Comparative analysis of energy and ecological indicators of a spark ignition engine running on different amount of petrol and bioethanol

Abstract

Results presented in experimental study, which extends of numerical modeling studies of petrol mixed with 10% bioethanol (E10), bioethanol mixed with 15% petrol (E85). During the test AVL BOOST program with modeled HR16DE spark ignition engine parameters were used. Bench tests carried out using the stoichiometric mixture λ = 1.0 and the lean mixture λ = 1.1. Results for λ = 1.2 were obtained by numerical modeling. The addition of bioethanol to petrol increases the oxygen content of the fuel therefor stoichiometric mixture requires less air. This allows the engine control unit to increase the amount of fuel injected. Lower bioethanol calorific value limits engine torque. After determining brake torque, break specific fuel consumption and ecological data, results of various fuels were determined. It was found that the highest engine brake torque was developed using mixture E85. E85 gives higher brake thermal efficiency (BTE), energy efficient increases when the mixture is leaner. However, it is not advisable to use lean mixture (λ > 1.1), as engine torque and power is reduced.