A low-temperature gravity heat pipe using carbon dioxide as a working medium and its filling method

Abstract

The invention discloses a low-temperature gravity heat pipe taking carbon dioxide as a working medium and a filling method of the low-temperature gravity heat pipe, and belongs to a low-temperature gravity heat pipe and a filling method thereof. The low-temperature gravity heat pipe comprises a one-way needle valve, a pipe body, insulation cotton and a quick-mounting one-way valve male head; the two ends of the pipe body are connected with the one-way needle valve and the quick-mounting one-way valve male head respectively, and the insulation cotton sleeves the outer wall of the pipe body. Thefilling method comprises two filling schemes, namely an emptying method and an evacuation method. In order to optimize the filling of the heat pipe, the operation is simple, the safety is high, and the performance of the obtained heat pipe is good; and the performance of the heat pipe obtained by the evacuation method is extremely excellent, and the heat transfer temperature difference is small.The gravity heat pipe has the advantages of being simple in structure, convenient to manufacture, low in cost, easy to popularize, simple in operation, and high in safety; the performance of the obtained heat pipe is good, the carbon dioxide is easy to prepare, the cost is low, the chemical property is stable, and the filling method is free of inflammability and corrosion, environment-friendly, easy to popularize and widely applicable to the fields of low-temperature cold storage, gas separation, methane purification, plateau frozen soil foundation reinforcement and the like.

Description

technical field [0001] The invention relates to a low-temperature gravity heat pipe and a filling method thereof, in particular to a low-temperature gravity heat pipe using carbon dioxide as a working medium and a filling method thereof. Background technique [0002] In recent years, low-temperature refrigeration technology has developed rapidly, such as low-temperature medical treatment (minimum about -120°C), spacecraft thermal control (-15°C to 50°C), space radiation heat dissipation (-50 to 600°C), and low-temperature refrigeration for infrared detectors. (-271.5℃~-123.5℃) and other fields require heat exchange at low temperatures. According to different working temperatures, refrigeration technology can be divided into general cooling technology (ambient temperature to -153°C) and cryogenic technology (below -153°C). The enhanced heat transfer in these fields has great impact on energy saving, environmental protection and equipment working effect. Significance. [000...

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Problems solved by technology

[0003] As a heat exchange element that works with the phase change of working fluid, the heat pipe has good isothermal properties and high heat transfer efficiency. It is widely used in the fields of aerospace temperature control and heat dissipation of electronic components. Low temperature fields such as foundation reinforcement have also been successfully applied, but overall, heat pipes have not been widely used in low temperature fields. The reason is mainly limited by the following two factors: First, the filling process of low temperature heat pipes is not mature enough. The most important link in the production process, filling is the process of filling the working medium into the tube body, but the common problem at present is that the filling equipment is relatively complicated, or the vacuum degree and the purity of the working medium do not meet the requirements, which affects the filling effect , and there are even potential safety problems, such as high pressure and toxicity; secondly, the lower limit of the temperature in the general cold temperature range is still not low enough. The boiling point of Freon refrigerant is about -30°C, and the boiling point of ammonia is -33.5°C. When the working temperature of the heat pipes of these two working fluids is lower than this temperature, the heat transfer performance will drop sharply.

[0006] At present, heat pipes using carbon dioxide as the working fluid are mostly used above 0°C. For example, in the application of data center heat dissipation, the working temperature is 10-20°C, and the use cases below 0°C are rare, so Its low temperature heat transfer advantage has not been brought into play

In addition, the current carbon dioxide filling methods are all directly filled in liquid form. Due to the high pressure of liquid carbon dioxide, leakage is easy to occur, so the requirements for the sealing of the filling equipment are high, and the high-pressure equipment itself has high requirements for safety. At the same time, the low temperature generated during the leakage of carbon dioxide will also have certain safety hazards

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