Abstract: A thermal management system includes a refrigeration circuit that cools at least a first coolant that circulates around a battery cooling loop. Refrigerant of the refrigeration circuit is cooled at a liquid-cooled condenser and at an air-cooled condenser. In certain examples, the liquid-cooled condenser is cooled by coolant circulating along a propeller arrangement cooling loop. In certain examples, the coolant from the propeller arrangement cooling loop may be combined with coolant from the battery cooling loop.

Abstract: A thermal management system enables fluid coupling of the cooling circuits for the battery and the propeller arrangements. More than one propeller arrangement can be serviced by the same cooling circuit, but distribution of the coolant may be finessed. Optional pathways are provided to use heated coolant for heating (e.g., de-icing, cabin heating, etc.) before cooling the coolant. Fluid coupling of conduits between and/or within the cooling circuits provide redundancy to accommodate various faults and equipment malfunctions.

Abstract: A thermal management system proactively provides cooling to powered components and/or the battery of an aircraft based on expected temperature rises of the components. The thermal management system may monitor maneuver commands input by a pilot and/or may monitor a flight plan including maneuver commands and associated trigger events to determine when to take proactive steps. The thermal management system may adjust a coolant flow rate and/or may adjust a refrigerant flow rate to increase or decrease the level of cooling provided to various components.

Abstract: A method and system for determining remaining useful life of an in-use injector of a reciprocating engine is disclosed. The method includes determining nozzle wear relationship data for different duty cycles of the in-use injector, and using the nozzle wear relationship data together with operating parameters for the reciprocating engine, and emission relationship data to determine actual emission levels for the in-use injector based on the wear relationship data and the emission relationship data. The method and system further include determining remaining useful life of the in-use injector based on actual emission levels and the nozzle wear relationship data; and controlling an operation of the reciprocating engine based on the actual emission levels.

Abstract: A method includes substantially eliminating surge of a compressor and reducing specific fuel consumption and exhaust emissions of an engine by adjusting exhaust flow through an exhaust gas recirculation system, by adjusting airflow through a compressor recirculation valve, by adjusting fuel injection timing, or by adjusting a combination thereof in response to variance in a plurality of parameters. The parameters include quantity of exhaust emissions, a maximum in-cylinder pressure of the engine, an area ratio of an exhaust gas recirculation mixer of the exhaust gas recirculation system, estimated or sensed compressor surge, engine load, altitude of operation, or combinations of the parameters thereof.

Abstract: A method and system for determining remaining useful life of an in-use injector of a reciprocating engine is disclosed. The method includes determining nozzle wear relationship data for different duty cycles of the in-use injector, and using the nozzle wear relationship data together with operating parameters for the reciprocating engine, and emission relationship data to determine actual emission levels for the in-use injector based on the wear relationship data and the emission relationship data. The method and system further include determining remaining useful life of the in-use injector based on actual emission levels and the nozzle wear relationship data; and controlling an operation of the reciprocating engine based on the actual emission levels.

Abstract: A system includes a controller that is configured to respond to engine load being at a designated engine load point by operating an engine with a lower exhaust gas recirculation (EGR) amount and a more advanced fuel injection timing than any other steady-state engine load point when EGR and fuel injection are enabled. The controller is further configured to respond to engine load being within a range of engine load points around the designated engine load point by increasing the EGR amount and retarding fuel injection timing as load increases and as load decreases away from the designated engine load point. This may result in decreased fuel consumption while maintaining emissions below designated levels.

Abstract: A system includes a controller that is configured to respond to engine load being at a designated engine load point by operating an engine with a lower exhaust gas recirculation (EGR) amount and a more advanced fuel injection timing than any other steady-state engine load point when EGR and fuel injection are enabled. The controller is further configured to respond to engine load being within a range of engine load points around the designated engine load point by increasing the EGR amount and retarding fuel injection timing as load increases and as load decreases away from the designated engine load point. This may result in decreased fuel consumption while maintaining emissions below designated levels.

Abstract: A system includes a controller operable to communicate with at least one sensor and an engine. The controller responds to one or more signals received from the sensor and influences engine operation based on determined engine operation threshold limits and information regarding a first fuel and a second, different fuel. The controller is configured to change or maintain engine operation based on the one or more signals compared to the threshold limits, and to change or maintain an engine fuel supply to control specific fuel consumption of at least one of the first and second fuels and to achieve values for the one or more signals in a determined range relative to the threshold limits. The one or more signals indicate an exhaust emissions parameter or at least one of pre-turbine temperature, fuel injection pressure, turbocharger rotational speed, peak firing pressure, rate of pressure rise, or knock intensity.

