Heat transfer characteristics of a parallel miniature heat pipe system

In this present study, the heat transfer characteristics of a parallel miniature heat pipes system (mHPs) intended for desktop computer processor cooling was experimentally investigated. The experimental system consisted of six single copper tube mHPs slotted into two copper blocks at the evaporator section and fifteen parallel copper sheets at the condenser section. The copper blocks were placed above the heat source (on the top of the computer processor) and the condenser section was provided with external fins perpendicular to the mHPs. Four working fluids, namely acetone, ethanol, methanol, and propanol-2 were used independently to probe the working fluids' effect on the thermal performance of the system. Heat transfer characteristics of the mHPs were determined based on the principle of phase change of the working fluids at different temperatures to evaluate the thermal performance. The thermal conductance and thermal resistance of the system were determined as the parameters of thermal performance. The results indicated that the thermal characteristics of the heat pipe varied significantly for different temperatures of the heat source at the evaporator and different working fluids. It was obtained that the methanol is the best working fluid to be used in a mHPs in comparison with other working fluids (acetone, ethanol, and propanol 2). Furthermore, the lowest evaporator surface temperature was achieved with the methanol based system.