A thermal management system, an aircraft, and an aircraft thermal management method

Abstract

The application discloses a heat management system, an aircraft and an aircraft heat management method. The heat management system comprises an expansion water tank, a first proportional valve connected between an output end of the expansion water tank and an input end of a circulating power branch, the circulating power branch and at least two symmetrically arranged heat dissipation branches. The circulating power branch is used for providing circulating driving force for the heat management system, one end of the circulating power branch is connected to the first proportional valve, the other end is connected to a second proportional valve, and the at least two symmetrically arranged heat dissipation branches are connected in parallel between an output end of the second proportional valve and an input end of the first proportional valve. The heat management system can not only improve the stability and safety of continuous operation of the heat management system under various working conditions, but also can guarantee the vibration and weight balance of the heat management system under various working conditions, so as to guarantee the flight safety of the aircraft.

Description

Technical Field

[0001] This application relates to the field of aircraft technology, and in particular to a thermal management system. This application also relates to an aircraft having the thermal management system and an aircraft thermal management method. Background Technology

[0002] Currently, eVTOL (electric vertical takeoff and landing) aircraft often employ a combination of air cooling and liquid cooling for heat dissipation. Specifically, the airflow introduced at the front reduces flow resistance while cooling the motor rotor and simultaneously driving the fan to rotate and dissipate heat. However, existing aircraft technologies do not consider improving the safety and reliability of the thermal management system. If the thermal management system fails, the stable operation of the aircraft's power system cannot be guaranteed, thus compromising flight safety. Furthermore, existing technologies do not disclose reasonable layout solutions for thermal management systems adapted to the compact shape and boundary dimensions of aircraft. An unreasonable layout of the thermal management system can lead to flow restrictions in some heat source thermal management branches, resulting in vibration and weight imbalances throughout the entire thermal management system.

[0003] Therefore, it is necessary for those skilled in the art to provide a thermal management system that can improve operational stability and safety under various operating conditions and ensure vibration and weight balance under various operating conditions, as well as an aircraft equipped with such a thermal management system. Summary of the Invention

[0004] The purpose of this application is to provide a thermal management system that can improve operational stability and safety under various operating conditions, and ensure vibration and weight balance under various operating conditions, thereby ensuring the flight safety of the aircraft. Another purpose of this application is to provide an aircraft including the above-mentioned thermal management system and an aircraft thermal management method.

[0005] To achieve the above objectives, this application provides a thermal management system, comprising:

[0006] Expansion tank;

[0007] The first proportional valve is connected to the output end of the expansion tank;

[0008] The circulating power branch is used to provide circulating driving force for the thermal management system. One end of the circulating power branch is connected to the first proportional valve, and the other end is connected to the second proportional valve.

[0009] At least two symmetrically arranged heat dissipation branches are connected in parallel between the output end of the second proportional valve and the input end of the first proportional valve.

[0010] In some embodiments, each heat dissipation branch includes a first electric drive series branch and a second electric drive series branch connected in parallel. One end of the first electric drive series branch is connected to one end of the second electric drive series branch through a third proportional valve, and the other end of the first electric drive series branch is connected to the other end of the second electric drive series branch through a fourth proportional valve.

[0011] In some embodiments, the first electric drive series branch includes a first motor and a first radiator connected in series, and the thermal management system further includes a first propeller, which is disposed toward the first radiator to provide external airflow to the first radiator;

[0012] The second electric drive series branch is provided with a second motor and a second radiator connected in series. The thermal management system also includes a second propeller, which is positioned toward the second radiator to provide external airflow to the second radiator.

[0013] The number of heat dissipation branches is an integer multiple of 2, and at least one pair of symmetrically arranged first propellers are tilt propellers and second propellers are hover propellers.

[0014] In some embodiments, the first electric drive series branch is further provided with a first controller, and the output terminal of the first controller connected in series with the first motor is connected to the first heat sink.

[0015] The second electric drive series branch is also equipped with a second controller, and the output terminal of the second controller connected in series with the second motor is connected to the second heat sink.

[0016] In some embodiments, the circulating power branch includes a first water pump series branch and a second water pump series branch connected in parallel. One end of the first water pump series branch is connected to one end of the second water pump series branch through a second proportional valve, and the other end of the first water pump series branch is connected to the other end of the second water pump series branch through a seventh proportional valve.

[0017] In some embodiments, the first water pump series branch includes a first check valve, a first water pump, and a second water pump. The input end of the first check valve is connected to the first output end of the seventh proportional valve. The first water pump and the second water pump are connected in series and then connected between the output end of the first check valve and the first input end of the second proportional valve. The second water pump series branch includes a second check valve, a third water pump, and a fourth water pump. The input end of the second check valve is connected to the second output end of the seventh proportional valve. The third water pump and the fourth water pump are connected in series and then connected between the output end of the second check valve and the second input end of the second proportional valve.

[0018] This application also provides an aircraft, including the thermal management system of any of the above, wherein the heat dissipation branches are symmetrically distributed about the central axis of the aircraft.

[0019] This application also provides a thermal management method for an aircraft, including:

[0020] Thermal management is performed during the vertical takeoff, takeoff mode transition, cruise, landing mode transition, and vertical landing phases of the aircraft. The specific process is as follows:

[0021] During the vertical takeoff phase of the aircraft, the circulating power branch provides maximum flow and pressure loss to the entire thermal management system, driving the coolant to circulate in the thermal management loop. The thermal management system pumps the cryogenic coolant proportionally into each of the parallel-connected heat dissipation branches through a first proportional valve. Each heat dissipation branch pumps the coolant proportionally into the first and second electric drive series branches connected in parallel. The tilt propeller is positioned towards the first radiator of the first electric drive series branch to provide external airflow to the first radiator. The hover propeller is positioned towards the second radiator of the second electric drive series branch to provide external airflow to the second radiator.

[0022] During the takeoff mode transition phase of the aircraft, the circulating power branch provides the maximum flow and pressure loss for the entire thermal management system. The thermal management system pumps the cryogenic coolant proportionally into each parallel-connected heat dissipation branch through the first proportional valve. Each heat dissipation branch distributes the coolant into the first and second electric drive series branches connected in parallel according to the calibrated ratio. According to the climb and cruise phases, the power corresponding to the climb speed and cruise speed is used to control the output ratio of the proportional valve in each electric drive series branch to the calibrated ratio.

[0023] When the aircraft enters the cruise phase, the circulating power branch reduces the flow and pressure loss of the entire thermal management circuit, and controls the coolant to circulate in each of the first electric drive series branches through the proportional valve.

