透平端支承是重型燃气轮机轴系设计中的重要组成部分。基于流固耦合的有限元法研究切向支承座的热态自适应对中机理。运用Pro/Engineer软件分别建立切向支承、扩压器、高温燃气和冷却气体的3维模型。然后结合支承座的结构特点和流体的物性参数,通过定义流固耦合接触界面,进行计算流体动力学(Computational fluid dynamics, CFD)计算,最后将得到的固体温度场作为热载荷传递到ANSYS软件中进行结构分析,得到切向支承的热变形和热应力场,并选取支承座8个检测点的变形量进行对比。结果表明,机座在热载荷下产生的变形通过切向支承板使轴承座发生强制性旋转,从而减小了中心标高的偏离,实现了热态下的自适应对中,为今后支承座的优化设计和试验研究提供了重要参考依据。
The turbine end support is of great significance in designing the shafting system of the heavy-duty gas turbine. The thermal adaptive alignment mechanism of the tangential support is investigated based on the fluid-solid coupling finite element method. 3-dimensional models of the tangential struts,diffuser cones, hot gas and cooling air are established through Pro/Engineering software. Then by defining the fluid-solid interfaces, a CFD analysis is carried out considering both the structural characteristics of support and the properties of fluids. With the calculated solid temperature field provided as thermal loads, a structural analysis is presented to obtain the thermal deformation and stress distributions of the tangential support through ANSYS software. 8 testing points on the support are selected to monitor deformations. By comparison, the results show that thermal deformations of the support are automatically eliminated though mandatory rotating on the bearing house imposed by the tangential plates, thus decrease the deviation of the center and achieve the adaptive alignment at thermal state. This is a very fundamental study on the optimization design and experiment of the support of gas turbine.