大型商船燃蒸柴联合循环动力系统设计与分析

Design and Analysis of Gas-Steam-Diesel Combined Cycle Power System for Large Commercial Ships

以17万m^3液化天然气(Liquefied Natural Gas,LNG)运输船为母型船,选取LM2500燃气轮机为主动力装置,联合蒸汽轮机和2台W?rtsil?12V34DF双燃料柴油机,设计出一套燃-蒸-柴联合循环动力系统。利用Aspen HYSYS软件模拟系统流程,经模拟与分析计算,该系统的设计方案合理可行,并得出燃气轮机负荷下的燃气轮机发电效率及其输出效率、燃蒸联合发电效率及其系统输出效率,各系统参数随燃气轮机负荷的增大呈现不同幅度的增大。将该系统的系统输出效率与柴油机的动力系统输出效率进行对比分析,结果表明:在理想工况下,两种系统的系统输出效率相当;在定速工况下,该系统的系统输出效率与柴油机的系统输出效率相比略低,而燃气轮机的NOx、SOx排放量较小,满足新公约要求。因此,该系统有很好的船舶实际应用价值。

A gas-steam-diesel combined cycle power system is designed for a 170000 m^3 LNG(Liquefied Natural Gas)carrier.The LM2500 gas turbine is selected as the main power unit and a steam turbine and two W?rtsil?12V34DF dual fuel diesel engines work with it.The system is simulated by means of Aspen HYSYS software.The gas turbine efficiency and power generation efficiency under condition of only the gas turbine loaded,the combined power generation efficiency,and system output efficiency are examined,which shows different increases of them as the load on the gas turbine increases.The output efficiency of the system is equivalent to that of a diesel engine only system under ideal conditions while a little lower under fixed speed condition.The gas turbine’s NOx and SOx emissions are small and meet the requirements of the new convention.Therefore the system has a good practical value for the ship.