Experimental assessment of changes in the control of operation of a supercharged compression-ignition engine to fuel consumption
Continuous work on the improvement of the internal combustion engine is justified by numerous predictions, which assume the dominance of this drive at least until 2050, followed by its significant share in the hybrid drive. For many years, ecology has been the dominant feature of the development of internal combustion engines. The introduction of standards defining the permissible level of pollution by exhaust gases has contributed to the creation of many technical solutions that are fastened into one clamp by the control system. The composition of chemical exhaust gases is a derivative of the fuel combustion process, another measure of which is its consumption. The paper describes an experiment related to the introduction of changes to the control software of a supercharged compression-ignition engine in order to reduce fuel consumption. In order to fulfill the research objective, the map shaping the torque in the range of low and medium engine speeds was modified. Among other things, the size of the fuel dose for a specific rotational speed at maximum engine load was changed and the boost pressure was increased. The latter operation was possible thanks to the variable geometry turbocharger. The control program also includes maps in which the permissible ratio of fuel and air in relation to the load and engine speed is determined, and maps in which the maximum fuel dose for a given mass air flow and boost pressure is specified. Neither of these maps has been modified as the engine is equipped with a diesel particulate filter, which would mean faster filter contamination resulting in more frequent self-regeneration and therefore possibly premature wear. A vehicle meeting the EURO 5 standard was selected for the experiment. The vehicle from 2007 was selected because many sources indicate the age of 13-14 as the average age of vehicles in Poland. The experiment was carried out on a chassis dynamometer (according to the NEDC test) and in road traffic conditions. The result is an average fuel consumption of 0.4 liters per 100 km lower than the factory target. Currently produced vehicles are subjected to the RDE (Real Driving Emissions) test and the changed NEDC test to WLTP (Worldwide harmonized Light-duty vehicles Test Procedure), which allows for better measurement results in relation to real conditions. Therefore, in the near future, it is planned to experiment with RDE tests using PEMS measuring equipment.
Tematyka artykułu: proces spalania w silnikach i jego kontrola
Autor: Zbigniew Sroka
Współautor(zy): Rafał Heda, Monika Magdziak-Tokłowicz