Dépouillements

Flow boiling heat transfer of carbon dioxide inside a small-sized microfin tube / Chaobin Dang in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 655-663 Titre : Flow boiling heat transfer of carbon dioxide inside a small-sized microfin tube Titre original : Transfert de chaleur lors de l'ébullition du dioxyde de carbone à l'intérieur d'un tube à microailettes de faible diamètre Type de document : texte imprimé Auteurs : Chaobin Dang, Auteur ; Nobori Haraguchi, Auteur ; Eiji Hihara, Auteur Année de publication : 2010 Article en page(s) : pp. 655-663 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Heat  exchanger  Tube  Microfin  Geometry  Carbon  dioxide  Boiling  Experiment  Heat  transfer  Pressure  drop Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : This study investigated the flow boiling heat transfer of carbon dioxide inside a small-sized microfin tube (mean inner diameter: 2.0 mm; helix angle: 6.3°) at a saturation temperature of 15 °C, and heat and mass flux ranges of 4.5–18 kW m−2 and 360–720 kg m−2 s−1, respectively. Although, experimental results indicated that heat flux has a significant effect on the heat transfer coefficient, the coefficient does not always increase with mass flux, as in the case of conventional refrigerants such as HFCs or HCFCs. Under certain conditions, the heat transfer coefficient at a high mass flux was lower than that at a lower mass flux, indicating that convective heat transfer had a suppression effect on nucleate boiling. The heat transfer coefficients in the microfin tubes were 1.9∼2.3 times the values in smooth tubes of the same diameter under the same experimental conditions, and the dryout quality was much higher, ranging from 0.9 to 0.95. The experimental results indicated that using microfin tubes may considerably increase the overall heat transfer performance. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000174 [article] Flow boiling heat transfer of carbon dioxide inside a small-sized microfin tube = Transfert de chaleur lors de l'ébullition du dioxyde de carbone à l'intérieur d'un tube à microailettes de faible diamètre [texte imprimé] / Chaobin Dang, Auteur ; Nobori Haraguchi, Auteur ; Eiji Hihara, Auteur . - 2010 . - pp. 655-663. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 655-663 Mots-clés : Heat  exchanger  Tube  Microfin  Geometry  Carbon  dioxide  Boiling  Experiment  Heat  transfer  Pressure  drop Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : This study investigated the flow boiling heat transfer of carbon dioxide inside a small-sized microfin tube (mean inner diameter: 2.0 mm; helix angle: 6.3°) at a saturation temperature of 15 °C, and heat and mass flux ranges of 4.5–18 kW m−2 and 360–720 kg m−2 s−1, respectively. Although, experimental results indicated that heat flux has a significant effect on the heat transfer coefficient, the coefficient does not always increase with mass flux, as in the case of conventional refrigerants such as HFCs or HCFCs. Under certain conditions, the heat transfer coefficient at a high mass flux was lower than that at a lower mass flux, indicating that convective heat transfer had a suppression effect on nucleate boiling. The heat transfer coefficients in the microfin tubes were 1.9∼2.3 times the values in smooth tubes of the same diameter under the same experimental conditions, and the dryout quality was much higher, ranging from 0.9 to 0.95. The experimental results indicated that using microfin tubes may considerably increase the overall heat transfer performance. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000174

Numerical simulation and experimental validation of internal heat exchanger influence on CO2 trans-critical cycle performance / Joaquim Rigola in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 664-674 Titre : Numerical simulation and experimental validation of internal heat exchanger influence on CO2 trans-critical cycle performance Titre original : Simulation numérique et validation expérimentale de l'influence de l'échangeur de chaleur interne sur la performance transcritique du CO2 Type de document : texte imprimé Auteurs : Joaquim Rigola, Auteur ; Nicolás Ablanque, Auteur ; Carlos D. Pérez-Segarra, Auteur Année de publication : 2010 Article en page(s) : pp. 664-674 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Refrigeration  system  Carbon  dioxide  Transcritical  cycle  Performance  Experiment  Exchanger  COP Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The present paper is a numerical and experimental comparative study of the whole vapour compression refrigerating cycle in general, and reciprocating compressors in particular, with the aim of showing the possibilities that CO2 offers for commercial refrigeration, considering a single-stage trans-critical cycle using semi-hermetic reciprocating compressors under small cooling capacity systems. The present work is focussed on the influence of using an internal heat exchanger (IHX) in order to improve the cycle performance under real working conditions. In order to validate the numerical results, an experimental unit specially designed and built to analyze trans-critical refrigerating equipments considering IHX has been built. Both numerical results and experimental data show reasonable good agreement, while the comparative global values conclude the improvement of cooling capacity and COP when IHX is considered in the CO2 trans-critical cycle. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000113 [article] Numerical simulation and experimental validation of internal heat exchanger influence on CO2 trans-critical cycle performance = Simulation numérique et validation expérimentale de l'influence de l'échangeur de chaleur interne sur la performance transcritique du CO2 [texte imprimé] / Joaquim Rigola, Auteur ; Nicolás Ablanque, Auteur ; Carlos D. Pérez-Segarra, Auteur . - 2010 . - pp. 664-674. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 664-674 Mots-clés : Refrigeration  system  Carbon  dioxide  Transcritical  cycle  Performance  Experiment  Exchanger  COP Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The present paper is a numerical and experimental comparative study of the whole vapour compression refrigerating cycle in general, and reciprocating compressors in particular, with the aim of showing the possibilities that CO2 offers for commercial refrigeration, considering a single-stage trans-critical cycle using semi-hermetic reciprocating compressors under small cooling capacity systems. The present work is focussed on the influence of using an internal heat exchanger (IHX) in order to improve the cycle performance under real working conditions. In order to validate the numerical results, an experimental unit specially designed and built to analyze trans-critical refrigerating equipments considering IHX has been built. Both numerical results and experimental data show reasonable good agreement, while the comparative global values conclude the improvement of cooling capacity and COP when IHX is considered in the CO2 trans-critical cycle. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000113

Design analysis of the novel Revolving Vane expander in a transcritical carbon dioxide refrigeration system / A. Subiantoro in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 675-685 Titre : Design analysis of the novel Revolving Vane expander in a transcritical carbon dioxide refrigeration system Titre original : Analyse de la conception d’un détendeur rotatif à palettes dans un système frigorifique au dioxyde de carbone transcritique Type de document : texte imprimé Auteurs : A. Subiantoro, Auteur ; K.T. Ooi, Auteur Année de publication : 2010 Article en page(s) : pp. 675-685 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Design  Rotary  compressor  Carbon  dioxide  Review  Performance  Expansion Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : In this paper, four possible design variants of the Revolving Vane expander have been examined in relation to their application when using CO2 as the working fluid in a refrigeration cycle. The detailed examination of the design components and illustrations are presented and discussed. The study shows that the Revolving Vane expander RV-I design configuration with the vane attached to the rotor and in which the rotor is also used as the driving component is the most superior design. It is found to have the highest mechanical efficiency and the most desirable variation of the power produced. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000046 [article] Design analysis of the novel Revolving Vane expander in a transcritical carbon dioxide refrigeration system = Analyse de la conception d’un détendeur rotatif à palettes dans un système frigorifique au dioxyde de carbone transcritique [texte imprimé] / A. Subiantoro, Auteur ; K.T. Ooi, Auteur . - 2010 . - pp. 675-685. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 675-685 Mots-clés : Design  Rotary  compressor  Carbon  dioxide  Review  Performance  Expansion Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : In this paper, four possible design variants of the Revolving Vane expander have been examined in relation to their application when using CO2 as the working fluid in a refrigeration cycle. The detailed examination of the design components and illustrations are presented and discussed. The study shows that the Revolving Vane expander RV-I design configuration with the vane attached to the rotor and in which the rotor is also used as the driving component is the most superior design. It is found to have the highest mechanical efficiency and the most desirable variation of the power produced. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000046

