Centrifugal Pumps In Liquid Recirculation Refrigeration Systems

The efficiency and operating flexibility advantages of liquid recirculation systems -- relative to direct expansion -- more than offset their added complexity in larger refrigeration systems. The basic elements of a liquid recirculation system, sometimes referred to as an overfeed system, are shown in Figure 1. As the term overfeed implies, much more liquid is fed to the evaporator than actually is vaporized. By overfeeding the evaporator, the coil inner surface is kept thoroughly wetted and has optimum heat transfer.