Compressed air energy storage system with electric auxiliary heating function

Abstract

The utility model discloses a compressed air energy storage system with electric auxiliary heating, which comprises an energy storage module, a corresponding compression module and a corresponding power generation module, the energy storage module comprises a gas storage container, a low-temperature storage tank, a high-temperature storage tank and an electric heating device, wherein the low-temperature storage tank and the high-temperature storage tank are matched with the gas storage container, and the electric heating device is arranged in the high-temperature storage tank. The compression module comprises a low-pressure compressor, a first heat exchanger, a high-pressure compressor and a second heat exchanger; the power generation module comprises a third heat exchanger, a high-pressure expansion machine, a fourth heat exchanger and a low-pressure expansion machine. According to the utility model, electricity and trough electricity which cannot be connected to the internet, such as abandoned wind and abandoned light, are utilized, energy is stored in the form of heat and compressed gas through the heat exchanger and the compressor, and energy is released in the expansion machine, so that the storage and conversion of electric energy are realized.

Description

Technical Field

[0001] The utility model relates to the technical field of energy and power, and in particular to a compressed air energy storage system with electric auxiliary heating. Background Art

[0002] At present, with the increase in the rate of wind and solar power abandonment and the large amount of electricity in the valley, the storage of excess electricity is becoming more and more popular. Compressed air energy storage has long been recognized as a feasible large-scale energy storage application technology. However, with the soaring prices of fossil fuels such as fuel oil and natural gas, the cost of related industries has been further increased for supplementary compressed air energy storage, and secondly, carbon emissions have increased, which is contrary to the country's advocacy of reducing carbon emissions. Therefore, it is of great significance to improve the existing compressed air energy storage technology, further improve the efficiency of compressed air circulation and reduce carbon emissions.

[0003] Prior art, CN202321892690.7 A new type of compressed air energy storage system, comprising: a compression system and a first expansion system and a second expansion system arranged in parallel, the compression system comprising a first air storage device and a second air storage device, the first expansion system comprising a first deflation valve connected to the outlet of the first air storage device, the second expansion system comprising a second deflation valve connected to the outlet of the second air storage device, the first deflation valve is connected to the first expansion machine through a first energy release heat exchange unit, the second deflation valve is connected to the second expansion machine through a second energy release heat exchange unit, the outlet of the first deflation valve is also connected to the outlet of the second deflation valve through a connecting valve, and the energy release heat exchange unit is also connected to the heat storage device for heat exchange. However, the compressed air energy storage system in the prior art has the following defects: 1. The compressed air energy storage system in the prior art involves multiple components and systems, such as air venting valves, heat exchange units, heat storage devices, etc. The system structure is relatively complex, which increases the maintenance and management costs of the system operation; 2. The compressed air energy storage system in the prior art is powered by the power grid and new energy power sources. In the energy conversion process, there is a lack of utilization of abandoned wind and solar power generation and valley electricity, resulting in reduced energy utilization efficiency.

[0004] Therefore, it is necessary to improve the compressed air energy storage system in the prior art to solve the above problems. Summary of the invention

[0005] The utility model overcomes the shortcomings of the prior art and provides a compressed air energy storage system with electric auxiliary heating, aiming to solve the problem of complex structure in the prior art and the problem of utilizing abandoned wind and solar energy.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a compressed air energy storage system with electric auxiliary heating, comprising: an energy storage module, and a compression module and a power generation module connected to the energy storage module, characterized in that;

[0007] The energy storage module comprises: a gas storage container, a low-temperature storage tank arranged in cooperation with the gas storage container, and a high-temperature storage tank connected to the low-temperature storage tank;

[0008] The compression module includes: a low-pressure compressor, a first heat exchanger connected to the low-pressure compressor, a high-pressure compressor connected to the first heat exchanger, and a second heat exchanger connected to the high-pressure compressor; the first heat exchanger and the second heat exchanger are respectively connected to the low-temperature storage tank and the high-temperature storage tank; the second heat exchanger is connected to the gas storage container;

[0009] The power generation module includes: a third heat exchanger, a high-pressure expander connected to the third heat exchanger, a fourth heat exchanger connected to the high-pressure expander, and a low-pressure expander connected to the fourth heat exchanger; the third heat exchanger is connected to the gas storage container; the third heat exchanger and the fourth heat exchanger are respectively connected to the low-temperature storage tank and the high-temperature storage tank.

[0010] In a preferred embodiment of the utility model, the low-pressure compressor and the high-pressure compressor use the power generation of abandoned wind and solar power and valley electricity, and the low-pressure compressor and the high-pressure compressor compress air into the air storage container.

[0011] In a preferred embodiment of the utility model, the high-temperature storage tank is provided with an electric heating device, and the electric heating device uses the power generation of abandoned wind and solar power and valley electricity.

