A multi-stage evaporation-condensation heat dissipation device for variable load

Abstract

This invention discloses a multi-stage evaporation-condensation heat dissipation device for variable loads, comprising an evaporator, a condenser, a liquid receiver, steam lines, and liquid lines. The evaporator consists of a shell, reinforcing columns, a capillary wick, a liquid channel, a steam channel, a liquid plug, and a steam plug. The condenser consists of a base plate, condensation channels, and movable baffles. The condenser has multiple corresponding steam inlets and liquid outlets, connected to multiple evaporators via steam and liquid lines, respectively. The baffles can move left and right within the condenser to adjust the area of ​​adjacent condensation channels. This invention features a simple structure; the condensation area of ​​each region can be adjusted to correspond to different heating powers of each evaporator, thus improving its heat dissipation efficiency. Furthermore, the evaporators and condensers are connected in series, eliminating the need for flow distribution and avoiding the heat dissipation deterioration problem caused by uneven flow distribution, as seen in parallel evaporator loop systems.

Description

Technical Field

[0001] This invention belongs to the field of heat dissipation technology for electronic devices. Background Technology

[0002] Gas-liquid phase change heat transfer technology has advantages such as high thermal conductivity and good temperature uniformity, and is increasingly used in the heat dissipation of electronic devices. For electronic devices with multiple heat sources, the current solution is to use multiple evaporators in parallel gas-liquid phase change heat transfer technology. The flow and heat transfer characteristics of gas-liquid two-phase flow are much more complex than those of single-phase flow. For heat dissipation devices with multiple evaporators operating in parallel, the large difference in the physical properties of the two-phase fluids and the complex flow process lead to uneven flow distribution among the parallel evaporators, causing heat dissipation deterioration. Furthermore, the condensation area inside the condenser of the heat dissipation device has a significant impact on its performance. Currently, condensers in heat dissipation devices are designed based on a fixed heat load. If the evaporator is under a variable load, an increase in heat load will cause insufficient condensation area, preventing the gaseous working fluid from completely condensing into a liquid working fluid. During the circulating phase change heat transfer process, the dryness of the gas-liquid inlet of the condenser will further increase, resulting in deterioration of heat transfer.

[0003] Reference 1 (Liu Chengzhi; Yang Fan; Dong Deping. A Dual Evaporator Loop Heat Pipe in the Medium-Low Temperature Range CN102121803A) proposes a dual evaporator loop heat pipe in the medium-low temperature range. Based on the dual evaporator loop heat pipe, a secondary condenser and a secondary evaporator liquid pool unit are introduced to construct a secondary loop. A certain heating power is applied to the secondary evaporator, shortening the cooling time of the medium-low temperature dual evaporator loop heat pipe. Furthermore, during loop heat pipe operation, the gaseous working fluid generated in the secondary evaporator enters the main liquid pool of the main evaporator liquid pool unit through the secondary loop, directing the heat leakage from the main evaporator towards the main liquid pool, reducing the impact of heat leakage on the loop heat pipe, and improving the heat transfer capacity of the loop heat pipe. This invention addresses the issue of two main evaporators in a parallel configuration of a heating device, requiring flow distribution. Under different heating power conditions, the evaporator with higher power will inevitably have higher internal flow resistance than the other evaporator, thus reducing the flow distribution in that branch and further deteriorating heat dissipation. Reference 2 (Liu Zhichun; He Song; Deng Weizhong; Liu Wei; Ma Zhengyuan. A Dual Evaporator Loop Heat Pipe CN111006529A) proposes a dual evaporator loop heat pipe. The first and second evaporators are connected to the inlet of the condenser via first and second steam transfer pipes, respectively. The condensate produced in the condenser is first mixed in a mixer, and then sent to the first and second evaporators via liquid transfer pipes, thus forming a dual evaporator loop heat pipe. This invention can meet the needs of large-area heat dissipation or heat dissipation from multiple heat sources, effectively improving the heat dissipation efficiency of the loop heat pipe. However, it also requires the flow rate to be distributed to the two evaporators, and heat dissipation deteriorates under different power operating conditions. Summary of the Invention

[0004] To address the problem of insufficient condensation area and uneven flow distribution leading to heat dissipation degradation in heat sources with variable loads, this invention proposes a multi-stage evaporation-condensation heat dissipation device for variable loads, which improves the performance of the heat dissipation device through variable condensation domain and multi-stage evaporation-condensation technology.

