Vaporization Cooling for Power Transformers

1. Outstanding characteristics of vaporization cooling is its remarkable effectiveness. By vaporization and condensation of a fluorocarbon coolant, and for a given temperature difference, rates of heat transfer several times as great as in oil by free convection may be obtained. 2. Vaporization cooling of power transformers is made possible by the advent of inert fluorocarbon coolants, characterized by their chemical inertness, thermal stability, nontoxicity, and a high dielectric strength of their vapors. 3. Operating thermal characteristics of vaporization-cooled transformers present many unusual features. They depend greatly upon design, and particularly on the presence or absence of a noncondensable gas in the transformer tank. The paper presents a study of these characteristics made on a large commercial unit.