Thermoelectric compressed air energy storage system

Abstract

The utility model discloses a thermoelectric type compressed air energy storage system which is composed of a compressed air system, an air expansion power generation system, an air storage system, a multi-stage compression heat recycling system, a fused salt heat storage system, an electric heating pressure water heat storage system, a multi-stage compression heat utilization heating expansion system and a two-stage heating heat supply initial station. The system not only realizes energy storage and release in the air compression and expansion process, but also can be timely adjusted according to real-time energy fluctuation of a power grid, so that energy is quickly converted between heat and electricity, quick peak regulation of the whole power grid system is realized, powerful support is provided for effective utilization of the energy of the whole power grid system, and the energy utilization rate of the whole power grid system is improved. The system has high electric energy storage and discharge efficiency, and is of great significance to safe, efficient and stable operation of a power grid.

Description

TECHNICAL FIELD

[0001] The utility model relates to compressed air energy storage, molten salt energy storage and thermal-electric decoupling, in particular to a thermal-electric compressed air energy storage system. BACKGROUND

[0002] At the current stage, the main source of electricity in China is coal, oil and natural gas, three widely used traditional energy sources. Compressed air energy storage is a large-capacity energy storage technology that has gained attention in recent years as a physical energy storage technology that can be used on a large scale in addition to pumped storage. In order to reduce fuel consumption and improve energy storage efficiency, a heat accumulator is a key link in an adiabatic compressed air energy storage system.

[0003] At the current stage, there are technologies such as steam extraction for heating, hot water storage for heating, low-pressure cylinder removal, electrode-type boiler technology, solid heat storage technology, heat pump technology, and coupling various energy storage technologies for deep peak shaving of thermal power generating units. Thermal power generating units have the characteristics of large base capacity and high energy grade, so their energy storage capacity is large and the cycle is long. Compared to electricity storage technology, heat storage technology has the advantages of simple structure and low investment, and is an effective way to achieve large-scale utilization of renewable energy and improve energy utilization rate, safety and economy. Among them, molten salt is a heat transfer and energy storage medium with excellent performance, which has the advantages of high use temperature, high stability, high heat transfer coefficient, high cost-effectiveness, and has been widely used in the field of thermal power.

[0004] In the future, the amount of thermal power generation in China will remain on a downward trend for a long time, and it will be difficult to meet the demand for peak shaving and frequency modulation. Therefore, energy storage is an effective means to balance power supply and demand, an important technology and basic equipment to support the new power system, and has important significance for promoting green energy transformation. UTILITY MODEL CONTENT

[0005] The utility model aims at providing a thermal-electric compressed air energy storage system to solve the above technical problems.

[0006] To achieve the above purpose, the utility model provides the following technical scheme.

[0007] The application discloses a compressed air energy storage system of a thermoelectric type, which is characterized in that the system comprises a compressed air system, an air expansion power generation system, a gas storage system, a multi-stage compression heat recycling system, a molten salt heat storage system, an electrically heated pressure water heat storage system, a final-stage compression heat recycling and cooling system and a two-stage heating and heat supply primary station; the compressed air system is used for pressurizing ambient air; the air expansion power generation system is used for expanding high-pressure air into a turbine to do work and drive a generator to generate power; the gas storage system is used for storing high-pressure air after pressurization; the multi-stage compression heat recycling system adopts different forms of heat exchangers to recycle and utilize low-temperature stage compression heat and high-temperature stage compression heat; the molten salt heat storage system adopts a molten salt-air heat exchanger group to store and utilize air compression heat; the electrically heated pressure water heat storage system is used for realizing stable heat supply of hot water through connection with a power grid; the final-stage compression heat recycling and cooling system is used for heating heat network circulating water or cooling high-pressure air of the final-stage compressor under different demand conditions; and the two-stage heating and heat supply primary station is used for simultaneously realizing supply of final-stage compressor outlet high-pressure air compression heat and partial heat in the pressure water heat tank to the heat network.

[0008] Further, the compressed air system comprises three stages, namely, a first compressor and a first motor, a second motor and a second compressor, and a third motor and a third compressor; an outlet a of the first compressor is connected with an inlet b of a first cooler; an outlet g of a second cooler is connected with an inlet h of the second compressor; an outlet i of the second compressor is connected with an inlet j of a third cooler; an outlet o of a fourth cooler is connected with an inlet p of the third compressor; an outlet q of the third compressor is connected with an inlet r of a final-stage heat exchanger; compressed air is discharged from the final-stage heat exchanger into a high-pressure gas storage tank through an inlet s; and the first, second and third compressors form a multi-stage series air compression system.

