Air compressor unit and compressed air energy storage system

Abstract

The application relates to the technical field of compressed air energy storage, and provides an air compressor unit and a compressed air energy storage system. The air compressor unit comprises: multi-stage air compressors connected in series, the variable compression efficiencies of the air compressors at different stages are equal, and the process parameter configurations of the air compressors at different stages satisfy the following conditions: wherein, m ci and respectively represent the mass flow and the compressed exhaust temperature of the air compressor at the i-th stage, and Constant represents that the product of the mass flow and the compressed exhaust temperature of the air compressor at each stage is equal. The air compressor unit and the compressed air energy storage system provided by the application can realize the optimal combination of the compressed exhaust temperatures at different stages and the total compression power by reasonably configuring the exhaust temperature parameter configurations among the air compressors at different stages, so that the overall energy efficiency of the system is improved.

Description

Technical Field

[0001] This invention relates to the field of compressed air energy storage technology, and in particular to an air compressor unit and a compressed air energy storage system. Background Technology

[0002] Advanced insulated compressed air energy storage, as a large-scale, long-term energy storage technology, has been successfully demonstrated in engineering projects of varying capacity levels in China. When absorbing energy, the compressed air energy storage system utilizes surplus electricity from renewable energy sources, thermal power plants, or off-peak electricity from the grid to drive an air compressor to compress ambient air, obtaining high-temperature, high-pressure compressed air. This compressed air then exchanges heat with a heat transfer medium, absorbing and storing the thermal energy. After releasing heat and cooling, the air enters the storage device, thus storing electrical energy using both the heat transfer medium and compressed air as carriers. When releasing energy, the stored compressed air again exchanges heat with the stored heat transfer medium, absorbing heat and heating up before entering an air expander to depressurize and perform work, driving a generator to generate electricity. Simultaneously, the cooled heat transfer medium is stored, thus achieving the regeneration of electrical energy.

[0003] According to the working principle of advanced adiabatic compressed air energy storage and power generation systems, the compression process has a dual impact on the overall energy storage characteristics of the system. First, the exhaust temperature during compression determines the system's heat storage temperature, which in turn determines the intake temperature during expansion. According to classical thermodynamics, the intake temperature is positively correlated with the output power during expansion. Therefore, increasing the exhaust temperature of the air compressor will increase the output power during expansion, thus contributing to improved overall system energy efficiency, provided the compression power remains constant. However, according to classical thermodynamics, as the exhaust temperature increases, the power output during compression also increases, resulting in an effect on overall system energy efficiency that is opposite to the impact of the exhaust temperature.

[0004] As shown above, the exhaust temperature and compression power consumption during the compression process have both positive and negative impacts on the energy efficiency of compressed air energy storage systems. Optimization is needed to determine the optimal combination of exhaust temperature and compression power consumption for each stage of the air compressor, thereby maximizing the overall system energy efficiency. Currently, there are no specific process design and optimization methods for advanced adiabatic compressed air energy storage air compressor units. Summary of the Invention

[0005] This invention provides an air compressor unit and a compressed air energy storage system to address the shortcomings of low energy efficiency in existing compressed air energy storage systems and improve their energy efficiency.

[0006] The first aspect of the present invention provides an air compressor unit, comprising: a multi-stage air compressor connected in series, wherein the variable compression efficiency of each stage of the air compressor is equal, and the process parameters of each stage of the air compressor are configured to satisfy the following conditions:

[0007]

[0008] Where, m ci The mass flow rate of the air compressor in stage i is the mass flow rate of the air passing through it. Let be the compressed exhaust temperature of the i-th stage air compressor, and Constant indicates that the product of the flow air mass flow rate and the compressed exhaust temperature of each stage air compressor is equal.

[0009] A second aspect of the present invention provides a compressed air energy storage system, comprising: an air compressor unit, a heat storage module, an expansion work module, and a heat storage gas device as described above;

[0010] The air compressor unit is connected to the heat storage gas device, the heat storage gas device is connected to the expansion work module, and the heat storage module is connected to both the air compressor unit and the expander unit.

[0011] According to the compressed air energy storage system provided by the present invention, the heat storage gas device includes a heat storage gas device body, and the heat storage gas device body is provided with a gas storage chamber and a heat storage cavity. The heat storage cavity is suitable for storing a heat storage medium that exchanges heat with compressed air, and the heat storage cavity is unidirectionally connected to the gas storage chamber.

