Composite two-stage core flat plate type loop heat pipe evaporator and loop heat pipe system

Abstract

The invention discloses a composite two-stage core flat plate type loop heat pipe evaporator and a loop heat pipe system, and relates to the technical field of heat dissipation, the composite two-stage core flat plate type loop heat pipe evaporator comprises an evaporation mechanism and a loop pipeline mechanism, the evaporation mechanism comprises an evaporator upper shell, an evaporator lower shell, a first-stage liquid absorption core and a second-stage liquid absorption core, the evaporator upper shell is of a flat plate type cavity structure, and the loop pipeline mechanism comprises a first steam pipeline, a second steam pipeline, a third steam pipeline, a stainless steel ferrule type elbow, a liquid pipeline and jacket type condensing equipment. Efficient heat dissipation of a high-heat-flux and complex heat source environment is achieved, the heat transfer performance and stability of the loop heat pipe system are remarkably improved, and the loop heat pipe system can be widely applied to the fields of electronic equipment heat dissipation, spacecraft thermal control, industrial thermal management and the like.

Description

Technical Field

[0001] The invention relates to the technical field of heat dissipation, and in particular to a composite two-stage core flat-plate loop heat pipe evaporator and a loop heat pipe system. Background Art

[0002] Loop heat pipe is a highly efficient thermal control technology, widely used in aerospace, electronic device cooling and industrial thermal management. Loop heat pipe achieves efficient heat transfer through phase change heat transfer and capillary drive. The performance of its core component, the evaporator, directly determines the heat transfer efficiency and stability of the system.

[0003] Flat-plate evaporators are widely used in electronic equipment heat dissipation due to their compact structure and suitability for contact with planar heat sources. As electronic equipment and spacecraft develop towards high power density and miniaturization, higher requirements are placed on the heat transfer performance and compactness of thermal control systems. Traditional loop heat pipe systems are difficult to take into account both high heat transfer efficiency and miniaturized design, and cannot meet the heat dissipation needs of new high-performance equipment. Therefore, a loop heat pipe system with high heat transfer performance and miniaturization advantages is developed, so that the liquid storage chamber and the gas collection chamber are distributed on the left and right sides of the liquid wick to achieve the effect of reducing the thickness and increasing space utilization.

[0004] The evaporator of a flat-plate loop heat pipe usually adopts a single capillary wick structure. Although this structure has certain heat transfer performance in low heat flux density scenarios, it is prone to dry-up under high heat flux density conditions, resulting in increased thermal resistance and decreased system performance. In addition, the single-core structure has poor adaptability under complex heat source conditions, which limits its application in the field of high-performance heat dissipation.

[0005] As the thermal problems of electronic components become increasingly serious, and the ideal conditions of a single stable heat source cannot be simply regarded during operation, it is very important to develop a flat-plate loop heat pipe that can respond quickly and take into account the heat dissipation of multiple or unstable high heat flux density heat sources. Summary of the invention

[0006] The object of the present invention is to provide a composite two-stage core flat-plate loop heat pipe evaporator and a loop heat pipe system to solve at least any one of the problems raised in the above background technology.

[0007] To achieve the above-mentioned object, the present invention provides the following technical solutions: a composite two-stage core flat-plate loop heat pipe evaporator and a loop heat pipe system, including an evaporation mechanism and a loop pipe mechanism;

[0008] The first-level liquid absorbent core and the second-level liquid absorbent core, the first-level liquid absorbent core is arranged at the middle left position in the evaporation chamber, the second-level liquid absorbent core is arranged in the groove at the top of the first-level liquid absorbent core, and the bottom of the first-level liquid absorbent core is provided with a plurality of steam grooves at equal intervals, the steam grooves are rectangular grooves and each steam groove has the same specifications,

[0009] Preferably, the evaporation mechanism also includes an upper shell of an evaporator and a lower shell of an evaporator, the upper shell of the evaporator is a flat cavity structure, the bottom of the upper shell of the evaporator is fixedly connected to the top of the lower shell of the evaporator, and an evaporation cavity is formed inside the upper shell of the evaporator and the lower shell of the evaporator, the right side of the first-level liquid absorption core and the second-level liquid absorption core in the evaporation cavity is a liquid storage chamber, the left side of the first-level liquid absorption core and the second-level liquid absorption core in the evaporation cavity is an air collecting chamber, an air outlet is provided in the middle position of the left side of the upper shell of the evaporator, and a liquid inlet is provided in the middle position of the front end of the upper shell of the evaporator near the right side.

