ABSTRACT
Physical modeling has been widely used in industry from geological studies to aerospace engineering to study complex fluid dynamics where engineering cal culations or computational fluid dynamics (CFD) are deemed either unreliable (the former) or uneconomical (the latter).1 In the field of combustion, physical model ing is employed in studying flow distribution involving combustion air, over-fire air (OFA), and flue gas recircu lation (FGR) as well as isothermal flows in combustion chambers of furnaces, boilers, heat recovery and steam
generators (HRSG), etc. Physical modeling is often used to study flow patterns prior to the commissioning of new furnaces and boilers to gain a better understanding of the flow characteristics and the interactions between various flow streams inside the combustion chamber and then to fine tune operating strategies and parameter settings. For burners with a common windbox or fur naces with a large number of burners (e.g., 520 burners) connected with extensive ductwork, physical modeling is routinely used to identify flow maldistributions and to engineer flow solutions through the use of internals such as turning vanes, baffles, splitters, kickers, etc., to ensure desired flow distribution and flow patterns.
