OCR Text |
Show INTRODUCTION Pulverized coal (PC) is extensively used in utility and industrial fossil boilers. The need to design more efficient combustion devices is quite clear since the energy shortage of the 1970s. The existing technology base for designing utility and industrial fossil boilers is primarily empirical and cannot be logically extended to study various effects (e.g., fuels, burner position and orientation, and boiler geometry) on system performance. Therefore, the technology base for PC combustion must be expanded if we are to better understand the complex combustion processes and eventually build more efficient combustion devices. One such way in which the fundamental aspects of combustion devices can be understood is through the application of computational methods. Computational methods in heat transfer and fluid flow have been advanced to the point that such methods are being applied to the simulation of complex - yet practical - combustion systems. These computational tools will ultimately be used by the designer to accurately determine the performance in the conceptual design stage. The first such computational method for PC corabustors was due to Gibson . Recent studies by Richter and Fleischhans ' , Lockwood, et al. , and Smith and Smoot have employed more sophisticated techniques and have demonstrated promise in predicting PC combustor performance. The present work is motivated by the need to improve understanding of the complex combustion processes by prediction methods and is distinguished by a highly organized program structure integrating the complex processes for fluid flow, radiation heat transfer, particle transport, turbulence, chemistry, combustion, etc., that permits updating physical models as new models become available. |