Experimental investigation of the effect of dynamic melting in a cylindrical shell-and-tube heat exchanger using water as PCM

• Published in: Applied energy Vol. 185; pp. 136 - 145
• Main Authors: Gasia, Jaume, Tay, N.H. Steven, Belusko, Martin, Cabeza, Luisa F., Bruno, Frank
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2017
• Subjects: Dynamic melting; Effectiveness; Heat transfer enhancement; Phase change material; Thermal energy storage; Heat transfer enhancement; Thermal energy storage; Phase change material; Effectiveness; Dynamic melting
• ISSN: 0306-2619; 1872-9118
• DOI: 10.1016/j.apenergy.2016.10.042

•Experimental results of the dynamic melting enhancement technique is presented.•Dynamic melting enhanced the heat transfer during the melting process.•Enhancement was obtained when the PCM flow rate is higher than the HTF flow rate.•Pumping power was shown to be negligible relative to the heat transfer enhancement.•Heat gains from the surroundings have influenced the system performance. In the present paper, an experimental study is carried out to evaluate the effect of the dynamic melting concept in a cylindrical shell-and-tube heat exchanger using water as the phase change material (PCM) and a potassium formate/water solution as the heat transfer fluid (HTF). The dynamic melting concept is a new heat transfer enhancement technique which consists of recirculating the liquid PCM during the melting process with a pump and thus increasing the overall heat transfer coefficient as a result of the dominance of the forced convection. The HTF flow rate was kept constant at 1 l/min and four different PCM flow rates of 0, 0.5, 1 and 2 l/min were tested. Results from the experimental analysis showed enhancements up to 65.3% on the melting period, up to 56.4% on the effectiveness, and 66% on the heat transfer rates when the PCM flow rate was twice the HTF flow rate. From these experiments, it can be concluded that dynamic melting is an effective technique for enhancing heat transfer during melting of PCM.