CN106931815A - Variable-diameter serial and parallel channel plate type pulsating heat pipe - Google Patents

Abstract

A variable diameter series, parallel groove plate type pulsating heat pipe, the variable diameter series, parallel groove plate type pulsating heat pipe comprises a hot end 1, a cold end 2, an intermediate body 3, and a head 4, characterized in that: the hot end 1 is a rectangular flat plate with uniformly distributed hot end channels 5; the cold end 2 is a rectangular flat plate with uniformly distributed cold end channels 6; the equivalent diameter of the cold end channel 6 is 1-10 times the equivalent diameter of the hot end channel 5; one end of the hot end 1 is connected to one end of the cold end 2; or the hot end 1 and the cold end 2 are connected through an intermediate body 3, and a mixing chamber 10 is provided on the intermediate body 3. The content of the present invention has obvious innovative changes in structure and heat transfer mechanism, is effective and conforms to physical theory. The present invention has achieved full satisfaction from the principle requirements of heat dissipation of high heat flux density components. Its application in high heat flux density components will surely help these devices to dissipate heat and cool, and has a positive role in promoting the development and progress of electronic, microelectronic, optoelectronic components and their corresponding fields.

Description

A variable-diameter series and parallel channel plate type pulsating heat pipe

technical field

The invention discloses a variable-diameter serial and parallel channel plate type pulsating heat pipe, which belongs to the technical field of heat transfer enhancement.

technical background

Today, integrated, efficient, and miniaturized electronic, microelectronic, and optoelectronic components have been widely used in various daily production and living equipment, greatly improving people's production efficiency and quality of life, and the process is endless. However, such devices face the same obstacle in the evolution of integration, high efficiency, and miniaturization—high heat flux density. According to investigations, the heat flux density of such components is generally close to or exceeds 100W/cm ² , and some even exceed 200W. /cm ² .

High heat flux will generally lead to excessive operating temperature of components.

As we all know, the performance of electronics, microelectronics, and optoelectronic devices is closely related to temperature, and the higher the temperature, the lower the performance. According to statistics, the performance of such components will decrease by 0.4 to 0.5% for every 1°C increase in temperature, and 55% of the failure rate of electronic products comes from overheating. Therefore, each component has its specified allowable operating temperature. For example, the IC chip is 85°C, the T/R component junction temperature is 125°C, and the LED junction temperature is 130°C. Overheating will affect the performance in the slightest, and cause burnout in severe cases. .

In addition, due to the differences in the structure of each component and the distribution of hot spots, the temperature distribution on the surface of the component is generally not uniform in practice. Uneven localized high temperature can cause damage.

In order to ensure the stable and efficient operation of components, it is necessary to ensure that they always meet the conditions of allowable operating temperature and uniform temperature, which means that they must be well and effectively dissipated.

Restricted by the installation site, allowable working temperature, and temperature uniformity, the heat dissipation of components must meet the principles of plane heat transfer, excellent heat transfer performance, good temperature uniformity, small footprint, large heat dissipation area, and simple and reliable principles.

The pulsating heat pipe is formed by a pulsating channel whose equivalent inner diameter satisfies the Bo number (Bond number). The working fluid exists randomly in the channel in the form of gas and liquid plugs. During operation, the working medium undergoes a complex movement under the pressure difference: the hot end The vaporized substance flows to the cold end, and after exothermic condensation, it returns to the cold end under the action of gravity and capillary force, reciprocating, and the circulation path is accompanied by the random generation and annihilation of gas and liquid plugs, forming strong disturbances and enhancing heat transfer. This working characteristic makes the heat transfer capacity of the pulsating heat pipe much better than that of the traditional heat pipe of the same diameter. The plate-type pulsating heat pipe is a flat heat pipe with a series of pulsating channels inside, which has both a natural heat-absorbing plane and a strong heat transfer capability of a pulsating heat pipe. According to the internal channel structure, the plate pulsating heat pipe can be divided into a single circuit plate pulsating heat pipe and a parallel channel plate pulsating heat pipe. The research shows that the parallel channel has the characteristics of short channel and homogeneity of the working medium, the movement resistance of the working medium is smaller, and the consistency of the thermal state and flow direction of the working medium between the channels is better, which makes it more effective in the start-up of the heat pipe, heat transfer thermal resistance and The temperature uniformity is superior to that of a single circuit, so the parallel channel plate pulsating heat pipe is more suitable for heat dissipation and cooling of components with high heat flux density.