[0009] The air expansion power generation system comprises two stages, namely, a first expander, a second expander, an exhaust chimney and a generator; heated air is introduced into a first heater through an inlet t; the air is introduced into an inlet z of the first expander through an outlet y of a second heater; the air is discharged from an outlet aa of the first expander; the air is introduced into a third heater through an inlet ab of the third heater; the air is introduced into an inlet ah of the second expander through an outlet ag of a fourth heater; the air is discharged from the second expander through the exhaust chimney; and the generator is connected with a power grid through a transformer.

[0010] The gas storage system comprises a high-pressure gas storage tank, which is used for storing compressed air cooled by the final-stage heat exchanger and discharged from the inlet s.

[0011] The connection form of the multi-stage compression heat recovery system and the molten salt heat storage system is that the molten salt in the molten salt hot tank flows out from the outlet aj and is divided into two streams: one stream flows into the second heater inlet x and flows out from the outlet w; the other stream flows into the fourth heater inlet af and flows out from the outlet ae; the two streams of molten salt flow out from the two outlets w and ae respectively, converge, flow into the molten salt cold tank from the inlet ak of the molten salt cold tank through the first variable frequency molten salt pump, flow out from the outlet aL of the molten salt cold tank, and are divided into two streams after the second variable frequency molten salt pump: one stream flows into the first cooler inlet d and flows out from the outlet c; the other stream flows into the third cooler inlet L and flows out from the outlet k; the two streams of molten salt flow out from the two outlets c and k respectively, converge, and flow into the molten salt hot tank from the inlet ai of the molten salt hot tank, to repeat the above cycle;

[0012] The connection form of the electric heating pressure water heat storage system is that the hot water in the pressure water hot tank flows out from the outlet an of the pressure water hot tank, is divided into two streams after the first control valve: one stream flows into the first heater inlet v and flows out from the first heater outlet u; the other stream flows into the third heater inlet ad and flows out from the third heater outlet ac; the two streams of water flow out from the two outlets u and ac respectively, converge, flow into the pressure water cold tank from the inlet ao of the pressure water cold tank through the first variable frequency water pump, flow out from the outlet ap of the pressure water cold tank, and are divided into two streams after the second variable frequency water pump: one stream flows into the second cooler inlet f and flows out from the second cooler outlet e; the other stream flows into the fourth cooler inlet n and flows out from the fourth cooler outlet m; the two streams of water flow out from the two outlets e and m respectively, converge, flow into the electric heating device from the inlet o, and flow out from the outlet p, and repeat the above cycle; the electric heating device heating module is connected with the transformer through an electric wire;

[0013] The last-stage compression heat recovery and cooling system comprises a cooling tower, a third control valve, a fourth control valve, a fifth control valve, a last-stage heat exchanger, a second non-return valve, a third non-return valve, and a circulating water pump; the cold water flowing into the last-stage heat exchanger inlet ar absorbs the heat of the hot air flowing into the last-stage heat exchanger inlet r, the hot water flows out from the last-stage heat exchanger outlet as and is divided into two streams; one stream flows to the first heat network heater inlet ax in the two-stage heat network heater through the fourth control valve, and the other stream flows into the cooling tower from the cooling tower inlet aq through the fifth control valve; the cooled cold water converges from the water flowing out from the second non-return valve and the third non-return valve, flows into the last-stage heat exchanger inlet ar again through the circulating water pump and the third control valve, and repeats the next cycle;

[0014] The two-stage heating heat supply first station: after the outlet an of the pressure water heat tank is branched, one branch passes through the second control valve, enters the second heat network heater from the inlet av of the second heat network heater, and is combined with the water flowing out from the outlet u of the first heater through the first check valve and the outlet of the second heat network heater ay, and then flows into the pressure water cold tank through the inlet ao by the first variable frequency water pump; one branch passes through the fourth control valve, enters the first heat network heater from the inlet ax of the first heat network heater, and is combined with the water flowing out from the outlet of the second and third check valves; hot water flows to the heat network from the outlet au of the second heat network heater, is heated by the first heat network heater and the second heat network heater after heat release in the heat network, and repeats the next cycle.

[0015] Further, the compressed air system is composed of two rows of three-stage air compressors; two-stage compression heat recovery heat exchanger groups, i.e. first and second cooler groups and third and fourth cooler groups, are arranged after the I and II stage air compressors, and the heat of the high-temperature stage first and third coolers and the low-temperature stage second and fourth coolers is stored in the molten salt heat tank and the pressure water heat tank respectively; the high-pressure air compressed by three stages is cooled by the last heat exchanger and stored in the high-pressure gas tank.

