太阳光热填料床放热过程动态特性分析

Analysis of Dynamic Characteristics of Solar Thermal Packed Bed Exothermic Process

为了改善太阳能不能连续稳定输出的问题,针对填料床放热过程,采用数值模拟方法研究了传热流体流速,温度以及填料床的高径比对填料床动态放热特性的影响规律。结果表明:在计算条件下,提高传热流体流速和温度是改善放热速率的关键参数,而提高填料床高径比有利于降低放热速率。当传热流体的进口流速由0.0005 m/s增加至0.0013 m/s,填料床的平均放热速率提高了150%,放热时间缩短了54%,对放热密度无影响;传热流体进口温度为473 K上升至513 K,填料床的平均放热速率下降了32%,放热时间延长了34%,放热密度下降了6%;填料床高径比由2.32增加至8.33,填料床的放热量无变化,放热完成时间增加了113%,填料床的放热速率下降了129%。

In order to improve the problem that solar energy can not be continuously and stably output,this paper studied the influence of flow rate and temperature of heat transfer fluid and the aspect ratio of packed bed on the dynamic heat release characteristics of packed bed in the exothermic process by the numerical simulation method.The results show that increasing the flow rate and temperature of heat trans⁃fer fluid are the key parameters to improve the heat release rate,and increasing the aspect ratio is benefi⁃cial to reduce the heat release rate under the calculation condition.When the inlet flow rate of heat trans⁃fer fluid increases from 0.0005 m/s to 0.0013 m/s,the average heat release rate of packed bed increa⁃ses by 150%and the heat release time decreases by 54%,and the heat release density is not affected;when the heat transfer fluid inlet temperature increases from 473 K to 513 K,the average heat release rate of packed bed decreases by 32%,the heat release time increases by 34%,and the heat release den⁃sity decreases by 6%;when the aspect ratio of packed bed increases from 2.32 to 8.33,the heat release of packed bed is not changed,the heat release completion time increases by 113%,and the heat release rate decreases by 129%.