HEAT-TRANSFER BY NUCLEATE POOL BOILING - GENERAL CORRELATION-BASED ON THERMODYNAMIC SIMILARITY

A 'general' equation for nucleate boiling heat transfer valid for various fluids is assumed to exist according to the hypothesis of thermodynamic similarity, modified by taking into account fluid specific parameters. The physical quantities are nondimensionalized in the new type of equation by fluid-specific scaling units being critical data or power products of critical data of the fluid. The equation and the fluid-specific reference values alpha0 of the heat transfer coefficient presented by Gorenflo for nearly 50 fluids are the empirical basis, to which the new equation is fitted. A resulting 'general' heat transfer correlation for nucleate boiling represents the reference values alpha0 of Gorenflo with a mean deviation of about 14%, depending on the number of fluid specific parameters taken into account for. The correlation is supposed to allow for estimating nucleate boiling heat transfer coefficients in poorly known fluids. Fluid properties at the actual boiling condition or specific reference values of the heat transfer coefficient are not required to apply the new type of correlation.