High-power hybrid power thermal management system

Abstract

The invention belongs to the technical field of aircraft thermal management, and discloses a high-power hybrid power thermal management system. Comprising a Stirling engine, a high-temperature heat pipe loop, a medium-temperature heat source loop and a low-temperature heat source loop. The Stirling engine comprises a Stirling engine and a Stirling cryocooler which are oppositely arranged, and harmonic oscillators are adopted between the Stirling engine and the Stirling cryocooler for phase modulation. One end of the Stirling engine serves as a high-temperature end to be connected with the high-temperature heat source loop; a room temperature end between the two is connected with a medium-temperature heat source loop; a temperature difference is constructed in the Stirling engine through the high-temperature heat source loop and the medium-temperature heat source loop, external heat is absorbed through the Stirling engine to generate work, and therefore corresponding cooling capacity is generated in the low-temperature heat source loop of the Stirling cryocooler.

Description

Technical Field

[0001] This invention belongs to the field of aircraft thermal management technology and discloses a high-power hybrid thermal management system. Background Technology

[0002] With the booming development of the new energy industry, the proportion of new energy aircraft, represented by hydrogen and electricity, in aviation is gradually increasing. Consequently, leading aviation nations worldwide have launched a series of development plans and research projects related to new energy aircraft and their propulsion systems. For pure electric propulsion, current battery technology cannot provide the energy density required for long-endurance flight. Hybrid power, however, combines the high energy density of engine fuel with the high power density of battery systems, offering advantages such as high power-to-weight ratio and energy conservation and emission reduction, making it a highly promising research direction. Taking a series hybrid power architecture as an example, the energy architecture consists of a turbine generator system, an energy storage system, an electric propulsion system, and an energy management system. The turbine generator system, as the main energy source for the hybrid power system, is composed of an engine-driven generator. As the takeoff weight of vertical takeoff and landing (VTOL) aircraft increases, the required power also increases, inevitably leading to increased heat generation in the turbine generator system, energy storage system, and electric propulsion system. Taking a megawatt-class turbine power generation system as an example, even if the generator efficiency reaches 96%, it will generate 40 kW of heat. Even if the high-power AC / DC efficiency reaches 99%, it will generate 10 kW of heat. In addition, the heat load of a large number of devices such as the engine, battery system, distributed drive motors and all motor controllers will make thermal management of hybrid aircraft a new problem.

[0003] Current thermal management systems for hybrid-powered aircraft still rely on existing thermal energy utilization methods common to traditional aircraft, consisting of conventional environmental control systems, battery thermal management systems, and lubrication systems. These systems lack deep interoperability, resulting in low power-to-weight ratios and low energy utilization rates. Furthermore, they cannot achieve integrated management and tiered utilization of different energy types. There is an urgent need to address this from the perspective of the hybrid power system and the overall aircraft to achieve rational allocation of onboard energy, enabling integrated management of different thermal load demands, realizing the recovery and utilization of thermal energy from the power system, reducing aircraft energy consumption, and improving overall energy efficiency. Summary of the Invention

[0004] Purpose of the invention: To provide a high-power hybrid power thermal management system that, through the efficient heat-to-work conversion of the Stirling engine, achieves comprehensive thermal management and utilization of engine exhaust, hybrid power eddy current system, propulsion system, battery system, and environmental control system. This realizes thermal self-adaptation and high integration of high-power hybrid aircraft, improves system energy efficiency, and has high application potential in high-power hybrid aircraft.

[0005] To address the aforementioned technical issues, this application provides a high-power hybrid power thermal management system, comprising: a Stirling engine, a high-temperature heat pipe circuit, a medium-temperature heat source circuit, and a low-temperature heat source circuit; The Stirling engine consists of a Stirling motor and a Stirling refrigerator, which are placed opposite each other and phase-tuned by a harmonic oscillator in the middle to reduce the overall size and weight of the system. One end of the Stirling engine is connected to the high-temperature heat source circuit as the high-temperature end, and the other end of the Stirling refrigerator is connected to the low-temperature heat source circuit as the low-temperature end. The middle section serves as the room temperature end, connecting to the medium-temperature heat source circuit. A temperature difference is created in the Stirling engine by establishing a high-temperature heat source circuit and a medium-temperature heat source circuit. The Stirling engine absorbs external heat to generate work, thereby generating corresponding cooling capacity in the low-temperature heat source circuit of the Stirling refrigerator.

