摘要
以西班牙Manzanares太阳能烟囱发电系统为原型,数值研究了烟囱形状、集热棚直径和集热棚离地高度等因素对太阳能发电系统的流动和传热特性的影响。研究结果表明:渐扩型的烟囱所达到的最大中心速度最高,而稳定时的中心速度最低;渐扩型与渐缩型较直筒型烟囱中心温度更高。渐缩型的烟囱其系统的质量流率最小,而渐扩型的烟囱其系统总传热速率最大。综合考虑,渐扩型设计的烟囱有助于流动和总传热率的提高。集热棚直径的增加能明显增强系统的流动和传热特性;但随直径的增加其增强效果逐渐减弱。集热棚外缘高度增加时,中心速度的增加程度逐渐减小,中心温度降低。集热棚外缘高度增加,系统的流动和传热特性均有所增强;但当高度超过3 m时其增强效果减弱,继续增加高度对流动和传热效果影响不大。
Based on the prototype of Manzanares solar chimney power generation system in Spain,the influence of the chimney shape,collector diameter and collector＇ s height from ground on the flow and heat transfer characteristics of solar chimney power plant system were numerically simulated.The results showed that：the maximum velocity is highest but the stable velocity is lowest in the central axis of diverging chimney.The central temperature in the diverging and converging chimney is higher than that in the straight chimney.The mass flow rate in the converging chimney is minimum but the total heat transfer rate is maximum in the diverging chimney.Comprehensive consideration suggests that the diverging design of chimney is beneficial to improve the flow rate and overall heat transfer rate.Increasing of collectors diameter significantly enhances the flow and heat transfer characteristics of the system,but the enhancement effect gradually weakens with the increasing of collectors diameter.The increased degree of the center velocity and center temperature decrease with the increasing outer height of collectors.The flow and heat transfer characteristics of the system are enhanced when the outer height of collectors increases.But the enhancement weakens when its height exceeds 3 m,and it has little effect on the flow and heat transfer characteristics to increase continuously the outer height of collectors.
出处
《科学技术与工程》
北大核心
2014年第24期74-79,共6页
Science Technology and Engineering
关键词
太阳能烟囱
集热棚
结构参数
传热
流动
solar chimney
solar collector
structure parameters
heat transfer
flow
