Air energy storage system utilizing ethylene gasification heat

Abstract

The utility model provides an air energy storage system utilizing ethylene gasification heat, which comprises an air compression subsystem, a liquid ethylene cold energy utilization subsystem and an air liquefaction subsystem, the liquid ethylene cold energy utilization subsystem is used for cooling compressed air by utilizing cold energy generated by gasification of liquid ethylene so as to fill up a cold capacity gap of air liquefaction, the air liquefaction subsystem is used for liquefying and storing the cooled air, and the liquid ethylene cold energy utilization subsystem comprises an ethylene conveying pipeline; the liquid ethylene cold energy cold storage heat exchanger is communicated with the ethylene conveying pipeline, the compressed air cooling heat exchanger is used for cooling compressed air, and the cold storage working medium circulation loop is used for transmitting cold energy of the liquid ethylene cold energy cold storage heat exchanger to the compressed air cooling heat exchanger; recovery of ethylene regasification waste cold and the requirement of a liquid air energy storage system for the cooling capacity can be met at the same time, and the overall round-trip efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of utilization and energy storage of ethylene gasification heat, and in particular to an air energy storage system utilizing the ethylene gasification heat. Background Art

[0002] Against the backdrop of expanding demand for clean energy, renewable energy generation technology is developing rapidly. However, the unpredictability and volatility of renewable energy power can have an impact on the power grid, threatening its stable operation.

[0003] Energy storage technology is the key to solving the impact of new energy power grid connection. Energy storage technology absorbs new energy power or low-cost grid power and releases power at the right time, which can not only eliminate the volatility of new energy power, but also achieve power peak regulation.

[0004] Existing energy storage technologies that can be connected to the grid on a large scale include compressed air energy storage and pumped storage. Compressed air energy storage uses the compression / expansion process of air to store / release electrical energy. Pumped storage absorbs electrical energy through water pumps to pump water to high-level reservoirs for storage, and releases electrical energy by driving generators through water release. However, both compressed air energy storage and pumped storage technologies are constrained by geographical conditions and their development is limited: compressed air energy storage relies on large-capacity gas storage space, such as abandoned mines and salt caverns; pumped storage relies on high-low terrain differences.

[0005] Liquid air energy storage technology is a new energy storage technology developed on the basis of compressed air energy storage technology. It uses liquid air as a medium to store electrical energy, greatly reducing the demand for gas storage space and overcoming the limitations of geographical conditions. However, there is a cold capacity gap in liquid air energy storage technology, which leads to a low air liquefaction rate and overall round-trip efficiency. External cold energy needs to be introduced to increase the liquefaction rate, thereby improving the overall round-trip efficiency.

[0006] Existing research on the coupling system of liquid air energy storage and external cold energy mainly focuses on the introduction of liquefied natural gas regasification cold energy, while there is less research on other external cold energy, such as the regasification cold energy of liquid ethylene. Liquid ethylene is usually regasified by direct heating of low-temperature steam. In this process, the cold energy of liquid ethylene is not reasonably utilized, and a large amount of cold energy is wasted. At the same time, a large amount of steam heat is consumed, resulting in a double loss of cold energy and heat energy. Utility Model Content

[0007] The purpose of the utility model is to solve the technical problem that in the prior art, liquid ethylene is usually directly heated by low-temperature steam to achieve regasification, in which the cold energy of the liquid ethylene is not reasonably utilized, the cold energy is wasted in large quantities, and there is a cold energy gap in the liquid air energy storage technology, which leads to low air liquefaction rate and overall round-trip efficiency. It is necessary to introduce external cold energy to improve the liquefaction rate.

[0008] In order to solve the above technical problems, the utility model provides an air energy storage system utilizing the heat of ethylene vaporization, which comprises: an air compression subsystem, a liquid ethylene cold energy utilization subsystem and an air liquefaction subsystem, wherein the air compression subsystem draws air from the outside and compresses the air to a target pressure, the liquid ethylene cold energy utilization subsystem utilizes the cold energy of liquid ethylene vaporization to cool the compressed air to fill the cold capacity gap of air liquefaction, and the air liquefaction subsystem liquefies the cooled air for storage, wherein the liquid ethylene cold energy utilization subsystem comprises an ethylene delivery pipeline, a liquid ethylene cold energy storage heat exchanger connected to the ethylene delivery pipeline, a compressed air cooling heat exchanger for cooling the compressed air, and a cold storage working medium circulation loop for transmitting the cold energy of the liquid ethylene cold energy storage heat exchanger to the compressed air cooling heat exchanger, and the cold storage working medium circulation loop stores and utilizes the cold energy of ethylene.

