Доступ предоставлен для: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-421-2

International Heat Transfer Conference 15
August, 10-15, 2014, Kyoto, Japan

Boiling Heat Transfer Characteristics and Film Boiling Collapse Temperature through the Two-Dimensional Temperature Field Measurement

Get access (open in a dialog) DOI: 10.1615/IHTC15.pbl.009511
pages 6295-6304

Аннотация

The behavior of rewetting on a high superheated and dry surface, focusing on rewetting temperature just as collapse of saturated and subcooled film boiling was investigated experimentally. Saturated and subcooled impingement jet experiments were conducted by using a silicon wafer and a silver plate with 41.5 × 41.5 mm (length × width) and pure water at atmospheric condition. Temperature of the test heater was measured by using a separated-type infrared thermometer from a back side of it. The MHF-temperature and the filmboiling heat transfer coefficient under saturated and subcooled impingement jet were obtained quantitatively from the present experiments. The MHF point temperatures near the center of test heater were similar to values obtained by equation of Dhir and Purohit. However, the MHF point temperature in outer region of test heater was 200 oC corresponded to Nishio's equation, in spite of liquid velocity and liquid subcooling. The temperatures at leading edge of liquid film on silver plate near stagnation region were about 300oC. However, the temperatures in outer region of test heater asymptotically also became 200 oC, in spite of liquid velocity, liquid subcooling and thermal conductivity of heater. According to the present experimental result of filmboiling heat transfer coefficient, new correlation of film-boiling heat transfer coefficient was presented. The behavior of rewetting on high superheated surface was simulated by using the transient heat conduction with the correlation of film and transition boiling heat transfer. The prediction agreed with the present experimental result in region of film boiling, qualitatively.