A thermo-acoustic coupled power and refrigeration system and method based on compressed air energy storage

Abstract

This application relates to the field of energy storage and multi-energy complementarity technology, and discloses a thermoacoustic coupling power generation-cooling system and method based on compressed air energy storage. The system includes a compressed air energy storage module, a thermal management module, a thermoacoustic power generation-cooling module, and a measurement and control module. In the energy storage stage, high-pressure air generated by an air compressor unit is stored in a high-pressure air tank, and the heat of compression is stored in a high-temperature heat storage tank. In the energy release stage, high-pressure air is introduced into a thermoacoustic engine to regulate the cavity pressure, and the heat energy from the high-temperature heat storage tank is input into the main heater of the thermoacoustic engine to establish a temperature difference. When the temperature difference reaches the oscillation critical value, the air in the cavity undergoes self-excited oscillation to generate sound waves. After the sound waves are split, they drive a linear generator to generate electrical energy and a thermoacoustic refrigerator to generate cooling energy, which is stored in a low-temperature cold storage tank. This invention achieves efficient coupling and flexible output of multiple energy sources through compressed air energy storage by adjusting impedance parameters and dynamically controlling the sound power ratio of power generation and cooling.

Description

Technical Field

[0001] This invention relates to the field of energy storage and multi-energy complementarity technology, specifically to a thermoacoustic coupling power generation-cooling system and method based on compressed air energy storage. Background Technology

[0002] As the penetration rate of renewable energy in the power grid continues to increase, energy storage technology plays a crucial role in mitigating energy fluctuations and regulating peak and frequency in the power grid. Compressed air energy storage systems, which store energy by compressing air during off-peak hours and releasing high-pressure air to generate electricity during peak hours, are an effective method for large-scale, long-term energy storage. The compression of air generates a significant amount of heat; therefore, efficiently recovering and utilizing this heat is key to improving the overall energy conversion efficiency of compressed air energy storage systems.

[0003] Thermoacoustic technology is based on the thermoacoustic effect to achieve the mutual conversion of thermal energy and sound energy. Thermoacoustic engines can convert thermal energy into sound wave energy, while thermoacoustic refrigerators use sound energy to generate cooling. Because thermoacoustic systems lack internal moving mechanical parts, they are characterized by high reliability, low maintenance costs, and environmentally friendly operation.

[0004] In existing energy storage and conversion applications, compressed air energy storage systems typically focus on single-function electrical output, with compression heat primarily used for air heating during the energy release phase. This limited energy utilization makes it difficult to meet the combined energy demands of users for both electricity and cooling. Conventional thermoacoustic power generation systems often require an additional independent pressurization system to increase the density and power density of the working medium, increasing the overall equipment size and operating costs. Furthermore, existing energy coupling systems typically operate at a fixed power ratio when facing external load fluctuations, lacking dynamic guidance and impedance regulation mechanisms for the internal acoustic energy. This prevents the system from flexibly allocating the cooling and electricity output ratio according to real-time changes in external grid load and cooling demand, resulting in a significant decrease in overall energy utilization efficiency under varying operating conditions. Therefore, achieving efficient physical coupling of compressed air energy storage and thermoacoustic technology at the pressurization, heat transfer, and multi-energy output stages, and establishing a dynamic energy allocation mechanism, are key technical challenges that need to be addressed in this field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a thermoacoustic coupling power generation-cooling system and method based on compressed air energy storage. This solves the problems of existing technologies, such as the single form of thermal utilization of compressed air energy storage, the need for additional pressurization of thermoacoustic equipment, and the lack of a dynamic energy distribution mechanism. These issues make it difficult to meet the requirements of efficient coupling and flexible adjustment of the cooling-electricity ratio in multi-energy complementary systems under varying operating conditions.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] The first aspect of the present invention provides a thermoacoustic coupling power generation-cooling system based on compressed air energy storage.

[0008] The system includes a compressed energy storage module, a thermal management module, a thermoacoustic power generation and cooling module, and a measurement and control module.

[0009] The compressed energy storage module includes an air compressor unit with an ambient air inlet and connected in sequence by pipelines, an interstage heat exchanger, an aftercooler, and a high-pressure air tank.

[0010] The thermal management module includes a low-temperature storage tank, and a heat medium circulation pump, an interstage heat exchanger, an aftercooler, and a high-temperature storage tank, which are connected in sequence by pipelines to form a heat medium circulation loop in which heat medium fluid flows.

[0011] The thermoacoustic power generation and refrigeration module includes a thermoacoustic engine, a linear engine, a resonant tube, and a thermoacoustic refrigerator.

[0012] The high-temperature heat storage tank is fluidly connected to the main heater of the thermoacoustic engine through a high-grade heat energy release channel, and the high-pressure gas storage tank is connected to the internal cavity of the thermoacoustic engine through a pressure pipeline.

[0013] The thermoacoustic engine is connected to the linear engine and the thermoacoustic refrigerator through an acoustic pipe and a resonant tube for sound power transmission, respectively. The cold end of the thermoacoustic refrigerator is connected to the cryogenic storage tank through a cryogenic energy intake channel.

[0014] The measurement and control module includes a main controller that communicates with each module to control the operating status of each module.

[0015] Furthermore, the air compressor unit can be configured to include a primary compressor, a secondary compressor, and a tertiary compressor, wherein the primary compressor is connected to the ambient air inlet and the primary interstage heat exchanger, and is sequentially connected to the secondary compressor, the secondary interstage heat exchanger, and the aftercooler.

[0016] The high-temperature heat storage tank adopts a double-layer pressure-bearing metal shell and is filled with rock wool insulation material. The internal heat transfer fluid is high-boiling-point heat transfer oil.

[0017] The gas supply pipeline of the high-pressure gas storage tank is equipped with a pressure regulating valve connected to the main controller.

[0018] The thermoacoustic engine is arranged in sequence along the fluid direction as a main heater, main regenerator, main cooler, thermal buffer tube, and acoustic power output tube. The main heater is used to acquire input heat, the main cooler is connected to a medium-temperature heat sink to release and remove heat, and the thermal buffer tube is connected to the acoustic power output tube to form acoustic power output.

[0019] The linear motor has a permanent magnet mover located inside the stator coil, and the thrust piston end face is connected to the acoustic power output tube.

[0020] A T-shaped resonant shunt tube is installed on the resonant tube to connect to the thermoacoustic refrigerator. The thermoacoustic refrigerator is equipped with a cold end heat exchanger, a secondary regenerator and a secondary cooler. The cold end heat exchanger is used to absorb low-temperature cold loads, the secondary cooler is connected to the ambient heat sink, and the cold load is connected to the low-temperature cold storage tank. A sound power regulator containing a stepper motor and a rotary acoustic impedance adjustment structure is installed at the branch node.

[0021] The measurement and control module also includes temperature sensors, pressure sensors, and displacement sensors installed inside the high-temperature heat storage tank, high-pressure gas storage tank, and linear engine, respectively, and each sensor is connected to the main controller.

[0022] This system combines thermoacoustic effects with compressed air energy storage through the aforementioned structure. The heat of compression generated by the air compressor unit during the energy storage phase is extracted through a heat exchange network and stored in a high-temperature heat storage tank.

[0023] The high-pressure air generated during the energy storage phase is stored in a high-pressure gas tank and introduced into the thermoacoustic engine as a pressurizing medium during the energy release phase to increase the average working pressure of the engine cavity, thereby increasing the density of the working gas and improving the power density of the thermoacoustic conversion.

