High-altitude aircraft cooling system based on phase change radiator

Abstract

The utility model provides a high-altitude aircraft heat dissipation system based on a phase change radiator. The high-altitude aircraft heat dissipation system comprises a flattened copper water heat pipe used for heat conduction, an aluminum huffing type vapor chamber and heat dissipation fins used for heat dissipation. The aluminum blowing type vapor chamber is sequentially provided with a condensation end, a heat insulation end and an evaporation end; the evaporation end of the aluminum huffing type vapor chamber is vertically arranged, and the heat insulation end of the aluminum huffing type vapor chamber has a bending angle of 85 degrees; the flattened copper water heat pipe is fixedly connected to the front face of the aluminum inflation type vapor chamber, and the cooling fins are fixedly connected to the back face of the condensation end. And the back surface of the evaporation end is in contact with the IGBT of the high-altitude aircraft. The utility model has the advantages of light weight, high strength and changeable heat conductivity coefficient, and realizes the heat dissipation problem of the aircraft under different working conditions of low altitude and high altitude.

Description

Technical Field

[0001] The utility model relates to the technical field of heat dissipation, and in particular to a high-altitude aircraft heat dissipation system based on a phase-change radiator. Background Art

[0002] As high-altitude aircraft need to fly at different altitudes and for longer flight times, the thermal power consumption of IGBT processors of high-altitude aircraft is increasing. The temperature of IGBT of high-altitude aircraft can only operate stably within the range of -40 to 80℃. Too high or too low temperature will cause IGBT failure, and then make the aircraft unable to fly normally. The existing thermal management and cooling system of high-altitude aircraft cannot meet the heat dissipation requirements under high power and variable working conditions. Therefore, developing a stable and reliable heat dissipation device to dissipate the high-power IGBT processor of high-altitude aircraft under variable working conditions, ensuring that the temperature of high-altitude aircraft is not too high at low altitude and not too low at high altitude, has become a crucial challenge on the road of aircraft development. Utility Model Content

[0003] In view of the technical problems existing in the prior art, the purpose of the utility model is to provide a high-altitude aircraft heat dissipation system based on a phase change radiator, which can realize automatic conversion of low thermal resistance at low altitude and normal temperature to high thermal resistance at high altitude and low temperature, and can effectively solve the heat dissipation problem of the aircraft under variable operating conditions.

[0004] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0005] A high altitude aircraft heat dissipation system based on a phase change radiator, comprising a flattened copper water heat pipe for heat conduction, an aluminum inflated heat spreader and heat dissipation fins for heat dissipation;

[0006] The aluminum inflated heat spreader is provided with a condensing end, an insulating end and an evaporating end in sequence; the evaporating end of the aluminum inflated heat spreader is arranged vertically, which is beneficial to the liquid reflux of the aluminum inflated heat spreader and the flattened copper-water heat pipe, thereby improving the overall thermal conductivity.

[0007] The heat-insulating end has a bending angle of 85°;

[0008] The flattened copper water heat pipe is fixedly connected to the front of the aluminum inflatable heat spreader, and the heat dissipation fins are fixedly connected to the back of the condensation end.

[0009] The back side of the evaporation end is in contact with the high-altitude aircraft IGBT, which facilitates heat transfer from the high-altitude aircraft IGBT to the aluminum inflatable heat spreader.

[0010] The aluminum inflated heat spreader and the heat dissipation fins are provided with mounting holes for connecting with other components of the high-altitude aircraft.

[0011] Furthermore, the front of the evaporation end is provided with an evaporation end flow channel and an evaporation end circular island; the front of the insulation end is provided with an insulation end strip flow channel and an insulation end strip island; the front of the condensation end is provided with a condensation end flow channel and a condensation end circular island; the evaporation end circular island and the condensation end circular island are circular structures and are arranged alternately, which is conducive to enhancing heat exchange; each flow channel of the aluminum inflatable heat spreader is provided with a working fluid. The insulation section island and the flow channel adopt a strip structure, and the flow resistance coefficient of this structure is small, which is more conducive to the reflux of the working fluid. The working fluid inside the aluminum inflatable heat spreader is octafluorocyclobutane, which has a freezing point of -42°C and can be used for high heat dissipation at high temperatures and low heat dissipation at low temperatures of aircraft IGBTs.

