磨煤机入口一次风量测量数值模拟研究  

NUMERICAL SIMULATION OF PRIMARY AIR MEASUREMENT AT THE INLET OF COAL MILL

作　　者：常毅君[1] 王晓冰 张波 牛国平 

机构地区：[1]华能玉环电厂,浙江玉环317604 [2]西安热工研究有限公司,陕西西安710032

出　　处：《热力发电》2012年第12期48-50,54,共4页Thermal Power Generation

摘　　要：磨煤机入口一次风量测量的稳定性和准确性较低,是由于冷、热风混合段到测量截面间的距离较短,冷、热风不能完全均匀混合所致。通过数值模拟的方法,在一次风管道内冷、热风混合处安装导流叶片,增加冷风的射流深度,使测量截面的温差从原来的166℃降到22℃,测量截面的速度变化范围从13～25.8m/s减小到20～22m/s。加装混流装置后,使冷、热风混合更充分,有效地改善了测量截面上速度和温度分布的均匀性,风量测量系数稳定,准确性明显提高。Because of the short distance between the hot-cold air mixed segment and the measuring cross section,the hot air was unable to fully mixed with the cold air,so the stability and accuracy of measurement for primary air at inlet of the coal mill was relatively low.Through numerical simulation,the guide blade was installed in primary air pipe where hot and cold air mixed together,to increase the penetration depth of the cold air.The temperature difference of the measured cross section dropped from 166 ℃ to 22 ℃,and the variation range of speed on it decreased from 13-25.8 m/s to 20-22 m/s.After the flow mixed device was installed,the hot and cold air were fully mixed,effectively improving the uniformity of speed and temperature distribution on the measuring cross section.The air flow measurement coefficient was stable and the accuracy was improved obviously.

关 键 词：磨煤机 一次风量 测量 温度流场 速度流场 

分 类 号：TK223.25[动力工程及工程热物理—动力机械及工程]