Dual-circuit loop heat pipe with integrated evaporator

Abstract

The present application discloses a dual-circuit loop heat pipe with an integrated evaporator, comprising an integrated evaporator, a microchannel capillary core, a liquid reservoir end cover and a condensing pipeline. The integrated evaporator comprises an evaporator body, an evaporator boss and an evaporator saddle. The inner cavity of the evaporator body comprises an evaporator cavity and two liquid reservoir cavities. The evaporator boss and the evaporator saddle are arranged on the outer surface of the evaporator body, and two steam overflow outlets connected to the evaporator cavity are arranged on the evaporator boss; the microchannel capillary core is interference fit in the evaporator cavity of the evaporator body; the two liquid reservoir end covers respectively block the open ends of the two liquid reservoir cavities, and the two liquid reservoir end covers are respectively provided with a connecting port connected to the liquid reservoir cavity; one end of the two condensing pipelines is respectively connected to the two steam overflow outlets, and the other ends of the two condensing pipelines are respectively passed through the liquid reservoir cavity and the evaporator cavity through the two connecting ports, and are inserted into the microchannel capillary core.

Description

Technical Field

[0001] The present application relates to the field of heat dissipation technology, and in particular to a dual-circuit loop heat pipe with an integrated evaporator. Background Art

[0002] The loop heat pipe is a two-phase high-efficiency heat transfer device that uses the capillary force generated by the capillary wick in the evaporator to drive the loop to run, and then uses the evaporation and condensation of the working fluid to transfer heat. It can transfer a large amount of heat under small temperature differences and long distances. Loop heat pipe technology has been widely used in the heat dissipation of various electronic devices. At present, most microelectronic devices use active heat dissipation technology, which is prone to problems such as high energy consumption, large size, high noise, low cooling efficiency and local overheating. In recent years, with the development of high-performance microelectronic equipment industry, the thermal management problem of chips has become a challenge that restricts the development of technologies such as 5G. While the function and heat flux density of chips are gradually increasing, the area of ​​chips is gradually shrinking. The loop heat pipe technology in the existing technology can no longer meet the development needs of the high-performance microelectronic equipment industry. Therefore, it is urgent to design a three-dimensional heat dissipation technology suitable for complex and narrow spaces. Summary of the invention

[0003] The present application provides a dual-circuit loop heat pipe with an integrated evaporator, which adopts an integrated design to integrate the evaporator body, the liquid storage body and the evaporator saddle, reducing the number of parts and components, reducing the processing difficulty and time. The integrated design makes the evaporator lighter and thinner while improving the reliability and mechanical strength of the structure. Combined with the dual-circuit structure, the overall design is more suitable for three-dimensional heat dissipation technology in complex and narrow spaces, which is beneficial to improving the operating stability and heat absorption efficiency of the loop heat pipe.

[0004] The specific technical solutions are as follows:

[0005] The embodiment of the present application provides a dual-circuit loop heat pipe with an integrated evaporator, comprising:

[0006] An integrated evaporator, the integrated evaporator comprising an integrally formed evaporator body, an evaporator boss and an evaporator saddle, the inner cavity of the evaporator body comprising an evaporator cavity and two liquid reservoir cavities, the two liquid reservoir cavities being symmetrically arranged on both sides of the evaporator cavity, and both of the two liquid reservoir cavities being open, the evaporator boss and the evaporator saddle being arranged on the outer surface of the evaporator body, and the evaporator boss being provided with two steam overflow ports communicating with the evaporator cavity;

[0007] a microchannel capillary wick, interference-fitted within the evaporator cavity of the evaporator body;

[0008] Two liquid reservoir end covers, each of the two ends of the evaporator body is connected to a liquid reservoir end cover, the two liquid reservoir end covers respectively block the open ends of the two liquid reservoir cavities, and the two liquid reservoir end covers are respectively provided with a connection port communicating with the liquid reservoir cavity;

[0009] Two condensation pipelines, one end of the two condensation pipelines is respectively connected to the two steam overflow ports, and the other ends of the two condensation pipelines are respectively passed through the two connecting ports to sequentially penetrate the liquid storage cavity and the evaporator cavity and are inserted into the microchannel capillary core.

[0010] In some embodiments of the present application, the outer surface of the evaporator body is cylindrical, the central axis of the evaporator body is parallel to the end face of the evaporator saddle, and the end face of the evaporator saddle is connected to the outer surface of the evaporator body in a circular arc transition.

