主给水调节阀节流窗口周向设计及其对流动特性的影响

安装于核电站二回路的主给水调节阀通过控制给水流量来调节蒸汽发生器内的水位高度,因此主给水调节阀的流动特性影响着核电站的运行安全与效率.首先,提出了无量纲的节流窗口周向布置不平衡度δ,进行主给水调节阀节流窗口周向设计;其次,利用经网格无关性与流量实验验证的数值模拟方法分析了阀内流场的速度和压力分布特性;最后,探讨了节流窗...

Circumferential design of throttling window of main feed water regulating valve and its influence on flow characteristics

The main feed water regulating valve(MFWRV)installed in the secondary circuit of the nuclear power plant regulates the water level in the steam generator by controlling the feedwater flow.Therefore,the flow characteristics of MFWRV affect the operation safety and efficiency of the nuclear power plant.Firstly,the dimensionless unbalance degreeδof circumferential arrangement of throttling window was proposed,and the circumferential arrangement of throttling window of MFWRV was designed;secondly,the numerical simulation method verified by grid independence and flow experiment was used to analyze the velocity and pressure distribution characteristics of the flow field in the valve;finally,the influence of the unbalance degree of the circumferential arrangement of the throttling window on the unbalance torque of the valve core and the flow coefficient of the valve was discussed.The results showed that the uneven pressure distribution at the bottom of the valve core would produce unbalanced torque to the valve core,increase the friction between the valve core and the sleeve,and then aggravate the abrasion between the valve core and the sleeve,which might cause the action stagnation of the valve core and shorten the service life of the valve core and the sleeve;when the valve opening was less than 40%,adjusting the circumferential arrangement of the throttling window had little effect on the unbalanced torque of the valve core;when the valve opening was greater than 40%,the unbalanced torque of the valve core could be effectively changed by adjusting the circumferential arrangement of the throttling window;under the same conditions,by increasing the unbalance degree of the circumferential arrangement of the throttling window from 0 to 0.5,the maximum unbalance torque of the valve core could be reduced by 22.10%,while the flow coefficient of the valve could be reduced by only 2.74%.The research results are conductive to the design and optimization of MFWRV and similar valves.