Shell and Tube Heat Exchanger

Shell and Tube Heat Exchanger Contents

1 Theory and Application
2 Shell and tube heat exchanger design
2.1 Selection of tube material
2.2 Applications and Uses
THEORY AND ITS APPLICATION
In the process of shell tube heat exchanger each fluid flows at different initial temperatures. The fluids can be either fluids or gases. These fluids flow occurs in the tubes within the shell. One of its fluid flows through the tube and the other flow outside the tube. One fluid transfers heat to the other through the surface walls of the tube. This happens either from tube to shell or vice versa. For better outcome the transfer of heat can be practiced in a large surface area with the use of many tubes and this leads way to use the extra heat. This is one of the conservative ways to save energy and practice an effective heat transfer.
The heat transfers through only one mode, that is with use of either liquid or gas. This is known as one phase or single phase heat transfer. The other type is two-phase heat exchangers where the state of the fluid is changed from either liquid to gas called boilers or from solid to gas called condensation and this takes place in the shell side. The process of conversion from liquid to gas occurs by heating a liquid to its boiling state to gas. Whereas the process of gas to liquid occurs by cooling vapor to its freezing point to condenser it into liquid. The types of machines used for boiling steam engines locomotors are more adversely large mostly cylindrically-shaped shell-and-tube heat exchangers. The shell and tube surface condensers are also used in the major power plant where the exhaust steam from the turbines are condensed to condensate water later it is recycled back into steam using steam generator.
SHELL AND TUBE HEAT EXCHANGER DESIGN
The shell and tube heat exchanger design of the tube can be of various shapes mostly the ends of the tubes would be interconnected through holes in tube sheets called Plenums (otherwise called water boxes). The design can either be of ‘U’ patter known as U tubes or in a straight pattern.
These ‘U’ pattern shell and tube heat exchanger can be seen in nuclear power plants know as pressurized water reactors and large heat exchangers called steam generators with two-phase. It can be used to generate power by boiling recycled water from surface condenser into steam which in turn drives a turbine. Mostly the shell and tube heat exchangers will have 1, 2 or 4 opening on the sides of the tube. In case of a shell tube with a single opening the fluid passes from one end of the tube to the other end.