[0011] In some embodiments of the present application, the central axis of each of the steam overflow outlets is perpendicular to the central axis of the evaporator body, and the central axis of each of the steam overflow outlets is parallel to the end surface of the evaporator saddle.

[0012] In some embodiments of the present application, the liquid reservoir end cover is a cylindrical structure with one end open, and a limiting boss is provided on the inner surface of the liquid reservoir end cover, the limiting boss limits and fixes the evaporator body, and the inner circumferential wall of the open end of the liquid reservoir end cover is interference fit with the outer circumferential wall of the evaporator body, and the liquid reservoir end cover and the evaporator body are sealed by casting rubber.

[0013] In some embodiments of the present application, the condensation pipeline includes a first connection part, a condensation part, and a second connection part, one end of the first connection part and one end of the second connection part are respectively connected to the two ends of the condensation part, the other end of the first connection part is connected to the steam overflow outlet, and the other end of the second connection part passes through the connection port in sequence through the liquid storage cavity and the evaporator cavity, and is inserted into the microchannel capillary core to one end close to the steam overflow outlet, the condensation part is a repeatedly bent planar serpentine tube structure formed by connecting a plurality of straight thin tubes and a plurality of bent thin tubes, and the planar serpentine tube structure is perpendicular to the central axis of the evaporator body.

[0014] In some embodiments of the present application, the condensation pipeline is formed by using a pipe through a pipe bending process, and the outer circumferential wall of the first connecting part and the inner circumferential wall of the steam overflow outlet are interference fit and sealed by casting rubber, and the second connecting part and the liquid storage tank end cover are sealed and connected by laser welding.

[0015] In some embodiments of the present application, each of the two reservoir end covers is provided with a filling port connected to the reservoir cavity.

[0016] In some embodiments of the present application, the integrated evaporator is made of a seventh-series aluminum alloy material, and the liquid reservoir end cover and the condensation pipeline are both made of 304 stainless steel material.

[0017] In some embodiments of the present application, the material of the microchannel capillary core is copper metal powder, the type of the copper metal powder is water-atomized spherical copper powder, and the particle size of the copper metal powder is 150 μm and 75 μm, the ratio of the two is 1:1, and the pore-forming agent of the microchannel capillary core is C 3 N 4 .

[0018] In some embodiments of the present application, the sintering process of the microchannel capillary core is: the pre-pressing pressure is 0.8t, the pre-pressing time is 5min, the sintering temperature of the vacuum sintering furnace is 800°C, the heating time is 70min, the insulation time is 70min, and the cooling method is to naturally cool to below 90°C and then open the furnace.

[0019] The innovative features of the embodiments of the present application include but are not limited to the following:

[0020] 1. In the present embodiment, an integrated design of integrating the evaporator, the liquid reservoir and the evaporator saddle is adopted, which is one of the innovative points of the embodiment of the present application. The interior of the integrated evaporator is machined so that the interior of the evaporator body includes both the evaporator cavity and the liquid reservoir cavity. The evaporator and the liquid reservoir are designed in an integrated manner, and the shape of the evaporator saddle is machined externally. The evaporator and the evaporator saddle are designed in an integrated manner, which greatly improves the integration of the evaporator part, reduces the number of parts and repeated wall designs, reduces the processing difficulty and time, and also improves the reliability and mechanical strength of the structure, which is beneficial to improving the operating stability of the loop heat pipe. In addition, the weight of the evaporator is reduced, which better adapts to the restrictions on the weight of the radiator in the complex and narrow heat dissipation space. In addition, unnecessary contact thermal resistance from the heat source to the capillary core is eliminated, thereby improving the heat transfer efficiency.

[0021] 2. In the present embodiment, the condensing line is connected to the integrated evaporator by an interference fit with the steam overflow outlet on the evaporator boss and is sealed by casting glue, which is one of the innovative points of the present application embodiment. The design of the evaporator boss provides a larger contact area for the bonding of the casting glue, improves the tightness of the bonding, and is beneficial to the tight fixation of the condensing line and the integrated evaporator. At the same time, the condensing line and the integrated evaporator are connected by gluing, which changes the common problem in the prior art that the evaporator and the condensing line can only be made of the same material. The integrated evaporator can use materials with faster heat transfer to improve the heat exchange efficiency, while the condensing line can use materials with lower heat transfer speed to reduce the occurrence of heat leakage, further improving the heat exchange capacity and operation stability of the loop heat pipe.