Experimental study on ammonia-water falling film absorption in external magnetic fields / Xiao Feng Niu in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 686-694 Titre : Experimental study on ammonia-water falling film absorption in external magnetic fields Titre original : Etude éxperimentale sur l’absorption d’un film tombant à ammoniac/eau dans les champs magnétiques externes Type de document : texte imprimé Auteurs : Xiao Feng Niu, Auteur ; Kai Du, Auteur ; Fu Xiao, Auteur Année de publication : 2010 Article en page(s) : pp. 686-694 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Absorption  system  Ammonia-water  Experiment  Falling  film  Absorber  Magnetic  field Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Experiments of ammonia–water falling film absorption were performed in magnetic fields of different intensities and different directions as well as under varied operating conditions. Experimental results showed that the outlet concentration of ammonia–water, the outlet temperature of cooling water and the amount of absorption heat and mass in downward magnetic field are higher than those in non-magnetic field. However, all of them decreased in the upward magnetic field. Therefore, it can be concluded that the magnetic field with the same direction as falling film enhances the absorption, and the magnetic field with the direction against falling film weakens the absorption of ammonia–water. The results also showed the effect of magnetic field on absorption was more obvious in solutions with low inlet concentration. The influences of the cooling water flow rate, the cooling water inlet temperature and the solution flow rate on absorption in magnetic field were similar to those without magnetic field. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000204 [article] Experimental study on ammonia-water falling film absorption in external magnetic fields = Etude éxperimentale sur l’absorption d’un film tombant à ammoniac/eau dans les champs magnétiques externes [texte imprimé] / Xiao Feng Niu, Auteur ; Kai Du, Auteur ; Fu Xiao, Auteur . - 2010 . - pp. 686-694. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 686-694 Mots-clés : Absorption  system  Ammonia-water  Experiment  Falling  film  Absorber  Magnetic  field Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Experiments of ammonia–water falling film absorption were performed in magnetic fields of different intensities and different directions as well as under varied operating conditions. Experimental results showed that the outlet concentration of ammonia–water, the outlet temperature of cooling water and the amount of absorption heat and mass in downward magnetic field are higher than those in non-magnetic field. However, all of them decreased in the upward magnetic field. Therefore, it can be concluded that the magnetic field with the same direction as falling film enhances the absorption, and the magnetic field with the direction against falling film weakens the absorption of ammonia–water. The results also showed the effect of magnetic field on absorption was more obvious in solutions with low inlet concentration. The influences of the cooling water flow rate, the cooling water inlet temperature and the solution flow rate on absorption in magnetic field were similar to those without magnetic field. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000204

Flow boiling heat transfer of ammonia/water mixture in a plate heat exchanger / Francisco Táboas in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 695-705 Titre : Flow boiling heat transfer of ammonia/water mixture in a plate heat exchanger Titre original : Transfert de chaleur lors de l'ébullition en écoulement d'un mélange d'ammoniac/eau dans un échangeur de chaleur à plaque Type de document : texte imprimé Auteurs : Francisco Táboas, Auteur ; Manel Vallès, Auteur ; Bourouis, Mahmoud, Auteur Année de publication : 2010 Article en page(s) : pp. 695-705 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Absorption  system  Heat  exchanger  Plate  exchanger  Experiment  Heat  transfer  Boiling  Ammonia–water Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The objective of this work is to contribute to the development of plate heat exchangers as desorbers for ammonia/water absorption refrigeration machines driven by waste heat or solar energy. In this study, saturated flow boiling heat transfer and the associated frictional pressure drop of ammonia/water mixture flowing in a vertical plate heat exchanger is experimentally investigated. Experimental data is presented to show the effects of heat flux between 20 and 50 kW m−2, mass flux between 70 and 140 kg m−2 s−1, mean vapour quality from 0.0 to 0.22 and pressure between 7 and 15 bar, for ammonia concentration between 0.42 and 0.62. The results show that for the selected operating conditions, the boiling heat transfer coefficient is highly dependent on the mass flux, whereas the influence of heat flux and pressure are negligible mainly at higher vapour qualities. The pressure drop increases with increasing mass flux and quality. However, the pressure drop is independent of the imposed heat flux. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700709002825 [article] Flow boiling heat transfer of ammonia/water mixture in a plate heat exchanger = Transfert de chaleur lors de l'ébullition en écoulement d'un mélange d'ammoniac/eau dans un échangeur de chaleur à plaque [texte imprimé] / Francisco Táboas, Auteur ; Manel Vallès, Auteur ; Bourouis, Mahmoud, Auteur . - 2010 . - pp. 695-705. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 695-705 Mots-clés : Absorption  system  Heat  exchanger  Plate  exchanger  Experiment  Heat  transfer  Boiling  Ammonia–water Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The objective of this work is to contribute to the development of plate heat exchangers as desorbers for ammonia/water absorption refrigeration machines driven by waste heat or solar energy. In this study, saturated flow boiling heat transfer and the associated frictional pressure drop of ammonia/water mixture flowing in a vertical plate heat exchanger is experimentally investigated. Experimental data is presented to show the effects of heat flux between 20 and 50 kW m−2, mass flux between 70 and 140 kg m−2 s−1, mean vapour quality from 0.0 to 0.22 and pressure between 7 and 15 bar, for ammonia concentration between 0.42 and 0.62. The results show that for the selected operating conditions, the boiling heat transfer coefficient is highly dependent on the mass flux, whereas the influence of heat flux and pressure are negligible mainly at higher vapour qualities. The pressure drop increases with increasing mass flux and quality. However, the pressure drop is independent of the imposed heat flux. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700709002825

Experimental study on adsorption kinetics of activated carbon/R134a and activated carbon/R507A pairs / Khairul Habib in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 706-713 Titre : Experimental study on adsorption kinetics of activated carbon/R134a and activated carbon/R507A pairs Titre original : Etude expérimentale sur la cinétique d'adsorption des couples actifs charbon actif/R134a et charbon actif/R507A Type de document : texte imprimé Auteurs : Khairul Habib, Auteur ; Bidyut B. Saha, Auteur ; Kazi A. Rahman, Auteur Année de publication : 2010 Article en page(s) : pp. 706-713 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Adsorption  system  Activated  carbon  R134a  R507A  Experiment  Adsorption Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The objective of this article is to evaluate adsorption kinetics of R134a and R507A on pitch based activated carbon experimentally by a constant volume variable pressure method at different adsorption temperatures ranging from 20 to 60 °C. These data are useful for the design of adsorption cooling and refrigeration systems and are unavailable in the literature. Data obtained from the kinetic studies were analyzed with various kinetic models and the Fickian diffusion model is found to be the most suitable overall. Guided by the experimental measurements, the surface diffusion is also estimated and is found that it follows the classical Arrhenius law within the experimental range. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000216 [article] Experimental study on adsorption kinetics of activated carbon/R134a and activated carbon/R507A pairs = Etude expérimentale sur la cinétique d'adsorption des couples actifs charbon actif/R134a et charbon actif/R507A [texte imprimé] / Khairul Habib, Auteur ; Bidyut B. Saha, Auteur ; Kazi A. Rahman, Auteur . - 2010 . - pp. 706-713. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 706-713 Mots-clés : Adsorption  system  Activated  carbon  R134a  R507A  Experiment  Adsorption Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The objective of this article is to evaluate adsorption kinetics of R134a and R507A on pitch based activated carbon experimentally by a constant volume variable pressure method at different adsorption temperatures ranging from 20 to 60 °C. These data are useful for the design of adsorption cooling and refrigeration systems and are unavailable in the literature. Data obtained from the kinetic studies were analyzed with various kinetic models and the Fickian diffusion model is found to be the most suitable overall. Guided by the experimental measurements, the surface diffusion is also estimated and is found that it follows the classical Arrhenius law within the experimental range. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000216

