Systems and methods for reducing engine overheating using liquid fuel
AssigneeFord Global Technologies, LLC
InventorAed Dudar
Life of this patent
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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.
Claims20
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.
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.
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.
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.
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.
Dependencies are inferred from the claim text.