[0022] 3. In this embodiment, an internal boss structure is machined inside the integrated evaporator to achieve an interference fit connection between the microchannel capillary core and the evaporator body. This is one of the innovations of the embodiment of the present application. It improves the assembly stability of the two while reducing the contact thermal resistance, and improves the heat exchange efficiency and operating stability.

[0023] 4. In the present embodiment, a limiting boss is provided inside the liquid reservoir end cover, and the liquid reservoir end cover is connected to the integrated evaporator by interference fit and sealed by casting glue, which is one of the innovative points of the embodiment of the present application, and improves the stability of the assembly between the two, and also improves a part of the sealing. In addition, a filling port is machined on the liquid reservoir end cover, which is also one of the innovative points of the embodiment of the present application, which is conducive to the vacuuming and filling operations of the loop heat pipe, improves the vacuum degree of the heat pipe, and further improves the temperature control effect, heat exchange capacity and working fluid circulation capacity of the loop heat pipe.

[0024] 5. In the present embodiment, the integrated evaporator adopts the seventh series aluminum alloy material, which is one of the innovative points of the embodiment of the present application. It reduces the thermal resistance of the evaporator, improves the heat exchange capacity and heat exchange efficiency of the evaporator, and also reduces the weight of the evaporator. In addition, the liquid reservoir end cover and the condensation pipeline are both made of 304 stainless steel material, which is also one of the innovative points of the embodiment of the present application. On the one hand, it is conducive to the laser welding between the condensation pipeline and the liquid reservoir end cover. On the other hand, it reduces the heat leakage of the liquid reservoir, prevents the liquid reservoir from drying out, and improves the stability of the loop heat pipe operation. In addition, it also reduces the heat leakage phenomenon in the condensation pipeline, which is conducive to long-distance heat transportation and realizes the targeted heat dissipation of the electronic equipment radiator.

[0025] 6. In this embodiment, the microchannel capillary core is made of copper metal powder, and the type of copper metal powder is water-atomized spherical copper powder, and the particle size is 150 μm and 75 μm, and the ratio is 1:1. At the same time, the pore-forming agent of the microchannel capillary core is C 3 N4 Carbon nitride material is one of the innovative points of the embodiment of the present application. The thermal conductivity of copper is relatively high, which improves the heat transfer efficiency of the microchannel capillary core. The pore size of the capillary core sintered under this parameter is appropriate, which is conducive to improving the suction performance. 3 N 4 As its pore-forming agent, it greatly improves the porosity of the capillary core, increases the heat exchange area and suction area, and improves the suction performance and heat exchange performance of the loop heat pipe. In addition, the sintering process of the microchannel capillary core is: the pre-pressing pressure is 0.8t, the pre-pressing time is 5min, the sintering temperature of the vacuum sintering furnace is 800℃, the heating time is 70min, the insulation time is 70min, and the cooling method is to naturally cool to below 90℃ with the furnace and then open the furnace. This is also one of the innovations of the embodiment of the present application. By optimizing the sintering process of the microchannel capillary core, the mechanical properties and suction performance of the sintered capillary core are improved, and at the same time, the heat exchange capacity and anti-gravity capacity of the loop heat pipe are improved.

[0026] 7. In the present embodiment, the condensation pipeline penetrates deep into the interior of the microchannel capillary core, which is one of the innovative points of the present application embodiment. It is conducive to the rapid entry of the working fluid into the microchannel capillary core, which improves the startup performance of the loop heat pipe while also improving the operating stability of the loop heat pipe.

[0027] 8. In the present embodiment, the loop heat pipe adopts an arrangement in which two identical liquid reservoirs and two identical condensing pipelines are symmetrically arranged on the left and right, which is one of the innovative points of the present embodiment. It can ensure that the loop heat pipe is in an anti-gravity environment, such as when the angle between the condenser and the horizontal plane is 90°, the two side loops can at least ensure that the microchannel capillary core on one side is in an infiltration state, thereby ensuring stable heat dissipation of the loop heat pipe. In addition, since the distribution of the internal working fluid is relatively random each time the loop heat pipe is started, the design of the dual-loop loop heat pipe in the present application can greatly improve its starting performance, reduce starting power and starting time. At the same time, the overall dual-loop loop heat pipe adopts a symmetrical design. The functions of the steam overflow groove and the liquid reservoir of the microchannel capillary core will be reversed when the angle of the loop heat pipe changes, so that the loop heat pipe can achieve the effect of reverse operation, which greatly improves the adaptability of the loop heat pipe to operate in an anti-gravity environment.

