Experimental study on a helium cryogenic closed loop two-phase thermosyphon with a long heat transport distance

• Published in: Cryogenics (Guildford) 2023-12, Vol.136, p.103759, Article 103759
• Main Authors: Hu, Rui, Song, Yuntao, Yang, Qingxi, Chen, Zhaoxi, Ding, Kaizhong
• Format: Article
• Language: English
• Subjects: Charging ratio; Closed loop two-phase thermosyphon; Condenser temperature; Heat load; Helium; Thermal performance
• ISSN: 0011-2275; 1879-2235
• DOI: 10.1016/j.cryogenics.2023.103759

•For the cryogenic CLTPT with a liquid charging ratio of 32.5 % at the condenser temperature of 4.36 K, the ETC is 30,000–60,000 W·m−1·K−1.•The ETC of the cryogenic CLTPT rises when the heat input to the evaporator is increased.•The ETC of the cryogenic CLTPT at the condenser temperature of 4.2 K decreases with increasing liquid filling ratios for liquid charging ratios between 25 % and 42.5 %, and the maximum transport is greater than or equal to 0.97 W.•The maximum transport first increases and then decreases with increasing liquid charging ratio.•It is found that the thermal performance of the cryogenic CLTPT can be improved by increasing the condenser temperature. In this paper, the thermal performance of a cryogenic closed loop two-phase thermosyphon (CLTPT) with a long heat transport distance is investigated experimentally. The cryogenic CLTPT consists of an evaporator and a condenser connected by two stainless steel tubes. Helium serves as the working fluid in the cryogenic CLTPT, and there is a vertical distance of 0.9 m between the condenser and the evaporator. The experiments are carried out to investigate the effects of heat load, charging ratio, and condenser temperature on the thermal performance of the cryogenic CLTPT. According to the findings, for the cryogenic CLTPT with a liquid charging ratio of 32.5 % and the condenser temperature of 4.36 K the effective thermal conductivity (ETC) is between 30,000 and 60,000 W·m−1·K−1, and the ETC rises when the heat load on the evaporator is increased. The ETC of the cryogenic CLTPT at the condenser temperature of 4.2 K decreases with increasing liquid charging ratios for liquid charging ratios between 25 % and 42.5 %, Additionally, the maximum heat transport initially rises and subsequently falls with rising liquid charging ratio. In the end, it is discovered that raising the condenser temperature of the cryogenic CLTPT enhances its thermal performance.