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Subcooled boiling heat transfer for turbulent flow of water in a short vertical tube / Koichi Hata in Journal of heat transfer, Vol. 132 N° 1 (Janvier 2010) 

Public ISBD [article]  in Journal of heat transfer > Vol. 132 N° 1 (Janvier 2010) . - pp. [011501-1/11] Titre : Subcooled boiling heat transfer for turbulent flow of water in a short vertical tube Type de document : texte imprimé Auteurs : Koichi Hata, Auteur ; Suguru Masuzaki, Auteur Article en page(s) : pp. [011501-1/11] Note générale : Physique Langues : Anglais (eng) Mots-clés : Subcooled  boiling  heat  transfer  Turbulent  flow  of  water  Short  vertical  tube Index. décimale : 536 Chaleur. Thermodynamique Résumé : The subcooled boiling heat transfer and the critical heat flux (CHF) due to exponentially increasing heat inputs with various periods (Q=Q0 exp(t/tau), tau=22.52 ms–26.31 s) were systematically measured by an experimental water loop flow and observed by an infrared thermal imaging camera. Measurements were made on a 3 mm inner diameter, a 66.5 mm heated length, and a 0.5 mm thickness of platinum test tube, which was divided into three sections (upper, mid, and lower positions). The axial variations of the inner surface temperature, the heat flux, and the heat transfer coefficient from nonboiling to critical heat flux were clarified. The results were compared with other correlations for the subcooled boiling heat transfer and authors' transient CHF correlations. The influence of exponential period (tau) and flow velocity on the subcooled boiling heat transfer and the CHF was investigated and the predictable correlation of the subcooled boiling heat transfer for turbulent flow of water in a short vertical tube was derived based on the experimental data. In this work, the correlation gave 15% difference for subcooled boiling heat transfer coefficients. Most of the CHF data (101 points) were within 15% and −30 to +20% differences of the authors' transient CHF correlations against inlet and outlet subcoolings, respectively DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Subcooled boiling heat transfer for turbulent flow of water in a short vertical tube [texte imprimé] / Koichi Hata, Auteur ; Suguru Masuzaki, Auteur . - pp. [011501-1/11]. Physique Langues : Anglais (eng) in Journal of heat transfer > Vol. 132 N° 1 (Janvier 2010) . - pp. [011501-1/11] Mots-clés : Subcooled  boiling  heat  transfer  Turbulent  flow  of  water  Short  vertical  tube Index. décimale : 536 Chaleur. Thermodynamique Résumé : The subcooled boiling heat transfer and the critical heat flux (CHF) due to exponentially increasing heat inputs with various periods (Q=Q0 exp(t/tau), tau=22.52 ms–26.31 s) were systematically measured by an experimental water loop flow and observed by an infrared thermal imaging camera. Measurements were made on a 3 mm inner diameter, a 66.5 mm heated length, and a 0.5 mm thickness of platinum test tube, which was divided into three sections (upper, mid, and lower positions). The axial variations of the inner surface temperature, the heat flux, and the heat transfer coefficient from nonboiling to critical heat flux were clarified. The results were compared with other correlations for the subcooled boiling heat transfer and authors' transient CHF correlations. The influence of exponential period (tau) and flow velocity on the subcooled boiling heat transfer and the CHF was investigated and the predictable correlation of the subcooled boiling heat transfer for turbulent flow of water in a short vertical tube was derived based on the experimental data. In this work, the correlation gave 15% difference for subcooled boiling heat transfer coefficients. Most of the CHF data (101 points) were within 15% and −30 to +20% differences of the authors' transient CHF correlations against inlet and outlet subcoolings, respectively DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]

