Compressed air energy storage system capable of recycling waste heat

Abstract

The utility model relates to a compressed air energy storage system capable of recycling waste heat. The system comprises: a compression assembly for compressing a gas; the gas storage assembly is connected with the compression assembly and used for storing compressed gas; the first heat exchange assembly is connected with the compression assembly and the heat storage assembly and used for storing the heated liquid working medium in the heat storage assembly after heat exchange is conducted on the compressed gas; the second heat exchange assembly is connected with the heat storage assembly and the expansion assembly. The expansion assembly is connected with the gas storage assembly and the generator; and the waste heat ORC power generation and external heat supply assembly is connected with the heat storage assembly and used for heating the liquid working medium to form a gaseous working medium, and after the gaseous working medium is expanded to do work, the gaseous working medium is condensed again to form the liquid working medium so as to supply heat to the outside. Therefore, by means of the compressed air energy storage system capable of recycling the waste heat, the problems that an existing compressed air energy storage system is fixed in topological structure, single in operation mode, narrow in operation working condition, low in system efficiency and the like are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage, and particularly relates to a compressed air energy storage system for waste heat recovery and utilization. Background Art

[0002] With the continuous increase of the proportion of new energy installed capacity in China, the peak-valley difference of the power grid has gradually increased, and the problems of abandoned wind and abandoned light are very serious. Energy storage is a key technology to promote the consumption of renewable energy. It is expected that by 2030, the installed capacity of new energy storage in China will reach 150 million kilowatts, and "new energy + energy storage" has gradually become one of the important means to solve the problem of new energy consumption in China. Compressed air energy storage is a large-scale physical energy storage technology that uses compressed air to store energy and can be widely used in peak shaving and valley filling of the power grid and large-scale new energy consumption.

[0003] In related technologies, the existing compressed air energy storage system generally contains a gas storage tank, and the multi-stage compressor and expander all operate in series.

[0004] However, the system has a fixed topological structure, a single operation mode, a narrow operation condition, and a low system efficiency, and thus needs to be improved urgently. Summary of the Utility Model

[0005] The utility model provides a compressed air energy storage system for waste heat recovery and utilization to solve the problems of the existing compressed air energy storage system, such as a fixed topological structure, a single operation mode, a narrow operation condition, and a low system efficiency, broaden the operation condition, and improve the efficiency of the compressed air energy storage system.

[0006] To achieve the above object, the first aspect embodiment of the utility model provides a compressed air energy storage system for waste heat recovery and utilization, including:

[0007] A compression assembly, a gas storage assembly, a first heat exchange assembly, an expansion assembly, a second heat exchange assembly, a heat storage assembly, and a waste heat ORC (Organic Rankine Cycle) power generation and external heat supply assembly, wherein,

[0008] The compression assembly is used for compressing gas;

[0009] The gas storage assembly is connected to the compression assembly and is used for storing the compressed gas;

[0010] The first input end of the first heat exchange assembly is connected to the compression assembly, the second input end of the first heat exchange assembly is connected to the first output end of the heat storage assembly, and the output end of the first heat exchange assembly is connected to the first input end of the heat storage assembly. The first heat exchange assembly is used for exchanging heat with the compressed gas and storing the heated liquid working medium in the heat storage assembly through the first input end of the heat storage assembly;

[0011] The input end of the second heat exchange component is connected to the second output end of the heat storage component. The first output end of the second heat exchange component is connected to the input end of the expansion component. The second output end of the second heat exchange component is connected to the second input end of the heat storage component;

[0012] The input end of the expansion component is connected to the gas storage component. The output end of the expansion component is connected to the generator;

[0013] The waste heat ORC power generation and external heat supply component is connected to the third output end of the heat storage component, and is used to heat the liquid working medium to form a gaseous working medium. After the gaseous working medium is used to expand and do work, it is re-condensed to form the liquid working medium for external heat supply.

[0014] Optionally, the compression component includes:

[0015] An air filter that is in contact with the outside atmosphere;

[0016] A first-stage compressor, the input end of which is connected to the air filter;

[0017] A first throttle valve, one end of which is connected to the first output end of the first-stage compressor;

[0018] A second throttle valve, one end of which is connected to the second output end of the first-stage compressor;

[0019] A second-stage compressor, the input end of which is connected to the other end of the first throttle valve;

[0020] A third throttle valve, one end of which is connected to the first output end of the second-stage compressor;

[0021] A fourth throttle valve, one end of which is connected to the second output end of the second-stage compressor;

[0022] A third-stage compressor, the input end of which is connected to the other end of the third throttle valve;

[0023] A fifth throttle valve, one end of which is connected to the first output end of the third-stage compressor;

[0024] A sixth throttle valve, one end of which is connected to the second output end of the third-stage compressor;

[0025] A fourth-stage compressor, the input end of which is connected to the other end of the sixth throttle valve;

[0026] The seventh throttle valve, one end of which is connected to the first output end of the fourth-stage compressor.

[0027] Optionally, the gas storage assembly includes:

[0028] A high-pressure gas storage unit, the first input end of which is connected to the other end of the fifth throttle valve, and the second input end of which is connected to the other end of the seventh throttle valve;

[0029] A medium-pressure gas storage unit, the first input end of which is connected to the other end of the fourth throttle valve, and the second input end of which is connected to the other end of the second throttle valve.

[0030] Optionally, the first heat exchange assembly includes:

[0031] A first heat exchanger, the first input end of which is connected to the first output end of the first-stage compressor through the first input end of the first heat exchange assembly;

[0032] A second heat exchanger, the first input end of which is connected to the first output end of the second-stage compressor through the first input end of the first heat exchange assembly;

[0033] A third heat exchanger, the first input end of which is connected to the first output end of the third-stage compressor through the first input end of the first heat exchange assembly;

[0034] A fourth heat exchanger, the first input end of which is connected to the first output end of the fourth-stage compressor through the first input end of the first heat exchange assembly.

