Dépouillements

Water-coupled carbon dioxide microchannel gas cooler for heat pump water heaters: Part I - Experiments in Revue internationale du froid, vol 34, issue 1 (janvier 2011)

Public ISBD [article]  inRevue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 7-16 Titre : Water-coupled carbon dioxide microchannel gas cooler for heat pump water heaters: Part I - Experiments Titre original : Refroidisseur de gaz à microcanaux au dioxyde de carbone pour les pompes à chaleur utilisées pour chauffer de l'eau sanitaire : Partie I - Expériences Type de document : texte imprimé Année de publication : 2012 Article en page(s) : pp. 7-16 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Pompe à chaleur; Chauffage; Eau sanitaire; Dioxyde de carbone; Cycle transcritique; Expérimentation; Refroidisseur de gaz; Microcanal Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : An experimental and analytical study on the performance of a compact, microchannel water- carbon dioxide (CO2) gas cooler was conducted. The gas cooler design under investigation used an array of serpentine refrigerant microchannel tubes wrapped around water passages containing offset strip fins, resulting in a generally counterflow configuration between the two fluids. Part I of this two-part paper addresses the experimental aspects. Data were obtained using an experimental heat pump facility at varying inlet conditions for three gas coolers of the same design, but different sizes. Measured heating capacity for the three gas coolers ranged from 1.5 to 6.5 kW. The results of this study are used in the companion paper (Part II) to develop a predictive heat exchanger model to optimize gas cooler design over a wide range of operating conditions, eliminating the need for expensive prototype development and testing. [article] Water-coupled carbon dioxide microchannel gas cooler for heat pump water heaters: Part I - Experiments = Refroidisseur de gaz à microcanaux au dioxyde de carbone pour les pompes à chaleur utilisées pour chauffer de l'eau sanitaire : Partie I - Expériences [texte imprimé] . - 2012 . - pp. 7-16. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 7-16 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Pompe à chaleur; Chauffage; Eau sanitaire; Dioxyde de carbone; Cycle transcritique; Expérimentation; Refroidisseur de gaz; Microcanal Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : An experimental and analytical study on the performance of a compact, microchannel water- carbon dioxide (CO2) gas cooler was conducted. The gas cooler design under investigation used an array of serpentine refrigerant microchannel tubes wrapped around water passages containing offset strip fins, resulting in a generally counterflow configuration between the two fluids. Part I of this two-part paper addresses the experimental aspects. Data were obtained using an experimental heat pump facility at varying inlet conditions for three gas coolers of the same design, but different sizes. Measured heating capacity for the three gas coolers ranged from 1.5 to 6.5 kW. The results of this study are used in the companion paper (Part II) to develop a predictive heat exchanger model to optimize gas cooler design over a wide range of operating conditions, eliminating the need for expensive prototype development and testing.

Water-coupled carbon dioxide microchannel gas cooler for heat pump water heaters: Part II – Model development and validation in Revue internationale du froid, vol 34, issue 1 (janvier 2011)

Public ISBD [article]  inRevue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 17-28 Titre : Water-coupled carbon dioxide microchannel gas cooler for heat pump water heaters: Part II – Model development and validation Titre original : Refroidisseur de gaz à microcanaux sur eau souterraine pour des pompes à chaleur au dioxyde de carbone utilisées pour chauffer de l'eau sanitaire : Partie II – Développement et validation du modèle Type de document : texte imprimé Année de publication : 2012 Article en page(s) : pp. 17-28 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : échangeur de chaleur; refroidisseur de gaz; dioxyde de carbone; cycle transcritique; micro-canal; pompe à chaleur; chauffage; eau sanitaire; modélisation - simulation Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : An experimental and analytical study on the performance of a compact, microchannel water-carbon dioxide (CO2) gas cooler was conducted. The experimental results addressed in Part I of this study are used here in Part II to develop an analytical model, utilizing a segmented approach to account for the steep gradients in the thermodynamic and transport properties of supercritical CO2. The model predicted gas cooler heat duty with an average absolute deviation of 7.5% with varying refrigerant and water inlet conditions. The segmented model reveals that near the pseudo-critical point, there is a significant local decrease in refrigerant-side thermal resistance, which yields a sharp increase in local heat duty. The impact of this spike on gas cooler performance is analyzed. Results from this study can be used to predict the effect of changing geometric parameters of the heat exchanger without the need for expensive prototype development and testing. [article] Water-coupled carbon dioxide microchannel gas cooler for heat pump water heaters: Part II – Model development and validation = Refroidisseur de gaz à microcanaux sur eau souterraine pour des pompes à chaleur au dioxyde de carbone utilisées pour chauffer de l'eau sanitaire : Partie II – Développement et validation du modèle [texte imprimé] . - 2012 . - pp. 17-28. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 17-28 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : échangeur de chaleur; refroidisseur de gaz; dioxyde de carbone; cycle transcritique; micro-canal; pompe à chaleur; chauffage; eau sanitaire; modélisation - simulation Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : An experimental and analytical study on the performance of a compact, microchannel water-carbon dioxide (CO2) gas cooler was conducted. The experimental results addressed in Part I of this study are used here in Part II to develop an analytical model, utilizing a segmented approach to account for the steep gradients in the thermodynamic and transport properties of supercritical CO2. The model predicted gas cooler heat duty with an average absolute deviation of 7.5% with varying refrigerant and water inlet conditions. The segmented model reveals that near the pseudo-critical point, there is a significant local decrease in refrigerant-side thermal resistance, which yields a sharp increase in local heat duty. The impact of this spike on gas cooler performance is analyzed. Results from this study can be used to predict the effect of changing geometric parameters of the heat exchanger without the need for expensive prototype development and testing.

