ENERGY AND EXERGY ANALYSES OF ACTIVE SOLAR STILLS USING WATER LOADED NANOFLUID

Abstract

The basin type active solar still with CuO nanoparticles has been investigated in the current study and energy, exergy analysis, energy matrices, exergoeconomic parameter, environeconomic parameter, and productivity has been presented. The prime objective of this design is to develop an energy efficient solar distillation system and produce potable water at a reasonable price. The single and double slope solar distillation systems N-PVT-CPC-HE with water loaded CuO nanoparticles have been studied in detail. A mathematical model developed for the proposed systems and life cycle cost analysis for single and double solar distiller units with N-PVT-CPC using a helically coiled heat exchanger with water loaded CuO nanoparticles has emanated out. The analysis of four different weather conditions viz type a, b, c and d days for each month of year has been done. Detailed computation of energy, exergy, and yield optimized at N=4 number of collectors and various parameters like cost of distillate, CO2 mitigation, carbon credit earned, environeconomic, productivity and exergoeconomic also have been computed. Generally, exergoeconomic parameters are computed by lost exergy per unit cost for the systems like mechanical, thermal, etc. as many researchers reported, while in proposed study to compute the exergy gain per unit cost because solar energy is free of cost available. Solar distillation is carried out at 0.14 m depth of water, N-PVT-Compound parabolic concentrator collectors and optimum flow rate for the composite climate condition of New Delhi, India. Water production cost in ₹/kg and $/kg has also been calculated. Solar distiller performance in terms of hourly productivity of distiller unit has for optimum number of collectors (N = 4), flow rate, and relative water depth have been determined. It has been concluded that double slope N-PVT-CPC active solar distiller unit with heat exchanger using CuO nanoparticles gives the best performance based on average energy, exergy, Page vii yield, cost of distillate, CO2 mitigation, carbon credit earned, environeconomic, productivity and exergoeconomic etc. Following contributions are made by annual analysis of the proposed systems with CuO nanoparticles. 1. Distillate cost is less for system-B than system-A. Annual distillate costs for 30 yrs at rate of interest 10% are 0.30₹/kg for system-B, 0.344₹/kg for system-A, and 0.338₹/kg for system-C. 2. System-A gives a higher value of carbon dioxide mitigation and carbon credit earned based on thermal energy and exergy. Mitigation per ton based on energy and exergy for system-A is 15.76% and 53.5% higher than system-B and system- C, respectively. 3. Annual productivity of system-B for 15, 20, 30, 50 years are 209.44%, 230.63%, 251.28%, and 262.04% respectively. 4. Exergoeconomic analysis based on exergoeconomic parameter (Rex) of the system-B for 15, 20, 30, 50 years are 0.0312, 0.0344, 0.03746, and 0.03906 kWh/₹, respectively.