摘要
针对超(超)临界火电机组疏水系统中存在的套筒式多级降压调节阀高温水高压降空化引起汽蚀破坏的问题,基于汽液传递理论与多级降压理论,引入Z-G-B空化模型与混合两相流模型,建立阀内流场高温水空化计算模型.研究了套筒层数与级间间隙对空化流动的影响,获得了不同套筒模型条件下的阀内流场压力、速度及汽液两相体积分布等流场信息.分析结果表明:多级套筒使阀内最低压力由1.5 MPa上升至4.0MPa,空化最大气体体积分数由0.99降低至0.18.增加套筒级数可有效实现逐级降压、限制流速的目的,还可抑制空化的发生及发展,同时增加级间间隙也有利于减轻空化.
Aiming at the problem of control valve cavitation damage in ultra-supercritical thermal power units drainage system,based on the vapor-liquid mass transport theory and multistage decompression theory,the cavitation calculation model was established by using Z-G-B model and two-phase flow model.The influence of sleeve stages and gap on flow was studied,and the pressure,velocity and two-phase volume distribution of flow field were obtained under different model conditions.The results show that multistage sleeve makes the minimum pressure rise from 1.5to 4.0 MPa,and makes the maximum vapor fraction reduce from 0.99 to 0.18.Increasing the sleeve stages and gap could achieve gradual decompression,velocity control and cavitation suppression effectively.
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2015年第3期37-41,共5页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(51349008)
甘肃省高校基本科研业务费资助项目
兰州理工大学优秀青年教师培养计划资助项目(Q201002)
关键词
超(超)临界
套筒式调节阀
多级降压
空化
计算流体力学
ultra-supercritical
sleeve control valve
multistage decompression
cavitation
computational fluid dynamics
