A high performance condenser for a loop heat pipe and a method for preparing the same

Abstract

The present invention provides a high-performance condenser of a loop heat pipe and a preparation method thereof, including S1, machining a groove at the center of a fin cross section; S2, pre-burying the condensing pipeline in the groove, and knocking the edge of the groove until it is deformed and clamps the condensing pipeline; S3, fixing the fin on a heating table; S4, applying a suspension to the weld, and brazing the groove and the condensing pipeline; S5, removing excess material from the fin by a machining center; S6, bending and shaping the condensing pipeline; S7, connecting the fin module and the condensing plate. The present invention pre-buries the condensing pipeline in the groove, knocks the edge of the groove to clamp the condensing pipeline, applies a cesium fluoroaluminate suspension mixed with water to the weld at 400°C, and uses an aluminum-zinc alloy as a brazing material, and adopts a flame heating method to perform steel-aluminum brazing of the groove and the condensing pipeline at 450°C, thereby improving the structural strength of the condenser and the brazing rate of the solder, and the condenser has good thermal coupling performance, simple processing technology, and high reliability.

Description

Technical Field

[0001] The invention relates to the technical field of radiators with large heat capacity and high heat flux density, and in particular to a high-performance condenser of a loop heat pipe and a preparation method thereof. Background Art

[0002] A loop heat pipe is a capillary pressure driven self-circulating two-phase fluid loop consisting of an evaporator, a condenser and a vapor-liquid pipeline. The condenser is an important component in a loop heat pipe system. A high-performance condenser needs to have high thermal conductivity, high reliability, light weight and simple preparation.

[0003] Traditional steel-aluminum condensers use thermal grease or structural adhesive to connect stainless steel pipes and aluminum alloy fins. This method is simple to prepare, but has poor thermal coupling performance, poor structural strength, thick fins, and poor overall performance.

[0004] The improved steel-aluminum condenser connects the stainless steel pipes and aluminum alloy fins by tin brazing. This method effectively improves the thermal coupling performance, structural strength and lightweight indicators, but the preparation process is complicated and there are reliability risks. All devices need to be nickel-plated before soldering, and tin-lead soldering equipment needs to be modified for process adaptability. The reliability is poor at high and low temperatures (reduced strength at high temperatures and there is a risk of tin epidemic at low temperatures). The overall performance of the solution is average.

[0005] The extruded aluminum profile condenser adopts the integrated extrusion molding method of pipe fins, which has good thermal coupling performance, high structural strength and good lightweight index. However, the manufacturing is complicated. Each update of the profile requires a separate mold, the fins of the bent part need to be milled off, and the dissimilar metal connection between the aluminum condenser and the stainless steel pipe requires a special conversion joint. The overall performance of the solution is not ideal. Summary of the invention

[0006] In order to solve the technical problems of low structural strength, poor thermal coupling performance, reliability risk and complex manufacturing process of the condenser in the prior art, the present invention is implemented as follows:

[0007] A method for preparing a high-performance condenser of a loop heat pipe, characterized in that it comprises the following steps:

[0008] S1. Processing a groove at the center of the fin section;

[0009] S2. Pre-bury the condensing pipeline in the groove, and knock the edge of the groove until it is deformed and clamps the condensing pipeline;

[0010] S3, fixing the fins to the heating table;

[0011] S4, applying the suspension onto the weld, and performing steel-aluminum brazing on the channel and the condensation pipeline;

[0012] S5, removing excess material of the fin by a machining center;

[0013] S6. Bend and shape the condensation pipeline according to the design requirements;

[0014] S7. Connect the fin module and the condensation plate.

[0015] Preferably, the step S3 further comprises step S3.1 of preheating the heating platform to 385°C-450°C.

[0016] Preferably, in step S4, the suspension is cesium fluoroaluminate mixed with water.

[0017] Preferably, in step S4, the brazing method is: using aluminum-zinc alloy as the brazing material, and performing steel-aluminum brazing by flame heating at 400° C.-480° C.

[0018] Preferably, the step S5 specifically includes welding the face milling plane, installing the face milling plane and thinning the fins.

[0019] A high-performance condenser of a loop heat pipe, manufactured using the above method, comprises an inlet pipeline, a fin module, an outlet pipeline and a condensing plate, characterized in that it also comprises bolts and a tee;

[0020] The fin module is fixedly connected to the condensation plate through the bolts;

[0021] The number of the fin modules is n, where n is an integer greater than or equal to 2;

[0022] The number of the tees is 2n-2;

[0023] The fin module includes three fins and one condensation pipeline;

[0024] The fin is provided with a groove, and the groove is welded to the condensation pipeline as a whole;

[0025] The inlet pipeline is connected to the inlet of the condensing pipeline in the first fin module through the tee;

[0026] The inlet of the condensing pipeline in the nth fin module is connected with the inlet of the condensing pipeline in the n-1th fin module through the tee;

[0027] The outlet pipeline is connected to the outlet of the condensing pipeline in the first fin module through the tee;

[0028] The outlet of the condensing pipeline in the nth fin module is connected with the outlet of the condensing pipeline in the (n-1)th fin module through the tee.

