论文部分内容阅读
水轮机金属蜗壳设计中不同断面结构型式的选择,会在一定程度上影响结构的受力特性和厂房布置尺寸。为分析金属蜗壳不同断面型式结构受力特性,对非圆形的三心圆蜗壳断面与圆形蜗壳断面结构在充水保压阶段进行了有限元数值计算。研究结果表明:相比于圆形断面蜗壳结构,三心圆蜗壳在充水保压时蜗壳直管段会发生较大的水平偏转位移,座环整体在水平向的变位也相对更大,对钢蜗壳整体的变形控制要求更高;而钢蜗壳断面内环向应力数值略有减小,但整体应力水平变化不大。因此,从水压试验和保压阶段蜗壳与座环结构的变形控制角度来看,在高水头充水保压蜗壳结构中采用非圆形断面蜗壳结构是不合适的。建议今后在金属蜗壳结构设计和埋设方式选择时,应该充分重视不同蜗壳断面结构型式对结构受力特性的影响,确保水电工程的顺利建设和安全运行。
The choice of different cross-section structure types in the design of turbine’s metal volute will affect the mechanical characteristics and the layout of the plant to a certain extent. In order to analyze the stress characteristics of different cross-section structures of metal volute, the finite element numerical calculation of non-circular three-heart-circular volute section and circular volute cross-section structure during water-filling and pressure-holding stage was carried out. The results show that compared with the circular volute spiral case, the horizontal spiral displacement of the straight volute of the three-heart-shaped volute at the time of water-filled and pressure-holding is relatively large, and the displacement of the seat ring in the horizontal direction is relatively more Large, the steel spiral case deformation control requirements are higher; and the steel spiral case cross-section of the ring to a slight decrease in the numerical stress, but the overall stress level did not change much. Therefore, it is not suitable to adopt a non-circular volute structure in the high-head water-filled volute retaining structure from the perspective of deformation control of the volute and the seat ring structure during the pressure test and the dwell phase. It is suggested that in the future, when choosing the design of metal volute structure and the way of embedding, we should give full attention to the influence of different volute section structure on the mechanical characteristics of the structure to ensure the smooth construction and safe operation of hydropower project.