In recent years, researchers have developed a variety of plate-type pulsating heat pipes with parallel channels in order to solve the problem of heat dissipation and cooling of high heat flux components. However, from the perspective of research and application, the performance of the parallel channel plate pulsating heat pipe developed is not good, and there are still some shortcomings. Therefore, how to scientifically and effectively solve the heat dissipation of components is still a difficult problem. If this problem is not solved, it will be serious. Affect the development of the above-mentioned fields, so the research and development of this problem is very necessary and urgent.

The relevant patents and academic researches that have been applied for so far are summarized as follows.

Chinese patent 201010279816.4 proposes a multi-channel parallel circuit pulsating heat pipe. The heat pipe is welded by two parallel and equal-length connecting pipes and several connecting pipes perpendicular to them. The pipe diameter meets the pulsation requirements, forming a parallel tank The channel plate type pulsating heat pipe has a strong pulsating heat transfer capability. Document 1 "Influence of Inclination Angle and Cooling Conditions on Heat Transfer Performance of Multi-channel Parallel Circuit Plate Pulsating Heat Pipe" (Acta Chemical Industry, Vol. ℃, its maximum heat flux density is 54.3W/cm ² , which is lower than the basic value of heat flux density of high heat flux components, and cannot meet the heat dissipation needs of high heat flux components. In addition, the document shows that under the conditions of cooling water flow rate of 9.0g/s, heating power of 149W, and acetone working medium, the temperature difference measured at two measuring points in the radial direction of the hot end that deviates from the central axis by a quarter of the plate width is about 5°C. It should be pointed out that this temperature difference does not represent the highest value of the temperature difference, reflecting that the heat pipe has poor temperature uniformity. Chinese patent 201110074375.9 proposes a double-sided channel plate-type pulsating heat pipe with parallel channels. The heat pipe is closed by a plate-type hollow shell inserted with periodic folded plates. The folded edges of the folded plate form multiple strips with the inner wall of the shell Pulse channel. During operation, the working fluid flows randomly in the channel with high-frequency impact to enhance heat transfer, and the shape is flat to facilitate contact with heat-dissipating objects. The strong heat dissipation capacity makes it suitable for heat dissipation and cooling of electronic components. However, the experimental research in Document 2 "Experimental Research on Heat Transfer Performance of Flat-plate Pulsating Heat Pipe" (Guangdong Chemical Industry, Vol. The tolerable heat flux is only 40W/cm ² , which is far from the heat flux of 100W/cm ² . Chinese patent 201110074384.8 proposes a single-sided corrugated plate pulsating heat pipe with parallel channels for cooling electronic components. The rectangular bottom plate of the heat pipe and the corrugated plate are bonded to form a series of pulsating channels, and then the two ends are closed through the connecting cavity. A plate-type pulsating heat pipe is formed. The corrugated plate not only increases the contact area with the air, but also makes the air turbulent, thereby enhancing the convective heat transfer on the air side. The movement and heat transfer behavior of the working fluid inside the heat pipe is similar to the aforementioned ZL201110074375.9, and the pipe also has a strong heat transfer capability. Literature 3 "Heat Transfer Performance of Flat Heat Pipe Based on Air Conditioning Energy Recovery" (Journal of Central South University, Vol. At 80°C and forced air cooling, the heat flux transmitted by the heat pipe is about 62.64W/cm ² , and the maximum temperature difference at the hot end is 5.7°C, which is still quite far from 100W/cm ² . The heat dissipation problem of the device, at the same time, the literature also shows that the cold end of the heat pipe will block the condensate and not return when the heating power is low, resulting in a sharp increase in the temperature of the hot end and a sharp drop in the temperature of the cold end, thereby greatly reducing the performance of the heat pipe.

The above situation shows that even if the parallel channel pulsating heat pipes with good heat dissipation effect are used, the actual heat dissipation effect is still not obvious. It can be expected that with the rapid improvement of the performance of components and devices in the future, their heat dissipation requirements will become more and more stringent. It can be seen that in order to achieve good heat dissipation for high heat flux components, it is necessary to understand the existing components in terms of structure and working principle. The breakthrough can only be achieved by comprehensive and thorough improvement of the parallel channel pulsating heat pipe.

