Exprimental Investigation of the influence of filling ratio on the thermal performance of pulsating heat pipes

Modern air conditioning systems, thermal management of electronic components and progress towards miniaturizing parts have attracted the attention of engineers towards using thermal transfer instruments with high-performance. One of these tools is pulsating heat pipes with low cost and high efficiency for transferring heat from the source with high temperature to low temperature source. In this paper, design and manufacture of a prototype pulsating heat pipe were analyzed . The designed model consists of 6 loops of copper pipes with 2.2 mm inner diameter and 4 mm external diameter. The height of the loop is 280 mm, length of the evaporator and condenser is 100 mm and the adiabatic section is 80 mm. One of the most important parameters in pulsating heat pipes is working fluid and filling ratio. In this paper, the gas R-22 and distilled water is used in four of filling ratio. The results showed that the evaporator temperature has increased with increasing input power and thermal performance of distilled water is better than gas. Also, the filling ratio of 60 percent of distilled water has the best performance among the other fillings ratio.