Dépouillements

Effet of temperature on the effective latent heat of fusion of ice in aqueous solutions in Revue internationale du froid, Vol.33, issue 8 (December 2010)  

Public ISBD [article]  inRevue internationale du froid > Vol.33, issue 8 (December 2010) . - pp1533- 1539 Titre : Effet of temperature on the effective latent heat of fusion of ice in aqueous solutions Titre original : Effet de la température sur la chaleur latente de fusion de glace dans les solutions acqueuses Type de document : texte imprimé Année de publication : 2011 Article en page(s) : pp1533- 1539 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Thermodynamique; Fusion; Glace; Solution aqueuse; Chaleur latente; Paramètre; Température Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000459 [article] Effet of temperature on the effective latent heat of fusion of ice in aqueous solutions = Effet de la température sur la chaleur latente de fusion de glace dans les solutions acqueuses [texte imprimé] . - 2011 . - pp1533- 1539. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > Vol.33, issue 8 (December 2010) . - pp1533- 1539 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Thermodynamique; Fusion; Glace; Solution aqueuse; Chaleur latente; Paramètre; Température Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur En ligne : http://www.sciencedirect.com/science/article/pii/S0140700710000459

Experimental study on heat transfer characteristics of ice slurry in Revue internationale du froid, Vol.33, issue 8 (December 2010)

Public ISBD [article]  inRevue internationale du froid > Vol.33, issue 8 (December 2010) . - pp. 1540–1549 Titre : Experimental study on heat transfer characteristics of ice slurry Titre original : Etude expérimentale sur les caractéristiques de transfert de chaleur des coulis de glace Type de document : texte imprimé Année de publication : 2011 Article en page(s) : pp. 1540–1549 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Coulis de glace; Fusion; Coefficient de transfert de chaleur; Écoulement laminaire; Écoulement turbulent Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : Heat transfer characteristics of ice slurry were investigated experimentally. The Reynolds number, diameter of the tubes and ice packing factor (IPF) were varied as experimental parameters. For laminar flow, it was found that the ratio of the Nusselt numbers increased with the IPF, and an approximation equation of the Nusselt number could be derived using the apparent Reynolds number, IPF and the ratio of the average diameter of the ice particles to the diameter of the test tube. For turbulent flow, the ratio of the Nusselt numbers was 1 for each condition in the case of a low IPF. However, the ratio of the Nusselt numbers increased with the IPF in the high-IPF region. Moreover, the apparent Reynolds number, which can be derived by treating the ice slurry as a pseudoplastic fluid, can be used to determine the condition under which variation in the heat transfer characteristics of ice slurry in turbulent flow occurs. [article] Experimental study on heat transfer characteristics of ice slurry = Etude expérimentale sur les caractéristiques de transfert de chaleur des coulis de glace [texte imprimé] . - 2011 . - pp. 1540–1549. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > Vol.33, issue 8 (December 2010) . - pp. 1540–1549 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Coulis de glace; Fusion; Coefficient de transfert de chaleur; Écoulement laminaire; Écoulement turbulent Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : Heat transfer characteristics of ice slurry were investigated experimentally. The Reynolds number, diameter of the tubes and ice packing factor (IPF) were varied as experimental parameters. For laminar flow, it was found that the ratio of the Nusselt numbers increased with the IPF, and an approximation equation of the Nusselt number could be derived using the apparent Reynolds number, IPF and the ratio of the average diameter of the ice particles to the diameter of the test tube. For turbulent flow, the ratio of the Nusselt numbers was 1 for each condition in the case of a low IPF. However, the ratio of the Nusselt numbers increased with the IPF in the high-IPF region. Moreover, the apparent Reynolds number, which can be derived by treating the ice slurry as a pseudoplastic fluid, can be used to determine the condition under which variation in the heat transfer characteristics of ice slurry in turbulent flow occurs.

