Compressed air energy storage system based on compression and expansion dual-purpose unit

Abstract

The invention relates to a compressed air energy storage system based on compression and expansion dual-purpose units, which comprises a first compression and expansion unit, a second compression and expansion unit, a first heat exchange cooling unit and a second heat exchange cooling unit. Gas enters the gas storage device according to the sequence of the first compression expansion unit, the first heat exchange cooling unit, the second compression expansion unit and the second heat exchange cooling unit, compression energy storage of the gas is achieved, and when the first heat exchange cooling unit and the second heat exchange cooling unit carry out cooling work on the gas, the gas enters the gas storage device; according to the compressed gas energy storage system, high-temperature energy carried by gas can be replaced in a heat exchange mode and stored in a mode of increasing liquid potential energy, electricity can be generated in a mode of reducing the liquid potential energy to preheat the gas when electric energy needs to be released, power loss of the compressed gas energy storage system during working is reduced, and a large amount of energy is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of special heat exchange devices for compressed air energy storage equipment, and in particular to a compressed air energy storage system based on a compression-expansion dual-purpose unit. Background Art

[0002] The principle of compressed air energy storage is to utilize the off-peak period of the power system, drive the air compressor with electricity to compress the air and store it in a large-capacity air storage chamber, and convert the electrical energy into storable compressed air potential energy. During the peak period of power demand, the compressed air is released and mixed with oil or natural gas for combustion to drive the gas turbine to generate power to meet the peak demand of the system. This process involves the conversion of electrical energy to potential energy and then to electrical energy. Compressed air energy storage is similar to pumped storage, but the difference is that pumped storage converts electrical energy into the gravitational potential energy of water, while compressed air energy storage converts electrical energy into the molecular potential energy of air (the 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, that is, the period of low power load, the air is compressed and stored using the remaining power. In the discharging stage, that is, the peak power load, the compressed air is released and mixed with fuel to drive the gas turbine to generate electricity, thereby meeting the power demand during peak hours. This process involves not only the conversion of electrical energy and potential energy, but also the participation of thermal energy. During the compression process, heat is generated due to the laws of thermodynamics; and in the process of compressed air expansion and work, heat absorption is required. Therefore, the key to compressed air energy storage technology is to achieve the optimal matching of molecular pressure potential energy and thermal energy.

[0004] The heat generated by compressed air mainly comes from the collision and friction of air molecules during the compression process, which will generate a lot of heat. 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 dissipate heat effectively, it is necessary to dissipate heat through a heat sink. The temperature of compressed air will increase with the increase of the compression ratio, which refers to the ratio of the outlet pressure to the 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 practical applications, it is necessary to select an appropriate compression ratio according to specific needs 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. As a power source, compressed air has the characteristics of cleanness and pollution-free, easy transportation, and the ability to store and release energy, so it is widely used. In a diesel engine, heat is also generated when air is compressed. This is because when air is compressed, the kinetic energy of air molecules is converted into heat energy, causing the temperature to rise.

[0006] In general, the heat generated by compressed air is an inevitable phenomenon in the compression process, and the amount of heat generated depends on 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 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%. The low efficiency of the compressed air energy storage system is mainly caused by the following three reasons: 1. When the compressed air unit compresses the air, a large amount of heat is generated, and the gas pipeline needs to be cooled. When cooling the air intake pipeline, the existing heat exchanger cannot reasonably utilize the displaced heat, and cannot convert and store it. The equipment is expensive and cannot maximize the recovery and utilization of the existing energy in the system.

[0008] Second, when the compressed air unit compresses the 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 when using the compressed air energy storage system to store electric energy.

[0009] 3. When power generation is needed, the compressed air energy storage system needs to heat the released high-pressure gas to achieve the power generation function. The existing equipment for heating the gas also consumes additional energy, resulting in considerable energy loss, increasing the loss when using the compressed air energy storage system to release electrical energy and wasting a lot of energy. Summary of the invention

[0010] The present invention provides a compressed air energy storage system based on a compression-expansion dual-purpose unit to solve the technical problem of excessive energy loss in existing compressed air energy storage systems.

