摘要
部分进汽以及变工况运行是小型工业汽轮机调节级流场及转子受力复杂的重要原因。本文采用计算流体力学方法对调节级整级模型进行数值计算,研究负荷变化对调节级内部流动特性和汽流激励力特性的影响。研究表明:负荷对调节级内部流体流动影响较大,动、静叶的总压损失系数与负荷呈负相关,即负荷越小损失系数越大;喷嘴隔断大小对动叶受力影响很大,隔断大,动叶受力会在经过隔断时发生骤变,隔断小,对动叶受力几乎没有影响;随着负荷的减小,轴向汽流力和周向汽流力都呈现出逐渐增大的趋势;动叶轴向汽流力和周向汽流力低频激振的基频都是193.05 Hz,与汽轮机轴频有关。
Partial steam admission and off design operation are the important reasons for the complex flow field and rotor stress in the governing stage of small industrial steam turbine.In this paper,the computational fluid dynamics(CFD)method is used to calculate the whole stage model of the governing stage,and the influence of load change on the flow characteristics and the steam flow exciting force characteristics of the governing stage is studied.The results show that the load has a great influence on the internal flow of the regulating stage,and the total pressure loss coefficient of the moving and stationary blades has a negative correlation with the load,that is,the smaller the load is,the greater the loss coefficient is.The size of the nozzle partition has a great influence on the force of the moving blades,and the force of the moving blades will change abruptly when passing through the partition,and the partition is small,which has little influence on the force of the moving blades.The influence of load on the axial and circumferential steam flow forces on the moving blades is that with the decrease of load,the axial and circumferential steam flow forces increase gradually.At the same time,it is found that the fundamental frequency of the low frequency excitation of the axial and circumferential steam flow forces is 193.05 Hz,which is related to the turbine shaft frequency.
作者
周海飞
杨爱玲
陈二云
韩艳龙
ZHOU Hai-fei;YANG Ai-ling;CHEN Er-yun;HAN Yan-long(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai,China,200093)
出处
《热能动力工程》
CAS
CSCD
北大核心
2020年第11期31-38,共8页
Journal of Engineering for Thermal Energy and Power
基金
国家自然科学基金(51106099,50976072)。
关键词
汽轮机
调节级
部分进汽
激励力
隔断
steam turbine
regulating stage
partial steam intake
exciting force
partition