[0024] During the landing mode transition phase of the aircraft, the circulating power branch ensures the flow and pressure loss of the entire thermal management loop. The thermal management system pumps the cryogenic coolant proportionally into each parallel-connected heat dissipation branch through the first proportional valve. Each heat dissipation branch distributes the coolant into the first and second electric drive series branches connected in parallel according to the calibrated ratio. Among them, the output ratio of the proportional valve in each electric drive series branch is controlled according to the power corresponding to the descent speed and cruise speed during the landing descent phase, which is the calibrated ratio.

[0025] During the vertical landing phase of the aircraft, the circulating power branch ensures the minimum flow and pressure loss of the entire thermal management circuit. The thermal management system pumps the cryogenic coolant proportionally into each parallel-connected heat dissipation branch through the first proportional valve. Each heat dissipation branch pumps the coolant proportionally into the first electric drive series branch and the second electric drive series branch connected in parallel.

[0026] Compared to the background technology described above, the thermal management system provided in this application includes an expansion tank, a first proportional valve, a circulating power branch, and at least two symmetrically arranged heat dissipation branches. The first proportional valve is connected between the output end of the expansion tank and the input end of the circulating power branch. The circulating power branch is used to provide circulating driving force for the thermal management system. One end of the circulating power branch is connected to the first proportional valve, and the other end is connected to the second proportional valve. At least two symmetrically arranged heat dissipation branches are connected in parallel between the output end of the second proportional valve and the input end of the first proportional valve. In this way, driven by the circulating power branch, the cryogenic coolant in the expansion tank flows through the first proportional valve to the second proportional valve. The second proportional valve distributes the cryogenic coolant into at least two symmetrically arranged heat dissipation branches according to a preset ratio, allowing the cryogenic coolant to complete heat exchange in the corresponding heat dissipation branches, thereby absorbing some of the heat generated in the corresponding heat dissipation branches. After heat dissipation, the coolant in each heat dissipation branch flows back to the first proportional valve, thereby remixing with the cryogenic coolant in the expansion tank to achieve continuous circulating cooling. This not only improves the stability and safety of the thermal management system under various operating conditions, but also ensures the vibration and weight balance of the thermal management system under various operating conditions, thus ensuring the flight safety of the aircraft. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0028] Figure 1 This is a connection diagram of the first thermal management system in the embodiments of this application;

[0029] Figure 2 for Figure 1 The diagram shows the thermal management system in the vertical takeoff phase.

[0030] Figure 3 for Figure 1 The diagram shows the thermal management system in the climbing mode transition phase.

[0031] Figure 4 for Figure 1 The diagram shows the thermal management system in the cruise phase.

[0032] Figure 5 for Figure 1 The diagram shows the thermal management system in the landing mode transition phase.

[0033] Figure 6 for Figure 1The diagram shows the thermal management system in the vertical descent phase.

[0034] Figure 7 for Figure 1 The diagram shows a thermal management system under the first thermal management margin.

[0035] Figure 8 for Figure 1 The diagram shows a thermal management system under the second thermal management margin.

[0036] Figure 9 This is a schematic diagram showing the connection between multi-rotor coupling mode two and multi-rotor coupling mode four;

[0037] Figure 10 for Figure 9 A schematic diagram of the layout structure of the thermal management system shown.

[0038] Figure 11 This is a connection diagram for multi-rotor coupling mode one;

[0039] Figure 12 This is a schematic diagram of the connection in the third coupling mode of the multi-rotor.

[0040] in:

[0041] 1-Expansion tank;

[0042] 2-First proportional valve;

[0043] 3-Circulating power branch, 31-First water pump series branch, 311-First check valve, 312-First water pump, 313-Second water pump, 32-Second water pump series branch, 321-Second check valve, 322-Third water pump, 323-Fourth water pump;

[0044] 4-Second proportional valve;

[0045] 5-Heat dissipation branch;

[0046] 501 - Third proportional valve, 502 - Fourth proportional valve, 503 - Fifth proportional valve, 504 - Sixth proportional valve;

[0047] 51-First electric drive series branch, 511-First controller, 512-First motor, 513-First heat sink;

[0048] 52-Second electric drive series branch, 521-Second controller, 522-Second motor, 523-Second heat sink;

[0049] 53-Third electric drive series branch, 531-Third controller, 532-Third motor, 533-Third radiator;

[0050] 54-Fourth electric drive series branch, 541-Fourth controller, 542-Fourth motor, 543-Fourth radiator;

[0051] 55-Fifth electric drive series branch, 551-Fifth controller, 552-Fifth motor, 553-Fifth radiator;

[0052] 56-Sixth electric drive series branch, 561-Sixth controller, 562-Sixth motor, 563-Sixth radiator;

[0053] 57-Seventh electric drive series branch, 571-Seventh controller, 572-Seventh motor, 573-Seventh radiator;

[0054] 58-Eighth electric drive series branch, 581-Eighth controller, 582-Eighth motor, 583-Eighth radiator;

[0055] 6-Seventh proportional valve;

[0056] 71-First propeller, 72-Second propeller, 73-Third propeller, 74-Fourth propeller, 75-Fifth propeller, 76-Sixth propeller, 77-Seventh propeller, 78-Eighth propeller;

[0057] 8-Fifth water pump. Detailed Implementation

[0058] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0059] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0060] It should be noted that the directional terms such as "upper end," "lower end," "left side," and "right side" mentioned below are defined based on the accompanying drawings in the instruction manual.

[0061] The thermal management system provided in this application includes an expansion tank 1, a first proportional valve 2, a circulating power branch 3, and at least two symmetrically arranged heat dissipation branches 5. The output end of the expansion tank 1 is connected to the first input end of the first proportional valve 2, the output end of the first proportional valve 2 is connected to the input end of the circulating power branch 3, the output end of the circulating power branch 3 is connected to a second proportional valve 4, and at least two symmetrically arranged heat dissipation branches 5 are connected in parallel between the output end of the second proportional valve 4 and the input end of the first proportional valve 2.

[0062] In this way, driven by the circulating power branch 3, the cryogenic coolant in the expansion tank 1 flows through the first proportional valve 2 to the second proportional valve 4. The second proportional valve 4 distributes the cryogenic coolant into at least two symmetrically arranged heat dissipation branches 5 according to a preset ratio, so that the cryogenic coolant completes heat exchange in the corresponding heat dissipation branch 5, thereby absorbing part of the heat generated in the corresponding heat dissipation branch 5. After heat dissipation, the coolant in each heat dissipation branch 5 flows back to the first proportional valve 2, thereby remixing with the cryogenic coolant in the expansion tank 1 to achieve continuous circulating cooling. This not only improves the stability and safety of the thermal management system under various operating conditions, but also ensures the vibration and weight balance of the thermal management system under various operating conditions, thereby ensuring the flight safety of the aircraft.

