Patent ID: 8733298
Filing Date: 2014-05-27
Classification: F02D

Abstract:
1. Method for controlling operation of an internal combustion engine configured to combust fuel in a compression-ignition combustion mode, comprising: monitoring oxygen concentration in an exhaust gas feedstream of the internal combustion engine, mass flowrate of intake air, and a commanded fuel pulse of the fuel; determining a stoichiometric air/fuel ratio of the fuel based on the oxygen concentration in the exhaust gas feedstream, the mass flowrate of intake air, and the commanded fuel pulse; determining a first blend ratio of biodiesel fuel and petrodiesel fuel of the fuel correlated to the stoichiometric air/fuel ratio of the fuel; and controlling engine operation in response to the first blend ratio of biodiesel fuel and petrodiesel fuel of the fuel; wherein determining the stoichiometric air/fuel ratio of the fuel based on the oxygen concentration in the exhaust gas feedstream, the mass flowrate of intake air, and the commanded fuel pulse comprises determining the stoichiometric air/fuel ratio in accordance with the following relationship: wherein