二甲醚对乙醇内燃机性能的影响

对乙醇掺二甲醚点燃式内燃机的性能进行研究.试验在加装了电控二甲醚喷射系统的内燃机上进行,从而保证乙醇与二甲醚能同时喷入进气道.在转速为1 800 r/min、进气道绝对压力为61.5 kPa、过量空气系数分别为1.0及1.1的条件下,通过逐渐增加二甲醚的喷射脉宽,使二甲醚占进气的体积分数从0加至3%.结果表明:随掺二甲醚体积分数的增加,内燃机指示热效率提高,循环变动降低,CO、HC排放降低,但NO_x略有升高.

Effect of Dimethyl Ether Addition on the Performance of Spark-ignition Ethanol Engine

The test was conducted on an ethanol fueled spark-ignition engine with low proportion of dimethyl ether. An electronically controlled dimethyl ether injection system was used in the test to ensure that ethanol and dimethyl ether were injected into the intake ports together. The dimethyl ether volume fraction increased from 0 to 3% by adjusting the dimethyl ether injection duration under an engine speed of 1 800 r/min, the intake manifold absolute pressure( MAP) of 61. 5 kPa, and two excess air ratios of 1. 0 and 1. 1, respectively. The experimental results show that the indicated thermal efficiency is improved, cyclical fluctuation is reduced, CO and HC emissions are dropped whereas NOx slightly increases at different excess air ratios with the addition of dimethyl ether.