Water tank pressure maintaining device of compressed air energy storage system and working method thereof

Abstract

The application discloses a compressed air energy storage system water tank pressure maintaining device and a working method thereof, which comprises a water tank, a water tank air supplementing module, a gas storage tank and a gas storage tank air supplementing module. The water tank air supplementing module comprises a starting air supplementing pipeline and a running air supplementing pipeline, the water tank is connected with the starting air supplementing pipeline and the running air supplementing pipeline through a compressed air pipeline, and a water tank pressure detecting element is arranged on the water tank. The starting air supplementing pipeline is connected with a compressor, the running air supplementing pipeline is connected with the gas storage tank, and the running air supplementing pipeline is controlled to be opened or closed according to the detected water tank pressure. The gas storage tank air supplementing module comprises an air compressor gas supply pipeline, a compressor gas supply pipeline and an expander gas supply pipeline, the gas storage tank is connected with the three gas supply pipelines, a gas tank pressure detecting element is arranged on the gas storage tank, and the three gas supply pipelines are controlled to be opened or closed according to the detected gas tank pressure. The water tank is maintained at a certain pressure, the pressure in the water tank is controlled within a certain range, and the water is kept in a liquid state and does not vaporize.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compressed air energy storage, in particular to a water tank pressure maintaining device of a compressed air energy storage system and a working method thereof. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] The compressed air energy storage technology is a power generation technology in which the air compression process and the expansion process are performed at different times. During energy storage, electric energy drives an air compressor through a motor to produce high-temperature and high-pressure air. After heat exchange through a heat exchanger, the cooled compressed air is stored in a gas storage system, and the compression heat is stored in a heat storage system. During energy release (power generation), the gas storage system releases the stored compressed air, which, after absorbing the compression heat stored in the heat storage system through the heat exchanger, enters an air expander to do work and expand, and drives a generator to output electric power.

[0004] Currently, compressed air energy storage systems mainly include advanced adiabatic compressed air energy storage systems, liquefied air energy storage systems, and supercritical compressed air energy storage systems. Regardless of which type, heat exchange is required during the energy storage process. Currently, heat exchangers and high and low temperature medium storage tanks are used to achieve heat storage and heat release. Since water has the advantages of strong adaptability, easy availability, high safety, and low cost, the high and low temperature medium in the storage tank is generally water.

[0005] The high and low temperature water tanks utilize water and air heat exchange in the compressed air energy storage system. The heated water is stored in the high temperature water tank, and the cooled water is stored in the low temperature water tank. The water in the high and low temperature water tanks is recycled to complete the air compression and expansion process.

[0006] However, at standard atmospheric pressure, the boiling point of water is 100℃. When the temperature of water exceeds 100℃, the water will vaporize. In the compressed air energy storage system, the temperature of water in the high temperature water tank will be higher than 100℃ depending on the system parameters. Once the water vaporizes, it will have a great impact on the safe operation of the entire compressed air system. Therefore, to ensure the safe and stable operation of the system, the problem of water vaporization in the water tank needs to be solved. SUMMARY

[0007] To solve the above problems, the present application provides a water tank pressure maintaining device of a compressed air energy storage system and a working method thereof. By maintaining the pressure of the water tank, the pressure in the water tank is controlled within a certain range, ensuring that the water remains in a liquid state and does not vaporize, thereby ensuring the safe and stable operation of the compressed air energy storage system.

[0008] To achieve the above purpose, the present application adopts the following technical solutions:

[0009] In a first aspect, the present application provides a water tank pressure maintaining device of compressed air energy storage system, comprising: a water tank, a water tank air supplement module, a gas storage tank and a gas storage tank air supplement module;

[0010] The water tank air supplement module comprises a starting air supplement pipeline and a running air supplement pipeline, the water tank is connected with the starting air supplement pipeline and the running air supplement pipeline through a compressed air pipeline, and a water tank pressure detection element is arranged on the water tank;

[0011] The starting air supplement pipeline is connected with a compressor, the running air supplement pipeline is connected with the gas storage tank, and the running air supplement pipeline is controlled to be opened or closed according to the detected water tank pressure;

[0012] The gas storage tank air supplement module comprises an air compressor air supply pipeline, a compressor air supply pipeline and an expander air supply pipeline, the gas storage tank is connected with the three air supply pipelines, and a gas tank pressure detection element is arranged on the gas storage tank, and the three air supply pipelines are controlled to be opened or closed according to the detected gas tank pressure.

