Optimal Design Of Upper Deck Structure Of Dual Fuel Design Ready VLCC On LNG C Type Tank

As the international community increases the control requirements for air pollutants in ships,supplies of low-sulphur fuel are tight,and the cost of fuel for ships goes up.The use of natural gas fuel has become one of the major alternatives for ship-owners and designers to consider.But at present,natural gas fuel filling facilities and network layout is not perfect,There is still uncertainty about the future price of natural gas fuels.The owners and designers more and more intends to seek a design more flexible,this is the default double fuel ship,to still use the traditional fuel power system in the design and construction stage of ship,but also take into account the needs of the future transformation of natural gas fuel power system,to facilitate future transformation of natural gas fuel and power system implementation.As a new concept proposed in recent years,the dual fuel vessel is not yet available for reference.To this end,this paper relies on 308 thousand tons VLCC preset dual fuel ship design examples.This paper mainly deals with the selection of LNG fuel tank location,the analysis of the local structure stress field and temperature field after the dual fuel transformation,and the economic problems of the structural design.Based on the deck equipment and outfitting layout characteristics of VLCC,the location of the LNG C-type module and its constraints were studied.Finite element analysis of LNG C-type tank and support structure using finite element analysis software PATRAN to the mainstream of domestic crude oil transportation company 308 K VLCC.The location and key limiting factors of LNG C-type tank are studied.The ship model and LNG C-type tank model is established based on finite element analysis software PATRAN.For the special connection form of woods,studied the modeling method and model updating method;studied the operating state(including the static load a variety of cargo tank loading condition),dynamic load(roll,pitch and heave)stress analysis method and superposition state.According to the thermal equilibrium theory,simplified LNG C-type tank heat exchange balance equation,analysis the temperature field of the LNG C-type tank;application of finite element analysis method,compared with the results of theoretical analysis,the correctness of theoretical analysis is verified.According to the analysis results,the optimal economic benefit as the goal,put forward different applicable to VLCC dual fuel design ready design scheme of deck structure.Considering the performance and cost factors,he design scheme of the deck reinforcement structure on the deck surface and the part of the LNG fuel tank seat is designed.The scheme can reduce the construction cost,construction difficulty and the cost of later modification while ensuring the structural strength.The analysis method and design scheme provide the design basis for the stress field analysis and temperature field of the preset dual fuel ship,and provide technical reference for the structural design of dual fuel design ready ship.