Patent ID: 11952931
Assignee: FRAUNHOFER GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
Field: Environmental technology (Chemistry)
Classification: CPC F  Y | IPC F

Claim 13:
14. A method for exhaust emission control, the method comprising:
supplying exhaust gas to an exhaust emission control device having at least one exhaust gas line (3) such that the exhaust gas is supplied to at least one particulate filter (31) and/or at least one exhaust gas catalytic converter (32, 33):
providing a heated catalyst assembly (2) upstream of the particulate filter (31) or the exhaust gas catalytic converter (32, 33), the heated catalyst assembly (2) having a housing (25) which has a catalyst support (5) therein, a fuel supply connection (62), an inlet (21) and an outlet (22) and which is connected to the exhaust gas line (3) in such a way that a portion of the exhaust gas flowing in the exhaust gas line (3) is supplied through the inlet (21) into the housing (25) and is discharged from the housing (25) through the outlet (22) back into the exhaust gas line (3) downstream of the inlet (21);
providing a pressure reduction device (7) in the at least one exhaust line (3), between the inlet (21) and the outlet (22) of the heated catalyst assembly (2);
supplying the heated catalyst assembly (2) with said portion of the exhaust gas through the inlet (21) to a first side (77) of the catalyst support (5);
supplying the heated catalyst assembly (2) with fuel through the fuel supply connection (62) to a second side (79) of the catalyst support (5), the second side (79) being opposite to the first side (77), such that the fuel and said portion of the exhaust gas are supplied to the catalyst support (5) in opposite directions;
at least partially reacting said fuel with said portion of the exhaust gas to create reaction products for heating exhaust gas flowing downstream in the exhaust gas line (3); and
supplying the heated exhaust gas to the particulate filter (31) or the exhaust gas catalytic converter (32, 33);
the method further comprising:
after a cold start, controlling the pressure reduction device (7) to be closed to establish a pressure difference between the inlet (21) and the outlet (22) to have a partial flow of the exhaust gas flowthrough the housing of the heated catalyst assembly; and
if a temperature of the exhaust gas is so high that additional heating of the exhaust emission control device is not required, controlling the pressure reduction device (7) to be opened to prevent additional heating of the exhaust emission control device.