| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce consumption of a sulfur solidification agent when the sulfur solidification agent is supplied to an engine to restrain sulfur poisoning of an NOx occlusion reducing catalyst. <P>SOLUTION: An NOx occlusion reducing catalyst 20 is installed to an exhaust passage 5 of an engine, to occlude NOx in the exhaust of a lean air-fuel ratio. An injection valve 40 directly injecting the fuel to a combustion chamber 1a is installed to the engine 1, to inject the fuel pressure-transferred from a fuel pump 43 to a common rail 41. An additive containing a sulfur solidification agent reacting with sulfur in the fuel by combustion to form solid sulfate is poured into a common rail from a tank 51 by a pump 53, and supplied from the injection valve to the combustion chamber together with the fuel. ECU 30 adjusts a pumping volume of the pump 53 to reduce a volume for pouring the additive to the common rail, or stop the pouring, when an atmospheric condition of the NOx occlusion reducing catalyst is a condition for difficultly absorbing SOX in the exhaust. This reduces consumption of the sulfur solidification agent. <P>COPYRIGHT: (C)2004,JPO |
