太阳能烟囱对带热源工业厂房自然通风特性的影响

Effect of Solar Chimney on Natural Ventilation in Industrial Workshop with Heat Source

提出了利用安装于屋顶的太阳能烟囱改善带热源工业厂房自然通风效果的方法,并用计算流体力学方法对4种不同形式的太阳能烟囱对厂房内自然通风的影响进行了数值模拟研究,用PMV/PPD对厂房内的热环境进行了评估。采用Realizable k-ε湍流模型及DO辐射模型对厂房内部的空气流动与压力分布进行了数值计算,结果表明,当把太阳能烟囱垂直安装于厂房屋顶的对称中心(SC-Ⅲ型)时,自然通风的通风量比原型增加了39%,厂房内平均风速增大了42.8%,效果最好。同时,热环境计算结果表明,当安装了太阳能烟囱后,PMV有不同程度的降低,其中SC-Ⅲ型的PMV从厂房原型的1.503降低到1.282,下降了16.5%,人员热舒适性提高。总的来说,太阳能烟囱使得厂房中不满意人员百分率(PPD)有所下降,其中SC-Ⅲ型厂房的PPD从厂房原型的51.063%下降到39.346%,降幅22.9%。

A design was proposed to improve the natural ventilation in an industrial workshop with heat source by solar chimney installed on roof of the workshop and the effect of 4 types of solar chimney on the natural ventilation in the work- shop was numerically simulated based on computational fluid dynamics （CFD） method. The thermal environment was evalu- ated by PMV （Predicted Mean Vote） and PPD （Percentage of Dissatisfied）. The air flow and pressure distribution in the workshop were calculated with Realizable k-~ turbulent model and discrete ordinate （DO） radiation model. Results showed that the ventilation rate increased by 39% and the averaged air velocity in the workshop increased by 42. 8% compared to the prototype when the solar chimney was vertically installed on the symmetric centre of the workshop roof （ as noted as SC - Ⅲ ）. The SC -Ⅲ solar chimney increased the averaged air velocity in the workshop, e. g. , the averaged air velocity in the workshop increased 42. 8%. Results on the thermal environment showed that the PMV index decreased when solar chimney was installed, e. g. , PMV decreased from 1. 503 for the prototype workshop to 1. 282 for SC - Ⅲ workshop, a 16. 5% decrease,which indicated that the thermal comfort was improved. Solar chimney decreased the PPD, e. g. , PPD decreased from 51. 063% for the prototype workshop to 39. 346% for SC - Ⅲ workshop,a decrease of 22. 9%.