[0010] Preferably, the primary wick is made of a highly thermally conductive porous material, the pore size of the primary wick is 5-20 μm, the porosity is 50%-70%, the secondary wick is made of a high capillary driving force material, the width of the secondary wick is 1-2 mm, and the length of each steam channel is 1-2 mm.

[0011] Preferably, the top of the first-level liquid absorbent core and the second-level liquid absorbent core are against the upper shell of the evaporator, the first-level liquid absorbent core and the bottom of the steam channel are against the lower shell of the evaporator, the first-level liquid absorbent core and the second-level liquid absorbent core are communicated with the liquid storage chamber, and the gas collecting chamber is communicated with the steam channel.

[0012] Preferably, the lower shell of the evaporator is made of copper, and the upper shell of the evaporator is made of stainless steel. The lower shell of the evaporator and the upper shell of the evaporator are connected by silver welding to ensure their airtightness, and the thickness of the silver welding is 1.5mm-3.0mm.

[0013] The loop pipeline mechanism includes a first steam pipeline, a second steam pipeline and a third steam pipeline, a stainless steel ferrule elbow, a liquid pipeline and a jacketed condensing device. The first steam pipeline, the second steam pipeline, the third steam pipeline and the liquid pipeline form a loop pipeline along the way. One end of the first steam pipeline is connected to the gas outlet and the third steam pipeline is detachably connected to the stainless steel ferrule elbow. The other end of the stainless steel ferrule elbow is detachably connected to the liquid pipeline. The other end of the liquid pipeline is connected to the liquid inlet of the upper shell of the evaporator, and the jacketed condensing device is detachably connected to the liquid pipeline.

[0014] Preferably, a heat source is provided outside the lower shell of the evaporator directly below the primary liquid wick, and the heat source is adhered to the bottom of the lower shell of the evaporator by applying thermal conductive silicone grease, and the thermal conductivity of the thermal conductive silicone grease is 10-16.8W / m·K.

[0015] Preferably, the first steam pipeline, the second steam pipeline and the third steam pipeline are a copper pipe, the copper pipe is bent at the first steam pipeline bending point and the second steam pipeline bending point using a pipe bender, and the liquid pipeline is made of copper.

[0016] Preferably, the first steam pipeline is connected to the air outlet on the left side of the upper shell of the evaporator by silver welding, and the liquid pipeline is welded to the liquid inlet at the front end of the upper shell of the evaporator by argon arc welding.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. The present invention adopts a composite secondary core structure design. The primary liquid absorbent core absorbs heat and provides preliminary capillary driving force, and the secondary liquid absorbent core enhances the liquid reflux capacity and provides additional capillary driving force. The two work together to improve the liquid supply efficiency, solve the problem that the single capillary core structure is easy to dry up under high heat flux density, reduce the risk of drying up, and significantly improve the heat transfer performance of the system. The structure of the primary liquid absorbent core and the secondary liquid absorbent core and the coordination with other components optimize the working fluid circulation path and make heat transfer more efficient.

[0019] 2. The composite secondary core structure of the present invention can be customized according to the distribution of different heat sources. Whether it is a dynamic heat source or a high power density scenario, it can respond quickly and achieve stable heat dissipation. It shows good adaptability in complex heat source environments and broadens the application scope of the loop heat pipe system.

[0020] 3. The present invention optimizes the capillary wick material, guide groove design and working fluid flow channel layout to ensure that the system has excellent heat transfer uniformity. During operation, it can effectively control the temperature fluctuation of the heat source and reduce the impact of temperature changes on system performance. Compared with traditional systems, the stability is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0022] Figure 2 is a cross-sectional view of the evaporator of the present invention;

[0023] Figure 3 It is a schematic diagram of the three-dimensional structure of the primary liquid absorbent core and the secondary liquid absorbent core of the present invention;

[0024] Figure 4 It is a front cross-sectional view of the primary liquid absorbent core and the secondary liquid absorbent core of the present invention;

[0025] Figure 5 is an oblique cross-sectional view of the evaporator of the present invention;

[0026] Figure 6 is an oblique cross-sectional view of the liquid absorbent core of the present invention;

[0027] Figure 7 is a side sectional view of the evaporator of the present invention;

[0028] Figure 8 It is a cross-sectional view of the gas collecting chamber of the present invention.

