Method and system for increasing the compression heat recovery rate of advanced adiabatic compressed air energy storage

Abstract

The application provides a system for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage, which comprises an air compression unit and an air turbine, and an energy storage and release unit, wherein the inlet of the tube passage of each heat exchanger is connected with the air compression unit through a pipeline, the outlet of the tube passage is connected with a gas storage device through a pipeline, the inlet of the shell passage is connected with a low-temperature water storage tank through a pipeline and a low-temperature circulating water pump, and the outlet of the tube passage is connected with a high-temperature water storage tank through a pipeline; the primary flow inlet of a bleed air ejector is connected with the gas storage device through a pipeline, the secondary flow inlet of the bleed air ejector is connected with air, the gas inlet of a reheater is connected with the mixed flow outlet of the bleed air ejector through a pipeline, the gas outlet is connected with the air turbine through a pipeline, the liquid inlet is connected with the high-temperature water storage tank through a pipeline and a high-temperature circulating water pump, and the liquid outlet is connected with the low-temperature water storage tank through a pipeline. The application also provides a method for improving the compression heat recovery of advanced adiabatic compressed air energy storage, and the application can effectively improve the compression heat recovery rate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy, in particular to a method and system for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage. BACKGROUND

[0002] The large-capacity advanced adiabatic compressed air energy storage system has many advantages such as large energy storage capacity, long energy release time, high system efficiency, zero fuel consumption, zero pollution emission, fast start-up speed, and strong regulation ability, and can play a key role in relieving power transmission line expansion, power load peak shaving, and large-scale consumption of new energy power, and is an important supporting technology to ensure the safe and stable operation of the power grid and to achieve the schedule.

[0003] Currently, the system efficiency (electrical-to-electrical conversion efficiency) of the most advanced adiabatic compressed air energy storage power station can reach 70%, that is, the compressed air stored by the compressor for every 100 degrees of electricity consumption can generate 70 degrees of electricity in the air turbine, and 30 degrees of electricity is lost. The loss of the advanced adiabatic compressed air energy storage system mainly occurs in the compression, heat storage and exchange, and expansion work processes. For example, Figure 1 shows the energy conversion process and loss in each link. Among them, 1-2 represents the adiabatic compression process of air in the compressor; 2-3 represents the cooling process of air in the inter-stage heat exchanger by circulating water, while the corresponding heating process of circulating water is 5-6; 3-4 represents the cooling process of air in the open water cooler, while the corresponding heating process of open water is 7-8; 6-5 represents the cooling process of circulating water in the reheating heat exchanger, and the heating process of air is 9-10; and 10-11 represents the work process of air in the air turbine.

[0004] There are irreversible losses in each link, resulting in a decrease in the system's work capacity. These irreversible losses come from air friction in the compression and expansion processes, and temperature difference in the heat exchange process, as shown by Q1 in Figure 1 . Domestic and foreign scholars have done a lot of research to reduce these losses. Due to the temperature difference in the heat exchange process, the maximum air temperature in the turbine is about 20℃ lower than that in the compressor after two heat exchanges. For example, for the medium-temperature technical route, the maximum air temperature in the air turbine is 170℃, and the maximum air temperature in the compressor is 195℃. Since the total amount of air in the compression and expansion processes remains unchanged, the compression heat is greater than the heat absorbed by the air reheating. The excess compression heat is carried away by the open cooling water, such as Figure 1 3-4 and 7-8 processes. These heat is finally discharged to the atmosphere, resulting in a loss of heat Q2. For the medium-temperature scheme of four-stage compression and three-stage expansion, Q2 is 16% of the total compression heat.

[0005] Reducing the heat exchange end difference can improve the utilization ratio of compression heat, increase the turbine inlet air temperature and increase the turbine power. The heat exchange end difference calculation formula is shown in formula (1).

[0006]

[0007] In the formula, δt is the heat exchanger end difference, ℃; Δt is the air temperature rise, ℃; k is the heat exchange coefficient, kW / m2; A is the heat exchange area, m2; C p is the air constant pressure specific heat capacity, kJ / (kg·℃); D is the air flow, kg / s.

