Diesel particulate filter unit and regeneration control method of the same

A diesel particulate filer unit comprising:

• a filter to capture particulates in exhaust gas of a diesel engine;
• a plurality of exhaust pressure sensors disposed in an exhaust passage of the diesel engine;
• and
• a regeneration control unit to start a regeneration operation of said filter, according to judgment results based on a comparison between exhaust pressures measured by the exhaust pressure sensors and a predetermined exhaust pressure judgment value, and to regenerate said filter by removing the particulates captured by said filter through combustion or chemical reaction by a catalyst, wherein
• said regeneration control unit estimates an ash accumulated quantity of ash leaked into the exhaust gas and accumulated in said filter, and corrects said exhaust pressure judgment value to judge a starting of the regeneration of the filter based on the estimated ash accumulated quantity, and
• wherein the regeneration control unit calculates an exhaust pressure coefficient corresponding to said estimated ash accumulated quantity, and corrects said exhaust pressure judgment value, to a value determined by multiplying a reference judgment value by the exhaust pressure coefficient.

A regeneration control method in a diesel particulate filer unit comprising a filter to capture particulates in exhaust gas of a diesel engine, a plurality of exhaust pressure sensors disposed in an exhaust passage;

• and a regeneration control unit to start a regeneration operation of said filter according to judgment results based on a comparison between exhaust pressures measured by the exhaust pressure sensors and a predetermined exhaust pressure judgment value, and to regenerate said filter by removing the particulates captured by said filter through combustion or chemical reaction by a catalyst, the method comprising:
• estimating an ash accumulated quantity of ash leaked into the exhaust gas and accumulated in said filter;
• and
• correcting said exhaust pressure judgment value to judge a starting of the regeneration of the filter based on the estimated ash accumulated quantity;
• and
• calculating an ash quantity accumulated in said filter during an engine operation state, from a torque of the engine and an engine speed, and calculating the estimated ash quantity, through the cumulative computation of the calculated ash quantity.

A regeneration control method in a diesel particulate filer unit comprising a filter to capture particulates in exhaust gas of a diesel engine, a plurality of exhaust pressure sensors disposed in an exhaust passage;

• and a regeneration control unit to start a regeneration operation of said filter, according to the judgment results based on a comparison between exhaust pressures measured by the exhaust pressure sensors and a predetermined exhaust pressure judgment value, and to regenerate said filter by removing particulates captured by said filter through combustion or chemical reaction by a catalyst, the regeneration control method, comprising:
• estimating an ash accumulated quantity of ash leaked into the exhaust gas and accumulated in said filter;
• correcting said exhaust pressure judgment value to judge a starting of the regeneration based on the estimated ash accumulated quantity;
• and
• calculating an exhaust pressure coefficient corresponding to said estimated ash accumulated quantity, and correcting said exhaust pressure judgment value to a value determined by multiplying a reference judgment value by the exhaust pressure coefficient.

A regeneration control method in a continuous regeneration type diesel particulate filer unit comprising:

• a filter with catalyst to capture particulates in exhaust gas from a diesel engine, and to burn the captured particulates by catalytic action, and an oxidation catalyst disposed upstream of the filter with catalyst with respect to a flow of the exhaust gas to raise an exhaust gas temperature through oxidation of HC and CO in the exhaust gas, the method comprising:
• raising the exhaust gas temperature through fuel injection control of the engine, during regeneration of said filter with catalyst under an engine operation condition between the oxidation catalyst and the filter with catalyst between the oxidation catalyst and the filter with catalyst in order to burn and remove particulates captured by said filter with catalyst;
• and
• raising the exhaust gas temperature in multiple stages in two or more stages.