[0029] In the figure: 1. Evaporator upper shell; 2. Evaporator lower shell; 3. Jacketed condensing equipment; 4. Second steam pipeline; 5. Bending point of first steam pipeline; 6. Third steam pipeline; 7. First steam pipeline; 8. Gas collecting chamber; 9. Steam channel; 10. Primary liquid wick; 11. Secondary liquid wick; 12. Liquid storage chamber; 13. Gas outlet; 14. Liquid inlet; 15. Liquid pipeline; 16. Stainless steel ferrule elbow; 17. Bending point of second steam pipeline. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The present invention provides Figure 1-8 A composite two-stage core flat-plate loop heat pipe evaporator and a loop heat pipe system are shown, including an evaporation mechanism and a loop pipe mechanism;

[0032] The evaporation mechanism includes an upper shell 1 of an evaporator, a lower shell 2 of an evaporator, a primary liquid absorbent core 10 and a secondary liquid absorbent core 11. The upper shell 1 of the evaporator is a flat cavity structure. The bottom of the upper shell 1 of the evaporator is fixedly connected to the top of the lower shell 2 of the evaporator, and an evaporation cavity is formed inside the upper shell 1 of the evaporator and the lower shell 2. The primary liquid absorbent core 10 is arranged at the middle left position in the evaporation cavity, and the secondary liquid absorbent core 11 is arranged in the groove at the top of the primary liquid absorbent core 10. A plurality of steam grooves 9 are evenly spaced at the bottom of the primary liquid absorbent core 10. The steam grooves 9 are rectangular grooves and each steam groove 9 has the same specifications. The right side of the primary liquid absorbent core 10 and the secondary liquid absorbent core 11 in the evaporation cavity is a liquid storage chamber 12, and the left side of the primary liquid absorbent core 10 and the secondary liquid absorbent core 11 in the evaporation cavity is a gas collecting chamber 8. An air outlet 13 is provided in the middle position of the left side of the upper shell 1, and a liquid inlet 14 is provided in the middle position near the right side of the front end of the upper shell 1 of the evaporator; the loop pipeline mechanism includes a first steam pipeline 7, a second steam pipeline 4 and a third steam pipeline 6, a stainless steel ferrule elbow 16, a liquid pipeline 15 and a jacketed condensing device 3, the first steam pipeline 7, the second steam pipeline 4, the third steam pipeline 6 and the liquid pipeline 15 form a loop pipeline along the way, one end of the first steam pipeline 7 is connected to the air outlet 13 and the third steam pipeline 6 is detachably connected to the stainless steel ferrule elbow 16, the other end of the stainless steel ferrule elbow 16 is detachably connected to the liquid pipeline 15, the other end of the liquid pipeline 15 is connected to the liquid inlet 14 of the upper shell 1 of the evaporator, and the jacketed condensing device 3 is detachably connected to the liquid pipeline 15.

[0033] When the evaporator is used, the heat source transfers heat to the working fluid (the working fluid is any one of water, R141 b, acetone, etc.) through the primary liquid absorption core 10. The working fluid evaporates to form steam and is discharged into the gas collecting chamber 8 through the steam channel 9. The steam overflows from the gas outlet 13 along the first steam pipeline 7, the second steam pipeline 4, the third steam pipeline 6 and the stainless steel ferrule elbow 16 to flow into the liquid pipeline 15 wrapped by the jacketed condensing device 3. The jacketed condensing device 3 condenses the steam in the liquid pipeline 15 into liquid. The condensed working fluid flows into the liquid storage chamber 12 through the liquid inlet 14, and under the action of the heat source, it forms a gas phase again through the primary liquid absorption core 10 and the secondary liquid absorption core 11 and flows into the gas collecting chamber 8, forming a complete flow cycle.