Numerical modeling of double-diffusive convection in ice slurry storage tank in Revue internationale du froid, Vol.33, issue 8 (December 2010)

Public ISBD [article]  inRevue internationale du froid > Vol.33, issue 8 (December 2010) . - pp. 1550–1558 Titre : Numerical modeling of double-diffusive convection in ice slurry storage tank Titre original : Modélisation de la convection à double diffusion dans un bac à accumulation de coulis de glace Type de document : texte imprimé Année de publication : 2011 Article en page(s) : pp. 1550–1558 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Accumulation thermique; Coulis de glace; Modélisation; Simulation; Fusion; Solution aqueuse Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : The interaction between laminar Rayleigh–Benard convection and non-isothermal melting process is studied for the case of ice slurry kept in a rectangular cavity heated from the bottom. Clear visualization of the Rayleigh–Benard convective cells and their interaction with the melting front are obtained. It is observed that the convective cells are characterized by zones of up-flow and down-flow, resulting in the development of a nonplanar interface. Because of the continuous advancement of the solid/liquid interface, the effective solid height of the cavity keeps decreasing. The results include also the evolution of the solid–liquid interface, the local temperature and the ice mass fraction inside the storage tank. [article] Numerical modeling of double-diffusive convection in ice slurry storage tank = Modélisation de la convection à double diffusion dans un bac à accumulation de coulis de glace [texte imprimé] . - 2011 . - pp. 1550–1558. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > Vol.33, issue 8 (December 2010) . - pp. 1550–1558 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Accumulation thermique; Coulis de glace; Modélisation; Simulation; Fusion; Solution aqueuse Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : The interaction between laminar Rayleigh–Benard convection and non-isothermal melting process is studied for the case of ice slurry kept in a rectangular cavity heated from the bottom. Clear visualization of the Rayleigh–Benard convective cells and their interaction with the melting front are obtained. It is observed that the convective cells are characterized by zones of up-flow and down-flow, resulting in the development of a nonplanar interface. Because of the continuous advancement of the solid/liquid interface, the effective solid height of the cavity keeps decreasing. The results include also the evolution of the solid–liquid interface, the local temperature and the ice mass fraction inside the storage tank.

Ice slurry crystallization based on kinetic phase-change modeling in Revue internationale du froid, Vol.33, issue 8 (December 2010)

Public ISBD [article]  inRevue internationale du froid > Vol.33, issue 8 (December 2010) . - pp. 1559–1568 Titre : Ice slurry crystallization based on kinetic phase-change modeling Titre original : Approché cinétique de la modélisation de la cristallisation des coulis de glace à changement de phase Type de document : texte imprimé Année de publication : 2011 Article en page(s) : pp. 1559–1568 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Coulis de glace; Cristallisation; Modélisation; simulation; Cinétique; Algorithme; Nucléation Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : Most crystallization models for ice slurries are based on the equilibrium thermodynamic approach, an assumption that is not made a priori here. We present results of simulations grounded on classical nucleation theory and crystal growth included in global Nakamura-type kinetics coupled with the one-dimensional nonlinear heat equation, another way to model the phase change. The work focuses on ice slurry crystallization using kinetic tools integrating the temperature glide for mixtures (i.e., the solid–liquid equilibrium temperature Tf depends on the residual fluid’s solute concentration) without any equilibrium assumption. The heat-transfer phenomena in the experimental device are first determined, and then the parameters of kinetic function of crystallization are identified for pure water samples and then for 15 wt% monopropylene glycol (MPG) – water mixtures. An inverse method is implemented with a genetic algorithm to determine the kinetic parameters. [article] Ice slurry crystallization based on kinetic phase-change modeling = Approché cinétique de la modélisation de la cristallisation des coulis de glace à changement de phase [texte imprimé] . - 2011 . - pp. 1559–1568. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > Vol.33, issue 8 (December 2010) . - pp. 1559–1568 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Coulis de glace; Cristallisation; Modélisation; simulation; Cinétique; Algorithme; Nucléation Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : Most crystallization models for ice slurries are based on the equilibrium thermodynamic approach, an assumption that is not made a priori here. We present results of simulations grounded on classical nucleation theory and crystal growth included in global Nakamura-type kinetics coupled with the one-dimensional nonlinear heat equation, another way to model the phase change. The work focuses on ice slurry crystallization using kinetic tools integrating the temperature glide for mixtures (i.e., the solid–liquid equilibrium temperature Tf depends on the residual fluid’s solute concentration) without any equilibrium assumption. The heat-transfer phenomena in the experimental device are first determined, and then the parameters of kinetic function of crystallization are identified for pure water samples and then for 15 wt% monopropylene glycol (MPG) – water mixtures. An inverse method is implemented with a genetic algorithm to determine the kinetic parameters.

