Heat Exchanger Research Paper

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1.1 Heat exchangers One of the important processes in engineering is the heat exchange between flowing fluids. Heat exchanger is a device used for the process of heat exchange between two fluids that are at different temperatures. Heat exchangers are one of the mostly used equipments in the process industries. One can realize their usage that any process which involves cooling, heating, condensation, boiling or evaporation will require a heat exchanger for these purposes. Process fluids, usually are heated or cooled before the process or undergo a phase change. Different heat exchangers are named according to their applications. For example, heat exchangers being used to condense are known as condensers, similarly heat exchangers for boiling…show more content…
It is the most common type of heat exchanger in oil refineries and other large chemical processes, and is suited for higher-pressure applications. Shell and tube heat exchangers are built of round tubes mounted in large cylindrical shells with the tube axis parallel to that of the shell. These are commonly used as oil coolers, power condensers, pre-heaters and steam generators in both fossil fuel and nuclear-based energy production applications. They are also widely used in process applications and in the air conditioning and refrigeration industry. They have larger heat transfer surface area to volume ratio than the most of common types of heat exchangers, and they are manufactured easily for a large variety of sizes and flow configurations. The shell-and-tube heat exchangers consist of a bundle of tubes enclosed within a cylindrical shell. One fluid flows through the tubes while the second fluid flow space between the tubes and shell. In shell and tube heat exchanger, the shell side stream flows across between pairs of baffled, and then flows parallel to the…show more content…
Extended or enhanced surface tubes are used when one fluid has a substantially lower heat transfer coefficient than the other fluid. Most recent developments are, a corrugated tube which has both integral inside turbulators as well as extended outside surface, and tubing which has outside surfaces designed to promote nucleate boiling. 1.4.2 Tube sheets The tubes are held in place by being inserted into holes in the tube sheet and there either expanded into grooves cut into the holes or welded to the tune sheet where the tube protrudes from the surface. The tube sheet is usually a single round plate of metal that has been suitably drilled and grooved to take the tubes, the gaskets, the spacer rods, and the bolt circle where it is fastened to the shell. However, where mixing between the two fluids must be avoided. The space between the tube sheets is open to the atmosphere so any leakage of wither fluid should be quickly detected. The tube sheet in addition to its mechanical requirements must withstand corrosive attack by both fluids in the heat exchanger and must be electrochemically compatible with the tube and all tube side material. Tube sheets are sometimes made from low carbon steel with a thin layer of corrosion-resisting alloy metallurgically bonded to one

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