CN111720805A

CN111720805A - High-power LED lamp heat abstractor

Info

Publication number: CN111720805A
Application number: CN202010692074.1A
Authority: CN
Inventors: 刘向东; 韩笑天; 陈永平; 徐德好
Original assignee: Nanjing Acme Thermal Energy Technology Co ltd; Yangzhou University
Current assignee: Nanjing Acme Thermal Energy Technology Co ltd; Yangzhou University
Priority date: 2020-07-17
Filing date: 2020-07-17
Publication date: 2020-09-29
Anticipated expiration: 2040-07-17
Also published as: CN111720805B

Abstract

A high-power LED lamp heat dissipation device belongs to the technical field of LED heat dissipation, and comprises an upper lampshade, a circuit board, a heat dissipation fan, a ribbed shell, a gas-liquid pulsating phase-change heat pipe, a mounting base, an LED lamp bead integrated board, a lower lampshade and a glass cover plate, wherein the device takes the gas-liquid pulsating phase-change heat pipe as a core heat transfer component, and efficiently transmits heat generated by a bottom high-power LED lamp bead array to a three-dimensional space and quickly dissipates the heat; the self-wetting fluid working medium filled in the tube can automatically wet the evaporation section of the heat pipe, so that the dry-out limit of the heat pipe can be effectively improved; the capillary suction force generated by the micro grooves on the inner wall surface of the heat pipe can also enhance the wettability of the working medium on the inner wall of the whole pipe body, so that the temperature uniformity and the heat transfer limit of the pipe body are further improved; compared with the traditional metal rib type LED illumination heat dissipation device and the traditional heat pipe type LED illumination heat dissipation devices such as a capillary heat pipe and a gravity heat pipe, the device has better heat transfer performance, higher heat transfer limit and more excellent working adaptability.

Description

High-power LED lamp heat abstractor

Technical Field

The invention belongs to the technical field of LED heat dissipation, relates to an LED lamp heat dissipation device, and particularly relates to high-power LED heat dissipation equipment.

Background

An LED (Light Emitting Diode) is a high-efficiency electro-optical conversion semiconductor device and is widely used in various lighting scenes. Because the luminous flux of a single LED lamp bead is low, a large number of array LED lamp beads are usually integrated in a practical high-power LED lamp (such as a projection lamp, a wall washing lamp and the like), so that the luminous flux of the LED lamp beads reaches the actual application requirement. It is noted that, although the electro-optic conversion efficiency of the LED is relatively high, most of the electrical energy will still be converted into thermal energy, and if the thermal energy is not effectively dissipated and cooled, the operating temperature of the LED chip will exceed the upper limit of the safe operating temperature (about 110 ℃), which in turn will cause the luminous flux of the LED chip to decay, the aging to be accelerated, or even destroy the failure. Especially for high-power LED lamps, there is a need to develop a reliable and efficient cooling and heat dissipating device to ensure stable luminous flux and durable and reliable operation performance.

At present, the cooling and heat dissipation of the LED lamp bead array mainly depends on a metal fin type heat dissipation body to conduct heat to a finned expansion heat exchange surface, and air forced convection is utilized to dissipate and release the heat. However, as the power density of LED devices increases continuously, due to the limited heat conduction capability of the metal fins, the existing heat dissipation method of the metal finned expanded heat exchange surface in cooperation with forced air convection cooling cannot meet the temperature control requirement of the LED chip. Therefore, in recent years, new heat dissipation/cooling technologies such as heat pipe heat dissipation, microchannel liquid cooling, jet impingement cooling, thermoelectric cooling, and the like have been emerging. The heat pipe heat dissipation technology is widely applied to the field of cooling and heat dissipation of high-power LED lamps by means of high-efficiency heat transfer capacity, reliable working performance and excellent plasticity. The technology mainly depends on a heat pipe (such as a capillary heat pipe, a gravity heat pipe and the like) to efficiently guide the heat generated by the LED lamp bead array to a finned expanded heat exchange surface matched with the heat pipe, and then the heat is dissipated through forced convection of air. However, the conventional heat pipes such as the capillary heat pipe and the gravity heat pipe which are commonly used at present mainly rely on the capillary suction force generated by the capillary structure in the heat pipe or the acting force such as gravity to drive the condensed working medium at the condensation section of the heat pipe to flow back to the evaporation section for gasification, heat absorption and phase change, so as to realize the continuous evaporation-condensed gas-liquid phase change circulation high-efficiency heat transfer in the pipe. Therefore, when the heat pipe is in an antigravity working mode (namely, the evaporation section (hot end) is located at the upper position and the condensation section (cold end) is located at the lower position), the backflow of the condensed working medium is blocked, the heat transfer efficiency is greatly reduced and even fails, so that technical bottlenecks of poor working adaptability, incapability of working in the antigravity direction and the like still exist in the related heat pipe type LED cooling and radiating device, and the application range of the heat pipe is greatly limited. Furthermore, the heat exchange performance of the metal finned extended heat dissipation surface matched with the heat pipe still needs to be further improved due to the limitation of the thermal conductivity of the solid metal.

