Liquid-cooled heat pipe radiator

Abstract

The utility model relates to a liquid-cooled heat pipe radiator. The liquid-cooled heat pipe radiator comprises a heat dissipation substrate, a liquid cooling plate and a variable heat conduction pipe, wherein the variable heat conduction pipe is connected between the heat dissipation substrate and the liquid cooling plate and transfers heat on the heat dissipation substrate to the liquid cooling plate for heat dissipation; the variable heat conduction pipe is filled with a liquid working medium and non-condensable gas. According to the liquid-cooled heat pipe radiator, the characteristic that the variable heat conduction pipes are different in heat conductivity under different working conditions is utilized, the heat resistance of the radiator can be changed along with the change of heat source power, when the heat source power is low, the heat dissipation efficiency is low, the heat source temperature is not too low, and when the heat source power is high, the heat dissipation efficiency is high, and the heat dissipation efficiency is high. And the temperature of the heat source is controlled within a proper working temperature range, so that the temperature of the IGBT device of the air conditioner is prevented from being lower than a condensation point.

Description

Technical Field

[0001] The utility model relates to the technical field of radiators, in particular to a liquid-cooled heat pipe radiator. Background Art

[0002] Heat pipe is a highly efficient heat transfer device, which is widely used in various fields due to its material and structural characteristics. Common heat pipes are filled with working fluid. When one end absorbs heat from the heat source, the fluid evaporates into gas, and the heat is quickly transferred to the other end through the evaporation and condensation cycle of the heat pipe. This heat transfer method does not rely on external force fields, and has the advantages of fast and uniform heat transfer, no need for electric drive, and no noise. Heat pipes can be used in heat dissipation systems, thermal management, refrigeration, energy recovery, and high temperature and high pressure environments. It not only improves the efficiency and performance of the device, but also saves energy and reduces environmental pollution. Among them, liquid-cooled heat pipe radiator is an efficient heat dissipation solution. It uses heat pipe technology and liquid cooling cycle to effectively transfer heat from the heat source to the radiator.

[0003] However, existing liquid-cooled heat pipe radiators have some problems in certain occasions. When using traditional liquid-cooled heat pipe radiators, the temperature of the coolant is fixed, but the temperature of the heating element changes with the heating power. Traditional liquid-cooled heat pipe radiators cannot well control the variable power heating element within a suitable temperature range.

[0004] For example, IGBT is the core device for energy conversion and transmission, and is a relatively technologically advanced product among current power electronic devices. Using IGBT for power conversion can improve the efficiency and quality of electricity use, and has the characteristics of high efficiency, energy saving and green environmental protection. When using IGBT heat dissipation components in air conditioners, if the temperature of the liquid cooling end is very low and the power of the heat source is very low, the traditional heat sink thermal resistance is almost constant, which will cause the temperature of the heat source to be very low. The water vapor in the humid air will condense when it hits the cold heat source, which will cause damage to the equipment. However, if the temperature of the liquid cooling end is increased, when the power of the heat source increases, the heat pipe heat sink cannot dissipate the heat from the heat source well, which affects the heat dissipation efficiency. Summary of the invention

[0005] Based on this, the purpose of the utility model is to provide a liquid-cooled heat pipe radiator.

[0006] A liquid-cooled heat pipe radiator comprises a heat dissipation substrate, a liquid cooling plate and a variable heat conduction pipe, wherein the variable heat conduction pipe is connected between the heat dissipation substrate and the liquid cooling plate and transfers the heat on the heat dissipation substrate to the liquid cooling plate for heat dissipation; the variable heat conduction pipe is filled with liquid working fluid and non-condensable gas.

[0007] The liquid-cooled heat pipe radiator described in the utility model utilizes the characteristic that the thermal conductivity of the variable heat pipe is different under different working conditions. The radiator will change its own thermal resistance as the power of the heat source changes. When the power of the heat source is low, the heat dissipation efficiency is low, so that the temperature of the heat source will not be too low. When the power of the heat source is high, the heat dissipation efficiency is high, and the temperature of the heat source is controlled within a suitable working temperature range.

[0008] Furthermore, it also includes a liquid cooling tube, and the liquid cooling plate is connected to the liquid cooling plate; the liquid cooling tube is filled with flowing low-temperature working medium to dissipate heat from the liquid cooling plate.

[0009] Furthermore, the heat dissipation substrate and the liquid cooling plate are respectively located at two ends of the variable heat conduction pipe in the axial direction.

[0010] Furthermore, a liquid wick is provided in the variable heat pipe, the liquid wick surrounds the inner side wall of the variable heat pipe and extends along its axial direction, and a gas channel is formed near the central axis of the variable heat pipe; the liquid working medium is absorbed by the liquid wick, and the non-condensable gas is located in the gas channel. The liquid wick is provided so that the liquid working medium is stored inside the liquid wick, and there is no requirement for the use direction.