[0029] Preferably, a plurality of mounting holes are provided on the condensing plate, and the fins are fixedly connected to the mounting holes by bolts.

[0030] Preferably, the outer diameter of the condensation pipeline is 3-5 mm.

[0031] Preferably, the condensation pipeline is made of stainless steel.

[0032] Preferably, the fins are made of aluminum alloy.

[0033] The implementation of the present invention can solve the technical problems of low structural strength, poor thermal coupling performance, reliability risk and complex processing and manufacturing process of the condenser in the prior art; in the present invention, the condenser pipeline is pre-buried in the groove, and the edge of the groove is knocked to clamp the condenser pipeline, and a cesium fluoroaluminate suspension mixed with water is applied to the weld at 400°C, and an aluminum-zinc alloy is used as the brazing material, and the groove and the condenser pipeline are brazed at 450°C by flame heating, thereby improving the structural strength of the condenser and the brazing rate of the solder, and the condenser has good thermal coupling performance, simple processing technology and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 It is a top view of the condenser in Example 1;

[0036] Figure 2 This is a production process flow chart of the condenser of Example 1;

[0037] Figure 3 It is a top view of the fin module in Example 1;

[0038] Figure 4 is a right side cross-sectional view of a fin that has not been machined in Example 1;

[0039] Figure 5 It is a right side cross-sectional view of the fin after machining in Example 1;

[0040] Figure 6 This is a top view of the condenser in Example 2.

[0041] In the above drawings, the figure numbers represent:

[0042] 1. Import pipeline

[0043] 2. Fin module

[0044] 2-1. Fins

[0045] 2-1-1, Groove

[0046] 2-2. Condensation pipeline

[0047] 3. Tee

[0048] 4. Export pipeline

[0049] 5. Condensation plate

[0050] 6. Bolts DETAILED DESCRIPTION

[0051] 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.

[0052] Example 1

[0053] In a specific embodiment 1, Figure 1 As shown, a high-performance condenser of a loop heat pipe includes an inlet pipeline 1, four groups of fin modules 2, six tees 3, an outlet pipeline 4, a condensing plate 5 and bolts 6. In this embodiment 1, the structures and functions of the four groups of fin modules 2 are the same, so in this embodiment 1, only one group of fin modules 2 is marked. Figure 3 As shown, the fin module 2 includes three fins 2-1 and a condensation pipeline 2-2, and the material of the fin 2-1 is aluminum alloy.

[0054] like Figure 1 As shown, the inlets of the condensing pipes 2-2 in the fin modules 2 of the first to third groups are respectively connected to three tees 3, wherein one tee 3 is connected to the inlet pipe 1, one tee 3 is connected to the inlet of the condensing pipe 2-2 of the fin module 2 of the fourth group, and the other tee 3 is respectively connected to the two tees 3 on the inlet pipe 1.

[0055] The outlets of the condensing pipes 2-2 of the fin modules 2 of the first to third groups are respectively connected to the other three tees 3, wherein one tee 3 is connected to the outlet pipe 4, one tee 3 is connected to the outlet of the condensing pipe 2-2 of the fourth group of fin modules 2, and the other tee 3 is connected to the two tees 3 on the outlet pipe 4.

[0056] like Figure 2As shown, a high-performance condenser of a loop heat pipe including four groups of fin modules 2 is prepared, and the specific preparation method is as follows:

[0057] S1. Aluminum alloy fin slotting: Machine a groove 2-1-1 with a diameter of 4.5mm and a depth of 3.75mm from the center to the surface at the center of the fin 2-1 section. Figure 4 The dimensions of the fin 2-1 before machining are 50 mm in width, 700 mm in length and 8 mm in thickness.

[0058] S2. Pre-embedded stainless steel pipeline: pre-embed the condensation pipeline 2-2 into the groove 2-1-1, and knock the edge of the groove 2-1-1 to deform and clamp the condensation pipeline 2-2 to prevent warping during the welding process. The condensation pipeline 2-2 is made of stainless steel with an outer diameter of 4mm.

[0059] S3. Preheating of aluminum alloy fins: Fix fin 2-1 onto the heating platform.

[0060] S3.1. Preheat the heating platform to 400°C.

[0061] S4. Flame brazing: Apply a suspension of cesium fluoroaluminate mixed with water to the weld. At high temperature, the water in the suspension evaporates, leaving a flux layer.

