Experimental and Computational Study of the Thermal Insulation Properties of Hollow Glass Microspheres

Abstract Hollow Glass Microsphere (HGM) is expected to be used in cryogenic liquid storage tanks as an insulating material with better insulation performance and lower maintenance cost instead of perlite. Obtaining the effective thermal conductivity of HGM can help to improve the insulation performance of cryogenic tanks. In this paper, a test system based on the transient plane source (TPS) method was designed and constructed, and the effective thermal conductivity of six models of HGMs from four suppliers at 200-300 K was measured. The results show that the effective thermal conductivity of HGMs at atmospheric pressure 200 K environment is only 25.87-35.84 w/(m·K). The effective thermal conductivity in the atmosphere and room temperature, as well as in low pressure and low temperature was calculated by the derived system of equations, which is in good agreement with the experimental results. The integrated thermal conductivity is still dominant in low pressure and low temperature, and the reduction of the true density contributes to the improvement of the HGM insulation performance.