A compressed air energy storage power generation system and method based on stepped sensible heat storage

Abstract

The present application relates to the technical field of energy power engineering and environmental engineering, and discloses a compressed air energy storage power generation system and method based on cascade sensible heat storage. The outlet of the air compressor is in communication with the high-temperature side air inlet of the cascade sensible heat storage device; the low-temperature side air outlet of the cascade sensible heat storage device is connected to the low-temperature side air inlet of the cascade sensible heat storage device through a heat exchange and gas storage integrated unit; the high-temperature side air outlet of the cascade sensible heat storage device is in communication with the air inlet of the combustor; the output end of the organic solid waste treatment unit is in communication with the fuel inlet of the combustor, forming an organic solid waste pyrolysis resource utilization channel; the flue gas outlet of the combustor is in communication with the air inlet of the expansion turbine, and the main shaft of the expansion turbine is matched with the generator set for outputting electric power. The present application relies on cascade heat storage to cooperate with air compression and energy release cycle, effectively reduces the heat transfer temperature difference between the fluid and the heat storage medium in the heat storage and heat release stages, and improves the compressed heat recovery level.

Description

Technical Field

[0001] This invention relates to the interdisciplinary field of energy and power engineering and environmental engineering, specifically to a compressed air energy storage power generation system and method based on cascaded sensible heat storage. Background Technology

[0002] Against the backdrop of a profound global energy transition, the installed capacity of renewable energy power generation, represented by wind and solar power, has experienced explosive growth. However, the inherent intermittency, volatility, and anti-peak-shaving characteristics of wind and solar power make it difficult to precisely match their power generation with the grid's load demand. This results in frequent wind and solar curtailment in areas rich in renewable energy, leading to a serious waste of clean energy. Simultaneously, the peak-valley load difference in my country's power system continues to widen, posing severe challenges to grid peak-shaving, frequency regulation, and safe and stable operation. Energy storage technology, as a key technology for smoothing grid load fluctuations and solving the problem of renewable energy grid integration and consumption, has become an indispensable and important component of the construction of new power systems.

[0003] Compressed air energy storage (CASS) is a physical energy storage technology with the potential for large-scale, long-term energy storage. Compared with pumped hydro storage, it has advantages such as shorter construction period, smaller environmental impact, and lower total life cycle cost, making it an important development direction in the field of large-scale energy storage. Currently, traditional afterburning CASS systems require the combustion of fossil fuels such as natural gas during the energy release phase to heat the compressed air at the expander inlet. This technology has two significant drawbacks: firstly, it generates large carbon emissions and has a high dependence on fossil fuels; secondly, a large amount of compression heat generated during the compression phase is not effectively recovered (often discharged directly into the environment via cooling water), resulting in low overall electro-electric conversion efficiency and poor operational economy. To overcome these drawbacks, the industry has developed advanced adiabatic CASS technology. This technology recovers and stores compression heat by adding a heat storage unit, directly preheating the inlet air during the energy release phase to achieve stable operation without afterburning. However, existing advanced adiabatic CASS systems generally adopt a single-stage solid sensible heat storage structure. During the heat storage and release process, there is a large temperature difference between the heat exchange fluid and the heat storage medium. This non-isothermal heat transfer process leads to severe irreversible heat loss, significantly reducing the efficiency of compression heat recovery. Furthermore, single-stage thermal storage units struggle to achieve cascaded matching and full recovery of compression heat. To meet the expander inlet temperature requirements, an additional heat source is still needed, hindering further improvements in system efficiency. Therefore, developing a compressed air energy storage technology based on cascaded sensible heat storage with low heat loss and high compression heat recovery efficiency has significant practical and engineering value.

[0004] Meanwhile, the annual production scale of organic solid waste (including waste biomass, waste plastics, municipal organic sludge, etc.) is enormous. Its harmless disposal and high-value resource utilization have become key issues urgently needing breakthroughs in the fields of ecological environmental protection and circular economy development. Pyrolysis technology, as one of the core technologies for the high-value utilization of organic solid waste, can convert organic solid waste into clean fuels such as high-calorific-value pyrolysis gas and pyrolysis oil in anaerobic or hypoxic environments, while simultaneously producing high-value-added byproducts such as carbon black, thus achieving the reduction, harmlessness, and resource utilization of organic solid waste. However, the compressed air energy storage systems mentioned earlier, whether traditional afterburning systems or advanced adiabatic compressed air energy storage systems, heavily rely on high-grade fossil fuel combustion to heat compressed air to meet the expander inlet parameter requirements during the energy release stage. Therefore, developing a technology system that deeply couples organic solid waste pyrolysis with compressed air energy storage, using pyrolysis gas and pyrolysis oil produced by pyrolysis to replace fossil fuel combustion in heating compressed air during the energy release stage, has significant engineering implications for achieving the resource utilization of organic solid waste and the low-carbon operation of energy storage systems. Summary of the Invention

[0005] In order to overcome the defects of the existing technology, the purpose of this invention is to provide a compressed air energy storage power generation system and method based on cascaded sensible heat storage, so as to solve the technical problems of large temperature difference in heat transfer, serious irreversible heat loss, and how to achieve low-carbon and efficient operation of energy storage system and high-value resource utilization of organic solid waste.