[0009] Furthermore, the liquid ethylene cold energy storage heat exchanger has a first heat exchange side and a second heat exchange side, the ethylene delivery pipeline is connected to the first heat exchange side pipeline, the compressed air cooling heat exchanger has a third heat exchange side and a fourth heat exchange side, the second heat exchange side and the third heat exchange side are connected by pipeline, the second heat exchange side and the third heat exchange side constitute a cold storage working medium circulation loop, the output end of the air compression subsystem is connected to the input end pipeline of the fourth heat exchange side, and the output end of the fourth heat exchange side is connected to the air liquefaction subsystem pipeline.

[0010] Furthermore, the cold storage working medium circulation loop also includes a first low-temperature storage tank, a circulation pump and a first high-temperature storage tank. The low-temperature cold storage working medium output from the second heat exchange side is led to the first low-temperature storage tank, the low-temperature cold storage working medium of the first low-temperature storage tank is led to the input end of the third heat exchange side, the high-temperature cold storage working medium after heat exchange output from the output end of the third heat exchange side is led to the first high-temperature storage tank, the high-temperature cold storage working medium of the first high-temperature storage tank is led to the input end of the second heat exchange side, and the circulation pump is used to drive the cold storage working medium to circulate in the cold storage working medium circulation loop.

[0011] Furthermore, it also includes an external heat source utilization subsystem, the input end of the external heat source utilization subsystem is connected to the output end pipeline of the air liquefaction subsystem, and the external heat source utilization subsystem uses the heat of the external heat source to heat the high-pressure and low-temperature air passed through the air liquefaction subsystem to high-pressure and high-temperature air.

[0012] Furthermore, it also includes an air turbine, the input end of the air turbine is connected to the output end pipeline of the external heat source utilization subsystem.

[0013] Furthermore, the external heat source utilization subsystem includes an external heat source, a heat storage working fluid circulation loop and an engine. The heat storage working fluid circulation loop stores and utilizes the heat of the external heat source. The heat absorption end of the engine is connected to the external heat source through the heat storage working fluid circulation loop, and the cold absorption end of the engine is connected to the output end of the air liquefaction subsystem.

[0014] Furthermore, the heat storage medium circulation loop includes a second low-temperature storage tank, a second high-temperature storage tank and a second circulation pump, the outlet of the external heat source is connected to the inlet pipeline of the second high-temperature storage tank, the outlet of the second high-temperature storage tank is connected to the input pipeline of the heat absorption end of the engine, the outlet of the engine is connected to the inlet pipeline of the second low-temperature storage tank, and the outlet of the second low-temperature storage tank is connected to the inlet pipeline of the external heat source.

[0015] Furthermore, it also includes a heat exchange heater, which has more than two heat exchange sides, the inlet of one heat exchange side of the heat exchange heater is connected to the outlet pipeline of the second high-temperature storage tank, and the outlet of the heat exchange side opposite to the inlet is connected to the inlet pipeline of the heat absorption end of the engine; the inlet of the other heat exchange side of the heat exchange heater is connected to the outlet pipeline of the cold absorption end of the engine, and the outlet of the heat exchange side opposite to the inlet is connected to the inlet pipeline of the air turbine.

[0016] Furthermore, the compressed air cooling heat exchanger also includes a fifth heat exchange side, the inlet of the fifth heat exchange side is connected to the air liquefaction subsystem pipeline, and the reflux cold air generated by the air liquefaction subsystem during the gas liquefaction process flows to the fifth heat exchange side.

[0017] Furthermore, it also includes a pre-compression air cooling heat exchanger, which uses the cold energy of ethylene and the cold energy of the air liquefaction subsystem to cool the air before compression. The air cooling heat exchanger has a sixth heat exchange side, a seventh heat exchange side and an eighth heat exchange side. The inlet of the sixth heat exchanger is connected to the outlet pipeline of the first low-temperature storage tank, the outlet of the sixth heat exchanger is connected to the inlet pipeline of the first high-temperature storage tank, the inlet of the seventh heat exchange side is connected to the atmospheric environment, the outlet of the seventh heat exchange side is connected to the inlet pipeline of the air compression subsystem, the inlet of the eighth heat exchange side is connected to the outlet pipeline of the fifth heat exchange side, and the outlet of the eighth heat exchange side is connected to the atmospheric environment.

[0018] It can be seen from the above technical solution that the beneficial effects of the utility model are: it can simultaneously meet the recovery of waste cold from ethylene regasification and the demand for cold capacity of the liquid air energy storage system, thereby improving the overall round-trip efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of an air energy storage system utilizing heat of ethylene gasification provided in the present application. DETAILED DESCRIPTION

[0020] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations therein are essentially for illustrative purposes rather than for limiting the present invention.

[0021] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0022] In order to further illustrate the principle and structure of the present utility model, the preferred embodiments of the present utility model are now described in detail with reference to the accompanying drawings.

[0023] See also Figure 1 , an air energy storage system utilizing ethylene vaporization heat provided in this embodiment, includes an air compression subsystem 100, a liquid ethylene cold energy utilization subsystem 200, an air liquefaction subsystem 300, an external heat source utilization subsystem 400, and an air expansion subsystem 500.

