A Hybrid Electric Power Cabin Thermal Management System for Aircraft and Its Control Method

Abstract

The present application discloses a thermal management system for a hybrid electric power cabin of an aircraft and its control method. The thermal management system for the hybrid electric power cabin of the aircraft includes an air incoming flow cooling system, a fuel cooling system, an air cycle cooling system, an evaporation cycle cooling system, a power battery heating system, and an electronic control unit. The air incoming flow cooling system, the fuel cooling system, the air cycle cooling system, the evaporation cycle cooling system, and the power battery heating system are controlled and connected to the electronic control unit. The present application correspondingly controls the air incoming flow cooling system, the fuel cooling system, the air cycle cooling system, the evaporation cycle cooling system, and the power battery heating system to perform comprehensive thermal management on the power battery, the lubricating oil system, the generator, the motor, the electronic control unit, and the engine body in the hybrid electric power cabin according to the current flight phase and the environmental temperature state, so as to meet the thermal management requirements of the hybrid electric power cabin in different flight phases and environmental states, and keep the hybrid electric power cabin in the best temperature state all the time.

Description

Technical Field

[0001] The present application relates to the technical field of aircraft thermal management, and in particular, to an aircraft hybrid electric power cabin thermal management system and a control method thereof. Background Art

[0002] The current aircraft hybrid electric power system uses a series architecture. After the engine generates electricity, the electric energy is allocated by an electronic control unit, and then drives the motor and the propeller / wheel; the power battery, as an energy storage device, can supplement and provide electric energy to drive the propeller / wheel together with the generator, or can absorb and store the excess electric energy of the generator. Compared with the traditional power system, the hybrid electric power system has added components such as high-power motors, high-power electronic control units, and power batteries. These components need to be compactly arranged in the power cabin and will generate a large amount of heat during operation. The thermal management requirements of different components vary greatly, and the existing thermal management solutions can no longer meet the requirements (especially in high-temperature summer weather).

[0003] Although water cooling can be used for the thermal management of batteries, motors, and electronic control units, due to weight reduction reasons, water cooling is not suitable for directly used in the thermal management of aircraft power cabins. Another cooling method for batteries, motors, and electronic control units is air cooling. This cooling method has poor efficiency and it is difficult to fully meet the cooling requirements of the hybrid electric power cabin in high-temperature summer weather. The thermal management solutions mentioned in the existing published papers and patents use air cooling and oil cooling. These thermal management solutions do not comprehensively consider the possible ways of air circulation cooling and evaporation cycle cooling of the power cabin. On the other hand, although some thermal management solutions introduce fuel cooling in the power cabin cooling, there is no specific solution for the power cabin cooling when the fuel is insufficient in the second half of the flight and during descent. Moreover, these existing thermal management solutions usually only focus on the thermal management of batteries, motors, and electronic control units, while ignoring the thermal management of the engine body, and do not consider the working characteristics of the engine in the entire thermal management solution. These existing thermal management solutions do not fully consider the different working states of the aircraft during flight. Although some thermal management solutions consider the thermal management in the takeoff / cruise / descent states, they do not fully consider the influence of the ambient temperature, nor do they consider the thermal management in special emergency states. On the other hand, these existing thermal management solutions generally adopt air cooling and open cycle cooling modes. This open cycle cooling mode has poor cooling effect when the ambient temperature is high, and cannot be used in combination with evaporation cycle cooling / air circulation cooling. Summary of the Invention

[0004] The present application provides an aircraft hybrid electric power cabin thermal management system to solve the technical problem that the existing thermal management technology cannot meet the cooling requirements of the aircraft hybrid electric power cabin under different working conditions.

[0005] The present application is achieved through the following solutions:

[0006] A hybrid electric power cabin thermal management system for an aircraft, comprising an air inlet cooling system, a fuel cooling system, an air circulation cooling system, an evaporation cycle cooling system, a power battery heating system and an electronic control unit. The air inlet cooling system, the fuel cooling system, the air circulation cooling system, the evaporation cycle cooling system, and the power battery heating system are controlled and connected to the electronic control unit. Among them:

[0007] The air inlet cooling system is connected to the power battery, the generator, the motor, the electronic control unit and the engine body for cooling; the fuel cooling system is connected to the generator, the motor, the electronic control unit and the lubricating oil system for cooling; the air circulation cooling system is connected to the power battery, the lubricating oil system, the generator, the motor, the electronic control unit and the engine body for cooling; the evaporation cycle cooling system is connected to the power battery for cooling; the power battery heating system is connected to the power battery and the engine body for heating. The electronic control unit is used to comprehensively thermally manage the power battery, the lubricating oil system, the generator, the motor, the electronic control unit and the engine body in the hybrid electric power cabin by correspondingly controlling the air inlet cooling system, the fuel cooling system, the air circulation cooling system, the evaporation cycle cooling system and the power battery heating system according to the current flight phase and environmental temperature state of the aircraft.

[0008] Further, the air inlet cooling system includes an air inlet, a third valve, a fourth valve, a converging cooling air flow converging port and a circulation fan connected by pipelines. The air inlet diverts a part of the incoming air after the propeller to the power battery through a pipeline and a third valve, a part to the generator, the motor and the electronic control unit through a fourth valve, and a part to the lubricating oil system and the cold end of the engine for cooling, and then converges at the converging cooling air flow converging port and is transported to the hot end of the engine. After mixing with the incoming air at the cold end of the engine, it cools the engine body together. Subsequently, the cooling air flow and the combustion gas in the engine body are discharged from the power cabin by the hot end of the engine and the circulation fan;

[0009] The fuel cooling system includes a fuel pump, a fuel tank and a first radiator connected by pipelines. The fuel pump diverts the fuel in the fuel tank to the generator, the motor, the electronic control unit and the lubricating oil system through a pipeline. The fuel after cooling flows back into the fuel tank after heat exchange through the first radiator, and the fuel for cooling the lubricating oil system enters the engine body for combustion work;

