CN101155495B - Micro-channel single phase convection and capillary groove phase inversion heat combined cooling method and device - Google Patents

Abstract

The invention discloses a microchannel single convective flow and capillary microgroove phase conversion heat combined cooling method and device thereof, which relate to a heat radiation cooling method and special components. The method is: the high-boiling point liquid working medium flows through the surface of the heating element, absorbs heat and enters many microchannels provided inside a heat-conducting material, and there are many capillary micro-grooves that can generate capillary force on the outer surface of the heat-conducting material. Force sucks another low-boiling point liquid working fluid into the capillary microgroove, and the high-boiling point liquid working medium in the microchannel transfers heat to the heat-conducting material through high-intensity micro-scale single convective heat transfer, and the heat-conducting material heats the outer surface Another low-boiling-point liquid working fluid in the capillary microgroove, this liquid working medium produces high-intensity evaporation and boiling after being heated, and takes away the heat of the heating element. The heat exchange structure in which microchannels are arranged inside the heat conduction material and capillary microgrooves are arranged on the outer surface is a special device for the method of the invention.

Description

Combination cooling method and device of microchannel single convective flow and capillary microgroove phase conversion heat

Technical field:

The invention relates to a heat radiation cooling method, in particular to a cooling method and a device for high-power electronic and optoelectronic devices.

Background technique:

At present, there are mainly two ways to cool high-power electronic and optoelectronic devices: one is to use heat sinks combined with fans for air cooling. Thermal silica gel (silicone grease) is used to reduce the thermal resistance of heat conduction, and the fan is placed on the end face of the heat dissipation fin to use the principle of convection heat transfer to dissipate heat to the environment through the surface of the fin to ensure that the device works within the normal operating temperature range. The main defect of this technology is: as the power of electronic and optoelectronic devices increases, the greater the heat dissipation required to maintain normal operating temperature, the greater the power consumption of the fan, and the greater the heat dissipation area required by the fins. The increase of the heat dissipation area will reduce the efficiency of the fins, and the total heat dissipation capacity cannot be greatly improved. Another method is to use a water pump for forced water cooling. The water flows through the surface of the heating element to take away the heat generated by the heating element. With the increase of the power of electronic and optoelectronic devices, the heat transfer area of the radiator will be larger, and the total cooling capacity will be the same. cannot be significantly increased.

Invention content:

The purpose of the present invention is to overcome the technical defects that the existing air-cooled and water-cooled heat dissipation technologies require a large heat dissipation area and insufficient heat dissipation capacity, and provide a microchannel single-convection and heat dissipation system with small heat dissipation area, high heat flow density and large total heat dissipation capacity. Capillary micro-groove phase-change heat combination cooling method and device thereof.

The technical solution of the present invention is: directly arrange many microchannels inside the heat conducting material to form a group of microchannels, and the size of the microchannels is suitable for enhancing heat exchange by using the microscale effect; arrange many capillary microgrooves on the outer surface of the heat conducting material to form microgrooves The size of the capillary microgroove is suitable for forming capillary force, so as to suck the liquid working medium at the edge of the capillary microgroove into the microchannel, and form a thin liquid film region capable of high-intensity phase conversion heat in the capillary microgroove. The liquid working medium with high boiling point flows through the surface of the heating element to absorb heat, then enters the microchannel inside the heat-conducting material, and transfers the heat to the heat-conducting material through high-intensity single-convection heat exchange. Another low-boiling-point liquid working fluid is heated to form high-intensity evaporation and boiling, which takes away the heat of the heating element, thereby cooling the heating element.

The boiling point of the high-boiling liquid working medium in the above-mentioned microchannel is 0°C to 300°C under normal pressure, the boiling point of the low-boiling liquid working medium in the capillary microgroove is 0°C to 150°C under normal pressure, and the liquid working medium in the capillary microgroove The boiling point of the microchannel is lower than that of the liquid working medium flowing in the microchannel.

The cross-section of the above-mentioned microchannels is circular, the diameter is in the range of 0.05-1 mm, the distance between the micro-channels is in the range of 0.05-5 mm, and the length of each micro-channel is in the range of 5-50 mm.

The width and depth of the capillary micro-grooves are in the range of 0.05-2 mm, and the distance between the capillary micro-grooves is in the range of 0.05-5 mm.

