	US 11,859,527 B2
	Method to control a burner for an exhaust system of an internal combustion engine
Matteo De Cesare, Torremaggiore (IT); Enrico Brugnoni, Perugia (IT); Marco Panciroli, Bologna (IT); and Federico Stola, Bologna (IT)
Assigned to MARELLI EUROPE S.P.A., Corbetta (IT)
Filed by MARELLI EUROPE S.P.A., Corbetta (IT)
Filed on Jun. 29, 2022, as Appl. No. 17/809,656.
Claims priority of application No. 102021000017255 (IT), filed on Jun. 30, 2021.
Prior Publication US 2023/0003154 A1, Jan. 5, 2023
Int. Cl. F01N 3/00 (2006.01); F01N 3/20 (2006.01); F01N 9/00 (2006.01); F01N 11/00 (2006.01)

CPC F01N 3/2033 (2013.01) [F01N 9/00 (2013.01); F01N 11/007 (2013.01); F01N 2240/14 (2013.01); F01N 2550/02 (2013.01)]

11 Claims

1. A method to control an internal combustion engine (1) provided with an exhaust system (2) for the exhaust gases of a motor vehicle having an exhaust duct (10) and an exhaust gas after-treatment system (14); the method comprises the steps of:

providing at least one catalytic converter (15, 17) arranged along the exhaust duct (10);

providing an oxygen sensor (18, 18*, 18**), that detects an air/fuel ratio of the exhaust gases, said oxygen sensor having an output that indicates a content of oxygen in the exhaust gases;

providing a burner (21), that introduces exhaust gases into the exhaust duct (10) so as to speed up a heating of said at least one catalytic converter (15, 17), wherein inside the burner (21) there is defined a combustion chamber (22), which receives fresh air through an air feeding device (23), which is provided with a pumping device (24) feeding air, and fuel from an injector (27), which is designed to inject fuel into the combustion chamber (22);

providing a spark plug (28) coupled to the burner (21) so as to ignite the mixture present inside the combustion chamber (22);

calculating a thermal power (P_OBJ) needed to reach a nominal operating temperature of said at least one catalytic converter (15, 17) obtained with an objective value (λ_OBJ) of the air/fuel ratio;

determining both an objective fuel flow rate (m_{F_OBJ}) and an objective air flow rate (m_{A_OBJ}) to be fed to the burner (21) in order to obtain the thermal power (P_OBJ) needed to reach the nominal operating temperature of said at least one catalytic converter (15, 17);

determining a nominal number (N_NOM) of revolutions with which to operate the pumping device (24) depending on the objective air flow rate (m_{A_OBJ}), on an ambient pressure (P_ATM), on an ambient temperature (T_ATM) and on an objective pressure (P_{A_OBJ}) of the air flowing into a shut-off valve (26) that regulates a duct (25) located downstream of the pumping device (24);

determining a closed-loop contribution (NC_L) of the number of revolutions with which to operate the pumping device (24) by means of a PID controller, which zeroes a difference between the objective value (λ_OBJ) of the air/fuel ratio and an actual value (λ) of the air/fuel ratio measured by the oxygen sensor (18, 18*, 18**);

determining a further contribution (NADAT) of the number of revolutions with which to operate the pumping device (24) depending on an integral action of the PID controller under stationary conditions;

determining an actual number (N) of revolutions with which to operate the pumping device (24) by determining the sum of the nominal number (N_NOM) of revolutions, of the closed-loop contribution (NC_L) of the number of revolutions with which to operate the pumping device (24) and of the further contribution (N_ADAT) of the number of revolutions with which to operate the pumping device (24); and

signaling a fault when the sum of the first closed-loop contribution (N_CL1), the second closed-loop contribution (N_CL2) and the further contribution (N_ADAT) of the number of revolutions with which to operate the pumping device (24) exceeds a predetermined threshold value (THR₁).