[0008] As can be seen from formula (1), when the heat exchange end difference is reduced from 10℃ to 5℃, Q2 can be fully utilized, and at this time, 25% of the heat exchange area needs to be increased, and the equipment investment will be greatly increased. If the heat exchange end difference is kept unchanged, the air flow of Q2 needs to be increased by 16%, and the heat exchange area only needs to be increased by 10%, thereby greatly reducing the equipment investment.

[0009] If the above goal can be achieved, it is an urgent problem to design a system and method which can effectively improve the recovery rate of compression heat under the premise of not significantly increasing the heat exchange area and keeping the heat exchange end difference unchanged. SUMMARY

[0010] In view of the deficiencies of the prior art, the purpose of the present application is to provide a method and system for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage, which aims to solve the problems raised in the technical background and can effectively improve the recovery rate of compression heat under the premise of not significantly increasing the heat exchange area and keeping the heat exchange end difference unchanged.

[0011] To solve the above technical problems, the first implementation scheme of the present application is a system for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage, which comprises an air compression unit and an air turbine, the air compression unit compresses low-temperature and low-pressure air to output high-temperature air for energy storage during valley electricity or when wind and light power generation resources are sufficient, and further comprises:

[0012] An energy storage and release unit comprises a heat exchanger, a gas storage device, a gas injection and extraction device, a reheater, a low-temperature water storage tank and a high-temperature water storage tank, wherein:

[0013] Each heat exchanger is used for heat exchange and energy storage of high-temperature air output by the air compression unit and low-temperature liquid working medium, the tube side inlet is connected with the air compression unit through a pipeline, the tube side outlet is connected with the gas storage device through a pipeline, the shell side inlet is connected with the low-temperature water storage tank through a pipeline and a low-temperature circulating water pump, and the tube side outlet is connected with the high-temperature water storage tank through a pipeline;

[0014] The air injection air extractor is used for increasing air flow and improving compressed heat recovery ratio, and has a primary flow inlet, a secondary flow inlet and a mixed flow outlet, the primary flow inlet is connected with the air storage device through a pipeline, the secondary flow inlet is communicated with air, and the low-temperature air sent by the primary flow inlet is mixed with the air sent by the secondary flow inlet and flows out through the mixed flow outlet;

[0015] Each reheater is used for heat exchange and energy release of the gas flowing out of the mixed flow outlet with the high-temperature liquid working medium, the gas inlet of each reheater is connected with the mixed flow outlet through a pipeline, the gas outlet is connected with the air turbine through a pipeline, the liquid inlet is connected with the high-temperature water storage tank through a pipeline and the high-temperature circulating water pump, and the liquid outlet is connected with the low-temperature water storage tank through a pipeline.

[0016] Preferably, the air injection air extractor and the reheater are both multiple, and the multiple air injection air extractors and the multiple reheaters are one-to-one corresponding and connected in series through pipelines.

[0017] Preferably, the air injection air extractor and the reheater are both multiple, and the mixed flow outlets of the multiple air injection air extractors are connected with the same output pipeline, so that the multiple air injection air extractors are connected in parallel, and the gas inlets of the reheaters are connected with the output pipeline through pipelines.

[0018] Preferably, the air injection air extractor is further provided with a controller, the secondary flow inlet is provided with a regulating valve, and the mixed flow outlet of the air injection air extractor is provided with a pressure measuring element, and the controller is connected with the regulating valve and the pressure measuring element, and is used for adjusting the opening degree of the regulating valve through the pressure of the mixed flow outlet obtained by the pressure measuring element.

[0019] When the measured value of the pressure measuring element at the mixed flow outlet of the air injection air extractor is lower than the target set value, the controller closes the regulating valve, so as to reduce the air suction amount of the air injection air extractor, and then increase the pressure of the mixed flow outlet of the air injection air extractor; when the measured value of the pressure measuring element at the mixed flow outlet of the air injection air extractor is higher than the target set value, the controller opens the regulating valve, so as to increase the air suction amount of the air injection air extractor, and then reduce the pressure of the mixed flow outlet of the air injection air extractor.