[0016] Further, the air expansion power generation system is driven by air turbine expanders, i.e. the first and second expanders, to output electric energy to the power grid; the high-pressure air is released from the high-pressure gas tank, heated to high pressure and high temperature by pressure water and molten salt, enters the high-pressure cylinder of the expander, i.e. the first expander, to generate power, and the exhaust gas is heated to medium pressure and high temperature by pressure water and molten salt, enters the low-pressure cylinder of the expander to generate power.

[0017] Further, the gas storage unit in the gas storage system is composed of at least one or more underground caverns, underground salt caves or high-pressure gas tanks.

[0018] Further, the I and II stage heat exchangers in the multi-stage compression heat recovery and utilization system are both designed in two stages, the second cooler, the fourth cooler, the first heater and the third heater are pressure water-air heat exchangers for recovering and utilizing low-temperature stage compression heat 180≤℃, the first cooler, the third cooler, the second heater and the fourth heater are molten salt-air heat exchangers for recovering and utilizing high-temperature stage compression heat 180≥℃, wherein the second cooler and the first heater are cross-flow heat exchangers, and the first cooler, the third cooler, the fourth cooler, the second heater, the third heater and the fourth heater are hairpin heat exchangers.

[0019] Further, the system high-temperature section compression heat 180≥℃, suitable for molten salt heat storage recovery, utilization and storage system; the system is composed of a molten salt hot tank, a molten salt cold tank, a variable frequency molten salt pump and a second variable frequency molten salt pump.

[0020] Further, the electric heating pressure water heat storage system is composed of a pressure water hot tank, a pressure water cold tank, a first variable frequency water pump and a second variable frequency water pump, and heat exchange is carried out through a second cooler, a fourth cooler, a first heater and a third heater; the electric heating device is installed before the pressure water hot tank inlet am, and during the low electricity consumption period, the pressure water flowing out of the fourth cooler outlet m is heated and stored in the pressure water hot tank, so that stable heat supply is realized; the heat stored in the pressure water hot tank is partially used for heating high-pressure air from a high-pressure gas tank and partially used for heating heat network circulating water, and the specific proportion depends on the first control valve and the second control valve adjustment opening, and heat and electricity cogeneration is realized.

[0021] Further, the last-stage compression heat recovery and cooling system includes a last-stage heat exchanger; during the heat supply period, the last-stage heat exchanger recovers last-stage compression heat together with the first heat network heater to heat the heat network circulating water, at this time, the fourth control valve is opened and the fifth control valve is closed, and the hot water circulation path is: last-stage heat exchanger→ fourth control valve→ first heat network heater→ third check valve→ circulating water pump→ last-stage heat exchanger;

[0022] During the non-heat supply period, the last-stage heat exchanger cools the high-pressure air at the last-stage compressor outlet together with the cooling tower, at this time, the fifth control valve is opened and the fourth control valve is closed, and the cooling water circulation path is: last-stage heat exchanger→ fifth control valve→ cooling tower→ second check valve→ circulating water pump→ third control valve→ last-stage heat exchanger.

[0023] Further, the two-stage heating heat supply first station includes a heat network circulating pump and a heat network heater group; the first heat network heater adopts a two-stage design, the first heat network heater is used to recover the compression heat carried by the high-pressure air at the III-stage compressor outlet, and the second heat network heater is used to further heat the heat network circulating water with part of the heat in the pressure water hot tank.

[0024] In actual application, the compressed air system, the air expansion power generation system, the gas storage system, the multi-stage compression heat recovery and utilization system, the molten salt heat storage system, the electric heating pressure water heat storage system, the last-stage compression heat recovery and cooling system and the two-stage heating heat supply first station are coupled and controlled, not only the energy storage and release of the air compression system are realized, but also the system can be adjusted in time according to the real-time energy fluctuation of the power grid, the rapid peak shaving of the entire power grid system is realized, and the heat supply and non-heat supply working conditions can be switched according to seasonal changes, so that the energy of the entire power grid system is effectively utilized, which has important significance for the safe and stable operation of the power grid, can produce good economic benefits and social benefits, and has good practical application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A thermoelectric type compressed air energy storage system schematic diagram;

[0026] 1. I stage compressor, 2. first motor, 3. second motor, 4. II stage compressor, 5. third motor, 6. III stage compressor, 7. first cooler, 8. second cooler, 9. third cooler, 10. fourth cooler, 11. molten salt hot tank, 12. molten salt cold tank, 13. first variable frequency molten salt pump, 14. second variable frequency molten salt pump, 15. electric heating device, 16. pressure water hot tank, 17. first control valve, 18. first variable frequency water pump, 19. pressure water cold tank, 20. second variable frequency water pump, 21. second control valve, 22. first heater, 23. second heater, 24. third heater, 25. fourth heater, 26. I stage expander, 27. II stage expander, 28. exhaust chimney, 29. generator, 30. transformer, 31. power grid, 32. heat grid, 33. heat grid circulating pump, 34. first heat grid heater, 35. second heat grid heater, 36. fourth control valve, 37. fifth control valve, 38. cooling tower, 39. second check valve, 40. third check valve, 41. circulating water pump, 42. third control valve, 43. final stage heat exchanger, 44. high pressure gas storage tank, 45. first check valve.

