Numerical And Experimental Study On The Heat Dissipation Of High-power Electronics Based On Loop Heat Pipe

Nowadays,with the updating and technological innovation of electronic components,such as phones and computers,these electronic devices tend to be more sophisticated and multifunctional,which brings increasingly the problem of heat dissipation.Many methods have been put forward for this problem.Considering the safety and convenience,the air cooling is an effective way for these devices.However,the force-air cooling can't achieve the requirement without the mechanical vibration.The natural convection requires a sufficiently large heat dissipation area.It becomes a very important issue that how to efficiently conduct heat to the sink surface.Therefore,it has been studied in this paper from the numerical simulation of electronic components and the experimental studies of loop heat pipe(LHP).A related optimization is carried out aiming to the heat dissipation of high-power devices without mechanical vibration.In the beginning,this article does some research on the issue about the heat dissipation of high-power electronic components,and the structure of the electronic components is analyzed based on the actual situation.Combined with different environmental conditions and based on the CFD simulation of electronic components,this article studies the temperature distribution and heat dissipation under different environmental temperature and different natural convection conditions.So the geometric parameters of the cooling surface can be determined,which helps to optimize the structural parameters of the heat conductors.With existing research literature about heat transfer,the pros and cons of different heat transfer methods are compared and analyzed.Combined with the actual requirements,this article compares the thermal property of the LHP and good conductors(such as copper and aluminum)by utilizing simulation.With numerical analysis and related research from both domestic and abroad,this article chooses the LHP as the heat transfer equipment because of its flexible structure,long distance adaptation and low thermal resistance.Through theoretical analysis of the operation principle about LHP and the numerical simulation,the aluminum-water LHP is designed as the experimental system,mainly including the structural design of the LHP,choice of the working medium and production of the capillary structure.The article also introduces the applying of heat source,filling in working medium,temperature acquisition implementation in detail.The working mechanism and the preparation process of the capillary structure are especially emphasized.On this LHP system,relevant experimental studies are carried on about the influence factors such as refrigerant charge,heat source power and cooling water temperature.When the heat source power is 20 W(140 W)and cooling water temperature keeps at 30?,by measuring the LHP's evaporator surface temperature with different refrigerant charge(10 ml to 80 ml),72% is chosen as the optimal refrigerant charge proportion.The article also does research on 7 series of constant heat source power from 20 W to 200 W as well as a variable heat source power condition.It finds out that the LHP system faces start-up difficulties and temperature fluctuation when the heat source power keeps low.With the power getting higher,these phenomena gradually disappear and LHP's thermal resistance decreases.When the power gets 200 W,the LHP system can control its maximum temperature below 100? and its thermal resistance can reach 0.13 ?/W.What's more,three conditions of the LHP system are studied when the cooling water temperature is 10?,20? and 30? respectively.The results show that the lower the cooling water temperature is,the lower the heat source temperature is,but the thermal resistance of the LHP system becomes larger.At the end of this article,referring to CFD simulation and experimental results,by utilizing the design method of the pressure vessel and ANSYS Workbench software,optimized structural design of the copper-water LHP system is completed for the high-power electronic components.