[0006] This invention is achieved through the following technical solution: In a first aspect, the present invention provides a compressed air energy storage power generation system based on cascaded sensible heat storage, including an air compressor, a cascaded sensible heat storage device, a heat exchange and gas storage integrated unit, an organic solid waste treatment unit, a burner, and an expansion turbine; The air compressor inlet is used to input electricity and ambient temperature and pressure air, and the air compressor outlet is connected to the high-temperature side air inlet of the cascade sensible heat storage device; the low-temperature side air outlet of the cascade sensible heat storage device is circulated to the low-temperature side air inlet of the cascade sensible heat storage device after passing through the heat exchange and air storage integrated unit; the high-temperature side air outlet of the cascade sensible heat storage device is connected to the air inlet of the burner, forming the main circulation path of compressed air energy storage and release. The input end of the organic solid waste treatment unit is used to input organic solid waste, and the output end of the organic solid waste treatment unit is connected to the fuel inlet of the burner, forming a pyrolysis resource utilization pathway for organic solid waste. The flue gas outlet of the burner is connected to the air inlet of the expansion turbine, and the main shaft of the expansion turbine is matched and connected to the generator set for power output.

[0007] Preferably, the cascade sensible heat storage device includes a storage device shell, which is a sealed pressure-bearing structure. One end of the storage device shell is provided with a high-temperature side air inlet and a high-temperature side air outlet, and the other end is provided with a low-temperature side air inlet and a low-temperature side air outlet. The heat storage tank shell is fitted with a heat insulation sleeve to block radial heat dissipation and reduce environmental heat loss. The heat storage tank shell is arranged axially from the high temperature side to the low temperature side, with a high temperature heat storage section, a medium temperature heat storage section and a low temperature heat storage section. The high temperature heat storage section, the medium temperature heat storage section and the low temperature heat storage section are filled with heat storage media at different temperatures for the cascade storage of compressible heat.

[0008] Furthermore, the high-temperature heat storage section, the medium-temperature heat storage section, and the low-temperature heat storage section are respectively located within the support sleeve, and each heat storage section is provided with gas guide plates at both ends of the axial direction and between adjacent heat storage sections. The adjacent gas guide plates and the corresponding support sleeve form a sealed heat storage cavity. The high-temperature heat storage section, the medium-temperature heat storage section, and the low-temperature heat storage section are respectively located in different sealed heat storage cavities. Each support sleeve is filled with a heat storage medium at a different temperature; gas guide plates are provided at both ends of the axial direction of each heat storage section and between adjacent heat storage sections to guide air evenly to the heat storage medium.

[0009] Furthermore, the gas guide plate has evenly distributed guide holes on its surface to guide air evenly to the heat storage medium.

[0010] Preferably, the heat exchange and gas storage integrated unit includes a first heat exchanger and a gas storage chamber; The low-temperature side outlet of the cascade sensible heat storage device is connected to the hot fluid side inlet of the first heat exchanger. Cold water is connected to the cold fluid side of the first heat exchanger. The cold fluid side outlet of the first heat exchanger is connected to the air inlet of the gas storage chamber. The air outlet of the gas storage chamber is connected to the low-temperature side inlet of the cascade sensible heat storage device.

[0011] Preferably, the organic solid waste treatment unit includes a crusher, a washing machine, a dryer, and a pyrolysis furnace; The crusher's inlet is used to input organic solid waste; the crusher's outlet is connected to the washer's inlet, the washer's outlet is connected to the dryer's inlet, the dryer's outlet is connected to the pyrolysis furnace's inlet, the pyrolysis gas and pyrolysis oil fuel outlets of the pyrolysis furnace are connected to the burner's fuel inlet, and the solid phase outlet of the pyrolysis furnace produces carbon black as a byproduct.

[0012] Preferably, the outlet of the expansion turbine is connected to the hot fluid side inlet of the second heat exchanger, the cold fluid side of the second heat exchanger is connected to cold water, and the flue gas outlet of the second heat exchanger is connected to the inlet of the flue gas purification device. The outlet of the flue gas purification device is a qualified flue gas emission outlet, forming a pathway for energy release and power generation, waste heat recovery, and flue gas treatment.

[0013] Secondly, the present invention also provides a compressed air energy storage power generation method based on cascaded sensible heat storage, which, based on the above-described compressed air energy storage power generation system based on cascaded sensible heat storage, includes the following process: The organic solid waste is pre-treated by the pretreatment equipment. The organic solid waste to be disposed of is sent to the organic solid waste treatment unit for treatment to obtain pyrolysis gas and pyrolysis oil products, which are then sent to the burner for storage and later use. When the air compressor is started, the ambient temperature and pressure air is compressed into high temperature and high pressure air by the air compressor. The air then undergoes heat exchange through the hot side channel of the cascade sensible heat storage tank. The high temperature and high pressure air flows sequentially through the high temperature storage section, the medium temperature storage section, and the low temperature storage section, thus achieving cascade storage of the heat of compression. High-pressure air cooled by the cascade sensible heat storage unit is then stored in a sealed manner through the heat exchange and gas storage integrated unit. During peak grid load periods, the system enters the energy release operation phase. The high-pressure air output from the heat exchange and gas storage integrated unit enters the cold side flow channel of the cascade sensible heat storage unit and flows in the opposite direction to the hot side air. It flows sequentially through the low-temperature heat storage section, the medium-temperature heat storage section, and the high-temperature heat storage section, gradually absorbing heat and completing the step-by-step preheating of the high-pressure air. High-temperature and high-pressure air, after being preheated in stages, is sent into the burner and mixed with pyrolysis gas and pyrolysis oil fuel for combustion. The resulting high-temperature and high-pressure flue gas is sent into the expansion turbine, where it expands and does work to drive the generator set to output stable electrical energy.

