300MW循环流化床锅炉NO_x生成特性的分析

Analysis on Formation Characteristics of NO_x in 300MW CFB

为了找到流化床锅炉NO_x生成的特性,以某电厂300 MW循环流化床锅炉为研究对象,对其进行试验分析。研究发现:NO_x生成量随氧量的增加而加速增加,最佳的氧量运行区间为2.9%~3.5%;NO_x生成量在175 MW附近达到最小值,随着负荷的升高和降低,NO_x生成量都加速增加,尤其低负荷增加速度更快;影响高负荷NO_x生成量增加的主要因素为炉内温度,但脱硝反应区温度位于脱硝温度窗口内;影响低负荷NO_x生成量增加的主要因素是流化风率,且脱硝反应区温度较低;由于流化风率的增加,导致流化床锅炉床温的下降速度超过脱硝反应区温度下降速度,且在负荷小于225 MW时,锅炉床温低于脱硝反应区温度。

To find out formation characteristics of NOx in CFB, the 300 MW CFB in power plant as the study object, was tested and analyzed. The result shows that the formation amount of NOx was accelerated increased along with O2, the best operation area of O2 was between 2.9% and 3.5%;the formation amount of NOx was minimum on 175 MW condition, the formation amount of NOx was accelerated increased along with load up and down, especially the low load;the main influencing factor was boiler temperature at high load, and the denitration area temperature was in the denitration window;the main influencing factor was fluidized air rate at low load, and the denitration area temperature was low;the bed temperature descending rate was higher than the denitration area temperature because of the fluidized air rate increasing, and the bed temperature was lower than the denitration area temperature when the load was lower than 225 MW.