燃煤锅炉烟气中SO_3生成的化学动力学模型和实验研究  

Kinetic modelling and experimental studies on SO_3 generation in flue gas for coal-fired boiler

作　　者：向柏祥[1] 杨海瑞[1] 吕俊复[1] 

机构地区：[1]清华大学热能工程系,北京100084

出　　处：《化工学报》2017年第7期2896-2909,共14页CIESC Journal

基　　金：国家重点基础研究发展计划项目(2014CB744305)~~

摘　　要：燃煤锅炉烟气中SO_3能对锅炉设备、大气环境造成包括低温腐蚀、粘污和蓝烟等一系列的危害。因而,对烟气中SO_3主要影响因素及其影响规律的研究对于预测和控制烟气中SO_3浓度以满足不断增长的节能减排标准有重要意义。基于文献中的C/H/O/N/S化学动力学模型的优化、整合建立了化学动力学模型,对烟气中SO_3主要影响因素及其影响规律进行计算研究。还基于自主设计搭建了全混流反应器测量装置,对上述计算工况中的SO_3浓度进行测量。研究发现,烟气中SO_3浓度主要受SO_2、O_2和H_2O的浓度,以及温度和反应停留时间等影响。SO_3浓度受烟气中CO、NO的影响也较为显著,但是受CO_2的影响不大。另外,随着反应停留时间的增加,烟气中SO_3浓度先后经历了3个不同阶段:急剧增加,增长趋势逐渐减缓和逐渐减少。Various harms on equipment and atmospheric environment, including low-temperature corrosion, fouling and blue plumes, can be caused by SO3 in flue gas for a coal-fired boiler. To predict and control SO3 concentration to meet the increasing demands for energy conservation and emission reduction, more accurate knowledge on the effect of the factors that influence SO3 in flue gas is required. Thus, in present work, a kinetic model was built by optimizing the previously developed kinetic models. The effect of the factors that influence SO3 in flue gas was studied by numerically calculating SO3 concentration under different conditions. Moreover, SO3 concentrations under the conditions mentioned above were measured using a perfectly stirred reactor measuring apparatus built in this work. It was found that SO3 concentration was apparently affected by the factors, namely, the concentrations of SO2, O2 and H2 O, as well as temperature and residence time. SO3 concentration was seemingly affected by the concentrations of CO and NO, while was less influenced by CO2 concentration. In addition, SO3 concentration underwent three stages of sharp increase, slow increase and gradual decrease with increasing residence time.

关 键 词：燃煤锅炉 反应动力学 实验验证 三氧化硫 烟道气 

分 类 号：TK229.6[动力工程及工程热物理—动力机械及工程]