[0035] Optionally, the expansion assembly includes:

[0036] An eighth throttle valve, one end of which is connected to the first output end of the high-pressure gas storage unit;

[0037] A first-stage expander, the input end of which is connected to the other end of the eighth throttle valve;

[0038] A ninth throttle valve, one end of which is connected to the output end of the first-stage expander;

[0039] A tenth throttle valve, one end of which is connected to the second output end of the high-pressure gas storage unit;

[0040] A second-stage expander, the input end of which is respectively connected to the other end of the ninth throttle valve and the other end of the tenth throttle valve;

[0041] The eleventh throttle valve, one end of the eleventh throttle valve is connected to the first output end of the medium-pressure gas storage unit, and the other end of the eleventh throttle valve is connected to the first output end of the second-stage expander;

[0042] The twelfth throttle valve, one end of the twelfth throttle valve is connected to the second output end of the second-stage expander;

[0043] The third-stage expander, the first input end of the third-stage expander is connected to the other end of the twelfth throttle valve;

[0044] The thirteenth throttle valve, one end of the thirteenth throttle valve is connected to the second output end of the medium-pressure gas storage unit, and the other end of the thirteenth throttle valve is connected to the second input end of the third-stage expander;

[0045] The fourteenth throttle valve, one end of the fourteenth throttle valve is connected to the output end of the third-stage expander;

[0046] The fourth-stage expander, the first input end of the fourth-stage expander is connected to the other end of the fourteenth throttle valve, and the output end of the fourth-stage expander is connected to the generator through the output end of the expansion assembly;

[0047] The fifteenth throttle valve, one end of the fifteenth throttle valve is connected to the third output end of the medium-pressure gas storage unit, and the other end of the fifteenth throttle valve is connected to the second input end of the fourth-stage expander.

[0048] Optionally, the second heat exchange assembly includes:

[0049] The fifth heat exchanger, the first output end of the fifth heat exchanger is connected to the input end of the first-stage expander through the first output end of the second heat exchange assembly;

[0050] The sixth heat exchanger, the first output end of the sixth heat exchanger is connected to the input end of the second-stage expander through the first output end of the second heat exchange assembly;

[0051] The seventh heat exchanger, the first output end of the seventh heat exchanger is connected to the first input end of the third-stage expander through the first output end of the second heat exchange assembly;

[0052] The eighth heat exchanger, the first output end of the eighth heat exchanger is connected to the first input end of the fourth-stage expander through the first output end of the second heat exchange assembly.

[0053] Optionally, the heat storage assembly includes:

[0054] High-temperature heat storage unit, the input end of the high-temperature heat storage unit is connected to the output ends of the first to fourth heat exchangers through the first input end of the heat storage component and the output end of the first heat exchange component, and the second output end of the high-temperature heat storage unit is connected to the second input ends of the fifth to eighth heat exchangers through the second output end of the heat storage component and the input end of the second heat exchange component;

[0055] Low-temperature heat storage unit, the output end of the low-temperature heat storage unit is connected to the second input ends of the first to fourth heat exchangers through the first output end of the heat storage component and the second input end of the first heat exchange component, and the second input end of the low-temperature heat storage unit is connected to the second output ends of the fifth to eighth heat exchangers through the second input end of the heat storage component and the second output end of the second heat exchange component.

[0056] Optionally, the waste heat ORC power generation and external heat supply component includes:

[0057] Hot water delivery unit, the input end of the hot water delivery unit is connected to the first output end of the high-temperature heat storage unit through the third output end of the heat storage component;

[0058] Evaporation unit, the first input end of the evaporation unit is connected to the output end of the hot water delivery unit;

[0059] First ORC turbine, the input end of the first ORC turbine is connected to the first output end of the evaporation unit;

[0060] ORC generator, one end of the ORC generator is connected to the input end of the first ORC turbine;

[0061] Second ORC turbine, the input end of the second ORC turbine is connected to the first output end of the evaporation unit, and the output end of the second ORC turbine is respectively connected to the other end of the ORC generator and the output end of the first ORC turbine.

[0062] Optionally, the waste heat ORC power generation and external heat supply component further includes:

[0063] Condensation unit, the input end of the condensation unit is respectively connected to the output ends of the first ORC turbine and the second ORC turbine;

[0064] Working fluid pump, the input end of the working fluid pump is connected to the output end of the condensation unit;

[0065] Preheater, the first input end of the preheater is connected to the output end of the working fluid pump, the first output end of the preheater is connected to the second input end of the evaporation unit, and the second input end of the preheater is connected to the second output end of the evaporation unit;

[0066] The heat load, the input end of the heat load is connected to the second output end of the preheater, and the output end of the heat load is connected to the third input end of the low-temperature heat storage unit.

[0067] Optionally, the types of the first to eighth heat exchangers are at least one of cross-flow type, hairpin type, and fixed tube sheet type.

[0068] According to the compressed air energy storage system for waste heat recovery and utilization proposed by the embodiment of the present invention, air is compressed by a compression component, and the compressed gas is stored through a gas storage component connected to the compression component. Through a waste heat ORC power generation and external heat supply component connected to the heat storage component, a liquid working medium is heated to form a gaseous working medium, and after the gaseous working medium expands to do work, it is re-condensed to form a liquid working medium for external heat supply. Thus, through this compressed air energy storage system for waste heat recovery and utilization, problems such as the fixed topological structure, single operation mode, narrow operation conditions, and low system efficiency of the existing compressed air energy storage system are solved, the operation conditions are broadened, and the efficiency of the compressed air energy storage system is improved.

