Combustion and emissions analysis of a cold, warm and hot-start diesel engine

Lodi, Faisal Samad 2021, Combustion and emissions analysis of a cold, warm and hot-start diesel engine, Ph.D. thesis, School of Engineering, Deakin University.

Attached Files
Name Description MIMEType Size Downloads

Title Combustion and emissions analysis of a cold, warm and hot-start diesel engine
Author Lodi, Faisal SamadORCID iD for Lodi, Faisal Samad orcid.org/0000-0002-5528-7366
Institution Deakin University
School School of Engineering
Faculty Faculty of Science, Engineering and Built Environment
Degree type Research doctorate
Degree name Ph.D.
Thesis advisor Bodisco, TimORCID iD for Bodisco, Tim orcid.org/0000-0002-5163-4762
Date submitted 2021
Summary Heavy-duty diesel engines operating on low-sulphur diesel fuel form the backbone of road transportation in Australia. The demand for all type of diesel vehicles in Australia is growing, owing to higher thermal efficiency and leaner combustion. However, in diesel engines, cold and intermediately-cold start is an area under-represented in the current literature.

This reported study is a thesis by publication. It presents a comparative analysis of the performance, combustion, and emissions characteristics of a diesel engine during cold, intermediately-cold, warm and hot-start. Experiments were performed on a modern, multicylinder, turbocharged, common rail Cummins diesel engine. A unique custom-design quasi-steady state drive cycle was designed, which facilitated the discretisation of engine warm-up into four stages: cold-start; intermediately-cold-start; warm start and hot-start, based on engine coolant and oil temperatures.

Advanced injection during the cold-start stage led to longer ignition delay and shorter combustion duration, as compared to the intermediately-cold-start stage. This resulted in an increase in peak in-cylinder pressure by 30% and peak apparent heat release rate (AHRR) by 5%, consequently, aiding a faster warm-up of the engine. The lubricating oil lagged the coolant temperature by ~10°C during warm-up.

The intermediate temperature phase of engine warm-up, comprised of the intermediately cold and warm start stage, was longer than the cold-start stage. In this stage, which started at the coolant temperature of 65°C, the injection timing was retarded. This resulted in shorter ignition delay and longer combustion duration. The peak in-cylinder pressure and peak AHRR were decreased in this stage. The indicated mean effective pressure (IMEP) and brake mean effective pressure (BMEP) decreased by 3% and the friction mean effective pressure (FMEP) decreased by 60% in this stage. Moreover, the brake specific fuel consumption (BSFC) increased by 7%.

The indicated specific nitrogen oxide (ISNOx) emissions decreased by 45%, while the indicated specific hydrocarbon (ISHC) emissions increased by 18% in this stage. The total particle number (PN) concentration decreased by 50%. The count median diameter (CMD) increased and the geometric standard deviation (GSD) of the particle size distribution decreased as the engine warmed up. A strong positive linear correlation was found between the PN concentration and the particle mass (PM) at all loads. As the lubricating oil temperature reached 90°C in the warm-start stage, the IMEP and BMEP increased by 8%. In this stage, the ISNOx and ISHC increased by 5% and 10%,The indicated specific nitrogen oxide (ISNOx) emissions decreased by 45%, while the indicated specific hydrocarbon (ISHC) emissions increased by 18% in this stage. The total particle number (PN) concentration decreased by 50%. The count median diameter (CMD) increased and the geometric standard deviation (GSD) of the particle size distribution decreased as the engine warmed up. A strong positive linear correlation was found between the PN concentration and the particle mass (PM) at all loads. As the lubricating oil temperature reached 90°C in the warm-start stage, the IMEP and BMEP increased by 8%. In this stage, the ISNOx and ISHC increased by 5% and 10%, respectively; and BSFC decreased by 3%.

Motored experiments on a cold engine at zero load conditions were conducted to calibrate the crank-shaft indicator of the experimental engine. Six different methods used for the determination of TDC were evaluated. The results obtained were analysed through rigorous sensitivity and statistical analysis and found to vary significantly. The results presented as kernel density estimates (KDEs), an estimate of the probability density function (pdf), with a visual representation, offered both qualitative and quantitative assessments. Thermodynamic loss angles ranging between -0.5° and -0.6°CA (degrees crank angle) were found for the engine under investigation. The contribution to new knowledge from this thesis in diesel engine cold and warm-start analysis can benefit gaseous and particulate emissions research and the automobile industry, moving towards Euro VII: the upcoming emissions regulation.respectively; and BSFC decreased by 3%.

Motored experiments on a cold engine at zero load conditions were conducted to calibrate the crank-shaft indicator of the experimental engine. Six different methods used for the determination of TDC were evaluated. The results obtained were analysed through rigorous sensitivity and statistical analysis and found to vary significantly. The results presented as kernel density estimates (KDEs), an estimate of the probability density function (pdf), with a visual representation, offered both qualitative and quantitative assessments. Thermodynamic loss angles ranging between -0.5° and -0.6°CA (degrees crank angle) were found for the engine under investigation.

The contribution to new knowledge from this thesis in diesel engine cold and warm-start analysis can benefit gaseous and particulate emissions research and the automobile industry, moving towards Euro VII: the upcoming emissions regulation.
Language eng
Indigenous content off
Description of original 305 p.
Restricted until 2021-11-01
Copyright notice ┬ęThe author
Persistent URL http://hdl.handle.net/10536/DRO/DU:30153664

Connect to link resolver
 
Unless expressly stated otherwise, the copyright for items in DRO is owned by the author, with all rights reserved.

Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 0 times in TR Web of Science
Scopus Citation Count Cited 0 times in Scopus
Google Scholar Search Google Scholar
Access Statistics: 31 Abstract Views, 1 File Downloads  -  Detailed Statistics
Created: Mon, 19 Jul 2021, 11:31:27 EST by Leanne Swaneveld

Every reasonable effort has been made to ensure that permission has been obtained for items included in DRO. If you believe that your rights have been infringed by this repository, please contact drosupport@deakin.edu.au.