For this reason, the inventor has conducted in-depth research and analysis on the working principle and structure of the current pulsating heat pipe with parallel channels, and found the following problems and deficiencies. 1. The equivalent diameter of the pulsation channel remains unchanged. In this case, the cold end has a stronger capillary effect and the fluidity of the working medium becomes poor. The working medium is especially prone to blockage when starting and low heating power, resulting in: ①The heat pipe cannot start smoothly , ② Difficulty in the return flow of the working medium and a good cycle cannot be established, resulting in abnormal operation of the heat pipe and a decrease in heat transfer capacity. 2. Each pulsating channel is a closed and independent channel, and the working fluid in the channel cannot exchange material between channels according to the difference and change of working conditions, which makes: ①It is difficult to eliminate the radial temperature difference between channels, resulting in uneven temperature uniformity at the hot end Good; ② There is no effective horizontal communication between the channels, which weakens the convective heat transfer capacity in the tube. 3. The traditional parallel channel plate pulsating heat pipe is a single-piece heat pipe. Due to the limitation of the heat dissipation area, its heat dissipation capacity cannot be large, and it is difficult to meet the cooling of high-power components.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, and propose a variable-diameter series and parallel connection with "plane heat transfer, excellent heat transfer performance, good temperature uniformity, small footprint, large heat dissipation area, simple and reliable". The channel plate type pulsating heat pipe is used for heat dissipation and cooling of high heat flux components, and provides assistance for the further development of technologies in the fields of electronics, microelectronics, and optoelectronics.

A variable-diameter series and parallel channel plate type pulsating heat pipe proposed by the present invention is realized through the following scheme:

A variable-diameter series, parallel channel plate type pulsating heat pipe, the variable diameter series, parallel channel plate type pulsating heat pipe includes a hot end 1, a cold end 2, an intermediate body 3, and a head 4, characterized in that: the hot end 1 is a rectangular flat plate with uniformly distributed equal-diameter hot-end passages 5 inside; the cold end 2 is a rectangular flat plate with uniformly distributed equal-diameter cold-end passages 6 inside; the equivalent diameter of the cold-end passage 6 is the equivalent diameter of the hot-end passage 5 1-10 times; one end of the hot end 1 is connected to one end of the cold end 2; or the hot end 1 and the cold end 2 are connected through an intermediate body 3, and a mixing chamber 10 is provided on the intermediate body 3.

The present invention is a variable-diameter serial and parallel channel plate type pulsating heat pipe, in which a balance hole 8 is provided on the partition wall of the adjacent hot end channel 5 in the hot end 1 and/or a balance hole 8 is provided on the partition wall of the adjacent cold end channel 6 in the cold end 2 Balance hole 9 is arranged.

The present invention is a variable-diameter series and parallel channel plate type pulsating heat pipe. One end of the intermediate body 3 is provided with a connection port connected to the hot end; the other end is provided with at least one connection port connected to the cold end. A cavity is provided in the middle, which constitutes a mixing chamber 10 .

The present invention is a variable-diameter series and parallel channel plate type pulsating heat pipe. One end of the hot end 1 is connected to the intermediate body 3, and the other end is provided with a sealing head 4, so that the uniformly distributed hot end channels 5 in the hot end 1 form a parallel structure; at least One end of a cold end 2 communicates with the intermediate body 3 , and the other end of the cold end 2 is provided with a head 4 , so that the uniformly distributed cold end channels 6 in the cold end 2 form a parallel structure. The number of cold ends 2 that can be connected to the intermediate body 3 is 1-5.

The present invention is a variable-diameter series and parallel channel plate type pulsating heat pipe. The length and width of the hot end 1 can be determined with reference to the size of the cooling object, but must be able to fully cover the cooling object; the hot end 1 and the cold end 2 The widths are equal, and the ratio of the length of the hot end to the total length of the cold end 2 is 0.1-1.0, preferably 0.2-0.67.

The present invention is a pulsating heat pipe with variable-diameter series and parallel channel plates. The equivalent diameter of the hot end channel 5 is 0.5-5mm, and the equivalent diameter of the cold-end channel 6 is 1-6mm, which meets the Bo number requirement and the working medium Can form a strong pulsating heat transfer effect in the channel.

