# US 2014/0196702 A1 · Ignition and Knock Tolerance in Internal Combustion Engine by Controlling EGR Composition > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0196702 A1 - Document ID: US20140196702A1 - Status: Published application - Kind: A1 - Application number: 13/742,627 - Filed: 2013-01-16 - Published: 2014-07-17 - Earliest claimed: 2013-01-16 - Assignees: Southwest Research Institute - Inventors: Jess W. Gingrich; Terrence F. Alger, II - Web page: https://patentgrep.com/patent/US20140196702A1 ## CPC - F02D 41/0065: {Specific aspects of external EGR control (constructional details of EGR system F02M26/00)} - F02D 19/0671: {Means to generate or modify a fuel, e.g. reformers, electrolytic cells or membranes} - F02D 19/081: {Adjusting the fuel composition or mixing ratio; Transitioning from one fuel to the other} - F02D 35/02: on interior conditions - F02D 41/0025: {Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures} - F02D 41/0052: {Feedback control of engine parameters, e.g. for control of air/fuel ratio or intake air amount} - F02M 26/15: in relation to engine exhaust purifying apparatus - F02M 26/35: with means for cleaning or treating the recirculated gases, e.g. catalysts, condensate traps, particle filters or heaters - F02M 26/36: with means for adding fluids other than exhaust gas to the recirculation passage; with reformers - F02M 26/43: in which exhaust from only one cylinder or only a group of cylinders is directed to the intake of the engine - F02M 26/46: for determining the characteristics of gases, e.g. composition - F02D 37/02: one of the functions being ignition - F02D 2200/1015: Engines misfires - F02M 26/04: with a single turbocharger - F02P 5/045: {combined with electronic control of other engine functions, e.g. fuel injection (in general F02D37/02)} - Y02T 10/30: Use of alternative fuels, e.g. biofuels - Y02T 10/40: Engine management systems - 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) - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF - F02P: IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES ({anti-pollution means for internal-combustion engines F02B17/00}; specially adapted for rotary-piston or oscillating-piston engines F02B53/12; {ignition of gas turbine plants F02C7/26; ignition of jet propulsion plants F02K9/95; starting of combustion engines F02N9/00}; ignition of combustion apparatus in general, glowing plugs F23Q; measuring of physical variables in general G01; controlling in general G05; data processing in general G06; electrical components in general see Section H; {ignition coils H01F38/12}; sparking plugs H01T13/00) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A method for improving ignition of a spark ignited internal combustion engine by controlling the composition of recirculated exhaust gas. It is assumed that the engine has a spark ignition system and an exhaust gas recirculation (EGR) loop such that at least one of the combustion cylinders is an EGR cylinder that generates an EGR stream carried by the EGR loop. Thus, the combustion charge is a mixture of air, fuel and recirculated exhaust. A first step is receiving combustibility data representing the current ignitability of the charge. It is then determined whether the energy of the ignition system is sufficient to ignite the charge. If not, the amount of hydrogen in the EGR stream is increased, which increases the ignitability of the charge. ## Claims ### Claim 1 A method of controlling the ignitability of the charge provided to combustion cylinders of an internal combustion engine, the engine having an ignition system and an exhaust gas recirculation (EGR) loop such that at least one of the combustion cylinders is an EGR cylinder that generates an EGR stream carried only by the EGR loop, and in which the charge is a mixture of air, fuel and recirculated exhaust, comprising: receiving combustibility data representing the current ignitability of the charge; determining whether the energy of the ignition system is sufficient to ignite the charge; and if the current energy of the ignition system is not sufficient to ignite the charge, increasing the amount of hydrogen in the EGR stream. ### Claim 2 (depends on 1) The method of claim 1, wherein the step of increasing the amount of hydrogen in the EGR stream is performed by providing a more rich air-fuel ratio to one or more of the EGR cylinder(s). ### Claim 3 (depends on 1) The method of claim 1, wherein the step of increasing the amount of hydrogen in the EGR stream is performed by providing post-combustion fuel injection to one or more of the EGR cylinder(s) for one or more engine cycles. ### Claim 4 (depends on 1) The method of claim 1, wherein the step of increasing the amount of hydrogen in the EGR stream is performed by injecting hydrogen into the EGR stream. ### Claim 5 (depends on 1) The method of claim 1, wherein the step of increasing the amount of hydrogen in the EGR stream is performed by injecting fuel into the EGR stream and using a reformer catalyst to generate hydrogen from this injected fuel. ### Claim 6 (depends on 1) The method of claim 1, wherein the combustibility data comprises the quantity delivered to the cylinders of one or more of the following: air, fuel and/or recirculated exhaust. ### Claim 7 (depends on 