[0028] The beneficial effects of the embodiments of the present application are as follows:

[0029] The dual-circuit heat pipe adopts a design that integrates the evaporator body, the liquid reservoir body and the evaporator saddle, and combines the dual-circuit structure to reduce the number of parts on the basis of improving the heat exchange capacity and anti-gravity characteristics of the heat pipe, greatly reducing the processing difficulty and processing cost while improving the operating stability. The integrated design makes the evaporator thinner and lighter while improving the reliability and mechanical strength of the structure, which is conducive to improving the operating stability and heat absorption efficiency of the heat pipe. The heat exchange efficiency is high and can be applied to micro-electronic devices such as drones that have strict requirements on heat pipe stability and weight. In addition, the dual-circuit heat pipe adopts a microchannel capillary core with high suction performance, which provides a larger heat exchange area and suction area, realizing efficient heat exchange of the heat source and good circulation capacity of the working fluid in the heat pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 A schematic diagram of the structure of a dual-circuit loop heat pipe with an integrated evaporator provided in an embodiment of the present application;

[0032] Figure 2 An exploded schematic diagram of a dual-circuit loop heat pipe with an integrated evaporator provided in an embodiment of the present application;

[0033] Figure 3 A schematic structural diagram of an integrated evaporator in a double-circuit loop heat pipe with an integrated evaporator provided in an embodiment of the present application;

[0034] Figure 4 A cross-sectional schematic diagram of an integrated evaporator in a double-circuit loop heat pipe with an integrated evaporator provided in an embodiment of the present application;

[0035] Figure 5 A schematic diagram of the structure of a liquid storage end cover in a double-circuit loop heat pipe with an integrated evaporator provided in an embodiment of the present application Figure 1 ;

[0036] Figure 6 A schematic diagram of the structure of a liquid storage end cover in a double-circuit loop heat pipe with an integrated evaporator provided in an embodiment of the present application Figure 2 ;

[0037] Figure 7 A partial cross-sectional schematic diagram of a dual-circuit loop heat pipe with an integrated evaporator provided in an embodiment of the present application;

[0038] Explanation of the reference numerals: 1 is an integrated evaporator, 11 is an evaporator body, 111 is an evaporator cavity, 112 is a liquid reservoir cavity, 12 is an evaporator boss, 121 is a steam overflow port, 13 is an evaporator saddle, 131 is an end face of the evaporator saddle 13, 2 is a microchannel capillary core, 3 is a liquid reservoir end cover, 31 is a connecting port, 32 is a filling port, 33 is a limiting boss, 4 is a condensation pipeline, 41 is a first connecting portion, 42 is a condensation portion, 421 is a straight capillary, 422 is a bent capillary, and 43 is a second connecting portion. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0040] It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The terms "including" and "having" in the embodiments of the present application and the accompanying drawings and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0041] The embodiment of the present application discloses a dual-circuit loop heat pipe with an integrated evaporator, which adopts an integrated design to integrate the evaporator body, the liquid storage body and the evaporator saddle, reducing the number of parts, reducing the difficulty and time of processing, and the integrated design makes the evaporator lighter and thinner while improving the reliability and mechanical strength of the structure. In combination with the dual-circuit structure, the overall three-dimensional heat dissipation technology is more suitable for complex and narrow spaces, which is conducive to improving the operating stability and heat absorption efficiency of the loop heat pipe. The following are detailed descriptions.

[0042] Figure 1 and Figure 2 FIG. 2 shows a dual-circuit heat pipe with an integrated evaporator according to an embodiment of the present application. Figure 1 and Figure 2As shown, the dual-circuit loop heat pipe mainly includes: an integrated evaporator 1, a microchannel capillary core 2, two liquid reservoir end caps 3 and two condensation pipelines 4. The integrated evaporator 1 adopts an integrated design, which integrates the evaporator body 11, the liquid reservoir and the evaporator saddle 13 into one body in combination with the liquid reservoir end cap 3, the microchannel capillary core 2 is arranged in the integrated evaporator 1, one end of the condensation pipeline 4 is connected to the steam overflow port 121 of the integrated evaporator 1, and the other end of the condensation pipeline 4 passes through the liquid reservoir end cap 3 and extends into the interior of the microchannel capillary core 2 to form a loop heat pipe. At the same time, the loop heat pipe adopts a dual-circuit structure, which reduces the number of components on the basis of improving the heat exchange capacity and anti-gravity characteristics of the loop heat pipe, greatly reduces the processing difficulty and processing cost, and improves the operation stability.

