CVN静叶透平级气动性能的数值计算与试验结果的比较及优化

Numerical Simulation and Optimization of the Aerodynamic Performance of the CVN Vane Turbine Stage and Comparison with Experimental Results

以某600MW汽轮机高压缸内的CVN（顶部反扭）静叶透平级为计算对象，以Fine／Turbo软件为模拟工具，计算了不同速比下的透平级的气动性能，并与试验结果进行对比，分析比较了级效率、反动度、流量系数等技术指标。结果表明数值计算结果与试验吻合较好，气动性能指标的变化趋势一致；最佳速比均介于0．52—0．53之间；该静叶叶型并不是最佳，静、动叶损失偏大，造成级效率偏低。通过改进静叶成型，提出了3种透平级的改进设计方案，经计算和比较得出正弯静叶透平级为最佳方案，其静、动叶损失最小，比原模型级可提高透平级效率1．2％。

The numerical simulation study based on Fine/Turbo software was carried out for a CVN （top anti-twist） vane turbine stage in a 600MW steam turbine high pressure cylinder, calculating the aerodynamic performance of the turbine stages under different speed ratios and comparing with test results, analysis and comparison of the stage efficiency, reaction degree,flow coefficient and other technical performance. The results show that the numerical results agree well with the experimental and indicate the consistent trend of aerodynamic performance; the optimal speed ratio is among 0.52 to 0.53; the CVN vane type is not the best because the vane and blade energy loss is too large and resulting in low-level stage efficiency. By improving the vane shape, this paper proposed three turbine stages of design improvements and analyzed their performance through numerical simulation and comparison, and conclusion show that the positive bowed vane turbine stage is the best option ,which has the minimal amount of vane and blade energy loss and can be increased turbine stage efficiency of 1.2% than the original stage.