The invention concerns a method of detecting hydrogen leakage from a power plant installation using hydrogen as fuel. A rate of supply of hydrogen to the power plant (the supply rate) is determined. A rate of change of mass of hydrogen in the tank arrangement (the rate of mass change) is determined. The supply rate is compared with the rate of mass change to determine whether leakage is taking place.

A method of detecting uncontrolled combustion in an internal combustion engine includes sampling in-cylinder pressure sensor configured to measure pressure in a cylinder of the engine and generate a pressure signal, calculating a combustion intensity metric based on the pressure signal, determining a parameter describing how close the engine is to an uncontrolled combustion condition based on the combustion intensity metric, and controlling a substitution rate of a first fuel and a second fuel based on one or more of the parameter and the combustion intensity metric.

A method for determining failure of an electromechanically actuated gas shut off valve includes sensing and recording a gas fuel rail pressure and a boost pressure from an air intake manifold at a first time after the dual fuel engine has been started. The method includes opening the gas shut off valve at a second time, holding the gas shut off valve in its open state, and then closing the gas shut off valve after a predetermined interval at a third time. The method includes comparing an actual gas rail pressure decay rate to a threshold gas rail pressure decay rate for the predetermined interval, and determining failure of the gas shut off valve when the actual gas rail pressure decay rate is less than the threshold gas rail pressure decay rate. Upon determining failure of the gas shut off valve, the method also includes initiating a mitigating action.

The present invention relates to a diagnosis method for an ethanol sensor of a flexible fuel vehicle, the diagnosis method including: a) the fuel refilling detection step of detecting whether fuel is filled to a fuel tank; b) the maximum changeable content range calculation step of calculating a content range of ethanol in the fuel stored in the fuel tank; c) the ethanol sensor value acquirement step of determining whether the data detected from an ethanol sensor converges into a given value; d) the oxygen sensor value acquirement step of determining whether the data detected from an oxygen sensor converges into a given value; and e) the ethanol sensor abnormality determination step of determining that an error is generated from the ethanol sensor if the data acquired at the ethanol sensor value acquirement step or the data acquired at the step is not a value in the calculated range.

A control circuit for a dual fuel generator includes a primary fuel valve to control the supply of a primary fuel, a secondary fuel valve to control the supply of a secondary fuel, a primary fuel pressure switch to detect the primary fuel, a secondary fuel pressure switch to detect the secondary fuel, and a controller. The controller is configured to receive a primary signal for availability of the primary fuel from the primary fuel pressure switch and a secondary signal for availability of the secondary fuel from the secondary and operate the primary fuel valve and the secondary fuel valve in response to the primary signal and the secondary signal. When the secondary fuel valve is open so that the secondary fuel is provided to the dual fuel generator, the control circuit is configured to ground the primary signal by connecting the primary fuel pressure switch to ground.

A system for exchanging of different fuels that can be used for operation of an engine. The system includes a fuel exchange unit, a control and an exchange return conduit. The fuel exchange unit is configured to deliver a first fuel at pressure into the injections system given a switched-off engine, in order to replace a second fuel, which is located in the injection system, with the first fuel. A fuel delivery system includes a media converter which includes a deflectable element. The media converter is driven by a drive unit via the fluid by way of the fluid being able to be led at a varying pressure to the media transformer via a first feed conduit, and is configured to deliver the fuel via a pumping effect.

An internal combustion engine in which an output from a fuel reformation cylinder is obtained based on a cylinder internal pressure and a rotational speed of the fuel reformation cylinder, and an output adjusting operation for adjusting an output from an output cylinder is executed so that a sum of the output from the fuel reformation cylinder and the output from the output cylinder matches with a required engine power. In this output adjusting operation, during a transient operation in which the required engine power is increased, the output from the output cylinder is increased by increasing the fuel supply amount to a combustion chamber. Then, the fuel supply amount to a fuel reformation chamber is gradually increased while the fuel supply amount to the combustion chamber is gradually reduced, so that a heat source is shifted from the fuel to the reformed fuel.

Both an improvement in detection accuracy of a valve opening position of a blocking valve and a reduction in time required for learning of the valve opening position are achieved. An evaporated fuel processing apparatus is provided with a learning device configured to learn the valve opening position of the blocking valve. The learning device learns the valve opening position (i) by stepwisely increasing a stroke amount by rotating a stepping motor by two steps at each time in a valve opening direction and (ii) by determining whether a difference between the stroke amount at present and the stroke amount corresponding to the valve opening position is one step of rotation of the stepping motor, or two steps, on the basis of pressure fluctuation on the canister side of the blocking valve associated with the rotation of the stepping motor when the blocking valve is opened, when learning the valve opening position.

A method for deposit mitigation in a gaseous fuel injector that introduces a gaseous fuel through a gaseous fuel orifice directly into a combustion chamber of an internal combustion engine includes at least one of a) reducing the ago length of the gaseous fuel orifice by substantially between 10% to 50% of a previous length of a previous gaseous fuel orifice showing deposit accumulation above a predetermined threshold; b) providing the gaseous fuel orifice with an inwardly and substantially linearly tapering profile; c) determining deposit mitigation is needed; and performing at least one of the following deposit mitigation techniques i) increasing gaseous fuel injection pressure wherein deposit accumulation is reduced during fuel injection; and ii) decreasing gaseous fuel temperature wherein a rate of deposit accumulation is reduced; and d) injecting compressed air through the gaseous fuel orifice during shutdown of the internal combustion engine; whereby torque loss in the internal combustion engine due to deposit accumulation in the gaseous fuel orifice is reduced below a predetermined value.

A method for starting a gaseous fuel internal combustion engine is disclosed. According to the disclosed method, the engine is rotated using a start device until a first speed threshold is reached. After reaching the first speed threshold, pilot fuel is supplied to a plurality of cylinders of the engine to combust the same. After performing an ignition health check, gaseous fuel is supplied to all or a relatively large number of cylinders to start accelerating the engine up to a second speed threshold.