摘要
采用指数格式和虚拟时间步法对湍流流动的控制方程进行离散 ,用空度方法处理流场中的屏式受热面 ,而假扩散则由解析方法消除 ,用SIMPLEC算法求解离散代数方程。研究了某 2 0 2 3t/h锅炉冷态模型中二次风采用集中反切和分散反切两种反切方式时炉内流场的特点 ,计算结果与首次基金项目 :机械工业技术发展基金资助项目 ( 95JB110 1)。采用六线涡量探针测量得到的炉内流场进行了对比 ,两者基本吻合。对四角切向燃烧煤粉炉 (切向炉 )而言 ,引起水平烟道入口存在流速偏差的主要原因是角动量流率 (AMFR)在水平烟道入口尚有较大的残余。计算结果显示 ,由于两种反切方式下各自流场结构特点不同 ,因而AMFR在炉膛燃烧器区域的最大值不同 ,沿炉膛高度的衰减规律也不同 ,分散反切方式比集中反切方式更能有效地防止炉内气流贴壁 ,对降低水平烟道入口的流速偏差也是有效的。
China)The SIMPLEC algorithm incorporated with the power-law scheme and the pseudo-ti me step had been employed to solve numerically the governing equations of the 3 -D turbulent flow field in a boiler furnace rated 2023t/h. The results agreed q ualitatively with the experimental data carried out by the 6-sensor hot-wire a nemometer. The simulation was done for two contrary modes of the ai r jets, i.e. GK1 and GK2. For the characteristics of the flow fields for the two cases is not the same, also the attenuation of Angular Moment Flow Rate (AMFR) along the height of the furnace and the maximum AMFR in the burner zone. The numerical results indicated that the separated contrary mode (identified as GK2 mode in the paper), compared with the concentrated one (identified as GK1 mode), can prevent efficiently the flow attachment to the walls. The separated mode ca n avoid the egregious increasing of AMFR during the attachment; also GK2 mode ha s positive impact to decrease the heat imbalance in the horizontal flue. Based o n the computation, several means are concluded to restrict and eliminate the res idual of the swirl caused by the residual of AMFR in the tangentially fired furn aces.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2001年第11期60-64,共5页
Proceedings of the CSEE
基金
机械工业技术发展基金资助项目 ( 95JB110 1)
关键词
大型电厂
锅炉
二次风
反切方式
数值计算
tangentially fired furnace
porosity
SIMPLEC
conc entrated, separated
