Operating a gaseous fuel engine system includes outputting control commands to a first fuel admission valve and a second fuel admission valve to admit, respectively, a gaseous fuel blend containing a gaseous hydrogen fuel (H2), and additional H2, into a gaseous fuel engine. An amount of the additional H2 is determined by way of the respective control command based on a performance target for an engine parameter varying on the basis of a relative amount of H2 in a combustion charge. Related apparatus and control logic is also disclosed.

Operating a gaseous fuel engine system includes controlling at least one of a delivery location, a delivery timing, or in situ mixing of a gaseous fuel with air, based on at least one engine system parameter upon the basis of which a blowby amount of a gaseous fuel to a crankcase varies. Crankcase accumulation of the gaseous fuel is maintained below a flammability limit. Related apparatus and control logic is also disclosed.

A fuel circulation system of a diesel type engine configured to use carbonaceous aqueous slurry or emulsion fuels. The diesel type engine includes a fuel injection system which is fluidly connected to the fuel circulation system. The fuel circulation system comprises: at least one fuel feed pump comprising a positive displacement pump located in the fuel circulation system before the fuel injection system, the fuel feed pump configured to supply a controlled amount of carbonaceous aqueous slurry fuel to the fuel injection system; and at least one volumetric flow controller comprising at least one of a second positive displacement pump configured to operate in reverse as a positive displacement pressure let-down device, or a volumetric flow valve operated as a positive displacement pressure let-down device, the volumetric flow controller located in the fuel circulation system after the fuel injection system, the volumetric flow controller providing a controlled regulation of return flow/fuel system pressure from the fuel injection system from zero to maximum flow/pressure.

Methods and systems are provided for maintaining combustion stability in a multi-fuel engine. In one example, a system may include first and second fuel systems to deliver liquid and gaseous fuels, respectively, to at least one cylinder of the engine, and a controller. The controller may be configured to supply the gaseous fuel to the at least one cylinder, inject the liquid fuel to the at least one cylinder to compression ignite the liquid fuel and combust the gaseous fuel in the at least one cylinder, and retard an injection timing of the injection 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. In some examples, the controller may further be configured to adjust an amount of the gaseous fuel relative to an amount of the liquid fuel based on the measured parameter.

An inward-firing dual fuel combustion burner system comprising a burner casing configured to receive a gaseous mixture at a burner inlet and to provide hot combustion gas at a burner output; a combustion substrate disposed within the burner casing, the substrate having a shape comprising at least a semi-cone, having a substrate angle measured from a longitudinal axis, having a substrate porosity defined by a plurality of pores, and having a substrate inner surface and a substrate outer surface; the substrate configured to receive the fuel-air mixture at the outer surface of the substrate, the fuel-air mixture passing through the pores at a mixture flow rate from the substrate outer surface toward the substrate inner surface; one or a plurality of oil nozzles disposed within the combustion cavity defined by the substrate in fluidic communication with a source of pre-heated and pre-pressurized oil fuel, an oil nozzle configured to receive the oil fuel and disperse the oil fuel into the cavity; the burner configured to be operated using either a gaseous premix fuel air mixture or a pre-heated and pre-pressurized liquid fuel oil; the burner configured such that, during gaseous premix fuel operation, the fuel-air mixture ignites near the plurality of pores to form a respective plurality of flamelets, each flamelet corresponding to one of the pores; and the burner configured such that, during oil fuel operation, the oil mixture ignites during isenthalpic expansion.

Systems, apparatus and methods include control techniques for controlling operation of pre-mixed internal combustion engines in response to a load shedding event. The control techniques determine, in response to the load shedding event, a number of cycles in which to skip combustion of the fuel in the at least one cylinder based on an air-fuel ratio limit in the exhaust flow, prevent combustion of the fuel in the at least one cylinder during the number of skipped cycles, and combust the fuel in the at least one cylinder each time the number of skipped cycles are complete.

An engine (21) including a main fuel injection valve (79), a pilot fuel injection valve (82), a liquid fuel supply rail pipe (42), and a pilot fuel supply rail pipe (47). The main fuel injection valve (79) supplies liquid fuel from the liquid fuel supply rail pipe (42) to a combustion chamber (110) during combustion in a diffusion combustion system. The pilot fuel injection valve (82) supplies pilot fuel from the pilot fuel supply rail pipe (47) to the combustion chamber (110) in order to ignite gaseous fuel during combustion in a premixed combustion system. The liquid fuel supply rail pipe (42) is disposed at one side of an imaginary vertical plane (P1) including an axis of a crank shaft. The pilot fuel supply rail pipe (47) is disposed at the side of the imaginary vertical plane (P1) at which the liquid fuel supply rail pipe (42) is disposed.

An ethanol engine system stabilizes components of reformed gas generated by a reformer and a calorific value of fuel supplied to an engine. The ethanol engine system includes a reservoir tank for an aqueous ethanol solution, a first supply device that supplies the aqueous ethanol solution to the reformer, a separator that cools mixed gas fed from the reformer, including the reformed gas, condenses water vapor included in the mixed gas and separates into gas and liquid, a reformed gas supply device that supplies the reformed gas separated by the separator to the engine, a recovery tank that collects a recovery solution separated by the separator, and a first recovery solution supply device that supplies the recovery solution in the recovery tank to the reformer or a second recovery solution supply device that supplies the recovery solution in the recovery tank to a combustion chamber of the engine.

A power system includes an intake arrangement configured to intake charge air; a fuel arrangement configured to store a blend of methane (CH.sub.4) and hydrogen (H.sub.2) fuel; an engine configured to receive, ignite, and combust a mixture of the charge air and the blend of methane (CH.sub.4) and hydrogen (H.sub.2) fuel; and a controller coupled to selectively command such that, in a first mode, the controller commands the one or more of the intake arrangement, the fuel arrangement, and the engine such that the charge air and the blend of methane (CH.sub.4) and hydrogen (H.sub.2) fuel are introduced at a stoichiometric equivalence ratio; and in a second mode, the controller commands the one or more of the intake arrangement, the fuel arrangement, and the engine such that the charge and the blend of methane (CH.sub.4) and hydrogen (H.sub.2) fuel are introduced at a lean equivalence ratio.

Provided is a fuel composition prepared by adding gas-to-liquid oil and water to light cycle oil to conduct emulsification. The fuel composition is used as a fuel for a diesel engine (12) in a ship (10). The ship (10) includes a fresh water tank (15), an LCO tank (13), and a GTL tank (14) configured to store water, light cycle oil, and gas-to-liquid oil, respectively, and a mixer (16) configured to mix the water, the light cycle oil, and the gas-to-liquid oil fed from the respective tanks to produce the fuel composition.