Comparative test of an internal combustion engine ecological indicators in real operating conditions and on a dynamic engine dynamometer

The paper presents internal combustion engine emission tests results, carried out in real operating conditions and in a laboratory stand equipped with a dynamic brake. The measuring stand simulates the vehicle's operating conditions registered in real traffic, which influenced the variability of the internal combustion engine operating parameters. The research route included urban roads with different traffic levels. The article discusses the method of creating the preparationprocedure of the route simulation, modeling of the vehicle properties and the driver's actions. The AXION R/S mobile device was used in the research. It belongs to the group of portable emissions measurement systems. It enabled carrying out analyzes for both the exhaust gases emission (CO, CO2, NOx and THC) as well as for the assessment of particulate emissions. In addition, a comparison of fuel consumption as well as speed runs recorded during tests have been presented. The test objects were two identical compression ignition engines with a displacement of 1.3 dm(3) and a maximum rated power of 66 kW. The exhaust gas aftertreatment systems included an oxidation catalyst and a particulate filter. The performed research allowed to assess the effectiveness of simulating the actual operating conditions on the engine dynamometer using the obtained emission characteristics. The need to further develop the mathematical models used in simulations was discussed. The performed analyzes lead to considerations being made regarding the idea of substituting road emission tests with measurements in laboratory conditions at dynamometer stations.