Numerical investigation of the effects of the use of propane-diesel as a dual fuel in a diesel engine on the combustion regime, engine performance and emission values

Stricter emission regulations against increasing emissions force automotive manufacturers to take different measures every day. These measures can be low temperature combustion technologies such as HCCI, PCCI or RCCI with the developing control technology, as well as the use of cleaner fuels such as biodiesel, LPG, CNG instead of diesel fuel. Within the scope of this thesis, numerical analyses have been carried out for a diesel engine to operate with a propane-diesel fuel pair. For these analyzes, first of all, 1-D model developed by using AVL Boost program was verified with experimental data in diesel combustion regime taken from Türk Traktör A.Ş. When the results of the 1-D model developed and the experimental data were compared in terms of brake thermal efficiency and soot emission, it was seen that there was 0.53% and 6.43% difference. Then, 3-D reactive flow analyses were performed using the ANSYS Forte program with boundary conditions and initial values taken from the 1-D model. The 3-D sector model results were compared with the experimental data in terms of brake thermal efficiency and soot emission and the difference rates were determined as 4.5% and 3.6%. In the 3-D full model results of these rates, it was determined as 0.47% and 18.5%. After ensuring the accuracy of the developed 1-D, 3-D sector and 3-D full models, dual fuel studies started with the determination of the maximum propane ratio that can be used as mass. It was observed that this rate was between 40% and 50%, taking the maximum pressure rise rate as a limit, and did not meet the NOX and CO emission norms. Then, in the use of 80% propane by mass; performance and emission values were examined by performing a parametric study with injection time, injection duration and EGR rate. As a result, improvement was achieved in shaft power by 10.9%, in brake thermal efficiency by 10.51% and in specific fuel consumption by 10.1%. In addition, while HC, CO and soot values were found to meet Stage IIIB norms, NOX emission was also normalized according to pure diesel results obtained numerically. As a result of normalization, 62% improvement was determined in NOX emission. With this improvement, it has been seen that NOX emission norms can be achieved by using propane-diesel dual fuel without using SCR.