# US 11,441,509 B2 · Fuel injector temperature mitigation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,441,509 B2 - Document ID: US11441509B2 - Status: Granted - Kind: B2 - Application number: 14/775,555 - Filed: 2014-03-06 - Published: 2016-02-04 - Granted: 2022-09-13 - Earliest claimed: 2013-03-12 - Assignees: Westport Fuel Systems Canada Inc. - Applicants: Westport Fuel Systems Canada Inc. - Inventors: Ning Wu; Mark E. Dunn - Web page: https://patentgrep.com/patent/US11441509B2 ## CPC - F02D 41/221: {relating to the failure of actuators or electrically driven elements} - F02D 13/0223: {Variable control of the intake valves only} - F02D 13/0234: {changing the valve timing only} - F02D 19/0623: {Failure diagnosis or prevention; Safety measures; Testing} - F02D 19/0642: {at least one fuel being gaseous, the other fuels being gaseous or liquid at standard conditions} - F02D 41/0002: {Controlling intake air} - F02D 41/3094: {the fuel injection being effected by at least two different injectors, e.g. one in the intake manifold and one in the cylinder} - 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 41/1454: {the characteristics being an oxygen content or concentration or the air-fuel ratio} - F02D 41/18: by measuring intake air flow - F02D 2041/001: {for engines with variable valve actuation} - F02D 2200/021: Engine temperature - F02D 2200/0414: Air temperature - F02D 2200/101: Engine speed - Y02T 10/12: Improving ICE efficiencies - 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) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A technique for fuel system protection for an internal combustion engine comprises determining direct fuel injector temperature as a function of engine operating parameters; and advancing intake valve timing when the temperature rises above a first predetermined value such that the temperature is maintained below a second predetermined value. ## Claims ### Claim 1 A method of fuel system protection for an internal combustion engine, comprising: introducing a directly injected fuel into a combustion chamber through a direct fuel injector; introducing a fumigated fuel upstream of an intake valve associated with the combustion chamber; and selectively operating said internal combustion engine with at least one of said directly injected fuel and said fumigated fuel; and while operating said internal combustion engine with only said fumigated fuel: determining a temperature as a function of engine operating parameters of said direct fuel injector that directly injects fuel into said combustion chamber; advancing intake valve timing of said intake valve of the combustion engine from a normal intake valve timing to an advanced intake valve timing when said temperature rises above a first predetermined value such that a duration of an overlap when the intake valve is open and an exhaust valve of said combustion chamber is open increases; increasing concentration of exhaust gas in the combustion chamber by trapping the exhaust gas in the combustion chamber; holding intake valve timing of the intake valve at said advanced intake valve timing until said temperature is below a second predetermined value; and returning intake valve timing of the intake valve to said normal intake valve timing from said advanced intake valve timing after said temperature is below said second predetermined value. ### Claim 2 (depends on 1) The method of claim 1, wherein said temperature is a transient temperature, said method further comprising: determining a steady state temperature of said direct fuel injector as a function of engine operating parameters; determining said transient temperature of said direct fuel injector as a function of said steady state temperature; wherein said first predetermined value and said second predetermined value are related by one of: said first predetermined value is greater than said second predetermined value; said first predetermined value is less than said second predetermined value; and said first predetermined value is equal to said second predetermined value. ### Claim 3 (depends on 1) The method of claim 1, wherein a portion of exhaust gases enter an intake manifold from the combustion chamber when the intake valve opens with the advanced intake valve timing. ### Claim 4 (depends on 1) The method of claim 1, wherein said first predetermined value is greater than said second predetermined value. ### Claim 5 (depends on 1) The method of claim 1, wherein said engine operating parameters are determinative of directly injected fuel quantity and fumigated fuel quantity introduced into said combustion chamber and frequency with which said fuel quantities are introduced. ### Claim 6 (depends on 1) The method of claim 1, further comprising retarding exhaust valve timing of the exhaust valve as a function of engine operating conditions such that said temperature is maintained below said second predetermined value. ### Claim 7 (depends on 6) The method of claim 6, wherein said engine operating conditions comprise engine speed, engine load and intake valve timing. ### Claim 8 (depends on 1) The method of claim 1, further comprising advancing ignition timing such that at least one of fuel consumption of said internal combustion engine and turbine inlet temperature are reduced. ### Claim 9 (depends on 1) The method of claim 1, wherein said engine operating parameters comprise at least two of engine speed, air mass flow, engine coolant temperature, equivalence ratio, spark timing, combustion phasing, manifold air temperature, effective EGR rate, intake charge oxygen concentration, trapped oxygen mass, fumigated fuel mass fraction, and directly injected fuel mass fraction. ### Claim 10 (depends on 1) The method of claim 1, wherein said directly injected fuel is selected from the group consisting of natural gas, gasoline, ethanol-gasoline blends and diesel, and said fumigated fuel is selected from the group consisting of gasoline, ethanol-gasoline blends, natural gas, ethane, methane, propane, biogas, landfill gas, dimethyl ether, hydrogen and known mixtures thereof. ### Claim 11 (depends on 1) The method of claim 1, wherein the intake valve closes closer to bottom dead center in a compression stroke when opened with the advanced intake valve timing compared to being opened with the normal intake valve timing. ### Claim 12 (depends on 1) The method of claim 1, wherein ignition timing remains the same between the normal intake valve timing and the advanced intake valve timing. ### Claim 13 (depends on 1) The method of claim 1, wherein an effective compression ratio increases when the intake valve timing is advanced. ### Claim 14 (depends on 1) The method of claim 1, wherein said directly injected fuel is different from said fumigated