超细煤粉再燃低NO_x燃烧技术的数值模拟

Numerical Simulation of Low NOx Recombustion Technique with Micro-pulverized Coal

为了验证超细煤粉作为再燃燃料的有效性,使用FLUENT软件对元宝山褐煤在燃烧试验研究装置中的进行了4个工况的数值模拟;1个为常规燃烧,3个为超细粉再燃工况.计算结果表明:超细粉再燃可以有效的降低NOx排放,与常规燃烧相比,脱除率为58.2%～72.5%;再燃区过量空气系数越小,越有利于NOx的还原;超细粉再燃工况中出口NOx排放量不仅与再燃区NOx的还原率有关,而且还与燃尽区新的NOx生成有关.

For the purpose of verifying the applicability of using micro-pulverized coal as a fuel in recombustion, numerical simulation of 4 cases of burning Yuanbaoshan coal in the combustion research furnace were investigated with the help of the FLUENT software; one case concerns conventional combustion, and three others concern recombustion of micro-pulverized coal. Calculation results show that recombustion of micro-pulverized coal can effectively reduce NOx emission by 58.2%-72.5%, compared to conventional combustion; the lower the excess air ratio in the recombustion zone, the more favourable conditions are for the reduction of NOx. In the recombustion mode of operation of micro-pulverized coal, the emitted amount of NOx at the outlet, not only depends on the reduction rate of NOx in the recombustion zone, but is also influenced by the incremental NOx formed in the burn-out zone.