An internal combustion engine system is described herein. The system uses compressed air from a compressor to purge at least a portion of a fuel from an internal combustion engine. During a purge operation, a controller opens and closes an injector of the fuel to be purged to allow the compressed air from the compressor to push at least a portion of the fuel back into a fuel tank through the injector. The controller deenergizes a fuel pump that pumps the fuel to be purged, allowing the pressure of the fuel that is to be purged to reduce to a pressure that allows the compressed air to flow into the injector.

The present invention discloses an oil-gas dual-purpose integrated switch. The oil-gas dual-purpose integrated switch comprises a valve and a knob switch for controlling an ignition coil and a carburetor solenoid valve; the valve cap is fixed on the valve body to form a valve cavity; the valve core is disposed in the valve body; the valve core passes through the valve cap to be fixed with the knob of the knob switch such that when the knob switch is rotated, the valve core is driven to rotate; the valve body is provided with an oil inlet pipe joint, an oil outlet pipe joint, a gas inlet pipe joint and a gas outlet pipe joint which are communicated with the valve cavity; the valve core is provided with an oil duct, and a gas duct. The oil-gas dual-purpose integrated switch can switch the oil path and the gas path randomly.

A marine drive system includes an engine, a fuel system that provides at least two different fuels to the engine, and a fuel selection means for selecting a fuel type. A control unit accesses a set of fuel-specific operating parameters based on the selected fuel type and controls the engine based on the set of fuel-specific operating parameters.

A device is provided, which makes it possible to perform a failure diagnostics for a filter more accurately even in the case of an internal combustion engine which is constructed to be capable of using both of gaseous fuel and liquid fuel. The device of the invention comprises judging means which judges any failure of the filter by comparing the added-up amount of the particulate matter contained in the exhaust gas as detected by a PM amount detecting sensor during a predetermined period and the added-up amount of the particulate matter contained in the exhaust gas as estimated by PM amount estimating means during the predetermined period, wherein the PM amount estimating means estimates the added-up amount of the particulate matter contained in the exhaust gas on the basis of the predetermined parameter and only a fuel injection amount of the liquid fuel out of a fuel injection amount of the gaseous fuel and the fuel injection amount of the liquid fuel.

Disclosed is a method for operating an engine for a vessel including an engine which can use both natural gas and fuel oil as fuel. According to the method for operating an engine for a vessel, each engine is operated in one of modes including: a gas mode in which the engine is driven using natural gas as fuel; a fuel oil mode in which the engine is driven using fuel oil as fuel; and a fuel distribution mode in which the engine simultaneously uses natural gas and fuel oil as fuel.

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.

The present invention discloses an oil-gas dual-purpose integrated switch. The oil-gas dual-purpose integrated switch comprises a valve and a knob switch for controlling an ignition coil and a carburetor solenoid valve; the valve cap is fixed on the valve body to form a valve cavity; the valve core is disposed in the valve body; the valve core passes through the valve cap to be fixed with the knob of the knob switch such that when the knob switch is rotated, the valve core is driven to rotate; the valve body is provided with an oil inlet pipe joint, an oil outlet pipe joint, a gas inlet pipe joint and a gas outlet pipe joint which are communicated with the valve cavity; the valve core is provided with an oil duct, and a gas duct. The oil-gas dual-purpose integrated switch can switch the oil path and the gas path randomly.

An internal combustion engine system is described herein. The system uses a mixer to mix two fuels to provide for a transition from using only one of the fuels to using only the other fuel as power demand changes. The output of the mixer is provided to the engine as a primary fuel. A controller opens and closes throttle valves to adjust the relative concentrations of a first fuel (e.g., diesel) and a second fuel (e.g., methanol) that enter the mixer. In some examples, rather than removing the desired performance and/or environmental benefits achieved by using the second fuel at power demand levels greater than the maximum achievable by only using the second fuel, the systems described herein allow the use of at least a portion of the second fuel in the primary fuel at those power demand levels.

A dual fuel engine includes an engine operable on a gaseous fuel and a liquid fuel and has an electrical power generator. The dual fuel engine also includes a carburetor attached to an intake of the engine to mix air and fuel and connect to a gaseous fuel source and a liquid fuel source. A liquid fuel cut-off connects to the carburetor to selectively interrupt a flow of liquid fuel to the engine. The liquid fuel cut-off is operable in open and closed states such that the liquid fuel cut-off interrupts the flow of liquid fuel when closed. The dual fuel engine also includes controller operably connected to operate the liquid fuel cut-off in the open and closed states, and the controller may be programmed to implement a delay period upon engine startup before closing the liquid fuel cut-off.

A multi-fuel engine includes an engine operable on a liquid fuel and a gaseous fuel. The multi-fuel engine also includes a liquid cutoff solenoid coupled to open and close a liquid fuel path to the engine, and a gaseous cutoff solenoid coupled to open and close a gaseous fuel source to the engine. A switch couples a power source to the liquid cutoff solenoid and the gaseous cutoff solenoid to switch between fuel sources on-the-fly during engine operation.