汽化潜热和黏度对含氧燃料喷雾特性影响研究

Investigation on Effects of Latent Heat of Vaporization and Viscosity on Spray Characteristics of Oxygenated Fuels

通过配比柴油/生物柴油/正丁醇混合燃料、柴油/汽油/正庚烷混合燃料,分别和柴油/2,5-二甲基呋喃混合燃料的汽化潜热和黏度一致。基于高压定容装置,利用高速摄影技术对不同含氧燃料的宏观喷雾特性进行研究,分析汽化潜热和黏度的改变对燃料喷雾锥角和贯穿距离的影响。结果表明:含氧燃料的黏度增大,喷雾锥角和贯穿距离均变小;且对喷雾锥角影响显著。汽化潜热增大,会引起喷雾锥角的降低和喷雾贯穿距的增大。相比于其他两种含氧燃料,柴油/2,5-二甲基呋喃混合燃料在相同试验工况下的喷雾特性更好,有利于增强燃料雾化混合质量。

Experimental fuels were carried out between diesel/biodiesel/n-butanol blended fuel and diesel/gasoline / n-heptane blended fuel,which their latent heat of vaporization and viscosity were the same as diesel /2,5-dimethylfuran blended fuel,respectively. The high speed imaging technique was applied to visually investigate the macroscopic spray characteristics of different oxygenated fuels in a high-pressure constant volume chamber. The effects of the variation of latent heat of vaporization and viscosity on spray process were studied in detail. Results showed that increasing viscosity leaded to significant decrease of spray cone angle as well as slight decrease of spray penetration. The increment of latent heat of vaporization resulted in decrease of spray cone angle but increase of spray penetration. Compared to other two kinds of oxygenated fuels,spray characteristics of diesel /2,5-dimethylfuran blended fuel was better at the same experimental condition. This indicates that it would be beneficial for enhancing the atomization qulity of oxygenated fuels.