Compressed air energy storage system sharing heat storage heat exchanger

Abstract

The invention discloses a compressed air energy storage system sharing a heat storage heat exchanger, the compressed air energy storage system comprises a compressor unit, a turbine unit, a heat storage and release assembly and a gas storage, a first compressor, a first heat exchanger, a second compressor, a second heat exchanger, a third compressor, a third heat exchanger and the gas storage are sequentially connected in series to form a compressed air passage; the gas storage, the third heat exchanger, the second heat exchanger, the second turbine, the first heat exchanger and the first turbine are sequentially connected in series to form a turbine air passage, the first heat exchanger and the second heat exchanger are connected with the high-temperature heat accumulator and the low-temperature heat accumulator, and the third heat exchanger is connected with the medium-temperature heat accumulator and the low-temperature heat accumulator. According to the compressed air energy storage system, the thought of graded heat storage is adopted, and the first heat exchanger, the second heat exchanger and the third heat exchanger are shared, so that the energy utilization rate, the working efficiency and the economical efficiency of the compressed air energy storage system can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric energy storage, and in particular to a compressed air energy storage system with a shared heat storage heat exchanger. Background Art

[0002] Compressed air energy storage, as a new type of energy storage technology, has received great attention from both inside and outside the industry in recent years and has developed very rapidly. Compressed air, as a physical energy storage technology, has the advantages of high safety, relatively short construction period, long life, and good environmental protection. In the related technology, the repeated arrangement of the heat accumulator and the heat exchanger of the compressed air energy storage system leads to redundancy of the heat exchange equipment and poor economy. At the same time, the non-steady-state compressor and the steady-state compressor share the heat accumulator. Since the working condition of the steady-state compressor is almost unchanged, the change of the working condition of the non-steady-state compressor causes the temperature of the air at its exhaust port to change continuously, which causes the temperature of the heat exchange medium in the shared heat accumulator to fluctuate, affecting the working efficiency of the compressed air energy storage system. In addition, the shared heat accumulator of the compressed air energy storage system will take into account the parameter design of the side with greater heat exchange demand, and there will be equipment redundancy on the side with less heat exchange demand, which is not economical. Therefore, there is room for improvement. Summary of the invention

[0003] The present invention proposes a compressed air energy storage system that shares a heat storage heat exchanger. The compressed air energy storage system has the advantage of high working efficiency.

[0004] According to an embodiment of the present invention, a compressed air energy storage system includes: a compressor unit, including a first compressor, a second compressor and a third compressor connected in sequence; a turbine unit, including a first turbine and a second turbine connected in sequence; a heat storage and release component, including a first heat exchanger, a second heat exchanger, a third heat exchanger, a high-temperature heat accumulator, a medium-temperature heat accumulator and a low-temperature heat accumulator; an air storage reservoir; the first compressor, the first heat exchanger, the second compressor, the second heat exchanger, the third compressor, the third heat exchanger, and the air storage reservoir are connected in series in sequence to form a compressed air passage, the air storage reservoir, the third heat exchanger, the second heat exchanger, the second turbine, the first heat exchanger, and the first turbine are connected in series in sequence to form a turbine air passage, the first heat exchanger and the second heat exchanger are connected to the high-temperature heat accumulator and the low-temperature heat accumulator, and the third heat exchanger is connected to the medium-temperature heat accumulator and the low-temperature heat accumulator.

[0005] According to the compressed air energy storage system of the embodiment of the present invention, by providing three types of heat accumulators, namely a high-temperature heat accumulator, a medium-temperature heat accumulator and a low-temperature heat accumulator, and adopting the idea of ​​graded heat storage, the energy utilization rate of the compressed air energy storage system can be improved, thereby improving the working efficiency of the compressed air energy storage system. In combination with the optimal applicable temperature of the heat exchange medium, a compressed air energy storage system with three-stage compression of a first compressor, a second compressor and a third compressor and a two-stage turbine of a first turbine and a second turbine is designed. By sharing the first heat exchanger, the second heat exchanger and the third heat exchanger, equipment redundancy can be reduced to improve the economy of the compressed air energy storage system.

