The development of a dual fuel engine electronic control unit and control strategy

A natural gas sequential injection dual fuel electronic control unit (ECU) was developed for the purpose to improve the performance of the dual fuel engine control system according to the calibration data. And a real-time diesel equivalent heating value substitution control strategy following the signal of original diesel injection pulse width was also proposed. A direct injection engine equipped with high pressure common rail system was converted into diesel/natural gas dual fuel engine and experiments were conducted to validate the functions of pilot diesel injection, natural gas injection, original diesel injection pulse width signal acquisition and the real-time equivalent heating value substitution control strategy. It indicates that the developed dual fuel ECU works stably and the dynamic performance of the dual fuel engine can be improved dramatically. The influence of natural gas injection timing on the total hydrogen carbon (THC) emissions is discussed, the significant influence on the THC emissions is found in the corresponding experiments. Adjusting natural gas injection timing in real-time facilitates avoiding early injection of natural gas, the THC can be reduced significantly. Especially, under light and medium loads, and the maximum reduction gets up to 32.6%.