Alternative Design Approach for Multipass and Multi-Stream Plate Heat Exchangers for Use in Heat Recovery Systems

This work presents an alternative approach for the preliminary design of plate and frame heat exchangers in complex flow arrangements and looks at the use of this type of exchanger in multi-stream applications. The need for a new design approach arises from the fact that most current design algorithms are industrially owned and thus are not readily available to the practicing engineer. The essential information required for the design of plate and frame heat exchangers are the heat transfer and friction performance data, which again are industrially owned. However, a few correlations for the most common type of plates have been reported in the open literature and, in this work, are used for the development of a design approach that exploits the concept of full utilization of allowable pressure drop. This method can be used as a first estimate for the determination of the surface area requirements of single-phase, two-stream heat exchangers. It is shown how the approach can be extended to the targeting and design of heat recovery systems or multi-stream exchangers where plate heat exchangers are a suitable option.