[0014] Preferably, the high-pressure air at the outlet of the air compressor is 10-30MPa and the temperature is 350-550℃; the high-temperature heat storage section of the cascade sensible heat storage device operates at 350-550℃, the medium-temperature heat storage section operates at 200-350℃, and the low-temperature heat storage section operates at 80-200℃.

[0015] Preferably, the temperature of the high-temperature and high-pressure flue gas at the burner outlet is 800-1100℃.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: This invention provides a compressed air energy storage power generation system based on cascaded sensible heat storage. By integrating a cascaded sensible heat storage structure, compressed air energy storage cycle, organic solid waste treatment, and combustion power generation unit, an integrated coupled operation architecture is constructed. This breaks the traditional single operation mode of compressed air energy storage. Relying on cascaded heat storage combined with air compression and energy release cycle, the heat transfer temperature difference between the fluid and the heat storage medium in the heat storage and heat release stages is effectively reduced, significantly reducing irreversible heat loss caused by non-isothermal heat transfer and improving the level of heat recovery and utilization. At the same time, an organic solid waste treatment pathway is introduced to convert organic solid waste into combustible products as auxiliary fuel to replace traditional high-grade fossil fuels. This achieves both harmless disposal and high-value resource utilization of organic solid waste, while reducing the system's fossil energy consumption. It promotes low-carbon and near-zero carbon emission operation of the energy storage power generation process. By using combustion heat generation combined with turbine work, it stably produces electricity, taking into account the dual value of grid energy storage peak shaving needs and solid waste treatment, and comprehensively improving the overall operating efficiency and environmental adaptability of the energy storage system.

[0017] Furthermore, by installing a thermal insulation sleeve inside the sealed, pressurized heat storage tank shell, radial heat loss can be effectively blocked, reducing heat loss from the external environment. At the same time, the axial direction is divided into three independent heat storage zones: high, medium, and low temperature. These zones are paired with heat storage media of different suitable temperatures, and heat is stored in stages according to the changes in air heat exchange temperature. This matches the heat exchange law of the gradually decreasing temperature of compressed air, reduces the local heat exchange temperature difference, weakens the energy loss during heat transfer, ensures the stability and specificity of the staged storage of compressed heat, and enhances the structural adaptability and heat retention effect of the staged heat storage.

[0018] Furthermore, by using support sleeves to separate the heat storage sections in different temperature zones, and cooperating with gas guide plates to form independent sealed heat storage cavities, energy waste caused by crosstalk between heat from different temperature zones and mixing of hot and cold airflows is avoided. Each heat storage section is independently filled with the corresponding heat storage medium, ensuring stable segmented heat storage conditions. At the same time, the regular layout of the guide plates constrains the airflow direction, allowing air to flow orderly through each heat storage area, preventing airflow deviation and short-circuiting problems, ensuring sufficient contact and heat exchange between air and the heat storage medium, and improving the uniformity and heat exchange sufficiency of the cascade heat storage and release process.

[0019] Furthermore, the evenly distributed flow guide holes on the surface of the gas guide plate can uniformly divide and guide the flowing air, disperse the concentrated airflow, and allow the air to fully diffuse and contact the heat storage medium. This eliminates local heat exchange blind spots, avoids additional heat loss caused by uneven local heat exchange intensity, makes the heat exchange across temperature zones more stable and balanced, optimizes the cascade heat exchange effect, and improves the overall heat utilization efficiency.

[0020] Furthermore, the integrated heat exchanger and the gas storage chamber form an integrated heat exchange and gas storage unit, which can cool the high-pressure air after the heat storage is cooled, reduce the air temperature in the gas storage process, reduce heat loss and pressure fluctuations during high-pressure air storage, ensure the sealed and stable storage of high-pressure air, meet the air buffer storage requirements of the energy storage stage, and at the same time realize the simple recovery of waste heat through cold water heat exchange, optimize the energy cascade utilization in the energy storage stage, provide stable gas source conditions for subsequent energy release and gas supply, and ensure the continuous and smooth operation of the energy storage cycle.

[0021] Furthermore, the entire process of organic solid waste pretreatment is completed through multiple steps including crushing, washing, drying, and pyrolysis. This effectively removes impurities from the solid waste, reduces its moisture content, and improves the efficiency of subsequent pyrolysis reactions. The pyrolysis gas and pyrolysis oil produced by pyrolysis can be directly used as clean fuels for combustion, realizing the energy conversion of solid waste. The solid phase products of pyrolysis can be recycled as carbon black by-products, extending the solid waste resource utilization industrial chain, increasing added economic value, and fully realizing the comprehensive utilization of organic solid waste through reduction, harmlessness, and high value.

[0022] Furthermore, by adding a back-end heat exchange and flue gas purification process at the exhaust end of the expansion turbine, the residual heat of the high-temperature flue gas after the turbine has done its work can be recovered, realizing the secondary utilization of waste heat, tapping into the value of the system's residual energy, reducing the waste caused by direct energy emissions, and at the same time purifying the combustion flue gas to remove harmful pollutants, ensuring that the flue gas meets emission standards, effectively controlling pollutant emissions during the energy storage power generation process, meeting the requirements of low-carbon and environmentally friendly operation, and reducing the negative impact of system operation on the surrounding ecological environment.

