A thermal management system and method for hybrid passenger aircraft electric propulsion equipment

Abstract

A thermal management system and method for hybrid passenger aircraft electric propulsion systems includes a fuel heat exchanger and a ram air heat exchanger. The fuel heat exchanger comprises three circuits: generator A, generator B, and a rectifier-lithium battery circuit. Each circuit ultimately exchanges heat with the fuel through either an oil / fuel heat exchanger or a liquid coolant / fuel heat exchanger. The ram air heat exchanger comprises three circuits: a propulsion motor controller-DC-DC circuit, a fuel cell circuit, and a propulsion motor circuit. Each circuit ultimately exchanges heat with the ram air through either an oil / ram air heat exchanger or a liquid coolant / ram air heat exchanger.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft thermal management, and in particular to a thermal management system and method applicable to electric propulsion equipment of hybrid passenger aircraft. Background Art

[0002] The hybrid electric propulsion system includes a power generation system, an energy storage system, a power distribution system, and a propulsion motor system. Its characteristics are:

[0003] The power generation system includes two generators and two rectifiers;

[0004] The energy storage system includes a lithium battery, a fuel cell, and a DC-DC converter;

[0005] The power distribution system includes a distribution panel box;

[0006] The propulsion motor system includes a propulsion motor and a propulsion motor controller;

[0007] The power generation system uses fuel and other energy sources through combustion and rectification to convert stored chemical energy into electrical energy. The energy storage system uses hydrogen and other energy sources through galvanic cell reactions and rectification to convert stored chemical energy into electrical energy. The power distribution system outputs electrical energy at different voltages and frequencies according to the needs of other systems. The propulsion motor system converts electrical energy into mechanical energy through electric motors, which are then used to generate flight power.

[0008] The electric propulsion equipment within the hybrid electric propulsion system will generate a certain amount of heat when operating, and thermal management must be considered. Otherwise, the continuous accumulation of heat will lead to excessive temperature, endangering safety.

[0009] The layout of electric propulsion equipment on the aircraft is as follows: Figure 1 As shown, the aircraft includes: one propulsion motor with its heat exchanger located in the aft compartment; one fuel cell with its heat exchanger located in the aft compartment; one lithium battery with its heat exchanger located in the center wing; two rectifiers with their heat exchangers located in the aft cargo hold; one DC-DC converter and one propulsion motor controller with their heat exchangers located in the bulk cargo hold; two generators, one under each wing; and one switchboard box, which is naturally cooled and not included in the thermal management system.

[0010] Electric propulsion equipment operates according to different control rules, as shown in the table below. Under different operating conditions, some equipment has a huge heat load, reaching hundreds of kilowatts.

[0011]

[0012] To reduce flight costs, hybrid passenger aircraft thermal management systems must be as small and lightweight as possible. Due to the numerous components, complex layout, high heat load, and numerous size and weight constraints (typically requiring a mass of less than 400 kg), thermal management technology has become a key factor limiting the development of hybrid passenger aircraft electric propulsion systems.

[0013] Existing technologies, such as CN201910934620.5, disclose a high-speed aircraft thermal management system that supports multiple heat sink configurations. This is a thermal management system for high-speed aircraft. Its heat sink relies more on fuel, skin heat exchange, and consumable heat sinks. The heat sink of hybrid passenger aircraft relies more on ram air. Similar technologies cannot meet the thermal management requirements of electric propulsion equipment.

[0014] CN202211009235.8 discloses a tiltrotor aircraft thermal management system specifically designed for small electric propulsion aircraft power systems. Due to its limited number of components, low heat dissipation power, and simple layout, it employs a relatively simple parallel-parallel architecture. Using similar technologies for hybrid passenger aircraft thermal management requires increased heat dissipation capacity, resulting in significant power losses and increased flight costs.

[0015] CN202011230067.6 discloses an integrated energy management system for hybrid electric propulsion aircraft. This system is designed for highly coupled operating conditions of powerplant components such as fans, combustors, and turbines. Because the operating conditions of electric propulsion equipment on hybrid passenger aircraft vary widely, using similar technologies makes it difficult to thermally manage these complex conditions.