[0013] As an optional implementation, the water tank comprises a high-temperature water tank and a low-temperature water tank;

[0014] The high-temperature water tank and the low-temperature water tank are connected through a communication pipe, and the communication pipe is connected with the water tank air supplement module through a compressed air pipeline;

[0015] The water tank pressures in the high-temperature water tank and the low-temperature water tank are consistent;

[0016] As an optional implementation, a first safety valve and a water tank pressure detection element are arranged on the communication pipe, and when the water tank pressure exceeds the take-off pressure of the first safety valve, the first safety valve automatically opens to release pressure, and the water tank pressure is kept within an allowable range without overpressure.

[0017] As an optional implementation, one end of the starting air supplement pipeline is connected with the water tank through a compressed air pipeline, the other end is connected to the compressor in sequence through a first electric shut-off valve, a second check valve and a first pressure reducing valve, and the compressed air from the compressor side is reduced and supplemented into the water tank.

[0018] As an optional implementation, one end of the running air supplement pipeline is connected with the water tank through a compressed air pipeline, the other end is connected to the gas storage tank in sequence through a first check valve, a shut-off valve and an automatic air supplement valve, and the running air supplement is provided by the gas storage tank.

[0019] As an optional implementation, when the water tank pressure is lower than the minimum allowable pressure of the water tank, the automatic air supplement valve is opened, the running air supplement pipeline is started, and the gas storage tank starts to supplement air;

[0020] When the water tank pressure is higher than the maximum allowable pressure of the water tank, the automatic air supplement valve is closed, the running air supplement pipeline is closed, and the gas storage tank stops supplementing air.

[0021] As an alternative embodiment, a second safety valve is further provided on the gas tank, and when the gas tank pressure exceeds the take-off pressure of the second safety valve, the second safety valve automatically opens to release pressure;

[0022] When the gas tank pressure is lower than the minimum allowable pressure of the gas tank, the gas tank is supplemented by the gas tank supplementing module;

[0023] When the gas tank pressure is higher than the maximum allowable pressure of the gas tank, the gas tank supplementing module stops supplementing.

[0024] As an alternative embodiment, one end of the compressor gas supply pipeline is connected to the compressor, and the other end is connected to the gas tank through the second pressure reducing valve, the fourth check valve, the third electric shut-off valve, and the inlet shut-off valve in sequence;

[0025] One end of the expander gas supply pipeline is connected to the expander, and the other end is connected to the gas tank through the third pressure reducing valve, the fifth check valve, the fourth electric shut-off valve, and the inlet shut-off valve in sequence;

[0026] One end of the air compressor gas supply pipeline is connected to the air compressor, and the other end is connected to the gas tank through the third check valve, the second electric shut-off valve, and the inlet shut-off valve in sequence;

[0027] The compressor gas supply pipeline and the expander gas supply pipeline do not operate at the same time, and when neither the compressor gas supply pipeline nor the expander gas supply pipeline operates, the air compressor gas supply pipeline is used for supplementing.

