Theoretical Derivation of Thermal Value Equations for Heating Furnaces

Hainan Wu, Wenqiang Sun, Jiuju Cai

Institute of Thermal and Environmental Engineering, Northeastern University, Shenyang, China.

DOI: 10.4236/ojapps.2012.22014                

Abstract

Based on thermal value theory, the aim of this paper is to deduce the theoretical formulas for evaluating the energy effective utilization degree in technological pyrological processes exemplified by metallurgical heating furnaces. Heat transfer models for continuous heating furnaces, batch-type heating furnaces, and regenerative heating furnaces are established, respectively. By analyzing the movement path of injected infinitesimal heat attached on steel or gas, thermal value equations of continuous, batch-type, and regenerative heating furnaces are derived. Then the influences of such factors as hot charging, gas preheating and intake time of heat on energy effective utilization degree are discussed by thermal value equations. The results show that thermal value rises with hot charging and air preheating for continuous heating furnaces, with shorter intake time when heat is attached on steel or longer intake time when heat is attached on gas for batch-type heating furnaces and that with more heat supply at early heating stage or less at late stage for regenerative heating furnaces.

Keywords

Thermal Value; Continuous Heating Furnace; Batch-Type Heating Furnace; Regenerative Heating Furnace;Energy Utilization Degree; Heat Transfer

Conflicts of Interest

The authors declare no conflicts of interest.

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