Spectroscopy of Infrared Emission Characteristics of Thermal Power Plant Boiler Coal Ash Deposits

摘要

Thermal radiation characteristics of ash deposits on a coal combustion boiler of an electric power plant are investigated. Normal emittance spectra in 2.5-25μm wavelength region and total normal emittance are measured on four kinds of ash at 600～1100K in heating and cooling processes. Ash layers are opaque for infrared radiation in the heating process of the powder. Emittance increases with an increase of wavelength and temperature, irrespective of chemical composition. Total emittance decreases with an increase of temperature. Emittance of sintered layers is higher after the sintering. In an ash layer, semi-transparency occurs with the sintering. The results are summarized from a thermal engineering aspect to determine a quantitative direction for evaluating the thermal radiation characteristics in safety design of a boiler system.