Heat Exchangers

Table of Contents

Heat exchangers are devices that are used to transfer heat between two flows (liquid or gas) without physically mixing them. This is done by having a physical barrier between them which acts as the medium to transfer the energy from one flow to the other. There are many different types of heat exchangers mainly because there are a variety of ways each design fulfills its purpose [1].

A double pipe heat exchanger is a simple design in which one pipe is held concentrically inside a larger one. The inner pipe acts as the conductive barrier between the fluid flowing within the inner pipe and inside the larger pipe [1].

For some background theory including equations and calculations, visit the link https://cheguide.com/double_pipe.html.

Plate and Frame heat exchangers are designed by stacking together plates which create a high turbulence and wall sheer stress, which both intern lead to a high heat transfer coefficient and high fouling resistance. The two fluids are fed into alternating plates and flow counter currently. The fluid with higher temperature travels up down one plate while the colder fluid travels up the neighboring plates [3].

An important note is the plate and frame heat exchangers can be externally insulated to reduce heat loss, which are usually removable. This is because plate and frame heat exchangers are regularly maintained, so permanent insulation is not practical [3].

For some background theory including equations and calculations, visit the link https://www.alfalaval.com/microsites/gphe/tools/calculation-method/. 

The shell and tube design has tubes containing a fluid housed within an outer cylindrical shell containing another fluid. The inner tubes are made out of a conductive material as to increase heat transfer between the two fluids. The surface area of the tube is determined by the tube bundle (the number of tubes), which dictates the hat transfer between them [5].

For a more extensive outline into specific measurements and header types of shell and pipe heat exchangers, check out the link. https://thermopedia.com/content/1121/

Spiral Heat Exchangers use two long metal plates that are rolled around a central core to create two fluid passages. The plates are welded at their ends to keep the liquid in its subsequent container [7].

For some background theory including equations and calculations, visit the link https://www.thermopedia.com/content/1144/