Flow and convection heat transfer characteristics of CO2 mixed with lubricating oil at super-critical pressures in small tube during cooling in Revue internationale du froid, vol 34, issue 1 (janvier 2011)

Public ISBD [article]  inRevue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 29-39 Titre : Flow and convection heat transfer characteristics of CO2 mixed with lubricating oil at super-critical pressures in small tube during cooling Titre original : Caractéristiques d'écoulement et de transfert de chaleur du CO2 mélangé avec de l'huile lubrifiante à des pressions surcritiques à l'intérieur de tubes de faible diamètre lors du refroidissement Type de document : texte imprimé Année de publication : 2012 Article en page(s) : pp. 29-39 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Dioxyde de carbone; Cycle transcritique; Mélange; Polyolester; Transfert de chaleur; Écoulement; Chute de pression Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : This paper describes the heat transfer and the pressure drop characteristics of CO2 mixed with small amounts of compatible lubricating oil at super-critical pressures inside horizontal tubes with inner diameters of 1.98 mm and 4.14 mm during cooling. The heat transfer coefficients and pressure drops were measured. The results show that for the oil-free cases, the correlation proposed by Dang and Hihara accurately predicted the heat transfer coefficients and Petukhov’s correlation was found to predict the frictional pressure drops reasonably. Entrainment of the lubricating oil reduced the heat transfer coefficients and increased the pressure drops. Analysis showed that the heat transfer coefficients of the CO2/oil mixture are strongly related to the density and viscosity ratios of the oil to the CO2. An empirical correlation was developed based on the measured data, which predicts most of the experimental data within a deviation of 20%. [article] Flow and convection heat transfer characteristics of CO2 mixed with lubricating oil at super-critical pressures in small tube during cooling = Caractéristiques d'écoulement et de transfert de chaleur du CO2 mélangé avec de l'huile lubrifiante à des pressions surcritiques à l'intérieur de tubes de faible diamètre lors du refroidissement [texte imprimé] . - 2012 . - pp. 29-39. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 29-39 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Dioxyde de carbone; Cycle transcritique; Mélange; Polyolester; Transfert de chaleur; Écoulement; Chute de pression Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : This paper describes the heat transfer and the pressure drop characteristics of CO2 mixed with small amounts of compatible lubricating oil at super-critical pressures inside horizontal tubes with inner diameters of 1.98 mm and 4.14 mm during cooling. The heat transfer coefficients and pressure drops were measured. The results show that for the oil-free cases, the correlation proposed by Dang and Hihara accurately predicted the heat transfer coefficients and Petukhov’s correlation was found to predict the frictional pressure drops reasonably. Entrainment of the lubricating oil reduced the heat transfer coefficients and increased the pressure drops. Analysis showed that the heat transfer coefficients of the CO2/oil mixture are strongly related to the density and viscosity ratios of the oil to the CO2. An empirical correlation was developed based on the measured data, which predicts most of the experimental data within a deviation of 20%.

Journal bearings design for a novel revolving vane compressor in Revue internationale du froid, vol 34, issue 1 (janvier 2011)