[0024] The heat energy released from the high-temperature thermal storage tank is input into the thermoacoustic engine through the main heater to establish a temperature gradient, causing the gas inside the cavity to undergo self-excited oscillation to generate sound waves, thus completing the conversion of thermal energy into sound energy.

[0025] After the acoustic energy enters the branch pipeline, part of it drives the thrust piston of the linear motor to reciprocate and generate electrical energy, while the other part enters the thermoacoustic refrigerator to expand, absorb heat, and generate cooling capacity, thus realizing the output of electrical energy and cooling capacity of the system.

[0026] A second aspect of the present invention provides a thermoacoustic coupling power generation-cooling method based on compressed air energy storage.

[0027] This method is based on the aforementioned system and includes the following steps: starting the air compressor unit to compress ambient air, the high-temperature air generated by compression flows through the interstage heat exchanger and aftercooler to transfer heat to the heat transfer fluid, the heated heat transfer fluid is stored in the high-temperature heat storage tank, and the cooled high-pressure air is stored in the high-pressure air storage tank.

[0028] By controlling the on / off state of the pressure pipeline connected to the high-pressure gas tank, the average pressure of the internal cavity of the thermoacoustic engine is adjusted to a preset working set value using the air in the high-pressure gas tank. The working set value is 1MPa to 10MPa. The heat medium circulation loop is then opened to transfer the heat energy in the high-temperature heat storage tank to the main heater of the thermoacoustic engine.

[0029] The thermoacoustic engine establishes a temperature difference under the action of the heat energy input by the main heater. When the temperature difference exceeds the preset oscillation critical value of 80°C to 100°C, the air in the internal cavity undergoes self-excited oscillation and generates high-intensity sound waves.

[0030] High-intensity sound waves drive a linear motor to perform linear reciprocating motion, converting sound energy into electrical energy output. Part of the high-intensity sound waves drive a thermoacoustic refrigerator to generate cooling at its cold end and store it in a low-temperature storage tank. The main controller adjusts the electrical load impedance of the linear motor and the sound wave flow state entering the thermoacoustic refrigerator according to the external electrical load and cooling load requirements, and dynamically controls the sound power ratio entering the linear motor and the thermoacoustic refrigerator.

[0031] This method achieves dynamic energy matching by controlling impedance parameters and the heat-work conversion process. During the thermoacoustic initiation stage, the externally input thermal energy creates a temperature gradient across the two ends of the main regenerator. When the temperature difference reaches the critical value for initiation, the expansion and compression process of the gas microparticles and the change in sound pressure produce a phase difference, overcoming the viscous dissipation within the system to generate acoustic power output.

[0032] During the energy distribution phase, the total acoustic power is shunted at the T-type resonant shunt tube. The main controller changes the mechanical impedance of the linear motor by adjusting its electrical load state, and synchronously drives the rotary acoustic impedance adjustment structure to change the acoustic impedance of the refrigeration unit branch.

[0033] By changing the ratio of the parallel acoustic impedances at both ends, the sound wave will generate a larger volumetric flow rate in the branch with lower impedance.

[0034] When the grid load increases, the controller increases the acoustic impedance on the chiller side and decreases the electrical load impedance of the generator, thereby increasing the acoustic power allocated to the linear motor; when the cooling demand increases, the impedance parameters are adjusted in the opposite direction, thus realizing the real-time allocation of thermoacoustic power generation and cooling power.

[0035] This invention provides a thermoacoustic coupling power generation-cooling system and method based on compressed air energy storage. It has the following beneficial effects: 1. This invention achieves physical coupling between compressed air energy storage and the thermoacoustic system by connecting the high-pressure air storage tank and the high-temperature heat storage tank to the internal cavity of the thermoacoustic engine and the main heater, respectively. The high-pressure air in the high-pressure air storage tank directly serves as the working medium of the thermoacoustic engine to increase the average operating pressure, eliminating the need for the independent pressurization device required by traditional thermoacoustic equipment. At the same time, the compression heat collected by the high-temperature heat storage tank is directly used as the driving heat source to drive the thermoacoustic system to start oscillation, thereby improving the overall energy conversion efficiency of the system.

[0036] 2. This invention utilizes a thermoacoustic engine to convert thermal energy into acoustic energy, and connects a linear generator and a thermoacoustic chiller through acoustic pipes and resonant tubes respectively, realizing the joint output of electrical energy and cooling capacity. This structure expands the single electrical energy output mode of the traditional compressed air energy storage system into a combined cooling and power mode, increasing the energy output path of the system and enabling it to adapt to the multi-dimensional energy demand of users for electrical and cooling loads.

[0037] 3. This invention sets up an acoustic power regulator at the branch node of the thermoacoustic system and synchronously adjusts the electrical load impedance of the linear generator and the acoustic impedance of the thermoacoustic chiller branch through the main controller, thus establishing a dynamic distribution mechanism for the cooling-electric ratio. By changing the impedance ratio of the branch parallel end in real time, the system can guide the distribution of the acoustic volume flow rate according to the actual external load demand, thereby flexibly controlling the acoustic power ratio of power generation and cooling, and ensuring the equipment operation flexibility under changing operating conditions. Attached Figure Description

[0038] Figure 1 This is a system diagram of the system and method of the present invention; Figure 2 This is a schematic diagram illustrating the energy quality changes and utilization of the present invention; Figure 3 This is a schematic diagram of the traveling wave thermoacoustic engine structure of the present invention; Figure 4 This is a schematic diagram of the control logic of the present invention.

[0039] The components include: 1. High-temperature heat storage tank; 2. High-grade heat energy release channel; 3. Thermoacoustic engine; 4. Sound power transmission; 5. Resonant tube; 6. Thermoacoustic refrigerator; 7. Low-temperature energy absorption channel; 8. Cooling load; 9. Medium-temperature heat sink; 10. Ambient heat sink; 11. Main heater; 12. Input heat; 13. Main regenerator; 14. Exhaust heat; 15. Main cooler; 16. Thermal buffer tube; 17. Sound power output tube; 18. Sound power output; 19. Linear engine; 20. Main controller; 21. Ambient air inlet; 22. First-stage compressor; 23. First-stage interstage heat exchanger; 24. Second-stage compressor; 25. Second-stage interstage heat exchanger; 26. Third-stage compressor; 27. Aftercooler; 28. High-pressure gas storage tank; 29. ​​Pressure regulating valve; 30. Heat medium circulation pump; 31. Low-temperature cold storage tank; 32. Power output terminal; 33. Sound power regulator. Detailed Implementation

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0041] Please see the appendix Figure 1 This invention provides a thermoacoustic coupling power generation-cooling system based on compressed air energy storage, including a compressed energy storage module, a thermal management module, a thermoacoustic power generation-cooling module, and a measurement and control module.

[0042] The compressed energy storage module is connected to the thermal management module via a heat exchanger. The compressed energy storage module is connected to the thermoacoustic power generation and cooling module via a pressure pipeline. The thermal management module is connected to the thermoacoustic power generation and cooling module via a heat transfer fluid pipeline. The monitoring and control module connects to each device to control its operating status.

[0043] Ambient air enters the air compressor unit through ambient air inlet 21. The air sequentially passes through a primary compressor 22, a primary interstage heat exchanger 23, a secondary compressor 24, a secondary interstage heat exchanger 25, a tertiary compressor 26, and an aftercooler 27, before finally being stored in a high-pressure air storage tank 28. The thermal management module includes a high-temperature heat storage tank 1, a low-temperature cold storage tank 31, and a heat medium circulation pump 30. The heat medium circulation pump 30 drives the heat medium fluid to flow through each stage of heat exchangers to absorb the heat generated by air compression, and after being heated, it enters the high-temperature heat storage tank 1 for storage.