[0024] The air compression subsystem 100 includes an air compressor 3. The air compressor 3 is used to compress air to a target pressure. The inlet stream of the air compressor 3 is the normal pressure cold air at the outlet of the seventh heat exchange side H7 of the liquid ethylene cold energy utilization subsystem 200, the outlet stream of the air compressor 3 is high pressure near normal temperature air, and the outlet of the air compressor 3 is connected to the inlet of the fourth heat exchange side H4 of the liquid ethylene cold energy utilization subsystem 200.

[0025] The liquid ethylene cold energy utilization subsystem 200 includes a liquid ethylene cold energy storage heat exchanger 6, a compressed air cooling heat exchanger 4, an ethylene low-grade cold energy absorption heat exchanger 7, a pre-compression air cooling heat exchanger 2, a cold user 13, low-temperature liquid ethylene 5, intermediate-cooled ethylene, normal temperature gaseous ethylene 8, a first low-temperature storage tank 9, a first high-temperature storage tank 11, a first circulating pump 10, a cold medium 12, normal temperature and pressure air, normal pressure cold air, high-pressure near-normal temperature air, high-pressure cold air, reverse cold air, reverse intermediate-cooled air and reverse normal temperature air 14.

[0026] The liquid ethylene cold energy storage heat exchanger 6 includes a first heat exchange side H1 and a second heat exchange side H2. The inlet stream of the first heat exchange side H1 of the liquid ethylene cold energy storage heat exchanger 6 is the low-temperature liquid ethylene 5 that needs to be gasified during the all-weather period, the outlet stream of the first heat exchange side H1 is the medium-cooled ethylene, and the outlet of the first heat exchange side H1 is connected to the inlet of the ninth heat exchange side H9 of the ethylene low-grade cold energy absorption heat exchanger 7. The inlet of the second heat exchange side H2 is connected to the outlet of the first high-temperature storage tank 11, the inlet stream of the second heat exchange side H2 is a high-temperature cold storage medium, the outlet stream of the second heat exchange side H2 is a low-temperature cold storage medium, and the outlet of the second heat exchange side H2 is connected to the inlet of the first low-temperature storage tank 9. The outlet of the first low-temperature storage tank 9 is connected to the inlet of the first circulating pump 10. The outlet stream of the first circulating pump 10 is divided into multiple streams, one of which is connected to the inlet of the third heat exchange side H3 of the compressed air cooling heat exchanger 4, and the remaining streams are connected to the inlet of the sixth heat exchange side H6 of the pre-compression air cooler. The compressed air cooling heat exchanger 4 includes a third heat exchange side H3, a fifth heat exchange side H5, and a fourth heat exchange side H4. The inlet stream of the third heat exchange side H3 is a low-temperature cold storage medium, and the outlet stream of the third heat exchange side H3 is a high-temperature cold storage medium. The outlet of the third heat exchange side H3 is connected to the inlet of the first high-temperature storage tank 11. The inlet of the fifth heat exchange side H5 is connected to the outlet of the twelfth heat exchange side H12 of the air liquefaction subsystem 300, the inlet stream of the fifth heat exchange side H5 is the counterflow cold air from the outlet of the twelfth heat exchange side H12 of the air liquefaction subsystem 300, the outlet of the fifth heat exchange side H5 is the counterflow medium cold air, and the outlet of the fifth heat exchange side H5 is connected to the inlet of the eighth heat exchange side H8 of the pre-compression air cooling heat exchanger 2. The inlet of the fourth heat exchange side H4 is connected to the outlet of the air compressor 3 of the air compression subsystem 100, the inlet stream of the fourth heat exchange side H4 is high-pressure near-normal temperature air, the outlet stream of the fourth heat exchange side H4 is high-pressure cold air, and the outlet of the fourth heat exchange side H4 is connected to the inlet of the eleventh heat exchange side H11 of the air liquefaction subsystem 300. The pre-compression air cooling heat exchanger 2 includes a sixth heat exchange side H6, an eighth heat exchange side H8 and a seventh heat exchange side H7. The inlet of the sixth heat exchange side H6 is connected to the remaining streams in the outlet of the first circulation pump 10, the inlet stream of the sixth heat exchange side H6 is a low-temperature cold storage medium, the outlet stream of the sixth heat exchange side H6 is a high-temperature cold storage medium, and the outlet of the sixth heat exchange side H6 is connected to the inlet of the first high-temperature storage tank 11.The inlet of the eighth heat exchange side H8 is connected to the outlet of the fifth heat exchange side H5 of the compressed air cooling heat exchanger 4, the inlet stream of the eighth heat exchange side H8 is the counterflow medium cold air, the outlet stream of the eighth heat exchange side H8 is the counterflow normal temperature air 14, and the eighth heat exchange side H8 leads to the atmosphere. The inlet of the seventh heat exchange side H7 is connected to the atmosphere, the inlet stream of the seventh heat exchange side H7 is the normal temperature and pressure air, the outlet stream of the seventh heat exchange side H7 is the normal pressure cold air, and the outlet of the seventh heat exchange side H7 is connected to the inlet of the air compressor 3.

