A compressed air energy storage system based on a compression-expansion dual unit

Abstract

The application relates to a compressed air energy storage system based on a compression-expansion dual-purpose unit, which comprises a first compression-expansion unit, a second compression-expansion unit, a first heat exchange cooling unit and a second heat exchange cooling unit. In use, air enters the whole system from the atmosphere, enters a gas storage device in the order of the first compression-expansion unit, the first heat exchange cooling unit, the second compression-expansion unit and the second heat exchange cooling unit, and the compression energy storage of the gas is realized. When the first heat exchange cooling unit and the second heat exchange cooling unit work to cool the gas, the high-temperature energy carried by the gas can be replaced through heat exchange, stored by increasing the potential energy of the liquid, and when the electric energy needs to be released, the gas can be preheated by generating electricity through the way of reducing the potential energy of the liquid, so that the power loss of the compressed gas energy storage system during work is reduced, and a large amount of energy is saved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of heat exchange devices for technical compressed air energy storage systems, and specifically to a compressed air energy storage system based on a compression-expansion dual unit. BACKGROUND

[0002] ‌The principle of compressed air energy storage is mainly to utilize the off-peak period of the power system, through the electric energy to drive the air compressor to compress and store air in a large capacity air storage room, converting electric energy into storable compressed air potential energy. During the peak period of electricity demand, the compressed air is released and mixed with oil or natural gas to burn, driving the gas turbine to generate electricity to meet the system peak shaving demand. This process involves the conversion of electric energy to potential energy and then to electric energy. Compressed air energy storage is similar to pumped storage, but the difference is that pumped storage converts electric energy into gravitational potential energy of water, while compressed air energy storage converts electric energy into molecular potential energy of air (pressure potential energy of gas molecules).

[0003] The process of compressed air energy storage includes two main stages: charging stage and discharging stage. In the charging stage, which is the off-peak period of power load, the remaining electric power is used to compress and store air. In the discharging stage, which is the peak period of power load, the compressed air is released and mixed with fuel to burn, driving the gas turbine to generate electricity to meet the peak period of electricity demand. This process not only involves the conversion of electric energy to potential energy, but also involves the participation of heat energy. In the compression process, heat is generated due to the law of thermodynamics; while in the process of compressed air expansion, heat absorption is needed. Therefore, the key to compressed air energy storage technology is to optimize the matching of molecular pressure potential energy and heat energy.

[0004] ‌The heat generated by compressed air is mainly from the process of compressing air, due to the collision and friction of air molecules, a large amount of heat is generated. This process not only occurs inside the compressor, but also causes the temperature of the compressor and the surrounding environment to rise. In order to effectively dissipate heat, heat dissipation devices are needed. The temperature of compressed air will increase with the increase of compression ratio, which is the ratio of outlet pressure to inlet pressure. When the compression ratio is small, the temperature rise of the compressor is small; when the compression ratio is large, the temperature rise of the compressor is large. Therefore, in actual application, appropriate compression ratio needs to be selected according to specific requirements to control the generation of heat.

[0005] In addition, the application of compressed air is not limited to generating heat, it is also widely used in various fields such as industrial production, transportation, medical equipment, etc. Compressed air as a power source has the characteristics of clean and pollution-free, convenient transportation, energy storage and release, etc., so it is widely used. In diesel engines, heat is also generated when air is compressed, because when air is compressed, the kinetic energy of air molecules is converted into heat energy, causing the temperature to rise.

[0006] Generally, the heat generated by compressed air is an inevitable phenomenon in the compression process, and the amount of heat generated depends on the size of the compression ratio and the specific conditions of the compression process.

[0007] Therefore, in the existing compressed air energy storage system, when the compressed air is working, the compressed air needs to be cooled, and the heat exchanger and other equipment used still need external power support, which requires additional energy consumption, resulting in low efficiency of the compressed air energy storage system, generally only about 40%-55%, and the main reasons for the low efficiency of the compressed air energy storage system are as follows:

[0008] 1. When the air compression unit compresses air, a large amount of heat is generated, and the gas pipeline needs to be cooled. When the intake pipeline is cooled, the existing heat exchanger cannot reasonably utilize the heat removed, and cannot convert and store it. The equipment is expensive, and the existing energy in the system cannot be recycled and utilized to the maximum extent.

