基于Spearman相关性和燃烧三维数值计算的汽油机碳氢排放分析

doi:10.13229/j.cnki.jdxbgxb.20230590

摘要/Abstract

摘要：

首先，采用Spearman相关性分析，针对不同型号的多种发动机，设计了基于面容比、面面比、侧隙和背隙容积、火力岸容积、缸垫死区容积、余隙容积，以及各容积占比等特征参数，研究了它们在冷启动工况对碳氢排放的影响；随后，采用燃烧三维数值计算的方法，从燃烧室几何结构和燃烧过程的角度解释了影响的原因。研究结果表明：余隙容积和余隙容积占比与冷启动碳氢排放的相关性最强，影响程度也最大，其他特征参数与冷启动碳氢排放相关性很小，其中，余隙容积占比的Spearman相关系数r_s为0.753 8，单尾检测P值<0.01，相关性非常显著；预燃室射流点火发动机在冷启动工况符合上述相关性分析的结论，但在热机工况下，由于预燃室的高温射流进入燃烧室余隙较早，引燃了其中的混合气，在燃烧早期就消耗了壁面附近的燃料，所以在当量比燃烧时，碳氢排放显著降低，而在稀薄燃烧时，并没有因为燃烧温度降低而导致碳氢排放升高，这也从另外一个角度解释和印证了余隙容积和余隙容积占比对碳氢排放影响的机理。本文研究结果可以为汽油机燃烧系统结构的合理设计提供理论依据和支撑。

关键词: 能源与动力工程, Spearman相关性分析, 碳氢排放, 燃烧室几何结构, 燃烧三维数值计算, 射流点火, 火花点火

Abstract:

Firstly， Spearman correlation analysis was used to design the characteristic parameters based on face-to-volume ratio， face-to-face ratio， side clearance and back clearance volumes， firepower shore volume， cylinder gasket dead zone volume， clearance volume， and the proportion of each volume， and investigate their effects on hydrocarbon emissions under cold start conditions. Then， the effect was explained from the viewpoint of combustion chamber geometry and combustion process by using combustion 3D simulation. The results show that the clearance volume and clearance volume proportion have the strongest correlation with cold start hydrocarbon emissions， and the other characteristic parameters have very little correlation with cold start hydrocarbon emissions. Meanwhile， Spearman correlation coefficient r_s and one-tailed test P-value of clearance volume proportion are 0.753 8 and <0.01 respectively， which mean the correlation is very significant. The pre-combustion chamber jet ignition engine in cold start condition is consistent with the conclusion of the above correlation analysis， but in theoretical air fuel ratio hot engine condition， the hydrocarbon emission of jet ignition is significantly lower than that of spark ignition because the high temperature jet from the pre-combustion chamber enters the combustion chamber clearance earlier， ignites the mixture in it， and consumes the fuel near the wall early in the combustion， and in lean combustion， it does not have higher hydrocarbon emission although it has lower combustion temperature. This also explains and confirms the mechanism of the effect of clearance volume and clearance volume proportion on hydrocarbon emission from another perspective. The research results can provide a theoretical basis and support for the design of gasoline engine combustion system structure.

Key words: energy and power engineering, Spearman correlation analysis, hydrocarbon emission, combustion chamber geometry structure, three-dimensional numerical calculation of combustion, jet ignition, spark ignition

中图分类号:

TK411

赵慧超,刘耀东,刘铭礼,宫艳峰,李显,赵川,孙平. 基于Spearman相关性和燃烧三维数值计算的汽油机碳氢排放分析[J]. 吉林大学学报(工学版), 2025, 55(3): 829-838.

Hui-chao ZHAO,Yao-dong LIU,Ming-li LIU,Yan-feng GONG,Xian LI,Chuan ZHAO,Ping SUN. Analysis of hydrocarbon emissions from gasoline engines based on spearman correlation and three⁃dimensional numerical calculation of combustion[J]. Journal of Jilin University(Engineering and Technology Edition), 2025, 55(3): 829-838.

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发动机	缸径/mm	冲程/mm	压缩比
1.0 L发动机	72	81.8	10
1.2 L发动机	72	73.6	9.8
1.4 L发动机A	76.5	75.6	10
1.4 L发动机B	76.5	75.6	11.5
1.5 L发动机A	76.5	81.5	11.5
1.5 L发动机B	76.5	81.5	10.7
1.6 L发动机	76.5	86.9	11.5
2.0 L发动机A	84	90	10.3
2.0 L发动机B	82.5	93	10.6
2.0 L预燃室发动机	82.5	113	17.5

样本数量n	单尾检测P值					双尾检测P值
样本数量n	0.25	0.1	0.05	0.025	0.01	0.5	0.2	0.1	0.05	0.02
4	0.6	1	1			0.6	1	1
5	0.5	0.8	0.9	1	1	0.5	0.8	0.9	1	1
6	0.371	0.657	0.829	0.886	0.943	0.371	0.657	0.829	0.886	0.943
7	0.321	0.571	0.714	0.786	0.893	0.321	0.571	0.714	0.786	0.893
8	0.31	0.524	0.643	0.738	0.833	0.31	0.524	0.643	0.738	0.833
9	0.267	0.483	0.6	0.7	0.783	0.267	0.483	0.6	0.7	0.783
10	0.248	0.455	0.564	0.648	0.745	0.248	0.455	0.564	0.648	0.745
11	0.236	0.427	0.536	0.618	0.709	0.236	0.427	0.536	0.618	0.709
12	0.217	0.406	0.503	0.587	0.678	0.217	0.406	0.503	0.587	0.678
13	0.209	0.385	0.484	0.56	0.648	0.209	0.385	0.484	0.56	0.648
14	0.2	0.367	0.464	0.538	0.626	0.2	0.367	0.464	0.538	0.626
15	0.189	0.354	0.446	0.521	0.604	0.189	0.354	0.446	0.521	0.604

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