[0027] The ethylene low-grade cold energy absorption heat exchanger 7 includes a ninth heat exchange side H9 and a tenth heat exchange side H10. The ninth heat exchange side H9 is the heat absorption side of the intermediate cooling ethylene, and the tenth heat exchange side H10 is the heat release side of the cold delivery medium 12. The inlet of the ninth heat exchange side H9 is connected to the outlet of the first heat exchange side H1, the inlet stream of the ninth heat exchange side H9 is intermediate cooling ethylene, the outlet of the ninth heat exchange side H9 is normal temperature gaseous ethylene 8, and the outlet of the ninth heat exchange side H9 leads to the downstream gaseous ethylene user. The outlet of the tenth heat exchange side H10 is connected to the inlet of the cold user 13, and the inlet of the tenth heat exchange side H10 is connected to the outlet of the cold user 13.

[0028] The air liquefaction subsystem 300 includes a cold storage / release heat exchanger 15, a low-temperature turbine 16, a gas-liquid separator 17, a low-temperature liquid air storage tank 18, and a low-temperature pump 19. The cold storage / release heat exchanger 15 includes an eleventh heat exchange side H11, a twelfth heat exchange side H12, and a thirteenth heat exchange side H13. The inlet of the eleventh heat exchange side H11 is connected to the outlet of the fourth heat exchange side H4, the inlet stream of the eleventh heat exchange side H11 is high-pressure cold air, the outlet stream of the eleventh heat exchange side H11 is high-pressure low-temperature air, and the outlet of the eleventh heat exchange side H11 is connected to the inlet of the low-temperature turbine 16. The outlet of the low-temperature turbine 16 is connected to the inlet of the gas-liquid separator 17. The gas phase outlet of the gas-liquid separator 17 is counter-flow low-temperature air, the gas phase outlet of the gas-liquid separator 17 is connected to the inlet of the twelfth heat exchange side H12, the liquid phase outlet of the gas-liquid separator 17 is low-temperature liquid air, and the liquid phase outlet of the gas-liquid separator 17 is connected to the inlet of the low-temperature liquid air storage tank 18. The inlet of the twelfth heat exchange side H12 is connected to the gas phase outlet of the gas-liquid separator 17, the inlet stream of the twelfth heat exchange side H12 is counter-flow low-temperature air, the outlet stream of the twelfth heat exchange side H12 is counter-flow cold air, and the outlet of the twelfth heat exchange side H12 is connected to the inlet of the fifth heat exchange side H5. The outlet stream of the low-temperature liquid air storage tank 18 is low-temperature liquid air, and the outlet of the low-temperature liquid air storage tank 18 is connected to the inlet of the low-temperature pump 19. The outlet stream of the low-temperature pump 19 is low-temperature high-pressure liquid air, and the outlet of the low-temperature pump 19 is connected to the inlet of the thirteenth heat exchange side H13. The inlet flow of the thirteenth heat exchange side H13 is low-temperature and high-pressure liquid air, the outlet flow of the thirteenth heat exchange side H13 is gaseous high-pressure cold air, and the outlet of the thirteenth heat exchange side H13 is connected to the inlet of the fourteenth heat exchange side H14 of the engine 20 in the external heat source utilization subsystem 400.

[0029] The external heat source utilization subsystem 400 includes an external heat source 23 , a second low-temperature storage tank 21 , a second high-temperature storage tank 24 , a second circulation pump 22 , a heat exchange heater 25 and an engine 20 .

[0030] The inlet of the external heat source 23 is connected to the outlet of the second circulation pump 22, and the outlet of the external heat source 23 is connected to the inlet of the second high temperature storage tank 24. The outlet of the second high temperature storage tank 24 is connected to the inlet of the seventeenth heat exchange side H17 of the heat exchange heater 25. The outlet of the seventeenth heat exchange side H17 of the heat exchange heater 25 is connected to the inlet of the fifteenth heat exchange side H15 of the engine 20. The outlet of the fifteenth heat exchange side H15 of the engine 20 is connected to the inlet of the second low temperature storage tank 21. The outlet of the second low temperature storage tank 21 is connected to the inlet of the second circulation pump 22. The inlet of the fourteenth heat exchange side H14 of the engine 20 is connected to the outlet of the thirteenth heat exchange side H13 of the air liquefaction subsystem 300. The outlet of the fourteenth heat exchange side H14 of the engine 20 is connected to the inlet of the sixteenth heat exchange side H16 of the heat exchange heater 25. The outlet of the sixteenth heat exchange side H16 of the heat exchange heater 25 is connected to the inlet of the air turbine 26 of the air expansion subsystem 500 .

