Thermo-hydraulic design of single and multi-pass helical baffle heat exchangers

• Shortcut design approach for helical baffle exchangers.
• Design of single and multipass units.
• Correction factor determined using the thermal effectiveness-Ntu model.
• Complex internal flows modelled as a network of simple flow arrangements.

A shortcut sizing approach for single and multipass heat exchangers with helical baffles is presented. An alternative approach for the determination of the correction factor of the logarithmic mean temperature difference as a function of the number of heat transfer units is introduced. Multipass arrangements give rise to complex internal heat flow paths; in this work, such flow paths are modelled using a simplified methodology that breaks up the complex flow and represents it as a network of simple arrangements such as counter flow and parallel flow. The network is solved to determine the outlet temperatures from where the correction factor is determined. The methodology is demonstrated on case studies from the open literature.