T型煤粉锅炉富氧燃烧的数值模拟

Numerical Simulation on Oxygen-enriched Combustion of T-shaped Pulverized Coal-fired Boiler

为研究采用富氧燃烧方式煤粉锅炉的燃烧特性,利用Fluent软件对一台T型煤粉锅炉的富氧燃烧过程进行了数值模拟,得到了一次风含氧体积分数变化时炉膛内温度场、速度场和烟气各组分物质的量浓度的分布.结果表明:富氧条件下整个炉膛温度水平高于空气助燃条件下;当含氧体积分数由21%增大至33%时,炉膛平均温度由1 413.2K升高为1 447.1K;当含氧体积分数增大至27%时,炉膛平均温度变化较明显,达到1 435.6K;当含氧体积分数大于29%时,炉膛平均温度变化不明显;变一次风风量富氧燃烧方式的含氧体积分数最佳范围为27%～29%.

To study the oxygen-enriched combustion characteristics of pulverized coal-fired boiler, numerical simulation was carried to the combustion process of a T-shaped boiler using Fluent software, during which the in-furnace temperature field, velocity field and mass concentration distribution of various gas components were obtained under conditions of different oxygen concentrations in primary air. Results show that the overall in-furnace temperature under oxygen-enriched condition is higher than that under air combustion condition; when the oxygen volume fraction is increased from 21% to 33%, the mean furnace temperature rises from 1 413.2 K to 1 447.1 K; when the oxygen volume fraction is increased to 27%, the mean furnace temperature changes obviously, reaching 1 435.6 K; when the oxygen volume fraction is in- creased to a degree more than 29%, the mean furnace temperature basically remains unchanged; the optimal oxygen volume fraction is 27%-29% under oxygen-enriched combustion mode with variable primary air volumes.