Investigation of major factors that cause diesel NOx formation and assessment of energy and exergy parameters using e-diesel blends

The study investigated the key factors that influence the formation of diesel nitrogen oxides (NOx) ethanol–diesel (e-diesel) blends. In the first phase of this investigation, a thermodynamic model was developed to simulate and analyse the different parameters that affect the NOx formation. GT-Power was used to develop the model. ANSYS was also used to compare the results of GT-Power. The simulated (GT-Power and ANSYS) data of cylinder pressure was validated with experimental in-cylinder pressure data. For the 1-D model development, a 4-cylinder diesel engine with a compression ratio of 22.6 was chosen. The engine speed was differed from 1400 rpm to 2400 rpm; the injection timing was varied from 30° before top dead centre (BTDC) to 20° after top dead centre (ATDC), the inlet air temperature were changed from 293 K to 393 K, and the injected masses were ranged from 32 mg to 92 mg. Also, the energetic and exergetic parameters with respect to oxygen ratio and equivalence ratio were investigated. For this investigation, three ethanol blends and neat diesel fuel were used. The first blend was prepared with 10% ethanol and 90% diesel (E10), Similarly, the E20, E30 were made. The simulated data indicated that higher in-cylinder combustion temperature, inlet temperature, injected mass, and advanced injection timing were the principal causes for higher NOx formation. Interesting to note that among the four fuels, all three blends showed less NOx relative to neat diesel. The energy and exergy parameters with oxygen ratio show insignificant variations among the four fuels.