[0016] Existing technologies are insufficient to meet the requirements for the design of thermal management systems for hybrid passenger aircraft's electric propulsion equipment. Therefore, it is necessary to design a thermal management system that is compatible with hybrid passenger aircraft to ensure the proper functioning of the electric propulsion equipment, which is of great significance to aircraft design and flight safety. Summary of the Invention

[0017] The purpose of the present invention is to resolve the contradiction between the design of hybrid electric propulsion system and the numerous electric propulsion devices, complex layout, large heat load, multiple volume and weight constraints of hybrid passenger aircraft. Taking into account the influence of heat dissipation requirements, available heat sinks, system weight, heat dissipation capacity and other aspects, a thermal management system suitable for electric propulsion devices of hybrid passenger aircraft is provided. Figure 2 As shown, it includes the terminal heat sink heat exchanger, electric propulsion equipment heat exchanger, working fluid box, sensor, PTC, pump, valve and pipeline, etc., and the technical solution for reasonable thermal management is as follows:

[0018] A thermal management system suitable for hybrid passenger aircraft electric propulsion equipment, including a portion where a fuel heat exchanger is located and a portion where a ram air heat exchanger is located; the thermal management system is characterized in that: the portion where the fuel heat exchanger is located is provided with three circuits, namely, a generator A circuit, a generator B circuit, and a rectifier-lithium battery circuit; depending on the different working fluids circulating in the system, each circuit ultimately exchanges heat with the fuel through a lubricating oil / fuel heat exchanger or a liquid-cooled working fluid / fuel heat exchanger; the portion where the ram air heat exchanger is located is provided with three circuits, namely, a propulsion motor controller-DC-DC circuit, a fuel cell circuit, and a propulsion motor circuit; depending on the different working fluids circulating in the system, each circuit ultimately exchanges heat with the ram air through a lubricating oil / ram air heat exchanger or a liquid-cooled working fluid / ram air heat exchanger.

[0019] Preferably, the generator A circuit includes an oil tank, a pump, a generator heat exchanger, and a sensor. The working fluid of this circuit, oil, flows from the oil tank, is pressure-regulated by the pump, and then flows through the flow and pressure sensors in sequence before flowing to the generator heat exchanger for heat exchange. After heat exchange, the oil flows out, passes through a temperature measuring point, flows to the fuel heat exchanger, and finally flows back to the oil tank.

[0020] The circuit structure of generator B is exactly the same as that of generator A, with only the layout position being different;

[0021] The rectifier-lithium battery circuit includes a fluid reservoir, pump, three-way valve, lithium battery heat exchanger, rectifier heat exchanger, and sensors. The working fluid in this circuit flows from the fluid reservoir, has its pressure regulated by the pump, and then flows through the three-way valve to the lithium battery heat exchanger and the rectifier heat exchanger for heat exchange. After heat exchange, the working fluid is measured by sensors for temperature, pressure, and flow. After converging, it flows to the fuel heat exchanger and finally back to the fluid reservoir. The lithium battery heat exchanger is equipped with a PTC to prevent the lithium battery from cooling too low.

[0022] Preferably, the propulsion motor controller-DC-DC circuit includes a fluid storage tank, a pump, a three-way valve, a propulsion motor controller heat exchanger, a DC-DC heat exchanger, and a sensor. The working fluid in this circuit flows from the fluid storage tank, is pressure-regulated by the pump, and then passes through the three-way valve. One path flows to the pump in front of the propulsion motor controller heat exchanger for further pressure regulation, and then flows to the propulsion motor controller heat exchanger for heat exchange; the other path flows to the DC-DC heat exchanger for heat exchange. After heat exchange, the temperature, pressure, and flow rate of the working fluid are measured by sensors, and after merging, it flows to the ram air heat exchanger and finally returns to the fluid storage tank.

[0023] The fuel cell circuit includes a liquid tank, a pump, a fuel cell heat exchanger, and a sensor. The working fluid in this circuit flows out of the liquid tank, and after the pressure is adjusted by the pump, it flows through the flow sensor and then flows to the fuel cell heat exchanger for heat exchange. After the working fluid flows out after heat exchange, it flows to the ram air heat exchanger after the temperature and pressure are measured by the sensor, and finally flows back to the liquid tank. The hydrogen required for the operation of the fuel cell is stored in a device connected to the fuel cell. A PTC is installed on the pipeline connecting the fuel cell and the fuel cell hydrogen storage device to ensure that the hydrogen temperature does not drop too low.