The plurality of capillary micro-grooves are densely arranged vertically on the outer surface of the heat-conducting material, and the cross-section is trapezoidal. The length of the upper base of the trapezoid is 0.05-2 mm, the length of the lower base is 0.08-2.5 mm, and the groove depth is 0.05-2 mm. The distance between the capillary grooves is 0.05-5 mm.

The plurality of capillary micro-grooves are densely arranged longitudinally on the outer surface of the heat-conducting material, the cross-section of which is triangular, the bottom and apex angles of the triangular grooves are 5°-60°, the groove depth is 0.05-2mm, and the distance between the capillary micro-grooves is 0.05 to 5mm.

A special device for realizing the above method—microchannel and capillary microgroove heat sink, including a thermally conductive material, inside the thermally conductive material are provided many microchannels to form a group of microchannels, and the size of the microchannels is suitable for strengthening by using microscale effects heat exchange; the outer surface is provided with many capillary micro-grooves to form a group of capillary micro-grooves, the size of the capillary micro-grooves is suitable for forming capillary force, so as to suck the liquid working substance on the edge of the capillary micro-grooves into the micro-channel, and A thin liquid film region capable of high-intensity phase transformation heat is formed in the microgroove.

The cross-section of the above-mentioned microchannels is circular, the diameter is in the range of 0.05-1 mm, the distance between the micro-channels is in the range of 0.05-5 mm, and the length of each micro-channel is in the range of 5-50 mm.

The above-mentioned microchannels are densely arranged laterally inside the heat-conducting material.

The width and depth of the capillary microgrooves are in the range of 0.05-2 mm, and the distance between the capillary micro-grooves is in the range of 0.05-5 mm.

The above-mentioned capillary microgrooves are vertically and densely arranged on the surface of the heat-conducting material.

The above-mentioned capillary microgrooves are vertically densely arranged, and the vertically densely arranged microgrooves are intersected with a plurality of transverse capillary microchannels, the width and depth of the transverse capillary microchannels are in the range of 0.05-2mm, and the spacing is in the range of 0.05-10mm.

Technical effect: the present invention absorbs heat through the part of the surface of the heating element that needs to dissipate heat, and then enters the microchannel inside the heat conducting material, through the high boiling point liquid working medium in the microchannel and the high Intensive micro-scale convective heat transfer and heat conduction of heat-conducting materials transfer heat to the outer surface of the heat-conducting material, and there are many capillary microgrooves that can generate capillary force on the outer surface of the heat-conducting material. The substance is sucked into the capillary microgroove, and a thin liquid film area capable of high-intensity phase-change heat is formed in the micro-groove, and the heat generated by the heating element is finally converted to Take it away from the outer surface of the heat-conducting material, so as to achieve the purpose of cooling the heating element. Studies at home and abroad have shown that the overall characteristics of flow and heat transfer at the microscale are quite different from the results in large-scale channels. The single convective heat transfer mode of liquid working fluid in microchannels has a high convective heat transfer coefficient, which is higher than that in large-scale channels. The convective heat transfer coefficient of conventional size single convection is at least an order of magnitude higher; at the same time, the evaporation and boiling of the working fluid in the capillary microgroove also have extremely high intensity, and the theoretical limit value of the evaporation and boiling heat flux is higher than that of the current high-performance chips. The heat flux is about two orders of magnitude higher. The single convective heat transfer of the liquid working fluid in the microchannels in the heat conducting material and the thin liquid film phase transfer heat of the liquid working medium in the capillary microgrooves on the outer surface of the heat conducting material belong to the The supernormal phenomenon of heat and mass transfer in the micro-scale space, using the combination of these two heat transfer methods can obtain very good cooling and heat dissipation effects. This high-efficiency microchannel single convection and capillary microgroove phase change combined cooling and heat dissipation can make the size of the heat exchange surface very small, so the present invention can largely solve the heat dissipation of current and future high-power electronic and optoelectronic devices Problems, reduce and control the operating temperature of high-power electronic and optoelectronic devices, ensure and improve the working performance of the devices.

When the diameter of the microchannel is in the range of 0.05-1mm, there is a very high convective heat transfer coefficient between the liquid working fluid flowing inside and the wall surface of the microchannel.

When the width and depth of the capillary microgroove are in the range of 0.05-2mm, the capillary force generated in the microgroove is strong, and has a strong ability to drive the flow of liquid working fluid.

