Loop Heat Pipe Manufacturing Technology And Performance Study

Recently,the aerospace industry has developed rapidly.The complex environment of space is increasing the demand for heat dissipation equipment.With the development of electronic devices to miniaturization and integration,the heat flux density of electronic component is increasing.if the temperature of electronic equipment can't be effectively controlled,it will have serious consequences.Loop heat pipe(LHP)is a two-phase heat transfer device,with high heat transfer efficiency,long transmission distance,the characteristics of gravity and without external drive,is considered to be the effective means to solve the problem of heat dissipation.The heat leak causes slow start speed and low heat transfer efficiency,which is bad for temperature control performance.To fabricate new material capillary wick and improve the structure of LHP system is an effective means to reduce heat leak.In this paper,AI2O3-Ni capillary wick is successful fabricated.By observing the SEM images,pumping performance testing,and measuring thermal conductivity of the capillary,the results proved that AI2O3 reduces the thermal conductivity of the capillary and does not affect the capillary pumping performance.In this paper,we designed the LHP system and the experimental platform was set up.The experimental data showed that the AI2O3-Ni capillary wick reduced the heat leak of LHP.In this paper,we designed a set of process of electroless copper plating on carbon fiber,and successfully prepared the copper-plating carbon fiber with high quality.The characteristics of copper-plating carbon fiber,which has high longitudinal thermal conductivity and low lateral thermal conductivity,are observed through the microscope.The porosity of copper-plating carbon fiber was measured as high as 85%.The performance curves of copper-plating carbon fiber and Ni capillary were compared,and copper-plating carbon fiber was found to have higher pumping performance.Copper-plating carbon fiber was used for capillary wick and a set of flat loop heat pipe(FLHP)system is designed.The test platform was established,and the FLHP can successfully started and run stably in 5 w-20 w.We analyzed start characteristics of FLHP under different power and filling ratio and the results showed:the higher the power,the shorter the start-up time;the higher the filling ratio,the more difficult it is for FLHP to start and the more effective it is to reduce the heat leak.By increasing PTFE insulation,the thermal resistance of the evaporator floor to the reservoir was increased,and the heat leak was reduced.This paper designed a dual compensation chamber LHP(DCCLHP).Studies showed that the dual compensation chamber structure reduced the heat leak,by enhancing the cooling effect of the reservoir.The maximum heat load is 55 w,when working temperature of evaporator is below 100? and thermal resistance of the system is 0.523?/w at 55w.The FLHP can operate smoothly at the power of 15w to 55w.