[0062] In this step, aluminum-zinc alloy is used as brazing material, and steel-aluminum brazing is performed at about 450°C by flame heating to ensure that the groove 2-1-1 is filled with brazing material. In this step, the thermal conductivity of aluminum alloy is about 150W / (mK), the brazing rate is high, and the thermal conductivity between the stainless steel pipeline and the aluminum alloy fin is good. Through this step, the thermal coupling of the condenser is improved, and steel-aluminum brazing belongs to medium-temperature brazing, the weld strength is stronger than the parent material strength, and the structural strength is high. The other two fins 2-1 in the four groups of fin modules 2 are brazed with the condensing pipeline 2-2 in turn in the same way, wherein the spacing between the fins 2-1 is 143mm.

[0063] S5, excess machining: remove the excess material of the fin 2-1 in the 4 sets of fin modules 2 through the machining center, including the welding face milling plane, the installation face milling plane and the fin thinning. Through this step, the lightweight index requirements can be met. The size of the formed fin 2-1 is 50mm wide, 700mm long, and 2mm thick. The boss that wraps the condensation pipe 2-2 is 7.5mm wide and 4.25mm high. Figure 5 shown.

[0064] S6. Bending and shaping: The condensing pipe 2-2 in each fin module 2 is bent and shaped according to the design requirements, so that the three fins 2-1 are at the same height and the distance between the center lines of the fins 2-1 is 125 mm. At this point, the production of the fin module 2 is completed.

[0065] S7, condensation plate installation: a plurality of installation holes are provided on the condensation plate 5, and the fins 2-1 in the four groups of fin modules 2 are connected and fixed to the condensation plate 5 by bolts 6. In this embodiment, the size of the condensation plate 5 is 800mm*1500mm*2mm. The condenser prepared according to the method in this embodiment 1 can be designed according to the needs of the diameter of the condensation pipeline 2-2, the length of the fins 2-1, the special configuration layout, etc. The manufacturing process is simple, and the fin modules 2 can be connected by the tee 3 to adjust the size of the condensation area, which is convenient for mass production and special customization.

[0066] Example 2

[0067] In a specific embodiment 2, Figure 6 As shown, a high-performance condenser of a loop heat pipe includes an inlet pipeline 1, two groups of fin modules 2, two tees 3, an outlet pipeline 4, a condensation plate 5 and bolts 6.

[0068] In the second embodiment, the structures and functions of the four groups of fin modules 2 are the same, so in the second embodiment, only one group of fin modules 2 is marked. Figure 3 As shown, the fin module 2 includes three fins 2-1 and a condensation pipeline 2-2, and the material of the fin 2-1 is aluminum alloy.

[0069] The inlet pipeline 1 is connected to the inlet of the condensation pipeline 2-2 in the first fin module 2 through a tee 3;

[0070] The inlet of the condensation pipeline 2-2 in the second fin module 2 is connected to the inlet of the condensation pipeline 2-2 in the first fin module 2 through a tee 3;

[0071] The outlet pipeline 4 is connected to the outlet of the condensation pipeline 2-2 in the first fin module 2 via a tee 3;

[0072] The outlet of the condensation pipeline 2 - 2 in the second fin module 2 is connected to the outlet of the condensation pipeline 2 - 2 in the first fin module 2 through a tee 3 .

[0073] like Figure 2 As shown, a high-performance condenser of a loop heat pipe including two groups of fin modules 2 is prepared, and the specific preparation method is as follows:

[0074] S1. Aluminum alloy fin slotting: Machine a groove 2-1-1 with a diameter of 4.5mm and a depth of 3.75mm from the center to the surface at the center of the fin 2-1 section. Figure 4 The dimensions of the fin 2-1 before machining are 50 mm in width, 700 mm in length and 8 mm in thickness.

[0075] S2. Pre-embedded stainless steel pipeline: pre-embed the condensation pipeline 2-2 into the groove 2-1-1, and knock the edge of the groove 2-1-1 to deform and clamp the condensation pipeline 2-2 to prevent warping during the welding process. The condensation pipeline 2-2 is made of stainless steel with an outer diameter of 4mm.

[0076] S3. Preheating of aluminum alloy fins: Fix fin 2-1 onto the heating platform.

[0077] S3.1. Preheat the heating platform to 400°C.

[0078] S4. Flame brazing: Apply a suspension of cesium fluoroaluminate mixed with water to the weld. At high temperature, the water in the suspension evaporates, leaving a flux layer.

