COMBUSTION CONTROL DEVICE FOR GAS ENGINE

摘要

The objective of the present invention is to improve the output and the thermal efficiency of a gas engine by advancing the ignition timing for each cylinder to the absolute maximum while suppressing knocking for all cylinders with a simple and inexpensive means. A first calculation unit (32) calculates a knocking limit ignition timing (Tia) for the representative cylinder (14a) from the cylinder pressure waveform. A second calculation unit (34) calculates a knocking limit ignition timing (Tia') for a representative cylinder (14a) by substituting a driving state quantity and basic engine specifications into a formula (1). A third calculation unit (36) determines a correction coefficient (C) by comparing the knocking limit ignition timings (Tia) and (Tia'). A fourth calculation unit (38) calculates the knocking limit ignition timings (Tib-Tif) for the cylinders other than the representative cylinder (14a) on the basis of the obtained correction coefficient (C). Preferably the fourth calculation unit (38) revises the correction coefficient (C) for each cylinder on the basis of test data obtained with a test engine of the same type as the gas engine (10).