混煤燃烧中的交互作用:掺烧方式和配风对着火和燃尽特性的影响

Interaction in Blended Coal Combustion Process: Effects of Coal Blend Way and Air Distribution Mode on Ignition and Burnout Characteristics of the Blended Coal

以某台布置双一次风喷口的试验炉为研究对象,采用数值模拟方法研究了混煤掺烧方式和优化配风对着火和燃尽特性的影响,揭示了氧竞争作用对混煤燃尽抑制的机理,并给出了优化调控方法。结果表明:掺烧方式是影响混煤燃烧着火特性的重要因素;在炉外掺混方式下,掺入高挥发分煤能够改善低挥发分煤的着火特性;掺烧方式对低挥发分煤燃尽特性的影响更显著;炉内掺烧方式可抑制混煤燃烧过程中的氧竞争作用,提高低挥发分煤的燃尽率;合理调整二次风配风量可进一步提高低挥发分煤的燃尽率和混煤的总燃尽率。

Taking the test furnace with double primary air nozzles as an object of study,numerical simulations were conducted to study the effects of coal blend way and air distribution mode on the ignition and burnout characteristics of the blended coal,and to reveal the inhibition mechanism of oxygen competition on the burnout rate,following which,optimal regulation methods were proposed.Results show that the coal blend way is an important factor that affects the ignition characteristics of the blended coal.In the out-furnace blend way,the ignition characteristics of low-volatile coal could be improved by blending in high-volatile coal,indicating that the coal blend way has significant influence on the burnout characteristics of low-volatile coal;whereas,in the in-furnace blend way,the oxygen competition could be inhibited between the low-and the high-volatile coal,while the burnout rate of low-volatile coal could be improved.Reasonable adjustment of secondary air distribution could further improve the burnout rate of both the low-volatile coal and the coal mixture.