Various methods and systems are provided for a multi-fuel capable engine. The system includes a liquid fuel system to deliver liquid fuel to an engine, a gaseous fuel system to deliver gaseous fuel to the engine, and a control system. The control system can control and test the liquid and gaseous fuel systems.

A reignition processing device for a gas engine for executing a reignition process of a cylinder during operation of a gas engine having multiple cylinders is provided with: an execution permission unit configured to, when at least one of the cylinders misfires, perform permission determination whether to execute the reignition process of the misfiring cylinder, on the basis of a damage diagnosis result based on an in-cylinder pressure of the misfiring cylinder, presence or absence of abnormality in a control device which performs combustion control and combustion diagnosis of the gas engine, an operational history related to the misfiring cylinder, and an operational state of the gas engine; and a reignition execution unit configured to execute the reignition process of the misfiring cylinder that is permitted by the permission determination to execute the reignition process.

A gas fuel supply system for supplying the gas fuel via an opening of an intake supply pipe that is connected to a combustion chamber in an engine operable in each of a gas fuel combustion mode and an oil fuel combustion mode includes: the gas fuel supply valve for regulating an amount of the gas fuel, the gas fuel supply valve having plural gas supply holes, from which the gas fuel is fed in a direction toward the opening when the valve is opened; and an opening regulation valve provided between the gas fuel supply valve and the opening and having an opening hole, an opening area of which can be regulated. The gas fuel supply system is configured that extended axes of all the gas supply holes pass through the fully opened opening hole.

An internal combustion engine, a method of operating the internal combustion engine, and a controller are disclosed. The method may comprise measuring a first pressure at a first position in a fluid line containing pressurized fluid; comparing the first pressure to a first threshold; in response to the first pressure exceeding the first threshold, transmitting a signal to depressurize the fluid line; after transmitting the signal to depressurize the fluid line, measuring a second pressure in the fluid line and comparing the second pressure to at least one of a second threshold and a third threshold, the second threshold being greater than the third threshold and less than the first threshold; and in response to the second pressure being less than the second threshold and exceeding the third threshold, transmitting another signal to depressurize the fluid line.

Methods and systems are provided for operating a fuel system configured to deliver a gaseous fuel to an engine. While the engine is shutdown, diagnostic routines may be performed to identify fuel system leaks or breaches. When the engine is subsequently restarted, fuel rail pre-priming is adjusted based on the presence of fuel system leaks.

Gas engine arrangement having a gas engine, a gas rail, via which a first gas in the form of fuel gas can be supplied to at least one gas metering device of the gas engine, and a gas control section, which is designed to supply fuel gas to the gas rail via a supply path on the outflow side. A purge line is passed into the gas rail. The gas engine arrangement is designed to selectively supply fuel gas or a second gas to the purge line, and the gas engine arrangement is designed to displace gas from the gas rail and to discharge it via the supply path when the fuel gas or second gas is supplied to the purge line.

An object of the present invention is to provide a gas leakage checking device and a method for the same, for checking fuel-gas leakage of safety shutoff valves simply and securely by measuring a pressure in a fuel supply pipe. The gas-leakage checking device 8 includes a first safety shutoff valve 81 disposed in a fuel-gas supply pipe 89 of the gas internal combustion engine 1 for permitting or shutting off a flow of the fuel gas, a second safety shutoff valve 82 disposed on a downstream side of the first safety shutoff valve 81, a gas-leakage checking pipe 89c branched from between the first and second safety shutoff valves 81, 82, a gas-discharge valve 83 disposed in the gas-leakage checking pipe 89c and configured to discharge the fuel gas between the first and second safety shutoff valves 81, 82, a first pressure meter P1 for detecting a pressure of the fuel gas in the gas-leakage checking pipe 89c, and second pressure meters P2, P3 disposed on a downstream side of the second safety shutoff valve 82, for detecting the pressure of the fuel gas in the fuel-gas supply pipe 89.

The present invention disclosed a system for generating and supplying hydrogen gas to an internal combustion engine. The system comprises at least one hydrogen generator unit configured to generate hydrogen gas from water received from a primary water tank connected to the hydrogen generating unit. The hydrogen generating unit is also connected to an electrical control unit of the hydrogen generator unit which controls supply of power from a power supply unit for the electrolysis of water at the hydrogen generating unit. The hydrogen generating unit also connected to a car electrical control unit whereby through the operation of the electrical control unit of the hydrogen generating unit connected to the car electrical control Unit it enables the system to control activation/deactivation of the hydrogen generating unit, the output rate of the hydrogen to be generated, the quantity of the hydrogen to be supplied to the engine system through a back fire prevention unit disposed between the primary water tank and the engine system.

Misfire classification method for an internal combustion engine, comprising: a step of determining whether the engine is subjected to a misfire; a step of obtaining at least one temperature signal being indicative of a temperature prevailing in a cylinder of the engine; and a step of determining a type of misfire in dependence on the obtained temperature signal.

A reignition processing device for a gas engine for executing a reignition process of a cylinder during operation of a gas engine having multiple cylinders is provided with: an execution permission unit configured to, when at least one of the cylinders misfires, perform permission determination whether to execute the reignition process of the misfiring cylinder, on the basis of a damage diagnosis result based on an in-cylinder pressure of the misfiring cylinder, presence or absence of abnormality in a control device which performs combustion control and combustion diagnosis of the gas engine, an operational history related to the misfiring cylinder, and an operational state of the gas engine; and a reignition execution unit configured to execute the reignition process of the misfiring cylinder that is permitted by the permission determination to execute the reignition process.