锅炉蓄热系数对协调控制系统参数影响定量分析

锅炉蓄热系数是影响火电机组协调控制系统，特别是锅炉侧控制器的参数。在依据锅炉设计运行数据计算锅炉蓄热系数的前提下，依据火电机组简化非线性动态模型对其进行工作点线性化后，针对典型炉跟机协调控制系统简化结构，直接推导出汽轮机高压缸进汽调节门开度控制机组发电负荷条件下，锅炉燃料量对汽轮机前蒸汽压力的传递函数。研究发现，锅炉侧等效被控制对象为积分特性的无自平衡对象，同时锅炉蓄热系数体现在对象增益项中，锅炉蓄热系数越大，对象增益项越小。依此规律设计600 MW机组协调控制的增益补偿逻辑，在50%~100%负荷获得了优良的控制效果。

Quantitative Analysis on Influence of Boiler Heat Storage Coefficient on Coordinated Control System Parameters

The boiler heat storage coefficient is the parameter which affects the coordinated control system, especially the controller on the boiler side in thermal power plants. Based on the values of different operation conditions calculated with the design and operation data, the heat storage coefficient is simplified linearly according to the simplified nonlinear dynamic model. After the linearization, the transfer function of boiler fuel flow versus throttle pressure is deduced for the simplified typical boiler-following-turbine coordinated control system structure under the condition of the generation loads controlled by HP cylinder regulating valve opening. The study results show that the boiler-side equivalent controlled object is the non-self-balanced object with integral characteristic, and the boiler heat storage coefficient is reflected in the object gain. The rule is that the bigger the heat storage coefficient is, the smaller the object gain will be. According to this rule, the gain compensation logic for the coordinated control system of a 600-MW unit is designed, which has obtained satisfying control performance in the load range of 50%~100%.