The use of metal piece additives to enhance heat transfer rate through an unconsolidated adsorbent bed / Hasan Demir in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 714-720 Titre : The use of metal piece additives to enhance heat transfer rate through an unconsolidated adsorbent bed Titre original : Additifs sous forme de particules métalliques utilisés afin d’augmenter le transfert de chaleur à travers un lit absorbant non consolidé Type de document : texte imprimé Auteurs : Hasan Demir, Auteur ; Moghtada Mobedi, Auteur ; Semra Ülkü, Auteur Année de publication : 2010 Article en page(s) : pp. 714-720 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Adsorption  system  Water  Silica  gel  Improvement  Adsorber  Additive  Particle  Metal  Thermal  conductivity  Bed Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The effects of metal piece additives on effective thermal conductivity and diffusivity of an unconsolidated adsorbent bed in which adsorbent is silica gel were investigated. The metal piece additives were copper, brass, aluminum and stainless steel with two different sizes as 1.0–2.8 mm and 2.8–4.75 mm. The effective thermal conductivity and diffusivity of the mixed bed were predicted by comparison of the experimental results with the solution of dimensionless heat conduction equation for the bed. The performed experiments showed that the addition 15wt% of aluminum pieces with sizes between 1.0 and 2.8 mm enhances the effective thermal diffusivity and conductivity of a pure silica gel bed by 157% and 242%, respectively. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000137 [article] The use of metal piece additives to enhance heat transfer rate through an unconsolidated adsorbent bed = Additifs sous forme de particules métalliques utilisés afin d’augmenter le transfert de chaleur à travers un lit absorbant non consolidé [texte imprimé] / Hasan Demir, Auteur ; Moghtada Mobedi, Auteur ; Semra Ülkü, Auteur . - 2010 . - pp. 714-720. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 714-720 Mots-clés : Adsorption  system  Water  Silica  gel  Improvement  Adsorber  Additive  Particle  Metal  Thermal  conductivity  Bed Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The effects of metal piece additives on effective thermal conductivity and diffusivity of an unconsolidated adsorbent bed in which adsorbent is silica gel were investigated. The metal piece additives were copper, brass, aluminum and stainless steel with two different sizes as 1.0–2.8 mm and 2.8–4.75 mm. The effective thermal conductivity and diffusivity of the mixed bed were predicted by comparison of the experimental results with the solution of dimensionless heat conduction equation for the bed. The performed experiments showed that the addition 15wt% of aluminum pieces with sizes between 1.0 and 2.8 mm enhances the effective thermal diffusivity and conductivity of a pure silica gel bed by 157% and 242%, respectively. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000137

Modeling of scroll compressors – improvements / Marie-Eve Duprez in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 721-728 Titre : Modeling of scroll compressors – improvements Titre original : Modélisation des compresseurs à spirale - améliorations Type de document : texte imprimé Auteurs : Marie-Eve Duprez, Auteur ; Eric Dumont, Auteur ; Marc Frère, Auteur Année de publication : 2010 Article en page(s) : pp. 721-728 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Screw  compressor  Heat  pump  Review  Improvement  Modelling  Flow  Energy  consumption  Heat  transfer Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : This paper presents an improvement of the scroll compressors model previously published by Duprez et al. (2007). This improved model allows the calculation of refrigerant mass flow rate, power consumption and heat flow rate that would be released at the condenser of a heat pump equipped with the compressor, from the knowledge of operating conditions and parameters. Both basic and improved models have been tested on scroll compressors using different refrigerants. This study has been limited to compressors with a maximum electrical power of 14 kW and for evaporation temperatures ranging from −40 to 15 °C and condensation temperatures from 10 to 75 °C. The average discrepancies on mass flow rate, power consumption and heat flow rate are respectively 0.50%, 0.93% and 3.49%. Using a global parameter determination (based on several refrigerants data), this model can predict the behavior of a compressor with another fluid for which no manufacturer data are available. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S014070071000006X [article] Modeling of scroll compressors – improvements = Modélisation des compresseurs à spirale - améliorations [texte imprimé] / Marie-Eve Duprez, Auteur ; Eric Dumont, Auteur ; Marc Frère, Auteur . - 2010 . - pp. 721-728. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 721-728 Mots-clés : Screw  compressor  Heat  pump  Review  Improvement  Modelling  Flow  Energy  consumption  Heat  transfer Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : This paper presents an improvement of the scroll compressors model previously published by Duprez et al. (2007). This improved model allows the calculation of refrigerant mass flow rate, power consumption and heat flow rate that would be released at the condenser of a heat pump equipped with the compressor, from the knowledge of operating conditions and parameters. Both basic and improved models have been tested on scroll compressors using different refrigerants. This study has been limited to compressors with a maximum electrical power of 14 kW and for evaporation temperatures ranging from −40 to 15 °C and condensation temperatures from 10 to 75 °C. The average discrepancies on mass flow rate, power consumption and heat flow rate are respectively 0.50%, 0.93% and 3.49%. Using a global parameter determination (based on several refrigerants data), this model can predict the behavior of a compressor with another fluid for which no manufacturer data are available. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S014070071000006X

Steady-state hybrid modeling of economized screw water chillers using polynomial neural network compressor model / Ling-Xiao Zhao in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 729-738 Titre : Steady-state hybrid modeling of economized screw water chillers using polynomial neural network compressor model Titre original : Modélisation hybride en régime permanent des refroidisseurs d’eau à vis munis d’économiseur, à l’aide d’un modèle polynomial à réseau neuronal Type de document : texte imprimé Auteurs : Ling-Xiao Zhao, Auteur ; Liang-Liang Shao, Auteur ; Chun-Lu Zhang, Auteur Année de publication : 2010 Article en page(s) : pp. 729-738 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Liquid  chiller  Screw  compressor  Injection  Modelling  Performance  Neural  network Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : This paper presents steady-state hybrid modeling and analysis of water chillers with economized screw compressors using intermediate gas injection. The hybrid chiller model consists of the polynomial neural network compressor model and other component models grounded on the first principles. The polynomial neural network compressor model works for all full-load and part-load conditions, both economized and non-economized modes. Good agreement between the predicted and measured performance of two compressors from the manufacturer is reached ranging from full-load to unload conditions. The hybrid chiller model predictions on the performance of two chillers agree with the test data within ±5% errors. Based on the validated model, further investigation on the optimal switch points between the economized and non-economized mode is conducted, which can be used to precisely improve the part-load performance of chillers. A simple linear correlation for switching the economized and non-economized mode is proposed as well. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000095 [article] Steady-state hybrid modeling of economized screw water chillers using polynomial neural network compressor model = Modélisation hybride en régime permanent des refroidisseurs d’eau à vis munis d’économiseur, à l’aide d’un modèle polynomial à réseau neuronal [texte imprimé] / Ling-Xiao Zhao, Auteur ; Liang-Liang Shao, Auteur ; Chun-Lu Zhang, Auteur . - 2010 . - pp. 729-738. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 729-738 Mots-clés : Liquid  chiller  Screw  compressor  Injection  Modelling  Performance  Neural  network Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : This paper presents steady-state hybrid modeling and analysis of water chillers with economized screw compressors using intermediate gas injection. The hybrid chiller model consists of the polynomial neural network compressor model and other component models grounded on the first principles. The polynomial neural network compressor model works for all full-load and part-load conditions, both economized and non-economized modes. Good agreement between the predicted and measured performance of two compressors from the manufacturer is reached ranging from full-load to unload conditions. The hybrid chiller model predictions on the performance of two chillers agree with the test data within ±5% errors. Based on the validated model, further investigation on the optimal switch points between the economized and non-economized mode is conducted, which can be used to precisely improve the part-load performance of chillers. A simple linear correlation for switching the economized and non-economized mode is proposed as well. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000095

