Various methods and systems are provided for controlling emissions and a likelihood of engine knock during combustion in a multi-fuel engine. A method for an engine includes mixing an amount of a first fuel and an amount of a second fuel to combust a fuel mixture having a fuel ratio of the first fuel relative to the second fuel, the first fuel having a faster combustion flame speed relative to the second fuel, the fuel mixture having an air-to-fuel ratio with an amount of air delivered to the engine. The method further includes controlling either or both of a speed of combustion and a stability of combustion of the fuel mixture with the amount of air delivered to the engine by changing at least one of the fuel ratio, the air-to-fuel ratio, or both of the fuel ratio and the air-to-fuel ratio.

An engine test method that causes a computer to execute a process including, acquiring, by a processer on the computer, a first test pattern in which an operation variable that is used for an engine test is changed in time series, inputting, based on the first test pattern, a first operation variable to a mathematical model that represents a time series response of an engine obtained by inputting a test pattern as a simulation of the engine test, monitoring, as a first monitoring parameter of engine abnormality, at least one of an air excess ratio, pressure and temperature of an intake manifold, pressure and temperature of an exhaust manifold, and a maximum cylinder pressure rise rate that are obtained by inputting the first operation variable to the mathematical model, holding, when the first monitoring parameter exceeds a first threshold value, the first operation variable until the first monitoring parameter is less than the first threshold value, creating, a history of the first operation variable in the simulation as a second test pattern, monitoring, as a second monitoring parameter, at least one of the air excess ratio, the pressure and the temperature of the intake manifold, the pressure and the temperature of the exhaust manifold, and the maximum cylinder pressure rise rate that are obtained by inputting a second operation variable to a real engine based on the second test pattern, holding, when the second monitoring parameter exceeds a second threshold value, the second operation variable until the second monitoring parameter is less than the second threshold value, and acquiring, time series data of the second operation variable and a controlled variable.

An air intake amount measurement device 200 includes an intake distributor 3 distributing intake air CYL to cylinders 11, 12, 13, and 14, a temperature detector 202 detecting a temperature Ti of the intake air CYL, a pressure detector 201 for detecting a pressure Pi of intake air CL, and a computing unit 100 that computes an air intake amount mfcyl of the intake air CYL on the basis of the temperature Ti transmitted from the temperature detector 202 and the pressure Pi transmitted from the pressure detector 201. The temperature detector 202 detects the temperature Ti of the intake air CYL at a region W spanning, out of an inside of the intake distributor 3, a first branch portion 31 and a second branch portion 32.

A vehicle includes an engine having an intake manifold and an exhaust manifold. An exhaust system is connected to the exhaust manifold and has an aftertreatment device. The aftertreatment device has a body defining inlet and outlet cones, a heating element, and a catalyst disposed in the body between the cones. An air-circulation system has conduit extending from downstream of the catalyst to the intake manifold and an air-circulation device configured to circulate air from the outlet cone, through the conduit to the intake manifold, through the engine, to the inlet cone, and through the aftertreatment device.

A controller for a motor vehicle having an internal combustion engine, and a device for detecting a fire in a fluid conduit, the device having a fluid state sensor for detecting a state variable of a fluid that is conducted in the fluid conduit, are provided. The determination of a fire situation is performed in a manner dependent on a signal of the fluid state sensor.

A control device for an engine is provided, which includes a combustion chamber formed by a cylinder and a piston, an intake air amount adjuster that adjusts an intake air amount supplied to the combustion chamber, a controller switchable of a combustion mode between a fuel-lean first combustion mode and a stoichiometric second combustion mode based on an engine operating state, and an intake air cooler that cools the intake air supplied to the combustion chamber. The controller controls the intake air cooler to start intake air cooling in response to a request for switching the combustion modes, and after the intake air cooling is started, controls the intake air amount adjuster to start the switching of the combustion modes, and then controls the intake air cooler and the intake air amount adjuster so that the switching of the combustion modes ends after the intake air cooling is finished.

Systems and methods for automatic calibration of large industrial engines in applications where the quality of the fuel supply is unknown and/or variable over time, particularly engines that drive compressors on a natural gas well site. A combination of throttles and an oxygen sensor including a mass-flow-air throttle and a mass-flow-gas throttle to determine the mass flow of air and mass flow of gas. As a response to exhaust gas oxygen level readings, the mass flow measurements are used to determine real time air-fuel ratios. An algorithm uses the air-fuel ratios as input data, wherein a microcontroller adjusts the throttles to meet engine performance demands. Additionally, using the air-fuel ratio data and suggested engine OEM calibration specifications as block multiplier inputs, particular fuel properties, such as British Thermal Unit (BTU) content, can be accurately interpolated, thereby enabling automatic calibration of the engine .

A control system of an electronic-controlled oil-gas dual fuel engine includes electronic control pumps, fuel gas injection electromagnetic valves, a fuel gas control device and a fuel oil control device. The fuel gas control device and the fuel oil control device are electrically connected with a control device of the engine. The fuel gas control device is electrically connected with the fuel gas injection electromagnetic valves and controls the opening time and the opening duration of each fuel gas injection electromagnetic valve installed on a pipeline between a natural gas rail and a cylinder cover air inlet channel of the engine. The fuel oil control device is electrically connected with the electronic control pumps, and controls the starting time and the operation duration of the electronic control pump, and the electronic control pumps are installed on a pipeline between an engine fuel oil rail and a cylinder cover fuel injector.

An engine management system and method may include a control system and method for controlling an internal combustion engine. The internal combustion engine may be a direct-injection engine using a Sonex Controlled Auto-Ignition (“SCAI”) combustion path. The control system and method may utilize fuel injection pressure, timing of start and end of injection, management of turbo airflow, fuel supplied, and other factors to provide reduced emissions and improved performance.

Methods and systems are provided for reverse purging of a fuel vapor canister of an engine. In one example, a method may include heating a fuel vapor canister, sealing a fuel tank in order to generate a vacuum in the fuel tank, and in response to the pressure in the fuel tank reaching a target vacuum, initiating reverse purging of the fuel vapor canister.