[0034] The primary absorbent core 10 is made of a highly thermally conductive porous material, the pore size of the primary absorbent core 10 is 5-20 μm, the porosity is 50%-70%, the secondary absorbent core 11 is made of a high capillary driving force material, the width of the secondary absorbent core 11 is 1-2 mm, and the size of the steam channel 9 is 1-2 mm.

[0035] The first-level absorbent core 10 made of high thermal conductivity porous material can quickly transfer the heat of the heat source to the working fluid, accelerate the vaporization speed of the working fluid, and improve the heat transfer efficiency of the evaporator. The appropriate pore size and porosity provide a good vaporization environment for the working fluid, ensure the balance between heat transfer and liquid supply, and facilitate the vaporization process of the working fluid. The second-level absorbent core 11 made of high capillary driving force material is conducive to enhancing the liquid reflux capacity, so that the condensed liquid working fluid can return to the evaporator cavity more smoothly, ensure the circulation efficiency of the working fluid in the system, and maintain the stable operation of the system. Secondly, the second-level absorbent core 11 can provide additional capillary driving force, and work in conjunction with the first-level absorbent core 10 to further promote the circulation of the working fluid in the system. Especially under high heat flux density conditions, it can effectively supplement power and avoid drying. In addition, the second-level absorbent core 11 can also prevent the steam generated by adverse heat leakage from flowing back into the liquid storage chamber 12. The size of the steam channel 9 is designed to be 1-2 mm, which meets the requirements of sufficient nucleation points and gas phase channels, while increasing the contact area with the uniform heat source of the bottom copper plate and improving the gasification efficiency.

[0036] The tops of the primary liquid absorbent core 10 and the secondary liquid absorbent core 11 are against the upper shell 1 of the evaporator, and the bottoms of the primary liquid absorbent core 10 and the steam channel 9 are against the lower shell 2 of the evaporator.

[0037] The primary liquid wick 10 and the secondary liquid wick 11 are tightly against the upper and lower shells of the evaporator, providing stable support for the internal structure of the evaporator; reducing the heat loss during the transfer process and improving the heat transfer performance of the entire system; the primary liquid wick 10 is against the lower shell 2 of the evaporator, ensuring that the gas phase working medium in the steam channel 9 can flow smoothly into the gas collecting chamber 8 without leakage or mixing; the secondary liquid wick 11 is against the upper shell 1 of the evaporator, which can effectively guide the liquid to reflux and prevent the liquid from entering the gas collecting chamber, ensuring the stability of the vapor-liquid separation, thereby improving the operating efficiency of the system; the tightly against connection method enhances the air tightness of the evaporator to a certain extent.

[0038] The primary liquid absorbent core 10 and the secondary liquid absorbent core 11 are both communicated with the liquid storage chamber 12 , and the gas collecting chamber 8 is communicated with the steam channel 9 .

[0039] The liquid storage chamber 12 is used to collect and evenly distribute the condensed water produced by condensation. The first-level liquid wick 10 and the second-level liquid wick 11 are connected to the liquid storage chamber 12, ensuring that the liquid working medium can be continuously added to the liquid wick, preventing the problem of the liquid wick drying up, and avoiding the impact of improper distribution of condensed water on system performance. The gas collecting chamber 8 is connected to the steam channel 9, avoiding the accumulation of gaseous working medium in the evaporator, ensuring the smooth progress of the evaporation process, and facilitating the continuous transfer of heat from the heat source to the working medium, and then cooling through the flow transfer of the gaseous working medium, ensuring the continuity of the system's heat transfer, achieving efficient heat transfer, and completing the circulation process of the working medium.

[0040] The lower shell 2 of the evaporator is made of copper, and the upper shell 1 of the evaporator is made of stainless steel. The lower shell 2 of the evaporator and the upper shell 1 of the evaporator are connected by silver soldering to ensure their airtightness, and the thickness of the silver soldering is 1.5mm-3.0mm.