[0006] Furthermore, the high-temperature heat source circuit comprises: a high-temperature end of the Stirling engine, a high-temperature heat source circuit circulation pump, a high-temperature heat exchanger, and corresponding pipeline circulation connections; The high-temperature heat source circuit uses a heat transfer fluid as the heat transfer medium. When the system is working, the heat transfer fluid flows through the heat exchanger to absorb the waste heat of the engine exhaust gas. Driven by the high-temperature heat source circuit circulation pump, it releases heat at the high-temperature end of the Stirling engine, while reducing the high-temperature exhaust temperature of the engine and reducing the intensity of infrared radiation signals.

[0007] Furthermore, the medium-temperature heat source circuit consists of the Stirling engine room temperature end, lubricating oil tank, medium-temperature heat source circuit circulation pump, motor unit, motor radiator unit, medium-temperature heat source circuit radiator, and corresponding pipeline circulation connection. Lubricating oil is used as the heat transfer medium; The lubricating oil, after being cooled by the radiator of the medium-temperature heat source circuit, flows through the room temperature end of the Stirling machine under the drive of the circulating pump of the medium-temperature heat source circuit. After absorbing the heat at the room temperature end, it is sent to the motor for heat exchange. After passing through the radiator of the motor itself, it returns to the radiator of the medium-temperature heat source circuit for heat dissipation, thus realizing the cascade utilization of the medium-temperature heat source.

[0008] Furthermore, the output end of the medium-temperature heat source loop circulation pump is connected to one end of a medium-temperature controllable four-way valve, and the other end of the medium-temperature controllable four-way valve is connected to the room temperature end of the Stirling machine. The other end connects to the engine and a high-power AC / DC converter, then returns to the radiator in the medium-temperature heat source circuit. The other end connects to the generator and returns to the radiator in the medium-temperature heat source circuit.

[0009] Furthermore, after passing through the Stirling engine room temperature end, the medium-temperature heat source circuit is connected in series with a first controllable three-way valve. The first controllable three-way valve is branched to the inlet of the cabin heating heat exchanger to generate heat in the cabin. The heat source can be used and adjusted on demand through the first controllable three-way valve. The outlet of the cabin heating heat exchanger is connected to the medium-temperature heat source circuit through the three-way valve.

[0010] Furthermore, a second controllable three-way valve is connected in series between the Stirling machine and the motor unit in the medium-temperature heat source circuit. A branch of this valve connects to the DC / DC converter, and the signal returns to the radiator in the medium-temperature heat source circuit. The second controllable three-way valve adaptively adjusts the flow rate required for heat dissipation from the motor and the DC / DC converter.

[0011] Furthermore, the low-temperature heat source circuit consists of a Stirling machine refrigeration end, a low-temperature heat source circuit circulation pump, a one-way valve, a liquid storage tank, and a cabin refrigeration heat exchanger, all connected by a pipeline. A cooling fluid is used as the heat transfer medium; After passing through the Stirling engine's refrigeration end, the refrigerant absorbs the cooling capacity of the refrigeration end heat exchanger. Driven by the low-temperature heat source loop circulation pump, the refrigerant is sent to the storage tank via a one-way valve. The storage tank stores a certain amount of refrigerant for loop heat dissipation. When facing the large cooling capacity demand caused by short-term high loads of the entire unit, the storage tank can greatly reduce the stringent requirements of the heat load on the output cooling capacity of the Stirling engine's refrigeration end. A third controllable three-way valve is connected in series between the output end of the storage tank and the cabin cooling heat exchanger. The cooling capacity is utilized and regulated on demand through the third controllable three-way valve. After generating the required cooling effect in the cabin through heat exchange, the refrigerant is sent back to the Stirling engine's refrigeration end to start the circulation again.