Public ISBD [article]  inRevue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 94-104 Titre : Journal bearings design for a novel revolving vane compressor Titre original : Conception des paliers lisses pour un nouveau compresseur à palettes rotatives Type de document : texte imprimé Année de publication : 2012 Article en page(s) : pp. 94-104 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Conditionnement d'air; Palier; Conception; Compresseur; Performance Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : This paper presents the theoretical details of the journal bearing design for Revolving Vane (RV) rotary type compressor. The mathematical models, force analysis, and the theoretical design analysis for the dynamically loaded journal bearing of the compressor are presented. The variations of the minimum oil film thickness and the maximum film pressure developed are shown and the influences of design parameters, compressor configurations, and operating conditions on the journal bearing performance are described. For an air-conditioning compressor of 1.5 kW cooling capacity, the lowest minimum oil film thickness for lower and upper journal bearings is 6.6 ?m and 4.3 ?m respectively, when the cylinder is simply supported and the rotor is cantilever-supported. The lowest minimum oil film thickness for the journal bearing, which supports the cylinder, reduces to 4.0 ?m if the cantilever-type support is used. Besides that, a short-fat configuration of RV compressor is favorable in the interest of lowering bearing forces. [article] Journal bearings design for a novel revolving vane compressor = Conception des paliers lisses pour un nouveau compresseur à palettes rotatives [texte imprimé] . - 2012 . - pp. 94-104. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 94-104 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Conditionnement d'air; Palier; Conception; Compresseur; Performance Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : This paper presents the theoretical details of the journal bearing design for Revolving Vane (RV) rotary type compressor. The mathematical models, force analysis, and the theoretical design analysis for the dynamically loaded journal bearing of the compressor are presented. The variations of the minimum oil film thickness and the maximum film pressure developed are shown and the influences of design parameters, compressor configurations, and operating conditions on the journal bearing performance are described. For an air-conditioning compressor of 1.5 kW cooling capacity, the lowest minimum oil film thickness for lower and upper journal bearings is 6.6 ?m and 4.3 ?m respectively, when the cylinder is simply supported and the rotor is cantilever-supported. The lowest minimum oil film thickness for the journal bearing, which supports the cylinder, reduces to 4.0 ?m if the cantilever-type support is used. Besides that, a short-fat configuration of RV compressor is favorable in the interest of lowering bearing forces.

An experimental study on oil discharge ratio at inverter-driven high shell pressure scroll compressor using R410A/PVE in Revue internationale du froid, vol 34, issue 1 (janvier 2011)

Public ISBD [article]  inRevue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp.105-112 Titre : An experimental study on oil discharge ratio at inverter-driven high shell pressure scroll compressor using R410A/PVE Titre original : Etude expérimentale sur le taux d'huile au refoulement d'un compresseur à spirale à pression élevée dans l'enveloppe entraîné par des variateurs de fréquence utilisant le R410A et l'huile polyvinyléther (PVE) Type de document : texte imprimé Année de publication : 2012 Article en page(s) : pp.105-112 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Compresseur à spirale; R410A; Huile; Refoulement Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : In this study, the oil discharge characteristics of a high shell pressure scroll compressor, which uses R410A as the refrigerant and PVE as the oil, were measured according to the conditions for oil management. The measurement of oil discharge ratio (ODR) in the system is very important to secure the operational reliability. It was made in real time through the refractive index sensor. ODR was greatly influenced by the mass flow rate and the dynamic viscosity of the refrigerant. As the rotation frequency of the compressor became higher, ODR increased rapidly. ODR at 120 Hz was 4.22 times higher than that at 60 Hz. At the same rotation frequency of the compressor, the increase of the suction pressure also played a role in increasing the ODR. In addition, in the zone where the ODR increased rapidly, the compressing efficiency of the compressor decreased significantly. [article] An experimental study on oil discharge ratio at inverter-driven high shell pressure scroll compressor using R410A/PVE = Etude expérimentale sur le taux d'huile au refoulement d'un compresseur à spirale à pression élevée dans l'enveloppe entraîné par des variateurs de fréquence utilisant le R410A et l'huile polyvinyléther (PVE) [texte imprimé] . - 2012 . - pp.105-112. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp.105-112 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Compresseur à spirale; R410A; Huile; Refoulement Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : In this study, the oil discharge characteristics of a high shell pressure scroll compressor, which uses R410A as the refrigerant and PVE as the oil, were measured according to the conditions for oil management. The measurement of oil discharge ratio (ODR) in the system is very important to secure the operational reliability. It was made in real time through the refractive index sensor. ODR was greatly influenced by the mass flow rate and the dynamic viscosity of the refrigerant. As the rotation frequency of the compressor became higher, ODR increased rapidly. ODR at 120 Hz was 4.22 times higher than that at 60 Hz. At the same rotation frequency of the compressor, the increase of the suction pressure also played a role in increasing the ODR. In addition, in the zone where the ODR increased rapidly, the compressing efficiency of the compressor decreased significantly.

Heat and mass transfer characteristics of a constrained thin-film ammonia–water bubble absorber in Revue internationale du froid, vol 34, issue 1 (janvier 2011)

