AMMONIA PULSATING HEAT PIPE: FULL VISUALIZATION AND THERMAL PERFORMANCE

摘要

In this paper, a novel study on performance of pulsating heat pipe using ammonia as working fluid is experimented.The tested pulsating heat pipe, consisting of 6 turns, was fully made of quartz glass tubes with 6 mm outer diameter and 2 mm inner diameter.The filling ratios is 70％.Wall temperature fluctuations of several key positions are recorded under a series charge of heat inputs.The visualization investigation is conducted to observe the oscillation and circulation flow with the advantage of high quality digital vedio camera, by which the unique thermodynamic behaviors are able to recognize and analyze more easily.The experimental results show that the startup power of the ammonia PHP required is very small, owing to ammonia has particular identity.It is observed that there are also occured unevenly distributed in slug-train during initial and operating state.Phenomenon such as circulation flow and local oscillations coupling coalescence of bubbles and formation of slug are observed.