3.2. Thermal performance and optimization of LED solar simulator.
For thermal optimization of the LED modules in solar cell simulator,
the temperatures of the different spots of the simulator
were measured and compared with the calculated data obtained
by CFD. The temperatures of the different spots in the LED solar
simulator that was fabricated in this research (no distance between
the LED module and the number of fins of the heat sink is 20 in this
case) was measured by physical contact method (thermal couple
method – Pt 100 X/±0.1 C). The experimental data was verified
by the simulation process which utilizes the finite volume method
(FVM). Based on the thermal optimization, the junction temperatures
of the LED packages were calculated using the same simulation
tool as a function of distance between the LED module and
number of fins of the heat sink. The measured temperatures
(0.9 sun) for the surface of the lens and heat sink are 86.0 C and
67.0 C, respectively, which are in good agreement with the simulated
data, 85.1 C, and 66.1 C, respectively. Simulated results obtained
from the CFD solver generally show lower temperatures
than the measured data due to the inherent assumption of clean
interface in the simulation model. Based on the matching of the
measured and simulated data, the junction temperatures of the
LED packages were estimated for various structure parameters of
LED modules for thermal optimization.
It