摘要
建立了一套基于激光诱导可见光法（laser-induced incandescence，LⅡ）及双色标定法的颗粒体积浓度定量诊断系统。该系统利用高能脉冲激光瞬间加热火焰中的纳米颗粒，使颗粒迅速升温到3500-4000K，从而诱发可见光，再利用双色法进行标定，确定光强与颗粒浓度的量化关系，从而计算出火焰中颗粒的绝对浓度以及二维分布。利用该系统测量电场影响下的碳烟颗粒浓度发现：外加电场可以降低火焰中碳烟颗粒的体积浓度，但在加压初期由于电场力作用而使浓度均有升高，±6kV后，离子风加强了物质间的混合，燃烧充分，浓度在小幅度升高后便持续剧烈下降，火焰高度也随之下降。热泳力瞬时采样法佐证了负电场对火焰碳烟颗粒浓度有更强的抑制作用，当电压为-15kV时，浓度降低至原浓度的10％。
A laser-induced incandescence （LⅡ） diagnostics system with 2-color calibration unit was set up. The system used a high-energy laser pulse to heat the soot particles in flame up to 3500-4000 K and induced the incandescence, then used the 2-color calibration unit to find the relationship between light intensity and absolute value of particle volume fraction, and finally get the 2-D image of soot particle volume fraction distribution. Based on this method, an optical experimental facility was set up to investigate the effect of electric fields on soot particle concentration in flames. With the presence of electric field, soot volume fraction will be decreased, but whatever it is negative or positive, the soot volume fraction will increase first because of the electric force below the value of ±6 kV. Ionic wind will take an important role to reduce the flame height and soot particles volume concentration after ±6 kV. Thermophoretic sampling particles diagnostics （TSPD） results show negative electric field is stronger than positive electric field in decreasing the soot volume concentration. When the voltage is -15 kV, the soot volume fraction is reduced to 10% of the value without electric field.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2008年第8期34-39,共6页
Proceedings of the CSEE