Analysis of resonant frequency of moving magnet linear compressor of stirling cryocooler / Ming Xia in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 739-744 Titre : Analysis of resonant frequency of moving magnet linear compressor of stirling cryocooler Titre original : Analyse de la fréquence de résonance du compresseur linéaire magnétique et mobile d'un cryorefroidisseur de Stirling Type de document : texte imprimé Auteurs : Ming Xia, Auteur ; Xiaoping Chen, Auteur Année de publication : 2010 Article en page(s) : pp. 739-744 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Cryocooler  Stirling  Simulation  Computational  fluid  dynamics  Frequency  Resonance  Magnetic  compressor Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : This paper analyzes resonant frequency of the moving magnet linear compressor of Stirling cryocooler. The CFD (Computational Fluid Dynamics) and FEM (Finite Element Method) are used for the analysis of resonant frequency with FLUENT 6.2 and ANSYS 11.0 and an experiment is designed for testing the resonant frequency of moving magnet linear compressor. Results from simulations and experiments showed that the resonant frequency of the moving magnet linear compressors is affected by the machine spring, the gas spring, the magnet spring, and the mass of moving assembly, while the resonant frequency of the moving coil linear compressors is only affected by the machine spring, the gas spring, and the mass of moving assembly. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000162 [article] Analysis of resonant frequency of moving magnet linear compressor of stirling cryocooler = Analyse de la fréquence de résonance du compresseur linéaire magnétique et mobile d'un cryorefroidisseur de Stirling [texte imprimé] / Ming Xia, Auteur ; Xiaoping Chen, Auteur . - 2010 . - pp. 739-744. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 739-744 Mots-clés : Cryocooler  Stirling  Simulation  Computational  fluid  dynamics  Frequency  Resonance  Magnetic  compressor Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : This paper analyzes resonant frequency of the moving magnet linear compressor of Stirling cryocooler. The CFD (Computational Fluid Dynamics) and FEM (Finite Element Method) are used for the analysis of resonant frequency with FLUENT 6.2 and ANSYS 11.0 and an experiment is designed for testing the resonant frequency of moving magnet linear compressor. Results from simulations and experiments showed that the resonant frequency of the moving magnet linear compressors is affected by the machine spring, the gas spring, the magnet spring, and the mass of moving assembly, while the resonant frequency of the moving coil linear compressors is only affected by the machine spring, the gas spring, and the mass of moving assembly. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000162

Modeling of a two-stage magnetic refrigerator with wavy-structure gadolinium heat exchangers / D. Vuarnoz in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 745-752 Titre : Modeling of a two-stage magnetic refrigerator with wavy-structure gadolinium heat exchangers Titre original : Modélisationon d’un réfrigérateur magnétique biétagé muni d’échangeurs de chaleur ondulés en gadolinium Type de document : texte imprimé Auteurs : D. Vuarnoz, Auteur ; A. Kitanovski, Auteur ; C. Gonin, Auteur Année de publication : 2010 Article en page(s) : pp. 745-752 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Magnetic  refrigerator  Two-stage  system  Modelling  Simulation  Performance-COP Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : In a rotary magnetic refrigerator a porous ring is turning in and out of a magnetic field region. The adiabatic demagnetization of the magnetocaloric material produces the “cold energy”. This is described by a discontinuous temperature decrease, known as adiabatic temperature difference. For such a machine a physical model has been developed, based on a mapping of the magneto-thermodynamic problem. In this model, in a basic centre cell, two coupled linear partial differential equations are solved, which have been programmed in the Modelica language. The operation of a magnetic refrigerator is simulated with numerous parameters. Steady state solutions are obtained to verify the coefficient of performance under stable operation conditions. Optimal running conditions – defined by maximum values of the coefficient of performance – are not presented in this article, but can now easily be obtained with the existing program. A simple regulation strategy is proposed and implemented into the program. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700709003119 [article] Modeling of a two-stage magnetic refrigerator with wavy-structure gadolinium heat exchangers = Modélisationon d’un réfrigérateur magnétique biétagé muni d’échangeurs de chaleur ondulés en gadolinium [texte imprimé] / D. Vuarnoz, Auteur ; A. Kitanovski, Auteur ; C. Gonin, Auteur . - 2010 . - pp. 745-752. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 745-752 Mots-clés : Magnetic  refrigerator  Two-stage  system  Modelling  Simulation  Performance-COP Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : In a rotary magnetic refrigerator a porous ring is turning in and out of a magnetic field region. The adiabatic demagnetization of the magnetocaloric material produces the “cold energy”. This is described by a discontinuous temperature decrease, known as adiabatic temperature difference. For such a machine a physical model has been developed, based on a mapping of the magneto-thermodynamic problem. In this model, in a basic centre cell, two coupled linear partial differential equations are solved, which have been programmed in the Modelica language. The operation of a magnetic refrigerator is simulated with numerous parameters. Steady state solutions are obtained to verify the coefficient of performance under stable operation conditions. Optimal running conditions – defined by maximum values of the coefficient of performance – are not presented in this article, but can now easily be obtained with the existing program. A simple regulation strategy is proposed and implemented into the program. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700709003119

A comprehensive parameter study of an active magnetic regenerator using a 2D numerical model / K.K. Nielsen in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 753-764 Titre : A comprehensive parameter study of an active magnetic regenerator using a 2D numerical model Titre original : Etude approfondie sur les paramètres des régénérateurs magnétiques actifs à l'aide d'un modèle numérique bidimensionnel Type de document : texte imprimé Auteurs : K.K. Nielsen, Auteur ; C. R. H. Bahl, Auteur ; A. Smith, Auteur Année de publication : 2010 Article en page(s) : pp. 753-764 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Magnetic  refrigerator  Simulation  Performance  Heat  transfer  Heat  exchange  Regenerator  Gadolinium Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A two-dimensional numerical heat transfer model is used to investigate an active magnetic regenerator (AMR) based on parallel plates of magnetocaloric material. A large range of parameter variations are performed to study the optimal AMR. The parameters varied are the plate and channel thicknesses, cycle frequency and fluid movement. These are cast into the non-dimensional units utilization, porosity and number of transfer units (NTU). The cooling capacity vs. temperature span is mapped as a function of these parameters and each configuration is evaluated through the maximum temperature span and exergy. The results show that the optimal AMR should have a utilization in the range 0.2–1 and an NTU higher than 10 and not necessarily more than 30. It is concluded that parallel plate-based regenerators face significant challenges in terms of manufacturability. However, the benefit of parallel plate regenerators is a very low pressure drop, which is needed for high performance. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000058 [article] A comprehensive parameter study of an active magnetic regenerator using a 2D numerical model = Etude approfondie sur les paramètres des régénérateurs magnétiques actifs à l'aide d'un modèle numérique bidimensionnel [texte imprimé] / K.K. Nielsen, Auteur ; C. R. H. Bahl, Auteur ; A. Smith, Auteur . - 2010 . - pp. 753-764. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 753-764 Mots-clés : Magnetic  refrigerator  Simulation  Performance  Heat  transfer  Heat  exchange  Regenerator  Gadolinium Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A two-dimensional numerical heat transfer model is used to investigate an active magnetic regenerator (AMR) based on parallel plates of magnetocaloric material. A large range of parameter variations are performed to study the optimal AMR. The parameters varied are the plate and channel thicknesses, cycle frequency and fluid movement. These are cast into the non-dimensional units utilization, porosity and number of transfer units (NTU). The cooling capacity vs. temperature span is mapped as a function of these parameters and each configuration is evaluated through the maximum temperature span and exergy. The results show that the optimal AMR should have a utilization in the range 0.2–1 and an NTU higher than 10 and not necessarily more than 30. It is concluded that parallel plate-based regenerators face significant challenges in terms of manufacturability. However, the benefit of parallel plate regenerators is a very low pressure drop, which is needed for high performance. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000058

