The distribution of heat loads to heat exchanging surfaces in process furnaces (fired heaters, boilers) is an important factor influencing efficiency of the process as well as lifetime of the unit. This work compares two heat flux measurement methods in a controlled environment of large-scale laboratory combustion facility. The experiment makes use of a low-NOx burner firing natural gas at 745 kW thermal duty. Heat fluxes are measured firstly by a water-cooled Schmidt-Boelter sensor (Hukseflux SBG01), which represents the typical approach applied in industrial practice. Second method is based on segmental design of water- cooled walls of the combustion chamber. The latter method provides total heat flux measurement on the process medium side and has several advantages over the standard method. This paper provides a comparison of heat flux distributions measured by the two methods as well as a quantitative analysis of the strong and weak points of both methods. Researchers and practitioners alike should find this paper helpful in interpretation of measured heat flux data.