Disclosure of Invention

The invention aims to provide a high-power LED lamp heat dissipation device aiming at the defects of the prior art, the device takes a gas-liquid pulsating phase change heat pipe as a heat transfer center and an extended heat dissipation surface, can realize high-efficiency leading-out and quick heat dissipation of a high-power LED lamp bead array, has excellent gravity adaptability (namely heat dissipation performance is insensitive to gravity direction change), and is simple and compact in structure and easy to install and maintain.

The technical scheme of the invention is as follows: a high-power LED lamp heat dissipation device comprises an upper lamp cover, a circuit board, an LED lamp bead integrated board, a lower lamp cover and a glass cover plate; the method is characterized in that: the LED lamp heat dissipation device is also composed of a heat dissipation fan, a ribbed shell, a gas-liquid pulsating phase change heat pipe and an installation base; the gas-liquid pulsating phase-change heat pipe is vertically and closely arranged in an installation groove of the installation base, a contacted pipe section forms a heat absorption evaporation section, the other pipe sections of the gas-liquid pulsating phase-change heat pipe are heat release condensation sections, the inner wall of the gas-liquid pulsating phase-change heat pipe is provided with an axial micro groove, a self-wetting fluid working medium is filled in the gas-liquid pulsating phase-change heat pipe, and the LED lamp bead integrated plate is attached to the other surface of the installation base; the finned shell is coaxially sleeved outside the gas-liquid pulsating phase change heat pipe as an enclosure structure and an installation frame, the upper end of the finned shell is fixedly connected with the radiating fan and the upper lamp cover, the lower end of the finned shell is fixedly connected with the installation base and the lower lamp cover, the circuit board is arranged in an inner cavity of the upper lamp cover, the radiating fan is clamped between the upper lamp cover and the finned shell, and the glass cover is arranged at the bottom end of the lower lamp cover.

The gas-liquid pulsating phase-change heat pipe is manufactured by winding and bending a single metal capillary tube with an inner groove by a plurality of turns to form a ring pattern, then connecting the ring pattern end to end, vacuumizing, and partially filling the self-wetting fluid working medium.

The number of the turns of the garland of the gas-liquid pulsating phase-change heat pipe is more than or equal to 16, the cross section of the channel is circular, the equivalent diameter is 1.5-3 mm, and the material of the pipe body is high-thermal-conductivity metal or alloy.

The inner wall of the gas-liquid pulsating phase change heat pipe is provided with axial micro grooves which are uniformly distributed along the circumferential direction of the cross section of the channel, the number of the grooves is more than or equal to 10, the cross section is trapezoidal, rectangular, triangular or omega-shaped, the equivalent diameter is 0.15-0.5 mm, and the depth of the grooves is not more than 20% of the equivalent diameter of the channel of the heat pipe.

The self-wetting fluid working medium is an azeotropic alcohol aqueous solution, and the gas-liquid pulsating phase change heat pipe is filled after being vacuumized, wherein the liquid filling volume is 40-55% of the total volume inside the heat pipe.