Public ISBD [article]  inRevue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 113-128 Titre : Heat and mass transfer characteristics of a constrained thin-film ammonia–water bubble absorber Titre original : Absorbeur à bulles à ammoniac-eau aux pellicules minces limitées : caractéristiques du transfert de chaleur et de masse Type de document : texte imprimé Année de publication : 2012 Article en page(s) : pp. 113-128 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Absorbeur; Microcanal; Bulle; Ammoniac; Eau Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : A study of absorption of ammonia vapour bubbles into a constrained thin-film of ammonia–water solution is presented. A large-aspect-ratio microchannel constrains the thickness of the weak solution film and ammonia vapour bubbles are injected from a porous wall. A counter flowing coolant in a minichannel removes the generated heat of absorption. Experiments and a simple one-dimensional numerical model are used to characterize the absorber performance at a nominal system pressure of 6.2 bar absolute. Effect of varying the mass flow rate of the weak solution, vapour flow rate, solution inlet temperature, and coolant inlet temperature on absorption heat and mass transfer rates and exit subcooling are discussed. Two absorber channel geometries, each of 600 ?m nominal depth, are considered: 1) a smooth-wall channel, and 2) a stepped-wall channel that has 2-mm deep trenches across the width of a channel wall. Results indicate that the reduction in coolant inlet temperature significantly enhances the mass transfer rates in both absorber geometries. While the stepped-wall geometry exhibits higher mass transfer rates at lower coolant inlet temperatures of 30 °C and 40 °C, the smooth-wall channel shows higher mass transfer rates at the highest coolant inlet temperature of 58 °C. Both absorption limited and residence time limited conditions are observed with variation of weak solution flow rate at fixed vapour flow rates. [article] Heat and mass transfer characteristics of a constrained thin-film ammonia–water bubble absorber = Absorbeur à bulles à ammoniac-eau aux pellicules minces limitées : caractéristiques du transfert de chaleur et de masse [texte imprimé] . - 2012 . - pp. 113-128. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 113-128 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Absorbeur; Microcanal; Bulle; Ammoniac; Eau Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : A study of absorption of ammonia vapour bubbles into a constrained thin-film of ammonia–water solution is presented. A large-aspect-ratio microchannel constrains the thickness of the weak solution film and ammonia vapour bubbles are injected from a porous wall. A counter flowing coolant in a minichannel removes the generated heat of absorption. Experiments and a simple one-dimensional numerical model are used to characterize the absorber performance at a nominal system pressure of 6.2 bar absolute. Effect of varying the mass flow rate of the weak solution, vapour flow rate, solution inlet temperature, and coolant inlet temperature on absorption heat and mass transfer rates and exit subcooling are discussed. Two absorber channel geometries, each of 600 ?m nominal depth, are considered: 1) a smooth-wall channel, and 2) a stepped-wall channel that has 2-mm deep trenches across the width of a channel wall. Results indicate that the reduction in coolant inlet temperature significantly enhances the mass transfer rates in both absorber geometries. While the stepped-wall geometry exhibits higher mass transfer rates at lower coolant inlet temperatures of 30 °C and 40 °C, the smooth-wall channel shows higher mass transfer rates at the highest coolant inlet temperature of 58 °C. Both absorption limited and residence time limited conditions are observed with variation of weak solution flow rate at fixed vapour flow rates.

Performance evaluation of combined adsorption refrigeration cycles in Revue internationale du froid, vol 34, issue 1 (janvier 2011)

Public ISBD [article]  inRevue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 129-137 Titre : Performance evaluation of combined adsorption refrigeration cycles Titre original : Evaluation de la performance des cycles frigorifiques combinés à adsorption Type de document : texte imprimé Année de publication : 2012 Article en page(s) : pp. 129-137 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Adsorption; Refroidissement; R134a; R507; Charbon actif-cycle Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : This paper presents the results of an investigation on the performance of combined adsorption refrigeration cycles. The novel combined cycle amalgamates the activated carbon (AC)-R507A as the bottoming cycle and AC-R134a cycle as the topping cycle and deliver refrigeration load at as low as ?10 °C at the bottoming cycle. The cycle simulation is based on the experimentally confirmed adsorption isotherms, kinetics and isosteric heat of adsorption data for R134a and R507A on highly porous based activated carbon of type Maxsorb III. The optimum cooling capacity, coefficient of performance (COP) and chiller efficiency are calculated in terms of cycle time, switching time, regeneration and brine inlet temperatures. Results show that the combined adsorption cycles are feasible even when low-temperature heat source is available. [article] Performance evaluation of combined adsorption refrigeration cycles = Evaluation de la performance des cycles frigorifiques combinés à adsorption [texte imprimé] . - 2012 . - pp. 129-137. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 129-137 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Adsorption; Refroidissement; R134a; R507; Charbon actif-cycle Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : This paper presents the results of an investigation on the performance of combined adsorption refrigeration cycles. The novel combined cycle amalgamates the activated carbon (AC)-R507A as the bottoming cycle and AC-R134a cycle as the topping cycle and deliver refrigeration load at as low as ?10 °C at the bottoming cycle. The cycle simulation is based on the experimentally confirmed adsorption isotherms, kinetics and isosteric heat of adsorption data for R134a and R507A on highly porous based activated carbon of type Maxsorb III. The optimum cooling capacity, coefficient of performance (COP) and chiller efficiency are calculated in terms of cycle time, switching time, regeneration and brine inlet temperatures. Results show that the combined adsorption cycles are feasible even when low-temperature heat source is available.