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0006] A multi-stage evaporation-condensation heat dissipation device for variable load includes: an evaporator 1, a condenser 2, a liquid receiver 3, a steam pipe 4, and a liquid pipe 5; the evaporator 1 includes a shell 6; the evaporator 1 includes n reinforcing columns 7, n≥1; the evaporator 1 includes a capillary wick 8; the evaporator 1 includes a liquid channel 9; the evaporator 1 includes a steam channel 10; the evaporator 1 includes a liquid plug 11; the evaporator 1 includes a steam plug 12; the condenser 2 includes a base plate 13; the condenser 2 includes m condensation channels 14, m≥1; the condenser 2 includes m-1 movable baffles 15; the outlet of the liquid receiver 3 is connected to the liquid inlet of the first evaporator 1-1. The gas outlet of evaporator 1-1 is connected to the top inlet of the first condensing channel 14-1 of condenser 2 via steam pipe 4. The bottom outlet of the first condensing channel 14-1 is connected to the liquid inlet of the second evaporator 1-2 via liquid pipe 5. The steam outlet of the second evaporator 1-2 is connected to the top inlet of the second condensing channel 14-2 of condenser 2. The bottom outlet of the second condensing channel 14-2 is connected to the liquid inlet of the third evaporator 1-3 via liquid pipe 5. The steam outlet of the mth evaporator 1-m is connected to the top inlet of the mth condensing channel 14-m of condenser 2. The bottom outlet of the mth condensing channel 14-m is connected to the inlet of the liquid receiver 3 via liquid pipe 5, thus forming the flow loop of the entire device.

[0007] Furthermore, the evaporator 1 has a flat plate structure. The capillary wick 8 is connected to the upper and lower cover plates of the shell 6 through the ribs on the shell 6, forming a steam channel 10 between the ribs. The upper and lower capillary wicks 8 form a liquid channel 9. The upper and lower cover plates are connected by reinforcing columns 7, which increases the structural strength of the evaporator 1 and also allows heat to be transferred from one side of the cover plate that is in contact with the heat source to the other side. The liquid channel 9 has a liquid plug 11 near the outlet of the evaporator 1, and the steam channel 10 has a steam plug 12 near the inlet of the evaporator 1. Since the liquid plug 11 and the steam plug 12 block one side of the liquid channel 9 and the steam channel 10 respectively, the liquid working fluid can only flow inside the liquid channel 9 after entering through the inlet of the evaporator 1. After the evaporator is heated, the liquid working fluid inside the capillary wick 8 undergoes a phase change to form a gas-liquid meniscus. Under the action of surface suction force, i.e., capillary force, the steam is driven into the steam channel 10 and enters the corresponding condensation channel 14 through the evaporator outlet. The special evaporator structure makes the working fluid form a directional flow inside the device, thereby determining the flow direction of the working fluid inside the entire device.

[0008] Furthermore, the condenser 2 has multiple mutually isolated condensing channels 14 inside, with the inlet of the condensing channel 14 at the top and the outlet at the bottom. The m-th condensing channel 14-m corresponds to the m-th evaporator. The baffle 15 can move its position left and right. The internal condensing area of ​​the m-th condensing channel 14-m is adjusted according to the heat load on the m-th evaporator.

[0009] Furthermore, the evaporator 1 is located in the lower part of the condenser 2, and the liquid working fluid of the condenser 2 flows back to the capillary wick 8 inside the evaporator 1.

[0010] Compared with the prior art, the present invention has the following significant advantages:

[0011] (1) The condenser of the present invention is divided into multiple condensation zones. The multiple condensation zones are concentrated in the same substrate to save space. The condensation area of ​​each zone can be adjusted by moving the position of the partition to correspond to the different heating power of each evaporator and improve its heat dissipation efficiency.

[0012] (2) The evaporators and condensers of the present invention are connected in series, so there is no need to distribute the flow rate. Unlike the parallel evaporator loop system, there will be no problem of heat dissipation deterioration caused by uneven flow distribution.

[0013] (3) Each evaporator of the present invention can be flexibly arranged in different positions, and the structural size can be adjusted according to the size of each heating device. This avoids the reduction in heat dissipation efficiency and the increase in weight caused by a single evaporator covering all heating devices, and is suitable for equipment where the heating devices are a certain distance apart.

[0014] (4) The present invention relies on the capillary wick to provide capillary force to drive the working fluid for heat transfer, and relies on the surface of the condenser for natural air cooling. The entire heat dissipation device does not require external power.

[0015] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the principle of the multi-stage evaporation-condensation heat dissipation device for variable load of the present invention.

[0017] Figure 2 This is a schematic diagram of the evaporator structure of the multi-stage evaporation-condensation heat dissipation device for variable load of the present invention.