[0027] a~ax are the import and export of each module. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application.

[0029] EMBODIMENT

[0030] REFERENCE Figure 1As shown, a thermoelectric type compressed air energy storage system, characterized in that it comprises a compressed air system, an air expansion power generation system, a gas storage system, a multi-stage compression heat recovery system, a molten salt heat storage system, an electrically heated pressure water heat storage system, a final stage compression heat recovery and cooling system and a two-stage heating and heat supply station; the compressed air system is used to pressurize ambient air, the air expansion power generation system is used to pass high-pressure air into a turbine for expansion and work, to drive a generator to generate electricity, the gas storage system is used to store high-pressure air after pressurization, the multi-stage compression heat recovery system recovers and utilizes low-temperature stage compression heat and high-temperature stage compression heat using different forms of heat exchangers, the molten salt heat storage system uses a molten salt-air heat exchanger group to store and utilize air compression heat, the electrically heated pressure water heat storage system is used to realize stable heat supply of hot water through connection with a power grid, the final stage compression heat recovery and cooling system is used to heat heat network circulating water or cool high-pressure air of the final stage compressor under different demand conditions, and the two-stage heating and heat supply station is used to simultaneously realize supply of high-pressure air compression heat of the final stage compressor and supply of part of heat in the pressure water heat tank to the heat network.

[0031] In the embodiment, the compressed air system has three stages, comprising a first motor 2 and an I-stage compressor 1, a second motor 3 and a II-stage compressor 4, and a third motor 5 and a III-stage compressor 6, an outlet a of the I-stage compressor is connected to an inlet b of a first cooler 7, an outlet g of a second cooler 8 is connected to an inlet h of the II-stage compressor 4, an outlet i of the II-stage compressor 4 is connected to an inlet j of a third cooler 9, an outlet o of a fourth cooler 10 is connected to an inlet p of the III-stage compressor 6, and an outlet q of the III-stage compressor is connected to an inlet r of a final stage heat exchanger 43, compressed air after heat release flows into a high-pressure gas storage tank 44 from an inlet s of the high-pressure gas storage tank 44; the compressors form a multi-stage series air compression system.

[0032] The air expansion power generation system has two stages, comprising a first-stage expander 26, a second-stage expander 27, an exhaust chimney 28 and a generator 29; heated air enters a first heater 22 through an inlet t, passes through an outlet y of a second heater 23, enters the first-stage expander 26 through an inlet z, flows out from an outlet aa after passing through the first-stage expander 26, enters a third heater 24 through an inlet ab, and is discharged from the exhaust chimney 28 after passing through the second-stage expander 27; the generator 29 is connected to a power grid 31 through a transformer 30.

[0033] The gas storage system comprises the high-pressure gas storage tank 44, which is used to store compressed air after cooling by the final stage heat exchanger 43.

[0034] The connection form of the multi-stage compression heat recovery system and the molten salt heat storage system is that the molten salt in the molten salt hot tank 11 flows out from the outlet aj and is divided into two streams: one stream flows into the second heater inlet x and flows out from the outlet w; the other stream flows into the fourth heater inlet af and flows out from the outlet ae. The two streams of molten salt flow out from the two outlets w and ae respectively, converge, and then flow into the molten salt cold tank 12 from the inlet ak of the molten salt cold tank 12 through the first variable frequency molten salt pump 13, flow out from the outlet aL of the molten salt cold tank 12, and are divided into two streams after the second variable frequency molten salt pump 14: one stream flows into the first cooler 7 from the inlet d and flows out from the outlet c; the other stream flows into the third cooler 9 from the inlet L and flows out from the outlet k; the two streams of molten salt flow out from the two outlets c and k respectively, converge, and then flow into the molten salt hot tank 11 from the inlet ai of the molten salt hot tank 11, and repeat the above cycle.

