| 摘要 |
2122012 9308394 PCTABS00021 An apparatus and method for controlling the boost pressure of air delivered to a gas fuelled internal combustion engine (10) from air compression means (32) such as a turbocharger. An engine management system (EMS) (20) controls a spark ignition system (24) as well as a gas delivery system (12) for controlling the delivery of gaseous fuel to a fuel inlet (18). Air is delivered to the engine (10) through air inlet (26) via air throttle means (28) which is also under the control of the EMS (20). Boost pressure is controlled by an exhaust control valve (52) which is operative to direct a proportion of the exhaust gases to turbocharger (32). The amount of compression of the air depends on the proportion of the exhaust gases diverted to the turbocharger (32), which is variable when the engine (10) is operating on gaseous fuel under the control of EMS (20). Pressure and temperature sensor (44) senses the actual boost pressure and provides a feedback signal to EMS (20) which then compares the actual pressure with a desired boost pressure determined in accordance with at least one operating parameter of the engine (10), such as engine speed and load, and adjusts the condition of control valve (52) accordingly.
|