Performance of an adiabatic cross-flow liquid-desiccant absorber inside a refrigerated warehouse in Revue internationale du froid, vol 34, issue 1 (janvier 2011)

Public ISBD [article]  inRevue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 138-147 Titre : Performance of an adiabatic cross-flow liquid-desiccant absorber inside a refrigerated warehouse Titre original : Performance d'un absorbeur à déshydratant liquide à écoulements croisés adiabatiques dans un entrepôt frigorifique Type de document : texte imprimé Année de publication : 2012 Article en page(s) : pp. 138-147 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Entreposage frigorifique; Déshydratant; Dégivrage; Consommation d'énergie; Diminution; Humidité Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : Liquid-desiccant systems have been extensively studied as a way of reducing the latent load on air conditioning systems. Most of the studies have targeted the removal of moisture from air at ambient conditions. The literature about the use of liquid desiccants in low temperature applications is scarce. In this study, a small-scale liquid-desiccant absorber is installed inside a commercial refrigerated warehouse. Its performance under realistic operating conditions inside a pre-cooling room is analyzed. The results show that the dew point temperature of the air downstream of the absorber is comparable to the evaporator surface temperature suggesting the potential to delay the formation of ice on the cooling coil. An internal heat exchanger is used to lower the temperature of the inlet liquid-desiccant flow to the absorber and the regeneration process is performed using only ambient air. The analysis of the reduction in water and energy consumption for a scaled-up system is also performed. [article] Performance of an adiabatic cross-flow liquid-desiccant absorber inside a refrigerated warehouse = Performance d'un absorbeur à déshydratant liquide à écoulements croisés adiabatiques dans un entrepôt frigorifique [texte imprimé] . - 2012 . - pp. 138-147. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 138-147 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Entreposage frigorifique; Déshydratant; Dégivrage; Consommation d'énergie; Diminution; Humidité Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : Liquid-desiccant systems have been extensively studied as a way of reducing the latent load on air conditioning systems. Most of the studies have targeted the removal of moisture from air at ambient conditions. The literature about the use of liquid desiccants in low temperature applications is scarce. In this study, a small-scale liquid-desiccant absorber is installed inside a commercial refrigerated warehouse. Its performance under realistic operating conditions inside a pre-cooling room is analyzed. The results show that the dew point temperature of the air downstream of the absorber is comparable to the evaporator surface temperature suggesting the potential to delay the formation of ice on the cooling coil. An internal heat exchanger is used to lower the temperature of the inlet liquid-desiccant flow to the absorber and the regeneration process is performed using only ambient air. The analysis of the reduction in water and energy consumption for a scaled-up system is also performed.

The influence of the magnetic field on the performance of an active magnetic regenerator (AMR) in Revue internationale du froid, vol 34, issue 1 (janvier 2011)

Public ISBD [article]  inRevue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 192-203 Titre : The influence of the magnetic field on the performance of an active magnetic regenerator (AMR) Titre original : Influence du champ magnétique actif sur la performance d'un régénérateur magnétique actif Type de document : texte imprimé Année de publication : 2012 Article en page(s) : pp. 192-203 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Réfrigérateur magnétique; Champ magnétique; Simulation; Modélisation; Performance; Variation Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : The influence of the time variation of the magnetic field, termed the magnetic field profile, on the performance of a magnetocaloric refrigeration device using the active magnetic regeneration (AMR) cycle is studied for a number of process parameters for both a parallel plate and packed bed regenerator using a numerical model. The cooling curve of the AMR is shown to be almost linear far from the Curie temperature of the magnetocaloric material. It is shown that a magnetic field profile that is 10% of the cycle time out of sync with the flow profile leads to a drop in both the maximum temperature span and the maximum cooling capacity of 20–40% for both parallel plate and packed bed regenerators. The maximum cooling capacity is shown to depend very weakly on the ramp rate of the magnetic field. Reducing the temporal width of the high field portion of the magnetic field profile by 10% leads to a drop in maximum temperature span and maximum cooling capacity of 5–20%. An increase of the magnetic field from 1 T to 1.5 T increases the maximum cooling capacity by 30–50% but the maximum temperature span by only 20–30%. Finally, it was seen that the influence of changing the magnetic field was more or less the same for the different regenerator geometries and operating parameters studied here. This means that the design of the magnet can be done independently of the regenerator geometry. [article] The influence of the magnetic field on the performance of an active magnetic regenerator (AMR) = Influence du champ magnétique actif sur la performance d'un régénérateur magnétique actif [texte imprimé] . - 2012 . - pp. 192-203. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 192-203 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Réfrigérateur magnétique; Champ magnétique; Simulation; Modélisation; Performance; Variation Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : The influence of the time variation of the magnetic field, termed the magnetic field profile, on the performance of a magnetocaloric refrigeration device using the active magnetic regeneration (AMR) cycle is studied for a number of process parameters for both a parallel plate and packed bed regenerator using a numerical model. The cooling curve of the AMR is shown to be almost linear far from the Curie temperature of the magnetocaloric material. It is shown that a magnetic field profile that is 10% of the cycle time out of sync with the flow profile leads to a drop in both the maximum temperature span and the maximum cooling capacity of 20–40% for both parallel plate and packed bed regenerators. The maximum cooling capacity is shown to depend very weakly on the ramp rate of the magnetic field. Reducing the temporal width of the high field portion of the magnetic field profile by 10% leads to a drop in maximum temperature span and maximum cooling capacity of 5–20%. An increase of the magnetic field from 1 T to 1.5 T increases the maximum cooling capacity by 30–50% but the maximum temperature span by only 20–30%. Finally, it was seen that the influence of changing the magnetic field was more or less the same for the different regenerator geometries and operating parameters studied here. This means that the design of the magnet can be done independently of the regenerator geometry.