[0069] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be understood through the practice of the present invention. Description of the Drawings

[0070] The above-mentioned and / or additional aspects and advantages of the present invention will become apparent and easy to understand from the following description of the embodiments in conjunction with the drawings, where:

[0071] Figure 1 It is a block diagram of a compressed air energy storage system for waste heat recovery and utilization provided according to an embodiment of the present invention;

[0072] Figure 2 It is a structural diagram of a compressed air energy storage system for waste heat recovery and utilization according to an embodiment of the present invention;

[0073] Figure 3 It is a schematic diagram of the air flow path of the compression side operation condition II provided according to an embodiment of the present invention;

[0074] Figure 4 It is a schematic diagram of the air flow path of the compression side operation condition IV provided according to an embodiment of the present invention;

[0075] Figure 5 It is a schematic diagram of the air flow path of the turbine side operation condition I provided according to an embodiment of the present invention;

[0076] Figure 6Schematic diagram of the air flow path of the turbine side operating condition III according to an embodiment of the present utility model. Detailed implementation manners

[0077] The embodiments of the present utility model will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present utility model, and should not be construed as a limitation to the present utility model.

[0078] The compressed air energy storage system for waste heat recovery and utilization proposed according to the embodiments of the present utility model will be described below with reference to the accompanying drawings.

[0079] Before introducing the compressed air energy storage system for waste heat recovery and utilization proposed by the embodiments of the present utility model, the relevant technical background will be briefly introduced.

[0080] It can be understood that compressed air energy storage has the advantages of large installed capacity, long energy storage time, short construction period, long service life, clean and environmentally friendly, etc., and can be widely used in aspects such as peak shaving and valley filling of smart grids, large-scale renewable energy power generation, etc. Its working principle is: during energy storage, low-valley electricity, abandoned wind, abandoned photovoltaic power, etc. are used to drive a compressor to compress air to a high-temperature and high-pressure state. After cooling, the high-pressure air is close to room temperature and stored in a gas storage device; during energy release, the high-pressure air is released from the gas storage device, enters an air turbine after being heated to expand and do work, drives a generator to generate electricity, and outputs electric energy.

[0081] As an important type of energy storage, compressed air energy storage has unique advantages that other types of energy storage such as pumped hydro energy storage and electrochemical energy storage do not have. Compared with pumped hydro energy storage, compressed air energy storage has a short construction period, relatively easy site selection, high ecological environment friendliness, and small resettlement problems; compared with the currently relatively mature lithium battery energy storage, compressed air energy storage has a long service life, many cycle times, good safety, clean and pollution-free, and the system performance does not decay. In addition, compressed air energy storage has frequency modulation and voltage regulation performance similar to that of traditional thermal power, as well as inertia and short-circuit current support, which is conducive to the safe and stable operation of the power system in future high-proportion new energy scenarios.

[0082] However, the range of grid power demand changes greatly. The structure of the ordinary compressed air energy storage system is fixed, and the multi-stage compressor and expander can only operate in series all the time, resulting in the compressor and expander not being able to work at the rated state, with low efficiency and energy loss; in addition, a part of the heat is generated when the air is compressed on the compression side. Without waste heat collection, energy is wasted. If this part of the heat can be fully utilized, the efficiency and benefit of the system can be significantly improved. Therefore, the problems of wide operating conditions of the compressed air energy storage system and waste heat recovery and utilization need to be solved urgently.

[0083] Figure 1 It is a schematic block diagram of a compressed air energy storage system for waste heat recovery and utilization according to an embodiment of the present invention.

[0084] Exemplarily, as Figure 1 shown, the compressed air energy storage system 10 for waste heat recovery and utilization includes: a compression component 1, a gas storage component 2, a first heat exchange component 3, an expansion component 4, a second heat exchange component 5, a heat storage component 6, and a waste heat ORC (Organic Rankine Cycle) power generation and external heat supply component 7. Among them, the compression component 1 is used to compress gas; the gas storage component 2 is connected to the compression component 1 and is used to store the compressed gas; the first input end of the first heat exchange component 3 is connected to the compression component 1, the second input end of the first heat exchange component 3 is connected to the first output end of the heat storage component 6, and the output end of the first heat exchange component 3 is connected to the first input end of the heat storage component 6, and is used to exchange heat with the compressed gas and then store the heated liquid working medium in the heat storage component 6 through the first input end of the heat storage component 6; the input end of the second heat exchange component 5 is connected to the second output end of the heat storage component 6, the first output end of the second heat exchange component 5 is connected to the input end of the expansion component 4, and the second output end of the second heat exchange component 5 is connected to the second input end of the heat storage component 6; the input end of the expansion component 4 is connected to the gas storage component 2, and the output end of the expansion component 4 is connected to the generator; the waste heat ORC power generation and external heat supply component 7 is connected to the third output end of the heat storage component 6, and is used to heat the liquid working medium to form a gaseous working medium, and after using the gaseous working medium to expand and do work, it is re-condensed to form a liquid working medium to supply heat to the outside.

[0085] Specifically, in combination with Figure 1 and Figure 2 shown, the compression component 1 is connected to the gas storage component 2, and the gas storage component 2 can store the gas compressed by the compression component 1; the gas storage component 2 is connected to the expansion component 4 and is used to drive expansion engines of different grades of the expansion component 4; the first heat exchange component 3 is connected to the compression component 1 and the heat storage component 6, and is used to recover the waste heat generated by the compression component 1 and store it in the heat storage component 6, and this waste heat can be shared by the expansion component 4 and the waste heat ORC power generation and external heat supply component 7; the second heat exchange component 5 is connected to the expansion component 4 and the heat storage component 6, and is used to use the heat in the heat storage component 6 to heat the expansion process and drive the engine to do work; the waste heat ORC power generation and external heat supply component 7 is connected to the heat storage component 6, and the heat of the heat storage component 6 is used to heat the liquid working medium and convert it into a gaseous working medium. After the gaseous working medium expands and does work, it is re-condensed to form a liquid working medium for the next round of heating and expansion process.

