Method for detecting the blending level of biodiesel fuel

摘要

A method is disclosed for detecting the blending level of biodiesel fuel in an internal combustion engine 110. An embodiment of the invention provides the steps of: setting at least two post injection fuel quantity reference values (QREF', QREF") respectively for known biodiesel blending percentage levels. These may be used to linearly extrapolate the relations ship between fuel quantity and blending level and provide a set of correlation values. A post injection fuel quantity value is evaluated and compared with the at least two post injection fuel quantity reference values (QREF', QREF"). The predetermined correlation set of values between the post injection fuel quantity value (Qsxx) and a biodiesel blending level (Bxx) is then used to obtain the blending level. The method may be used to detect the blending level of biodiesel added to the exhaust gas when regeneration of a diesel particulate filter (DPF) is necessary without requiring any additional sensors.