[0063] Of course, depending on actual needs, the number of heat dissipation branches 5 can be an integer multiple of 2, that is, the number of heat dissipation branches 5 can be set to 2, 4, 6, 8, etc. As a preferred embodiment, this embodiment uses two heat dissipation branches 5 as an example for specific explanation.

[0064] In some embodiments, each heat dissipation branch 5 includes a first electric drive series branch 51 and a second electric drive series branch 52 connected in parallel. One end of the first electric drive series branch 51 and one end of the second electric drive series branch 52 are connected through a third proportional valve 501, and the other end of the first electric drive series branch 51 and the other end of the second electric drive series branch 52 are connected through a fourth proportional valve 502.

[0065] The following explanation uses two heat dissipation branches (5) as an example.

[0066] Please see Figure 1 The first heat dissipation branch 5 is connected between the first output end of the second proportional valve 4 and the second input end of the first proportional valve 2, and the second heat dissipation branch 5 is connected between the second output end of the second proportional valve 4 and the third input end of the first proportional valve 2.

[0067] In the first heat dissipation branch 5, the first electric drive series branch 51 is provided with a first controller 511, a first motor 512 and a first heat sink 513. The output terminal of the first controller 511 and the first motor 512 connected in series is connected to the first heat sink 513, thereby forming the first electric drive series branch 51. The second electric drive series branch 52 is provided with a second controller 521, a second motor 522 and a second heat sink 523. The output terminal of the second controller 521 and the second motor 522 connected in series is connected to the second heat sink 523, thereby forming the second electric drive series branch 52.

[0068] In other words, the first electric drive series branch 51 and the second electric drive series branch 52 are connected in parallel to form the first heat dissipation branch 5 (also called the first electric drive parallel branch). Specifically, the input end of the first electric drive series branch 51 is connected to the first output end of the third proportional valve 501, and the output end of the first electric drive series branch 51 is connected to the first input end of the fourth proportional valve 502; the input end of the second electric drive series branch 52 is connected to the second output end of the third proportional valve 501, and the output end of the second electric drive series branch 52 is connected to the second input end of the fourth proportional valve 502.

[0069] In the second heat dissipation branch 5, the third electric drive series branch 53 is provided with a third controller 531, a third motor 532 and a third heat sink 533. The output terminal of the third controller 531 and the third motor 532 connected in series is connected to the third heat sink 533, thereby forming the third electric drive series branch 53. The fourth electric drive series branch 54 is provided with a fourth controller 541, a fourth motor 542 and a fourth heat sink 543. The output terminal of the fourth controller 541 and the fourth motor 542 connected in series is connected to the fourth heat sink 543, thereby forming the fourth electric drive series branch 54.

[0070] In other words, the third electric drive series branch 53 and the fourth electric drive series branch 54 are connected in parallel to form the second heat dissipation branch 5 (also called the second electric drive parallel branch). Specifically, the input end of the third electric drive series branch 53 is connected to the first output end of the fifth proportional valve 503, and the output end of the third electric drive series branch 53 is connected to the first input end of the sixth proportional valve 504; the input end of the fourth electric drive series branch 54 is connected to the second output end of the fifth proportional valve 503, and the output end of the fourth electric drive series branch 54 is connected to the second input end of the sixth proportional valve 504.

[0071] Understandably, given the large amount of heat generated by the entire aircraft, but the limited space of the structure, there is not enough room to install a blower to ensure that the external airflow meets the heat dissipation requirements. By installing a radiator inside the fuselage arm, the ram air from the propeller is used to compensate for the lack of a blower, which satisfies both the configuration design and the heat dissipation requirements, while also having a significant advantage in terms of weight.

[0072] The circulating power branch 3 can be any pipeline equipped with a fluid drive device that can guarantee the fluid power, flow rate, and head requirements within the thermal management system. For example, the circulating power branch 3 can include multiple power branches connected in parallel, so that one or more power branches can be opened according to actual application needs. Alternatively, the circulating power branch 3 can include only a single power branch, with a fluid drive device, such as a pump or hydraulic motor, installed on any power branch. In order to meet the flow rate and head requirements, two or more pumps or hydraulic motors can be connected in series on a single power branch.

[0073] In some embodiments, the circulating power branch 3 includes a first water pump series branch 31 and a second water pump series branch 32. One end of the first water pump series branch 31 and one end of the second water pump series branch 32 are connected through a second proportional valve 4, and the other end of the first water pump series branch 31 and the other end of the second water pump series branch 32 are connected through a seventh proportional valve 6.

[0074] In other words, the first water pump series branch 31 and the second water pump series branch 32 are connected in parallel through the second proportional valve 4 and the seventh proportional valve 6 to form the circulating power branch 3 (also known as the water pump parallel branch). Each of the first water pump series branch 31 and the second water pump series branch 32 is equipped with a check valve and a water pump; during safe operation of the system, the first water pump series branch 31 and the second water pump series branch 32 can serve as backups for each other, improving the reliability of the thermal management system.

[0075] Preferably, the first water pump series branch 31 is provided with a first check valve 311, a first water pump 312, and a second water pump 313, and the second water pump series branch 32 is provided with a second check valve 321, a third water pump 322, and a fourth water pump 323. The input end of the first check valve 311 is connected to the first output end of the seventh proportional valve 6, and the first water pump 312 and the second water pump 313 are connected in series between the output end of the first check valve 311 and the first input end of the second proportional valve 4; the input end of the second check valve 321 is connected to the second output end of the seventh proportional valve 6, and the third water pump 322 and the fourth water pump 323 are connected in series between the output end of the second check valve 321 and the second input end of the second proportional valve 4.

[0076] It should be noted that connecting two water pumps in series on a branch line can meet the flow rate and head requirements of the system under various operating conditions.

[0077] In addition, the first output end of the second proportional valve 4 is connected to the input end of the third proportional valve 501, the second output end of the second proportional valve 4 is connected to the input end of the fifth proportional valve 503; the output end of the fourth proportional valve 502 is connected to the second input end of the first proportional valve 2, the output end of the sixth proportional valve 504 is connected to the third input end of the first proportional valve 2, and the first input end of the first proportional valve 2 is connected to the output end of the expansion tank 1.