The rib type shell peripheral wall is made of high-strength and high-thermal-conductivity alloy, a plurality of groups of axial reinforcing ribs are used as supports, the rib type shell peripheral wall is formed by stacking a plurality of layers of annular ribs, and a gap is reserved between every two layers of annular ribs to form a hollow-out shutter structure.

The periphery of the upper lamp shade is provided with a first lug, the periphery of the cooling fan is provided with a second lug, the periphery of the upper end of the ribbed shell is provided with a third lug, the periphery of the lower end of the ribbed shell is provided with a fourth lug, and the third lug on the upper end of the ribbed shell is fixedly connected with the cooling fan and the upper lamp shade through a first fixing bolt; and the fourth lug at the lower end of the rib type shell is fixedly connected with the mounting base and the lower lampshade through a second fixing bolt.

The invention has the beneficial effects that: the invention provides a high-power LED lamp heat dissipation device, which takes a gas-liquid pulsating phase change heat pipe as a core heat transfer component, and can efficiently transmit heat generated by a bottom high-power LED lamp bead array to a three-dimensional space and quickly dissipate the heat; meanwhile, the self-wetting fluid working medium filled in the tube can automatically wet the evaporation section of the heat pipe, so that the dry-out limit of the heat pipe can be effectively improved; moreover, the capillary suction force generated by the micro grooves on the inner wall surface of the heat pipe can also enhance the wettability of the working medium on the inner wall of the whole pipe body, so that the temperature uniformity and the heat transfer limit of the pipe body are further improved; particularly, the heat pipe garland-shaped multi-turn structure can effectively superpose the phase change saturation driving pressure difference between each turn of condensation section and evaporation section, eliminate the influence of gravity on the working performance of the heat pipe and ensure that the heat pipe can normally work in any angle arrangement mode; therefore, compared with the existing metal rib type LED illumination heat dissipation device and the traditional heat pipe type LED illumination heat dissipation device such as a capillary heat pipe, a gravity heat pipe and the like, the device has better heat transfer performance, higher heat transfer limit and more excellent working adaptability. Moreover, the device adopts a modular component design, has a simple and compact structure and is easy to install and maintain.

Drawings

FIG. 1 is a schematic view of the assembly structure of the present invention.

Fig. 2 is a heat dissipation diagram of the present invention.

Fig. 3 is a schematic view of the upper lamp cover structure of the present invention.

Fig. 4 is a schematic view of a heat dissipation fan according to the present invention.

Fig. 5 is a schematic structural view of a ribbed shell according to the present invention.

FIG. 6 is a schematic view of a gas-liquid pulsating phase-change heat pipe structure according to the present invention.

Fig. 7 is a schematic view of the structure of the mounting base of the present invention.

Fig. 8 is a schematic structural diagram of an LED lamp bead integrated board according to the present invention.

Fig. 9 is a schematic structural view of a lower lamp cover in the invention.

In the figure: the LED lamp comprises an upper lampshade 1, a lug 101, a fixing bolt 101a, a fixing nut 101b, a lead hole 102, a circuit board 2, a cooling fan 3, a lug 301, a fan blade 302, a fan reinforcing rib 303, a ribbed shell 4, a lug 401, a lug 402, a fixing bolt 402a, a ribbed shell reinforcing rib 403, a gas-liquid pulsation phase change heat pipe 5, a mounting base 6, a threaded hole 601, a mounting groove 602, an LED lamp bead integrated board 7, an LED lamp bead 701, a lower lampshade 8, a threaded hole 801 and a glass cover plate 9.

Detailed Description

The invention will be further described with reference to the accompanying drawings in which:

as shown in fig. 1-2, a high-power LED lamp heat dissipation device is formed by assembling an upper lamp cover 1, a circuit board 2, a heat dissipation fan 3, a ribbed shell 4, a gas-liquid pulsating phase change heat pipe 5, a mounting base 6, an LED lamp bead integrated board 7, a lower lamp cover 8, and a glass cover plate 9. The gas-liquid pulsating phase change heat pipe 5 is vertically and closely mounted on the mounting surface of a preset mounting groove 602 of the mounting base 6, a contact pipe section forms a heat absorption evaporation section, and the rest pipe sections are heat release condensation sections; the other side of the mounting base 6 is coaxially attached to an LED lamp bead integrated board 7; all the contact surfaces are connected by high-temperature-resistant heat-conducting glue. The ribbed shell 4 is used as an enclosure structure and a mounting frame, coaxially sleeved on the outer side of the gas-liquid pulsating phase change heat pipe 5, passes through the lug 402 through the fixing bolt 402a, is connected to the mounting base 6 and the threaded hole 801 on the lower lampshade 8 and is fixed; the upper lampshade 1, the heat radiation fan 3 and the ribbed shell 4 are connected in series and fastened with a fixing nut 101b through a fixing bolt 101a penetrating through