[0012] The heat storage chamber is provided with a first gas outlet, the gas storage chamber is provided with a second gas outlet, the second gas outlet is connected to the bottom of the heat storage chamber, and the first gas outlet is connected to the expansion work module.

[0013] According to the compressed air energy storage system provided by the present invention, the heat storage and gas storage device body is provided with a one-way partition mechanism, which divides the inner cavity of the heat storage and gas storage device body into the gas storage chamber and the heat storage chamber.

[0014] According to the compressed air energy storage system provided by the present invention, the heat storage chamber is provided with a liquid phase space and a gas phase space. The liquid phase space is suitable for storing a heat storage medium that exchanges heat with compressed air. The gas phase space is located above the liquid phase space, and the first gas outlet is provided in the gas phase space.

[0015] According to the compressed air energy storage system provided by the present invention, a heat exchange structure is provided in the liquid phase space.

[0016] According to the compressed air energy storage system provided by the present invention, the heat exchange structure is provided with baffles on the upper and lower sides respectively, and the baffles are provided with gas passages suitable for gas passage.

[0017] According to the compressed air energy storage system provided by the present invention, an air distribution zone is provided below the heat exchange structure.

[0018] In the compressed air energy storage system provided by the present invention, the heat exchange structure is a heat exchange fin.

[0019] In the compressed air energy storage system provided by the present invention, the heat storage medium is water or heat storage oil.

[0020] The air compressor unit and compressed air energy storage system provided by the present invention can achieve the optimal combination of exhaust temperature of each stage of the air compressor and total compression power by reasonably configuring the exhaust temperature parameters between each stage of the air compressor, thereby improving the overall energy efficiency of the system.

[0021] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of one embodiment of the air compressor unit provided by the present invention;

[0024] Figure 2 This is a schematic diagram of a second embodiment of the air compressor unit provided by the present invention;

[0025] Figure 3 This is a schematic diagram of the compressed air energy storage system provided in an embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of a heat storage gas device in a compressed air energy storage system provided in an embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of a compressed air energy storage system in the prior art.

[0028] 1. Gas storage chamber; 2. Heat storage chamber; 201. First gas outlet; 202. Second gas outlet; 203. Liquid phase space; 2031. Air distribution area; 204. Gas phase space; 3. One-way separation mechanism; 4. Heat exchange fins; 5. Baffle; 6. Heat storage and gas storage device; 7. First air compressor; 8. Second air compressor; 9. First heat exchanger; 10. First expander; 11. Second expander; 12. Second heat exchanger; 13. Third heat exchanger; 14. Heat storage module. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0030] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0031] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0032] Overview of existing technologies:

[0033] Based on the working principle of advanced adiabatic compressed air energy storage power generation systems, it is known that the exhaust temperature and compression power consumption of the air compressor in the system have both positive and negative impacts on the energy efficiency of the compressed air energy storage system. Optimization is needed to determine the optimal combination of exhaust temperature and compression power consumption for each stage of the compressor, thereby maximizing the overall energy efficiency of the system. Currently, there are no specific process design and optimization methods for advanced adiabatic compressed air energy storage air compressor units.

[0034] In addition, such as Figure 5 The diagram shows a schematic of an existing compressed air energy storage system, which includes at least two stages (taking two stages as an example) of multi-stage air compressor units C1 and C2 connected in series. Heat exchangers are installed at the outlet of each stage of air compressor, such as heat exchanger H1 after air compressor C1, which is used to exchange heat with high-temperature compressed exhaust gas using a heat transfer medium. After the compressed air releases heat and cools down, it enters the next stage air compressor or air storage AS. The heat transfer medium, after absorbing heat and warming up, enters the heat storage system HS for storage, thereby converting the electrical energy input from outside the system into the pressure potential energy contained in the compressed air and the compressive heat energy contained in the heat transfer medium for storage respectively. The system also includes multi-stage series expanders T1 and T2 (taking two stages as an example), and heat exchangers H2 and H3 are installed before the inlet of each expander. These heat exchangers are used to heat the intake air with a heat transfer medium. After the compressed air absorbs heat and becomes hotter, it enters the expander to do work, reduce pressure and temperature, and then enters the heat exchanger before the next expander to absorb heat and become hotter again or be discharged into the environment. The heat transfer medium that has released heat and cooled down is returned to the heat storage system HS for storage, thereby using the compressed air and high-temperature heat transfer medium stored in the system to regenerate electrical energy.

