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Une étude expérimentale de la nucléation bullaire d'un frigorigène dans des écoulements en ébullition sous pression.

An experimental investigation of bubble nucleation of a refrigerant in pressurized boiling flows.

Auteurs : SOHEL MURSHED S. M., VEREEN K., STRAYER D., et al.

Type d'article : Article

Résumé

An experimental investigation is performed to determine the effect of system pressure and heat flux on flow boiling and associated bubble characteristics of a refrigerant in a narrow vertical duct. A high-pressure flow boiling test loop was built and TLC (thermo-chromic liquid crystal) was applied to the back of the heater foil for high resolution and accurate measurement of heater surface temperature. Refrigerant R134a is used as the test fluid at different pressures ranging from 690 to 827 kPa and different heat fluxes to quantify their influence in bubble characteristics such as bubble nucleation, growth, departure, and coalescence. Two synchronized high resolution and high-speed cameras are used to simultaneously capture TLC images as well as bubbling activities at high frame rates. By varying flow rate and system pressure, TLC and bubble images were captured and analyzed. Results show that the bubble generation frequency and size increase with heat flux. An increase in pressure from 690 to 827 kPa increased the bubble frequency and size by about 32 Hz and 20 micrometers, respectively. Bubble coalescence was also observed after departure from the nucleation site.

Détails

  • Titre original : An experimental investigation of bubble nucleation of a refrigerant in pressurized boiling flows.
  • Identifiant de la fiche : 2011-0079
  • Langues : Anglais
  • Source : Far and Near in Water & Energy - vol. 35 - n. 12
  • Date d'édition : 12/2010
  • DOI : http://dx.doi.org/10.1016/j.energy.2010.07.052

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