Effect of Xenon Gas and Foils on a Multi-Foil Insulation

The miniaturization of thermal installations has been also extended to compact insulations in processes maintained at low or high temperatures, and restricted to minimal heat losses or gains. The current investigation has been conducted experimentally and numerically, aiming to predict the performance of a multi-foil array, in which xenon gas is entrapped between steel foils, separated and supported by widely spaced ceramic particles. A parametric study of the effect of an increased number of foils, as compared to the experimental array, shows the preferred directions to design of such arrays. The performance of an array operated with xenon gas at near-atmospheric pressure is compared to the performance of arrays filled with other gases. The low thermal conductivity of xenon gas leads to a lower effective thermal pseudo-conductivity of the array in all the pressure range, as compared to arrays operated with other gases. The equations of conduction and radiation are solved numerically for a wide range of pressures in temperature range of 20–500°C. Good agreement with experimental results is achieved.