Optimal and critical values of geometrical parameters of shell and helically coiled tube heat exchangers

In the present study, calculations of the heat transfer and entropy generation have been performed for the steady state forced convection heat transfer in shell and helically coiled tube heat exchangers. The effect of geometrical parameters of the heat exchanger including: tube diameter (d t ), coil diameter (d c ), diameter of the inlet of shell (d v ), shell diameter (d sh ), height of the coil (H c ), height of the shell (H sh ), pitch (p) and the distance between the inlet and outlet of the shell (f) on the heat transfer rate and entropy generation has been investigated simultaneously. The critical and optimal values of these parameters have been obtained which minimize and maximize the COD (heat transfer rate per entropy generation), respectively.