Experimental Research And Mathematical Modeling Of SCR DeNO_x For Fossil-Fired Power Plant

Selective Catalytic Reduction (SCR) of NOx is the worldwide main technology for NOx control of flue gas from coal-fired power plant at present and even in the quite long time.Along with the fast development of economy, the growth of electric power demand and strengthening of environmental protection, the market demand of SCR DeNOx technology increases continually in China. In the period of'10th five year', the research and development of SCR DeNOx technology was placed on the national program of the research and development of science and technology of China. The work in the thesis is the main part of the sub-project of Hi-Tech Research and Development Program of China ('863 Program') of'10th five year'-'Flue Gas Cleaning Technology of Large Scale Coal-Fired Power Plant'.The present paper work takes the practical application of SCR technology as the research goal, takes the design and operation of the technology as the core of research. The works consist of experimental research of laboratory-scale and pilot-scale on SCR DeNOx, experimental research on flow and mixing of gas in reactor, mathematical modeling and simulation of SCR process, research on operation characteristics of SCR reactor and design analysis of SCR reactor.The main achievements of innovation obtained in the present paper work are as follows:(1) Mathematical modeling of SCR DeNOx processA mathematical model of SCR DeNOx process is established based on the test data of macroscopic reaction properties of catalyst obtained in the experiment of laboratory-scale and the mechanism of SCR DeNOx, and the corresponding computer software is developed. Combining the numerical solution of the partial differential equation with the non-restraint nonlinear optimization algorithm, a calculating procedure of key parameters of SCR DeNOx model is proposed which only uses macroscopic reaction data of SCR DeNOx. By means of this method, operation data of actual SCR DeNOx system can be directly used in the SCR mathematical model.(2) Research of mixing and flow-uniforming technology of gas in SCR reactorThe static mixer and flow-uniformizer of gas are developed and their technical indexes reach the level of international convention, consequently lay a foundation for engineering application of SCR DeNOx system. Based on SCR mathematical model and probability description of reactant non-uniformity, a simulation analysis method of influence of reactant non-uniformity on DeNOx performance is proposed. This method may be used in the analysis of design and operation of SCR DeNOx system.(3) Analysis of design and operation analysis of SCR reactorThe SCR mathematical model is used to simulate the effect of gas parameter variation of boiler on the performance of SCR reactor and the operation characteristics of SCR reactor under variable working condition are revealed.Based on the SCR mathematical model and the catalyst deactivation model, the design and analysis method of the SCR reactor which takes the catalyst deactivation into account is proposed.Based on the SCR mathematical model and the probability distribution description of uncertainty of condition of the design and operation of SCR system, a simulation method is proposed to analyze the influence of uncertainty factor on SCR reactor performance.Above mentioned results of simulation and analysis is significant to guide the design and operation of SCR system.