# US 2019/0170052 A1 · Systems and methods for reducing engine overheating using liquid fuel > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170052 A1 - Document ID: US20190170052A1 - Status: Published application - Kind: A1 - Application number: 15/832,025 - Filed: 2017-12-05 - Published: 2019-06-06 - Earliest claimed: 2017-12-05 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Aed Dudar - Web page: https://patentgrep.com/patent/US20190170052A1 ## CPC - F01P 9/02: Cooling by evaporation, e.g. by spraying water on to cylinders (evaporation and condensation of liquid coolant in closed cycles F01P3/22 {; evaporation or evaporation apparatus for physical or chemical purposes, e.g. evaporation of liquids for gas phase reactions B01B1/005}) - F02B 39/10: electric - F02D 13/06: Cutting-out cylinders - F02D 35/025: {by determining temperatures inside the cylinder, e.g. combustion temperatures} - F02D 41/0087: {Selective cylinder activation, i.e. partial cylinder operation (deceleration cut-off F02D41/123)} - F02D 41/047: {Taking into account fuel evaporation or wall wetting; (special correction after fuel cut-off F02D41/126)} - F02D 41/086: {taking into account the temperature of the engine} - F02P 9/002: {Control of spark intensity, intensifying, lengthening, suppression (by means of current control in the storage devices F02P3/05, F02P3/09, during starting F02P15/12)} - F01P 2003/021: {Cooling cylinders} - F02D 41/0007: {for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12)} - F02D 41/042: {for stopping the engine} - F02D 2041/389: {for injecting directly into the cylinder} - F02D 2200/021: Engine temperature - Y02T 10/12: Improving ICE efficiencies - F01P: COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES (arrangements in connection with cooling of propulsion units in vehicles B60K11/00; heat-transfer, heat-exchange or heat-storage materials C09K5/00; {cooling of gas-turbine engines F02C7/12}; heat exchange in general, radiators F28) - 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) - 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 Systems and methods are provided for cooling an overheated engine using a combination of variable displacement engine (VDE) technology and direct injection technology. In one example, a method may include deactivating a subset of engine cylinders based on an engine temperature and directly injecting liquid fuel into the deactivated cylinders. In this way, an increased thermal conductivity of the liquid fuel compared to air decreases the engine temperature at a faster rate than when air-based engine cooling methods are used, thereby preventing overheating-related engine degradation. ## Claims ### Claim 1 A method, comprising: deactivating a subset of cylinders of a multiple cylinder engine based on a temperature of the engine; and directly injecting fuel into each of the subset of cylinders during the deactivation. ### Claim 2 (depends on 1) The method of claim 1, wherein the deactivating the subset of cylinders based on the temperature of the engine comprises: operating with the engine temperature greater than a threshold temperature, and in response to the engine temperature being greater than the threshold temperature, deactivating the subset of cylinders; and operating with the engine temperature less than or equal to the threshold temperature, and in response to the engine temperature being less than or equal to the threshold temperature, not deactivating the subset of cylinders. ### Claim 3 (depends on 2) The method of claim 2, further comprising an intake valve, an exhaust valve, and a spark plug coupled to each cylinder, and wherein the deactivating includes fully closing the intake valve and the exhaust valve of each of the subset of cylinders and disabling sparking of the spark plug of each of the subset of cylinders so that the injected fuel is not combusted. ### Claim 4 (depends on 3) The method of claim 3, further comprising: after a threshold time duration of the deactivation is reached, activating the intake valve and the exhaust valve coupled to each of the subset of engine cylinders; and exhausting the injected fuel. ### Claim 5 (depends on 4) The method of claim 4, further comprising: after exhausting the injected fuel, enabling sparking of the spark plug coupled to each of the subset of cylinders in response to the engine temperature being less than or equal to the threshold temperature. ### Claim 6 (depends on 1) The method of claim 1, wherein directly injecting the fuel into the subset of cylinders during the deactivation includes performing fuel injections via a fuel injector coupled to each of the subset of cylinders each time a piston within each of the subset of cylinders is at a plurality of predefined positions. ### Claim 7 (depends on 6) The method of claim 6, wherein the plurality of predefined positions includes top dead center, bottom dead center, and a position between top dead center and bottom dead center. ### Claim 8 (depends on 6) The method of claim 6, wherein directly injecting the fuel into the subset of cylinders during the deactivation further includes reducing an injection pressure compared to the injection pressure outside of the deactivation, and wherein an amount of fuel injected during the deactivation is greater than the amount of fuel injected outside of the deactivation. ### Claim 9 A method, comprising: in response to overheating of a multi-cylinder engine and based on operating conditions, selecting between cooling the engine via flowing air through one or more of the engine cylinders while disabling fueling of the one or more engine cylinders and fueling a subset of the engine cylinders with liquid fuel that is not combusted while deactivating intake and exhaust valves of each of the subset of engine cylinders. ### Claim 10 (depends on 9) The method of claim 9, wherein the one or more of the engine cylinders may be either the same as or different cylinders than the subset of the engine cylinders, and an engine overheating condition is determined based on an engine temperature and is independent of an exhaust temperature. ### Claim 11 (depends on 10) The method of claim 10, wherein the operating conditions include the engine temperature and an engine status (e.g., “on” or “off”), and the selecting comprises: cooling the engine via flowing air through the one or more of the engine cylinders while disabling fueling of the one or more engine cylinders in response to the engine temperature being greater than a first, lower threshold temperature while the engine is off; cooling the engine via flowing air through the