[0006] According to some embodiments of the present invention, control valves for controlling on and off are provided between the first compressor, the first turbine and the first heat exchanger, between the first heat exchanger and the second compressor and the second turbine, between the second compressor and the second turbine and the second heat exchanger, between the second heat exchanger and the third compressor and the third heat exchanger, and between the third heat exchanger and the third compressor and the gas storage reservoir, and the heat storage and release assembly also includes a driving pump for controlling the flow direction of the heat exchange medium.

[0007] According to some embodiments of the present invention, the heat exchange medium in the heat storage and release assembly is heat transfer oil.

[0008] According to some embodiments of the present invention, the compressed air energy storage system also includes a cooler arranged in the low-temperature heat accumulator and a cooling tower connected to the cooler, and a first circuit connected to the cooling tower and a second circuit connected to the low-temperature heat accumulator are formed in the cooler.

[0009] According to some embodiments of the present invention, the flow rates of the first compressor, the second compressor and the third compressor are fixed and are the same as the average flow rates of the first turbine and the second turbine, the air temperature output by the first compressor and the second compressor is K1, the air temperature input by the second compressor and the third compressor is K2, the air temperature input by the first turbine and the second turbine is K3, the air temperature output by the first turbine and the second turbine is K4, and K1, K2, K3 and K4 satisfy K1-K2=K3-K4.

[0010] According to some embodiments of the present invention, the pressure value in the gas storage reservoir ranges from 8 to 14 MPa.

[0011] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1is a schematic diagram of a compressed air energy storage system according to an embodiment of the present invention;

[0013] Figure 2 is a schematic diagram of a compressed air energy storage system in an energy storage process according to an embodiment of the present invention;

[0014] Figure 3 Schematic diagram of a compressed air energy storage system in the energy release process according to an embodiment of the present invention.

[0015] Reference numerals:

[0016] 100. Compressed air energy storage system; 11. First compressor; 12. Second compressor; 13. Third compressor; 21. First turbine; 22. Second turbine; 31. First heat exchanger; 32. Second heat exchanger; 33. Third heat exchanger; 34. High-temperature heat accumulator; 35. Medium-temperature heat accumulator; 36. Low-temperature heat accumulator; 37. Cooler; 4. Gas storage. DETAILED DESCRIPTION

[0017] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0018] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific processes and examples of materials, but those of ordinary skill in the art can be aware of the applicability of other processes and / or the use of other materials.

[0019] The following describes a compressed air energy storage system 100 using a common heat storage heat exchanger according to an embodiment of the present invention with reference to the accompanying drawings.

[0020] like Figure 1-Figure 3As shown, the compressed air energy storage system 100 according to an embodiment of the present invention includes: a compressor unit, a turbine unit, a heat storage and release component and an air storage reservoir 4, the compressor unit includes a first compressor 11, a second compressor 12 and a third compressor 13 connected in sequence, the turbine unit includes a first turbine 21 and a second turbine 22 connected in sequence, the heat storage and release component includes a first heat exchanger 31, a second heat exchanger 32, a third heat exchanger 33, a high-temperature heat accumulator 34, a medium-temperature heat accumulator 35 and a low-temperature heat accumulator 36, the first compressor 11, The first heat exchanger 31, the second compressor 12, the second heat exchanger 32, the third compressor 13, the third heat exchanger 33, and the air storage reservoir 4 are connected in series in sequence to form a compressed air passage; the air storage reservoir 4, the third heat exchanger 33, the second heat exchanger 32, the second turbine 22, the first heat exchanger 31, and the first turbine 21 are connected in series in sequence to form a turbine air passage; the first heat exchanger 31 and the second heat exchanger 32 are connected to the high-temperature heat accumulator 34 and the low-temperature heat accumulator 36; the third heat exchanger 33 is connected to the medium-temperature heat accumulator 35 and the low-temperature heat accumulator 36.

