A Review on Thermal Performance of Different Working Fluids in A Dual Diameter Circular Heat Pipe
Pages : 108-111;http://dx.doi.org/10.14741/Ijcet/22774106/spl.4.2016.20
In this paper, a review on heat transfer performance of a 40 cm-length circular heat pipe with screen mesh wick, experimentally investigated is carried out. This heat pipe is made of copper with two diameters; larger in the evaporator and smaller in the adiabatic and condenser. Three different liquids including water, methanol, and ethanol are separately filled within the heat pipe. Low heat fluxes are applied (up to 2500 W/m2) in the evaporator and constant temperature water bath is used at three levels including 15, 25, and 35 ºC in the condenser. Results demonstrate that higher heat transfer coefficients are obtained for water and ethanol in comparison with methanol. Furthermore, increasing heat flux increases the evaporator heat transfer coefficient. For the case of methanol, some degradation in heat transfer coefficient is occurred at high heat fluxes which can be due to the surface dry out effect. Increasing the inclination angle decreases the heat pipe thermal resistance.
Keywords: Heat pipe; Thermal resistance, Heat transfer coefficient, Methanol, Ethanol, Water