[0012] Furthermore, the low-temperature heat source circuit also includes: a motor controller, a generator controller, and a battery system; The branch of the third controllable three-way valve is connected to one end of the cryogenic controllable four-way valve. The other end of the cryogenic controllable four-way valve is connected to the motor controller, generator controller, and battery system respectively. The flow required for heat dissipation of the motor controller, generator controller, and battery system is balanced and matched through the cryogenic controllable four-way valve. Then, the flow returns to the cold end of the Stirling machine through the four-way valve to start the cycle again.

[0013] Furthermore, the motor unit includes N motors arranged in parallel, each motor having its own motor radiator.

[0014] Furthermore, a DC / DC group comprises N DC / DC units arranged in parallel.

[0015] In summary, the beneficial effects of the present invention are as follows: This invention establishes a high-power hybrid power thermal management system based on a Stirling engine. Through the efficient heat-to-work conversion of the Stirling engine, it realizes the comprehensive thermal management and utilization of engine exhaust, hybrid eddy current system, propulsion system, battery system and environmental control system. It achieves thermal self-adaptation and high integration of high-power hybrid aircraft, improves system energy efficiency, and has high application potential in high-power hybrid aircraft. Attached Figure Description

[0016] Figure 1 A schematic diagram of thermal management for high-power hybrid power systems; 101: Stirling engine cold end; 102: Stirling engine room temperature end; 103: Stirling engine high temperature end; 201: Low temperature heat source loop circulation pump; 202: One-way valve; 203: Liquid receiver; 204: Controllable three-way valve; 205: Controllable four-way valve; 206: Battery system; 207: Generator controller; 208: Motor controller; 301: Lubricating oil tank; 302: Medium temperature heat source loop circulation pump; 303: Controllable four-way valve; 304: Engine; 305: AC / DC; 306: Generator; 307: Medium temperature heat source loop radiator; 401: Controllable three-way valve; 402: Controllable three-way valve; 403: Motor 1; 404: Motor radiator 1; 405: Motor N; 406: Motor radiator N; 407: DC / DC 1; 408: DC / DC N; 501: Cabin cooling heat exchanger, 502: Cabin heating heat exchanger; 601: High-temperature heat source loop circulation pump, 602: High-temperature heat exchanger. Detailed Implementation

[0017] Figure 1 The diagram shows an embodiment of a high-power hybrid thermal management architecture, which mainly includes a Stirling engine, a high-temperature heat pipe circuit, a medium-temperature heat source circuit, a low-temperature heat source circuit, and corresponding pumps and radiator volume controllable valves.

[0018] The Stirling machine comprises a Stirling engine and a Stirling refrigerator, which are placed opposite each other and phase-tuned by a harmonic oscillator. A temperature difference is created in the Stirling engine through a high-temperature heat source circuit and a medium-temperature heat source circuit. The Stirling engine absorbs external heat to generate work, thereby generating corresponding cooling in the low-temperature heat source circuit of the Stirling refrigerator.

[0019] The high-temperature heat source circuit consists of the high-temperature end 103 of the Stirling engine, the high-temperature heat source circuit circulation pump 601, the high-temperature heat exchanger 602, and corresponding pipelines. The high-temperature heat source circuit uses a heat transfer fluid as the heat transfer medium. When the system is working, the heat transfer fluid flows through the heat exchanger 602 to absorb the waste heat of the engine exhaust gas, and is then driven by the high-temperature heat source circuit circulation pump 601 to release heat at the high-temperature end 103 of the Stirling engine.

