基于Over Conductivity方法的汽轮机启动温度场分析研究

Analysis and Research on Temperature Field of Steam Turbine Start-Up Process Based on Over Conductivity Method

汽轮机的频繁快速启停和深度调峰运行对机组寿命影响显著,为了准确预测汽轮机关键部件的使用寿命,必须快速准确地获得汽轮机启动过程的温度分布。为了提高启动温度场的计算效率,尝试将Over Conductivity(OC)方法应用于暖机阶段,通过对流换热方法计算蒸汽焓降中传热所占比值,将热流密度边界与OC方法相结合,进行温度场的模拟计算与验证。结果表明,使用OC方法模拟的启动轴封进汽和暖机阶段的温度分布,不仅计算结果准确性较高,也保证了有限元分析的模型和方法的一致性。研究成果可为汽轮机暖机过程采用OC方法进行温度场快速模拟提供参考。

The frequent and rapid start-up and shut-down of the steam turbine and the deep peak shaving operation have a significant impact on the life of the unit.In order to accurately predict the service life of the key components of the steam turbine,the temperature distribution during the start-up process of the steam turbine must be obtained quickly and accurately.In order to improve the calculation efficiency of the temperature field during start-up,the Over Conductivity(OC)method is applied to the calculation of warm-up phase.The proportion of heat transfer in the steam enthalpy drop is calculated using the convective heat transfer method,and the temperature field calculation and verification are conducted with the combination of the heat flux density boundary and the OC method.The results show that using the OC method,the simulation of the temperature distribution in the shaft seal during the steam intake and warm-up phases of the start-up not only has a result with higher accuracy,but also ensures the consistency of the finite element analysis model and method.The research result can provide reference for the application of OC method in the rapid simulation of temperature field during the warm-up in steam turbines.