High-power LED heat dissipation device cooperating with illumination light source direction change

Abstract

The invention relates to the technical field of electronic component heat dissipation, in particular to a high-power LED heat dissipation device cooperating with lighting source direction change, which comprises pulsating heat plates and pulsating heat pipes, the pulsating heat pipes are arranged in the center of the LED heat dissipation device, the pulsating heat plates are radially arranged around the pulsating heat pipes, and the pulsating heat pipes are arranged in the pulsating heat plates. The pulsating heat plate and the pulsating heat pipe are communicated with each other through the upper vapor-liquid cavity and the lower vapor-liquid cavity, and vapor-liquid working media in the pulsating heat pipe, the pulsating heat plate, the upper vapor-liquid cavity and the lower vapor-liquid cavity are communicated with each other. The pulsating heat pipe structure, the pulsating heat plate structure and the vapor-liquid cavity structure are combined together, the heat transfer performance of the pulsating heat pipe can be improved, the phase change heat transfer area of the LED heat dissipation device and the heat transfer temperature difference between the LED heat dissipation device and air can be increased, the problem of continuous drying-out of an evaporation section of the pulsating heat pipe under the working conditions of high heat flow density and severe heat transfer is effectively solved, and the service life of the pulsating heat pipe is prolonged. The heat dissipation requirements of the LED in different light source directions are met, and the use places of the LED are further widened.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic component heat dissipation, in particular to a high-power LED heat dissipation device cooperating with the direction change of a lighting source. BACKGROUND

[0002] LEDs have been widely used in lighting, backlight, automotive and other fields due to their low energy consumption, small size, long service life, high light efficiency, fast response speed and other advantages. However, the current market LEDs generally have low photoelectric conversion efficiency (about 30%) and high junction temperature due to heat accumulation, which directly affects their light emitting effect and service life. At the same time, considering the diversity of LED use places, it is particularly important to achieve sufficient heat dissipation of LEDs in different light source directions, which also poses new challenges for the design of LED heat sinks.

[0003] Currently, the market LED heat sinks mainly use gravity heat pipes and heat dissipation fins or vapor-liquid cavities and heat dissipation fins. Both of them use the phase change of the working medium for heat transfer, but there are still significant defects in actual application: on the one hand, the heat dissipation fin part has a gradually decreasing temperature along the height direction of the fin, which restricts the overall structure heat dissipation performance; on the other hand, the heat dissipation performance of the vapor-liquid cavity structure is extremely sensitive to the inclination angle, and the gravity heat pipe is prone to dryout phenomenon in the evaporation section at a specific inclination angle, which seriously affects the stability of heat dissipation. SUMMARY

[0004] In order to overcome the shortcomings of the prior art, the present application provides a high-power LED heat dissipation device cooperating with the direction change of a lighting source, which uses a new heat dissipation structure combining pulsating heat pipes, pulsating heat plates and vapor-liquid cavities, can significantly improve the heat transfer performance of the pulsating heat pipe and the phase change heat transfer area of the LED heat dissipation device, and at the same time meet the heat dissipation needs of LEDs in different light source directions, further widening the use places of LEDs.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows: A high-power LED heat dissipation device cooperating with the direction change of a lighting source, comprising a pulsating heat plate and a pulsating heat pipe, the pulsating heat pipe is arranged at the center of the LED heat dissipation device, the pulsating heat plate is arranged radially around the pulsating heat pipe, and the pulsating heat plate and the pulsating heat pipe are in communication through an upper vapor-liquid cavity and a lower vapor-liquid cavity, and the vapor-liquid working medium in the pulsating heat pipe, the pulsating heat plate and the upper and lower vapor-liquid cavities flows through each other.

[0006] Further, the center of the upper vapor-liquid cavity is installed with an LED light source substrate through a screw, and the LED light source substrate is installed with an LED light source, and the light source direction of the LED light source changes within a 2π solid angle range with the whole heat dissipation device.

[0007] Further, the center part of the upper vapor-liquid cavity is a rectangular solid structure, and the periphery is a ring-shaped hollow structure, a Tesla valve channel is formed in the rectangular solid structure, two Tesla valve channels at both sides are connected with the ring-shaped hollow structure at one end, and the ring-shaped hollow structure has a channel at one end face connected with the pulsating heat plate. The inside of the lower vapor-liquid cavity is a cylindrical hollow structure, and the cylindrical hollow structure has a channel at one end face connected with the pulsating heat plate. The inside diameters of the upper vapor-liquid cavity and the lower vapor-liquid cavity are all less than or equal to 4 mm.