[0035] The connection form of the electric heating pressure water heat storage system is that the hot water in the pressure water hot tank 16 flows out from the outlet an of the pressure water hot tank 16, is divided into two streams after the first control valve 17: one stream flows into the first heater 22 from the inlet v and flows out from the outlet u of the first heater 22; the other stream flows into the third heater 24 from the inlet ad and flows out from the outlet ac of the third heater 24; the two streams of water flow out from the two outlets u and ac respectively, converge, and then flow into the pressure water cold tank 19 from the inlet ao of the pressure water cold tank 19 through the first variable frequency water pump 18, flow out from the outlet ap of the pressure water cold tank 19, and are divided into two streams after the second variable frequency water pump 20: one stream flows into the second cooler 8 from the inlet f and flows out from the outlet e of the second cooler 8; the other stream flows into the fourth cooler 10 from the inlet n and flows out from the outlet m of the fourth cooler 10; the two streams of water flow out from the two outlets e and m respectively, converge, and then flow into the electric heating device 15 from the inlet o and flow out from the outlet p, and repeat the above cycle. The heating module of the electric heating device 15 is connected with the transformer 30 through an electric wire.

[0036] The last-stage compression heat recovery and cooling system includes a cooling tower 38, a third control valve 42, a fourth control valve 36, a fifth control valve 37, a last-stage heat exchanger 43, a second check valve 39, a third check valve 40, and a circulating water pump 41: the cold water flowing into the last-stage heat exchanger 43 from the inlet ar absorbs the heat of the hot air flowing into the last-stage heat exchanger 43 from the inlet r, and then the hot water flows out from the outlet as of the last-stage heat exchanger 43 and is divided into two streams. One stream flows to the first heat network heater 34 from the inlet ax of the two-stage heat network heater through the fourth control valve 36; the other stream flows into the cooling tower 38 from the inlet aq of the cooling tower 38 through the fifth control valve 37. The cooled cold water converges with the water flowing out from the second check valve 39 and the third check valve 40, flows into the last-stage heat exchanger 43 from the inlet ar again through the circulating water pump 41 and the third control valve 42, and repeats the next cycle.

[0037] The two-stage heating heat supply first station: after the an outlet of the pressure water heat tank 16 is branched, one branch enters the second heat network heater 35 from the second heat network heater 35 inlet av through the second control valve 21, and the water flowing out from the first heater outlet u is combined with the water flowing out from the second heat network heater 35 outlet aw through the first check valve 45, and flows into the pressure water cold tank 19 through the inlet ao by the first variable frequency water pump 18, and one branch enters the first heat network heater 34 from the first heat network heater 34 inlet ax after the fourth control valve 36, and the water flowing out from the second heat network heater 34 outlet ay is combined with the water flowing out from the second check valve 39 outlet. The hot water flows to the heat network 32 from the second heat network heater 35 outlet au, and after the heat network 32 releases heat, the heat network circulating pump 33 enters the first heat network heater 34 and the second heat network heater 35 from the first heat network heater 34 inlet at to absorb heat, and the next cycle is repeated.

[0038] In this embodiment, the compressed air system is composed of two rows of three-stage air compressors; two-stage compression heat recovery heat exchanger groups, i.e., the first cooler 7, the second cooler 8 group and the third cooler 9, the fourth cooler 10 group, are arranged after the I, II stage air compressors, and the heat of the high-temperature stage first cooler 7 and the third cooler 9 and the heat of the low-temperature stage second cooler 8 and the fourth cooler 10 are stored in the molten salt heat tank 11 and the pressure water heat tank 16, respectively; the high-pressure air compressed by three stages is cooled by the last-stage heat exchanger 43 and stored in the high-pressure gas storage tank 44.

[0039] In this embodiment, the air expansion power generation system is driven by an air turbine expander, i.e., a first-stage expander 26 and a second-stage expander 27, to output electric energy to the power grid 31. The high-pressure air is discharged from the high-pressure gas storage tank 44, heated to high pressure and high temperature by two-stage heating (i.e., the first heater 22 and the second heater 23), enters the high-pressure cylinder of the expander, i.e., the first-stage expander 26, to generate power, and the exhaust gas is heated to medium pressure and high temperature by two-stage heating (i.e., the third heater 24 and the fourth heater 25), enters the low-pressure cylinder of the expander, i.e., the second-stage expander 27, to generate power.

[0040] In this embodiment, the gas storage unit in the gas storage system is composed of at least one or more underground chambers, underground salt caves or high-pressure gas storage tanks.

[0041] In the present embodiment, the multi-stage compression heat recovery system is designed with two stages for each of the first and second heat exchangers, the second cooler 8, the fourth cooler 10, the first heater 22 and the third heater 24 are pressure water-air heat exchangers for recovering and utilizing low-temperature compression heat ≤180℃, and the first cooler 7, the third cooler 9, the second heater 23 and the fourth heater 25 are molten salt-air heat exchangers for recovering and utilizing high-temperature compression heat ≥180℃, wherein the second cooler 8 and the first heater 22 are cross-flow heat exchangers, and the first cooler 7, the third cooler 9, the fourth cooler 10, the second heater 23, the third heater 24 and the fourth heater 25 are hairpin heat exchangers.