[0009] 2. When the air compression unit compresses air, the existing heat exchanger needs to use additional electric energy to drive the liquid flow in the heat exchanger, and also needs to use additional electric energy to cool the heat exchange liquid, which increases the loss of the compressed air energy storage system when storing electric energy.

[0010] 3. When power generation is needed, the compressed air energy storage system needs to heat the released high-pressure gas to achieve power generation function. The existing equipment for heating the gas also needs to consume additional energy, which causes not small energy loss, increases the loss of the compressed air energy storage system when releasing electric energy, and wastes a lot of energy. SUMMARY

[0011] The present application provides a compressed air energy storage system based on a compression and expansion dual-purpose unit to solve the technical problem of excessive energy loss of the existing compressed air energy storage system.

[0012] The application discloses a compressed air energy storage system based on a compression-expansion dual-purpose unit, which comprises a first compression-expansion unit, a second compression-expansion unit, a first heat exchange cooling unit and a second heat exchange cooling unit, the air inlet of the first compression-expansion unit is connected with the atmosphere to extract gas from the atmosphere, the air outlet of the first compression-expansion unit is connected with a first gas storage pipeline, the first gas storage pipeline is cooled by the first heat exchange cooling unit, one end of the first gas storage pipeline away from the first compression-expansion unit is connected with the second compression-expansion unit, the first compression-expansion unit and the second compression-expansion unit are driven by external power, the air outlet of the second compression-expansion unit is connected with a second gas storage pipeline, the second gas storage pipeline is cooled by the second heat exchange cooling unit, one end of the second gas storage pipeline away from the second compression-expansion unit is connected with a gas storage device, and the first heat exchange cooling unit and the second heat exchange cooling unit are both connected with a thermal potential conversion device.

[0013] Further, the thermal potential conversion device comprises a first generator, and the first generator is connected with a potential storage device.

[0014] Further, the potential storage device comprises a high-potential pool with a relatively high position and a low-potential pool with a relatively low position, the low-potential pool is connected with the high-potential pool through a pipeline provided with a water pump, two cooling pipes are arranged on the high-potential pool, one of the two cooling pipes is connected with the first heat exchange cooling unit, and the other of the two cooling pipes is connected with the second heat exchange cooling unit, the first heat exchange cooling unit and the second heat exchange cooling unit are both connected with an air outlet pipeline, the air outlet pipeline is connected with the first generator, the first generator can convert kinetic energy of gas into electric energy and input the electric energy into an external battery, and the external battery can supply power to the water pump to pump water in the low-potential pool into the high-potential pool.

[0015] Further, a communication pipe is arranged on one side of the high-potential pool, a pipe opening of the communication pipe is connected with an electric push rod through a connecting piece, the electric push rod is controlled by a controller, the controller is connected with the external battery through a detection device, a water receiving groove is arranged at the pipe opening of the communication pipe and connected with the low-potential pool, and the controller controls the electric push rod to lift the height of the pipe opening of the communication pipe when the detection device detects that the external battery is insufficient in power.

[0016] Further, a liquid filter device is arranged on the cooling pipe, and a second generator is arranged on the cooling pipe, the second generator can convert kinetic energy of water into electric energy and input the electric energy into the external battery.

[0017] Further, the first heat exchange cooling unit comprises a first heat exchange cooling pool, the first gas storage pipeline passes through the first heat exchange cooling pool, one end of the first heat exchange cooling pool is connected with the high-potential pool through the cooling pipe, the other end is provided with a water outlet pipe, the water outlet pipe is provided with an electromagnetic valve, the first heat exchange cooling pool is provided with a gas outlet pipeline above, the gas outlet pipeline is provided with a pressure increasing valve, and one end of the gas outlet pipeline away from the first heat exchange cooling pool is connected with the first generator.