[0023] This invention also provides a compressed air energy storage power generation method based on cascaded sensible heat storage. First, organic solid waste pretreatment and fuel storage are completed, with clean alternative fuels pre-stocked to ensure a stable fuel supply during power generation. During the energy storage stage, compressed air flows sequentially through multi-temperature zone heat storage sections to complete tiered heat storage, conforming to the air temperature change pattern. This process reduces heat exchange temperature differences and irreversible energy loss. During the energy release stage, air flows in the opposite direction to absorb heat step by step, achieving precise heat return and improving air preheating uniformity and heating efficiency. The preheated high-pressure air is then mixed with solid waste pyrolysis products for combustion, enhancing combustion work capacity and stably driving the generator set to continuously generate electricity. This achieves an orderly cycle of energy storage and release, deeply integrating compressed air energy storage with the solid waste pyrolysis utilization process, reducing dependence on fossil fuels throughout the entire process, and enabling efficient, low-carbon, and continuous system operation.

[0024] Furthermore, by defining the compressed air parameters and the temperature range of each heat storage section, the temperature gradient of air compression heat generation is precisely matched with the working temperature range of the tiered heat storage medium. This ensures precise adaptation between high-temperature compressed air and high-temperature heat storage section, and between medium- and low-temperature airflow and corresponding temperature range heat storage section. This avoids the huge temperature difference caused by direct heat exchange between high-temperature fluid and low-temperature medium, suppresses heat loss from the parameter control level, and precisely divides the heat storage levels. This makes the graded storage and release of compressed heat more in line with actual operating conditions, improving the matching degree of heat storage and release and the level of refined energy utilization.

[0025] Furthermore, limiting the flue gas temperature range at the burner outlet can provide a stable and high-quality high-temperature flue gas working medium for the expansion turbine, ensuring the dynamic stability and efficiency of the expansion work inside the turbine. This avoids insufficient power generation due to excessively low flue gas temperature or equipment damage caused by excessively high temperature. Relying on a suitable combustion temperature ensures complete combustion of fuel, improves the combustion utilization rate of solid waste pyrolysis fuel, reduces energy waste and pollutant generation caused by incomplete combustion, and balances power generation output efficiency with low-carbon and environmentally friendly combustion effects. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the system structure in an embodiment of the present invention; Figure 2 This is a three-dimensional structural diagram of the cascade sensible heat storage device in an embodiment of the present invention; Figure 3 This is a three-dimensional cross-sectional view of the cascade sensible heat storage device in an embodiment of the present invention; Figure 4 This is an exploded structural diagram of the cascade sensible heat storage device in an embodiment of the present invention; In the diagram: 1. Air compressor; 2. Cascade sensible heat storage tank; 3. Gas guide plate; 4. Heat storage medium unit; 5. First heat exchanger; 6. Gas storage chamber; 7. Crusher; 8. Washing machine; 9. Dryer; 10. Pyrolysis furnace; 11. Burner; 12. Expansion turbine; 13. Second heat exchanger; 14. Flue gas purification device; 15. Thermal insulation sleeve; 16. Support sleeve; 41. First heat storage medium; 42. Second heat storage medium; 43. Third heat storage medium. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0028] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0029] The purpose of this invention is to provide a compressed air energy storage power generation system and method based on cascaded sensible heat storage, in order to solve the technical problems of large temperature difference in heat transfer, serious irreversible heat loss, and how to achieve low-carbon and efficient operation of energy storage systems and high-value resource utilization of organic solid waste.

[0030] The present invention will now be described in further detail with reference to the accompanying drawings: Example 1 See Figure 1 In one embodiment of the present invention, a compressed air energy storage and power generation system based on cascaded sensible heat storage is provided to achieve deep coupling of compressed air energy storage-release cycle with organic solid waste resource utilization, reduce irreversible energy loss of the system, and achieve low-carbon and high-efficiency operation. Its specific structure is as follows: The system mainly includes an air compressor 1, a cascade sensible heat storage tank 2, a heat exchange and gas storage integrated unit, an organic solid waste treatment unit, a burner 11, and an expansion turbine 12. These components work together to form a complete energy storage, solid waste treatment, power generation, and exhaust gas treatment pathway. The specific connection relationships and structural details are as follows: The air compressor 1, as the core power component of the energy storage stage, can be connected to the surplus power during the off-peak period of the power grid and normal temperature and pressure air at its inlet. By consuming the surplus power, the normal temperature and pressure air is compressed into high temperature and high pressure air. The outlet of the air compressor 1 is sealed and connected to the high temperature side air inlet of the cascade sensible heat storage device 2 to ensure that all the high temperature and high pressure air can enter the cascade sensible heat storage device 2 for heat exchange and heat storage.

