Abstract: With aqueous ethanol of 50% volume fraction as working fluid and filling ratio of 50%, heat transfer performances of multi-loop pulsating heat pipe (PHP) are studied by experiment and mechanism. Heat transfer effects are compared between aqueous ethanol and ethanol. The results show that thermal resistance of PHP with aqueous ethanol is lower than that with ethanol and the maximum of heating power with aqueous ethanol is higher than that with ethanol obviously. The minimum of thermal resistance with working fluid of aqueous ethanol and inclination angle of 90° is about 0.1 °C/W, and the maximum of heating power is about 300 W. Thermal resistance with working fluid of ethanol and inclination angle of 60° is 1.34～1.49 times higher than that with aqueous ethanol, and the ratio with inclination angle of 30° is 1.28～1.50.

Key words: Aqueous ethanol, Ethanol, Heat transfer performances, Inclination angle