基于太阳墙技术的太阳能热气流发电系统的数值模拟

Numerical Simulation of the Solar Chimney Power Plant System Based on Solar-wall Technology

结合太阳能热气流发电系统和多孔板集热墙的特点,设计了一种基于太阳墙技术的太阳能热气流发电系统,分析了该系统内的传热与流动过程,在局部非热力学平衡的条件下,采用双方程多孔介质模型耦合空腔内的流动和传热过程进行了数值模拟,分析了多孔板的渗透率对入口流速、出口速度、出口温度、系统抽力和系统最大输出功率的影响。结果表明,提高多孔板的渗透率,使烟囱内气流速度增大,入口处气流速度变得不均匀、温升减小、抽力降低、系统最大可能的输出功率先增大,后减小。计算结果表明存在一个最优的孔隙率,可以获得比较均匀的入口流速,系统效果最优。

According to the characteristics of the Solar Chimney Power Plant System and the heat collecting wall with porous plate, a novel of solar-wall chimney power plant systems was designed and the flow and heat transfer process in this system were ana- lyzed. The flow and heat transfer process in coupling cavities was simulated by using two-equation porous media model to describe the flow and heat transfer process under the condition of local thermal equilibrium. The effect of the porous permeability on inlet flow velocity,exit velocity,exit temperature,chimney draft and output power were ana- lyzed. The results show that gas flow velocity in chimney will increase, the inlet gas flow velocity is nonuniform, the temperature rise and chimney draft reduce and the out- put power increase then reduce when porous permeability increase. The calculating re sults also show that there is an optimal permeability value which can obtain more uniform inlet flow velocity and best effect.