COMPUTER SIMULATION OF CI ENGINES FUELLED WITH BIOFUELS BY MODELLING INJECTION IRATE LAW PUBLISHEDCalin ICLODEAN, Nicolae BURNETE
This paper presents scientific studies on the development and use of analytical models of the processes occurring during operation of a single cylinder compression ignition engine with direct injection, powered by biofuels. Combustion parameters like cylinder pressure, rate of increased pressure and rate of heat released have been obtained experimentally, and they were studied by simulation, using the injection law iRate. The use of biofuels has been boosted by the severity of current rules on emissions standards and requirements for keeping satisfactory performance in compliance with these rules. The present rules promote the use of biofuels for replacing classic fuels, to help promote use of renewable energy. The AVL MCC combustion model is extended to predict the rate of injection based on the nozzle flow calculation with the injection law iRate. This model determines the injection rate of fuel flow delivered by the injectors. To validate the experimental data measured by test data obtained from simulations is necessary to change the ignition delay time of ignition defined in the optimization model for the engine. In simulations with various models of biodiesel (B10, B20, B50 and B100) showed a decrease of heat released from burning due to low calorific value that is biodiesel. The levels of emissions of nitrogen oxides NO x emissions increase as the concentration of biodiesel due to increased concentration of oxygen in biodiesel. Also due to increased concentration of oxygen in biodiesel concentration values of CO decreases with increasing participation by mixing biodiesel use. Pollutant emissions that have been studied in the simulations with biofuel are nitrogen oxides NO x and CO carbon monoxide. Reduction of NO x content of exhaust gases can be controlled by setting an optimal point of advance depending on load and engine speed and combustion gas recirculation inlet in place of oxygen for decrease the fuel combustion temperature.
biofuels, simulation, rate of heat released, pollutant emissions, iRate, AVL Boost