This simulation demonstrates the effects of flow output between two like pumps operating in parallel maintaining a constant pressure using three different control strategies. Understanding how flow can be affected using different methods of control is critical for the reliability and energy consumption of the pump.
1 - Synchronous Torque: This method of control synchronizes the torque of the pumps. This allows the work load of the pumps to be distributed evenly creating a better flow balance between pumps with different head performance characteristics commonly caused by pump wear or dissimilar pumps.
2 - Synchronous Speed: This method of control synchronizes the speed of the pumps. For identical pumps with no wear, this is an effective method to balance the flow of the pumps.
3 - Constant Slave: This method of control runs a fixed speed pump with a variable speed trim pump. This method of control is the least preferred as it typically yields a very small speed turndown, forces the variable speed pump back on the performance curve and creates a flow dead-band that can not be met without running the trim pump below recommended minimum flow.