Setting multiple transverse capillary channels with width and depth in the range of 0.05-2mm and spacing in the range of 0.05-10mm can ensure the capillary driving force of the liquid working fluid flowing along the longitudinal capillary channels under ultra-high heat load, so that the evaporation The lost liquid working medium is replenished in time, thereby improving the cooling efficiency.

Description of drawings:

Fig. 1 is the first structural representation of microchannel and capillary microgroove heat sink of the present invention;

Fig. 2 is a schematic diagram of the arrangement of capillary microgrooves on the outer surface of the present invention;

Fig. 3 is A-A sectional schematic diagram of Fig. 2;

Fig. 4 is the second structural representation of capillary microgroove in microchannel and capillary microgroove heat sink of the present invention;

Fig. 5 is a schematic diagram of the third structure of the capillary microgroove in the microchannel and capillary microgroove heat sink of the present invention.

Detailed ways:

Embodiment 1: see Fig. 1, a lot of circular microchannels 2 are set inside metal plate or other heat-conducting materials 1, form microchannel group, and many rectangular capillary microgrooves 3 are set on the outer surface, form capillary microgroove group, this band A heat exchange structure with microchannels and capillary grooves is called a heat sink. As shown in Fig. 1 and Fig. 3, the microchannels 2 are densely arranged horizontally inside the heat-conducting material 1, and as shown in Fig. 1 and Fig. 2, the capillary microgrooves 3 are densely arranged longitudinally. The diameter of the microchannel 2 is in the range of 0.05-1mm, the distance between the microchannels is in the range of 0.05-5mm, the length of each microchannel is in the range of 5-50mm, and the cross-section of the microchannel is circular, and the capillary microgroove 3 The channel is a rectangular micro channel, its width and channel depth are in the range of 0.05-2mm, and the distance between the micro-channels is in the range of 0.05-5mm. Absolute ethanol or distilled water have capillary attraction. The high-boiling-point liquid working medium in the microchannel flows through the surface of the heating element, absorbs the heat of the heating element, and then enters the microchannel 2. In the microchannel 2, a high-intensity convective heat exchange occurs with the metal plate heat-conducting material 1, and the metal plate conducts heat. The material 1 generates heat, and at the same time, the capillary force sucks another low-boiling liquid working medium into the capillary micro-groove 3 on the surface of the metal plate heat-conducting material 1, and the liquid working medium evaporates and boils away in the heated area of the capillary micro-groove 3 A large amount of heat, so as to realize the heat dissipation and cooling of the heating element. The heat generating body can be electronic and optoelectronic devices or other heat generating bodies.

The boiling point of the high-boiling liquid working fluid in the microchannel under normal pressure is 0°C to 300°C, the boiling point of the low-boiling liquid working medium in the capillary microgroove is 0°C to 150°C under normal pressure, and the liquid working fluid in the capillary microgroove The boiling point is lower than the boiling point of the liquid working medium flowing in the microchannel.

Embodiment 2: As shown in FIG. 2, a plurality of capillary microgrooves 3 of the heat sink in this embodiment are densely arranged longitudinally, and a plurality of transverse capillary microgrooves 3' are arranged crosswise on the densely arranged longitudinal capillary microgrooves 3. The capillary microchannels 3' arranged horizontally can ensure the capillary driving force of the liquid working medium flowing along the longitudinal capillary microchannels 3 under ultra-high heat load, so that the liquid working medium evaporated in the heated area can be replenished in time, thereby improving the cooling efficiency. In this embodiment, the groove width of the capillary micro-channel 3 is 0.2mm, the groove depth is 0.5mm, and the groove spacing is 0.2mm, and the groove width of the transverse capillary micro-channel 3' is 0.4mm, the groove depth is 0.8mm, and the groove spacing is 5mm.

Embodiment 3: See Fig. 4, a plurality of capillary grooves 4 of the heat sink of this embodiment are vertically densely arranged, and its cross-section is trapezoidal, the length of the upper base of the trapezoid is 0.2 mm, the length of the lower base is 0.4 mm, and the groove depth is 0.8mm, the spacing is 0.2mm.

Embodiment 4: As shown in Fig. 5, a plurality of capillary microgrooves 5 of the heat sink of this embodiment are vertically densely arranged, and its cross section is triangular.