[0078] Meanwhile, the thermal management system also includes a first propeller 71, a second propeller 72, a third propeller 73, and a fourth propeller 74. The first propeller 71 is disposed toward the first radiator 513 to provide external airflow to the first radiator 513. The second propeller 72 is disposed toward the second radiator 523 to provide external airflow to the second radiator 523. The third propeller 73 is disposed toward the third radiator 533 to provide external airflow to the third radiator 533. The fourth propeller 74 is disposed toward the fourth radiator 543 to provide external airflow to the fourth radiator 543.

[0079] It should be noted that the first propeller 71 and the third propeller 73 are both tilting propellers, while the second propeller 72 and the fourth propeller 74 are both hovering propellers. During the climbing phase, the four propellers provide external airflow to their respective radiators. Their combination is as follows: the first propeller 71 and the first radiator 513 are combined to form the first heat exchange module; the second propeller 72 and the second radiator 523 are combined to form the second heat exchange module; the third propeller 73 and the third radiator 533 are combined to form the third heat exchange module; and the fourth propeller 74 and the fourth radiator 543 are combined to form the fourth heat exchange module.

[0080] The climb phase includes the vertical takeoff phase and the climb cruise phase. During the climb phase, the power of the motors and motor controllers is at the maximum value during normal flight. However, the propellers operate differently during the vertical takeoff phase and the climb cruise phase.

[0081] Please refer to the following: Figure 2 During the vertical takeoff phase, two types of propellers provide upward lift, and the aircraft gradually rises above the ground. The thermal management connection during this phase involves the operation of the first water pump series branch 31, with the first water pump 312 and the second water pump 313 operating at the same high speed to ensure maximum flow and pressure loss throughout the thermal management circuit. The first water pump series branch 31 drives the coolant to circulate throughout the sealed thermal management circuit. The first water pump series branch 31, through the second proportional valve 4, pumps the cryogenic coolant into the first and second heat dissipation branches 5 and 5 at a 1:1 ratio via pipelines. The third proportional valve 501 distributes the cryogenic coolant through pipelines into the first electric drive series branch 51 and the second electric drive series branch 52 at a 1:1 ratio, and the fifth proportional valve 503 distributes the cryogenic coolant through pipelines into the third electric drive series branch 53 and the fourth electric drive series branch 54 at a 1:1 ratio. In this way, the low-temperature coolant absorbs some of the heat generated by the electric drive operation, which is transferred through the cold plate, within the motor controller and motor cooling channels. The coolant's temperature rises after absorbing heat, while the high-temperature coolant enters the radiator through pipes. The four series-connected branches of the electric drive system circulate simultaneously, and the four heat exchange modules operate concurrently, carrying away the heat from the liquid flowing through the radiator. The high-temperature liquid output from the electric drive system dissipates heat within the radiator and is cooled to a low-temperature output. As long as the water pump operates continuously, the coolant can continuously circulate within the thermal management system, producing a cooling effect.

[0082] Please refer to the following: Figure 3During the mode transition phase, the tilt propellers gradually tilt forward from vertically upward, allowing the aircraft to gradually gain forward speed. The propulsion system then serves as the power source for forward flight. During this phase, the airflow generated by the first propeller 71 and the third propeller 73 transitions from vertical to tilted to horizontal, while the airflow generated by the second propeller 72 and the fourth propeller 74 remains vertical. The hovering power and level flight power differ during this phase, resulting in different heat generation. The output ratios of the third proportional valve 501 and the fifth proportional valve 503 are different to accommodate these different drive power requirements. The connection method for this phase involves the first water pump series branch 31 operating, with the first water pump 312 and the second water pump 313 operating at the same high speed to ensure maximum flow and pressure loss throughout the thermal management circuit. The first water pump series branch 31 drives the coolant to circulate throughout the sealed thermal management circuit. The first water pump series branch 31 pumps the low-temperature coolant into the first heat dissipation branch 5 and the second heat dissipation branch 5 at a 1:1 ratio through the pipeline via the second proportional valve 4. The third proportional valve 501 distributes the low-temperature coolant into the first electric drive series branch 51 and the second electric drive series branch 52 according to the calibrated ratio through the pipeline. The fifth proportional valve 503 distributes the low-temperature coolant into the third electric drive series branch 53 and the fourth electric drive series branch 54 according to the calibrated ratio through the pipeline. The calibrated ratio is based on the climbing and cruise phases, and the power corresponding to the climbing speed and cruise speed is used to control the output ratio of the third proportional valve 501 and the fifth proportional valve 503. In this way, the low-temperature coolant absorbs some of the heat generated by the electric drive through the cold plate in the motor controller and motor cooling channels. The coolant's temperature rises after absorbing heat, and the high-temperature coolant enters the radiator through pipes. The four series-connected branches of the electric drive circulate simultaneously. The propellers of the second and fourth heat exchange modules provide external flow to the radiator vertically; the propellers of the first and third heat exchange modules provide external flow to the radiator through air vents. With all four heat exchange modules working simultaneously, the heat flowing through the radiator is carried away. The high-temperature liquid output from the electric drive system dissipates heat and cools down within the radiator, becoming a low-temperature liquid for output. As long as the water pump operates continuously, the coolant can continuously circulate in the thermal management system, producing a cooling effect.

[0083] Please refer to the following: Figure 4During the cruise phase, the tilt propellers provide the power for the aircraft's forward flight. The airflow generated by the first propeller 71 and the third propeller 73 is horizontal during this phase, while the second propeller 72 and the fourth propeller 74 do not generate airflow. The hovering drive is inactive during this phase, and no heat is generated. The inactive hovering drive condition is coupled through the output ratios of the third proportional valve 501 and the fifth proportional valve 503. This connection method allows the first water pump series branch 31 to operate at its rated speed, reducing the flow and pressure loss of the entire thermal management circuit. Specifically, the first water pump series branch 31 drives the coolant to circulate throughout the sealed thermal management circuit. The first water pump series branch 31 pumps the low-temperature coolant into the first electric drive series branch 51 and the third electric drive series branch 53 in a 1:1 ratio through the second proportional valve 4. The second output terminal of the third proportional valve 501 and the second output terminal of the fifth proportional valve 503 are closed. The first output terminal of the third proportional valve 501 distributes the low-temperature coolant into the first electric drive series branch 51 through the pipeline, and the first output terminal of the fifth proportional valve 503 distributes the low-temperature coolant into the third electric drive series branch 53 through the pipeline. The low-temperature coolant absorbs some of the heat generated by the electric drive through the cold plate in the motor controller and motor cooling channels. After absorbing heat, the coolant's temperature rises, and the high-temperature coolant enters the radiator through pipes. The first electric drive series branch 51 and the third electric drive series branch 53 flow simultaneously. The propellers of the first and third heat exchange modules provide external flow to the radiator through air vents. Both heat exchange groups work simultaneously, carrying away the heat from the liquid flowing through the radiator. The high-temperature liquid output from the electric drive system dissipates heat and cools down within the radiator, becoming a low-temperature liquid for output. As long as the water pump operates continuously, the coolant can continuously circulate in the thermal management system, producing a cooling effect.