[0031] according to Figure 2 , Figure 3 as well as Figure 4As shown, the cascaded sensible heat storage tank 2 is the core heat storage component of the system, used to realize the cascaded storage and release of compressible heat. It includes a storage tank shell, which adopts a sealed pressure-bearing structure, capable of withstanding the action of high-temperature and high-pressure air, ensuring the safety of system operation. One end of the storage tank shell is provided with a high-temperature side air inlet and a high-temperature side air outlet, and the other end is provided with a low-temperature side air inlet and a low-temperature side air outlet, respectively adapting to the airflow requirements of the energy storage and energy release stages. A thermal insulation sleeve 15 is attached to the inner wall of the storage tank shell. The thermal insulation sleeve 15 is made of a high-temperature resistant material with excellent thermal insulation performance, used to block the radial heat dissipation of heat inside the storage tank, effectively reducing environmental heat loss and improving heat retention rate.

[0032] The heat storage tank shell is arranged axially from the high-temperature side to the low-temperature side, with a high-temperature heat storage section, a medium-temperature heat storage section, and a low-temperature heat storage section. The three heat storage sections are respectively located in the support sleeve 16. The support sleeve 16 is made of metal and serves to provide axial support and isolate the temperature zones. Gas guide plates 3 are provided at both ends of the axial direction of each heat storage section and between adjacent heat storage sections. The adjacent gas guide plates 3 and the corresponding support sleeve 16 form a sealed heat storage cavity. The high-temperature heat storage section, the medium-temperature heat storage section, and the low-temperature heat storage section are respectively set in different sealed heat storage cavities to avoid heat crosstalk between different temperature zones and ensure the stability of the heat storage conditions in each temperature zone.

[0033] Each sealed heat storage cavity is filled with heat storage medium units 4 adapted to different temperatures. The high-temperature heat storage section is filled with a first heat storage medium 41, suitable for high-temperature conditions of 350-550℃; the medium-temperature heat storage section is filled with a second heat storage medium 42, suitable for medium-temperature conditions of 200-350℃; and the low-temperature heat storage section is filled with a third heat storage medium 43, suitable for low-temperature conditions of 80-200℃. This achieves tiered storage of compressible heat, matching the heat exchange law of gradual cooling of high-temperature, high-pressure air. The gas guide plate 3 has evenly distributed guide holes on its surface to uniformly guide air to the corresponding heat storage medium unit 4 in the heat storage section, preventing airflow deviation and short-circuiting, ensuring sufficient contact and heat exchange between the air and the heat storage medium unit 4, and improving heat exchange efficiency.

[0034] The heat exchange and gas storage integrated unit is used to cool and seal the high-pressure air discharged from the cascade sensible heat storage device 2. It includes a first heat exchanger 5 and a gas storage chamber 6. The low-temperature side outlet of the cascade sensible heat storage device 2 is connected to the hot fluid side inlet of the first heat exchanger 5. Cold water is connected to the cold fluid side of the first heat exchanger 5. After the high-temperature and high-pressure air is cooled by the cascade sensible heat storage device 2, it enters the first heat exchanger 5 to exchange heat with the cold water, further recovering the waste heat of the air. The cold water can be supplied externally after absorbing heat, realizing the secondary utilization of waste heat. The cold fluid side outlet of the first heat exchanger 5 is connected to the air inlet of the gas storage chamber 6. The cooled high-pressure air is sent into the gas storage chamber 6 for sealed storage. The outlet of the gas storage chamber 6 is connected to the low-temperature side inlet of the cascade sensible heat storage device 2, forming an energy storage-release air circulation path.

[0035] The organic solid waste treatment unit is used to achieve the harmless and high-value treatment of organic solid waste and to provide clean fuel for the burner 11. It includes a crusher 7, a washer 8, a dryer 9, and a pyrolysis furnace 10. The inlet of the crusher 7 is used to input the organic solid waste to be treated, and the crusher 7 crushes the organic solid waste to a preset particle size for subsequent processing. The outlet of the crusher 7 is connected to the inlet of the washer 8, which is used to remove impurities from the organic solid waste and improve the efficiency of the subsequent pyrolysis reaction. The outlet of the washer 8 is connected to the dryer 9. The inlet of the dryer 9 is connected to the outlet of the pyrolysis furnace 10. The dryer 9 is used to remove free water from the organic solid waste to avoid the water affecting the pyrolysis effect. The outlet of the dryer 9 is connected to the outlet of the pyrolysis furnace 10. The pyrolysis furnace 10 pyrolyzes the pretreated organic solid waste in an oxygen-free or oxygen-deficient environment. The pyrolysis gas and pyrolysis oil fuel outlets of the pyrolysis furnace 10 are connected to the fuel inlet of the burner 11. The pyrolysis products are transported to the burner 11 as fuel for standby. The solid phase outlet of the pyrolysis furnace 10 produces carbon black by-product, realizing the resource utilization of organic solid waste.

[0036] The burner 11 is used to achieve the mixed combustion of air and fuel, and to provide high-temperature and high-pressure flue gas to the expansion turbine 12. Its air inlet is connected to the high-temperature side outlet of the stepped sensible heat storage tank 2, and its fuel inlet is connected to the pyrolysis furnace 10 of the organic solid waste treatment unit. It can mix and burn the preheated air output from the stepped sensible heat storage tank 2 with pyrolysis gas and pyrolysis oil. The flue gas outlet of the burner 11 is connected to the air inlet of the expansion turbine 12. The main shaft of the expansion turbine 12 is matched and connected to the generator set. The high-temperature and high-pressure flue gas expands and does work in the expansion turbine 12, driving the generator set to output stable electrical energy, realizing energy conversion and output.