Claims (9)

1. A microchannel single convective flow and capillary microgroove phase conversion heat combination cooling method, is characterized in that, the steps are as follows: a) The high-boiling-point liquid working medium flows through the part on the surface of the heating element that needs to be dissipated, absorbs heat, and enters many micro-channels provided inside a heat-conducting material; b) There are many capillary micro-grooves capable of generating capillary force outside the heat-conducting material, and the capillary force sucks another low-boiling point liquid working substance into the capillary micro-groove; c) The high-boiling-point liquid working medium in the microchannel transfers heat to the heat-conducting material through high-intensity micro-scale single convective heat exchange with the wall of the microchannel; d) The heat-conducting material heats the low-boiling liquid working medium in the capillary micro-groove on the outer surface of the heat-conducting material. After being heated, the liquid working medium produces high-intensity evaporation and boiling in the capillary micro-groove, thereby taking away the heat of the heating element. Cool down the heating element. 2. The combined cooling method of microchannel single convection and capillary microgroove phase conversion heat according to claim 1, characterized in that, the boiling point of the high-boiling liquid working medium in the microchannel under normal pressure is 0° C. to 300° C. °C, the boiling point of the low-boiling liquid working medium in the capillary microgroove under normal pressure is 0 °C to 150 °C, and the boiling point of the liquid working medium in the capillary microgroove is lower than the boiling point of the liquid working medium flowing in the microchannel. 3. The combined cooling method of microchannel single convection and capillary microgroove phase conversion heat according to claim 1, characterized in that, the diameter of the microchannel is within the range of 0.05 to 1 mm, and the spacing is within the range of 0.05 to 5 mm , the length of each microchannel is in the range of 5-50 mm; the cross-section of the capillary micro-grooves is rectangular, its width and depth are in the range of 0.05-2 mm, and the distance between the capillary micro-grooves is in the range of 0.05-5 mm. 4. A special device for the combined cooling method of microchannel single convection and capillary microgroove phase change heat according to claim 1, characterized in that it comprises a heat conducting material, and many microchannels are arranged inside the heat conducting material to form Micro-channel group, the size of the micro-channel is suitable for enhancing heat exchange by using micro-scale effects; the outer surface of the heat-conducting material is provided with many capillary micro-grooves to form a group of capillary micro-grooves, the size of the capillary micro-grooves is suitable for forming capillary force, so that the The liquid working fluid on the side of the capillary micro-groove is sucked into the capillary micro-groove. 5. The special device according to claim 4, characterized in that, the diameter of the microchannel is within the range of 0.05 to 1 mm, the spacing is within the range of 0.05 to 5 mm, and the length of each microchannel is within the range of 5 to 50 mm; The cross section of the capillary micro-groove is rectangular, the width and depth thereof are in the range of 0.05-2 mm, and the distance between the capillary micro-grooves is in the range of 0.05-5 mm. 6. The special device according to claim 4 or 5, characterized in that, said many microchannels are arranged horizontally and densely in the heat-conducting material, and a plurality of capillary microgrooves are vertically densely arranged on the outer surface of the heat-conducting material, and the microchannels Going towards an Orthogonal setting. 7. The special device according to claim 6, characterized in that, the capillary microgrooves are vertically densely arranged on the outer surface of the heat-conducting material, and a plurality of transverse capillary microgrooves are arranged crosswise on the plurality of longitudinally densely arranged capillary microgrooves, The cross-section of the transverse capillary micro-groove is rectangular, its width and depth are in the range of 0.05-2 mm, and the distance between the capillary micro-grooves is in the range of 0.05-10 mm. 8. The special device according to claim 4, characterized in that, said many capillary microgrooves are densely arranged longitudinally on the outer surface of the heat-conducting material, and its cross-section is trapezoidal, the length of the upper base of the trapezoid is 0.05-2mm, and the lower bottom The side length is 0.08-2.5mm, the groove depth is 0.05-2mm, and the distance between capillary and micro-grooves is 0.05-5mm. 9. The special device according to claim 6, characterized in that the many capillary microgrooves are densely arranged longitudinally on the outer surface of the heat-conducting material, and the cross-section is triangular, and the bottom and apex angles of the triangular grooves are 5°-60°, The groove depth is 0.05-2mm, and the distance between the capillary grooves is 0.05-5mm.

Images