Combustion of LPG / DME gas mixtures in an SI engine with correction of the ignition advance angle

The paper presents the results of tests on a SI engine fueled with an LPG/DME blends of various composition. A number of experimental studies and calculations using a mathematical model were carried out to examine the suitability of this fuel. These tests allowed for the analysis of the changes taking place in the combustion process and the assessment of the main operating parameters of the engine. The results of the analysis of the combustion process make it possible to observe how the heat is released and how the indicated pressure changes, depending on the share of DME in the fuel mixture. The scope of the tests performed included engine and vehicle tests on a chassis dynamometer and a series of simulation tests conducted on the basis of the obtained results. The engine was powered by an LPG/DME fuel mixture with different proportions of components. The share of DME ranged from 0% to 30% of the fuel mass. The obtained results reflect the operation of the engine in the full load range and selected rotational speeds. Measurement series were made for different settings of the ignition advance angle. Based on the obtained results, a corrected map of the ignition advance angle was developed. The obtained results confirm the usefulness of using the LPG/DME mixture to power the SI engine.