SCI和EI收录∣中国化工学会会刊

›› 2016, Vol. 24 ›› Issue (8): 1065-1073.DOI: 10.1016/j.cjche.2016.04.026

• Chemical Engineering Thermodynamics • Previous Articles     Next Articles

Modeling and simulation of urea-water-solution droplet evaporation and thermolysis processes for SCR systems

Xubo Gan, Dongwei Yao, Feng Wu, Jiawei Dai, Lai Wei, Xingwen Li   

  1. Institute of Power Machinery and Vehicular Engineering, Zhejiang University, Hangzhou 310027, China
  • Received:2015-07-29 Revised:2016-03-12 Online:2016-09-21 Published:2016-08-28
  • Supported by:
    Supported by the National High Technology Research and Development Program of China (2013AA065301), the Fundamental Research Funds for the Central Universities (2016QNA4014), and the State Key Laboratory of Clean Energy Utilization at Zhejiang University (ZJUCEU2016006).

Modeling and simulation of urea-water-solution droplet evaporation and thermolysis processes for SCR systems

Xubo Gan, Dongwei Yao, Feng Wu, Jiawei Dai, Lai Wei, Xingwen Li   

  1. Institute of Power Machinery and Vehicular Engineering, Zhejiang University, Hangzhou 310027, China
  • 通讯作者: Dongwei Yao
  • 基金资助:
    Supported by the National High Technology Research and Development Program of China (2013AA065301), the Fundamental Research Funds for the Central Universities (2016QNA4014), and the State Key Laboratory of Clean Energy Utilization at Zhejiang University (ZJUCEU2016006).

Abstract: A reliable mathematical model of urea-water-solution (UWS) droplet evaporation and thermolysis is developed. The well known Abramzon-Sirignano evaporation model is corrected by introducing an adjustment coefficient considering the different evaporation behaviors of UWS droplet at different ambient temperatures. A semidetailed kinetic scheme of urea thermolysis is developed based on Ebrahimian's work. Sequentially, the evaporation characteristics, decomposition efficiency of a single UWS droplet and deposit formation are simulated. As a result, the relation of evaporation time, relative velocity, exhaust temperature and droplet initial diameter is presented. Synchronously, it indicates that temperature is the decisive factor for urea thermolysis. Different temperatures result in different deposit components, and deposit yield is significantly influenced by temperature and decomposition time. The current work can provide guidance for designing urea injection strategy of SCR systems.

Key words: SCR, UWS evaporation, Urea thermolysis, Semi-detailed kinetic, Simulation

摘要: A reliable mathematical model of urea-water-solution (UWS) droplet evaporation and thermolysis is developed. The well known Abramzon-Sirignano evaporation model is corrected by introducing an adjustment coefficient considering the different evaporation behaviors of UWS droplet at different ambient temperatures. A semidetailed kinetic scheme of urea thermolysis is developed based on Ebrahimian's work. Sequentially, the evaporation characteristics, decomposition efficiency of a single UWS droplet and deposit formation are simulated. As a result, the relation of evaporation time, relative velocity, exhaust temperature and droplet initial diameter is presented. Synchronously, it indicates that temperature is the decisive factor for urea thermolysis. Different temperatures result in different deposit components, and deposit yield is significantly influenced by temperature and decomposition time. The current work can provide guidance for designing urea injection strategy of SCR systems.

关键词: SCR, UWS evaporation, Urea thermolysis, Semi-detailed kinetic, Simulation