电站锅炉一次风系统模型

Primary Air System Model of Power Plant

火电机组需要利用各个环节储能来提高负荷响应速率。锅炉磨煤机内存储有大量煤粉,通过控制一次风量与给煤量的动态配比,可以在短时间内快速改变锅炉燃烧强度,建立一次风系统简化非线性动态模型是此项研究的基础。在分析磨煤机、一次风机等设备结构及工作原理基础上,通过机理分析方法和统计分析方法确定模型结构和模型参数,建立一次风系统微分方程形式的非线性动态模型。模型能够反映燃料量、一次风机动叶角度与一次风压、一次风量之间的动态关系。利用一台600 MW机组实际运行数据,将燃料量、一次风机动叶角度引入模型,对比模型输出以及机组实际的一次风压、一次风量信号,在50%-100%负荷范围内能较好吻合,验证模型的准确性。

Thermal power units need to improve load response speed by using all aspects of the energy storage. Mill of boiler have storaged mass coal. By controlling the dynamic ratio between primary air flow and coal feed rate,combustion intensity can be changed rapidly the in a short period of time. The foundation of tis study is the establishment of a nonlinear dynamic model of primary air systems. The model,created by analyzing the equipment structure and principles of mill,primary air fan and other equipment,consists of several differential equations which determined by mechanism analysis,and the model parameters are determined by statistical analysis. Using this model,the dynamic relationship between fuel flow,rotor blades angle of primary air fan and primary air flow,primary air pressure can be easily reflected. The primary air flow and primary air pressure of a 600 MW unit and the new model which use the actual data of fuel flow and rotor blades angle of primary air fan fit well in range of 50%- 100% load level. The result indicates the accuracy of this new model.