Numerical simulation and its verification for an active magnetic regenerator in Revue internationale du froid, vol 34, issue 1 (janvier 2011)

Public ISBD [article]  inRevue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 204-215 Titre : Numerical simulation and its verification for an active magnetic regenerator Titre original : Régénérateur magnétique actif : simulation numérique et vérification Type de document : texte imprimé Année de publication : 2012 Article en page(s) : pp. 204-215 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Réfrigérateur magnétique; Modélisation; Simulation; Comparaison; Expérimentation; Gadolinium Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : In this study, a one-dimensional model for the active magnetic regenerator (AMR) is established and verified by comparison with the experimental results. Besides four basic governing equations concerning mass and momentum conservation of heat transfer fluid and energy conservation of fluid and magnetic refrigerant, energy conservation of the regenerator wall is considered to achieve high accuracy and generalization. For the verification, a room temperature AMR has been fabricated with Gd and Halbach array. The AMR is operated by helium compressor with a rotary valve so that the effect of gas-compression/expansion also exists. Instantaneous mass flow rate and temperature distributions are measured during the experiment. Measured values are utilized as the boundary conditions and compared with the simulation results. Instead of cooling capacity or COP, simulation results are directly compared with the experimental results by temperature distribution in the AMR. The model and simulation results predict temperature distribution of the AMR properly at cyclic steady-state. [article] Numerical simulation and its verification for an active magnetic regenerator = Régénérateur magnétique actif : simulation numérique et vérification [texte imprimé] . - 2012 . - pp. 204-215. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 204-215 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Réfrigérateur magnétique; Modélisation; Simulation; Comparaison; Expérimentation; Gadolinium Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : In this study, a one-dimensional model for the active magnetic regenerator (AMR) is established and verified by comparison with the experimental results. Besides four basic governing equations concerning mass and momentum conservation of heat transfer fluid and energy conservation of fluid and magnetic refrigerant, energy conservation of the regenerator wall is considered to achieve high accuracy and generalization. For the verification, a room temperature AMR has been fabricated with Gd and Halbach array. The AMR is operated by helium compressor with a rotary valve so that the effect of gas-compression/expansion also exists. Instantaneous mass flow rate and temperature distributions are measured during the experiment. Measured values are utilized as the boundary conditions and compared with the simulation results. Instead of cooling capacity or COP, simulation results are directly compared with the experimental results by temperature distribution in the AMR. The model and simulation results predict temperature distribution of the AMR properly at cyclic steady-state.

Performance optimization of a two-circuit cycle with parallel evaporators for a domestic refrigerator–freezer in Revue internationale du froid, vol 34, issue 1 (janvier 2011)

Public ISBD [article]  inRevue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 216-224 Titre : Performance optimization of a two-circuit cycle with parallel evaporators for a domestic refrigerator–freezer Titre original : Optimisation de la performance d'un cycle à deux circuits muni d'évaporateurs parallèles pour un réfrigérateur/congélateur domestique Type de document : texte imprimé Année de publication : 2012 Article en page(s) : pp. 216-224 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Réfrigérateur domestique; Écoulement parallèle; Cycle; Performance; Optimisation Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : A two-circuit cycle with parallel evaporators (called a “parallel cycle”) for a domestic refrigerator–freezer (RF) shows energy saving potential compared with a conventional cycle with a single loop or serial evaporators because of a low compression ratio in the fresh food compartment (R)-operation. The objective of this study is to investigate the effects of the refrigerant charge, R-capillary tube, and refrigerant recovery operation on the performance of a parallel cycle. In addition, design guidelines for the heat transfer area and air flow rate of an R-evaporator are proposed. When the parallel cycle was optimized in terms of the refrigerant charge and R-capillary tube diameter, the energy consumption was reduced by 7.8% over a bypass two-circuit cycle with the same RF platform. In addition, an additional energy saving of 1.8% was obtained by the optimization of the operating sequence and refrigerant recovery operation. [article] Performance optimization of a two-circuit cycle with parallel evaporators for a domestic refrigerator–freezer = Optimisation de la performance d'un cycle à deux circuits muni d'évaporateurs parallèles pour un réfrigérateur/congélateur domestique [texte imprimé] . - 2012 . - pp. 216-224. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 216-224 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Réfrigérateur domestique; Écoulement parallèle; Cycle; Performance; Optimisation Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : A two-circuit cycle with parallel evaporators (called a “parallel cycle”) for a domestic refrigerator–freezer (RF) shows energy saving potential compared with a conventional cycle with a single loop or serial evaporators because of a low compression ratio in the fresh food compartment (R)-operation. The objective of this study is to investigate the effects of the refrigerant charge, R-capillary tube, and refrigerant recovery operation on the performance of a parallel cycle. In addition, design guidelines for the heat transfer area and air flow rate of an R-evaporator are proposed. When the parallel cycle was optimized in terms of the refrigerant charge and R-capillary tube diameter, the energy consumption was reduced by 7.8% over a bypass two-circuit cycle with the same RF platform. In addition, an additional energy saving of 1.8% was obtained by the optimization of the operating sequence and refrigerant recovery operation.

