Experiment Investigation Of Binary Mixed Fluid Effect On Heat Transfer Efficiency Of Pulsating Heat Pipe

According to the industrial integration and miniaturization in recent years, mechanical equipment’s calorific value in unit volume is rapid rise, especially Marine equipment heat dissipation problems, challenging the traditional cooling technology. It also restricts the development of corresponding equipment upgrades. Pulsating heat pipe/Oscillating heat pipe (PHP/OHP) known as the most promising one of the means in solving the problem of narrow space with high heat flux cooling in the21st century. PHP have many advantages as small, simple structure, low cost, good heat transfer performance, work stability, variety structure, strong adaptability, etc. Even PHP’s structure is simple, but in the actual operation process the influence factors of it are very complicated, especially in the use of water and HFE-7100binary mixed fluid with different proportion, in the process of the experiment the gas liquid two phase flow and the physical properties of the working medium and heat transfer phenomena will become more complicated.In this paper, based on the discussion of existing literature, using the binary mixed fluid in closed loop PHP made a systematic experimental study. Firstly use copper standard PHP (1) studied the influence of PHP heat transfer performance with binary mixed fluid by the changing test Angles;(2) studied the different binary mixed fluid affect the performance of PHP heat transfer;(3) studied the binary mixed fluid influence on PHP working medium flow pattern. The second using the Quartz PHP for Visualization experiment (1) the influence of different test Angles on PHP heat transfer performance under the binary mixed fluid (2) different binary mixed fluid effect on PHP heat transfer performance.Experimental results show that:(1) using binary mixed fluid as the working medium of the PHP and the flow pattern have a great difference with water as working medium, the higher percent of the HFE-7100inside the working medium, the working fluid is more likely to circulation and more faster more stable, but it also suppresses the flow pulsation frequency and amplitude of working medium (2) the incline Angle of PHP make an obvious effect on its heat transfer performance of the binary mixed fluid, such as the start-up performance,heat transfer performance and stability of work will be affected significantly, especially those working medium with higher percent HFE-7100have a big deterioration in heat transfer performance at lower slope Angle (3) different binary mixed fluid have great influence in heat transfer performance, working medium with5:5ratio have the best heat transfer performance above all binary mixed fluid.(4) PHP with binary mixed fluid medium did not got a good heat transfer performance, because PHP around90%of the heat transfer rely on the sensible heat, but HFE-7100’s sensible is low and which inhibits pulsating heat transfer at the same time, lead to binary mixed fluid having bad pulse frequency and amplitude compared with deionizer water medium. Then, heat transfer performance become poor.