Study on annual performance of the solar still using shape-stabilized phase change materials with economic analysis

Abstract

Solar still using phase change materials (PCM) can enhance desalination. Due to the long-term running of the desalination plants, therefore the annual performance of solar still using shape-stabilized PCM (SSPCM) was studied with economic analysis in this paper. Firstly, a comprehensive model coupling with still energy balance and annual solar radiation was built to assess the annual performance of the solar still, the internal heat conduction was considered particularly for modelling of heat transfer in SSPCM. Then an experimental solar still using SSPCM was performed to testify the built model by still temperature and production. Moreover, three solar stills were concerned to simulate the annual performance, including: conventional solar still (without PCM), solar still with SSPCM, solar still with SSPCM and solar collector. The results showed that the annual production of the solar still with SSPCM, solar still with SSPCM and solar collector were 750 L/m2 and 1000 L/m2, 28.4%, 71.2% higher than that of conventional solar still respectively. And the annual efficiency for the three solar stills were 28%, 39%, 55%. The solar still with SSPCM got the lowest TAC with about 0.123 ¥/L at the first year whose payback period of the solar still with SSPCM was the shortest which was about 7 years with water price of 0.2 ¥/L.