Heat transfer performance of pulsating heat pipes with water-acetone mixtures

Experiments of pulsating heat pipes (PHP) were conducted, with water, acetone and water/acetone binary mixtures at different ratios (13:1, 4:1, 1:1, 1:4, 1:13) under various filling ratios (35%-70%) and heat inputs (10-100 W). The experimental results were analyzed with the feature of physical property and phase change for mixture. The results show that because of lower boiling point, specific heat and latent heat for evaporation, the mixture solution requires lower heating power to initial PHP than water. At low filling ratios, compared to mixtures except that with relatively low acetone concentration (e. g. water/acetone 13:1), pure working fluids are relatively easier to dry out in PHP. With the heat input of 50 W, PHPs with pure working fluid are dried, while those with mixtures maintain relatively low thermal resistance. The mixture with a little water (e. g. water/acetone 1:13) can significantly improve the dry state in PHP, while that with a little acetone (e. g. water/acetone 13:1) does not significantly improve the dry situation. At high filling ratios, heat transfer performance of PHP with pure working fluids are better than mixtures. In the range from 35 W to 50 W, the PHPs with pure working fluids present lower thermal resistance. At higher heat input (50-100 W), the PHP with water has lower thermal resistance compared to that with mixture. The study on heat transfer performance of PHP provides references for further research on the heat transfer mechanism of PHP and establishment of theoretical models on heat transfer characteristics. © All Rights Reserved.