[0044] The thermoacoustic power generation and cooling module includes a thermoacoustic engine 3, a linear generator 19, and a thermoacoustic refrigerator 6. The thermal energy from the high-temperature heat storage tank 1 is transferred to the main heater 11 of the thermoacoustic engine 3 through the high-grade heat energy release channel 2. The high-pressure air storage tank 28 is connected to the thermoacoustic engine 3 through a pressure regulating valve 29, injecting high-pressure air into the thermoacoustic engine 3 to maintain the set ambient static pressure.

[0045] A portion of the acoustic power enters the linear generator 19 to generate electrical energy, which is then output from the electrical output terminal 32. The remaining acoustic power is transmitted along the resonant tube 5 and enters the thermoacoustic refrigerator 6. The gas temperature decreases at the cold load location, absorbing heat from the low-temperature cold load side 8 through the low-temperature energy absorption channel 7 to output cooling capacity. An acoustic power regulator 33 is installed in the front-end piping of the thermoacoustic refrigerator 6. The main controller 20 receives sensor feedback data and controls the operating status of the heat transfer fluid circulation pump 30, pressure regulating valve 29, linear generator 19, and acoustic power regulator 33.

[0046] Please see Figure 1 The diagram details the overall system architecture and equipment connections. Air enters from the left, passing sequentially through first- to third-stage compressors (22, 24, 26), inter-stage heat exchangers (23, 25), and aftercooler 27, finally being stored in high-pressure storage tank 28. High-temperature heat storage tank 1 establishes a closed-loop high-grade heat energy release channel 2 with the main heater of thermoacoustic engine 3 via heat medium circulation pump 30. Alternating sound waves 4 generated by thermoacoustic engine 3 are partially converted into electrical energy by linear generator 19 (extracted from electrical output terminal 32), and the other part enters thermoacoustic refrigeration system 6 via acoustic power regulator 33 for cooling and absorbing heat from cooling load 8. Simultaneously, the diagram indicates the paths for waste heat to be discharged to medium-temperature heat sink 9 and ambient heat sink 10, respectively. The dashed lines represent the measurement and control communication network between main controller 20 and underlying components (including low-temperature cold storage tank 31, pressure regulating valve 29, acoustic power regulating valve 33, etc.).

[0047] Please see the appendix Figure 1 This invention provides a thermoacoustic coupling power generation-cooling method based on compressed air energy storage, comprising the following steps: S10, during the compression and energy storage stage, the air compressor unit is started to compress the ambient air. The high-temperature air generated by compression flows through the interstage heat exchanger to transfer heat to the heat medium fluid and is stored in the high-temperature heat storage tank 1. The cooled high-pressure air is stored in the high-pressure air storage tank 28. S20, during the hot press injection stage, the pressure regulating valve 29 is opened, and the air in the high pressure storage tank 28 is used to adjust the average pressure in the thermoacoustic circuit to the working set value. The hot circuit circulation is started to transfer the heat energy in the high temperature heat storage tank 1 to the main heater 11 of the thermoacoustic engine 3. S30, during the thermoacoustic oscillation stage, the thermoacoustic engine 3 establishes a temperature difference under the action of the thermal energy input by the main heater 11. When the temperature difference exceeds the oscillation critical value, the internal gas undergoes self-excited oscillation and generates high-intensity sound waves. S40, in the energy conversion output stage, the high-intensity sound wave drives the linear generator 19 to perform linear reciprocating motion to convert sound energy into electrical energy. Part of the high-intensity sound wave drives the thermoacoustic refrigerator 6 to generate cooling at the cold end. The main controller 20 adjusts the electrical load impedance of the linear generator 19 and the current flow state of the sound power regulator 33 according to the external electrical load and cooling load requirements, and dynamically controls the sound power ratio entering the linear generator 19 and the thermoacoustic refrigerator 6.

[0048] Based on the overall system architecture described above, the system includes independent structural units that perform air compression and energy storage functions. In this embodiment, this unit mainly consists of an air compressor unit, interstage heat exchange equipment, and a high-pressure air storage tank 28. The air compressor unit adopts a multi-stage reciprocating piston compressor or screw compressor, which uses externally input mechanical work to compress ambient air at normal pressure to a high-pressure state step by step. The design pressure range is set based on the static pressure conditions required for subsequent acoustic resonance of the system, and the specific numerical range is set from 5.0 MPa to 15.0 MPa.

[0049] S110, ambient air is introduced into the air compressor unit through ambient air inlet 21 and undergoes multi-stage compression. The air undergoes initial compression in the first-stage cylinder, its volume shrinks, and the thermal motion of gas molecules intensifies, leading to compression to an initial high pressure and generating associated heat of compression. The structure of the compressor cylinder's exhaust valve and the transmission method of the piston connecting rod can be selected and set by those skilled in the art based on preset flow rate and pressure ratio parameters. The specific mechanical structure is well-known in the field and will not be described in detail here.

[0050] Before performing specific thermodynamic calculations, it is necessary to clarify that the gas pressurization process is based on the thermodynamic polytropic compression principle. In actual operating conditions, due to heat exchange between the cylinder interior and the external environment, the air compression process approximates a polytropic compression process. The exhaust temperature of each stage of the compressor is comprehensively affected by its intake absolute temperature, the intake-to-exhaust pressure ratio, and the air polytropic index. To maintain the physical integrity of the intake-to-exhaust pressure ratio, the intake pressure of each stage is supported by the ambient atmospheric pressure or the exhaust pressure of the preceding stage under actual operating conditions, and its value is always greater than zero. In this embodiment, to obtain a high-grade heat source required for subsequent thermoacoustic oscillation, the first-stage compressor 22 compresses the ambient air from 0.1 MPa to 1.2 MPa, at which point the exhaust temperature of the first-stage compressor rises to approximately 320°C.

[0051] S120, the interstage heat exchanger extracts the heat of compression. The high-temperature, high-pressure airflow discharged from the first-stage compressor 22 enters the first-stage interstage heat exchanger 23. The airflow exchanges heat counter-currently with the heat transfer fluid in the shell side, and this counter-current arrangement aims to maximize the heat transfer temperature difference within the system to improve heat exchange efficiency. The air releases heat and lowers its own temperature. The cooled air then sequentially enters the second-stage compressor 24 for a second pressurization to 4.0 MPa, is cooled again by the second-stage interstage heat exchanger 25, and finally enters the third-stage compressor 26 for compression to 10.0 MPa. After passing through the third-stage compressor 26, the air flows into the aftercooler 27 for final cooling.

[0052] The total heat power captured by the system during the multi-stage compression and cooling process is the sum of the products of the air mass flow rate in each compressor stage, the specific heat capacity of air at constant pressure under the current pressure environment, and the inlet and outlet heat transfer temperature difference. This macroscopic energy conservation logic quantifies the scale of high-grade heat sources available to the system, providing fundamental data support for the measurement and control components to calculate subsequent thermoacoustic work parameters.

[0053] S130, the high-pressure gas storage tank 28 performs the storage of high-pressure gas and the pressure boosting of the pipeline network. High-pressure gas, compressed and cooled through various stages, is injected into the high-pressure gas storage tank 28 via connecting pipelines. The high-pressure gas storage tank 28 is an alloy steel container with a wall thickness conforming to the rated pressure standard. This container has a dual physical function in the system: it not only serves as the main carrier of the physical energy storage medium, storing externally input energy in the form of air pressure potential energy; its internal high-pressure volume space also acts as a constant pressure source and pressure stabilizing compensation chamber for the subsequent thermoacoustic pipelines. A pressure regulating valve 29 is installed on the gas supply pipeline at the bottom of the high-pressure gas storage tank 28. Opening the pressure regulating valve 29 allows gas at a set pressure to be output externally, thereby dynamically establishing and maintaining a high average static pressure environment in the externally connected closed pipeline, thus meeting the operational requirements of the thermoacoustic transducer under high-density working medium conditions.

