The Heat Transfer Performance Of Pulsating Heat Pipe Heat Sink On Experimental Study And Its Application

With the rapid development of the electronic information industry and the popularization of electronic products.Electronic components are developing towards miniaturization and high integration.The working efficiency and safety of electronic components are seriously affected by temperature.If cooling cannot be effectively carried out,the performance of electronic components will deteriorate,or even burn down,causing huge losses to the whole system.The traditional way of heat dissipation has been unable to meet the current and future development needs,so the development of a new type of heat dissipation equipment,improve the heat dissipation ability is to meet the future challenges of the inevitable requirements.Pulsating heat pipe is a new type of heat dissipation element.It has been studied because of its simple structure,low cost,high heat transfer efficiency,and flexible arrangement.The heat transfer performance of pulsating heat pipe is mainly affected by geometric parameters,working fluid properties and operating conditions.Among these,the study of geometric parameters and operating conditions have important guiding significance for the practical application of pulsating heat pipe.To study the influence of geometric parameters and operating conditions on the heat transfer performance of pulsating heat pipe,theoretical support is provided for improving the heat transfer performance of pulsating heat pipe.In this paper,experiments are conducted by controlling the second type of boundary conditions,and data are analyzed by combining the temperature oscillation curve with the image of the infrared thermal imager.The following research is mainly carried out:(1)By using the method of dimensional analysis and force analysis,this paper expounds on the main reasons why gravity affects the running characteristics of pulsating heat pipe and provides a theoretical basis for how to change the angle and make reasonable use of gravity.(2)The start-up performance of single row pulsating heat pipe at different angles and the heat transfer performance during quasi-steady oscillation were studied.The start-up and heat transfer performance of pulsating heat pipe can be improved by changing the angle of the pipe.It is found that when the angle is 90°,the pulsating heating tube has the shortest start time,the lowest start temperature and the smallest overshoot temperature difference.Moreover,there is no intermittent phenomenon in unsteady operation.(3)Designed a single layer double-row pipe pulsating heat pipe with connecting pipe,and carried out an experimental study on the connection and disconnection of the connecting pipe.The study shows that the connecting pipe can promote the flow of the working medium between the two sides of the pipe,which is beneficial to start the pulsating heat pipe under lower heat load.When the connecting pipe is disconnected and the inclination Angle is 90°,the temperature variation trend of both sides of the pulsating heat pipe is highly consistent.(4)Analyze the heat transfer resistance of pulsating heat pipes in single row pipe and double row pipe under different working conditions.The results show that when the dip angle is 90°,the single row pipe and double row pipe pulsating heat pipe have smaller heat transfer resistance.For the double-row pipe pulsating heat pipe,when the connected pipe is connected,the pulsating heat pipe has good start-up performance and heat transfer performance under low heat load.When the connecting pipe is disconnected,the pulsating heat pipe has smaller heat transfer resistance and higher heat transfer efficiency under high heat load.(5)The application of pulsating heat pipe in electronic components,LED lighting,aerospace,solar energy,waste heat recovery is discussed and prospected.