Novel approach to proper design of combustion and radiant chambers

Abstract

Combustion and radiant chambers with inbuilt heat transfer surfaces are integral parts of a wide range of process and power equipment such as fired heaters, power boilers, or incinerator furnaces. Operating problems that many of these combustion chambers suffer from are typically due to the design procedures using data of insufficient accuracy regarding the calculated local heat transfer data in individual parts of the chambers equipped with modern low-NOx burners. These problems, obviously, force the designers to devise more accurate design procedures for the respective equipment. The paper therefore discusses the main results obtained so far in the course of a several years long research effort and presents a basic outline of an up-to-date, novel approach to proper design of combustion and radiant chambers with inbuilt heat transfer surfaces. The three most important and – considering the current design practice – also original components of the presented novel approach which significantly improve the quality of the resulting combustion chamber designs are (i) experimental determination of the actual burner heat flux distribution, (ii) determination of the actual fuel burnout profile of the burner from the obtained heat flux profile using the validated MPF model, and (iii) utilisation of the respective fuel burnout profile in the course of design of the combustion chamber and its inbuilt heat transfer surfaces together with calculation of the local heat flux distribution via the plug-flow-based method, thus replacing the currently used design methods based on the “well stirred” models.