Performance evaluation of a walking beam type reheating furnace based on energy and exergy analysis

Abstract

A walking beam type reheating furnace with advanced control technology has been evaluated by combined energy and exergy analysis. In order to gain insight into the performance of the present furnace, the results of energy analysis are compared with those in published papers and the irreversibility of the furnace is analyzed via exergy destruction calculation. The results show that slabs preheated before charged into the furnace can save fuel and improve energy utilization. The structure and material of the wall and roof show good thermal insulation. However, the oxidized scale is a little more and the temperature of flue gas is high in the present reheating furnace. The energy efficiency of the furnace is 71.01%, while exergy efficiency is 51.41%, indicating a potential for energy-saving improvements of the present furnace. The exergy destruction of the furnace accounts for 28.36% of total exergy input which is mainly caused by heat transfer through a finite temperature difference (14.71%), fuel combustion (11.66%) and scale formation (1.99%).

Optimization of Exergy Efficiency in a Walking Beam Reheating Furnace Based on Numerical Simulation and Entropy Generation Analysis

“…J. Zhao et al [8] investigated process matching and waste heat recovery measures by establishing an energy and exergy flow model for the hot rolling process. W. Rong et al [9] investigated the influence of slab oxidation on exergy efficiency.…”