Exergetic Analysis and Assessment of Industrial Furnaces

This study presents exergy analysis of a natural gas-fired radiant tube-heating furnace. In the analysis, actual data over a test period of 3 h were used. Exergy efficiencies, destructions, losses, and entropy generation of the furnace were determined. For an average furnace temperature of 666.6°C, average exergy efficiency value was calculated to be 9.6%. The exergy destruction rate was obtained to be 5.34 kW while exergy rates of the flue gases, exergy losses, and exergy steel were 12.53 kW, 44.28 kW, and 6.6 kW, respectively. On the other hand, the exergy rate of the product (steel) was found to be between 4.61 kW and 9.88 kW over the 15 min test periods, and it reached a maximum rate at the end of the second hour.