Heat exchangers can be defined as any devices that are used to transmit enthalpy — thermal energy, amid fluids, amid fluids and solid surfaces, or amid fluids and solid particulates, at diverse temperatures when these systems are in thermal interaction. There are typically not any outer heat and work contacts when working with heat exchangers. Distinctive uses include cooling or heating of fluids and condensation or evaporation of fluid. Additional applications may include recovering or rejecting heat, sterilizing, pasteurizing, fractionating, distilling, concentrating, crystallizing, or controlling a processing fluid. A few heat exchangers have fluids that exchange heat directly contacting each other. However, majority of the heat exchangers, heat transmission amid fluids occur through a separating partition or in and out through a partition in an ephemeral way, and fluids don’t leak or mix. Some of the examples include automobile radiators, shell and tube exchangers, evaporators, condensers, cooling towers and air preheaters (Abd & Naji, 2017).
The STHE is a kind of heat exchanger model and it is mostly used as heat exchanger in companies that refine oils and their products as well as in different processes that deal with chemicals. This is because this type of heat exchangers are best suited to operate under very high pressure. Just as the name suggests, this kind of heat exchanger is made up of a shell which basically a huge pressure container containing tube bundles inside.