Abstract: A reciprocating engine system includes a cylinder, a piston disposed within the cylinder, a knock sensor disposed proximate to the cylinder and configured to detect vibrations of the cylinder, piston, or both, a crankshaft sensor configured to sense a crank angle of a crankshaft, and a controller communicatively coupled to the knock sensor and the crankshaft sensor. The controller is configured to receive a raw knock signal from the knock sensor and a crank angle signal from the crankshaft sensor corresponding to vibrations of the cylinder, piston, or both relative to the crank angle of the crankshaft, convert the raw knock signal into a digital value signal, and at least one of a crank angle for a start of combustion, a peak firing pressure, a percentage of fuel mass fraction burn, or a combination thereof, based on the digital value signal and the crank angle.

Abstract: A method includes receiving a plurality of signals from a plurality of sensors coupled to a dual fuel engine. The method further includes altering an actual speed of the dual fuel engine to obtain a predetermined air-fuel ratio in response to a changed operating condition of the dual fuel engine determined based on the plurality of signals, so as to maintain operation of the dual fuel engine between knock and misfire conditions.

Abstract: A system includes an engine coupled with a primary shaft that drives a first electric generator for generating electrical power via a gear subsystem. The system also includes a turbocharger assembly having at least one gas turbine engine configured for driving the primary shaft and coupled in parallel with the engine. The turbocharger assembly includes multiple compressors configured to provide a flow of compressed fluid into both the engine and the at least one gas turbine engine and multiple turbines configured to utilize exhausts from both the engine and the one gas turbine for driving the primary shaft. Further, the system includes a controller configured to operate a plurality of valves for controlling optimal intake fluid pressure into the engine and the turbocharger assembly and fuel injections into the engine and the at least one gas turbine engine.

Abstract: A method of operating an internal combustion engine is provided. The method includes combusting a mixture of fresh air and fuel within multiple cylinders. The method also includes directing a first portion of exhaust gases into a first-stage turbine and a second-stage turbine of a turbocharger for expanding the exhaust gases, directing a second portion of exhaust gases from the exhaust manifold via an exhaust channel bypassing the first-stage turbine and recirculating a third portion of exhaust gases into an intake manifold after mixing with fresh air. The method includes controlling at least one of: reducing a normal engine speed at each engine power setting while maintaining constant engine power level by increasing a fuel injection per cycle; concurrently increasing a flow rate of the third portion of exhaust gas during recirculation; and advancing a fuel injection timing for reducing emission levels that meets Tier 4 requirements.

Abstract: Various methods and systems are provided for maintaining combustion stability in a multi-fuel engine. In one example, a system comprises a first fuel system to deliver liquid fuel to at least one cylinder of an engine, a second fuel system to deliver gaseous fuel to the at least one cylinder, and a controller. The controller is configured to supply the gaseous fuel to the at least one cylinder, inject the liquid fuel to the at least one cylinder thereby to ignite the liquid fuel and the gaseous fuel in the at least one cylinder via compression-ignition, and adjust an amount of the gaseous fuel relative to an amount of the liquid fuel based on a measured parameter associated with auto-ignition of end gases subsequent to the compression-ignition of the liquid fuel.

Abstract: A system and method for generating an improved syngas are disclosed. The system includes a mixing unit, a heat exchanger, an engine and a water gas shift (WGS) reactor. The mixing unit is configured to mix a hydrocarbon fuel, an oxidant, and water to generate a fuel mixture. The heat exchanger is coupled to the mixing unit and configured to receive the fuel mixture and generate a heated fuel mixture. The engine is coupled to the heat exchanger and configured to receive the heated fuel mixture and generate an exhaust syngas. The WGS reactor is coupled to the engine and configured to receive the exhaust syngas and provide a water gas shift reaction of the hydrogen, carbon monoxide and the water vapor in the exhaust syngas to provide a reduction in a level of carbon monoxide in the exhaust syngas and an increase in a level of hydrogen in the exhaust syngas to generate the improved syngas.

