一种电站用超(超)临界锅炉调节阀临界流流场特性分析

针对超(超)临界电站锅炉调节阀在国产化进程中汽蚀失效问题,结合某电站调节阀出现的阀门管配系统底板汽蚀击穿现象,基于两相空化流动控制方程和Fluent流场数值模拟手段,展开对该调节阀及其管配系统流场特性分析并进行了结构优化。模拟结果表明,原锥压式调节阀在开度较小的情况下介质发生了严重的汽化现象,气化率达90%以上,介质速度高,以至于底板被冲击至击穿。根据电站锅炉用给水泵流量结构特性,提出一种笼罩式调节阀,优化结构在喉口区域含汽量减少了32.75%,盲板附近的速度降低79.03%,管配系统安全。模拟结果较好的展现了阀门流场的分布规律,为该类调节阀结构设计与优化提供了理论指导,对该类阀门国产化起到积极的意义。

Field Characteristics Analysis of the Boiler Regulating Valve for Ultra Supercritical System

In view of the cavitation phenomenon of the power station boiler regulating valve of the ultra-supercritical during the process of localization, the numerical simulation is carried out to analyze the regulating valve and its pipe system according to two-phase cavitation flow control equation by Fluent. It can be concluded that the medium has high speed and serious vaporization phenomenon of the original cone structure in the case of small opening, the vapor volume fraction is more than 90%. One porous kind of regulating valve is put forward according to the characteristics of the flow structure of the feed water pump for a power station boiler, and the optimization structure has reduced vapor volume fraction by 32.75% and velocity by 79.03%, which shows that the security of the pipe system is verified. The results have some certain guiding significance on the design of the water storage tank valve to promote the collectivization and nationalization of this kind of valve.