Study On The Fleet Planning For Carrying Imported Grain In China

From 2000 to 2020,China’s grain imports increased by 800%,and China has become the world’s largest grain importer.With the large increase in the amount of imported grain shipping,the demand for imported grain shipping capacity is also growing.In the Several Opinions on Promoting the Healthy Development of the Marine Industry,the State Council raised the requirement of improving the transport guarantee capacity of key materials such as crude oil,iron ore,liquefied natural gas,coal and grain.However,with the capacity of China’s own bulk grain ships,the strategic goal of guaranteeing grain transportation can not be achieved alone.Against its own capacity shortage situation,this paper studies the "difference" China import food during shipping fleet planning problem,the problem is studied in the protection of import food shipping requirements,on the basis of how to design the fleet size and structure,how to configure the ships,the ships to the lowest total cost,more competitive in the international market.This paper first analyzes the trade status quo and supply and demand relationship of China’s imported grain market,so as to have a clear understanding of the trend of China’s imported grain maritime demand during the 14 th Five-Year Plan period.On this basis,the paper analyzes the influencing factors of the uncertain demand for imported grain by sea from three aspects of economy,politics and international environment.According to the historical data,combined with the actual situation,the main source countries,shipping routes and shipping enterprises of imported grain in China are obtained.In this paper,a robust optimization model of scenario set with uncertain demand is established from the perspective of national overall planning with the goal of minimizing the total cost.LINGO was used to solve the model,and the solution results of the robust optimization model were compared with the optimal target values of each sub-scenario deterministic model.Results show that although the robust optimization model of the optimal target value than the optimal target value of each scene deterministic model is high,but the cost of relative difference within 4%,and verify the robust optimization model robustness and robustness of the model,the robust optimization model of demand uncertainty stronger fleet planning problems handling ability,planning decision more reliable.The results of the decision determine the development scale,structure and detailed route allocation plan of China’s imported grain transportation fleet during the 14 th Five-Year Plan period,and also reflect the trend of large ships,which has a certain reference value for the planning of China’s imported grain transportation fleet.