LNG-Fueled Carrier Cold Energy Cascade Utilization

Natural gas has been widely used with its high efficiency,environmental pollution-free and other characteristics.It will replace oil as the world's major energy in the 21 st century,inject new vitality to the global economic development.In the process of storage and transportation of Natural Gas,it is necessary to liquefied natural gas to be Liquefied Natural Gas(Liquefied Natural Gas,or LNG).LNG-fueled carrier has made great progress while LNG has been widely applied.Large amount of cold energy can be made in running of LNG-fueled carrier,and it will not only cause serious waste of resources,but also cause pollution to the environment if it can not rationally used.Based on the actual energy consumption of LNG power ship,this paper designs a cascade utilization scheme of cold energy cascade for LNG power ship,and makes a reasonable utilization of a large amount of cold energy released during LNG gasification process.Firstly,the energy consumption of LNG power ship under the actual operating conditions of seawater desalination,low temperature cold storage,high temperature cold storage,air conditioning and other modules to calculate the energy consumption.Combined with the LNG gasification process of cooling capacity and the module on the cold energy level,determine the cascade utilization program that LNG cold energy can be used for low-temperature cold energy generation,desalination,low temperature cold storage,high temperature cold storage and air conditioning module cold energy.Secondly,the analysis process to determine the process of the various modules are used secondary refrigerant.And through the analysis of the transmission temperature of the working temperature range,physical characteristics and other factors,low temperature cooling power generation,desalination,low temperature cold storage,high temperature cold storage and air conditioning modules select Trifluoromethane(R23),R410 A,R410A,20% calcium chloride solution and 60% ethylene glycol solution as refrigerant.Thirdly,using ASPEN PLUS software to model the cascade utilization scheme of cold energy for LNG power tank.Through the Energy analysis,determine the main factors affecting the utilization of cold energy and the influence law,and analysis to the module in the loss of concentration and heat exchanger part.The heat exchanger in each module is optimized and focuses on energy loss of cold energy of heat exchanger for power generation and desalination module optimization.Determining the best operating parameters of the program,and finally the efficiency of theprogram reached 55.90%.And determining the energy loss,high efficiency,low energy utilization of cold energy of LNG powered ship reasonable and efficient cold energy cascade utilization scheme.LNG power ship cold energy cascade utilization program is conducive to the ship energy saving,in line with the development trend of green shipping.Cold energy can reduce or eliminate the traditional gasification process,and it can save a lot of high-grade LNG cold energy and high-grade thermal energy,reduce ship energy consumption and the impact of traditional gasification on the environment.In addition,the use of LNG cold energy can also reduce the consumption of other forms of energy,is of great significance to reduce the operating costs of the ship to improve the economic efficiency of the ship.The design and application of LNG cold energy for ship air conditioning,ship cold storage and seawater desalination are provided for theoretical guidance and technical support for the comprehensive utilization of cold energy in ships,and it can also provided reference for the application of LNG cold energy in other fields.