lugs

401, 301 and 101; a fan reinforcing rib 303 is processed on the heat radiation fan 3, and the gas-liquid pulsating phase change heat pipe 5 is pressed from the top end; the circuit board 2 is attached to the top of the heat radiation fan 3 and is arranged in the inner cavity of the upper lampshade 1; the glass cover plate 9 closes the lower lamp housing 8 from the bottom.

As shown in fig. 3, in the high-power LED lamp heat dissipation device, an upper lamp cover 1 is a "hat-shaped" hollow-out grille structure for cooling air to enter, a lug 101 matched with a rib-type shell lug 401 is processed at a "hat brim" position as a fixed structure, and a lead hole 102 is processed at the center of a hat top for leading in a power supply lead of an LED lamp.

As shown in fig. 4, in the high-power LED lamp heat dissipation device, the heat dissipation fan 3 is an axial flow fan, the edge of the fan is processed with a lug 301 matched with a rib-type housing lug 401 as a fixing structure, the bottom end of the fan is processed with a fan stiffener 303 as a bearing structure for covering the gas-liquid pulsating phase-change heat pipe 5, and the covering surface of the fan stiffener 303 is provided with a soft contact material.

As shown in fig. 5, a heat dissipation device for a high power LED lamp, a ribbed housing 4 is a hollow cylindrical structure, the upper and lower ends of which are processed with

lugs

401 and 402 as fixing structures, the peripheral wall of which is supported by a plurality of sets of axial reinforcing ribs 403 and is formed by stacking a plurality of layers of annular ribs, a gap is left between each two layers of annular ribs to form a hollow louver structure for cooling air to flow out, and the tube body is made of high strength and high thermal conductivity alloy, such as 6063 and 6061 aluminum (alloy); when the heat dissipation device is installed, the heat dissipation device is guaranteed to be tightly pressed with the installation base 6 and keep good thermal contact, so that the heat dissipation area of the installation base 6 is further expanded, and a certain heat dissipation auxiliary effect is achieved.

As shown in fig. 6, a high power LED lamp heat sink, a gas-liquid pulsating phase change heat pipe 5, the pipe body is made of high thermal conductivity metal or alloy, such as copper (alloy), aluminum (alloy), nickel (alloy), etc., and is made by bending a single inner groove metal capillary into a square spring shape, then extending and curling the metal capillary and forming the metal capillary end to end, then vacuuming and partially filling the metal capillary with a self-wetting fluid working medium. The inner groove metal capillary is manufactured through a hot drawing process, the cross section of a heat pipe channel is circular, the equivalent diameter of the channel is 1.5-3 mm, and the number of bending turns is more than or equal to 16. A plurality of axial micro grooves are uniformly distributed on the inner wall of the heat pipe channel along the circumferential direction, the number of the grooves is more than or equal to 10, and the cross sections of the grooves can be trapezoidal (A), rectangular (A-1), triangular (A-2) and omega-shaped (A-3), as shown in FIG. 6; the equivalent diameter of the micro-groove is between 0.15 and 0.5mm, and the depth of the groove is not more than 20 percent of the equivalent diameter of the heat pipe channel. The heat pipe channel is vacuumized until the absolute pressure is less than or equal to 10^-3After Pa, filling a self-wetting fluid working medium, wherein the liquid filling volume is 40-55% of the total volume inside the heat pipe; the self-wetting fluid working medium is azeotropic alcohol water-solubleThe surface tension of the liquid, such as n-butanol aqueous solution, n-heptanol aqueous solution and the like, can be increased along with the temperature rise, so that the liquid can spontaneously move from a low-temperature section to a high-temperature section in the working process of the heat pipe, and the automatic wetting of the inner wall surface of the evaporation section of the heat pipe is realized.