[0028] In a second aspect, the application provides a working method of a water tank pressure maintaining device of a compressed air energy storage system, which is used in the water tank pressure maintaining device of the compressed air energy storage system of the first aspect, and includes:

[0029] When the water tank is started for the first time, the water tank is supplied with compressed air from the compressor side through the starting supplementing pipeline;

[0030] During operation, the opening and closing of the running supplementing pipeline is controlled according to the detected water tank pressure to supply the water tank with air;

[0031] When the water tank pressure is lower than the minimum allowable pressure of the water tank, the automatic supplementing valve is opened to start the running supplementing pipeline, and the gas tank starts to supplement; when the water tank pressure is higher than the maximum allowable pressure of the water tank, the automatic supplementing valve is closed to close the running supplementing pipeline, and the gas tank stops supplementing;

[0032] According to the detected gas tank pressure, when the gas tank pressure is lower than the minimum allowable pressure of the gas tank, the gas tank is supplemented by the gas tank supplementing module, and when the gas tank pressure is higher than the maximum allowable pressure of the gas tank, the gas tank supplementing module stops supplementing;

[0033] The air tank air supplement module comprises an air compressor air supply pipeline, a compressor air supply pipeline and an expander air supply pipeline, the compressor air supply pipeline and the expander air supply pipeline are not operated at the same time, and when neither the compressor air supply pipeline nor the expander air supply pipeline is operated, air is supplemented by the air compressor air supply pipeline.

[0034] In a third aspect, the application provides a compressed air energy storage system, comprising the water tank pressure maintaining device, the compressor and the expander of the compressed air energy storage system according to the first aspect.

[0035] The compressor is used for supplementing air to the water tank.

[0036] The compressor and the expander are used for supplementing air to the air tank, and the compressor and the expander are not operated at the same time when supplementing air to the air tank.

[0037] Compared with the prior art, the application has the following beneficial effects:

[0038] The application provides a water tank pressure maintaining device of a compressed air energy storage system and a working method thereof, compressed air is used for maintaining pressure of the water tank, the pressure in the water tank is controlled within a certain range, the water is always in a liquid state and does not vaporize, and the safe and stable operation of the compressed air energy storage system is ensured.

[0039] The application provides a water tank pressure maintaining device of a compressed air energy storage system and a working method thereof, a high-temperature water tank and a low-temperature water tank are connected, after initial filling of compressed air, only the leakage amount of compressed air needs to be supplemented subsequently, related matching equipment is small in type selection, and investment is saved.

[0040] The application provides a water tank pressure maintaining device of a compressed air energy storage system and a working method thereof, three air supply pipelines of an air tank air supplement module, that is, the working condition that the compressor and the expander are not operated at the same time is fully utilized, the reliability of the air source is ensured, air is supplemented by the air compressor when neither the compressor nor the expander is operated, the stability of the air supplement pressure is ensured, frequent operation of the air compressor is avoided, the system is optimized, and plant power consumption is saved.

[0041] The advantages of the additional aspects of the application will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0042] The drawings accompanying the specification of the application form a part of the application and serve to provide further understanding of the application, the illustrative embodiments of the application and the description thereof serve to explain the application, and do not constitute an improper limitation on the application.

[0043] Figure 1 A compressed air energy storage system water tank pressure maintaining device schematic diagram provided for the first embodiment of the application;

[0044] Wherein, 1-1, high temperature water tank, 1-2, low temperature water pipe, 1-3, communication pipe, 1-4, first pressure transmitter, 1-5, first safety valve, 1-6, compressed air pipe, 1-7, water pipe, 2-1, automatic air supply valve, 2-2, shut-off valve, 2-3, first check valve, 2-4, bypass valve, 2-5, operation air supply pipe, 2-6, first pressure reducing valve, 2-7, second check valve, 2-8, first electric shut-off valve, 2-9, start-up air supply pipe, 3-1, gas storage tank, 3-2, second safety valve, 3-3, second pressure transmitter, 3-4, outlet shut-off valve, 3-5, inlet shut-off valve, 4-1, air compressor, 4-2, third check valve, 4-3, second electric shut-off valve, 4-4, air compressor gas supply pipe, 4-5, second pressure reducing valve, 4-6, fourth check valve, 4-7, third electric shut-off valve, 4-8, compressor gas supply pipe, 4-9, third pressure reducing valve, 4-10, fifth check valve, 4-11, fourth electric shut-off valve, 4-12, expander gas supply pipe. DETAILED DESCRIPTION

[0045] The application will be further described below in connection with the drawings and examples.

