摘要
针对改进进汽段的设计、提高机组经济性、降低机组噪声的目的,用数值方法研究了10 MW给水泵汽轮机组速关阀和调阀系统的全开工况下的流动和噪声。求解了全三维N-S方程和k-ε湍流模型得到进汽系统内部的稳态流场,从流场的速度分布云图、湍动能分布云图和涡量分布云图出发,分析了压力损失产生的原因,将瞬态分析得到的流体边界压力随时间的脉动通过傅里叶变换,转换成频域下的声压值,得到进汽系统内各个壁面的二级子噪声源的分布云图,并分析了调阀喉部处各频率下的声压大小。研究结果表明,进汽系统内的总压损达6.06%,其中速关阀部分产生的压损为1.98%,调阀部分产生的压损为4.08%,调阀喉部及折弯处为气动噪声辐射的主要位置,噪声辐射能量最大的频率为30 Hz。
Aiming to improve the design of the steam intake segment,increase the efficiency of the unit,reduce the production of the noise,flow conditions and noise emissions of a certain 10 MW industrial steam turbine＇s quick-closing valve and governing valves system at the point of full-opening is studied by numerical simulation. The steady flow distribution have been analyzed by a 3-dimensional calculation method of solving 3-dimensional Navier-Stokes equations together with k-ε turbulence model. By analyzing the velocity contour,turbulence kinetic energy contour and vorticity contour,the reason of pressure loss is discussed. Using Fourier transform on the fluid boundary＇s pressure fluctuation obtained by transient analysis,dipole noise emission source contour within the intake system is obtained. The results indicate that the total pressure drop within the intake system flow passage amounts to 6. 06%. The pressure drop within the quick-closing valve and the governing valves amounts to 1. 98% and 4. 08% respectively. The results indicate that the throat and band segment of the governing valves are the main noise emission location,and the frequency of the largest noise emission is 30 Hz.
出处
《机电工程》
CAS
2016年第6期709-712,717,共5页
Journal of Mechanical & Electrical Engineering
基金
浙江省科技厅优先主题重大工业项目(2008C01063)
关键词
工业汽轮机
喷嘴调节
调阀
流场
噪声
industrial steam turbine
nozzle governing
governing valve
flow field
noise
