Loop heat pipe

Abstract

A loop heat pipe comprises an evaporator, a vapor line, a condenser, a liquid line and a compensator, the evaporator and the compensator share an outer shell, the compensator has a second capillary core inside; a first capillary core is located in the evaporator and forms a first vapor cavity and a second vapor cavity between the evaporator and the shell; the vapor line connects the first vapor cavity to the condenser; the liquid line connects the condenser to the compensator; a secondary line is further provided to connect the second vapor cavity to the condenser or the liquid line. The loop heat pipe has small heat leakage from the evaporator to the compensator, reduces the requirement for supercooling degree and improves heat transfer performance.

Description

Technical Field

[0001] This invention relates to a heat transfer device, and more particularly to a loop heat pipe. Background Technology

[0002] A loop heat pipe is an advanced heat transfer element. During operation, the pressure and temperature of the evaporator are higher than those of the compensator, resulting in heat leakage from the evaporator to the compensator. According to the operating principle of a loop heat pipe, this heat leakage needs to be offset by the subcooling of the reflux liquid to maintain the thermal balance of the compensator. However, this increases the temperature difference between the hot and cold ends of the loop heat pipe, degrading its heat transfer performance. Therefore, it is necessary to minimize this heat leakage. Heat conduction through the shell between the evaporator and the compensator, and through the capillary wick of the loop heat pipe, is a significant source of this heat load; therefore, reducing this heat conduction is crucial for improving the heat transfer performance of the loop heat pipe. Summary of the Invention

[0003] In view of this, the present invention provides a loop heat pipe that can reduce heat leakage from the evaporator to the compensator and improve its heat transfer performance.

[0004] The present invention adopts the following technical solution:

[0005] A loop heat pipe includes an evaporator, a gas pipeline, a condenser, a liquid pipeline, and a compensator. The evaporator and the compensator share an external housing, which includes an upper housing and a lower housing. The upper and lower housings together define a sealed chamber and are provided with a first capillary wick. The first capillary wick divides the sealed chamber into the evaporator and the compensator. The first capillary wick is located within the evaporator. The first capillary wick includes a main portion and a residual portion. The main portion is located away from the compensator and forms a first vapor chamber with the housing. The residual portion is located close to the compensator and forms a second vapor chamber with the housing. The compensator contains a second capillary wick, which is in contact with or connected to the first capillary wick.

[0006] The first capillary wick isolates the second vapor chamber from the first vapor chamber to prevent the gaseous working fluid from flowing between the second vapor chamber and the first vapor chamber. The first capillary wick also isolates the second vapor chamber from the compensator to prevent the gaseous working fluid from flowing between the second vapor chamber and the compensator.

[0007] The gas pipeline connects the first steam chamber to the condenser;

[0008] The liquid pipeline connects the condenser to the compensator; it also includes,

[0009] The secondary pipeline connects the second vapor chamber to the condenser, or connects the second vapor chamber to the liquid pipeline.

[0010] Optionally, the first capillary core is an integral capillary structure, and the remaining part of the first capillary core has multiple recessed structures. The multiple recessed structures are connected by a groove to form the second vapor chamber with the shell.

[0011] Optionally, the first capillary core is a powder sintered body.

[0012] Optionally, the first capillary core is formed by stacking multiple capillary structures.

[0013] Optionally, the capillary layer has through holes, and the through holes on adjacent capillary layers at least partially overlap to form a through channel. The capillary layer near the upper shell or near the lower shell has a channel that connects to the through channel and forms the second steam chamber with the shell.

[0014] Optionally, the capillary structure layer is made of one or more layers of wire mesh, metal fiber felt, or foam metal, and the multiple capillary structure layers constituting the first capillary core may be made of the same or different materials.

[0015] Optionally, the second capillary is a part of the first capillary, formed by the remainder of the first capillary extending toward the compensator.

[0016] Optionally, the second capillary core is a separate capillary structure.

[0017] Optionally, the evaporator and the compensator are arranged horizontally or vertically.

[0018] Optionally, the main part of the first capillary core has a shape with a large surface area, such as a shovel-shaped core.

[0019] Compared with existing technologies, the loop heat pipe of this invention, during operation, causes heat leakage from the evaporator along the shell to the compensator, and from the first capillary wick inside the evaporator to the compensator, to vaporize the working fluid in the second vapor chamber, absorbing the aforementioned heat load. The vaporized working fluid enters the secondary pipeline, condenses, and eventually returns to the compensator. This significantly reduces the subcooling requirement of the liquid working fluid in the evaporator, thereby improving the performance of the loop heat pipe. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of one embodiment of a loop heat pipe according to the present invention;

[0021] Figure 2 for Figure 1 A schematic diagram of the upper and middle shell after it is opened;

[0022] Figure 3 This is a schematic diagram of a first embodiment of the first capillary wick and the second capillary wick in this invention;

[0023] Figure 4 This is a schematic diagram of a second embodiment of the first capillary and the second capillary in this invention;

[0024] Figure 5 for Figure 4 Exploded view.

