Study On Application Feasibility Of Double Reduction Ratio Gear Box Applied On Push Boat

There are large numbers of push-train fleets in China at present. With improvement of Inland River channel and related technology of push boat, push-train fleet is being one of main transportation ways of Inland River in China.Propulsion plant commonly is made up of medium-and-high speed marine diesel engine, single deduction gear box and FPP (fixed pitch propeller) in transportation push-train fleet in China at present. Disadvantages for above the propulsion plant are as follows:Firstly, after a period of time, service power of marine diesel engine is decreased, and the hull resistance is increased. Therefore, matching running point between diesel engine and propeller changes, the propulsion plant can not work in Optimum matching running Point, the propulsion efficiency decreases and diesel engine fuel consumption increases.Secondly, according to multiple running condition push boat, when propeller is designed in full load condition and push boat works in unload condition, diesel engine works in part load, diesel engine performance deteriorates. Propeller works in "light load" condition, propeller efficiency decreases obviously. Therefore, the propulsion efficiency and propulsion thrust of propeller decreases. Decreasing of fleet sailing speed effects fleet operation efficiency. When propeller is designed in unload condition and if push boat works in full load condition, diesel engine always works in part load, diesel engine performance deteriorates and propeller works in "light load" condition, propeller efficiency decreases obviously.In this thesis, application of double reduction gear box on push boat can resolve above disadvantages of propulsion plant. In order to demonstrate feasibility of double reduction gear box applied on push boat, the follows are studied in the thesis.Firstly, analyze matching characteristics of diesel engine and propeller with single or double reduction gear box theoretically and put forward to theoretical foundation of reconstruction.Secondly, select a push-train fleet, design propeller by MAU propeller and calculate double reduction ratio.Thirdly, draw Open Water Curve of propeller and propulsion characteristics curve of diesel engine in unload condition and different reduction ratio and analyze feasibility of fleet reconstruction.The thesis aims to offer some relevant suggestions for reference to ship winners who reconstruct propulsion plant of old push boat.