DOI QR코드

DOI QR Code

Thermal Conductivity Measurement of Insulation Material for Superconducting Application

  • Received : 2011.05.03
  • Accepted : 2011.05.27
  • Published : 2011.05.31

Abstract

The thermal properties of insulation material are essential to develop a high-temperature superconducting (HTS) power cable to be operated at around liquid nitrogen temperature. Unlike metallic materials, nonmetallic materials have a high thermal resistance; therefore special attention needs to be paid to estimate heat flow correctly. Thus, we have developed a precise instrument for measuring the thermal conductivity of insulating materials over a temperature range from 40 K to near room temperature using a cryocooler. Firstly, the measurement of thermal conductivity for Teflon is carried out for accuracy confirmation. For a supplied heat flux, the temperature difference between warm and cold side is measured in steady state, from which the thermal conductivity of Teflon is calculated and compared with published result of NIST. In addition, the apparent thermal conductivity of Polypropylene laminated paper (PPLP) is presented and its temperature dependency is discussed.

Keywords

References

  1. F. Broggi and L. Rossi, "Test of an apparatus for thermal conductivity measurements of superconducting coil blocks and materials at cryogenic temperature," Rev. Sci. Instrum., vol. 67, no. 9,pp.3193-3200, 1996 https://doi.org/10.1063/1.1147583
  2. A. Hofmann, "The thermal conductivity of cryogenic insulation materials and its temperature dependence," Cryogenics, vol. 46, pp. 815-824, 2006 https://doi.org/10.1016/j.cryogenics.2006.08.001
  3. F. Rondeaux, Ph. Bredy and J. M. Rey, "Thermal conductivity measurements of epoxy systems at low temperature," A19 Conf: Proc., vol. 614, pp. 197-203, 2002.
  4. C. L. Tsai, H. Weinstock and W. C. Overton, "Low temperature thermal conductivity of Stycast 2850 FT," Cryogenics, vol. 18, pp. 562-563, 1978 https://doi.org/10.1016/0011-2275(78)90162-5
  5. A. L. Nayak and C. L. Tien, "thermal conductivity of micros ph ere cryogenic insulation," Advance in Cryogenic Engineering, vol. 22, pp.251-262, 1997
  6. P. Scheuerpflug, H. Morper, G. Neubert and J. Fricke, "Low-temperature thermal transport in silica aerogels," J. Phys. D: Appl. Phys., vol. 24, pp. 1395-1403, 1991 https://doi.org/10.1088/0022-3727/24/8/025
  7. H. J. M. ter Brake and G. F. M. Wiegerinck, "Low-power cryocoolcr survey," Cryogenics, vol. 42, pp. 705-718, 2002 https://doi.org/10.1016/S0011-2275(02)00143-1
  8. A. de Wade, "Pulse-tube refrigerators: principle, recent developments, and prospects," Physica B, vol. 280, pp. 479-482, 2000. https://doi.org/10.1016/S0921-4526(99)01840-2
  9. S. Mukoyama, M. Vagi, N. Fujiwara and H. Ichikawa, "Conceptual design of 275 kV class high-Tc superconducting cable," Physica C, vol. 470,pp. 1563-1566, 2010 https://doi.org/10.1016/j.physc.2010.05.162
  10. A. Ishiyama, X. Wang, H. Ueda, M. Vagi, S. Mukoyama, N. Kashima, S. Nagaya and Y. Shiohara, "Over-current characteristics of superconducting model cable using YBSO coated conductors," Physica C, vol. 468, pp. 2041-2045, 2008 https://doi.org/10.1016/j.physc.2008.05.276
  11. G. K. White, Experimental Techniques in Low-temperature Physics, Clarendon Press, 1989.
  12. F. P. Incropera and D. P. DeWitt, Fundamentals of Heat and Mass Transfer, John Wiley & Sons, 1996
  13. Cryogenic Material Properties, NIST, [Online] Available: http://www.cryogenics.nist.gov/

Cited by

  1. Specific Heat Measurement of Insulating Material using Heat Diffusion Method vol.14, pp.2, 2012, https://doi.org/10.9714/psac.2012.14.2.032