[0043] Specifically, Figure 1 – Figure 7 As shown, the integrated evaporator 1 adopts an integrated design that integrates the evaporator body 11, the liquid reservoir and the evaporator saddle 13, including the integrally formed evaporator body 11, the evaporator boss 12 and the evaporator saddle 13. The evaporator body 11 is a structure that is hollow inside and open at both ends. The inner cavity of the evaporator body 11 includes an evaporator cavity 111 and two liquid reservoir cavities 112 that are interconnected. The two liquid reservoir cavities 112 are symmetrically arranged on both sides of the evaporator cavity 111. Both liquid reservoir cavities 112 are open. The microchannel capillary core 2 is interference-fitted in the evaporator cavity 111 of the evaporator body 11, and both ends of the evaporator body 11 are connected to a liquid reservoir end cap 3. The two liquid reservoir end caps 3 respectively block the open ends of the two liquid reservoir cavities 112, thereby forming two relatively closed liquid reservoir cavities 112 at both ends of the evaporator cavity 111, that is, constituting the liquid reservoir of the integrated evaporator 1. In addition, a connection port 31 connected to the liquid reservoir cavity 112 is respectively provided on the two liquid reservoir end covers 3, so as to be used for connecting the integrated evaporator 1 with the condensation pipeline 4. At the same time, the evaporator boss 12 and the evaporator saddle 13 are both provided on the outer surface of the evaporator body 11, and the evaporator boss 12 is provided with two steam overflow ports 121 connected to the evaporator cavity 111, and the steam overflow ports 121 are correspondingly provided with the microchannel capillary core 2 which is interference-fitted in the evaporator cavity 111, and are used for connecting the integrated evaporator 1 with the condensation pipeline 4. The two condensation pipelines 4 are symmetrically provided at both ends of the integrated evaporator 1, one end of the two condensation pipelines 4 is respectively connected to the two steam overflow ports 121, and the other ends of the two condensation pipelines 4 are respectively passed through the liquid reservoir cavity 112 and the evaporator cavity 111 through the two connection ports 31, and are inserted into the interior of the microchannel capillary core 2.

[0044] In some embodiments, Figure 3 and Figure 4As shown, the outer surface shape of the evaporator body 11 is a cylindrical surface, that is, the evaporator body 11 is a tubular structure with a hollow interior and openings at both ends. At the same time, the inner diameter of the evaporator cavity 111 is smaller than the inner diameter of the liquid storage cavity 112 on both sides thereof, so as to achieve an interference fit between the microchannel capillary core 2 and the integrated evaporator 1, and reduce the contact thermal resistance while improving the assembly stability, thereby improving the heat exchange efficiency and operation stability. Furthermore, the central axis of the evaporator body 11 is parallel to the end face 131 of the evaporator saddle 13, and the end face 131 of the evaporator saddle 13 is connected to the outer surface of the evaporator body 11 by a circular arc transition. In the specific implementation process, the integrated evaporator 1 is formed by machining metal materials. The internal machining forms a hollow tubular structure including the evaporator cavity 111 and the liquid storage cavity 112, which greatly improves the integration of the evaporator part, reduces the number of parts, reduces the difficulty and time of machining, and also improves the reliability and mechanical strength of the structure, which is conducive to improving the operating stability of the loop heat pipe. The internal of the integrated evaporator 1 is machined to form an inner boss structure (i.e., the evaporator cavity 111) with an inner diameter smaller than the inner diameter of the liquid storage cavity 112 on both sides thereof, and has an interference fit with the microchannel capillary core 2, which improves the assembly stability while reducing the contact thermal resistance, improves the heat exchange efficiency, and further improves the operating stability of the loop heat pipe. The external machining forms the shape of the evaporator saddle 13, integrates the evaporator and the evaporator saddle, further reduces the repeated wall design, thereby reducing the weight of the evaporator, and can better adapt to the restrictions on the weight of the radiator in the complex and narrow heat dissipation space. At the same time, it also eliminates the unnecessary contact thermal resistance from the heat source to the microchannel capillary core 2, and improves the heat transfer efficiency. In addition, an evaporator boss 12 is machined on the outer surface of the integrated evaporator 1, and a steam overflow port 121 is provided on the evaporator boss 12. The condensing line 4 and the steam overflow port 121 are interference fit and sealed by casting glue. Such a design is conducive to the tight fixation of the condensing line 4 and the integrated evaporator 1. The design of the evaporator boss 12 provides a larger contact area for the bonding of the casting glue, thereby improving the tightness of the bonding. At the same time, the introduction of the bonding process has changed the common problem in the prior art that the evaporator and the condensing line can only be made of the same material. The integrated evaporator 1 in the present application can use materials with faster heat transfer to improve the heat exchange efficiency, while the condensing line 4 can use materials with lower heat transfer speed to reduce the occurrence of heat leakage, thereby further improving the heat exchange capacity and operation stability of the loop heat pipe.In further detail, the end surface of the evaporator boss 12 away from the evaporator body 11 is a plane with semicircular ends and a rectangle in the middle. The diameter of the semicircle is the same as the width of the rectangle, and the diameters of the semicircles at both ends are compatible with the steam overflow outlet 121. At the same time, the central axis of each steam overflow outlet 121 is perpendicular to the central axis of the evaporator body 11, and the central axis of each steam overflow outlet 121 is parallel to the end surface 131 of the evaporator saddle 13. In addition, the evaporator boss 12 can also be designed as two cylindrical structures with diameters compatible with the steam overflow outlet 121. While ensuring the fastening strength between the condensation line 4 and the integrated evaporator 1, the volume of the evaporator boss 12 is reduced as much as possible, thereby reducing the overall weight of the integrated evaporator 1.

