Extending the Use of Welded Plate Heat Exchangers to Multi-Stream Applications

Abstract

Compabloc is a trademark of Alpha Laval and is one of the most efficient types of welded plate compact exchangers (WPHE). Their construction features and thermal performance make this technology suitable for application in a wide range of temperatures and pressures. This work focuses on the compabloc type of welded plate and presents a conceptual extension of the design to the case of multi-stream applications. WPHE units are finding wider application in heat recovery systems due to their construction features that enable them to operate at high temperatures and pressures. Besides, the corrugated surfaces employed by this type of units create high heat transfer performance at the expense of increased pressure drop which makes them transmit the required heat duty within a smaller exchanger size compared with conventional geometries. Their geometrical characteristics make it suitable for applications where more than two streams can meet their thermal duties within the same structure. This paper presents the design considerations for the use of compabloc exchangers that handle multiple streams. The multi-stream capabilities can be potentially used in the reduction of the number of heat exchanger units in heat recovery networks. The paper looks first at a thermohydraulic approach for the design of compabloc exchangers based on the full absorption of the pressure drop, then the methodology is extended to the case of multi-stream applications. The approach is demonstrated on a case study.