[0010] The air circulation cooling system includes a fifth valve, a third radiator, a cooling turbine, an eighth valve, and a seventh valve connected by pipelines. The compressed gas in the engine body is successively led through the compressor bleed port, the fifth valve, the third radiator, and the cooling turbine. Then, a part of it is introduced into the intake port through the eighth valve and cools the power battery, the lubricating oil system, the generator, the motor, the electronic control unit, and the engine body together with the air inflow cooling system. Another part is led into the power battery through the seventh valve to cool the power battery. The cooled air converges at the cooling air flow confluence port, and the cooling air flow confluence port transports the air flow to the hot end of the engine. Subsequently, the hot end of the engine and the circulation fan discharge the cooling air flow and the combustion gas in the engine body out of the power cabin together;

[0011] The evaporation cycle cooling system includes a compressor, a second radiator, an expansion valve, and an evaporation cooling device connected in sequence to form a closed cycle. The evaporation cooling device is used to cool the power battery;

[0012] The power battery heating system includes a sixth valve and a first valve connected by pipelines. A part of the high-temperature gas discharged from the hot end of the engine is introduced into the power battery through the sixth valve and pipelines to heat the power battery. The heated gas converges at the cooling air flow confluence port through the first valve. The cooling air flow confluence port transports the air flow to the hot end of the engine. Subsequently, the hot end of the engine and the circulation fan discharge the cooling air flow and the combustion gas in the engine body out of the power cabin together.

[0013] Further, the second radiator is a condensation radiator.

[0014] Further, the power battery heating system further includes a heating device. One end of the heating device is connected to the power battery through a second valve, and the other end is connected to the cooling air flow confluence port.

[0015] Further, the heating device is a PCT heating device.

[0016] Further, phase change materials are arranged around the power battery.

[0017] On the other hand, this application also provides a control method for a thermal management system of an aircraft hybrid power cabin, including the steps:

[0018] S1. Obtain the current flight state and environmental temperature state of the aircraft. The flight state includes the takeoff stage, the flight cruise stage, and the special emergency state. The flight cruise stage includes the first half of the cruise and the second half of the cruise. The special emergency state includes engine power limitation and battery power limitation. The environmental temperature state includes high-temperature weather and low-temperature weather;

[0019] S2. Control the air intake cooling system, fuel cooling system, air cycle cooling system, evaporation cycle cooling system, and power battery heating system to comprehensively manage the heat of the power battery, lubricating oil system, generator, motor, electronic control unit, and engine body in the hybrid power cabin according to the current flight stage and environmental temperature status of the aircraft.

[0020] Further, the step S2 specifically includes the steps:

[0021] S21. When the current flight state and environmental temperature state are in the takeoff stage in high-temperature weather, control the air intake cooling system and fuel cooling system to cool the lubricating oil system, generator, motor, and electronic control unit together, cool the engine body through the air intake cooling system, and cool the power battery through the evaporation cycle cooling system;

[0022] S22. When the current flight state and environmental temperature state are in the takeoff stage in low-temperature weather, control the air intake cooling system and fuel cooling system to cool the lubricating oil system, generator, motor, and electronic control unit together, cool the engine body through the air intake cooling system; control the cooling or heating of the power battery according to the flight condition and temperature threshold. If the power battery needs to be cooled, control the air intake cooling system to cool it. If the power battery needs to be heated, control the power battery heating system to heat it.

[0023] Further, the step S2 specifically further includes the steps:

[0024] S23. When the current flight state is the first half of the cruise, control the air intake cooling system and fuel cooling system to cool the lubricating oil system, generator, motor, and electronic control unit together, cool the engine body through the air intake cooling system; control the cooling or heating of the power battery according to the flight condition and temperature threshold. If the power battery needs to be cooled, control the air intake cooling system to cool it. If the power battery needs to be heated, control the power battery heating system to heat it; the air cycle cooling system selects to be put into operation to cool the lubricating oil system, generator, motor, electronic control unit, engine body, and power battery according to the flight condition requirements;

[0025] S24. When the current flight state is the second half of the cruise, control the air intake cooling system, fuel cooling system, and air cycle cooling system to cool the lubricating oil system, generator, motor, and electronic control unit together, and the power battery selects the evaporation cycle cooling system, air cycle cooling system, or air intake cooling system for cooling according to the environmental temperature and engine operating state.

[0026] Further, the step S2 specifically further includes the steps:

[0027] S25. If the current flight state is when the engine power is limited, control the air inlet cooling system and the fuel cooling system to cool the lubricating oil system, the generator, the motor, and the electronic control unit together. The engine body is cooled by the air inlet cooling system, and the power battery is cooled by one or more of the air inlet cooling system, the air cycle cooling system, and the phase change material cooling;

[0028] S26. If the current flight state is when the battery power is limited, turn off the air cycle cooling system and the evaporation cycle cooling system, and control the air inlet cooling system and the fuel cooling system to cool the lubricating oil system, the generator, the motor, and the electronic control unit together. The power battery and the engine body are cooled by the air inlet cooling system.

[0029] Compared with the prior art, the present application has the following beneficial effects:

[0030] The present application provides a hybrid electric power cabin thermal management system for an aircraft and its control method. The system includes an air inlet cooling system, a fuel cooling system, an air cycle cooling system, an evaporation cycle cooling system, a power battery heating system, and an electronic control unit. The electronic control unit can correspondingly control the air inlet cooling system, the fuel cooling system, the air cycle cooling system, the evaporation cycle cooling system, and the power battery heating system to perform comprehensive thermal management on the power battery, the lubricating oil system, the generator, the motor, the electronic control unit, and the engine body in the hybrid electric power cabin, meeting the thermal management requirements of the hybrid electric power cabin in different flight stages and different environmental states, and enabling the hybrid electric power cabin to always be in the best temperature state according to different flight stages and environmental temperature states; by controlling the air inlet cooling system, the fuel cooling system, the air cycle cooling system, the evaporation cycle cooling system, and the power battery heating system, the present application can make the cooling of the power battery of the aircraft include two forms: closed-loop and open-loop. When the environmental temperature is high, the closed-loop evaporation cycle cooling system is used for cooling; when the environmental temperature is low, open-air cooling is adopted, that is, the air inlet cooling system and the air cycle cooling system enable the battery compartment to always obtain good cooling efficiency and meet the cooling requirements under different environmental temperatures. The present application introduces the air cycle cooling system, improves the overall cooling efficiency of the system, and reduces the energy waste caused by the large amount of gas that needs to be discharged by the engine to prevent surge. In addition, the present application can also effectively manage the heat in the hybrid electric power cabin in two emergency situations of engine power limitation and battery limitation.