[0045] In other specific embodiments, Figure 1 , Figure 5 and Figure 6 As shown, the reservoir end cover 3 is a cylindrical structure with one end open, and a limiting boss 33 is provided on the inner surface of the reservoir end cover 3. When the reservoir end cover 3 and the integrated evaporator 1 are assembled, the limiting boss 33 limits and fixes the evaporator body 11. At the same time, the inner circumferential wall of the reservoir end cover 3 located at the open end and the outer circumferential wall of the evaporator body 11 are interference fit, and the reservoir end cover 3 and the evaporator body 11 are sealed by casting glue. The design of the limiting boss 33 can realize the limiting fixation of the evaporator body 11, and the connection and fixation between the reservoir end cover 3 and the outer surface of the evaporator body 11 can be realized by the interference fit between the outer surface of the reservoir end cover 3 and the evaporator body 11, thereby improving the stability of the positioning assembly. At the same time, the design of the limiting boss 33 also improves a part of the sealing performance. Furthermore, a filling port 32 connected to the liquid reservoir cavity 112 is respectively provided on the two liquid reservoir end covers 3. The filling port 32 is provided on the liquid reservoir end covers 3 through mechanical processing, which is beneficial to the vacuuming and filling operations of the loop heat pipe, improves the vacuum degree of the heat pipe, and further improves the temperature control effect, heat exchange capacity and working fluid circulation capacity of the loop heat pipe.

[0046] In some embodiments, Figure 1 , Figure 2 and Figure 7As shown, the condensation pipeline 4 includes a first connection part 41, a condensation part 42 and a second connection part 43. One end of the first connection part 41 and one end of the second connection part 43 are respectively connected to the two ends of the condensation part 42, and the other end of the first connection part 41 is connected to the steam overflow port 121. The other end of the second connection part 43 passes through the liquid storage cavity 112 and the evaporator cavity 111 in sequence through the connection port 31, and is inserted into the microchannel capillary core 2 to the end close to the steam overflow port 121. The condensation pipeline 4 is extended into the interior of the microchannel capillary core 2, which is beneficial for the working fluid to quickly enter the microchannel capillary core 2, thereby improving the startup performance of the loop heat pipe and the operation stability of the loop heat pipe. At the same time, the condensation part 42 is a repeatedly bent planar serpentine tube structure formed by connecting a plurality of straight thin tubes 421 and a plurality of bent thin tubes 422, and the planar serpentine tube structure is perpendicular to the central axis of the evaporator body 11. During the specific implementation process, the condensation pipeline 4 is formed by using a pipe through a pipe bending process, and the outer wall of the first connecting part 41 is interference fit with the inner wall of the steam overflow outlet 121 and is sealed by casting glue. The second connecting part 43 and the liquid storage tank end cover 3 are sealed by laser welding, which improves the fastening performance and sealing performance of the connection.