[0012] Furthermore, the aluminum inflated heat spreader, the flattened copper-water heat pipe and the heat dissipation fins are fixedly connected by soldering, thereby reducing the interface thermal resistance between the aluminum inflated heat spreader and the flattened copper-water heat pipe and between the aluminum inflated heat spreader and the heat dissipation fins, thereby improving the overall heat dissipation efficiency.

[0013] The flattened copper-water heat pipe is provided with a liquid wick sintered with grooved composite copper powder. The working medium is deionized water, and the flattening thickness is 4mm. Corresponding to the aluminum inflated heat spreader, the flattened copper-water heat pipe includes a vertical section, a bending section and a horizontal section in sequence.

[0014] The heat dissipation fins include a bottom plate, and a plurality of fin bodies are arranged above the bottom plate. The cross section of the fin bodies is a trapezoidal structure that is narrow at the top and wide at the bottom. This structure increases the contact area between the fin bodies and the fin bottom plate, improves the heat conduction area, reduces wind resistance, increases convection heat transfer performance, and improves the heat dissipation effect. A connecting base plate is arranged below the bottom plate, and the connecting base plate matches the shape of the condensing end of the aluminum inflatable heat spreader and is connected to each other.

[0015] Two symmetrical mounting holes are processed on the bottom plate for mounting the fins and other parts of the high-altitude aircraft.

[0016] In general, the utility model has the following advantages:

[0017] 1. The utility model can change the heat resistance of the radiator according to the working state of the high-altitude aircraft. Under low-altitude normal temperature conditions, the high-altitude aircraft IGBT generates heat, which is transferred to the aluminum inflated heat spreader and the flattened copper-water heat pipe by heat conduction. The internal working fluid of the aluminum inflated heat spreader and the flattened copper-water heat pipe undergoes a gas-liquid phase change, which can quickly transfer the IGBT heat source temperature to the heat dissipation fins and conduct forced convection heat exchange with the air, so that the temperature of the high-altitude aircraft IGBT will not be too high; under high-altitude low-temperature conditions, when the ambient temperature reaches -50°C or below, the internal working fluid of the aluminum inflated heat spreader and the copper-water heat pipe freezes and loses its high thermal conductivity, the thermal resistance of the heat dissipation device increases, and the overall thermal conductivity decreases, so that the temperature of the high-altitude aircraft IGBT will not be too low. The different heat dissipation requirements of the high-altitude aircraft heat source IGBT under low-altitude normal temperature conditions and high-altitude low-temperature conditions are met.

[0018] 2. The utility model is an aluminum inflated heat spreader with gas-liquid phase change and a flattened copper water heat pipe welded in parallel. Compared with a single aluminum inflated heat spreader and a single heat pipe, it has lower thermal resistance and higher strength.

[0019] 3. The heat sink fins of the utility model adopt a trapezoidal structure with a narrow upper part and a narrow lower part, which not only increases the contact area between the fins and the fin substrate and improves the heat conduction area, but also reduces wind resistance, increases convection heat transfer performance, improves heat dissipation effect, and reduces the gravity of the heat sink fins to achieve the goal of lightweighting.

[0020] 4. Each component of the utility model adopts standard manufacturing technology, and the size is strictly controlled, which is convenient for the inspection and maintenance of the heat dissipation system; the heat dissipation device of the utility model is an aluminum blown heat sink, a flattened copper water heat pipe and a heat dissipation fin. The processing technology of the heat dissipation element is mature and does not require special processing. It is a more common heat dissipation element on the market, which is conducive to saving the research and development costs of related equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is an exploded view of a heat dissipation device of an embodiment of the utility model;

[0022] Figure 2 It is the overall assembly relationship diagram of the utility model;

[0023] Figure 3 It is a left view of the utility model;

[0024] Figure 4 This is a schematic diagram of the structure of the flattened copper-water heat pipe of the utility model;