Abstract: Fuel injector wear compensation methodologies for use with internal combustion engines that alter the injection schedule over the life of the fuel injector(s) by using methods that conduct a primary injection of fuel in the engine (primary fuel event), per an injection schedule within an engine cycle; compare a measured engine parameter(s) to a reference value(s); and then alter the injection schedule applied to the engine, based on the comparing. Another method comprises: during injection events, inject a first fuel in a combustion chamber of the engine; measure an engine parameter(s) of the engine during operation; compare the engine parameter(s) to a reference value(s); add a post injection event of a second fuel during the injection events, based on the comparison. The methods can be applied with single or dual fuels.

Abstract: Methods of operating an internal combustion engine that has two exhaust paths, the first path having an aftertreatment system. One method includes: operating the engine at idle; directing the exhaust flow through the first exhaust path; detecting an exhaust temperature below a predetermined temperature and/or operation of the engine at idle; and diverting all, or some, of the exhaust flow through the second exhaust path, based on the detecting. Another method includes detecting an engine condition that is indicative of an oil accumulation above a threshold and diverting the exhaust flow through the second exhaust path, based on detecting this engine condition. An exhaust subsystem that includes a controller that employs these methods is disclosed.

Abstract: A method of adjusting operation of an internal combustion engine includes injecting fuel into cylinders of the internal combustion engine (first fuel operation); obtaining a first fuel exhaust temperature profile during the first fuel operation; injecting two fuels into the cylinders in a duel fuel operation; obtaining a duel fuel exhaust temperature profile; and adjusting the injection quantity and/or an injection timing of one fuel in a cylinder(s), based on a difference between the first fuel exhaust temperature profile and the duel fuel exhaust temperature profile. Other methods of operating with single fuel and using sensors other than exhaust temperature sensors are disclosed.

Abstract: Various methods and systems are provided for maintaining combustion stability in a multi-fuel engine. In one example, a system comprises a first fuel system to deliver liquid fuel to at least one cylinder of an engine, a second fuel system to deliver gaseous fuel to the at least one cylinder, and a controller. The controller is configured to supply the gaseous fuel to the at least one cylinder, inject the liquid fuel to the at least one cylinder thereby to ignite the liquid fuel and the gaseous fuel in the at least one cylinder via compression-ignition, and adjust an amount of the gaseous fuel relative to an amount of the liquid fuel based on a measured parameter associated with auto-ignition of end gases subsequent to the compression-ignition of the liquid fuel.

Abstract: Dual-fuel engine system includes cylinders in which the cylinders have an intake valve and an exhaust valve that control a flow of fluid into and out of a combustion chamber of the corresponding cylinder. The intake valve is configured to have an intake valve closure (IVC) timing. The dual-fuel engine system is configured to operate in a single-fuel mode and a dual-fuel mode. The combustion chamber and a piston are designed to provide a compression ratio. The dual-fuel engine system also includes one or more processors that are operably coupled to and configured to control operation of the first fuel injector. The compression ratio and the IVC timing are selected to achieve a target pre-combustion temperature. The target pre-combustion temperature permits the dual-fuel engine system to operate at a high substitution rate in the dual-fuel mode and at a sufficient fuel efficiency in the single-fuel mode.

Abstract: A method of operating a reciprocating engine comprises recirculating exhaust gas from a first cylinder of the engine to an intake stream or air-fuel mixture of a second cylinder of the engine such that a boost pressure of the first cylinder is greater than a boost pressure of the second cylinder. An engine retrofit system and two-cycle engine employing aspects of the method are also disclosed. The present invention has been described in terms of specific embodiment(s), and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.

Abstract: Various methods and systems are provided for adjusting an air-fuel ratio for combustion in an engine. In one embodiment, a method for an engine (e.g., a method for controlling an engine system) comprises responding to a sensed change in a load on the engine, or indications of engine knock or misfire, by one or more of: altering a speed of the engine, adjusting a fueling flow rate into at least one cylinder of the engine, and adjusting a position of a valve in a bypass passage configured to direct compressed intake air away from cylinders of the engine to obtain a determined air-fuel ratio; and thereby maintaining an air-fuel ratio in a determined range.