[0008] Further, the pulsating heat pipe comprises a pulsating heat pipe evaporation section and a pulsating heat pipe condensation section, the pulsating heat pipe evaporation section is composed of the Tesla valve channel in the rectangular solid structure in the upper vapor-liquid cavity, and the pulsating heat pipe condensation section is composed of a plurality of U-shaped circular pipes, the inside diameter of the circular pipe is less than or equal to 6 mm, the circular pipes at the same end of the Tesla valve channel are connected with each other, and the pulsating heat pipe condensation section is arranged with a connecting pipe for connecting the Tesla valve channel and the lower vapor-liquid cavity.

[0009] Further, the Tesla valve channel is composed of a Tesla valve main pipe and a plurality of Tesla valve branch pipes, the Tesla valve branch pipes are arranged staggered at both sides of the Tesla valve main pipe, and each Tesla valve branch pipe is tangentially connected with the Tesla valve main pipe. The Tesla valve main pipe is a continuously variable diameter structure, and the equivalent diameters of the Tesla valve branch pipes and the Tesla valve main pipe are all less than or equal to 6 mm.

[0010] It is worth noting that, before use, the whole LED heat dissipation device needs to be vacuumized, and then a certain amount of working medium is filled and packaged. On the premise of not affecting the heat dissipation effect of the pulsating heat pipe condensation section, the more the pulsating heat plate structures are, the better.

[0011] The pulsating heat pipe, the pulsating heat plate and the vapor-liquid cavity structure with high heat dissipation characteristics are reasonably combined together, the vapor-liquid working medium flows between the three, the heat dissipation area of the phase change heat transfer is greatly increased, the heat transfer temperature difference between the heat dissipation component and the air is improved, and the heat dissipation effect is further enhanced compared with the traditional radiator structure.

[0012] The evaporation section of the pulsating heat pipe is designed as a Tesla valve structure, which can promote the circulation flow of the working medium in the pulsating heat pipe, and at the same time, the pressure difference formed by the circulation flow of the vapor-liquid in the pulsating heat pipe can promote the liquid working medium to flow into the pulsating heat pipe from the vapor-liquid cavity, reduce the occurrence of the "dry burning" phenomenon of the pulsating heat pipe evaporation section, and enhance the heat transfer performance of the pulsating heat pipe.

[0013] The application breaks through the influence of the heat source position on the heat transfer performance of the pulsating heat pipe, so that the LED heat dissipation structure still has good heat dissipation performance when the direction of the LED light source changes, and the application market prospect of the LED is widened. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 The whole structure schematic diagram of the high-power LED heat dissipation device which cooperates with the direction change of the lighting source for the embodiment of the present application; Figure 2 The upper liquid cavity cross section schematic diagram of the present application; Figure 3 The lower liquid cavity cross section schematic diagram of the present application; Figure 4 The connection schematic diagram of the pulsating heat plate and the upper liquid cavity and the lower liquid cavity of the present application; Figure 5 The internal fluid passage structure schematic diagram of the high-power LED heat dissipation device which cooperates with the direction change of the lighting source for the embodiment of the present application; Figure 6 The whole structure schematic diagram of the Tesla valve pulsating heat pipe of the present application; Figure 7 The detailed structure schematic diagram of the Tesla valve pulsating heat pipe of the present application; Figure 8 The Tesla valve structure schematic diagram of the present application.

[0015] In the figure: 1, LED light source substrate; 2, upper liquid cavity; 3, lower liquid cavity; 4, pulsating heat plate; 5, pulsating heat pipe; 5-1, pulsating heat pipe evaporation section; 5-2, pulsating heat pipe condensation section; 5-2-1, pulsating heat pipe condensation section connecting pipe; 6, screw; 7, Tesla valve channel; 7-1, Tesla valve main pipe; 7-2, Tesla valve branch pipe; 8, connecting port A; 9, connecting port B; 10, connecting port C; 11, connecting port D; 12, forward flow inlet; 13, reverse flow inlet. DETAILED DESCRIPTION