[0047] In some specific implementation processes, such as Figure 1 and Figure 2 As shown, the integrated evaporator 1 is made of seven series aluminum alloy material, which reduces the thermal resistance of the evaporator, improves the heat exchange capacity and efficiency of the evaporator, and also reduces the weight of the evaporator. The liquid reservoir end cover 3 and the condensing line 4 are both made of 304 stainless steel material. On the one hand, it is conducive to the laser welding between the condensing line 4 and the liquid reservoir end cover 3. On the other hand, it reduces the heat leakage of the liquid reservoir, prevents the liquid reservoir from drying out, and improves the stability of the loop heat pipe operation. In addition, it also reduces the heat leakage phenomenon at the condensing line 4, which is conducive to long-distance heat transportation and realizes the targeted heat dissipation of the electronic equipment radiator.

[0048] In other specific implementation processes, such as Figure 1 and Figure 2 As shown, the microchannel capillary core 2 is made of copper metal powder. The thermal conductivity of copper is relatively high, which improves the heat transfer efficiency of the microchannel capillary core 2. By selecting the type of copper metal powder as water-atomized spherical copper powder and adding the particle sizes of 150 μm and 75 μm in a 1:1 ratio, the pore size of the capillary core sintered under such parameters is appropriate, which is conducive to improving the suction performance. In addition, the pore-forming agent of the microchannel capillary core 2 is C 3 N 4Carbon nitride material greatly improves the porosity of the capillary core, increases the heat exchange area and suction area, and improves the suction performance and heat exchange performance of the loop heat pipe. Furthermore, the sintering process of the microchannel capillary core 2 is: the pre-pressing pressure is 0.8t, the pre-pressing time is 5min, the sintering temperature of the vacuum sintering furnace is 800℃, the heating time is 70min, the insulation time is 70min, and the cooling method is to cool naturally to below 90℃ and then open the furnace. By optimizing the sintering process of the microchannel capillary core 2, the mechanical properties and suction performance of the sintered capillary core are improved, and at the same time, the heat exchange capacity and anti-gravity capacity of the loop heat pipe are improved.

[0049] In this application, if Figure 1 and Figure 2 As shown, the loop heat pipe is symmetrically arranged with two identical liquid reservoirs and two identical condensing lines 4. Such an arrangement can ensure that the loop heat pipe is in an anti-gravity environment, such as when the angle between the condenser and the horizontal plane is 90°, the two side loops can at least ensure that the microchannel capillary core 2 on one side is in an infiltration state, so as to ensure the stable heat dissipation of the loop heat pipe. In addition, since the distribution of the internal working fluid is relatively random each time the loop heat pipe is started, the design of the dual-loop loop heat pipe in this application can greatly improve its starting performance, reduce the starting power and starting time. At the same time, the overall design of the dual-loop loop heat pipe adopts a symmetrical design. The functions of the steam overflow channel and the liquid reservoir of the microchannel capillary core 2 will be reversed when the angle of the loop heat pipe changes, so that the loop heat pipe can achieve the effect of reverse operation, which greatly improves the adaptability of the loop heat pipe to operate in an anti-gravity environment.

[0050] In summary, the present application discloses a dual-circuit loop heat pipe with an integrated evaporator, which adopts a design that integrates the evaporator body, the liquid storage body and the evaporator saddle, and combines the dual-circuit structure, thereby reducing the number of parts on the basis of improving the heat exchange capacity and anti-gravity characteristics of the loop heat pipe, greatly reducing the processing difficulty and processing cost while improving the operating stability, and the integrated design makes the evaporator thinner and lighter while improving the reliability and mechanical strength of the structure, which is conducive to improving the operating stability and heat absorption efficiency of the loop heat pipe, and has high heat exchange efficiency, and can be applied to microelectronic devices such as drones that have strict requirements on heat pipe stability and weight. In addition, the dual-circuit loop heat pipe adopts a microchannel capillary core with high suction performance, which provides a larger heat exchange area and suction area, and realizes efficient heat exchange of the heat source and good circulation capacity of the working medium in the heat pipe.

[0051] Those skilled in the art will appreciate that the drawings are only schematic diagrams of an embodiment, and the components in the drawings are not necessarily necessary to implement the present invention. It should also be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0052] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of the embodiments of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0053] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope described in the claims.