[0031] In addition to the purposes, features, and advantages described above, the present application has other purposes, features, and advantages. The following will refer to the drawings to further describe the present application in detail. Brief Description of the Drawings

[0032] The accompanying drawings, which form a part of this application, are used to provide a further understanding of this application. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0033] Figure 1 is a schematic diagram of the principle of the hybrid electric power cabin thermal management system of the aircraft in the preferred embodiment of the present invention;

[0034] Figure 2 is a schematic diagram of the flow of the control method of the hybrid electric power cabin thermal management system of the aircraft in the preferred embodiment of the present invention;

[0035] Figure 3 is a schematic diagram of the working principle of the take-off thermal management system in high temperature weather in the preferred embodiment of the present invention;

[0036] Figure 4 is a schematic diagram of the working principle of the take-off thermal management system in low temperature weather in the preferred embodiment of the present invention;

[0037] Figure 5 is a schematic diagram of the working principle of the thermal management system in the second half of the cruise in the preferred embodiment of the present invention;

[0038] Figure 6 is a schematic diagram of the working principle of the thermal management system with limited engine power in the preferred embodiment of the present invention;

[0039] Figure 7 is a schematic diagram of the working principle of the thermal management system with limited battery power in the preferred embodiment of the present invention;

[0040] Figure 8 is a schematic diagram of the working principle of the preheating mode in the preferred embodiment of the present invention.

[0041] In the figure: 1. fuel tank; 2. first radiator; 3. lubricating oil system; 4. fuel pump; 5. heating device; 6. cooling air flow confluence port; 7. first valve; 8. second valve; 9. power battery; 10. evaporative cooling device; 11. air inlet; 12. expansion valve; 13. second radiator; 14. compressor; 15. third valve; 16. fourth valve; 17. electronic control unit; 18. motor; 19. generator; 20. hot end of the engine; 21. cold end of the engine; 22. circulation fan; 23. fifth valve; 24. sixth valve; 25. third radiator; 26. cooling turbine; 27. seventh valve; 28. eighth valve. Detailed Embodiments

[0042] The following will describe the embodiments of this application in detail with reference to the accompanying drawings. However, this application can be implemented in many different ways defined and covered by the following.

[0043] As Figure 1As shown in the figure, a preferred embodiment of the present application provides a thermal management system for a hybrid electric power cabin of an aircraft, including an air inflow cooling system, a fuel cooling system, an air cycle cooling system, an evaporation cycle cooling system, a power battery heating system, and an electronic control unit 17. The air inflow cooling system, the fuel cooling system, the air cycle cooling system, the evaporation cycle cooling system, and the power battery heating system are controlled and connected to the electronic control unit. Among them:

[0044] The air inflow cooling system is connected to the power battery 9, the generator 19, the motor 18, the electronic control unit 17, and the engine body for cooling; the fuel cooling system is connected to the generator 19, the motor 18, the electronic control unit 17, and the lubricating oil system 3 for cooling; the air cycle cooling system is connected to the power battery 9, the lubricating oil system 3, the generator 19, the motor 18, the electronic control unit 17, and the engine body for cooling; the evaporation cycle cooling system is connected to the power battery 9 for cooling; the power battery heating system is connected to the power battery 9 and the engine body for heating. The electronic control unit is used to comprehensively manage the heat of the power battery 9, the lubricating oil system 3, the generator 19, the motor 18, the electronic control unit 17, and the engine body in the hybrid electric power cabin by controlling the air inflow cooling system, the fuel cooling system, the air cycle cooling system, the evaporation cycle cooling system, and the power battery heating system according to the current flight stage and environmental temperature state of the aircraft.

[0045] Preferably, the air inflow cooling system includes an air inlet 11, a third valve 15, a fourth valve 16, a converging cooling air flow converging port 6, and a circulation fan 22 connected by pipelines. The air inlet 11 diverts a part of the incoming air after the propeller to the power battery 9 through a pipeline via the third valve 15, a part to the generator 19, the motor 18, and the electronic control unit 17 via the fourth valve 16, and a part to the lubricating oil system 3 and the cold end 21 of the engine for cooling, and then converges at the converging cooling air flow converging port 6 and is transported to the hot end 20 of the engine to be mixed with the incoming air from the cold end 21 of the engine to cool the engine body together. Subsequently, the cooling air flow and the combustion gas in the engine body are discharged from the power cabin by the hot end 20 of the engine and the circulation fan 22;

[0046] The fuel cooling system includes a fuel pump 4 and a fuel tank 1, and a first radiator 2 connected by pipelines. The fuel pump 4 diverts the fuel in the fuel tank 1 through a pipeline to the generator 19, the motor 18, the electronic control unit 17, and the lubricating oil system 3. After cooling, the fuel returns to the fuel tank 1 after heat exchange through the first radiator 2. The fuel for cooling the lubricating oil system 3 enters the engine body for combustion work;

[0047] The air circulation cooling system includes a fifth valve 23, a third radiator 25, a cooling turbine 26, an eighth valve 28, and a seventh valve 27 connected by pipelines. The compressed gas in the engine body is successively led through the compressor bleed port, the fifth valve 23, the third radiator 25, and the cooling turbine 26. Then, a part of it is introduced into the intake port 11 through the eighth valve 28 to cool the power battery 9, the lubricating oil system 3, the generator 19, the motor 18, the electronic control unit 17, and the engine body together with the air inflow cooling system. Another part is led into the power battery through the seventh valve 27 to cool the power battery. The cooled air converges at the cooling air flow confluence port 6, and the cooling air flow confluence port 6 transports the air flow to the hot end 20 of the engine. Subsequently, the hot end 20 of the engine and the circulation fan 22 discharge the cooling air flow and the combustion gas in the engine body out of the power compartment together;

[0048] The evaporation cycle cooling system includes a compressor 14, a second radiator 13, an expansion valve 12, and an evaporation cooling device 10 connected in sequence to form a closed cycle. The evaporation cooling device 10 is used to cool the power battery 9;

[0049] The power battery heating system includes a sixth valve 24 and a first valve 7 connected by pipelines. A part of the high-temperature gas discharged from the hot end 20 of the engine is introduced into the power battery 9 through the sixth valve 24 and the pipeline to heat the power battery 9. The heated gas converges at the cooling air flow confluence port 6 through the first valve 7. The cooling air flow confluence port 6 transports the air flow to the hot end 20 of the engine. Subsequently, the hot end 20 of the engine and the circulation fan 22 discharge the cooling air flow and the combustion gas in the engine body out of the power compartment together.