[0041] The evaporator is processed by CNC metal welding, which is convenient for integration with other components of the loop heat pipe system and improves the convenience of system assembly and maintenance. Copper has excellent thermal conductivity. The lower shell 2 of the evaporator made of copper can quickly transfer the heat of the heat source to the working fluid inside the evaporator, improving the heat absorption efficiency of the evaporator. Stainless steel has good strength, corrosion resistance and high temperature resistance. The upper shell 1 of the evaporator made of stainless steel can ensure long-term stable operation under complex environments, is not easily damaged by corrosion, and can withstand a certain pressure to ensure system safety. Silver welding is used to connect the upper shell 1 of the evaporator with the lower shell 2 of the evaporator, and the thickness of the silver welding is controlled at 1.5mm-3.0mm, which can effectively ensure the air tightness of the evaporator. Good air tightness can prevent the leakage of working fluid and maintain the stability of the amount of working fluid in the system. At the same time, the silver welding connection also enhances the connection strength between the upper and lower shells, so that when the evaporator is affected by external factors such as vibration and temperature changes, the upper and lower shells will not easily become loose or separated.

[0042] The first steam pipeline 7, the second steam pipeline 4 and the third steam pipeline 6 are a copper pipe, which is bent at the first steam pipeline bending point 5 and the second steam pipeline bending point 17 by a pipe bender, and the liquid pipeline 15 is made of copper.

[0043] A single copper tube is bent to form multiple sections of steam pipelines. Compared with using multiple independent pipes to connect, the number of connection points between pipes is greatly reduced. Reducing the number of connection points can improve the air tightness and stability of the entire loop heat pipe system, ensuring long-term and reliable operation of the system. At the same time, it simplifies the processing of the pipelines, eliminating the need for complex processing and connection operations on multiple independent pipes, reducing processing steps and material waste, and reducing production costs.

[0044] A heat source is arranged outside the lower shell 2 of the evaporator directly below the primary liquid wick 10. The heat source is adhered to the bottom of the lower shell 2 of the evaporator by applying thermal conductive silicone grease. The thermal conductivity of the thermal conductive silicone grease is 10-16.8 W / m·K.

[0045] When the heat source generates heat, the thermal grease can quickly transfer the heat to the lower shell 2 of the evaporator, and then to the working fluid in the first-level wick 10, promoting the evaporation of the working fluid and improving the heat dissipation efficiency of the entire loop heat pipe system. On the other hand, by applying thermal grease to bond the heat source and the lower shell 2 of the evaporator, not only good heat conduction is achieved, but also the connection stability between the two is enhanced. The thermal grease has a certain viscosity, which can make the heat source and the lower shell 2 of the evaporator fit tightly, reducing the relative displacement caused by vibration or other external factors. In actual application scenarios, such as electronic equipment that may be vibrated during operation, this stable connection method can ensure continuous and stable heat transfer, avoiding the influence of loose connection on the heat dissipation effect.

[0046] The first steam pipeline 7 is connected to the gas outlet 13 on the left side of the upper shell 1 of the evaporator by silver welding, and the liquid pipeline 15 is welded to the liquid inlet 14 at the front end of the upper shell 1 of the evaporator by argon arc welding.

[0047] Silver welding and argon arc welding both have good welding effects, which can ensure the joint strength and sealing of the connection, prevent leakage of the working fluid, and the tight welding connection reduces the thermal resistance of the connection. For the steam pipeline, the heat can be transferred more smoothly from the evaporator to the first steam pipeline 7 through the gas outlet; for the liquid pipeline 15, the heat carried by the liquid working fluid can also be more efficiently transferred to the evaporator through the liquid inlet 14. This optimizes the heat transfer path of the entire loop heat pipe system, helps to improve the heat dissipation performance of the system, and enables the heat source to cool down more quickly.

[0048] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A composite two-stage core flat-plate loop heat pipe evaporator, characterized in that: including an evaporation mechanism; The evaporation mechanism comprises a primary liquid wick (10) and a secondary liquid wick (11); the primary liquid wick (10) is arranged at a left position in the middle of the evaporation chamber; the secondary liquid wick (11) is arranged in a channel at the top of the primary liquid wick (10); a plurality of steam channels (9) are arranged at equal intervals at the bottom of the primary liquid wick (10); the steam channels (9) are rectangular grooves and each steam channel (9) has the same specifications.