[0018] Further, the second heat exchange cooling unit comprises a second heat exchange cooling pool, the second gas storage pipeline passes through the second heat exchange cooling pool, one end of the second heat exchange cooling pool is connected with the high-potential pool through the cooling pipe, the other end is provided with a water outlet pipe, the water outlet pipe is provided with an electromagnetic valve, the second heat exchange cooling pool is provided with a gas outlet pipeline above, the gas outlet pipeline is provided with a pressure increasing valve, and one end of the gas outlet pipeline away from the second heat exchange cooling pool is connected with the first generator.

[0019] Further, the external battery is further connected with a solar power generation device and a wind power generation device.

[0020] Further, the gas storage device is connected with a energy releasing pipeline, the energy releasing pipeline is connected with the second compression and expansion unit through a preheating device, the second compression and expansion unit is connected with the first compression and expansion unit through the energy releasing pipeline, the energy releasing pipeline is externally provided with a preheating device, and the preheating device is used for heating the energy releasing pipeline so as to heat the air in the energy releasing pipeline.

[0021] Further, the first compression and expansion unit is connected with a first gas filter.

[0022] Further, the first compression and expansion unit is connected with a second gas filter.

[0023] The application can realize the following technical effects:

[0024] 1. When the compression air unit compresses air, a large amount of heat is generated in the system, which is replaced by heat exchange, and the steam engine is used to generate electricity and store, and then the liquid potential energy is used to store, and when the electric energy needs to be released, the liquid potential energy is used to generate electricity, so that the energy generated in the compression air energy storage system is recycled to the maximum extent.

[0025] 2. The gravity potential energy of the liquid can be used to replace the electric energy required by the liquid flow of the heat exchanger, and the natural cooling method can be used to replace the additional electric energy to cool the liquid in the heat exchanger, so that the consumption of electric energy by the heat exchanger is completely avoided.

[0026] 3. The compressed air generated and stored can be used to power the gas heating device needed in the later power generation, further reducing the loss of external power.

[0027] 4. It can be used in various environments, and can be used with the power generation device suitable for the selected environment (such as wind power generation, solar power generation, etc.).

[0028] The foregoing general description and the following description are only exemplary and explanatory, and are not intended to limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0029] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, which are schematic and are not intended to be limiting of the embodiments, and in which like numerals refer to like elements, and wherein:

[0030] Figure 1 is a system flow diagram of the compressed air process in a compressed air energy storage system based on a compression-expansion dual unit of the present application;

[0031] Figure 2 is a system flow diagram of the high-pressure gas power generation process in a compressed air energy storage system based on a compression-expansion dual unit of the present application;

[0032] Figure 3 is a running schematic diagram of a thermal potential conversion device in a compressed air energy storage system based on a compression-expansion dual unit of the present application. DETAILED DESCRIPTION

[0033] In order to be able to understand the features and technical contents of the embodiments of the present application more fully, the implementation of the embodiments of the present application will be described in detail below with reference to the accompanying drawings, which are only used for reference and do not limit the embodiments of the present application. In the following technical description, in order to facilitate explanation, a plurality of details are provided to provide a full understanding of the disclosed embodiments. However, one or more embodiments can still be implemented without these details. In other cases, well-known structures and devices can be simplified to show.

[0034] The terms "first", "second", etc. in the specification and claims of the embodiments of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the embodiments of the present application described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.

[0035] In the embodiments of the present application, the terms "upper", "lower", "inner", "middle", "outer", "front", "back" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the embodiments of the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation. In addition, in addition to indicating the orientation or positional relationship, the above-mentioned terms can also be used to indicate other meanings, for example, the term "upper" can also be used to indicate a certain dependent relationship or connection relationship in some cases. For those skilled in the art, the specific meanings of these terms in the embodiments of the present application can be understood according to the specific circumstances.

[0036] In addition, the terms "set", "connected", "fixed" should be broadly understood. For example, "connected" can be fixed connection, detachable connection, or integral structure; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through an intermediate medium, or internal communication between two devices, elements or components. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0037] Unless otherwise specified, the term "a plurality of" means two or more, and the term "a plurality of groups" means two groups or more.

