BITS Faculty Publications
Permanent URI for this communityhttp://localhost:4000/handle/123456789/1867
Browse
3 results
Search Results
Item Numerical and experimental investigation of melting process in spherical pcm capsule used for low-temperature thermal energy storage systems(IOP, 2019) Srinivasan, P.The present work deals with the experimental and numerical investigation of melting process of phase change material used for low temperature thermal energy storage applications. Thermal energy storage is a good solution to bridge the gap between energy supply and energy demand. The unconstrained melting of paraffin wax having melting range of 570C to 610C was studied in simple spherical glass capsule. The objective of the subject work is to perform the experimental and numerical analysis of melting process in spherical capsule subjected to constant wall temperature. Ansys Fluent 18 is used for computation purpose. In experimental analysis, melting process was observed through visual capturing of interface between solid and liquid. Melting fraction and temperature at the centre of PCM capsule are monitored both experimentally and numerically. Good consistency in results were observed.Item Numerical simulations and experimental investigations to study the melting behavior of beeswax in a cylindrical container at different angular positions(Elsevier, 2021-12) Srinivasan, P.Phase Change Materials (PCMs) are widely used in Latent Heat Thermal Energy Storage Systems (LHTES). This work aims to study the melting behavior of low-temperature phase change materials in cylindrical containers placed at different angular positions. Simulations were performed using ANSYS FLUENT by applying the enthalpy porosity model to analyze melting of beeswax in a cylindrical glass tube subject to an isothermal wall condition. The tube was placed at angular positions of 0°, 30°, 60° and 90° to the horizontal in order to study the effect of angular position on melting behavior. The simulation results were then validated by performing experiments and capturing images at regular intervals of time to track the solid-liquid interface. Image processing using MATLAB was performed on the captured images to study the variation of melt fraction as a function of time. It is observed that the experimental results were in good agreement with the simulations. From these studies, it was observed that the total melting time increases with the angle of tilt from 0° to 90° Initially, the melting progressed similar to the analytical solutions of one-dimensional phase-change heat transfer. As the melting continued, the experimental and numerical results deviated from the analytical solutions and the rate of melting increased due to convection effects. The results obtained in this study can be used to predict the melting behavior of PCMs in a solar flat plate collector kept at different angular inclinations. This result can be kept in mind while designing a thermal energy storage system to set an appropriate angle to match the cycle time of the system.Item SWOT analyses of high-temperature phase change materials for thermal energy storage(Elsevier, 2020) Srinivasan, P.High-Temperature Latent heat thermal energy storage (HTLHTES) is gaining importance to store thermal energy at high temperature. Large storage capacity, compact system and near-isothermal operating conditions are some of the added advantages of LHTES over sensible heat thermal energy storage (SHTES). HTLHTES system uses phase change material (PCM) to store thermal energy. This research identifies the possible integration of HTLHTES in Concentrated Solar power (CSP) plant at high-temperature. Energy storage improves the dispatchability of CSP plants. At high temperature, thermal reliability and corrosion behaviour of PCM are significant challenges. A detailed analysis of state-of-art technology and recent advancement in the field of high-temperature PCM are presented while focusing on problems and its solutions. The report is summarised in strength-Weakness-Opportunities-threats (SWOT) table on parameters like thermophysical properties, material response and corrosion behaviour of PCM. SWOT results highlight the strength, weakness of PCM and opportunities and threats for future research of high-temperature PCM. At present, the authors of this study are investigating the phase change behaviour of Al-Si alloys through modelling and simulation. SWOT analysis of this alloy, when compared to other PCMs, is done to understand the applicability of the alloy as LHTES. In this study, the authors also proposed a thermophysical property-based newer approach to compare PCMs.