调节阀流量系数几种计算方法的比较

Comparison of Several Calculation Methods for Control Valve Flow Coefficient

流量系数是衡量调节阀流通能力的量化指标,是选用调节阀口径的主要依据。介绍了膨胀系数法、临界流量系数法、多项式法和正弦法的计算方法与不同点。选择4个典型工况,分别用临界流量系数法、多项式法、膨胀系数法计算其流量系数及误差,并对计算结果进行比较,发现相互之间的误差均很小,不影响调节阀口径的选用,由此说明这几种流量系数计算方法都可以使用。

Flow coefficient is the quantitative index of measuring control valve capacity. It is also the principle basis of selecting nominal diameter for control valve. The calculation method and difference for methods of expansion coefficient, critical flow coefficient, multinomial and sine are introduced. The flow coefficient and error are calculated respectively used critical flow coefficient method, multinomial method and expansion coefficient method under 4 selected typical operating conditions. The results show the error is very little to each other after comparation among them. This error will not selecting nominal diameter of control valve. All four methods can be used to calculate flow coefficient.