# US 10,865,678 B2 · Methods and systems for an exhaust gas aftertreatment arrangement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,865,678 B2 - Document ID: US10865678B2 - Status: Granted - Kind: B2 - Application number: 16/290,728 - Filed: 2019-03-01 - Published: 2019-09-12 - Granted: 2020-12-15 - Earliest claimed: 2018-03-08 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Evgeny Smirnov; Robert Ukropec; Dirk Roemer; Maria Armiento; Jan Harmsen - Web page: https://patentgrep.com/patent/US10865678B2 ## CPC - F01N 3/0814: {combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts} - F01N 3/0885: {Regeneration of deteriorated absorbents or adsorbents, e.g. desulfurization of NOx traps} - F01N 3/0842: {Nitrogen oxides} - F01N 3/2066: {Selective catalytic reduction [SCR]} - F01N 3/22: Control of additional air supply only, e.g. using by-passes or variable air pump drives - F01N 9/00: Electrical control of exhaust gas treating apparatus (monitoring or diagnostic devices for exhaust-gas treatment apparatus F01N11/00; conjoint electrical control of two or more combustion engine functions F02D43/00) - F01N 11/007: {the diagnostic devices measuring oxygen or air concentration downstream of the exhaust apparatus} - F01N 13/0093: {the purifying devices are of the same type} - F02D 41/028: {Desulfurisation of NOx traps or adsorbent} - F01N 2270/00: Mixing air with exhaust gases - F01N 2430/06: by varying fuel-air ratio, e.g. by enriching fuel-air mixture - F01N 2560/025: for measuring or detecting O2, e.g. lambda sensors - F01N 2570/14: Nitrogen oxides - F01N 2610/146: Control thereof, e.g. control of injectors or injection valves - F01N 2900/1402: Exhaust gas composition - F01N 2900/1602: Temperature of exhaust gas apparatus - F02D 2200/0802: Temperature of the exhaust gas treatment apparatus - Y02T 10/40: Engine management systems - F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16) - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract Methods and systems are provided for an exhaust gas arrangement. In one example, a system comprises an air supply device arranged between a first LNT and a second LNT. The air supply device positioned to adjust an air/fuel ratio and a temperature of exhaust gas flowing to the second LNT and devices downstream thereof. ## Claims ### Claim 1 A system comprising: a first lean NOx trap arranged upstream of a second lean NOx trap in an exhaust passage; an air injector arranged between the first and second lean NOx traps; a selective catalytic reduction device arranged downstream of the second lean NOx trap; and a controller with computer-readable instructions stored on non-transitory memory thereof that when executed enable the controller to: adjust an air flow from the air injector during a regeneration of the first lean NOx trap; and adjust the air flow during the regeneration of the second lean NOx trap with a rich exhaust gas in response to a temperature of the rich exhaust gas being greater than a threshold temperature. ### Claim 2 (depends on 1) The system of claim 1, wherein the air injector is positioned to inject air directly into a portion of the exhaust passage downstream of an exhaust gas sensor arranged between the first and second lean NOx traps, wherein a rate of the air flow of the air injector is based on a difference between a lambda value of an exhaust gas and a stoichiometric lambda value to block the rich exhaust gas from passing through the second lean NOx trap during the regeneration of the first lean NOx trap. ### Claim 3 (depends on 1) The system of claim 1, wherein the instructions further enable the controller to adjust the air flow from the air injector and adjust an engine air/fuel ratio to a rich air/fuel ratio in response to the second lean NOx trap requesting a desulfation, wherein the air flow is adjusted to lean an exhaust gas air/fuel ratio exiting the second lean NOx trap. ### Claim 4 (depends on 3) The system of claim 3, wherein the air flow increases as a load of the second lean NOx trap decreases during the regeneration of the second lean NOx trap when the temperature of the rich exhaust gas is greater than the threshold temperature. ### Claim 5 (depends on 1) The system of claim 1, wherein the second lean NOx trap is in a far-underbody position. ### Claim 6 (depends on 1) The system of claim 1, wherein the air injector is the only air injector of the exhaust passage, and wherein another air injector is not arranged between the second lean NOx trap and the selective catalytic reduction