[0024] The propulsion motor circuit includes the oil tank, pump, propulsion motor heat exchanger, and sensors. The lubricating oil in this circuit flows from the oil tank, is pressure-regulated by the pump, and then flows through flow and pressure sensors before being transferred to the propulsion motor heat exchanger for heat exchange. After heat exchange, the oil flows out, passes through a temperature measurement point, flows to the ram air heat exchanger, and finally returns to the oil tank.

[0025] The mass of the thermal management system based on the above invention is shown in the following table, and its characteristics are: the total mass is less than 400 kg.

[0026] Mass composition Mass / kg heat exchanger 185.2 pipeline 19.6 working fluid 165.9 Working fluid box 4 pump 18 Valves, sensors, etc. 3.9 Total mass 396.6

[0027] Beneficial effects

[0028] The present invention disperses the electric propulsion equipment with a large heat load into two parts according to the equipment layout position, forming a distributed architecture containing multiple terminal heat sink heat exchangers, thereby reducing the heat exchange capacity requirements of a single terminal heat sink heat exchanger and reducing the difficulty of design and manufacturing.

[0029] The present invention disperses the electric propulsion equipment in the same part into different circuits according to the liquid cooling medium type requirements and working conditions of the equipment, and optimizes the circuit combination according to the working time and weight cost of the equipment to form a local parallel circuit, so that each device can exchange heat nearby, reducing the length of the connecting pipeline, thereby reducing the system mass to less than 400kg.

[0030] The present invention arranges a separate pump, liquid storage tank, and sensor for each circuit based on the liquid cooling medium flow, temperature, and pressure requirements of the equipment, so that the cooling of each device can be individually controlled, thereby improving temperature control accuracy and reducing system operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the layout of the electric propulsion equipment of the hybrid passenger aircraft targeted by the present invention.

[0032] Figure 2 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0033] Based on the equipment layout, the present invention divides the equipment into two sections. Furthermore, based on the equipment's thermal power, different terminal heat sinks are assigned to each section, namely, fuel and ram air, creating a section with a fuel heat exchanger and a section with a ram air heat exchanger. This significantly reduces the power required by a single terminal heat sink, solving the problem of high thermal load.

[0034] Within each section, circuits are divided according to the equipment's liquid cooling fluid requirements. For equipment using the same liquid cooling fluid, circuits are further combined based on equipment operating time and potential quality trade-offs, forming localized parallel circuits that allow for heat exchange within close proximity to the equipment. This shortens the length of piping connecting the equipment, reducing system volume and weight, addressing the challenges of numerous devices, complex layouts, and numerous volume and weight constraints.

[0035] Specifically, the mass components include heat exchangers, pipes, working fluids, working fluid tanks, pumps, valves, sensors, etc. The mass calculation method is as follows:

[0036] (1) Heat exchanger:

[0037]

[0038]

[0039] (W HEX ) dry =V HEX ×ρ HEX ×(1-σ)

[0040]

[0041] Among them, ΔT1 is the inlet temperature difference, ΔT2 is the outlet temperature difference, ΔT m is the average temperature difference, V HEX Indicates the volume of the heat exchanger, A HEX Indicates that the heat exchange area is determined according to the power of each device and the heat transfer coefficient of the heat exchanger (determined according to the power of each device and the heat transfer coefficient of the heat exchanger), β is the heat exchanger design parameter, and represents the compactness of the heat exchanger (taken as 1100), W HEX is the mass of the heat exchanger, (W HEX ) wet is the mass of the heat exchanger containing the working fluid, (W HEX ) dry is the mass of the heat exchanger without working fluid, ρ HEX Represents the density of the heat exchanger material (aluminum, calculate the upper limit of weight, take 2700kg / m 3 ), σ represents the porosity of the heat exchanger (taken as 0.5), ρ coolant Represents the density of the cooling medium (take 1036.24kg / m 3 ).

