we are designing a STHX . To design an exchanger to subcool codensate from methanol condenser from 95°C to 45°C. Flow rate of methanol = 200000kg/hr. Brackish water will be used as coolant with temperature rise from 25°C to 40°C. (Using Kerns Method)
The shell of a shell and tube heat exchanger is typically designed using the pressure vessel code. In that case only the maximum expected pressure and temperature are factors in design.
Since you are designing STHX, The Shell of heat exchanger does not form the main heat transfer surface area. It only loose some heat in to the atmosphere. Hence heat transfer calculations are ruled out. The major consideration is Corrosion rate and life time. For the normal shell materials with normal flow velocity The maximum corrosion rate is 5mm/year. At the end of life time also system integrity should not fail means it should have structural strength too. So the minimum wall Thickness is Corrosion Rate X Life in Years X Factor of Safety = Thickness in mm.