[0084] Please refer to the following: Figure 5During the landing mode transition phase, the tilt propulsion system gradually tilts, and the propeller disk direction gradually changes from forward to vertically upward. The hover propulsion system activates, gradually providing upward lift. During this phase, the electric drive power is low, and the tilt propeller's power serves as the aircraft's power source for level flight. The airflow direction generated by the first propeller 71 and the third propeller 73 during this phase transitions from horizontal to tilted to vertical, while the airflow direction generated by the second propeller 72 and the fourth propeller 74 is vertical. The hover power and level flight power differ during this phase, resulting in different heat generation. The output ratios of the third proportional valve 501 and the fifth proportional valve 503 are different to adapt to different drive power levels. The connection method for this phase is that the first water pump series branch 31 operates at its rated speed to ensure the flow rate and pressure loss of the entire thermal management circuit. Specifically, the first water pump series branch 31 drives the coolant to circulate throughout the sealed thermal management circuit. The second proportional valve 4 pumps the low-temperature coolant into the first heat dissipation branch 5 and the second heat dissipation branch 5 at a 1:1 ratio through the pipeline. The third proportional valve 501 distributes the low-temperature coolant into the first electric drive series branch 51 and the second electric drive series branch 52 according to the calibrated ratio through the pipeline. The fifth proportional valve 503 distributes the low-temperature coolant into the third electric drive series branch 53 and the fourth electric drive series branch 54 according to the calibrated ratio through the pipeline. The calibrated ratio is based on the power corresponding to the descent speed and the cruise speed during the landing and descent phase, which controls the output ratio of the third proportional valve 501 and the fifth proportional valve 503. In this way, the low-temperature coolant absorbs some of the heat generated by the electric drive through the cold plate in the motor controller and motor cooling channels. The coolant's temperature rises after absorbing heat, and the high-temperature coolant enters the radiator through pipes. The four series-connected branches of the electric drive circulate simultaneously. The propellers of the second and fourth heat exchange modules provide external flow to the radiator vertically; the propellers of the first and third heat exchange modules provide external flow to the radiator through air vents. With all four heat exchange groups working simultaneously, the heat flowing through the radiator is carried away. The high-temperature liquid output from the electric drive system dissipates heat and cools down within the radiator, becoming a low-temperature liquid for output. As long as the water pump operates continuously, the coolant can continuously circulate in the thermal management system, producing a cooling effect.

[0085] Please refer to the following: Figure 6During the vertical descent phase, the connection method is that the first water pump series branch 31 operates, while the first water pump 312 and the second water pump 313 operate at the same low speed to ensure minimum flow and pressure loss in the entire thermal management circuit. Specifically, the first water pump series branch 31 drives the coolant to circulate in the sealed thermal management circuit. The first water pump series branch 31 pumps the low-temperature coolant into the first heat dissipation branch 5 and the second heat dissipation branch 5 at a 1:1 ratio through the pipeline via the second proportional valve 4; the third proportional valve 501 distributes the low-temperature coolant into the first electric drive series branch 51 and the second electric drive series branch 52 at a 1:1 ratio through the pipeline; and the fifth proportional valve 503 distributes the low-temperature coolant into the third electric drive series branch 53 and the fourth electric drive series branch 54 at a 1:1 ratio through the pipeline. In this way, the low-temperature coolant absorbs some of the heat generated by the electric drive through the cold plate in the motor controller and motor cooling channels. After absorbing heat, the coolant's temperature rises, and the high-temperature coolant enters the radiator through the pipes. The second electric drive series branch 52 and the fourth electric drive series branch 54 flow simultaneously. The propellers of the first and third heat exchange modules provide external flow to the radiator. The two heat exchange modules work simultaneously, carrying away the heat of the liquid flowing through the radiator. The high-temperature liquid output from the electric drive system dissipates heat and cools down in the radiator, becoming a low-temperature liquid for output. As long as the water pump operates continuously, the coolant can continuously circulate in the thermal management system, producing a cooling effect.

[0086] Please refer to the following: Figure 7 When the first water pump 312 or the second water pump 313 in the first water pump series branch 31 fails, the first output terminal of the seventh proportional valve 6 is closed and the second output terminal of the seventh proportional valve 6 is opened. The second water pump series branch 32 is used to meet the thermal management margin and ensure the safety of the aircraft.

[0087] Please refer to the following: Figure 8 When one of the electronic water pumps in the two water pump series branches fails, or when three water pumps in the two water pump series branches fail simultaneously, the output of the coupling electronic three-way valve forms a branch with the fault-free water pump, increasing the speed of the single water pump to the maximum speed, ensuring that the aircraft has enough time to turn and land before the thermal management completely fails.

[0088] It should be noted that under normal operating conditions, the two pumps in a single branch operate at the appropriate speed; when a single pump fails, the two pumps in the other branch are switched to operate at the appropriate speed; in extreme cases where a single pump fails in both circuits, the speed of the pump without the fault in one of the branches can be increased to fully ensure the effectiveness of the aircraft's power system, thereby ensuring sufficient flight time for an emergency landing.

[0089] It should be noted that the first proportional valve 2 and the second proportional valve 4 are proportional four-way valves, while the third proportional valve 501, the fourth proportional valve 502, the fifth proportional valve 503, the sixth proportional valve 504, and the seventh proportional valve 6 are all proportional three-way valves.

[0090] The aforementioned multi-heat-source thermal management system, applied to eVTOL aircraft, organically couples multiple series-connected electric drive branches with multiple series-connected water pump branches to form a thermal management system, combining gaseous and liquid heat dissipation. Based on varying ambient temperatures and the different heat generation rates of different flight profiles of the aircraft, the system, through the rational coupling of electronic water pump speed control and valve ratio control, can meet the thermal management requirements of seven modes: vertical takeoff, takeoff mode transition, climb cruise, cruise flight, landing descent, landing mode transition, and vertical landing, maximizing energy utilization and ensuring both safety and endurance. Furthermore, a margin design is incorporated to address the failure of the electronic water pumps in the thermal management system, ensuring safety and the feasibility of safe landing under extreme conditions.

