双卷流燃烧室与油束夹角匹配对柴油机排放的影响

Effects of spray angle on the emissions characteristics of diesel engine matched with double swirl combustion system

为了优化喉口直径96 mm的双卷流燃烧室的排放特性，通过试验对喷油油束夹角进行匹配。选取油束夹角为155°和160°的喷油器进行试验。在外特性和部分负荷特性的试验数据显示，油束夹角为155°时，颗粒浓度比油束夹角为160°时低0．02～0．27 mg/m3，NOx浓度比油束夹角为160°时高14×10-6～70×10-6（NOx与总排气体积比的10-6）。通过试验数据解释了造成上述排放特性的原因，并运用仿真分析阐明了上述排放特性的形成机理。研究表明采用油束夹角为155°时，可以有效降低颗粒排放，若采用缸外处理NOx ，可以达到国4排放标准。

For the purpose of optimizing the emission characteristics of a double swirl combustion chamber with a throat size of 96 mm, tests were carried out for selecting a proper spray angle. The spay angles of 155° and 160° were applied for testing an oil sprayer. The data from the tests of the general performance and partial load property showed that, when the spay angle is 155°, the concentration of the particle is lower than that at 160° by 0.02~0. 27 mg/m3, and the NOx concentration is higher by 14×10-6~70×10-6（10-6 of the ratio between NOx and the total e-mitted gas） . The emission results were explained by the experimental data and the formation mechanism of the a-bove emission characteristics was explained by the simulation analysis. The research shows that the emission of the particle may be effectively reduced by the application of a spray angle of 155°;in addition, if NOx is processed out-side of the cylinder, the CHN4 emission level may be realized.