Abstract: Due to a few changes in the electric unit pump system of the original mechanical fuel injection system of diesel engine structure, with relatively low demand for fuel quality, and with stably mission, it is suitable for the flameproof diesel engine. With the explosion protection system introduced, the performance of the electronic control unit pump diesel engine is reduced, and the emission is increased. In which an average of 6.06% of the torque is fell, and an average of 8.28% of the power, and the fuel consumption rate is increased by an average of 2.67%, and CO is increased by an average of 170%, and NOx is increased by an average of 7.78%. There is little influence on the fuel injection quantity and injection pressure of the electronically controlled unit pump diesel engine with fuel injection timing by AMESIM simulation model. The injection timing characteristics of the electronic control unit pump fuel under different rotational speed is used for the reasonable matching in fuel injection timing and injection pulse width, to some extent, which compensate the loss of the performance in the working conditions after the explosion-proof system added in the electric unit pump diesel engine, as well as the emissions improved within a certain scope, and the best matching point of the torque working condition and the rated conditions obtained.

Key words: Electronic unit pump, explosion-proof diesel engine, injection timing, fuel injection quantity