[0011] The present invention discloses a compressed air energy storage system based on a compression-expansion dual-purpose unit, comprising a first compression-expansion unit, a second compression-expansion unit, a first heat exchange cooling unit and a second heat exchange cooling unit, wherein an air inlet of the first compression-expansion unit is connected to the atmosphere to extract gas from the atmosphere, an air outlet of the first compression-expansion unit is connected to a first gas storage pipeline, the first gas storage pipeline is cooled by the first heat exchange cooling unit, an end of the first gas storage pipeline away from the first compression-expansion unit is connected to the second compression-expansion unit, the first compression-expansion unit and the second compression-expansion unit are both driven by external electricity, an air outlet of the second compression-expansion unit is connected to a second gas storage pipeline, the second gas storage pipeline is cooled by the second heat exchange cooling unit, an end of the second gas storage pipeline away from the second compression-expansion unit is connected to a gas storage device, and the first heat exchange cooling unit and the second heat exchange cooling unit are both connected to a thermal potential conversion device.

[0012] Furthermore, the thermal potential conversion device includes a first generator, and the first generator is connected to a potential storage device.

[0013] Furthermore, the potential 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 to the high-potential pool through a pipeline equipped with a water pump. Two cooling pipes are provided on the high-potential pool, one of which is connected to the first heat exchange cooling unit, and the other is connected to the second heat exchange cooling unit. The first heat exchange cooling unit and the second heat exchange cooling unit are both connected to exhaust pipelines, and the exhaust pipelines are connected to the first generator. The first generator can convert gas kinetic energy into electrical energy and input it into an external battery. The external battery can power the water pump to pump water in the low-potential pool into the high-potential pool.

[0014] Furthermore, a connecting pipe is provided at one side of the high potential pool, the pipe mouth of the connecting pipe is connected to an electric push rod through a connector, the electric push rod is controlled by a controller, the controller is connected to the external power outlet through a detection device, a water receiving trough is provided at the pipe mouth of the connecting pipe, and the water receiving trough is connected to the low potential pool. When the detection device detects that the power of the external battery is insufficient, it will send a signal to the controller, and the controller will control the electric push rod to raise the height of the pipe mouth of the connecting pipe.

[0015] Furthermore, a liquid filtering device is provided on the cooling pipe, and a second generator is provided on the cooling pipe. The second generator can convert the kinetic energy of water into electrical energy and input it into an external battery.

[0016] Furthermore, 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 to the high potential pool through the cooling pipe, and the other end even has a water outlet pipe, and an electromagnetic valve is provided on the water outlet pipe. An air outlet pipeline is provided above the first heat exchange cooling pool, and a boost valve is provided on the air outlet pipeline. The air outlet pipeline is connected to the first generator at one end away from the first heat exchange cooling pool.

[0017] Furthermore, the second heat exchange cooling unit includes 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 to the high potential pool through the cooling pipe, and the other end even has a water outlet pipe, and an electromagnetic valve is provided on the water outlet pipe. An air outlet pipeline is provided above the second heat exchange cooling pool, and a boost valve is provided on the air outlet pipeline. The air outlet pipeline is connected to the first generator at one end away from the second heat exchange cooling pool.

[0018] Furthermore, the external battery is also connected to a solar power generation device and a wind power generation device.

[0019] Furthermore, the gas storage device is connected to an energy release pipeline, the energy release pipeline is connected to the second compression-expansion unit through a preheating device, the second compression-expansion unit is connected to the first compression-expansion unit through the energy release pipeline, and a preheating device is arranged outside the energy release pipeline, and the preheating device is used to heat the energy release pipeline and thus heat the air in the energy release pipeline.

[0020] Furthermore, the first compression expansion unit is connected to a first gas filter.

[0021] Furthermore, the first compression-expansion unit is connected to a second gas filter.

[0022] The present invention provides the following technical effects: 1. When the compressed air unit compresses the air, a large amount of heat is generated in the system, which is replaced by heat exchange, and stored by using a steam engine to generate electricity and store it. Then, it is stored by increasing the potential energy of the liquid. When the electric energy needs to be released, it generates electricity by reducing the potential energy of the liquid, thereby recycling the energy generated when compressing the air in the compressed air energy storage system to the greatest extent.

[0023] 2. The gravitational potential energy of the liquid can be used to replace the electric energy required for the flow of the heat exchanger liquid, and natural cooling can be used instead of using additional electric energy to cool the liquid in the heat exchanger, thereby completely avoiding the consumption of electric energy by the heat exchanger.

