太阳辐射填料床储热特性研究

针对给定太阳日辐射曲线,研究集成蓄热单元的太阳光热系统的整体能量的动态转化特性及关键参数影响规律。结果表明：填料床总储热量与传热流体进口流速呈非线性变化,当传热流体进口流速 u_f =0.006 m/s时,填料床总储热量最大;在给定填料总容量和u_f =0.006 m/s的条件下,填料床高径比为5的填料床具有更高的储热能力;在该计算条件下,u_f =0.006 m/s、填料床高径比为5及填料量相对值为1时,太阳光热能实现最大程度上的转化和储存。

INVESTIGATION OF HEAT STORAGE CHARACTERISTICS OF SOLAR RADIATION PACKED BED

A solar thermal energy collection unit and a packed bed thermal energy storage unit is integrated, and the effect of dynamic matching characteristics of solar thermal input unit and the heat storage unit on its overall energy utilization performance is studied. Based on the given dailysolar radiation curve, influences of the key parameters, including the HTF flow rate, the height-to-diameter ratio and the relative storage capacity on the overall thermal performance of the integrated solar energy system also are studied. The results show that the relationship between the total heat energy storage of packed bed and the inlet velocity of heat transfer fluid shows a nonlinear change. The maximal thermal energy is stored in the packed bed when the HTF mass flow rate uf is 0.006 m/s. Under the condition of u_f at 0.006 m/s and at the fixed PCM package, the optimal packed bed height-to-diameter ratio of 5 is achieved. With u_f of 0.006 m/s, the height-to-diameter ratio of 5, and the relative value of the filler amount is of 1, the maximal solar energy conversion efficiency is obtained in this research.