[0046] It should be noted that the following detailed description is exemplary in nature and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0047] It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, as the scope of the application will be limited only by the appended claims. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Unless otherwise required by context, singular terms shall include pluralities and vice versa. Plural elements can be separated by a hyphenated form and can contain hyphenated forms.

[0048] The embodiments in the application and the features in the embodiments can be combined with each other without conflict.

[0049] Example 1

[0050] The compressed air energy storage technology is a power generation technology in which air compression and expansion processes are performed at different times. When the system stores energy, the water in the low-temperature water tank is heated by a heat exchanger and becomes high-temperature water which is stored in the high-temperature water tank. When the system releases energy (generates power), the water in the high-temperature water tank is cooled by the heat exchanger and becomes low-temperature water which is stored in the low-temperature water tank. Through the continuous storage and release of heat by the high-temperature water tank and the low-temperature water tank, the compressed air energy storage system operates.

[0051] However, in the process of heat storage and release of the high-temperature water tank and the low-temperature water tank, when the low-temperature water absorbs heat and becomes high-temperature water, the water temperature exceeds 100℃ at standard atmospheric pressure, and the water vaporizes. In order to avoid the phase change of water, a certain pressure needs to be set for the high-temperature water tank and the low-temperature water tank to ensure that the water does not vaporize, thereby ensuring the safe and stable operation of the system.

[0052] Therefore, the embodiment provides a compressed air energy storage system water tank pressure maintaining device, which ensures that the pressure in the water tank is controlled within a certain range, ensures that the water is always in a liquid state and does not vaporize, and thereby ensures that the compressed air energy storage system can operate safely and stably.

[0053] Specifically, it includes a water tank, a water tank air supplement module, a gas storage tank and a gas storage tank air supplement module.

[0054] The water tank air supplement module includes a start-up air supplement pipeline and a running air supplement pipeline, the water tank is connected with the start-up air supplement pipeline and the running air supplement pipeline through a compressed air pipeline, and a water tank pressure detection element is arranged on the water tank.

[0055] The start-up air supplement pipeline is connected with a compressor, the running air supplement pipeline is connected with the gas storage tank, and the running air supplement pipeline is controlled to open and close according to the detected water tank pressure.

[0056] The gas storage tank air supplement module includes an air compressor gas supply pipeline, a compressor gas supply pipeline and an expander gas supply pipeline, the gas storage tank is connected with the three gas supply pipelines, and a gas tank pressure detection element is arranged on the gas storage tank, and the three gas supply pipelines are controlled to open and close according to the detected gas tank pressure.

[0057] In combination Figure 1 The compressed air energy storage system water tank pressure maintaining device is described in detail.

[0058] In the embodiment, the water tank includes a high-temperature water tank 1-1 and a low-temperature water tank 1-2.

[0059] The high-temperature water tank 1-1 and the low-temperature water tank 1-2 are connected through a communication pipe 1-3 to ensure that the water tank pressures in the high-temperature water tank 1-1 and the low-temperature water tank 1-2 are consistent.

[0060] The water tank pressure detection member adopts a first pressure transmitter 1-4, a first safety valve 1-5 and a first pressure transmitter 1-4 are arranged on the communication pipe 1-3, the water tank pressure is detected by the first pressure transmitter 1-4, so that the water tank pressure in the high-temperature water tank 1-1 and the low-temperature water tank 1-2 is kept within the allowable range and does not exceed the pressure; and when the water tank pressure exceeds the take-off pressure of the first safety valve 1-5, the first safety valve 1-5 automatically opens to release the pressure, so as to ensure the safety of the equipment.

