الفهرس 
صفحة العنوانOnly 14 pages are availabe for public view
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Abstract
Concentrating photovoltaic/Thermal (CPV/T) is an alternative technique used to
convert directly the solar energy to electrical energy. Using the microchannel heat sink
(MCHS) to cool concentrating photovoltaic cells (CPV) system is a promising method, which
can lead to an enhancement in its performance. Optimization technique is used to provide the
optimal design for MCHS, channel width (W ch), channel height (Hch) and number of channel
(N). This showed that N is the most significant parameter affecting the cell temperature.
Accordingly, flow and thermal fields are analyzed for N= 26, 52, 78 and 104, at various
concentration ratio (CR) and mass flow rate. In addition, Ab03-water nanofluid with different
concentrations (<p= I %, 3 % and 5 %) as a coolant is studied. Moreover, modifying the
polycrystalline silicon solar cell structure to utilize a higher solar concentration ratio is essential
to enhance its performance and solar cell o~tput power. Thus, a new modified design of a
polycrystalline silicon solar cell is developed. In this new design, variations of the Ethylene-
Vinyl Acetate (EV A) upper-and lower-layer thickness along with the interval width between
two consecutive silicon layers are investigated.
To determine the effect of varying the design parameters on the performance of the
CPV/T system at various solar concentration ratios, a three-dimensional comprehensive model
for the solar cell integrated with a microchannel heat sink is developed. The parameters such
as solar cell temperature, temperature uniformity, electrical efficiency, electrical power, net
gained power, thermal power and thermal efficiency are evaluated from the simulation. The
model is numerically simulated and validated with numerical results and measurements.
The results revealed that the optimal design variables are 609.722 urn, 1146.000 urn
and 67 for the Wch, Hch and N, respectively. In addition, increasing N, significantly decrease the
solar cell temperature. Using the nanofluids slightly enhance the cooling process compared to
pure water at the selected range of the mass flowrate. This enhancement leads to a slight
decrease in the solar cell temperature. The solar cell efficiency in addition to the pressure DROP
slightly increases as <p increases. The structure study showed that at CR=20, reducing the lower
EV A layer thickness from 1.0 mm to 0.2 mm results in decreasing the maximum cell
temperature from 102.3 QC to 69.3 QC. With further increase in the concentration ratio up to 30,
the maximum cell temperature reduces from 138.3 QC to 87.0 QC.