Impact of condenser heat transfer on energy and exergy performance of active single slope solar still under hot climate conditions

• Published in: Solar energy 2020-07, Vol.204, p.79-89
• Main Authors: Hassan, Hamdy, Yousef, Mohamed S., Fathy, Mohamed, Ahmed, M. Salem
• Format: Article
• Language: English
• Subjects: Air cooling; Carbon dioxide; Carbon dioxide emissions; Climatic conditions; Cooling; Cooling rate; Cost analysis; Desalination; Distilled water; Economic analysis; Efficiency; Energy and exergy; Environmental; Exergoeconomic; Exergy; Heat sinks; Heat transfer; Hot climates; Liquid cooling; Parabolic trough solar collector; Solar collectors; Solar energy; Solar still; Summer; Thermodynamics
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2020.04.026

•Using HSC and FW increases daily still productivity of CSS + PTC in summer by 24.7%.•MSS + PTC + FW achieves maximum energy efficiency of 19.4.•MSS + PTC + FW achieves maximum exergy efficiency while CSS + PTC has the minimum.•MSS with PTC has the minimum freshwater cost while MSS + PTC + U has the maximum.•MSS + PTSC achieves the best performance-based exergoeconomic approach. This study experimentally investigates the performance of solar still coupled with a parabolic trough solar collector (PTSC) at different cooling rates based on energy, exergy, exergoeconomic, and enviroeconomic standpoints. Different solar still systems are considered; conventional solar still (CSS), solar still with heat sink condenser (MSS) and coupled with PTSC (MSS + PTSC), MSS having an umbrella and coupled with PTSC (MSS + PTSC + U), MSS with PTSC and condenser forced air cooling (MSS + PTSC + FA), and MSS + PTSC with condenser forced water cooling (MSS + PTSC + FW). Experiments are conducted under hot climate conditions of Sohag city, Egypt. Results indicated that the freshwater yield of all studied systems in ascending order is as follow; CSS + PTSC, MSS + PTSC + U, MSS + PTSC, MSS + PTSC + FA, and MSS + PTSC + FW in summer with value of 7.74, 8.02, 8.68, 9.11, and 9.45 kg/m2, respectively. The maximum exergy efficiency of 1.34% in summer is achieved in case of MSS + PTSC + FW system. The economic analysis shows that distilled water cost is minimum for MSS + PTSC + FW (~0.02 $/L), while it is maximum for MSS + PTSC + U (~0.022 $/L). It can be concluded that high freshwater production and less distilled water cost are making the enhanced solar desalination system feasible and competitive. Minimum exergy efficiency occurs in case of CSS + PTC with a value of 1.197% and MSS has higher average daily exergy efficiency. MSS + PTSC achieves the best performance-based exergoeconomic approach. MSS + PTSC + FW is by far the best system in cutting down CO2 emissions.