one or more of the engine cylinders while disabling fueling of the one or more engine cylinders in response to the engine temperature being greater than [[a]]the first, lower threshold temperature and less than or equal to a second, higher threshold temperature while the engine is on; and cooling the engine via fueling the subset of the engine cylinders with liquid fuel that is not combusted while deactivating the intake and exhaust valves of each of the subset of engine cylinders in response to the engine temperature being greater than the second, higher threshold temperature while the engine is on. ### Claim 12 (depends on 11) The method of claim 11, further comprising an electric boosting device coupled to an intake of the engine, and wherein cooling the engine via flowing air through the one or more of the engine cylinders while disabling fueling of the one or more engine cylinders includes operating a compressor of the electric boosting device at a desired speed determined based on at least one of the engine status, the engine temperature, and the exhaust temperature. ### Claim 13 (depends on 12) The method of claim 12, further comprising an electric motor configured to electrically spin the engine, and wherein cooling the engine via flowing air through the one or more of the engine cylinders while disabling fueling of the one or more engine cylinders while the engine is off includes disabling fueling to all of the engine cylinders and spinning the engine electrically. ### Claim 14 (depends on 11) The method of claim 11, wherein cooling the engine via flowing air through the one or more of the engine cylinders while disabling fueling of the one or more engine cylinders while the engine is on includes disabling fueling to a determined number of engine cylinders while enabling fueling to a remaining number of engine cylinders, and wherein the engine cylinders selected for the determined number of engine cylinders changes at predetermined times. ### Claim 15 (depends on 11) The method of claim 11, wherein cooling the engine via fueling the subset of the engine cylinders with liquid fuel that is not combusted while deactivating the intake and exhaust valves of each of the subset of engine cylinders comprises: fully closing the intake and exhaust valves of each of the subset of engine cylinders; disabling spark plugs coupled to each of the subset of engine cylinders; injecting a desired amount of liquid fuel into each of the subset of engine cylinders over a plurality of injections; maintaining the intake and exhaust valves of each of the subset of engine cylinders fully closed for a duration after completing the plurality of injections to allow the liquid fuel to vaporize as it absorbs heat from the engine; and opening the intake and exhaust valves of each of the subset of engine cylinders to exhaust the vaporized fuel after the duration elapses. ### Claim 16 A system, comprising: an engine including a plurality of cylinders coupled to a crankshaft, each cylinder including a piston, an intake valve, an exhaust valve, a spark plug, and a fuel injector coupled directly thereto; a fuel system configured to deliver pressurized fuel from a fuel tank to the fuel injector; a first electric motor coupled to the crankshaft receiving electrical power from a system battery; a supercharger compressor coupled to the intake of the engine and driven by a second electric motor receiving electrical power from the system battery; a temperature sensor for estimating an engine temperature; a temperature sensor coupled to an exhaust passage of the engine upstream of an emission control device; and a controller storing executable instructions in non-transitory memory that, when executed, cause the controller to: during an engine overheating condition and while the engine is on, perform each of cooling the engine using intake airflow while fueling is selectively disabled to a number of cylinders and cooling the engine using liquid fuel injected into each of a subset of cylinders that are deactivated while operating in a variable displacement engine (VDE) mode under different operating conditions; and during the engine overheating condition and while the engine is off, cool the engine using airflow from the supercharger compressor while spinning the engine unfueled via the first electric motor. ### Claim 17 The system of 16, wherein the overheating condition includes the engine temperature being greater than a lower threshold temperature, and the different operating conditions include a first operating condition in which the engine temperature is less than or equal to a higher threshold temperature and a second operating condition in which the engine temperature is greater than the higher threshold temperature. ### Claim 18 The system of 17, wherein cooling the engine using the intake airflow while the fueling is selectively disabled to the number of cylinders is performed during the first operating condition, and cooling the engine using the liquid fuel injected into each of the subset of cylinders that are deactivated while operating in the VDE mode is performed during the second operating condition. ### Claim 19 (depends on 16) The system of claim 16, wherein cooling the engine using the intake airflow while the fueling is selectively disabled to the number of cylinders comprises: determining the number of cylinders to operate unfueled based on at least one of engine speed, the engine temperature, a rate of increase of the engine temperature, and a torque demand; disabling fuel injection to the determined number of cylinders in a distributive fashion; and operating the supercharger compressor at a speed determined based on at least one of the engine temperature, the rate of increase of the engine temperature, and an exhaust temperature measured by the temperature sensor coupled to the exhaust passage. ### Claim 20 (depends on 16) The system of claim 16, wherein cooling the engine using liquid fuel injected into each of the subset of cylinders that are deactivated while operating in the VDE mode comprises: deactivating the subset of the cylinders by maintaining the intake valve and the exhaust valve coupled to each of the subset fully closed and disabling the spark plug coupled to each of the subset; injecting fuel into each of the subset at a plurality of piston positions and at an injection pressure that is less than the injection pressure of the cylinders that remain active; and agitating the fuel within the subset of the cylinders for a duration before opening the intake valve and the exhaust valve of each of the subset to exhaust the fuel.