Numerical Investigation on Effects of Assigned EGR Stratification on a Heavy Duty Diesel Engine with Two-Stage Fuel Injection
External exhaust gas recirculation (EGR) stratification in diesel engines contributes to reduction of toxic emissions. Weak EGR stratification lies in that strong turbulence and mixing between EGR and intake air by current introduction strategies of EGR. For understanding of ideal EGR stratification...
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MDPI AG
2018-02-01
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| Series: | Energies |
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| Online Access: | http://www.mdpi.com/1996-1073/11/3/515 |
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| author | Zhaojie Shen Wenzheng Cui Xiaodong Ju Zhongchang Liu Shaohua Wu Jianguo Yang |
| author_facet | Zhaojie Shen Wenzheng Cui Xiaodong Ju Zhongchang Liu Shaohua Wu Jianguo Yang |
| author_sort | Zhaojie Shen |
| collection | DOAJ |
| description | External exhaust gas recirculation (EGR) stratification in diesel engines contributes to reduction of toxic emissions. Weak EGR stratification lies in that strong turbulence and mixing between EGR and intake air by current introduction strategies of EGR. For understanding of ideal EGR stratification combustion, EGR was assigned radically at −30 °CA after top dead center (ATDC) to organize strong EGR stratification using computational fluid dynamics (CFD). The effects of assigned EGR stratification on diesel performance and emissions are discussed in this paper. Although nitric oxides (NOx) and soot emissions are both reduced by means of EGR stratification compared to uniform EGR, the trade-off between NOx and soot still exists under the condition of arranged EGR stratification with different fuel injection strategies. A deterioration of soot emissions was observed when the interval between main and post fuel injection increased, while NO emissions increased first then reduced. The case with a 4 °CA interval between main and post fuel injection is suitable for acceptable NO and soot emissions. Starting the main fuel injection too early and too late is not acceptable, which results in high NO emissions and high soot emissions respectively. The start of the main fuel injection −10 °CA ATDC is suitable. |
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| format | Article |
| id | doaj.art-7b7d8fb3f5af4a31a3a456d903f8c90e |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-04-11T22:46:19Z |
| publishDate | 2018-02-01 |
| publisher | MDPI AG |
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| series | Energies |
| spelling | doaj.art-7b7d8fb3f5af4a31a3a456d903f8c90e2022-12-22T03:58:44ZengMDPI AGEnergies1996-10732018-02-0111351510.3390/en11030515en11030515Numerical Investigation on Effects of Assigned EGR Stratification on a Heavy Duty Diesel Engine with Two-Stage Fuel InjectionZhaojie Shen0Wenzheng Cui1Xiaodong Ju2Zhongchang Liu3Shaohua Wu4Jianguo Yang5School of Automotive Engineering, Harbin Institute of Technology, Weihai 264209, ChinaSchool of Automotive Engineering, Harbin Institute of Technology, Weihai 264209, ChinaSchool of Automotive Engineering, Harbin Institute of Technology, Weihai 264209, ChinaState Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun 130025, ChinaSchool of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, ChinaSchool of Automotive Engineering, Harbin Institute of Technology, Weihai 264209, ChinaExternal exhaust gas recirculation (EGR) stratification in diesel engines contributes to reduction of toxic emissions. Weak EGR stratification lies in that strong turbulence and mixing between EGR and intake air by current introduction strategies of EGR. For understanding of ideal EGR stratification combustion, EGR was assigned radically at −30 °CA after top dead center (ATDC) to organize strong EGR stratification using computational fluid dynamics (CFD). The effects of assigned EGR stratification on diesel performance and emissions are discussed in this paper. Although nitric oxides (NOx) and soot emissions are both reduced by means of EGR stratification compared to uniform EGR, the trade-off between NOx and soot still exists under the condition of arranged EGR stratification with different fuel injection strategies. A deterioration of soot emissions was observed when the interval between main and post fuel injection increased, while NO emissions increased first then reduced. The case with a 4 °CA interval between main and post fuel injection is suitable for acceptable NO and soot emissions. Starting the main fuel injection too early and too late is not acceptable, which results in high NO emissions and high soot emissions respectively. The start of the main fuel injection −10 °CA ATDC is suitable.http://www.mdpi.com/1996-1073/11/3/515injection timingexhaust gas stratificationdiesel combustionemissions |
| spellingShingle | Zhaojie Shen Wenzheng Cui Xiaodong Ju Zhongchang Liu Shaohua Wu Jianguo Yang Numerical Investigation on Effects of Assigned EGR Stratification on a Heavy Duty Diesel Engine with Two-Stage Fuel Injection Energies injection timing exhaust gas stratification diesel combustion emissions |
| title | Numerical Investigation on Effects of Assigned EGR Stratification on a Heavy Duty Diesel Engine with Two-Stage Fuel Injection |
| title_full | Numerical Investigation on Effects of Assigned EGR Stratification on a Heavy Duty Diesel Engine with Two-Stage Fuel Injection |
| title_fullStr | Numerical Investigation on Effects of Assigned EGR Stratification on a Heavy Duty Diesel Engine with Two-Stage Fuel Injection |
| title_full_unstemmed | Numerical Investigation on Effects of Assigned EGR Stratification on a Heavy Duty Diesel Engine with Two-Stage Fuel Injection |
| title_short | Numerical Investigation on Effects of Assigned EGR Stratification on a Heavy Duty Diesel Engine with Two-Stage Fuel Injection |
| title_sort | numerical investigation on effects of assigned egr stratification on a heavy duty diesel engine with two stage fuel injection |
| topic | injection timing exhaust gas stratification diesel combustion emissions |
| url | http://www.mdpi.com/1996-1073/11/3/515 |
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