[0016] The present application will be described in detail below with specific embodiments. The following embodiments will help the person skilled in the art to further understand the present application, but do not limit the present application in any form. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0017] In order to effectively solve the problem of continuous "dry burning" of the evaporation section of the pulsating heat pipe under high heat flux density and severe heat transfer conditions, meet the heat dissipation needs of the LED in different light source directions, and further expand the use of the LED, the present application fully considers the advantages of the pulsating heat pipe, such as simple structure, flexible arrangement, good heat transfer performance, and small gravity influence, introduces the pulsating heat plate structure (invention patent with publication number CN117423796B) previously researched as the heat dissipation fin of the LED heat dissipation device, adds a Tesla valve structure to the evaporation section of the introduced pulsating heat pipe structure to promote the circulation flow of the working medium in the pulsating heat pipe, simultaneously, introduces a vapor-liquid cavity to make the pulsating heat pipe and the pulsating heat plate communicate, so as to improve the heat transfer performance of the pulsating heat pipe and the phase change heat transfer area of the LED heat dissipation device, and meet the heat dissipation needs of the LED in different light source directions. Specifically, the present application provides a high-power LED heat dissipation device cooperating with the change of the light source direction, which comprises a pulsating heat plate 4 and a pulsating heat pipe 5, the pulsating heat pipe 5 is arranged at the center of the LED heat dissipation device, the pulsating heat plate 4 is arranged around the pulsating heat pipe 5 in a radial manner, the pulsating heat plate 4 and the pulsating heat pipe 5 are interconnected through an upper vapor-liquid cavity 2 and a lower vapor-liquid cavity 3, and the vapor-liquid working medium in the pulsating heat pipe 5, the pulsating heat plate 4, the upper vapor-liquid cavity 2 and the lower vapor-liquid cavity 3 can flow to each other. The center of the upper vapor-liquid cavity 2 is fixedly installed with an LED light source substrate 1 through a screw 6, the LED light source is installed on the LED light source substrate 1, and the light source direction of the LED can be changed in a 2π solid angle range along the whole heat dissipation device.

[0018] The periphery of the upper vapor-liquid cavity 2 is an annular hollow structure, the center part is a rectangular solid structure, a Tesla valve channel 7 is processed in the rectangular solid structure, and one end of the two Tesla valve channels 7 located on the two sides is communicated with the annular hollow structure in the upper vapor-liquid cavity 2. The inside of the lower vapor-liquid cavity 3 is a cylindrical hollow structure, and the lower end surface of the annular hollow structure and the upper end surface of the cylindrical hollow structure are both provided with a passage communicated with the pulsating heat plate 4, that is, the annular hollow structure and the cylindrical hollow structure are communicated through the pulsating heat plate 4. The inner diameters of the inner cavities of the upper vapor-liquid cavity 2 and the lower vapor-liquid cavity 3 are all ≤4mm.

[0019] The pulsating heat pipe 5 comprises a pulsating heat pipe evaporation section 5-1 and a pulsating heat pipe condensation section 5-2, the pulsating heat pipe evaporation section 5-1 is composed of the Tesla valve channel 7 in the rectangular solid structure in the upper vapor-liquid cavity 2; the pulsating heat pipe condensation section 5-2 is composed of a plurality of U-shaped arranged circular pipes, the inner diameter of the circular pipe is ≤6mm, the circular pipes located at the same end of the Tesla valve channel 7 are communicated with each other, and the pulsating heat pipe condensation section 5-2 is arranged with a pulsating heat pipe condensation section connecting pipe 5-2-1 for connecting the Tesla valve channel 7 and the lower vapor-liquid cavity 3.

[0020] The Tesla valve branch pipes 7-2 on both sides of the Tesla valve channel 7 are staggered, and the Tesla valve branch pipes 7-2 are tangent to the Tesla valve main pipe 7-1, and the equivalent diameters of the Tesla valve branch pipes 7-2 and the Tesla valve main pipe 7-1 are all less than or equal to 6 mm, and the Tesla valve main pipe 7-1 forms a continuous variable diameter structure due to the staggered arrangement of the Tesla valve branch pipes 7-2 on both sides, which helps to promote the circulation of the working medium.

