# US 10,119,501 B2 · Systems and methods for controlling EGR flow during transients > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,119,501 B2 - Document ID: US10119501B2 - Status: Granted - Kind: B2 - Application number: 15/139,140 - Filed: 2016-04-26 - Published: 2016-09-01 - Granted: 2018-11-06 - Earliest claimed: 2013-11-04 - Assignees: Cummins Inc. - Applicants: Cummins Inc. - Inventors: Marten H. Dane; Sudhanshu Talwar - Web page: https://patentgrep.com/patent/US10119501B2 ## CPC - F02M 26/43: in which exhaust from only one cylinder or only a group of cylinders is directed to the intake of the engine - F01N 3/0842: {Nitrogen oxides} - F02B 37/18: by bypassing exhaust {from the inlet to the outlet of turbine or to the atmosphere} - F02D 41/005: {according to engine operating conditions} - F02D 41/26: using computer, e.g. microprocessor - F02M 26/04: with a single turbocharger - F02M 26/07: Mixed pressure loops, i.e. wherein recirculated exhaust gas is either taken out upstream of the turbine and reintroduced upstream of the compressor, or is taken out downstream of the turbine and reintroduced downstream of the compressor - F02M 26/10: having means to increase the pressure difference between the exhaust and intake system, e.g. venturis, variable geometry turbines, check valves using pressure pulsations or throttles in the air intake or exhaust system - Y02T 10/12: Improving ICE efficiencies - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF - 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) - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - 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 Systems, apparatus, and methods are disclosed that include a divided exhaust engine configured to control an EGR fraction in the charge flow to the cylinders in response to an EGR fraction overshoot condition, an exhaust pressure change in the EGR loop, and/or a transient operating condition. ## Claims ### Claim 1 A system comprising: an internal combustion engine having at least one primary exhaust gas recirculation (EGR) cylinder connected to an EGR passage and a plurality of non-primary EGR cylinders connected to an exhaust passage, and a turbine operatively connected to a compressor; wherein the EGR passage is connected to an intake system to provide an EGR flow from the at least one primary EGR cylinder to the intake system; wherein the intake system provides a charge flow to the at least one primary EGR cylinder and the plurality of non-primary EGR cylinders, the charge flow including an EGR fraction corresponding to an expected EGR flow from the at least one primary EGR cylinder; and a controller operably connected to the internal combustion engine, the controller including a non-transitory computer readable medium with executable instructions to determine an EGR fraction deviation condition and to divert at least a portion of the EGR flow to a secondary location via regulating a valve in response to the EGR fraction deviation condition; wherein the secondary location is positioned at an inlet to at least one of the compressor in the intake system and to a catalyst in the exhaust passage and is lower in pressure than a primary location defined as a connection of the EGR passage to the intake system. ### Claim 2 (depends on 1) The system of claim 1, wherein the secondary location is at the inlet to the compressor of the intake system, wherein the compressor is upstream of the connection of the EGR passage to the intake system. ### Claim 3 (depends on 1) The system of claim 1, wherein the secondary location is at the inlet to the catalyst in the exhaust passage. ### Claim 4 (depends on 3) The system of claim 3, wherein the exhaust passage includes the turbine upstream of the catalyst. ### Claim 5 (depends on 1) The system of claim 1, wherein the secondary location is connected to the EGR passage with an EGR flow diversion passage. ### Claim 6 (depends on 5) The system of claim 5, wherein the EGR flow diversion passage includes one of a dump valve and a pop off valve that is opened in response to the EGR fraction deviation condition mitigation command. ### Claim 7 (depends on 1) The system of claim 1, wherein the EGR fraction deviation condition is an EGR fraction overshoot condition. ### Claim 8 (depends on 1) The system of claim 1, wherein the at least one primary EGR cylinder includes two primary EGR cylinders. ### Claim 9 (depends on 1) The system of claim 1, wherein the controller is configured further comprising executable instructions to fuel the plurality of non-primary EGR cylinders at a lean air-to-fuel ratio in response to the EGR fraction deviation condition mitigation command diverting EGR flow to the secondary location, wherein the secondary location is the inlet to the catalyst in the exhaust passage. ### Claim 10 (depends on 1) The system of claim 1, wherein the secondary location includes a first secondary location in the intake system and a second secondary location in the exhaust passage. ### Claim 11 A method of controlling an exhaust gas recirculation flow in an internal combustion engine having at least one primary exhaust gas recirculation (EGR) cylinder connected to an EGR passage and a plurality of non-primary EGR cylinders connected to an exhaust system, and a turbine operatively connected to a compressor, comprising: passing the exhaust flow from the non-primary EGR cylinders through the