Objective A method for calculating and selecting the minimum specific energy consumption working point is developed to solve the problem of high energy consumption in the short-distance slurry transport of dredgers.

Methods Based on the relevant models of pump pressure, pipeline resistance, critical flow velocity and pump cavitation established in previous research, the minimum energy consumption per cubic meter of particles is taken as the goal, and the pump speed which is most familiar and easily controlled by the workers is taken as the optimization variable. A double optimization method combining the minimum energy consumption search of the transport system and the optimization of multiple pump speeds is adopted to calculate and select the minimum energy consumption working point of the dredger with multiple pumps in a series, and the algorithm is verified by taking the construction of the "Xin Hai Lang" dredger with three different types of centrifugal pumps under specific working conditions as a case.

Results The calculation results show that the specific-energy consumption of the working point optimized by this algorithm model is 11.8% lower than that of the maximum production working point.

Conclusions  The application of these research results can effectively make up for existing optimization methods that aim at production capacity (maximum production), providing feasible references for energy saving and emission reduction in dredging projects.