[0042] In the present embodiment, the molten salt heat storage recovery, utilization and storage system is applicable to the high-temperature compression heat ≥180℃ scheme, and the system is composed of a molten salt hot tank 11, a molten salt cold tank 12, a variable frequency molten salt pump 13 and a second variable frequency molten salt pump 14.

[0043] In the present embodiment, the electric heating pressure water heat storage system is composed of a pressure water hot tank 16, a pressure water cold tank 19, a first variable frequency water pump 18 and a second variable frequency water pump 20, and heat exchange is performed through the second cooler 8, the fourth cooler 10, the first heater 22 and the third heater 24. The electric heating device 15 (which can be an electrode boiler or an electromagnetic heater) is installed before the inlet am of the pressure water hot tank 16, and during the low electricity consumption period, the pressure water flowing out of the outlet m of the fourth cooler 10 is heated and stored in the pressure water hot tank 16, so as to realize stable heat supply, and the heat stored in the pressure water hot tank 16 is partially used for heating high-pressure air (when expanding to generate electricity) from the high-pressure gas tank 44 and partially used for heating heat network circulating water, depending on the adjustment opening of the first control valve 17 and the second control valve 21, and realizing cogeneration.

[0044] In the present embodiment, the final-stage compression heat recovery and cooling system includes a final-stage heat exchanger 43, which, together with the first heat network heater 34, recovers final-stage compression heat and heats heat network circulating water during the heating period. First, the final-stage heat exchanger recovers compression heat, and the heat network circulating water is heated by the heat network heater in the first stage: at this time, the third control valve 42 and the fourth control valve 36 are opened, the fifth control valve 37 is closed, and the hot water circulation path is: the final-stage heat exchanger 43→the fourth control valve 36→the first heat network heater 34→the third check valve 40→the circulating water pump 41→the final-stage heat exchanger 43; second, the heat network circulating water is heated by the heat network heater in the second stage by using the heat in the pressure water hot tank, i.e., the second control valve 21 is opened for adjustment, and the pressure water flow path is: the pressure water hot tank 16→the second control valve 21→the second heat network heater 35→the first check valve 45→the first variable frequency water pump 18→the pressure water cold tank 19.

[0045] In the embodiment, when the compressed air energy storage system is in the non-compressed energy storage operation condition, the heat network circulating water is only heated by the heat in the pressure water heat tank in a single stage, and the pressure water flow is: the pressure water heat tank 16→the second control valve 21→the second heat network heater 35→the first check valve 45→the first variable frequency water pump 18→the pressure water cold tank 19, which is consistent with the foregoing.

[0046] In the embodiment, during the non-heating period, the final stage heat exchanger 43 and the cooling tower 38 together cool the high-pressure air at the outlet of the final stage compressor, at this time, the third control valve 42 and the fifth control valve 37 are opened, and the fourth control valve 36 is closed, and the cooling water circulation path is: the final stage heat exchanger 43→the fifth control valve 37→the cooling tower 38→the second check valve 39→the circulating water pump 41→the third control valve 42→the final stage heat exchanger 43.

[0047] In the embodiment, the two-stage heating heat supply first station includes a heat network circulating pump 33 and a heat network heater group, the heat network heater adopts a two-stage design, the first heat network heater 34 is used to recover the compression heat carried by the high-pressure air at the outlet of the III stage compressor 6, and the second heat network heater 35 is used to further heat the heat network circulating water by using part of the heat in the pressure water heat tank 16.

[0048] The specific embodiments described herein are merely illustrative of the spirit of the present application. Those skilled in the art to which the present application belongs can make various modifications or supplements to the described specific embodiments or use similar ways to replace, but will not deviate from the range defined by the spirit of the present application.

Claims

1. A thermoelectric type compressed air energy storage system, characterized by, The system comprises a compressed air system, an air expansion power generation system, a gas storage system, a multi-stage compression heat recovery system, a molten salt heat storage system, an electrically heated pressure water heat storage system, a final-stage compression heat recovery and cooling system, and a two-stage heating and heat supply primary station; the compressed air system is used for pressurizing ambient air, the air expansion power generation system is used for expanding high-pressure air into a turbine to do work and drive a generator to generate power, the gas storage system is used for storing high-pressure air after pressurization, the multi-stage compression heat recovery system recovers and utilizes low-temperature stage compression heat and high-temperature stage compression heat by using different forms of heat exchangers, the molten salt heat storage system stores and utilizes air compression heat by using a molten salt-air heat exchanger group, the electrically heated pressure water heat storage system is used for realizing stable heat supply of hot water by connecting to a power grid, the final-stage compression heat recovery and cooling system is used for heating heat network circulating water or cooling high-pressure air of the final-stage compressor under different demand conditions, and the two-stage heating and heat supply primary station is used for simultaneously realizing supply of high-pressure air compression heat of the final-stage compressor and supply of part of heat in the pressure water heat tank to the heat network.

