变频测量轴流泵汽蚀性能的方法

Method for Measuring Cavitation Performance of Axial Flow Pump by Frequency Conversion

为满足准确测量轴流泵汽蚀性能采用了一种新型方法,在干坑内使用实验主电机采用变频装置启动。通过调节电机不同工作频率,测量不同频率下的泵实际运行转速,将额定点流量换算到对应变频转速下的流量。通过调节出口阀的开度大小,使流量达到换算值。用压力变送器测量出泵进出口同一时间的压力值。换算到额定点的性能。当扬程下降3%时,则说明轴流泵发生汽蚀,该点即汽蚀点。实验结果显示采用变频测量轴流泵汽蚀性能的方法,泵进出口压力波动小,当泵发生汽蚀时,泵的性能变化明显。通过此方法汽蚀性能测量更准确、更简洁方便、实用。

In order to accurately measure the cavitation performance of axial flow pump,a new method is adopted.The main motor used in dry pit is started by frequency conversion device.By adjusting different working frequencies of the motor,the actual running speed of the pump at different frequencies is measured,and the rated point flow is converted to the flow at the corresponding variable frequency speed.By adjusting the opening of the outlet valve,the flow rate can reach the conversion value.Measure the pressure value of the pump inlet and outlet at the same time with the pressure transmitter.Performance converted to rated point.When the head drops by 3%,it means that the axial flow pump has cavitation,which is the cavitation point.The experimental results show that when the cavitation performance of axial flow pump is measured by frequency conversion,the pressure fluctuation at the inlet and outlet of the pump is small,and the pump performance changes obviously when cavitation occurs.The cavitation performance measurement by this method is more accurate,concise,convenient and practical.