Abstract: A system includes a controller operable to communicate with at least one sensor and an engine. The controller responds to one or more signals received from the sensor and influences engine operation based on determined engine operation threshold limits and information regarding a first fuel and a second, different fuel. The controller is configured to change or maintain engine operation based on the one or more signals compared to the threshold limits, and to change or maintain an engine fuel supply to control specific fuel consumption of at least one of the first and second fuels and to achieve values for the one or more signals in a determined range relative to the threshold limits. The one or more signals indicate an exhaust emissions parameter or at least one of pre-turbine temperature, fuel injection pressure, turbocharger rotational speed, peak firing pressure, rate of pressure rise, or knock intensity.

Abstract: A method includes substantially reducing specific fuel consumption and exhaust emissions of an engine by adjusting an exhaust flow from a set of predetermined cylinders among a plurality of cylinders of the engine through an exhaust gas recirculation system to an intake manifold, by adjusting a temperature of a cooler of the exhaust gas recirculation system, and by adjusting a fuel injection timing, in response to variance in a plurality of parameters of the engine.

Abstract: A method of operating a compression-ignition engine includes adjusting timing of fuel injection if a sensed parameter indicative of a maximum pressure within a combustion chamber varies relative to a selected pressure and if fuel injection timing is greater than a preselected timing.

Abstract: A method of operating a turbocharged system includes controlling speed of a turbocharger and substantially eliminating choke of a compressor coupled to a turbine by adjusting exhaust flow through a turbine wastegate, or by adjusting airflow through a compressor recirculation valve, or by adjusting a combination thereof in response to variance in parameters including compressor inlet temperature, compressor inlet pressure, and turbocharger speed.

Abstract: An improved high viscosity fuel injection pressure reduction system and method is disclosed for use in an internal combustion engine. The system may include a first fuel line and a second fuel line. The first fuel line may be configured to be coupled upstream of a combustion chamber of the engine when the engine is operated with the first fuel and to provide a first pressurized volume when installed. Likewise, the second fuel line may be configured to be coupled upstream of the combustion chamber of the engine when the engine is operated with the second fuel and to provide a second pressurized volume when installed. The first and second volumes of the fuel lines may provide peak injection pressures lower than a desired pressure when the engine is operated with the first and second fuels, respectively.

Abstract: A method, in certain embodiments, includes controlling a first parameter set (e.g., fuel injection timing, engine speed, etc.) of an engine to reduce specific fuel consumption to account for a plurality of different fuels alone or in combination with one another. The method also may include controlling a second parameter set (e.g., engine duration, engine speed, manifold air pressure, fuel supply temperature, fuel supply pressure, etc.) of the engine to reduce the possibility of exceeding design limits associated with the engine to account for the plurality of different fuels alone or in combination with one another.

Abstract: A technique is provided for improved response of internal combustion engines to increased load demands. The engine is equipped with an air storage tank that stores compressed air. The air may be stored at an elevated pressure (e.g., manifold air pressure) during normal full load operation of the engine. Valving maintains the compressed air isolated during normal operation. During transitory periods of higher power output demand, the compressed air is directed to the engine, and output of a turbo-driven compressor can be vented to avoid surge. The technique allows for quicker reaction to load demands, and improved combustion during transitory periods, and reduced particulate and smoke emissions.

Abstract: A method includes substantially reducing specific fuel consumption and exhaust emissions of an engine by adjusting an exhaust flow from a set of predetermined cylinders among a plurality of cylinders of the engine through an exhaust gas recirculation system to an intake manifold, by adjusting a temperature of a cooler of the exhaust gas recirculation system, and by adjusting a fuel injection timing, in response to variance in a plurality of parameters of the engine.

Abstract: A method includes substantially eliminating surge of a compressor and reducing specific fuel consumption and exhaust emissions of an engine by adjusting exhaust flow through an exhaust gas recirculation system, by adjusting airflow through a compressor recirculation valve, by adjusting fuel injection timing, or by adjusting a combination thereof in response to variance in a plurality of parameters. The parameters include quantity of exhaust emissions, a maximum in-cylinder pressure of the engine, an area ratio of an exhaust gas recirculation mixer of the exhaust gas recirculation system, estimated or sensed compressor surge, engine load, altitude of operation, or combinations of the parameters thereof.

Abstract: A method, in certain embodiments, includes controlling a first parameter set (e.g., fuel injection timing, engine speed, etc.) of an engine to reduce specific fuel consumption to account for a plurality of different fuels alone or in combination with one another. The method also may include controlling a second parameter set (e.g., engine duration, engine speed, manifold air pressure, fuel supply temperature, fuel supply pressure, etc.) of the engine to reduce the possibility of exceeding design limits associated with the engine to account for the plurality of different fuels alone or in combination with one another.

Abstract: A system, in certain embodiments, includes a low pressure exhaust gas recirculation (EGR) system configure to route exhaust gas upstream of a compressor coupled to an intake of an engine in a low temperature environment. The system also includes a high pressure EGR system configure to route exhaust gas downstream of the compressor and upstream of the intake at a high altitude and/or in a low pressure environment. The system, in some embodiments, also may include a flow control configured to change flow of the exhaust gas of the low pressure and high pressure EGR systems based on operating limits and environmental conditions including temperature and pressure.