Patent ID: 7987696
Filing Date: 2011-08-02
Classification: G01N

Abstract:
1. A fuel distillation property determining apparatus designed to determine a cetane value of fuel to be injected into a diesel engine by a fuel injection system which works to perform, in a cycle, a sub-injection which injects an injection quantity that is a quantity of the fuel smaller than that in a main injection into the diesel engine at a time when the fuel is to be burned in the diesel engine preceding or following the main injection, comprising: sub-injection control means for controlling the fuel injection system to perform a sequence of the sub-injections, a first one of the sub-injections being to spray a first quantity of the fuel as the injection quantity, a following one of the sub-injections being to spray a second quantity of the fuel as the injection quantity which is different from the first quantity; physical quantity acquiring means for acquiring a given physical quantity indicating a state of burning of the fuel in the diesel engine; physical quantity variation sensitivity determining means for determining a physical quantity variation sensitivity which is defined by a ratio of a quantity variation that is a difference between a first value of the physical quantity, as acquired upon execution of the first one of the sub-injections, and a second value of the physical quantity, as acquired upon execution of the following one of the sub-injections, to a difference between the first quantity and the second quantity; and fuel distillation property determining means for determining a cetane value of the fuel based on a predefined relation between the physical quantity variation sensitivity and the cetane value.