[0025] In the above diagram: 1-Evaporator, 2-Gas pipeline, 3-Condenser, 4-Liquid pipeline, 5-Compensator, 6-Secondary pipeline, 11-First capillary wick, 51-Second capillary wick, 12-First steam chamber, 13-Second steam chamber, 111-Main part of the first capillary wick, 112-Remaining part of the first capillary wick, 110, 110a, 110b, 110c, 110d-Capillary structure layer, 1121-Recessed structure, 1122-Groove, 1123-Through hole, 1124-Through channel, 1125-Channel, 100-Shell, 101-Upper shell, 102-Lower shell. Detailed Implementation

[0026] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0027] Please refer to Figure 1 and Figure 2 This is a schematic diagram of an embodiment of a loop heat pipe according to the present invention. It includes an evaporator 1, a gas line 2, a condenser 3, a liquid line 4, a compensator 5, and a secondary line 6. The evaporator 1 and the compensator 5 share an outer casing 100, which includes an upper casing 101 and a lower casing 102. The upper casing 101 and the lower casing 102 form a closed chamber containing a first capillary wick 11, which divides the closed chamber into the evaporator 1 and the compensator 5. The first capillary wick 11 includes a main portion 111 and a remaining portion 112. The main portion 111 is located away from the compensator 5, and the remaining portion 112 is located close to the compensator 5.

[0028] The second capillary wick 51 is located inside the compensator 5. The first capillary wick 11 is in contact with or connected to the second capillary wick 51.

[0029] The main portion 111 of the first capillary wick and the housing 100 form a first vapor chamber 12. The remaining portion 112 of the first capillary wick and the housing 100 form a second vapor chamber 13. A gas pipeline 2 connects the first vapor chamber 12 to the condenser 3, and a liquid pipeline 4 connects the condenser 3 to the compensator 5. In this embodiment, a secondary pipeline 6 connects the second vapor chamber 13 to the condenser 3. However, this is not a limitation; the secondary pipeline 6 can also connect the second vapor chamber 13 to the liquid pipeline 4.

[0030] The main part 111 of the first capillary core has a large surface area, such as a shovel-shaped part.

[0031] In this embodiment, the evaporator 1 and the compensator 5 are arranged horizontally, but this is not a limitation; the evaporator 1 and the compensator 5 can also be arranged vertically.

[0032] The basic working principle of this invention is as follows: The lower shell 102 of the evaporator 1 comes into contact with the heat source, causing the evaporator 1 to absorb heat. The working fluid in the first steam chamber 12 vaporizes. The vaporized working fluid enters the condenser 3 along the gas pipeline 2. After releasing heat and condensing in the condenser 3, it returns to the compensator 5 along the liquid pipeline 4 and returns to the evaporator 1 under the capillary force of the first capillary wick 11 and the second capillary wick 51, thus completing one cycle. Meanwhile, since the temperature and pressure inside the evaporator 1 are higher than those inside the compensator 5, the evaporator 1 conducts heat to the compensator 5 through the shell 100 and the first capillary wick 11. When the heat is conducted to the second vapor chamber 13, the working fluid in the second vapor chamber 13 is heated and vaporized, absorbing the heat. Then, the gaseous working fluid flows into the condenser 3 along the secondary pipeline 6. After releasing heat and condensing in the condenser 3, it returns to the compensator 5 along with the condensed working fluid flowing through the gas pipeline 2 via the liquid pipeline 4, and returns to the evaporator 1 under the capillary force of the first capillary wick 11 and the second capillary wick 51, thus completing one cycle. In this way, the heat leaking from the evaporator 1 into the compensator 5 is significantly reduced. This significantly reduces the subcooling requirement of the liquid working fluid in the evaporator 1, thereby improving the performance of the loop heat pipe.

[0033] Please refer to Figure 3 This is a schematic diagram of a first embodiment of the first capillary wick and the second capillary wick in this invention. The first capillary wick 11 is an integral capillary structure, comprising a main portion 111 and a remaining portion 112. The remaining portion 112 of the first capillary wick has multiple recessed structures 1121, which are connected together by grooves 1122 and, together with the housing 100 (not shown in the figure), form a second vapor chamber 13. The first capillary wick 11 can be a powder sintered body, but is not limited thereto. The second capillary wick 51 can be a part of the first capillary wick 11, extending from the remaining portion 112 of the first capillary wick towards the compensator 5. However, it is not limited thereto; the second capillary wick 51 can also be a separate capillary structure, formed by sintering powder on the lower housing 102 (not shown in the figure) and contacting the first capillary wick 11. The main portion 111 of the first capillary wick is serrated.

