The Mean Apparent Thermal Conductivity of a Newly Improved Polyurethane Foam with Blowing Agent of HFC-245fa under Low Temperature

摘要

Polyurethane (PU) foam is widely used in storage and transportation systems of cryogenic liquid. Because of high ozone depletion potential (ODP), CFCs are being phased out as blowing agents in the polyurethane foam industry. To meet the urgent need of thermal insulation and substitute for traditional foam with blowing agent of CFCs, a new PU foam was developed. But the coefficient of thermal conductivity of the new foam is not available at present when it is used for cryogenic storage tank and pipes. In this paper, the mean apparent thermal conductivity under low temperature of the new PU foam with blowing agent of HFC-245fa, which has zero ODP, was investigated. The relationship between density and the thermal conductivity was experimentally studies. The result proved that the newly developed material had a better performance in thermal insulating system and provided a reference data when use the material under low temperature. At last, the mechanism of heat transfer in the foams was analyzed.