[0025] Figure 5 This is a schematic diagram of the structure of the aluminum inflatable soaking plate of the utility model;

[0026] Figure 6 This is a schematic diagram of the structure of the aluminum inflatable soaking plate of the utility model;

[0027] Figure 7 This is a schematic diagram of the structure of the aluminum inflatable soaking plate without islands and flow channels on one side of the utility model;

[0028] Figure 8 This is the left view of the inflatable soaking plate of the utility model;

[0029] Fig. 9 This is a schematic diagram of the heat dissipation fin structure of the utility model;

[0030] Fig.10 This is a schematic diagram of the heat dissipation fin structure of the utility model;

[0031] Fig.11 This is a front view of the heat dissipation fin of the utility model;

[0032] Fig.12 This is a thermal resistance network diagram of a heat dissipation device according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0034] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Fig. 9 As shown, a high-altitude aircraft heat dissipation system based on a phase change radiator includes a flattened copper-water heat pipe 1 for heat conduction, an aluminum inflated heat spreader 2, and a heat dissipation fin 3 for heat dissipation;

[0035] like Figure 1 , Figure 2 , Figure 3 , Figure 5 , Figure 6 , Figure 7 and Figure 8 As shown, the aluminum inflatable heat spreader 2 is provided with a condensation end 2-10, an insulation end 2-9 and an evaporation end 2-8 in sequence; the insulation end 2-9 is bent 85°, the evaporation end 2-8 is in a vertical state, the condensation end 2-10 is 85° with the vertical direction, and the condensation end 2-10 is welded with a heat dissipation fin 3.

[0036] like Figure 4 The flattened copper-water heat pipe 1 is provided with a liquid wick sintered with a grooved composite copper powder. Corresponding to the aluminum inflated heat spreader 2, the flattened copper-water heat pipe 1 includes a vertical section 1-1, a bending section 1-2 and a horizontal section 1-3 in sequence.

[0037] The flattened copper-water heat pipe 1 is fixedly connected to the front of the aluminum inflatable heat spreader 2, and the heat dissipation fin 3 is fixedly connected to the front of the evaporation end 2-8; Figure 2 As shown, the aluminum inflated heat spreader 2, the flattened copper-water heat pipe 1 and the heat dissipation fins 3 are all connected by soldering, which reduces the interface thermal resistance between the aluminum inflated heat spreader 2 and the flattened copper-water heat pipe 1 and the aluminum inflated heat spreader and the heat dissipation fins 3, thereby improving the overall heat dissipation efficiency.

[0038] The back side of the condensing end 2-10 is in contact with the high-altitude aircraft IGBT; when the high-altitude aircraft IGBT works at low altitude, the heat generated is transferred to the evaporating end 2-8 by heat conduction, the evaporating end 2-8 absorbs heat, and the internal working fluid absorbs heat and the liquid vaporizes into gas, the gas flows to the condensing end 2-10, the gas releases heat and liquefies into liquid, and flows back to the evaporating end 2-8. Since there is no liquid absorption core structure inside the aluminum inflatable heat spreader 2, the evaporating end 2-8 is consistent with the direction of gravity, and the condensing end 2-10 is designed to have an angle of 5° with the horizontal plane, which is more conducive to the reflux of the internal working fluid liquid.

[0039] The front of the evaporation end 2-8 is provided with an evaporation end flow channel 2-2 and an evaporation end circular island 2-3; the front of the condensation end 2-10 is provided with a condensation end flow channel 2-6 and a condensation end circular island 2-7; the evaporation end circular island 2-3 and the condensation end circular island 2-7 are circular structures and are arranged in a staggered manner, and the staggered circular island design is more conducive to heat transfer; the front of the insulation end 2-9 is provided with an insulation end strip flow channel 2-4 and an insulation end strip island 2-5, and the strip shape has a small flow resistance, which is conducive to liquid reflux. Based on the combined effect of the above two designs, the thermal conductivity of the aluminum inflatable heat spreader 2 is improved, the thermal resistance of the aluminum inflatable heat spreader 2 is reduced, and the heat dissipation effect of the entire heat dissipation device is improved.