[0035] In practical applications, compressed air energy storage systems typically use fixed-volume pressure vessels to store compressed air. During the inflation process, the exhaust pressure of the air compressor unit will continuously increase as the amount of air in the storage device increases. To ensure the stability of the air compressor exhaust temperature and thus the stability of the operating temperature of the heat storage system, the air compressor unit is generally divided into two compression stages, such as... Figure 5 As shown: Air compressor C1 has a stable discharge pressure, forming a constant-pressure compression section, which can provide a stable temperature discharge for heat exchange with the heat transfer medium in heat exchanger H1, thus providing a stable high-temperature heat transfer medium for the heat storage system HS; the discharge pressure of air compressor C2 continuously increases during the filling process of air storage chamber AS, and therefore its discharge temperature continuously increases, unable to provide the compression heat energy supply for the temperature. Generally, a chiller driven by a cooling tower is used to directly cool it, and the heat energy is dissipated into the external environment as heat loss, such as... Figure 5 The cooler CT is shown in the image.

[0036] As can be seen from the above, in the existing technical solution, the compressed heat energy generated in the non-constant pressure section is lost in the form of dissipation and cannot be effectively recovered and utilized. Furthermore, during the gas release power generation process, as the fixed-volume gas storage chamber AS releases gas, the gas volume continuously decreases and the gas pressure drops. When the gas pressure drops to a certain value, it cannot meet the minimum inlet pressure requirement of the expander T1, forcing the system to stop operating. The remaining compressed air in the gas storage chamber AS cannot be effectively utilized. Simultaneously, according to the expansion cooling effect, the temperature inside the gas storage chamber will also decrease with the gas pressure. According to the gas state equation, the decrease in temperature will increase the density of compressed air, further accelerating the decrease in gas pressure inside the gas storage chamber. Therefore, when the gas pressure drops to the minimum inlet pressure of the expander, more compressed air will be retained in the gas storage chamber AS and cannot be effectively utilized, resulting in a low volume utilization rate of the gas storage chamber.

[0037] In view of the shortcomings of existing compressed air energy storage systems, the present invention provides an air compressor unit and a compressed air energy storage system.

[0038] The following is combined with Figures 1 to 4 This invention describes the air compressor unit and compressed air energy storage system provided by the present invention.

[0039] It should be noted that the air compressor unit provided by this invention has two application scenarios: one is for design scheme optimization in the system design phase, and the other is for operation scheme optimization in the actual operation phase. The following details specific embodiments of the air compressor unit provided by this invention applied to design scheme optimization in the system design phase and operation scheme optimization in the actual operation phase.

[0040] Design scheme optimization applied in the system design phase

[0041] like Figure 1 The diagram shown is a schematic of one embodiment of the air compressor unit provided by the present invention. In this embodiment, the constant pressure section air compressor unit includes multiple air compressors A1 to An connected in series. The variable compression efficiency of each air compressor is equal. Heat exchangers B1 to Bn are provided between adjacent air compressors. Each heat exchanger uses a low-temperature heat transfer medium to exchange heat with the air compressor exhaust, reducing the air compressor exhaust temperature to the ambient temperature level before it enters the next stage air compressor. At the same time, gas-liquid separators S1 to Sn are provided between adjacent air compressors. The gas-liquid separators are used to separate the liquid water generated by the condensation of compressed air after cooling, preventing the liquid water from entering the subsequent process flow. Therefore, the mass flow rate of the air entering the next stage air compressor will be less than that of the previous stage air compressor. The process parameter configuration of each stage air compressor satisfies the following conditions:

[0042]

[0043] Where, m ciLet be the mass flow rate of the air passing through the i-th stage air compressor. Let represent the compressed exhaust temperature of the i-th stage air compressor. "Constant" indicates that the product of the mass flow rate of the air flowing through each stage of the air compressor and the compressed exhaust temperature is equal. "Constant" signifies a constant, meaning that the product of the mass flow rate of the air flowing through each stage of the air compressor and the compressed exhaust temperature is equal, and the value of this product is the same constant.

[0044] Due to gas-liquid separation, the mass flow rate of the air passing through each stage of the air compressor is not equal. At this time, attention should be paid to the product of the mass flow rate of the air passing through each stage of the air compressor and the exhaust temperature of the compressed air, as the exhaust temperatures of each stage of the air compressor are different.

