Closed circuit heat exchange system and method with reduced water consumption

摘要

The heat exchange system (8) may be arranged as a fluid cooler or as a fluid condenser. Three heat exchange sections are provided: a dry indirect contact heat exchange section (16); a second indirect contact heat exchange section (28) that is operable in either a wet or dry mode; and a direct contact heat exchange section (76). At low temperatures, the system operates dry with primary heat extraction performed by the dry indirect contact heat exchange section (16). At higher temperatures, the air streams may be adiabatically saturated with evaporative liquid to pre-cool them below the dry bulb temperature before entering the dry indirect contact heat exchange section. At still higher temperatures, the apparatus may be operated in a wet mode with the primary heat extraction performed by the second indirect contact heat exchange section (28). Heat is extracted from the process fluid while selectively distributing or not distributing the evaporative liquid over the second indirect contact heat exchange section (28). <IMAGE>