[0061] The high-temperature water tank 1-1 comprises a high-temperature water inlet and a high-temperature water outlet, the high-temperature water inlet is connected with the air-water heat exchanger through the water pipeline 1-7, and the high-temperature water outlet is connected with the air-water heater through the water pipeline 1-7; similarly, the low-temperature water tank 1-2 comprises a high-temperature water inlet and a high-temperature water outlet, the high-temperature water inlet is connected with the air-water heater through the water pipeline 1-7, and the high-temperature water outlet is connected with the air-water heat exchanger through the water pipeline 1-7, so as to complete the circulation operation of the high-temperature water and the low-temperature water.

[0062] The high-temperature water tank 1-1 and the low-temperature water tank 1-2 are both provided with a compressed air interface, the compressed air pipeline 1-6 is connected with the compressed air interface, the compressed air pipeline 1-6 is connected with the water tank air supplement module, the high-temperature water tank 1-1 and the low-temperature water tank 1-2 are supplemented with air through the water tank air supplement module, the pressure maintaining operation of the high-temperature water tank 1-1 and the low-temperature water tank 1-2 is completed, and it is ensured that the water does not gasify.

[0063] In the embodiment, the water tank air supplement module comprises a starting air supplement pipeline 2-9 and a running air supplement pipeline 2-5.

[0064] The starting air supplement pipeline 2-9 is used for supplementing air to the high-temperature water tank 1-1 and the low-temperature water tank 1-2 at the initial start, one end of the starting air supplement pipeline 2-9 is connected with the high-temperature water tank 1-1 and the low-temperature water tank 1-2 through the compressed air pipeline 1-6, the other end is sequentially connected to the compressor through the first electrically-operated shut-off valve 2-8, the second check valve 2-7 and the first pressure reducing valve 2-6, and the compressed air on the side of the compressor is reduced and supplemented into the high-temperature water tank 1-1 and the low-temperature water tank 1-2.

[0065] Since the air supplement amount at the initial start is large, a certain amount of compressed air is filled into the high-temperature water tank 1-1 and the low-temperature water tank 1-2 by the compressor according to the water tank pressure requirement; the specific air supplement path is: air supplement to the high-temperature water tank 1-1 and the low-temperature water tank 1-2 through the first pressure reducing valve 2-6, the second check valve 2-7, the first electrically-operated shut-off valve 2-8, the starting air supplement pipeline 2-9, the compressed air pipeline 1-6 and the communication pipe 1-3.

[0066] The operation air supplement pipeline 2-5 is used for supplementing air according to the leakage amount when the high-temperature water tank 1-1 and the low-temperature water tank 1-2 are in operation, one end of the operation air supplement pipeline 2-5 is connected to the high-temperature water tank 1-1 and the low-temperature water tank 1-2 through the compressed air pipeline 1-6, and the other end is connected to the gas storage tank 3-1 in sequence through the first check valve 2-3, the shut-off valve 2-2 and the automatic air supplement valve 2-1, and the operation air supplement is provided by the gas storage tank 3-1;

[0067] The water tank pressure is detected according to the first pressure transmitter 1-4 arranged on the water tank, the automatic air supplement valve 2-1 is opened and closed according to the water tank pressure, and the operation air supplement pipeline 2-5 is started or stopped;

[0068] When the water tank pressure is lower than the set minimum allowable pressure, the automatic air supplement valve 2-1 is opened, and air supplement is performed through the gas storage tank 3-1, the outlet shut-off valve 3-4, the shut-off valve 2-2, the air supplement valve 2-1, the first check valve 2-3, the operation air supplement pipeline 2-5, the compressed air pipeline 1-6 and the communication pipeline 1-3;

[0069] When the water tank pressure is higher than the set maximum allowable pressure, the automatic air supplement valve 2-1 is closed, and the gas storage tank 3-1 stops air supplement.

[0070] In the embodiment, the bypass valve 2-4 is further arranged between the first check valve 2-3 and the gas storage tank 3-1.

[0071] In the embodiment, the gas storage tank 3-1 realizes automatic air supplement of the high-temperature water tank 1-1 and the low-temperature water tank 1-2 according to the pressure setting of the first pressure transmitter 1-4 and the automatic air supplement valve 2-1.

