Methanol MAP Optimization For Methanol/diesel Dual Fuel Engine Based On ANN And GA

When methanol is used to be an alternative energy on commercial vehicles, as its cetane number is very low and a poor spontaneous combustion capacity, it should be ignited instead of burn itself. Layout methanol injection apparatus in the port of diesel engine, The combustion style with a small amount of diesel injected per cycle change the engine a little but change the economy and emission a lot, it also can be used in different kinds of diesel vehicle with a slight change in its engine. In the application process, if methanol is injected too little, its vicarism of emission improvement will be not obvious; but if injected too much, engine would get a severe cyclic variation even misfire. In this issue, the amount of methanol supplement is demanded. Using mathematical models to calculate the best amount of methanol injection is very difficult, so methanol injection MAP’s calibration is usually measured by a lot of bench test and influenced by calibration engineers subjectively.This article introduces the bench experiment which has been emplaced methanol injection equipment on 4B26 engine’s inlet. It record parameters such as speed, load,methanol consumption, diesel consumption, emissions, etc as Artificial Neural Network’s training samples. Then simulate dual-fuel engine’s input and output relationship by BP Artificial Neural Network’s powerful nonlinear mapping ability,and then search for the best amount of methanol injection by Genetic Algorithm’s better global search capability.The results show that Artificial Neural Network can quickly and easily simulate the actual operation of the engine. Artificial Neural Network and Genetic Algorithm jointed model can identify the most methanol injection quantities in different loads and different speeds with HC emission limited. In that case, methanol can be more used, and a lower NOx and soot emission. Nine points have be chosen evenly distributed through out the MAP. The result shows that the engine with new MAP consumes much more methanol than the original one in the nine points experiment.The new method uses methanol more effectively, improves dual-fuel engine’s emission more significantly and gives a reasonable suggestion in the adjustment of control strategy.