[0020] Preferably, all the pipelines are provided with valves.

[0021] Preferably, all the air compression units include multiple air compressors and multiple synchronous motors, the multiple air compressors and the multiple synchronous motors are one-to-one corresponding and coaxially connected through shaft couplings.

[0022] Preferably, the air turbine is coaxially connected with a generator, so as to release energy during the power peak period, so as to ensure the power supply during the power peak period.

[0023] Preferably, the gas outlets of multiple reheaters are connected in parallel via pipelines that supply gas into the air turbine.

[0024] The second technical solution provided by this invention is: a method for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage, comprising the following steps:

[0025] During energy storage: The air compressor, driven by a synchronous motor, compresses low-temperature, low-pressure air from the atmosphere. The output high-temperature, high-pressure air is sent to the tube side of the heat exchanger through pipelines. High-pressure cold water from the low-temperature water storage tank is sent to the shell side of the heat exchanger through pipelines and a low-temperature circulating water pump. In the heat exchanger, the high-temperature, high-pressure air and the high-pressure cold water exchange heat and store energy. The high-temperature air after heat exchange becomes low-temperature, high-pressure air and is stored in the air storage device. The high-pressure cold water a after heat exchange becomes high-pressure hot water a and is sent to the high-temperature water storage tank.

[0026] During energy release: Low-temperature, high-pressure air in the gas storage device is sent into the ejector through the primary inlet and will entrain external air through the secondary inlet. After mixing in the ejector, the mixture is sent to the gas inlet of the reheater through the mixing outlet of the ejector. High-pressure hot water b from the high-temperature water storage tank is sent into the reheater through the high-temperature circulating water pump and pipeline. High-pressure hot water b exchanges heat with the mixed gas sent into the reheater to release energy.

[0027] When the measured value of the mixed flow outlet of the air ejector is lower than the target set value, the controller closes the regulating valve to reduce the air intake of the air ejector, thereby increasing the mixed flow outlet pressure of the air ejector; when the measured value of the mixed flow outlet of the air ejector is higher than the target set value, the controller opens the regulating valve to increase the air intake of the air ejector, thereby reducing the mixed flow outlet pressure of the air ejector.

[0028] After the high-pressure, low-temperature mixed gas is transformed into a high-temperature, high-pressure gas, it is fed into an air turbine to drive the generator to rotate, and is used to output electrical energy during peak electricity demand periods.

[0029] Preferably, the multiple synchronous motors compress air to store energy during off-peak hours or when wind and solar power resources are abundant, and the air turbine releases energy to generate electricity during peak hours.

[0030] Compared with the prior art, the advantages of this invention are as follows:

[0031] The system and method for improving the heat recovery rate of advanced adiabatic compressed air energy storage proposed in this invention can effectively improve the heat recovery rate of compression without changing the heat exchanger temperature difference or significantly increasing the heat exchange area. The reason for this problem is that in traditional compressed air energy storage, the air flow rate is equal during both compression and expansion processes. Due to the heat exchanger temperature difference, the heat generated during compression cannot be fully utilized during expansion. For example, the heat absorbed by the air as it rises from 35°C to 170°C before expansion is less than the heat released by the air as it drops from 195°C to 40°C after compression—the heat of compression. This excess heat of compression cannot be utilized and is carried away by the open cooling water, leading to a decrease in system efficiency. To avoid this, this invention utilizes the entrainment effect of an air ejector during the heat release process to increase the air flow rate entering the air turbine. While maintaining a constant air temperature rise before expansion, this increases the utilization rate of the heat of compression, thereby improving system efficiency. Furthermore, for compression-side heat exchange, the decrease in air temperature remains constant, so the total area of ​​the heat exchanger and cooler remains essentially unchanged. For expansion-side heat exchange, the increase in air temperature remains constant, and the heat exchange differential between the hot and cold fluids remains constant, so the area of ​​the expansion-side heat exchanger only increases slightly. Therefore, this invention can effectively improve the recovery rate of compression heat and enhance system efficiency, i.e., electro-electric conversion efficiency, without changing the heat exchanger differential or significantly increasing the heat exchange area. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the energy conversion process and loss stages in an advanced adiabatic compressed air energy storage system.

