Volume 51

Numerical study of two-phase flow during evaporation in a microchannel coil evaporator for refrigeration systems  Xiaohui Yu, Qinqin Kong, Sensen Jiang, Hongna Qiao

Abstract

The miniaturization of electronic devices generates high heat flux, so evaporators that combine miniaturization and heat transfer capabilities are needed to meet the heat transfer requirements. In this paper, the inner flow and heat transfer characteristics of a microchannel coil evaporator were investigated using numerical analysis. The effects of evaporating pressure, and heat flux on the heat transfer coefficient, outlet temperature, and outlet vapor volume fraction were analyzed. In addition, a comparison was made with a rectangular evaporator designed with an equivalent diameter of 0.4 mm. The results indicate that the microchannel coil evaporator can reach the maximum outlet temperature of 53.75 °C, and the heat transfer coefficient is 1835.6 W/m2. Compared to it, the area of the microchannel rectangular evaporator is reduced by 69% and the outlet temperature of the evaporator is decreased by 5.4% for the same amount of heat change. Meanwhile, the heat transfer coefficient has improved by 11.2%.

Keywords numerical analysis, evaporating pressure, heat flux, microchannel coil evaporator, heat transfer coefficient