Session: 02-03: Natural Gas

Paper Number: 148392

148392 - Experimental Analysis on Ignition Stage Characteristics of Rcci Combustion Operated With Renewable Alternative High Reactivity Fuels and Natural Gas at Low Load 

Abstract: 

Maximizing fuel conversion efficiency while reducing emissions from standard Internal Combustion Engines has become a primary focus in supporting the global goal of decarbonizing the transportation sector. RCCI combustion has been identified as a viable solution to achieve better engine performance and emissions levels, especially for heavy-duty diesel vehicles. The use of renewable alternative fuels in RCCI engines is growing rapidly because of the potential for net-zero CO2 emissions from this solution. Despite the remarkable benefits that can be achieved using RCCI combustion, the chemical interaction between the air-Low Reactivity Fuel mixture and the High Reactivity fuel strongly impacts the ignition stage of the combustion, which can lead to unstable conditions, especially at low load. This work analyzes the ignition characteristics of different Renewable OMEs compared to conventional diesel when used as High Reactivity fuels in RCCI combustion. Polyoxymethylene Dimethyl Ether (POMDME), and Propylene Glycol Mono Methyl Ether (P1P) were considered along with Natural Gas to characterize the impact of different fuel chemistry in a potential net-zero CO2 free application. The experimental activity was conducted in a 1.8-liter single-cylinder research engine operating at a nominal load of 5 bar IMEP and 1339 rpm. Different injection parameters were tested, such as injection timing, number of injections, injection pressure, and percentage energy split (PES) between High and Low reactivity fuels. The results show a strong impact of the mixture chemistry on the ignition stage, especially when high percentages of NG and diesel were used, i.e., PES (~80%). When running Renewable OMEs, due to the lower energy density of such fuels, the bigger quantity of HRF decreases the chemistry interaction between LRF and HRF. This aspect has been shown to be beneficial in increasing the efficiency of the ignition stage and the stability of the combustion. The use of P1P and POMDME can be considered promising for overcoming the known limitations that hinder the adoption of RCCI for heavy-duty engines.

Presenting Author: Giacomo Silvagni University of Bologna

Presenting Author Biography: Dr. Giacomo Silvagni is a post-doc researcher at the University of Bologna (Italy). After his bachelor's and master’s in mechanical engineering at the University of Bologna, Giacomo focused his PhD and post-doc activities on studying and testing advanced combustion methodology in a compression-ignited engine. Besides that, his activity is focused on the development of control-oriented strategies and their implementation on a rapid control prototyping platform aimed at improving combustion controllability and engine performance and reducing pollutants for both conventional and advanced combustion methodologies. He was also involved in a research project with the University of Alabama as a research aide for studying alternative renewable fuels applied to dual-fuel heavy-duty engines. Besides combustion-related research tasks, His research mainly focuses on developing zero-carbon sustainable powertrains and propulsion systems through experimental and simulation points of view.

Authors:

Giacomo Silvagni University of Bologna
Davide Moro University of Bologna
Abhinandhan Narayanan The University of Alabama
Stephen Mundy The University of Alabama
Vittorio Ravaglioli University of Bologna
Kalyan Kumar Srinivasan The University of Alabama
Sundar Rajan Krishnan The University of Alabama