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Kinetic and Multidimensional Transport Coupled Numerical Investigation of Nox Formation During Syngas and Natural Gas Combustion

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Kinetic and Multidimensional Transport Coupled Numerical Investigation of Nox Formation During Syngas and Natural Gas Combustion University of South Carolina Scholar Commons Theses and Dissertations Spring 2020 Kinetic and Multidimensional Transport Coupled Numerical Investigation of Nox Formation During Syngas and Natural Gas Combustion Sheikh Farhan Ahmed Follow this and additional works at: https://scholarcommons.sc.edu/etd Part of the Mechanical Engineering Commons Recommended Citation Ahmed, S. F.(2020). Kinetic and Multidimensional Transport Coupled Numerical Investigation of Nox Formation During Syngas and Natural Gas Combustion. (Doctoral dissertation). Retrieved from https://scholarcommons.sc.edu/etd/5672 This Open Access Dissertation is brought to you by Scholar Commons. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. KINETIC AND MULTIDIMENSIONAL TRANSPORT COUPLED NUMERICAL INVESTIGATION OF NOX FORMATION DURING SYNGAS AND NATURAL GAS COMBUSTION by Sheikh Farhan Ahmed Bachelor of Science Bangladesh University of Engineering & Technology, 2008 Master of Science Bangladesh University of Engineering and Technology, 2010 Submitted in Partial Fulfillment of the Requirements For the Degree of Doctor of Philosophy in Mechanical Engineering College of Engineering and Computing University of South Carolina 2020 Accepted by: Tanvir I. Farouk, Major Professor Bihter Padak, Committee Member Sang Hee Won, Committee Member Jamil A. Khan, Committee Member Cheryl L. Addy, Vice Provost and Dean of the Graduate School © Copyright by Sheikh Farhan Ahmed, 2020 All Rights Reserved ii DEDICATION This thesis is dedicated to my parents whose persistent support and inspiration helped me in every step of my career and worked as magic get through all the difficulties that I faced in the long journey towards this highest academic degree. iii ACKNOWLEDGEMENTS The author of this thesis expresses his sincere gratitude towards his family, colleagues, faculty members and co-authors for their unconditional support and sacrifice in this long journey of the Ph.D. study. The author would like to mention a few names to acknowledge them as a token of appreciation. First of all, I would like to thank my Dissertation Committee members (Dr. Bihter Padak, Dr. Sang Hee Won, and Dr. Jamil Khan) for their suggestion, constructive comments and most importantly, for their time that they gave me to enrich this thesis work. I received a huge round of appreciation from many educators and scientists around the globe for my new model. It would not be possible without them. Besides, I will never forget the departmental staffs (Ms. Misty O’Donnell, Ms. Lalitha Ravi and Ms. Renee Jenkins) who made my journey a smooth one with their assistance. During this long journey, I spent a wonderful time with my colleagues in the ReActing Systems and Advanced Energy Research (RASAER) lab. All the useful discussions, and friendly conversations were inspiration for me. I am highly blessed working with such a wonderful, cooperative and wise team of researchers. In addition to this, financial support is another important factor for a Ph.D. researcher. I would like to thank my federal and private funding agencies. I am glad to mention the name of an educator- Dr. Frederick L. Dryer who, not only shaped my knowledge in combustion and chemical kinetics through useful discussion, but iv also taught me the philosophical aspects of science. I feel honored having Dr. Dryer in most of my scientific publications as my coauthor, whose unique way of disseminating scientific ideas is worth learning. I am also thankful to my wife Badrunnessa Sultana and my son Faaiz Saalif Ahmed for their support in this tough journey. They stood as my backbone during the most difficult parts of this journey and supported me persistently to overcome them. My parents (Abdus Sattar and Sabiha Begum) were my motivation and resort to love whenever needed. No words can explain the sacrifices they made throughout their life to show me the way to reach my goals. You are and always will be my inspiration. Finally, my sincere gratitude is for my Ph.D. supervisor and mentor- Dr. Tanvir Farouk, whose care, support, guidance and motivation helped me to become an independent researcher. I am truly honored working with his amazing personality, who not only directed me towards my goal by his mentorship, but also supported me in every aspects of life. Thank you. v ABSTRACT The primary objective of this thesis work is focused on the chemical kinetic modeling of the formation of Oxides of Nitrogen (collectively termed as NOx), regarded as a major pollutant emitted by combustion devices, and the application of that model to simulate