R&D And Application Of Trailing Suction Hopper Dredger Efficient Energy-saving Drag Head

Trailing suction dredgers are high energy consumption construction vessels.Research and application of energy-saving dredging equipment to reduce energy consumption can not only save dredging enterprises fuel costs and reduce construction costs,but also reduce the pollution caused by ships,both economic and environmental protection benefit can be obtained.As one of the main equipments of trailing suction dredger,the drag head is installed at the lowest end of the suction rake pipe.The drag head is close to the mud surface which is at the bottom of the water in order to loosen the soil under the towing force of the ship,at last,the mud pump will discharge mixture muddy water to the natto or throw to side way.This process is digging work which can complete dredging and excavation purposes.Therefore,the performance of drag head directly affects the production efficiency and production cost of suction hopper dredger.Against the background of the continuous development of new technology in the dredging industry in the world,aiming at the special situation of dredging engineering in Changjiang Estuary and special soil conditions,this paper makes a theoretical study and related structural design of the new efficient energy saving drag head,and makes it operate on Hangjun 9002,Xinhaihu and Xinhaihu vessels in the 12.5m deep waterway maintenance project of the 3rd phase of the Yangtze River Estuary in Shanghai as testing.The construction efficiency of dredging projects has been greatly improved with this series of drag heads and a good production effect has been achieved.This paper starts with the basic structure and working principle of drag head,finds out the defects of the old drag head,and analysis the energy-saving principle of active and efficient drag head.On the above basis,the CFD simulation software was used to develop active high efficiency drag head,and the series of drag head were used in actual production,and the effect of energy-saving and emission-reduction was analyzed.By comparing the practical application of old dredger drag head and energy-efficient drag head on Hangjun 9002,Xinhaihu and Xinhaima from 2012 to 2013 in the deepwater channel dredging maintenance in the third phase of the Changjiang Estuary,in the same construction environment,the efficient energy saving drag head can the construction efficiency by 30%-40%when compared with the older drag head,save 4875.53 tons of standard coal for the project and reduce the amount of carbon dioxide emissions by 11,977.72 tons.