Dirui Wu , Shiguang Wu , Jun Tan , Han Tan , Renjun Xue , Yujia Zhai , Dong Ma , Shuting Lu , Haizheng Dang
{"title":"Numerical simulation and experimental validation of the heat transfer characteristics in a circuit gas gap heat switch for the dilution refrigerator","authors":"Dirui Wu , Shiguang Wu , Jun Tan , Han Tan , Renjun Xue , Yujia Zhai , Dong Ma , Shuting Lu , Haizheng Dang","doi":"10.1016/j.cryogenics.2024.103818","DOIUrl":null,"url":null,"abstract":"<div><p>The gas gap heat switch (GGHS) used for controlling heat transfer between different stages can be an important component for the precooling process of some dilution refrigerators. In this paper, a novel circuit GGHS is a rotationally symmetric heat switch assembly with annular fin arrangements to strengthen the heat-transferring effect. A numerical model considering <sup>4</sup>He actual gas properties is proposed to investigate the heat transfer characteristics in the circuit GGHS, in which the effects of charge pressure, cold end temperature, thickness and length of walls on the mean thermal conductance (MTC) are studied. Simulation results show that the MTC increases with the growing cold end temperature, wall thickness, and length, respectively. Given the pressure of 10 kPa, cold end temperature of 4.2 K, wall thickness of 0.97 mm, and wall height of 66 mm, the theoretical MTC is 0.828 W/K. Experimental results indicate that the proposed simulation model is reasonable. Furthermore, the increment of the MTC decreases with the growing temperature. The GGHS used in experiments had a cold end temperature of 4 K, wall thickness of 0.65 mm, and wall height of 33 mm; the measured MTC was 0.219 W/K. Only when the temperature is above 10 K does the charge pressure have a pronounced effect on the MTC. This study provides helpful theoretical guidance for the design and optimization of the circuit GGHS.</p></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":null,"pages":null},"PeriodicalIF":1.8000,"publicationDate":"2024-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cryogenics","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0011227524000389","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"PHYSICS, APPLIED","Score":null,"Total":0}
引用次数: 0
Abstract
The gas gap heat switch (GGHS) used for controlling heat transfer between different stages can be an important component for the precooling process of some dilution refrigerators. In this paper, a novel circuit GGHS is a rotationally symmetric heat switch assembly with annular fin arrangements to strengthen the heat-transferring effect. A numerical model considering 4He actual gas properties is proposed to investigate the heat transfer characteristics in the circuit GGHS, in which the effects of charge pressure, cold end temperature, thickness and length of walls on the mean thermal conductance (MTC) are studied. Simulation results show that the MTC increases with the growing cold end temperature, wall thickness, and length, respectively. Given the pressure of 10 kPa, cold end temperature of 4.2 K, wall thickness of 0.97 mm, and wall height of 66 mm, the theoretical MTC is 0.828 W/K. Experimental results indicate that the proposed simulation model is reasonable. Furthermore, the increment of the MTC decreases with the growing temperature. The GGHS used in experiments had a cold end temperature of 4 K, wall thickness of 0.65 mm, and wall height of 33 mm; the measured MTC was 0.219 W/K. Only when the temperature is above 10 K does the charge pressure have a pronounced effect on the MTC. This study provides helpful theoretical guidance for the design and optimization of the circuit GGHS.
期刊介绍:
Cryogenics is the world''s leading journal focusing on all aspects of cryoengineering and cryogenics. Papers published in Cryogenics cover a wide variety of subjects in low temperature engineering and research. Among the areas covered are:
- Applications of superconductivity: magnets, electronics, devices
- Superconductors and their properties
- Properties of materials: metals, alloys, composites, polymers, insulations
- New applications of cryogenic technology to processes, devices, machinery
- Refrigeration and liquefaction technology
- Thermodynamics
- Fluid properties and fluid mechanics
- Heat transfer
- Thermometry and measurement science
- Cryogenics in medicine
- Cryoelectronics