2. A thermoelectric compressed air energy storage system according to claim 1, wherein, The compressed air system comprises three stages, including a first compressor and a first motor, a second motor and a second compressor, and a third motor and a third compressor, the outlet a of the first compressor is connected to the inlet b of a first cooler, the outlet g of a second cooler is connected to the inlet h of the second compressor, the outlet i of the second compressor is connected to the inlet j of a third cooler, the outlet o of a fourth cooler is connected to the inlet p of the third compressor, the outlet q of the third compressor is connected to the inlet r of a final-stage heat exchanger, and compressed air flows into a high-pressure gas storage tank from the inlet s after heat release, and the compressors form a multi-stage series air compression system; The air expansion power generation system comprises two stages, including a first expander, a second expander, an exhaust chimney, and a generator, heated air enters a first heater from the inlet t, enters the inlet z of the first expander from the outlet y of a second heater, flows out from the outlet aa after entering the first expander, enters a third heater from the inlet ab of the third heater, enters the inlet ah of the second expander from the outlet ag of a fourth heater after being heated, and is discharged from the exhaust chimney after entering the second expander, and the generator is connected to a power grid through a transformer; The gas storage system comprises a high-pressure gas storage tank for storing compressed air cooled by the final-stage heat exchanger and flowing in from the inlet s; The connection form of the multi-stage compression heat recycling system and the molten salt heat storage system is that the molten salt in the molten salt hot tank flows out from the outlet aj and is divided into two streams: one stream flows into the second heater inlet x and flows out from the outlet w; the other stream flows into the fourth heater inlet af and flows out from the outlet ae; the two streams of molten salt flow out from the two outlets w and ae respectively, are combined, flow into the molten salt cold tank from the inlet ak of the molten salt cold tank through the first variable frequency molten salt pump, flow out from the outlet aL of the molten salt cold tank, are divided into two streams after the second variable frequency molten salt pump, one stream flows into the first cooler inlet d and flows out from the outlet c, and the other stream flows into the third cooler inlet L and flows out from the outlet k; the two streams of molten salt flow out from the two outlets c and k respectively, are combined, flow into the molten salt hot tank from the inlet ai of the molten salt hot tank, and repeat the above cycle; The connection form of the electric heating pressure water heat storage system is that the hot water in the pressure water hot tank flows out from the outlet an of the pressure water hot tank, is divided into two streams after the first control valve: one stream flows into the first heater inlet v and flows out from the first heater outlet u; the other stream flows into the third heater inlet ad and flows out from the third heater outlet ac; the two streams of water flow out from the two outlets u and ac respectively, are combined, flow into the pressure water cold tank from the inlet ao of the pressure water cold tank through the first variable frequency water pump, flow out from the outlet ap of the pressure water cold tank, are divided into two streams after the second variable frequency water pump, one stream flows into the second cooler inlet f and flows out from the second cooler outlet e, and the other stream flows into the fourth cooler inlet n and flows out from the fourth cooler outlet m; the two streams of water flow out from the two outlets e and m respectively, are combined, flow into the electric heating device from the inlet o and flow out from the outlet p, and repeat the above cycle; the heating module of the electric heating device is connected with the transformer through an electric wire; The last-stage compression heat recycling and cooling system comprises a cooling tower, a third control valve, a fourth control valve, a fifth control valve, a last-stage heat exchanger, a second check valve, a third check valve and a circulating water pump; the cold water flowing into the last-stage heat exchanger inlet ar absorbs the heat of the hot air flowing into the last-stage heat exchanger inlet r, the hot water flows out from the last-stage heat exchanger outlet as and is divided into two streams; one stream flows to the first heat network heater inlet ax in the two-stage heat network heater through the fourth control valve, and the other stream flows into the cooling tower from the cooling tower inlet aq through the fifth control valve; the cooled cold water is combined with the water flowing out from the second check valve and the third check valve, flows into the last-stage heat exchanger inlet ar again through the circulating water pump and the third control valve, and repeats the next cycle; The two-stage heating heat supply first station: after being branched from the outlet an of the pressure water heat tank, one of the streams enters the second heat network heater from the second heat network heater inlet av through the second control valve, and is combined with the water flowing out from the first heater outlet u through the first check valve and the second heat network heater outlet aw, and flows into the pressure water cold tank through the inlet ao by the first variable frequency water pump, and one of the streams branched from the outlet as of the last-stage heat exchanger enters the first heat network heater from the first heat network heater inlet ax through the fourth control valve, and is combined with the stream from the outlet of the second check valve through the third check valve and the second heat network heater outlet ay; the hot water flows to the heat network from the second heat network heater outlet au, and after heat release in the heat network, the hot water enters the first heat network heater and the second heat network heater from the first heat network heater inlet at by the heat network circulating pump to absorb heat, and the next cycle is repeated.