[0086] For ease of understanding, the compression component 1, the gas storage component 2, the first heat exchange component 3, the expansion component 4, the second heat exchange component 5, the heat storage component 6, and the waste heat ORC power generation and external heat supply component 7 will be described in detail below in sequence.

[0087] Optionally, the compression component 1 includes: an air filter 1-1, a first-stage compressor 1-2, a second-stage compressor 1-3, a third-stage compressor 1-4, a fourth-stage compressor 1-5, a first throttle valve K1, a second throttle valve K2, a third throttle valve K3, a fourth throttle valve K4, a fifth throttle valve K5, a sixth throttle valve K6, and a seventh throttle valve K7. Among them, the air filter 1-1 is in contact with the outside atmosphere; the input end of the first-stage compressor 1-2 is connected to the air filter 1-1; one end of the first throttle valve K1 is connected to the first output end of the first-stage compressor 1-1; one end of the second throttle valve K2 is connected to the second output end of the first-stage compressor 1-1; the input end of the second-stage compressor 1-3 is connected to the other end of the first throttle valve K1; one end of the third throttle valve K3 is connected to the first output end of the second-stage compressor 1-3; one end of the fourth throttle valve K4 is connected to the second output end of the second-stage compressor 1-3; the input end of the third-stage compressor 1-4 is connected to the other end of the third throttle valve K3; one end of the fifth throttle valve K5 is connected to the first output end of the third-stage compressor 1-4; one end of the sixth throttle valve K6 is connected to the second output end of the third-stage compressor 1-4; the input end of the fourth-stage compressor 1-5 is connected to the other end of the sixth throttle valve K6; one end of the seventh throttle valve K7 is connected to the first output end of the fourth-stage compressor 1-5.

[0088] Specifically, as Figure 2 shown, the compression component 1 includes: an air filter 1-1, a first-stage compressor 1-2, a second-stage compressor 1-3, a third-stage compressor 1-4, a fourth-stage compressor 1-5, a first throttle valve K1, a second throttle valve K2, a third throttle valve K3, a fourth throttle valve K4, a fifth throttle valve K5, a sixth throttle valve K6, and a seventh throttle valve K7. There is a throttle valve connected between every two adjacent stages of compressors. According to the surplus situation of the input power, the working conditions of the four-stage compressor can be flexibly adjusted by controlling the on-off of the throttle valve, which is beneficial for each stage of the compressor in the compression component 1 to work at the rated working condition to a greater extent, thereby improving the operating efficiency of the entire system.

[0089] Among them, an air filter 1-1, a first-stage compressor 1-2, a throttle valve K1, a second-stage compressor 1-3, a throttle valve K3, a third-stage compressor 1-4, a throttle valve K6, a fourth-stage compressor 1-5, a throttle valve K7, a high-pressure gas storage unit 6-1, a throttle valve K8, a first-stage expander 4-1, a throttle valve K9, a second-stage expander 4-2, a throttle valve K12, a third-stage expander 4-3, a throttle valve K14, a fourth-stage expander 4-4 and a generator are connected in sequence to form a complete air flow path. During the energy storage process, as Figure 3 and Figure 4 shown, the air in the atmosphere enters the first-stage compressor 1-2 through the air filter 1-1 for compression. After compression, the temperature and pressure of the air rise. The high-pressure and high-temperature air output by the first compressor 1-2 recovers its heat through the heat exchanger 3-1 and stores the heat in the high-temperature heat storage unit 6-1. It is possible to decide whether to start the second, third, and fourth-stage compressors according to the input energy situation. Finally, the air output by the compressor can freely choose to enter the high-pressure gas storage unit 2-1 or the low-pressure gas storage unit 2-2 for storage.

[0090] Optionally, the gas storage assembly 2 includes: a high-pressure gas storage unit 2-1 and a medium-pressure gas storage unit 2-2. Among them, the first input end of the high-pressure gas storage unit 2-1 is connected to the other end of the fifth throttle valve K5, and the second input end of the high-pressure gas storage unit 2-1 is connected to the other end of the seventh throttle valve K7; the first input end of the medium-pressure gas storage unit 2-2 is connected to the other end of the fourth throttle valve K4, and the second input end of the medium-pressure gas storage unit 2-2 is connected to the other end of the second throttle valve K2.

[0091] Specifically, as Figure 2 shown, the gas storage assembly 2 includes two gas storage units, namely a high-pressure gas storage unit 2-1 and a medium-pressure gas storage unit 2-2. The high-pressure gas storage unit 2-1 is connected to the third-stage compressor through the throttle valve K5 and is connected to the fourth-stage compressor through the throttle valve K7. The medium-pressure gas storage unit 2-2 is connected to the first-stage compressor 1-2 through the throttle valve K2 and is connected to the second-stage compressor 1-3 through the throttle valve K4, and is respectively used to store the high-pressure gas and the medium-low pressure gas obtained by compressing through the compression assembly 1.

[0092] Optionally, the first heat exchange assembly 3 includes: a first heat exchanger 3-1, a second heat exchanger 3-2, a third heat exchanger 3-3, and a fourth heat exchanger 3-4. Among them, the first input end of the first heat exchanger 3-1 is connected to the first output end of the first-stage compressor 1-2 through the first input end of the first heat exchange assembly 3; the first input end of the second heat exchanger 3-2 is connected to the first output end of the second-stage compressor 1-3 through the first input end of the first heat exchange assembly 3; the first input end of the third heat exchanger 3-3 is connected to the first output end of the third-stage compressor 1-4 through the first input end of the first heat exchange assembly 3; the first input end of the fourth heat exchanger 3-4 is connected to the first output end of the fourth-stage compressor 1-5 through the first input end of the first heat exchange assembly 3.

