Miller循环中速柴油机燃烧和排放特性的模拟  

Numerical simulation of combustion and emission characteristics of medium speed diesel engine under Miller cycle conditions

作　　者：冷先银[1] 赵强 隆武强[3] 田江平[3] 魏胜利[1] 王爱国 钟兵 王红新 

机构地区：[1]江苏大学汽车与交通工程学院,江苏镇江212013 [2]陕西柴油机重工有限公司,陕西兴平7131003 [3]大连理工大学内燃机研究所,辽宁大连116023

出　　处：《中南大学学报（自然科学版）》2014年第12期4407-4414,共8页Journal of Central South University:Science and Technology

基　　金：国家科技支撑计划项目(2012BAG02B00);江苏大学高级专业人才科研启动基金资助项目(12JDG080);江苏高校优势学科建设工程资助项目(苏政办发[2011]118号)~~

摘　　要：为探索某船用中速柴油机在Miller循环条件下的燃烧和NOx排放特性,采用三维CFD计算程序模拟该机的缸内工作过程,探讨充量温度、喷油定时和几何压缩比等参数对燃烧和NOx排放的影响。研究结果表明:随着充量温度的降低,滞燃期曲轴转角和最高压力升高率持续增加,而指示油耗率和NOx排放率都呈现先降低后升高的趋势;在较低充量温度下,延迟喷油定时对滞燃期曲轴转角的影响不太大,而增加几何压缩比可以有效缩短滞燃期曲轴转角,进一步降低NOx排放;综合优化上述参数,得到的最优方案使该型柴油机额定负荷NOx排放降低52.4%,且在所计算的曲轴转角范围内指示燃油消耗率基本保持不变。In order to examine the combustion and emission characteristics of a medium speed marine diesel engine under Miller cycle conditions, three-dimensional computational fluid dynamics（CFD） modeling was used to simulate the in-cylinder work processes. The effects of charge temperature, fuel injection timing and geometric compression ratio were analyzed. The results show that with the decrease of the charge temperature, the ignition delay and the maximum pressure rise rate continuously increase, while both the indicated fuel consumption and NOx emission rate decrease first and then increase. Moreover, under low charge temperature of Miller cycle conditions, retarding the fuel injection timing barely affects the ignition delay, whereas enhancing the geometric compression ratio can evidently shorten the ignition delay. Finally, an optimization of initial charge temperature, injection timing and geometric compression ratio is acquired, leading to 52.4% reduction of NOx emission, without notable penalties in indicated specified fuel consumption.

关 键 词：中速柴油机 Miller循环 燃烧 排放 数值模拟 温度 压缩比 

分 类 号：TK421[动力工程及工程热物理—动力机械及工程]