2. The evaporation mechanism further comprises an evaporator upper shell (1) and an evaporator lower shell (2); the evaporator upper shell (1) is a flat cavity structure; the bottom of the evaporator upper shell (1) is fixedly connected to the top of the evaporator lower shell (2); and an evaporation cavity is formed inside the evaporator upper shell (1) and the evaporator lower shell (2); the right side of the primary liquid wick (10) and the secondary liquid wick (11) in the evaporation cavity is a liquid storage chamber (12); the left side of the primary liquid wick (10) and the secondary liquid wick (11) in the evaporation cavity is a gas collecting chamber (8); an air outlet (13) is provided at the middle position of the left side of the evaporator upper shell (1); and a liquid inlet (14) is provided at the middle position of the front end of the evaporator upper shell (1) near the right side.

3. The composite two-stage core flat-plate loop heat pipe evaporator according to claim 1, characterized in that: The primary liquid absorbent core (10) is made of a high thermal conductivity porous material, the pore size of the primary liquid absorbent core (10) is in the range of 5-20 μm, and the porosity is 50%-70%. The secondary liquid absorbent core (11) is made of a high capillary driving force material, the width of the secondary liquid absorbent core (11) is 1-2 mm, and the length of each steam channel (9) is 1-2 mm.

4. The composite two-stage core flat-plate loop heat pipe evaporator according to claim 1, characterized in that: The tops of the primary liquid absorbent core (10) and the secondary liquid absorbent core (11) are in contact with the upper outer shell (1) of the evaporator, the bottoms of the primary liquid absorbent core (10) and the steam channel (9) are in contact with the lower outer shell (2) of the evaporator, the primary liquid absorbent core (10) and the secondary liquid absorbent core (11) are both in communication with the liquid storage chamber (12), and the gas collecting chamber (8) is in communication with the steam channel (9).

5. The composite two-stage core flat-plate loop heat pipe evaporator according to claim 1, characterized in that: The lower shell (2) of the evaporator is made of copper, and the upper shell (1) of the evaporator is made of stainless steel. The lower shell (2) of the evaporator and the upper shell (1) of the evaporator are connected by silver soldering to ensure air tightness, and the thickness of the silver soldering is 1.5 mm to 3.0 mm.

6. A loop heat pipe system based on a composite two-stage core flat-plate loop heat pipe evaporator, characterized in that: It comprises the composite secondary core flat-plate loop heat pipe evaporator according to claims 1 to 5, and also comprises a first steam pipeline (7), a second steam pipeline (4) and a third steam pipeline (6), a stainless steel ferrule elbow (16), a liquid pipeline (15) and a jacketed condensing device (3), wherein the first steam pipeline (7), the second steam pipeline (4), the third steam pipeline (6) and the liquid pipeline (15) form a loop pipeline along the way, one end of the first steam pipeline (7) is connected to the gas outlet (13) and the third steam pipeline (6) is detachably connected to the stainless steel ferrule elbow (16), the other end of the stainless steel ferrule elbow (16) is detachably connected to the liquid pipeline (15), the other end of the liquid pipeline (15) is connected to the liquid inlet (14) of the upper shell (1) of the evaporator, and the jacketed condensing device (3) is detachably connected to the liquid pipeline (15).

7. The loop heat pipe system based on the composite two-stage core flat-plate loop heat pipe evaporator according to claim 6, characterized in that: A heat source is provided outside the lower shell (2) of the evaporator directly below the primary liquid wick (10), and the heat source is adhered to the bottom of the lower shell (2) of the evaporator by applying thermal conductive silicone grease, and the thermal conductivity of the thermal conductive silicone grease is 10-16.8 W / m·K.

8. The loop heat pipe system based on the composite two-stage core flat-plate loop heat pipe evaporator according to claim 6, characterized in that: The first steam pipeline (7), the second steam pipeline (4) and the third steam pipeline (6) are each a copper pipe, and the copper pipe is bent at the first steam pipeline bending point (5) and the second steam pipeline bending point (17) using a pipe bender, and the liquid pipeline (15) is made of copper.

9. The loop heat pipe system based on the composite two-stage core flat-plate loop heat pipe evaporator according to claim 6, characterized in that: The first steam pipeline (7) is connected to the gas outlet (13) on the left side of the upper shell (1) of the evaporator by silver welding, and the liquid pipeline (15) is welded to the liquid inlet (14) at the front end of the upper shell (1) of the evaporator by argon arc welding.

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