Effect of pre-chamber fuel injection parameters and EGR on the combustion and emissions of a heavy-duty diesel engine

ABSTRACT

This numerical simulation investigated the impact of pre-chamber fuel injection timing, injection angle, and exhaust gas recirculation (EGR) on combustion and emissions in a heavy-duty diesel engine using a pre-chamber combustion system. The results illustrate that the pre-chamber combustion system exhibits the potential to enhance the indicated thermal efficiency (ITE) of a diesel engine, while specific pre-chamber configurations can concurrently lower both NOx and soot emissions. The optimized cases show that the sustained turbulence generated by the pre-chamber enhances the redistribution of the unburned mixtures in the cylinder. The sustained turbulence leads to a broader range of gas mixtures near the equivalence ratio(Φ) of 1, resulting in complete combustion and lower NOx and soot emissions. In the optimized pre-chamber combustion system (with pre-chamber injection timing (PIT) at 0°CA ATDC and pre-chamber injection angle (PIA) at 54.5°), introducing 3% EGR results in a reduction of 11.61% in NOx emissions and 9.97% in soot emissions compared with the baseline engine.

KEYWORDS:

• Diesel engine
• pre–chamber
• turbulence kinetic energy
• emissions
• combustion
• thermal efficiency

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported and funded by the Open Subject of State Key Laboratory of Engines of Tianjin University [grant number K2023-01] and the Postgraduate Research & Practice Innovation Program of Jiangsu Province [grant number JXSS_025].

Notes on contributors

Yingying Lu

Professor Yinying Lu obtained her bachelor’s degree in Thermal Energy and Power Engineering from Shandong University in 2003. Subsequently, she earned her master’s degree in Engineering Thermophysics from Jiangsu University in 2007. In 2012, she received her Ph.D. in Power Machinery and Engineering from the State Key Laboratory of Engines and Combustion at Tianjin University. Her doctoral research primarily focused on numerical simulation and experimental study of new combustion modes and control strategies and mechanisms for heavy-duty diesel engines. In 2013, she was appointed as a lecturer at the School of Mechanical and Power Engineering at Nanjing Tech University, where she served until 2023. Currently, Professor Lu is an associate professor at the School of Mechanical and Power Engineering at Nanjing Tech University.

Yufeng Chen

Yufeng Chen earned her B.Eng. degree in vehicle engineering from Nanjing Tech University, China, in 2021. She is currently pursuing her M.Eng. degree in the School of Mechanical and Power Engineering, Nanjing Tech University, Nanjing 211816, China. His research interests include prechamber combustion systems, combustion and emission control of heavy-duty diesel engines.

Daochen Zhang

Daochen Zhang commenced his postgraduate studies at Nanjing Tech University in 2022, within the School of Mechanical and Power Engineering, specializing in Energy and Power. He became a member of Professor Lu Yingying’s research group, dedicating his efforts to the study of combustion and emissions in internal combustion engines. With the mentorship of Professor Lu and his senior peer Chen Yufeng, he has contributed to multiple publications. Currently, he is in the process of submitting a paper he authored.

Lingfeng Zhong

Lingfeng Zhong earned his B.Eng. degree in vehicle engineering from Nanjing Tech University, China, in 2021. He is currently pursuing his M.Eng. degree in the School of Mechanical and Power Engineering, Nanjing Tech University, Nanjing 211816, China. His research interests include gas-assisted atomization injection, small aviation piston engine, and intelligent control and machine learning.

Yi Qian

Qian Yi obtained his bachelor’s degree in Automotive Service Engineering from Jiangsu Institute of Technology in 2023. Since 2023, he has been pursuing a master’s degree in Mechanical Engineering at Nanjing Tech University. Currently, under the guidance of Professor Yinying Lu, he is conducting research on the combustion mechanisms of methane-hydrogen blended porous media and combustion and emission control of hydrogen engines.

Yiqiang Pei

Yiqiang Pei is currently associate professor, Ph.D supervisor in School of Mechanical Engineering, Tianjin University. He received M.S. and Ph.D degrees from Tianjin University in 2000 and 2007, respectively. He was a visiting scholar at Brunel University and Hertfordshire University in 2009 and 2014, respectively. His research mainly focuses on combustion process of internal combustion engines and its optimal control. He has undertaken a good number of important research projects, like National High-tech R&D Program of China (863 Program), the National Natural Science Foundation of China and so on.