[0031] The second low-temperature storage tank 21 and the second high-temperature storage tank 24 are used to store the heat storage medium before and after the external heat source 23 absorbs heat, and the second circulation pump 22 provides circulation power for the circulation process of the heat storage medium. The external heat source 23 is used to provide heat to heat the circulating heat storage medium. The inlet stream of the external heat source 23 is the low-temperature heat storage medium, and the outlet stream of the external heat source 23 is the high-temperature heat storage medium. The heat exchange heater 25 includes a sixteenth heat exchange side H16 and a seventeenth heat exchange side H17. The seventeenth heat exchange side H17 is the heat release side of the high-temperature heat storage medium, the inlet stream of the seventeenth heat exchange side H17 is the high-temperature heat storage medium, and the outlet stream of the seventeenth heat exchange side H17 is the medium-temperature heat storage medium. The sixteenth heat exchange side H16 is the heat absorption side before the air expands, the inlet stream of the sixteenth heat exchange side H16 is the medium-temperature high-pressure air, and the outlet stream of the sixteenth heat exchange side H16 is the high-temperature high-pressure air. The engine 20 includes fourteenth and fifteenth heat exchange sides H15. The fifteenth heat exchange side H15 is the heat release side of the medium-temperature heat storage medium, the inlet of the fifteenth heat exchange side H15 is the medium-temperature heat storage medium, and the outlet of the fifteenth heat exchange side H15 is the low-temperature heat storage medium. The fourteenth heat exchange side H14 is the heat absorption side of the vaporized high-pressure cold air, the inlet of the fourteenth heat exchange side H14 is the vaporized high-pressure cold air, and the outlet of the fourteenth heat exchange side H14 is the medium-temperature high-pressure air. The engine 20 performs work driven by the heat flow of the fifteenth heat exchange side H15 and the fourteenth heat exchange side H14.

[0032] The air expansion subsystem 500 includes an air turbine 26. The inlet of the air turbine 26 is connected to the outlet H16 of the sixteenth heat exchange side of the external heat source utilization subsystem 400, the inlet stream of the air turbine 26 is gaseous high-pressure and high-temperature air, the outlet stream of the air turbine 26 is gaseous normal-pressure and medium-temperature air, and the outlet of the air turbine 26 is ambient air.

[0033] It can be selected that the engine 20 mentioned above can be a Stirling engine, a steam engine, a thermoacoustic engine, an external combustion turbine, a compression ignition external combustion engine, a spark ignition external combustion engine and other types of engines, as well as various power cycles such as an organic Rankine cycle, a steam Rankine cycle, a Kalina cycle, and a Brayton cycle.

[0034] It can be selected that the air compressor 3 described above can be a compressor structure of piston type, screw type, centrifugal type, axial flow type, inclined plate type, scroll type, etc. The compressor can include one or more compressors, and the multiple compressors can be connected in series, in parallel or in combination to form a corresponding compressor group.

[0035] It can be selected that the air turbine 26 described above can be a turbine structure such as piston type, screw type, centrifugal type, axial flow type, diagonal flow type, vortex type, etc. The turbine can include one or more turbines, and the multiple turbines can be connected in series, in parallel or in combination to form a corresponding turbine unit.

[0036] It can be selected that the heat storage method of the external heat source 23 mentioned above can be thermal oil circulation heat storage, thermal molten salt circulation heat storage, or hot water circulation heat storage, etc., and can also be replaced by a solid phase packed bed heat storage device or a solid phase moving packed bed heat storage device, as well as various combinations of one or more of them.

[0037] It can be selected that the various types of heat exchangers mentioned above can be tubular heat exchangers, plate heat exchangers, direct contact heat exchangers, and various heat storage heat exchangers. The heat exchange method of each type of heat exchanger is not limited, whether it is a countercurrent arrangement, a cocurrent arrangement or other arrangements, it is within the protection scope of the present utility model.

[0038] It can be selected that the cold energy storage method in the liquid ethylene cold energy utilization subsystem 200 and the air liquefaction subsystem 300 described above is not limited, and not only can methanol, methanol aqueous solution of any concentration, R600, R160, R290, R11, R123, R610, R601, ethanol, ethanol aqueous solution of any concentration, isopropane, acetone and other organic, inorganic or mixed liquid phase working fluids be used for cold storage, or metal, rock, glass, solid polymer, solid compound and other organic, inorganic or mixed solid phase working fluids be used for cold storage, or various phase change materials can be used for cold storage, and one or more combinations thereof.

[0039] Optionally, the liquid ethylene cold energy utilization subsystem 200 described above can be replaced by a form in which liquid ethylene and air are directly heat exchanged without using a cold storage medium, or a form in which cold storage medium or liquid ethylene and air are directly heat exchanged in different time periods.

[0040] It can be selected that the number of splits of the outlet flow of the first circulating pump 10 mentioned above matches the number of air compressor 3 stages and the number of air coolers, but the distribution ratio is not limited, and it can be a variety of distribution methods such as equal enthalpy rise distribution, equal mass flow distribution, equal temperature rise distribution, equal cooling temperature, etc.