Abstract: A system in one embodiment includes at least one cylinder, a supplemental boost supply, and a supply line. The at least one cylinder is configured for use in a reciprocating internal combustion engine, and includes a combustion portion and a crank portion on opposite sides of a piston. The at least one cylinder also includes an intake port and an exhaust port in fluid communication with the combustion portion. The supplemental boost supply is configured to provide a supplemental air supply to the combustion portion of the engine when the engine is idling to increase pressure in the combustion portion. The supply line couples the supplemental boost supply to the intake port.

Abstract: A control system for an engine includes one or more processors configured to determine when a change in one or more of oxygen or fuel supplied to an engine. The one or more processors also are configured to, responsive to determining the change in oxygen and/or fuel supplied to an engine, direct one or more fuel injectors of the engine to begin injecting fuel into one or more cylinders of the engine during both a first fuel injection and a second fuel injection during each cycle of a multi-stroke engine cycle of the one or more cylinders.

Abstract: Various methods and systems are provided for a combustion system of an engine. In one example, a combustion system comprises a piston crown bowl with a central apex, a combustion chamber operable at a compression ratio in a range of from about 13:1 to about 17:1, the combustion chamber formed at least partially by the piston crown bowl, and a fuel injector with a nozzle extending into a central portion of the combustion chamber that is operable to inject fuel directly into the combustion chamber, the nozzle defining a number of apertures that is in a range of from six to ten.

Abstract: A method involves comparing a determined operating parameter of an engine, with a predefined operating parameter. The method further involves controlling a fuel source and an ignition source of the engine so as to operate at least one engine cylinder in a skip fire mode for at least one cycle of a crank shaft when the determined operating parameter is greater than the predefined operating parameter. The controlling involves transitioning the fuel source from a normal mode to the skip fire mode for the at least one cycle of the crank shaft either before transitioning the ignition source from the normal mode to the skip fire mode or when the ignition source is operated in the normal mode.

Abstract: A method involves controlling a fuel injector to inject a first quantity of a fuel into a cylinder from a plurality of cylinders, of an engine and detecting a first value of a parameter associated with the engine. The method further involves controlling the fuel injector to inject a second quantity of the fuel different from the first quantity of the fuel, into the cylinder of the engine and detecting a second value of the parameter associated with the engine. The method also involves comparing the first value with the second value and detecting a hardware anomaly associated with the engine based on the comparison of the first value with the second value.

Abstract: Various methods and systems are provided for adjusting an air-fuel ratio for combustion in an engine. In one embodiment, a method for an engine (e.g., a method for controlling an engine system) comprises responding to a sensed change in a load on the engine, or indications of engine knock or misfire, by one or more of: altering a speed of the engine, adjusting a fueling flow rate into at least one cylinder of the engine, and adjusting a position of a valve in a bypass passage configured to direct compressed intake air away from cylinders of the engine to obtain a determined air-fuel ratio; and thereby maintaining an air-fuel ratio in a determined range.

Abstract: A method for optimal fueling of an engine is disclosed. The method includes determining a quantity of exhaust residuals in each cylinder among a plurality of cylinders in the engine. Further, the method includes determining at least one of an intake and exhaust manifolds temperature, at least one of an intake and exhaust manifolds pressure, and a quantity of a first fuel being injected to each cylinder, and calculating a characteristic temperature of each cylinder based on the quantity of exhaust residuals, at least one of the intake and exhaust manifolds temperature and pressure, and the quantity of the first fuel. The method further includes determining a substitution rate of the first fuel for each cylinder based on the characteristic temperature, and controlling at least one of the quantity of the first fuel, and a quantity of a second fuel being injected to each cylinder based on the substitution rate.