[0012] In a preferred embodiment of the utility model, the high-temperature storage tank is provided with a solar heating device.

[0013] In a preferred embodiment of the utility model, the air discharge pipeline of the high-pressure expander is provided with a bypass connected to the air storage container.

[0014] In a preferred embodiment of the utility model, a plurality of regulating devices are arranged on the connecting pipelines between the high-temperature storage tank and the third heat exchanger and the fourth heat exchanger.

[0015] In a preferred embodiment of the present invention, the high-pressure expander is replaced by a pressure regulating or throttling device.

[0016] In a preferred embodiment of the utility model, the high-pressure expander and the low-pressure expander are connected to a generator.

[0017] In a preferred embodiment of the utility model, working fluid is arranged in the low-temperature storage tank and the high-temperature storage tank. The working fluid in the low-temperature storage tank flows into the first heat exchanger and the second heat exchanger to absorb the heat of the compressed air and then flows into the high-temperature storage tank.

[0018] In a preferred embodiment of the utility model, the working fluid in the high-temperature storage tank flows into the third heat exchanger and the fourth heat exchanger respectively to heat the air discharged from the gas storage container and the high-pressure expander, and then enters the low-temperature storage tank.

[0019] The utility model solves the defects existing in the background technology, and has the following beneficial effects:

[0020] (1) The utility model utilizes the power generation of abandoned wind and solar power and valley electricity, and stores the electric energy in the form of heat and high-pressure gas in high-temperature storage tanks and gas storage containers through heat exchangers and compressors, thereby realizing the effective utilization and conversion of energy and improving the overall energy utilization efficiency. At the same time, the electric heating device can not only increase the temperature of the working fluid in the high-temperature storage tank, but also convert the electric energy into heat energy and store it in the high-temperature storage tank, so as to improve the working capacity of the expander and the energy storage conversion efficiency of the system. Due to heat loss or when long-term energy storage is required or other reasons, the temperature of the working fluid in the high-temperature storage tank is lower than the design value. The electric heating device can utilize the electricity that cannot be connected to the grid, such as abandoned wind and solar power, to increase the temperature of the working fluid in the high-temperature storage tank to within the design range.

[0021] (2) The utility model uses a control valve to adjust the amount of air heated by the heat exchanger to maximize the energy conversion efficiency. When the efficiency of converting the heating power or the collected solar energy into electricity generation is lower than a certain threshold, the amount of air heated by the heat exchanger can be reduced to zero to achieve energy efficiency optimization.

[0022] (3) The utility model adopts a solar heating device to heat the working fluid in the high-temperature storage tank, utilizes renewable energy to achieve clean energy utilization, and reduces dependence on traditional energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The utility model is further described below in conjunction with the accompanying drawings and embodiments;

[0024] Figure 1 It is a structural diagram of a preferred embodiment of the utility model;

[0025] In the figure: 1. gas storage container; 2. low-temperature storage tank; 3. high-temperature storage tank; 4. low-pressure compressor; 5. high-pressure compressor; 6. first heat exchanger; 7. second heat exchanger; 8. low-pressure expander; 9. high-pressure expander; 10. third heat exchanger; 11. fourth heat exchanger. DETAILED DESCRIPTION

[0026] The present invention will now be further described in detail in conjunction with the accompanying drawings and embodiments. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0027] like Figure 1 As shown, a compressed air energy storage system with electric auxiliary heating includes: an energy storage module, and a compression module and a power generation module connected to the energy storage module; the compression module uses the power that cannot be connected to the Internet, such as abandoned wind and abandoned solar power, and the valley electricity to drive the compressor to compress air, and the air is compressed by the compressor and then transported to the gas storage container 1; the electric heating device in the energy storage module uses the power that cannot be connected to the Internet, such as abandoned wind and abandoned solar power, to store the electric energy in the form of heat in the high-temperature storage tank 3; when electricity is needed, the power generation module sends the high-pressure air in the gas storage container 1 into the heat exchanger to absorb the heat of the working fluid in the high-temperature storage tank 3, and then enters the high-pressure expander 9 and the low-pressure expander 11 in turn to work, driving the generator to generate electricity. As the power generation proceeds, the pressure in the gas storage container 1 drops to a certain threshold, and the valve is closed so that the air in the gas storage container 1 no longer flows into the high-pressure expander 9; at the same time, the bypass valve is opened so that the air in the gas storage container 1 directly flows into the heat exchanger 11 and the low-pressure expander 8 to work.