[0021] That is, the exhaust port of the first compressor 11 is connected to the intake port of the second compressor 12 through the first heat exchanger 31, the exhaust port of the second compressor 12 is connected to the intake port of the third compressor 13 through the second heat exchanger 32, the exhaust port of the third compressor 13 is connected to the air storage reservoir 4 through the third heat exchanger 33, and at the same time, the air storage reservoir 4 is connected to the intake port of the second turbine 22 through the third heat exchanger 33 and the second heat exchanger 32 in sequence, and the exhaust port of the second turbine 22 is connected to the intake port of the first turbine 21 through the first heat exchanger 31. Therefore, the air compressed by the first compressor 11 can be discharged through the exhaust port and can enter the second compressor 13 through the first heat exchanger 31. The air compressed by the second compressor 12 is discharged through the exhaust port and can enter the third compressor 13 through the second heat exchanger 32 for tertiary compression. The air compressed by the third compressor 13 is discharged through the exhaust port and can enter the gas storage reservoir 4 through the third heat exchanger 33, that is, the electrical energy is used for the storage of compressed air through the compressor unit; the compressed air in the gas storage reservoir 4 can enter the second turbine 22 through the third heat exchanger 33 and the second heat exchanger 32 in sequence, and the air at the exhaust port of the second turbine 22 can enter the second turbine 21 through the first heat exchanger 31, so that the turbine unit can generate electricity through the compressed air released from the gas storage reservoir 4.

[0022] In addition, the low-temperature heat accumulator 36 is connected to the high-temperature heat accumulator 34 through the first heat exchanger 31 and the second heat exchanger 32. The heat exchange medium in the low-temperature heat accumulator 36 can enter the high-temperature heat accumulator 34 through the first heat exchanger 31 and the second heat exchanger 32 respectively, and the heat exchange medium in the high-temperature heat accumulator 34 can enter the low-temperature heat accumulator 36 through the first heat exchanger 31 and the second heat exchanger 32 respectively, that is, the heat exchange medium flows through the first heat exchanger 31 and the second heat exchanger 32 when flowing between the low-temperature heat accumulator 36 and the high-temperature heat accumulator 34, so that the heat exchange medium flowing through the first heat exchanger 31 and the second heat exchanger 32 can increase or decrease the temperature of the gas flowing through the first heat exchanger 31 and the second heat exchanger 32. At the same time, the low-temperature heat accumulator 36 is connected to the medium-temperature heat accumulator 35 through the third heat exchanger 33. The heat exchange medium in the low-temperature heat accumulator 36 can enter the medium-temperature heat accumulator 35 through the third heat exchanger 33, and the heat exchange medium in the medium-temperature heat accumulator 35 can enter the low-temperature heat accumulator 36 through the third heat exchanger 33. That is, the heat exchange medium flows through the third heat exchanger 33 when flowing between the low-temperature heat accumulator 36 and the medium-temperature heat accumulator 35, so that the heat exchange medium flowing through the third heat exchanger 33 can increase or decrease the temperature of the gas flowing through the third heat exchanger 33.

[0023] When the air is transported to the air storage 4 through the compressor unit, the air pressure in the air storage 4 is continuously increased. Usually, the third compressor 13 needs to gradually increase the output pressure through the sliding pressure setting to ensure the efficiency of transporting air to the air storage 4. It can be understood that the temperature of the air compressed by the compressor is proportional to the pressure, which causes the air temperature output by the third compressor 13 to fluctuate with the change of pressure. Therefore, during the energy storage process, the heat exchange medium in the low-temperature heat accumulator 36 enters the medium-temperature heat accumulator 35 through the third heat exchanger 33, which can avoid the temperature fluctuation of the air compressed by the third compressor 13 from affecting the temperature of the heat exchange medium in the high-temperature heat accumulator 34. For example, it can avoid the mixed storage of the medium-temperature heat storage medium and the high-temperature heat storage medium to reduce the thermal energy quality in the high-temperature heat accumulator 34. In other words, by setting three types of heat accumulators, namely the high-temperature heat accumulator 34, the medium-temperature heat accumulator 35 and the low-temperature heat accumulator 36, and adopting the idea of ​​graded heat storage, the energy utilization rate of the compressed air energy storage system 100 can be improved, thereby improving the working efficiency of the compressed air energy storage system 100.