[0018] Figure 3 This is a cross-sectional view of the evaporator of the multi-stage evaporation-condensation heat dissipation device for variable load according to the present invention.

[0019] Figure 4 This is a longitudinal sectional view of the evaporator of the multi-stage evaporation-condensation heat dissipation device for variable load according to the present invention.

[0020] Figure 5 This is a cross-sectional view of the condenser of the multi-stage evaporation-condensation heat dissipation device for variable load according to the present invention.

[0021] Among them, 1. Evaporator; 2. Condenser; 3. Liquid receiver; 4. Steam pipeline; 5. Liquid pipeline; 6. Shell; 7. Reinforcing column; 8. Capillary wick; 9. Liquid channel; 10. Steam channel; 11. Liquid plug; 12. Steam plug; 13. Base plate; 14. Condensation channel; 15. Baffle. Detailed Implementation

[0022] To illustrate the technical solution and objectives of this invention, the invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0023] Combination Figure 1 , Figure 2 The embodiments of the present invention include an evaporator 1, a condenser 2, a liquid receiver 3, a steam pipeline 4, and a liquid pipeline 5; the evaporator 1 includes a shell 6; the evaporator 1 includes 18 reinforcing columns 7; the evaporator 1 includes a capillary wick 8; the evaporator 1 includes a liquid channel 9; the evaporator 1 includes a steam channel 10; the evaporator 1 includes a liquid plug 11; the evaporator 1 includes a steam plug 12; the condenser 2 includes a base plate 13; the condenser 2 includes four condensation channels 14; and the condenser 2 includes three movable partitions 15.

[0024] The outlet of the liquid reservoir 3 is connected to the liquid inlet of the first evaporator 1-1. The gas outlet of the evaporator 1-1 is connected to the top inlet of the first condensing channel 14-1 of the condenser 2 via the steam pipe 4. The bottom outlet of the first condensing channel 14-1 is connected to the liquid inlet of the second evaporator 1-2 via the liquid pipe 5. The steam outlet of the second evaporator 1-2 is connected to the top inlet of the second condensing channel 14-2 of the condenser 2. The bottom outlet of the second condensing channel 14-2 is connected to the liquid inlet of the third evaporator 1-3 via the liquid pipe 5. The steam outlet of the fourth evaporator 1-4 is connected to the top inlet of the fourth condensing channel 14-4 of the condenser 2. The bottom outlet of the fourth condensing channel 14-4 is connected to the inlet of the liquid reservoir 3 via the liquid pipe 5, forming the flow loop of the entire device. The condensing channel is composed of parallel channels.

[0025] The evaporator 1 has a flat plate structure. The capillary wick 8 is connected to the upper and lower cover plates of the shell 6 via ribs on the shell 6, forming a steam channel 10 between the ribs. A liquid channel 9 is formed between the upper and lower capillary wicks 8. The upper and lower cover plates are connected by reinforcing columns 7, which increases the structural strength of the evaporator 1 and also allows heat to be transferred from one side of the cover plate to the other. The liquid channel 9 has a liquid plug 11 near the outlet of the evaporator 1, and the steam channel 10 has a steam plug 12 near the inlet of the evaporator 1. Since the liquid plug 11 and the steam plug 12 respectively block the liquid channel... On one side of the evaporator 1 inlet, the liquid working medium can only flow inside the liquid channel 9 after entering through the inlet of the evaporator 1. However, the other side of the liquid channel 9 is blocked, so the liquid working medium can only flow into the capillary wick 8. After the evaporator 1 is heated, the liquid working medium undergoes a phase change inside the capillary wick 8 to form a gas-liquid meniscus. Under the action of surface suction force, i.e. capillary force, the steam is driven into the steam channel 10. Since one side of the steam channel 10 is blocked, it can only flow out through the other side into the corresponding condensation channel 14. The special evaporator structure makes the working medium form a directional flow inside the device.

[0026] The condenser 2 has multiple mutually isolated condensing channels 14 inside. The inlet of the condensing channel 14 is at the top and the outlet is at the bottom. The m-th condensing channel 14-m corresponds to the m-th evaporator. The baffle 15 can move left and right inside the condenser 2 to adjust the area of ​​adjacent condensing channels 14. The size of the condensing area of ​​the m-th condensing channel 14-m can be adjusted according to the heat load on the m-th evaporator, so that the steam working fluid entering each area can be fully condensed, thereby improving the heat dissipation efficiency of the device.

[0027] The evaporator 1 is located in the lower part of the condenser 2, thereby ensuring that the return liquid working fluid of the condenser 2 fully wets the capillary core 8 inside the evaporator 1 and avoids heat transfer deterioration caused by insufficient return working fluid.

