CN108775827A - Oscillating heat pipe and the method for realizing high charge download cable heat dissipation using oscillating heat pipe - Google Patents

Abstract

The invention discloses an oscillating heat pipe and a method for using the oscillating heat pipe to realize heat dissipation of a high-charge-carrying cable. The oscillating heat pipe is bent by a long and thin copper pipe to form a single or multiple elbows, and finally connected end to end to form a closed loop; A liquid filling port is provided in the closed circuit, which is used for the fluid working medium injected after the copper tube is evacuated, so that the fluid in the copper tube always maintains a vapor-liquid two-phase state, and the liquid filling port is sealed after the liquid filling is completed; The fluid distribution in the copper tube presents an interval state of a section of liquid and a section of gas. The curved copper tube is divided into two parts according to the spatial distribution, one part is the heat dissipation and condensation section, and the other is the heating and evaporation section. The structure of the oscillating heat pipe is simple, only a thin copper tube with a diameter of about 3mm is bent to form a serpentine pipe with a closed end to end loop, and the structure can be flexible and diverse, easy to match with a variety of cable wiring methods, and can be far away from the surrounding Combined with cold source, the cost of heat dissipation is low.

Description

Oscillating heat pipe and method of using oscillating heat pipe to realize high charge load cable cooling

technical field

The invention relates to the technical field of cable heat dissipation, in particular to an oscillating heat pipe and a method for using the oscillating heat pipe to realize heat dissipation of a high-charge-carrying cable.

Background technique

With the rapid development of economy and society, and people's pursuit of a better life. Various high-power-density power batteries, motors, and other high-power power electronic devices are developing rapidly, requiring high-current-density cables to meet their power-on requirements. For example: the cables required for fast charging of electric vehicles, the cables between battery modules inside electric vehicles and the connecting cables have high current densities and high heat generation of cables, which can easily cause aging of cables and even cause safety problems. In order to ensure the safety of its use, it is necessary to take certain measures to dissipate the heat of the cable in time to ensure that the temperature of the cable is always maintained within a safe range.

In addition, the cables with high heat generation are arranged in a compact space environment in many cases, and there is a long distance away from the cold source, it is not convenient to directly increase the cable diameter and arrange the air radiator or due to the long distance. May be in contact with a cold source for heat exchange. Therefore, it is necessary to seek more advanced and flexible heat dissipation technology to solve the cooling problem of these cables.

Contents of the invention

In view of the deficiencies in the prior art, the object of the present invention is to provide an oscillating heat pipe which has good heat dissipation performance and can run for a long time.

To achieve the above object, the present invention adopts the following technical solutions:

An oscillating heat pipe, the oscillating heat pipe is bent by a long and thin copper tube to form a single or multiple elbows, and finally connected end to end to form a closed circuit; a liquid filling port is provided in the closed circuit for the copper The fluid working medium injected after the tube is evacuated keeps the fluid in the copper tube in a vapor-liquid two-phase state. After the liquid filling is completed, the liquid filling port is sealed; the fluid distribution in the copper tube presents an interval state of a section of liquid and a section of gas. , The curved copper tube is divided into two parts according to the spatial distribution, one part is the heat dissipation and condensation section, and the other is the heating and evaporation section.

The diameter of the copper pipe is 2-3mm.

The cold source of the radiating and condensing section is an air-cooled aluminum fin radiator or a liquid-cooled cold plate; the heating source of the heating and evaporating section is a cable.

An oscillating heat pipe, the oscillating heat pipe is flat, the flat copper tube is provided with a plurality of microchannels, the microchannels are bent and connected end to end to form a loop, and adjacent microchannels communicate with each other to form a large closed loop, A liquid filling port is provided in the closed circuit, which is used for the fluid working medium injected after the microchannel is evacuated, so that the fluid in the microchannel always maintains a vapor-liquid two-phase state, and the liquid filling port is sealed after the liquid filling is completed; The fluid distribution in the microchannel presents an interval state of a section of liquid and a section of gas. The microchannel is divided into two parts according to the spatial distribution, one part is the heat dissipation and condensation section, and the other is the heating and evaporation section.

Microribs are arranged on the inner wall of the microchannel to increase the inner surface area of the microchannel.

