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Measurement of the local void fraction at high pressures in a heating channel; Mesure du taux de vide a haute pression dans un canal chauffant

Abstract

Void fraction measurements were made in two phase flow boiling systems at high pressures in a uniformly heated, rectangular channel with a high aspect ratio. The local void fraction values were calculated from measurements of the absorption of a thin collimated X-ray beam (2 mm x 0.05 mm). The mean void fraction in a horizontal section results from integration of the local values across the section. At a fixed measuring station the quality and- void fraction were varied by changing the heat flux, flow rate and pressure systematically. Two channels were used differing in length and thickness (150.8 cm x 5.3 cm x 0.2 cm and the significant features of this study are: -1) The void fraction measurements are among the first obtained at such high pressure (80 to 140 kg/cm{sup 2}); -2) In the experimental region under consideration the measurements are systematic and numerous enough to allow accurate interpolations: mass velocity from 50 to 220 g/cm{sup 2}.s, heat flux from 40 to 170 W/cm{sup 2} and calculated steam quality from -0.2 to 0.2; -3) Many tests were performed under local boiling conditions with the mean temperature of the fluid below the saturation temperature; and -4) These results were compared  More>>
Authors:
Martin, R [1] 
  1. Commissariat a l'Energie Atomique, Grenoble (France). Centre d'Etudes Nucleaires
Publication Date:
Jul 01, 1969
Product Type:
Thesis/Dissertation
Report Number:
CEA-R-3781
Resource Relation:
Other Information: TH: These ES-sciences; 88 refs; PBD: 1969
Subject:
42 ENGINEERING; BENCH-SCALE EXPERIMENTS; HEAT TRANSFER; PRESSURE RANGE MEGA PA 01-10; PRESSURE RANGE MEGA PA 10-100; TWO-PHASE FLOW; VOID FRACTION
OSTI ID:
20547227
Research Organizations:
CEA Grenoble, 38 (France); Grenoble-1 Univ., Faculte des Sciences, 38 (France)
Country of Origin:
France
Language:
French
Other Identifying Numbers:
TRN: FR04R3781002834
Availability:
Available from INIS in electronic form
Submitting Site:
FRN
Size:
[199] pages
Announcement Date:
Feb 01, 2005

Citation Formats

Martin, R. Measurement of the local void fraction at high pressures in a heating channel; Mesure du taux de vide a haute pression dans un canal chauffant. France: N. p., 1969. Web.
Martin, R. Measurement of the local void fraction at high pressures in a heating channel; Mesure du taux de vide a haute pression dans un canal chauffant. France.
Martin, R. 1969. "Measurement of the local void fraction at high pressures in a heating channel; Mesure du taux de vide a haute pression dans un canal chauffant." France.
@misc{etde_20547227,
title = {Measurement of the local void fraction at high pressures in a heating channel; Mesure du taux de vide a haute pression dans un canal chauffant}
author = {Martin, R}
abstractNote = {Void fraction measurements were made in two phase flow boiling systems at high pressures in a uniformly heated, rectangular channel with a high aspect ratio. The local void fraction values were calculated from measurements of the absorption of a thin collimated X-ray beam (2 mm x 0.05 mm). The mean void fraction in a horizontal section results from integration of the local values across the section. At a fixed measuring station the quality and- void fraction were varied by changing the heat flux, flow rate and pressure systematically. Two channels were used differing in length and thickness (150.8 cm x 5.3 cm x 0.2 cm and the significant features of this study are: -1) The void fraction measurements are among the first obtained at such high pressure (80 to 140 kg/cm{sup 2}); -2) In the experimental region under consideration the measurements are systematic and numerous enough to allow accurate interpolations: mass velocity from 50 to 220 g/cm{sup 2}.s, heat flux from 40 to 170 W/cm{sup 2} and calculated steam quality from -0.2 to 0.2; -3) Many tests were performed under local boiling conditions with the mean temperature of the fluid below the saturation temperature; and -4) These results were compared to the predictions of certain models presented in the literature and simple empirical formulae were developed to fit the experimental results. (author) [French] Des mesures de taux de vide ont ete effectuees sur un ecoulement eau-vapeur a haute pression dans un canal vertical, de section rectangulaire tres allongee et chauffe a flux uniforme. Les valeurs du taux de vide local sont obtenues a partir des mesures de l'absorption d'un faisceau de rayons X finement collimate (2 mm x 0,05 mm). La valeur du taux de vide moyen dans une section droite s'en deduit par integration. Cette section droite ou sont realisees les mesures est fixe et, a pression, debit et flux donnes, les variations du titre et du taux de vide sont obtenues par variations de l'enthalpie d'entree. Deux geometries ont ete etudiees differant par la longueur et l'epaisseur (150,8 cm x 5,3 cm x 0,2 cm et 100,8 cm x 5,3 cm x 0,28 cm). Cette etude presente les caracteres suivants: - 1) Les distributions du taux de vide local sont parmi les premieres obtenues a de telles pressions (80 a 140 kg/cm{sup 2}); - 2) Dans le domaine considere les mesures sont suffisamment systematiques et nombreuses pour permettre des interpolations precises: vitesse massique de 50 a 220 g/cm{sup 2}.s, flux thermique de 40 a 170 W/cm{sup 2}, titre dans la section de mesures de -0,2 a +0,2; - 3) De nombreux essais ont ete realises en ebullition locale, lorsque la temperature moyenne du fluide est inferieure a la temperature de saturation; et - 4) Les resultats obtenus ont permis de tester certains modeles existant dans la litterature et de proposer des formules empiriques simples adaptees aux conditions experimentales considerees. (auteur)}
place = {France}
year = {1969}
month = {Jul}
}