Preliminary evaluation of wet/dry cooling concepts for power plants

A large number of possible combinations of air and water flow arrangements and sequences are analyzed. The heat tranfer effectiveness of each was established, based on the assumption of constant size of the dry and wet subsystems. The water consumption required to augment a constant-sized dry subsystem for maintaining cooling capability at a dry bulb temperature in excess of the design conditions for the dry system alone was determined. Results are presented which point to a number of significant conclusions relative to the preferred arrangement of the dry and wet subsystems in dry/wet heat rejection systems. The conclusions are based on the assumption that the wet cooling is used only to augment the dry cooling capability and that minimum consumption of water is a primary consideration.