Documents disponibles écrits par cet auteur

Experimental evaluation of a controlled hybrid two-phase multi-microchannel cooling and heat recovery system driven by liquid pump and vapor compressor / Duan Wu in International journal of refrigeration, Vol. 36 N° 2 (N° spécial) (Mars 2013) 

Public ISBD [article]  in International journal of refrigeration > Vol. 36 N° 2 (N° spécial) (Mars 2013) . - pp. 375–389 Titre : Experimental evaluation of a controlled hybrid two-phase multi-microchannel cooling and heat recovery system driven by liquid pump and vapor compressor Titre original : Evaluation expérimentale d'un système hybride et régulé de refroidissement diphasique à microcanaux et de récupération de chaleur entraîné par une pompe et un compresseur de vapeur Type de document : texte imprimé Auteurs : Duan Wu, Auteur ; Jackson Braz Marcinichen, Auteur ; John Richard Thome, Auteur Année de publication : 2013 Article en page(s) : pp. 375–389 Note générale : Refrigeration Langues : Anglais (eng) Mots-clés : Data  center;  Chip;  Cooling;  Heat  recovery;  Two-phase  flow;  Controller Résumé : The energy use in data centers is on an accelerating rise due to both demand and technological limitations. Today, the most widely used cooling strategy for data centers is refrigerated air-cooling. Unfortunately, air-cooling presents phenomenally low efficiencies. Therefore green computing paradigms are needed to improve energy efficiency by several orders of magnitude and allow a continued chip scaling for tackling the energy crisis in future-generation data centers. A promising solution would be implementing direct on-chip two-phase cooling technology, which not only improves the heat removal efficiency but also permits the reuse of waste heat since the two-phase coolant can cool CPUs effectively at 60 °C. In the present work a specific cooling cycle using micro-evaporation technology has been experimentally evaluated considering different aspects such as cooling cycle and energy recovery efficiencies and controllability. In resume, this novel cycle shows strong competence in energy usage, heat recovery and controllability towards green data center. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700712003106 [article] Experimental evaluation of a controlled hybrid two-phase multi-microchannel cooling and heat recovery system driven by liquid pump and vapor compressor = Evaluation expérimentale d'un système hybride et régulé de refroidissement diphasique à microcanaux et de récupération de chaleur entraîné par une pompe et un compresseur de vapeur [texte imprimé] / Duan Wu, Auteur ; Jackson Braz Marcinichen, Auteur ; John Richard Thome, Auteur . - 2013 . - pp. 375–389. Refrigeration Langues : Anglais (eng) in International journal of refrigeration > Vol. 36 N° 2 (N° spécial) (Mars 2013) . - pp. 375–389 Mots-clés : Data  center;  Chip;  Cooling;  Heat  recovery;  Two-phase  flow;  Controller Résumé : The energy use in data centers is on an accelerating rise due to both demand and technological limitations. Today, the most widely used cooling strategy for data centers is refrigerated air-cooling. Unfortunately, air-cooling presents phenomenally low efficiencies. Therefore green computing paradigms are needed to improve energy efficiency by several orders of magnitude and allow a continued chip scaling for tackling the energy crisis in future-generation data centers. A promising solution would be implementing direct on-chip two-phase cooling technology, which not only improves the heat removal efficiency but also permits the reuse of waste heat since the two-phase coolant can cool CPUs effectively at 60 °C. In the present work a specific cooling cycle using micro-evaporation technology has been experimentally evaluated considering different aspects such as cooling cycle and energy recovery efficiencies and controllability. In resume, this novel cycle shows strong competence in energy usage, heat recovery and controllability towards green data center. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700712003106

Flow boiling characteristics for R1234ze(E) in 1.0 and 2.2 mm circular channels / Cristiano Bigonha Tibiriçá in Journal of heat transfer, Vol. 134 N° 2 (Fevrier 2012) 

