A robust pulsating heat pipe cooler for integrated high power LED chips

This paper presents a closed loop pulsating heat pipe (CLPHP) with specific pipe arrangement for high power LED cooling. Two CLPHPs were fabricated and charged with DI water and methanol, respectively. The effects of gravity force and working fluid on the heat transfer performance were investigated carefully. Results show that the water-CLPHP performed better than the methanol-CLPHP, with a minimum thermal resistance of 0.06 A degrees C/W at a 220 W heat load under air natural convection situation. In addition, the gravity force can help the CLPHP starting up and enhance the robustness of the thermal transportation at steady state. Finally, the real application to cooling a 100 W LED chip indicates that the proposed CLPHP can meet the thermal control requirement for integrated high power LEDs. Nevertheless, the low cost and light weight of the proposed CLPHP heat sink are very suitable for the LED lighting devices.