LNG Cold Energy Cascading Utilization Research Of Lager Ocean-going Vessel

With the advancement of national clean energy strategy,The International Maritime Organization(IMO)has declared stricter mission standard,which leading more lager ocean-going vessel power changed form fuel oil to natural gas.In this context,the scale of LNG power carriers,LNG carriers and LNG-FSRU,which represents lager ocean-going vessel,continues to grow rapidly.The amount of LNG consumed or exported by ocean-going vessels is very large.At present,seawater or jacket cooling water and other heat sources are frequently used for heating in the process of LNG vaporization,which a large amount of high-grade cold energy are not utilized and wasted.Therefore,this article has done relevant research work about project designing and software development for LNG cold energy utiliazation of lager ocean-going vessel.The project design of vessel LNG cold energy utilization as follows.The basic principles of LNG cold energy cascade utilization are determined by the cold exergy analysis,and the main influencing factors of LNG cold energy utilization are analyzed.Based on this theoretical basis,the load of marine air-conditioning,cold storage,sea desalination and the amount of LNG cold energy are calculated of LNG powered carrier,LNG carrier and LNG-FSRU.The comparison between the cooling load and the vessel LNG cold verified the possibility of developing LNG cold energy cascading utiliazation.Finally,specific utilization project for LNG powered carrier,LNG carriers,and LNG-FSRU are designed considered factors such as the heat source,operational characteristics,and demand for cold energy products.In the projects,the cold energy is mainly used for marine air-conditioning,cold storage,electricity generation,seawater desalination and so on.The LNG cold energy cascade utilization scheme was simulated and optimized.Through the comparison and introduction of the exergy analysis model,the analysis method of the gray box analysis model was established.According to the specific requirements of each type of vessel cold energy utilization system,the appropriate refrigerant mediums are selected.On this basis,the cold energy cascade utilization program of LNG powered carrier,LNG carrier,and LNG-FSRU are simulated.The cold energy cascading utilization system are optimized and operating parameters are got as regarding the exergy efficiency as the objected function to analyze the system,in which the exergy utilization efficiency is improved.Cold energy utilization system simulation software is developed.The main influencing factors of cold energy utilization are analyzed and the cold energy utilization program for different working conditions is simulated and optimized,which provides data foundation for software development.A vessel cold energy utilization simulation system software is developed which uses the force control configuration software as development platform to carry out interface design and program preparation.The simulation system could quickly achieve the operation scheme and parameters of the vessel’s cold energy utilization system.The simulation system could quickly achieve the operation scheme and parameters of the vessel’s cold energy utilization system.Systematic and specific technical support for the practical application of marine LNG cold energy is provided through the research work of design,simulation optimization and software development.