【摘要】 由于汽轮机内部空间的限制及船用汽轮机多工况的要求,部分船用汽轮机采用了短座阀。因扩压段长度的大幅减小,阀门的气动性能及强度振动特性产生较大变化,对汽轮机总体性能有较大的影响。本文对某短座阀在试验研究的基础上进行了数值计算分析:通过气动试验,得到某船用汽轮机短座阀的流量系数与提升力系数曲线簇;基于可压缩N-S方程,利用S-A湍流模型及有限积分法,采用四面体非结构性网格,对此阀门进行了数值模拟计算。通过对该阀门的数值计算得到在不同相对开度及不同压比下的计算结果与试验结果吻合良好;得到对各种短座阀广泛适用的计算方法,为船用调节阀、旁通阀的设计和性能分析提供了重要依据。更多还原

【Abstract】 Owing to the restriction of inner space in a marine steam turbine and its multi-regime operation requirements short-seat valves are employed in some marine steam turbines. Due to a considerable reduction of diffusion section length a relatively great change will take place in the aerodynamic performance and strength/vibration characteristics of the short-seat valve. This, in turn, can affect to a fairly great extent the general performance of the steam turbine. Based on the experimental study of a short-seat valve the authors have performed a numerical calculation and analysis. Through aerodynamic tests a group of curves was obtained for the flow rate and lifting force coefficients of a marine steam turbine short-seat valve. On the basis of a compressible N-S equation and by using a S-A turbulent flow model, a finite integral method and the non-structural network of a four-faced body a numerical simulation calculation was carried out for the above-mentioned valve. The numerical calculation of the valve has revealed that the calculated results at various relative degrees of valve opening and various pressure ratios agree quite well with the test results. In addition, a calculation method generally applicable for various kinds of short-seat valves was obtained, hus providing an important basis for the design and performance analysis of marine regulating valves and bypass valves.更多还原