External speed characteristics in engine with multi-stage fuel injection

Increasingly higher demands pnt on piston internal combustion engines arę aimed at reducing their harmful impact on the natural environment. This refers primarily to nitrogen oxides, particulate matter and noise emissions. The reduction in emissions ofnoxious components oj exhaust gases in engines is achieved by means of, among others, the use of catalysts decreasing nitrogen oxide emissions, particulate matter filters and oxidising catalysts decreasing carbon monoxide and hydrocarbon emissions. Common Rail injection systems make it possible to increase the engine power, and to reduce fuel consumption, exhaust gas toxicity and noise produced by engines. With Common Rail systems, the pattern of fuel injection process can be designed, consequently the combustion process can be controlled. The paper presents the results of test bench investigations into a compression ignition 1.3 Multijet engine with multistage fuel injection, which is manufactured in Poland by Fiat-GM Powertrain Polska Company. The tests were conducted at a stand constructed at the Heat Engines Laboratory ofthe Kielce University of Technology. The scope of investigations included determining economic and energetic parameters of the engine work, and also environmental parameters, such as the concentration of nitrogen oxides NOX, carbon monoxide CO and carbon dioxide CO2 in exhaust gases, and exhaust gas smokiness. In tests, the engine operated under speed conditions and it was fuelled by two commercial diesel oils that had different physical and chemical properties