为了研究双燃料发动机缸内燃烧情况及其排放特性，本文以4135ACa型高速柴油机为基础研究对象，利用商用CFD软件FIRE对其进行一定燃气工况下的数值计算，通过导入CHEMKIN所构建的化学动力学机理与喷雾破碎、湍流流动等基础模型相结合，构建了发动机的三维工作过程，并分析了不同喷油策略对该工况下发动机燃烧及排放的影响。结果表明随着喷油提前角的减小，燃烧放热规律整体后移，缸内爆发压力与温度随喷油提前角减小而减小，但是瞬时放热率均大于纯柴油。在喷油提前角为4 ℃A BTDC时，缸内爆发压力接近纯柴油状态，NOx排放量与纯柴油工况相近，当喷油提前角为2 ℃A BTDC时，NOx排放满足要求，但缸内平均温度仍比纯柴油模式要高。
In order to study the combustion and emission characteristics of marine dual-fuel engines, We take advantage of FIRE, a commercial CFD software, to carry out numerical simulation on 4135ACa-type high-speed diesel engine fueled with natural gas. By importing the chemical kinetic mechanism constructed by CHEMKIN and coupling with the internal models of spray and turbulence, We assembled the Three-dimensional working progress of the dual fuel engine and analyzed the impact on combustion and emission caused by different fuel injection strategies. The result shows that the phenomenon of heat release delayed and the mean temperature and pressure decreased with the decrease of start of injection, but all the rate of heat release is larger than the diesel model. The in-cylinder break pressure is close to the diesel model and the emission of NOx is familiar with the pure diesel working condition, when the start of injection is 4 ℃A BTDC. When it reached 2 ℃A BTDC, the emission of NOx is acceptable, but the in-cylinder mean temperature is still higher than diesel model.
2020,42(1): 111-115 收稿日期：2018-10-31
DOI：10.3404/j.issn.1672-7649.2020.01.022
分类号：U664.31
基金项目：上海市科学技术委员会资助项目(17170712100)
作者简介：苏祥文(1994-),男,硕士研究生.研究方向为船舶动力系统
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