Heat Transfer Fundamentals

Abstract

In this chapter, the basics of heat conduction and transfer are discussed. The chapter contains 29 exercises, which illustrate Fourier Law, the solving of heat transfer coefficients for multi-layered flat and cylindrical partitions, the determination of a quasi-steady-state temperature field and the computation of a radiant tube temperature in boilers. Critical thickness of thermal insulation on the surface of the cylindrical tube is first determined analytically, then calculated. The methods for solving selected inverse steady-state heat conduction problems, which occur during heat flux measurement carried out by means of different types of sensors, are presented here. A great deal of attention is paid to the determination of temperature distribution and the efficiency of simple, circular, rectangular and hexagonal fins. The calculation results of efficiency in complex-shape fins, determined by means of an equivalent circular fin method and segment method, are compared with the results obtained from FEM. Examples that illustrate the computation of a heat transfer coefficient in pipes finned longitudinally and crosswise are presented here as well. Three exercises deal with the way steady-state temperature distribution is determined using control volume method. These exercises present the methods for solving problems and the computational programs used. In the last exercise of this chapter, temperature distribution and circular fin efficiency is determined under the assumption that thermal conductivity of the fin’s material is temperature dependent.