[0011] Furthermore, the heat dissipation substrate and one end of the liquid cooling plate are close to each other; a plurality of interconnected grooves extending in parallel directions are provided on the same side plate surface of the heat dissipation substrate and the liquid cooling plate, and the same variable heat conduction pipe is arranged in the same interconnected groove.

[0012] Furthermore, the heat dissipation substrate is an I-shaped structure, and a plurality of grooves extending in parallel directions are connected on the outer sides of the two plates of the heat dissipation substrate, and the same variable heat conduction pipe extends from the outer side of the heat dissipation substrate plate on one side to the outer side of the plate on the other side; the liquid cooling plate is closely attached to the outer side of one of the plates of the heat dissipation substrate. The heat dissipation substrate is set to an I-shaped structure, and the overall longitudinal length of the radiator is reduced, saving space.

[0013] Furthermore, multiple grooves extending in parallel directions are connected on the two side panels of the heat dissipation substrate, and the same variable heat conduction pipe is connected to the two side outer panels of the heat dissipation substrate, wherein one side outer panel of the heat dissipation substrate is bonded to the liquid cooling plate. The overall thickness of the radiator is reduced and the heat dissipation capacity is increased.

[0014] Furthermore, the variable heat conduction pipe is flattened and embedded in the groove, and silicone grease is filled in the embedding gap.

[0015] Furthermore, the diameter of the variable heat conduction pipe is preferably 2 mm to 20 mm, and the length is preferably 50 mm to 500 mm.

[0016] Furthermore, the non-condensable gas is preferably nitrogen or argon.

[0017] In order to better understand and implement the present invention, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0019] Figure 2 It is a schematic diagram of the connection cross section between the heat dissipation substrate and the variable heat conduction pipe;

[0020] Figure 3 It is a schematic diagram of the connection cross section between the liquid cooling plate and the variable heat conduction pipe;

[0021] Figure 4 A schematic diagram of a variable heat conduction pipe using a liquid wick structure;

[0022] Figure 5 The schematic diagram of the structure of the liquid wick is a sawtooth structure;

[0023] Figure 6 This is a schematic diagram of the structure of Embodiment 2 of the present utility model;

[0024] Figure 7 This is a schematic diagram of the structure of Example 3 of the utility model. DETAILED DESCRIPTION

[0025] The utility model provides a liquid-cooled heat pipe radiator, which comprises a heat dissipation substrate 1, a liquid cooling plate 2, a variable heat conduction pipe 3 and a liquid cooling pipe 4. The heat dissipation substrate 1 is located at one end of the variable heat conduction pipe 3, and the liquid cooling plate 2 is located at the other end of the variable heat conduction pipe 3. The variable heat conduction pipe 3 is filled with at least non-condensable gas and liquid working medium, and is provided with a gas channel and a liquid channel. The liquid cooling pipe 4 is connected to the liquid cooling plate 2, and the liquid cooling pipe 4 is filled with flowing low-temperature working medium to dissipate heat from the liquid cooling plate 2. When dissipating heat, the heat source contacts the heat dissipation substrate 1 and heats the liquid working medium in the variable heat conduction pipe 3 close to the side of the heat dissipation substrate 1 to form a vapor-like gaseous working medium, and the gaseous working medium and the non-condensable gas flow along the gas channel in the variable heat conduction pipe 3 to the side close to the liquid cooling plate 2. Under the action of the liquid cooling pipe 4, the gaseous working medium is cooled and converted into a liquid working medium again, and flows along the liquid channel to the side of the variable heat conduction pipe 3 close to the heat dissipation substrate 1 to continue to dissipate heat. The following is a specific implementation of the utility model:

[0026] Example 1

[0027] See also Figure 1-4In this embodiment, the liquid-cooled heat pipe radiator includes a heat dissipation substrate 1, a liquid cooling plate 2, a variable heat conduction pipe 3 and a liquid cooling pipe 4. The heat dissipation substrate 1 and one end of the liquid cooling plate 2 are close to each other, one end of the variable heat conduction pipe 3 is connected to the heat dissipation substrate 1, and the other end is connected to the liquid cooling plate 2. The outer wall of the liquid cooling pipe 4 is connected to the liquid cooling plate 2, and the liquid cooling pipe 4 is connected to an external water source.

[0028] The heat dissipation substrate 1 and the liquid cooling plate 2 are made of aluminum 6063, and a plurality of interconnected grooves extending in parallel directions are formed on the same side of the heat dissipation substrate 1 and the liquid cooling plate 2 by wire cutting and CNC technology, and the same variable heat conduction pipe 3 is arranged in the same interconnected groove. The liquid cooling plate 2 has two cylinders on one side thereof for sleeve-mounting the liquid cooling pipe 4.

