基于模型自适应汽轮机调节门流量特性优化研究及应用

Optimization on Valve Flow Characteristics of Steam Turbine Based on Model Self-Adaptation and Its Application

汽轮机调节门流量特性影响机组安全稳定运行和负荷调节性能。首先,针对采用喷嘴配汽方式的汽轮机调节门结构类型,通过模型自适应算法,建立顺序阀方式下的非线性调节门流量特性模型,实现调节门流量特性优化计算。其次,对该模型进行仿真研究,系统仿真结果表明,采用RBF神经网络结构的单阀流量特性仿真模型具有较高的模型精度,利用模型自适应优化算法可获得近似理想的线性度和最佳调节门重叠度。最后,将仿真结果应用在某660 MW机组上,试验结果表明,该方法不仅改善调节门流量特性线性度,而且降低调节门重叠度,改善AGC负荷响应性能,减少调节门晃动和机组节流损失。

The valve flow characteristics of steam turbines have significant impacts on the system security and operation stability as well as load regulation performance of the units.In this paper,regarding the valve structure in nozzle governing,the non-linear valveflow characteristic model is first built for sequence valve control by taking advantage of model adaptive algorithm to conduct flow characteristic linearization based on optimization arithmetic.Second,the simulation study is carried out on this model.The results indicate that the single flow characteristic simulation model adopting RBF network has high model precision.By virtue of the model adaptive optimization algorithm approximate ideal linearity and optimum valve overlap can be obtained.Finally,the simulation resultis applied to a660-MW unit.The test result shows that the method can not only improve the linearity of the valve flow characteristics,but also lower the valve overlap,improve the AGC load response performance and alleviate the valve shaking issue and reduce the throttling losses of the unit.