Ultrasonic enhancement on heat transfer of palmitic-stearic acid as PCM in unit by experimental study

In this work, ultrasonic is firstly used to enhance the heat transfer rate of palmitic acid-stearic acid eutectic mixture (PA-SA) in a cylindrical stainless-steel unit. The heating boundary condition of the phase change material (PCM) is constant wall temperature condition in this work. The effects of ultrasonic parameters including ultrasonic power and operation time on heat transfer enhancement of PA-SA are experimentally studied. The results show that the heat transfer rate in melting process of PA-SA increases with the increasing of ultrasonic power, Specifically, heat transfer rate is increased by 10.64%, 23.40% and 31.91% at the ultrasonic power of 60 W, 105 W and 150 W respectively. The heat transfer rate of PA-SA is also increased with the increasing of ultrasonic action time. Effect of ultrasonic on heat transfer enhancement varies in terms of different ultrasonic action stage of the charging process. Therefore, the optimal effect of ultrasonic on heat transfer enhancement can be obtained by using intermittence ultrasonic. In conclusion, it is an effective way to enhance the heat transfer of PCM used in the latent heat storage system by intruding ultrasonic.