Abstract: By analyzing the phenomenon of frosting and defrosting of evaporator, the scheme of shortening defrosting time of cryogenic vertical cabinet is verified. Using aluminum tube heating wire instead of steel tube heating wire for defrosting, Lengthening the size of steel tube heating wire and improving the power of defrosting heating wire, and program-controlled defrosting cut-off temperature, an effective way to shorten the defrosting time of household cryogenic refrigerators has been obtained. The main conclusions are as follows: the defrosting time is shortened by 5.5% when the aluminum tube heating wire replaces the steel tube heating wire; By lengthening the size of the heating wire, the defrosting time is reduced by 19.0%; The program controls the defrosting cut-off temperature, and the defrosting time is reduced by 24.1%.

Key words: Defrosting time, Frosting, Cryogenic