预燃室式柴油天然气双燃料船用发动机热效率优化燃烧控制策略仿真研究  

Simulation Study on Improving Thermal Efficiency of Diesel/Natural Gas Dual Fuel Marine Engine

作　　者：郑尊清[1] 毛一玲 刘腾 刘博 叶映[1] 刘海峰[1] ZHENG Zunqing;MAO Yiling;LIU Teng;LIU Bo;YE Ying;LIU Haifeng(State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China;China Shipbuilding Power Engineering Institute, Shanghai 200120, China)

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072 [2]中船动力研究院有限公司,上海200120

出　　处：《内燃机工程》2020年第6期19-28,共10页Chinese Internal Combustion Engine Engineering

基　　金：船用低速机工程(一期)研制(工信部联装函[2017]21号)。

摘　　要：基于CONVERGE软件建立了预燃室式柴油、天然气双燃料船用二冲程发动机的三维计算流体动力学(CFD)模型,研究了压缩比、引燃柴油质量、喷射压力及引燃柴油喷射角度对燃烧过程的影响,探索了提高柴油、天然气双燃料船用发动机热效率的燃烧策略。结果表明:提高压缩比可以提高缸内的最高燃烧压力,从而有效提高热效率,但受发动机机械强度的限制,压缩比为12.5时可以获得较佳的效果;适当增大引燃油量和喷射压力,可以增加射流火焰的着火点,增强点火能量,对热效率略有改善;调节引燃柴油的喷射角度,将引燃油喷射到CH4浓度较高区域可以获得更好的引燃效果,降低指示燃料消耗率;提高压缩比至12.5结合推迟喷油策略可以明显地改善热效率。The three-dimensional computational fluid dynamics(CFD)model for a diesel/natural gas dual-fuel marine two-stroke pre-chamber engine was established by using a new generation of thermal fluid analysis software(CONVERGE),and the effect of compression ratio,pilot diesel mass,injection pressure and injection angle on combustion process was studied to improve the thermal efficiency of the engine.Results show that increasing compression ratio can enhance maximum burst pressure in the cylinder,thus effectively improving thermal efficiency.However,due to the limitation of the mechanical strength of the engine,a better effect can be obtained when the compression ratio is 12.5.Properly increasing the amount of pilot diesel and the injection pressure can increase the ignition point of jet flame and promote the enhancement of ignition energy,which is beneficial to improve thermal efficiency.Adjusting the injection angle of pilot diesel to inject it into the CH4-rich area can achieve a better pilot effect and therefore reduce fuel consumption.In short,increasing the compression ratio,combined with delayed pilot injection has a more obvious effect on improving thermal efficiency.

关 键 词：船用二冲程发动机 双燃料 热效率 压缩比 引燃柴油 

分 类 号：TK432[动力工程及工程热物理—动力机械及工程]