Thermal property of insulating material at cryogenic temperature

• Published in: Journal of mechanical science and technology Vol. 26; no. 7; pp. 2125 - 2128
• Main Authors: Choi, Yeon Suk, Kim, Dong Lak
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Heidelberg Korean Society of Mechanical Engineers 01.07.2012; 대한기계학회
• Subjects: Analytical and numerical techniques; Applied sciences; Classical transport; Control; Dynamical Systems; Electrical engineering. Electrical power engineering; Engineering; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Heat conduction; Heat transfer; Industrial and Production Engineering; Mechanical Engineering; Physics; Statistical physics, thermodynamics, and nonlinear dynamical systems; Testing. Reliability. Quality control; Transport processes; Vibration; 기계공학; Thermal conductivity; Insulation material; Cryogenic temperature; Heat transfer; Heat sources; Thermal insulation; Thermal bridge; Heat flow; Non metallic material; Space heating; Metallic material; Thermal properties; Thermal resistance; Polypropylene; Ambient temperature; Thermal insulating material; High-Tc superconductors; Insulating paper; Effective medium model; Thermal conduction
• ISSN: 1738-494X; 1976-3824
• DOI: 10.1007/s12206-012-0528-y

The thermal property of insulation material is essential in developing high temperature superconductor (HTS) devices operating at around liquid nitrogen temperature. Unlike metallic materials, nonmetallic materials have a thermal resistance; therefore, accurate estimate of the heat flow is difficult in the case of nonmetallic materials. In this study, a precise instrument is developed for measuring the thermal property of insulating materials over a temperature range of 30 K to approximately the room temperature by using a cryocooler. The cold head of the cryocooler is thermally anchored to the thermal link and used to cool the apparatus to a desired temperature. The temperature distribution in specimen is measured with respect to the supplied heating power, from which the thermal conductivity is calculated and compared with published data for accuracy confirmation. The effective thermal conductivity of polypropylene laminated paper (PPLP) is presented and the trend in the behavior of conductivity near liquid nitrogen temperature is also discussed.