Experimental and numerical analysis of radiative entropy generation in industrial and boiler furnaces

Abstract

In this paper, based on the radiative entropy generation formula and the inverse radiation analysis, experimental and numerical analysis of the radiative entropy generation in an oil-fired industrial furnace and a coal-fired boiler furnace is presented. The radiative entropy generation in two-dimensional enclosure solved by Discrete Ordinates method was verified by the second-law thermodynamics analysis. With the reconstructed temperature distribution and radiative properties through the inverse radiation analysis, the radiative entropy generation in the furnace and total net radiative heat on the wall were given. The effects of temperature distribution and optical thickness on total net radiative heat and radiative entropy generation in the furnaces were analyzed. Numerical and experimental results proved, when the optical thickness is small, with the decrease of non-uniformity of temperature distribution of medium, the radiative entropy generation due to radiative processes of medium decreases, and total net radiative heat on the wall also decreases which causes the decrease of the radiative entropy generation due to radiative process on the wall. However, when the optical thickness is large, with the decrease of non-uniformity of temperature distribution of medium, the radiative entropy generation due to radiative processes of medium decreases, but total net radiative heat on the wall increases which causes the increase of the radiative entropy generation due to radiative process on the wall.