Abstract: As one of the key indexes to measure the energy efficiency of water heaters, thermal insulation performance directly affects the use and promotion of water heaters. With more and more high requirements for energy saving and environmental protection ideas, the thermal insulation performance of water heater tank is paid more and more attention to by production enterprises. Through experimental verification and theoretical analysis, this paper systematically studied the influence law of foaming raw material ratio and foaming layer density on the insulation performance of the water tank. The results showed that when the ratio of isocyanate and combined polyether polyol was 1.05:1, the foam layer density was 38~45Kg/m³, the insulation performance of the water tank was better, and the temperature drop of the water tank could be reduced.

Key words: Water heater, Rigid polyurethane foam, The ratio of isocyanate to the combination polyether polyol, The density of foam layer