Effect of Non-Convective Zone Thickness on Thermal Efficiency of Salt Gradient Solar Ponds

An improved radiation transmission and thermal efficiency model for solar ponds has been proposed based on both the Hull Model and Wang/Seyed-Yagoobi Model in this paper. The new model is more accurate to actual measured conditions because multiple reflections and turbidity effects are included. Absorption penetration, thermal conductivity loss and thermal efficiency under different Non-Convective Zone thicknesses are numerically analyzed and thoroughly discussed. The results show that ΔT/I0 plays a critical role for the thermal efficiency of solar pond. Furthermore, it is found through calculation that there is an optimum thickness of the Non-Convective Zone. When the Non-Convective Zone thickness is less than this critical threshold, both temperature and thermal efficiency are decreased with increasing turbidity. However, when the Non-Convective Zone thickness is greater than this critical threshold, the increasing turbidity within a certain range will be beneficial to improve the thermal efficiency of solar pond. In addition, optimum Non-Convective Zone thickness is also related to the temperature, turbidity, salinity variation and bottom reflectivity.

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