[0050] Among them, the second radiator 13 is a condensation radiator.

[0051] Among them, the power battery heating system further includes a heating device 5. One end of the heating device 5 is connected to the power battery 9 through a second valve 8, and the other end is connected to the cooling air flow confluence port 6. The heating device 5 is a PCT heating device.

[0052] Phase change materials, such as paraffin phase change materials, are arranged around the power battery 9.

[0053] The air flow rate of the air inflow cooling system, the fuel flow rate of the fuel cooling system, and the air flow rate of the air circulation cooling system are controlled by the electronic control unit 17. Flow regulating valves are respectively arranged on the pipelines of the air inflow cooling system, the fuel cooling system, and the air circulation cooling system. Each flow regulating valve is electrically connected to the electronic control unit 17. The electronic control unit 17 adjusts the air flow rate of the air inflow cooling system, the fuel flow rate of the fuel cooling system, and the air flow rate of the air circulation cooling system by controlling the opening degree of each flow regulating valve, so as to further control the cooling speed of each cooling system to meet the thermal management requirements under corresponding working conditions.

[0054] In the above embodiments, the cooling methods of the hybrid electric power cabin of the aircraft include air incoming flow cooling, fuel cooling, air circulation cooling, and evaporation cycle cooling. Air incoming flow cooling uses the air after the propeller for cooling. Fuel cooling uses the fuel in the fuel tank for cooling. Air circulation cooling uses a large amount of compressed gas led out from the engine, and these compressed gases are depressurized and cooled in the turbine of the environmental control system. The evaporation cycle cooling principle is similar to that of a common air conditioner, including a compressor 14, a condenser, an evaporator, an expansion valve 12, etc., and electric energy is required to achieve the cooling cycle.

[0055] In order to effectively manage the heat of different components of the hybrid electric power cabin, the above embodiments manage the power cabin in a partitioned manner, including a high-temperature area (engine), a medium-temperature area (motor and electronic control unit), and a power battery (low-temperature area). The generator and the motor are collectively referred to as the motor. The engine lubricating oil system uses fuel cooling and air cooling, and the motor and the electronic control unit are also cooled by fuel and air. The main heat management requirements of the electronic control unit come from power electronic power devices such as IGBT / SiC; the battery management unit, the engine control unit, and the aircraft control unit usually have independent cooling designs and relatively small cooling requirements, which are not involved in this technical solution.

[0056] When the temperature of the power battery 9 is high, the risk of its thermal runaway is very high. When the temperature is low, the charge and discharge capacity of the power battery drops significantly. The cooling methods of the power battery include air incoming flow cooling, fuel cooling, air circulation cooling, and evaporation cycle forced cooling, which are flexibly selected according to the flight conditions.

[0057] The cooling of the lubricating oil system, the motor, and the electronic control unit adopts an open cycle. After the air enters the power cabin, it first cools the above-mentioned equipment, and finally is ejected and discharged in the exhaust device.

[0058] The air cooling of the power battery includes an open cycle and a closed evaporation cycle; when the air temperature is low, an open air cycle is adopted; when the ambient temperature is high, a closed evaporation cycle cooling is adopted. If the above methods still cannot fully meet the cooling requirements of the power battery, the temperature of the battery pack rises to the melting point of the paraffin phase change material (about 42 degrees Celsius), and the paraffin around the battery can absorb a large amount of heat, effectively preventing thermal runaway.

[0059] A thermal management system for a hybrid electric power cabin of an aircraft provided by the above embodiment includes an air inlet cooling system, a fuel cooling system, an air cycle cooling system, an evaporation cycle cooling system, a power battery heating system, and an electronic control unit 17. The electronic control unit 17 can correspondingly control the air inlet cooling system, the fuel cooling system, the air cycle cooling system, the evaporation cycle cooling system, and the power battery heating system to perform comprehensive thermal management on the power battery 9, the lubricating oil system 3, the generator 19, the motor 18, the electronic control unit 17, and the engine body in the hybrid electric power cabin, so as to meet the thermal management requirements of the hybrid electric power cabin in different flight stages and different environmental states, and enable the hybrid electric power cabin to always be in the best temperature state according to different flight stages and environmental temperature states; By controlling the air inlet cooling system, the fuel cooling system, the air cycle cooling system, the evaporation cycle cooling system, and the power battery heating system, the power battery cooling of the aircraft can include two forms: closed-loop and open-loop. When the environmental temperature is high, the closed-loop evaporation cycle cooling system is used for cooling; When the environmental temperature is low, open-air cooling is adopted, that is, the air inlet cooling system and the air cycle cooling system enable the battery compartment to always obtain better cooling efficiency and meet the cooling requirements under different environmental temperatures. The air cycle cooling system is introduced in this application to improve the overall cooling efficiency of the system and reduce the energy waste caused by the large amount of gas that needs to be discharged by the engine to prevent surge. In addition, this embodiment can also effectively manage the heat in the hybrid electric power cabin in two emergency situations: engine power limitation and battery limitation.

[0060] As Figure 2 shown, another preferred embodiment of this application also provides a control method for a thermal management system of a hybrid electric power cabin of an aircraft, including the steps:

[0061] S1. Obtain the current flight state and environmental temperature state of the aircraft. The flight state includes a takeoff stage, a flight cruise stage, and a special emergency state. The flight cruise stage includes the first half of the cruise and the second half of the cruise. The special emergency state includes engine power limitation and battery power limitation; The environmental temperature state includes high-temperature weather and low-temperature weather;

[0062] S2. Correspondingly control the air inlet cooling system, the fuel cooling system, the air cycle cooling system, the evaporation cycle cooling system, and the power battery heating system to perform comprehensive thermal management on the power battery 9, the lubricating oil system 3, the generator 19, the motor 18, the electronic control unit 17, and the engine body in the hybrid electric power cabin according to the current flight stage and environmental temperature state of the aircraft.