6) The method of claim 6, wherein the combustibility data further comprises data representing the in-cylinder pressure and/or temperature. ### Claim 8 (depends on 1) The method of claim 1, wherein the step of increasing the amount of hydrogen is performed by providing a calculated increase in hydrogen. ### Claim 9 (depends on 1) The method of claim 1, wherein the step of increasing the amount of hydrogen is performed by increasing the hydrogen incrementally until ignitability is achieved. ### Claim 10 An improved internal combustion engine, the engine having a spark ignition system and an exhaust gas recirculation (EGR) loop such that at least one of the combustion cylinders is an EGR cylinder that generates an EGR stream carried by the EGR loop, and in which the combustion charge is a mixture of air, fuel and recirculated exhaust, the improvements comprising: a control unit programmed to perform at least the following tasks: to receive combustibility data representing the current ignitability of the combustion charge, to determine whether the energy of the ignition system is sufficient to ignite the charge; and if the current energy of the ignition system is not sufficient to ignite the charge, to generate at least one control signal that results in an increase in the amount of hydrogen in the EGR stream. ### Claim 11 (depends on 10) The engine of claim 10, wherein the control signal results in providing a more rich air-fuel ratio to one or more of the EGR cylinder(s). ### Claim 12 (depends on 10) The engine of claim 10, wherein the control signal activates post-combustion fuel injection to one or more of the EGR cylinder(s) for one or more engine cycles, and wherein the improvement further comprises a fuel injector(s) operable to inject fuel into that cylinder(s). ### Claim 13 (depends on 10) The engine of claim 10, wherein the control signal activates injection of hydrogen into the EGR stream, and wherein the improvement further comprises an injector operable to inject hydrogen into the EGR stream. ### Claim 14 (depends on 10) The engine of claim 10, wherein the control signal activates injection of fuel into the EGR stream and wherein the improvement further comprises an injector operable to inject fuel into the EGR stream and a reformer catalyst operable to generate hydrogen from this injected fuel. ### Claim 15 (depends on 10) The engine of claim 10, wherein the combustibility data comprises the quantity delivered to the cylinders of one or more of the following: air, fuel and/or recirculated exhaust. ### Claim 16 (depends on 15) The engine of claim 15, wherein the combustibility data further comprises data representing the in-cylinder pressure and/or temperature. ### Claim 17 (depends on 10) The engine of claim 10, wherein one or more of the cylinders is a dedicated EGR cylinder. ### Claim 18 A method of operating an internal combustion engine, the engine having an intake manifold and having multiple cylinders, comprising: operating at least one cylinder of the engine as a an exhaust gas recirculation (EGR) cylinder, such that the exhaust from the at least one EGR cylinder is completely recirculated to the intake manifold; providing the engine with an exhaust gas recirculation loop in which recirculated exhaust flows from the at least one dedicated EGR cylinder into the intake manifold without fluid communication to the exhaust exiting the engine; wherein the recirculated exhaust is combined with fresh intake air prior to entering the cylinders; operating the at least one EGR cylinder at a different air-fuel ratio than the non EGR cylinders; controlling the composition of the recirculated exhaust by controlling the air-fuel ratio provided to the at least one EGR cylinder; wherein the step of controlling the composition is performed to produce exhaust gas from the at least one dedicated EGR cylinder having a concentration of hydrogen or carbon monoxide or both, the concentration predetermined to provide a desired ignition timing of the remaining (non dedicated) cylinders. ### Claim 19 A method of operating an internal combustion engine, the engine having an intake manifold and having multiple cylinders, comprising: operating at least one cylinder of the engine as a an exhaust gas recirculation (EGR) cylinder, such that the exhaust from the at least one EGR cylinder is completely recirculated to the intake manifold; providing the engine with an exhaust gas recirculation loop in which recirculated exhaust flows from the at least one dedicated EGR cylinder into the intake manifold without fluid communication to the exhaust exiting the engine; wherein the recirculated exhaust is combined with fresh intake air prior to entering the cylinders; operating the at least one EGR cylinder at a different air-fuel ratio than the non EGR cylinders; controlling the composition of the recirculated exhaust by controlling the air-fuel ratio provided to the at least one EGR cylinder; wherein the step of controlling the composition is performed to produce exhaust gas from the at least one dedicated EGR cylinder having a composition predetermined to provide a desired increase in anti-knock properties. ### Claim 20 (depends on 19) The method of claim 19, wherein the EGR cylinder is operated with a different fuel than the non EGR cylinders.