[0024] 3. The electric energy generated and stored when compressing the air can be used to power the gas heating device required for subsequent power generation, further reducing external power loss.

[0025] 4. It can be used in a variety of environments, and can be used with suitable power generation devices (such as wind power generation, solar power generation, etc.) according to the selected environment.

[0026] The foregoing general description and the following description are exemplary and explanatory only and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] One or more embodiments are exemplarily described by corresponding drawings, and these exemplary descriptions and drawings do not limit the embodiments. Elements with the same reference numerals in the drawings are regarded as similar elements, and wherein: Figure 1 It is a system flow diagram of the air compression process in a compressed air energy storage system based on a compression-expansion dual-purpose unit of the present invention; Figure 2 It is a system flow diagram of a high-pressure gas power generation process in a compressed air energy storage system based on a compression-expansion dual-purpose unit of the present invention; Figure 3 It is a schematic diagram of the operation of a thermal potential conversion device in a compressed air energy storage system based on a compression-expansion dual-purpose unit of the present invention. DETAILED DESCRIPTION

[0028] In order to be able to understand the features and technical contents of the embodiments of the present invention in more detail, the implementation of the embodiments of the present invention is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present invention. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0029] The terms "first", "second", etc. in the description and claims of the embodiments of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present invention described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0030] In the embodiments of the present invention, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly used to better describe the embodiments of the present invention and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction. Moreover, in addition to being used to indicate directions or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present invention can be understood according to the specific circumstances.

[0031] In addition, the terms "disposed", "connected", and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0032] Unless otherwise specified, the term "plurality" means two or more and "plurality" means two or more.

[0033] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present invention may be combined with each other.

[0034] like Figure 1 , Figure 2 , Figure 3 As shown, the present invention discloses a compressed air energy storage system based on a compression-expansion dual-purpose unit, which includes 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 to the atmosphere to extract gas from the atmosphere. The first compression-expansion unit is connected to a first gas filter, and the first heat exchange cooling unit and the second heat exchange cooling unit are both connected to a thermal potential conversion device.

[0035] Such a setting can firstly ensure that the gas inhaled by the device is almost unlimited and ensure sufficient gas supply. In addition, a gas filtering device is provided at the air inlet to ensure that the first compression-expansion unit and the second compression-expansion unit will not cause dust accumulation inside the equipment when absorbing gas due to dust or impurities in the air, thereby affecting the working efficiency, or even causing damage or failure of the equipment in serious cases, thereby improving the service life of the equipment and ensuring the stability of the stored gas.

[0036] See also Figure 3The potential 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 to the high-potential pool through a pipeline equipped with a water pump. Two cooling pipes are arranged on the high-potential pool, one of which is connected to the first heat exchange cooling unit, and the other is connected to the second heat exchange cooling unit. The first heat exchange cooling unit and the second heat exchange cooling unit are both connected to exhaust pipelines, and the exhaust pipelines are connected to the first generator. The first generator can convert the kinetic energy of the gas into electrical energy and input it into an external battery. The external battery can power the water pump to pump water in the low-potential pool into the high-potential pool.

[0037] With such a configuration, when setting up the compressed air energy storage system based on the compression-expansion dual-purpose unit, the environment to be selected is extremely convenient. In an environment with a natural terrain height difference, it is only necessary to dig or find a suitable high-potential pool and a low-potential pool, connect the pipeline and a dry set of main equipment and auxiliary equipment, and then put it into use, which greatly reduces the cost of building a high-potential artificial building to serve as a high-potential pool. In the compressed air energy storage system based on the compression-expansion dual-purpose unit, since most of the equipment used is low-cost, the high-potential pool, the low-potential pool and the gas storage device can all be found in the natural environment or built at a low cost, which can save a lot of engineering budget. Expenses, even if a suitable natural geographical environment has not been found, since the technical and construction requirements for the high-potential tank, low-potential tank and gas storage device in the compressed air energy storage system based on the compression-expansion dual-purpose unit are relatively low, a small amount of cost can be consumed through artificial construction to meet the various use and manufacturing conditions required for the high-potential tank, low-potential tank and gas storage device mentioned above, ensuring that the compressed air energy storage system based on the compression-expansion dual-purpose unit can achieve the above functions, while being able to convert, store and release electrical energy, it is energy-saving and environmentally friendly, and the manufacturing cost is much lower than the existing large-scale compressed air energy storage system.