Another object of the present invention is to provide a method of utilizing the above-mentioned oscillating heat pipe to realize heat dissipation of a high-charge-carrying cable. The heating and evaporating section of the oscillating heat pipe is closely attached to the cable, and the heat dissipation and condensation section is combined with a cold source.

Embed the heated evaporation section of the oscillating heat pipe into the tight insulation of the cable.

The beneficial effects of the present invention are:

Heat transfer is based on fluid phase change, with high heat transfer efficiency and fast heat dissipation speed; at the same time, the structure of the oscillating heat pipe is simple, and only a thin copper tube with a diameter of about 3mm is bent to form a loop serpentine pipe with a closed end and end, and the structure can be flexible and diverse. It is easy to match with a variety of cable routing methods, and can be combined with the surrounding long-distance cold source, and the heat dissipation cost is low.

Description of drawings

Fig. 1 is a schematic diagram of the working structure of the oscillating heat pipe provided by Embodiment 1 of the present invention;

Fig. 2 is a cross-sectional view of the oscillating heat pipe provided by Embodiment 2 of the present invention;

Fig. 3 is a partially enlarged schematic diagram in Fig. 2;

Fig. 4 is a schematic diagram of the cross-sectional arrangement of the single elbow oscillating heat pipe and the cooled cable in the third embodiment;

Fig. 5 is a cross-sectional view in Fig. 4;

Fig. 6 is a schematic diagram of the cross-sectional layout structure of multiple elbow oscillating heat pipes and cooled cables in Embodiment 3;

Fig. 7 is a cross-sectional view in Fig. 6;

Fig. 8 is a schematic diagram of an electric vehicle cable cooled by an oscillating heat pipe in Embodiment 4;

Explanation of reference signs: 1-thin copper tube, 2-liquid filling port, 3-radiation condensation section, 4-heating evaporation section, 5-cable copper core, 6-insulation layer, 7-power battery pack, 8-cold plate , 8a-cold plate coolant inlet, 8b-cold plate coolant outlet, 9-flat tube, 10-microchannel, 11-microfin.

Detailed ways

Below, in conjunction with accompanying drawing and specific embodiment, the present invention is described further:

Embodiment one

As shown in FIG. 1 , the oscillating heat pipe provided in this embodiment is formed by bending a long and thin copper pipe 1 to form single or multiple bends, and finally connects end to end to form a closed circuit. The diameter of the copper tube should not be too large, generally about 3mm, and there must be a liquid filling port 2 for injecting a certain proportion of fluid working medium after vacuumizing the oscillating heat pipe. Be careful not to completely fill the tube body, so that the fluid in the copper tube is always Maintain a vapor-liquid two-phase state. After the liquid filling is completed, the liquid filling port is sealed. The fluid working fluid can be water, methanol and other common working fluids for heat pipes. The copper tube does not need to be filled with capillary material like traditional heat pipes, and a certain degree of fluid flow must be maintained. Due to the capillary force of the thin copper tube and the gas-liquid two-phase state of the working medium, the fluid distribution in the copper tube generally presents a spaced state of a section of liquid and a section of gas. Then, the elbow is roughly divided into two parts according to the spatial distribution, one is the heat dissipation and condensation section 3 , and the other is the heating and evaporation section 4 . The heating source can be a heating power electronic module, a cable, etc., and this figure 1 is an example of heating by winding an electric heating wire. The condensing section 3 can rely on the copper tube to be close to or embedded in the finned heat exchanger or the cold source module, so that the heat can be dissipated from the copper tube to the surrounding environment or absorbed by the cold source. At this time, the steam in the condensation section is condensed into liquid, and the vapor-state working medium section is gradually shortened. The section is extended, so that the fluid flows due to the pressure imbalance between the evaporating section and the condensing section, and the working medium oscillates back and forth between the condensing section 3 and the evaporating section 4. Realize the heat transport of the heating section from the evaporation section 3 to the condensation section 4.

