SCR脱硝催化剂宏观性能评估和寿命预测方法研究

Study on Methodology of SCR Catalyst Macroscopical Performance Evaluation and Lifetime Prediction

针对实际烟气流场和飞灰沉积对选择性催化还原(SCR)脱硝催化剂寿命预测有较大影响的问题,在对大量现场和实验室测试数据进行研究基础上,提出了用SCR脱硝反应器潜能来表征和衡量实际烟气条件下的催化剂整体宏观性能。结合催化剂活性表征方法,构建了SCR脱硝催化剂宏观性能评估和寿命预测方法,用反应器潜能劣化函数宏观预测催化剂剩余寿命,再通过每层催化剂活性劣化函数,可得到具体的催化剂增加、更换或再生方案。以某1 000 MW机组为例,对NOx超低排放改造方案进行了比选,结果表明:低氮燃烧改造和旧催化剂再生均是提高脱硝装置性能的经济有效方法,二者相结合,效果最佳。

Regarding the significant impacts of flue gas flow fields and ash deposition on the SCR catalyst lifetime prediction in practice, the SCR reactor potential is proposed to represent and evaluate the macroscopical performance of muhilayer series catalyst based on the analysis of the mass field and laboratory test data. Combined with the characterization of catalyst activity, a novel methodology is established to evaluate the macroscopical performance and precisely predict the catalyst lifetime by adopting the potential and activity degradation function. Through the degradation function of the catalyst of each layer, the specific plans of catalyst addition, replacement and regeneration can be determined. This method has been successfully used for the comparison and selection of the ultra-low NOx emission retrofitting plan of a 1 000-MW unit. The outcome indicates that low NOx combustion retrofit and used catalyst regeneration are both efficient and economical ways to improve the SCR performance. Nevertheless, the combination of these two methods together can achieve the best effects.