[0020] The intermediate-temperature heat source circuit consists of a Stirling engine room temperature terminal 102, an oil tank 301, an intermediate-temperature heat source circuit circulation pump 302, an engine 304, a generator 306, a high-power AC / DC converter 305, a cabin heating heat exchanger 502, an electric motor 405, an electric motor radiator 406, a DC / DC converter 408, an intermediate-temperature heat source circuit radiator 307, controllable valves, and corresponding pipelines. The intermediate-temperature heat source circuit uses lubricating oil as the heat transfer medium. When the system is operating, the lubricating oil, cooled by the intermediate-temperature heat source circuit radiator 307, is driven by the intermediate-temperature heat source circuit circulation pump 302. Based on the cooling requirements of the heat load, the flow rate is regulated by a controllable four-way valve 303, and the oil is divided into three paths to the heat load. The first path flows through the cascade flow path of the engine 304 and the high-power AC / DC converter 305, and then returns to the intermediate-temperature heat source circuit radiator 307 for heat dissipation; the second path flows through the generator 306 and then returns to the intermediate-temperature heat source circuit radiator 307 for heat dissipation. The third oil path first flows through the Stirling engine's room temperature end 102, absorbing heat from the room temperature end heat exchanger. Then, the flow rate is regulated by the controllable three-way valve 401 and sent to subsequent heat loads. When the cabin requires heating, the controllable three-way valve 401 directs the lubricating oil to the cabin heating heat exchanger 502, where heat exchange occurs to produce the desired heating effect. At this time, the lubricating oil temperature in the pipeline decreases, and the flow rate is regulated by the controllable three-way valve 402 before being sent to the motor and DC / DC converter for heat exchange. When the cabin does not require heating, the controllable three-way valve 401 disconnects the cabin oil path, and the oil is directly sent to the motor and DC / DC converter after being regulated by the controllable three-way valve 402. Motors 1 through N are arranged in parallel, as are DC / DC converters 1 through N. After passing through the motor's built-in radiator 406, the motor oil and the lubricating oil in the DC / DC oil path return to the medium-temperature heat source circuit radiator 307 for heat dissipation. The arrangement of the three circuits ensures that the heat dissipation requirements of the three circuits are not significantly different. The radiator 307 of the medium-temperature heat source circuit is cooled by ram air, and the motor radiator 406 can dissipate part of the heat from the motor under the action of the downflow and ram air.

[0021] The cryogenic heat source circuit consists of a Stirling engine refrigeration end 101, a cryogenic heat source circuit circulation pump 201, a one-way valve 202, a liquid storage tank 203, a battery system 206, a generator controller 207, a motor controller 208, a cabin cooling heat exchanger 501, controllable valves, and corresponding pipelines. The cryogenic heat source circuit uses a cooling fluid as the heat transfer medium. When the system is operating, the cooling fluid passes through the Stirling engine refrigeration end 103 and absorbs the cooling capacity of the cooling end heat exchanger. To avoid the high power-to-weight ratio requirement of the refrigeration unit caused by directly sending the cooling fluid to various heat loads, the cooling fluid is sent to the liquid storage tank 203 via the one-way valve 202 under the drive of the cryogenic heat source circuit circulation pump 201. The liquid storage tank 203 stores a certain amount of cooling fluid for circuit heat dissipation. The cooling fluid in the liquid storage tank 203 also prevents thermal shock to the Stirling engine in the cryogenic heat source circuit, ensuring stable operation of the Stirling engine. When the cabin requires cooling, the refrigerant flowing from the reservoir 203 is regulated by a three-way valve 204 and then sent to the cabin cooling heat exchanger 501, the battery system, and the motor controller. The refrigerant flowing through the cabin cooling heat exchanger 501 generates the required cooling effect within the cabin and is then sent to the Stirling engine cooling end 101 to restart the cycle. When the cabin does not require cooling, the controllable three-way valve 204 disconnects the cabin flow path, and the refrigerant is sent directly to the battery system and the motor controller. The battery system 206, generator controller 207, and motor controller 208 are arranged in parallel, and the required refrigerant flow rates at these three locations are regulated by a controllable four-way valve. After flowing through the battery system 206, generator controller 207, and motor controller 208, the refrigerant returns to the Stirling engine cooling end 101 to restart the cycle.

Claims

1. A high-power hybrid power thermal management system, characterized in that: The system includes: a Stirling engine, a high-temperature heat pipe circuit, a medium-temperature heat source circuit, and a low-temperature heat source circuit; A Stirling machine consists of a Stirling engine and a Stirling refrigerator, which are placed opposite each other and phase-tuned by a harmonic oscillator in between. One end of the Stirling engine is connected to the high-temperature heat source circuit as the high-temperature end, and the other end of the Stirling refrigerator is connected to the low-temperature heat source circuit as the low-temperature end. The middle section serves as the room temperature end, connecting to the medium-temperature heat source circuit. A temperature difference is created in the Stirling engine by establishing a high-temperature heat source circuit and a medium-temperature heat source circuit. The Stirling engine absorbs external heat to generate work, thereby generating corresponding cooling capacity in the low-temperature heat source circuit of the Stirling refrigerator.