[0037] In this embodiment, the outlet of the expansion turbine 12 is connected to the hot fluid side inlet of the second heat exchanger 13, and the cold fluid side of the second heat exchanger 13 is connected to cold water to recover the residual heat of the flue gas discharged from the expansion turbine 12. After absorbing heat, the cold water can be supplied to the outside to improve the energy utilization rate of the system. The flue gas outlet of the second heat exchanger 13 is connected to the inlet of the flue gas purification device 14. The flue gas purification device 14 is used to remove harmful pollutants in the flue gas to ensure that the flue gas meets the emission standards. The outlet of the flue gas purification device 14 is the emission outlet of the compliant flue gas, forming a complete path for energy release and power generation, waste heat recovery, and flue gas treatment.

[0038] This embodiment provides a compressed air energy storage power generation system based on cascaded sensible heat storage. Through its cascaded sensible heat storage structure design, it significantly reduces the temperature difference between the heat exchange fluid and the storage medium unit 4 during heat storage and release, fundamentally reducing irreversible energy losses caused by non-isothermal heat transfer. Simultaneously, through the deep coupling of organic solid waste pyrolysis and compressed air energy storage, pyrolysis products replace high-grade fossil fuels, achieving the harmless and high-value utilization of organic solid waste and promoting near-zero carbon emission operation of the system. This system has broad application potential in fields such as new power system energy storage and organic solid waste disposal. The cascaded sensible heat storage structure design of the reaction system of this invention significantly reduces the temperature difference between the heat exchange fluid and the storage medium during heat storage and release, thereby fundamentally reducing irreversible energy losses caused by non-isothermal heat transfer. Simultaneously, the deep coupling of organic solid waste pyrolysis and compressed air energy storage enables the replacement of high-grade fossil fuels with pyrolysis products (pyrolysis gas, pyrolysis oil), thus achieving the harmless and high-value utilization of organic solid waste and near-zero carbon emission operation of the system. Through a tiered sensible heat storage structure design, irreversible heat loss during the heat storage and release process can be effectively reduced, improving the efficiency of compression heat recovery and the system's energy utilization rate. Simultaneously, the system can be adapted and adjusted in conjunction with an organic solid waste pyrolysis unit, further realizing fossil energy substitution and solid waste resource utilization. This characteristic gives the system broad application potential in fields such as energy storage in new power systems and organic solid waste disposal.

[0039] Example 2 This embodiment also provides a compressed air energy storage power generation method based on cascaded sensible heat storage, which is implemented based on the compressed air energy storage power generation system based on cascaded sensible heat storage described in Embodiment 1. This method can realize the coordinated operation of energy storage, solid waste treatment and power generation, improve energy utilization, and achieve low-carbon and high-efficiency power generation. The specific steps are as follows: The first step, pretreatment of organic solid waste and fuel storage: The organic solid waste is pretreated by the pretreatment equipment. The organic solid waste to be disposed of is fed into the crusher 7 and crushed to the preset particle size. Then, it is fed into the washing machine 8 to remove impurities and the dryer 9 to remove free moisture, so as to obtain pretreated material that meets the requirements of pyrolysis. The pretreated organic solid waste material is fed into the pyrolysis furnace 10 and pyrolysis reaction is carried out in an anaerobic or hypoxic environment. The pyrolysis reaction temperature is 300-600℃, the reaction pressure is atmospheric pressure or slightly positive pressure, and the material reaction residence time is 30-90 min. After the reaction is completed, the solid product carbon black is discharged and collected from the bottom of the pyrolysis furnace 10, and the pyrolysis gas and pyrolysis oil products are sent to the burner 11 for storage and backup, thus completing the resource conversion of organic solid waste and fuel storage.

[0040] The second step, energy and heat storage stage: The first heat exchanger 5 is activated, and air compressor 1 is started simultaneously. Surplus electricity generated during off-peak hours is connected to the power grid. Normal temperature and pressure air is compressed into high-temperature and high-pressure air by air compressor 1. The high-pressure air at the outlet of air compressor 1 has a pressure of 10-30 kcal / kg. High-pressure air with a pressure of MPa and a temperature of 350-550℃ enters the cascade sensible heat storage unit 2 through the hot-side flow channel of the cascade sensible heat storage unit 2, and flows sequentially through the high-temperature heat storage section, the medium-temperature heat storage section, and the low-temperature heat storage section, gradually releasing the heat of compression and heating the corresponding heat storage medium unit 4 of each section. The high-temperature heat storage section operates at a temperature of 350-550℃, the medium-temperature heat storage section operates at a temperature of 200-350℃, and the low-temperature heat storage section operates at a temperature of 80-200℃, realizing the cascade storage of the heat of compression. After being cooled by the cascade sensible heat storage unit 2, the high-pressure air enters the first heat exchanger 5 to exchange heat with the cold-side ambient temperature cold water, further recovering the waste heat of the air. After the cold water absorbs heat, it forms hot water for external supply. Finally, the cooled high-pressure air is sent into the air storage chamber 6 to complete the sealed storage, completing the energy storage and heat storage process.

[0041] The third step is the energy release and power generation stage: During the peak period of the power grid load, the second heat exchanger 13 is turned on to enter the energy release operation stage; the high-pressure air stored in the gas storage chamber 6 is output and enters the cold side flow channel of the cascade sensible heat storage tank 2. It flows in the opposite direction to the hot side air and flows through the low temperature heat storage section, the medium temperature heat storage section and the high temperature heat storage section in sequence, gradually absorbing the heat stored in each heat storage medium unit 4, completing the step-by-step preheating of the high-pressure air, and restoring the high-pressure air to a high temperature state.