[0038] See also Figure 1 The air outlet of the first compression and expansion unit is connected to the first air storage pipeline, and the first air storage pipeline is cooled by the first heat exchange cooling unit. The first heat exchange cooling unit includes a first heat exchange cooling pool. The first air storage pipeline passes through the first heat exchange cooling pool. One end of the first heat exchange cooling pool is connected to the high potential pool through a cooling pipe, and the other end even has a water outlet pipe. An electromagnetic valve is arranged on the water outlet pipe. An air outlet pipeline is arranged above the first heat exchange cooling pool, and a boost valve is arranged on the air outlet pipeline. The end of the air outlet pipeline away from the first heat exchange cooling pool is connected to the first generator.

[0039] When there is sufficient electricity and it is necessary to use the compressed air energy storage system based on the compression and expansion dual-purpose unit to convert and store excess electrical energy, such a setting can realize that the heat generated by the compressed air when the first compression and expansion machine is working is absorbed and transferred in time, and at the same time, the transferred heat is carried in the water. By controlling the opening and closing of each pipeline through a reasonable valve body, it is possible to effectively utilize the power generated when the air is compressed to heat the water in the first heat exchange cooling pool, so that the water is heated to generate water vapor and thus generate pressure, and then replace the pressure of the water vapor with the kinetic energy of the generator impeller, thereby realizing the energy conversion of pressure into rotational energy and kinetic energy into electricity, and converting it into electricity through the generator to realize power generation using the principle of the steam engine, and the electric energy can be transferred or stored by existing conventional means as backup power. Although there will be different degrees of energy loss in the secondary conversion process here, since the electric energy converted by the generator is converted from the heat energy generated by the compressed air that has not been fully utilized in the existing technology, it is undoubtedly a technical means that can bring additional electricity. At the same time, the coolant in the first heat exchange cooling unit provided in the present device relies on the natural gravity of water flowing from the high potential pool to the low potential pool, replacing the heat exchange function of the existing heat exchanger. In essence, it can be said to be an energy-saving and environmentally friendly heat exchanger that does not require electric drive and can provide additional electricity. No additional power is required, which saves the electric energy consumed by the traditional heat exchanger to drive the flow of liquid during use, further saving electricity consumption and energy. The addition of these two can achieve a relatively full utilization of electric energy. And such a setting is more environmentally friendly, especially in the wild and other locations, there is no need to use additional power supply lines to connect the heat exchanger, and there is no need to consume additional funds to purchase large heat exchangers, saving a lot of costs.

[0040] See also Figure 1The first gas storage pipeline is connected to the second compression-expansion unit at one end away from the first compression-expansion unit, the first compression-expansion unit and the second compression-expansion unit are both driven by external electricity, the second compression-expansion unit is connected to the second gas storage pipeline at the gas outlet, the second gas storage pipeline is cooled by the second heat exchange cooling unit, the second heat exchange cooling unit includes 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 to the high potential pool through a cooling pipe, and the other end even has a water outlet pipe, an electromagnetic valve is arranged on the water outlet pipe, an gas outlet pipeline is arranged above the second heat exchange cooling pool, a boost valve is arranged on the gas outlet pipeline, and the gas outlet pipeline is connected to the first generator at one end away from the second heat exchange cooling pool. Such a setting can realize that the heat generated by the compressed air is absorbed and transferred in time when the second compression expander is working. At the same time, the transferred heat is carried in the water. By controlling the opening and closing of each pipeline through a reasonable valve body, the power generated when the air is compressed can be effectively used to heat the water in the second heat exchange cooling pool, so that the water is heated to produce water vapor and thus generate pressure, and then the pressure of the water vapor is replaced by the kinetic energy of the generator impeller, thereby realizing the energy conversion of pressure to rotational energy and kinetic energy to electricity, and converting it into electricity through the generator to realize power generation using the principle of steam engine, and the electric energy can be transferred or stored by existing conventional means as backup power. Although there will be different degrees of energy loss in the secondary conversion process here, since the electric energy converted by the generator is converted from the heat energy generated by the compressed air that has not been fully utilized in the existing technology, it is undoubtedly a technical means that can bring additional electricity. At the same time, the coolant in the second heat exchange cooling unit provided in the device relies on the natural gravity of water flowing from the high potential pool to the low potential pool, replacing the heat exchange function of the existing heat exchanger. In essence, it can be said to be an energy-saving and environmentally friendly heat exchanger that does not require electric drive and can provide additional electricity. No additional power is required, which saves the electric energy consumed by the traditional heat exchanger to drive the flow of liquid during use, further saving electricity consumption and energy. The addition of these two can achieve a relatively full utilization of electric energy. And such a setting is more environmentally friendly, especially in the wild and other locations, there is no need to use additional power supply lines to connect the heat exchanger, and there is no need to consume additional funds to purchase large heat exchangers, saving a lot of costs.