[0041] Optionally, the type of the low-temperature turbine 16 described above is not limited, and it may be a low-temperature turbine with a liquid expander or a pure liquid expander, or may be other throttling elements, such as various throttling valves.

[0042] It can be selected that the type of the gas-liquid separator 17 mentioned above is not limited and can be microporous filtration separation, screen separation, packing separation, centrifugal separation, baffle separation (baffle separation) or gravity sedimentation separation.

[0043] It can be selected that the type of the cryogenic liquid air storage tank 18 described above is not limited, and it can be a Dewar tank, a cryogenic storage tank, a single containment tank, a double containment tank, a full containment tank or a membrane tank, etc.

[0044] It can be selected that the flow arrangement of the heat exchange between the high-temperature heat storage medium and the heat exchange heater 25 and the heating heat exchange side of the engine 20 described above is not limited. Not only can the same flow stream flow through the heat exchange heater 25 and the heating heat exchange side of the engine 20 in sequence, but it can also be replaced by a flow stream that is split and flows through the heat exchange heater 25 and the heating heat exchange side of the engine 20 respectively and then re-merges, or a combined flow arrangement based on the above methods.

[0045] It can be selected that the types of the second low-temperature storage tank 21, the second high-temperature storage tank 24, the first low-temperature storage tank 99, and the first high-temperature storage tank 11 described above are not limited, and can be vertical storage tanks, horizontal storage tanks, trough storage tanks, etc. The storage tank can be one or more connected combination tanks.

[0046] Optionally, the external heat source 23 described above can be replaced by waste heat or residual heat from industrial processes such as cement, steel, thermal power, ceramics, geothermal energy, biomass energy, solar energy, and fossil fuel combustion, as well as a combination of one or more of these.

[0047] It can be selected that the types of the cryopump 19, the first circulating pump 10, and the second circulating pump 22 described above are not limited, and can be reciprocating, rotary, centrifugal, mixed flow, axial flow, vortex, etc. The cryopump 19, the first circulating pump 10, and the second circulating pump 22 can be one or more connected in series, in parallel, or in combination.

[0048] It can be selected that the cooling medium 12 mentioned above is not limited, and can be a gaseous medium such as pressurized air, nitrogen, or a liquid medium such as methanol aqueous solution of any concentration, or a combination of one or more thereof.

[0049] It can be selected that the cold users 13 mentioned above are not limited and can be various cold users 13 such as fresh food cold storage, database cooling, industrial refrigeration, etc.

[0050] The utility model provides an air energy storage system utilizing ethylene gasification heat. The process flow is as follows:

[0051] At the beginning of the energy storage stage (low power consumption period), the feed air 1 at normal temperature and pressure is cooled to normal pressure cold air by the pre-compression air cooling heat exchanger 2, and then compressed to a high pressure near normal temperature state by absorbing electric energy by the air compressor 3. After that, the air at high pressure near normal temperature absorbs the cold storage medium from the first low temperature storage tank 9 and the cold air from the cold storage / cold release heat exchanger 15 in the compressed air cooling heat exchanger 4, and is further cooled to a low temperature state by absorbing the cold storage medium in the cold storage / cold release heat exchanger 15 and the cold air from the reverse low temperature air of the gas-liquid separator 17. Then, the high pressure and low temperature air is cooled and reduced in pressure to a low temperature near normal pressure gas-liquid two-phase state by the low temperature turbine 16, and is separated into gas and liquid by the gas-liquid separator 17. Among them, the low temperature gaseous air reverses and passes through the cold storage / cold release heat exchanger 15, the post-compression air cooling heat exchanger 4 and the pre-compression air cooling heat exchanger 2 in turn to release cold. The cryogenic liquid air is stored in the cryogenic liquid air storage tank 18, marking the end of the energy storage stage.

[0052] At the beginning of the energy release phase (peak power consumption period), the low-temperature and normal-pressure liquid air is pumped by the low-temperature pump 19 to the cold storage / release heat exchanger 15 to release cold energy and gasify, wherein the cold energy is absorbed and stored by the cold storage medium in the cold storage / release heat exchanger. After releasing the cold energy, the high-pressure gaseous cold air passes through the fourteenth heat exchange side H14 of the engine 20 and the sixteenth heat exchange side H16 of the heat exchange heater 25 in turn, absorbing heat to heat up to a high-temperature and high-pressure state. Among them, the heat of the heat exchange heater 25 directly comes from the heat release of the high-temperature heat storage medium in the second high-temperature storage tank 24, and the heat release of the engine 20 is the heat release of the engine 20 cycle process driven by the heat release of the heat storage medium. After absorbing the heat, the air in the high-temperature and high-pressure state drives the air turbine 26 to work and generate electrical energy, and the air turbine exhausts 27 to the atmosphere. The heat of the heat storage medium comes from the external heat source 23: the low-temperature heat storage medium from the second low-temperature storage tank 21 absorbs heat through the external heat source 23 under the driving force of the second circulation pump 22 to increase its temperature, and then the high-temperature heat storage medium flows into the second high-temperature storage tank 24 to wait for the energy release phase to begin, and then flows through the heat exchange heater 25 and the engine 20 to release heat.

