Phase change materials (PCMs) are used to store thermal energy. They possess high specific energy at nearly constant temperatures. The usage of the PCMs is limited due to their very low thermal conductivity, which results in poor heat transfer. To overcome this problem usage of fins is a potential technique. In the current analysis, the surface area of the heat transfer fluid (HTF) tube is increased by radial (R-type), spiral (S-type), and longitudinal (L-type) fins. A 3D numerical analysis of melting and solidification is carried out on R-type, S-type, and L-type shell and tube (S&T) PCM heat exchanger (HX) by considering the inclination effects. Lauric acid is used as PCM. Phase change time, energy ratio, and exergy efficiency are considered to analyze the performance of HXs. MOORA analysis is carried out to select the best HX. It is observed that R-type HX at the vertical position has shown better performance among the selected HXs. Among the considered geometries, the maximum average exergy efficiency is obtained for 45° inclination with R-type HX and minimum for horizontally positioned L-type HX during both melting and solidification. The charging time of the vertically positioned HX, when compared to 45o oriented HX with R type, S type, and L type HX is observed to decrease by 47.5%, 45.7%, and 23%, respectively.
Storing the thermal energy using the materials' latent heat capacity is a prominent and well-established technique; these materials are termed phase-change materials (PCMs). For low-temperature applications mostly organic PCMs are available. These PCMs possess very less thermal conductivity, which results in a low rate of heat transfer. To overcome this problem usage of fins and the addition of nanoparticles (NPs) to PCM are two potential methods. In the present study, three-dimensional numerical analysis of melting and solidification is performed on the radial, spiral, and longitudinal finned PCM-based shell and tube heat exchangers with the addition of NPs to PCM. Numerical analysis is carried out with various volume fractions of NPs in the PCM. Based on the study it is observed that the PCM-based heat exchanger with radial fins has the lowest melting time, average temperature, and energy storage ratio. For longitudinal fins melting time is maximum and it also has the maximum average temperature and energy storage ratio. It is observed that the addition of NPs showed a significant effect on the phase change process. For all the selected geometries the average exergy efficiency is not more than 4.4% during solidification.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.