[0063] This embodiment provides a control method for the thermal management system of an aircraft hybrid-electric power cabin. This method finely controls the thermal management of the aircraft hybrid-electric power cabin in segments, and different thermal management strategies are adopted in the takeoff phase, flight phase, and descent phase. Both the ambient temperature and the fuel tank level of the aircraft will affect the thermal management strategy. Among them, after obtaining the current flight state and ambient temperature state of the aircraft, the electronic control unit 17 can correspondingly control the air inflow cooling system, fuel cooling system, air cycle cooling system, evaporation cycle cooling system, and power battery heating system to comprehensively manage the heat of the power battery 9, lubricating oil system 3, generator 19, motor 18, electronic control unit 17, and engine body in the hybrid-electric power cabin, meeting the thermal management requirements of the hybrid-electric power cabin in different flight phases and different environmental states, and enabling the hybrid-electric power cabin to always be in the best temperature state according to the different flight phases and ambient temperature states; this embodiment can also effectively manage the heat in the hybrid-electric power cabin in two emergency situations of engine power limitation and battery limitation.

[0064] In a preferred embodiment of the present application, step S2 specifically includes the following steps:

[0065] S21. When the current flight state and ambient temperature state are the takeoff phase in high-temperature weather, control the air inflow cooling system and the fuel cooling system to cool the lubricating oil system 3, generator 19, motor 18, and electronic control unit 17 together. The engine body is cooled by the air inflow cooling system, and the power battery 9 is cooled by the evaporation cycle cooling system.

[0066] S22. When the current flight state and ambient temperature state are the takeoff phase in low-temperature weather, control the air inflow cooling system and the fuel cooling system to cool the lubricating oil system 3, generator 19, motor 18, and electronic control unit 17 together. The engine body is cooled by the air inflow cooling system; the power battery 9 controls cooling or heating according to the flight condition and temperature threshold. If the power battery 9 needs to be cooled, control the air inflow cooling system to cool it. If the power battery 9 needs to be heated, control the power battery heating system to heat it.

[0067] This embodiment mainly relates to the thermal management control in the takeoff phase, where:

[0068] Step S21 mainly targets the take-off stage in high-temperature weather (in airworthiness regulations, the air temperature refers to 30°C - 45°C, and some models are required to adapt to high-temperature environments above 55°C). During this take-off stage, the power demand of the aircraft is very high, while the engine power drops significantly in high-temperature environments. At this time, the power of the aircraft is provided jointly by the power battery 9 and the gas turbine engine, and the power provided by the power battery increases. The cooling requirements of the engine, generator 19, power battery 9, electronic control unit 17, and motor 18 are all very high. At this time, simple air inflow cooling cannot meet the cooling requirements of the power cabin.

[0069] The thermal management strategy for the above situation is as Figure 3 shown. In this embodiment, an evaporation cycle cooling system is used to provide cooling for the important and sensitive device of the power battery 9. At this time, the eighth valve 28, seventh valve 27, third valve 15, fifth valve 23, sixth valve 24, second valve 8, and first valve 7 are closed, and the fourth valve 16 is opened.

[0070] After the fuel comes out of the fuel tank 1, it is used to cool the motor and the electronic control unit 17, and then returns to the fuel tank 1; the fuel circulation flow rate is adjusted according to the temperature of the motor (or electronic control unit). When the temperature is high, the rotation speed of the fuel pump 4 is increased to increase the fuel cooling flow rate. Fuel cooling combined with air inflow cooling can meet the cooling requirements of the motor and the electronic control unit 17, and a part of the heat of the heated fuel is exchanged to the atmospheric environment through the first radiator 2.

[0071] When the temperature in high-temperature weather in summer may be higher than the target temperature (20°C - 30°C) of the power battery 9, the power battery 9 is wrapped in a closed battery compartment and evaporation cycle cooling is used to exchange heat to the atmospheric environment through the second radiator 13.

[0072] A part of the air inflow behind the propeller enters the cold end 21 of the engine to provide intake air and cold end cooling for the engine; a part is used to cool the lubricating oil system 3, generator 19, motor 18, and electronic control unit 17, and the cooling gas is introduced into the hot end 20 of the engine to take away the heat of the hot end 20 of the engine and prevent the engine compartment and the surrounding environment from overheating.

[0073] Step S22 mainly targets the take-off stage in low-temperature weather (usually referring to an atmospheric environment temperature of -20°C to -40°C). In extremely cold weather, the hybrid electric system needs to be preheated before take-off before the engine starts. The preheating principle is shown in Figure 8 . At this time, the third valve 15, fourth valve 16, sixth valve 24, and second valve 8 are opened, and the eighth valve 28, seventh valve 27, fifth valve 23, and first valve 7 are closed.

[0074] In low-temperature weather, the power reserve of the engine increases significantly, while the power provided by the power battery 9 decreases significantly, and the power battery 9 may even operate without discharging. The cooling requirements of the engine 20, generator 19, power battery 9, electronic control unit 17, and motor 18 all decrease. Among them, the power battery 9 may still need to be appropriately heated (depending on the deviation between the power battery temperature and the thermal management target temperature. For example, when the power battery temperature is lower than 10°C, the power battery is heated). In low-temperature weather, the air inflow capacity is very strong, and the fuel internal circulation flow rate and air inflow flow rate can be further adjusted downwards (depending on the lubricating oil temperature, motor / electronic control unit temperature, and fuel temperature. The adjustment measures are different in different situations. For example, when the motor temperature is lower than 60°C, the imported fuel temperature of the aeroengine is lower than 10°C, and the lubricating oil and electronic control unit temperatures are normal, the fuel internal circulation flow rate of the motor cooling flow path can be increased, and the air inflow flow rate of the motor cooling flow path can be decreased, so as to maintain both the motor temperature and the imported fuel temperature within a suitable range).

