Modeling and Simulation of Solar Compound Parabolic Concentrator-Integrated Low-Temperature Thermal Desalination System

Abstract

This study introduces an innovative approach to saline water desalination using a stationary compound parabolic concentrator (CPC) to power a low-temperature thermal desalination (LTTD) system. The integration of CPC into LTTD was thermodynamically modeled and simulated under tropical climatic conditions. Key parameters, including hot feed saline water temperature, temperature gradient, cold-water inlet temperature, feed saline water flowrate, flash chamber pressure, and varying salinity levels, were examined for their impact on freshwater production. Additionally, the design requirements for CPC arrays and economic considerations were thoroughly analyzed to achieve a large-scale freshwater production capacity of 1000 L/day. The results showed that increasing the thermal gradient, feed saline water temperature, and flowrate, while decreasing the flash chamber pressure, significantly enhanced freshwater production. For example, as the temperature gradient increased from 7 °C to 20 °C, the average freshwater yield rose from 75.23 L /h to 120.19 L /h. Achieving the target freshwater production required 126 to 152 CPC units with an area of approximately 3 m2 for hot feed saline water temperatures between 37 °C and 50 °C. Furthermore, increasing the feed saline water flowrate from 7500 L /h to 22,500 L /h resulted in a 66.48% increase in freshwater yield. Reducing flash chamber pressure from 12.35 kPa to 4.5 kPa led to a substantial increase in potable water production, ranging from 21.65% to 90.9% across different temperature gradients. The study also evaluated the effects of salinity levels, finding a slight decrease in freshwater production with higher salinity.