| 摘要 |
In a compression stoke of a diesel engine, injection in a small fuel injection amount is carried out from an injector into a cylinder such that fuel injection completes by the time when an in-cylinder temperature reaches 750K. In a period from timing at which the in-cylinder temperature has reached 750K to when the in-cylinder temperature reaches 900K, a thermal energy amount resulting from combustion of a fuel is accumulated as a low-temperature oxidation reaction energy amount. Where the thermal energy amount in the case where the entire fuel in the small fuel injection amount is combusted is a total energy amount, the ratio of the low-temperature oxidation reaction energy amount to the total energy amount is obtained as an energy ratio. The energy ratio is applied to a cetane number determination map, and a cetane number of the fuel is extracted from the cetane number determination map. |
