Experimental Evaluation of Closed Loop Pulsating Heat Pipe with Water based Working Fluids

In this paper, thermal performance of closed-loop pulsating heat pipe was experimentally analysed. PHP consists of three different sections namely evaporator, adiabatic and condenser. For experimentation copper tube having 2.0 and 3.6 inner and outer diameter respectively was considered. Water, Ethanol, Methanol, Acetone and binary mixtures are selected as working fluids. 50%, filling ratio is considered. Copper tube bent into 8 turns with 16 parallel channels is considered for experimentation. Heat inputs ranging from 20 to 100 W was supplied depending upon the operating range of fluids. Experiments are conducted by placing PHP at vertical bottom heat mode. For a better understanding of PHP experimental study is considered as one of the important influencing parameter i. e. working fluid. At different heat inputs, Characteristics of the average evaporator temperature and thermal resistance were analysed. The results shows that with increase of heat input thermal resistance decreases more rapidly. In comparison with the other working fluids, acetone gives best performance. Among binary and pure working fluids binary shows good performance. Water, acetone, binary mixture exhibits better heat transfer performance characteristics compared to other binary mixtures. Among all the orientations vertical bottom mode position gives the least thermal resistance values compared to other positions of PHP.