[0093] Specifically, as Figure 2 shown, the first heat exchange assembly 3 includes multiple heat exchangers, namely the first heat exchanger 3-1, the second heat exchanger 3-2, the third heat exchanger 3-3, and the fourth heat exchanger 3-4. A heat exchanger is provided after each stage of the compressor to recover the heat generated during the compression process. This heat can be used to heat water or heat-conducting oil and stored in the high-temperature heat storage unit 6-1 to avoid energy loss.

[0094] Optionally, the expansion assembly 4 includes: a first-stage expander 4-1, a second-stage expander 4-2, a third-stage expander 4-3, a fourth-stage expander 4-4, an eighth throttle valve K8, a ninth throttle valve K9, a tenth throttle valve K10, an eleventh throttle valve K11, a twelfth throttle valve K12, a thirteenth throttle valve K13, a fourteenth throttle valve K14, and a fifteenth throttle valve K15. One end of the eighth throttle valve K8 is connected to the first output end of the high-pressure gas storage unit 2-1; the input end of the first-stage expander 4-1 is connected to the other end of the eighth throttle valve K8; one end of the ninth throttle valve K9 is connected to the output end of the first-stage expander 4-1; one end of the tenth throttle valve K10 is connected to the second output end of the high-pressure gas storage unit 2-1; the input ends of the second-stage expander 4-2 are respectively connected to the other ends of the ninth throttle valve K9 and the tenth throttle valve K10; one end of the eleventh throttle valve K11 is connected to the first output end of the medium-pressure gas storage unit 2-2, and the other end of the eleventh throttle valve K11 is connected to the first output end of the second-stage expander 4-2; one end of the twelfth throttle valve K12 is connected to the second output end of the second-stage expander 4-2; the first input end of the third-stage expander 4-3 is connected to the other end of the twelfth throttle valve K12; one end of the thirteenth throttle valve K13 is connected to the second output end of the medium-pressure gas storage unit 2-2, and the other end of the thirteenth throttle valve K13 is connected to the second input end of the third-stage expander 4-3; one end of the fourteenth throttle valve K14 is connected to the output end of the third-stage expander 4-3; the first input end of the fourth-stage expander 4-4 is connected to the other end of the fourteenth throttle valve K14, and the output end of the fourth-stage expander 4-4 is connected to the generator through the output end of the expansion assembly 4; one end of the fifteenth throttle valve K15 is connected to the third output end of the medium-pressure gas storage unit 2-2, and the other end of the fifteenth throttle valve K15 is connected to the second input end of the fourth-stage expander 4-4.

[0095] Specifically, as Figure 2As shown in the figure, the expansion assembly 4 includes a first-stage expander 4-1, a second-stage expander 4-2, a third-stage expander 4-3, a fourth-stage expander 4-4, an eighth throttle valve K8, a ninth throttle valve K9, a tenth throttle valve K10, an eleventh throttle valve K11, a twelfth throttle valve K12, a thirteenth throttle valve K13, a fourteenth throttle valve K14, and a fifteenth throttle valve K15. A throttle valve is connected between every two adjacent stages of expanders. The first-stage expander 4-1 is connected to the high-pressure gas storage unit 2-1 through the throttle valve K8. The second-stage expander 4-2 is connected to the high-pressure gas storage unit 2-1 through the throttle valve K10. The second-stage expander 4-2 is connected to the medium-pressure gas storage unit 2-2 through the throttle valve K11. The third-stage expander 4-3 is connected to the medium-pressure gas storage unit 2-2 through the throttle valve K13. The fourth-stage expander 4-4 is connected to the medium-pressure gas storage unit 2-2 through the throttle valve K15. The high-pressure gas storage unit 2-1 and the medium-pressure gas storage unit 2-2 can drive expanders of different grades. The expansion assembly 4 can flexibly adjust the operation of the four-stage expanders by controlling the opening and closing of the throttle valves according to the power demand of the power grid, and can also freely select the gas storage unit to avoid waste of gas pressure, which is beneficial for each stage of the expanders in the expansion assembly 4 to work at the rated working condition to a greater extent, thereby improving the operating efficiency of the entire system.

[0096] During the expansion power generation process, as Figure 5 and Figure 6 shown, the air in the high-pressure gas storage unit 2-1 or the low-pressure gas storage unit 2-2 can be utilized. According to the power demand of the power grid, the opening of each throttle valve and each stage of expander is determined. The air is first heated in the heat exchanger and then enters the corresponding expander to perform expansion work. The pressure and temperature of the gas decrease, and finally the generator is driven to generate electricity and is discharged into the atmosphere.

[0097] Optionally, the second heat exchange assembly 5 includes: a fifth heat exchanger 5-1, a sixth heat exchanger 5-2, a seventh heat exchanger 5-3, and an eighth heat exchanger 5-4. Among them, the first output end of the fifth heat exchanger 5-1 is connected to the input end of the first-stage expander 4-1 through the first output end of the second heat exchange assembly 5. The first output end of the sixth heat exchanger 5-2 is connected to the input end of the second-stage expander 4-2 through the first output end of the second heat exchange assembly 5. The first output end of the seventh heat exchanger 5-3 is connected to the first input end of the third-stage expander 4-3 through the first output end of the second heat exchange assembly 5. The first output end of the eighth heat exchanger 5-4 is connected to the first input end of the fourth-stage expander 4-4 through the first output end of the second heat exchange assembly 5.

