配燃尽风的旋流燃烧器对NO_x排放和燃尽率影响的试验研究

Experimental Investigation on the Effect of Over Fire Air on NO_x Emission and Burnout Ratio for a Swirling Burner

热态模拟试验是在1台1 MW的热态煤粉燃烧试验炉上进行的,用2台双调风旋流燃烧器对冲燃烧,并且在主燃烧器上方的不同位置还布置了燃尽风装置(OFA)。主燃烧器使用的是变截面的一次风管和碰撞环相结合,在一次风管内,风粉气流在惯性的作用下分离为外浓内淡的环状气流,从而实现了燃烧器喷口处沿直径方向的浓淡分布。通过对陕北神华优质烟煤、山西河津劣质烟煤和山西长治贫煤这三种特性相差较大的煤的燃烧对比实验,得到了燃尽风布置的相对位置变化,对NO_x的生成和对飞灰含碳量的影响作用,同时也得到了NO_x的生成和燃尽率之间的相互关系,以及对燃烧的稳定性、经济性的影响因素,其结果对工程设计和实际应用有着重要的指导意义。

Pilot tests have been carried out on a 1 MW pulverized coal furnace to clarify the NOx emission and coal combustion characteristics from a new type radial bias whirl burner. In the test furnace two opposing dual register whirl burners are arranged with Over Fire Air （OFA） nozzle along the furnace height. The burner has a cross-section changing primary air pipe. Inside the primary air pipe, the pulverized coal and air mixture is divided into two streams, i.e. , the pulverized coal rich annular jet outside and the pulverized coal lean annular jet inside, due to inertial force, resulting in a dense-dilute pulverized coal concentration pro- file in the radial direction of the burner nozzle. The tests are performed by using Shanbei SH high rank bituminous coal （SH coal）, Shanxi Hejin low rank bituminous coal （HJ coal） and Shanxi Changzhi lean coal （CZ coal）. The purpose of the tests is to make clear the effects of the relative position of OFA nozzle, and the various combinations of these parameters, on the production and emission of NOx, the carbon burnout. As such, the relationship between NOx emission and carbon burnout and the relationship between combustion stability and economy can be obtained. These test results are of significance for industrial design.