关键词: 煤粉, 燃烧特性, 渣, 低尘燃烧, 数值模拟

Abstract: The technology of pulverized coal low-dust slagging combustion, which is most suitable to small industrial furnaces, was introduced. Numerical method was used to simulate the burning characteristics of a f400 mm combustor. In addition to selecting several proper models for gaseous flow, solid phase flow, coal combustion and NO emission, the behavior of coal particles near the wall was discussed. Based on these models, the two-phase flow and combustion characteristics in the combustor were analyzed in detail. The predicted temperatures and NO concentrations were compared with the experimental data from the combustor, and acceptable agreement was achieved. Based on the experimental data and computational analysis, the old slag combustor was modified because of some defects. The recent experimental results proved that the performance of the new combustor was much superior to old one at low stoichiometric ratio, offering the advantages of high carbon burning efficiency, not very high temperature at the rear of combustor, high slag-capturing efficiency and low NO emission. When stoichiometric ratio is about 0.8, NO concentration at the rear of combustor is about 400 mg/Nm3, which is much less than that in conventional cyclone combustors.

Key words: pulverized coal, burning characteristics, slag, low-dust combustion, numerical simulation