Abstract: Aiming at the refrigeration air duct system of a refrigerator with two door double system and evaporator bottom installation structure, the three-dimensional volute model of logarithmic spiral line is created by using UG law curve method to quickly match the centrifugal fan. Then the numerical model creation and simulation research of the refrigeration room and refrigeration air duct system are carried out, which proves that the logarithmic spiral line volute has excellent aerodynamic performance, it can meet the stringent requirements of long-distance air supply of small air volume centrifugal fans. The performance of the whole machine is verified by experiments. The temperature fluctuation in and between drawers is within 1℃. The research results have certain reference value for the optimal design of the volute and air duct system of the refrigerator installed at the bottom of the evaporator.

Key words: The refrigerator, The evaporator, Bottom installation, Logarithmic spiral curve, Spiral case, Frozen air duct