[0024] In addition, in combination with the optimal applicable temperature of the heat exchange medium, a compressed air energy storage system 100 is designed with three-stage compression of a first compressor 11, a second compressor 12 and a third compressor 13 and a two-stage turbine type of a first turbine 21 and a second turbine 22. By sharing the first heat exchanger 31, the second heat exchanger 32 and the third heat exchanger 33, equipment redundancy can be reduced to improve the economy of the compressed air energy storage system 100.

[0025] Specifically, when the compressor unit is working, the heat exchange medium in the low-temperature heat accumulator 36 is transported toward the first heat exchanger 31, the second heat exchanger 32 and the third heat exchanger 33, wherein the heat exchange medium in the low-temperature heat accumulator 36 is at a relatively low temperature. Therefore, when the air compressed by the first compressor 11 passes through the first heat exchanger 31, the heat exchange medium entering the first heat exchanger 31 can absorb the heat of the air compressed by the first compressor 11; when the air compressed by the second compressor 12 passes through the second heat exchanger 32, the heat exchange medium entering the second heat exchanger 32 can absorb the heat of the air compressed by the second compressor 12; the heat exchange medium after absorbing heat in the first heat exchanger 31 and the second heat exchanger 32 flows into the high-temperature heat accumulator 34 for storage; when the air compressed by the third compressor 13 passes through the third heat exchanger 33, the heat exchange medium entering the third heat exchanger 33 can absorb the heat of the air compressed by the third compressor 13; the heat exchange medium after absorbing heat in the third heat exchanger 33 flows into the medium-temperature heat accumulator 35 for storage.

[0026] In addition, by cooling the air compressed by the first compressor 11 and the second compressor 12 respectively through the first heat exchanger 31 and the second heat exchanger 32, the temperature of the air entering the second compressor 12 and the third compressor 13 can be reduced, thereby avoiding overheating damage to the second compressor 12 and the third compressor 13, which is beneficial to extending the service life of the second compressor 12 and the third compressor 13. In addition, air with a lower temperature is easier to be compressed, thereby reducing the power consumption of the second compressor 12 and the third compressor 13 and improving the equipment efficiency of the second compressor 12 and the third compressor 13. At the same time, the compressed air entering the gas storage reservoir 4 can be cooled by the third heat exchanger 33, thereby increasing the air density in the gas storage reservoir 4 and further increasing the gas storage capacity of the gas storage reservoir 4.

[0027] When the turbine unit is working, the heat exchange medium in the high-temperature heat accumulator 34 is transported toward the first heat exchanger 31 and the second heat exchanger 32, and the heat exchange medium in the medium-temperature heat accumulator 35 is transported toward the third heat exchanger 33, wherein the heat exchange medium in the high-temperature heat accumulator 34 and the medium-temperature heat accumulator 35 is at a higher temperature. Therefore, when the compressed air discharged from the gas storage reservoir 4 passes through the third heat exchanger 33, the temperature of the compressed air discharged from the gas storage reservoir 4 can be heated by the heat exchange medium entering the third heat exchanger 33. When the air heated by the third heat exchanger 33 passes through the second heat exchanger 32, the air heated by the third heat exchanger 33 can be heated again by the heat exchange medium entering the second heat exchanger 32. When the air after turbine of the second turbine 22 enters the first heat exchanger 31, the air after turbine of the second turbine 22 can be heated by the heat exchange medium entering the first heat exchanger 31. The heat exchange medium after heat release in the first heat exchanger 31, the second heat exchanger 32 and the third heat exchanger 33 flows into the low-temperature heat accumulator 36 for storage.

