Particular applications of infrared thermography temperature measurements for diagnostics of overhead heat pipelines
نویسنده
چکیده
Different parameters influence the results of infrared measurements of temperature. The emissivity of the surface under consideration as well as the temperature of the ambient elements may be specified among these parameters. Convective and radiative heat transfer takes place between thermal pipelines and its surrounding. In the case of low temperature of the sky, the radiation heat exchange is very intensive and the temperature of the top part of the horizontal pipeline is much lower than the bottom part. This phenomenon has been confirmed by calculations carried out by means of CFD Fluent. The aforementioned phenomenon causes difficulties during evaluation of the quality of the thermal insulation of the pipeline. Circumstances connected with this phenomenon have been recognised and explained in this paper. Examples of calculations have been made and the results have been presented. Denotations and subscripts Denotations Subscripts T temperature, K At atmospheric air ε emissivity G ground T ∆ difference of temperature, K S external shell of pipeline Sk sky
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