Various methods and systems are provided for a method for a multi-pressure fueling system. In one example, the multi-pressure fueling system includes providing a first fuel delivery pressure enabling high pressure direct injection of a fuel at a first injector and a second fuel delivery pressure insufficient for high pressure direct injection, at a second injector, based on engine operation.

Timing of HHO gas injection into a 4-stroke engine is optimized based on engine operating parameters to improve fuel economy.

A method for monitoring a fuel supply system in an internal combustion engine includes the steps of: recording a first pressure value in the fuel supply system in a region of the fuel supply system associated with a pre-filter and upstream of a low pressure pump; recording a second pressure value in the fuel supply system downstream of the low pressure pump in a region of the fuel supply system associated with a primary filter; monitoring the first pressure value and the second pressure value for an error state of the fuel supply system; and recognizing the error state only if the error state is plausible on a basis of both the first pressure value and the second pressure value.

Methods, systems and devices for evaluating incoming air to an engine, industrial controller including engine controls, valves and solenoids, for concentrations of explosive or combustible gases or vapors, and actuating process control including but not limited to shutting down an engine or other industrial process to control an outcome including the prevention of an overspeed condition when pre-set or calculated elevated gas or vapor concentrations are detected. In some embodiments industrial control including engine shutdown may be achieved conventionally via an electronic kill signal, a shutdown of the fuel injector, carburetor or fuel pump, and in emergency conditions by the shutoff of incoming air to an air intake, turbocharger, or other air delivery systems. Decisions based on explosive gas or vapor concentrations and species and the use of networking to allow additional systems to take action before explosive gases or vapors reach said other valve-sensor devices can provide additional safety.

Systems and methods regarding a ducted fuel injection (DFI) combustion system for an internal combustion engine can control an injection timing of a fuel injector to output fuel injections through at least one duct and into a combustion chamber of the internal combustion engine. The injection timing can include one or more pilot injections according to a predetermined range before top dead center (BTDC) for a combustion cycle; and a main injection into the combustion chamber for the combustion cycle after all of the one or more pilot injections. A first amount of the fuel injected for the main injection can be greater than a second amount of fuel injected for the one or more pilot injections. The predetermined range before top dead center (BTDC) of the one or more pilot injections can be from 85 to 40 degrees BTDC.

A control device controls a drive current that flows through a drive coil of a fuel injection valve that is electromagnetically driven. A control device includes a determination unit configured to determine whether a supply fuel pressure, which is a pressure of fuel supplied to the fuel injection valve, is higher than a determination pressure at which the fuel pressure is determined abnormally high; a first control unit configured to control the drive current in a first mode when the determination unit determines that the supply fuel pressure is not higher than the determination pressure; and a second control unit configured to control the drive current in a second mode that facilitates maintaining of the fuel injection valve in an open state more than in the first mode when the determination unit determines that the supply fuel pressure is higher than the determination pressure.

A control system of an electronic-controlled oil-gas dual fuel engine includes electronic control pumps, fuel gas injection electromagnetic valves, a fuel gas control device and a fuel oil control device. The fuel gas control device and the fuel oil control device are electrically connected with a control device of the engine. The fuel gas control device is electrically connected with the fuel gas injection electromagnetic valves and controls the opening time and the opening duration of each fuel gas injection electromagnetic valve installed on a pipeline between a natural gas rail and a cylinder cover air inlet channel of the engine. The fuel oil control device is electrically connected with the electronic control pumps, and controls the starting time and the operation duration of the electronic control pump, and the electronic control pumps are installed on a pipeline between an engine fuel oil rail and a cylinder cover fuel injector.

Methods and systems are provided for reverse purging of a fuel vapor canister of an engine. In one example, a method may include heating a fuel vapor canister, sealing a fuel tank in order to generate a vacuum in the fuel tank, and in response to the pressure in the fuel tank reaching a target vacuum, initiating reverse purging of the fuel vapor canister.

Vehicle fuel fill control systems may anticipate vehicle refueling events in order to control the timing of fuel tank depressurization sequences. In a first embodiment, a global positioning system (GPS) is utilized to anticipate the vehicle refueling event prior to initializing the depressurization sequence. In another embodiment, a camera system is utilized to anticipate the refueling event prior to initializing the depressurization sequence. In yet another embodiment, both the GPS and the camera system may be utilized to anticipate the refueling event. By anticipating refueling events, customer wait time for gaining refueling access may be reduced.

Methods and systems for supply of fuel for a turbine-driven fracturing pump system used in hydraulic fracturing may be configured to identify when the supply pressure of primary fuel to a plurality of gas turbine engines of a plurality of hydraulic fracturing units falls below a set point, identify a gas turbine engine of the fleet of hydraulic fracturing units operating on primary fuel with highest amount of secondary fuel available, and to selectively transfer the gas turbine engine operating on primary fuel with the highest amount of secondary fuel from primary fuel operation to secondary fuel operation. Some methods and systems may be configured to transfer all gas turbine engines to secondary fuel operation and individually and/or sequentially restore operation to primary fuel operation and/or to manage primary fuel operation and/or secondary fuel operation for portions of the plurality of gas turbine engines.