[0042] The heat transfer coefficient of the heat exchanger is tentatively set at 30.68W / (m 2 ·K), considering that the heat transfer temperature difference of the terminal heat sink is consistent with that of the cooling medium, the logarithmic mean temperature difference can be determined to be approximately 60°C and 90°C.

[0043] (2) Pipeline:

[0044]

[0045] ρ pipe Represents the density of the pipe material (aluminum, take 2700kg / m 3 ), wall thickness is 1mm, D out Represents the outer diameter, D H represents the equivalent diameter (the circular channel is the inner diameter, which is 250 mm), and L represents the length of the pipeline (total length is 30 m).

[0046] (3) Working fluid:

[0047]

[0048] D H represents the equivalent diameter (the inner diameter of the circular channel is taken as the inner diameter of different circuits), and L represents the length of the pipeline.

[0049] (4) Working fluid box:

[0050]

[0051]

[0052]

[0053] The working fluid box is a cube, t represents the wall thickness (take 1mm), K r represents the cooling medium fitting coefficient under different working conditions (taking 20% ​​redundancy into account, take 1.2), ρ reservoir Represents the density of the liquid storage tank material (aluminum, take 2700kg / m 3 ).

[0054] (5) Pump:

[0055]

[0056] W pump =K pump ×Displacement pump +1.1

[0057] Displacement pump is the empirical formula, K pumpIt is the unit conversion coefficient (take 237879.8).

[0058] (6) Valves and sensors:

[0059] Valves, sensors, etc. are calculated as 1% of the total weight of the system excluding valves and sensors.

[0060] In each circuit, pumps, fluid tanks, and sensors are installed based on the equipment's liquid cooling fluid temperature, pressure, and flow requirements to regulate and control the temperature, pressure, and flow of the circuit's fluid. The sensors measure and feed the data back to the control system, which then makes adjustments to achieve temperature, pressure, and flow control.

[0061] When the working fluid temperature before the equipment is too low or the working fluid temperature after the equipment is too high, according to the approximate formula when the temperature difference is not large

[0062]

[0063] Where Φ is the heat flow, is the flow rate, c P is the specific heat capacity at constant pressure, t2 is the working fluid temperature after the device, and t1 is the working fluid temperature before the device. You can increase the flow rate or activate the PTC to improve the temperature rise and ensure the normal operating temperature range of the device. If the flow rate is lower than the device requirements, you can also increase the flow rate.

[0064] When the pressure is too high, according to the pump rated working condition performance formula

[0065] Δp=Kn 2

[0066] Among them, Δp is the pressure rise, K is the pressure rise coefficient, and n is the speed. The pump speed can be reduced to reduce the pressure and ensure the normal operating pressure range of the equipment.

[0067] For the rectifier-lithium battery circuit and propulsion motor controller-DC-DC circuit with multiple devices, a three-way valve is set to achieve separate adjustment and control of the working fluid in the same circuit.

[0068] The fuel heat exchanger, located in a section where the operating conditions of various devices vary significantly and require relatively independent control, is configured with three circuits: generator A circuit, generator B circuit, and rectifier-lithium battery circuit. Depending on the working fluid circulating within the system, each circuit ultimately exchanges heat between the oil in the oil tank and the fuel heat exchanger, or between the liquid-cooled working fluid in the oil tank and the fuel in the fuel heat exchanger. The fuel then dissipates heat from the system through processes such as combustion.

[0069] Generator A circuit includes an oil tank, pump, generator heat exchanger, and sensors. The working fluid in this circuit, oil, flows from the oil tank, is pressure-regulated by a pump, and then flows through flow and pressure sensors to confirm that it meets equipment operating conditions. The oil then flows to the generator heat exchanger for heat exchange. After heat exchange, the oil flows to a temperature sensor, which provides temperature feedback to the control system to form a subsequent regulation strategy. When the temperature rises, the pump and valve are adjusted to increase flow, heat exchange, and lower equipment temperature. The oil then flows to the fuel heat exchanger, where it exchanges heat with the fuel heat sink. The oil then returns to the oil tank, completing the working fluid cycle and continuing operation to ensure that Generator A's temperature meets requirements. When Generator A is not operating, the pump and valve are shut off to reduce system power consumption.