[0053] For the low-temperature liquid ethylene 5, the low-temperature liquid ethylene 5 releases high-grade cold energy through the liquid ethylene cold energy cold storage heat exchanger 6, and this part of high-grade cold energy is absorbed by the cold storage medium from the first high-temperature storage tank 11 and stored in the first low-temperature storage tank 9. The low-temperature cold storage medium stored in the first low-temperature storage tank 9 and the counterflow cold air from the cold storage / cold release heat exchanger 15 release cold energy together to cool the near-normal temperature high-pressure air from the air compressor 3, and the cold storage medium that has released all the cold energy returns to the first high-temperature storage tank 11. The counterflow cold air that has released part of the cold energy and the remaining part of the low-temperature cold storage medium from the first low-temperature storage tank 9 cool the feed air 1 at normal temperature and pressure in the pre-compression air cooler 2, and the cold storage medium that has released all the cold energy returns to the first high-temperature storage tank 11, and the counterflow cold air is directly discharged into the atmosphere after being heated to normal temperature. After releasing high-grade cold energy in the liquid ethylene cold energy storage heat exchanger 6, the intermediate-cooled ethylene releases low-grade cold energy through the ethylene low-grade cold energy absorption heat exchanger 7 to be heated to room-temperature gaseous ethylene 8. The low-grade cold energy of this part of ethylene is absorbed by the cold delivery medium 12 and delivered to the cold user 13.

[0054] The utility model provides an air energy storage system utilizing the heat of ethylene vaporization, which fills the cooling capacity gap of the traditional liquid air energy storage system by introducing the regasification waste cold cooling air of liquid ethylene, obtains a higher air liquefaction rate and reduces the compression power consumption by cooling before compression.

[0055] The utility model provides an air energy storage system utilizing the heat of ethylene vaporization, which introduces heat from an external heat source 23 to provide the heat required for air rewarming and heating, and drives the engine to work to increase power generation, thereby improving the overall efficiency of the system and achieving good economy and thermodynamic performance.

[0056] The utility model provides an air energy storage system utilizing the heat of ethylene vaporization, which stores the regasification cold of ethylene by means of an intermediate cold storage medium, thereby achieving efficient and high value-added utilization of the cold of ethylene, ensuring an uninterrupted gasification process of ethylene and avoiding the safety risk of explosion caused by direct heat exchange between ethylene and air.

[0057] The utility model provides an air energy storage system utilizing ethylene vaporization heat, which applies waste cooling of liquid ethylene regasification to cool air before and after compression, thereby reducing compression process temperature and air compression power consumption and improving system efficiency.

[0058] The utility model provides an air energy storage system using the heat of ethylene gasification, which increases the power generation and efficiency of the system by adding an engine 20 to use the heat of an external heat source 23 as a heat source to do work.

[0059] The utility model provides an air energy storage system utilizing the heat of ethylene vaporization, which uses the heat released by the engine 20 to preheat the gaseous cold air. It not only utilizes the coldness of the gaseous cold air to provide a low-temperature cold source for the engine 20, thereby improving the efficiency of the engine 20, but also reasonably utilizes the heat released by the engine 20.

[0060] In summary, the air energy storage system using ethylene vaporization heat provided by the utility model can simultaneously meet the recovery of waste cold from ethylene regasification and the demand for cold capacity of the liquid air energy storage system, and flexibly introduces heat from an external heat source 23 to improve system efficiency.

[0061] Although the utility model has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the utility model can be implemented in a variety of forms without departing from the spirit or essence of the utility model, it should be understood that the above-mentioned embodiments are not limited to any of the aforementioned details, but should be widely interpreted within the spirit and scope defined by the attached claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the attached claims.

Claims

1. An air energy storage system utilizing ethylene gasification heat, characterized in that: The invention comprises an air compression subsystem, a liquid ethylene cold energy utilization subsystem and an air liquefaction subsystem. The air compression subsystem draws air from the outside and compresses the air to a target pressure. The liquid ethylene cold energy utilization subsystem utilizes the cold energy of liquid ethylene gasification to cool the compressed air to fill the cold capacity gap of air liquefaction. The air liquefaction subsystem liquefies the cooled air and stores it. The liquid ethylene cold energy utilization subsystem comprises an ethylene transport pipeline, a liquid ethylene cold energy storage heat exchanger connected to the ethylene transport pipeline, a compressed air cooling heat exchanger for cooling the compressed air, and a cold storage working medium circulation loop for transmitting the cold energy of the liquid ethylene cold energy storage heat exchanger to the compressed air cooling heat exchanger. The cold storage working medium circulation loop stores and utilizes the cold energy of ethylene.