[0028] In addition, the air temperature at the intake port of the first turbine 21 and the second turbine 22 is heated by the first heat exchanger 31, the second heat exchanger 32 and the third heat exchanger 33, thereby increasing the thermal energy of the air entering the first turbine 21 and the second turbine 22, thereby providing more energy to the first turbine 21 and the second turbine 22 to do work, thereby improving the working efficiency of the turbines.

[0029] According to the compressed air energy storage system 100 of the embodiment of the present invention, by providing three types of heat accumulators, namely a high-temperature heat accumulator 34, a medium-temperature heat accumulator 35 and a low-temperature heat accumulator 36, and adopting the idea of ​​graded heat storage, the energy utilization rate of the compressed air energy storage system 100 can be improved, thereby improving the working efficiency of the compressed air energy storage system 100. In combination with the optimal applicable temperature of the heat exchange medium, a three-stage compression of a first compressor 11, a second compressor 12 and a third compressor 13 and a two-stage turbine type compressed air energy storage system 100 with a first turbine 21 and a second turbine 22 are designed. By sharing the first heat exchanger 31, the second heat exchanger 32 and the third heat exchanger 33, equipment redundancy can be reduced to improve the economy of the compressed air energy storage system 100.

[0030] In some embodiments, the first heat exchanger 31 , the second heat exchanger 32 , and the third heat exchanger 33 may each be composed of a plurality of heat exchange modules connected in series or in parallel, thereby increasing the heat exchange capacity of the first heat exchanger 31 , the second heat exchanger 32 , and the third heat exchanger 33 .

[0031] According to some embodiments of the present invention, control valves for controlling on and off are provided between the first compressor 11 and the first turbine 21 and the first heat exchanger 31, between the first heat exchanger 31 and the second compressor 12 and the second turbine 22, between the second compressor 12 and the second turbine 22 and the second heat exchanger 32, between the second heat exchanger 32 and the third compressor 13 and the third heat exchanger 33, and between the third heat exchanger 33 and the third compressor 13 and the gas storage reservoir 4, and the heat storage and release component also includes a driving pump for controlling the flow direction of the heat exchange medium. Thus, the working state of the compressed air energy storage system 100 can be flexibly switched by controlling the on and off of multiple control valves and controlling the flow direction of the heat exchange medium in the heat storage and release component by driving the pump.

[0032] Specifically, when the compressor unit is working, the driving pump drives the heat exchange medium to flow from the low-temperature heat accumulator 36 toward the first heat exchanger 31, the second heat exchanger 32 and the third heat exchanger 33, opens the control valve between the first heat exchanger 31 and the first compressor 11 and the second compressor 12, closes the control valve between the first heat exchanger 31 and the first turbine 21 and the second turbine 22, opens the control valve between the second heat exchanger 32 and the second compressor 12 and the third compressor 13, closes the control valve between the second heat exchanger 32 and the second turbine 22 and the third heat exchanger 33, and The control valve between the third heat exchanger 33 and the third compressor 13 and the gas storage reservoir 4 is opened, so the air compressed by the first compressor 11 can enter the gas storage reservoir 4 through the first heat exchanger 31, the second compressor 12, the second heat exchanger 32, the third compressor 13 and the third heat exchanger 33 in sequence. At the same time, part of the heat exchange medium of the low-temperature heat accumulator 36 can enter the high-temperature heat accumulator 34 for storage after passing through the first heat exchanger 31 and the second heat exchanger 32, and part can enter the medium-temperature heat accumulator 35 for storage after passing through the third heat exchanger 33. At this time, the compressed air energy storage system 100 is in the energy storage process.