device. ### Claim 7 (depends on 1) The system of claim 1, wherein a rate of the air flow during the regeneration of the second lean NOx trap adjusts the rich exhaust gas to be less rich upstream of the second lean NOx trap, wherein the exhaust gas downstream of the second lean NOx trap device is lean. ### Claim 8 An engine system comprising: an exhaust passage fluidly coupled to an engine, the exhaust passage housing a first LNT upstream of a second LNT, and a SCR device arranged downstream of the second LNT; an injector positioned to inject air directly into a portion of the exhaust passage between the first LNT, the second LNT, and an exhaust gas sensor; and a controller with computer-readable instructions stored on non-transitory memory thereof that when executed enable the controller to: adjust an engine air/fuel ratio to a rich air/fuel ratio and an air flow rate of the injector in response to a temperature of the second LNT being greater than a threshold temperature, wherein the air flow rate increases as a load of the second LNT decreases. ### Claim 9 (depends on 8) The engine system of claim 8, wherein the air flow rate is further based on the rich air/fuel ratio, and wherein an air/fuel ratio of exhaust gas between the injector and the second LNT is adjusted to equal to a lean air/fuel ratio via an air injection during a regeneration of the first LNT. ### Claim 10 (depends on 8) The engine system of claim 8, wherein the instructions further enable the controller to adjust the engine air/fuel ratio to the rich air/fuel ratio and the air flow rate of the injector in response to a second LNT regeneration request. ### Claim 11 (depends on 10) The engine system of claim 10, wherein an air/fuel ratio of exhaust gas flowing to the second LNT is rich but less rich than the engine air/fuel ratio via the air flow rate, and wherein an air/fuel ratio of exhaust gas downstream of the second LNT is a lean air/fuel ratio. ### Claim 12 (depends on 11) The engine system of claim 11, wherein the air/fuel ratio of exhaust gas flowing to the second LNT is increased toward a stoichiometric air/fuel ratio as the load of the second LNT decreases, and wherein the air/fuel ratio to the selective catalytic device remains equal to the lean air/fuel ratio. ### Claim 13 (depends on 8) The engine system of claim 8, wherein the instructions further enable the controller to adjust the air flow rate to zero in response to the temperature of the second LNT being greater than or equal to a threshold DeSOx temperature, wherein the threshold DeSOx temperature is less than the threshold temperature. ### Claim 14 (depends on 8) The engine system of claim 8, wherein the instructions further enable the controller to adjust the air flow rate in response a temperature of the second LNT exceeding the threshold temperature in response to an air/fuel ratio sensed between the first LNT and the second LNT being less than 1, wherein the air flow rate is based on a difference between the temperature of the second LNT and the threshold temperature, wherein as the difference increases the air flow rate increases. ### Claim 15 (depends on 14) The engine system of claim 14, wherein the air/flow rate is reduced to zero in response to the temperature of the second LNT falling below the threshold temperature. ### Claim 16 A method comprising: injecting air from an injector of an air supply device positioned to inject between a first LNT and a second LNT in response to the first LNT being desulfated; wherein the injecting air from the injector is in response to a temperature of the second LNT being less than a threshold DeSOx temperature; and injecting air from the injector in response to the temperature of the second LNT being greater than an upper threshold temperature, which is greater than the threshold DeSOx temperature, wherein an air supply rate is based on a difference between the temperature of the second LNT and the upper threshold temperature. ### Claim 17 (depends on 16) The method of claim 16, wherein injecting air further comprises adjusting the air supply rate of the injector based on an air/fuel ratio of exhaust gas between the first LNT and the second LNT, and wherein the air supply rate increases as a difference between the air/fuel ratio and a stoichiometric air/fuel ratio increases. ### Claim 18 (depends on 16) The method of claim 16, further comprising deactivating the injector to no longer inject air in response to the temperature of the second LNT being greater than the threshold DeSOx temperature.