Numerical Investigation of Thermal Performance Enhancement of Solar Reservoir using Flash Cycle

Abstract

The main objective of this research is to model a solar reservoir system located in Dehradun, Uttarakhand, India. Solar reservoir acts as both a collector and long-term storage for thermal energy, potentially providing heat for a full year. Using a single input, the latitude angle, solar radiation for the location is calculated. A one-dimensional time-dependent steady-state model is employed to predict the annual temperature behavior within the storage zone of the solar reservoir. The model analyses the temperature range achievable in the lower convection zone (LCZ) of the reservoir. The findings suggest that the LCZ can reach temperatures as high as 80°C. Additionally, the study demonstrates that an increase in feed temperature can improve overall system efficiency. At the end of summer, temperatures as high as 70 °C were observed in the solar pond at a depth of 1.32 m. It reached 26 °C at its lowest point in early April. In an artificial solar pond, salt water is utilised to inhibit convection. There was a 26% concentration of salt NACL at the lake's bottom. The kind and concentration of salt have an impact on the pond's stability. It was determined that 80 g/kg of water is the ideal salt level for the small solar pond. This study demonstrates the potential for maintaining both salinity gradient and thermal performance over an extended period. Future research efforts could benefit from larger-scale experiments that bridge the gap between controlled environments and real-world applications.