An engine control system includes an engine calibration module that sets fuel injection timing based on one of N cetane number (CN) values, wherein N is an integer greater than one. A combustion noise module generates a combustion noise signal based on cylinder pressure in a compression ignition (CI) engine during combustion. A fuel quality determination module compares the combustion noise signal to N predetermined combustion noise levels corresponding to the N CN values, and that selects the one of the N CN values based on the comparison.

A fuel injector feeds fuel to a combustion chamber of a cylinder of a dual-fuel engine and includes: a main body having a needle guide; a nozzle needle guidable in the needle guide; a needle fuel chamber defined by the main body, coupleable to the combustion chamber, wherein the orifices are open in a first position of the nozzle needle and closed in a second position of the nozzle needle; a first line arranged in the main body, and being coupled to the needle fuel chamber, via the first line a fuel being introduceable into the needle fuel chamber. In the main body a second line is coupleable to the needle guide and to a control chamber of a control valve of the fuel injector, wherein via the second line a fuel is feedable to the needle guide as barrier fluid and to the control chamber as working fluid.

For powering a vehicle, a high energy density fuel is preferred. However, for example when the high energy fuel is highly concentrated hydrogen peroxide, this fuel may be dangerous to handle; especially when the person handling the fuel is a normal consumer filling a fuel reservoir of his vehicle at a gas station. The present invention therefore provides a vehicle arranged to receive a diluted—and thus safer—fuel, and to density this fuel to a concentrated fuel in low quantities on board for direct use. To this end a fuel densifier is provided in the vehicle arranged for receiving liquid diluted fuel and arranged to provide a concentrated fuel based on the diluted fuel, the concentrated fuel having a higher energy density than the diluted fuel. A power conversion module of the vehicle is arranged to convert the concentrated fuel to kinetic energy for powering the vehicle.

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 camshaft includes, as a cam that opens and closes an exhaust valve and an intake valve, a ball cam whose protrusion amount changes according to rotation of the camshaft, wherein the camshaft has a double structure consisting of an inner shaft and an outer shaft provided in a manner that the inner shaft is helically displaced with respect to the outer shaft around an axis of the camshaft according to a rotation speed of the camshaft, and the ball cam is accommodated movably in a guide groove provided in the inner shaft and protrudes from the outer shaft, and a protrusion amount of the ball cam from the outer shaft changes when the ball cam moves in the guide groove due to the helical displacement of the inner shaft with respect to the outer shaft.

Some embodiments described herein relate to a method of operating a compression ignition engine. The method of operating the compression ignition engine includes opening an intake valve to draw a volume of air into a combustion chamber, closing an intake valve, and moving a piston from a bottom-dead-center (BDC) position to a top-dead-center (TDC) position in the combustion chamber at a compression ratio of at least about 15:1. The method further includes injecting a volume of fuel into the combustion chamber at an engine crank angle between about 330 degrees and about 365 degrees during a first time period. The fuel has a cetane number less than about 40. The method further includes combusting substantially all of the volume of fuel. In some embodiments, a delay between injecting the volume of fuel into the combustion chamber and initiation of combustion is less than about 2 ms.

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.

A method is provided for operating an internal combustion piston engine, including introducing air into a cylinder of the engine, compressing the air in a first compression stroke of the cylinder, providing fuel into the cylinder for a first combustion, with a portion of the oxygen in the compressed air as oxidant, in a first power stroke succeeding the first compression stroke, to produce residues including oxygen, compressing the residues in a second compression stroke succeeding the first power stroke, and providing, after the first combustion, fuel into the cylinder for a second combustion, with at least a portion of the oxygen of the residues as oxidant, in a second power stroke succeeding the second compression stroke, wherein the first compression stroke is repealed immediately after the second power stroke, and the introduction of air into the cylinder is done at the end of the second power stroke and/or at the beginning of the first compression stroke.

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.

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.