[0054] Based on the waste heat resources generated in the aforementioned compression energy storage stage, the system is equipped with an independent thermal management unit to achieve heat capture, storage, and distribution. In this embodiment, the thermal management module mainly includes a heat medium circulation pump 30, a high-temperature heat storage tank 1, a low-temperature cold storage tank 31, and fluid delivery pipelines connecting each component.

[0055] S210, to effectively gather the dispersed compression heat, the system constructs a closed fluid transport network through a heat medium circulation pump 30. The heat medium circulation pump 30 starts and overcomes the pipeline resistance, driving the heat medium fluid to flow directionally in the closed-loop pipeline. The heat medium fluid uses high-boiling-point heat transfer oil to prevent phase change boiling when absorbing high-temperature exhaust heat from the compressor, thereby maintaining the stability of the fluid dynamics within the pipeline network. The heat transfer oil flows sequentially along the pipeline network through the first-stage interstage heat exchanger 23, the second-stage interstage heat exchanger 25, and the aftercooler 27 located at the end. Inside each of these heat exchange devices, the low-temperature heat transfer oil and the high-temperature compressed air employ a counter-current heat exchange mechanism. This counter-current arrangement ensures that the two fluids maintain a relatively uniform heat transfer temperature difference throughout the entire flow direction, thereby improving the heat recovery rate. Regarding the specific shell and tube structure of the interstage heat exchanger and the arrangement of the internal baffles, those skilled in the art can perform conventional calculations and designs based on the preset heat exchange load; the specific flow channel layout is well-known in the field and will not be elaborated here.

[0056] S220, the heat transfer oil that has completed heat absorption and heating is collected and flows into the internal cavity of the high-temperature thermal storage tank 1. To achieve long-term, cross-time-dimension scheduling of thermal energy, the high-temperature thermal storage tank 1 adopts a double-layer pressure-bearing metal shell design. The interlayer space of this double shell is filled with high-density rock wool insulation material (with a thickness of not less than 200mm) to block the heat conduction from the internal high temperature to the external environment, ensuring that the heat loss rate of the high-temperature thermal storage tank 1 is less than 1% / day.

[0057] Because the system needs to dynamically assess the total available thermal storage capacity to determine the timing of switching to subsequent cooling or power generation modes, the monitoring and control unit needs to quantify the heat loss in this thermal storage stage in real time. Based on the combined application of Fourier's law of thermal conductivity and Newton's law of cooling, the heat loss power dissipated into the environment per unit time is proportional to the comprehensive heat transfer coefficient, the effective heat exchange surface area of ​​the high-temperature thermal storage tank 1, and the heat transfer temperature difference between the average temperature of the heat transfer oil inside the high-temperature thermal storage tank 1 and the absolute temperature of the external natural environment. The comprehensive heat transfer coefficient is jointly determined by the metal tank body and the rock wool insulation layer, and to meet the engineering insulation requirements, its value is typically controlled within the range of 0.03 W / (m²). 2 ·K) to 0.05W / (m 2 Between ·K). The above steady-state heat transfer assessment logic objectively reflects the energy dissipation rate of the thermal storage equipment under the current environment.

[0058] In addition to thermal energy storage, the S230 system's thermal management module also includes a cold energy allocation mechanism. The cryogenic storage tank 31 is connected to the thermoacoustic refrigeration system via an independent reflux network to store and buffer low-grade cold energy generated by subsequent refrigeration cycles.

[0059] When the system receives a power generation or cooling command, the thermal energy enters the release phase. The output end of the high-temperature heat storage tank 1 establishes a thermodynamic connection with the subsequent thermoacoustic power unit. Specifically, the system controls the corresponding valve to open, and the high-temperature heat transfer oil in the high-temperature heat storage tank 1 is precisely pumped into the main heater 11 of the thermoacoustic engine 3 through the high-grade thermal energy release channel 2. At the end of this transmission path, the heat transfer oil flows through the finned tube bundle structure inside the main heater 11, transferring its high-grade compression thermal energy (temperature range between 150℃ and 350℃, for example, around 280℃ based on 1.2MPa exhaust) across the metal wall to the working gas inside the thermoacoustic engine 3. After releasing heat and significantly cooling down, the heat transfer oil then returns to the cycle starting point along the return pipeline to continue participating in the next round of compression heat absorption process. This closed-loop thermal path not only avoids the waste of the heat storage medium but also ensures that the driving heat source can be stably and continuously coupled to the thermoacoustic conversion system.

[0060] Based on the pressure and thermal energy conditions provided by the aforementioned pipeline network, the system converts the acquired high-grade thermal energy into acoustic mechanical work through a thermoacoustic engine module. In this embodiment, the thermoacoustic engine 3 constitutes the core infrastructure for the entire acoustic power excitation and output.

[0061] S310, physical structure encapsulation and high-pressure charging. The traveling wave-shaped thermoacoustic engine 3 is externally encased in a ring-shaped high-strength alloy steel pressure-resistant shell. This shell not only encloses the internal working gas but also provides mechanical support to withstand the internal high pressure. To increase the overall acoustic power output of the system without changing the physical dimensions of the equipment, a high-pressure gas tank 28 is connected to the pressure wave node of the thermoacoustic engine 3 via an external pipeline and a pressure regulating valve 29. By precisely injecting high-pressure air, the system dynamically increases and maintains the average static pressure of the internal loop. Injecting high-pressure gas at the wave node minimizes the interference of airflow on the acoustic field resonance mode while ensuring that the static pressure of the entire loop remains consistent with that of the gas tank.

[0062] In addition, although this embodiment mainly describes air as the sound propagation medium, the high-pressure gas filled in the system is not limited to air; helium, argon, or mixtures thereof can also be used. Air stored in the high-pressure gas tank can transfer pressure to the helium-filled thermoacoustic circuit through a physical diaphragm, utilizing helium's better thermal conductivity and lower Prandtl number to achieve higher thermoacoustic conversion efficiency.

[0063] Before elucidating the intrinsic mechanism of high-pressure energy transmission, it is necessary to clarify the basic physical laws governing the energy carried by sound waves within a sound field. The energy carried by sound waves transmitted within a sound field is directly controlled by the amplitude of gas pressure oscillations and the properties of the medium. The sound power flux density is calculated based on the following acoustic characteristic relationships: ; In the formula, Represents the acoustic power flux density; This represents the average density of the working gas within the system. The speed of sound of the working gas in its current state; This represents the alternating dynamic pressure amplitude. To ensure the absolute physical completeness of the above multiplication model, the average density of the working gas in the system under actual operating conditions is used. Speed ​​of sound of the working gas in its current state All are rigidly supported by the inherent properties of the material and absolute temperature, and their values ​​are always greater than zero, ensuring the validity of the energy density assessment. Because the system maintains a relatively constant pressure ratio through structural design, the alternating dynamic pressure amplitude... It is directly proportional to the average static pressure. Based on this physical correlation, by significantly increasing the average static pressure through an external high-pressure gas storage tank (for example, increasing it to a high-pressure condition of 8.0 MPa, which can increase the gas density and acoustic impedance by about 80 times compared to conventional atmospheric pressure), the pressure square term at the end of the above formula increases exponentially, thereby achieving a significant increase in acoustic power output per unit cross-sectional area, enabling industrial-grade high-power output in extremely compact spaces.

