Optimization Study On Pipeline Of Deep-sea Mining System

Along with the running up of land resources, deep sea exploitation has been important strategic goal of big countries of the world, there are significant meanings to realize efficient and low-energy-consumption piping of deep sea mine. In this paper, we consider a 4000 m deep-sea mining riser and adopt the lift program using multi-stage centrifugal pump. The detailed research method is as follows: apply the basic theory of mud transport in a vertical pipe, determine the allowable minimum mixture speed, estimate the pressure loss of large particles during lift for specific pulp density and pipe diameter, optimize the pump series and pipe diameter combining the characteristics of centrifugal pump, so as to achieve a stable, efficient mineral lift with low power consumption.To sum up, the contents of this article include:(1) Determine the physical parameters of riser and pulp, establish the physical model;(2) Determine the allowable minimum mixture speed for different pipe diameter;(3) Figure out the characteristic curve of pump with different caliber for different pulp concentration;(4) Calculate pipe resistance for each specific pipe diameter and pulp concentration;(5) Set pump series in a proper range and figure out the operation point of system combining pipe resistence curve and pump characteristic curve;(6) Take energy consumption per unit production as the optimization index, optimize pump series and pipe diameter on the basis of ensuring better play of pump efficiency, controlling energy consumption within the assembly power of mother ship and saving materials.Study results of this thesis show that energy consumption per unit production at a critical pump series can be obtained at the minimum, it also ensures higher production and better efficiency of pump. Based on pulp concentration of 0.20 and mother ship's power rationing of 30000 kW, riser diameter of 600 mm and pump series of 23 can ensure the lowest energy consumption per unit production and make pump efficiency at a high level, which is just adopted as the ultimate optimization program of deep-sea mining pipeline system.