[0040] like Figure 5 , Figure 6 , Figure 7 and Figure 8 As shown, the working fluid inside the aluminum inflatable heat spreader 2 is octafluorocyclobutane C4F8, which has a freezing point of -42°C. The temperature of the aircraft at high altitude is lower than -50°C, so the working fluid inside the aluminum inflatable heat spreader 2 freezes at high altitude; the working fluid inside the flattened copper-water heat pipe 1 is deionized water, which will also freeze at high altitude; the working fluid inside the aluminum inflatable heat spreader 2 and the flattened copper-water heat pipe 1 loses its high thermal conductivity after freezing, and due to the existence of the internal steam cavity, the thermal conductivity of the aluminum inflatable heat spreader 2 is lower than that of aluminum, and the thermal conductivity of the flattened copper-water heat pipe 1 is lower than that of copper; based on the above two points, the thermal conductivity of this heat dissipation device is lower under high altitude conditions, so that the temperature of the aircraft IGBT will not be too low.

[0041] like Fig. 9 , Fig.10 and Fig.11As shown, the heat dissipation fin 3 includes a base plate 3-1, and a plurality of fin bodies 3-3 are arranged above the base plate 3-1. The cross-section of the fin body 3-3 is a trapezoidal structure that is narrow at the top and wide at the bottom. This structure not only increases the contact area between the fin body 3-3 and the fin base plate 3-1 and improves the heat conduction area, but also reduces wind resistance, increases convection heat transfer performance, and improves heat dissipation effect. A connecting substrate 3-4 is provided below the base plate 3-1. The connecting substrate 3-4 matches the shape of the condensation end 2-10 of the aluminum inflatable heat spreader 2 and is connected to each other.

[0042] The left and right ends of the fin base plate 3-1 are processed into "ear"-like structures. This design ensures that the fins are well installed and fixed to other components of the high-altitude aircraft, which can reduce shaking when the high-altitude aircraft is flying at high speed. This design also reduces the gravity of the entire fin, achieving the purpose of lightweight; the fins are parallel to the direction of wind speed, which reduces air resistance and increases the convection heat transfer coefficient between the fins and the air.

[0043] The aluminum inflated heat spreader 2 and the heat dissipating fins 3 have mounting holes 3 - 2 for connecting with other components of the high-altitude aircraft.

[0044] like Fig.12 As shown, assuming that the heat generation power of the high-altitude aircraft IGBT is Q, the total thermal resistance of the new phase-change heat sink is R, where R ct1 is the interface thermal resistance between the heat source and the evaporation end 2-8 of the aluminum inflatable heat spreader, R ct2 is the interface thermal resistance between the aluminum inflatable heat spreader condensation end 2-10 and the heat dissipation fin 3, R eva1 and R con1 are the radial thermal resistances of the evaporation end 2-8 and the condensation end 2-10 of the aluminum inflatable heat spreader, R ctr1 and R ctr2 is the radial interface thermal resistance between the aluminum inflatable heat spreader 2 and the flattened copper water heat pipe 1, R eva2 and R con2 is the radial thermal resistance of the vertical section 1-1 and the horizontal section 1-3 of the flattened copper-water heat pipe 1, R h is the axial thermal resistance of the flattened copper-water heat pipe 1, R ct3 is the thermal resistance of the interface between the aluminum inflated heat spreader 2 and the flattened copper water heat pipe 1, R vc is the axial thermal resistance of the aluminum inflatable heat spreader 2, R fin is the thermal resistance of the heat sink 3. From the thermal resistance network diagram, the total thermal resistance R of the new phase change heat sink can be obtained as:

[0045]

[0046] R z =R eva1 +R ctr1 +R eva2 +Rh +R con2 +R ctr2 +R con2

[0047] When the aircraft is flying at low altitude, the aluminum inflatable heat spreader 2 has a simple manufacturing process and its inner cavity usually has no liquid absorption core structure, and its thermal conductivity K eff Generally lower than heat pipes, heat pipes have a liquid absorption core structure inside, and the thermal resistance is lower than the aluminum inflatable heat spreader 2 structure. The flattened copper-water heat pipe 1 and the aluminum inflatable heat spreader 2 form a parallel heat transfer system. According to the above formula, the thermal resistance of the new parallel structure reduces the thermal resistance of a single aluminum inflatable heat spreader 2, improves the heat transfer performance of the entire module, and after the two gas-liquid phase change devices are connected in parallel, the mechanical strength of the entire new phase change radiator is improved.