[0075] The thermal management strategy for the above situation is as Figure 4 shown. At this time, the seventh valve 27, eighth valve 28, fifth valve 23, and valve 8 are closed, and the third valve 15, fourth valve 16, sixth valve 24, and first valve 7 are opened. The suitable operating temperature of the power battery 9 is generally below 40 degrees Celsius. Since the exhaust gas temperature of the engine is relatively high, usually around 300 to 600 degrees Celsius, it cannot be directly used to heat the power battery 9 and needs to be mixed with the air inflow to a suitable temperature before being used for battery heating. The air inflow cooling system and the fuel cooling system together cool the lubricating oil system 3, generator 19, motor 18, and electronic control unit 17, and the engine is cooled through the air inflow cooling system; the power battery 9 controls cooling or heating according to the flight condition and temperature threshold. If the power battery 9 needs cooling, it is cooled by the air inflow cooling system. If the power battery needs heating, it is heated by the power battery heating system to ensure that the power battery 9 is always at a suitable operating temperature.

[0076] In a preferred embodiment of the present application, the step S2 specifically further includes the steps:

[0077] S23. When the current flight state is the first half of the cruise, control the air inflow cooling system and the fuel cooling system to cool the lubricating oil system 3, generator 19, motor 18, and electronic control unit 17 together, and the engine body is cooled through the air inflow cooling system; the power battery 9 controls cooling or heating according to the flight condition and temperature threshold. If the power battery 9 needs cooling, control the air inflow cooling system to cool it. If the power battery needs heating, control the power battery heating system to heat it; the air circulation cooling system selects to cool the lubricating oil system 3, generator 19, motor 18, electronic control unit 17, engine body, and power battery 9 according to the flight condition requirements.

[0078] S24. When the current flight state is the second half of the cruise, control the air inflow cooling system, fuel cooling system, and air cycle cooling system to cool the lubricating oil system 3, generator 19, motor 18, and electronic control unit 17 together. The power battery 9 selects the evaporation cycle cooling system, air cycle cooling system, or air inflow cooling system for cooling according to the ambient temperature and engine operating state.

[0079] This embodiment mainly relates to the thermal management control during the cruise phase, where:

[0080] Step S23 mainly targets the thermal management during the first half of the cruise. When the aircraft is cruising in the air, the power consumption is generally small. The power battery 9, as an energy storage component, adjusts the operating state of the engine, and the charge and discharge current is small. The cooling requirements of the engine, generator 19, power battery 9, electronic control unit 17, and motor 18 are all reduced.

[0081] The thermal management strategy for the above situation during the first half of the cruise is as follows: Since the cooling capacity of the usually air inflow is strong, combined with the fuel internal circulation cooling, it can meet the cooling requirements of the lubricating oil system 3, motor 18, generator 19, and electronic control unit 17. At this time, the charge and discharge environment of the power battery 9 is relatively mild, and the thermal management strategy needs to be selected according to the temperature of the power battery 9. If the power battery 9 does not work for a long time, the cooling of the power battery 9 should be stopped, and if the temperature is too low, the power battery 9 also needs to be heated. If the power battery 9 has a sharp temperature rise due to high-power charge and discharge at certain times, the power battery 9 should be cooled at this time. If the power battery 9 needs cooling, it is cooled by the air inflow cooling system, and if the power battery 9 needs heating, it is heated by the power battery heating system. The specific cooling method can be selected according to the needs Figures 3 to 7 of the type in.

[0082] Step S24 mainly targets the thermal management during the second half of the cruise. During the second half of the flight (including the aircraft landing process), the fuel of the aircraft is continuously consumed, and the fuel available for cooling the motor and electronic control unit 17 is continuously reduced. At the same time, the temperature of the fuel tank 1 continuously rises during the fuel cooling process, which makes the cooling capacity of the fuel continuously decline. In situations such as aircraft landing and takeoff, emergency, and acceleration, the motor and electronic control unit 17 may generate a large amount of heat, so the demand for cooling the motor and electronic control unit 17 exists for a long time. Especially in summer when the temperature is high, relying solely on air inflow and fuel cooling in the second half of the flight may not be able to meet the cooling requirements of the motor 18, generator 19, and electronic control unit 17.

[0083] The thermal management strategy for the above situation during the second half of the cruise is as Figure 5As shown, at this time, the eighth valve 28, the fourth valve 16, and the fifth valve 23 are opened, while the seventh valve 27, the third valve 15, the sixth valve 24, the second valve 8, and the first valve 7 are closed.

[0084] For example, in the second half of the summer cruise, evaporative cycle cooling and air cycle cooling are introduced. The incoming air cooling system, the fuel cooling system, and the air cycle cooling system together cool the lubricating oil system 3, the generator 19, the motor 18, and the electronic control unit 17. The engine body is cooled by the incoming air cooling system and the air cycle cooling system, and the power battery 9 is cooled by selecting the evaporative cycle cooling system.

[0085] Considering that the engine may operate at a low power state during low-altitude cruise, the engine usually needs to release a large amount of gas to prevent surging. These gases can be collected and used for air cycle cooling, thereby improving the overall cooling efficiency of the system.

[0086] In a preferred embodiment of the present application, the step S2 specifically further includes the steps of:

[0087] S25. If the current flight state is that the engine power is limited, control the incoming air cooling system and the fuel cooling system to cool the lubricating oil system 3, the generator 19, the motor 18, and the electronic control unit 17 together. The engine body is cooled by the incoming air cooling system, and the power battery 9 is cooled by one or more of the incoming air cooling system, the air cycle cooling system, and the phase change material cooling.

[0088] S26. If the current flight state is that the battery power is limited, turn off the air cycle cooling system and the evaporative cycle cooling system, control the incoming air cooling system and the fuel cooling system to cool the lubricating oil system 3, the generator 19, the motor 18, and the electronic control unit 17 together, and the power battery 9 and the engine body are cooled by the incoming air cooling system.