[0041] The second gas storage pipeline is connected to the gas storage device at one end away from the second compression expansion unit.

[0042] It can ensure that the air filtered by the first filter is in a completely closed state and enters the air storage device without contacting the outside air, thereby further ensuring the cleanliness of the compressed air. On the premise of protecting the compressed air equipment and pipelines, it can also protect the equipment and pipelines that the air passes through when releasing.

[0043] A liquid filtering device is arranged on the cooling pipe, and a second generator is arranged on the cooling pipe. The second generator can convert the kinetic energy of water into electrical energy and input it into an external battery.

[0044] Such an arrangement can firstly ensure that the water in the high-potential pool is clean when entering the second generator, preventing debris in the water from causing damage to the second generator; secondly, it can ensure that the debris in the water will not enter the first heat exchange cooling pool or the second heat exchange cooling pool, causing blockage or damage to the structure in the first heat exchange cooling pool or the second heat exchange cooling pool; it can also prevent it from causing 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; similarly, it can also prevent debris from clogging the pipeline when water vapor in the first heat exchange cooling pool or the second heat exchange cooling pool is discharged, thereby ensuring the safe and long-term use of the equipment and the power generation efficiency of the generator, thereby realizing the recycling of electric energy to the greatest extent, saving energy to the greatest extent, and reducing energy loss.

[0045] Among them, a connecting pipe is provided on one side of the high-potential pool, the pipe mouth of the connecting pipe is connected to the electric push rod through a connecting piece, the electric push rod is controlled by a controller, and the controller is connected to the external electrical output through a detection device. A water receiving trough is provided at the pipe mouth of the connecting pipe, and the water receiving trough is connected to the low-potential pool.

[0046] With such a configuration, when the detection device detects that the external battery power is insufficient (insufficient wind power generation, insufficient solar power generation, insufficient power generation of the generator below the high-potential pool, insufficient power generation of the first and second heat exchange cooling pools, etc.), it will send a signal to the controller, and the controller will control the electric push rod to lift the height of the connecting pipe mouth, thereby increasing the water level of the high-potential pool during the circulation, thereby maintaining sufficient power in the external battery by technical means of increasing the power generation below the high-potential pool.

[0047] Conversely, when the detection device detects that the external battery has sufficient power (insufficient wind power generation, insufficient solar power generation, insufficient power generation of the generator below the high-potential pool, insufficient power generation of the first and second heat exchange cooling pools, etc.), it will send a signal to the controller, and the controller will control the electric push rod to lower the height of the connecting pipe mouth, thereby lowering the water level of the high-potential pool during the circulation, thereby maintaining sufficient power in the external battery by technical means of reducing the power generation below the high-potential pool.

[0048] The gas storage device is connected to an energy release pipeline, the energy release pipeline is connected to the second compression expansion unit through a preheating device, the second compression expansion unit is connected to the first compression expansion unit through an energy release pipeline, and a preheating device is arranged outside the energy release pipeline, the preheating device is used to heat the energy release pipeline and thus heat the air in the energy release pipeline.

[0049] See also Figure 2When there is a shortage of electricity and the compressed air energy storage system based on the compression-expansion dual-purpose unit needs to be used 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 gas pressure into kinetic energy and then into electrical energy for output. Since the energy is clean, compared with the existing heating method of mixing fuel and burning, it saves fuel resources and does not produce any harmful substances, thereby achieving the output of electrical energy under the premise of energy saving and environmental protection, so as to solve the problem of temporary power shortage.

