Entropy generation analysis and cooling time estimation of a blast furnace in natural convection environment

Abstract

The overarching aim of this study is to evaluate entropy production and estimate the cooling time of the a furnace. A computational investigation is carried out to calculate the free convection from the blast furnace with variation in its cross-sectional area. The various relevant parameters are changed, such as different Rayleigh numbers fluctuating from 10+4 to 10+7, the wall temperature of the cylinder varying from 375 K to 600 K, and the unitless ratio of cylinder length to the maximum diameter L/D (values varies between 3.24 to 5.4). The ANSYS Fluent 18 is used to simulate the present problem. In this study, the entropy production estimated by fluid friction and heat transfer, and related irreversibilities are quantified. The heat transfer decreases with increase in unitless ratio L/D and Rayleigh numbers for the given temperature. It is also observed that the heat transfer and fluid friction irreversibilities reduce when L/D increases. The schemes of static temperature and entropy generation are made to understand the thermodynamic pattern. Furthermore, the standpoint of thermodynamic first and second laws is embodied in the merit function (I/Q) to evaluate thermal performance. The lumped capacitance approach is adopted to measure the cooling time of the choosen geometry. � 2022 Taylor & Francis Group, LLC.