[0089] This embodiment mainly relates to the thermal management control in special emergency states, where:

[0090] Step S25 mainly aims at the thermal management when the engine power is limited. In some cases, the engine may have an in-air failure and can only be used with reduced power. At this time, the power battery 9 needs to discharge at a high power within a short time during the descent, while the total power of the motor may slightly decrease and it can safely descend within a short time. In this case, the heat dissipation and cooling requirements of the power battery 9 increase significantly, the cooling requirements of the motor and the electronic control unit 17 remain relatively unchanged, and the power that the entire power system can provide decreases significantly.

[0091] A thermal management strategy for the above-mentioned situation of engine power limitation is as follows: The generator 19, the motor 18, and the electronic control unit 17 are cooled by the fuel and air inflows. The cooling of the power battery 9 can be achieved by one or several of the following cooling methods: air inflow cooling, air circulation cooling, and paraffin phase change material cooling. Possible cooling combinations include, but are not limited to, the following: When the ambient temperature is very low (below 10 °C), only air inflow cooling is required; when the ambient temperature is relatively high (above 30 °C), air circulation cooling and paraffin phase change cooling are required (the principle is shown in Figure 6 ), and the paraffin phase change material is arranged around the power battery 9; when the ambient temperature is moderate (10 °C - 30 °C), air inflow cooling and air circulation cooling are used.

[0092] As Figure 6 shown, the cooling method of the power battery 9 when the ambient temperature is relatively high is presented. At this time, the eighth valve 28, the third valve 15, the sixth valve 24, and the second valve 8 are closed, and the seventh valve 27, the fourth valve 16, the fifth valve 23, and the first valve 7 are opened. The power battery 9 uses air circulation cooling and paraffin phase change cooling.

[0093] In this situation of engine power limitation, a relatively large amount of compressed gas still needs to be discharged to prevent surging, and this compressed gas can be used for air circulation cooling.

[0094] Step S26 mainly focuses on the thermal management of battery power limitation. In another special case, a part of the power battery 9 fails (to ensure safety, the power battery 9 is designed such that when a part breaks down, the other parts can still be used), and the high-power use of the remaining part of the power battery 9 is also restricted. In this case, the cooling requirement of the power battery 9 weakens, and the cooling capacity of the motor and the electronic control unit 17 remains relatively unchanged. At this time, the engine needs to operate at a high power state, and the aircraft power demand is relatively large, and air circulation cooling and evaporation cycle cooling are not provided.

[0095] The thermal management strategy for the above-mentioned situation of thermal management of battery power limitation is as Figure 7 shown. The seventh valve 27, the eighth valve 28, the fifth valve 23, the sixth valve 24, and the second valve 8 are closed, and the first valve 7, the third valve 15, and the fourth valve 16 are opened. The air inflow cooling system and the fuel cooling system together cool the lubricating oil system 3, the generator 19, the motor 18, and the electronic control unit 17. The power battery 9 and the engine body are cooled by the air inflow cooling system.

[0096] The existing invention adopts an open-loop cooling mode, which has poor cooling performance when the ambient temperature is high. The battery compartment cooling of the present invention includes two forms: closed-loop and open-loop. When the ambient temperature is high, closed-loop evaporation cycle cooling is adopted; when the ambient temperature is low, open-air cooling is adopted, so that the battery compartment can always obtain better cooling efficiency.

[0097] In the existing invention, the engine usually operates at a low power state during cruising. The engine usually needs to discharge a large amount of gas to prevent surging, resulting in energy waste. The present invention introduces a cooling turbine and air cycle cooling to improve the overall cooling efficiency of the system.

[0098] The existing solutions do not consider the thermal management in special emergency situations. The present invention has developed a special thermal management strategy for two emergency situations: engine power limitation and battery limitation, further improving the applicability of thermal management.

[0099] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0100] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these changes and modifications.

Claims

1. A thermal management system for a hybrid electric power cabin of an aircraft, characterized in that, It includes an air inlet cooling system, a fuel cooling system, an air cycle cooling system, an evaporation cycle cooling system, a power battery heating system, and an electronic control unit (17). The air inlet cooling system, the fuel cooling system, the air cycle cooling system, the evaporation cycle cooling system, and the power battery heating system are connected to the electronic control unit for control. Among them: The air inlet cooling system is connected to the power battery (9), the generator (19), the motor (18), the electronic control unit (17), and the engine body for cooling; the fuel cooling system is connected to the generator (19), the motor (18), the electronic control unit (17), and the lubricating oil system (3) for cooling; the air cycle cooling system is connected to the power battery (9), the lubricating oil system (3), the generator (19), the motor (18), the electronic control unit (17), and the engine body for cooling; the evaporation cycle cooling system is connected to the power battery (9) for cooling; the power battery heating system is connected to the power battery (9) and the engine body for heating. The electronic control unit is used to comprehensively thermally manage the power battery (9), the lubricating oil system (3), the generator (19), the motor (18), the electronic control unit (17), and the engine body in the hybrid electric power cabin according to the current flight phase and environmental temperature state of the aircraft.