[0029] The heat dissipation substrate 1 is fixed to the heat source by screws or glue.

[0030] The diameter of the variable heat pipe 3 is preferably 2 mm to 20 mm, and the length is preferably 50 mm to 500 mm. In this embodiment, the variable heat pipe 3 is a copper-water heat pipe with a length of 230 mm, a diameter of 8 mm, and a thickness of 0.3 mm. The pressure in the variable heat pipe 3 is pumped to 10 -3 After Pa, 2 g of pure water is filled as a liquid working medium, 1.62 μg of argon is filled as a non-condensable gas, and argon arc welding is used to seal the variable heat conduction pipe 3.

[0031] Preferably, a wick 32 is provided in the variable heat pipe 3, and the wick 32 surrounds the inner wall of the variable heat pipe 3 and extends axially thereof, so that a gas channel 33 is formed near the central axis of the variable heat pipe 3. Projected along the axis of the variable heat pipe 3, the outermost layer of the variable heat pipe 3 is the copper tube 31, the middle layer is the wick 32 serving as a liquid channel, and the innermost layer is the gas channel 33. The wick 32 can be a copper powder sintered wick, a grooved wick, or a copper wire mesh wick. The liquid working medium is absorbed by the wick 31, and the non-condensable gas is located in the gas channel 33. Further, the wick 32 has a plurality of fine holes extending radially along the variable heat pipe 3, and the pore size on the side close to the copper tube 31 is smaller than the pore size on the side close to the gas channel 33, so as to reduce the resistance of the gas working medium entering the gas channel 33. For further information, please refer to Figure 5 The side of the liquid wick that is connected to the gas channel is a serrated structure, which increases the contact area with the gas channel and improves the thermal conductivity.

[0032] The heat dissipation working principle of the variable heat pipe 3 is as follows: the variable heat pipe 3 is divided into an evaporation section close to the heat dissipation substrate 1 and a condensation section close to the liquid cooling plate 2. When the variable heat pipe 3 dissipates heat, the evaporation section is heated, the working liquid in the liquid wick 32 evaporates, the vapor enters the gas channel 33, flows to the condensation section, the non-condensable gas is driven to the condensation section, the vapor reaches the condensation section, condenses after heat exchange with the liquid cooling plate 2 in the condensation section, the condensed liquid is absorbed by the liquid wick 32, and is absorbed to the evaporation section through the capillary action of the liquid wick 32. The non-condensable gas driven to the condensation section gathers in the condensation section to form a gas plug, which occupies part of the space of the condensation section, reducing the effective area of ​​evaporation and condensation heat exchange in the condensation section, and the gas plug has a certain "elasticity". When the heating load increases, the vapor pressure increases, the gas plug is compressed, the gas plug length becomes shorter, the effective working area of ​​the condensation section increases, and the thermal conductivity of the variable heat pipe 3 is very high. On the contrary, when the heat load becomes smaller, the steam pressure decreases, the gas plug length becomes longer, the effective heat exchange area of ​​the condensation section decreases, and the heat conduction capacity of the variable heat pipe 3 decreases. According to the heat conduction theory, when the heating load becomes larger, the area of ​​the condensation section and the corresponding equivalent thermal conductivity coefficient change, so that the change range of the working temperature of the variable heat pipe 3 decreases, thereby achieving the purpose of controlling the working temperature of the heating element.

[0033] Preferably, the variable heat pipe 3 can be flattened, and its thickness after flattening is preferably 0.1 mm to 10 mm. In this embodiment, the variable heat pipe 3 is hot-pressed and flattened to 3 mm, and is embedded in the grooves of the heat dissipation substrate 1 and the liquid cooling plate 2. The embedded gap is filled with gold silicone grease with a thermal conductivity of 4.85 W / m·k to reduce its contact thermal resistance.

[0034] The liquid cooling tube 4 is bent into a U shape and sleeved in the cylinder of the liquid cooling plate 2. Water or fluoride is used as a liquid cooling medium in the liquid cooling tube 4. The liquid cooling tube 4 is bent to reduce the longitudinal length of the radiator.

[0035] During operation, the heat generated by the heating element is transferred to the liquid cooling tube 4 through the heat dissipation substrate 1, the variable heat pipe 3, and the liquid cooling plate 2, and the liquid cooling medium in the liquid cooling tube 4 takes away the heat. The temperature of the heating element is controlled at an appropriate temperature by utilizing the different thermal conductivity characteristics of the variable heat pipe 3 under different working conditions.

