Shell and Tube Heat Exchangers
The following section will discuss different types of heat exchangers. The researcher can read through this link it describes in detail the different types of heat exchangers.
A video showing a Shell Tube Heat exchanger:
Another good visual video
The following image is not by me but used as a link to search Google for images relating to shell and tube heat exchangers
Pressure losses due to friction occurs through out the heat exchanger interior that is for both used fluids. Leading to both a decrease in flow velocity and a drop in flow pressure. The use of the continuity equation is to calculate flow rates. You will need to use the Bernoulli equation for the single stream problems such as the pipes. But for the heat exchanger application will only give you a acceptable estimate of the expected outlet velocity by using the volume integration method for the Bernouli equation.
The classical form of the continuity equation cannot be used for the heat exchanger problem .Because it doesn’t represent a single stream problem. Single stream problems are encountered in pipes and ducts. While none single stream problems require numerical methods and that’s where the power of CFD comes. None single stream problems occur in soils, blood flows and turbulence. Yes mass conservation is achieved. This means you can only use the continuity equation after you have calculated the velocities and pressures using another method, such as the momentum conservation method. In addition you will have to use the volume integral form of the continuity equation. Because if you integrate throughout the inner control surfaces of the heat exchanger there will be a change in the flow cross section.
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