As shown in fig. 7, in the heat dissipation device for a high power LED lamp, the mounting base 6 is a circular metal plate, the material of the mounting base can be selected from high thermal conductivity metals or alloys, such as copper (alloy), aluminum (alloy), nickel (alloy), etc., and an inner threaded hole 601 is formed in the outer ring for fixing. One surface of the heat pipe is milled to form a mounting groove 602, the size of the mounting groove 602 is well matched with the bottom end of the gas-liquid pulsating phase change heat pipe 5, and heat conducting glue needs to be coated during mounting and matched with the reinforcing ribs 303 on the cooling fan 3 to be pressed and fixed from the top so as to reduce thermal contact resistance.

As shown in fig. 8, in the high-power LED lamp heat dissipation device, an array of LED lamp beads 701 in a circumferential array is welded on an LED lamp bead integrated board 7, and in order to improve the heat conduction capability, an aluminum-based material can be selected for a PCB board. The high-temperature-resistant heat-conducting glue is coaxially attached to the groove-free flat surface of the mounting base 6 during mounting, and the mounting base 6 can be additionally fixed by screws in an enhanced mode for improving mounting strength.

As shown in fig. 9, in the high-power LED lamp heat dissipation device, the lower lamp cover 8 is a hollow "hat-shaped" structure, a threaded hole 801 is formed in the top "hat rim", the lower lamp cover is fixed to the mounting base by a bolt 402a, the lower lamp cover is sealed by a glass cover plate 9, a sealing ring and a fastening part, and meanwhile, light-reflecting and light-condensing devices such as a light-condensing cup can be designed as required.

As shown in fig. 1-9, a heat dissipation device for a high power LED lamp has the following heat dissipation principle: the gas-liquid pulsating phase-change heat pipe 5 is a core heat transfer component. As shown by a hollow solid arrow in fig. 2, heat generated by the LED lamp bead 701 array is absorbed by the evaporation section of the gas-liquid pulsating phase-change heat pipe 5 through the LED lamp bead integrated board 7 and the mounting base 6; in the condensation section, the cooling fan 3 sucks cooling air from the hollow grilles of the upper lamp shade 1 and blows the cooling air to the LED lamp bead integrated board 7, and the wind direction is shown by dotted arrows, so that the cooling air-liquid pulsating phase change heat pipe 5 passes through the condensation section and the hollow louver structure of the rib type shell 4 and then is sent into the external environment. Therefore, under the coupling action of phase change saturation pressure difference between the condensation section and the evaporation section and initial random gas-liquid embolism unbalanced pressure distribution, working media in the gas-liquid pulsating phase change heat pipe 5 transfer heat by means of self-excited reciprocating pulsating gas-liquid phase change, and efficient transportation and rapid dispersion of heat absorption capacity of the evaporation section to the condensation section are achieved. Meanwhile, the self-wetting fluid working medium filled in the tube can automatically wet the evaporation section of the heat pipe, so that the dry-out limit of the heat pipe can be effectively improved; moreover, the capillary suction force generated by the micro grooves on the inner wall surface of the heat pipe can also enhance the wettability of the working medium on the inner wall of the whole pipe body, so that the temperature uniformity and the heat transfer limit of the pipe body are further improved; particularly, the heat pipe garland-shaped multi-turn structure can effectively superpose the phase change saturation driving pressure difference between each turn of condensation section and evaporation section, eliminate the influence of gravity on the working performance of the heat pipe and ensure that the heat pipe can normally work in any angle arrangement mode; therefore, compared with the existing metal rib type LED illumination heat dissipation device and the traditional heat pipe type LED illumination heat dissipation device such as a capillary heat pipe, a gravity heat pipe and the like, the device has better heat transfer performance, higher heat transfer limit and more excellent working adaptability. Moreover, the device adopts a modular component design, has a simple and compact structure and is easy to install and maintain.

