Critical Modeling & Exergy Analysis of Multi Phase Change Materials Storage System

چکیده مقاله

Using the phase change materials (PCMs) can help to store thermal energy as latent heat method in the multi PCMs storage system. In this research study, an analytical model has been developed for solar thermal storage system. An especial shell and tube heat exchanger is considered to heat exchange purpose. Double pipes have been used as tubes and PCMs allocated on the shell side of the double pipes for the heat exchanger. The hot heat transfer fluid (HTF) flows across the tube banks to charge the thermal energy storage system during the charging cycle. The thermal energy absorbed in PCMs while the HFT temperature reduced in the charging process. The heat exchanger tube length is function of HTF residence time then the equivalent length is defined in the presented model. The validity of the proposed model has been checked by comparison between the analytical results and numerical data obtained before using CFD simulation. The result shows that required times to melt of the PCMs for the presented study has the consistency of about 0.928 with CFD results in different PCMs melting percentages. Also the required time to melt of the PCMs for the presented study has the consistency of 0.915 with CFD results in different air inlet temperatures. Therefore the presented model can predict the system behavior also can apply for cascaded PCMs storage systems for exergy analysis.