[0042] The fourth step is combustion, power generation, and waste heat and flue gas treatment: The high-temperature and high-pressure air, after being preheated in stages, is sent to the burner 11 and mixed with the pyrolysis gas and pyrolysis oil fuel supplied by the pyrolysis furnace 10 for combustion, generating high-temperature and high-pressure flue gas. The temperature of the high-temperature and high-pressure flue gas at the outlet of the burner 11 is 800-1100℃, which matches the air intake parameters of the expansion turbine 12. The high-temperature and high-pressure flue gas is sent to the expansion turbine 12, where it expands and performs work, driving the generator set to output stable electrical energy, thus realizing energy conversion and output.

[0043] The flue gas discharged from the expansion turbine 12 is sent to the second heat exchanger 13 to exchange heat with the ambient temperature cold water on the cold side to recover the waste heat of the flue gas. After absorbing heat, the cold water forms hot water for external supply, further tapping the value of the system's residual energy. The low-temperature flue gas after heat exchange is sent to the flue gas purification device 14 for treatment to remove harmful pollutants from the flue gas. After meeting the standards, it is discharged into the atmospheric environment, completing the entire process of energy release and power generation, waste heat recovery and flue gas treatment.

[0044] This embodiment provides a compressed air energy storage power generation method based on cascaded sensible heat storage. Relying on a cascaded sensible heat storage structure, it achieves precise cascaded storage and release of compressed heat, effectively reducing irreversible heat loss in the heat storage and release process, and improving the efficiency of compressed heat recovery and system energy utilization. At the same time, by replacing fossil fuels with organic solid waste pyrolysis products, it achieves high-value utilization of organic solid waste and near-zero carbon emission operation of the system, taking into account the needs of grid energy storage peak shaving and solid waste treatment. The operation process is continuous and stable, and it is adapted to the development needs of new power systems.

[0045] In summary, this invention employs a segmented, tiered sensible heat storage structure to address the problems of large temperature differences and severe irreversible heat losses in existing single-stage heat storage systems. It achieves tiered recovery of compression heat, significantly improving the system's compression heat recovery efficiency and overall energy utilization rate. Simultaneously, it realizes deep coupling between the compressed air energy storage system and the organic solid waste pyrolysis process. The pyrolysis gas and pyrolysis oil produced from the organic solid waste pyrolysis replace high-grade fossil fuels, burning and heating compressed air during the energy release phase. This eliminates the system's dependence on fossil fuels, simultaneously achieving low-carbon, high-efficiency operation of the energy storage system and high-value resource utilization of organic solid waste, thus enhancing the system's practical engineering value.

[0046] Finally, it should be noted that this invention is not limited to any specific type of heat exchanger structure, heat storage medium type, or guide plate opening form. Any solution that achieves efficient cascaded energy exchange and uniform heat transfer can be considered an equivalent alternative to the spirit and essence of this invention. For example, for different operating conditions, the number of heat storage unit segments can be adjusted, different types of heat storage media can be adapted, or the guide plate opening structure can be optimized to achieve the same technical effect. Any equivalent changes, substitutions, or improvements made based on the concept of this invention should be included within the scope of protection of this invention.

Claims

1. A compressed air energy storage and power generation system based on cascaded sensible heat storage, characterized in that, It includes an air compressor (1), a cascade sensible heat storage tank (2), a heat exchange and gas storage integrated unit, an organic solid waste treatment unit, a burner (11), and an expansion turbine (12). The inlet of the air compressor (1) is used to input electricity and normal temperature and pressure air. The outlet of the air compressor (1) is connected to the high temperature side air inlet of the cascade sensible heat storage tank (2). The low temperature side air outlet of the cascade sensible heat storage tank (2) is circulated to the low temperature side air inlet of the cascade sensible heat storage tank (2) after passing through the heat exchange and air storage integrated unit. The high temperature side air outlet of the cascade sensible heat storage tank (2) is connected to the air inlet of the burner (11) to form the main circulation path of compressed air energy storage and release. The input end of the organic solid waste treatment unit is used to input organic solid waste, and the output end of the organic solid waste treatment unit is connected to the fuel inlet of the burner (11) to form a pyrolysis resource utilization pathway for organic solid waste. The flue gas outlet of the burner (11) is connected to the air inlet of the expansion turbine (12), and the main shaft of the expansion turbine (12) is matched and connected to the generator set for power output.

2. The compressed air energy storage and power generation system based on cascaded sensible heat storage according to claim 1, characterized in that, The cascade sensible heat storage device (2) includes a storage device shell, which is a closed pressure-bearing structure. One end of the storage device shell is provided with a high-temperature side air inlet and a high-temperature side air outlet, and the other end is provided with a low-temperature side air inlet and a low-temperature side air outlet. The heat storage tank shell is fitted with a heat insulation sleeve (15) to block radial heat dissipation and reduce environmental heat loss. The heat storage tank shell is arranged axially from the high temperature side to the low temperature side, with a high temperature heat storage section, a medium temperature heat storage section and a low temperature heat storage section. The high temperature heat storage section, the medium temperature heat storage section and the low temperature heat storage section are filled with heat storage medium (4) at different temperatures for the staged storage of compressive heat.

