Patent ID: 9394840
Filing Date: 2016-07-19
CPC Classification: F02D,Y02T

Claim Text:
1. A fuel property determination system for a compression ignition internal combustion engine, comprising: a first parameter changing unit that is configured to change a fuel injection pressure for varying a degree of mixing of fuel and air that are supplied into a combustion chamber of the internal combustion engine; a second parameter changing unit that is configured to change a fuel injection timing for varying a combustion temperature of a mixture of fuel and air; a determination unit that includes an NOx concentration detecting unit that is configured to detect an NOx concentration in exhaust gas flowing through an exhaust passage, the determination unit being configured to determine that a timing at which the NOx concentration in the exhaust gas indicates a maximum value is a timing at which the combustion temperature indicates the maximum value when the fuel injection pressure is changed under the condition that the fuel injection timing is fixed; a first recording unit that is configured to record the fuel injection pressure at the timing at which the determination unit determines that the combustion temperature indicates the maximum value under the condition that the fuel injection timing is fixed to a predetermined first setting value as a first recorded value; a second recording unit that is configured to record the fuel injection pressure at the timing at which the determination unit determines that the combustion temperature indicates the maximum value under the condition that the fuel injection timing is fixed to a predetermined second setting value as a second recorded value; and a fuel property determination unit that is configured to determine a cetane number and evaporation index of the fuel on the basis of the first recorded value and the second recorded value.