The influence of volume variation in a homogeneous prechamber ignition system in combustion characteristics and exhaust emissions

Abstract

Research on prechamber ignition systems has become increasingly frequent as they promote significant reductions in engineout emissions with low cost of implementation. In these systems, the combustion starts in an auxiliary chamber and flows through the interconnecting holes, in form of jets, to the main chamber, where it ignites the air-fuel mixture contained therein. Besides the air-fuel ratio, the geometry of the prechamber presents fundamental parameters that influence combustion characteristics and, consequently, the exhaust emissions. This paper aims to evaluate the effects of prechamber volume variation in combustion and emissions of a commercial engine equipped with a homogeneous charge prechamber ignition system. For this, three volumes were considered in stationary tests of a multi-cylinder engine operating under stoichiometric conditions in 1500 rpm and 3.3 bar of IMEP. The results indicated that the increase in volume within the limits considered present increase in the energy released and, hence, in the burning speed, reducing the combustion duration. Comparing to the baseline spark plug system, the prechamber with 3.8% of the main combustion chamber volume presented the best configuration among the evaluated volumes, with an increase in the evolution of pressure traces and reductions in around 13% in unburned hydrocarbons (HC) and nitrogen oxides (NO x) engine-out emissions.

Experimental Study of the Performance of Turbo-Charged Gasoline Direct-Injection Engine Based on Different Pre-Chamber Structures

“…Given the difficulties for traditional spark plugs to realize high-quality ignition and combustion in lean-burn environments [7], many new ignition systems were developed, including high-energy ignition systems, multi-point ignition systems, and pre-chamber jet ignition systems. Some studies showed that pre-chamber Turbulent Jet Ignition (TJI) is superior to conventional spark ignition in improving engine fuel economy [8].…”

Experimental evaluation of methanol-gasoline fuel blend on performance, emissions and lubricant oil deterioration in SI engine

“…4,5 This adverse climate change mainly due to emissions from vehicles and compelling the whole world to make strong policies for the control of exhaust emissions from vehicles as transport sector is majorly responsible for deterioration of an environment. 6,7 These policy pacts embrace UN framework convention held in 1992, Kyoto protocol held in 1998, Copenhagen accord held in 2009, Doha amendment in 2012 and Paris agreement in 2015. 8 It is estimated that 95% of energy used in vehicles worldwide fulfilled by fossil fuels and the contribution of transport sector in deteriorating air quality is approximated up to 60%–80% of toxic environmental emissions.…”