Frequency control
The operating point deviation from the high efficiency zone is the basic condition for the pump to be governor. When the multi-stage centrifugal pump speed change, the valve opening remains the same (usually the maximum opening), the pipeline system characteristics unchanged, and the water supply capacity and head characteristics will be changed. In the required flow is less than the rated flow of the case, the head of the variable frequency speed control than the valve, so the water supply power required for variable frequency speed control is smaller than the valve.
Obviously, compared with the valve throttle, the energy saving effect of variable frequency speed regulation is very prominent, and the working efficiency of the horizontal multi-stage centrifugal pump is higher. In addition, use of frequency control, not only helps to reduce the possibility of pump cavitation, but also through the acceleration / deceleration time preset to extend the start / stop process, the dynamic torque is reduced, thereby eliminating the destructive water hammer effect of to a great extent, the water pump is extended and the life of piping system
