Control strategy for diesel engine auxiliary loads to reduce emissions during engine power level changes

摘要

A diesel locomotive includes a number of auxiliary subsystems operating in conjunction with the locomotive diesel engine and deriving their energy, from the diesel engine. Included among the subsystems are various cooling systems, the battery charging system, and the electrical generation system, comprising one or more alternators drivingly coupled to the engine shaft. Each of the subsystems includes a component that is activated when one or more operational conditions associated with the subsystem are met. For instance, an engine cooling system fan motor is activated when the coolant temperature exceeds a predetermined value. Similarly, a battery charger is activated when the battery voltage falls below a predetermined value, and an alternator blower is activated when the main or auxiliary alternator temperature exceeds a predetermined value. The activation of these power consuming auxiliary devices while the diesel engine is transitioning from a first load state to a higher load state, causes the formation of excessive smoke emissions. According to the present invention, the activation of these auxiliary components is delayed until the diesel engine has reached steady-state operation, after which the elements are activated as required. Also, in the event a subsystem operational parameter exceeds a predetermined critical limit, the auxiliary device is immediately activated, even if the diesel engine is in a transition state to a higher load value.