Performance of vapor compression systems with compressor oil flooding and regeneration in Revue internationale du froid, vol 34, issue 1 (janvier 2011)

Public ISBD [article]  inRevue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp.225-233 Titre : Performance of vapor compression systems with compressor oil flooding and regeneration Titre original : Performance des systèmes à compression de vapeur munis de compresseurs avec suralimentation en huile et régénération Type de document : texte imprimé Année de publication : 2012 Article en page(s) : pp.225-233 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Conditionnement d'air; Froid; Régénération; Noyé; Efficacité-compression Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : Vapor compression refrigeration technology has seen great improvement over the last several decades in terms of cycle efficiency through a concerted effort of manufacturers, regulators, and research engineers. As the standard vapor compression systems approach practical limits, cycle modifications should be investigated to increase system efficiency and capacity. One possible means of increasing cycle efficiency is to flood the compressor with a large quantity of oil to achieve a quasi-isothermal compression process, in addition to using a regenerator to increase refrigerant subcooling. In theory, compressor flooding and regeneration can provide a significant increase in system efficiency over the standard vapor compression system. The effectiveness of compressor flooding and regeneration increases as the temperature lift of the system increases. Therefore, this technology is particularly well suited towards lower evaporating temperatures and high ambient temperatures as seen in supermarket refrigeration applications. While predicted increases in cycle efficiency are over 40% for supermarket refrigeration applications, this technology is still very beneficial for typical air-conditioning applications, for which improvements in cycle efficiency greater than 5% are predicted. It has to be noted though that the beneficial effects of compressor flooding can only be realized if a regenerator is used to exchange heat between the refrigerant vapor exiting the evaporator and the liquid exiting the condenser. [article] Performance of vapor compression systems with compressor oil flooding and regeneration = Performance des systèmes à compression de vapeur munis de compresseurs avec suralimentation en huile et régénération [texte imprimé] . - 2012 . - pp.225-233. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp.225-233 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Conditionnement d'air; Froid; Régénération; Noyé; Efficacité-compression Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : Vapor compression refrigeration technology has seen great improvement over the last several decades in terms of cycle efficiency through a concerted effort of manufacturers, regulators, and research engineers. As the standard vapor compression systems approach practical limits, cycle modifications should be investigated to increase system efficiency and capacity. One possible means of increasing cycle efficiency is to flood the compressor with a large quantity of oil to achieve a quasi-isothermal compression process, in addition to using a regenerator to increase refrigerant subcooling. In theory, compressor flooding and regeneration can provide a significant increase in system efficiency over the standard vapor compression system. The effectiveness of compressor flooding and regeneration increases as the temperature lift of the system increases. Therefore, this technology is particularly well suited towards lower evaporating temperatures and high ambient temperatures as seen in supermarket refrigeration applications. While predicted increases in cycle efficiency are over 40% for supermarket refrigeration applications, this technology is still very beneficial for typical air-conditioning applications, for which improvements in cycle efficiency greater than 5% are predicted. It has to be noted though that the beneficial effects of compressor flooding can only be realized if a regenerator is used to exchange heat between the refrigerant vapor exiting the evaporator and the liquid exiting the condenser.

Performance limit for economized cycles with continuous refrigerant injection in Revue internationale du froid, vol 34, issue 1 (janvier 2011)