[0045] like Figure 2 The diagram shown is a schematic of a second embodiment of the air compressor unit provided by the present invention. In this embodiment, the constant pressure section air compressor unit includes multiple air compressors A1 to An connected in series. The variable compression efficiency of each air compressor is equal. Heat exchangers B1 to Bn are provided between adjacent air compressors. Each heat exchanger uses a low-temperature heat transfer medium to exchange heat with the exhaust gas of the air compressor, reducing its temperature to the ambient temperature level before it enters the next stage air compressor. When the air contains no moisture or has low humidity, a gas-liquid separator is not installed. At this time, the air flow mass flow rate of each air compressor is equal, and the process parameter configuration of each air compressor satisfies the following conditions:

[0046]

[0047] in, Let represent the compression and discharge temperature of the i-th stage air compressor. "Constant" indicates that the compression and discharge temperatures of all stages of the air compressor are equal. Similarly, "Constant" represents a constant, meaning that the compression and discharge temperatures of all stages of the air compressor are equal, and their numerical values ​​are all the same constant.

[0048] In other words, under ideal conditions, since there is no moisture separation, the mass flow rate of the air passing through each stage of the air compressor is equal. Therefore, it is only necessary to make the compression and exhaust temperatures of each stage of the air compressor equal.

[0049] Optimization of operation plan during actual operation phase

[0050] Even if the multi-stage air compressor unit meets the above-mentioned optimized configuration conditions under the design conditions, the actual operating parameters of each stage of the air compressor may deviate from the predetermined configuration due to interference factors such as the actual operating environment and pipeline resistance. By measuring the mass flow rate of the air passing through each stage of the air compressor and the compressed exhaust temperature, it is possible to quickly and conveniently determine whether there is a deviation in the actual operating parameters of each stage of the air compressor based on the above-mentioned optimized configuration conditions.

[0051] If the actual operation deviates from the optimal configuration conditions, the exhaust pressure of each stage of the air compressor can be adjusted by means of outlet throttling or inlet guide vanes, provided that the safety operation constraints of the air compressor module are met. At the same time, the flow rate and exhaust temperature of each stage of the air compressor are monitored, and it is calculated whether the above-mentioned optimal configuration conditions are met or as close as possible.

[0052] The air compressor unit provided by this invention can achieve the optimal combination of exhaust temperature of each stage of the compressor and total compression power by reasonably configuring the exhaust temperature parameters between each stage of the air compressor, thereby improving the overall energy efficiency of the system.

[0053] like Figure 3 As shown, another aspect of the present invention provides a compressed air energy storage system, comprising: an air compressor unit, a heat storage module, an expansion work module, and a heat storage gas device 6 as described in the above embodiment. The heat storage gas device 6 is suitable for auxiliary heat storage and gas storage in the compressed air energy storage system.

[0054] Specifically, such as Figure 4 As shown, the heat storage and gas storage device 6 includes a heat storage and gas storage device body. The heat storage and gas storage device body is provided with a gas storage chamber 1 and a heat storage cavity 2. The heat storage cavity 2 is suitable for storing a heat storage medium that exchanges heat with compressed air. The heat storage cavity 2 is unidirectionally connected to the gas storage chamber 1. The heat storage cavity 2 is provided with a first gas outlet 201, and the gas storage chamber 1 is provided with a second gas outlet 202. The second gas outlet 202 is connected to the bottom of the heat storage cavity 2 through a pipeline.

[0055] In this embodiment, the gas storage chamber 1 and the heat storage chamber 2 are both located inside the main body of the heat storage and gas storage device. Since the heat storage medium is usually liquid (water or heat storage oil), in this embodiment, the heat storage chamber 2 is set below the gas storage chamber 1 so that the compressed air can flow upward naturally after entering the heat storage chamber 2 and exchange heat with the heat storage medium therein. After the heat exchange, it enters the gas storage chamber 1 for storage.

[0056] In this embodiment, the one-way communication between the heat storage chamber 2 and the gas storage chamber 1 specifically means that the air inside the heat storage and gas storage device body can only enter the gas storage chamber 1 through the heat storage chamber 2, but cannot enter the heat storage chamber 2 from the gas storage chamber 1.

[0057] As an example, a one-way separation mechanism 3, such as a one-way valve, can be provided between the gas storage chamber 1 and the heat storage chamber 2 to divide the inner cavity of the heat storage and gas storage device body into two independent cavities, the gas storage chamber 1 and the heat storage chamber 2, and the gas can only enter the gas storage chamber 1 from the heat storage chamber 2 through the one-way separation mechanism 3.

