核电厂合流型硼酸三通调节阀的流量特性研究

Study on the flow characteristics of boric acid three-way converging regulating valve for nuclear plant

针对核电厂合流型硼酸三通调节阀出现的流量分配调节能力差、响应时间长、部分阀位调节性能失效等问题,分析了三通阀在不同阀位及不同工况下的流动特性,建立了数值仿真模型,绘制流量特性曲线和流量分配曲线,并通过流量试验数据进行验证。研究发现:阀中腔易产生低速涡旋,降低阀流通能力,该现象在中间开度影响更为明显;出口总流量较大时,阀芯受不平衡力矩,影响阀开启和关闭性能;出口总流量较小时,30%~80%之间的阀位调节性能较弱;三通阀两入口管路内压力不等导致一部分阀位失去调节功能,且在两入口管路内压力差一定的条件下,三通总流量越小,阀位失效范围越大。研究结果可为给该类阀门结构优化设计提供理论指导和依据。

For the problems of poor flow distribution and regulation capability appearing in boric acid three-way converging regulating valve for nuclear plant,long response time,regulating performance failure in some disc positions,etc.,the flow characteristics of three-way valve at different valve positions and under different working conditions were analyzed,a numerical simulation model was established,the flow characteristic curve and flow rate distribution curve were plotted,and verified by the actual experimental data.It is found that the valve cavity is easy to produce low-speed vortex,which reduces the flow capacity of the valve,and the effect of the low-speed vortex is more obvious at middle opening.When the total outlet flow rate is high,the valve core is acted by the unbalance torque,which affects the valve opening and closing performance.When the total outlet flow rate is low,the adjustment performance between 30%and 80%valve position is weak.The total pressure in the two inlet pipes of the three-way valve is unequal,leading to the loss of regulating function of some valve positions.And under the condition of a certain inlet pressure difference,the smaller the total flow rate of the three-way valve is,the larger the failure range of the valve positions is.The research results can provide theoretical guidance and basis for structural optimization design of such type of valves.