Investigation of the cooling performance of a double-layer liquid-cooled plate with circular arc-shaped flow channels for thermal management of light-emitting diodes

Abstract

Since the integration and heat flux of high-power light-emitting diodes (LEDs) are continuously increasing in response to the rising demand for illumination, high-power LEDs require a sophisticated thermal management system to ensure stable operation and prolonged service life. In the present work, a double-layer liquid-cooled plate with circular arc-shaped flow channels was developed. Circular arc-shaped flow channels may help the fluid flow against the channels' wall more effectively by preventing the development of eddy and impact flow and minimizing flow resistance. Combining it with the double-layer design may conduct cooling in the hot spot area twice as effectively. Numerical analysis and experimentation were conducted to explore the hydraulic properties and cooling performance of the plate, and the LED chips' arrangement schemes were examined. Water and ethylene glycol solutions with varying mass concentrations are utilized as the working fluids. The pin temperatures and illumination characteristics of LED chips were assessed after being cooled using the created plate at various flow rates. The results demonstrate the advantages of the proposed liquid-cooled plate's flow characteristics and cooling capability. After cooling, the LED chips' pin temperatures may be kept below 50 °C. When the flow rate was increased from 0.03 L/min to 0.18 L/min and the operating power of the LEDs was 300 W, the luminous intensity of the chips rose by 1440–1680 lx. Based on the temperature of the surrounding environment, the appropriate working fluid should be employed in practical applications. Furthermore, when the j/f coefficient is large, less pump work is needed, and the plate cools more effectively. It satisfies the need for a lightweight cooling system because the produced liquid-cooled plate weighs only 200 g.