Study On High Power LED Liquid Cooling System

The fourth generation light source LED(Light Emitting Diode) has lots of advantages, such as energy saving, environment protection and so on. The junction temperature directly restricts its quality and service life as the power and heat flux increase. The traditional air-cooling can’t meet the requirements of thermal design. Therefore, it is very significant that we develop new liquid cooling system and structures to ensure the normal work and life of LED.This paper analyzes the common heat dissipation methods for high power LED, and the cold plate liquid cooling system applied to high power LED is proposed. Targeting on high pole light with high power, a new secondary liquid cooling system, in which the pole of high pole light replaces the cold plate with fins to finish the secondary cooling of water is proposed. Through theoretical analysis and numerical simulation, the feasibility of secondary cooling with pole is proved, pointing out that the design key of the whole system is LED cold plate radiator.Six new channels including bi-S type channel, S with center entrance type channel, bi-S with entrance on the upper cover type channel, spiral type channel, U type channel, Z type channel are proposed on studying the disadvantages of the conventional channels including liner type channel and S type channel, and theoretically analyze the features and advantages of every kind of channel.Build the physical and mathematical models of the new type channels and respectively carry out numerical calculation on each channel by changing the entrance velocity, entrance temperature and heat source power. Study the effects of the main parameters on cold plate performances, so as to optimize the channel parameters and put forward the optimized channel schemes. At last compare the optimized model of every new type channel with the two traditional S type channels, and the results show that, except for the Z type port, the comprehensive performances of the rest five kinds of channels are better than two traditional S type channels’.Finally the optimized models of five new channels are applied to new type high power LED liquid cooling system, which will provide theoretical guide for engineering applications.