[0070] The circuit structure of generator B is exactly the same as that of generator A. However, due to the long distance between the equipment layout and the shared use of generator A, an independent circuit is arranged.

[0071] The rectifier-lithium battery circuit includes a fluid reservoir, a pump, a three-way valve, a lithium battery heat exchanger, a rectifier heat exchanger, and sensors. The working fluid in this circuit flows from the fluid reservoir, is pressure-regulated by a pump to a suitable flow rate, and then is diverted by a three-way valve to provide independent cooling conditions for the two devices. The working fluid then exchanges heat through the lithium battery heat exchanger and the rectifier heat exchanger. After heat exchange, sensors measure temperature, pressure, and flow, and provide feedback to the control system to inform subsequent regulation strategies. If pressure or flow is unsuitable, the pump or three-way valve is adjusted to alter the working fluid distribution. If temperature rises, the pump and valve are adjusted to increase flow, thereby increasing heat exchange and lowering device temperature. After reunion, the working fluid flows to the fuel heat exchanger, where it transfers heat to the fuel heat sink. The working fluid returns to the fluid reservoir, completing the working fluid cycle and continuously operating to ensure that the rectifier and lithium battery temperatures meet requirements. The lithium battery heat exchanger is equipped with a PTC to prevent the lithium battery temperature from falling too low. When the rectifier is not working, adjust the pump and three-way valve to reduce system power consumption.

[0072] In the area where the ram air heat exchanger is located, three circuits are configured due to the significant differences in operating conditions among various devices and the relatively independent control requirements: the propulsion motor controller-DC-DC circuit, the fuel cell circuit, and the propulsion motor circuit. Depending on the working fluid circulating within the system, each circuit ultimately exchanges heat with the ram air through either the lubricating oil / ram air heat exchanger or the liquid-cooled working fluid / ram air heat exchanger.

[0073] The propulsion motor controller-DC-DC circuit consists of a fluid reservoir, pump, three-way valve, propulsion motor controller heat exchanger, DC-DC heat exchanger, and sensors. The working fluid in this circuit flows from the fluid reservoir, is pressure-regulated by the main pump to a suitable level for diversion, and then diverted by the three-way valve to provide independent cooling conditions for the two devices. One path of the working fluid flows to the branch pump, where its pressure is regulated to a level suitable for the propulsion motor controller. It then flows to the propulsion motor controller heat exchanger for heat exchange. The other path of the working fluid flows to the DC-DC heat exchanger for heat exchange. After heat exchange, the temperature, pressure, and flow rate of the two paths of working fluid are measured by sensors and fed back to the control system to inform subsequent regulation strategies. When the temperature rises, the pump and valve are adjusted to increase the flow rate, thereby increasing heat exchange and reducing the device temperature. When the pressure or flow rate is unsuitable, the main pump or three-way valve is adjusted to change the working fluid distribution. After reunion, the working fluids flow to the ram air heat exchanger, where they transfer heat to the ram air heat sink. The working fluid flows back to the tank, completing the working fluid cycle. Continuous operation ensures that the propulsion motor controller and DC-DC converter meet temperature requirements. When the propulsion motor controller is not operating, the main pump and three-way valve are adjusted, and the branch pump is turned off to reduce system power consumption.

[0074] The fuel cell circuit consists of a fluid reservoir, a pump, a fuel cell heat exchanger, and sensors. The working fluid in this circuit flows from the reservoir, is pressure-regulated by a pump, and then passes through a flow sensor to confirm that it meets the equipment's operating conditions. The working fluid then flows to the fuel cell heat exchanger for heat exchange. After heat exchange, the working fluid exits, where its temperature and pressure are measured by sensors and fed back to the control system to inform subsequent regulation strategies. When the temperature rises, the pump and valves are adjusted to increase flow, heat exchange, and reduce equipment temperature. When pressure exceeds the limit, the pump is adjusted to reduce pressure. The working fluid then flows to the ram air heat exchanger, where it exchanges heat with the ram air heat sink. The working fluid returns to the reservoir, completing the working fluid cycle and continuously operating to ensure the fuel cell temperature meets the required level. When the fuel cell is not operating, the pump and valve are turned off to reduce system power consumption. The hydrogen required for fuel cell operation is stored in a device connected to the fuel cell. A PTC is installed in the piping connecting the fuel cell to the fuel cell hydrogen storage device to prevent the hydrogen temperature from dropping too low.

