Experimental investigation of pulsation behaviour and performance of pulsating heat pipe

Abstract

This paper focuses on the experimental study of a closed-loop pulsating heat pipe with water. The unsteady state experiment was conducted to understand the role of different evacuation pressure, variable heat input and filling ratio on the PHP behaviour. The DAQ system did temperature measurements of the pipe at 13 locations for variable heat inputs, evacuation pressure, and filling ratio. PHP thermal behaviour is evaluated in terms of temperature variation with time, thermal resistance, effective thermal conductivity, and pulsation frequency. The strong pulsating effect is observed at 0.0799 bar. The thermal resistance of the heat pipe declines with the decrease in evacuation pressure. The lowest thermal resistance 0.05,786 K/W is observed at 0.0799 bar evacuation pressure with 30% FR, 6 times lower than 90% FR. Effective thermal conductivity rises with the decrease in evacuation pressure. The highest effective thermal conductivity of 10,233.32 W/mK is found at 30% FR and 0.0799 bar evacuation pressure, 7.5 times higher than atmospheric pressure. So, better performance is observed at low evacuation pressure of 0.0799 bar and 30% FR. This study benefits the heat transfer of integrated circuit technology and electronic devices because of its high effective thermal conductivity.