An air-standard cycle and a thermodynamic perspective on operational limits of Ranque–Hilsh or vortex tubes / José Roberto Simões-Moreira in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 765-773 Titre : An air-standard cycle and a thermodynamic perspective on operational limits of Ranque–Hilsh or vortex tubes Titre original : Cycle à air traditionnel, aspects thermodynamiques et limites du fonctionnement des tubes Ranque-Hilsch ou vortex Type de document : texte imprimé Auteurs : José Roberto Simões-Moreira, Auteur Année de publication : 2010 Article en page(s) : pp. 765-773 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Vortex  tube  Thermodynamic  cycle  Ranque-Hilsch  Energy  balance  COP Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A Thermodynamic air-standard cycle was envisaged for Ranque–Hilsh (R–H) or Vortex Tubes to provide relevant Thermodynamic analysis and tools for setting operating limits according to the conservation laws of mass and energy, as well as the constraint of the Second Law of Thermodynamics. The study used an integral or control volume approach and resulted in establishing working equations for evaluating the performance of an R–H tube. The work proved that the coefficient of performance does not depend on the R–H tube operating mode, i.e., the same value is obtained independently if the R–H tube operates either as a heat pump or as a refrigeration device. It was also shown that the isentropic coefficient of performance displays optima values of cold and hot mass fractions for a given operating pressure ratio. Finally, the study was concluded by comparing the present analysis with some experimental data available in the literature for operating pressures ranging 2–11 atm. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000198 [article] An air-standard cycle and a thermodynamic perspective on operational limits of Ranque–Hilsh or vortex tubes = Cycle à air traditionnel, aspects thermodynamiques et limites du fonctionnement des tubes Ranque-Hilsch ou vortex [texte imprimé] / José Roberto Simões-Moreira, Auteur . - 2010 . - pp. 765-773. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 765-773 Mots-clés : Vortex  tube  Thermodynamic  cycle  Ranque-Hilsch  Energy  balance  COP Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A Thermodynamic air-standard cycle was envisaged for Ranque–Hilsh (R–H) or Vortex Tubes to provide relevant Thermodynamic analysis and tools for setting operating limits according to the conservation laws of mass and energy, as well as the constraint of the Second Law of Thermodynamics. The study used an integral or control volume approach and resulted in establishing working equations for evaluating the performance of an R–H tube. The work proved that the coefficient of performance does not depend on the R–H tube operating mode, i.e., the same value is obtained independently if the R–H tube operates either as a heat pump or as a refrigeration device. It was also shown that the isentropic coefficient of performance displays optima values of cold and hot mass fractions for a given operating pressure ratio. Finally, the study was concluded by comparing the present analysis with some experimental data available in the literature for operating pressures ranging 2–11 atm. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000198

Numerical analysis of the effects of nozzles number on the flow and power of cooling of a vortex tube / Rahim Shamsoddini in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 774-782 Titre : Numerical analysis of the effects of nozzles number on the flow and power of cooling of a vortex tube Titre original : Analyse numérique de l'effet du nombre de tuyères sur l'écoulement et la puissance refroidissante d'un tube vortex Type de document : texte imprimé Auteurs : Rahim Shamsoddini, Auteur ; Alireza Hossein Nezhad, Auteur Année de publication : 2010 Article en page(s) : pp. 774-782 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Refrigeration  system  Vortex  tube  Modelling  Simulation  Geometry  Nozzle Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : In this paper, the effects of the nozzles number on the flow and power of cooling of a vortex tube are studied, using a three-dimensional numerical fluid dynamic model. Vortex tube has interesting functions and several industrial applications, and, as a refrigerator, it is used as a spot cooling device in industry. High-pressure compressible fluid enters the vortex tube and leaves its cold and hot outlets at lower and higher temperatures than that of the inlet flow, respectively. A few experimental and a fewer numerical studies have been conducted in recent years on the effects of nozzles number of a vortex tube. However, in this paper, the effects of nozzles number on the flow and power of cooling of a counter-flow vortex tube are investigated comprehensively. It is observed that as the number of nozzles is increased, power of cooling increases significantly while cold outlet temperature decreases moderately. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000101 [article] Numerical analysis of the effects of nozzles number on the flow and power of cooling of a vortex tube = Analyse numérique de l'effet du nombre de tuyères sur l'écoulement et la puissance refroidissante d'un tube vortex [texte imprimé] / Rahim Shamsoddini, Auteur ; Alireza Hossein Nezhad, Auteur . - 2010 . - pp. 774-782. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 774-782 Mots-clés : Refrigeration  system  Vortex  tube  Modelling  Simulation  Geometry  Nozzle Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : In this paper, the effects of the nozzles number on the flow and power of cooling of a vortex tube are studied, using a three-dimensional numerical fluid dynamic model. Vortex tube has interesting functions and several industrial applications, and, as a refrigerator, it is used as a spot cooling device in industry. High-pressure compressible fluid enters the vortex tube and leaves its cold and hot outlets at lower and higher temperatures than that of the inlet flow, respectively. A few experimental and a fewer numerical studies have been conducted in recent years on the effects of nozzles number of a vortex tube. However, in this paper, the effects of nozzles number on the flow and power of cooling of a counter-flow vortex tube are investigated comprehensively. It is observed that as the number of nozzles is increased, power of cooling increases significantly while cold outlet temperature decreases moderately. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000101

Comparison of different turbulence models in predicting the temperature separation in a Ranque–Hilsch vortex tube / T. Dutta in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 783-792 Titre : Comparison of different turbulence models in predicting the temperature separation in a Ranque–Hilsch vortex tube Titre original : Comparaison de plusieurs modèles de turbulence dans la prévision de la séparation de température à l’intérieur d’un tube à vortex Ranque–Hilsch Type de document : texte imprimé Auteurs : T. Dutta, Auteur ; K.P. Sinhamahapatra, Auteur ; S. S. Bandyopdhyay, Auteur Année de publication : 2010 Article en page(s) : pp. 783-792 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Ranque–Hilsch  vortex  tube  CFD  modelling  Turbulence  model  Temperature  separation Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : An axisymmetric computational fluid dynamics (CFD) model is used to compare the influence of different Reynolds Averaged Navier–Stokes (RANS) based turbulence models in predicting the temperature separation in a Ranque–Hilsch vortex tube. The standard κ–ɛ, RNG κ–ɛ, standard κ–ω and SST κ–ω turbulence models are used in this study. The performance curves (hot and cold outlet temperatures versus hot outlet mass fraction) obtained by using these turbulence models are compared with the experimental results. The objective is to select an appropriate turbulence model for the simulation of the flow phenomena in a vortex tube with optimum computational expense. The performance analysis shows that among all the turbulence models investigated in this study, temperature separation predicted by the standard κ–ɛ turbulence model is closer to the experimental results. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700709002916 [article] Comparison of different turbulence models in predicting the temperature separation in a Ranque–Hilsch vortex tube = Comparaison de plusieurs modèles de turbulence dans la prévision de la séparation de température à l’intérieur d’un tube à vortex Ranque–Hilsch [texte imprimé] / T. Dutta, Auteur ; K.P. Sinhamahapatra, Auteur ; S. S. Bandyopdhyay, Auteur . - 2010 . - pp. 783-792. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 783-792 Mots-clés : Ranque–Hilsch  vortex  tube  CFD  modelling  Turbulence  model  Temperature  separation Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : An axisymmetric computational fluid dynamics (CFD) model is used to compare the influence of different Reynolds Averaged Navier–Stokes (RANS) based turbulence models in predicting the temperature separation in a Ranque–Hilsch vortex tube. The standard κ–ɛ, RNG κ–ɛ, standard κ–ω and SST κ–ω turbulence models are used in this study. The performance curves (hot and cold outlet temperatures versus hot outlet mass fraction) obtained by using these turbulence models are compared with the experimental results. The objective is to select an appropriate turbulence model for the simulation of the flow phenomena in a vortex tube with optimum computational expense. The performance analysis shows that among all the turbulence models investigated in this study, temperature separation predicted by the standard κ–ɛ turbulence model is closer to the experimental results. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700709002916