[0033] Figure 2 This is a schematic diagram of the structure of the air ejector and the airflow suction process of the present invention.

[0034] Figure 3 This is a schematic diagram of a system for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage, as provided in this invention.

[0035] Figure 4 This is a schematic diagram of the connection between the gas ejector and the first-stage reheater in this invention. Figure 1 .

[0036] Figure 5 This is a schematic diagram of the connection between the gas ejector and the first-stage reheater in this invention. Figure 2 .

[0037] Explanation of reference numerals in the attached figures:

[0038] 1. Low-temperature, low-pressure air; 2. Air compressor; 3. Synchronous motor; 4. High-temperature, high-pressure air; 5. Heat exchanger; 6. High-pressure, low-temperature air; 7. Injection valve; 8. High-pressure air header; 9. Air storage device; 10. Venting valve; 11. Air ejector; 12. Pressure measuring element; 13. Regulating valve; 14. Reheater; 15. High-temperature, high-pressure mixed gas delivery pipe; 16. Main gas regulating combined valve; 17. Air turbine; 18. Generator; 19. Low-temperature water storage tank; 20. High-pressure cold water header; 21. Low-temperature circulating water pump; 22. High-pressure cold water a; 23. High-pressure hot water a; 24. High-pressure hot water header; 25. High-temperature water storage tank; 26. High-temperature circulating water pump; 27. High-pressure hot water b; 28. High-pressure cold water b. Detailed Implementation

[0039] To make the above-mentioned objectives, features, and advantages of the embodiments of the present invention more apparent and understandable, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] The inventors discovered that the air ejector can use high-pressure air to draw in low-pressure air, thereby increasing the airflow. For example... Figure 2 As shown, high-pressure air stored in the air storage chamber is used as the primary flow, and atmospheric air (secondary flow) is drawn in through entrainment, ultimately forming a mixed flow to increase the airflow entering the air turbine. Currently, ejector pumps are widely used in scientific research on improving the efficiency of compressed air energy storage systems, resulting in many patents and papers, such as their use at the outlet of the final compressor to increase the injection flow rate of the air storage chamber, and at the turbine inlet to maintain a constant turbine inlet pressure. However, in this study, increasing the turbine inlet airflow through an ejector pump to improve the utilization rate of compression heat has not yet been investigated. If the goal of this patent can be achieved, the efficiency of the compressed air energy storage system can be significantly improved while keeping the heat exchanger terminal temperature constant.

[0041] In view of this, the present invention provides a method and system for improving the heat recovery rate of advanced adiabatic compressed air energy storage, aiming to solve the problems mentioned in the technical background, and can effectively improve the heat recovery rate of compression without keeping the heat exchanger terminal difference constant and without significantly increasing the heat exchange area.

[0042] like Figures 2-5 As shown, this invention provides a system for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage, including an air compression unit and an air turbine 17. The air compression unit compresses low-temperature, low-pressure air 1 and outputs high-temperature air for energy storage when off-peak electricity or wind and solar power resources are abundant. The system also includes:

[0043] The energy storage and release unit includes a heat exchanger 5, a gas storage device 9, a gas ejector 11, a reheater 14, a low-temperature water storage tank 19, and a high-temperature water storage tank 25, wherein:

[0044] Each heat exchanger 5 is used for heat exchange and energy storage between the high-temperature air output from the air compression unit and the low-temperature liquid working fluid. Its tube-side inlet is connected to the air compression unit through a pipeline, its tube-side outlet is connected to the air storage device 9 through a pipeline, its shell-side inlet is connected to the low-temperature water storage tank 19 through a pipeline and the low-temperature circulating water pump 21, and its tube-side outlet is connected to the high-temperature water storage tank 25 through a pipeline.

