Water Resources and Power

In order to clarify the change rule of hydraulic performance in the transition process of large-scale shaft tubular pump unit, a transient calculation model of shaft tubular pump unit is constructed based on the Flowmaster software. The change rule of rotational speed, flow rate, power and head with time variation are obtained in the start-up process, emergency shutdown and normal shutdown of pump unit. When the fast gate is installed with or without flap gate, the start-up and shutdown hydraulic characteristics of pump unit are compared. The results show that the backflow is effectively prevented by extending the fast gate opening time, but the maximum start-up head and transient starting power of pump unit are obviously increased. When the flap gates are installed in the fast gate, the reliability of pump unit start-up can be improved, and the maximum start-up head and maximum starting power of pump can be reduced. The fast gate with or without flap gate has little effect on the transient physical parameters of pump unit shutdown. In order to reduce the pump reversal time, the inverted flow rate and the maximum transient reversal speed, the fast gate should be closed as soon as possible after pump unit shutdown.