[0091] Please refer to the following: Figure 9 and Figure 10 In some embodiments, hovering-driven heat dissipation (with a branch for hovering propellers) and tilt-driven heat dissipation (with a branch for tilt propellers) are connected in parallel to form a heat dissipation branch 5. With the central axis of the aircraft as the axis of symmetry, the aircraft is provided with 2, 4, 6, or even 2N heat dissipation branches 5 symmetrically arranged along the central axis.

[0092] Two heat dissipation branches 5 are connected in parallel through two electronic three-way valves between the output end of the second proportional valve 4 and the input end of the first proportional valve 2. In other words, multiple heat dissipation branches 5 are connected in parallel to form a total heat dissipation loop, which can maintain the balance of vibration and weight of the thermal management system.

[0093] Taking four heat dissipation branches 5 as an example, the first heat dissipation branch 5 and the second heat dissipation branch 5 are connected in parallel through two electronic three-way valves between one output terminal of the second proportional valve 4 and the second input terminal of the first proportional valve 2. The third heat dissipation branch 5 and the fourth heat dissipation branch 5 are connected in parallel through two electronic three-way valves between the other output terminal of the second proportional valve 4 and the third input terminal of the first proportional valve 2.

[0094] Specifically, in the first heat dissipation branch 5, the first electric drive series branch 51 includes a first controller 511, a first motor 512, and a first heat sink 513. The output terminal of the first controller 511 and the first motor 512 connected in series is connected to the first heat sink 513, thus forming the first electric drive series branch 51. The second electric drive series branch 52 includes a second controller 521, a second motor 522, and a second heat sink 523. The output terminal of the second controller 521 and the second motor 522 connected in series is connected to the second heat sink 523, thus forming the second electric drive series branch. 52; In the second heat dissipation branch 5, the third electric drive series branch 53 is equipped with a third controller 531, a third motor 532, and a third heat sink 533. The output terminal of the third controller 531 and the third motor 532 connected in series is connected to the third heat sink 533, thus forming the third electric drive series branch 53. The fourth electric drive series branch 54 is equipped with a fourth controller 541, a fourth motor 542, and a fourth heat sink 543. The output terminal of the fourth controller 541 and the fourth motor 542 connected in series is connected to the fourth heat sink 543, thus forming the fourth electric drive series branch 5. 4; In the third heat dissipation branch 5, the fifth electric drive series branch 55 is equipped with a fifth controller 551, a fifth motor 552, and a fifth heat sink 553. The output terminal of the fifth controller 551 and the fifth motor 552 connected in series is connected to the fifth heat sink 553, thus forming the fifth electric drive series branch 55. The sixth electric drive series branch 56 is equipped with a sixth controller 561, a sixth motor 562, and a sixth heat sink 563. The output terminal of the sixth controller 561 and the sixth motor 562 connected in series is connected to the sixth heat sink 563, thus forming the sixth electric drive series branch 56. In the fourth heat dissipation branch 5, the seventh electric drive series branch 57 is equipped with a seventh controller 571, a seventh motor 572 and a seventh heat sink 573. The output terminal of the seventh controller 571 and the seventh motor 572 connected in series is connected to the seventh heat sink 573, thus forming the seventh electric drive series branch 57. The eighth electric drive series branch 58 is equipped with an eighth controller 581, an eighth motor 582 and an eighth heat sink 583. The output terminal of the eighth controller 581 and the eighth motor 582 connected in series is connected to the eighth heat sink 583, thus forming the eighth electric drive series branch 58.

[0095] It should be noted that the first propeller 71 and the first heat sink 513 are combined to form the first heat exchange module; the second propeller 72 and the second heat sink 523 are combined to form the second heat exchange module; the third propeller 73 and the third heat sink 533 are combined to form the third heat exchange module; the fourth propeller 74 and the fourth heat sink 543 are combined to form the fourth heat exchange module; the fifth propeller 75 and the fifth heat sink 553 are combined to form the fifth heat exchange module; the sixth propeller 76 and the sixth heat sink 563 are combined to form the sixth heat exchange module; the seventh propeller 77 and the seventh heat sink 573 are combined to form the seventh heat exchange module; and the eighth propeller 78 and the eighth heat sink 583 are combined to form the eighth heat exchange module.

[0096] exist Figure 9 In the thermal management system shown, the circulating power branch 3 is equipped with at least a fifth water pump 8. The input end of the fifth water pump 8 is connected to the output end of the first proportional valve 2, and the output end of the fifth water pump 8 is connected to the input end of the second proportional valve 4. The circulating power branch 3 can be any pipeline equipped with a fluid drive device that can guarantee the fluid power, flow rate, and head requirements within the thermal management system. For example, the circulating power branch 3 can include multiple power branches connected in parallel, so that one or more power branches can be activated according to actual application needs. Alternatively, the circulating power branch 3 can include only a single power branch, with a fluid drive device, such as a pump or hydraulic motor, installed on any power branch. Or, to meet the flow rate and head requirements, two or more pumps or hydraulic motors can be connected in series on a single power branch.

[0097] Understandably, in order to ensure that the heat dissipation branch 5 of each flight profile has air intake and to maintain the vibration and weight balance of the thermal management system, the hovering rotor (also known as the hover propeller) and the tilt rotor (also known as the tilt propeller) will be coupled in different ways throughout the flight profile of the aircraft, and the corresponding thermal management will also be coupled.

[0098] Multirotor coupled mode 1 (vertical takeoff and vertical landing phases): 8 rotors provide upward lift, such as... Figure 11 As shown;

[0099] Multirotor Coupling Mode Two (Takeoff Mode Conversion): The forward tilting propeller disk gradually tilts forward from vertically upward, the aircraft gradually gains forward speed, the wings gradually provide lift, and the hovering propulsion system gradually unloads, as... Figure 9 As shown;

[0100] Multirotor Coupling Mode 3 (Climb Cruise, Level Cruise, Landing Descent): The hovering propulsion system is off, while the tilt propulsion system continuously provides power throughout the fixed-wing flight process, such as... Figure 12 As shown.

[0101] Multirotor Coupling Mode Four (Landing Mode Transition Phase): The tilt propulsion system gradually tilts, the rotor disk direction gradually changes from forward to vertical upward, the hover propulsion system aerodynamics gradually provides upward lift, and the wing gradually unloads, such as... Figure 9 As shown.

[0102] Considering the coupling modes of the four rotors, thermal management performance, weight, vibration and other factors, a set of hovering rotors and tilting rotors are connected in parallel to form a heat dissipation branch 5, and multiple heat dissipation branches 5 are then connected in parallel to form a total heat dissipation loop.

