High-temperature radiative cooling is essential for solar absorbers,as it mitigates efficiency degradation resulting from thermal accumulation.While porous structures have proven effective in enhancing absorber perfor...High-temperature radiative cooling is essential for solar absorbers,as it mitigates efficiency degradation resulting from thermal accumulation.While porous structures have proven effective in enhancing absorber performance,practical manufacturing processes and prolonged operational wear inevitably introduce surface roughness and structural deviations,which profoundly impact radiative properties.This study constructs a ZnS/Ag solar absorber model with surface roughness and employs the finite-difference time-domain method to investigate how characteristic length,surface roughness,porosity,pore shape factor,and taper influence its radiative properties in the 3μm-5μm band at 750 K.Results show optimal absorption at a 1μm characteristic length with a 36.72%improvement compared to the model with l=0.25μm,increased absorption with higher porosity with a 69.29%improvement at 0.6 compared to the non-porous structure,lower circularity with a 19.03%improvement for C=0.89 compared to C=1.00,while surface roughness with a 61.24%improvement at RMS=0.031 compared to RMS=0 and taper with a 38.29%improvement at β=20°compared to β=0°also exert significant effects.This work provides engineering design guidelines for high-efficiency,low-cost absorbers.展开更多
基金funded by the National Natural Science Foundation of China,grant number 52406102,received by Haiyan YuShandong Provincial Natural Science Foundation,grant number ZR2023QE258,received by Haiyan Yu.
文摘High-temperature radiative cooling is essential for solar absorbers,as it mitigates efficiency degradation resulting from thermal accumulation.While porous structures have proven effective in enhancing absorber performance,practical manufacturing processes and prolonged operational wear inevitably introduce surface roughness and structural deviations,which profoundly impact radiative properties.This study constructs a ZnS/Ag solar absorber model with surface roughness and employs the finite-difference time-domain method to investigate how characteristic length,surface roughness,porosity,pore shape factor,and taper influence its radiative properties in the 3μm-5μm band at 750 K.Results show optimal absorption at a 1μm characteristic length with a 36.72%improvement compared to the model with l=0.25μm,increased absorption with higher porosity with a 69.29%improvement at 0.6 compared to the non-porous structure,lower circularity with a 19.03%improvement for C=0.89 compared to C=1.00,while surface roughness with a 61.24%improvement at RMS=0.031 compared to RMS=0 and taper with a 38.29%improvement at β=20°compared to β=0°also exert significant effects.This work provides engineering design guidelines for high-efficiency,low-cost absorbers.
