NUMERICAL SIMULATION STUDY OF THE HEAT-TRANSFER PREFORMANCE OF PULSATING HEAT PIPE AT MEDIUM AND LOW TEMPERATURE

Pulsating heat pipe(PHP) is a high-efficiency heat transfer device with simple structure and excellent heattransfer performance. In order to study the pulsating heat pipe which can be used in cryogenic refrigerator at the liquid R508B zone,a three-dimensional numerical model was established and numerically analyzed based on the VOF method in the paper. The filling ratio(30%,50%,and 70%) and input power(20 W, 40 W, 60 W, 80 W, 100 W and 120 W) were applied in present numerical investigation. The distributions of vapor-liquid in PHP after the initial of working fluid and the temperature distribution were simulated. The influence of filling ratio and input power effect on the performance of heat transfer was discussed. The simulation results show that the characteristics of the flow in the R508B zone are similar with the room temperature PHP,when the heat pipe working at the stabilization stage, the fluctuation of temperature is periodic.The heat transfer performance of pulsating heat pipe is changed with the increase of heating power, when the filling ratio is low,the temperature difference and the equivalent thermal resistance of cold and hot part are relatively small in the low heating power, the equivalent thermal resistance will increase in the high heating power. When the filling ratio is high,the temperature difference and the equivalent thermal resistance of cold and hot part are relatively big in the low heating power, and the equivalent thermal resistance will decrease with the increasing of heating power.