Boiling Superheat Correlation

A correlation of boiling heat transfer coefficients was reported in ANL-5260 under the dimensionless groups of 

The same dimensionless groups when employed in an analysis of the U.C.L.A. and M.I.T. local boiling superheat data resulted in a new correlation for the wall superheat of Atgg. The proposed correlation for pressure ranges from 250 to 2500 psia is 

Buchberg, R, Bromberg, Final Report on Studies in Boiling Heat Transfer, University of California, COO-24, March,, 195,1. 

Rohsenow, J. A, Clark, Heat Transfer and Pressure Drop Data for High Heat Flux Density to Water at High Subcritical Pressures, Office of Naval Research Technical Report No. 3, April, 1951. 

SUPER-IMPOSED OSCILLOGRAPH TRACES SHOWING COMPARISON BETWEEN WALL TEMPERATURE OF DRY TUBE AND WATER-FILLED TUBE 

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The nucleate boiling superheat AT has been described as a function of the heat flow-density complex equations. There exist essentially tw o kinds of boiling correlations the transport equations valid for a special configuration and equations closely related to the equilibrium thermodynamics of quasi-static systems. The transport equations determine the details of the heat transport mechanism with consideration of the force field and special conditions of each particular system, but they are so complex that it is difficult to arrive at satisfactory equations which will be valid in the entire range of pressures from the triple to the critical point. 

Likewise, the microscopic heat-transfer term takes accepted empirical correlations for pure-component pool boiling and adds corrections for mass-transfer and convection effects on the driving forces present in pool boiling. In addition to dependence on the usual physical properties, the extent of superheat, the saturation pressure change related to the superheat, and a suppression factor relating mixture behavior to equivalent pure-component heat-transfer coefficients are correlating functions. 

Fluid-Specific Correlations. Since water is the most widely boiled fluid in forced convection (i.e., in power generation systems), it was natural that correlations specific to water were developed at an early stage. Perhaps the best known of such correlations is that of Jens and Lottes [252], which relates the wall superheat to the heat flux and pressure as follows... 

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