华电技术 ›› 2019, Vol. 41 ›› Issue (5): 17-21.

• 研究与开发 • 上一篇    下一篇

中速磨煤机入口一次风混流及均流技术研究

  

  1. 1.云南电网有限责任公司电力科学研究院,昆明〓650217; 2.华北电力大学 控制与计算机工程学院,北京〓102206
  • 出版日期:2019-05-25

Study on flow mixing and equalizing technique of primary air  at inlet of medium speed coal mills

  1. 1.Electric Power Research Institute,Yunnan Power Grid Company Limited, Kunming 650217, China; 2.School of Control and Computer Engineering, North China Electric Power University, Beijing 102206, China
  • Published:2019-05-25

摘要:

针对国内某大型燃煤电厂600MW机组锅炉中速磨煤机入口一次风量、风温测量不准确,锅炉负荷、风量、风温和燃烧量控制无法自动投入等问题,采用计算流体动力学(CFD)数值模拟方法设计了3套冷、热一次风混流及均流装置,并对均流效果进行比较,结果表明:设计的冷、热一次风混流及均流装置都能够很好地满足风量测量元件对测量截面流场均匀性和温度场均匀性的要求,能够消除矩形风道内的漩涡、调整气流的偏向,使得风量测量截面气流的来流方向正对风量测量元件;风量测量截面的速度相对标准偏差降至6%以下,温度相对标准偏差降至2%以下,一次风总压损的增加保持在300Pa以内;方案3的截面平均速度和平均温度相对标准偏差最小,其均流效果最优。

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Abstract:

The measurements of the primary air flow rate and air temperature of medium speed mills in a 600MW unit are usually not accurate.Therefore control systems of boiler load, air flow rate,air temperature and burning load cannot work automatically.By CFD numerical simulations, 3 sets of coldhot primary air flow mixing and equalizing devices are designed.Comparing their currentsharing effects, all the coalhot primary air flow mixing and equalizing devices above can satisfy the measuring requirement on uniformity of flow field and temperature field at the measuring section, can eliminate the vortex, can adjust the deflection of airflow in the rectangle primary air duct, and can make the incoming air direction on the measuring section be vertical to the detecting device. The relative standard deviation of the air velocity and air temperature drop to 6% and 2% respectively.The total pressure losses of primary air are less than 300Pa.The average velocity and temperature at crosssection of scheme 3 is of the smallest relative standard deviation,and its current sharing effect is optimal.

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