Open Access

ARTICLE

Experimental Analysis of the Influence of Exhaust Thermal Management on Engine NO_x Emission

Jinliang Zhu¹, Xiulei Wang¹, Guihua Wang¹, Xianglin Zhong², Zhenguo Li³, Zhiming Wang¹, Ke Sun^1,*, Shuzhan Bai^1,*
1 School of Energy and Power Engineering, Shandong University, Jinan, 250061, China
2 China Automotive Technology & Research Center Co., Ltd., Tianjin, 300300, China
3 National Engineering Laboratory of Mobile Source Emission Control Technology, Tianjin, 300300, China
* Corresponding Authors: Ke Sun. Email: ; Shuzhan Bai. Email:
(This article belongs to this Special Issue: Recent Advances in Fluid Mechanics and Thermal Sciences)

Fluid Dynamics & Materials Processing 2022, 18(3), 701-711. https://doi.org/ 10.32604/fdmp.2022.019311

Received 16 September 2021; Accepted 03 December 2021; Issue published 22 February 2022

Abstract

Exhaust thermal management is essential to allow engines to meet the Euro VI emissions standards and reducing nitrogen oxide emissions is one of the most important targets being pursued nowadays. Along these lines, in the present study, engine’s thermal performances have been evaluated on the basis of a WHTC test, namely a transient engine dynamometer schedule defined by the global technical regulation (GTR) developed by the UN ECE GRPE group (the GTR is covering a world-wide harmonized heavy-duty certification (WHDC) procedure for engine exhaust emissions). The influence of thermal management on fuel consumption, intake, and tailpipe NO_x have been quantitatively analyzed for the overrun state. The results have shown that there can be a strong influence on the after-treatment temperatures and tailpipe NO_x. In particular, the average temperature upstream of the diesel oxidation catalyst (DOC) has been found to increase from 245°C to 254°C, the average temperature of the selective catalytic reduction (SCR) to increase from 248°C to 253°C, the SCR’s minimum temperature to increase from 196°C to 204°C, and the peak value of the NO_x emissions in the low-temperature region to decrease from 73 to 51 mg/s. However, the influence of the overrun state’s thermal management strategy on the fuel consumption, the air intake, the ammonia storage, the NO₂/NO_x ratio, and the urea consumption has been observed to be relatively limited.

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Keywords

Intake throttling valve; NO_x emissions; overrun; diesel

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