摘要:
A direct injection spark ignition multi-cylinder internal combustion engine operative in a controlled auto-ignition combustion mode includes a direct fuel injection system, a spark ignition system and a controllable engine valve system. The air/fuel ratio in the exhaust gas feedstream and an intake mass air flow are measured and an actual air/fuel ratio is calculated based upon the intake mass air flow and engine fueling. Magnitude of a negative valve overlap period between an exhaust valve closing and an intake valve opening is adjusted based upon the measured mass air flow. Timing of pre-injection fueling is adjusted during the negative valve overlap period based upon the measured air/fuel ratio.
摘要:
A gaseous fuel engine including an exhaust gas recirculation system (28) and method for operating a gaseous fuel engine are provided. The exhaust gas recirculation system (28) has an adjustable flow and is operable to supply exhaust gas to at least one engine cylinder. The engine further includes means for determining a value indicative of a charge density of a combustion mixture that includes gaseous fuel, air and exhaust gas supplied to the at least one cylinder, and adjusting a flow quantity through the exhaust gas recirculation system (28) based at least in part on the value.
摘要:
An engine operating method and a direct injection gaseous fuelled system directly injects a gaseous fuel into a combustion chamber during a compression stroke, commands gaseous fuel injection pressure to a target value that is determined as a function of at least one pre-selected engine parameter, measures actual gaseous fuel injection pressure and adjusts fuel injection pulsewidth to correct for differences between the target value and the actual gaseous fuel injection pressure to thereby inject the desired mass quantity of gaseous fuel as determined from an engine map.
摘要:
This disclosure teaches a method of controlling a direct injection internal combustion engine and predicting the behaviour of a direct injection internal combustion engine. An estimation of initial cylinder pressure, air flow and EGR flow (if applicable) is used to establish a system that provides engine behaviour by integrating an injection module, combustion module and engine control module to provide data indicative of engine behaviour such as brake torque and power, air flow, EGR flow, cylinder pressure, brake specific fuel consumption, start of combustion, heat release rate, turbo-charger speed and other variables. These values can then be used to adjust commanded variables such as start of injection, commanded pulse width, rail pressure to meet operator demand. Also the output data can be used as a tool to determine how a conceptualised engine design will behave. This is particularly useful for gaseous-fuelled internal combustion engines where cylinder pressure influences behaviour of injected gases in light of the fact that rail pressure and cylinder pressure are, generally, of a similar magnitude.
摘要:
Disclosed is a method and apparatus to create an environment within a combustion chamber of an internal combustion engine suitable for auto-ignition and combustion of a fuel that will not otherwise auto-ignite. Underhigh load conditions a pilot quantity of the fuel is injected in the combustion chamber of an internal combustion engine during the compression stroke of the piston. The quantity and timing of the fuel are chosen to heat anintake charge within the combustion chamber to a temperature at or above the auto-ignition temperature of thefuel by the time required for a main injection of the fuel to drive the piston during the power stroke. Generally, auto-ignition temperatures should be reached at or near top dead center of the piston. Also, disclosed is aninjector design to deliver the fuel in manner taught by the method.
摘要:
Disclosed is a method and apparatus to create an environment within a combustion chamber of an internal combustion engine suitable for auto-ignition and combustion of a fuel that will not otherwise auto-ignite. Underhigh load conditions a pilot quantity of the fuel is injected in the combustion chamber of an internal combustion engine during the compression stroke of the piston. The quantity and timing of the fuel are chosen to heat anintake charge within the combustion chamber to a temperature at or above the auto-ignition temperature of thefuel by the time required for a main injection of the fuel to drive the piston during the power stroke. Generally, auto-ignition temperatures should be reached at or near top dead center of the piston. Also, disclosed is aninjector design to deliver the fuel in manner taught by the method.