柴油机气缸内局部瞬态碳粒浓度、火焰温度改进双色法测量系统

An Improved Two-color Method Measurement System for Local Transient Soot Concentration and Flame Temperature in the Cylinder of Diesel Engines

介绍了一套新的改进双色法柴油机气缸内局部瞬态火焰温度和碳粒浓度测试系统 ,其测试原理利用了颗粒的衍射理论 ,细致地考虑了柴油机气缸内碳粒云的光学参数。测试系统中采用了分叉光纤从而省去了一套复杂的光学分光系统。新型的探头设计较好地解决了蓝宝石窗面的积炭问题。对测试系统进行了标定。在缸盖火力面上布置两个具有代表性的测点来测量火焰温度和碳粒浓度。测试结果表明 :活塞凹坑部位火焰温度和碳粒浓度均较高 ;在活塞挤流区 ,循环变动很大。

The system using a new improved two-color method to measure local instantaneous flame temperature and soot concentration in the cylinder of diesel engines was presented. The measuring principal, which considered the optical parameters of particulate cloud in detail, was based on the particulate diffraction theory. In this measuring system, a branching optical fiber was adopted; thereby a set of complicate spectrometer system could be omitted. The new probe design could effectively eliminate the soot deposit on the sapphire window. The measuring system was calibrated. Two representative measuring positions were arranged in the cylinder head to measure the flame temperature and the soot concentration. The measuring results showed that the flame and the soot concentration were relatively high in the bowl region of piston, and in the crown region of piston the cylinder variation was relatively large. The significant differences of time of appearance both in soot concentration and flame temperature were found between the two measuring positions.