Fundamental heat-transfer processes related to phase-change thermal-storage media

Technical Report · Fri Jan 01 04:00:00 EST 1982

OSTI ID:5536180

Sparrow, E M

Research on fundamental heat transfer processes which occur in phase-change thermal storage systems is described. The research encompasses both freezing and melting and includes both experiment and analysis. Five distinct but interrelated research problems are described. The first two of the investigated problems deal with phase change which occurs inside a vertical tube. These studies, both experimental, were motivated by the encapsulated storage concept whereby the phase-change medium is contained within a sealed tube while the flowing heat transfer fluid passes over the outside of the tube. Both freezing and melting were investigated. The results included the heat extracted (for freezing), and heat input (for melting), and the separate contributions of the latent heat energy and of the sensible heat energies of the liquid and the solid phases. The shapes of the freezing and melting fronts were measured directly. Whereas natural convection had a strong effect on the melting results, the freezing results were little affected by natural convection. The third and fourth pieces of research were computational in nature. A new and powerful finite-difference method was formulated for solving two-dimensional phase-change problems. The method was applied to solve the freezing problem which occurs when a coolant-carrying tube passes through a phase-change medium. The last of the research problems was an experiment aimed at determining the natural convection heat transfer coefficients associated with freezing outside a cooled vertical tube. It was found that the coefficients were insensitive to the thickness of the frozen layer. This legitimizes the use of a time-independent local heat transfer conefficient in the analysis of the timewise growth of the frozen layer.

• Research Organization: Minnesota Univ., Minneapolis (USA). Dept. of Mechanical Engineering
• DOE Contract Number: AS02-79ER10343
• OSTI ID: 5536180
• Report Number(s): DOE/ER/10343-03; ON: DE82007944
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
250600* -- Energy Storage-- Thermal
42 ENGINEERING
420400 -- Engineering-- Heat Transfer & Fluid Flow
CONVECTION
DATA
ENERGY STORAGE
ENERGY TRANSFER
EQUIPMENT
EXPERIMENTAL DATA
FINITE DIFFERENCE METHOD
FLUIDS
FREEZING
HEAT STORAGE
HEAT TRANSFER
INFORMATION
ITERATIVE METHODS
LATENT HEAT STORAGE
LIQUIDS
MATERIALS
MELTING
NATURAL CONVECTION
NUMERICAL DATA
NUMERICAL SOLUTION
PHASE CHANGE MATERIALS
PHASE TRANSFORMATIONS
STORAGE
THERMAL ENERGY STORAGE EQUIPMENT
TUBES