[0064] S320, based on the establishment of a high-pressure operating environment, requires the internal construction of a temperature difference boundary and thermodynamic framework to drive thermoacoustic oscillation. The main heater 11 and main cooler 15 are arranged axially opposite each other inside the thermoacoustic engine 3, with the main regenerator 13 tightly installed between them. The main heater 11 is connected to the high-grade heat release channel 2, receiving the input heat 12 transported by the heat transfer network; simultaneously, the main cooler 15 is connected to an external ambient temperature water circulation pipeline, continuously removing unusable exhaust heat 14 from system operation and discharging it into the medium-temperature heat sink 9, thereby maintaining the large temperature gradient difference required for oscillation. A heat buffer tube 16 is further connected in series axially along the pipeline on the output side of the main heater 11. The heat buffer tube 16 uses a thin-walled metal tube with low thermal conductivity, providing physical space for hot air expansion and blocking direct solid heat conduction from the high-temperature zone main heater 11 to the ambient temperature zone end acoustic power output pipeline, thereby maintaining the extreme temperature difference between the oscillation core ends. The selection of the specific length and diameter ratio of the heat buffer tube can be conventionally deduced by those skilled in the art based on the wavelength of the sound wave. The parameter settings are well-known techniques in this field and will not be elaborated here.

[0065] S330, driven by the aforementioned axial temperature gradient, the working gas completes a microscopic thermomechanical cycle inside the main regenerator 13. The main regenerator 13 is densely filled with high-mesh (e.g., 60 to 120 mesh, preferably 100 mesh) stainless steel wire mesh or ceramic honeycomb. When the temperature difference between the heating end and the cooling end exceeds the oscillation threshold, the gas micro-particles in the micro-channels of the wire mesh spontaneously undergo thermodynamic processes of compression, heat absorption, expansion, and heat release, generating thermoacoustic self-excited oscillations. This converts thermal energy into mechanical energy in the form of sound waves, which is then transmitted to the outside through the thermal buffer tube 16 and the resonant tube 5.

[0066] The system's operating frequency was chosen to be 50Hz to directly match the power frequency. At this frequency, if a mixture of helium and air is used as the working fluid, its thermal penetration depth is approximately 0.2mm, which perfectly matches the hydraulic radius of a 100-mesh wire mesh, minimizing viscous dissipation between the gas and the solid framework.

[0067] Please see Figure 3 The diagram visually illustrates the circulation loop of the working gas flowing along the traveling wave direction within the annular pipe. External heat input 12 is introduced into the main heater 11. The working gas within the system undergoes heat exchange within the dense main regenerator 13, and is discharged to the outside (low-temperature side) via the main cooler 15 on the other side. After the heat excites sound waves, the acoustic energy is transmitted through the thermal buffer tube 16 and the annular main resonant pipe 17, and finally output to the outside from the acoustic power output interface 18. The waveform diagram in the center of the diagram visually illustrates the acoustic field characteristics within the pipe, where the letter P represents sound pressure and U represents air velocity. As can be seen from the waveform diagram, the peaks and troughs of the sound pressure P and air velocity U are perfectly aligned, meaning they are in phase. This in-phase traveling wave acoustic field characteristic causes gas particles to move towards the high-temperature end during compression and towards the low-temperature end during expansion, forming the core physical basis for achieving efficient thermoacoustic energy conversion.

[0068] To evaluate the energy utilization level of this thermoacoustic conversion stage, the system does not use a rigid, single theoretical formula for limitation, but rather conducts a dynamic evaluation based on fundamental thermodynamic principles. The thermomechanical conversion efficiency of the traveling wave thermoacoustic cycle is theoretically capped by the Carnot cycle efficiency, determined by the operating temperatures at both the hot and cold ends of the system. As the input temperature of the main heater 11 increases and the exhaust temperature of the main cooler 15 decreases, the thermal relaxation loss of the gas within the microscopic regenerator channels of the system relatively decreases, and its actual operating efficiency approaches the Carnot efficiency infinitely (the percentage relative to the Carnot efficiency can reach 50%-60%, and the thermoelectric conversion efficiency is expected to reach 30%-40%). Combined with compression heat recovery, the overall electrical conversion efficiency of the system is expected to reach over 65%; if the cooling capacity of the refrigeration system is further considered, the comprehensive energy utilization efficiency can exceed 80%. This thermodynamic conversion logic provides a decision-making basis for the system to dynamically adjust the input flow rate and temperature threshold of the front-end heat transfer oil, ensuring that the system is always in the optimal thermoacoustic conversion range under complex power grid dispatching conditions.

[0069] Based on the high-pressure sound waves generated by the aforementioned thermoacoustic engine, the system transmits a portion of the acoustic power to the generator unit for electromechanical energy conversion via the acoustic power output tube 17. In this embodiment, the linear generator 19 achieves efficient direct conversion from acoustic mechanical work to electrical energy.

[0070] S410, the alternating pressure wave excited by the thermoacoustic engine 3 acts directly on the thrust piston end face of the linear generator 19 through the acoustic power output pipe 17. The linear generator 19 adopts a moving magnet linear generator (or a moving coil, moving iron, or piezoelectric ceramic transducer, etc., as a form of acoustic-to-electric conversion), and its interior is filled with the same high-pressure gas as the thermoacoustic system. The internal structure mainly includes a thrust piston, a permanent magnet mover, a stator coil, and a leaf spring support assembly. This direct-coupled de-turbine design eliminates the crank connecting rod or turbine impeller in traditional rotating machinery, and utilizes the frictionless characteristics of gas bearings or leaf spring supports to eliminate mechanical losses and dynamic seal losses at the physical level. As for the specific winding method of the stator coil and the magnetic circuit arrangement of the permanent magnet, those skilled in the art can perform conventional design according to the preset voltage level. Its specific electromagnetic structure is well-known in the art and will not be described in detail here.

[0071] S420, driven by the aforementioned alternating pressure wave, the electromechanical energy conversion mechanism is initiated. The thrust piston drives the permanent magnet mover to reciprocate linearly within the stator coil. The mover's motion causes a periodic change in the magnetic flux passing through the stator coil, inducing an alternating electromotive force at the ends of the stator coil according to Faraday's law of electromagnetic induction. This induced electrical energy is then led out from the power output terminal 32 and connected to an external power grid or load.

[0072] The acoustic-mechanical work absorbed by the linear generator 19 is directly controlled by the dynamic pressure amplitude at the thrust piston end face, the volume velocity amplitude of the piston movement, and the cosine of the phase difference between the two. Based on this acoustic characteristic relationship, the system dynamically changes the relative phase relationship between the generator mover speed and the internal gas pressure oscillation by adjusting the electromagnetic impedance (i.e., electromagnetic damping force) of the external electrical load through the back-end rectifier-inverter circuit, ultimately maximizing the acoustic power extraction efficiency and achieving maximum power point tracking.

[0073] S430, to ensure efficient energy coupling between the thermoacoustic engine and the linear generator, the system must meet strict acoustic impedance matching conditions. The mechanical natural frequency of the linear generator 19 must be consistent with the acoustic operating frequency of the thermoacoustic system (such as the aforementioned 50Hz). The mechanical basis for this frequency domain matching is based on a single-degree-of-freedom spring oscillator model, and the mechanical natural frequency of the moving components of the linear generator... The calculation formula is as follows: ; In the formula, The mechanical natural frequency representing the moving components of a linear generator; It represents the total equivalent stiffness of the system, and its value is determined by the superposition of the mechanical stiffness of the leaf spring and the stiffness of the high-pressure gas spring in the system. This represents the total kinematic mass of the moving components, including the mass of the thrust piston and the permanent magnet mover (e.g., the mover mass is designed to be 5 kg). To ensure the absolute completeness of this division operation in both physical and algorithmic logic, in the actual physical components, the total kinematic mass of the moving components... It is an inherently constant real value that is always greater than zero, thus eliminating mathematical singularities where the denominator tends to zero and the square root of a negative number from the physical boundary.

