System and method for cooling an electric aircraft
By embedding pulsating heat pipes (PHP) in the shell of the electric aircraft and combining the heat diffusion shell, the problem of poor heat diffusion in traditional cooling systems is solved, achieving more efficient cooling effects and heat diffusion.
Patent Information
- Application Number
- CN202411464473.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-10-20
- Filing Date
- 2024-10-21
- Publication Date
- 2025-04-22
AI Technical Summary
Traditional cooling systems lead to poor heat diffusion in electric aircraft, and heat is concentrated in the shell part close to the heat source, making it impossible to effectively utilize the entire area of the shell, resulting in a reduced cooling effect.
A combined cooling system with a pulsating heat pipe (PHP) and a heat diffusion housing, which includes an evaporator and condenser section, where the refrigerant absorbs and releases heat, thereby achieving a more uniform heat diffusion over the entire surface area of the housing.
It improves heat transfer capability and heat flow density, can more effectively utilize the total area of the shell, increase the cooling effect, and can withstand the gravity acceleration experienced by the aircraft, is insensitive to direction and has a simple structure.
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Figure CN119865994A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to systems and methods for cooling an electric aircraft. Background Art
[0002] Electric aircraft rely on electric motors to generate lift and / or thrust. Electric aircraft also use a variety of other electronic devices to control aircraft functions and complete various tasks. One type of electric aircraft may be an electric vertical take-off and landing vehicle (eVTOL). These electronic devices may be packaged within a housing. These electronic devices may generate a large amount of heat, which requires cooling to keep the electronics within their optimal operating temperature range. Traditional cooling systems may involve using the surface of the housing to spread the heat, as well as other types of cooling devices. Traditional cooling systems may result in poor heat spreading capabilities around the surface of the electronic device packaging, resulting in reduced cooling effectiveness and reduced electronic function. Summary of the invention
[0003] Electronic devices generate heat during operation. As electronic devices operate in more demanding situations, they generate more and more heat. To operate efficiently, electronic devices need to be kept within an ideal operating temperature range. Therefore, electronic devices need to be cooled. Typically, electronic devices are surrounded by protective casings that can help prevent damage to the electronic devices, but this may also further capture the heat generated by the electronic devices. The casing can utilize a cooling system to try to cool the electronic devices. Traditional cooling systems may involve using the surface area of the casing itself to diffuse the heat outward. However, traditional cooling systems may result in poor heat diffusion along the casing, where most of the heat stays in the part of the casing close to the heat source, and almost no heat is diffused to the part of the casing farthest from the heat source. This results in inefficient use of the surface area of the casing due to the failure to use the entire surface area for cooling. This effect is particularly evident in electric aircraft, because the electric motors that provide lift or thrust generate a lot of heat due to the high power requirements required to drive the electric aircraft. Therefore, a cooling system with higher cooling capacity in the same space is needed to meet the cooling needs of electric aircraft.
[0004] The present system may be a cooling system that is more efficient than conventional fins by combining the use of a pulsating heat pipe (PHP) with a heat diffusion housing. The PHP may also be referred to as an oscillating heat pipe (OHP). The PHP includes a channel having an evaporator portion and a condenser portion. A refrigerant is arranged in the channel. The refrigerant may move between the evaporator portion and the condenser portion, transitioning between a gas phase and a liquid phase. This transition may absorb and release heat, thereby absorbing heat from the electronic device and releasing the heat into the airflow at the end of the fin away from the housing. This may provide the advantages of higher heat transfer capability, high heat flux density diffusion capability, the ability to withstand the gravitational acceleration experienced by an aircraft, orientation insensitivity, and a simple structure.
[0005] In one embodiment, a motor assembly includes a motor housing having an end face, a motor located in the motor housing, and an electronic component arranged on the end face of the motor housing, wherein the electronic component includes a housing, the housing includes a housing inner wall and a housing outer wall, wherein the space between the housing inner wall and the housing outer wall defines a first housing width, and at least one PHP is embedded in the first housing width.
[0006] In another embodiment, a motor assembly includes a motor housing having an end face, a motor located in the motor housing, and an electronic component arranged on the end face of the motor housing, wherein the electronic component includes a housing, the housing including a housing inner wall, a housing outer wall, wherein the space between the housing inner wall and the housing outer wall defines a first housing width, a housing inner bottom, and a housing outer bottom, wherein the space between the housing outer bottom and the housing inner bottom defines a second housing width, wherein the first housing width and the second housing width include a single channel having at least one connection point, and at least one PHP is embedded in the single channel.
