| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust emission control system including an exhaust purification catalyst containing a predetermined latent heat storage medium, capable of avoiding the fracture of the exhaust purification catalyst resulting from a temperature gradient that occurs in the exhaust purification catalyst as much as possible.SOLUTION: An internal combustion engine exhaust emission control system provided in an exhaust passage of an internal combustion engine and including an exhaust purification catalyst containing a predetermined latent heat storage medium, comprises: a heater heating the exhaust purification catalyst by supplying electric power to the heater; detection means detecting occurrence of a temperature gradient state in which a temperature difference between regions of the exhaust purification catalyst is equal to or greater than a predetermined temperature difference, on the basis of a phase change of the predetermined latent heat storage medium contained in the exhaust purification catalyst; and heating control means preferentially heating a low-temperature region relatively low in temperature of the exhaust purification catalyst in the temperature gradient state over the other regions if the detection means detects the occurrence of the temperature gradient state. |