[0072] In the embodiment, the gas storage tank 3-1 is provided with the outlet shut-off valve 3-4 and the inlet shut-off valve 3-5, the outlet shut-off valve 3-4 is connected to the shut-off valve 2-2, and the inlet shut-off valve 3-5 is connected to the gas storage tank air supplement module.

[0073] In the embodiment, the gas storage tank 3-1 is further provided with a gas tank pressure detection member, the gas tank pressure detection member adopts a second pressure transmitter 3-3, and the gas tank pressure interlocking control is realized by the second pressure transmitter 3-3 to ensure that the gas tank pressure in the gas storage tank 3-1 is within a certain range.

[0074] When the gas tank pressure is lower than the minimum allowable pressure, the gas storage tank air supplement module supplements air to the gas storage tank 3-1;

[0075] When the gas tank pressure is higher than the maximum allowable pressure, the gas storage tank air supplement module stops air supplement.

[0076] In the embodiment, the gas tank 3-1 is further provided with a second safety valve 3-2. When the pressure in the gas tank 3-1 exceeds the take-off pressure of the second safety valve 3-2, the second safety valve 3-2 is automatically opened to release pressure, thereby ensuring the safety of the equipment.

[0077] In the embodiment, the gas tank air supplement module includes an air compressor air supply pipeline 4-4, a compressor air supply pipeline 4-8, and an expander air supply pipeline 4-12. The three air supply pipelines supply air to the gas tank 3-1.

[0078] The first air source is compressed air from the compressor side, the second air source is compressed air from the expander side, and the third air source is air from the air compressor. When the first or second air source fails, the third air source can be used as a backup air source for the first and second air sources.

[0079] In the embodiment, one end of the compressor air supply pipeline 4-8 is connected to the compressor, and the other end is sequentially connected to the gas tank 3-1 through a second pressure reducing valve 4-5, a fourth check valve 4-6, a third electric shut-off valve 4-7, and an inlet shut-off valve 3-5.

[0080] One end of the expander air supply pipeline 4-12 is connected to the expander, and the other end is sequentially connected to the gas tank 3-1 through a third pressure reducing valve 4-9, a fifth check valve 4-10, a fourth electric shut-off valve 4-11, and an inlet shut-off valve 3-5.

[0081] One end of the air compressor air supply pipeline 4-4 is connected to the air compressor 4-1, and the other end is sequentially connected to the gas tank 3-1 through a third check valve 4-2, a second electric shut-off valve 4-3, and an inlet shut-off valve 3-5.

[0082] In the embodiment, since the compressor and the expander do not operate at the same time, the gas tank air supplement process is as follows:

[0083] When the compressor is operating, the gas tank 3-1 is supplied with compressed air from the compression side after pressure reduction. The specific path is: compressor air supply pipeline 4-8, second pressure reducing valve 4-5, fourth check valve 4-6, third electric shut-off valve 4-7, inlet shut-off valve 3-5, and gas tank 3-1.

[0084] When the expander is operating, the gas tank 3-1 is supplied with compressed air from the expansion side after pressure reduction. The specific path is: expander air supply pipeline 4-12, third pressure reducing valve 4-9, fifth check valve 4-10, fourth electric shut-off valve 4-11, inlet shut-off valve 3-5, and gas tank 3-1.

[0085] When neither the compressor nor the expander is running, the air supplement is supplied by the air compressor 4-1, and the specific path is: air compressor 4-1, air compressor air supply pipeline 4-4, third check valve 4-2, second electric shut-off valve 4-3, inlet shut-off valve 3-5 and air tank 3-1.

[0086] The water tank pressure maintaining device provided in the embodiment uses compressed air to maintain the pressure of the water tank, ensures that the pressure in the water tank is controlled within a certain range, ensures that the water is always in a liquid state and does not vaporize, and further ensures the safe and stable operation of the compressed air energy storage system.

