Back to results
US 2025/0025832 A1Published application
Method for adapting an nh3 dosing amount and an nh3 fill level distribution of an scr catalyst for an scr exhaust gas aftertreatment system with at least one scr catalyst
AssigneeRobert Bosch GmbH
InventorsArman Khosravani, Stefanos Tzivanakis, Thorsten Meier
Life of this patent
Estimating the term…
Abstract
Method for adapting an NH3 dosing amount and an NH3 fill level distribution of an SCR catalyst (22) for an SCR exhaust gas aftertreatment system (25) having at least one SCR catalyst (22).
Claims12
A method for adapting an NH3 dosing amount and an NH3 fill level distribution of an SCR catalyst (22) for an SCR exhaust gas aftertreatment system (25) having at least one SCR catalyst (22), wherein the at least one SCR catalyst (22) is divided into at least two bricks,
- wherein a first NOx sensor signal (NOx1) upstream of the SCR catalyst (22) and downstream of the internal combustion engine (10) is determined by means of a first NOx sensor (31),
- wherein a second NOx sensor (32) is used to determine a second NOx sensor signal (NOx2) downstream of the SCR catalyst (22),
- wherein the first and second NOx sensors (31, 32) have a transverse sensitivity to ammonia (NH3),
- wherein a division of the second NOx sensor signal (NOx2) into a modeled NOx mass flow (NOxN1) and a modeled NH3 mass flow (NH3M1) is determined by means of a model (N1) stored on the control unit (100),
- wherein an evaluation window (EX) is started as a function of a first criterion and ended as a function of a second criterion,
- wherein a cumulative modeled NH3 mass flow (NH3M1, EX) is determined via the evaluation window (EX) and a first cumulative NH3 mass flow (NH3M1,EX) is determined by means of an SCR model (M1),
- wherein an overdosing model (M2) is determined based on the SCR model (M1) which receives an increased NH3 dosing amount compared to the SCR model (M1),
- wherein a second cumulative NH3 mass flow (NH3M2, EX) is determined by means of the overdosing model (M2),
- wherein an overdosing model (M3) is determined based on the SCR model (M1) which receives a reduced NH3 dosing amount compared to the SCR model (M1),
- wherein a third cumulative NH3 mass flow (NH3M3, EX) is determined by means of the underdosing model (M3),
- wherein an adaptation value (NH3Adaption) between the modeled NH3 mass flow (NH3N1) and the first NH3 mass flow (NH3M1, EX) is determined by means of a predeterminable controller, and
- wherein, an adaptation of an NH3 dosing amount and/or an adaptation of the fill level distribution of the bricks of the SCR catalyst (22) is performed as a function of the cumulative modeled NH3 mass flows (NH3M1,EX) and the cumulative second and third NH3 mass flow (NH3M2, EX, NH3M3, EX).
9 more elements
A non-transitory, computer-readable medium containing instructions that when executed by a computer cause the computer to adapt an NH3 dosing amount and an NH3 fill level distribution of an SCR catalyst (22) for an SCR exhaust gas aftertreatment system (25) having at least one SCR catalyst (22), wherein the at least one SCR catalyst (22) is divided into at least two bricks,
- by determining a first NOx sensor signal (NOx1) upstream of the SCR catalyst (22) and downstream of the internal combustion engine (10) via a first NOx sensor (31),
- by determining a second NOx sensor signal (NOx2) downstream of the SCR catalyst (22) via a second NOx sensor (32),
- wherein the first and second NOx sensors (31, 32) have a transverse sensitivity to ammonia (NH3),
- by providing a division of the second NOx sensor signal (NOx2) into a modeled NOx mass flow (NOxN1) and determining a modeled NH3 mass flow (NH3N1) via a model (N1) stored on the control unit (100),
- by starting an evaluation window (EX) is started as a function of a first criterion and ended as a function of a second criterion,
- by determining a cumulative modeled NH3 mass flow (NH3M1, EX) via the evaluation window (EX) and a first cumulative NH3 mass flow (NH3M1,EX) is determined via an SCR model (M1),
- by determining an overdosing model (M2) based on the SCR model (M1) which receives an increased NH3 dosing amount compared to the SCR model (M1),
- by determining a second cumulative NH3 mass flow (NH3M2, EX) via of the overdosing model (M2),
- by determining an overdosing model (M3) based on the SCR model (M1) which receives a reduced NH3 dosing amount compared to the SCR model (M1),
- by determining a third cumulative NH3 mass flow (NH3M3, EX) by means of the underdosing model (M3),
- by determining an adaptation value (NH3Adaption) between the modeled NH3 mass flow (NH3N1) and the first NH3 mass flow (NH3M1, EX) via a predeterminable controller, and
- by adapting an NH3 dosing amount and/or adapting the fill level distribution of the bricks of the SCR catalyst (22) as a function of the cumulative modeled NH3 mass flows (NH3N1, EX) and the cumulative second and third NH3 mass flow (NH3M2, Ex,NH3M3, EX).
9 more elements
Dependencies are inferred from the claim text.