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.

The present invention relates to a gas tank arrangement (100) for an internal combustion engine (102), said gas tank arrangement (100) comprising a gas tank (104) for containing a combustible gas, and an additional gas tank (106) arranged in upstream fluid communication with said internal combustion engine (102), wherein the gas tank arrangement (100) further comprises a valve arrangement (108) positioned in fluid communication with the internal combustion engine (102), wherein the valve arrangement (108) is further arranged in upstream fluid communication with the gas tank (104) and the additional gas tank (106) for controllably direct combustible gas from the internal combustion engine (102) to either the gas tank (104) or the additional gas tank (106).

Provided is a fuel-reforming device comprising: an ammonia tank (4); a reformer (5) for reforming ammonia and generating high-concentration hydrogen gas having a hydrogen content of at least 99%; a mixing tank (7) for mixing ammonia and hydrogen for temporary storage; and a control means (10) for controlling the respective supply amounts of ammonia and high-concentration hydrogen gas that are supplied to the mixing tank (7). The control means (10) calculates the combustion rate coefficient C of mixed gas with respect to a reference fuel on the basis of equation (1). Equation (1): S.sub.0=S.sub.H?C+S.sub.A?(1?C). In equation (1), S.sub.0 is the combustion rate of the reference fuel, S.sub.H is the combustion rate of hydrogen, S.sub.A is the combustion rate of ammonia, and C is the combustion rate coefficient of mixed gas. In addition, on the basis of equation (2), the control means (10) determines the volume fractions of ammonia and hydrogen that are supplied to the mixing tank. Equation (2): C=1?exp(?A?M.sub.B). In equation (2), M is the volume fraction of hydrogen in mixed gas, and A and B are constants.

The present invention relates to a method for supplying fuel for a motor of a vehicle by a fuel supply system comprising: a first tank for containing a first fuel; supply means for supplying fuel to the motor; a supply line, for allowing said first fuel to pass from said first tank to said supply means; a return line, for allowing fuel to pass from said supply means to said first tank; a recirculating line, connected with said supply line and said return line, for allowing fuel to pass from said return line to said supply line; and valve means, configured to selectively direct fuel from said return line to said supply line by said recirculating line, or to said first tank; wherein said method comprises the steps of controlling the speed vehicle; controlling the vehicle motor load; defining a first threshold value of the vehicle speed; defining a second threshold value for the vehicle motor load; letting said first fuel passing from said first tank to said supply means through said supply line, and from said supply means to said first tank through said return line, preventing passage of fuel along said recirculating line, when the vehicle speed is lower than said first threshold value and/or motor load is lower than said second threshold value; or making said first fuel passing from said first tank to said supply means through said supply line and then through a closed circuit comprising a part of said return line, said recirculating line and a portion of said supply line, permitting passage of said first fuel through said recirculating line, so that said first fuel arrives again within said supply means, when the vehicle speed is higher than said first threshold value and motor load is higher than said second threshold value, so as to prevent an excessive increase within said first tank caused by inlet within the first tank of the first fuel warm arriving from said supply means.

A two-stroke internal combustion engine achieves high performance levels by using an innovatively timed sequence of injecting and igniting fuel and oxidant. The operating cycle of the engine does not utilize a compression process. This permits the injection of fuel and oxidant to be coordinated with the initiation of the combustion process in such a way that the engine achieves high efficiency and provides high torque, while at the same time producing low thermal loading of engine components and low levels of engine noise and vibration.

Provided is a fuel-reforming device comprising: an ammonia tank (4); a reformer (5) for reforming ammonia and generating high-concentration hydrogen gas having a hydrogen content of at least 99%; a mixing tank (7) for mixing ammonia and hydrogen for temporary storage; and a control means (10) for controlling the respective supply amounts of ammonia and high-concentration hydrogen gas that are supplied to the mixing tank (7). The control means (10) calculates the combustion rate coefficient C of mixed gas with respect to a reference fuel on the basis of equation (1). Equation (1): S.sub.0=S.sub.H?C+S.sub.A?(1?C). In equation (1), S.sub.0 is the combustion rate of the reference fuel, S.sub.H is the combustion rate of hydrogen, S.sub.A is the combustion rate of ammonia, and C is the combustion rate coefficient of mixed gas. In addition, on the basis of equation (2), the control means (10) determines the volume fractions of ammonia and hydrogen that are supplied to the mixing tank. Equation (2): C=1?exp(?A?M.sub.B). In equation (2), M is the volume fraction of hydrogen in mixed gas, and A and B are constants.

A controller for a hydrogen engine is provided. Control circuitry performs, after a stop request for the hydrogen engine, a water reduction process that reduces a proportion of water vapor in exhaust gas. The control circuitry stops the hydrogen engine after operating the hydrogen engine with the water reduction process executed.

A first condition is set to such a condition of a fuel injection amount of a fuel injection valve and an opening degree of a throttle valve that an air excess ratio in a cylinder becomes greater than or equal to a prescribed value set as a value greater than 1.2 while satisfying a target output of an internal combustion engine. A second condition is set to such a condition of the fuel injection amount and the opening degree of the throttle valve that the air excess ratio in the cylinder becomes 1 or less while satisfying the target output of the internal combustion engine. A controller of the internal combustion engine is configured to obtain the first and second operating conditions that correspond to the target output, and select one of the operating conditions in accordance with the operating situation of the internal combustion engine.

An opposed-piston engine is configured to use hydrogen fuel. The opposed-piston engine has at least one cylinder and a pair of pistons disposed for opposed motion in a bore of the cylinder. Hydrogen fuel is directly side-injected into the cylinder in a compression stroke of the opposed-piston engine, mixed with charge air in the cylinder, and auto-ignited in a combustion chamber formed in the cylinder between the pistons during the compression stroke. A method of operating the hydrogen opposed-piston engine includes switching between a first ignition mode using an externally-generated ignition impulse to ignite the mixture of hydrogen fuel and charge air, and a second ignition mode using compression to ignite the mixture.