飞灰含氨量对脱硝装置氨逃逸测定的影响

Influence of Ammonia Concentration in Fly Ash on Ammonia Slip Detection of Denitration Equipments

为控制烟气中生成的硫酸氢氨对空气预热器冷段的腐蚀、降低空气预热器的堵灰风险和减少脱硝还原剂用量,脱硝设施对氨逃逸有严格规定。试验发现飞灰中氨含量对测定脱硝装置氨逃逸有明显的影响,飞灰对自由态氨和化合态氨的吸附是安装脱硝装置之后氨逃逸较低但其压降却有明显增大的主要原因,因此建议对烟气脱硝的电厂测量氨逃逸的同时增加飞灰中氨含量的测定,以协助对空气预热器阻堵与否的判断。

In order to control the corrosion on the cold section of the air preheater caused by NHaHSO4 in the flue gas, reduce the risk of ash accretion in the air preheater and lower the consumption of denitration catalyst, the specifications on ammonia slip are quite strict for the denitration equipments. The tests on ammonia slip indicate that the ammonia contents in fly ash have great impacts on ammonia slip; the NH3 and NH4^＋ absorption by fly ash is the main reason for the low ammonia slip but the large pressure drop of the denitration equipments. Therefore, it is suggested that power plants detect ammonia slip and the ammonia contents in fly ash at the same time to determine whether the air preheater is blocked up.