Numerical and experimental investigation on heat transfer of multi-heat sources mounted on a fined radiator within embedded heat pipes in an electronic cabinet

Abstract

In this paper, a finned heat sink for thermal management inside electrical cabinets was proposed to address the heat dissipation problem of some electronic equipment which are high heat flux and compact structure. The cooling system is mainly composed of four identical radiators, eight water-charged wickless L-shape heat pipes are embedded at the bottom of each radiator, and hollow fins are used in the condensation section of the heat pipes to enhance heat transfer. A thermal resistance network model of the heat pipe electric cabinet based on the superposition method was conceived. At the first part, experiments are conducted to measure the temperature of the heat source and the air in the air-flow passage. Transient and steady-state studies were carried out under different heating powers at the ambient temperature of 30 °C–35 °C. The maximum temperature difference between each heat source under forced convection is only 3.2 °C, which is more uniform than 10.36 °C in natural convection. The second part proposed a three-dimensional numerical model to further evaluate the heat transfer performance of the heat sink. The distribution characteristics of temperature field and flow field inside the cabinet are obtained by numerical calculation, and the variation of Ra number with height is further calculated. Taking the continuous junction temperature lower than 85 °C as the condition that the components in the cabinet can operate safely, the limit heat dissipation of the cooling device through natural convection can reach 763 W.