[0038] It should be noted that the embodiments in the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0039] As shown in Figure 1 , Figure 2 , Figure 3 The present application discloses a compressed air energy storage system based on compression and expansion dual-purpose unit, which comprises a first compression and expansion unit, a second compression and expansion unit, a first heat exchange and cooling unit and a second heat exchange and cooling unit. The first compression and expansion unit is connected with the atmosphere for extracting gas from the atmosphere. The first compression and expansion unit is connected with a first gas filter. The first heat exchange and cooling unit and the second heat exchange and cooling unit are both connected with a thermal potential conversion device.

[0040] Such arrangement can first ensure that the inhaled gas of the device is almost unlimited, ensuring sufficient gas supply. The gas filtering device arranged at the gas inlet can ensure that the first compression and expansion unit and the second compression and expansion unit will not cause dust accumulation inside the equipment when inhaling gas due to dust or impurities in the inhaled air, thereby affecting the working efficiency, or even causing damage or failure of the equipment in severe cases, thereby improving the service life of the equipment and ensuring the stability of the stored gas.

[0041] Referring to Figure 3The storage device includes a high-potential pool with a relatively high position and a low-potential pool with a relatively low position, the low-potential pool is connected with the high-potential pool through a pipeline provided with a water pump, the high-potential pool is provided with two cooling pipes, one of which is connected with the first heat exchange cooling unit, and the other of which is connected with the second heat exchange cooling unit, the first heat exchange cooling unit and the second heat exchange cooling unit are both connected with an air outlet pipeline, the air outlet pipeline is connected with the first generator, the first generator can convert the kinetic energy of the gas into electric energy and input the electric energy into an external battery, and the external battery can supply power to the water pump to pump the water in the low-potential pool into the high-potential pool.

[0042] Thus, when the compressed air energy storage system based on the compression-expansion dual-purpose unit is arranged, the environment is extremely convenient to select, in an environment with a natural height difference, only the suitable high-potential pool and low-potential pool need to be dug or found, and the pipeline and the main equipment and auxiliary equipment are connected, so that the system can be put into use, thereby greatly reducing the cost of building a high man-made building as a high-potential pool. Since the equipment used in the compressed air energy storage system based on the compression-expansion dual-purpose unit is mostly low-cost, the high-potential pool, the low-potential pool and the gas storage device can be found or built at low cost in the natural environment, a large amount of engineering budget can be saved, and even if a suitable natural geographical environment is not found, since the technical and construction requirements of the high-potential pool, the low-potential pool and the gas storage device in the compressed air energy storage system based on the compression-expansion dual-purpose unit are relatively low, the high-potential pool, the low-potential pool and the gas storage device can also be built artificially to meet the various use and manufacturing conditions required by the high-potential pool, the low-potential pool and the gas storage device, so that the compressed air energy storage system based on the compression-expansion dual-purpose unit can realize the above functions, and can realize the conversion, storage and release of electric energy, is energy-saving and environment-friendly, and has a manufacturing cost much lower than that of the existing large-scale compressed air energy storage system.

[0043] Referring to Figure 1 The first compression-expansion unit is connected with a first gas storage pipeline, the first gas storage pipeline is cooled through a first heat exchange cooling unit, the first heat exchange cooling unit includes a first heat exchange cooling pool, the first gas storage pipeline passes through the first heat exchange cooling pool, one end of the first heat exchange cooling pool is connected with the high-potential pool through a cooling pipe, the other end is provided with a water outlet pipe, the water outlet pipe is provided with an electromagnetic valve, an air outlet pipeline is arranged above the first heat exchange cooling pool, the air outlet pipeline is provided with a pressure booster, and one end of the air outlet pipeline away from the first heat exchange cooling pool is connected with the first generator.