[0087] Embodiment 2

[0088] The embodiment provides a working method of the water tank pressure maintaining device of the compressed air energy storage system described in embodiment 1, comprising:

[0089] When the water tank is started for the first time, the water tank is supplied with air through the starting air supplement pipeline from the compressed air on the compressor side;

[0090] During operation, the opening and closing of the operation air supplement pipeline is controlled according to the detected water tank pressure to supply air to the water tank;

[0091] When the water tank pressure is lower than the minimum allowable pressure of the water tank, the automatic air supplement valve is opened, the operation air supplement pipeline is started, and the air tank starts to supplement air; when the water tank pressure is higher than the maximum allowable pressure of the water tank, the automatic air supplement valve is closed, the operation air supplement pipeline is closed, and the air tank stops supplementing air;

[0092] According to the detected air tank pressure, when the air tank pressure is lower than the minimum allowable pressure of the air tank, the air tank is supplemented with air by the air tank supplement module; when the air tank pressure is higher than the maximum allowable pressure of the air tank, the air tank supplement module stops supplementing air;

[0093] The air tank supplement module comprises an air compressor air supply pipeline, a compressor air supply pipeline and an expander air supply pipeline, the compressor air supply pipeline and the expander air supply pipeline do not run at the same time, and when neither the compressor air supply pipeline nor the expander air supply pipeline is running, the air supplement is supplied by the air compressor air supply pipeline.

[0094] Embodiment 3

[0095] The embodiment provides a compressed air energy storage system, comprising the water tank pressure maintaining device described in embodiment 1, a compressor and an expander;

[0096] The compressor is used to supplement air to the water tank;

[0097] The compressor and the expander are used to supplement air to the air tank, and the compressor and the expander do not run at the same time when supplementing air to the air tank.

[0098] The above describes the specific embodiments of the present application in combination with the drawings, but is not a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications or variations made by those skilled in the art on the basis of the technical solutions of the present application without creative labor are still within the protection scope of the present application.

Claims

1. A water tank pressure maintaining device of a compressed air energy storage system, characterized by, The application relates to a water tank and a water tank air supplement module. The water tank air supplement module comprises a starting air supplement pipeline and a running air supplement pipeline, the water tank is connected with the starting air supplement pipeline and the running air supplement pipeline through a compressed air pipeline, and a water tank pressure detection element is arranged on the water tank. The starting air supplement pipeline is connected with a compressor, the running air supplement pipeline is connected with a gas storage tank, and the running air supplement pipeline is controlled to be opened or closed according to the detected water tank pressure. The starting air supplement pipeline is used for supplementing air to the water tank when the water tank is started for the first time, one end of the starting air supplement pipeline is connected with the water tank through the compressed air pipeline, the other end is sequentially connected with the compressor through a first electrically-operated shut-off valve, a second check valve and a first pressure reducing valve, compressed air from the side of the compressor is reduced in pressure and then supplemented into the water tank, and the specific air supplement path is: air is supplemented into the water tank through the first pressure reducing valve, the second check valve, the first electrically-operated shut-off valve, the starting air supplement pipeline, the compressed air pipeline and a communication pipeline. The running air supplement pipeline is used for supplementing air to the water tank according to the leakage amount when the water tank is running, one end of the running air supplement pipeline is connected with the water tank through the compressed air pipeline, the other end is sequentially connected with the gas storage tank through a first check valve, a shut-off valve and an automatic air supplement valve, and the gas storage tank provides running air supplement. When the water tank pressure is lower than the set minimum allowable pressure, the automatic air supplement valve is opened, air is supplemented through the gas storage tank, an outlet shut-off valve, the shut-off valve, an air supplement valve, the first check valve, the running air supplement pipeline, the compressed air pipeline and the communication pipeline. When the water tank pressure is higher than the set maximum allowable pressure, the automatic air supplement valve is closed, and the gas storage tank stops supplementing air. The gas storage tank air supplement module comprises a compressed air machine air supply pipeline, a compressor air supply pipeline and an expander air supply pipeline, the gas storage tank is connected with the three air supply pipelines, a gas tank pressure detection element is arranged on the gas storage tank, and the three air supply pipelines are controlled to be opened or closed according to the detected gas tank pressure. The water tank comprises a high-temperature water tank and a low-temperature water tank.

