LNG动力船燃料舱动态保压模拟OA

Driven by global carbon neutrality goals,Liquefied Natural Gas(LNG)has emerged as a key alternative fuel in the maritime sector owing to its high calorific value and low carbon emissions.However,Natural Boil-off Gas(NBOG)generated by natural evaporation during LNG storage and transportation causes continuous pressure buildup in fuel tanks,posing safety risks.Therefore,accurate prediction of tank pressure variations and optimization of Boil-off Gas(BOG)management strategies are of significant importance.A 6,000 m3 Type-C twin-tank LNG-powered vessel is taken as the research object.Based on a representative round-trip route,fuel consumption and tank pressure dynamics under typical operating conditions,including ballast voyage,laden voyage,port entry/departure,and cargo loading/unloading,are systematically simulated.A thermodynamic evaporation model is developed based on the Peng-Robinson equation of state,and a coupled simulation of fuel supply and pressure control is implemented in MATLAB.Results indicate that tank pressure follows a rise-then-fall pattern during the evaporation phase.When tank pressure reaches the critical threshold,the reliquefaction system automatically intervenes to effectively suppress further pressure growth.Compared with ballast voyages,LNG consumption rates during laden voyages increase by 14.0%and 25.3%at speeds of 9.5 and 11.0 knots,respectively.When tank pressure exceeds 0.208 MPa,BOG is triggered to replace LNG as auxiliary fuel supply,reducing the LNG consumption rate by 19.5%.The findings demonstrate that phased pressure control strategy combined with dynamic fuel switching can enhance fuel utilization efficiency while ensuring operational safety,providing theoretical basis and technical reference for optimized operation of LNG-powered vessels.