Claims

1. A high-power LED lamp heat dissipation device comprises an upper lamp shade (1), a circuit board (2), an LED lamp bead integrated board (7), a lower lamp shade (8) and a glass cover plate (9); the method is characterized in that: the LED lamp heat dissipation device is also composed of a heat dissipation fan (3), a ribbed shell (4), a gas-liquid pulsating phase change heat pipe (5) and a mounting base (6); the gas-liquid pulsating phase-change heat pipe (5) is vertically and tightly arranged in an installation groove (602) of the installation base (6), a contacted pipe section forms a heat absorption evaporation section, the rest pipe sections of the gas-liquid pulsating phase-change heat pipe (5) are heat release condensation sections, an axial micro groove is arranged on the inner wall of the gas-liquid pulsating phase-change heat pipe (5), a self-wetting fluid working medium is filled in the gas-liquid pulsating phase-change heat pipe (5), and the LED lamp bead integrated plate (7) is attached to the other surface of the installation base (6); the utility model discloses a lamp shade, including rib formula casing (4), installation frame, installation base (6), lower lamp shade (8), circuit board (2) set up lamp shade (1) inner chamber, radiator fan (3) centre gripping is in go up between lamp shade (1) and the rib formula casing (4) are put as the coaxial cover of envelope and installation frame the outside of gas-liquid pulsation phase transition heat pipe (5), the upper end of rib formula casing (4) with radiator fan (3), last lamp shade (1) are connected fixedly, the lower extreme of rib formula casing (4) with installation base (6), lower lamp shade (8) are connected fixedly, circuit board (2) set up lamp shade (1) inner chamber, radiator fan (3) centre gripping is in go up between lamp shade (1) and the.

2. The heat sink for high power LED lamp as claimed in claim 1, wherein: the gas-liquid pulsating phase-change heat pipe (5) is manufactured by winding and bending a single metal capillary tube with an inner groove into a ring shape by multiple turns, connecting the ring shape end to end, vacuumizing, and partially filling the working medium of the self-wetting fluid.

3. The heat sink for high power LED lamp as claimed in claim 1, wherein: the number of the turns of the garland of the gas-liquid pulsating phase-change heat pipe (5) is more than or equal to 16, the cross section of the channel is circular, the equivalent diameter is 1.5-3 mm, and the pipe body is made of high-thermal-conductivity metal or alloy.

4. The heat sink for high power LED lamp as claimed in claim 1, wherein: the inner wall of the gas-liquid pulsating phase-change heat pipe (5) is provided with axial micro grooves which are uniformly distributed along the circumferential direction of the channel section, the number of the grooves is more than or equal to 10, the section is trapezoidal, rectangular, triangular or omega-shaped, the equivalent diameter is 0.15-0.5 mm, and the depth of the grooves is not more than 20% of the equivalent diameter of the heat pipe channel.

5. The heat sink for high power LED lamp as claimed in claim 1, wherein: the self-wetting fluid working medium is an azeotropic alcohol aqueous solution, and is filled after the self-excitation gas-liquid pulsation phase change heat pipe of the flower ring-shaped inner groove is vacuumized, wherein the liquid filling volume is 40-55% of the total volume in the heat pipe.

6. The heat sink for high power LED lamp as claimed in claim 1, wherein: the peripheral wall of the rib type shell (4) is made of high-strength and high-thermal-conductivity alloy, multiple groups of axial reinforcing ribs are used as supports and are stacked through multiple layers of annular ribs, and a gap is reserved between every two layers of annular ribs to form a hollow-out shutter structure.

7. The heat sink for high power LED lamp as claimed in claim 1, wherein: the periphery of the upper lampshade (1) is provided with a first lug (101), the periphery of the cooling fan (3) is provided with a second lug (301), the periphery of the upper end of the ribbed shell (4) is provided with a third lug (401), the periphery of the lower end of the ribbed shell (4) is provided with a fourth lug (402), and the third lug on the upper end of the ribbed shell (4) is fixedly connected with the cooling fan (3) and the upper lampshade (1) through a first fixing bolt (101 a); the fourth lug at the lower end of the rib type shell (4) is fixedly connected with the mounting base (6) and the lower lampshade (8) through a second fixing bolt (402 a).