TY - JOUR N2 - Lean mixture burning leads to a decrease in the temperature of the combustion process and it is one of the methods of limiting nitric oxide emissions. It also increases engine efficiency. An effective method to correct lean mixture combustion can be a two-stage system of stratified mixture combustion in an engine with a prechamber. This article presents the results of laboratory research on an SI engine (spark ignition) with a two-stage combustion system with a cylinder powered by gasoline and a prechamber powered by propane-butane gas LPG (liquefied petroleum gas). The results were compared to the results of research on a conventional engine with a one-stage combustion process. The test engine fuel mixture stratification method, with a two-stage combustion system in the engine with a prechamber, allowed to burn a lean mixture with an average excess air factor equal to 2.0 and thus led to lower emissions of nitrogen oxides in the exhaust of the engine. The test engine with a conventional, single-stage combustion process allowed to properly burn air-fuel mixtures of excess air factors λ not exceeding 1.5. If the value λ > 1.5, the non-repeatability factor COVLi increases, and the engine efficiency decreases, which makes it virtually impossible for the engine to operate. The engine with a two-stage combustion process, working with λ = 2.0, the Qin/Qtot = 2.5%, reduced the NOx content in the exhaust gases to a level of about 1.14 g/kWh. This value is significantly lower than the value obtained in a conventional engine, which worked at λ = 1.3 with comparable non-repeatability of successive cycles (about 3%) and a similar indicated efficiency (about 34%), was characterised by the emissions of NOx in the exhaust equal to 26.26 g/kWh. L1 - http://journals.pan.pl/Content/84663/PDF/18-paper-Jamrozik.pdf L2 - http://journals.pan.pl/Content/84663 PY - 2011 IS - No 4 December EP - 471 DO - 10.2478/v10176-011-0036-0 KW - engine with two-stage combustion system KW - prechamber KW - excess air factor KW - indicated work KW - indicated efficiency KW - non-repeatability factor of the indicated work A1 - Jamrozik, Arkadiusz A1 - Tutak, Wojciech PB - Polish Academy of Sciences Committee of Chemical and Process Engineering DA - 2011 T1 - A study of performance and emissions of SI engine with a two-stage combustion system SP - 453 UR - http://journals.pan.pl/dlibra/publication/edition/84663 T2 - Chemical and Process Engineering ER -