离心泵转速对工作点参数的影响

利用离心泵特性曲线测定装置,在固定阀门开度下,通过改变离心泵的转速,测出不同阀门开度下系统管路的特性曲线;在固定转速下,通过改变系统管路阀门开度,测出不同转速下离心泵的特性曲线。绘制出所有特性曲线,找出泵的工作点。拟合出所有特性曲线的方程,统计分析出转速对泵工作点的流量、扬程和轴功率的影响。结果表明:当转速变化量为20 %时,流量与转速qv1/qv2=k₁(n₁/n₂)]的比例系数k₁=0.96～1.52;扬程与转速H₁/H₂=k₂(n₁/n₂)²]的关系式中k₂=0.81～1.56;轴功率与转速(N₁/N₂=k₃(n₁/n₂)³)的关系式中k₃=0.66～1.37。根据离心泵的比例定律,理论上k₁≈k₂≈k₃≈1,但实验证明,离心泵的比例定律系数在实际工作中变化范围较大,应予修正。讨论了实验条件下离心泵的适配管路,为离心泵在实际应用中节约能源和高效利用提供依据。

Influence of Rotating Speed of Centrifugal Pump on Its Parameters at Operating Point

Test device of centrifugal pump performance was appied to this work for determining the following data. With fixed valve opening, tube performance curve was determined by variable pump rotating speed(n). With fixed pump rotating speed, pump performance curve was determined by variable valve opening. All the above performance curves were drawn, and the pump opertating points were found. The fitting equations of both pump and tube performance were worked out. The influence of rotating speed on volume flow(q_v), head(H) and power (N) at working point of centrifugal pump were statistically analysed. The results showed that when rotating speed variation was within 20%,qv1/qv2=k₁(n₁/n₂), where k₁ was from 0.96 to 1.52; H₁/H₂=k₂(n₁/n₂)², where k₂ was from 0.81 to 1.56; N₁/N₂=k₃(n₁/n₂)³, where k₃ was from 0.66 to 1.37. According to the law of centrifugal pump. Theoretically k₁≈k₂≈k₃≈1, while practically the proportional coefficients changed in a larger range. In this work, we worked out the optimum tube system for the pump in the device for the high efficiency, and offered some basement data for saving energy and high efficient research of centrifugal pump.