[0034] Please refer to Figure 4 and Figure 5This is a schematic diagram of a second embodiment of the first capillary wick and the second capillary wick in this invention. The first capillary wick 11 is formed by stacking multiple capillary structure layers 110, forming a main portion 111 and a remaining portion 112 of the first capillary wick. Multiple through holes 1123 are present on the capillary structure layers 110, and the through holes 1123 on adjacent capillary structure layers such as capillary structure layers 110b and 110c partially overlap to form through channels 1124. A channel 1125 is present on the capillary structure layer 110a near the housing 100 (not shown in the figure). The channel 1125 connects all through channels 1124 and forms a second vapor chamber 13 with the housing 100. In this embodiment, the second capillary wick 51 is a part of the first capillary wick 11, formed by extending from the capillary structure layer 110d near the lower housing 102 (not shown in the figure) towards the compensator 5.

[0035] The capillary layer 110 is made of one or more layers of wire mesh, metal fiber felt, or metal foam. The capillary layers 110a, 110b, 110c, and 110d may be made of the same or different materials.

[0036] The through holes 1123 on adjacent capillary layers 110 partially overlap compared to completely overlap, and the resulting through channels 1124 have a larger surface area, which can absorb more heat leakage from the first capillary core 11 to the compensator 5, resulting in better performance.

[0037] Based on the above embodiments of the loop heat pipe of the present invention, the present invention can significantly reduce heat leakage from the evaporator to the compensator through the shell and capillary wick, thereby improving its heat transfer performance.

[0038] Finally, it should be emphasized that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A loop heat pipe, comprising an evaporator, a gas line, a condenser, a liquid line, and a compensator, characterized in that, The evaporator and the compensator share an outer casing, which includes an upper casing and a lower casing. The upper casing and the lower casing together define a sealed chamber and are provided with a first capillary wick. The first capillary wick divides the sealed chamber into the evaporator and the compensator. The first capillary wick is located inside the evaporator. The first capillary wick includes a main portion and a residual portion. The main portion is away from the compensator and forms a first vapor chamber with the casing. The residual portion is close to the compensator and forms a second vapor chamber with the casing. The compensator contains a second capillary wick, which is in contact with or connected to the first capillary wick. The first capillary wick isolates the second vapor chamber from the first vapor chamber to prevent the gaseous working fluid from flowing between the second vapor chamber and the first vapor chamber. The first capillary wick also isolates the second vapor chamber from the compensator to prevent the gaseous working fluid from flowing between the second vapor chamber and the compensator. The gas pipeline connects the first steam chamber to the condenser; The liquid line connects the condenser to the compensator; include, The secondary pipeline connects the second vapor chamber to the condenser, or connects the second vapor chamber to the liquid pipeline.

2. A loop heat pipe according to claim 1, characterized in that: The first capillary core is an integral capillary structure, and the remaining part of the first capillary core has multiple recessed structures. The multiple recessed structures are connected by a groove and form the second vapor chamber with the shell.

3. A loop heat pipe according to claim 2, characterized in that: The first capillary core is a powder sintered body.

4. A loop heat pipe according to claim 1, characterized in that: The first capillary core is formed by stacking multiple layers of capillary structures.

5. A loop heat pipe according to claim 4, characterized in that: The capillary layer has through holes, and the through holes on adjacent capillary layers at least partially overlap to form a through channel. The capillary layer near the upper shell or near the lower shell has a channel that connects to the through channel and forms the second steam chamber with the shell.

6. A loop heat pipe according to claim 4 or 5, characterized in that: The capillary structure layer is made of one or more layers of wire mesh, metal fiber felt, or foam metal, and the multiple capillary structure layers constituting the first capillary core may be made of the same or different materials.

7. A loop heat pipe according to claim 1, characterized in that: The second capillary is a part of the first capillary, formed by the remainder of the first capillary extending toward the compensator.

8. A loop heat pipe according to claim 1, characterized in that: The second capillary core is a separate capillary structure.

9. A loop heat pipe according to claim 1, characterized in that: The evaporator and the compensator are arranged horizontally or vertically.

10. A loop heat pipe according to claim 1, characterized in that: The main part of the first capillary core is shovel-shaped.

Images