The effect of certain geometrical factors on dryout for high quality steam/water mixtures flowing in a vertical internally heated annulus at 1000 psia

Conference · Tue Jan 01 04:00:00 EST 1963

OSTI ID:4875400

Collier, J. G.; Wikhammer, G. A.; Moeck, E. O.; Macdonald, I. P.L.

Measurements have been made of the dryout'' heat flux (a term introduced to describe the critical'' or burnout'' heat flux for high steam qualities) for steam/water mixtures in the annular and dispersed flow patterns at 1000 psia. The test section consisted of an electrically heated element 0.6-in. OD having a length of either 19 in. or 29 in. located centrally inside a vertical 0.825-in. ID tube. Steam/ water mixtures were formed by spraying water into slightiy superheated steam. Experiments were carried out with various unheated cylindrical sections (0.6-in. OD and up to 40 in. long) attached to the upstream end of the heater. It was found that as the unheated section lengih was decreased so the dryout heat flux was reduced. With no unheated section ahead of the heater, dryout occurred at a low heat flux and simultaneously over the whole heater surface. It is assumed that a liquid film builds up on the unheated section, is transferred to the heated section by shear forces and is then thinned by evaporation and entrainment over the heated length. The one hundred and nine experimental data points have been correlated by this model with an rms deviation of 18%. (auth)

• Research Organization: Atomic Energy of Canada Ltd., Chalk River, ON (Canada)
• NSA Number: NSA-17-032260
• OSTI ID: 4875400
• Report Number(s): CONF-129--2
• Country of Publication: United States
• Language: English

Related Subjects

ANNULAR SPACE
BURNOUT
CONFIGURATION
DISPERSIONS
ELECTRICITY
ENGINEERING AND EQUIPMENT
ERRORS
EVAPORATION
FILMS
FLOW MODELS
FLUID FLOW
HEATING
LABORATORY EQUIPMENT
LIQUIDS
MATHEMATICS
MEASURED VALUES
MECHANICS
STANDARDS
STEAM
SUPERHEATING
SURFACES
WATER
ZONES