Public ISBD [article]  in Journal of heat transfer > Vol. 134 N° 2 (Fevrier 2012) Titre : Flow boiling characteristics for R1234ze(E) in 1.0 and 2.2 mm circular channels Type de document : texte imprimé Auteurs : Cristiano Bigonha Tibiriçá, Auteur ; Gherhardt Ribatski, Auteur ; John Richard Thome, Auteur Année de publication : 2012 Note générale : Heat transfer Langues : Anglais (eng) Mots-clés : Boiling  Flow  visualisation  Heat  transfer  Microchannel  flow  Pattern  formation  Pipe  flow  Refrigerants Index. décimale : 536 Chaleur. Thermodynamique Résumé : Experimental flow boiling heat transfer results are presented for horizontal 1.0 and 2.2 mm I.D. (internal diameter) stainless steel tubes for tests with R1234ze(E), a new refrigerant developed as a substitute for R134a with a much lower global warming potential (GWP). The experiments were performed for these two tube diameters in order to investigate a possible transition between macro and microscale flow boiling behavior. The experimental campaign includes mass velocities ranging from 50 to 1500 kg/m2 s, heat fluxes from 10 to 300 kW/m2, exit saturation temperatures of 25, 31 and 35 °C, vapor qualities from 0.05 to 0.99 and heated lengths of 180 mm and 361 mm. Flow pattern characterization was performed using high speed videos. Heat transfer coefficient, critical heat flux and flow pattern data were obtained. R1234ze(E) demonstrated similar thermal performance to R134a data when running at similar conditions. DEWEY : 536 ISSN : 0022-1481 En ligne : http://www.asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JHTRAO00013400 [...] [article] Flow boiling characteristics for R1234ze(E) in 1.0 and 2.2 mm circular channels [texte imprimé] / Cristiano Bigonha Tibiriçá, Auteur ; Gherhardt Ribatski, Auteur ; John Richard Thome, Auteur . - 2012. Heat transfer Langues : Anglais (eng) in Journal of heat transfer > Vol. 134 N° 2 (Fevrier 2012) Mots-clés : Boiling  Flow  visualisation  Heat  transfer  Microchannel  flow  Pattern  formation  Pipe  flow  Refrigerants Index. décimale : 536 Chaleur. Thermodynamique Résumé : Experimental flow boiling heat transfer results are presented for horizontal 1.0 and 2.2 mm I.D. (internal diameter) stainless steel tubes for tests with R1234ze(E), a new refrigerant developed as a substitute for R134a with a much lower global warming potential (GWP). The experiments were performed for these two tube diameters in order to investigate a possible transition between macro and microscale flow boiling behavior. The experimental campaign includes mass velocities ranging from 50 to 1500 kg/m2 s, heat fluxes from 10 to 300 kW/m2, exit saturation temperatures of 25, 31 and 35 °C, vapor qualities from 0.05 to 0.99 and heated lengths of 180 mm and 361 mm. Flow pattern characterization was performed using high speed videos. Heat transfer coefficient, critical heat flux and flow pattern data were obtained. R1234ze(E) demonstrated similar thermal performance to R134a data when running at similar conditions. DEWEY : 536 ISSN : 0022-1481 En ligne : http://www.asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JHTRAO00013400 [...]

Flow pattern-based flow boiling heat transfer model for microchannels / Etienne Costa-Patry in International journal of refrigeration, Vol. 36 N° 2 (N° spécial) (Mars 2013) 

Public ISBD [article]  in International journal of refrigeration > Vol. 36 N° 2 (N° spécial) (Mars 2013) . - pp. 414–420 Titre : Flow pattern-based flow boiling heat transfer model for microchannels Titre original : Modèle du transfert de chaleur lors de l'ébullition en écoulement fondé sur la configuration de l'écoulement pour les microcanaux Type de document : texte imprimé Auteurs : Etienne Costa-Patry, Auteur ; John Richard Thome, Auteur Année de publication : 2013 Article en page(s) : pp. 414–420 Note générale : Refrigeration Langues : Anglais (eng) Mots-clés : Flow  pattern;  Microchannels;  Heat  transfer;  Flow  boiling Résumé : A new flow pattern-based prediction method for heat transfer coefficients in microchannels was developed based on recent experimental results for several multi-microchannel evaporators in silicon and copper and for single-microchannel tubes in stainless steel. In the present paper, some updates to the three-zone flow boiling model for slug flow are presented, including further proof that the dryout thickness is well represented by setting it equal to the measured channel roughness for the silicon, copper and stainless steel test surfaces. Next, a non-circular channel version of the Cioncolini–Thome unified annular flow model for convective boiling is proposed. These two methods are joined together into a flow pattern-based method using a new heat flux-dependent flow pattern transition criterion between slug flow and annular flow. The method predicts the results quite accurately and also captures the trends in the heat transfer coefficients well. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700712003490 [article] Flow pattern-based flow boiling heat transfer model for microchannels = Modèle du transfert de chaleur lors de l'ébullition en écoulement fondé sur la configuration de l'écoulement pour les microcanaux [texte imprimé] / Etienne Costa-Patry, Auteur ; John Richard Thome, Auteur . - 2013 . - pp. 414–420. Refrigeration Langues : Anglais (eng) in International journal of refrigeration > Vol. 36 N° 2 (N° spécial) (Mars 2013) . - pp. 414–420 Mots-clés : Flow  pattern;  Microchannels;  Heat  transfer;  Flow  boiling Résumé : A new flow pattern-based prediction method for heat transfer coefficients in microchannels was developed based on recent experimental results for several multi-microchannel evaporators in silicon and copper and for single-microchannel tubes in stainless steel. In the present paper, some updates to the three-zone flow boiling model for slug flow are presented, including further proof that the dryout thickness is well represented by setting it equal to the measured channel roughness for the silicon, copper and stainless steel test surfaces. Next, a non-circular channel version of the Cioncolini–Thome unified annular flow model for convective boiling is proposed. These two methods are joined together into a flow pattern-based method using a new heat flux-dependent flow pattern transition criterion between slug flow and annular flow. The method predicts the results quite accurately and also captures the trends in the heat transfer coefficients well. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700712003490

