Abstract: A value of ignition delay and a value of a flame spread rate are measured with respect to fuel which is an object to be determined. When the measured value of the ignition delay falls within a range which is smaller than a reference line and constitutes a first range or falls within a range which is larger than a reference line and constitutes the first range, goodness or badness of quality of fuel is determined based on goodness or badness of quality of fuel which is decided in accordance with the first range. When the measured value of ignition delay falls within a range between the reference line and a reference line which constitutes a second range, goodness or badness of quality of fuel is determined based on whether or not a measured value of a flame spread rate falls within a good product range.

Abstract: A value of ignition delay and a value of a flame spread rate are measured with respect to fuel which is an object to be determined. When the measured value of the ignition delay falls within a range which is smaller than a reference line and constitutes a first range or falls within a range which is larger than a reference line and constitutes the first range, goodness or badness of quality of fuel is determined based on goodness or badness of quality of fuel which is decided in accordance with the first range. When the measured value of ignition delay falls within a range between the reference line and a reference line which constitutes a second range, goodness or badness of quality of fuel is determined based on whether or not a measured value of a flame spread rate falls within a good product range.

Abstract: A fuel quality evaluation apparatus and evaluation method enable a reliable evaluation at a low cost. The apparatus includes a combustion chamber which causes an injected fuel to combust, temperature control means which adjusts an interior temperature of the combustion chamber before injection, injection control means which controls the injection, light intensity measurement means which measures flame combustion light intensity, and analysis means which analyzes the measurement result and evaluates a fuel quality. The analysis means causes the fuel to combust a plurality of times, identifies a transformation of a flame light intensity, and evaluates the quality of the fuel based on a variation in the light intensity transformations for each combustion.

Abstract: A fuel quality evaluation apparatus and evaluation method enable a reliable evaluation at a low cost. The apparatus includes a combustion chamber which causes an injected fuel to combust, temperature control means which adjusts an interior temperature of the combustion chamber before injection, injection control means which controls the injection, light intensity measurement means which measures flame combustion light intensity, and analysis means which analyzes the measurement result and evaluates a fuel quality. The analysis means causes the fuel to combust a plurality of times, identifies a transformation of a flame light intensity, and evaluates the quality of the fuel based on a variation in the light intensity transformations for each combustion.