[0075] The propulsion motor circuit includes an oil tank, a pump, a propulsion motor heat exchanger, and sensors. The working fluid of this circuit, the oil, flows out of the oil tank, and after the pressure is adjusted by the pump, it flows through the flow and pressure sensors in sequence to confirm that it meets the operating conditions of the equipment. The oil flows to the propulsion motor heat exchanger for heat exchange. After heat exchange, the oil flows out, the temperature is measured by the temperature measuring point, and the feedback is given to the control system to form a subsequent adjustment strategy. When the temperature rises, the pump and valve are adjusted to increase the flow rate, increase the heat exchange, and reduce the temperature of the equipment. The oil flows to the ram air heat exchanger and exchanges heat to the ram air heat sink. The oil flows back to the oil tank, completing the working fluid cycle, and continues to operate to ensure that the propulsion motor temperature meets the requirements. When the propulsion motor is not working, the pump and valve are turned off to reduce system power consumption.

[0076] Based on the above embodiments, the present invention completes the thermal management of the electric propulsion equipment of the hybrid passenger aircraft and obtains a set of typical working fluid temperatures at the inlet and outlet of the equipment, as shown in the following table.

[0077]

[0078]

[0079] In summary, this invention designs a thermal management system for electric propulsion systems in hybrid passenger aircraft, based on the layout, load, and control principles of the electric propulsion equipment, as well as the type, flow rate, and pressure requirements of the liquid cooling fluid. Building on existing technologies, this system addresses the design challenges posed by the numerous electric propulsion devices, complex layout, high heat load, and numerous volume and weight constraints, by deploying multiple terminal heat sinks to distribute the heat load, establishing multiple, partially parallel circuits to reduce system weight, and deploying independent pumps, fluid tanks, and sensors to improve control precision.

[0080] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions merely illustrate the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A thermal management system for a hybrid passenger aircraft electric propulsion system, comprising a fuel heat exchanger and a ram air heat exchanger; characterized by: The fuel heat exchanger is located in a section with three circuits: generator A circuit, generator B circuit, and rectifier-lithium battery circuit. Depending on the working fluid circulating in the system, each circuit ultimately exchanges heat with the fuel through either the lubricating oil / fuel heat exchanger or the liquid-cooled working fluid / fuel heat exchanger. The ram air heat exchanger is located in a system with three circuits: a propulsion motor controller-DC-DC circuit, a fuel cell circuit, and a propulsion motor circuit. Depending on the working fluid circulating in the system, each circuit ultimately exchanges heat with the ram air through either the lubricating oil / ram air heat exchanger or the liquid-cooled working fluid / ram air heat exchanger. The generator A circuit includes an oil tank, a pump, a generator heat exchanger, and sensors. The lubricating oil in this circuit flows from the oil tank, is pressure-regulated by the pump, and then flows through the flow and pressure sensors before flowing to the generator heat exchanger for heat exchange. After heat exchange, the oil flows out, passes through a temperature measuring point, flows to the fuel heat exchanger, and finally returns to the oil tank. The circuit structure of generator B is exactly the same as that of generator A, with only the layout position being different; The rectifier-lithium battery circuit includes a fluid storage tank, a pump, a three-way valve, a lithium battery heat exchanger, a rectifier heat exchanger, and a sensor. The working fluid in this circuit flows out of the fluid storage tank, has its pressure adjusted by the pump, and then flows through the three-way valve to the lithium battery heat exchanger and the rectifier heat exchanger for heat exchange. After heat exchange, the temperature, pressure, and flow rate of the working fluid are measured by sensors. After converging, the fluid flows to the fuel heat exchanger and finally returns to the fluid storage tank. The lithium battery heat exchanger is equipped with a PTC to ensure that the lithium battery temperature does not drop too low.