[0048] High-altitude aircraft IGBT heat dissipation method and heat transfer path:

[0049] When the high-altitude aircraft is flying at a low altitude, the high-altitude aircraft is in a normal temperature environment. The high-altitude aircraft IGBT releases heat and transfers it to the evaporation end 2-8. The evaporation end 2-8 absorbs heat and transfers it to the flattened copper-water heat pipe 1. The working fluid heat-absorbing liquid inside the aluminum inflated heat plate 2 and the flattened copper-water heat pipe 1 vaporizes into gas, and the gas flows to the condensation end 2-10. The gas releases heat and liquefies into liquid. Under the action of gravity, the liquid in the aluminum inflated heat plate 2 flows from the evaporation end 2-8 to the condensation end 2-10. The flattened copper-water heat pipe 1 is under the dual action of gravity and the liquid absorption core. The liquid flows from the horizontal section 1-3 to the vertical section 1-1, and the repetitive phase change effect realizes the efficient conduction of heat; the aluminum inflated heat spreader 2 and the flattened copper water heat pipe 1 are in parallel composite structure, and the thermal resistance is lower than that of a single aluminum inflated heat spreader 2, and the thermal conductivity is 1 to 2 orders of magnitude of the thermal conductivity of pure copper (402W / (m·K)); the heat of the aluminum inflated heat spreader 2 is transferred to the heat sink 3 by heat conduction, and the fin body 3-3 of the heat sink 3 is parallel to the wind speed of the air, and forced convection heat exchange is performed, and the heat on the heat sink 3 is taken away by the air. In this heat dissipation process, the aluminum inflated heat spreader 2 and the flattened copper-water heat pipe 1 in parallel have high thermal conductivity, and the heat generated by the high-altitude aircraft IGBT can be efficiently and quickly transferred to the heat dissipation fin 3 by heat conduction. The fin body 3-3 of the heat dissipation fin 3 adopts a trapezoidal structure with a narrow upper part and a narrow lower part. This structure increases the contact area between the fin body 3-3 and the fin bottom plate 3-1, improves the heat conduction area, reduces wind resistance and increases the convection heat transfer performance. The center line of the fin body 3-3 is parallel to the wind speed. This design also further increases the convection heat transfer effect between the fin body 3-3 and the air; the phase change device has efficient heat conduction and the heat dissipation of the heat dissipation fin 3, so that the temperature of the high-altitude aircraft IGBT is not too high, and the temperature of the high-altitude aircraft IGBT is controlled within a first preset value. In this embodiment, the first preset value is 80°C.

[0050] When the high-altitude aircraft is in a high-altitude low-temperature working condition, the ambient temperature is lower than -50°C, and the working fluid inside the aluminum inflatable heat spreader 2 and the flattened copper-water heat pipe 1 freezes. The aluminum inflatable heat spreader 2 and the flattened copper-water heat pipe 1 cannot conduct heat through the internal working fluid gas-liquid phase change, and thus lose their high thermal conductivity. Due to the existence of the vapor cavity, the thermal conductivity of the aluminum inflatable heat spreader 2 is lower than that of aluminum, and the thermal conductivity of the flattened copper-water heat pipe 1 is lower than that of pure copper. Under high-altitude working conditions, the thermal conductivity of the heat dissipation device is low, so that the temperature of the heat dissipation high-altitude aircraft IGBT is not too low, and the temperature of the high-altitude aircraft IGBT is not lower than the second preset value. In this embodiment, the second preset value is -40°C.