The present invention is a variable-diameter serial and parallel channel plate type pulsating heat pipe. Balance holes 8 are arranged on the partition walls of the adjacent hot-end channels 5 in the hot-end 1 according to the pitch a, and the range of the pitch a is: 5mm≤a≤100mm; Balance holes 9 are arranged on the partition wall of the adjacent cold end channels 6 in the cold end 2 according to the pitch d, and the range of the pitch d is: 5mm≤d≤200mm; the balance holes 8 and 9 are used for the exchange of substances between the channels.

The present invention is a variable-diameter series and parallel channel plate type pulsating heat pipe. The equivalent diameter of the balance hole 8 at the hot end is 0.5-3.0 mm; the equivalent diameter of the balance hole 9 at the cold end is 0.8-4.5 mm.

The present invention is a variable-diameter serial and parallel channel plate type pulsating heat pipe. The axes of the balance holes arranged on the adjacent partition walls of the hot end channel 5 and the cold end channel 6 are coincident or misaligned.

The present invention is a variable-diameter serial and parallel channel plate type pulsating heat pipe. The length of the mixing chamber 10 provided in the intermediate body 3 is f: 3mm≤f≤100mm.

A variable-diameter serial and parallel channel plate type pulsating heat pipe, at least one surface of the rectangular plate at the cold end 2 is provided with a cooling fin 7 .

The cross-sectional shapes of the hot end 1 and the cold end 2 are parallelograms.

The cross-sectional shape of the hot end passage 5 and the cold end passage 6 is one of parallelogram, triangle, circle, ellipse, trapezoid and polygon.

The hot end 1 must be installed on top of the cold end 2 .

The metal material used in the variable-diameter series and parallel channel plate pulsating heat pipe is selected from one of carbon steel, stainless steel, aluminum alloy, and copper alloy.

The working medium of the variable diameter series and parallel channel plate pulsating heat pipe is selected from one of deionized distilled water, ethanol, acetone, ammonia water, methanol, R141b or a mixture thereof.

Technical effect of the present invention

The variable-diameter series and parallel channel plate type pulsating heat pipe proposed by the present invention is applied to the heat dissipation and cooling of high heat flux density electronics, microelectronics, and optoelectronic components, and has the following advantages and effects.

The variable-diameter series and parallel channel plate type pulsating heat pipe is composed of 5 parts: hot end, cold end, intermediate body, head and working medium, wherein: ① The hot end and the cold end are uniformly distributed equal-diameter pulsating grooves The radial partition of the channel is a flat plate with balance holes according to the pitch; ②The intermediate body is the cold and hot end connector with an unobstructed clearance mixing chamber; ③The head is the end closure of the heat pipe with a certain space. The movement of the working fluid of the heat pipe composed of the above five parts will have a great change compared with the existing technology, and at the same time, it will have a positive impact on the heat transfer process inside the heat pipe, and can significantly improve the heat transfer performance and temperature uniformity of the heat pipe. The basic situation As follows: ① Cold and hot end diameter reduction and its function. Specifically speaking, diameter reduction is to appropriately increase the equivalent diameter of the cold end and change the equivalent diameter ratio of the cold and hot ends. In order for the working fluid to appear a pulsating state with strong heat transfer ability in the channel, according to the surface tension and capillary principle, the channel diameter must meet the required range of Bo number, which makes the actual pipe diameter relatively small, such as cold and hot If the end pipe diameter cannot be changed, the lower temperature cold end may affect the fluidity of the working fluid due to the enhanced capillary action. This situation is more prominent in the stage of start-up or low heating power. At this time, the temperature of the cold end is very low, and the flow resistance of the working fluid is significantly increased due to the hysteresis of the capillary contact angle, which leads to the stagnation and blockage of the working fluid at the cold end, which seriously affects the The start-up and heat transfer cooling capacity of the heat pipe. Also according to the principle of capillary action, appropriately increasing the equivalent diameter of the cold end channel can effectively reduce the capillary resistance of the cold end, which is conducive to the convenient and timely return of the working fluid, and has a very positive effect on establishing a good circulation of the working fluid and improving the heat transfer capacity of the heat pipe. . ②The benefits brought by the intermediate body, first, use the mixing chamber to make the working fluid form a secondary parallel connection, that is, the parallel connection of the hot end and the parallel connection of the cold end. Temperature and heat dissipation capacity, and can evenly return the working fluid at the cold end, which helps to promote the establishment of a stable working condition. The second is that multiple cold-end connections can be realized, which provides a powerful method for increasing and adjusting the heat dissipation area. The third is that the intermediate body has brought many changes to the traditional parallel channel plate heat pipe. For example, the integrated cold and hot ends can be separated, the continuous channel can be disconnected, and a single hot end can be configured with multiple cold ends. The performance of the pulsating heat pipe offers ample possibilities. ③There are several functions of the balance hole. First, when the temperature and pressure in a certain part of the channel are high, the working fluid can enter the adjacent channel through the balance hole in the form of pulse or jet, and form a horizontal series structure, so that the adjacent The material and temperature between the channels are more balanced, which is especially beneficial to solve and eliminate the temperature unevenness in the radial direction of the hot end. Second, the random impact of the working fluid in the radial direction changes the heat and mass transfer in the tube from two-dimensional heat and mass exchange. Three-dimensional, which greatly enhances the heat transfer in the tube. Third, the balance holes in adjacent channels can be misplaced, and changing the misalignment can optimize and adjust the flow and heat transfer in the tank;