Forced convective heat transfer in supercooled phase-change material suspensions with stochastic crystallization in Revue internationale du froid, Vol.33, issue 8 (December 2010)

Public ISBD [article]  inRevue internationale du froid > Vol.33, issue 8 (December 2010) . - pp. 1569–1582 Titre : Forced convective heat transfer in supercooled phase-change material suspensions with stochastic crystallization Titre original : Suspensions surrefroidies de matériaux à changement de phase à cristallisation stochastique: transfert de chaleur lors de la convection forcée Type de document : texte imprimé Année de publication : 2011 Article en page(s) : pp. 1569–1582 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Frigoporteur; Matériau; Changement de phase; Modélisation; Simulation; Fusion; Cristallisation; Suspension; Nucléation Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : A model has been developed for the simulation of laminar hydrodynamic and heat transfer characteristics in a horizontal circular tube for a suspension flow with micro-size phase-change material (PCM) particles. The energy equation is formulated by taking into consideration the heat absorption (or release) due to the phase-change process. The heat source or heat generation term in the energy equation is derived from solutions for freezing or melting inside the particles. The supercooling breakdown induced by the stochastic character of the crystallization is taken into account in the modeling with nucleation laws. The solutions were compared to experimental results obtained by different authors. [article] Forced convective heat transfer in supercooled phase-change material suspensions with stochastic crystallization = Suspensions surrefroidies de matériaux à changement de phase à cristallisation stochastique: transfert de chaleur lors de la convection forcée [texte imprimé] . - 2011 . - pp. 1569–1582. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > Vol.33, issue 8 (December 2010) . - pp. 1569–1582 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Frigoporteur; Matériau; Changement de phase; Modélisation; Simulation; Fusion; Cristallisation; Suspension; Nucléation Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : A model has been developed for the simulation of laminar hydrodynamic and heat transfer characteristics in a horizontal circular tube for a suspension flow with micro-size phase-change material (PCM) particles. The energy equation is formulated by taking into consideration the heat absorption (or release) due to the phase-change process. The heat source or heat generation term in the energy equation is derived from solutions for freezing or melting inside the particles. The supercooling breakdown induced by the stochastic character of the crystallization is taken into account in the modeling with nucleation laws. The solutions were compared to experimental results obtained by different authors.

Study on formation of ice slurry by W/O emulsion (discussion for promoting propagation of supercooling dissolution due to AC voltage impression) in Revue internationale du froid, Vol.33, issue 8 (December 2010)