[0007] In another embodiment, an electric vertical take-off and landing (eVTOL) aircraft includes a motor assembly, the motor assembly including a motor housing having an end surface, a motor located in the motor housing, and an electronic assembly arranged on the end surface of the motor housing, wherein the electronic assembly includes a housing, the housing including a housing inner wall and a housing outer wall, wherein the space between the housing inner wall and the housing outer wall defines a first housing width, and at least one PHP is embedded in the first housing width.
[0008] Additional features and advantages of the techniques described in the present disclosure will be set forth in the detailed description that follows, and in part will be apparent to those skilled in the art or may be learned by practicing the techniques described in the present disclosure, including the detailed description that follows, the claims, and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The following detailed description of the present disclosure may be better understood when read in conjunction with the following drawings:
[0010] Figure 1 schematically illustrating a front cross-sectional view of a housing having a first housing width and a second housing width and a connection point including a single fluid connection channel and a PHP embedded within the single fluid connection channel;
[0011] Figure 2 schematically illustrating a front cross-sectional view of a housing having a first housing width and a PHP embedded within the first housing width;
[0012] Figure 3 schematically illustrates a front cross-sectional view of an electric motor, housing, plurality of fins, and propeller assembly according to one or more embodiments shown and described herein; and
[0013] Figure 4 A system configured for an eVTOL is schematically shown.
[0014] Reference will now be made in more detail to various embodiments of the present disclosure, some of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. DETAILED DESCRIPTION
[0015] Embodiments of the present disclosure utilize PHPs in an electronic enclosure to provide cooling for components of an electric machine such as an eVTOL. More specifically, the system includes one or more PHPs located within the width of the enclosure housing the electronic equipment to increase the heat spreading efficiency of the enclosure. The portion of the PHP closest to the heat source serves as an evaporator. The portion of the PHP farthest from the heat source and placed in the airflow of the electric aircraft serves as a condensing portion. This arrangement allows heat to be spread more evenly throughout the enclosure and has greater cooling capacity to remove heat from the electronic equipment.
[0016] The PHP is a complete loop such that the internal contents can pass from the evaporator section to the condenser section, back to the evaporator section, etc. In some embodiments, the PHP can be arranged in a serpentine manner such that a single PHP can include multiple condenser sections and multiple evaporator sections all within a single PHP, and in some embodiments all embedded within a single internal channel.
[0017] In some embodiments, the housing condenser portion may have one or more cooling fins arranged around the perimeter of the housing.
[0018] The term "evaporator" refers to the portion of the PHP where the liquid is converted from a liquid state to a gaseous state and absorbs heat. The term "condenser" refers to the portion of the PHP where the gas is converted from a gaseous state to a liquid state and releases heat.
[0019] Conventional cooling systems may limit heat dissipation and concentrate heat in the portion of the housing closest to the heat source. This does not efficiently utilize the full area of the housing because the heat is not spread throughout the housing and also reduces the amount of heat removed from the heat source that the housing is designed to cool compared to conventional cooling systems. Compared to conventional cooling systems, embodiments of the present disclosure may more effectively transfer heat to the entire housing to more efficiently utilize the total area of the housing and increase the dissipation of heat throughout the housing. This embodiment may also dissipate more heat away from the heat source than conventional cooling systems.
[0020] Reference now Figure 1, showing a front cross-sectional view of an embodiment of the system 100. The system 100 includes a housing 110. The housing 110 includes a housing wall 123. The housing wall 123 includes a housing inner wall 115 and a housing outer wall 112. The housing inner wall 115 and the housing outer wall 112 define a first housing width W1. The housing 110 also includes a housing bottom 124. The housing bottom 124 includes a housing inner bottom 119 and a housing outer bottom 118. The housing inner bottom 119 and the housing outer bottom 118 define a second housing width W2. The first housing width W1 and the second housing width W2 include a single fluid connection channel 122. The single fluid connection channel 122 includes a connection point 121. The connection point 121 can be a corner of the housing 110. The PHP 130 can be embedded in the single fluid connection channel 122. The PHP condenser portion 132 can be embedded in the first housing width W1. The PHP evaporator portion 131 can be embedded in the second housing width W2.
[0021] This embodiment may allow the electronics 113 to be disposed on the housing bottom 124 so that they are close to the PHP evaporator portion 131. The housing wall 123 may be disposed in the airflow of the propeller 102 so that the airflow may be close to the PHP condenser portion 132. A plurality of fins 125 may be attached to the housing wall 123.
[0022] In some embodiments, the PHP 130 includes a single circuit for the refrigerant within a single fluid connection channel 122, such that the portion of the PHP 130 embedded within the second shell width W2 can be used as a PHP evaporator portion 131, and the portion of the PHP embedded within the first shell width W1 can be used as a PHP condenser portion 132. In other embodiments, the PHP 130 includes multiple circuits for the refrigerant within the shell width, such that the PHP 130 includes a single closed circuit with multiple PHP evaporator portions 131 embedded within the second shell width W2 and multiple PHP condenser portions 132 embedded within the first shell width W1, which are included within a single PHP 130.
