利用高速摄影研究二甲基醚的喷雾特性

本文利用高速摄影技术在定容压力室中,通过6孔电磁喷射器,研究了二甲基醚（DME）的喷雾特性。结果表明,二甲基醚的喷雾射程随着定容压力室内气体压力的增加而减少;喷雾锥角则随和的升高而增大,在相同的条件下,二甲基 喷射锥角大于 喷射锥角;喷雾射程则低于柴油的喷雾射程。Hiroyasu喷雾射程的计算模型,通过适当的系数修正可以用于DME喷雾射程预测,由于DME喷雾射程和着火延迟期都比柴油短,在屐机缸内着火时刻,柴油的喷雾射程约为DME的2倍,从高速摄影的喷雾影像中可以清楚的看到,DME的蒸发速度明显比柴油快。

An Experimental Study on the Spray Characteristics of Dimethyl Ether by Using a High Speed Video Camera

The spray charcteristics of dimethyl ether (DME) were investigated by using a high speed video camera with a 6-hole electromagnetic injector on a constant volume chamber. The results show that with the increase in chamber pressure, DME spray tip penetrations decreased and spray cone angles increased.Under the same conditions, DME spray cone angles were larger and spray penetrations were shorter than those of diesel. The calculation model of Hiroyasu can be used to evaluate the spray tip penetrations of DME when some coefficients in the model were modified. Due to the fact that both the spray penetration and ignition delay of DME are shorter than those of diesel, the spray penetrations of DME were about half that of diesel at the start of ignition. Owing to the low boiling point, DME vaporization processes were shorter than that of diesel.