Abstract:
Solar energy is the most plentiful energy source on the planet, with around 1 kilowatt per square
meter (kW/m2
) of solar radiation reaching the earth's surface in clear conditions when the sun is
near the zenith. This thesis's major goal is to investigate the numerical analysis of heat transfer
enhancement in the PTSC employing twisted tape with perforated plates and nanofluid. The
Tonatiuh ray tracing software is used to generate an optical model of the PTSC. A binary file
containing the results of the ray-traced analysis is exported to MATLAB for further processing.
Through surface and curve fitting to the data, the distribution of heat flux on the absorber tube's
outer surface is determined. For the ANSYS Fluent Computational Fluid Dynamics (CFD) code,
user-defined functions (UDFs) are made using the fitting relations. In ANSYS Fluent, the UDFs
are employed for the boundary conditions and thermo-physical properties of nanofluid to solve
fluid flow as well as heat transfer to the heat transfer fluid in the absorber tube. Because of their
excellent thermal conductivity, water- 𝑍𝑟𝑂2 nanofluids at a concentration ratio of (𝑖.𝑒.𝜙 = 0%,
𝜙 = 0.2%, 𝜙 = 0.6%, 𝑎𝑛𝑑 𝜙 = 1%) are used in this work to enhance heat transfer. The flow
inside the absorber tube was a fully developed and steady-state turbulent flow. Using CFD and kβ
𝜀 RNG turbulence model with enhanced wall treatment, the hydrodynamic and heat transfer
coefficients are determined using the finite volume method. The SIMPLE algorithm is used in the
pressure velocity coupling approach, and a second-order upwind scheme is used for discretization.
The thermal effects of using water-𝑍𝑟𝑂2 nanofluid with different concentrations with perforated
plates and twisted tape inserts are investigated. Pitch ratios (l/D) = 12.78 and 23.32 of the
perforated plate (PP) and the twisted tapes (TT) with twist ratios of (y/w) = 4, 5, and 6 are inserted
into the centre of the stream. The Reynolds number covered is in the range of 4000 to 10000 for
the turbulent flow of 𝑍𝑟𝑂2 nanofluid in the absorber tube. The investigation demonstrates that the
combination of TT and PP for the Nusselt number, friction factor, and thermal performance factor
is in the range of 132.39% to 321.37%, 232.13% to 551.58%, and 1.25 to 2.256, respectively over
the plain tube. The highest thermal performance factor in the order of 2.256 over a plain tube was
obtained for the integrated device consisting of the TT with (y/w) = 4 and PP with (l/D) = 12.78
at a concentration of 1% water- 𝑍𝑟𝑂2 nanofluid and at a Reynolds number of 7000.
