Experimental Study On Heat Transfer Characteristic Of Plate Pulsating Heat Pipe

Pulsating heat pipe (PHP) is a new type of heat pipes, and because of simple structure, easy manufacturing and high thermal conductivity, it has wide range of applications. Heat transfer of pulsating heat pipe includes latent heat and sensible heat. The two-phase system which embodies multi-disciplinary physics is so complicated that the investigation on pulsating heat pipe s is still at a primary stage.Plate pulsating heat pipe which can realize small and compact is studied in this paper. The experimental study focuses on the features of plate pulsating heat pipe's start-up and running, and the influence that some important factors make on heat transfer. The movements of liquid slugs and model heat transfer have been theoretically studied.In the experiment, at first plate pulsating heat pipe is designed and experimental system of pulsating heat pipe is set up. Through the experiment, it is found how the plate pulsating heat pipe starts up and operates, there is a specific threshold for plate pulsating heat pipe's start-up power, pulsating heat pipe can be set up only when the heating power reaches the threshold or beyond, and after the pulsating heat pipe is set up the temperature difference narrows and the heat resistance reduces. Besides, the start-up power of plate pulsating heat pipe has some relationship with operation factors (filling rate working fluid, smaller content of non-condensable gas in the heat pipe). The start-up power is the least when acetone is chosen as the working fluid.The experiment has also studies the influence that other operation factors make on heat transfer. It is found that the optimal filling rate is at about 30% and the vertical bottom heating works better than the declining pipe heating. Heat pipe structural parameters (tube area, tube shape, and turning number) can better the performance of plate pulsating heat pipe with larger tube area and more turnings. Additionally, the heating tube with triangle shape performs better than the one with rectangular shape.A single liquid slug model is built on the model of masses, momentum,and energy .By numerical method, the movements of the liquid slug and the heat transfer condition of the model have been analyzed. The theoretical model studies on the influence that the heating power, tube size, the temperature on the heating and cooling part, and different working fluid make on the movement of the liquid slug and the heat transfer condition of the model. By increasing the heating power, tube diameter, heating section temperature and decreasing the cold section temperature, the velocity of liquid slug become faster and heat transfer performance become better.