THE IMPACT OF AIR FILTER ON OPERATIONAL PROPERTIES OF ENGINE WITH THE COMMON RAIL FUEL SUPPLY SYSTEM

Abstract

The objective of this research project was to determine the percentage impact of dry-medium air filter being used in Fiat Multijet 1.3 JTD engine on its operational properties (engine flexibility and specific fuel consumption). Experiments were performed according to the requirements of research methods specified in the piston combustion engine standard in force. In order to make comparisons, operational parameters of the power unit (torque, effective power and specific fuel consumption) were measured with dry-medium air filter (with a new filter element) being fitted and with air filter being removed. Each point of respective characteristic curves was determined based on four measurements as their mean value. Also boost pressure, which could be of importance for results, was considered in the experiments. However, the degree of EGR valve lift, the operation of which could also appear to be important, was not taken into account. For each measuring point of respective characteristic curves, the ranges of measurement uncertainties were determined. Expanded standard uncertainties were calculated based on the Guide to the Expression of Uncertainty in Measurement. The experiments being carried out allowed concluding that the engine with air filter was less flexible by approx. 20% when compared to that without air filter, whereas its specific fuel consumption was greater by approx. 9%. The degree of air filter pollution affects its flow resistance and, which is related to this, engine torque and its effective power as well as its flexibility decrease but fuel consumption increases.