2. The thermal management system for hybrid passenger aircraft electric propulsion equipment according to claim 1, characterized in that: a propulsion motor controller-DC-DC circuit includes a fluid reservoir, a pump, a three-way valve, a propulsion motor controller heat exchanger, a DC-DC heat exchanger, and a sensor; the working fluid in this circuit flows from the fluid reservoir, is pressure-regulated by the pump, passes through the three-way valve, and then flows to the pump upstream of the propulsion motor controller heat exchanger for further pressure regulation before flowing to the propulsion motor controller heat exchanger for heat exchange; another path flows to the DC-DC heat exchanger for heat exchange; after heat exchange, the working fluid is measured for temperature, pressure, and flow by sensors, and then flows to the ram air heat exchanger after merging, and finally flows back to the fluid reservoir; The fuel cell circuit includes a liquid tank, a pump, a fuel cell heat exchanger, and a sensor. The working fluid in this circuit flows out of the liquid tank, is pressure-regulated by the pump, flows through the flow sensor, and then flows to the fuel cell heat exchanger for heat exchange. After heat exchange, the working fluid flows out, and after the temperature and pressure are measured by the sensor, it flows to the ram air heat exchanger and finally flows back to the liquid tank. The hydrogen required for the operation of the fuel cell is stored in a device connected to the fuel cell; a PTC is installed on the pipeline connecting the fuel cell and the fuel cell hydrogen storage device to ensure that the hydrogen temperature does not drop too low; The propulsion motor circuit includes a lubricating oil tank, a pump, a propulsion motor heat exchanger and a sensor. The working fluid lubricating oil in this circuit flows out from the lubricating oil tank, and after the pressure is adjusted by the pump, it flows through the flow and pressure sensors in sequence, and then flows to the propulsion motor heat exchanger for heat exchange; after heat exchange, the lubricating oil flows out, flows to the ram air heat exchanger through the temperature measuring point, and finally flows back to the lubricating oil tank.

3. A thermal management method for hybrid passenger aircraft electric propulsion equipment, the method being based on the thermal management system for hybrid passenger aircraft electric propulsion equipment according to claim 1, and characterized by: The hybrid passenger aircraft electric propulsion system is divided into two parts. These two parts are allocated as different terminal heat sinks for fuel and ram air according to the thermal power of the equipment, thereby forming a part where the fuel heat exchanger is located and a part where the ram air heat exchanger is located. Within each part, a number of circuits are divided according to the type of liquid cooling medium required for the equipment. For equipment using the same liquid cooling medium, the circuits are combined according to the equipment operating time and quality cost, thereby forming local parallel circuits, allowing the equipment to perform heat exchange nearby. By shortening the length of the pipes of the connected devices, the volume and weight of the system are reduced.

4. The thermal management method for hybrid passenger aircraft electric propulsion equipment according to claim 3, characterized by: The mass components include heat exchangers, pipelines, working fluids, working fluid boxes, pumps, valves, and sensors.

5. The thermal management method for hybrid passenger aircraft electric propulsion equipment according to claim 4, wherein the mass of the heat exchanger is calculated as follows: (W HEXdry =V HEX ×r HEX ×(1-σ) in, ΔT1 is the inlet temperature difference, ΔT2 is the outlet temperature difference, ΔT m is the average temperature difference, V HEX Indicates the volume of the heat exchanger, A HEX It indicates that the heat exchange area is determined according to the power of each device and the heat transfer coefficient of the heat exchanger. β is the design parameter of the heat exchanger, which indicates the compactness of the heat exchanger. W HEX is the mass of the heat exchanger, (W HEX ) wet is the mass of the heat exchanger containing the working fluid, (W HEX ) dry is the mass of the heat exchanger without working fluid, ρ HEX represents the heat exchanger material density, σ represents the heat exchanger porosity, ρ coolant Represents the density of the cooling medium.

6. The thermal management method for hybrid passenger aircraft electric propulsion equipment according to claim 4, wherein the mass of the pipeline is calculated as follows: in, W pipe is the pipeline mass, ρ pipe Represents the density of the pipe material, D out Represents the outer diameter, D H represents the equivalent diameter, and L represents the length of the pipe.

7. The thermal management method for hybrid passenger aircraft electric propulsion equipment according to claim 4, wherein the mass of the working fluid is calculated as follows: in, W coolant is the mass of the working fluid, ρ coolant is the working fluid density, D H represents the equivalent diameter, and L represents the length of the pipe.

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