[0050] See also Figure 2 , the first compression expansion unit is connected to a second gas filter. Such a setting can first ensure that the exhaust air is clean air, and secondly, the exhaust air can be screened and purified. Since the compressed air energy storage system based on the compression expansion dual-purpose unit often needs to use the sealed mine caves and rock caves in the wild to store gas, the second gas filter can prevent the underground harmful gas from being discharged and polluting the atmosphere, so as to achieve the storage and conversion of real clean energy. On the premise of realizing the basic technical functions of electric energy conversion, storage, conversion and release required by the conventional compressed air energy storage system based on the compression expansion dual-purpose unit, it effectively avoids the exhaust gas polluting the atmosphere due to the special working environment or the damage of the gas storage device or the invasion of external harmful gases into the gas storage device, so as to achieve real clean and environmental protection.

[0051] The external battery is also connected to a solar power generation device and a wind power generation device.

[0052] It can make full use of all energy-generating devices in the existing environment to provide the initial operating power for the entire system, truly realizing the self-powering and self-operation of the entire system, without consuming any external electricity, and without the need to connect any external power transmission wires, etc., saving costs on a large scale. It can even serve as an electricity output unit by itself. In normal times, when there is no surplus electricity that needs compressed air energy storage, it can also become an electricity output unit by itself to provide electricity to the outside world.

[0053] Application scenario of an exemplary embodiment: When the compressed air energy storage system based on the compression and expansion dual-purpose unit is needed to convert and store electricity when the electricity is sufficient, the external circuit is connected to the first compression and expansion unit and the second compression and expansion unit, and the air is extracted from the atmosphere, passes through the first filter and enters the first compression and expansion unit, and the gas is compressed and discharged through the first gas storage pipeline. At the same time, the first heat exchange cooling unit cools the first gas storage pipeline filled with high-temperature gas and replaces heat. The replaced heat is used to heat the water in the first heat exchange cooling pool to generate water vapor. After reaching a certain pressure through the boost valve, it is transmitted to the generator. The basic steam engine can be used to generate electricity remotely, and the electricity generated by the generator is temporarily stored in the external battery.

[0054] When the gas in the first gas storage pipeline enters the second compression expansion unit, it needs to pass through the second heat exchange cooling unit to cool the second gas storage pipeline filled with high-temperature gas and perform heat replacement. The replaced heat is used to heat the water in the second heat exchange cooling pool to generate water vapor. After reaching a certain pressure through the boost valve, it is transmitted to the generator. The basic steam engine can be used to generate electricity remotely, and the electricity generated by the generator is temporarily stored in an external battery.

[0055] It should be noted at this point that the electric energy of the external battery can also be stored in advance by means of wind power generation, solar power generation, etc., by first installing the wind power generation or solar power generation device and the external battery when installing the compressed air energy storage system based on the compression-expansion dual-purpose unit, and then collecting electricity in advance.

[0056] The electric energy stored in the external battery can be used to drive the water pump to pump water from the ground potential pool to the high potential pool. The water in the high potential pool falls naturally due to gravity, passes through the liquid filtering device and then generates electricity through the generator, making full use of 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 respectively through the liquid pipeline, cooling 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. After the temperature of the water in the first heat exchange cooling pool and the second heat exchange cooling pool reaches a certain height, the solenoid valve is opened to change the water. The battery valve is set so that the water vapor generated by the first heat exchange cooling pool and the second heat exchange cooling pool when cooling the first gas storage pipeline and the second gas storage pipeline will not flow out of the water pipeline to cause energy waste. When the water needs to be changed, it can be opened to allow the water in the first heat exchange cooling pool and the second heat exchange cooling pool to flow into the low potential pool through the opened solenoid valve and cool naturally. In this way, the cycle can achieve the maximum storage of electricity while ensuring the basic compressed gas storage function without the need for external power intervention.

