STUDY OF HEAT TRANSFER MECHANISMS, FORMATION OF TEMPERATURE ANOMALIES AND DETERMINATION OF GEOMETRIC PARAMETERS OF FLUE PIPE LEAKS

Abstract

An analysis of modern foreign and domestic research and publications related to the causes of the formation of the main types of discontinuities and damage in the structural layers of the most common industrial chimneys in Ukraine, remote diagnosis of their technical condition by developing theoretical calculation models of temperature fields and models of temperature fields of artificial discontinuities in the structure was performed smoke pipe and passive thermal imaging method using modern thermal imagers. Based on the analysis of the essence of the heat transfer process in thermal non-destructive testing of industrial objects, it is shown that the main information parameter for the passive thermal imaging method is the local temperature difference between defective and defect-free zones on the surface of the controlled object.

The results of studies of heat transfer mechanisms are presented and the heat flow densities through the single-layer homogeneous and three-layer heterogeneous walls of the smoke pipe are determined, and the complete thermal resistances of the thermal conductivity of the constructive layers of the given cylindrical walls of the pipe are obtained. The mechanism of determining the initial temperature on the outer surface of the flue at any point during commissioning and its achievement of the standard mode at a given flue gas temperature is justified. Examples of the occurrence of discontinuities in one and three structural layers of a three-layer chimney structure ("defect over defect" principle) and the mechanism of formation of anomalies on the outer surface of the chimney in the form of histograms of the temperature field are given.

The principle of implementation of the method of thermography of the outer surface of the smoke pipe by the remote passive thermal imaging method and the determination of the sizes and shapes of histograms of anomalies of the temperature field and the geometric parameters of pipe discontinuities when diagnosing its technical condition are considered.