Essay On Heat Transfer

1.1 GENERAL BACKGROUND

Heat transfer is by virtue thermal energy stored in temperature-dependent motion of particles. The exchange of kinetic energy of particles occurs through the boundary between two systems which are at different temperatures from each other or from their surroundings. Heat transfer constantly occurs from a region of high temperature to the region of lower temperature. Heat transfer changes the internal energy of both systems according to the Thermodynamics. The Second Law of Thermodynamics defines the concept of thermodynamic entropy. Heat transfer is the study of thermal energy transport within a medium or among neighboring media by molecular interaction, fluid motion, and electro-magnetic waves, resulting from a spatial

in chemical operations, minimization of building heat losses using improved insulation techniques, thermal control of space vehicles, heat treatment of metals, dispersion of atmospheric pollutants. A thermal system contains matter or substance and this substance may change by transformation or by exchange of mass with the surroundings. To perform a thermal analysis of a system, we need to use thermodynamics, which allows for quantitative description of the substance. This is done by defining the boundaries of the system, applying the conservation principles, and examining how the system participates in thermal energy exchange and

Convection more likely occurs with a greater variation in density between the two fluids, a larger acceleration due to gravity that drives the convection through the convecting medium. Radiation describes any process in which energy emitted by one body travels through a medium or through space absorbed by another body. Radiation occurs in nuclear weapons, nuclear reactors, radioactive radio waves, infrared light, visible light, ultraviolet light, and X-rays