In summary. The content of the present invention has obvious innovative changes in terms of structure and heat transfer mechanism, is effective and conforms to physical theory. The present invention achieves all-round satisfaction in view of the heat dissipation principle requirements of components with high heat flux density. Its application in high heat flux components will definitely help the heat dissipation and cooling of these devices, and will play a positive role in promoting the development and progress of electronics, microelectronics, optoelectronic components and their corresponding fields.

Description of drawings

Accompanying drawing 1 Embodiment 1 is a front view of a variable-diameter serial and parallel channel plate pulsating heat pipe with single cold end.

Accompanying drawing 2 is the sectional view of accompanying drawing 1.

Accompanying drawing 3 is the hot end sectional view of accompanying drawing 1.

Accompanying drawing 4 is the cold end sectional view of accompanying drawing 1.

Accompanying drawing 5 is the structural diagram of the type I intermediate of accompanying drawing 1.

Accompanying drawing 6 is the head structure diagram of accompanying drawing 1.

Accompanying drawing 7 is the front view of a variable-diameter serial and parallel channel plate type pulsating heat pipe with dual cold ends in embodiment 2.

Accompanying drawing 8 is the structure diagram of type II intermediate of accompanying drawing 7.

Accompanying drawing 9 is the front view of a variable-diameter serial and parallel channel plate type pulsating heat pipe in embodiment 3 of the third cold end.

Accompanying drawing 10 is the structure diagram of type III intermediate in accompanying drawing 9.

In the figure: 1-hot end, 2-cold end, 3-intermediate body, 4-head, 5-hot end channel, 6-cold end channel, 7-radiating fin, 8-hot end balance hole, 9- Cold end balance hole, 10-mixing chamber.

Each specific embodiment will be described below in conjunction with the accompanying drawings. The examples are only for illustrating the present invention and are not intended to limit the scope of the present invention. Various modifications to the present invention made by those skilled in the art after reading the content of the present invention also belong to the scope of the appended claims of the present invention.

Embodiment one

Referring to accompanying drawings 1, 2, 3, 4, 5, 6, the variable-diameter series and parallel channel plate pulsating heat pipes include one of the hot ends 1, one of the cold ends 2, and one of the Type I intermediate body 3, two heads 4, characterized in that: the hot end 1 is a rectangular flat plate with uniformly distributed equal-diameter hot-end channels 5 inside; the cold end 2 is a uniformly distributed internally equal-diameter cold end The channel 6 is a rectangular plate; the equivalent diameter of the channel 6 at the cold end is 2.67 times the equivalent diameter of the channel 5 at the hot end; the hot end 1 and the cold end 2 are connected through the intermediate body 3 .

A balance hole 8 is provided on the partition wall of the adjacent hot end channel 5 in the hot end 1 , and a balance hole 9 is provided on the partition wall of the adjacent cold end channel 6 in the cold end 2 .

