Peculiarities of heat transfer in a flat disk-shaped evaporator of a loop heat pipe

• A flat disk-shaped evaporator of loop heat pipe is studied.
• An effect of convection in the wick on evaporator temperature is considered.
• Two models for simulation of thermal processes in the evaporator are presented.
• Simulation data shows the liquid filtration has a weak cooling effect.
• Heat transfer in the wick is mainly fulfilled over its framework.

Two models of a flat disk-shaped evaporator of a loop heat pipe have been developed for analyzing the effect of the convective component on heat transfer in a wick, and also on heat-exchange processes in an evaporation zone. Simulation data were obtained for two evaporators. The first evaporator was made entirely of copper, and the second had a body of stainless steel and a nickel wick. The geometrical dimensions of the evaporators were equal. The diameter of the heating zone was 30 mm. Calculations were made for heat fluxes from 2.8 ⋅ 104 to 4.2 ⋅ 105 W/m2. Water was used as a working fluid. An analysis of the results has shown that the contribution of the convective component to the overall heat transfer is small. The higher the thermal conductivity of the wick, the smaller the effect that the convection has on the temperature distribution in the evaporator.