[0057] When there is a shortage of electricity and it is necessary to use the compressed air energy storage system based on the compression-expansion dual-purpose unit to generate electricity, the gas is released from the gas storage device, passes through the energy release pipeline and the preheating device, so that the high-pressure air in the energy release pipeline is heated, and the pressure increases again, thereby optimizing the gas movement to drive the power generation device in the compression-expansion dual-purpose 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 electrical energy for output. The whole process does not produce any toxic and harmful gases, and can ensure that external toxic and harmful gases will not spread into the atmosphere to pollute the environment. In addition, since the energy is clean and no harmful substances are produced, it is achieved that electrical energy can be output under the premise of energy saving and environmental protection to solve the problem of temporary power shortage.

[0058] The above description and the accompanying drawings fully illustrate the embodiments of the present invention so that those skilled in the art can practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The embodiments of the present invention are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A compressed air energy storage system based on a compression-expansion dual-purpose unit, characterized in that: include: A first compression-expansion unit, a second compression-expansion unit, a first heat exchange cooling unit, a second heat exchange cooling unit and a thermal potential conversion device; The first compression expansion unit has an air inlet connected to the atmosphere, extracts gas from the atmosphere, and is driven by external electricity; The first compression expansion unit has a gas outlet connected to a first gas storage pipeline, the first gas storage pipeline is cooled by a first heat exchange cooling unit, and one end of the first gas storage pipeline away from the first compression expansion unit is connected to the second compression expansion unit; The second compression-expansion machine unit is driven by external electricity, and the gas outlet of the second compression-expansion machine unit is connected to a second gas storage pipeline; The second gas storage pipeline is cooled by a second heat exchange cooling unit, and the second gas storage pipeline is connected to a gas storage device at one end away from the second compression expansion unit; The first heat exchange cooling unit and the second heat exchange cooling unit are both connected to the thermal potential conversion device.

2. A compressed air energy storage system based on a compression-expansion dual-purpose unit according to claim 1, characterized in that: The thermal potential conversion device comprises a first generator, and the first generator is connected to a potential storage device.

3. A compressed air energy storage system based on a compression-expansion dual-purpose unit according to claim 2, characterized in that: The potential 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 to the high-potential pool through a pipeline equipped with a water pump. Two cooling pipes are arranged on the high-potential pool, one of which is connected to the first heat exchange cooling unit, and the other is connected to the second heat exchange cooling unit. The first heat exchange cooling unit and the second heat exchange cooling unit are both connected to exhaust pipelines, and the exhaust pipelines are connected to the first generator. The first generator can convert gas kinetic energy into electrical energy and input it into an external battery. The external battery can power the water pump to pump water in the low-potential pool into the high-potential pool.

4. A compressed air energy storage system based on a compression-expansion dual-purpose unit according to claim 3, characterized in that: The cooling pipe is provided with a liquid filtering device, and the cooling pipe is provided with a second generator, and the second generator can convert the kinetic energy of water into electrical energy and input it into an external battery.

5. A compressed air energy storage system based on a compression-expansion dual-purpose unit according to claim 3, characterized in that: 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 to the high potential pool through the cooling pipe, and the other end even has a water outlet pipe, and an electromagnetic valve is arranged on the water outlet pipe. An air outlet pipeline is arranged above the first heat exchange cooling pool, and a boost valve is arranged on the air outlet pipeline. The air outlet pipeline is connected to the first generator at one end away from the first heat exchange cooling pool.

6. A compressed air energy storage system based on a compression-expansion dual-purpose unit according to claim 3, characterized in that: The second heat exchange cooling unit includes 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 to the high potential pool through the cooling pipe, and the other end even has a water outlet pipe, and an electromagnetic valve is arranged on the water outlet pipe. An air outlet pipeline is arranged above the second heat exchange cooling pool, and a boost valve is arranged on the air outlet pipeline. The air outlet pipeline is connected to the first generator at one end away from the second heat exchange cooling pool.

7. A compressed air energy storage system based on a compression-expansion dual-purpose unit according to claim 3, characterized in that: The external battery is also connected to a solar power generation device and a wind power generation device.

8. A compressed air energy storage system based on a compression-expansion dual-purpose unit according to claim 2, characterized in that: The gas storage device is connected to an energy release pipeline, the energy release pipeline is connected to the second compression expansion unit through a preheating device, the second compression expansion unit is connected to the first compression expansion unit through an energy release pipeline, and a preheating device is arranged outside the energy release pipeline, and the preheating device is used to heat the energy release pipeline and thus heat the air in the energy release pipeline.

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

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

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