[0033] When the turbine unit is working, the driving pump drives the heat exchange medium to flow from the high-temperature heat accumulator 34 toward the first heat exchanger 31 and the second heat exchanger 32, and at the same time drives the heat exchange medium to flow from the medium-temperature heat accumulator 35 toward the third heat exchanger 33, closes the control valve between the first heat exchanger 31 and the first compressor 11 and the second compressor 12, opens the control valve between the first heat exchanger 31 and the first turbine 21 and the second turbine 22, closes the control valve between the second heat exchanger 32 and the second compressor 12 and the third compressor 13, opens the control valve between the second heat exchanger 32 and the second turbine 22 and the third heat exchanger 33. The control valve between the third heat exchanger 33 and the third compressor 13 is closed, and the control valve between the third heat exchanger 33 and the gas storage reservoir 4 is opened. Therefore, the compressed air of the gas storage reservoir 4 can pass through the third heat exchanger 33, the second heat exchanger 32, the second turbine 22, the first heat exchanger 31, the first turbine 21 in sequence and finally be discharged. At the same time, the heat exchange medium of the high-temperature heat accumulator 34 can enter the low-temperature heat accumulator 36 for storage after passing through the first heat exchanger 31 and the second heat exchanger 32, and the heat exchange medium of the medium-temperature heat accumulator 35 can enter the low-temperature heat accumulator 36 for storage after passing through the third heat exchanger 33. At this time, the compressed air energy storage system 100 is in the energy release process.

[0034] According to some embodiments of the present invention, the heat exchange medium in the heat storage and release assembly is heat transfer oil. Among them, heat transfer oil has the advantages of uniform heating, accurate temperature control, good heat transfer effect, energy saving, convenient transportation and operation, so that the heat exchange medium can absorb and release more heat. Therefore, the heat exchange medium can absorb more heat when the compressor unit is working, increase the temperature of the heat exchange medium in the high-temperature heat accumulator 34, and release more heat when the turbine unit is working, so as to increase the temperature of the air entering the first turbine 21 and the second turbine 22, which is conducive to improving the power generation efficiency of the turbine unit.

[0035] According to some embodiments of the present invention, the compressed air energy storage system 100 further includes a cooler 37 disposed in the low-temperature heat accumulator 36 and a cooling tower connected to the cooler 37, wherein a first circuit connected to the cooling tower and a second circuit connected to the low-temperature heat accumulator 36 are formed in the cooler 37. That is, the heat exchange medium in the low-temperature heat accumulator 36 can enter the cooler 37 through the second circuit and then return to the low-temperature heat accumulator 36, and the coolant in the cooling tower can enter the cooler 37 through the first circuit and then return to the cooling tower, so that the coolant can absorb the heat of the heat exchange medium in the low-temperature heat accumulator 36 and discharge the heat to the atmosphere. Therefore, only a cooler 37 with a relatively small power is required to be disposed next to the low-temperature heat accumulator 36, and the medium in the low-temperature heat accumulator 36 can be slowly cooled to a set temperature in the several hours gap between the two energy storage processes and the energy release process cycle, thereby reducing the heat exchange area of ​​the cooler 37 and the power of the cooling tower, and improving the economy of the system. Among them, the coolant of the cooling tower can be water, which has a high specific heat capacity and low cost, thereby improving the heat transfer efficiency of the cooling tower and reducing the cost of the cooling tower.

[0036] It is understandable that, since the first heat exchanger 31, the second heat exchanger 32 and the third heat exchanger 33 cannot completely release heat when releasing energy, after an energy storage process and an energy release process are completed, the temperature of the heat exchange medium returned to the low-temperature heat accumulator 36 is generally higher than the set temperature. Therefore, by setting a cooler 37 and a cooling tower to cool the heat exchange in the low-temperature heat accumulator 36, it is possible to avoid the excessive temperature of the heat exchange medium in the low-temperature heat accumulator 36 affecting the heat absorption effect of the heat exchange medium, and at the same time, it is possible to avoid the air temperature of the air intake of the second compressor 12 and the third compressor 13 being too high during the energy storage process, which is beneficial to improving the stability of the compressor unit. Among them, the set temperature refers to the temperature at which the heat exchange medium in the low-temperature heat accumulator 36 is normally located.