[0074] The engineering significance of this natural frequency model lies in the fact that, by pre-designing and changing the number and thickness of the leaf springs, the overall equivalent stiffness of the system can be statically adjusted. The parameters are set so that the mechanical natural frequency of the linear generator's moving components is precisely matched to the operating frequency of the thermoacoustic engine 3. This matching mechanism can induce electromechanical and acoustic resonances within the system, and effectively counteract the inertial force of the moving components by utilizing the restoring force generated by mechanical stiffness and gas stiffness, ensuring that the overall energy conversion efficiency of the system is maintained within the optimal operating range.

[0075] Based on the extraction of acoustic power by the linear generator, the system utilizes the remaining acoustic power through a thermoacoustic chiller module, thereby achieving cascaded combined cooling and power generation. In this embodiment, the thermoacoustic chiller 6 constitutes the core execution unit that consumes acoustic mechanical work and outputs low-grade cold energy.

[0076] In S510, to rationally distribute the acoustic energy in the main circuit to the refrigeration stage, the thermoacoustic refrigerator 6 establishes acoustic coupling (series or parallel) with the main circuit of the thermoacoustic engine 3 through a T-shaped resonant shunt pipe (acoustic waveguide). This T-shaped resonant shunt pipe adopts a side-branch parallel pipe connection architecture, and its pipe diameter and cross-sectional area have undergone rigorous acoustic impedance calculations to form a specific shunt ratio with the main resonant pipe. This physical branching structure can guide some of the high-pressure waves not extracted by the generator into the refrigerator's interior, providing the necessary acoustic driving force for the subsequent reverse thermodynamic cycle.

[0077] In S520, driven by a continuous alternating pressure wave, high-pressure oscillating gas enters the thermoacoustic refrigerator and undergoes a reverse Stirling cycle. The refrigerator also contains a cooling load 8 (i.e., a low-temperature cooling load), a secondary regenerator, and a secondary cooler. During the periodic compression and expansion of the acoustic waves, the high-mesh metal mesh inside the secondary regenerator acts as a heat storage medium, causing the gas particles to change state under the pumping action of acoustic power. The gas particles, defying the natural heat transfer direction, continuously absorb heat from the low-temperature cooling load 8 through the low-temperature energy absorption channel 7, and release it to the secondary cooler at ambient temperature, ultimately being discharged to the ambient heat sink 10 where external cooling water carries away the dissipated heat.

[0078] The actual effective cooling power of the system is determined by the product of the effective acoustic power entering the thermoacoustic refrigerator 6 through the T-shaped resonant shunt and the system's acoustic cooling coefficient, after deducting the extraneous heat leakage power flowing back from the ambient temperature end to the cold end. The system's acoustic cooling coefficient, used as an engineering evaluation benchmark, typically ranges from 0.5 to 1.5, with its specific value influenced by the combined effects of internal flow resistance and the temperature difference between the hot and cold ends. This subtraction model clearly separates the independent physical effects of effective cooling and passive thermodynamic losses. Based on this model, the system can dynamically monitor the input acoustic mechanical work during operation. The determination of its cooling output state does not rely solely on monitoring a single extreme value of the cold end temperature, but rather on a multi-dimensional weighted logic based on the current acoustic work input, the heat leakage deviation caused by the ambient temperature, and the target cooling capacity requirement. Through this multi-source operating condition evaluation, the system can precisely control the input acoustic work, ensuring that the effective cooling capacity always exceeds the extraneous heat leakage power, maintaining a stable and positive cooling output.

[0079] Please see Figure 2 The left vertical axis of the figure shows the four key thermodynamic temperature levels of the system, with corresponding English abbreviations: This indicates the high temperature level of the system, representing the temperature range where high-temperature heat source 1 is located; This indicates the medium temperature level, corresponding to the medium temperature heat sink 9 discharged by the thermoacoustic engine; This indicates the ambient temperature, corresponding to the ambient heat sink 10 for the heat dissipation of the thermoacoustic chiller. This indicates the low-temperature stage (Cold Temperature), corresponding to the final low-temperature cooling load 8 obtained by the system. As shown by the arrows in the diagram, the energy quality exhibits a progressively decreasing quality and work-doping characteristic in the utilization process: the heat energy from the high-temperature heat source 1 is input into the thermoacoustic engine 3 through the high-grade heat energy release channel 2, and part of the heat energy is converted into high-frequency sound waves 4 which are transmitted and do work in the resonant tube 5. The remaining heat energy slides down and is discharged into the medium-temperature heat sink 9. The transmitted acoustic mechanical work then enters the thermoacoustic refrigerator 6 to drive the reverse refrigeration cycle, extracts heat from the low-temperature cooling load 8 through the low-temperature energy absorption channel 7, and finally combines the heat dissipation generated by the acoustic work and discharges it into the environmental heat sink 10.

[0080] S530, based on the low-temperature refrigeration effect generated by the aforementioned reverse heat engine cycle at cooling load 8, the system needs to effectively export and store the cooling capacity. The fluid pipelines inside cooling load 8 are connected to an external circulation pump. The external circulation system uses an ethylene glycol aqueous solution as the secondary refrigerant. Based on the excellent antifreeze properties of the ethylene glycol aqueous solution, those skilled in the art can reasonably set its volume concentration according to the set target refrigeration temperature range to avoid freezing and pipe blockage in the heat exchange network. The low-temperature secondary refrigerant, after absorbing the cooling capacity, is transported to the low-temperature storage tank 31 for buffer storage, or directly pumped to the external low-temperature cooling load side to meet actual cooling needs. This physical isolation and distribution mechanism of the hot and cold media constructs a complete energy output network for the system's combined cooling and power generation.

[0081] Based on the acoustic coupling architecture of the power generation and cooling units described above, the system is equipped with a measurement and control and acoustic power regulation module to achieve dynamic response of the cooling and electrical loads and precise distribution of acoustic power under complex operating conditions. In this embodiment, the module mainly consists of a data acquisition sensor network (such as pressure sensors, temperature sensors, and displacement sensors), a central measurement and control unit (main controller 20), and an acoustic power regulator 33.

[0082] In the S610 system operation, to achieve real-time perception of the underlying status, the measurement and control system uses a cluster of sensors distributed across nodes such as the heat medium pipeline network, cold storage tank, high-pressure gas storage tank, and the linear generator actuator stroke to collect the operational physical quantities of each node in real time. The collected parameters mainly cover the internal oil temperature of the high-temperature heat storage tank, the refrigerant temperature of the cold storage tank, and the real-time power load of the external power grid. Considering the inherent differences in the hardware sampling frequencies of different physical types of sensors, the main controller 20 uses a time-window-based linear interpolation algorithm to perform timestamp alignment processing on the aforementioned multi-source time-series data before performing underlying data fusion. This preprocessing logic eliminates the delay in condition determination and data misalignment caused by asynchronous sampling, ensuring the timeliness and physical correspondence of the input to the subsequent decision-making algorithm.

