Study of heat transfer in Shell and Tube heat exchanger.
Introduction:
Heat Exchanger is device that facilitates heat exchange between two or more fluids.
They are used wherever efficient heat energy transfer is required particularly petrochemical plants, petroleum refinery, natural gas processing, air conditioners and refrigerators, sewage treatment etc. Considering wide spectrum it swaps , the device is a necessity in most of the industrial applications.
Categorization:
Broadly Heat Exchanger can be classified in six types: (Ref. Shah 1981)
1)According to transfer process
• Indirect Contact Type
• Direct Contact Type
2)According to no. of fluids
• Two fluid
• More than two fluids
3)According to surface compactness
• Gas to fluid
• Liquid to Liquid and Phase Change
4)Construction Type
• Tubular
• Plate Type
• Extended Surface
• Regenerative
5)On basis of flow arrangements
• Single Pass
• Multipass
6)Heat Transfer Mechanisms
Theory:
Transfer type heat exchanger uses two fluids and head conduction is through the wall
(separation between two fluids). Transfer type heat exchanger is used in the lab, more specifically Multipass Heat Exchanger. One of the fluid passes through tube while the other uses shell as it 's transfer medium.
Principle used is conservation of Heat Energy.
Heat lost by the hot fluid (qh) =Heat gained by the cold fluid (qc) qh=mcCpc(Tco-Tci) Qavg=(qc+qh)/2
U=Qavg/(AaΔTm)
Experimental Setup
The experiment setup uses 1-2 Pass Shell and Tube heat exchanger. There are two types of flows- 1) Utility flow (hot water here)
2) Processed flow (tap water here)
Hot water is heated in a reservoir through heating coils and pumped through a magnet driven light duty pump into the tubes and cold water flows through shell. Fluid flow is controlled through the rotometer.
Technical Details(Lab Manual, Che 391)
Shell: Material SS, ID 146mm, length 500mm with 4, 25% cut baffles
Tube: 24 Nos, Material
References: J.P. Holman, “Heat Transfer”, 10th Edition Shah, 1981 McCabe, Smith, Hariott, “Unit Operations of Chemical Engineering Lab Manual CHE 391 Perry’s Chemical Engineering Handbook Data calculation through: Antoine.frostburg.edu/chem