Subcooled water flow boiling heat transfer in a short SUS304-tube with twisted-tape insert / Koichi Hata in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 5 (Mai 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 5 (Mai 2011) . - 11 p. Titre : Subcooled water flow boiling heat transfer in a short SUS304-tube with twisted-tape insert Type de document : texte imprimé Auteurs : Koichi Hata, Auteur ; Suguru Masuzaki, Auteur Année de publication : 2012 Article en page(s) : 11 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Boiling  Heat  transfer  Invertors  Pipe  flow  Pumps  Swirling  flow  Turbulence  Undercooling Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The subcooled boiling heat transfer and the steady-state critical heat fluxes (CHFs) in a short SUS304-tube with twisted-tape insert are systematically measured for mass velocities (G=4016–13,850 kg/m2 s), inlet liquid temperatures (Tin=285.82–363.96 K), outlet pressures (Pout=764.76–889.02 kPa), and exponentially increasing heat input (Q=Q0 exp(t/tau), tau=8.5 s) by the experimental water loop comprised of a multistage canned-type circulation pump controlled by an inverter. The SUS304 test tube of inner diameter (d=6 mm), heated length (L=59.5 mm), effective length (Leff=49.1 mm), L/d (=9.92), Leff/d (=8.18), and wall thickness (delta=0.5 mm) with average surface roughness (Ra=3.18 µm) is used in this work. The SUS304 twisted tape with twist ratio, y(=H/d=(pitch of 180 deg rotation)/d), of 3.39 is used. The relation between inner surface temperature and heat flux for the SUS304-tube with the twisted-tape insert are clarified from nonboiling to CHF. The subcooled boiling heat transfer for SUS304-tube with the twisted-tape insert is compared with our empty SUS304-tube data and the values calculated by our and other workers' correlations for the subcooled boiling heat transfer. The influences of the twisted-tape insert and the swirl velocity on the subcooled boiling heat transfer and the CHFs are investigated into details and the widely and precisely predictable correlations of the subcooled boiling heat transfer and the CHFs for turbulent flow of water in the SUS304-tube with twisted-tape insert are given based on the experimental data. The correlations can describe the subcooled boiling heat transfer coefficients and the CHFs obtained in this work within −25 to +15% difference. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Subcooled water flow boiling heat transfer in a short SUS304-tube with twisted-tape insert [texte imprimé] / Koichi Hata, Auteur ; Suguru Masuzaki, Auteur . - 2012 . - 11 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 5 (Mai 2011) . - 11 p. Mots-clés : Boiling  Heat  transfer  Invertors  Pipe  flow  Pumps  Swirling  flow  Turbulence  Undercooling Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The subcooled boiling heat transfer and the steady-state critical heat fluxes (CHFs) in a short SUS304-tube with twisted-tape insert are systematically measured for mass velocities (G=4016–13,850 kg/m2 s), inlet liquid temperatures (Tin=285.82–363.96 K), outlet pressures (Pout=764.76–889.02 kPa), and exponentially increasing heat input (Q=Q0 exp(t/tau), tau=8.5 s) by the experimental water loop comprised of a multistage canned-type circulation pump controlled by an inverter. The SUS304 test tube of inner diameter (d=6 mm), heated length (L=59.5 mm), effective length (Leff=49.1 mm), L/d (=9.92), Leff/d (=8.18), and wall thickness (delta=0.5 mm) with average surface roughness (Ra=3.18 µm) is used in this work. The SUS304 twisted tape with twist ratio, y(=H/d=(pitch of 180 deg rotation)/d), of 3.39 is used. The relation between inner surface temperature and heat flux for the SUS304-tube with the twisted-tape insert are clarified from nonboiling to CHF. The subcooled boiling heat transfer for SUS304-tube with the twisted-tape insert is compared with our empty SUS304-tube data and the values calculated by our and other workers' correlations for the subcooled boiling heat transfer. The influences of the twisted-tape insert and the swirl velocity on the subcooled boiling heat transfer and the CHFs are investigated into details and the widely and precisely predictable correlations of the subcooled boiling heat transfer and the CHFs for turbulent flow of water in the SUS304-tube with twisted-tape insert are given based on the experimental data. The correlations can describe the subcooled boiling heat transfer coefficients and the CHFs obtained in this work within −25 to +15% difference. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]