One end of the hot end 1 is connected to the intermediate body 3, and the other end is provided with a head 4, so that the uniformly distributed hot end channels 5 in the hot end 1 form a parallel structure; one end of the cold end 2 communicates with the intermediate body 3, and the cold end The other end of the end 2 is provided with a sealing head 4, so that the evenly distributed cold end channels 6 in the cold end 2 form a parallel structure.

A mixing chamber 10 is provided on the intermediate body 3 connected between the hot end 1 and the cold end 2 .

The width of the hot end 1 and the cold end 2 are equal, and the ratio of the length of the hot end to the total length of the cold end 2 is 0.67.

The equivalent diameter of the hot-end channel 5 is 1.5 mm, and the equivalent diameter of the cold-end channel 6 is 4 mm, which meets the Bo number requirement, and the working fluid can form a strong pulsating heat transfer effect in the channel.

Balance holes 8 are set on the partition wall of the adjacent hot end channel 5 in the hot end 1 according to the pitch a, and the pitch a=10mm; balance holes are set on the partition wall of the adjacent cold end channel 6 in the cold end 2 according to the pitch d 9. The pitch d=10mm; the balance holes 8 and 9 are used for the exchange of substances between the channels.

The equivalent diameter of the balance hole 8 at the hot end is 1.7 mm; the equivalent diameter of the balance hole 9 at the cold end is 1.7 mm.

The axes of the balance holes provided on the adjacent partition walls of the hot end channel 5 and the cold end channel 6 are coincident.

The length f of the mixing chamber 10 provided by the intermediate body 3 is 5 mm.

The two surfaces of the rectangular plate of the cold end 2 are provided with cooling fins 7 .

The cross-sectional shapes of the hot end 1 and the cold end 2 are rectangular.

The cross-sectional shapes of the hot end channel 5 and the cold end channel 6 are rectangular.

The hot end 1 must be installed above the cold end 2 to ensure the return flow of working fluid.

The metal material used in the variable-diameter series and parallel channel plate pulsating heat pipe is stainless steel.

The working fluid of the variable-diameter series and parallel channel plate pulsating heat pipe is deionized distilled water.

Embodiment 1 is the simplest form of a variable-diameter series and parallel channel plate pulsating heat pipe, which is reliable in operation and easy to install and process, and is suitable for high heat flux components with slightly lower heating power.

Embodiment two

Referring to accompanying drawings 3, 4, 6, 7, and 8, the variable-diameter series and parallel channel plate pulsating heat pipes include one hot end 1, two cold ends 2, and one type II heat pipe. The intermediate body 3 and the three heads 4 are characterized in that: the hot end 1 is a rectangular flat plate with uniformly distributed equal-diameter hot-end channels 5 inside; the cold end 2 is an internally uniformly distributed equal-diameter cold-end channel 6 The equivalent diameter of the channel 6 at the cold end is 1.67 times the equivalent diameter of the channel 5 at the hot end; the hot end 1 and the cold end 2 are connected through the intermediate body 3 .

A balance hole 8 is provided on the partition wall of the adjacent hot end channel 5 in the hot end 1 , and a balance hole 9 is provided on the partition wall of the adjacent cold end channel 6 in the cold end 2 .

One end of the hot end 1 is connected to the intermediate body 3, and the other end is provided with a head 4, so that the uniformly distributed hot end channels 5 in the hot end 1 form a parallel structure; one end of the cold end 2 communicates with the intermediate body 3, and the cold end The other end of the end 2 is provided with a sealing head 4, so that the evenly distributed cold end channels 6 in the cold end 2 form a parallel structure.

A mixing chamber 10 is provided on the intermediate body 3 connected between the hot end 1 and the cold end 2 .

The width of the hot end 1 and the cold end 2 are equal, and the ratio of the length of the hot end to the total length of the cold end 2 is 0.6.

The equivalent diameter of the hot-end channel 5 is 2.1 mm, and the equivalent diameter of the cold-end channel 6 is 3.7 mm, which meets the Bo number requirement, and the working fluid can form a strong pulsating heat transfer effect in the channel.

Balance holes 8 are set on the partition wall of the adjacent hot end channel 5 in the hot end 1 according to the pitch a, and the pitch a=15mm; balance holes are set on the partition wall of the adjacent cold end channel 6 in the cold end 2 according to the pitch d 9. The pitch d=20mm; the balance holes 8 and 9 are used for the exchange of substances between the channels.

