摘要 |
Provided is a gas engine that performs air-fuel ratio control in accordance with compositional changes in fuel gas. This gas engine (1) is equipped with an A/F valve (22) and a solenoid valve (21), is configured in a manner so as to perform perturbation by means of the solenoid valve (21), is provided with a control unit (10) that performs perturbation by means of the solenoid valve (21) by varying the solenoid valve (21) to the lean side and the rich side from a predetermined aperture in the state of the A/F valve (22) being opened to a predetermined aperture during specific engine operating conditions resulting from a baseline fuel gas, the control unit (10) adjusts the aperture of the A/F valve (22) in a manner so that, in the case that the output average value (b) obtained from a pre oxygen sensor (31) provided to an exhaust pathway (13) of the gas engine (1) during actual operation in a period during which the operating state of the gas engine (1) is considered to be uniform deviates from an output target value (a) of the pre oxygen sensor (31) provided to the control unit (10) under said conditions, the output average value (b) becomes the output target value (a). |