Study On Refit Of Diesel /LNG Dual-fuel Ship In Inland River

With the rapid development of the global economy,the massive use of petroleum fuel has caused serious air pollution problems.Nowadays,the environmental climate problem has seriously affected the life and social development of human beings.As a big emitter of greenhouse gases,China must vigorously develop green economy and improve human living environment.Especially in recent years,the environment-friendly ships that use liquefied natural gas as ship power energy have been developed rapidly,which has boosted the demanding for matching Marine LNG storage tanks.Generally speaking,the design and installation of Marine LNG storage tank is complicated,and it is necessary to study the installation stress of the tank and the risk of using LNG as fuel.In view of this research direction and objective,this paper conducts research and analysis from the following aspects :(1)analyze the air pollution caused by diesel fuel ships,list the advantages of using LNG as ship fuel and practice exploration of LNG as ship power fuel;(2)based on the working principle of dual-fuel ship system,the form of dual-fuel engine room is analyzed;(3)Marine is briefly introduced the classification and structure characteristics of LNG storage tanks,analyses the design principle of Marine C type LNG storage tank,through the establishment of the saddle,internal and external tank,storage tank fittings finite element model of the storage tank support structure in each part of the four kinds of typical working conditions of the force on the finite element analysis,based on the results of preliminary analysis by setting the strengthen the elbow surface structure is improved,reinforcing the strength calculation results show that after C type LNG storage tank to meet the requirements of the ship working conditions;(4)qualitative analysis was carried out on the risks in the process of LNG fuel filling through the accident tree analysis method.Firstly,a fuel filling fire and explosion accident tree was established.The model of the accident tree was established under Easy Draw software.The results of structural importance coefficient were analyzed,and the prevention and control measures against the risk of LNG tank leakage fire were proposed.This chapter also analyzes the precautions of LNG fuel loading operation and puts forward some Suggestions for safe operation;(5)At the end of this paper,the refit of "wanfeng 918"(dry cargo ship)is taken as an example to analyze the economy of refit and the influence of refit on the arrangement of this type of ship.Through the study of this paper,finite element analysis is carried out on the stress of each part of the tank under four typical working conditions,which provides guidance for the tank installation on the ship.The risks in the process of LNG fuel refueling are analyzed theoretically,and the operation Suggestions for LNG fuel refueling are put forward.In the case of host load,fuel substitution rate,natural gas and diesel price changes,the economy of conversion of dual-fuel power ship is analyzed,which provides reference for conversion of inland waterway dry cargo ship into dual-fuel power ship and is of great significance for future conversion.