[0037] According to some embodiments of the present invention, the flow rates of the first compressor 11, the second compressor 12, and the third compressor 13 are fixed and the same as the average flow rates of the first turbine 21 and the second turbine 22, the air temperature output by the first compressor 11 and the second compressor 12 is K1, the air temperature input by the second compressor 12 and the third compressor 13 is K2, the air temperature input by the first turbine 21 and the second turbine 22 is K3, and the air temperature output by the first turbine 21 and the second turbine 22 is K4, and K1, K2, K3, and K4 satisfy K1-K2=K3-K4. Among them, K1-K2 is the temperature reduction amplitude of the gas discharged from the first compressor 11 by the first heat exchanger 31 and the temperature reduction amplitude of the gas discharged from the second compressor 12 by the second heat exchanger 32, that is, the temperature increase amplitude of the heat exchange medium in the first heat exchanger 31 and the second heat exchanger 32 during the energy storage process; K3-K4 is the temperature reduction amplitude of the gas after passing through the second turbine 22 and the temperature reduction amplitude of the gas after passing through the first turbine 21. Furthermore, since heat exchange power = temperature difference × specific heat of air × air flow rate, where the temperature difference refers to the above-mentioned temperature rise or fall amplitude, and the specific heat of air changes very little during the energy storage process and the energy release process, at the same time, during the energy storage process, the air flow rates of the first compressor 11 and the second compressor 12 are fixed and the same, during the energy release process, the average air flow rates of the first turbine 21 and the second turbine 22 are the same, and the fixed flow rates of the first compressor 11 and the second compressor 12 are the same as the average flow rates of the first turbine 21 and the second turbine 22. Therefore, by setting K1-K2=K3-K4, the heat absorbed by the heat exchange medium through the first heat exchanger 31 and the second heat exchanger 32 per unit time during the energy storage process and the heat consumed by the first turbine 21 and the second turbine 22 per unit time during the energy release process can be close to each other, thereby avoiding equipment redundancy of the heat storage and release components and improving the equipment utilization rate of the heat storage and release components.

[0038] According to some embodiments of the present invention, the pressure value range of the gas storage reservoir 4 is 8-14 MPa. The gas storage reservoir 4 is a fixed volume gas storage reservoir, so the pressure in the gas storage reservoir 4 increases continuously during the energy storage process, and the pressure in the gas storage reservoir 4 decreases continuously during the energy release process.

[0039] Reference below Figure 2-Figure 3 A compressed air energy storage system 100 according to a specific embodiment of the present invention is described. It is worth noting that the following description is only exemplary and is intended to be used to explain the present invention, but cannot be understood as limiting the present invention.

[0040] like Figure 2As shown, the compressed air energy storage system 100 is in the energy storage process, the air of the compressor unit adopts a fixed flow rate, the set temperature of the heat exchange medium in the low-temperature heat accumulator 36 is 25°C, the heat exchange medium is heat transfer oil, and the heat exchange medium flows out of the low-temperature heat accumulator 36, a part of the heat exchange medium passes through the first heat exchanger 31 and enters the high-temperature heat accumulator 34, a part of the heat exchange medium passes through the second heat exchanger 32 and enters the high-temperature heat accumulator 34, and the other part passes through the third heat exchanger 33 and enters the medium-temperature heat accumulator 35. The air temperature at the exhaust port of the first compressor 11 is 320°C, and the exhaust port of the first compressor 11 is 100°C. The air at the air inlet is cooled to 50°C after passing through the first heat exchanger 31, and then enters the second compressor 12. The air temperature at the exhaust port of the second compressor 12 is 320°C. The air temperature at the exhaust port of the second compressor 12 is cooled to 50°C after passing through the second heat exchanger 32, and then enters the third compressor 13. The air at the exhaust port of the third compressor 13 is cooled by the third heat exchanger 33 and then enters the gas storage reservoir 4. The heat exchange end difference between the first heat exchanger 31 and the second heat exchanger 32 is 10°C. Therefore, the heat transfer oil entering the high-temperature heat accumulator 34 is 310°C.

