Experimental study of microrectangular groove structure covered with multi mesh layers on performance of flat plate heat pipe for LED lighting module

Abstract

The paper presents a novel concept for a coronary-stent-like model to solve the problem of compactness between wick and copper mesh, which can enhance the performance of the hybrid structure flat plate heat pipe (FPHP) of LED lighting modules. The various wick structures combine axial rectangular grooved structures, manufactured in aluminum extraction, and the concept of a coronary-stent-like model, which provides a supportive copper mesh and wick structure. In this study, the performance of FPHP was experimentally measured at different inclination angles and heating areas. The axial rectangular groove structure and copper mesh layer structures have different permeabilities and capillary pumping forces, and combining these two structures could be beneficial for pumping the required operational fluid across the axial groove structure and from the condenser to the evaporator under different inclinations of the flat plate heat pipe. The exterior wall temperature of the FPHP was measured to evaluate the thermal resistance and vapor heat transfer coefficient at the condenser and evaporator for 31×31 and 10×10mm2 heating areas. The experimental result showed that the FPHP has better performance in both the junction temperature of the LED light module and the uniformity of the substructure temperature. The highest FPHP temperature was decreased by 28%, as compared to a commercial substrate. In addition, a 200W LED light module, running for 9h with FPHP, maintained luminance at about 2080 lux due to its low thermal resistance and high capillary force.