超超临界机组锅炉储水罐调节阀内流场特性及优化

Flow field in regulating valve of water storage tank for ultra supercritical unit boiler:characteristics and optimization

超超临界机组锅炉储水罐调节阀是机组的重要阀门之一。为了探索该阀门的内部流场变化规律,本文建立了该阀门流场模型,基于Fluent软件湍流模型与多相流技术相结合,对阀门流场进行了模拟。结果表明:该阀门在设计结构及其工况下,介质处于临界状态,其流过阀杆、阀座间隙时会发生严重的汽化作用,使得流场极不稳定;阀杆角度对流场有较大影响,随着阀杆角度增加,介质速度会逐渐降低,汽化总量减少;在阀门管配流道增加匀流板后,流场速度可降低19.2%,含汽总量降低86.4%,整个流场变得较为均匀。

Control valves of water storage tank in ultra-supercritical unit boiler is important valves in the power plant system. In order to explore the changing law of interior flow field of the valve, the flow filed model of this valve was established, and analysis was carried out based on the Fluent turbulence model and multiphase flow technology. The results show that,with the design structure and conditions,the fluid is in critical state,serious evaporation will occur when it flows through the gap between the valve stem and seat,which will make the flow field be extremely unsteady. The valve stem angle has a great effect on the flow field, as the angle increases, the fluid velocity decreases gradually and the total evaporation quantity reduces. When two plates are added into the pipe system,the flow field speed is reduced by 19.2% while the total amount of volume fraction is 86.4% ,which means the entire flow field becomes uniform. The re- suits have a theoretical guidance to the structural design and optimization of the valve, and also have a posi- tive significance to promote the localization of the valve.