[0044] When the power is sufficient to need to use the compressed air energy storage system based on the compression and expansion dual-purpose unit to convert and store the excess power, the arrangement can realize that the heat generated by the compressed air when the first compression and expansion machine works is timely absorbed and transferred, and at the same time, the transferred heat is carried in water, and by reasonably controlling the opening and closing of each pipeline by the valve body, the power generated when the air is compressed can be effectively used to heat the water in the first heat exchange cooling pool, so that the water is heated to generate water vapor to generate pressure, and then the pressure of the water vapor is replaced by the kinetic energy of the generator impeller, so as to realize the energy conversion of pressure kinetic energy and kinetic energy to electric power, and the electric power is converted by the generator to realize power generation by the principle of steam engine, and the electric power can be transferred or stored by the existing conventional means as standby power. Although there is energy loss in the secondary conversion process here, but since the electric power converted by the generator is converted from the heat energy generated by the compressed air which is not fully utilized in the existing technology, it is undoubtedly that the technical means can bring additional electric power. At the same time, the cooling liquid in the first heat exchange cooling unit of the device is replaced by the natural gravity of the water flowing from the high potential pool to the low potential pool, instead of the heat exchange function of the existing heat exchanger, which can be said to be an energy-saving and environmentally friendly heat exchanger that does not need to be driven by electric power and can provide additional electric power. Without additional power supply, it saves the electric power consumed by the traditional heat exchanger in driving the liquid flow when in use, further saving the consumption of electric power and energy. The two can be added to realize the more sufficient use of electric power. And the arrangement is more environmentally friendly, especially when there is no need to use additional power supply lines to connect the heat exchanger in the wild and other locations, and there is no need to consume additional funds to purchase large heat exchangers, which saves a lot of cost.

[0045] See Figure 1The first compressed expander set and the second compressed expander set are driven by external power, the second compressed expander set is connected with the second gas storage pipeline, the second gas storage pipeline is cooled by the second heat exchange cooling set, the second heat exchange cooling set comprises a second heat exchange cooling pool, the second gas storage pipeline passes through the second heat exchange cooling pool, one end of the second heat exchange cooling pool is connected with the high-potential pool through a cooling pipe, the other end is even provided with a water outlet pipe, the water outlet pipe is provided with an electromagnetic valve, an air outlet pipeline is arranged above the second heat exchange cooling pool, the air outlet pipeline is provided with a pressure booster valve, and one end of the air outlet pipeline away from the second heat exchange cooling pool is connected with the first generator. The heat generated by the compressed air during the operation of the second compressed expander set can be absorbed and transferred in time, and at the same time, the transferred heat is carried in water. By reasonably controlling the opening and closing of each pipeline through the valve body, the power generated when the air is compressed can be effectively utilized to heat the water in the second heat exchange cooling pool, so that the water is heated to generate water vapor to generate pressure, and the pressure of the water vapor is replaced by the kinetic energy of the generator impeller, so that the energy conversion from pressure to kinetic energy and from kinetic energy to electric power is realized. The principle of the steam engine is used to realize power generation, and the electric energy can be transferred or stored by the existing conventional means as standby power. Although there is energy loss in the secondary conversion process, the electric energy converted by the generator is converted from the heat energy generated by the compressed air which is not fully utilized in the existing technology. It is undoubtedly that the technical means can bring additional power. At the same time, the cooling liquid in the second heat exchange cooling set of the device relies on the natural gravity of the water flowing from the high-potential pool to the low-potential pool to replace the heat exchange function of the existing heat exchanger. In essence, it can be said that it is an energy-saving and environmentally friendly heat exchanger that does not need to be driven by electric energy and can provide additional power. Without additional power supply, the electric energy consumed by the traditional heat exchanger in driving the liquid flow during use is saved, further saving the consumption of electric energy and energy. The two can be added to realize the full utilization of electric energy. And the setting is more environmentally friendly, especially in the field and other locations without the need for additional power supply lines to connect the heat exchanger and without the need for additional funds to purchase large heat exchangers, saving a lot of costs.

[0046] The second gas storage pipeline is connected with the gas storage device at one end away from the second compressed expander set.

[0047] The air filtered by the first filter can be completely in a sealed state and enter the gas storage device without contacting the external air, thereby further ensuring the cleanliness of the compressed air and protecting the equipment and pipelines during air release.

[0048] The cooling pipe is provided with a liquid filtering device, and the cooling pipe is provided with a second generator, which can convert kinetic energy of water into electric energy and input the electric energy into an external battery.