Claims

1. A double-circuit loop heat pipe with an integrated evaporator, characterized in that: include: An integrated evaporator, the integrated evaporator comprises an integrally formed evaporator body, an evaporator boss and an evaporator saddle, the inner cavity of the evaporator body comprises an evaporator cavity and two liquid storage cavities, the two liquid storage cavities are symmetrically arranged on both sides of the evaporator cavity, and the two liquid storage cavities are both opened, the evaporator boss and the evaporator saddle are both arranged on the outer surface of the evaporator body, and the evaporator boss is provided with two steam overflow outlets connected to the evaporator cavity; wherein the outer surface shape of the evaporator body is a cylindrical surface, the central axis of the evaporator body is parallel to the end face of the evaporator saddle, and the end face of the evaporator saddle is connected to the outer surface of the evaporator body by a circular arc transition; the central axis of each of the steam overflow outlets is perpendicular to the central axis of the evaporator body, and the central axis of each of the steam overflow outlets is parallel to the end face of the evaporator saddle; a microchannel capillary wick, interference-fitted within the evaporator cavity of the evaporator body; Two liquid reservoir end covers, one of the liquid reservoir end covers is connected to both ends of the evaporator body, the two liquid reservoir end covers respectively block the open ends of the two liquid reservoir cavities, and the two liquid reservoir end covers are respectively provided with a connection port communicating with the liquid reservoir cavity; wherein the liquid reservoir end cover is a cylindrical structure with one end open, a limiting boss is provided on the inner surface of the liquid reservoir end cover, the limiting boss limits and fixes the evaporator body, and the inner peripheral wall of the open end of the liquid reservoir end cover is interference fit with the outer peripheral wall of the evaporator body, and the liquid reservoir end cover and the evaporator body are sealed by casting glue; Two condensation pipelines, one end of the two condensation pipelines is respectively connected with the two steam overflow outlets by interference fit and sealed by casting glue, and the other ends of the two condensation pipelines are respectively passed through the two connecting ports to pass through the liquid reservoir cavity and the evaporator cavity in sequence, and are inserted into the microchannel capillary core; wherein, the condensation pipeline comprises a first connecting part, a condensation part and a second connecting part, one end of the first connecting part and one end of the second connecting part are respectively connected with the two ends of the condensation part, the other end of the first connecting part is connected to the steam overflow outlet, the other end of the second connecting part is passed through the connecting port to pass through the liquid reservoir cavity and the evaporator cavity in sequence, and is inserted into the microchannel capillary core to one end close to the steam overflow outlet, the condensation part is a repeatedly bent planar serpentine tube structure formed by connecting a plurality of straight thin tubes and a plurality of bent thin tubes, and the planar serpentine tube structure is perpendicular to the central axis of the evaporator body.

2. The double-circuit loop heat pipe with an integrated evaporator according to claim 1, characterized in that: The condensation pipeline is formed by using a pipe through a pipe bending process, and the outer wall of the first connecting part and the inner wall of the steam overflow outlet are interference fit and sealed by casting rubber, and the second connecting part and the liquid storage tank end cover are sealed by laser welding.

3. The double-circuit loop heat pipe with an integrated evaporator according to claim 1, characterized in that: The two liquid reservoir end covers are respectively provided with a filling port connected to the liquid reservoir cavity.

4. The double-circuit loop heat pipe with an integrated evaporator according to claim 1, characterized in that: The integrated evaporator is made of 7-series aluminum alloy material, and the liquid storage end cover and the condensation pipeline are both made of 304 stainless steel material.

5. The double-circuit loop heat pipe with an integrated evaporator according to claim 1, characterized in that: The material of the microchannel capillary core is copper metal powder, the type of the copper metal powder is water-atomized spherical copper powder, and the particle size of the copper metal powder is 150 μm and 75 μm, the ratio of the two is 1:1, and the pore-forming agent of the microchannel capillary core is C3N4.

6. The double-circuit loop heat pipe with an integrated evaporator according to claim 5, characterized in that: The sintering process of the microchannel capillary core is as follows: pre-pressing pressure is 0.8t, pre-pressing time is 5min, sintering temperature of the vacuum sintering furnace is 800°C, heating time is 70min, heat preservation time is 70min, and cooling method is to cool naturally to below 90°C and then open the furnace.

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