2. The water tank pressure maintaining device of compressed air energy storage system according to claim 1, characterized in that, The high-temperature water tank and the low-temperature water tank are connected through a communication pipeline, the communication pipeline is connected with the water tank air supplement module through a compressed air pipeline. The water tank pressures in the high-temperature water tank and the low-temperature water tank are consistent. A first safety valve and a water tank pressure detection element are arranged on the communication pipeline, and when the water tank pressure exceeds the take-off pressure of the first safety valve, the first safety valve is automatically opened to release pressure, and the water tank pressure is kept within the allowable range and does not exceed pressure.

3. The water tank pressure maintaining device of compressed air energy storage system according to claim 2, characterized in that, A second safety valve is further arranged on the gas storage tank, and when the gas tank pressure in the gas storage tank exceeds the take-off pressure of the second safety valve, the second safety valve is automatically opened to release pressure.

4. The water tank pressure maintaining device of compressed air energy storage system according to claim 1, characterized in that, When the gas tank pressure is lower than the minimum allowable pressure of the gas tank, the gas storage tank is supplemented with air by the gas storage tank air supplement module. When the gas tank pressure is higher than the maximum allowable pressure of the gas tank, the gas storage tank air supplement module stops supplementing air. One end of the compressor air supply pipeline is connected with the compressor, the other end is sequentially connected with the gas storage tank through a second pressure reducing valve, a fourth check valve, a third electrically-operated shut-off valve and an inlet shut-off valve.

5. The water tank pressure maintaining device of compressed air energy storage system according to claim 1, characterized in that, One end of the expander air supply pipeline is connected with the expander, the other end is sequentially connected with the gas storage tank through a third pressure reducing valve, a fifth check valve, a fourth electrically-operated shut-off valve and the inlet shut-off valve. ​ One end of the air compressor air supply pipeline is connected to the air compressor, and the other end is connected to the air tank through the third check valve, the second electric shut-off valve and the inlet shut-off valve in sequence; The compressor air supply pipeline and the expander air supply pipeline do not operate at the same time, and when the compressor air supply pipeline and the expander air supply pipeline do not operate, air is supplied by the air compressor air supply pipeline.

6. A method of operating a water tank pressure maintaining device of a compressed air energy storage system, characterized by, The water tank pressure maintaining device for the compressed air energy storage system of any one of claims 1-5 comprises: When the water tank is started for the first time, the water tank is supplied with air through the starting air supply pipeline from the compressed air on the compressor side; During operation, the opening and closing of the operation air supply pipeline is controlled according to the detected water tank pressure to supply air to the water tank; When the water tank pressure is lower than the minimum allowable pressure of the water tank, the automatic air supply valve is opened, the operation air supply pipeline is started, and the air tank starts to supply air; when the water tank pressure is higher than the maximum allowable pressure of the water tank, the automatic air supply valve is closed, the operation air supply pipeline is closed, and the air tank stops supplying air; According to the detected air tank pressure, when the air tank pressure is lower than the minimum allowable pressure of the air tank, the air tank is supplied with air by the air tank air supply module, and when the air tank pressure is higher than the maximum allowable pressure of the air tank, the air tank air supply module stops supplying air; The air tank air supply module comprises an air compressor air supply pipeline, a compressor air supply pipeline and an expander air supply pipeline, the compressor air supply pipeline and the expander air supply pipeline do not operate at the same time, and when the compressor air supply pipeline and the expander air supply pipeline do not operate, air is supplied by the air compressor air supply pipeline.

7. A compressed air energy storage system characterized in that, The compressed air energy storage system of any one of claims 1-5 comprises a water tank pressure maintaining device, a compressor and an expander; The compressor is used to supply air to the water tank; The compressor and the expander are used to supply air to the air tank, and the compressor and the expander do not operate at the same time when the air tank is supplied with air.

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