[0036] Example 2

[0037] See also Figure 6The structure of this embodiment is basically the same as that of embodiment 1, except that: the heat dissipation substrate 1 is an I-shaped structure, the groove is provided on the outer side of the two opposite plates of the heat dissipation substrate 1, and the same variable heat conduction pipe 3 extends from the outer side of the plate of the heat dissipation substrate 1 on one side to the outer side of the plate of the other side. The liquid cooling plate 2 is tightly attached to the outer side of one of the plates of the heat dissipation substrate 1, and the heating element is arranged on the outer side of the other plate. The overall longitudinal length of the radiator is reduced, saving space. The variable heat conduction pipe 3 is flattened and bent, and connected to the heat dissipation substrate 1 and the liquid cooling plate 2 by welding to reduce the contact thermal resistance.

[0038] Example 3

[0039] See also Figure 7 This embodiment is basically the same as the embodiment 1, except that the grooves are provided on the two side panels of the heat dissipation substrate 1, and the same variable heat conduction pipe 3 is flattened and bent and connected to the two side outer panels of the heat dissipation substrate 1, so that the variable heat conduction pipe 3 is flush with the two side outer panels of the heat dissipation substrate 1, and one side outer panel of the heat dissipation substrate 1 is attached to the liquid cooling plate 2. With this structure, the radiator is thinner as a whole and has a stronger heat dissipation capacity, and a lower thermal resistance can be achieved when a low thermal resistance working condition is required.

[0040] The liquid-cooled heat pipe radiator described in the utility model utilizes the characteristic that the variable heat pipe 3 has different thermal conductivity under different working conditions. The radiator will change its own thermal resistance as the power of the heat source changes. When the power of the heat source is low, the heat dissipation efficiency is low, so that the temperature of the heat source will not be too low. When the power of the heat source is high, the heat dissipation efficiency is high, and the temperature of the heat source is controlled within a suitable operating temperature range. When the air-conditioning IGBT device works at a low temperature, the power of the radiator is reduced to prevent the temperature of the air-conditioning IGBT device from being lower than the dew point.

[0041] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, and the utility model is also intended to include these modifications and modifications.

Claims

1. A liquid-cooled heat pipe radiator, characterized in that: It includes a heat dissipation substrate, a liquid cooling plate and a variable heat conduction pipe, wherein the variable heat conduction pipe is connected between the heat dissipation substrate and the liquid cooling plate and transfers the heat on the heat dissipation substrate to the liquid cooling plate for heat dissipation; The variable heat conduction pipe is filled with liquid working medium and non-condensable gas.

2. The liquid-cooled heat pipe radiator according to claim 1, characterized in that: It also includes a liquid cooling tube, which is connected to the liquid cooling plate; the liquid cooling tube is filled with flowing low-temperature working medium to dissipate heat from the liquid cooling plate.

3. The liquid-cooled heat pipe radiator according to claim 2, characterized in that: The heat dissipation substrate and the liquid cooling plate are respectively located at two ends of the variable heat conduction pipe in the axial direction.

4. The liquid-cooled heat pipe radiator according to claim 3, characterized in that: A liquid wick is provided in the variable heat conducting pipe, the liquid wick surrounds the inner side wall of the variable heat conducting pipe and extends along its axial direction, and a gas channel is formed near the central axis of the variable heat conducting pipe; the liquid working medium is absorbed by the liquid wick, and the non-condensable gas is located in the gas channel.

5. The liquid-cooled heat pipe radiator according to claim 4, characterized in that: The heat dissipation substrate and one end of the liquid cooling plate are close to each other; a plurality of interconnected grooves extending in parallel directions are provided on the same side plate surface of the heat dissipation substrate and the liquid cooling plate, and the same variable heat conduction pipe is arranged in the same interconnected groove.

6. The liquid-cooled heat pipe radiator according to claim 4, characterized in that: The heat dissipation substrate is an I-shaped structure, and a plurality of grooves extending in parallel directions are connected to each other on the outer sides of the two plates of the heat dissipation substrate. The same variable heat conduction pipe extends from the outer side surface of the heat dissipation substrate plate on one side to the outer side surface of the plate on the other side; the liquid cooling plate is tightly attached to the outer side surface of one of the plate surfaces of the heat dissipation substrate.

7. The liquid-cooled heat pipe radiator according to claim 4, characterized in that: A plurality of interconnected grooves extending in parallel directions are provided on both side panels of the heat dissipation substrate, and a same variable heat conduction pipe is connected to both side outer panels of the heat dissipation substrate, wherein one side outer panel of the heat dissipation substrate is bonded to the liquid cooling plate.

8. The liquid-cooled heat pipe radiator according to any one of claims 5 to 7, characterized in that: The variable heat conduction pipe is flattened and embedded in the groove, and silicone grease is filled in the embedding gap.

9. The liquid-cooled heat pipe radiator according to claim 8, characterized in that: The variable heat conduction pipe has a diameter ranging from 2 mm to 20 mm and a length ranging from 50 mm to 500 mm.

10. The liquid-cooled heat pipe radiator according to claim 9, characterized in that: The non-condensable gas is nitrogen or argon.

Images