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Show Paper No 18 Prediction and Measurement of N O x and Combustion Characteristics in T wo Natural Gas Flames E.H. Chui\ P.MJ. Hughes* and CM. Mueller** *CANMET Energy Technology Centre, Natural Resources Canada, 1 Haanel Dr., Nepean, Ontario, Canada K 1 A 1M1 **Advanced Scientific Computing Ltd., 554 Parkside Dr., Unit 4, Waterloo, Ontario, Canada N2L 5Z4 ABSTRACT Given the need for simulation tools to enhance performance in industrial processes using natural gas as fuel, this study proposes a practical modelling strategy that can predict N O x and combustion characteristics in industrial-scale units. To quantify the confidence limit of this model, its prediction was compared with detailed pilot-scale measurements of major species composition, NOx , temperature and temperature probability-density-functions in two natural gas flames. The validation results indicate that the proposed model can provide good engineering estimates of N O x production and flame characteristics. Hence, it can be utilized for trend and sensitivity studies. Key Words: Modelling, Natural Gas Flames, NOx. INTRODUCTION Due to its clean burning characteristics, availability and competitive pricing, natural gas is the fuel of choice for a wide variety of combustion processes in Canadian industry. For performance enhancement and environmental assessment, there is a growing interest in utilizing mathematical tools like computational fluid dynamic (CFD) modelling to study design ideas and alternative options in operation. Despite many advances having been made in C F D , its reliability in simulating turbulent industrial flames cannot be easily generalized because currently available simulation codes still contain a lot of simplifications of the actual combustion process. A n informative current review on the challenge facing turbulent combustion modelling can be found in Bray (1996). The objective of this study is to compare the numerically simulated results with experimental pilot-scale measurements of N O x in two natural gas flames generated by commercially available industrial burners. The modelling approach discussed here is chosen with the criterion that it should easily be implemented in industrial-scale applications. The purpose of the study is to establish the accuracy of such a modelling approach in predicting N O x formation characteristics in industrial natural gas flames and hence, determine its usefulness in assessing the environmental impact of practical combustion units. |