ENGINE, ENGINE EXHAUST TEMPERATURE CONTROLLING DEVICE AND CONTROLLING METHOD

摘要

An engine exhaust temperature controlling device and a controlling method for maintaining the cylinder exhaust temperature of a gas engine within a specified range to prevent misfire and knocking. If an engine revolution speed is higher than a specified one at S1, a cylinder exhaust temperature is sampled at specified time intervals at S2, an average of exhaust temperatures is calculated at S3, a load percentage at that point of time is judged at S4, and an average exhaust temperature Tave and an exhaust temperature Tn at each cylinder are compared at S5 to judge which is larger, its deviation DELTATn or a set deviation Tlimit at the above load percentage. If the former is smaller, an exhaust temperature is within a set deviation, thereby not requiring the adjustment of a fuel injection period and allowing the system to return to S2. If the former is larger, whether to increase or decrease the opening period of the electronic fuel injection valve is judged at S6. If the valve opening period is to be increased, the system moves to S7 and if it is to be decreased, the system moves to S8. If an engine revolution speed is higher than a specified one at S9, steps S2-S6 are repeated and if lower than a specified one at S9, a control operation is stopped.