A gasoline-diesel complex combustion engine may include a cylinder including a cylinder body in which a combustion chamber is formed to generate a driving power by combusting a gasoline fuel and a diesel fuel and a cylinder head formed to cover an upper portion of the cylinder body, a pair of intake ports formed in the cylinder head, a pair of exhaust ports formed in the cylinder head, a diesel injector disposed in a center of the cylinder head, a pair of spark plugs disposed on opposite sides of the diesel injector, a first intake pipe and a second intake pipe mounted in the intake ports, an exhaust pipe mounted in the exhaust ports, a pair of intake valves disposed in the first and second intake pipes, and a gasoline injector disposed in the first and second intake pipes to inject the gasoline fuel into the combustion chamber.

Systems and methods for separating higher octane fuel from a fuel mixture are presented. In one example, higher octane fuel is separated from lower octane fuel and allowed to condense in a fuel tank holding higher octane fuel so that parasitic engine losses are not increased by having to separate higher octane fuel from lower octane fuel a second time. The approach may be applied to fuel systems that include multiple fuel tanks storing different types of fuel.

In a method and an arrangement for determining a fuel quality of a fuel for a combustion engine fuel is conveyed from a low pressure fuel tank to a high-pressure volume, and injected into at least one cylinder of the combustion engine. A control valve is provided for controlling directly or indirectly the amount of fuel injected into the at least one cylinder. An actual value of a timing signal of the control valve is compared to a reference value of the timing signal of the control valve and a fuel quality parameter is derived from a difference between the actual value and the reference value of the timing signal of the control valve and/or that a fuel quality parameter is derived from a gradient of the pressure increase during a build-up phase of the pressure in the high-pressure volume compared to a reference value of the gradient of the pressure increase in the high-pressure volume.

In a fuel supply device for separating raw fuel into high-octane fuel and low-octane fuel and supplying the fuel, to arrange the structural components compactly and to facilitate sealing against fuel vapor, the fuel supply device (1) includes: a raw fuel tank (2) for storing raw fuel; a separator (6) provided inside the raw fuel tank to separate the raw fuel into high-octane fuel that contains a greater amount of components with high octane numbers than the raw fuel and low-octane fuel that contains a greater amount of components with low octane numbers than the raw fuel; and a high-octane fuel tank (5) provided inside the raw fuel tank to store the high-octane fuel separated from the raw fuel by the separator.

Methods and systems are provided for accurately determining the composition of a knock control fluid using sensors already present in the engine system. An intake or an exhaust oxygen sensor is used to estimate the water and the alcohol content of a knock control fluid that is direct injected into an engine cylinder responsive to an indication of abnormal combustion. A change in the pumping current of the oxygen sensor due to the water content of the knock control fluid is distinguished from a change in the pumping current of the oxygen sensor due to the alcohol content of the knock control fluid.

Low-reactivity fuel such as gasoline is provided to a diesel engine cylinder sufficiently early in the injection stroke that it will be premixed. High reactivity fuel such as diesel fuel is then injected during the compression stroke, preferably around 40-60 before Top Dead Center (TDC), to provide a stratified distribution of fuel reactivity within the cylinder, one which provides ignition (the start of main heat release) at or near TDC, preferably at 0-10 prior to TDC. At that time, the low-reactivity fuel is again injected and burns in a diffusion-controlled manner owing to its lower reactivity, thereby providing greater power output (and thus increased load) with little or no increase in peak heat release rate (PHRR) and combustion noise.

A fuel storage apparatus includes a fuel tank, a heat exchanger, a fuel pipe, and a medium pipe. The heat exchanger performs heat exchange between fuel inside the fuel tank and a heat exchange medium. The fuel pipe is provided inside the fuel tank and delivers the fuel to the heat exchanger. The medium pipe is provided outside the fuel tank and delivers the heat exchange medium to the heat exchanger. The heat exchanger includes a first joint and a second joint. The first joint is provided inside the fuel tank and is connectable to the fuel pipe. The second joint is provided outside the fuel tank and is connectable to the medium pipe.

A dual fuel system includes a first pressurized fuel reservoir, a first fuel pump fluidly connected to the first pressurized fuel reservoir, a second pressurized fuel reservoir, and a second fuel pump including a pump outlet fluidly connected to the second pressurized fuel reservoir, a pumping chamber, an actuating fluid inlet fluidly connected to at least one of the first fuel pump or the first pressurized fuel reservoir, and at least one pumping element. The first fuel pump may have excess capacity, at least at times, so as to provide a pressurized first fuel for actuating the second fuel pump. The at least one pumping element may include an intensifier or de-intensifier plunger such that a flow rate of a second pressurized fuel from the second fuel pump is different than a flow rate of the first pressurized fuel from the first fuel pump as an actuating fluid for the second fuel pump. Related apparatus and methodology is also disclosed.

Engine control apparatus includes: an engine including an injector and ignition plug, and a controller configured to control the injector and ignition plug to switch combustion mode to a second homogenous charge compression ignition combustion of reformed fuel with ignition at required torque less than a first predetermined value, to a first homogenous charge compression ignition combustion of reformed fuel, obtained by reforming a portion of gasoline fuel into peroxide, without ignition at required torque more than the first predetermined value and less than a second predetermined value, to spark ignition combustion of gasoline with ignition at required torque more than the second predetermined value and less than a third predetermined value, and to diffusion combustion of reformed fuel without ignition at required torque more than the third predetermined value.

A fuel injector is capable of injecting a plurality of different fuels in a single fuel injection event, the fuel injector including: a nozzle at an end of the fuel injector, the nozzle having a tip, openings in the tip of the nozzle through which fuel is configured to be injected, and a check valve member with a tip located within the nozzle, the check valve member being movable between an injection position in which fuel is injected via the openings and a closed position in which the openings are closed. The fuel injector further includes a primary fuel path within the fuel injector, a pilot fuel path within the fuel injector, and a mixing volume connecting the primary fuel path and the pilot fuel path when the check valve member is in the closed position.