[0049] In this way, firstly, the water in the high-potential pool can be guaranteed to be clean when entering the second generator, preventing damage to the second generator caused by impurities in the water; secondly, the impurities in the water cannot enter the first heat exchange cooling pool or the second heat exchange cooling pool, preventing the structure in the first heat exchange cooling pool or the second heat exchange cooling pool from being blocked or damaged, preventing damage to the first gas storage pipeline and the second gas storage pipeline in the first heat exchange cooling pool or the second heat exchange cooling pool, and preventing the pipeline from being blocked when the water vapor in the first heat exchange cooling pool or the second heat exchange cooling pool is discharged, thereby guaranteeing the safe and long-term use of the equipment and the power generation efficiency of the generator, and maximizing the recycling of electric energy and the saving of energy and reducing energy loss.

[0050] The high-potential pool is provided with a communication pipe on one side, the pipe opening of the communication pipe is connected with an electric push rod through a connecting piece, the electric push rod is controlled by a controller, the controller is connected with the external electric power supply through a detection device, and a water receiving groove is arranged at the pipe opening of the communication pipe and connected with the low-potential pool.

[0051] In this way, when the detection device detects that the external battery is insufficient in power (the wind power generation is insufficient, the solar power generation is insufficient, the power generation of the generator below the high-potential pool is insufficient, the power generation of the first and second heat exchange cooling pools is insufficient, etc.), a signal is sent to the controller, the controller controls the electric push rod to lift the height of the pipe opening of the communication pipe, so that the water level of the high-potential pool can be increased in the cycle, and the external battery is maintained to have sufficient power through the technical means of increasing the power generation below the high-potential pool.

[0052] Conversely, when the detection device detects that the external battery is sufficient in power (the wind power generation is insufficient, the solar power generation is insufficient, the power generation of the generator below the high-potential pool is insufficient, the power generation of the first and second heat exchange cooling pools is insufficient, etc.), a signal is sent to the controller, the controller controls the electric push rod to lower the height of the pipe opening of the communication pipe, so that the water level of the high-potential pool can be reduced in the cycle, and the external battery is maintained to have sufficient power through the technical means of reducing the power generation below the high-potential pool.

[0053] The gas storage device is connected with an energy release pipeline, the energy release pipeline is connected with the second compression expander set through a preheating device, the second compression expander set is connected with the first compression expander set through the energy release pipeline, and the energy release pipeline is externally provided with the preheating device.

[0054] Referring to Figure 2When power is insufficient and the compressed air energy storage system based on the compression-expansion dual unit needs to generate electricity, the gas is released from the gas storage device, passes through the energy release pipeline and the preheating device, and then passes through the first compression-expansion unit and the second compression-expansion unit to convert the pressure of the gas into kinetic energy and then into electrical energy for output. Since the energy is clean, compared with the existing mixed fuel combustion heating method, fuel resources are saved, and no harmful substances are generated, realizing the output of electrical energy under the premise of energy saving and environmental protection to solve the problem of temporary power shortage.

[0055] Referring to Figure 2 The first compression-expansion unit is connected with a second gas filter device. Such an arrangement can first ensure that the discharged air is clean air, and secondly can screen and purify the discharged air. Since the compressed air energy storage system based on the compression-expansion dual unit mostly needs to store gas by means of sealed caves, rock caves, etc. in the wild, the second gas filter can prevent underground harmful gases from being discharged to pollute the atmosphere, achieving true clean energy storage and conversion. On the premise of realizing the basic technical functions of electrical energy conversion, storage, conversion, and release required by conventional compressed air energy storage systems based on compression-expansion dual units, the discharged gas pollutes the atmosphere when the working environment is special or the gas storage device is damaged or external harmful gases invade the gas storage device, achieving true clean and environmental protection.

[0056] The external battery is also connected with a solar power generation device and a wind power generation device.

[0057] All energy production devices that can provide energy in the existing environment can be fully utilized to provide the entire system with pre-operation power, truly realizing self-power supply and self-operation of the entire system, without consuming any external power or connecting any external power transmission wires, etc., greatly saving costs. Even as an electric power production unit, in the case that there is no surplus electricity to be compressed and stored, it can itself become an electric power production unit to provide electricity to the outside world.