Two-phase heat transfer and high-speed visualization of refrigerant flows in 100 × 100 μm2 silicon multi-microchannels / Sylwia Szczukiewicz in International journal of refrigeration, Vol. 36 N° 2 (N° spécial) (Mars 2013) 

Public ISBD [article]  in International journal of refrigeration > Vol. 36 N° 2 (N° spécial) (Mars 2013) . - pp. 402–413 Titre : Two-phase heat transfer and high-speed visualization of refrigerant flows in 100 × 100 μm2 silicon multi-microchannels Titre original : Transfert de chaleur diphasique et visualisation à grande vitesse de l'écoulement de frigorigènes à l'intérieur de microcanaux multiples en silicium d'une taille de 100 × 100 μm2 Type de document : texte imprimé Auteurs : Sylwia Szczukiewicz, Auteur ; Navid Borhani, Auteur ; John Richard Thome, Auteur Année de publication : 2013 Article en page(s) : pp. 402–413 Note générale : Refrigeration Langues : Anglais (eng) Mots-clés : Multi-microchannel  evaporator;  Silicon  chip;  Two-phase  cooling;  Refrigerant;  Infra-red  camera;  High-speed  visualization Résumé : Two-phase flow boiling of R245fa, R236fa, and R1234ze(E) in 100 × 100 μm2 parallel microchannels for cooling of future 3D-ICs has been investigated. Significant flow instabilities, back flow, and non-uniform flow distribution among the channels were observed in the micro-evaporator without any inlet restrictions (micro-orifices). Therefore, to prevent such problems, rectangular restrictions were placed at the inlet of each channel and the two-phase flow flashed by the micro-orifices was identified as the most optimal operating condition. In the present study, a novel in-situ pixel-by-pixel technique was developed to calibrate the raw infra-red images, thus converting them into two-dimensional temperature fields of 10’000 pixels over the test section surface operating at 60 Hz. Tests showed that the base heat flux of 48.6 W cm−2 could be dissipated whilst keeping the micro-evaporator’s temperature below 85 °C. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700712003131 [article] Two-phase heat transfer and high-speed visualization of refrigerant flows in 100 × 100 μm2 silicon multi-microchannels = Transfert de chaleur diphasique et visualisation à grande vitesse de l'écoulement de frigorigènes à l'intérieur de microcanaux multiples en silicium d'une taille de 100 × 100 μm2 [texte imprimé] / Sylwia Szczukiewicz, Auteur ; Navid Borhani, Auteur ; John Richard Thome, Auteur . - 2013 . - pp. 402–413. Refrigeration Langues : Anglais (eng) in International journal of refrigeration > Vol. 36 N° 2 (N° spécial) (Mars 2013) . - pp. 402–413 Mots-clés : Multi-microchannel  evaporator;  Silicon  chip;  Two-phase  cooling;  Refrigerant;  Infra-red  camera;  High-speed  visualization Résumé : Two-phase flow boiling of R245fa, R236fa, and R1234ze(E) in 100 × 100 μm2 parallel microchannels for cooling of future 3D-ICs has been investigated. Significant flow instabilities, back flow, and non-uniform flow distribution among the channels were observed in the micro-evaporator without any inlet restrictions (micro-orifices). Therefore, to prevent such problems, rectangular restrictions were placed at the inlet of each channel and the two-phase flow flashed by the micro-orifices was identified as the most optimal operating condition. In the present study, a novel in-situ pixel-by-pixel technique was developed to calibrate the raw infra-red images, thus converting them into two-dimensional temperature fields of 10’000 pixels over the test section surface operating at 60 Hz. Tests showed that the base heat flux of 48.6 W cm−2 could be dissipated whilst keeping the micro-evaporator’s temperature below 85 °C. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700712003131