[0103] exist Figure 10In the thermal management system shown, the first controller 511 / first motor 512 and the second controller 521 / second motor 522 are connected in parallel to form the first multi-rotor parallel heat dissipation branch; the third controller 531 / third motor 532 and the fourth controller 541 / fourth motor 542 are connected in parallel to form the second multi-rotor parallel heat dissipation branch; the fifth controller 551 / fifth motor 552 and the sixth controller 561 / sixth motor 562 are connected in parallel to form the third multi-rotor parallel heat dissipation branch; and the seventh controller 571 / seventh motor 572 and the eighth controller 581 / eighth motor 582 are connected in parallel to form the fourth multi-rotor parallel heat dissipation branch.

[0104] It is understandable that each flight profile and each heat dissipation branch of the aforementioned aircraft has air intake, and can maintain the balance of vibration and weight of the thermal management system.

[0105] Thus, the thermal management system provided in this application embodiment has three main operating modes, and it is necessary to ensure vibration and weight balance of the thermal management system in each operating mode:

[0106] In multi-rotor coupling mode one: 8 rotors provide upward lift, and 4 multi-rotor cooling branches operate with the same flow rate;

[0107] In multi-rotor coupling mode 2 and multi-rotor coupling mode 4, the tilt rotor adjusts its attitude and the hovering rotor works. Depending on the different attitudes of the tilt rotor, the four multi-rotor heat dissipation branches 5 work in parallel in the same state, but the thermal management working states of the tilt rotor and the hovering rotor inside the parallel connection are different.

[0108] In multi-rotor coupling mode 3, the four multi-rotor heat dissipation branches 5 are connected in parallel and operate in the same state, but the thermal management of the tilt rotor inside the parallel connection is not working, while the thermal management of the hover rotor is working.

[0109] The aircraft provided in this application includes the thermal management system described in the above specific embodiments; wherein, the heat dissipation branch 5 is symmetrically distributed about the central axis of the aircraft, and other parts of the aircraft can refer to the prior art, which will not be elaborated here.

[0110] This application also provides a thermal management method for an aircraft, used to perform thermal management during the vertical takeoff, takeoff mode transition, cruise, landing mode transition, and vertical landing phases of an aircraft, specifically including:

[0111] During the vertical takeoff phase of the aircraft, the circulating power branch 3 provides the maximum flow and pressure loss for the entire thermal management system, driving the coolant to circulate in the thermal management loop. The thermal management system pumps the cryogenic coolant proportionally into each of the parallel-connected heat dissipation branches 5 through the first proportional valve 2. Each heat dissipation branch 5 pumps the coolant proportionally into the first electric drive series branch 51 and the second electric drive series branch 52 connected in parallel. The tilt propeller is positioned towards the first radiator 513 of the first electric drive series branch 51 to provide external airflow to the first radiator 513. The hover propeller is positioned towards the second radiator 523 of the second electric drive series branch 52 to provide external airflow to the second radiator 523.

[0112] During the takeoff mode transition phase of the aircraft, the circulating power branch 3 provides the maximum flow and pressure loss for the entire thermal management system. The thermal management system pumps the cryogenic coolant proportionally into each of the parallel-connected heat dissipation branches 5 through the first proportional valve 2. Each heat dissipation branch 5 distributes the coolant into the first electric drive series branch 51 and the second electric drive series branch 52 connected in parallel according to the calibrated ratio. According to the climb and cruise phases, the power corresponding to the climb speed and cruise speed is used to control the output ratio of the proportional valve in each electric drive series branch to the calibrated ratio.

[0113] When the aircraft enters the cruise phase, the circulating power branch 3 reduces the flow and pressure loss of the entire thermal management circuit, and controls the coolant to circulate in each of the first electric drive series branches 51 through the proportional valve.

[0114] During the landing mode transition phase of the aircraft, the circulating power branch 3 ensures the flow and pressure loss of the entire thermal management loop. The thermal management system pumps the cryogenic coolant proportionally into each of the parallel-connected heat dissipation branches 5 through the first proportional valve 2. Each heat dissipation branch 5 distributes the coolant into the first electric drive series branch 51 and the second electric drive series branch 52 connected in parallel according to the calibrated ratio. Among them, the output ratio of the proportional valve in each electric drive series branch is controlled according to the power corresponding to the descent speed and the cruise speed during the landing descent phase, which is the calibrated ratio.

[0115] During the vertical landing phase of the aircraft, the circulating power branch 3 ensures the minimum flow and pressure loss of the entire thermal management circuit. The thermal management system pumps the cryogenic coolant proportionally into each of the parallel-connected heat dissipation branches 5 through the first proportional valve 2. Each heat dissipation branch 5 pumps the coolant proportionally into the first electric drive series branch 51 and the second electric drive series branch 52 connected in parallel.

[0116] More specifically, please refer to the following: Figure 2During the vertical takeoff phase of the aircraft, the two types of propellers (tilt propellers and hover propellers) in at least two heat dissipation branches 5 are controlled to provide lift. After one of the water pump series branches in the control cycle power branch 3 is opened, the coolant in the expansion tank 1 flows through the first proportional valve 2 to the second proportional valve 4 and is distributed by the second proportional valve 4 before flowing into at least two heat dissipation branches 5. In any heat dissipation branch 5, the coolant is further distributed and flows into the electric drive series branch where the two types of propellers are located, and flows back to the first proportional valve 2 after completing heat exchange.

[0117] Please refer to the following: Figure 3 During the takeoff mode transition phase of the aircraft, the first type of propeller (i.e., the tilt propeller) in at least two heat dissipation branches 5 is controlled to gradually tilt forward from providing upward lift, while the second type of propeller (i.e., the hover propeller) continues to provide upward lift. After one of the water pump series branches in the control cycle power branch 3 is opened, the coolant in the expansion tank 1 flows through the first proportional valve 2 to the second proportional valve 4 and is distributed by the second proportional valve 4 before flowing into at least two heat dissipation branches 5. In any heat dissipation branch 5, the coolant is further distributed and flows into the electric drive series branch where the two types of propellers are located, and flows back to the first proportional valve 2 after completing heat exchange.

[0118] Please refer to the following: Figure 4 When the aircraft enters the cruise phase, the first type of propeller (i.e., tilt propeller) in at least two heat dissipation branches 5 is controlled to generate forward flight power, and the second type of propeller (i.e., hover propeller) stops working. After one of the water pump series branches in the control circulation power branch 3 is turned on, the coolant in the expansion tank 1 flows through the first proportional valve 2 to the second proportional valve 4 and is distributed by the second proportional valve 4 before flowing into the electric drive series branch where the first type of propeller is located in at least two heat dissipation branches 5, and flows back to the first proportional valve 2 after completing heat exchange.