Experimental study and modeling of cooling ceiling systems using steady-state analysis / Néstor Fonseca Diaz in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 793-805 Titre : Experimental study and modeling of cooling ceiling systems using steady-state analysis Titre original : Titre Etude expérimentale et modélisation des systèmes de plafond refroidissant à l'aide d'une analyse du régime permanent Type de document : texte imprimé Auteurs : Néstor Fonseca Diaz, Auteur ; Jean Lebrun, Auteur ; Philippe André, Auteur Année de publication : 2010 Article en page(s) : pp. 793-805 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Air  conditioning  Experiment  Geometry  Coil  Cooling  Ceiling  Modelling Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : This article presents the results of an experimental study performed to develop a computational model of cooling ceiling systems. The model considers the cooling ceiling as a fin. Only the dry regime is considered. From ceiling and room dimensions, material description of the cooling ceiling and measurement of supply water mass flow rate and air and water temperatures, the model calculates the cooling ceiling capacity, ceiling surface average temperature and water exhaust temperature. Fin efficiency, mixed convection close to the cooling ceiling (generated by the ventilation system) and panel perforations influence are studied. The theoretical approach gives to the user an appropriate tool for preliminary calculation, design and diagnosis in commissioning processes in order to determine the main operating conditions of the system in cooling mode. A series of experimental results got on four types of cooling ceilings are used in order to validate the model. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700709002886 [article] Experimental study and modeling of cooling ceiling systems using steady-state analysis = Titre Etude expérimentale et modélisation des systèmes de plafond refroidissant à l'aide d'une analyse du régime permanent [texte imprimé] / Néstor Fonseca Diaz, Auteur ; Jean Lebrun, Auteur ; Philippe André, Auteur . - 2010 . - pp. 793-805. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 793-805 Mots-clés : Air  conditioning  Experiment  Geometry  Coil  Cooling  Ceiling  Modelling Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : This article presents the results of an experimental study performed to develop a computational model of cooling ceiling systems. The model considers the cooling ceiling as a fin. Only the dry regime is considered. From ceiling and room dimensions, material description of the cooling ceiling and measurement of supply water mass flow rate and air and water temperatures, the model calculates the cooling ceiling capacity, ceiling surface average temperature and water exhaust temperature. Fin efficiency, mixed convection close to the cooling ceiling (generated by the ventilation system) and panel perforations influence are studied. The theoretical approach gives to the user an appropriate tool for preliminary calculation, design and diagnosis in commissioning processes in order to determine the main operating conditions of the system in cooling mode. A series of experimental results got on four types of cooling ceilings are used in order to validate the model. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700709002886

Microclimatic control in the museum environment: Air diffusion performance / Fabrizio Ascione in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 806-814 Titre : Microclimatic control in the museum environment: Air diffusion performance Titre original : Règulation du microclimat dans les musées : Performance de la diffusion d'air Type de document : texte imprimé Auteurs : Fabrizio Ascione, Auteur ; Francesco Minichiello, Auteur Année de publication : 2010 Article en page(s) : pp. 806-814 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Air  conditioning  Museum  Simulation  Computational  fluid  dynamics  Comparison  Air  diffuser  Regulation-temperature Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : For the conservation of cultural heritage, museums need appropriate HVAC systems. Besides the time stability of the microclimatic parameters in the exhibition rooms, a high spatial uniformity is necessary and, thus, an optimal performance of the air diffusion systems. Using numerical codes based on Building Energy Performance Simulation (BEPS) and Computational Fluid Dynamics (CFD) techniques, in this paper an analysis has been carried out to compare different suitable air diffusion equipments, as regards uniformity of thermal-hygrometric and kinetic fields in a modelled typical exhibition room. For various part load conditions, the values of thermal-hygrometric parameters in different volumes of the room have been evaluated, as well as an innovative spatial thermal-hygrometric performance index. Globally estimating indoor temperature, relative humidity and their uniformity, for high exhibition rooms (5 m) the swirling diffusers have shown the best average performances, followed by the perimetrical stripes of slot diffusers, while for very high rooms (9 m) nozzles have resulted preferable. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700709003120 [article] Microclimatic control in the museum environment: Air diffusion performance = Règulation du microclimat dans les musées : Performance de la diffusion d'air [texte imprimé] / Fabrizio Ascione, Auteur ; Francesco Minichiello, Auteur . - 2010 . - pp. 806-814. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 806-814 Mots-clés : Air  conditioning  Museum  Simulation  Computational  fluid  dynamics  Comparison  Air  diffuser  Regulation-temperature Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : For the conservation of cultural heritage, museums need appropriate HVAC systems. Besides the time stability of the microclimatic parameters in the exhibition rooms, a high spatial uniformity is necessary and, thus, an optimal performance of the air diffusion systems. Using numerical codes based on Building Energy Performance Simulation (BEPS) and Computational Fluid Dynamics (CFD) techniques, in this paper an analysis has been carried out to compare different suitable air diffusion equipments, as regards uniformity of thermal-hygrometric and kinetic fields in a modelled typical exhibition room. For various part load conditions, the values of thermal-hygrometric parameters in different volumes of the room have been evaluated, as well as an innovative spatial thermal-hygrometric performance index. Globally estimating indoor temperature, relative humidity and their uniformity, for high exhibition rooms (5 m) the swirling diffusers have shown the best average performances, followed by the perimetrical stripes of slot diffusers, while for very high rooms (9 m) nozzles have resulted preferable. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700709003120

Modeling heat exchangers under consideration of manufacturing tolerances and uncertain flow distribution / O. Abdelaziz in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 815-828 Titre : Modeling heat exchangers under consideration of manufacturing tolerances and uncertain flow distribution Titre original : Modélisation des échangeurs de chaleur tenant compte des tolérances lors de la fabrication et l′irrégularité de l′écoulement Type de document : texte imprimé Auteurs : O. Abdelaziz, Auteur ; R. Radermacher, Auteur Année de publication : 2010 Article en page(s) : pp. 815-828 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Heat  exchanger  Geometry  Calculation  Simulation  Performance  Parameter  Manufacturing  Flow  Monte  Carlo Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Small dimensions found in modern and novel heat exchanger (HX) designs encounter very challenging manufacturing issues. With current manufacturing techniques HXs in small dimensions will exhibit large tolerances relative to design variables. Hence, the anticipated variation in performance is a concern. Furthermore, small flow channel dimensions are very susceptible to severe fouling and even blockage. Therefore, flow distribution would be uncertain. These uncertainties in dimensions and flow distribution should be accounted for during the design and performance evaluation of new HX geometries with focus on ultra-compact designs. This paper outlines an effort to theoretically evaluate the performance of an air-to-water HX, assembled from tubes with non-conventional heat transfer surfaces. Vertical spacing within this HX is subject to a predefined statistical distribution compounded with uncertainty in water flow rate through each flow path (i.e., tube). A new implementation technique for ɛ-NTU is proposed in order to accommodate different air conditions on both tube sides. A Monte Carlo simulation approach is used to estimate the HX performance distribution. This approach is applied to three HX designs showing the performance degradation subject to geometrical and flow uncertainties. The simulation results under uncertainty provided useful insights into the reasons for the performance degradation and showed great impact to the uncertainty distribution. Overall, the proposed HX design with the smallest dimensions showed the least performance degradation due to manufacturing and operating conditions uncertainty. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000071 [article] Modeling heat exchangers under consideration of manufacturing tolerances and uncertain flow distribution = Modélisation des échangeurs de chaleur tenant compte des tolérances lors de la fabrication et l′irrégularité de l′écoulement [texte imprimé] / O. Abdelaziz, Auteur ; R. Radermacher, Auteur . - 2010 . - pp. 815-828. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 815-828 Mots-clés : Heat  exchanger  Geometry  Calculation  Simulation  Performance  Parameter  Manufacturing  Flow  Monte  Carlo Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Small dimensions found in modern and novel heat exchanger (HX) designs encounter very challenging manufacturing issues. With current manufacturing techniques HXs in small dimensions will exhibit large tolerances relative to design variables. Hence, the anticipated variation in performance is a concern. Furthermore, small flow channel dimensions are very susceptible to severe fouling and even blockage. Therefore, flow distribution would be uncertain. These uncertainties in dimensions and flow distribution should be accounted for during the design and performance evaluation of new HX geometries with focus on ultra-compact designs. This paper outlines an effort to theoretically evaluate the performance of an air-to-water HX, assembled from tubes with non-conventional heat transfer surfaces. Vertical spacing within this HX is subject to a predefined statistical distribution compounded with uncertainty in water flow rate through each flow path (i.e., tube). A new implementation technique for ɛ-NTU is proposed in order to accommodate different air conditions on both tube sides. A Monte Carlo simulation approach is used to estimate the HX performance distribution. This approach is applied to three HX designs showing the performance degradation subject to geometrical and flow uncertainties. The simulation results under uncertainty provided useful insights into the reasons for the performance degradation and showed great impact to the uncertainty distribution. Overall, the proposed HX design with the smallest dimensions showed the least performance degradation due to manufacturing and operating conditions uncertainty. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000071