[0045] The ejector 11 is used to increase air flow and improve the compression heat recovery ratio. The ejector 11 has a primary flow inlet, a secondary flow inlet and a mixed flow outlet. The primary flow inlet is connected to the air storage device 9 through a pipeline. The secondary flow inlet is in communication with the air and is used to mix the low-temperature air sent in by the primary flow inlet with the air sent in by the secondary flow inlet and then flow out through the mixed flow outlet.

[0046] Each reheater 14 is used to exchange heat and release energy between the gas flowing out of each mixed flow outlet and the high-temperature liquid working fluid. Its gas inlet is connected to the mixed flow outlet through a pipeline, its gas outlet is connected to the air turbine 17 through a pipeline, its liquid inlet is connected to the high-temperature water storage tank 25 through a pipeline and the high-temperature circulating water pump 26, and its liquid outlet is connected to the low-temperature water storage tank 19 through a pipeline.

[0047] Specifically, there are multiple ejector pumps 11 and reheaters 14, and these multiple ejector pumps 11 and reheaters 14 are connected in series via pipelines in a one-to-one correspondence. The one-to-one correspondence and series connection of multiple ejector pumps 11 and reheaters 14 increases the airflow rate at the air turbine inlet. Under the condition of a constant heat exchange terminal difference, more air can be recovered and utilized, thus recovering more heat of compression.

[0048] Specifically, there are multiple ejector jets 11 and reheaters 14, and the mixing outlets of the multiple ejector jets 11 are connected to the same output pipeline, so that the multiple ejector jets 11 are connected in parallel. The gas inlet of each reheater 14 is connected to the same output pipeline through a pipeline. The multiple ejector jets 11 connected in parallel and then connected to each reheater 14 increases the air flow rate at the air turbine inlet. Under the condition of constant heat exchange terminal difference, more air can be recovered and more compression heat can be utilized.

[0049] Specifically, the ejector pump 11 is also equipped with a controller, a regulating valve 13 is provided on the secondary flow inlet, and a pressure measuring element 12 is provided on the mixed flow outlet of the ejector pump 11. The controller is connected to the regulating valve 13 and the pressure measuring element 12, and is used to regulate the opening of the regulating valve 13 by adjusting the mixed flow outlet pressure obtained by the pressure measuring element 12.

[0050] When the measured value of the pressure measuring element 12 at the mixed flow outlet of the air ejector 11 is lower than the target set value, the controller closes the regulating valve 13 to reduce the air intake of the air ejector 11, thereby increasing the mixed flow outlet pressure of the air ejector 11; when the measured value of the pressure measuring element 12 at the mixed flow outlet of the air ejector 11 is higher than the target set value, the controller opens the regulating valve 13 to increase the air intake of the air ejector 11, thereby reducing the mixed flow outlet pressure of the air ejector 11.

[0051] By setting the pressure setpoint of the controller, comparing the setpoint with the measured value of the pressure measuring element 12, the opening of the valve 13 is controlled so that the air ejector 11 can draw in an appropriate amount of air. Otherwise, the amount of air drawn in may be inappropriate, resulting in too low turbine inlet pressure or too little air drawn in.

[0052] Specifically, all pipelines are equipped with valves; the pipelines serve to collect and distribute the working fluid (air / water), while the valves serve to deliver the working fluid into the pipelines and distribute it externally.

[0053] Specifically, all air compression units include multiple air compressors 2 and multiple synchronous motors 3, with each air compressor 2 and synchronous motor 3 corresponding to one another and connected coaxially via couplings.

[0054] Specifically, the air turbine 17 is coaxially connected to the generator 18 to release energy during peak electricity demand periods, thereby ensuring power supply during peak demand periods.

[0055] Specifically, the pipelines connected to the gas outlets of multiple reheaters 14 are connected in parallel and then fed into the air turbine 7. The purpose of this is that, normally, the air turbine receives gas evenly from both sides. If the number of reheaters is not equal to 2, the gas needs to be distributed into 2 streams before entering the air turbine.