2. The thermal management system for the hybrid electric power cabin of an aircraft according to claim 1, characterized in that The air inlet cooling system includes an air inlet (11), a third valve (15), a fourth valve (16), a confluence cooling air confluence port (6), and a circulation fan (22) connected by pipelines. The air inlet (11) diverts a part of the incoming air after the propeller to the power battery (9) through the pipeline via the third valve (15), a part to the generator (19), the motor (18), and the electronic control unit (17) via the fourth valve (16), and a part to the lubricating oil system (3) and the cold end (21) of the engine for cooling, and then converges at the confluence cooling air confluence port (6) and is transported to the hot end (20) of the engine to be mixed with the incoming air from the cold end (21) of the engine to cool the engine body together. Subsequently, the cooling air is discharged from the power cabin together with the combustion gas in the engine body by the hot end (20) of the engine and the circulation fan (22); The fuel cooling system includes a fuel pump (4), a fuel tank (1), and a first radiator (2) connected by pipelines. The fuel pump (4) diverts the fuel in the fuel tank (1) through the pipeline to the generator (19), the motor (18), and the electronic control unit (17). After cooling, the fuel returns to the fuel tank (1) after heat exchange through the first radiator (2). The fuel tank (1) is connected to the lubricating oil system (3) by a pipeline. The fuel output from the fuel tank (1) cools the lubricating oil system (3) and then enters the engine body for combustion work. The air circulation cooling system includes a fifth valve (23), a third radiator (25), a cooling turbine (26), an eighth valve (28), and a seventh valve (27) connected by pipelines. After the compressed gas in the engine body passes through the compressor and the bleed air port in sequence, and then through the fifth valve (23), the third radiator (25), and the cooling turbine (26), a part of the gas is introduced into the intake port (11) through the eighth valve (28) to cool the power battery (9), the lubricating oil system (3), the generator (19), the motor (18), the electronic control unit (17), and the engine body together with the air inflow cooling system. Another part of the gas is introduced into the power battery through the seventh valve (27) to cool the power battery. The cooled air converges into the cooling air flow confluence port (6), and the cooling air flow confluence port (6) transports the air flow to the hot end (20) of the engine. Subsequently, the hot end (20) of the engine and the circulation fan (22) discharge the cooling air flow and the combustion gas in the engine body out of the power cabin together; The evaporation cycle cooling system includes a compressor (14), a second radiator (13), an expansion valve (12), and an evaporation cooling device (10) connected in sequence to form a closed cycle. The evaporation cooling device (10) is used to cool the power battery (9); The power battery heating system includes a sixth valve (24) and a first valve (7) connected by pipelines. A part of the high-temperature gas discharged from the hot end (20) of the engine is introduced into the power battery (9) through the sixth valve (24) and the pipeline to heat the power battery (9). The heated gas converges into the cooling air flow confluence port (6) through the first valve (7). The cooling air flow confluence port (6) transports the air flow to the hot end (2) of the engine. Subsequently, the hot end (20) of the engine and the circulation fan (22) discharge the cooling air flow and the combustion gas in the engine body out of the power cabin together.

3. The thermal management system for the hybrid electric power cabin of the aircraft according to claim 2, characterized in that, The second radiator (13) is a condensation radiator.

4. The hybrid electric power cabin thermal management system for an aircraft according to claim 2, wherein The power battery heating system further includes a heating device (5). One end of the heating device (5) is connected to the power battery (9) through a second valve (8), and the other end is connected to the cooling air flow confluence port (6).

5. The thermal management system for the hybrid electric power cabin of an aircraft according to claim 4, characterized in that, The heating device (5) is a PCT heating device.

6. The thermal management system for the hybrid electric power cabin of an aircraft according to claim 2, characterized in that, Phase change materials are arranged around the power battery (9).

7. A control method for a thermal management system of a hybrid electric power cabin of an aircraft according to any one of claims 1 to 6, characterized in that, Including the steps: S1. Obtain the current flight state and environmental temperature state of the aircraft. The flight state includes the takeoff stage, the flight cruise stage, and the special emergency state. The flight cruise stage includes the first half of the cruise and the second half of the cruise. The special emergency state includes engine power limitation and battery power limitation. The environmental temperature state includes high-temperature weather and low-temperature weather; S2. Accordingly control the air inflow cooling system, the fuel cooling system, the air circulation cooling system, the evaporation cycle cooling system, and the power battery heating system to perform comprehensive thermal management on the power battery (9), the lubricating oil system (3), the generator (19), the motor (18), the electronic control unit (17), and the engine body in the hybrid power cabin according to the current flight stage and environmental temperature state of the aircraft.

8. The control method according to claim 7, wherein The step S2 specifically includes the steps: S21. When the current flight state and ambient temperature state are in the takeoff stage in high-temperature weather, control the air inflow cooling system and the fuel cooling system to cool the lubricating oil system (3), the generator (19), the motor (18) and the electronic control unit (17) together. The engine body is cooled by the air inflow cooling system, and the power battery (9) is cooled by the evaporation cycle cooling system; S22. When the current flight state and ambient temperature state are in the takeoff stage in low-temperature weather, control the air inflow cooling system and the fuel cooling system to cool the lubricating oil system (3), the generator (19), the motor (18) and the electronic control unit (17) together. The engine body is cooled by the air inflow cooling system; the power battery (9) controls cooling or heating according to the flight condition and the temperature threshold. If the power battery (9) needs to be cooled, control the air inflow cooling system to cool it. If the power battery (9) needs to be heated, control the power battery heating system to heat it.

9. The control method according to claim 8, characterized in that, The step S2 further includes the step: S23. When the current flight state is the first half of the cruise, control the air inflow cooling system and the fuel cooling system to cool the lubricating oil system (3), the generator (19), the motor (18) and the electronic control unit (17) together. The engine body is cooled by the air inflow cooling system; the power battery (9) controls cooling or heating according to the flight condition and the temperature threshold. If the power battery (9) needs to be cooled, control the air inflow cooling system to cool it. If the power battery needs to be heated, control the power battery heating system to heat it; The air circulation cooling system selects to be put into cooling the lubricating oil system (3), the generator (19), the motor (18), the electronic control unit (17), the engine body and the power battery (9) according to the flight condition requirements; S24. When the current flight state is the second half of the cruise, control the air inflow cooling system, the fuel cooling system and the air circulation cooling system to cool the lubricating oil system (3), the generator (19), the motor (18) and the electronic control unit (17) together. The power battery (9) selects the evaporation cycle cooling system, the air circulation cooling system or the air inflow cooling system for cooling according to the ambient temperature and the engine working state.

10. The control method according to claim 8, characterized in that, The step S2 further includes the step: S25. When the current flight state is that the engine power is limited, control the air inflow cooling system and the fuel cooling system to cool the lubricating oil system (3), the generator (19), the motor (18) and the electronic control unit (17) together. The engine body is cooled by the air inflow cooling system, and the power battery (9) is cooled by one or more of the air inflow cooling system, the air circulation cooling system and the phase change material cooling; S26. When the current flight state is limited by battery power, turn off the air circulation cooling system and the evaporation cycle cooling system, and control the air inlet cooling system and the fuel cooling system to cool the lubricating oil system (3), the generator (19), the motor (18) and the electronic control unit (17) together. The power battery (9) and the engine body are cooled by the air inlet cooling system.

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