The equivalent diameter of the balance hole 8 at the hot end is 2 mm; the equivalent diameter of the balance hole 9 at the cold end is 2.3 mm.

The axes of the balance holes provided on the adjacent partition walls of the hot-end channel 5 and the cold-end channel 6 have offsets of distances b and e, where b=7.5mm and e=10mm.

The length f of the mixing chamber 10 provided by the intermediate body 3 is 7mm.

The two surfaces of the rectangular plate of the cold end 2 are provided with cooling fins 7 .

The cross-sectional shapes of the hot end 1 and the cold end 2 are rectangular.

The cross-sectional shapes of the hot end channel 5 and the cold end channel 6 are rectangular.

The hot end 1 must be installed above the cold end 2 to ensure the return flow of working fluid.

The metal material used in the variable-diameter series and parallel channel plate pulsating heat pipe is copper alloy.

The working fluid of the variable-diameter series and parallel channel plate pulsating heat pipe is acetone.

Embodiment 2 is a form of two cold ends of variable-diameter series and parallel channel plate pulsating heat pipes, which is moderately difficult to manufacture and can be used for high heat flux components with relatively large heating power.

Embodiment Three

Referring to accompanying drawings 3, 4, 6, 9, and 10, the variable-diameter series and parallel channel plate type pulsating heat pipe includes 1 of the hot ends 1, 3 of the cold ends 2, and 1 of the type III The intermediate body 3 and four said heads 4 are characterized in that: the hot end 1 is a rectangular flat plate with uniformly distributed equal-diameter hot-end channels 5 inside; the cold end 2 is an internally uniformly distributed equal-diameter cold-end channel 6 The equivalent diameter of the channel 6 at the cold end is 1.13 times the equivalent diameter of the channel 5 at the hot end; the hot end 1 and the cold end 2 are connected through the intermediate body 3 .

A balance hole 8 is provided on the partition wall of the adjacent hot end channel 5 in the hot end 1 , and a balance hole 9 is provided on the partition wall of the adjacent cold end channel 6 in the cold end 2 .

One end of the hot end 1 is connected to the intermediate body 3, and the other end is provided with a head 4, so that the uniformly distributed hot end channels 5 in the hot end 1 form a parallel structure; one end of the cold end 2 communicates with the intermediate body 3, and the cold end The other end of the end 2 is provided with a head 4, so that the evenly distributed cold end channels 6 in the cold end 2 form a parallel structure.

A mixing chamber 10 is provided on the intermediate body 3 connected between the hot end 1 and the cold end 2 .

The width of the hot end 1 and the cold end 2 are equal, and the ratio of the length of the hot end to the total length of the cold end 2 is 0.5.

The equivalent diameter of the hot-end channel 5 is 3.1 mm, and the equivalent diameter of the cold-end channel 6 is 3.5 mm, which meet the Bo number requirement, and the working fluid can form a strong pulsating heat transfer effect in the channel.

Balance holes 8 are set on the partition wall of the adjacent hot end channel 5 in the hot end 1 according to the pitch a, and the pitch a=20mm; balance holes are set on the partition wall of the adjacent cold end channel 6 in the cold end 2 according to the pitch d 9. The pitch d=30mm; the balance holes 8 and 9 are used for the exchange of substances between the channels.

The equivalent diameter of the balance hole 8 at the hot end is 1.8 mm; the equivalent diameter of the balance hole 9 at the cold end is 2.5 mm.

The axes of the balance holes provided on the adjacent partition walls of the hot-end channel 5 and the cold-end channel 6 have offsets of distances b and e, where b=7.5mm and e=15mm.

The length f of the mixing chamber 10 provided by the intermediate body 3 is 20 mm.

The two surfaces of the rectangular plate of the cold end 2 are provided with cooling fins 7 .

The cross-sectional shapes of the hot end 1 and the cold end 2 are rectangular.

The cross-sectional shapes of the hot end channel 5 and the cold end channel 6 are rectangular.

The hot end 1 must be installed above the cold end 2 to ensure the return flow of working fluid.

The metal material used in the variable diameter series and parallel channel plate type pulsating heat pipe is aluminum alloy.

The working fluid of the variable-diameter series and parallel channel plate pulsating heat pipe is ethanol.