[0056] This invention provides a method for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage. The method, based on a system for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage, includes the following steps:

[0057] During energy storage: When the synchronous motor 3 is started, the air compressor 2, driven by the synchronous motor 3, compresses the low-temperature, low-pressure air 1 from the atmosphere. The output high-temperature, high-pressure air is sent into the tube side of the heat exchanger 5 through the pipeline. The high-pressure cold water from the low-temperature water storage tank 19 is sent into the shell side of the heat exchanger 5 through the pipeline and the low-temperature circulating water pump 21. In the heat exchanger 5, the high-temperature, high-pressure air and the high-pressure cold water a22 exchange heat and store energy. The high-temperature air after heat exchange becomes low-temperature, high-pressure air 6 and is stored in the air storage device 9. The high-pressure cold water 22 after heat exchange becomes high-pressure hot water a23 and is sent into the high-temperature water storage tank 11.

[0058] During energy release: the low-temperature high-pressure air 6 in the gas storage device 9 is sent into the ejector 11 through the primary inlet, and external air is drawn in through the secondary inlet. After being mixed in the ejector 11, it is sent into the gas inlet of the reheater 14 through the mixed outlet of the ejector 11. The high-pressure hot water b in the high-temperature water storage tank 25 is sent into the reheater 14 through the high-temperature circulating water pump 26 and pipeline. The high-pressure hot water b exchanges heat with the mixed gas sent into the reheater 14 to release energy.

[0059] When the measured value of the mixed flow outlet of the air ejector 11 is lower than the target set value, the controller 12 closes the regulating valve 13 to reduce the air intake of the air ejector 11, thereby increasing the mixed flow outlet pressure of the air ejector 11; when the measured value of the mixed flow outlet of the air ejector 11 is higher than the target set value, the controller 12 opens the regulating valve 13 to increase the air intake of the air ejector 11, thereby reducing the mixed flow outlet pressure of the air ejector 11.

[0060] After the high-pressure, low-temperature mixed gas is transformed into a high-temperature, high-pressure gas, it is sent into the air turbine 17 to drive the generator 18 to rotate, which is used to output electrical energy during peak electricity demand.

[0061] Specifically, the multiple synchronous motors 3 compress air to store energy during off-peak hours or when wind and solar power resources are abundant, and the air turbine 17 releases energy to generate electricity during peak hours.

[0062] This invention provides a specific embodiment in which the compressed air energy storage system operates through two independent processes. Based on a 300MW-class compressed air energy storage system equipped with an air ejector, the system process and the role of the air ejector in improving compression heat recovery are explained.

[0063] (a) The first workflow is energy storage during off-peak hours or when wind and solar resources are plentiful.

[0064] During energy storage, low-temperature, low-pressure air 1 from the environment is drawn in by air compressor 2, which is driven by synchronous motor 3. After passing through the compressor, the air becomes high-temperature, high-pressure air 4, which is cooled by high-pressure cold water 22 in heat exchanger 5 to form high-pressure, low-temperature air 6. It enters the high-pressure air header 8 through the air injection valve 7 and is finally stored in the air storage device 9. The high-pressure cold water 22 comes from the low-temperature water storage tank 19. The high-pressure cold water a22 from the low-temperature water storage tank 19 is pressurized by the cold water circulation pump 21 through the high-pressure cold water header 20 and supplied to the heat exchanger 5. After heat exchange, the water temperature rises to become high-pressure hot water a23, which flows into the high-pressure hot water header 24 and is stored in the high-temperature water storage tank 25, waiting to heat the low-temperature, high-pressure air from the air storage chamber during peak electricity demand periods. Unlike conventional compressed air energy storage, this invention uses more high-pressure cold water in the heat exchange stage to directly cool the high-temperature and high-pressure air 4 to the target value, thereby obtaining more high-pressure hot water 23 which is stored in the hot water tank. When the turbine is put into operation, it can heat more air. Instead of using too much open cooling water as in traditional compressed air energy storage, which would cause a large amount of compression heat to be forced to be discharged into the atmosphere and wasted, this invention achieves more recovery of compression heat.

[0065] (ii) The second workflow is the energy release during peak electricity consumption periods.