2. The system according to claim 1, characterized in that: The high-temperature heat source circuit comprises: a high-temperature end of the Stirling engine, a high-temperature heat source circuit circulation pump, a high-temperature heat exchanger, and corresponding pipelines connected in a circulation manner. The high-temperature heat source circuit uses a heat transfer fluid as the heat transfer medium. When the system is working, the heat transfer fluid flows through the heat exchanger to absorb the waste heat of the engine exhaust gas. Driven by the high-temperature heat source circuit circulation pump, it releases heat at the high-temperature end of the Stirling engine.

3. The system according to claim 2, characterized in that: The medium-temperature heat source circuit consists of the Stirling machine room temperature end, lubricating oil tank, medium-temperature heat source circuit circulation pump, motor unit, motor radiator unit, medium-temperature heat source circuit radiator, and corresponding pipeline circulation connection. Lubricating oil is used as the heat transfer medium; The lubricating oil, cooled by the radiator of the medium-temperature heat source circuit, flows through the room temperature end of the Stirling engine under the drive of the circulating pump of the medium-temperature heat source circuit. After absorbing the heat at the room temperature end, it is sent to the motor for heat exchange. After passing through the radiator of the motor itself, it returns to the radiator of the medium-temperature heat source circuit for heat dissipation.

4. The system according to claim 3, characterized in that: The output of the medium-temperature heat source loop circulation pump is connected to one end of a medium-temperature controllable four-way valve, and the other end of the medium-temperature controllable four-way valve is connected to the room temperature end of the Stirling machine. The other end connects to the engine and a high-power AC / DC converter, then returns to the radiator in the medium-temperature heat source circuit. The other end connects to the generator and returns to the radiator in the medium-temperature heat source circuit.

5. The system according to claim 4, characterized in that: The medium-temperature heat source circuit is connected in series with the first controllable three-way valve after passing through the room temperature end of the Stirling engine. The first controllable three-way valve is branched to the inlet of the cabin heating heat exchanger to generate heat in the cabin. The outlet of the cabin heating heat exchanger is connected to the medium-temperature heat source circuit through the three-way valve.

6. The system according to claim 5, characterized in that: A second controllable three-way valve is connected in series between the Stirling machine and the motor unit in the medium-temperature heat source circuit. The second controllable three-way valve is branched to the DC / DC group and then returns to the radiator in the medium-temperature heat source circuit after passing through the DC / DC group.

7. The system according to claim 6, characterized in that: The low-temperature heat source circuit consists of a Stirling machine refrigeration end, a low-temperature heat source circuit circulation pump, a one-way valve, a liquid storage tank, and a cabin refrigeration heat exchanger, all connected by a pipeline. A cooling fluid is used as the heat transfer medium; After passing through the Stirling machine's refrigeration end, the cooling fluid absorbs the cooling capacity of the refrigeration end heat exchanger. Driven by the low-temperature heat source loop circulation pump, the cooling fluid is sent to the storage tank via a one-way valve. The storage tank stores a certain amount of cooling fluid for loop heat dissipation. The cooling fluid flowing out of the storage tank is sent to the cabin refrigeration heat exchanger. After exchanging heat in the cabin and producing the required cooling effect, it is sent back to the Stirling machine's refrigeration end to start the circulation again.

8. The system according to claim 7, characterized in that: The low-temperature heat source circuit also includes: a motor controller, a generator controller, and a battery system; A third controllable three-way valve is connected in series between the liquid storage tank output and the cabin cooling heat exchanger. A branch of the third controllable three-way valve is connected to one end of a cryogenic controllable four-way valve. The other end of the cryogenic controllable four-way valve is connected to the motor controller, generator controller, and battery system, respectively. The liquid then flows back to the Stirling machine refrigeration end through the four-way valve to restart the cycle.

9. The system according to claim 3, characterized in that: The motor unit consists of N motors arranged in parallel, each motor having its own radiator.

10. The system according to claim 6, characterized in that: A DC / DC group consists of N DC / DC converters arranged in parallel.

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