Significance of spectral radiation properties for the design of thermal plants

摘要

For the design of thermal plants the radiative heat transfer is usually calcualted by means of grey, i.e. non-spectral, approaches. The aim of the investigatyion described herein is to verify the differnces between these grey approaches and the exact spectral approaches in principle. For that first measurements of spectral emissivities of the concerning mjetallic and refractory materials were carried out. Afterwards a simplified mathematical model of radiation heat transfer in industrial furnaces was developed. By using the measured emissivities calculations for typical configurations of industrial furnaces were performaed. The results show that, dependent on the configuration, considerable differences between spectral and grey approaches amy occur.