[0023] Reference now Figure 2, showing a front view of an embodiment of the system 100. The system 100 includes a housing 110 having a housing inner wall 115 and a housing outer wall 112. The housing inner wall 115 and the housing outer wall 112 define a first housing width W1. The PHP 130 can be embedded within the first housing width W1. The PHP 130 includes a channel in which vapor plugs and liquid plugs of a refrigerant are alternately arranged. As a non-limiting example, R404A can be used as a refrigerant. In some embodiments, the PHP 130 includes a single circuit for the refrigerant within the first housing width W1, so that the portion of the PHP 130 closest to the heat source can be used as a PHP evaporator portion 131, and the portion of the PHP farthest from the heat source can be used as a PHP condenser portion 132. In another embodiment, PHP 130 includes multiple circuits for refrigerant within housing width W1 such that PHP 130 includes a single closed circuit with multiple PHP evaporator sections 131 closest to the heat source and multiple PHP condenser sections 132 farthest from the heat source in a single PHP 130. Electronic device 113 may be a heat source for system 100.
[0024] Reference now Figure 3 , shows an example system 100, such as a system for an eVTOL. System 100 includes a housing 110, a motor 101, one or more electronic devices 113, a propeller 102, and a propeller shaft 103. Electronic devices 113 are arranged within a housing cavity 111. A plurality of fins 125 extend from the exterior of housing 110. Propeller shaft 103 is connected to motor 101 and propeller 102. Housing 110 may have a through hole 117 to allow propeller shaft 103 to extend from motor 101 to propeller 102. Propeller 102 may provide lift, thrust, or a combination of lift and thrust. Any number of fins 125 may be provided.
[0025] The electronic device 113 in the housing cavity 111 may be one or more different electronic devices 113. The electronic device 113 may be included in an inverter circuit, including power electronics, gate driver electronics, and / or similar devices. The electronic device 113 may include a capacitor, an insulated gate bipolar transistor, a power MOSFET, or any other electronic device. The electronic device 113 may be a heat source for the system 100, where the electronic device generates heat during operation.
[0026] The housing 110 surrounding the electronic device 113 can have a variety of shapes, including but not limited to a cylinder, a ring, or a rectangular prism. The housing 110 can be made of a variety of materials, including but not limited to aluminum. The housing 110 includes at least one wall and an inner cavity (i.e., a closed body). The housing 110 has a housing wall 123 and a housing bottom 124. In some embodiments, there may be multiple housings 110 arranged together, each housing 110 having at least one fin 125 attached thereto.
[0027] The fins 125 can be mounted on the housing 110. For example, the fins 125 can be mounted on the housing 110 by various methods, including but not limited to soldering, brazing, and welding. In some embodiments, the fins 125 and the housing 110 can be made of a single piece of material (e.g., by casting or machining). The fins 125 can have a variety of shapes, including but not limited to cylinders or rectangular prisms.
[0028] See now Figure 4 , the system 100 is shown on an eVTOL 140. A plurality of electric motors 101 may be used, which are coupled to a plurality of propellers 102 by a plurality of propeller shafts 103. The eVTOL 140 may take off and land vertically using the lift from the plurality of propellers 102. The plurality of propellers 102 may also provide thrust so that the eVTOL 140 may move forward. The airflow from the propellers 102 may also provide airflow to the fins 125 (not shown), the housing walls 123 (not shown), or both the fins 125 and the housing walls 123. The airflow may cause the PHP condenser portion 132 to condense the refrigerant within the PHP 130, thereby cooling the electronic equipment 113.
[0029] There is a need for a cooling system for an electric aircraft that has enhanced cooling capacity and can operate in the same space as a conventional cooling system. The cooling system can embed the PHP within the width of the housing. The PHP can be embedded within the housing bottom and the housing wall to increase the cooling capacity of the system by utilizing more of the housing surface area. Electronic devices can be disposed in the housing where they generate heat. The electronic devices can be mounted on the housing floor so that they are in contact with the evaporator portion of the PHP. The airflow from the electric aircraft propeller can pass through the condenser portion of the PHP. This arrangement can utilize most of the surface area of the housing (including the bottom and walls) to maximize the cooling effect of the system.
[0030] It should be noted that one or more of the following claims use the terms "herein," "wherein," or "wherein" as transitional phrases. For the purpose of defining the present technology, it should be noted that these terms are introduced in the claims as open transitional phrases that are used to introduce a description of a series of structural features and should be interpreted like the more commonly used open introductory term "comprising."