[0058] like Figure 4As shown in this embodiment of the invention, the heat storage chamber 2 is provided with a liquid phase space 203 and a gas phase space 204. The liquid phase space 203 is suitable for storing the heat storage medium that exchanges heat with compressed air, and the gas phase space 204 is located above the liquid phase space 203. The first gas outlet 201 is located in the gas phase space 204. By setting the heat storage chamber 2 as a liquid phase space 203 and a gas phase space 204, after the compressed air exchanges heat with the heat storage medium in the liquid phase space 203, it can enter the gas phase space 204 for collection, which facilitates its entry into the gas storage chamber 1 or into the expander in the compressed air energy storage system.

[0059] like Figure 4 As shown, in this embodiment of the invention, a heat exchange structure is provided in the liquid phase space 203. Specifically, the heat exchange structure is a heat exchange fin 4, which is immersed in the liquid heat storage medium. When compressed air enters the liquid phase space 203, it can fully exchange heat with the heat storage medium on the surface of the heat exchange fin 4, thereby improving the heat exchange efficiency.

[0060] like Figure 4 As shown, in a further embodiment of the present invention, partitions 5 are respectively provided on the upper and lower sides of the heat exchange fins 4, and gas passages suitable for gas passage are provided on the partitions 5. Figure 4 (Not shown in the image). On one hand, the baffle 5 located below the heat exchange fins 4 can provide some support and fixation for the heat exchange fins 4. On the other hand, the gas through holes provided on it can evenly introduce compressed air into the liquid phase space 203, further improving the heat exchange efficiency. The baffle 5 located above the heat exchange fins 4 can also evenly distribute the gas overflowing from the liquid phase space 203 into the gas phase space 204, improving the stability of the device during operation.

[0061] like Figure 4 As shown, in a further embodiment of the present invention, an air distribution zone 2031 is provided below the heat exchange fins 4, and the air distribution zone 2031 is connected to the second gas outlet 202 through a pipeline. By setting the air distribution zone 2031, the compressed air entering the heat storage chamber 2 can first play a certain buffering role, and the gas can evenly distribute the compressed air, so that it can evenly enter the liquid phase space 203 to exchange heat with the heat storage medium, thereby further improving the heat exchange efficiency.

[0062] In this embodiment, the air compressor unit is exemplified by two stages: a first air compressor 7 and a second air compressor 8, with a first heat exchanger 9 located between the first air compressor 7 and the second air compressor 8. The expansion work module is also exemplified by two stages: a first expander 10 and a second expander 11, with a second heat exchanger 12 located between the first expander 10 and the heat storage module 14, and a third heat exchanger 13 located between the second expander 11 and the heat storage module 14. The first gas outlet 201 is connected to the second expander 11 through the gas inlet of the third heat exchanger 13.

[0063] In the embodiment of the compressed air energy storage system provided by the present invention, the compressed air energy storage system further includes a power generation module ( Figure 3 (Not shown in the image), the power generation module is connected to the expansion work module. It can use the work done by the expansion of air to generate electricity.

[0064] The working principle of the compressed air energy storage system provided by this invention is as follows:

[0065] like Figure 3 and Figure 4 As shown, during the system's air-filled energy storage, the system utilizes surplus electricity from renewable energy sources, thermal power generation, or off-peak electricity from the power grid to drive the air compressor unit to continuously compress air. The exhaust from the constant-pressure compression section air compressor (first air compressor 7, hereinafter the same) first passes through the first heat exchanger 9 to exchange heat with the heat transfer medium and cool down before entering the non-constant-pressure section air compressor (second air compressor 8, hereinafter the same) for further compression. The air compressed by the non-constant-pressure section air compressor enters the heat storage chamber 2 through the air inlet at the bottom of the heat storage chamber 2. Simultaneously, the heat transfer medium absorbs heat and heats up in the first heat exchanger 9 before entering the heat storage system for storage. The compressed air enters the area where the heat exchange fins 4 are located through the air distribution area 2031. While moving upwards, it fully exchanges heat with the heat storage medium on the surface of the heat exchange fins 4, storing the heat in the heat storage medium. The air after heat exchange enters the gas phase space 204 and enters the air storage chamber 1 for storage through a one-way mechanism.