[0079] In this step, aluminum-zinc alloy is used as brazing material, and flame heating is used to perform steel-aluminum brazing at about 450°C to ensure that the groove 2-1-1 is filled with brazing material. In this step, the thermal conductivity of aluminum alloy is about 150W / (mK), the brazing rate is high, and the thermal conductivity between the stainless steel pipeline and the aluminum alloy fin is good. Through this step, the thermal coupling of the condenser is improved, and steel-aluminum brazing belongs to medium-temperature brazing, the weld strength is stronger than the parent material strength, and the structural strength is high. The other two fins 2-1 in each group of fin modules 2 are brazed with the condensing pipeline 2-2 in turn in the same way, wherein the spacing between the fins 2-1 is 143mm.

[0080] S5, excess machining: remove the excess material of the three fins 2-1 through the machining center, including the welding face milling plane, the installation face milling plane and the fin thinning. Through this step, the lightweight index requirements can be met. The dimensions of the formed fin 2-1 are 50mm wide, 700mm long and 2mm thick. The boss that wraps the condensation pipe 2-2 is 7.5mm wide and 4.25mm high. Figure 5 shown.

[0081] S6. Bending and shaping: The condensing pipe 2-2 in each fin module 2 is bent and shaped according to the design requirements, so that the three fins 2-1 are at the same height and the distance between the center lines of the fins 2-1 is 125 mm. At this point, the production of the fin module 2 is completed.

[0082] S7, condensation plate installation: a number of installation holes are provided on the condensation plate 5, and the fins 2-1 in the four groups of fin modules 2 are connected and fixed to the condensation plate 5 by bolts 6. In this embodiment, the size of the condensation plate 5 is 800mm*750mm*2mm. The condenser prepared according to the method in this embodiment 1 can be designed according to the needs of the diameter of the condensation pipeline 2-2, the length of the fin 2-1, the special configuration layout, etc., the manufacturing process is simple, and the fin module 2 can be connected through the tee 3 to adjust the size of the condensation area, which is convenient for mass production and special customization.

Claims

1. A method for preparing a high-performance condenser of a loop heat pipe, characterized in that: The steps include: S1. Processing a groove at the center of the fin section; S2. Pre-bury the condensing pipeline in the groove, and knock the edge of the groove until it is deformed and clamps the condensing pipeline; S3, fix the fins to the heating table; S4, applying the suspension onto the weld to braze the channel and the condensation pipeline; S5, removing excess material of the fin by a machining center; S6, bending and shaping the condensation pipeline; S7. Connect the fin module and the condensation plate.

2. The method for preparing a high-performance condenser of a loop heat pipe according to claim 1, characterized in that: The step S3 also includes step S3.1 of preheating the heating platform to 385° C.-450° C.

3. The method for preparing a high-performance condenser of a loop heat pipe according to claim 2, characterized in that: In the step S4, the suspension is cesium fluoroaluminate mixed with water.

4. The method for preparing a high-performance condenser of a loop heat pipe according to claim 3, characterized in that: In step S4, the brazing method is: using aluminum-zinc alloy as brazing material, and performing steel-aluminum brazing at 400° C.-480° C. by flame heating.

5. The method for preparing a high-performance condenser of a loop heat pipe according to claim 1, characterized in that: The step S5 specifically includes welding the face milling plane, installing the face milling plane and thinning the fins.

6. A high-performance condenser for a loop heat pipe, the high-performance condenser prepared by the method according to any one of claims 1 to 5, comprising an inlet pipeline, a fin module, an outlet pipeline, bolts, a tee and a condensation plate, characterized in that: The fin module is fixedly connected to the condensation plate through the bolts; The number of the fin modules is n, where n is an integer greater than or equal to 2; The number of the tees is 2n-2; The fin module includes three fins and one condensation pipeline; The fin is provided with a groove, and the groove is welded to the condensation pipeline as a whole; The inlet pipeline is connected to the inlet of the condensing pipeline in the first fin module through the tee; The inlet of the condensing pipeline in the nth fin module is connected with the inlet of the condensing pipeline in the n-1th fin module through the tee; The outlet pipeline is connected to the outlet of the condensing pipeline in the first fin module through the tee; The outlet of the condensing pipeline in the nth fin module is connected with the outlet of the condensing pipeline in the (n-1)th fin module through the tee.

7. The high performance condenser of a loop heat pipe according to claim 6, characterized in that: The condensing plate is provided with a plurality of mounting holes, and the fins are fixedly connected to the mounting holes by bolts.

8. The high performance condenser of a loop heat pipe according to claim 6, characterized in that: The outer diameter of the condensation pipeline is 3-5 mm.

9. The high performance condenser of a loop heat pipe according to claim 8, characterized in that: The condensation pipeline is made of stainless steel.

10. The high performance condenser of a loop heat pipe according to claim 6, characterized in that: The material of the fin is aluminum alloy.

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