主蒸汽非定常性对中压第一级温度场和流场的影响

Influence of the main steam unsteadiness on the temperature field and flow field of medium pressure at the first stage

以600 MW超超临界汽轮机中压缸为研究对象,采用气热耦合数值模拟方法研究非定常性对中压第一级温度场和流场的影响。针对有、无冷却蒸汽的两种工况,使用ANSYS CFX 10.0提供的Redich Kwong干蒸汽介质,k-epsilon湍流模型,总温方程热传导模型,研究了一个周期内动叶片表面温度分布和流场分布。研究结果表明,冷却蒸汽流动的非定常性对冷却效果、压力场和温度场的影响显著,主蒸汽流动的非定常性的影响可以忽略;蒸汽冷却为动叶增大了近10倍左右的热应力。

Taking the pressure cylinder of a 600 MW ultra supercritical steam turbine as the research object, the influence of unsteadiness on the temperature field and flow field of medium pressure at the first stage is studied by using the numerical simulation method of conjugate heat transfer. According to the two conditions with and without cooling steam, the research of rotor blade surface temperature distribution and flow field distribution in a period is taken by using Redich Kwong dry steam medium provided by ANSYS CFX 10, k - epsilon turbulence model and heat conduction model of total temperature equation. The results show that the unsteadiness of the cooling steam flow has an obvious effect on the cooling effect, pressure field and temperature field ; the influence of the unsteadiness of the main steam flow can be neglected ; the thermal stress of rotor blade is increased nearly 10 times by steam cooling.