exhaust system to atmosphere; recirculating exhaust flow from the at least one primary EGR cylinder through the EGR passage to an intake system, the intake system providing a charge flow including an EGR fraction corresponding to an amount of EGR flow from the at least one primary EGR cylinder in the charge flow; during a transient operating condition of the internal combustion engine, determining with the controller an EGR fraction deviation condition in the charge flow to the plurality of non-primary EGR cylinders and the at least one primary EGR cylinder; mitigating the EGR fraction deviation condition whether the EGR flow is in an overshoot condition with the controller; and adjusting a valve to divert at least a portion of the EGR flow to a secondary location in response to determining the EGR fraction deviation condition; wherein the secondary location is positioned at an inlet to at least one of the compressor in the intake system and to a catalyst in the exhaust system and is lower in pressure than a primary location defined as a connection of the EGR passage to the intake system. ### Claim 12 (depends on 11) The method of claim 11, wherein the adjusting the valve to divert at least a portion of the EGR flow to the secondary location includes the secondary location is at the inlet to the compressor of the intake system, wherein the compressor is upstream of the connection of the EGR passage to the intake system. ### Claim 13 (depends on 11) The method of claim 11, wherein the adjusting the valve to divert at least a portion of the EGR flow to the secondary location includes the secondary location is at the inlet to the catalyst in the exhaust system. ### Claim 14 (depends on 11) The method of claim 11, wherein the adjusting the valve to divert at least a portion of the EGR flow to the secondary location includes the secondary location is connected to the EGR passage with an EGR flow diversion passage. ### Claim 15 (depends on 14) The method of claim 14, wherein the EGR fraction deviation condition is an EGR fraction overshoot condition in which an actual EGR fraction exceeds an expected EGR fraction, and further comprising opening one of a dump valve and a pop off valve in the EGR flow diversion passage in response to determining the EGR fraction deviation condition. ### Claim 16 (depends on 11) The method of claim 11, wherein the at least one primary EGR cylinder includes two primary EGR cylinders. ### Claim 17 (depends on 11) The method of claim 11, wherein the EGR fraction deviation condition is an EGR fraction overshoot condition in which an actual EGR fraction exceeds an expected EGR fraction and the secondary location is at the inlet to the catalyst in the exhaust system, and further comprising fueling the plurality of non-primary EGR cylinders at a lean air-to-fuel ratio in response to determining the EGR fraction overshoot condition. ### Claim 18 (depends on 11) The method of claim 11, wherein determining the EGR fraction deviation condition includes detecting an accelerator tip-out condition. ### Claim 19 (depends on 11) The system of claim 11, wherein the adjusting the valve to divert at least a portion of the EGR flow to the secondary location includes the secondary location having a first secondary location in the intake system and a second secondary location in the exhaust system. ### Claim 20 An apparatus, comprising: an internal combustion engine including a plurality of cylinders, at least one of the plurality of cylinders being a primary exhaust gas recirculation (EGR) cylinder connected to an intake system to provide an EGR flow that mixes with an intake flow to form a charge flow to the plurality of cylinders, and remaining ones of the plurality of cylinders being connected to an exhaust system to provide an exhaust flow to an after treatment device of the exhaust system, and a turbine operatively connected to a compressor; a controller comprising: an EGR fraction determination module determining an actual EGR fraction in the charge flow; an EGR fraction deviation condition module determining an EGR fraction deviation condition in response to the actual EGR fraction and an expected EGR fraction; and an EGR fraction deviation condition mitigation module outputting an EGR fraction deviation mitigation command in response to the EGR fraction deviation condition, wherein the EGR fraction deviation command is operable to control a valve to divert at least a portion of the EGR flow to a secondary location, wherein the secondary location is positioned at an inlet to at least one of the compressor in the intake system and to the after treatment device being downstream of the turbine in the exhaust system and is lower in pressure than a mixing location of the EGR flow with the intake flow. ### Claim 21 (depends on 20) The apparatus of claim 20, wherein the EGR fraction deviation condition module determining an EGR fraction overshoot condition in response to the actual EGR fraction exceeding the expected EGR fraction. ### Claim 22 (depends on 20) The apparatus of claim 20, wherein the valve is located in a diversion passage connecting the secondary location with EGR flow upstream of the mixing location. ### Claim 23 (depends on 20) The apparatus of claim 20, wherein the EGR fraction deviation condition module determining the actual EGR fraction in response to at least one of an EGR flow and an accelerator tip-in condition.