transport coupled multidimensional distribution of NOx in a reacting flow. The underlying motivation of this kinetic modeling is the noted discrepancies among the existing models, which become critical in selecting the correct model in advanced gas turbine and engine research. The first part of this work is the performance evaluation and comparison of the existing models. Based on their performances, an updated kinetic model is proposed to predict NOx emission during syngas combustion. The proposed model performs reasonably well against global as well as detailed validation targets over a wide range of temperature, pressure and fuel loading. The second part is the extension of the kinetic modeling to simulate NOx formation during natural gas combustion. This extension is focused to predict emission characteristics during natural gas combustion in gas turbines and engines. In addition to the available literature data, the performance of the extended chemical kinetic model is also tested against new experimental measurements on flow reactors, provided by one of our collaborators. The third part of this work evaluates the performance of the proposed chemical kinetic model to predict multi-dimensional experiments. A pressure based finite volume code under OpenFOAM platform is utilized to simulate the experiments involving McKenna burner driven flow reactor configuration. The model is capable to capture the vi flat flame and post flame structure. The predictions identify an oscillatory pattern of the reacting flow inside the flow tube, dictated by the constantly evolving recirculation zone, originated from the back-flow dilutions. A methodology is proposed to minimize NOx emission by the application of external electric field. The final part of this work reports simulation results on the influence of DC driven radial electric field on the emission characteristics of NOx and CO for premixed CH4/air jet flame. The simulations are conducted over a range of equivalence ratio and jet flow rate for a configuration representative of a test-scale experimental setup. Over the entire range of flowrate conditions, both the stoichiometric and rich fuel-oxidizer mixture showed a decrease in maximum NOx in presence of electric field. For CO emissions, the presence of electric field reduces the concentration under fuel rich conditions and vice versa for stoichiometric flame. Another feature of this modeling work is the utilization of both homogeneous and transport-dependent experimental validation targets. The performance of the model shows reasonably well against various experimental venues. vii TABLE OF CONTENTS DEDICATION ................................................................................................................... iii ACKNOWLEDGEMENTS ............................................................................................... iv ABSTRACT ....................................................................................................................... vi LIST OF FIGURES ........................................................................................................... xi CHAPTER 1 INTRODUCTION .........................................................................................1 1.1 PROBLEM STATEMENT ................................................................................2 1.2 ORGANIZATION OF THE THESIS WORK ..................................................8 1.3 PEER-REVIEWED PUBLICATIONS ..............................................................9 CHAPTER 2 COMPUTATIONAL STUDY OF NOX FORMATION IN SYNGAS COMBUSTION AT ELEVATED PRESSURE ................................................................12 2.1 ABSTRACT .....................................................................................................13 2.2 INTRODUCTION ...........................................................................................13 2.3 DETAILED MECHANISM FORMULATION APPROACH ........................17 2.4 MODEL PERFORMANCE .............................................................................21 2.5 SUMMARY .....................................................................................................44 CHAPTER 3 KINETIC MODELING OF NOX FORMATION FOR SYNTHETIC NATURAL GAS COMBUSTION UNDER GAS TURBINE RELEVANT CONDITIONS ...................................................................................................................46 3.1 ABSTRACT .....................................................................................................47 3.2 INTRODUCTION ...........................................................................................48 viii 3.3 DETAILED MODEL FORMULATION APPROACH ..................................51 3.4 EXPERIMENTAL SETUP AND PROCEDURES .........................................55 3.5 MODEL PERFORMANCE BASED ON VPFR EXPERIMENTAL
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