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US 11,686,235 B2Granted
Control of pre-SCR ammonia dosing based on look-ahead data
AssigneeScania CV AB
InventorBjörn Harnemo
Life of this patent
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Abstract
A method for controlling an exhaust gas aftertreatment system, wherein the system includes a first selective catalytic reduction (SCR) device, a catalytic particulate filter arrangement arranged downstream of the first SCR device, and a second selective catalytic reduction (SCR) device arranged downstream of the catalytic particulate filter arrangement. The method includes estimating future exhaust conditions based upon predicted vehicle operating conditions (s403); —estimating a future NOx conversion demand based on the estimated future exhaust conditions (s405); —dosing a reducing agent from a first reducing agent dosing device at a rate based at least on the estimated future NOx conversion demand (s406).
Claims12
A method for controlling an exhaust gas aftertreatment system, wherein the exhaust gas aftertreatment system comprises:
- a first reducing agent dosing device;
- a first selective catalytic reduction (SCR) device arranged downstream of the first reducing agent dosing device;
- a catalytic particulate filter arrangement arranged downstream of the first SCR device, wherein the catalytic particulate filter arrangement comprises a catalysed particulate filter, or wherein the catalytic particulate filter arrangement comprises an oxidation catalyst and a particulate filter arranged downstream of the oxidation catalyst;
- a second reducing agent dosing device arranged downstream of the catalytic particulate filter arrangement;
- and
- a second selective catalytic reduction (SCR) device arranged downstream of the second reducing agent dosing device;
- and wherein the method comprises the steps of:
- estimating future exhaust conditions based upon predicted vehicle operating conditions;
- estimating a future NOx conversion demand based on the estimated future exhaust conditions;
- and
- dosing a reducing agent from the first reducing agent dosing device at a rate based at least on the estimated future NOx conversion demand, wherein the method further comprises the steps of:
- comparing the estimated future NOx conversion demand with a predetermined upper threshold limit and a predetermined lower threshold limit for NOx conversion demand;
- and dosing a reducing agent from the first reducing agent dosing device, wherein
- if the estimated future NOx conversion demand is lower than the predetermined upper threshold limit and higher than the predetermined lower threshold limit, the reducing agent is dosed at a predetermined baseline rate;
- and
- if the estimated future NOx conversion demand is higher than the predetermined upper threshold limit, the reducing agent is dosed at an elevated rate that is higher than the predetermined baseline rate;
- and
- wherein
- if the estimated future NOx conversion demand is lower than the predetermined lower threshold limit, then the reducing agent is dosed at a lower rate than the predetermined baseline rate.
16 more elements
An exhaust gas aftertreatment system comprising:
- a first reducing agent dosing device;
- a first selective catalytic reduction (SCR) device arranged downstream of the first reducing agent dosing device;
- a catalytic particulate filter arrangement arranged downstream of the first SCR device, wherein the catalytic particulate filter arrangement comprises a catalysed particulate filter, or wherein the catalytic particulate filter arrangement comprises an oxidation catalyst and a particulate filter arranged downstream of the oxidation catalyst;
- a second reducing agent dosing device arranged downstream of the catalytic particulate filter arrangement;
- a second selective catalytic reduction (SCR) device arranged downstream of the second reducing agent dosing device;
- a control unit arranged to estimate future exhaust conditions based upon predicted vehicle operating conditions;
- and
- the control unit arranged to estimate a future NOx conversion demand based on the estimated future exhaust conditions;
- wherein the exhaust gas aftertreatment system is arranged to dose a reducing agent from the first reducing agent dosing device based at least on the estimated future NOx conversion demand;
- the control unit arranged to compare the estimated future NOx conversion demand with a predetermined upper threshold limit for NOx conversion demand and a predetermined lower threshold limit for NOx conversion demand;
- wherein the exhaust gas aftertreatment system is arranged to dose a reducing agent from the first reducing agent dosing device at a predetermined baseline rate if the estimated future NOx conversion demand is lower than the predetermined upper threshold limit and higher than the predetermined lower threshold limit;
- and
- wherein the exhaust gas aftertreatment system is arranged to dose the reducing agent from the first reducing agent dosing device at an elevated rate that is higher than the predetermined baseline rate if the estimated future NOx conversion demand is higher than the predetermined upper threshold limit;
- and
- wherein the exhaust gas aftertreatment system is arranged to dose the reducing agent from the first reducing agent dosing device at a lower rate than the predetermined baseline rate if the estimated future NOx conversion demand is lower than the predetermined lower threshold limit.
12 more elements
Dependencies are inferred from the claim text.