[0066] When the system generates electricity by releasing gas, compressed air flows out from the second gas outlet 202 of the gas storage chamber 1 and enters the lower part of the heat storage chamber 2. It then enters the area where the heat exchange fins 4 are located through the air distribution area 2031. While moving upward, it fully exchanges heat with the surface of the heat exchange fins 4 and the heat storage medium, raising the temperature of the compressed air. Afterward, part of the compressed air that has absorbed heat and increased in temperature enters the third heat exchanger 13 for further heating and expansion to do work. The other part of the compressed air enters the gas storage chamber 1 through a one-way structure to heat the air inside and raise the temperature inside the gas storage chamber 1.

[0067] As described above, in the compressed air energy storage system provided by this invention, the air compressor unit can achieve the optimal combination of exhaust temperature and total compression power by rationally configuring the exhaust temperature parameters between each stage of the air compressor, thereby improving the overall energy efficiency of the system. The heat storage device 6, through a rational design of its structure and charging / discharging process, can store the non-constant temperature compression heat energy in the exhaust gas from the non-constant pressure compression section into the system, avoiding heat loss. Furthermore, by utilizing the stored compression heat energy, the expander intake air can be preheated during the discharge process, thus achieving heat recovery utilization of the stored heat energy. Simultaneously, some of the stored compression heat energy can enter the storage chamber 1 with the preheated compressed air, offsetting the temperature drop in the storage chamber 1 during discharge and even raising its temperature, thereby allowing the storage chamber 1 to discharge as much compressed air as possible within the same operating pressure range, improving the volume utilization rate of the storage chamber 1. By improving the air compressor unit and the heat storage device, the compressed air energy storage system can significantly improve the system's energy efficiency.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A compressed air energy storage system, characterized in that, include: Air compressor unit, heat storage module, expansion work module and heat storage gas device; The air compressor unit is connected to the heat storage gas device, the heat storage gas device is connected to the expansion work module, and the heat storage module is connected to both the air compressor unit and the expander unit. The air compressor unit includes: a multi-stage air compressor connected in series, wherein the variable compression efficiency of each stage of the air compressor is equal, and a heat exchanger is provided between adjacent air compressors. Each heat exchanger uses a low-temperature heat transfer medium to exchange heat with the air compressor exhaust, reducing the exhaust temperature of the air compressor to the ambient temperature level before it enters the next stage air compressor. Simultaneously, a gas-liquid separator is provided between adjacent air compressors to separate the liquid water generated by condensation after the compressed air is cooled, preventing the liquid water from entering subsequent processes. Therefore, the mass flow rate of the air entering the next stage air compressor will be less than that of the previous stage air compressor. The process parameters of each stage of the air compressor are configured to meet the following conditions: ； in, For the first The mass flow rate of the air compressor described above. For the first The compressed exhaust temperature of the air compressor described above. This indicates that the product of the mass flow rate of the air passing through each stage of the air compressor is equal to the compressed exhaust temperature; The heat storage and gas storage device includes a heat storage and gas storage device body. The heat storage and gas storage device body is provided with a gas storage chamber and a heat storage cavity. The heat storage cavity is suitable for storing a heat storage medium that exchanges heat with compressed air. The heat storage cavity is unidirectionally connected to the gas storage chamber. The heat storage chamber is provided with a first gas outlet, the gas storage chamber is provided with a second gas outlet, the second gas outlet is connected to the bottom of the heat storage chamber, and the first gas outlet is connected to the expansion work module. The heat storage and gas storage device body is provided with a one-way partition mechanism, which divides the inner cavity of the heat storage and gas storage device body into the gas storage chamber and the heat storage chamber. The heat storage chamber is provided with a liquid phase space and a gas phase space. The liquid phase space is suitable for storing the heat storage medium that exchanges heat with compressed air. The gas phase space is located above the liquid phase space, and the first gas outlet is located in the gas phase space.

2. The compressed air energy storage system according to claim 1, characterized in that, The liquid phase space is equipped with a heat exchange structure.

3. The compressed air energy storage system according to claim 2, characterized in that, The heat exchange structure is provided with baffles on the upper and lower sides, and the baffles are provided with gas passages suitable for gas passage.

4. The compressed air energy storage system according to claim 2, characterized in that, An air distribution zone is provided below the heat exchange structure.

5. The compressed air energy storage system according to claim 2, characterized in that, The heat exchange structure is a heat exchange fin.

6. The compressed air energy storage system according to claim 1, characterized in that, The heat storage medium is water or heat storage oil.

Images