| 摘要 |
A gas engine is controlled to constant speed even if the gas quality changes. With a calibrated throttle valve 11 and a special calibrated gas-metering block 19 comprising valve 5, temperature sensors 16, 10 and pressure sensors 6, 4, 23, 18, the gas flow and the air-fuel mixture flow are measured. Using these measurements and stored data together with the measured engine power (from kilowatt load sensor 16), the Wobbe index which represents the thermal heat of the gas is calculated. With this information the digital controller 7 positions the throttle valve 11 for sufficient mixture flow to maintain engine speed under changing load and the gas metering block is set for matching the air-fuel ratio for required emission values. The system can compensate for changing gas quality by calculating the Wobbe index without using a Lambda sensor. |
