Abstract: Polyurethane foam is the most important insulation material for fridge freezer. It can be regarded as homogeneous thermal insulation material. With the change of temperature, humidity and pressure, the thermal conductivity also changes. When the refrigerator is working, the room temperature is different, leading to different insulation properties of polyurethane foam, so we need a more reasonable method to evaluate polyurethane foam insulation performance. At the same time, different room temperature of the refrigerator is different, the foam insulation performance between the rooms is different, so the thickness of the foam layer should also be different, so as to draw a reasonable thickness of the foam layer.

Key words: Polyurethane foam, Thermal load simulation, Comprehensive thermal conductivity, Thickness of foam layer