[0058] Application scenarios of an exemplary embodiment:

[0059] When the power is in need of using the compressed air energy storage system based on the compression and expansion dual-purpose unit to convert and store electricity, connect the external circuit to the first compression and expansion unit and the second compression and expansion unit, air is extracted from the atmosphere, enters the first compression and expansion unit after passing through the first filter, and the gas is compressed and discharged through the first gas storage pipeline. At the same time, the first heat exchange cooling unit cools and replaces the heat of the first gas storage pipeline filled with high-temperature gas, the replaced heat is used to heat the water in the first heat exchange cooling pool to generate water vapor, which is transmitted to the generator after reaching a certain pressure through the pressure increasing valve, and the basic steam engine is used to generate electricity. The electricity generated by the generator is transmitted to the external battery for temporary storage.

[0060] When the gas in the first gas storage pipeline enters the second compression and expansion unit, it needs to pass through the second heat exchange cooling unit to cool and replace the heat of the second gas storage pipeline filled with high-temperature gas, the replaced heat is used to heat the water in the second heat exchange cooling pool to generate water vapor, which is transmitted to the generator after reaching a certain pressure through the pressure increasing valve, and the basic steam engine is used to generate electricity. The electricity generated by the generator is transmitted to the external battery for temporary storage.

[0061] At this time, it should be noted that the electric energy of the external battery can also be stored in advance by wind power generation, solar power generation and other ways, and only when the compressed air energy storage system based on the compression and expansion dual-purpose unit is installed, the wind power generation or solar power generation device and the external battery are installed first, and the electricity can be collected in advance.

[0062] The electric energy stored in the external battery can be used to drive the water pump to extract the water in the high-potential pool to the high-potential pool, and the water in the high-potential pool naturally falls due to gravity, passes through the liquid filter device, and generates electricity through the generator, fully utilizes the gravitational potential energy of the water in the high-potential pool, and then enters the first heat exchange cooling pool and the second heat exchange cooling pool through the liquid pipeline respectively. The first gas storage pipeline in the first heat exchange cooling pool and the second gas storage pipeline in the second heat exchange cooling pool are cooled and cooled, and when the temperature of the water in the first heat exchange cooling pool and the second heat exchange cooling pool reaches a certain height, the electromagnetic valve is opened to change the water, and the battery valve is set to make the first heat exchange cooling pool and the second heat exchange cooling pool in the first gas storage pipeline and the second gas storage pipeline. The water vapor generated by cooling will not flow out of the water pipeline to cause energy waste, and when the water needs to be changed, the water in the first heat exchange cooling pool and the second heat exchange cooling pool can flow into the low-potential pool through the opened electromagnetic valve, and is naturally cooled. This cycle can ensure the basic compression and storage function without the intervention of external power and maximize the storage of electricity.

[0063] When power shortage needs to use the compressed air energy storage system based on the compression-expansion dual unit to generate electricity, the gas is released from the gas storage device, passes through the energy release pipeline and the preheating device, the high-pressure air in the energy release pipeline is heated, the pressure is raised again to optimize the gas movement to drive the power generation device in the compression-expansion dual unit to optimize the power generation effect, when the gas passes through the first compression-expansion unit and the second compression-expansion unit, the first compression-expansion unit and the second compression-expansion unit convert the pressure of the gas into kinetic energy and then into electric energy to output, the whole process does not produce any toxic and harmful gas, and can ensure that the external toxic and harmful gas cannot be dispersed into the atmosphere to pollute the environment, and since the energy is clean, no harmful substances are produced, realizing the output of electric energy under the premise of energy saving and environmental protection to solve the problem of temporary power shortage.

[0064] The above description and drawings sufficiently illustrate embodiments of the present application to enable one skilled in the art to practice them. Other embodiments can include structural and other changes. The embodiments are representative only. Individual components and functions are optional unless explicitly required, and the order of operations can be varied. Portions and features of some embodiments can be included in, or alternate, portions and features of other embodiments. Embodiments of the present application are not limited to the structures described above and shown in the drawings, and can be varied in many ways. The scope of the present application is limited only by the claims that follow.