[0031] It should be understood that any two quantitative values assigned to a property may form a range for that property, and that all range combinations formed by all stated quantitative values for a given property are contemplated in the present disclosure.
[0032] Having described the subject matter of the present disclosure in detail and with reference to specific embodiments, it should be noted that the various details described in the present disclosure should not be considered to be related to the essential components of the various embodiments described in the present disclosure, even though specific elements may be shown in each of the accompanying drawings. Instead, the appended claims should be considered as the only representation of the scope of the present disclosure and the corresponding scope of the various embodiments described in the present disclosure. It is further apparent that modifications and variations may be made without departing from the scope of the appended claims.
Claims
1. A motor assembly, comprising: a motor housing having an end surface; an electric motor located within a motor housing; An electronic component is arranged on an end face of a motor housing, and the electronic component comprises: a housing comprising a housing inner cavity, a housing outer wall, and a housing inner wall, wherein a first housing width is located between the housing inner wall and the housing outer wall; at least one electronic device located within the interior cavity of the housing; and One or more pulsating heat pipes are embedded within the first housing width.
2. The motor assembly of claim 1, wherein the portion of the housing interior that contacts the at least one electronic device is an evaporator, and the portion of the housing interior that does not contact the at least one electronic device is a condenser.
3. The motor assembly of claim 1, wherein the at least one electronic device is in contact with an inner wall of the housing.
4. The motor assembly according to claim 1, further comprising: a propeller shaft coupled to the electric motor and extending through the opening in the housing; as well as A propeller is coupled to the propeller shaft, wherein rotation of the propeller causes air to pass over the outer wall of the housing.
5. The electric motor assembly of claim 1, wherein the pulsating heat pipe has a plurality of condenser sections and a plurality of evaporator sections.
6. A motor assembly comprising: a motor housing having an end surface; an electric motor located within a motor housing; An electronic component is arranged on an end face of a motor housing, and the electronic component comprises: a housing comprising a housing inner cavity, a housing outer wall and a housing inner wall, and a housing outer bottom and a housing inner bottom, wherein a first housing width is between the housing inner wall and the housing outer wall, wherein a second housing width is between the housing outer bottom and the housing inner bottom, and the first housing width and the second housing width comprise a single fluid connection channel, the single fluid connection channel comprising at least one connection point; at least one electronic device located within the single fluid connection channel; and One or more pulsating heat pipes are embedded within the single fluid connection channel.
7. The electric motor assembly of claim 6, wherein the first housing width is an evaporation portion of the pulsating heat pipe and the second housing width is a condensation portion of the pulsating heat pipe.
8. The motor assembly of claim 6, wherein the plurality of electronic devices contact an inner wall of the housing.
9. The motor assembly of claim 6, further comprising: a propeller shaft coupled to the electric motor and extending through the opening in the housing; as well as A propeller is coupled to the propeller shaft, wherein rotation of the propeller causes air to pass over the outer wall of the housing.
10. The electric motor assembly of claim 6, wherein the pulsating heat pipe has a plurality of condenser sections and a plurality of evaporator sections.
11. An electric vertical take-off and landing vehicle (eVTOL), comprising: An electric motor assembly comprising: a motor housing having an end surface; an electric motor located within a motor housing; An electronic component is arranged on an end face of a motor housing, and the electronic component comprises: a housing including a housing interior cavity, a housing exterior wall, and a housing inner wall, wherein a first housing width is between the housing inner wall and the housing outer wall, and the housing defines an enclosure; at least one electronic device located within the enclosure; and One or more pulsating heat pipes are embedded within the first housing width.
12. The eVTOL of claim 11, further comprising: an outer shell outsole and an outer shell insole, wherein the second outer shell width is between the outer shell outsole and the outer shell insole, and the first outer shell width and the second outer shell width include a single fluid connection channel, the single fluid connection channel including at least one connection point; and The one or more pulsating heat pipes are embedded within the single fluid connection channel. 13 . The eVTOL of claim 11 , wherein the portion of the housing interior that contacts the at least one electronic device is an evaporator, and the portion of the housing interior that does not contact the at least one electronic device is a condenser. The eVTOL of claim 11 , wherein the plurality of electronic devices contact an inner wall of the housing.
15. The eVTOL of claim 11, further comprising: a propeller shaft coupled to the electric motor and extending through the opening in the housing; as well as A propeller is coupled to the propeller shaft, wherein rotation of the propeller causes air to pass over the outer wall of the housing.
16. The eVTOL of claim 11, wherein the pulsating heat pipe has a plurality of condensation sections and a plurality of evaporation sections.