[0041] like Figure 3 As shown, the compressed air energy storage system 100 is in the energy release process, the average flow rate of the turbine unit air is the same as the fixed flow rate of the compressor unit, part of the heat exchange medium flowing out of the high-temperature heat accumulator 34 passes through the first heat exchanger 31 and enters the low-temperature heat accumulator 36, and the other part passes through the second heat exchanger 32 and enters the low-temperature heat accumulator 36. The heat exchange medium in the medium-temperature heat accumulator 35 passes through the third heat exchanger 33 and enters the low-temperature heat accumulator 36. The air flows out from the gas storage reservoir 4 and can heat the air at the exhaust port of the gas storage reservoir 4 to 30°C after passing through the third heat exchanger 33. The heat exchange end difference between the first heat exchanger 31 and the second heat exchanger 32 is 10°C. After passing through the second heat exchanger 32, the air can be heated to 300°C and then enter the second turbine 22. The air temperature at the exhaust port of the second turbine 22 is 30°C. After entering the first heat exchanger 31, the air can be heated to 300°C and then enter the first turbine 21. The air temperature at the exhaust port of the first turbine 21 is 30°C.

[0042] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0044] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A compressed air energy storage system using a common heat storage heat exchanger, characterized in that: include: A compressor unit, comprising a first compressor, a second compressor and a third compressor connected in sequence; A turbine unit, comprising a first turbine and a second turbine connected in sequence; A heat storage and release assembly, comprising a first heat exchanger, a second heat exchanger, a third heat exchanger, a high-temperature heat accumulator, a medium-temperature heat accumulator and a low-temperature heat accumulator; Gas storage; The first compressor, the first heat exchanger, the second compressor, the second heat exchanger, the third compressor, the third heat exchanger, and the air storage are connected in series in sequence to form a compressed air passage, the air storage, the third heat exchanger, the second heat exchanger, the second turbine, the first heat exchanger, and the first turbine are connected in series in sequence to form a turbine air passage, the first heat exchanger and the second heat exchanger are connected to the high-temperature heat accumulator and the low-temperature heat accumulator, and the third heat exchanger is connected to the medium-temperature heat accumulator and the low-temperature heat accumulator.

2. The compressed air energy storage system according to claim 1, characterized in that: Control valves for controlling on and off are provided between the first compressor, the first turbine and the first heat exchanger, between the first heat exchanger and the second compressor and the second turbine, between the second compressor and the second turbine and the second heat exchanger, between the second heat exchanger and the third compressor and the third heat exchanger, and between the third heat exchanger and the third compressor and the gas storage reservoir. The heat storage and release component also includes a driving pump for controlling the flow direction of the heat exchange medium.

3. The compressed air energy storage system according to claim 1, characterized in that: The heat exchange medium in the heat storage and release component is heat transfer oil.

4. The compressed air energy storage system according to claim 1, characterized in that: The compressed air energy storage system also includes a cooler arranged on the low-temperature heat accumulator and a cooling tower connected to the cooler, and a first circuit connected to the cooling tower and a second circuit connected to the low-temperature heat accumulator are formed in the cooler.

5. The compressed air energy storage system according to claim 1, characterized in that: The flow rates of the first compressor, the second compressor and the third compressor are fixed and are the same as the average flow rates of the first turbine and the second turbine. The air temperature output by the first compressor and the second compressor is K1, the air temperature input by the second compressor and the third compressor is K2, the air temperature input by the first turbine and the second turbine is K3, and the air temperature output by the first turbine and the second turbine is K4. K1, K2, K3 and K4 satisfy K1-K2=K3-K4.

6. The compressed air energy storage system according to claim 1, characterized in that: The pressure value range of the gas storage is 8-14MPa.

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