Modeling and numerical simulation of solar cooker with PCM as thermal energy storage

摘要

In this article, mathematical modeling and numerical simulation of phase change materials (PCMs) used as latent heat thermal energy storage in a solar cooker have been conducted. The PCM to store thermal energy is packed in many small hollow cylinders and placed in a larger cylinder tank. Heat transfer fluid (HTF) which flows parallel to the PCM cylinder is used to distribute heat from the solar collector to the PCM storage unit and vice versa. A mathematical model describing the behaviour of temperature in the PCM and HTF is used. Numerical solutions are obtained by transforming heat conduction equations of the PCM and HTF into enthalpy equation and solving it by using the Godunov method. Thermal performance during charging and discharging process of several selected PCMs is investigated. The simulation results showed that magnesium nitrate hexahydrate has the highest capacity to store solar thermal energy whereas erythritol can achieve the highest temperature history during charging time and at the first 54 minutes of discharging time. The results provide an important information to design a solar cooker prototype equipped with thermal energy storage that has a good thermal performance.