Design And Performance Study Of LNG Supply System In Natural Gas Engine

The increasingly stringent emission regulations are driving ship owners to take measures to cope with emission limits.Among all the emission reducing method for marine engines,the use of LNG as an alternative fuel has attracted more and more attention due to large decreasing of emission and remaining high economic.However,with a process of gas-liquid phase transformation,the fuel supply system of natural gas engine(especially LNG engine)is quite different from that of traditional diesel engine.Therefore,it is of great significance to carry out the design and performance investigation of LNG supply system in natural gas engine.In this paper a LNG supply system is designed for WP10 natural gas engine which is used in an inland LNG vessel.According to the different functions of the system components,the system is divided into four parts,namely storage module,transport module,gasification module and valve group module.The key components,such as storage tanks,vaporizer,piping and so on,are calculated and selected for performance analysis.According to the safety requirements of LNG supply system,the monitoring system and accident handling system are designed hierarchically which provides equipment reference and function analysis.Considering the working principle of LNG gasification system,a combined model of gasifier-engine cooling system was established in AMEsim environment.The gasification process of LNG was analyzed as well as the effects of LNG and cooling water physical parameters on the gasification process.Result shows that slight variation of LNG temperature at the gasifier inlet makes little difference on the gasifier performance.The gasification effect will be weakened by the increase of LNG flow rate.Both the temperature and flow rate of cooling water at gasifier inlet affect the gasification process.The result can provide a theoretical basis for improving the efficiency of LNG gasification in practical applications.The results of the thesis provide fundamentals and engineering application of LNG supply system design.