[0028] The energy storage module includes: a gas storage container 1, a low-temperature storage tank 2 arranged in cooperation with the gas storage container 1, and a high-temperature storage tank 3 connected to the low-temperature storage tank 2 and an electric heating device in the tank; a working medium is arranged in the low-temperature storage tank 2 and the high-temperature storage tank 3; a condensate drainage and water absorption device is arranged in the gas storage container 1, which is used to process the condensate accumulated in the gas storage container 1 to ensure the normal operation of the system and prevent moisture or water from having a negative impact on the system;

[0029] The compression module includes: a low-pressure compressor 4, a first heat exchanger 6 connected to the low-pressure compressor 4, a high-pressure compressor 5 connected to the first heat exchanger 6, and a second heat exchanger 7 connected to the high-pressure compressor 5; the first heat exchanger 6 and the second heat exchanger 7 are respectively connected to the low-temperature storage tank 2 and the high-temperature storage tank 3; the second heat exchanger 7 is connected to the gas storage container 1, and an air condensate drain outlet is provided on the pipeline between the second heat exchanger 7 and the gas storage container 1 to treat the air condensate that may accumulate in the pipeline to ensure the normal operation of the pipeline; the low-pressure compressor 4 and the high-pressure compressor 5 use the abandoned wind and solar power and the valley power, and the low-pressure compressor 4 and the high-pressure compressor 5 compress the air into the gas storage container 1; the low-temperature working fluid in the low-temperature storage tank 2 enters the first heat exchanger 6 and the second heat exchanger 7 respectively to exchange heat with the compressed air, and after absorbing the heat of the compressed air, it flows into the high-temperature storage tank 3 and is stored;

[0030] The power generation module includes: a third heat exchanger 10, a high-pressure expander 9 connected to the third heat exchanger 10, a fourth heat exchanger 11 connected to the high-pressure expander 9, and a low-pressure expander 8 connected to the fourth heat exchanger 11; the third heat exchanger 10 is connected to the gas storage container 1; the third heat exchanger 10 and the fourth heat exchanger 11 are respectively connected to the low-temperature storage tank 2 and the high-temperature storage tank 3; the high-pressure expander 9 is connected to a generator. When power generation is required, the high-temperature working fluid in the high-temperature storage tank 3 flows into the third heat exchanger 10 and the fourth heat exchanger 11 respectively, heats the high-pressure air sent from the gas storage container 1 and the air flowing out of the high-pressure expander 9, transfers the heat to the air, and then flows into the low-temperature storage tank 2 for storage.

[0031] If the low-pressure compressor 4 and the high-pressure compressor 5 still cannot reach the pressure in the gas storage container 1, a compressor unit can be added as needed. At the same time, a heat exchanger is added at the compressor outlet, and the working fluid in the low-temperature storage tank 2 absorbs the heat of the compressed air and flows into the high-temperature storage tank 3.

[0032] When the efficiency of converting the heating amount into the power generation is higher than 10% or it is feasible after economic evaluation, an electric heating device or a solar heating device is added to the high temperature storage tank 3 .

[0033] The high temperature storage tank 3 is provided with an electric heating device, which uses the electricity that cannot be connected to the Internet, such as abandoned wind and solar power, and valley electricity; the high temperature storage tank 3 is also provided with a solar heating device; comprehensively consider the influencing factors to avoid damage to the expander, and ensure that the air temperature after the high temperature working fluid is heated meets the system design requirements. The outlet pipeline of the gas storage container 1 may not be provided with a pressure regulating or constant pressure device, and at the same time, a number of regulating devices are provided on the connecting pipelines between the high temperature storage tank 3 and the third heat exchanger 10 and the fourth heat exchanger 11, so that the heat exchange of the third heat exchanger 10 and the fourth heat exchanger 11 matches the flow of the high pressure expander 9 and the low pressure expander 8, and ensure that the inlet temperature of the high pressure expander 9 and the low pressure expander 8 is within a suitable range, which not only ensures the high efficiency of the system, but also avoids problems caused by overheating or overcooling.

[0034] The third heat exchanger 10 and the fourth heat exchanger 11 are both provided with temperature control devices to control the heating amount of the air by the third heat exchanger 10 and the fourth heat exchanger 11, and the heating amount changes with the decrease of the inlet pressure of the high-low pressure expander 8. When the pressure drop causes the efficiency of the final conversion of the heating electricity into the power generation to be less than 5%, the heating amount of the air by the third heat exchanger 10 and the fourth heat exchanger 11 can be reduced to zero. When the solar energy collection system is used to heat the work in the high-temperature storage tank 3, when the conversion efficiency of the collected heat into the power generation is less than 3%, the heating amount of the air by the third heat exchanger 10 and the fourth heat exchanger 11 can be reduced to zero. When the efficiency of the final conversion of the heating electricity or the collected solar energy into the power generation is not less than 5%, the third heat exchanger 10 and the fourth heat exchanger 11 can heat the air.

