Thermosyphon solar water heating system with Cu/water nanofluid and wire coil configurations: Efficiency, energy, economic, environmental, and heat transfer study

The techno‐economical analysis such as collector size, weight, cost, embodied energy, and environmental aspects were performed for Cu/water nanofluid flow in flat plate collector with various kinds of wire coil configurations based on the collector efficiency. Results show, the collector thermal efficiency is augmented for Cu/water nanofluids rather than water in the collector. By using ϕ = 0.3% nanofluid in collector its thermal efficiency is 61.47% but with water it is 56.68%; the collector thermal efficiency is further enhanced to 68.48% at ϕ = 0.3% nanofluid with wire coil configuration of p / d = 1.79. The collector area is reduced to 2.76 m 2 for ϕ = 0.3% nanofluid but it is 3 m 2 for water in the collector; collector area is further lowered to 2.48 m 2 for ϕ = 0.3% nanofluid with wire coil configuration of p / d = 1.79. The Nusselt number raise is 20.46% and further rose to 46.23% for ϕ = 0.3% nanofluid with wire coil configuration of p / d = 1.79 against water. The penalty in friction factor is 1.24‐ and 1.44‐times for ϕ = 0.3% nanofluid with and without wire coil configuration of p / d  = 1.79 over the water.