Modelling and experimental validation of the hot-gas defrost process of an air-cooled evaporator / J. Alberto Dopazo in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 829-839 Titre : Modelling and experimental validation of the hot-gas defrost process of an air-cooled evaporator Titre original : Modélisation et validation expérimentale du processus de dégivrage à l'aide de gaz chaud d'un évaporateur refroidi par air Type de document : texte imprimé Auteurs : J. Alberto Dopazo, Auteur ; José Fernández-Seara, Auteur ; Francisco J. Uhía, Auteur Année de publication : 2010 Article en page(s) : pp. 829-839 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Evaporator  Modelling  Simulation  Experiment  Process  Defrosting  Hot  gas Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A detailed transient simulation model has been developed to predict and evaluate the performance of the hot-gas defrost process of an air-coil evaporator. In the model, the defrost process is subdivided into six stages: preheating, tube frost melting start, fin frost melting start, air presence, tube-fin water film and dry-heating. In each stage, the control volume is subdivided into systems represented by a single node, which has the representative properties of the system. A finite difference approach was used to solve the model equations. The results include the time required to defrost, the distribution of the energy during defrost process, the instantaneous refrigerant properties and the instantaneous fin and tube temperature distribution. The results are compared with experimental data obtained in a local storage facility under actual operating conditions and also using data available in the literature. The model results substantially agree with the experimental data in both cases. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000083 [article] Modelling and experimental validation of the hot-gas defrost process of an air-cooled evaporator = Modélisation et validation expérimentale du processus de dégivrage à l'aide de gaz chaud d'un évaporateur refroidi par air [texte imprimé] / J. Alberto Dopazo, Auteur ; José Fernández-Seara, Auteur ; Francisco J. Uhía, Auteur . - 2010 . - pp. 829-839. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 829-839 Mots-clés : Evaporator  Modelling  Simulation  Experiment  Process  Defrosting  Hot  gas Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A detailed transient simulation model has been developed to predict and evaluate the performance of the hot-gas defrost process of an air-coil evaporator. In the model, the defrost process is subdivided into six stages: preheating, tube frost melting start, fin frost melting start, air presence, tube-fin water film and dry-heating. In each stage, the control volume is subdivided into systems represented by a single node, which has the representative properties of the system. A finite difference approach was used to solve the model equations. The results include the time required to defrost, the distribution of the energy during defrost process, the instantaneous refrigerant properties and the instantaneous fin and tube temperature distribution. The results are compared with experimental data obtained in a local storage facility under actual operating conditions and also using data available in the literature. The model results substantially agree with the experimental data in both cases. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000083

An experimental study of the flow of R-407C in an adiabatic helical capillary tube / M.K. Mittal in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 840-847 Titre : An experimental study of the flow of R-407C in an adiabatic helical capillary tube Titre original : Etude expérimentale sur l‘écoulement du R-407C dans un tube capillaire adiabatique hélicoïdal Type de document : texte imprimé Auteurs : M.K. Mittal, Auteur ; Ravi Kumar, Auteur ; Akhilesh Gupta, Auteur Année de publication : 2010 Article en page(s) : pp. 840-847 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Helical  tube  Capillary  Experiment  Flow  R-407C  Correlation  Flow Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : This paper presents an experimental investigation of coiling effect on the flow of R-407C in an adiabatic helical capillary tube. It has been observed that the coiling of capillary tube significantly influences the mass flow rate of R-407C through the adiabatic helical capillary tube. For the sake of comparison, the experiments have also been conducted for straight capillary tube and it has been observed that the mass flow rates in coiled capillary tube are 5–10 percent less than those in a straight one. The data obtained from the experiments have been analyzed and non-dimensional correlations for the prediction of mass flow rate of R-407C in straight and helical capillary tube have been developed. The proposed correlations predict our experimental data in an error band of ±10 percent. The predictions by developed correlations are also in good agreement with the data of other investigators. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000034 [article] An experimental study of the flow of R-407C in an adiabatic helical capillary tube = Etude expérimentale sur l‘écoulement du R-407C dans un tube capillaire adiabatique hélicoïdal [texte imprimé] / M.K. Mittal, Auteur ; Ravi Kumar, Auteur ; Akhilesh Gupta, Auteur . - 2010 . - pp. 840-847. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 840-847 Mots-clés : Helical  tube  Capillary  Experiment  Flow  R-407C  Correlation  Flow Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : This paper presents an experimental investigation of coiling effect on the flow of R-407C in an adiabatic helical capillary tube. It has been observed that the coiling of capillary tube significantly influences the mass flow rate of R-407C through the adiabatic helical capillary tube. For the sake of comparison, the experiments have also been conducted for straight capillary tube and it has been observed that the mass flow rates in coiled capillary tube are 5–10 percent less than those in a straight one. The data obtained from the experiments have been analyzed and non-dimensional correlations for the prediction of mass flow rate of R-407C in straight and helical capillary tube have been developed. The proposed correlations predict our experimental data in an error band of ±10 percent. The predictions by developed correlations are also in good agreement with the data of other investigators. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000034

Effects of flash tank vapor injection on the heating performance of an inverter-driven heat pump for cold regions / Jaehyeok Heo in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 848-855 Titre : Effects of flash tank vapor injection on the heating performance of an inverter-driven heat pump for cold regions Titre original : Effets de ĺinjection de la vapeur du réservoir intermédiaire sur la performance en application chauffage d'une pompe à chaleur entraînée par convertisseur dans les climats froids Type de document : texte imprimé Auteurs : Jaehyeok Heo, Auteur ; Min Woo Jeong, Auteur ; Yongchan Kim, Auteur Année de publication : 2010 Article en page(s) : pp. 848-855 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Heat  pump  Two-stage  system  Variable  speed  Compressor  Experiment  Injection  Performance  COP Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A heat pump has received much attention as substitute for the conventional boiler or heating coil because of its high efficiency. For the wide application of the heat pump, the most important design factor is the performance degradation upon its installation in tropical and cold regions. In this study, the effects of flash tank vapor injection on the heating performance of a two-stage heat pump with an inverter-driven twin rotary compressor were measured and analyzed for compressor frequency ranging from 50 to 100 Hz at ambient temperatures of −15, −5, and 5 °C. The COP and heating capacity of the injection cycle were enhanced by 10% and 25%, respectively, at the ambient temperature of −15 °C. The total mass flow rate of the injection cycle was 30–38% higher than that of the non-injection cycle. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000022 [article] Effects of flash tank vapor injection on the heating performance of an inverter-driven heat pump for cold regions = Effets de ĺinjection de la vapeur du réservoir intermédiaire sur la performance en application chauffage d'une pompe à chaleur entraînée par convertisseur dans les climats froids [texte imprimé] / Jaehyeok Heo, Auteur ; Min Woo Jeong, Auteur ; Yongchan Kim, Auteur . - 2010 . - pp. 848-855. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 848-855 Mots-clés : Heat  pump  Two-stage  system  Variable  speed  Compressor  Experiment  Injection  Performance  COP Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A heat pump has received much attention as substitute for the conventional boiler or heating coil because of its high efficiency. For the wide application of the heat pump, the most important design factor is the performance degradation upon its installation in tropical and cold regions. In this study, the effects of flash tank vapor injection on the heating performance of a two-stage heat pump with an inverter-driven twin rotary compressor were measured and analyzed for compressor frequency ranging from 50 to 100 Hz at ambient temperatures of −15, −5, and 5 °C. The COP and heating capacity of the injection cycle were enhanced by 10% and 25%, respectively, at the ambient temperature of −15 °C. The total mass flow rate of the injection cycle was 30–38% higher than that of the non-injection cycle. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000022

