Objective  The calculation and selection method of minimum specific energy consumption working point is developed to solve the problem of high energy consumption in 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 the 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. The 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 series, and the algorithm is verified by taking the construction of "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 the research results can effectively make up for the existing optimization methods aiming at production capacity (maximum production), and provide a feasible reference for energy saving and emission reduction of dredging projects.