3. A thermoelectric compressed air energy storage system according to claim 2, wherein, The compressed air system is composed of two rows of three-stage air compressors; two-stage compressed heat recovery heat exchanger groups, i.e. first cooler, second cooler group and third cooler, fourth cooler group, are arranged after the I, II stage air compressors, and the obtained high-temperature stage first cooler, third cooler heat and low-temperature stage second cooler, fourth cooler heat are respectively stored in the molten salt heat tank and the pressure water heat tank; the high-pressure air compressed by three stages is stored in the high-pressure gas storage tank after being cooled by the last-stage heat exchanger.

4. A thermoelectric compressed air energy storage system according to claim 2, wherein, The air expansion power generation system is driven by the air turbine expanders, i.e. the I-stage expander and the II-stage expander, to output electric energy to the power grid; the high-pressure air is discharged from the high-pressure gas storage tank, heated to high pressure and high temperature by the pressure water and the molten salt, and enters the high-pressure cylinder of the expander, and the exhaust gas is heated to medium pressure and high temperature by the pressure water and the molten salt, and enters the low-pressure cylinder of the expander to generate power.

5. A thermoelectric compressed air energy storage system according to claim 2, wherein, The gas storage unit in the gas storage system is composed of at least one or more underground chambers, underground salt caves or high-pressure gas storage tanks.

6. A thermoelectric compressed air energy storage system according to claim 2, wherein, The I, II stage heat exchangers in the multi-stage compressed heat recovery and utilization system are both designed in two stages, the second cooler, the fourth cooler, the first heater and the third heater are pressure water-air heat exchangers for recovering and utilizing low-temperature stage compressed heat 180≤℃, the first cooler, the third cooler, the second heater and the fourth heater are molten salt-air heat exchangers for recovering and utilizing high-temperature stage compressed heat 180≥℃, wherein the second cooler and the first heater are cross-flow heat exchangers, and the first cooler, the third cooler, the fourth cooler, the second heater, the third heater and the fourth heater are hairpin heat exchangers.

7. A thermoelectric compressed air energy storage system according to claim 2, wherein, The system high-temperature stage compressed heat 180≥℃ is suitable for the molten salt heat storage recovery, utilization and storage system; the system is composed of a molten salt heat tank, a molten salt cold tank, a variable frequency molten salt pump and a second variable frequency molten salt pump.

8. A thermoelectric compressed air energy storage system according to claim 2, wherein, The electric heating pressure water heat storage system is composed of a pressure water heat tank, a pressure water cold tank, a first variable frequency water pump and a second variable frequency water pump, and heat exchange is conducted through a second cooler, a fourth cooler, a first heater and a third heater; the electric heating device is installed before an inlet am of the pressure water heat tank, and during the low electricity consumption period, the pressure water flowing out from the fourth cooler outlet m is heated and stored in the pressure water heat tank, so that stable heat supply is realized; the heat stored in the pressure water heat tank is partially used for heating high pressure air from a high pressure gas tank, and partially used for heating heat network circulating water, and the specific usage depends on the first control valve and the second control valve adjustment opening, and heat and electricity cogeneration is realized.

9. A thermoelectric compressed air energy storage system according to claim 2, wherein, The last stage compression heat recovery and cooling system comprises a last stage heat exchanger, during the heat supply period, the last stage heat exchanger recovers the last stage compression heat together with the first heat network heater; during the non-heat supply period, the last stage heat exchanger cools the high pressure air at the outlet of the last stage compressor together with the cooling tower.

10. A thermoelectric compressed air energy storage system according to claim 2, wherein, The two-stage heating heat supply first station comprises a heat network circulating pump and a heat network heater group; the heat network heat exchanger adopts a two-stage design, the first heat network heater is used to recover the compression heat carried by the high pressure air at the outlet of the III stage compressor, and the second heat network heater further heats the heat network circulating water by using part of the heat in the pressure water heat tank.

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