A method of reducing cold start emissions in a series mode hybrid electric vehicle, including an internal combustion engine with an exhaust duct having a catalyst and a downstream oxygen sensor, an output of the combustion engine being connected to an electric generator with a power output of at least 10 kW that is connected to an electric motor which is coupled to a drive shaft of two or more wheels. The method includes detecting a cold start condition, injecting fuel into the engine such that combustion at a lambda value, λ, is achieved for which λ>1, running the engine at a speed of 1000 rpm or higher, determining if the efficiency of the catalyst reaches a first level, setting λ to about 1 after the predetermined efficiency level of the catalyst has been reached, and reducing the speed to working conditions when the catalyst efficiency reaches a second level.

The present disclosure describes an engine system that can achieve at least one of the followings: suppressing of generating of nitrogen oxides and suppressing of remaining of uncombusted hydrocarbons. The engine system has a combustion chamber to which air and a gas fuel are supplied, and is configured to combust the gas fuel. The engine system includes a liquid fuel injecting unit, and a control unit. The liquid fuel injecting unit is configured to inject a liquid fuel thereby to ignite the gas fuel. The control unit is configured to control the liquid fuel injecting unit. The control unit is configured to control the liquid fuel injecting unit so that injection of the liquid fuel is performed after a flame propagation after ignition of the gas fuel is ended.

An internal combustion-type engine or powertrain that is capable of burning wet-alcohol fuel mixture and including a piston reciprocating within a cylinder attached to a cylinder head and connecting to a crank shaft via a connecting rod. An intake cam and valve is mounted within an intake port formed in the cylinder head and an exhaust cam and valve is mounted within an exhaust port also formed in the cylinder head. A pressurized fuel source is introduced into the cylinder by a fuel injector and the percentage of water in the alcohol/water mix operates to prolong the cylinder pressure in order to increase a mean effective pressure (IMEP), leading to a higher torque (improved Brake Mean Effective Pressure—BMEP) of the engine via a longer pressure pulse attained during the period of preferred mechanical advantage of the crank-arm of the engine.

A compression ignition engine system allows use of hydrous fuels, in particular hydrous biofuels, with high water content (e.g., 20-85% water). The hydrous fuel is pressurized, and also preferably heated via the engine's exhaust gas, to increase its enthalpy, and is then directly injected into the engine cylinder(s) near top dead center. The system provides brake thermal efficiency increases of 20% or more versus a comparable system using conventional diesel fuel, while allowing the use of inexpensive undistilled or lightly distilled biofuels.

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 of controlling an engine is provided, which includes, during motoring of the engine, injecting, by an injector, fuel for analysis into a cylinder of the engine at a specific timing after an intake valve of the cylinder is closed. The method includes acquiring, by a controller, a crank angle period from a start timing of the fuel injection to a timing of a pressure inside the cylinder reaching a reference pressure, in response to signals of a crank angle sensor and an in-cylinder pressure sensor. The method includes determining, by the controller, a property of the fuel injected by the injector by comparing the acquired crank angle period with a reference crank angle period, the reference crank angle period being from an injection start timing when a standard fuel is injected into the cylinder to a timing of the pressure inside the cylinder reaching the reference pressure.

An engine controlling method is provided, which includes, during motoring of the engine, outputting, by an in-cylinder pressure sensor, to a controller a signal indicative of a reference pressure corresponding to a pressure change after an intake valve of a cylinder of the engine is closed when not performing fuel injection, and then injecting, by an injector, fuel for analysis into the cylinder at a specific timing after the intake valve is closed. The method includes, by the controller, acquiring a crank angle period from the intake valve close timing, through the fuel injection, to a timing of the in-cylinder pressure reaching the reference pressure based on signals from the in-cylinder pressure sensor and a crank angle sensor, and determining a property of the injected fuel by comparing the acquired crank angle period with that of a standard fuel based on stored information on a property of the standard fuel.

A method of controlling an engine is provided, which includes the steps of, during motoring of the engine, injecting, by an injector, fuel for analysis into a cylinder at a specific timing after an intake valve of the cylinder of the engine is closed, outputting to a controller, by an in-cylinder pressure sensor, a signal corresponding to a pressure inside the cylinder at least at a timing when a specific crank angle period has passed from the fuel injection timing, and determining, by the controller, a property of the fuel injected by the injector, by comparing a pressure value measured by the in-cylinder pressure sensor with a reference pressure value inside the cylinder measured at a timing when the specific crank angle period has passed after a standard fuel is injected into the cylinder at the specific timing.

A control system for an aero compression combustion drive assembly, the aero compression combustion drive assembly having an engine member, a transmission member and a propeller member, the control system including a sensor for sensing a pressure parameter in each of a plurality of compression chambers of the engine member, the sensor for providing the sensed pressure parameter to a control system device, the control system device having a plurality of control programs for effecting selected engine control and the control system device acting on the sensed pressure parameter to effect a control strategy in the engine member A control method is further included.

A piston engine is provided; the piston engine has a cylinder, a main piston and an auxiliary piston; a combustion chamber is formed between the main piston and the auxiliary piston within the cylinder; the main piston has an crankpin offset L0, the auxiliary piston and the main piston move in different frequencies, an extended constant V≈Vc of the combustion chamber is formed from θ to >10° CA; when at a=θ=arc sin[L0/(L+R)] the main piston is at its top dead center; at a=arc sin(L0/R) the side force on the main piston is 0; when peak pressure of combustion is located at PPmax by choosing ignition timing, the most effective torque can be obtained; the torque is controlled by the amount of fuel injected; engine knocking can be prevented by retarded ignition at a>θ.