Various methods and systems are provided for controlling emissions and a likelihood of engine knock during combustion in a multi-fuel engine. A method for an engine includes mixing an amount of a first fuel and an amount of a second fuel to combust a fuel mixture having a fuel ratio of the first fuel relative to the second fuel, the first fuel having a faster combustion flame speed relative to the second fuel, the fuel mixture having an air-to-fuel ratio with an amount of air delivered to the engine. The method further includes controlling either or both of a speed of combustion and a stability of combustion of the fuel mixture with the amount of air delivered to the engine by changing at least one of the fuel ratio, the air-to-fuel ratio, or both of the fuel ratio and the air-to-fuel ratio.

A drawdown compressor assembly for recovering natural gas from a gas line includes a first tubing configured for connection to a first pipe of the gas line at a one end of the first tubing. A compressor is attached to an opposite end of the first tubing and configured to draw natural gas from the first pipe through the first tubing and into the compressor for being compressed by the compressor. A second tubing is connected to the compressor at one end of the second tubing and configured for connection to a second pipe of the gas line at an opposite end of the second tubing. Activation of the compressor draws the natural gas from the first pipe through the first tubing and delivers compressed natural gas to the second pipe through the second tubing.

Provided is a fuel tank having a built-in component placeable with high accuracy. The fuel tank has a built-in component, and the built-in component includes: a carrier as a rigid body having fittings; and pillars having fitted portions to be respectively fitted into the fittings of the carrier; wherein the fittings include at least one slidable fitting having one of the fitted portions of the pillars slidably fitted thereinto due to post-molding shrinkage of the fuel tank, and a fixed fitting having another one of the fitted portions of the pillars fitted thereinto so as not to be slidable, wherein a slidable direction of the at least one slidable fitting is directed toward the fixed fitting.

A fuel pump system, comprising an inlet line and a motorized pump, a first selector valve in fluid communication with an inlet line at a first inlet port and in fluid communication with the motorized pump outlet via a first outlet branch at a second inlet port to receive fuel from the motorized pump outlet. The system can also include a main fuel pump in fluid communication with the first selector valve and a second selector valve, wherein the second selector valve can be in fluid communication with the main fuel pump and in fluid communication with the motorized pump outlet.

An engine operable in a premixed combustion system and a diffusion combustion system. The engine includes a main fuel injection valve, a pilot fuel injection valve, a liquid fuel tank, a main fuel supply path, a pilot fuel supply path, a pilot fuel filter, a pilot fuel high-pressure pump, a pilot fuel tank, and a pilot fuel supply pump. The pilot fuel tank stores pilot fuel sent from the pilot fuel high-pressure pump and not injected by the pilot fuel injection valve. This pilot fuel is sent to an automatic backwash filter and a pilot fuel filter while not passing through the liquid fuel tank.

An engine operable in a premixed combustion system and a diffusion combustion system. The engine includes a main fuel injection valve, a pilot fuel injection valve, a liquid fuel tank, a main fuel supply path, a pilot fuel supply path, a pilot fuel filter, a pilot fuel high-pressure pump, a pilot fuel tank, and a pilot fuel supply pump. The pilot fuel tank stores pilot fuel sent from the pilot fuel high-pressure pump and not injected by the pilot fuel injection valve. This pilot fuel is sent to an automatic backwash filter and a pilot fuel filter while not passing through the liquid fuel tank.

Provided is a pressure regulator and a fuel pump module having the same, which may be easily assembled by including fewer components, the pressure regulator including: a first housing including a guide part positioned therein and guiding movement of a valve, and an outlet part communicating with an inner space thereof and discharging a fluid; a second housing coupled to the first housing, having a valve accommodating space, including a valve seating part, and including an inlet part introducing a fluid; a valve positioned in the valve accommodating space, and moved to thus open and close a fluid flow; and an elastic member interposed between the valve and the first housing to bring the valve into close contact with the valve seating part.

To ease work of transferring a fuel from a fuel supply tank to a fuel tank, a fuel supply guide to be used to supply the fuel by using the fuel supply tank to the fuel tank having a tank body for storing the fuel and a fuel supply port on the upper side of the tank body includes a support member provided on an upper portion of the fuel tank, and a body member projecting from the support member in a direction away from the fuel supply port as the body member extends upward and projecting higher than the fuel supply port. The body member is capable of receiving the fuel supply tank by an upper portion thereof to support the fuel supply tank.

Systems and methods for supplying primary fuel and secondary fuel to an internal combustion engine may include supplying a first amount of the primary fuel and a second amount of the secondary fuel to the internal combustion engine. The system may include a first manifold to provide primary fuel to the internal combustion engine, and a primary valve associated with the first manifold to provide fluid flow between a primary fuel source and the internal combustion engine. A second manifold may provide secondary fuel to the internal combustion engine, and a fuel pump and/or a secondary valve may provide fluid flow between a secondary fuel source and the internal combustion engine. A controller may determine a total power load, the first amount of primary fuel, and the second amount of secondary fuel to supply to the internal combustion engine to meet the total power load.

An engine including a main fuel injection valve, a pilot fuel injection valve, a liquid fuel supply rail pipe, and a pilot fuel supply rail pipe. The main fuel injection valve supplies liquid fuel from the liquid fuel supply rail pipe to a combustion chamber during combustion in a diffusion combustion system. The pilot fuel injection valve supplies pilot fuel from the pilot fuel supply rail pipe to the combustion chamber in order to ignite gaseous fuel during combustion in a premixed combustion system. The liquid fuel supply rail pipe is disposed at one side of an imaginary vertical plane including an axis of a crank shaft. The pilot fuel supply rail pipe is disposed at the side of the imaginary vertical plane at which the liquid fuel supply rail pipe is disposed.