fuel. ### Claim 15 (depends on 1) The method of claim 1, wherein said engine operating parameters in said function of engine operating parameters for determining said temperature include a directly injected fuel mass fraction and/or a fumigated fuel mass fraction. ### Claim 16 (depends on 1) The method of claim 1, wherein the increasing concentration of exhaust gas in the combustion chamber by trapping the exhaust gas in the combustion chamber includes drawing the exhaust gas into an intake manifold of the combustion chamber and reintroducing the exhaust gas into the combustion chamber with the fumigated fuel and air. ### Claim 17 An apparatus for fuel system protection in an internal combustion engine comprising: a direct fuel injector for introducing a directly injected fuel into a combustion chamber of said internal combustion engine; a fumigation system for introducing a fumigated fuel upstream of an intake valve of said combustion chamber; and a controller programmed to: selectively introduce said directly injected fuel through said direct fuel injector and said fumigated fuel through said fumigation system; and while operating said internal combustion engine with only said fumigated fuel: determine a temperature of said direct fuel injector as a function of engine operating parameters; advance intake valve timing of an intake valve of the internal combustion engine from a normal valve timing to an advanced intake valve timing when said temperature rises above a first predetermined value such that a duration of an overlap when the intake valve is open and an exhaust valve of said combustion chamber is open increases; increase concentration of exhaust gas in the combustion chamber by trapping the exhaust gas in the combustion chamber; hold intake valve timing of the intake valve at said advanced intake valve timing until said temperature is below a second predetermined value; and return intake valve timing of the intake valve to said normal intake valve timing from said advanced intake valve timing after said temperature is below said second predetermined value. ### Claim 18 (depends on 17) The apparatus of claim 17, wherein said first predetermined value is greater than said second predetermined value. ### Claim 19 (depends on 17) The apparatus of claim 17, wherein said controller is further programmed to, in addition to or instead of advancing intake valve timing of the intake valve, retard exhaust valve timing of the exhaust valve as a function of engine operating conditions such that said temperature is maintained below said second predetermined value. ### Claim 20 (depends on 17) The apparatus of claim 17, wherein said controller is further programmed to advance ignition timing such that at least one of fuel consumption of said internal combustion engine and turbine inlet temperature are reduced. ### Claim 21 (depends on 17) The apparatus of claim 17, wherein the increase concentration of exhaust gas in the combustion chamber by trapping the exhaust gas in the combustion chamber includes drawing the exhaust gas into an intake manifold of the combustion chamber and reintroducing the exhaust gas into the combustion chamber with the fumigated fuel and air. ### Claim 22 (depends on 17) The apparatus claim 17, wherein the intake valve closes closer to bottom dead center in a compression stroke when opened with the advanced intake valve timing compared to being opened with the normal intake valve timing. ### Claim 23 (depends on 17) The apparatus of claim 17, wherein ignition timing remains the same between the normal intake valve timing and the advanced intake valve timing. ### Claim 24 (depends on 17) The apparatus of claim 17, wherein an effective compression ratio increases when the intake valve timing is advanced. ### Claim 25 (depends on 17) The apparatus of claim 17, wherein said directly injected fuel is different from said fumigated fuel. ### Claim 26 (depends on 17) The apparatus of claim 17, wherein said engine operating parameters in said function of engine operating parameters for determining said temperature include a directly injected fuel mass fraction and/or a fumigated fuel mass fraction. ### Claim 27 A method of fuel system protection for an internal combustion engine comprising: during calibration of said internal combustion engine: introducing a directly injected fuel into a combustion chamber through a direct fuel injector; introducing a fumigated fuel upstream of an intake valve; and selectively operating said internal combustion engine with at least one of said directly injected fuel and said fumigated fuel; and while operating said internal combustion engine with only said fumigated fuel: determining a temperature as a function of engine operating parameters of said direct fuel injector that directly injects fuel into said combustion chamber; calibrating said engine to advance intake valve timing of said intake valve of the combustion engine from a normal intake valve timing to an advanced intake valve timing when said temperature rises above a first predetermined value such that a duration of an overlap between when the intake valve is open and an exhaust valve of said combustion chamber is open increases; increasing concentration of exhaust gas in the combustion chamber by trapping the exhaust gas in the combustion chamber; holding intake valve timing of the intake valve at said advanced intake valve timing until said temperature is below a second predetermined value; and returning intake valve timing of the intake valve to said normal intake valve timing from the advanced intake valve timing after said temperature is below said second predetermined value; during normal operation of said internal combustion engine: determining said temperature of said direct fuel injector as a function of engine operating parameters; and performing a temperature mitigation technique when said temperature rises above a third predetermined value such that said temperature is maintained below a fourth predetermined value. ### Claim 28 (depends on 27) The apparatus of claim 27, wherein said directly injected fuel is different from said fumigated fuel. ### Claim 29 (depends on 27) The apparatus of claim 27, wherein said engine operating parameters in said function of engine operating parameters for determining said temperature include a directly injected fuel mass fraction and/or a fumigated fuel mass fraction. ### Claim 30 (depends on 27) The method of claim 27, wherein the increasing concentration of exhaust gas in the combustion chamber by trapping the exhaust gas in the combustion chamber includes drawing the exhaust gas into an intake manifold of the combustion chamber and reintroducing the exhaust gas into the combustion chamber with the fumigated fuel and air.