Embodiment 3 is a form of three cold ends of variable-diameter series and parallel channel plate pulsating heat pipes, which is slightly more difficult to manufacture, but can be used for high heat flux components with large heating power.

In order to test the heat dissipation effect of the heat pipe of this scheme, the inventor designed and manufactured a simple test piece:

The heat pipe in Example 1 was tested on the cooling condition of a plane heating body. The material of the heat pipe was stainless steel, and only a balance hole was opened at the hot end. Under the condition of temperature control of 85°C and natural air cooling, the measured The maximum heat flux density that the heat pipe specimen can withstand is 62.7W/cm ² , and the temperature deviation of the hot end is 3.2°C, achieving a better cooling effect than the traditional parallel channels.

The heat pipe in Example 2 was tested on the cooling of a plane heating body. The material of the heat pipe was aluminum, and the cooling method was changed to water cooling. The maximum heat flux that the heat pipe specimen could bear was 150W when the temperature was controlled at 85°C. /cm ² , the temperature deviation of the hot end is 2.3°C, and the cooling effect is much better than that of the traditional parallel channels.

Claims (10)

1. a kind of reducing series and parallel conduit plate type pulsating heat pipe, the reducing series and parallel conduit plate type pulsating heat pipe includes heat End, cold end, end socket, it is characterised in that：The hot junction is the rectangular flat of internal uniform isometrical hot junction passage；The cold end is interior The rectangular flat of the uniform isometrical cold end passage in portion；The equivalent diameter of the cold end passage is the 1-10 of hot junction passage equivalent diameter Times；The one end in the hot junction is connected with one end of cold end；Or the hot junction is connected with cold end by intermediate, is set on intermediate There is a hybrid chamber.

2. a kind of reducing series and parallel conduit plate type pulsating heat pipe according to claim 1, it is characterised in that：Phase in hot junction 1 The partition that the partition of adjacent hot junction passage is provided with adjacent cold ends passage in balance pipe and/or cold end is provided with balance pipe.

3. a kind of reducing series and parallel conduit plate type pulsating heat pipe according to claim 1, it is characterised in that：The centre Body one end is provided with a connector being connected with hot junction；The other end is provided with least one connector being connected with cold end, intermediate Middle part be provided with cavity, the cavity constitute hybrid chamber.

4. a kind of reducing series and parallel conduit plate type pulsating heat pipe according to claim 3, it is characterised in that：Hot junction one end It is connected with intermediate, the other end is provided with end socket, uniform hot junction passage in hot junction is formed parallel-connection structure；One end of cold end is with Mesosome is connected, and the other end of cold end is provided with end socket, uniform cold end passage in cold end is formed parallel-connection structure.

5. a kind of reducing series and parallel conduit plate type pulsating heat pipe according to claim 3, it is characterised in that：The centre The length of the hybrid chamber that body is set is f：3mm≤f≤100mm.

6. a kind of reducing series and parallel conduit plate type pulsating heat pipe according to claim 5, it is characterised in that：The hot junction Width with the cold end is equal, the hot end length and the total length of the cold end the ratio between for 0.1~1.0, preferably 0.2~ 0.67。

7. a kind of reducing series and parallel conduit plate type pulsating heat pipe according to claim 1, it is characterised in that：The hot junction The equivalent diameter of passage is 0.5~5mm, and the equivalent diameter of the cold end passage is 1~6mm.

8. a kind of reducing series and parallel conduit plate type pulsating heat pipe according to claim 2, it is characterised in that：Phase in hot junction Balance pipe is set by pitch a on the partition of adjacent hot junction passage, the scope of pitch a is：5mm≤a≤100mm；It is adjacent cold in cold end Hold and balance pipe is set by pitch d on the partition of passage, the scope of pitch d is：5mm≤d≤200mm；The equivalent of hot junction balance pipe A diameter of 0.5~3.0mm；The equivalent diameter of cold end balance pipe is 0.8~4.5mm.

9. a kind of reducing series and parallel conduit plate type pulsating heat pipe according to claim 8, it is characterised in that：It is logical in hot junction The axis of the balance pipe set in road, the adjacent partitions of cold end passage overlaps or misplaces.

10. a kind of reducing series and parallel conduit plate type pulsating heat pipe according to claim 1-9 any one, its feature exists In：At least one surface of the rectangular flat of the cold end is provided with radiating fin.