[0066] The process uses an air ejector 11 to increase airflow and improve the compression heat recovery ratio.

[0067] During energy release, the high-temperature, low-pressure air 6 in the gas storage device 9 is evenly distributed to each jet ejector 11 by the high-pressure air header 8; the vent valve 10 is opened, and the high-pressure, low-temperature air 6 enters the jet ejector 11. As it flows rapidly, it draws in outdoor air, which enters through the regulating valve 13; the regulating valve 13 can adjust the amount of air drawn in. When the outlet pressure of the jet ejector is lower than the target value, the controller 12 closes the regulating valve 13 to reduce the amount of air drawn in, thereby increasing the mixed flow outlet pressure of the jet ejector 11. When the measured value of the mixed flow outlet of the jet ejector 11 is higher than the target set value, the controller 12 opens the regulating valve 13 to increase the amount of air drawn in by the jet ejector 11, thereby reducing the mixed flow outlet pressure of the jet ejector 11.

[0068] After passing through the air ejector 11, more air flows into the first-stage reheater 14, where it is heated to a high-temperature state 15 by the high-pressure hot water b27. Then, it enters the high-pressure air turbine 17 through the main gas regulating valve 6 to expand and do work, driving the generator 18 to generate electricity and ensure power supply during peak hours. The high-pressure hot water b27 originates from the high-temperature water storage tank 25 and is pressurized by the hot water circulation pump 26 and supplied to the reheater 14 after passing through the high-pressure hot water header 24. After heat exchange, the high-pressure hot water b27 becomes high-pressure cold water b28 and is stored in the low-temperature water storage tank 19.

[0069] Unlike conventional compressed air energy storage, this invention delivers more high-temperature, high-pressure air to the air turbine 17, thereby enhancing the work capacity of the air turbine 17. The increased air volume originates from the suction effect of the ejector, and the increased heat comes from the recovered compression heat.

[0070] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A system for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage, comprising an air compression unit and an air turbine (17), characterized in that, The air compression unit compresses low-temperature, low-pressure air (1) and outputs high-temperature air for energy storage when there is sufficient off-peak electricity or wind and solar power resources. It also includes: The energy storage and release unit includes a heat exchanger (5), a gas storage device (9), a gas ejector (11), a reheater (14), a low-temperature water storage tank (19), and a high-temperature water storage tank (25), wherein: Each heat exchanger (5) is used for heat exchange and energy storage between the high-temperature air output from the air compression unit and the low-temperature liquid working fluid. Its tube side inlet is connected to the air compression unit through a pipeline, its tube side outlet is connected to the gas storage device (9) through a pipeline, its shell side inlet is connected to the low-temperature water storage tank (19) through a pipeline and the low-temperature circulating water pump (21), and its shell side outlet is connected to the high-temperature water storage tank (25) through a pipeline. The ejector pump (11) is used to increase airflow and improve the compression heat recovery ratio. The ejector pump (11) has a primary inlet, a secondary inlet and a mixing outlet. The primary inlet is connected to the gas storage device (9) through a pipeline. The secondary inlet is connected to the air and is used to mix the low-temperature air sent in by the primary inlet with the air sent in by the secondary inlet and then flow out through the mixing outlet. Each reheater (14) is used to exchange heat and release energy between the gas flowing out of each mixing outlet and the high-temperature liquid working fluid. Its gas inlet is connected to the mixing outlet through a pipeline, its gas outlet is connected to the air turbine (17) through a pipeline, its liquid inlet is connected to the high-temperature water storage tank (25) through a pipeline and the high-temperature circulating water pump (26), and its liquid outlet is connected to the low-temperature water storage tank (19) through a pipeline. The ejector pump (11) is also equipped with a controller, and the secondary inlet is equipped with a regulating device. The valve (13) is provided with a pressure measuring element (12) at the mixed flow outlet of the ejector (11). The controller is connected to the regulating valve (13) and the pressure measuring element (12) and is used to adjust the opening of the regulating valve (13) by the mixed flow outlet pressure obtained by the pressure measuring element (12). When the measured value of the pressure measuring element (12) at the mixed flow outlet of the ejector (11) is lower than the target set value, the controller closes the regulating valve (13) to reduce the air intake of the ejector (11) and thus increase the mixed flow outlet pressure of the ejector (11). When the measured value of the pressure measuring element (12) at the mixed flow outlet of the ejector (11) is higher than the target set value, the controller opens the regulating valve (13) to increase the air intake of the ejector (11) and thus reduce the mixed flow outlet pressure of the ejector (11).