[0083] The S620 system, addressing the dynamic distribution of acoustic mechanical work between the linear generator and the thermoacoustic refrigerator, incorporates an acoustic regulating valve at the branch node of the T-shaped resonant shunt. This acoustic regulating valve employs a stepper motor-driven rotary acoustic impedance adjustment structure. Based on the principle of sound field transmission, the system can directly alter the physical acoustic impedance parameters of the refrigeration branch by changing the valve core's rotational opening through the central control unit. When the acoustic impedance of the refrigeration branch increases, more alternating volumetric flow in the main circuit is forced towards the linear generator end. The specific pressure-resistant sealing structure of the acoustic regulating valve and the flow channel transition design within the valve body can be conventionally designed by those skilled in the art based on the working gas pressure level; its specific mechanical construction is well-known in the field and will not be elaborated upon here.

[0084] The S630, designed to optimize the acoustic-power allocation ratio under fluctuating environmental parameters and dynamic energy loads, incorporates a Long Short-Term Memory (LSTM) network decision model in its central control unit. The specific network topology consists of an input layer, two LSTM hidden layers (each containing 64 neurons), and a fully connected output layer. Based on the actual physical scenario of system operation, the model input layer data is defined as a four-dimensional feature vector, specifically including the ambient reference temperature, target cooling capacity deviation, grid demand power deviation, and the estimated release heat of the current high-temperature thermal storage tank. The physical reason for choosing these four parameters as inputs is that the ambient temperature and estimated heat directly determine the system's current available thermal energy boundary, while the cooling and power deviations directly reflect the external load absorption requirements, forming a supply-demand relationship. After extracting time-series dynamic features from the hidden layers, the input data is mapped and output by the fully connected layer as a continuous control variable with a value ranging from 0 to 1. This variable is directly mapped to the target opening percentage commanded by the acoustic regulating valve of the cooling branch in the physical operational state.

[0085] S640, before the aforementioned prediction model is deployed online, an offline supervised training process must be completed. Training samples are derived from historical operating datasets of similar systems under different seasonal conditions, while label data consists of manually verified valve opening values ​​that correspond to the system achieving its highest overall energy efficiency. During training, the model uses mean squared error as the basic loss function for gradient backpropagation and network weight updates, converging and solidifying the network's internal weights to enable the model to generalize under operating conditions and extrapolate strategies.

[0086] The final decision output of the model does not rely on one-sided monitoring of extreme values ​​for a single power generation or cooling capacity, but rather on a weighted evaluation based on multi-objective requirements. The comprehensive energy efficiency evaluation index within the central monitoring and control system... Dynamic calculations are performed based on the following formula: ; In the formula, The index represents the overall energy efficiency evaluation index under the current operating conditions of the system; This represents the actual electrical power output of the linear generator. This represents the target power setting for the current power grid dispatch. This represents the actual cooling power output of the thermoacoustic refrigerator. The target cooling power setting represents the cooling load side; and These represent the weighting coefficients for the power generation side and the cooling side, respectively. The sum of their values ​​is fixed at 1, and their specific ratios are dynamically determined based on the economic benefit ratio of the current electricity price to the cooling price.

[0087] To ensure the completeness of the above algorithm logic and avoid program exceptions during operation, it is necessary to prevent mathematical singularities that may arise from the division operation. When the system briefly does not receive external power grid dispatch commands or cooling demand commands (i.e., or When the value approaches 0, the underlying program of the central measurement and control unit will forcibly assign a very small positive bias constant to the corresponding denominator (e.g., set to 10). 5 This fault-tolerance mechanism eliminates computational overflow errors caused by division by zero at the code level, ensuring the persistent stability of the thermoacoustic coupling distribution control.

[0088] Please see Figure 4 This diagram illustrates the closed-loop feedback control mechanism of the main controller 20 for complex operating conditions. The main controller 20 is internally divided into two major decision-making modules: power generation control and cooling control. Its external inputs receive power generation and temperature setpoints from operators or the upper-level power grid. On the feedback loop side, the main controller 20 receives real-time monitoring data from multiple sensors, including: pressure feedback from the high-pressure gas tank to the thermoacoustic engine air path (circular marker P in the diagram represents the Pressure sensor), temperature feedback from the cooling load side and the chiller side (circular marker T in the diagram represents the Temperature sensor), and frequency / voltage feedback from the output of the linear generator 19 (f / V in the diagram represents Frequency and Voltage). Based on the deviation between the setpoints and feedback values, the main controller 20 outputs a valve opening signal to precisely adjust the flow regulating valve (i.e., the pressure regulating valve) at the front end, and simultaneously outputs a sound power regulation signal to control the sound power regulator. This dynamically changes the acoustic impedance matching state of the generator and chiller branches, achieving intelligent tracking and adaptive adjustment of the system's dual cooling and power objectives.

[0089] Based on the above physical architecture and intelligent control algorithm, the main controller 20 can achieve flexible switching of the system in multiple scenarios through intelligent scheduling, specifically the following four operating strategies and modes: Energy Storage Mode. This mode is triggered when the grid is in a low-price period or when there is a surplus of renewable energy. It aims to convert excess electrical energy into pressure potential energy and heat energy. The system operates as follows: Air compressor units 22, 24, and 26 are started to perform air compression operations; simultaneously, heat transfer fluid circulation pump 30 is started to pump low-temperature heat transfer oil to interstage heat exchangers 23 and 25. After absorbing the heat of compression and heating up, the heat transfer oil is sent to high-temperature heat storage tank 1 for storage; at the same time, high-pressure air after multi-stage compression is continuously charged into high-pressure air storage tank 28 until the pressure reaches the set upper limit threshold for air storage (e.g., 10 MPa).

[0090] Power Generation Mode. This mode is triggered when the grid is under peak load and the user end mainly exhibits electricity demand. The system operates as follows: First, pressure build-up is performed by opening the pressure regulating valve 29 and using the gas in the high-pressure gas storage tank to charge the thermoacoustic circuit to the rated operating static pressure (e.g., 8MPa), entering a high-energy-density standby state; then, heating is performed by starting the heat medium circulation pump and introducing high-temperature heat transfer oil into the main heater 11; when the temperature difference between the main heater and the main cooler exceeds the critical oscillation value (approximately 80°C to 100°C), the working fluid self-excites and oscillates, causing the pressure wave amplitude in the pipe to rise rapidly; when the pressure ratio reaches a preset threshold (e.g., 1.1), the system connects to the electrical load of the linear generator 19, and the thermoacoustic mechanical work is mainly used to drive the generator to generate electricity; at this time, the main controller significantly increases the acoustic impedance of the refrigeration branch by adjusting the acoustic impedance regulating valve and puts the linear generator in an impedance matching state to absorb most of the acoustic work, thereby suppressing the operation of the thermoacoustic refrigerator 6 and putting it in a low-load or off state.

[0091] Cogeneration Mode. This mode is triggered during peak periods such as summer when users simultaneously experience demand for both electricity and air conditioning cooling. The system operates as follows: First, the system maintains its basic operating state in the aforementioned power generation mode. The main controller 20 reduces the acoustic impedance of the cooling branch by changing the opening of the acoustic impedance regulating valve, and can simultaneously adjust the inverter current to actively deflect the mechanical extraction impedance of the linear generator, so that excess acoustic power in the circuit is naturally diverted to the thermoacoustic chiller branch with relatively lower acoustic impedance. The thermoacoustic chiller 6 then starts cooling work, reducing the temperature of the cooling load 8 to the set range (e.g., 0°C to 5°C), and starts the glycol circulation pump to deliver cooling to the user side. During operation, the main controller continuously assesses the dynamic balance of heating and cooling loads. If the electrical load increases, the impedance of the cooling branch is increased to allow acoustic waves to flow back to the generator; conversely, if the cooling load increases, the impedance of the cooling branch is decreased to increase the cooling output.

