A Heat Exchanger Is a Device Built for Efficient Heat Transfer From One Medium to Another

A Heat Exchanger is a device built for efficient heat transfer from one medium to another. A solid wall separates the media, so that they never mix, or they may be in direct contact. They are widely used in space heating, refrigeration, air conditioning, power plants, chemical plants, petrochemical plants, petroleum refineries, and natural gas processing. A Shell and Tube Heat Exchanger is a class of Heat Exchanger designs. It is the most common type of heat exchanger in oil refineries and other large chemical processes, and is suited for higher-pressure applications. As its name implies, this type of heat exchanger consists of a shell (a large pressure vessel) with a bundle of tubes inside it. One fluid runs through the tubes, and another fluid flows over the tubes (through the shell) to transfer heat between the two fluids. The set of tubes is called a tube bundle, and may be composed by several types of tubes: plain, longitudinally finned, etc. Shell and Tube Heat Exchangers are typically used for high-pressure applications (with pressures greater than 30 bar and temperatures greater than 260 C). This is because the shell and tube heat exchangers are robust due to their shape. Heat is transferred from one fluid to the other through the tube walls, either from tube side to shell side or vice versa. The fluids can be either liquids or gases on either the shell or the tube side. In order to transfer heat efficiently, a large heat transfer area should be used, leading to the use of many tubes. In this way, waste heat can be put to use. This is an efficient way to conserve energy. Source: hicow.com/heat-transfer