INTRODUCTION
Background of the Study
Heat exchangers have been used extensively and play an important role in the capital cost, energy efficiency and physical size of refrigeration and air conditioning systems. In this dissertation, a simulation tools to improve effectiveness and efficiency in design, rating, and analysis of air to refrigerant heat exchangers including conventional finned tube coils and emerging micro channel heat exchanger, Coil Designers, is developed and investigated using a general-purpose modeling concept and user friendly interface.
The basic concept of a heat exchanger is based on the premise that the loss of heat on the high temperature side is exactly the same as the heat gained in the low temperature side after the heat and mass flow through the heat exchanger. Heat exchanger ‘simply’ exchanges the heat between those two sides; as a result, it is decreasing the temperature of higher temperature and increasing the temperature of lower temperature side. But designing heat exchanger might a challenge; it needs iteration for manual calculation.
Many factors have to be considered in heat exchanger selection. Generally suitability of types of heat exchanger to be used in processing industrials is selected based on TEMA (Tubular Exchanger Manufacturer Association) Standards. TEMA divides heat exchanger into classes based on their application.
A shell a tube heat exchanger is one of the standards designs of heat exchanger. It is most common types of heat exchanger in oil refineries and other large chemical processes, and it is suite for high pressure applications. As its name implies, this type of heat exchanger consists of a shell (a large pressure vessel) with a bundle inside the shell.
The basic principle of operation is very simply as flow of two fluids with different temperature brought into close contact but prevented from mixing by a physical barrier. Then the temperature between two fluids tends to equalize by transfer of heat through the tube wall. The fluids can be either liquids or gases or either the shell or the tube side. In order to transfer the heat efficiency, a large heat transfer area should be used, leading to the use of many tubes. In a way, waste heat can be put to use. This is an efficient way to conserve energy.
At this point the researcher conducted this study because of increasing the problem of the heat pollution and to minimize the consumption of energy.