[0092] Frequency Regulation Mode. Given that the thermoacoustic system utilizes a high-frequency gaseous working fluid with mechanical rotational inertia, its response rate is far superior to traditional mechanical turbine units, enabling rapid response to the grid's ultra-fast frequency regulation commands. The system operates as follows: Upon receiving a grid frequency / power increase command, the system quickly opens the inlet of the pressure regulating valve, rapidly increasing the loop pressure (e.g., from 8MPa to 9MPa), causing the output power to surge instantaneously within milliseconds (ms). Upon receiving a power reduction command, the system quickly opens the exhaust valve, returning some of the working fluid gas to the low-pressure side or safely discharging it, causing the loop pressure to drop rapidly, thereby achieving an instantaneous reduction in output power. This millisecond-level pressure control capability allows the entire system to play a significant role in supporting the dynamic stability of the grid through energy storage and peak regulation.

Claims

1. A thermoacoustic coupled power generation-cooling system based on compressed air energy storage, characterized in that, It includes a compressed energy storage module, a thermal management module, a thermoacoustic power generation and cooling module, and a measurement and control module; The compressed energy storage module includes an air compressor unit with an ambient air inlet (21) and connected in sequence by pipelines, an interstage heat exchanger, an aftercooler (27), and a high-pressure air storage tank (28). The thermal management module includes a low-temperature storage tank (31), a heat medium circulation pump (30) connected in sequence to form a heat medium circulation loop in which heat medium fluid flows, the interstage heat exchanger, the aftercooler (27) and the high-temperature storage tank (1). The thermoacoustic power generation and cooling module includes a thermoacoustic engine (3), a linear engine (19), a resonant tube (5), and a thermoacoustic refrigerator (6). The high-temperature heat storage tank (1) is fluidly connected to the main heater (11) of the thermoacoustic engine (3) through the high-grade heat energy release channel (2), and the high-pressure gas storage tank (28) is connected to the internal cavity of the thermoacoustic engine (3) through the pressure pipeline. The thermoacoustic engine (3) is connected to the linear engine (19) and the thermoacoustic refrigerator (6) through an acoustic pipe for sound power transmission (4) and the resonant tube (5). The cold end of the thermoacoustic refrigerator (6) is connected to the low-temperature storage tank (31) through a low-temperature energy intake channel (7). The measurement and control module includes a main controller (20) that is communicatively connected to each of the modules and is used to control the operating status of each of the modules.

2. The system according to claim 1, characterized in that, The air compressor unit includes a primary compressor (22), a secondary compressor (24) and a tertiary compressor (26). The interstage heat exchanger includes a primary interstage heat exchanger (23) and a secondary interstage heat exchanger (25). The first-stage compressor (22) is connected to the ambient air inlet (21) and the first-stage interstage heat exchanger (23). The primary interstage heat exchanger (23) is connected to the secondary compressor (24); The secondary compressor (24) is connected to the secondary interstage heat exchanger (25); The secondary interstage heat exchanger (25) is connected to the tertiary compressor (26); The three-stage compressor (26) is connected to the aftercooler (27).

3. The system according to claim 1, characterized in that, The high-temperature heat storage tank (1) is equipped with a double-layer pressure-bearing metal shell; The double-layer pressure-bearing metal shell is filled with rock wool insulation material; The heat transfer fluid is a high-boiling-point heat transfer oil.

4. The system according to claim 1, characterized in that, The high-pressure gas storage tank (28) is equipped with a pressure regulating valve (29) on its gas supply pipeline. The high-pressure gas storage tank (28) is connected to the thermoacoustic engine (3) through the pressure regulating valve (29); The main controller (20) is connected to the pressure regulating valve (29).

5. The system according to claim 1, characterized in that, The thermoacoustic engine (3) also includes a main regenerator (13), a main cooler (15), a heat buffer tube (16), and a sound power output tube (17). The main regenerator (13) is installed between the main heater (11) and the main cooler (15); The main heater (11) is used to obtain input heat (12), and its output end is connected to the heat buffer tube (16). The main cooler (15) is connected to a medium-temperature heat sink (9) to release and remove heat (14). The heat buffer tube (16) is connected to the acoustic power output tube (17) to form an acoustic power output (18).

6. The system according to claim 5, characterized in that, The linear motor (19) includes a thrust piston, a permanent magnet mover, a stator coil, and a leaf spring support assembly; The thrust piston is connected to the permanent magnet mover; The permanent magnet mover is placed inside the stator coil; The acoustic power output tube (17) is connected to the end face of the thrust piston; The stator coil is connected to the power output terminal (32).

7. The system according to claim 1, characterized in that, The resonant tube (5) is provided with a T-shaped resonant shunt tube, and the thermoacoustic refrigerator (6) is connected to the resonant tube (5) through the T-shaped resonant shunt tube; The thermoacoustic refrigerator (6) is equipped with a cold end heat exchanger, a secondary heat exchanger and a secondary cooler. The cold end heat exchanger is used to absorb low-temperature cooling loads (8), and the secondary cooler is connected to the ambient heat sink (10). The cold load (8) is connected to the cryogenic storage tank (31).

8. The system according to claim 7, characterized in that, A sound power regulator (33) is provided at the branch node of the T-type resonant shunt tube. The acoustic power regulator (33) includes a stepper motor and a rotary acoustic impedance adjustment structure; The main controller (20) is connected to the stepper motor.

9. The system according to claim 1, characterized in that, The measurement and control module also includes a temperature sensor, a pressure sensor, and a displacement sensor; The temperature sensor is installed inside the high-temperature thermal storage tank (1); The pressure sensor is installed inside the high-pressure gas storage tank (28); The displacement sensor is installed inside the linear motor (19); The temperature sensor, the pressure sensor, and the displacement sensor are connected to the main controller (20).

10. A thermoacoustic coupling power generation-cooling method based on compressed air energy storage, characterized in that, The thermoacoustic coupling power generation-cooling system based on compressed air energy storage, as described in any one of claims 1-9, comprises the following steps: The air compressor unit is started to compress the ambient air. The high-temperature air generated by the compression flows through the interstage heat exchanger and aftercooler (27) to transfer heat to the heat medium fluid. The heated heat medium fluid is stored in the high-temperature heat storage tank (1), and the cooled high-pressure air is stored in the high-pressure air storage tank (28). By controlling the on / off state of the pressure pipeline connected to the high-pressure gas storage tank (28), the average pressure of the internal cavity of the thermoacoustic engine (3) is adjusted to a preset working setting value using the air in the high-pressure gas storage tank (28), the working setting value is 1MPa to 10MPa, and the heat medium circulation loop is opened to transfer the heat energy in the high-temperature heat storage tank (1) to the main heater (11) of the thermoacoustic engine (3); The thermoacoustic engine (3) establishes a temperature difference under the action of the heat energy input by the main heater (11). When the temperature difference exceeds the preset oscillation threshold, the air in the internal cavity undergoes self-excited oscillation and generates high-intensity sound waves. The oscillation threshold is 80°C to 100°C. The high-intensity acoustic wave drives the linear motor (19) to perform linear reciprocating motion and convert acoustic energy into electrical energy output. Part of the high-intensity acoustic wave drives the thermoacoustic refrigerator (6) to generate cold energy at the cold end of the thermoacoustic refrigerator (6) and store it in the low-temperature storage tank (31). The main controller (20) adjusts the electrical load impedance of the linear motor (19) and the acoustic wave flow state entering the thermoacoustic refrigerator (6) according to the external electrical load and cold load (8) requirements, and dynamically controls the acoustic power ratio between the linear motor (19) and the thermoacoustic refrigerator (6).

Images