Experimental investigation and analytical prediction of a multi-channel flat heat pipe thermal performance

Abstract

Recently, multi-channel flat heat pipes have been developed to improve the heat recovery from flat surfaces, such as solar panels and batteries. In this paper, the thermal performance of a multi-channel flat heat pipe is experimentally investigated and analytically predicted. The multi-channel heat pipe studied transmits heat from silicone flat heaters to a water flow circulating inside a cooling manifold. The manifold heat sink is a flat aluminium surface comprising channels in which water recovers thermal energy by forced convection. The impact of the water flow rate on the working temperature of the heat pipe is investigated. To predict the performance and working temperature of the multi-channel flat heat pipe, a theoretical model has been developed. The thermal model considers the two-phase heat transfer in a multi-channel heat pipe geometry. It is shown that the heat pipe working temperature decreases with the water flow rate as a result of a reduced forced convection resistance of the manifold. Finally, the analytical multi-channel flat heat pipe model developed is compared with experimental data. It is shown that the thermal model, considering both cooling manifold and the multi-channel heat pipe geometry, is able to predict the heat pipe working temperature evolution within 7%.