Patent ID: 7735313
Filing Date: 2010-06-15
Classification: B01D,F01N,F02D,Y02T

Abstract:
1. A method of raising exhaust-gas temperature in an exhaust-gas after-treatment device, comprising: providing an oxygen storage capacitor substance which releases oxygen when an air-fuel ratio of an exhaust-gas is in a rich condition and stores oxygen as well as heats itself up in a lean condition; and controlling the air-fuel ratio of the exhaust-gas flowing into the exhaust-gas after-treatment device so that the rich condition and the lean condition are alternately repeated when the exhaust-gas temperature is not higher than a given temperature at a time other than regeneration control of the exhaust-gas after-treatment device, wherein in the rich condition, utilizing the heat generated by an oxidation reaction between the oxygen released from the oxygen storage capacitor substance and a reducing agent, and utilizing the self-heating generated by reversible oxidation reaction of the oxygen storage capacitor substance when alternating between the rich condition and the lean condition, the temperature of a catalyst surface carrying the oxygen storage capacitor substance is raised, and thereby the temperature of the exhaust gas after-treatment device is raised.