Public ISBD [article]  inRevue internationale du froid > Vol.33, issue 8 (December 2010) . - pp. 1598–1604 Titre : Study on formation of ice slurry by W/O emulsion (discussion for promoting propagation of supercooling dissolution due to AC voltage impression) Titre original : Etude sur la génération de coulis de glace à l’aide d’une émulsion eau-huile (discussion sur la proportion de la propagation de la dissolution surrefroidie sous l’effet d’une tension électrique alternative) Type de document : texte imprimé Année de publication : 2011 Article en page(s) : pp. 1598–1604 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Coulis de glace;Émulsion;Eau;Huile;Enquête;Procédé;Champ électrique;Courant alternati Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : In an ice storage system, use of a water-in-oil (W/O) emulsion is an effective means of forming ice slurry. It is possible to form ice slurry by cooling the emulsion without the adhesion of ice to a cooling wall because water contained in the emulsion does not come in direct contact with the cooling wall. However, the start of propagation of supercooling dissolution barely occurs and the subsequent rate of propagation is much slower. In a previous study, it was clarified that DC voltage impression to the emulsion was effective in promoting the propagation of supercooling dissolution of the emulsion. In the present paper, the validity of applying an AC voltage to the emulsion in place of a DC voltage is discussed. Moreover, under a fixed composition ratio of water and oil in the emulsion, influences of varying the magnitudes of the applied AC voltage and frequency on the propagation process are clarified. [article] Study on formation of ice slurry by W/O emulsion (discussion for promoting propagation of supercooling dissolution due to AC voltage impression) = Etude sur la génération de coulis de glace à l’aide d’une émulsion eau-huile (discussion sur la proportion de la propagation de la dissolution surrefroidie sous l’effet d’une tension électrique alternative) [texte imprimé] . - 2011 . - pp. 1598–1604. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > Vol.33, issue 8 (December 2010) . - pp. 1598–1604 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Coulis de glace;Émulsion;Eau;Huile;Enquête;Procédé;Champ électrique;Courant alternati Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : In an ice storage system, use of a water-in-oil (W/O) emulsion is an effective means of forming ice slurry. It is possible to form ice slurry by cooling the emulsion without the adhesion of ice to a cooling wall because water contained in the emulsion does not come in direct contact with the cooling wall. However, the start of propagation of supercooling dissolution barely occurs and the subsequent rate of propagation is much slower. In a previous study, it was clarified that DC voltage impression to the emulsion was effective in promoting the propagation of supercooling dissolution of the emulsion. In the present paper, the validity of applying an AC voltage to the emulsion in place of a DC voltage is discussed. Moreover, under a fixed composition ratio of water and oil in the emulsion, influences of varying the magnitudes of the applied AC voltage and frequency on the propagation process are clarified.

Encapsulated phase change material under cyclic pulsed heat load in Revue internationale du froid, Vol.33, issue 8 (December 2010)

Public ISBD [article]  inRevue internationale du froid > Vol.33, issue 8 (December 2010) . - pp. 1648–1656 Titre : Encapsulated phase change material under cyclic pulsed heat load Titre original : Matériau à changement de phase encapsulé à charge thermique à pulsations Type de document : texte imprimé Année de publication : 2011 Article en page(s) : pp. 1648–1656 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Accumulation thermique; Matériau; Changement de phase; Modélisation; Simulation; Énergie solaire; Amélioration Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : The objective of this work is to investigate numerically a storage system formed by a cylindrical tank which is randomly packed with spheres having uniform sizes and encapsulating paraffin as phase change material (PCM). The packed bed is tested for various complex input temperature signals of the working fluid as well as for different internal layouts. A stochastic differential Langevin equation is used to add some randomness in the sinusoidal inlet working fluid temperature signal. The results obtained put into evidence the noticeable sensitivity of the bed response to the adjunction of such a low amplitude stochastic signal. The results obtained for a multi-slab configuration indicate also that it is possible to maximise the energy stored under a latent form by properly selecting and ordering the different PCM’s in the bed. [article] Encapsulated phase change material under cyclic pulsed heat load = Matériau à changement de phase encapsulé à charge thermique à pulsations [texte imprimé] . - 2011 . - pp. 1648–1656. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > Vol.33, issue 8 (December 2010) . - pp. 1648–1656 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Accumulation thermique; Matériau; Changement de phase; Modélisation; Simulation; Énergie solaire; Amélioration Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : The objective of this work is to investigate numerically a storage system formed by a cylindrical tank which is randomly packed with spheres having uniform sizes and encapsulating paraffin as phase change material (PCM). The packed bed is tested for various complex input temperature signals of the working fluid as well as for different internal layouts. A stochastic differential Langevin equation is used to add some randomness in the sinusoidal inlet working fluid temperature signal. The results obtained put into evidence the noticeable sensitivity of the bed response to the adjunction of such a low amplitude stochastic signal. The results obtained for a multi-slab configuration indicate also that it is possible to maximise the energy stored under a latent form by properly selecting and ordering the different PCM’s in the bed.