[0098] As Figure 2As shown, the second heat exchange assembly 5 includes a plurality of heat exchangers, namely, the fifth heat exchanger 5-1, the sixth heat exchanger 5-2, the seventh heat exchanger 5-3, and the eighth heat exchanger 5-4. A heat exchanger is provided at the inlet of each stage of expander, and the recovered waste heat can be used to heat the gas during the expansion process, thereby improving the operating efficiency of the system.

[0099] Optionally, the types of the first to eighth heat exchangers are at least one of cross-flow type, hairpin type, and fixed tube sheet type.

[0100] It can be understood that there are many types of heat exchangers, including but not limited to cross-flow type, hairpin type, and fixed tube sheet type. Among them, the cross-flow heat exchanger realizes the uniform transfer of heat through the alternating diversion and recombination mixing process of the fluid between the shell and the tube bundle; the hairpin heat exchanger adopts a spiral hairpin tube design to improve the heat transfer efficiency and meet the requirements of energy conservation and environmental protection; the fixed tube sheet heat exchanger has the advantages of simple structure and low manufacturing cost, but it is more difficult to clean the shell side. The selection and application of the heat exchanger can be comprehensively considered according to specific process conditions, fluid properties, heat transfer requirements and other factors.

[0101] Optionally, the heat storage assembly 6 includes: a high-temperature heat storage unit 6-1 and a low-temperature heat storage unit 6-2. Among them, the input end of the high-temperature heat storage unit 6-1 is connected to the output ends of the first to fourth heat exchangers 3-1 to 3-4 through the first input end of the heat storage assembly 6 and the output end of the first heat exchange assembly 3, and the second output end of the high-temperature heat storage unit 6-1 is connected to the second input ends of the fifth to eighth heat exchangers 5-1 to 5-4 through the second output end of the heat storage assembly 6 and the input end of the second heat exchange assembly 5; the output end of the low-temperature heat storage unit 6-2 is connected to the second input ends of the first to fourth heat exchangers 3-1 to 3-4 through the first output end of the heat storage assembly 6 and the second input end of the first heat exchange assembly 3, and the second input end of the low-temperature heat storage unit 6-2 is connected to the second output ends of the fifth to eighth heat exchangers 5-1 to 5-4 through the second input end of the heat storage assembly 6 and the second output end of the second heat exchange assembly 5.

[0102] Specifically, as Figure 2As shown, the heat storage assembly 6 includes a high-temperature heat storage unit 6-1 and a low-temperature heat storage unit 6-2, namely a high-temperature heat storage tank and a low-temperature heat storage tank. The high-temperature heat storage unit 6-1 can be connected to the first-stage compressor 1-2 through the first heat exchanger 3-1, and connected to the second-stage compressor 1-3 through the second heat exchanger 3-2, and connected to the third-stage compressor 1-4 through the third heat exchanger 3-3, and connected to the fourth-stage compressor 1-5 through the fourth heat exchanger 3-4. The low-temperature heat storage unit 6-2 can be connected to the first-stage expander 4-1 through the fifth heat exchanger 5-1, and connected to the second-stage expander 4-2 through the sixth heat exchanger 5-2, and connected to the third-stage expander 4-3 through the seventh heat exchanger 5-3, and connected to the fourth-stage expander 4-4 through the eighth heat exchanger 5-4. When the gas in the gas storage assembly 2 drives the expansion assembly 4 to generate electricity, it can consume the heat in the high-temperature heat storage unit 6-1, and the heat with reduced temperature finally returns to the low-temperature heat storage unit 6-2.

[0103] Optionally, the waste heat ORC power generation and external heat supply assembly 7 includes: a hot water delivery unit 7-1, an evaporation unit 7-2, a first ORC turbine 7-3, an ORC generator 7-4, and a second ORC turbine 7-5. Among them, the input end of the hot water delivery unit 7-1 is connected to the first output end of the high-temperature heat storage unit 6-1 through the third output end of the heat storage assembly 6; the first input end of the evaporation unit 7-2 is connected to the output end of the hot water delivery unit 7-1; the input end of the first ORC turbine 7-3 is connected to the first output end of the evaporation unit 7-2; one end of the ORC generator 7-4 is connected to the input end of the first ORC turbine 7-3; the input end of the second ORC turbine 7-5 is connected to the first output end of the evaporation unit 7-2, and the output end of the second ORC turbine 7-5 is respectively connected to the other end of the ORC generator 7-4 and the output end of the first ORC turbine 7-3.

[0104] Optionally, the waste heat ORC power generation and external heat supply assembly 7 further includes: a condensation unit 7-6, a working fluid pump 7-7, a preheater 7-8, and a heat load 7-9. Among them, the input end of the condensation unit 7-6 is respectively connected to the output end of the first ORC turbine 7-3 and the output end of the second ORC turbine 7-5; the input end of the working fluid pump 7-7 is connected to the output end of the condensation unit 7-6; the first input end of the preheater 7-8 is connected to the output end of the working fluid pump 7-7, the first output end of the preheater 7-8 is connected to the second input end of the evaporation unit 7-2, and the second input end of the preheater 7-8 is connected to the second output end of the evaporation unit 7-2; the input end of the heat load 7-9 is connected to the second output end of the preheater 7-8, and the output end of the heat load 7-9 is connected to the third input end of the low-temperature heat storage unit 6-2.