3. A compressed air energy storage and power generation system based on cascaded sensible heat storage according to claim 2, characterized in that, The high-temperature heat storage section, the medium-temperature heat storage section and the low-temperature heat storage section are respectively located in the support sleeve (16), and each heat storage section is provided with a gas guide plate (6) at both ends of the axial direction and between adjacent heat storage sections. The adjacent gas guide plates (3) and the corresponding support sleeve (16) form a sealed heat storage cavity. The high-temperature heat storage section, the medium-temperature heat storage section and the low-temperature heat storage section are respectively set in different sealed heat storage cavities. Each support sleeve (16) is filled with a heat storage medium (4) at a different temperature; gas guide plates (6) are provided at both ends of the axial direction of each heat storage section and between adjacent heat storage sections to guide air evenly to the heat storage medium (4).

4. A compressed air energy storage and power generation system based on cascaded sensible heat storage according to claim 3, characterized in that, The gas guide plate (3) has uniformly arranged guide holes on its surface, which are used to guide air uniformly to the heat storage medium (4).

5. A compressed air energy storage and power generation system based on cascaded sensible heat storage according to claim 1, characterized in that, The heat exchange and gas storage integrated unit includes a first heat exchanger (5) and a gas storage chamber (6); The low-temperature side outlet of the cascade sensible heat storage tank (2) is connected to the hot fluid side inlet of the first heat exchanger (5). Cold water is connected to the cold fluid side of the first heat exchanger (5). The cold fluid side outlet of the first heat exchanger (5) is connected to the air inlet of the gas storage chamber (6). The air outlet of the gas storage chamber (6) is connected to the low-temperature side inlet of the cascade sensible heat storage tank (2).

6. A compressed air energy storage and power generation system based on cascaded sensible heat storage according to claim 1, characterized in that, The organic solid waste treatment unit includes a crusher (7), a washing machine (8), a dryer (9), and a pyrolysis furnace (10). The inlet of the crusher (7) is used to input organic solid waste; the outlet of the crusher (7) is connected to the inlet of the washing machine (8), the outlet of the washing machine (8) is connected to the inlet of the dryer (9), the outlet of the dryer (9) is connected to the inlet of the pyrolysis furnace (10), the pyrolysis gas and pyrolysis oil fuel outlets of the pyrolysis furnace (10) are connected to the fuel inlet of the burner (11), and the solid phase outlet of the pyrolysis furnace (10) produces carbon black by-product.

7. A compressed air energy storage and power generation system based on cascaded sensible heat storage according to claim 1, characterized in that, The outlet of the expansion turbine (12) is connected to the hot fluid side inlet of the second heat exchanger (13), the cold fluid side of the second heat exchanger (13) is connected to cold water, and the flue gas outlet of the second heat exchanger (13) is connected to the inlet of the flue gas purification device (14). The outlet of the flue gas purification device (14) is a qualified flue gas emission outlet, forming a path for energy release and power generation, waste heat recovery, and flue gas treatment.

8. A compressed air energy storage and power generation method based on cascaded sensible heat storage, characterized in that, A compressed air energy storage power generation system based on cascaded sensible heat storage as described in any one of claims 1-7 includes the following process: The organic solid waste is pre-treated by the pretreatment equipment. The organic solid waste to be disposed of is sent to the organic solid waste treatment unit for treatment to obtain pyrolysis gas and pyrolysis oil products, which are then sent to the burner (11) for storage. Start the air compressor (1), and the normal temperature and pressure air is compressed into high temperature and high pressure air through the air compressor (1). The air is then transferred to the hot side channel of the cascade sensible heat storage tank (2) for heat exchange. The high temperature and high pressure air flows through the high temperature storage section, the medium temperature storage section and the low temperature storage section in sequence to achieve cascade storage of the compressed heat. High-pressure air cooled by the cascade sensible heat storage unit is then stored in a sealed manner through the heat exchange and gas storage integrated unit. During the peak period of the power grid load, the high-pressure air output of the heat exchange and gas storage integrated unit enters the cold side flow channel of the cascade sensible heat storage unit (2), flows in the opposite direction to the hot side air, and flows through the low temperature heat storage section, the medium temperature heat storage section and the high temperature heat storage section in sequence, gradually absorbing heat and completing the step-by-step preheating of the high-pressure air. High-temperature and high-pressure air, after being preheated in stages, is sent into the burner (11) and mixed with pyrolysis gas and pyrolysis oil fuel for combustion. The resulting high-temperature and high-pressure flue gas is sent into the expansion turbine (12). The flue gas expands and does work in the expansion turbine, driving the generator set to output stable electrical energy.

9. A compressed air energy storage and power generation method based on cascaded sensible heat storage according to claim 1, characterized in that, The high-pressure air at the outlet of the air compressor (1) is 10-30 MPa and the temperature is 350-550℃; the working temperature of the high-temperature heat storage section of the stepped sensible heat storage device (2) is 350-550℃, the working temperature of the medium-temperature heat storage section is 200-350℃, and the working temperature of the low-temperature heat storage section is 80-200℃.

10. A compressed air energy storage and power generation method based on cascaded sensible heat storage according to claim 1, characterized in that, The high-temperature and high-pressure flue gas temperature at the outlet of the burner (11) is 800-1100℃.

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