Published 1967 | Version v1
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Forced convection of ammonia. Liquid ammonia. Case of large wall to fluid temperature differences

Creators

  • 1. Commissariat a l'Energie Atomique, 38 - Grenoble (France). Centre d'Etudes Nucleaires

Description

Two test tubes were used: Inconel (ID 3 mm, OD 3.5 mn length 300 mm) and tantalum (ID 3 mm, OD 4 mm; length 450 mm). Measurements were performed in the following conditions inlet temperature of subcooled liquid from +4 deg C to + 54 deg C; inlet pressure from 10 to 42, bars; mass velocity from 33 to 243 g/cm2.s; maximum heat flux 583 W/cm2; maximum wall temperature 1523 deg C; steam quality reaching 1. When the flow is liquid, a film of vapor is formed on the heated wall. Using the Martinelli-Nelson parameter Xtt a correlation of the heat transfer coefficients is presented in the two-phase region. This correlation is analogous to the one developed for liquid hydrogen. In the gaseous phase region the correlation established is: Nu 0.0046 Re0.95 Pr0.4 with a film temperature of t0.5. The Martinelli-Nelson method gives fairly good results for pressure drop evaluation. Gross experimental results are published separately. (authors)

Availability note (English)

Available from INIS in electronic form

Abstract (French)

Deux tubes d'essais ont ete utilises: inconel (diametre 3 x 3,5 mm; longueur 300 mm) et tantale (diametre 3 x 4 mm; longueur 450 mm). Les mesures ont ete effectuees dans les conditions suivantes: temperature d'entree du liquide sous-refroidi, + 4 deg C a + 54 deg C; pression d'entree, 10 a 42 bars; vitesse massique, 33 a 243 g/cm2.s; densite de flux de chaleur maximum 583 W/cm2; temperature maximale de la paroi: 1523 deg C; titre de vapeur atteignant 1. Quand l'ecoulement est liquide, il se forme un film de vapeur sur la paroi. En double-phase on a etabli une correlation des coefficients d'echanges, utilisant le parametre de Martinelli et Nelson Xtt, analogue a celle obtenue pour l'hydrogene liquide. En phase gazeuse la correlation presentee est: Nu = 0,0046 Re0,95 Pr0,4 avec une temperature de film de t0,5. La methode de Martinelli et Nelson donne d'assez bons resultats pour le calcul des pertes de charge. Les resultats experimentaux bruts sont presentes separement. (auteurs)

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Additional details

Additional titles

Original title (French)
Convection forcee de l'ammoniac. Premiere partie. Ammoniac liquide. Cas de grands ecarts de temperatures entre fluide et paroi

Publishing Information

Imprint Pagination
43 p.
Report number
CEA-R--3088-B

INIS

Country of Publication
France
Country of Input or Organization
France
INIS RN
36055465
Subject category
S42: ENGINEERING;
Descriptors DEI
AMMONIA; CORRELATIONS; CRITICAL HEAT FLUX; DISSOCIATION HEAT; FILM BOILING; FLOW RATE; FORCED CONVECTION; FRICTION FACTOR; PRESSURE DEPENDENCE; PRESSURE DROP; RADIANT HEAT TRANSFER; REYNOLDS NUMBER; TEMPERATURE DISTRIBUTION; TWO-PHASE FLOW
Descriptors DEC
BOILING; CONVECTION; DIMENSIONLESS NUMBERS; ENERGY TRANSFER; ENTHALPY; FLUID FLOW; HEAT FLUX; HEAT TRANSFER; HYDRIDES; HYDROGEN COMPOUNDS; MASS TRANSFER; NITROGEN COMPOUNDS; NITROGEN HYDRIDES; PHASE TRANSFORMATIONS; PHYSICAL PROPERTIES; REACTION HEAT; THERMODYNAMIC PROPERTIES

Optional Information

Notes
16 refs.