Critical thermal loads during the boiling of a saturated liquid in tubes

Abstract

Comparison of theoretical and experimental heat transfer data of various authors indicated that only the consideration of the hydrodynamic factors could lead to the derivation of generalized conclusions. For this reason the dependence of the critical heat load on various criteria in the case of the boiling of a nonviscous liquid in a large volume was examined on the basis of the hydrodynamic theory. Absence of sufficient data prevented consideration of the effect of the tube diameters on the critical heat flux during the flow of water-- steam mixtures through the tubes; all the data considered involve tests with tube diameters ranging from 6 to 10 mm, Comparison of the data of the various authors showed a divergence by a factor of 2 to 3, even though parameters such as flow rate, pressure, steam content of the liquid, and the tube diameters were identical. The piotted data indicate that when the steam content at the inlet point was equal to 0, the critical heat load remained constant but introduction of steam--water mixture resulted in an increase of the critical heat load. (TTT)