 is opened, and the condensed water in the water collecting structure flows into the water collecting well 2 along the drainage pipeline 5.

[0076] By using the above drainage method, the air cushion is formed by the upper air pressure in the water collecting well 2, the air pressure in the water collecting well 2 is adjusted by the pressure regulating structure, so that the pressure difference between the gas storage 1 and the water collecting well 2 is controlled, the accumulated water in the gas storage 1 can automatically flow from the relatively high-pressure gas storage 1 to the relatively low-pressure water collecting well 2, the efficient drainage of the accumulated water is ensured, the service life of the gas storage 1 is increased, and the maintenance cost is reduced; at the same time, the drainage process only occurs in the second working state of the gas storage 1, that is, the low-pressure pressure maintaining state, and the compressed air is zero loss, which is beneficial to save energy and ensure the working efficiency of the power station.

[0077] It should be noted that each of the embodiments in the present specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the embodiments can be mutually referred to.

[0078] It should also be noted that in this paper, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations, nor can it be understood as indicating or implying relative importance. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or terminal device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or terminal device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or terminal device including the element.

[0079] The above provides a detailed description of the technical solutions of the present application. In this paper, the principle and implementation mode of the present application are described by specific examples. The above description of the embodiments is only used to help understand the present application, and the content of the specification should not be understood as limiting the present application. At the same time, for those skilled in the art, according to the present application, there will be different forms of changes in specific implementation and application range, which do not need and cannot enumerate all the implementation ways, and the obvious changes or changes derived therefrom are still within the protection scope of the present application.

Claims

1. A drainage system for an artificial underground gas storage facility with compressed gas storage, characterized in that, include: Water collection structure, water collection well and pressure regulating structure; The water collection structure is located at the bottom of the gas storage tank and is used to collect condensate formed inside the gas storage tank; the bottom of the water collection structure is connected to the bottom of the water collection well through a drainage pipe; the pressure regulating structure is located on the water collection well. The gas storage tank includes a first working state and a second working state; the gas storage tank is connected to a first gas supply pipe and an exhaust pipe; the input end of the first gas supply pipe is connected to a gas source, which is used to provide compressed air to the gas storage tank; the first gas supply pipe is equipped with an inlet valve, and the exhaust pipe is equipped with an outlet valve. A second gas supply pipe is connected to the water collection well, and the input end of the second gas supply pipe is connected to the gas source. The gas source is also used to provide compressed air to the water collection well; the air pressure in the water collection well comes from the gas source. In the first working state, the gas pressure inside the gas storage tank is at the first operating pressure; In the second operating state, the gas pressure inside the gas storage tank is at a second operating pressure, which is lower than the first operating pressure; The pressure regulating structure is used to adjust the gas pressure in the water collection well to be lower than the gas pressure in the gas storage tank in the second working state, so that the condensate in the water collection structure flows into the water collection well along the drainage pipe; the pressure regulating structure includes a pressure regulating valve, which is installed on the second gas transmission pipeline.

2. The drainage system of the compressed gas storage artificial underground gas storage facility according to claim 1, characterized in that: The water collection well is pre-filled with water at an initial height.

3. The drainage system of the compressed gas storage artificial underground gas storage facility according to claim 1, characterized in that: The drainage system also includes a flow guiding structure, which is located at the bottom of the gas storage tank; The first connecting end of the flow guiding structure is connected to the inner wall of the gas storage tank, and the second connecting end of the flow guiding structure is connected to the water collection structure. The flow guiding structure is used to receive the condensate formed in the gas storage tank and guide the condensate to the water collection structure.

4. The drainage system of the compressed gas storage artificial underground gas storage facility according to claim 3, characterized in that: The side of the flow guiding structure facing the interior of the gas storage tank is set as an inclined surface; The water collection structure includes a water collection trough, which is located at the end of the inclined surface with a lower height.

5. The drainage system of the compressed gas storage artificial underground gas storage facility according to claim 4, characterized in that: The slope of the inclined surface is greater than or equal to 3%.

6. The drainage system of the compressed gas storage artificial underground gas storage facility according to claim 4, characterized in that: A drainage groove is provided on the inclined surface, the extension direction of the drainage groove is consistent with the inclination direction of the inclined surface, and the interior of the drainage groove is connected to the interior of the water collection groove.

7. The drainage system of the compressed gas storage artificial underground gas storage facility according to claim 1, characterized in that: The drainage pipe is equipped with a drainage valve, and the drainage system also includes a controller connected to the drainage valve for controlling the opening or closing of the drainage valve.

8. The drainage system of the compressed gas storage artificial underground gas storage facility according to claim 7, characterized in that: The water collection structure is equipped with a liquid level detection element, which is used to detect the current liquid level in the water collection structure. The controller is connected to the liquid level detection element and is used to control the drain valve to open when the detected current liquid level reaches a first preset height, or to control the drain valve to close when the detected current liquid level reaches a second preset height.

9. The drainage system of the compressed gas storage artificial underground gas storage facility according to claim 8, characterized in that: The liquid level detection element includes a first liquid level sensor and a second liquid level sensor; The first liquid level sensor is set at a first height position within the water collection structure to detect whether the current liquid level has reached a first preset height; The second liquid level sensor is located at a second height within the water collection structure to detect whether the current liquid level has reached a second preset height.

10. The drainage system of the compressed gas storage artificial underground gas storage facility according to claim 1, characterized in that: The gas storage tank is equipped with a pressure detection element, which is used to detect the gas pressure inside the gas storage tank.

11. A drainage method, using the drainage system of a compressed gas storage artificial underground gas storage facility as described in any one of claims 1-10, characterized in that, include: Compressed air is introduced into the gas storage tank to increase the gas pressure inside the tank. Injection stops when the gas pressure reaches the first operating pressure, and the gas storage tank is in a first operating state. The gas storage tank is connected to a first gas supply pipe and an exhaust pipe. The input end of the first gas supply pipe is connected to a gas source, which provides compressed air to the gas storage tank. An inlet valve is installed on the first gas supply pipe, and an outlet valve is installed on the exhaust pipe. The gas storage tank exhausts gas to the outside, causing the gas pressure inside the gas storage tank to drop. When the gas pressure inside the gas storage tank reaches the second operating pressure, the exhaust stops, and the gas storage tank is in the second working state. In the second working state, the pressure in the water collection well is adjusted by the pressure regulating structure so that the pressure in the water collection well is lower than the pressure inside the gas storage tank. The drainage pipe is then opened, allowing the condensate in the water collection structure to flow into the water collection well along the drainage pipe. A second gas supply pipe is connected to the water collection well, and the input end of the second gas supply pipe is connected to the gas source, which is also used to provide compressed air to the water collection well. The pressure regulating structure includes a pressure regulating valve, which is installed on the second gas supply pipe. The pressure in the water collection well originates from the gas source.

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