A method for CO.sub.2 certification and/or CO.sub.2-dependent homologation of vehicles that takes into account at least one design feature of the vehicle, which is characterized in that the detected use of a CO.sub.2-reduced fuel is taken into account as a design feature of the vehicle.

The present invention relates to a diagnosis method for an ethanol sensor of a flexible fuel vehicle, the diagnosis method including: a) the fuel refilling detection step of detecting whether fuel is filled to a fuel tank; b) the maximum changeable content range calculation step of calculating a content range of ethanol in the fuel stored in the fuel tank; c) the ethanol sensor value acquirement step of determining whether the data detected from an ethanol sensor converges into a given value; d) the oxygen sensor value acquirement step of determining whether the data detected from an oxygen sensor converges into a given value; and e) the ethanol sensor abnormality determination step of determining that an error is generated from the ethanol sensor if the data acquired at the ethanol sensor value acquirement step or the data acquired at the step is not a value in the calculated range.

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.

A method of characterizing a mixed fuel flow period is provided. The method includes flowing a mixed fuel, the mixed fuel being comprised of at least a first fuel type and a second fuel type, the mixed fuel flow period being determined where the fuel is switched from the first fuel type to the second fuel type, determining a density of the first fuel type and a density of the second fuel type, and determining a total flow, the total flow being determined from the density of the first fuel type and the density of the second fuel type.

The present disclosure provides a method for predicting a fluid type, comprising sensing, by a first sensor, mass flow data of a fluid in an engine, wherein the first sensor operates based on a first fluid property; sensing, by a second sensor, mass flow data of the fluid, wherein the second sensor operates based on a second fluid property; and detecting, by a logic circuit of a controller, a percent difference in the mass flow data provided by the first and second sensors, the percent difference indicating that the fluid is comprised of at least a first fluid type.

A lubricity estimation device is applied to a fuel supply system that supplies a fuel to an internal combustion engine, and includes a mixing ratio estimation unit and a lubrication index calculation unit. The mixing ratio estimation unit estimates the mixing ratio of each of plural types of molecular structures included in the fuel. The lubrication index calculation unit calculates a lubrication index, representing the lubricity of an outer peripheral portion S1 of the piston of a fuel pump and an outer peripheral portion of the valve body of a fuel injection valve by the fuel, based on the mixing ratio estimated by the mixing ratio estimation unit.

Methods and systems are provided for estimating ethanol content in fuel, water content in fuel, and an age of the fuel in a vehicle engine. In one example, a method may include estimating fuel ethanol content, water content, or fuel age based on a resonant frequency (f) of pressure pulsations, a change in fuel rail pressure (p), and a damping coefficient () of pressure pulsations in the fuel rail as estimated after a fuel injection or a pump stroke. One or more engine operating parameters may be adjusted based on the estimated fuel ethanol content, water content, and fuel age.

A power generation system comprises a fuel gas supply device 13 for controlling methane concentration or carbon dioxide concentration in a mixed gas MG containing methane and carbon dioxide within a setting range for the concentration in the fuel gas of a gas engine 11, and for supplying the mixed gas MG to the gas engine 11 as the fuel gas, and a gas concentration sensor 14 for measuring the carbon dioxide concentration or the methane concentration of the mixed gas MG. The fuel gas supply device 13 comprises a carbon dioxide removal device 16 for removing carbon dioxide in the mixed gas MG, and an operating condition control device 17 for controlling an operating condition that affects an increase or decrease of a carbon dioxide removal rate of the carbon dioxide removal device 16, and the operating condition control device 17 controls the operating condition of the carbon dioxide removal device 16 based on the measurement result of the gas concentration sensor 14, thereby controlling the concentration of methane and carbon dioxide in the mixed gas.

Embodiments of the present invention include a method and apparatus for supplying conditioned natural gas to dual fuel engines.

The present disclosure provides a method for predicting a fluid type, comprising sensing, by a first sensor, mass flow data of a fluid in an engine, wherein the first sensor operates based on a first fluid property; sensing, by a second sensor, mass flow data of the fluid, wherein the second sensor operates based on a second fluid property; and detecting, by a logic circuit of a controller, a percent difference in the mass flow data provided by the first and second sensors, the percent difference indicating that the fluid is comprised of at least a first fluid type.