Performance and cost analysis of photovoltaic thermal (PVT)-compound parabolic concentrator (CPC) collector integrated solar still using CNT-water based nanofluids

In present research article, analytical analysis has been performed to inspect the performance and thermo-physical characteristics of partially covered series connected N- photovoltaic thermal (PVT)-compound parabolic concentrator (CPC) collectors integrated double slope solar still coupled with helically coiled heat exchanger (HE) incorporating single wall carbon nanotubes (SWCNT) and multiwall carbon nanotubes (MWCNT)- water based nanofluid. Temperature, heat transfer coefficients (HCTs), and Nusselt number in different section; and thermal energy/exergy, and productivity - of the proposed system have been investigated in detail for 1% concentration of CNTs; 25 kg basin fluid (BF/NF) mass, 0.03 kg/s mass flow rate (optimized), and four number of PVT-CPC collectors (optimized) for hot weather conditions of New Delhi. Enhancement around 46.4%, 46.7%, 76.7% in HTCs of PVT-CPC collector, helically coiled aluminum HE and DSSS section respectively have been observed for SWCNT-water based nanofluid. Percentage enhancement in total yield obtained using SWCNT and MWCNT is found to be 65.7% and 28.1% respectively. From the cost analysis, the production cost Cp (Rs. /litre) of daily yield obtained from the system with SWCNT [0.975 (i = 4%),0.982 (i = 8%),and 1.028 (i = 10%)],and MWCNT [1.23 (i = 4%),1.24 (i = 8%),and 1.30 (i = 10%)] for n = 30 is found to be very nominal.