the ENGINEERING page
Information about: Typical Overall Heat Transfer Coefficients ( U )
The thermal design of a heat exchanger is a trial and error process as there are many possible designs that will be able to transfer the required amount of heat from the hot to the cold fluid. This requires a first design to be evaluated by calculations and then optimized. For this a first estimate of the overall heat transfer coefficient is needed, which is provided by this tabulation. The calculations that follow this preliminary design are elaborate. Manual calculations take a lot of time and need to be checked for correctness. To optimise the design quickly, easily and accurately there is expensive software on the market that will do the calculations for you. The engineering page offers the calculation services free of charge, it will cover most of the industrial applications and will give clear warnings if your case is outside the range of the methods used. Additionally it is much easier to use.
So the method offered by the engineering page comprises:
• Use 'typical U - values' as a starting point
• Use 'shells in series / tentative sizing' for the preliminary design with this value
• Use 'thermal rating' to do the calculation work for the detailed thermal design