Experimental Research Of Flat Plate Cpl And Numerical Simulation For Evaporator

Space technology is one of the most popular and the fastest growing science in twenty-first century. Because of high-power and high heat flux electronic equipments widely used and space limitation on spacecrafts, traditional thermal control devices have been difficult to meet the requirements. In recent years, a sort of thermal control device (Capillary Pumped Loop) has been concerned, which has more compact structure and more stable performance and higher heat transfer capability. It depends on capillary force driving CPL system from porous media and working fluid phase changing. Therefore, CPL is more suitable for spacecraft thermal control systems due to the characteristics of high power and long-distance transmission.This thesis introduces development of CPL from homeland and abroad and expounds operation principles and heat transfer characteristics. This thesis improves former CPL system. By turning the evaporator over and splitting a cross channel on liquid pipeline to evaporator, the new structure eliminates influence of non-condensated gas to CPL system. And the influence of non-condensated gas is carried into qualitative analysis. Non-condensated gas will block liquid pipeline, which leads to dry-out phenomena.A series of startup and operation capability experiments are carried out under the conditions of gravity assisted and non gravity assisted. The experiment results show: under the gravity assisted condition, CPL could start up smoothly when heat load is 100W to 800W (heat flux up to 2.05W/ cm~2); under the non gravity assisted condition, CPL could start up smoothly when heat load is 100W to 500W (heat flux up to 1.28W/ cm~2). Through operation capability experiments, the results show that the CPL system has the capability of well bearing mutative heat load.This thesis establishes a three-dimensional model of evaporator of CPL system. And heat transfer and fluid flow characteristics under different heat flux densities are numerically simulated using mixture model of FLUENT software. Moreover, flow and heat transfer conditions in evaporator are simulated by changing size and transforming figure of vapor channel. After a series of numerical simulation, the thesis hopes to offer suggestions for optimal design of evaporator.