[0119] Please refer to the following: Figure 5 During the landing mode transition phase of the aircraft, the first type of propeller (i.e., tilt propeller) in at least two heat dissipation branches 5 gradually changes from providing forward power to providing upward lift, and the second type of propeller (i.e., hover propeller) starts and provides upward lift. After one of the water pump series branches in the control circulation power branch 3 is opened, the coolant in the expansion tank 1 flows through the first proportional valve 2 to the second proportional valve 4 and is distributed by the second proportional valve 4 before flowing into at least two heat dissipation branches 5. In any heat dissipation branch 5, the coolant is further distributed and flows into the electric drive series branch where the two types of propellers are located, and flows back to the first proportional valve 2 after completing heat exchange.

[0120] Please refer to the following: Figure 6During the vertical landing phase of the aircraft, the two types of propellers (tilt propellers and hover propellers) in at least two heat dissipation branches 5 are controlled to provide lift. After one of the water pump series branches in the control cycle power branch 3 is opened, the coolant in the expansion tank 1 flows through the first proportional valve 2 to the second proportional valve 4 and is distributed by the second proportional valve 4 before flowing into at least two heat dissipation branches 5. In any heat dissipation branch 5, the coolant is further distributed and flows into the electric drive series branch where the two types of propellers are located, and flows back to the first proportional valve 2 after completing heat exchange.

[0121] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0122] The thermal management system, aircraft, and aircraft thermal management method provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the solution and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A thermal management system, characterized in that, include: Expansion tank; The first proportional valve is connected to the output end of the expansion tank; A circulating power branch is used to provide circulating driving force for the thermal management system. One end of the circulating power branch is connected to the first proportional valve, and the other end is connected to the second proportional valve. At least two symmetrically arranged heat dissipation branches are connected in parallel between the output end of the second proportional valve and the input end of the first proportional valve. Each of the aforementioned heat dissipation branches includes a first electric drive series branch and a second electric drive series branch connected in parallel. One end of the first electric drive series branch is connected to one end of the second electric drive series branch through a third proportional valve, and the other end of the first electric drive series branch is connected to the other end of the second electric drive series branch through a fourth proportional valve.

2. The thermal management system as described in claim 1, characterized in that, The first electric drive series branch is provided with a first motor and a first radiator connected in series. The thermal management system further includes a first propeller, which is positioned toward the first radiator to provide external airflow to the first radiator. The second electric drive series branch is provided with a second motor and a second radiator connected in series. The thermal management system also includes a second propeller, which is arranged toward the second radiator to provide external airflow to the second radiator. The number of heat dissipation branches is an integer multiple of 2, and at least one pair of symmetrically arranged first propellers are tilt propellers and second propellers are hover propellers.

3. The thermal management system as described in claim 2, characterized in that, The first electric drive series branch is also provided with a first controller, and the output terminal of the first controller connected in series with the first motor is connected to the first heat sink; The second electric drive series branch is also provided with a second controller, and the output terminal of the second controller connected in series with the second motor is connected to the second heat sink.

4. The thermal management system as described in claim 1, characterized in that, The circulating power branch includes a first water pump series branch and a second water pump series branch connected in parallel. One end of the first water pump series branch is connected to one end of the second water pump series branch through a second proportional valve, and the other end of the first water pump series branch is connected to the other end of the second water pump series branch through a seventh proportional valve.

5. The thermal management system as described in claim 4, characterized in that, The first water pump series branch includes a first check valve, a first water pump, and a second water pump. The input end of the first check valve is connected to the first output end of the seventh proportional valve. The first water pump and the second water pump are connected in series and then connected between the output end of the first check valve and the first input end of the second proportional valve. The second water pump series branch includes a second check valve, a third water pump, and a fourth water pump. The input end of the second check valve is connected to the second output end of the seventh proportional valve. The third water pump and the fourth water pump are connected in series and then connected between the output end of the second check valve and the second input end of the second proportional valve.

6. An aircraft, characterized in that, The thermal management system includes any one of claims 1-5, wherein the heat dissipation branches are symmetrically distributed about the central axis of the aircraft.

7. A thermal management method for an aircraft, characterized in that, include: Thermal management is performed during the vertical takeoff, takeoff mode transition, cruise, landing mode transition, and vertical landing phases of the aircraft. The specific process is as follows: During the vertical takeoff phase of the aircraft, the circulating power branch provides maximum flow and pressure loss to the entire thermal management system, driving the coolant to circulate in the thermal management loop. The thermal management system pumps the cryogenic coolant proportionally into each of the parallel-connected heat dissipation branches through a first proportional valve. Each heat dissipation branch pumps the coolant proportionally into the first and second electric drive series branches connected in parallel. The tilt propeller is positioned towards the first radiator of the first electric drive series branch to provide external airflow to the first radiator. The hover propeller is positioned towards the second radiator of the second electric drive series branch to provide external airflow to the second radiator. During the takeoff mode transition phase of the aircraft, the circulating power branch provides the maximum flow and pressure loss for the entire thermal management system. The thermal management system pumps the cryogenic coolant proportionally into each parallel-connected heat dissipation branch through the first proportional valve. Each heat dissipation branch distributes the coolant into the first and second electric drive series branches connected in parallel according to the calibrated ratio. According to the climb and cruise phases, the power corresponding to the climb speed and cruise speed is used to control the output ratio of the proportional valve in each electric drive series branch to the calibrated ratio. When the aircraft enters the cruise phase, the circulating power branch reduces the flow and pressure loss of the entire thermal management circuit, and controls the coolant to circulate in each of the first electric drive series branches through the proportional valve. During the landing mode transition phase of the aircraft, the circulating power branch ensures the flow and pressure loss of the entire thermal management loop. The thermal management system pumps the cryogenic coolant proportionally into each parallel-connected heat dissipation branch through the first proportional valve. Each heat dissipation branch distributes the coolant into the first and second electric drive series branches connected in parallel according to the calibrated ratio. Among them, the output ratio of the proportional valve in each electric drive series branch is controlled according to the power corresponding to the descent speed and cruise speed during the landing descent phase, which is the calibrated ratio. During the vertical landing phase of the aircraft, the circulating power branch ensures the minimum flow and pressure loss of the entire thermal management circuit. The thermal management system pumps the cryogenic coolant proportionally into each parallel-connected heat dissipation branch through the first proportional valve. Each heat dissipation branch pumps the coolant proportionally into the first electric drive series branch and the second electric drive series branch connected in parallel.

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