[0105] Specifically, as Figure 2As shown in the figure, the waste heat ORC power generation and external heat supply component 7 includes a hot water delivery unit 7-1 (i.e., a hot water delivery pump), an evaporation unit 7-2 (i.e., an evaporator), a first ORC turbine 7-3, an ORC generator 7-4, a second ORC turbine 7-5, a condensation unit 7-6 (i.e., a condenser), a working fluid pump 7-7, a preheater 7-8, and a heat load 7-9. The high-temperature heat storage unit 6-1 is connected to the hot water delivery unit 7-1. The hot water delivery unit 7-1 is connected to the evaporation unit 7-2. The first ORC turbine 7-3 and the second ORC turbine 7-5 are connected to both sides of the ORC generator 7-4. The first ORC turbine 7-3 is also connected to the evaporation unit 7-2. The second ORC turbine 7-5 is also sequentially connected to the condensation unit 7-6, the working fluid pump 7-7, and the preheater 7-8 to achieve the overall internal interconnection of the waste heat ORC power generation and external heat supply component 7. Among them, the hot water delivery unit 7-1 can control the power generation amount and the external heat supply amount of the waste heat ORC power generation and external heat supply component 7 by adjusting the flow rate of hot water, realizing the balance between supply and demand. The high-temperature hot water that has absorbed heat first flows through the evaporation unit 7-2. The preheater 7-8 provides heat for power generation and supplies heat to the external heat load through the external heat supply loop, realizing the efficient utilization of energy.

[0106] During the waste heat ORC power generation and external heat supply process, the cold water in the low-temperature heat storage unit 6-2 is transported to the first heat exchange component 3 to absorb the compression heat, forming high-temperature hot water and storing it in the high-temperature heat storage unit 6-1. Then, it is sent into the evaporation unit 7-2 and the preheater 7-8 of the ORC power generation system by the hot water delivery unit 7-1 to heat the liquid working fluid to form a gaseous working fluid. The gaseous working fluid enters the first ORC turbine 7-3 and the second ORC turbine 7-5 to expand and do work, driving the ORC generator 7-4 to generate electricity. Then, it enters the condensation unit 7-6 and condenses into a liquid working fluid. Then, it is sent into the preheater 7-8 by the working fluid pump 7-7, and the liquid working fluid in the preheater 7-8 is sent to the external heat load 7-9 for heat supply. The main function of the ORC turbine is to expand the high-temperature and high-pressure steam generated by the working fluid heated through the heat exchanger, thereby converting thermal energy into mechanical energy and driving the ORC generator 7-4 to generate electricity.

[0107] According to the compressed air energy storage system for waste heat recovery and utilization proposed by the embodiment of the present invention, air is compressed by a compression component, the compressed gas is stored through a gas storage component connected to the compression component, and the liquid working fluid is heated to form a gaseous working fluid through a waste heat ORC power generation and external heat supply component connected to a heat storage component. After the gaseous working fluid expands and does work, it is re-condensed into a liquid working fluid to supply heat to the outside. Thus, through this compressed air energy storage system for waste heat recovery and utilization, problems such as the fixed topological structure, single operation mode, narrow operation conditions, and low system efficiency of the existing compressed air energy storage system are solved, the operation conditions are broadened, and the efficiency of the compressed air energy storage system is improved.

[0108] Furthermore, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0109] In the description of this specification, the description with reference to terms such as "an embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0110] Although the embodiments of the present utility model have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present utility model. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present utility model.

Claims

1. A compressed air energy storage system for waste heat recovery, characterized in that: include: Compression component, gas storage component, first heat exchange component, expansion component, second heat exchange component, heat storage component and waste heat ORC power generation and external heat supply component, among which, The compression assembly is used to compress gas; The gas storage component is connected to the compression component and is used to store compressed gas; The first input end of the first heat exchange component is connected to the compression component, the second input end of the first heat exchange component is connected to the first output end of the heat storage component, and the output end of the first heat exchange component is connected to the first input end of the heat storage component, so as to store the heated liquid working medium in the heat storage component through the first input end of the heat storage component after heat exchange with the compressed gas; The input end of the second heat exchange component is connected to the second output end of the heat storage component, the first output end of the second heat exchange component is connected to the input end of the expansion component, and the second output end of the second heat exchange component is connected to the second input end of the heat storage component; The input end of the expansion assembly is connected to the gas storage assembly, and the output end of the expansion assembly is connected to the generator; The waste heat ORC power generation and external heat supply component is connected to the third output end of the heat storage component, and is used to heat the liquid working medium to form a gaseous working medium, and after the gaseous working medium is expanded to do work, it is re-condensed to form the liquid working medium to provide heat to the outside.

2. The compressed air energy storage system for waste heat recovery according to claim 1 is characterized in that: The compression component comprises: An air filter, wherein the air filter is in contact with the outside atmosphere; a first-stage compressor, wherein an input end of the first-stage compressor is connected to the air filter; a first throttle valve, one end of which is connected to a first output end of the first-stage compressor; a second throttle valve, one end of which is connected to a second output end of the first-stage compressor; a second-stage compressor, wherein an input end of the second-stage compressor is connected to the other end of the first throttle valve; a third throttle valve, one end of the third throttle valve being connected to the first output end of the second-stage compressor; a fourth throttle valve, one end of which is connected to the second output end of the second-stage compressor; a third-stage compressor, wherein an input end of the third-stage compressor is connected to the other end of the third throttle valve; a fifth throttle valve, one end of which is connected to the first output end of the third-stage compressor; a sixth throttle valve, one end of which is connected to the second output end of the third-stage compressor; a fourth-stage compressor, wherein an input end of the fourth-stage compressor is connected to the other end of the sixth throttle valve; A seventh throttle valve, one end of which is connected to the first output end of the fourth-stage compressor.

3. The compressed air energy storage system for waste heat recovery according to claim 2 is characterized in that: The gas storage assembly comprises: A high-pressure gas storage unit, wherein a first input end of the high-pressure gas storage unit is connected to the other end of the fifth throttle valve, and a second input end of the high-pressure gas storage unit is connected to the other end of the seventh throttle valve; A medium-pressure gas storage unit, wherein a first input end of the medium-pressure gas storage unit is connected to the other end of the fourth throttle valve, and a second input end of the medium-pressure gas storage unit is connected to the other end of the second throttle valve.

