Polymethoxy Dimethyl Ether/汽油混合燃料喷雾特性实验研究

Experimental Study on Spray Characteristics of Polymethoxy Dimethyl Ether and Gasoline Blended Fuel

为了明确聚甲氧基二甲醚(PODE)掺混对汽油喷雾特性的影响,利用定容弹试验台和高速纹影摄像装置对不同喷射压力和环境温度下的汽油(G100)、PODE(P100)及其混合燃料(G80P20、G50P50)的宏观喷雾特性进行了实验研究,获得了燃料的喷雾过程图像,并提取了喷雾贯穿距离、喷雾锥角和喷雾投影面积等特征参数。实验结果表明,随PODE掺混比增大,混合燃料喷雾贯穿距离和喷雾锥角增大,且环境温度较高时,不同燃料之间的差异较大;喷射压力较大时,燃料喷雾投影面积较大,4种燃料的喷雾投影面积的差异也较大;随环境温度升高,混合燃料喷雾投影面积减小,且其减小幅度随PODE掺混比增大而减弱。G100的喷雾投影面积随环境温度升高大幅度减小,而P100的喷雾投影面积几乎不随实验范围内环境温度的升高而改变;掺混20%PODE的混合燃料具有比汽油略大的喷雾贯穿距离、喷雾锥角和喷雾投影面积,油气混合质量与汽油类似,更高比例PODE掺混会使燃料与空气混合程度和蒸发性能变差。

In order to clarify the influence of PODE(polymethoxy dimethyl ether)blending on the spraying characteristics of gasoline,the macroscopic spraying characteristics of gasoline(G100),PODE(P100),and the blended fuels(G80P20/G50P50)are investigated in a constant volume chamber equipped with high-speed schlieren photography system at different injection pressures and ambient temperatures.Results show that higher PODE blending ratios accelerate the spray tip penetration(STP)of the test fuel,and as the ambient temperature increases,the discrepancy in STP of different fuels becomes more and more significant.Higher injection pressure produces larger spray projected area(SPA)and larger discrepancy in SPA of the fuels.With the increase of ambient temperature,the SPA of the fuel decreases,and the variation trend decreases with the PODE mixing ratio.With the increase of ambient temperature,the SPA of G100 decreases significantly,while that of P100 almost does not change.The mixed fuel with 20%PODE has slightly larger STP,spray cone angle(SCA)and SPA than those of gasoline,and the quality of the gas-oil mixture is similar to that of pure gasoline,while more PODE mixing will make the atomization and evaporation quality worse.