[0021] The Tesla valve channel 7 of the pulsating heat pipe evaporation section 5-1 can promote the circulation of the working medium, specifically, when the working medium flows into the Tesla valve channel 7 from the forward flow inlet 12, most of the working medium will flow along the Tesla valve main pipe 7-1, and only a small amount of working medium will enter the Tesla valve branch pipes 7-2 on both sides, at this time, the flow pressure drop of the working medium is small, and the flow efficiency is close to that of ordinary straight pipes; when the working medium flows into the Tesla valve channel 7 from the reverse flow inlet 13, the bifurcated structure of the Tesla valve channel 7 will force the fluid to repeatedly turn and collide, and each bifurcation will cause kinetic energy loss, at this time, the working medium flow has a large flow resistance.

[0022] The Tesla valve channel 7 is introduced in the pulsating heat pipe evaporation section 5-1, the heat generated by the LED is transmitted to the Tesla valve channel 7 through the heat-conducting silicone grease, the working medium in the Tesla valve channel 7 absorbs heat to generate bubbles, and the bubbles will flow in the direction with smaller resistance in the Tesla valve channel 7, thereby pushing the working medium to flow into the pulsating heat pipe condensation section 5-2, realizing the heat transfer to the pulsating heat pipe condensation section 5-2, and at the same time, due to the opposite directions of the adjacent Tesla valve channels 7, there will be obvious upflow pipes and downflow pipes in the pipes on both sides of the bend of the pulsating heat pipe condensation section 5-2, thereby promoting the circulation of the working medium in the pulsating heat pipe 5.

[0023] When the LED light source direction is downward (the upper vapor-liquid cavity 2 is below, and the lower vapor-liquid cavity 3 is above), due to the effect of gravity, compared with the lower vapor-liquid cavity 3, the liquid working medium is mainly located in the upper vapor-liquid cavity 2. At this time, the LED installed at the pulsating heat pipe evaporation section 5-2 generates heat, and the pulsating heat pipe 5 starts to circulate and flow to transfer heat under the action of the Tesla valve channel 7. The circulation of the working medium in the pulsating heat pipe 5 causes a certain pressure difference between the pulsating heat pipe 5 and the upper vapor-liquid cavity 2. The pressure difference promotes the liquid working medium in the upper vapor-liquid cavity 2 to enter the pulsating heat pipe 5 through the connecting port B9 to circulate and flow to transfer heat. Finally, the vapor-liquid working medium flows back to the upper vapor-liquid cavity 2 through the connecting port A8, and the gas bubbles that are not completely condensed further rise to the lower vapor-liquid cavity 3 through the pulsating heat plate 4 structure after entering the upper vapor-liquid cavity 2 through the connecting port A8. The vapor working medium is condensed into liquid when moving to the pulsating heat plate 4 structure and the lower vapor-liquid cavity 3 structure, and flows back to the upper vapor-liquid cavity 2 along the pulsating heat plate 4 structure, and finally reflows into the pulsating heat pipe 5 through the connecting port B9. The heat generated by the LED is finally dissipated through the pulsating heat pipe condensing section 5-2, the pulsating heat plate 4 structure and the lower vapor-liquid cavity 3 structure.

[0024] When the LED light source direction is upward (the upper vapor-liquid cavity 2 is above, and the lower vapor-liquid cavity 3 is below), due to the effect of gravity, compared with the upper vapor-liquid cavity 2, the liquid working medium is mainly located in the lower vapor-liquid cavity 3. When the LED installed at the pulsating heat pipe evaporation section 5-1 generates heat, the pulsating heat pipe 5 starts to circulate and flow to transfer heat under the action of the Tesla valve channel 7. At this time, the working medium in the upper vapor-liquid cavity 2 enters the pulsating heat pipe 5 from the connecting port B9, and the working medium completes heat transfer in the pulsating heat pipe 5 and reflows into the upper vapor-liquid cavity 2 from the connecting port A8. The vapor working medium entering the upper vapor-liquid cavity 2 further moves to the pulsating heat plate 4 to transfer heat. It is worth noting that at this time, due to the different flow rates of the working medium, a certain pressure difference is caused between the two ends of the pulsating heat pipe condensing section connecting pipe 5-2-1. The pressure difference promotes the liquid working medium in the lower vapor-liquid cavity 3 to flow from the connecting port D11 to the connecting port C10. The liquid working medium further flows into the Tesla valve channel 7 from the connecting port C10. When the liquid working medium flows from the connecting port C10 to the connecting port B9, it has a large flow resistance, thereby promoting the liquid working medium to flow into the pulsating heat pipe 5 and participate in the circulation and flow heat transfer process, rather than directly flowing into the upper vapor-liquid cavity 2. It is worth noting that the circulation of the working medium in the pulsating heat pipe 5 and the process of the liquid working medium flowing from the lower vapor-liquid cavity 3 into the pulsating heat pipe 5 in the present application effectively solve the problem of continuous "dry burning" of the pulsating heat pipe evaporation section 5-1 of the pulsating heat pipe 5 under high heat flux density conditions.

