Fundamental heat transfer processes related to phase change thermal storage media

Technical Report · Thu Jan 01 04:00:00 EST 1981

DOI:https://doi.org/10.2172/6941424· OSTI ID:6941424

Sparrow, E. M.; Ramsey, J. W.

Research on fundamental heat transfer processes which occur in phase-change thermal storage systems is described. The research encompasses both melting and freezing, and includes both experiment and analysis. The status of four research problems is discussed. One of the freezing problems was focused on investigating, via experiment, the extent to which freezing can be enhanced by the attachment of fins to the external surface of a cooled vertical tube situated in a liquid phase-change medium. Very substantial enhancements were encountered which neutralize the degradation of freezing due to the thermal resistance of the frozen layer and to natural convection in the liquid phase. The second of the freezing problems was analytical in nature and sought to obtain solutions involving both the phase-change medium and the heat transfer fluid used either to add heat to or extract heat from the medium. For freezing on a plane wall, it was possible to obtain a closed-form analytical solution, while for freezing about a coolant-carrying circular tube, a new numerical methodology was devised to obtain finite-difference solutions. For melting, quantitative design-quality heat transfer coefficients were determined experimentally for melting adjacent to a heated vertical tube. These experiments explored the effects of solid-phase subcooling and of open versus closed top containment on the coefficients. A dimensionless correlation enables these results to be used for a wide range of phase-change media. Studies on melting of a phase-change material situated within a circular tube are in progress.

• Research Organization: Minnesota Univ., Minneapolis (USA). Dept. of Mechanical Engineering
• Sponsoring Organization: USDOE Office of Basic Energy Sciences
• DOE Contract Number: AS02-79ER10343
• OSTI ID: 6941424
• Report Number(s): DOE/ER/10343--02
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
250600* -- Energy Storage-- Thermal
ANALYTICAL SOLUTION
COOLING
ENERGY STORAGE
ENERGY TRANSFER
EQUIPMENT
FINS
FREEZING
HEAT STORAGE
HEAT TRANSFER
LATENT HEAT STORAGE
MATERIALS
MATHEMATICAL MODELS
MELTING
PHASE CHANGE MATERIALS
PHASE TRANSFORMATIONS
STORAGE
SUBCOOLING
THERMAL ENERGY STORAGE EQUIPMENT
TUBES