Chemical Thermohydraulics of Steam Generating Systems

In steam generating systems, the concentration of solutes in contact with heat transfer surfaces, a decisive factor in determining the actual material corrosive environment, exceeds that of the bulk fluid. The ratio of the local to bulk concentration can vary from a factor of less than ten for normal boiling on clean surfaces to five or six orders of magnitude under dryout conditions. The literature of this important technological question is reviewed and the various models that have been proposed to explain and predict the concentration process are examined in terms of chemical and thermohydraulic fundamentals. The concentration process in thin porous deposits at high heat fluxes is still unresolved