The Experimental Study And Numerical Simulation On Heat Dissipation Of LED Device Based On Loop Heat Pipe

Light sources have become an indispensable part of us with the improvement of era.The high power white LED has turned into a kind of new light source of replacing incandescent light bulb and fluorescent lamp gradually.The high power white LED which was used to illuminate has so longer lifetime and higher luminous efficiency than the traditional light source that it owns move expansive prospect in the lighting marketplace.The high power white LED sends out more and more heat due to its node temperature and heat flow density became high,meanwhile,it has the trend to miniaturization,high integration,high speed and high frequency in the direction of development.The lifetime of LED will be influenced seriously if the heat which produced can not send out in time.The higher requirement was put forward about the heat dissipation of high power white LED that used to light.It has been a core problem of solving high power white LED about how to transfer the heat in time.This paper realizes the more excellent heat dissipating function because of using loop heat pipe(LHP)to transfer the heat of LED timely and finding the finest charging rate across the experiment after analyzing the transmission theory of LHP.The result proved that the reasonable air pressure can reduce junction temperature effectively through study the influence of air pressure on the heat dissipation of LED chip.The change of input power could alter the function of the heat pipe,and the thermal resistance of system will change with the different angle of the evaporator.This paper simulates LHP evaporation simply through the heat of LED chip by transferring heat on phase change with using the CFD software.Then,it also simulates the heat situation of condensing side.At the same time,it simulate the influence of the heat dissipation on air pressure across the result of experiment,and it realize optimizing through simulating the heat dissipation of condensing side by adding different shape of fin in the condensing side of LHP that it changes circular tube to oval tube.It adds the fins to the conventional LHP in the paper that proved it owns better heat dissipation effect.The result reveals that heat exchange amount in the condensing side increases with the augment of speed which comes in the air,and it also verified that changing the area of heat dissipation in the condensing side when the air pressure add to a settled level could accelerate the heat exchange of the condensing side in the time.The use of LHP to the heat dissipation of high power white LED device wasproved feasible.It gains a better solution of junction temperature about LED device based on the experiment study and software simulation optimizing,so it makes LED device popularize preferably and improves the energy saving features of LED device.