Claims

1. A compressed air energy storage system based on a compression-expansion dual-purpose unit, characterized in that, include: The unit comprises a first compression expander, a second compression expander, a first heat exchange and cooling unit, a second heat exchange and cooling unit, and a heat potential conversion device. The first compression expander unit has its air inlet connected to the atmosphere, drawing gas from the atmosphere and is driven by external electricity; The outlet of the first compression expander unit is connected to a first gas storage pipeline, which is cooled by a first heat exchange cooling unit. The end of the first gas storage pipeline away from the first compression expander unit is connected to the second compression expander unit. The second compression expander unit is driven by external electricity, and the outlet of the second compression expander unit is connected to a second gas storage pipeline; The second gas storage pipeline is cooled by the second heat exchange cooling unit, and the end of the second gas storage pipeline away from the second compression expansion unit is connected to the gas storage device. Both the first heat exchange cooling unit and the second heat exchange cooling unit are connected to the heat potential conversion device; The thermal potential conversion device includes a first generator, which is connected to a potential storage device. The energy storage device includes a high-potential pool at a relatively high position and a low-potential pool at a relatively low position. The low-potential pool is connected to the high-potential pool via a pipeline equipped with a water pump. The high-potential pool is equipped with two cooling pipes, one of which is connected to the first heat exchange cooling unit and the other to the second heat exchange cooling unit. Both the first and second heat exchange cooling units are connected to an exhaust pipe, which is connected to the first generator. The first generator is used to convert the kinetic energy of the gas into electrical energy, which is input into an external battery. The external battery is used to power the water pump to pump water from the low-potential pool into the high-potential pool.

2. The compressed air energy storage system based on a compression-expansion dual-purpose unit according to claim 1, characterized in that, A liquid filtration device is installed on the cooling pipe, and a second generator is installed on the cooling pipe. The second generator is used to convert the kinetic energy of the water into electrical energy and input it into an external battery.

3. The compressed air energy storage system based on a compression-expansion dual-purpose unit according to claim 1, characterized in that, The first heat exchange cooling unit includes a first heat exchange cooling pool, a first gas storage pipeline passing through the first heat exchange cooling pool, one end of the first heat exchange cooling pool being connected to the high-potential pool via the cooling pipe, and the other end being provided with a water outlet pipe, on which a solenoid valve is provided. An air outlet pipeline is provided above the first heat exchange cooling pool, on which a booster valve is provided, and the end of the air outlet pipeline away from the first heat exchange cooling pool is connected to the first generator.

4. A compressed air energy storage system based on a compression-expansion dual-purpose unit according to claim 1, characterized in that, The second heat exchange cooling unit includes a second heat exchange cooling pool, a second gas storage pipeline passing through the second heat exchange cooling pool, one end of the second heat exchange cooling pool being connected to the high-potential pool via the cooling pipe, and the other end being provided with a water outlet pipe, on which a solenoid valve is installed. An air outlet pipeline is provided above the second heat exchange cooling pool, on which a booster valve is installed, and the end of the air outlet pipeline away from the second heat exchange cooling pool is connected to the first generator.

5. A compressed air energy storage system based on a compression-expansion dual-purpose unit according to claim 1, characterized in that, The external battery is also connected to a solar power generation device and a wind power generation device.

6. A compressed air energy storage system based on a compression-expansion dual-purpose unit according to claim 1, characterized in that, The gas storage device is connected to an energy release pipeline, which is connected to the second compression expander unit via a preheating device. The second compression expander unit is connected to the first compression expander unit via the energy release pipeline. A preheating device is installed outside the energy release pipeline to heat the energy release pipeline and thus heat the air in the energy release pipeline.

7. A compressed air energy storage system based on a compression-expansion dual-purpose unit according to claim 1, characterized in that, The first compression expander unit is connected to a first gas filter.

8. A compressed air energy storage system based on a compression-expansion dual-purpose unit according to claim 1, characterized in that, The first compression expander unit is connected to a second gas filtration device.

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