[0028] In some embodiments, the evaporator 1 has fins on its surface.

[0029] In some embodiments, the surface of the condenser 2 has fins.

[0030] In some embodiments, the condenser 2 has a cavity instead of multiple condensation channels.

[0031] In some embodiments, the condenser 2 is installed at an angle.

[0032] The evaporator has a length of 100-300mm, a width of 100-300mm, and a thickness of 10-20mm. The internal steam channel of the evaporator has a length of 70-270mm, a width of 1-3mm, and a depth of 1-2mm. The liquid channel has a length of 70-270mm, a width of 90-290mm, and a depth of 5-10mm. The condenser has a length of 500-1000mm, a width of 500-1000mm, and a thickness of 10-30mm. The internal single condenser channel of the condenser has a length of 400-900mm, a width of 5-10mm, and a depth of 5-10mm. The baffle plate has a thickness of 2mm.

Claims

1. A multi-stage evaporation-condensation heat dissipation device for variable load, characterized in that: The system includes an evaporator (1), a condenser (2), a liquid reservoir (3), a steam pipeline (4), and a liquid pipeline (5); the evaporator (1) includes a shell (6); the evaporator (1) includes n reinforcing columns (7), n≥1; the evaporator (1) includes a capillary wick (8); the evaporator (1) includes a liquid channel (9); the evaporator (1) includes a steam channel (10); the evaporator (1) includes a liquid plug (11); the evaporator (1) includes a steam plug (12); the condenser (2) includes a base plate (13); the condenser (2) includes m condensation channels (14), m≥1; the condenser (2) includes m-1 movable partitions (15); the outlet of the liquid reservoir (3) is connected to the liquid inlet of the first evaporator (1-1), and the gas outlet of the first evaporator (1-1) is connected to... The steam pipe (4) is connected to the top inlet of the first condensing channel (14-1) of the condenser (2), and the bottom outlet of the first condensing channel (14-1) is connected to the liquid inlet of the second evaporator (1-2) through the liquid pipe (5); the steam outlet of the second evaporator (1-2) is connected to the top inlet of the second condensing channel (14-2) of the condenser (2); the bottom outlet of the second condensing channel (14-2) is connected to the liquid inlet of the third evaporator (1-3) through the liquid pipe (5); the steam outlet of the mth evaporator (1-m) is connected to the top inlet of the mth condensing channel (14-m) of the condenser (2); the bottom outlet of the mth condensing channel (14-m) is connected to the inlet of the liquid reservoir (3) through the liquid pipe (5), forming the flow loop of the entire device. The condensing channel is composed of parallel channels. The surface of the evaporator (1) has fins.

2. The multi-stage evaporation-condensation heat dissipation device for variable load according to claim 1, characterized in that: The evaporator (1) has a flat plate structure. The capillary wick (8) is connected to the upper and lower cover plates of the shell (6) through the ribs on the shell (6). A steam channel (10) is formed between the ribs, and a liquid channel (9) is formed between the upper and lower capillary wicks (8). The upper and lower cover plates are connected by reinforcing columns (7). The liquid channel (9) has a liquid plug (11) near the outlet side of the evaporator (1), and the steam channel (10) has a steam plug (12) near the inlet side of the evaporator (1). Due to the liquid plug (11) and steam... The plug (12) blocks one side of the liquid channel (9) and the steam channel (10) respectively. After the liquid working medium enters through the inlet of the evaporator (1), it can only flow inside the liquid channel (9). After the evaporator is heated, the liquid working medium inside undergoes a phase change inside the capillary core (8) to form a gas-liquid meniscus. Under the action of surface suction force, i.e. capillary force, the steam is driven into the steam channel (10) and enters the corresponding condensation channel (14) through the evaporator outlet. The above evaporator structure makes the working medium form a directional flow inside the device.

3. The multi-stage evaporation-condensation heat dissipation device for variable load according to claim 1, characterized in that: The condenser (2) has multiple mutually isolated condensing channels (14) inside. The inlet of the condensing channel (14) is at the top and the outlet is at the bottom. The m-th condensing channel (14-m) corresponds to the m-th evaporator. The baffle (15) can move its position left and right. The internal condensing area of ​​the m-th condensing channel (14-m) is adjusted according to the heat load on the m-th evaporator.

4. The multi-stage evaporation-condensation heat dissipation device for variable load according to claim 1, characterized in that: The evaporator (1) is located in the lower part of the condenser (2), and the liquid working fluid of the condenser (2) flows back to the capillary wick (8) inside the evaporator (1).

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