Research On Cooling Of High-power LED Based On Pulsating Heat Pipe

High-power LED as a kind of energy-saving light source, its featuressuch as energy saving, environmental protection, light color purity, highphotosynthetic efficiency, long service life, etc, make it widely used in thefield of road lighting. However, when high-power LED works, about85%~90%of input electric energy changes into thermal energy, which produces agreat quantity of heat, if this heat can’t be sent out timely and effectively, thejunction temperature of chip would rises continuously, thus speeding up theageing of the chip and shortening the life of the device. Therefore, the rise oftemperature of LED chip should be controlled, and the heat it releases shouldbe moved efficiently. Thus it can be seen that it is meaningful to explore theeffective heat dissipation of high power LED lamp. In this paper, the maincontent is:（1）Studied the heat dissipation mechanism of pulsating heat pipe in theLED street light and LED lamp cooling performance experimental platform isestablished. With infrared thermal imager LED lights, the temperature ofsingle loop pulsating heat pipe is tested, whose working medium is R123,charging rate45%, and the angle is90°, to discuss the influence of heatingpower on thermal resistance.（2）The radiator thermal resistance network diagram is acquired byadopting thermal simulation method which takes a pulsating heat pipe finradiator as the research object and the thermal resistance value and chipjunction temperature is also calculated. On this basis, the numericalsimulation analysis is studied by using ICEPAK thermal analysis software. Itturns out that the theoretical calculation result agrees with the simulationresults.（3）Also studied the influences on the chip junction temperature by thefin spacing, fin spacing and thickness, fin size, fin heat transfer area and finheat pipe hole position.（4）The numerical analysis of the loop pulsating heat pipe thermalmodule is carried out. To test and verify the reliability of simulation, the pointtemperature meter and infrared thermal imaging temperature measurement forthe lamp are respectively adopted, thus finding near the heat pipe of the two chips of temperature is higher than middle chip temperature. The relativedeviations of experimental and simulated values are within the error range.