Air infiltration in domestic refrigerators / Clito Afonso in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 856-867 Titre : Air infiltration in domestic refrigerators : The influence of the magnetic seals conservation Titre original : Infıltration d'air dans les réfrigérateurs domestiques: influence de l'état des joints magnétiques Type de document : texte imprimé Auteurs : Clito Afonso, Auteur ; Manuel Castro, Auteur Année de publication : 2010 Article en page(s) : pp. 856-867 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Domestic  refrigerator  Review  Seals  Process  Measurement  Infiltration  Air Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : One component of the heat exchange rate in domestic refrigerators/freezers and of the other all types of refrigeration stores is the air infiltration due to the air exchange rate between inside and outside of the store trough the magnetic seals of the doors. Due to their use (opening and closing the doors) they become leaky with the time. So, it is necessary to know to measure them in a proper way in order to be able to quantify which percentage of the energy consumption of the compressor is used to overcome the air infiltration rate. In this work the tracer gas technique was used for the measurement of the air infiltration rate in a household double door commercial refrigerator. Through several tests carried out it was possible to analyse the influence of the magnetic seal conservation condition on the air exchange rates of the refrigerator. It was concluded that the air infiltration rates were strongly dependent on the door seals conservation conditions. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700709002849 [article] Air infiltration in domestic refrigerators = Infıltration d'air dans les réfrigérateurs domestiques: influence de l'état des joints magnétiques : The influence of the magnetic seals conservation [texte imprimé] / Clito Afonso, Auteur ; Manuel Castro, Auteur . - 2010 . - pp. 856-867. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 856-867 Mots-clés : Domestic  refrigerator  Review  Seals  Process  Measurement  Infiltration  Air Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : One component of the heat exchange rate in domestic refrigerators/freezers and of the other all types of refrigeration stores is the air infiltration due to the air exchange rate between inside and outside of the store trough the magnetic seals of the doors. Due to their use (opening and closing the doors) they become leaky with the time. So, it is necessary to know to measure them in a proper way in order to be able to quantify which percentage of the energy consumption of the compressor is used to overcome the air infiltration rate. In this work the tracer gas technique was used for the measurement of the air infiltration rate in a household double door commercial refrigerator. Through several tests carried out it was possible to analyse the influence of the magnetic seal conservation condition on the air exchange rates of the refrigerator. It was concluded that the air infiltration rates were strongly dependent on the door seals conservation conditions. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700709002849

Computing the partial volume of pressure vessels / Bent Wiencke in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 868-876 Titre : Computing the partial volume of pressure vessels Titre original : Calcul du volume partiel des récipients sous pression Type de document : texte imprimé Auteurs : Bent Wiencke, Auteur Année de publication : 2010 Article en page(s) : pp. 868-876 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Refrigeration  system  Vessel  Storage  Two-phase  mixture  Calculation  Volume  Parameter  Geometry Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The computation of the partial and total volume of pressure vessels with various type of head profiles requires detailed knowledge of the head profile geometry. Depending on the type of head profile the derivation of the equations can become very complex and the calculation process cumbersome. Certain head profiles require numerical methods to obtain the partial volume, which for most application is beyond the scope of practicability. This paper suggests a unique method that simplifies the calculation procedure for the various types of head profiles by using one common set of equations without the need for numerical or complex computation methods. For ease of use, all equations presented in this paper are summarized in a single table format for horizontal and vertical vessels. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700709002734 [article] Computing the partial volume of pressure vessels = Calcul du volume partiel des récipients sous pression [texte imprimé] / Bent Wiencke, Auteur . - 2010 . - pp. 868-876. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 868-876 Mots-clés : Refrigeration  system  Vessel  Storage  Two-phase  mixture  Calculation  Volume  Parameter  Geometry Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The computation of the partial and total volume of pressure vessels with various type of head profiles requires detailed knowledge of the head profile geometry. Depending on the type of head profile the derivation of the equations can become very complex and the calculation process cumbersome. Certain head profiles require numerical methods to obtain the partial volume, which for most application is beyond the scope of practicability. This paper suggests a unique method that simplifies the calculation procedure for the various types of head profiles by using one common set of equations without the need for numerical or complex computation methods. For ease of use, all equations presented in this paper are summarized in a single table format for horizontal and vertical vessels. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700709002734

Effects of pre-treatment, freezing and frozen storage on the texture of Boletus edulis (Bull: Fr.) mushrooms / Grażyna Jaworska in International journal of refrigeration, Vol. 33 N° 4 (Juin 2010) 

Public ISBD [article]  in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 877-885 Titre : Effects of pre-treatment, freezing and frozen storage on the texture of Boletus edulis (Bull: Fr.) mushrooms Titre original : Les effets du pré-traitement, de la congélation et de l'entreposage sous forme congelée sur la texture des champignons (Boletus edulis) Type de document : texte imprimé Auteurs : Grażyna Jaworska, Auteur ; Emilia Bernaś, Auteur Année de publication : 2010 Article en page(s) : pp. 877-885 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Edible  mushroom  Review  Post-harvest  treatment  Frozen  Refrigerated  storage  Quality  Texture Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The aim of the present work was to determine changes in the texture of Boletus edulis resulting from blanching or soaking and blanching, freezing and twelve months' frozen storage. The texture was examined using instrumental as well as sensory profiling methods. Instrumental textural profile analysis (TPA) showed that, there was a reduction in hardness, chewiness and gumminess of 77–100% and an increase in cohesiveness of 121–521% after frozen storage, when compared to the raw material. Measurements using a Kramer shear cell revealed that the changes occurring at all stages of the investigation were similar. The end, the work required to cut strips of mushroom decreased by 3–32%, while the force increased by 27–110%. In the evaluation of texture through sensory profiling, the greatest changes in the characteristics listed occurred as a result of pre-treatment and frozen storage. There was a decrease in hardness, brittleness, crispiness and firmness of 0.7–3.5 points, accompanied by an increase in wateriness of 1.8–4.0 points. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000125 [article] Effects of pre-treatment, freezing and frozen storage on the texture of Boletus edulis (Bull: Fr.) mushrooms = Les effets du pré-traitement, de la congélation et de l'entreposage sous forme congelée sur la texture des champignons (Boletus edulis) [texte imprimé] / Grażyna Jaworska, Auteur ; Emilia Bernaś, Auteur . - 2010 . - pp. 877-885. Génie Mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 33 N° 4 (Juin 2010) . - pp. 877-885 Mots-clés : Edible  mushroom  Review  Post-harvest  treatment  Frozen  Refrigerated  storage  Quality  Texture Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The aim of the present work was to determine changes in the texture of Boletus edulis resulting from blanching or soaking and blanching, freezing and twelve months' frozen storage. The texture was examined using instrumental as well as sensory profiling methods. Instrumental textural profile analysis (TPA) showed that, there was a reduction in hardness, chewiness and gumminess of 77–100% and an increase in cohesiveness of 121–521% after frozen storage, when compared to the raw material. Measurements using a Kramer shear cell revealed that the changes occurring at all stages of the investigation were similar. The end, the work required to cut strips of mushroom decreased by 3–32%, while the force increased by 27–110%. In the evaluation of texture through sensory profiling, the greatest changes in the characteristics listed occurred as a result of pre-treatment and frozen storage. There was a decrease in hardness, brittleness, crispiness and firmness of 0.7–3.5 points, accompanied by an increase in wateriness of 1.8–4.0 points. DEWEY : 621.5 ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000125

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