[0035] The high-pressure expander 9 is replaced by a pressure regulating or throttling device, so that the inlet pressure of the low-pressure expander 8 is maintained near the design point. At this time, the main purpose of the third heat exchanger 10 is to heat the high-pressure air to prevent the high-pressure air from appearing in liquid and solid working fluids after pressure regulation or throttling, and the gas temperature is too low to cause adverse effects on related equipment, components, pipelines and instruments on the flow channel. When one set of pressure regulating or throttling devices cannot meet the requirements, multiple sets of pressure regulating or throttling devices can be connected in series, and a gas heat exchanger is set in front of each set of pressure regulating or throttling devices, and the heat is provided by the working fluid in the high-temperature storage tank.

[0036] The flow mode of the working fluid in the first heat exchanger 6, the second heat exchanger 7, the third heat exchanger 10 and the fourth heat exchanger 11 can be cocurrent, countercurrent and crosscurrent. The preferred flow mode of the working fluid is countercurrent, which is beneficial to improving heat exchange efficiency, optimizing system process design and improving overall performance.

[0037] When the utility model is used, the system is composed of an energy storage module, a compression module and a power generation module, which can effectively utilize the power generation of abandoned wind and solar power as well as valley power. During the compression process, the heat of the compressed air is transferred and stored in the high-temperature storage tank 3 through the heat exchanger, and the heat is recovered and utilized during the power generation process to improve energy efficiency.

[0038] The above is based on the ideal embodiment of the utility model. Through the above description, relevant personnel can make various changes and modifications without deviating from the technical concept of the utility model. The technical scope of this utility model is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A compressed air energy storage system with electric auxiliary heating, comprising: An energy storage module, and a compression module and a power generation module connected to the energy storage module, characterized in that; The energy storage module comprises: a gas storage container (1), a low-temperature storage tank (2) arranged in cooperation with the gas storage container (1), and a high-temperature storage tank (3) connected to the low-temperature storage tank (2); The compression module comprises: a low-pressure compressor (4), a first heat exchanger (6) connected to the low-pressure compressor (4), a high-pressure compressor (5) connected to the first heat exchanger (6), and a second heat exchanger (7) connected to the high-pressure compressor (5); the first heat exchanger (6) and the second heat exchanger (7) are respectively connected to the low-temperature storage tank (2) and the high-temperature storage tank (3); the second heat exchanger (7) is connected to the gas storage container (1); The power generation module comprises: a third heat exchanger (10), a high-pressure expander (9) connected to the third heat exchanger (10), a fourth heat exchanger (11) connected to the high-pressure expander (9), and a low-pressure expander (8) connected to the fourth heat exchanger (11); the third heat exchanger (10) is connected to the gas storage container (1); the third heat exchanger (10) and the fourth heat exchanger (11) are respectively connected to the low-temperature storage tank (2) and the high-temperature storage tank (3).

2. A compressed air energy storage system with electric auxiliary heating according to claim 1, characterized in that: The low-pressure compressor (4) and the high-pressure compressor (5) use the power generated by abandoned wind and solar power as well as valley electricity, and the low-pressure compressor (4) and the high-pressure compressor (5) compress air into the air storage container (1).

3. A compressed air energy storage system with electric auxiliary heating according to claim 1, characterized in that: The high-temperature storage tank (3) is provided with an electric heating device, and the electric heating device uses the power generation of abandoned wind and solar power and valley electricity.

4. A compressed air energy storage system with electric auxiliary heating according to claim 1, characterized in that: The high-temperature storage tank (3) is provided with a solar heating device.

5. A compressed air energy storage system with electric auxiliary heating according to claim 1, characterized in that: The air discharge pipeline of the high-pressure expander (9) is provided with a bypass connected to the air storage container (1).

6. A compressed air energy storage system with electric auxiliary heating according to claim 1, characterized in that: A plurality of regulating devices are provided on the connecting pipelines between the high-temperature storage tank (3) and the third heat exchanger (10) and the fourth heat exchanger (11).

7. A compressed air energy storage system with electric auxiliary heating according to claim 1, characterized in that: The high-pressure expander (9) is replaced by a pressure regulating or throttling device.

8. A compressed air energy storage system with electric auxiliary heating according to claim 1, characterized in that: The high-pressure expander (9) and the low-pressure expander (8) are connected to a generator.

9. A compressed air energy storage system with electric auxiliary heating according to claim 1, characterized in that: The low-temperature storage tank (2) and the high-temperature storage tank (3) are provided with working fluid, and the working fluid in the low-temperature storage tank (2) flows into the first heat exchanger (6) and the second heat exchanger (7) to absorb the heat of the compressed air and then flows into the high-temperature storage tank (3).

10. A compressed air energy storage system with electric auxiliary heating according to claim 5, characterized in that: The working fluid in the high-temperature storage tank (3) flows into the third heat exchanger (10) and the fourth heat exchanger (11) respectively to heat the air discharged from the gas storage container (1) and the high-pressure expander (9) and then enters the low-temperature storage tank (2).

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