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ISSN Online: 2377-424X

ISBN Print: 0-89116-299-2

International Heat Transfer Conference 7
September, 6-10, 1982, Munich, Germany

OPTICAL MEASUREMENT OF WATER SUPERHEAT NEAR A RAPIDLY HEATED WALL AT ATMOSPHERIC PRESSURE

Get access (open in a dialog) DOI: 10.1615/IHTC7.2680
pages 479-484

摘要

An interferometric device is tested to measure the average temperature of a liquid contained in a small hole, 8 µm in diameter. From the data, the temperature of the water at the wall at incipient boiling is calculated. The wall superheat ΔTsatONB is also obtained from the resistance of the heating strip, and the wall heat flux q w is calculated from the unsteady heat diffusion equation.
The experiments were carried out with a temperature rise rate up to 2.5 K/µs. This corresponds to wall heat fluxes below 2 107 w/m2 and results in ΔTsatONB below 85 K. No evidence of discontinuity at the wall between the fluid and the solid temperatures was found. The experiments show that ΔTsatONB increases with the wall heat flux qONB for incipient boiling as was previously reported by Lurie and Johnson [l], Nghiem et al. [2], although for lower values of ΔTsatONB and qONB - Our results are consistent with a quasi-steady incipient boiling criterion that was developped by Hsu, Bergles and Rohsenow (HBR criterion).
The inherent limitation of the optical device for the detection of the incipient boiling did not enable the thermodynamic limit of superheat to be reached.