Analysis of operating conditions and emissions of the selected components of exhaust gas during SI engine braking phase

This paper presents analysis of conditions of CO2, CO, HC and NOX emissions during engine braking phase invehicles with 1.6 SI engine, based on the results of investigations by Professor Romaniszyn. The analysis aimed to determine the effect of cooling of catalytic converter and engine chamber on emissions of toxins and fuel efficiency in next driving phase. Based on own investigations, the synthesis of fuel consumption under three non-driving conditions of engine operation (i.e. continuous drive, engine braking and drive in neutral) is also presented. Current research centres often carry out extensive investigations of fuel efficiency and emissions of toxic compounds during real use of vehicles. Their results, due to previous assumptions or limitations in the scope of investigations, rarely provide an overall view of the problem. These attempts are typically made in scientific papers and dissertations [1-3]. Selective approach to the problem can be justified by the complexity and varied impact of each phase of engine 's operation on fuel consumption under unsteady heat conditions. Fuel consumption map in speed-acceleration coordinates for vehicle and engine, characteristics of CH emissions, parameters of engine braking phase and temperature characteristics of exhaust gases before catalytic converter are presented in the paper.