4. The compressed air energy storage system for waste heat recovery according to claim 3 is characterized in that: The first heat exchange component comprises: a first heat exchanger, wherein a first input end of the first heat exchanger is connected to a first output end of the first stage compressor through a first input end of the first heat exchange assembly; a second heat exchanger, wherein a first input end of the second heat exchanger is connected to a first output end of the second-stage compressor through a first input end of the first heat exchange assembly; a third heat exchanger, wherein a first input end of the third heat exchanger is connected to a first output end of the third-stage compressor through a first input end of the first heat exchange assembly; A fourth heat exchanger, wherein a first input end of the fourth heat exchanger is connected to a first output end of the fourth-stage compressor through a first input end of the first heat exchange component.

5. The compressed air energy storage system for waste heat recovery according to claim 4 is characterized in that: The expansion assembly comprises: an eighth throttle valve, one end of which is connected to the first output end of the high-pressure gas storage unit; a first-stage expander, wherein an input end of the first-stage expander is connected to the other end of the eighth throttle valve; a ninth throttle valve, one end of which is connected to the output end of the first-stage expander; a tenth throttle valve, one end of which is connected to the second output end of the high-pressure gas storage unit; a second-stage expander, wherein an input end of the second-stage expander is respectively connected to the other end of the ninth throttle valve and the other end of the tenth throttle valve; an eleventh throttle valve k, one end of the eleventh throttle valve being connected to the first output end of the medium-pressure gas storage unit, and the other end of the eleventh throttle valve being connected to the first output end of the second-stage expander; a twelfth throttle valve, one end of which is connected to the second output end of the second-stage expander; a third-stage expander, wherein a first input end of the third-stage expander is connected to the other end of the twelfth throttle valve; a thirteenth throttle valve, one end of the thirteenth throttle valve being connected to the second output end of the medium-pressure gas storage unit, and the other end of the thirteenth throttle valve being connected to the second input end of the third-stage expander; a fourteenth throttle valve, one end of which is connected to the output end of the third-stage expander; a fourth-stage expander, wherein a first input end of the fourth-stage expander is connected to the other end of the fourteenth throttle valve, and an output end of the fourth-stage expander is connected to the generator through an output end of the expansion assembly; A fifteenth throttle valve, one end of the fifteenth throttle valve is connected to the third output end of the medium-pressure gas storage unit, and the other end of the fifteenth throttle valve is connected to the second input end of the fourth-stage expander.

6. The compressed air energy storage system for waste heat recovery according to claim 5 is characterized in that: The second heat exchange component comprises: a fifth heat exchanger, wherein a first output end of the fifth heat exchanger is connected to an input end of the first-stage expander through a first output end of the second heat exchange assembly; a sixth heat exchanger, wherein a first output end of the sixth heat exchanger is connected to an input end of the second-stage expander through a first output end of the second heat exchange assembly; a seventh heat exchanger, wherein a first output end of the seventh heat exchanger is connected to a first input end of the third-stage expander through a first output end of the second heat exchange assembly; An eighth heat exchanger, wherein a first output end of the eighth heat exchanger is connected to a first input end of the fourth-stage expander through a first output end of the second heat exchange assembly.

7. The compressed air energy storage system for waste heat recovery according to claim 6 is characterized in that: The heat storage component comprises: A high-temperature heat storage unit, wherein the input end of the high-temperature heat storage unit is connected to the output ends of the first to fourth heat exchangers through the first input end of the heat storage component and the output end of the first heat exchange component, and the second output end of the high-temperature heat storage unit is connected to the second input ends of the fifth to eighth heat exchangers through the second output end of the heat storage component and the input end of the second heat exchange component; A low-temperature heat storage unit, wherein the output end of the low-temperature heat storage unit is connected to the second input ends of the first to fourth heat exchangers through the first output end of the heat storage component and the second input end of the first heat exchange component, and the second input end of the low-temperature heat storage unit is connected to the second output ends of the fifth to eighth heat exchangers through the second input end of the heat storage component and the second output end of the second heat exchange component.

8. The compressed air energy storage system for waste heat recovery according to claim 7 is characterized in that: The waste heat ORC power generation and external heat supply components include: A hot water delivery unit, wherein the input end of the hot water delivery unit is connected to the first output end of the high-temperature heat storage unit through the third output end of the heat storage assembly; an evaporation unit, wherein a first input end of the evaporation unit is connected to an output end of the hot water delivery unit; a first ORC turbine, wherein an input end of the first ORC turbine is connected to a first output end of the evaporation unit; an ORC generator, one end of the ORC generator being connected to an input end of the first ORC turbine; A second ORC turbine, wherein an input end of the second ORC turbine is connected to the first output end of the evaporation unit, and an output end of the second ORC turbine is respectively connected to the other end of the ORC generator and the output end of the first ORC turbine.

9. The compressed air energy storage system for waste heat recovery according to claim 8, characterized in that: The waste heat ORC power generation and external heat supply component also includes: a condensing unit, wherein an input end of the condensing unit is connected to an output end of the first ORC turbine and an output end of the second ORC turbine respectively; A working fluid pump, wherein an input end of the working fluid pump is connected to an output end of the condensing unit; A preheater, wherein a first input end of the preheater is connected to an output end of the working fluid pump, a first output end of the preheater is connected to a second input end of the evaporation unit, and a second input end of the preheater is connected to a second output end of the evaporation unit; A heat load, wherein the input end of the heat load is connected to the second output end of the preheater, and the output end of the heat load is connected to the third input end of the low-temperature heat storage unit.

10. The compressed air energy storage system for waste heat recovery according to claim 9, characterized in that: The types of the first to eighth heat exchangers are at least one of a cross-flow type, a hairpin type and a fixed tube sheet type.

Images