FIG. 2.
The solar energy storage in SOAP: (a) Effect of optical lens array on water temperatures as a function of distance from the inlet (L) in the SOAP channel and corresponding schematic illustration of SOAP's designs (left) without optical lens and (right) with optical lens array on top of the fluidic channel. The optical lens focuses solar radiation to the microfluidic channel. (b) Detailed geometry of the SOAP system in our simulation and (c) design variables of optical lens diameter (D) and micro channel width (w) are considered in our simulation. (d) Several SOAP designs with different ratios of the lens diameter to channel width (D/w) (top row) and corresponding temperature profiles in the channels (bottom row). (e) Quantitative plot of average temperatures along the channels with respect to D/w, ranging from 1.0 to 3.0. (f) Effect of D/w on the solar collector efficiency of solar radiation. The solar collector efficiency is calculated according to the Equation (4). The mass flow rate is 10−6 kg/s.