In an exemplary embodiment, an internal combustion engine, in which a valve is opened and closed when a piston reciprocates in a cylinder, has a configuration to perform repeatedly the following combined strokes: an intake stroke.fwdarw.a compression stroke.fwdarw.a combustion stroke.fwdarw.an exhaust stroke in a four-cycle internal combustion engine are combined with an intake and compression stroke.fwdarw.a combustion and exhaust stroke in a two-cycle internal combustion engine. The internal combustion engine can reduce pumping loss in a six-cycle internal combustion engine and increase the output.

In an aspect, a system includes a mixer configured to mix a fuel stream with a solvent to form a mixed stream, the solvent having a higher affinity for a second component of the fuel stream than for a first component of the fuel stream. The system includes a first separator configured to separate the mixed stream into (i) a first fuel fraction including the first component of the fuel stream and (ii) a mixed fraction including the second component of the fuel stream based on a difference in volatility of the first fuel fraction and the mixed fraction. The system includes a second separator configured to separate the mixed fraction into a second fuel fraction including the second component of the fuel stream and a solvent fraction.

Embodiments disclosed herein relate generally to systems and methods of operating internal combustion (IC) engines, and more specifically to systems and methods of starting compression ignition (CI) engines when the surrounding environment is significantly colder than the normal operating temperature of the engine (i.e., cold-starting). In some embodiments, the CI engine can include an ignition-assist device. In some embodiments, a method of operating a CI engine during cold-start can include opening an intake valve to draw a volume of air into the combustion chamber, moving a piston from a bottom-dead-center position to a top-dead-center position in a combustion chamber at a compression ratio of between about 15 and about 25, injecting a volume of fuel, the fuel having a cetane number of less than about 30, closing the intake valve, and combusting substantially all of the volume of fuel.

A method for operating an internal combustion engine with detection of the fuel used for injection is described. In the method, the elasticity modulus of the fuel to be injected is determined at a first and a second injection pressure. A difference value is calculated from the difference between the two elasticity modulus values related to the pressure difference and is compared with a differentiating value. The fuel being used is detected depending on whether the difference value is above or below the differentiation value. In particular, the method is used for differentiating diesel fuel EN590 and biodiesel.

An adaptive, any-fuel reciprocating engine using sensor feedback integration of high-speed optical sensors with real-time control loops to adaptively manage the electronic actuation schemes over a range of engine loads and fuels. The engine uses one or more optical sensors to collect specific types of gas property data via a spectroscopic technique to adaptively control various components within the engine.

A vehicular propulsion system, a vehicular fuel system and a method of operating an internal combustion engine. A separation unit that makes up a part of the fuel system may selectively receive and separate at least a portion of onboard fuel and a flowable adsorbent in order to separate the fuel into octane-enhanced and cetane-enhanced fuel components. A controller may be used to determine a particular operating condition of the internal combustion engine such that the onboard fuel can be sent to one or more combustion chambers within the internal combustion engine without first passing through the separation unit during one operating condition, or instead to the separation unit in situations where the internal combustion engine may require an octane-rich or cetane-rich mixture in another operating condition.

Methods and systems are provided for a fuel supply system for an internal combustion engine system, in particular of a motor vehicle, having at least one liquefied petroleum gas (LPG) tank for storing an LPG fuel and at least one direct injection unit, which has a direct injection fuel distributor and direct injection valves that can be supplied with fuel via said distributor. In order to improve supply of the internal combustion engine system with LPG fuel, the fuel supply system includes a booster pump inserted between the LPG tank and the direct injection fuel distributor. A discharge side of the booster pump is connected directly to the direct injection fuel distributor by at least one line, and the direct injection valves each have a closure part that rises outward from a valve seat to open the respective direct injection valve.

A first engine fuel, for example diesel fuel, is reformed (preferably via steam reforming) to produce syngas for use as a second engine fuel, with the fuels then both being used in an internal combustion engine to perform Reactivity Controlled Compression Ignition (RCCI). The syngas is produced and supplied to the engine as a supercritical fluid, thereby avoiding the pumping losses that would occur if syngas was pressurized for supply/injection. The reforming is done by a reformer which is provided as a unit with the engine (e.g., both the engine and reformer are onboard a vehicle), thereby effectively allowing use of a single fuel for RCCI engine operation.

A vehicular propulsion system, a vehicular fuel system and a method of producing fuel for an internal combustion engine. A separation unit that makes up a part of the fuel system includes one or more adsorbent-based reaction chambers to selectively receive and separate at least a portion of onboard fuel into octane-enhanced and cetane-enhanced components. Regeneration of an adsorbate takes place through interaction with a solvent, while subsequent separation allows the solvent to be reused. A controller may be used to determine a particular operational condition of the internal combustion engine such that the onboard fuel can be sent to one or more combustion chambers within the internal combustion engine without first passing through the separation unit, or instead to the separation unit in situations where the internal combustion engine may require an octane-rich or cetane-rich mixture.

According to one or more embodiments, an internal combustion engine may be operated by a method including one or more of the steps of passing a first fuel and a second fuel into a combustion chamber of an engine cylinder to form a fuel mixture, and combusting the fuel mixture with a spark plug to translate the piston housed in the engine cylinder and rotate a crank shaft coupled to the piston. The engine cylinder may include a cylinder head and cylinder sidewalls, and the combustion chamber may be defined at least partially by the cylinder head, the cylinder sidewalls, and the piston. The first fuel may include a greater octane rating than the second fuel. The combustion chamber may include an end gas region and a central region, the central region more near to the spark plug than the end gas region. The first fuel and second fuel may be passed into the combustion chamber such that the end gas region has a greater concentration of the first fuel than the central region, and the central region has a greater concentration of the second fuel than the end gas region.