摘要:
An exhaust gas purification system for an internal combustion engine is provided with a filter including a selective catalytic reduction NOx catalyst carried thereon. Further, a post-catalyst is provided for an exhaust gas passage disposed on a downstream side from the filter. The post-catalyst has an oxidizing function, and the post-catalyst has such a function that the production of N2 based on the oxidation of ammonia is facilitated in a predetermined first temperature area. A filter regeneration process execution unit is programmed to control the temperature of the post-catalyst to be in the first temperature area while adjusting the temperature of the filter to be in a predetermined second temperature area lower than a filter regeneration temperature during a certain period of time.
摘要:
An object of the present invention is to appropriately remove, from an exhaust gas, HC, CO, and ammonia flowing out from a filter (SCRF) on which an SCR catalyst is carried. In the present invention, a post-catalyst 8 is provided for an exhaust gas passage of an internal combustion engine on a downstream side from SCRF along with a flow of the exhaust gas. The post-catalyst 8 is constructed to include an adsorption reduction part 81c which adsorbs ammonia and which reduces NOx by using ammonia as a reducing agent, a first oxidation part 81b which oxidizes ammonia, and a second oxidation part 82 which oxidizes HO and CO.
摘要:
In order to suppress ammonia from flowing out during regeneration treatment of a filter carrying an SCR catalyst, the prevent invention provides an exhaust emission control system of an internal combustion engine, including a first stage catalyst having an oxidation function, a fuel supply device configured to supply fuel to the first stage catalyst, a filter provided in the exhaust passage downstream of the first stage catalyst and carrying a selective redaction type NOx catalyst, an ammonia supply device configured to supply ammonia to the filter, a filter-regeneration-treatment executing unit configured to execute filter regeneration treatment, and a control unit configured to supply, when the filter regeneration treatment is not executed, the ammonia in an amount corresponding to an amount of the NOx emitted from the internal combustion engine, and to supply, when the filter regeneration treatment is executed, the ammonia in an amount corresponding to an amount of the NOx obtained by subtracting, from the amount of the NOx emitted from the internal combustion engine, an amount of the NOx reduced by the fuel which passes through the first stage catalyst.
摘要:
In an exhaust gas purification system for an internal combustion engine provided with a filter supporting an SCR catalyst, the present invention is intended to suppress HC and CO from being discharged to the outside at the time of the execution of filter regeneration processing, and to carry out the filter regeneration processing in an efficient manner. In the present invention, a post-catalyst having an oxidation function is arranged in an exhaust passage at the downstream side of the filter. Then, when the temperature of the post-catalyst is lower than a predetermined activation temperature at the time the execution of the filter regeneration processing is requested, the temperature of the post-catalyst is raised by carrying out control of raising the temperature of the exhaust gas discharged from the internal combustion engine, and control increasing the flow rate of the exhaust gas, before the execution of the filter regeneration processing.
摘要:
An object of the present invention is to suppress HC, CO, and NOx from being discharged to the outside when a filter regeneration process is executed in an exhaust gas purification system for an internal combustion engine provided with a filter including an SCR catalyst carried thereon. In the present invention, a post-catalyst is provided for an exhaust gas passage disposed on a downstream side from the filter. The post-catalyst has an oxidizing function, and the post-catalyst has such a function that the production of N2 based on the oxidation of ammonia is facilitated in a predetermined first temperature area. Further, when the filter regeneration process is executed, the temperature of the post-catalyst is adjusted to be in the first temperature area while adjusting the temperature of the filter to be in a predetermined second temperature area lower than a filter regeneration temperature during a certain period of time.
摘要:
An object of the present invention is to appropriately remove, from an exhaust gas, HC, CO, and ammonia flowing out from a filter (SCRF) on which an SCR catalyst is carried. In the present invention, a post-catalyst 8 is provided for an exhaust gas passage of an internal combustion engine on a downstream side from SCRF along with a flow of the exhaust gas. The post-catalyst 8 is constructed to include an adsorption reduction part 81c which adsorbs ammonia and which reduces NOx by using ammonia as a reducing agent, a first oxidation part 81b which oxidizes ammonia, and a second oxidation part 82 which oxidizes HO and CO.
摘要:
An exhaust gas purifying catalyst of the present invention includes: a first metal oxide selected from the group of praseodymium oxide, terbium oxide, and a combination thereof; a second metal oxide that is neodymium oxide; a third metal oxide that is zirconia or a combination of zirconia and ceria; and a fourth metal oxide selected from the group of lanthanum oxide, yttrium oxide, barium oxide, calcium oxide, strontium oxide, silicon oxide and a combination thereof.
摘要:
A three way catalyst and an NOx storage catalyst are arranged in an engine exhaust passage. In an engine low load operating region, a combustion is performed under a lean air-fuel ratio, and when NOx should be released from the NOx storage catalyst, the air-fuel ratio in a combustion chamber is made rich. In an engine medium load operating region, the base air-fuel ratio is made lower as compared with the engine low load operating region, and the air-fuel ratio in the combustion chamber is made rich at a shorter period as compared with the engine low load operating region. When the operating state of the engine is switched from the engine low load operating region to the engine medium load operating region, the air-fuel ratio in the combustion chamber is temporarily made rich, and the degree of richness of the air-fuel ratio at this time is stepwise lowered.
摘要:
The NOx storage catalyst and the NOx selective reduction catalyst are arranged in the engine exhaust passage. In the engine low load operating region, a combustion is performed in the combustion chamber under a lean base air-fuel ratio and the air-fuel ratio in the combustion chamber is made rich when NOx should be released from the NOx storage catalyst. In the engine medium load operating region, the base air-fuel ratio is made smaller, a degree of richness of the air-fuel ratio is made smaller, and a period in which the air-fuel ratio is made rich is made shorter so that an amount of ammonia which is produced per unit time when the air-fuel ratio is made rich falls compared with the time of engine low load operation.
摘要:
The NOx storage catalyst and the NOx selective reduction catalyst are arranged in the engine exhaust passage. In the engine low load operating region, a combustion is performed in the combustion chamber under a lean base air-fuel ratio and the air-fuel ratio in the combustion chamber is made rich when NOx should be released from the NOx storage catalyst. In the engine medium load operating region, the base air-fuel ratio is made smaller, a degree of richness of the air-fuel ratio is made smaller, and a period in which the air-fuel ratio is made rich is made shorter so that an amount of ammonia which is produced per unit time when the air-fuel ratio is made rich falls compared with the time of engine low load operation.