The Experimental Study Of Pump-assisted Loop Heat Pipes System

With the development of electronic technology, electronic components are highly integrated, which leads to the miniaturization of the size. These components will work with a high heat flux, while the traditional cooling technology cannot meet the demand of heat transfer. This will cause local high temperature on the surface of the components, which affect the reliability of the operation. Loop heat pipe(LHP) is a high efficient and passive heat transfer device, which transfers heat by two-phase cycle of the working fluid that evaporates in the evaporator and condenses in the condenser. However, with the application of electronic devices in the space technology, the traditional LHP systems have great limitations on the transmission distance and operation stability. Therefore, the traditional LHP systems need to be improved.A pump assisted loop heat pipe system was designed in this paper, include the fabrication of the system. Evaporator is the core component whose design determines the operating characteristics of the system directly. A “pipe-in-pipe” style condenser in this paper dissipates heat to the ambient. The ejector is utilized to take away the liquid condensed in the condenser quickly and reduce the pressure in the vapor loop simultaneously, so that the vaporization temperature and the evaporator wall temperature will also be decreased. Reservoir has the extra liquid. Micro-pump offers the main power in the system circulation.The system was tested in terms of start-up and steady state performance under different condition. The regularity and mechanism of the system operation was put forward by research.The experiment results showed that a 1.5 m-long heat transmission was realized. The system can work steady with a range of the heat load from 10 W to 140W(while the heating area was 10.2cm2), and the working temperature was < 80 oC. Besides, the System has a relatively safe start-up performance. The evaporation temperature and pump power has the function of regulating the working temperature of the system. In the actual process of temperature control of electronic devices, it is necessary to meet the different needs of the actual.