On the hot-spot-controlled critical heat flux mechanism in pool boiling of saturated fluids
In this paper, we further investigate the hypothesis that the critical heat flux (CHF) occurs when some point on the heated surface reaches a high enough temperature that liquid can no longer contact that point, resulting in a gradual but continuous increase in the overall surface temperature. This hypothesis unifies the occurrence of the CHF and the quenching of hot surfaces by relating both to the same concept, i.e., the ability of a liquid to contact a hot surface. We use a two-dimensional transient conduction model to study the boiling phenomenon in the second transition region of saturated pool nucleate boiling on a horizontal surface. The heater surface is assumed to consist of two regions: a dry patch region formed as a result of complete evaporation of the thinner liquid macrolayers and a two-phase macrolayer region formed by numerous vapor stems penetrating relatively thick liquid macrolayers. The constitutive relations used to determine the stem-macrolayer configuration in the two-phase macrolayer region of the boiling surface were reevaluated for Gaertner`s clean water and water-nickel/salt solution. 29 refs.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 10137585
- Report Number(s):
- LA-UR-92-756; CONF-9203122-2; ON: DE92011352
- Resource Relation:
- Conference: Engineering Foundation conference on pool and external flow boiling,Santa Barbara, CA (United States),22-27 Mar 1992; Other Information: PBD: [1992]
- Country of Publication:
- United States
- Language:
- English
Similar Records
Unifying the controlling mechanisms for the critical heat flux and quenching: The ability of liquid to contact the hot surface
Unifying the controlling mechanisms for the critical heat flux and quenching: The ability of liquid to contact the hot surface