蒸汽稀释均匀性对天然气扩散火焰污染物排放特性的影响

Influence of the Uniformity of Steam Diluted on the Emissions Characteristics of the Pollutants from a Natural Gas Diffused Flames

采用数值模拟与实验相结合的方法进行蒸汽稀释均匀性对天然气扩散火焰污染物排放特性影响的研究。建立化学反应网络模型,通过零维模拟研究天然气/蒸汽掺混不均匀度对CO、NO_x生成的影响规律。利用某天然气扩散燃烧器,实验研究蒸汽稀释比和稀释均匀性对天然气扩散火焰结构和污染物生成的影响。结果表明,蒸汽稀释均匀性对火焰结构影响较小,但增强稀释均匀性后反应区OH峰值信号强度减弱,NO_x、CO均呈下降趋势。

In gas turbine-based power plants in China, there exists commonly a problem that yellow smoke is produced in the startup process at low loads and high emissions of pollutants from diffused flames on duty are regarded as the main causes. A numerical simulation method combined with tests was em- ployed to study the influence of the uniformity of steam diluted on the emissions characteristics of pollu- tants from natural gas diffused flames. A chemical reaction network model was established and a zero-di- mension simulation was conducted to investigate the law governing the influence of the non-uniformity of natural gas/steam mixed and diluted on the production of CO and NOx. On a natural gas diffusion burn- er, the influence of the steam dilution ratio and uniformity on natural gas diffused flame configuration and formation of pollutants was experimentally studied. It has been found that the steam dilution uniformity will have a relatively small influence on the flame configuration, however, to enhance the dilution uniformity will make the strength of the OH peak signal weakened and NOx and CO assume a descending tendency. The forgoing can offer reference for solving the yellow smoke problem in the startup process of gas turbine units and expanding the range of operating conditions at low NOx emissions.