2. The system for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage according to claim 1, characterized in that, There are multiple ejector pumps (11) and multiple reheaters (14), and the multiple ejector pumps (11) and multiple reheaters (14) correspond one-to-one and are connected in series by pipelines.

3. The system for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage according to claim 1, characterized in that, There are multiple ejector pumps (11) and reheaters (14), and the mixing outlets of multiple ejector pumps (11) are connected to the same output pipeline so that multiple ejector pumps (11) are connected in parallel, and the gas inlet of each reheater (14) is connected to the output pipeline through a pipeline.

4. The system for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage according to claim 1, characterized in that, Valves are installed on all of the pipelines.

5. The system for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage according to claim 1, characterized in that, All air compression units include multiple air compressors (2) and multiple synchronous motors (3), with each air compressor (2) and synchronous motor (3) corresponding to one another and connected coaxially via couplings.

6. The system for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage according to claim 1, characterized in that, The air turbine (17) is coaxially connected to the generator (18) and is used to release energy during peak electricity demand periods to ensure power supply during peak demand periods.

7. The system for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage according to claim 1, characterized in that, The gas outlets of multiple reheaters (14) are connected in parallel to the pipelines and then fed into the air turbine (7).

8. A method for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage, characterized in that, This method, based on the system for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage as described in any one of claims 1 to 7, includes the following steps: During energy storage: The air compressor (2) compresses the low-temperature, low-pressure air (1) from the atmosphere under the drive of the synchronous motor (3). The output high-temperature, high-pressure air is sent into the tube side of the heat exchanger (5) through the pipeline. The high-pressure cold water in the low-temperature water storage tank (19) is sent into the shell side of the heat exchanger (5) through the pipeline and the low-temperature circulating water pump (21). In the heat exchanger (5), the high-temperature, high-pressure air and the high-pressure cold water a (22) exchange heat and store energy. The high-temperature air after heat exchange becomes low-temperature, high-pressure air (6) and is stored in the gas storage device (9). The high-pressure cold water a (22) after heat exchange becomes high-pressure hot water a (23) and is sent into the high-temperature water storage tank (25). During energy release: Low-temperature high-pressure air (6) in the gas storage device (9) is sent into the ejector (11) through the primary inlet and will draw in external air through the secondary inlet. After mixing in the ejector (11), it is sent to the gas inlet of the reheater (14) through the mixing outlet of the ejector (11). High-pressure hot water b (27) in the high-temperature water storage tank (25) is sent into the reheater (14) through the high-temperature circulating water pump (26) and pipeline. High-pressure hot water b (27) and mixed gas sent into the reheater (14) exchange heat and release energy. When the measured value of the mixed flow outlet of the ejector (11) is lower than the target set value, the controller (12) closes the regulating valve (13) to reduce the air intake of the ejector (11) and thereby increase the mixed flow outlet pressure of the ejector (11); when the measured value of the mixed flow outlet of the ejector (11) is higher than the target set value, the controller (12) opens the regulating valve (13) to increase the air intake of the ejector (11) and thereby reduce the mixed flow outlet pressure of the ejector (11). After the high-pressure low-temperature mixed gas is transformed into a high-temperature high-pressure gas, it is sent into an air turbine (17) to drive the generator (18) to rotate, and is used to output electrical energy during peak electricity demand.

9. The method for improving the compression heat recovery rate of advanced adiabatic compressed air energy storage according to claim 8, characterized in that, Multiple synchronous motors (3) compress air to store energy during off-peak hours or when wind and solar power resources are abundant, and the air turbine (17) releases energy to generate electricity during peak hours.

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