[0051] In this embodiment, the optimal operating temperature range of the high-altitude aircraft IGBT is -40℃~80℃. Both too high and too low temperatures will cause the high-altitude aircraft IGBT to malfunction and fail to work normally. Therefore, the high-altitude aircraft IGBT has different heat dissipation requirements under low-altitude normal temperature conditions and high-altitude low-temperature conditions. The heat dissipation system of the utility model can realize the automatic conversion of low thermal resistance under low-altitude normal temperature and high thermal resistance under high-altitude low temperature, meeting the different heat dissipation requirements of the high-altitude aircraft IGBT. Under low-altitude normal temperature conditions, the aluminum inflated heat plate 2 and the flattened copper water heat pipe 1 are started at the same time, and the two phase change heat dissipation devices form a parallel heat dissipation system with low thermal resistance. The high-altitude aircraft IGBT efficiently dissipates heat, so that the temperature of the high-altitude aircraft IGBT is not too high; under high-altitude low-temperature conditions, the internal working medium of the aluminum inflated heat plate 2 and the flattened copper water heat pipe 1 freezes and loses its high thermal conductivity, and the thermal resistance of the heat dissipation device increases, which hinders the heat dissipation of the aircraft heat source IGBT, so that the temperature of the high-altitude aircraft IGBT is not too low. Ensure that the IGBT of high-altitude aircraft can be within the optimal operating temperature range under low-altitude normal temperature conditions and high-altitude low-temperature conditions.

[0052] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principle of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A high altitude aircraft cooling system based on a phase change radiator, characterized in that: It comprises a flattened copper-water heat pipe (1) for heat conduction, an aluminum inflated heat spreader (2) and a heat dissipation fin (3) for heat dissipation; The aluminum inflatable heat spreader (2) is provided with a condensation end (2-10), an insulation end (2-9) and an evaporation end (2-8) in sequence; the evaporation end (2-8) of the aluminum inflatable heat spreader (2) is vertically arranged, and the insulation end (2-9) has a bending angle of 85°; the aluminum inflatable heat spreader has a side with an island and a flow channel named the front side, and a side without an island and a flow channel named the back side; The flattened copper-water heat pipe (1) is fixedly connected to the front side of the aluminum inflatable heat spreader (2), and the heat dissipation fin (3) is fixedly connected to the back side of the condensation end (2-10); The back side of the condensation end (2-10) is in contact with the high altitude aircraft IGBT.

2. A high altitude aircraft cooling system based on a phase change radiator according to claim 1, characterized in that: The front of the evaporation end (2-8) is provided with an evaporation end flow channel (2-2) and an evaporation end circular island (2-3); the front of the insulation end (2-9) is provided with an insulation end strip flow channel (2-4) and an insulation end strip island (2-5); the front of the condensation end (2-10) is provided with a condensation end flow channel (2-6) and a condensation end circular island (2-7); the evaporation end circular island (2-3) and the condensation end circular island (2-7) are circular structures and are arranged in a staggered manner; each flow channel of the aluminum inflatable heat spreader (2) is provided with a working medium.

3. A high altitude aircraft cooling system based on a phase change radiator according to claim 2, characterized in that: Corresponding to the aluminum inflated heat spreader (2), the flattened copper-water heat pipe (1) comprises a vertical section (1-1), a bent section (1-2) and a horizontal section (1-3) in sequence.

4. The high altitude aircraft cooling system based on a phase change radiator according to claim 1, characterized in that: The flattened copper-water heat pipe (1) is provided with a liquid absorbing core sintered with grooved composite copper powder.

5. The high altitude aircraft cooling system based on phase change radiator according to claim 1, characterized in that: The heat dissipation fins (3) include a base plate (3-1), a plurality of fin bodies (3-3) are arranged above the base plate (3-1), and the cross-section of the fin bodies (3-3) is a trapezoidal structure that is narrow at the top and wide at the bottom; a connecting substrate (3-4) is arranged below the base plate (3-1), and the connecting substrate (3-4) matches the shape of the condensation end (2-10) of the aluminum inflatable heat spreader (2), and the two are connected to each other.

6. The high altitude aircraft cooling system based on phase change radiator according to claim 1, characterized in that: The aluminum inflated heat spreader (2) and the heat dissipation fins (3) have mounting holes for connecting with other components of the high-altitude aircraft.

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