[0025] It should be noted that when the LED light source is horizontal, in order to ensure that the liquid working medium can always flow into the pulsating heat pipe 5 structure from the connecting port B9 or the connecting port C10, the selection of the liquid filling rate of the LED heat dissipation device needs to meet that the connecting port B9 located at the upper vapor-liquid cavity 2 or the connecting port D11 located at the lower vapor-liquid cavity 3 can be immersed by the liquid working medium.

[0026] The above shows and describes the basic principles, main features and advantages of the present application. It should be understood by those skilled in the art that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only preferred examples of the present application and are not intended to limit the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A high power LED heat sink device for cooperative illumination of directional changes in light sources, characterized by: The pulsating heat plate and the pulsating heat pipe are arranged in the center of the LED heat dissipation device, the pulsating heat plate is arranged around the pulsating heat pipe in a radial manner, and the pulsating heat plate and the pulsating heat pipe are in communication with each other through the upper vapor-liquid cavity and the lower vapor-liquid cavity, and the pulsating heat pipe, the pulsating heat plate, and the vapor-liquid working medium in the upper vapor-liquid cavity and the lower vapor-liquid cavity are in circulation with each other.

2. A high power LED heat sink device for cooperative illumination light source direction change as claimed in claim 1, characterized in that: An LED light source substrate is installed at the center of the upper vapor-liquid cavity, and an LED light source is installed on the LED light source substrate, and the light source direction of the LED light source changes within the range of 2π solid angle along the whole heat dissipation device.

3. A high power LED heat sink device for cooperative illumination light source direction change as claimed in claim 1, characterized in that: The center of the upper vapor-liquid cavity is a rectangular solid structure, and the periphery is a ring-shaped hollow structure, a Tesla valve channel is processed in the rectangular solid structure, both ends of the two Tesla valve channels on both sides are in communication with the ring-shaped hollow structure, and one end face of the ring-shaped hollow structure is in communication with the pulsating heat plate through a channel.

4. A high power LED heat sink device for cooperative illumination light source direction change as claimed in claim 1, characterized in that: The inside of the lower vapor-liquid cavity is a cylindrical hollow structure, and one end face of the cylindrical hollow structure is in communication with the pulsating heat plate through a channel.

5. A high power LED heat sink device for cooperative illumination light source direction change as claimed in claim 1, characterized in that: The inner diameters of the inner cavities of the upper vapor-liquid cavity and the lower vapor-liquid cavity are all ≤4mm.

6. A high power LED heat sink device for cooperative illumination light source direction change as claimed in claim 1, characterized in that: The pulsating heat pipe comprises a pulsating heat pipe evaporation section and a pulsating heat pipe condensation section, the pulsating heat pipe evaporation section is composed of the Tesla valve channel in the rectangular solid structure in the upper vapor-liquid cavity, the pulsating heat pipe condensation section is composed of a plurality of U-shaped arranged circular pipelines, the inner diameter of the circular pipeline is ≤6mm, the circular pipelines at the same end of the Tesla valve channel are in communication with each other, and a connecting pipe for connecting the Tesla valve channel and the lower vapor-liquid cavity is arranged in the pulsating heat pipe condensation section.

7. A high power LED heat sink device for cooperating with a light source to change the direction of the light source, as recited in claim 3, wherein: the plurality of fins are arranged in a plurality of rows; and the plurality of rows are arranged in a plurality of columns. The Tesla valve channel is composed of a Tesla valve main pipe and a plurality of Tesla valve branch pipes, the Tesla valve branch pipes are arranged on both sides of the Tesla valve main pipe in a staggered manner, and each Tesla valve branch pipe is tangent to the Tesla valve main pipe.

8. A high power LED heat sink device for cooperating with a directional change of a light source, as recited in claim 7, wherein: The Tesla valve main pipe is a continuously variable diameter structure, and the equivalent diameters of the Tesla valve branch pipes and the Tesla valve main pipe are all ≤6mm.

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