Subcooled flow boiling critical heat flux (CHF) and its application to fusion energy components. Part I. A review of fundamentals of CHF and related data base
The present understanding of critical heat flux (CHF) in subcooled flow boiling with water is reviewed and fusion reactor component high-heat flux (HHF) requirements are outlined. This survey (Parts I and II), which contains a representative coverage of the literature over the last 30 years, is concerned only with CHF in the subcooled flow boiling regime. CHF data base parameter ranges are also given as an aid for fusion component designers in locating the appropriate data for an application. Because of the relatively HHF levels and long pulse durations in the next generation reactors, fusion components must be actively cooled. All fusion components are heated nonuniformly over their surface and their surface area ranges from 0.1 to 1000 m/sup 2/. Although most components are subjected to fluxes from about 0.005 kW/cm/sup 2/ (first wall) to near 1 kW/cm/sup 2/ (limiters and divertors), some components are subjected to fluxes from 2 kW/cm/sup 2/ (first wall in compact reactors) to 8 kW/cm/sup 2/ (beam dumps). Subcooled flow boiling has the greatest potential of accommodating the steady-state HHF levels encountered by fusion reactor components. Although the available heat flux data base brackets those for most fusion components, the existing data are sparse or nonexistent for the length-to-diameter ratios (e.g., >200 for limiters and >50 for beam dumps) necessary for future HHF fusion components. There are more than 20 parameters that influence subcooled flow boiling CHF and many other tested techniques that enhance heat transfer by a factor of >2. The engineering implementation and design of fusion components cannot be optimized until the physical relationships between the maximum CHF and both the flow parameters and thermophysical properties have been determined. This can be accomplished only if improvements are made in the understanding of the fundamental mechanisms controlling the heat transfer and CHF in the subcooled flow boiling regime.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- OSTI ID:
- 5918783
- Journal Information:
- Fusion Technol.; (United States), Vol. 7:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CRITICAL HEAT FLUX
DATA BASE MANAGEMENT
REVIEWS
SUBCOOLED BOILING
THERMONUCLEAR REACTORS
BEAM DUMPS
DIVERTORS
FIRST WALL
HEAT TRANSFER
HYDRAULICS
LIMITERS
TEMPERATURE EFFECTS
THERMONUCLEAR REACTOR COOLING SYSTEMS
WATER
BOILING
COOLING SYSTEMS
DOCUMENT TYPES
ENERGY SYSTEMS
ENERGY TRANSFER
FLUID MECHANICS
HEAT FLUX
HYDROGEN COMPOUNDS
MANAGEMENT
MECHANICS
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
THERMONUCLEAR REACTOR WALLS
700204* - Fusion Power Plant Technology- Cooling Systems