Experimental Study on Transient Behaviors of Gas in Thermal Insulation Media at Rapid Depressurization

Abstract

Thermal insulation system is often used to high temperature gas-cooled reactors. In the present paper, transient behavior of the gas flow in thermal insulation media is ex- perimentally studied in the case of sudden decrease of coolant pressure. The structure of these systems is capable of substituting for the simplified model that the gas in a container filled with porous insulation media exhausts from a balancing hole to the main flow. In the case of rapid depressurization, transient behaviors are measured by pressure sensors along an axial direction of the insulation layer, changing experimental parameters such as pressure gradient, opening of a balancing hole and packed density. The induced pressure is measured along the axial direction of the insulation layer. The induced pres- sure difference and the peak value of pressure difference are summarized with parameters. Lastly, a satisfactory agreement between experimantal and analytical results is obtained for several specified cases of testing.