Embodiment two

In order to ensure good contact between the oscillating heat pipe and the cold/heat source, such as cables, cold plates, etc., as shown in Figure 2-3, the oscillating heat pipe can be made flat, and the cross section of the flat heat pipe is shown in Figure 3. A plurality of microchannels 10 are arranged in the flat tube, and the effect of each microchannel 10 can be equivalent to the fine copper tube 1 in the embodiment one, can be designed with the structure that each microchannel communicates at the two ends of the flat tube, the communication of each microchannel The form can refer to the connection of the thin copper tubes in FIG. 1 , so that the fluid can oscillate back and forth in each microchannel 10 in the flat tube 9 to exchange heat, realizing the function of an oscillating heat pipe. In addition, in order to enhance the heat transfer effect, some micro-ribs 11 can be processed on the inner wall of the micro-channel to increase the inner surface area of the micro-channel 10 and enhance heat transfer.

Embodiment three

A method for cooling a high current density cable by using an oscillating heat pipe, wherein the heating and evaporating section 4 of the oscillating heat pipe is closely combined with the cable insulating layer 6 . According to the heating power of the cable, the oscillating heat pipe can be designed as a single elbow as shown in Figure 4-5, two elbows as shown in Figure 6-7, or more elbows, distributed around the cable, and finally It is best to evenly insert into the insulating layer 6. And the heat dissipation condensation section 3 of the oscillating heat pipe is combined with the cold source to realize the heat dissipation function. The cold source can be in the form of an air-cooled aluminum fin radiator, a liquid-cooled cold plate, etc., and it can be set differently according to the actual application.

Embodiment Four

The present embodiment utilizes the oscillating heat pipe to cool the battery cable of the electric vehicle. As shown in FIG. The inlet 8a and outlet 8b are taken away after entering and exiting. The cable 5 connecting the battery pack with the motor and the charging device can be cooled by the above-mentioned oscillating heat pipe. The cold plates 8 of the set are in close contact. Like this, cable 5 also can generate heat when battery pack 7 works, and they can utilize cold plate 8 to carry out cooling at the same time, kill two birds with one stone, also can satisfy the requirement of limited space in the car, compact structure.

Those skilled in the art can make various other corresponding changes and deformations according to the above-described technical solutions and concepts, and all these changes and deformations should fall within the protection scope of the claims of the present invention.

Claims (7)

1. An oscillating heat pipe, characterized in that, the oscillating heat pipe is bent to form a single or multiple elbows by a slender copper tube, and finally connected end to end to form a closed circuit; a liquid filling port is provided in the closed circuit , used for the fluid working medium injected after the copper tube is evacuated, so that the fluid in the copper tube always maintains a vapor-liquid two-phase state. After the liquid filling is completed, the liquid filling port is sealed; the fluid distribution in the copper tube presents a section of liquid, A section of gas interval state, the curved copper tube is divided into two parts according to the spatial distribution, one part is the heat dissipation and condensation section, and the other part is the heating and evaporation section. 2. The oscillating heat pipe according to claim 1, wherein the diameter of the copper pipe is 2-3 mm. 3. The oscillating heat pipe according to claim 1, wherein the cold source of the heat dissipation and condensation section is an air-cooled aluminum fin radiator or a liquid-cooled cold plate; the heating source of the heating and evaporation section is a cable . 4. An oscillating heat pipe, characterized in that, the oscillating heat pipe is flat, and a plurality of microchannels are arranged in the flat copper tube, and the microchannels are zigzagged and connected end to end to form a loop, and the adjacent microchannels communicate with each other. A large closed circuit is formed, and a liquid filling port is set in the closed circuit, which is used for injecting the fluid working medium after the microchannel is evacuated, so that the fluid in the microchannel always maintains a vapor-liquid two-phase state. After the liquid filling is completed The liquid filling port is sealed; the fluid distribution in the microchannel presents an interval state of a section of liquid and a section of gas, and the microchannel is divided into two parts according to the spatial distribution, one part is a heat dissipation and condensation section, and the other is a heating and evaporation section. 5. The oscillating heat pipe according to claim 4, characterized in that micro-ribs are arranged on the inner wall of the micro-channel to increase the inner surface area of the micro-channel. 6. A method for utilizing the oscillating heat pipe described in any one of claims 1-5 to realize heat dissipation of a high-charge-carrying cable, characterized in that the heating and evaporating section of the oscillating heat pipe is closely attached to the cable, and the heat dissipation and condensation section is connected to the cold source. combined. 7. The method for realizing heat dissipation of a high charge-carrying cable by using an oscillating heat pipe as claimed in claim 6, characterized in that the heating and evaporating section of the oscillating heat pipe is embedded in the tight insulating layer of the cable.