2. The air energy storage system utilizing ethylene gasification heat according to claim 1, characterized in that: The liquid ethylene cold energy storage heat exchanger has a first heat exchange side and a second heat exchange side, the ethylene delivery pipeline is connected to the first heat exchange side pipeline, the compressed air cooling heat exchanger has a third heat exchange side and a fourth heat exchange side, the second heat exchange side and the third heat exchange side are connected by pipeline, the second heat exchange side and the third heat exchange side constitute a cold storage working medium circulation loop, the output end of the air compression subsystem is connected to the input end pipeline of the fourth heat exchange side, and the output end of the fourth heat exchange side is connected to the air liquefaction subsystem pipeline.

3. The air energy storage system using ethylene gasification heat according to claim 2, characterized in that: The cold storage medium circulation loop also includes a first low-temperature storage tank, a circulation pump and a first high-temperature storage tank. The low-temperature cold storage medium output from the second heat exchange side is led to the first low-temperature storage tank, the low-temperature cold storage medium of the first low-temperature storage tank is led to the input end of the third heat exchange side, the high-temperature cold storage medium after heat exchange output from the output end of the third heat exchange side is led to the first high-temperature storage tank, the high-temperature cold storage medium of the first high-temperature storage tank is led to the input end of the second heat exchange side, and the circulation pump is used to drive the cold storage medium to circulate in the cold storage medium circulation loop.

4. The air energy storage system using ethylene gasification heat according to claim 1, characterized in that: It also includes an external heat source utilization subsystem, the input end of the external heat source utilization subsystem is connected to the output end pipeline of the air liquefaction subsystem, and the external heat source utilization subsystem uses the heat of the external heat source to heat the high-pressure and low-temperature air passed through the air liquefaction subsystem to high-pressure and high-temperature air.

5. The air energy storage system using ethylene gasification heat according to claim 4, characterized in that: It also includes an air turbine, the input end of the air turbine is connected to the output end pipeline of the external heat source utilization subsystem.

6. The air energy storage system using ethylene gasification heat according to claim 5, characterized in that: The external heat source utilization subsystem includes an external heat source, a heat storage working fluid circulation loop and an engine. The heat storage working fluid circulation loop stores and utilizes the heat of the external heat source. The heat absorption end of the engine is connected to the external heat source through the heat storage working fluid circulation loop, and the cold absorption end of the engine is connected to the output end of the air liquefaction subsystem.

7. The air energy storage system using ethylene gasification heat according to claim 6, characterized in that: The heat storage medium circulation loop includes a second low-temperature storage tank, a second high-temperature storage tank and a second circulation pump. The outlet of the external heat source is connected to the inlet pipeline of the second high-temperature storage tank, the outlet of the second high-temperature storage tank is connected to the input pipeline of the heat absorption end of the engine, the outlet of the engine is connected to the inlet pipeline of the second low-temperature storage tank, and the outlet of the second low-temperature storage tank is connected to the inlet pipeline of the external heat source.

8. The air energy storage system using ethylene gasification heat according to claim 7, characterized in that: It also includes a heat exchange heater, which has more than two heat exchange sides. The inlet of one heat exchange side of the heat exchange heater is connected to the outlet pipeline of the second high-temperature storage tank, and the outlet of the heat exchange side opposite to the inlet is connected to the inlet pipeline of the heat absorption end of the engine; the inlet of the other heat exchange side of the heat exchange heater is connected to the outlet pipeline of the cold absorption end of the engine, and the outlet of the heat exchange side opposite to the inlet is connected to the inlet pipeline of the air turbine.

9. The air energy storage system using ethylene gasification heat according to claim 3, characterized in that: The compressed air cooling heat exchanger also includes a fifth heat exchange side, the inlet of which is connected to the air liquefaction subsystem pipeline, and the reflux cold air generated by the air liquefaction subsystem during the gas liquefaction process leads to the fifth heat exchange side.

10. The air energy storage system using ethylene gasification heat according to claim 9, characterized in that: It also includes a pre-compression air cooling heat exchanger, which uses the cold energy of ethylene and the cold energy of the air liquefaction subsystem to cool the air before compression. The air cooling heat exchanger has a sixth heat exchange side, a seventh heat exchange side and an eighth heat exchange side. The inlet of the sixth heat exchanger is connected to the outlet pipeline of the first low-temperature storage tank, the outlet of the sixth heat exchanger is connected to the inlet pipeline of the first high-temperature storage tank, the inlet of the seventh heat exchange side is connected to the atmospheric environment, the outlet of the seventh heat exchange side is connected to the inlet pipeline of the air compression subsystem, the inlet of the eighth heat exchange side is connected to the outlet pipeline of the fifth heat exchange side, and the outlet of the eighth heat exchange side is connected to the atmospheric environment.

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