The influence of timing injection on NO_x emissions is well known in the literature. If for new engines the requirements imposed by Annex 6 of MARPOL (the document limiting pollutant emissions to ships) are easy to meet, the problem of reducing NO_x emissions for in-service engines is a difficult one. The only practical solutions in this situation are to change the injection advance and the injector opening pressure. Practically this is done on the test bench by making adjustments and measurements. This paper aims to analyze this problem using a simulation software developed by the author. The software used simulates the engine cycle without gas exchange processes with the aid of a multidimensional 2.5 D model, completed with phenomenological models for injection modeling. NO_x emissions are calculated using a system of 10 equations based on the extended Zeldovich mechanism of which 4 are kinetic and 6 at equilibrium. Complex numerical simulations are presented for the most important operating modes of the chosen engine, performed for different injection timing. The results obtained are compared at the end with the experimental measurements performed on the test bench in order to evaluate the accuracy of the simulations performed and the practical utility of the results obtained to achieve the proposed objective.

定时喷射对 NO _x排放的影响在文献中是众所周知的。如果对于新发动机，MARPOL 附则 6（限制船舶污染物排放的文件）的要求很容易满足，那么减少在役发动机的 NO _x排放问题是一个难题。在这种情况下，唯一可行的解​​决方案是改变喷射提前量和喷射器开启压力。实际上，这是通过调整和测量在测试台上完成的。本文旨在使用作者开发的仿真软件来分析这个问题。所使用的软件借助多维 2.5 D 模型模拟没有气体交换过程的发动机循环，并配有用于喷射建模的唯象模型。不_x排放量是使用基于扩展的 Zeldovich 机制的 10 个方程系统计算的，其中 4 个是动力学的，6 个处于平衡状态。针对所选发动机最重要的运行模式，针对不同的喷射正时进行复杂的数值模拟。最后将获得的结果与在测试台上进行的实验测量进行比较，以评估所执行的模拟的准确性以及获得的结果的实际效用，以实现所提出的目标。