A novel lambda-based EGR (exhaust gas recirculation) modulation method for a turbocharged diesel engine under transient operation

Bolan Liu, Fujun Zhang, Changlu Zhao, Xiaohui An and Haijun Pei

Energy, 2016, vol. 96, issue C, 521-530

Abstract: Exhaust gas recirculation (EGR) is one of the major technical measures used on diesel engines to restrain NOx emission. Intake oxygen concentration has been proved to be the more substantial parameter to control NOx than EGR rate. However, the mechanism is hard to be utilized due to the difficulty of acquiring the real-time intake oxygen concentration. In the present study, a novel lambda-based intake oxygen model was built and validated. By using this model, two types of transient EGR modulation were performed, which illustrates the validity for NOx overshot elimination under the load transient. Based on the intake system schematic and the law of mass conservation, the model was deducted to find the relationship of intake oxygen concentration, EGR rate and lambda. Then the model was validated on a four-cylinder turbocharged diesel engine by following steps. Firstly, both steady and transient state test were conducted, the result shows that intake oxygen concentration is more related to NOx emission under transient working conditions. Then the model was validated under different speed and load. The result shows that intake oxygen concentration is linear to the ratio of EGR rate to lambda. Finally, transient EGR operation is performed. Under two types of transient operation, the emission performance is different. The lambda-based EGR modulation method is more effective in the constant-speed load transient. NOx overshot is eliminated without harm soot too much. In the constant-load speed transient, the modulation is still following the commonly accepted trade-off relationship. The study shows that the method could be effectively utilized in diesel load transient emissions control.

Keywords: Diesel engine; Exhaust gas recirculation; Transient NOx emission; Intake oxygen concentration model (search for similar items in EconPapers)
Date: 2016
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (4)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0360544215017429
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:energy:v:96:y:2016:i:c:p:521-530

DOI: 10.1016/j.energy.2015.12.097

Access Statistics for this article

Energy is currently edited by Henrik Lund and Mark J. Kaiser

More articles in Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().