Public ISBD [article]  inRevue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 234-242 Titre : Performance limit for economized cycles with continuous refrigerant injection Titre original : Limites de la performance des cycles à économiseur avec injection continue de frigorigène Type de document : texte imprimé Année de publication : 2012 Article en page(s) : pp. 234-242 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Système; Multiétagé; Modélisation; Injection; Économies d'énergie; Cycle-thermodynamique Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : While economizing can improve the performance of vapor compression cycles, the cost of multi-stage compressors has limited its implementation to large-scale applications. However, the development of compressors with injection ports presents new opportunities for economizing in smaller-scale applications. In addition to eliminating the need for a costly multi-stage compressor, multiple injection ports can be added at relatively low cost to further improve cycle performance. In the current study, a model was developed to study the effect of the number of injection ports on performance and determine the limit to performance with injection. The model predicts that continuous injection, in which economized refrigerant is injected at an infinite number of ports to maintain saturated vapor in the compressor, provides very significant performance improvements for air-conditioning and refrigeration applications. At standard operating conditions, the COP increases between 18% and 51% depending on the application, with higher temperature lift cycles benefiting most significantly. [article] Performance limit for economized cycles with continuous refrigerant injection = Limites de la performance des cycles à économiseur avec injection continue de frigorigène [texte imprimé] . - 2012 . - pp. 234-242. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 234-242 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Système; Multiétagé; Modélisation; Injection; Économies d'énergie; Cycle-thermodynamique Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : While economizing can improve the performance of vapor compression cycles, the cost of multi-stage compressors has limited its implementation to large-scale applications. However, the development of compressors with injection ports presents new opportunities for economizing in smaller-scale applications. In addition to eliminating the need for a costly multi-stage compressor, multiple injection ports can be added at relatively low cost to further improve cycle performance. In the current study, a model was developed to study the effect of the number of injection ports on performance and determine the limit to performance with injection. The model predicts that continuous injection, in which economized refrigerant is injected at an infinite number of ports to maintain saturated vapor in the compressor, provides very significant performance improvements for air-conditioning and refrigeration applications. At standard operating conditions, the COP increases between 18% and 51% depending on the application, with higher temperature lift cycles benefiting most significantly.

Investigating performance of microchannel evaporators with different manifold structures in Revue internationale du froid, vol 34, issue 1 (janvier 2011)

Public ISBD [article]  inRevue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 292-302 Titre : Investigating performance of microchannel evaporators with different manifold structures Titre original : Etude sur la performance des évaporateurs à microcanaux des collecteurs de structures différentes Type de document : texte imprimé Année de publication : 2012 Article en page(s) : pp. 292-302 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Microcanal; Évaporateur; Distribution de l'écoulement; Expérimentation Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : In this paper, the performances of microchannel evaporators with different manifold structures are experimentally investigated. Eight evaporator samples with 7 different designs of the I/O manifold and 5 different designs of the return manifold are made for this study. The performances of the evaporator samples are tested on a psychometric calorimeter test bench with the refrigerant 134A at a real automotive AC condition. The results on the variations of the cooling capacity and air temperature distribution of the evaporator due to the deflector designs in the I/O manifold and flow hole arrangements in the return manifold are presented and analyzed. By studying the KPI’s for the performance of an evaporator, the design trade-off for an evaporator designer is summarized and discussed. [article] Investigating performance of microchannel evaporators with different manifold structures = Etude sur la performance des évaporateurs à microcanaux des collecteurs de structures différentes [texte imprimé] . - 2012 . - pp. 292-302. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 292-302 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Microcanal; Évaporateur; Distribution de l'écoulement; Expérimentation Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : In this paper, the performances of microchannel evaporators with different manifold structures are experimentally investigated. Eight evaporator samples with 7 different designs of the I/O manifold and 5 different designs of the return manifold are made for this study. The performances of the evaporator samples are tested on a psychometric calorimeter test bench with the refrigerant 134A at a real automotive AC condition. The results on the variations of the cooling capacity and air temperature distribution of the evaporator due to the deflector designs in the I/O manifold and flow hole arrangements in the return manifold are presented and analyzed. By studying the KPI’s for the performance of an evaporator, the design trade-off for an evaporator designer is summarized and discussed.

The heat transfer performance of horizontal tube bundles in large falling film evaporators in Revue internationale du froid, vol 34, issue 1 (janvier 2011)

Public ISBD [article]  inRevue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 303-316 Titre : The heat transfer performance of horizontal tube bundles in large falling film evaporators Titre original : Performance en termes de transfert de chaleur des faisceaux de tubes horizontaux dans les évaporateurs à film tombant de grandes dimensions Type de document : texte imprimé Année de publication : 2012 Article en page(s) : pp. 303-316 Langues : Anglais (eng) Français (fre) Catégories : 000.Informatique, information, ouvrages généraux Mots-clés : Évaporateur; Film tombant; Faisceau; Modélisation; Simulation; Transfert de chaleur Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : The performance of the horizontal heat transfer tube bundles in falling film evaporators in large compression refrigeration systems was investigated with numerical simulation in this paper. Four types of tubes, including plain tubes, and enhanced surface tubes of Turbo-B, Turbo-BII and Turbo-EHP, were employed in the simulation. Some factors, such as tube kind, tube pass arrangement, dry patch area on tube surface, liquid refrigerant flow rate, and number of flooded tubes, were analyzed based on simulated results. In the study, the maldistribution of liquid refrigerant flow caused by the distributor apparatus was discussed, which severely affects the performance of falling film evaporators according to the simulation. Some calculated results were verified by the experiment. These discussions and results can be used to guide the design of falling film evaporators under realistic flow conditions. [article] The heat transfer performance of horizontal tube bundles in large falling film evaporators = Performance en termes de transfert de chaleur des faisceaux de tubes horizontaux dans les évaporateurs à film tombant de grandes dimensions [texte imprimé] . - 2012 . - pp. 303-316. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 303-316 Catégories : 000.Informatique, information, ouvrages généraux Mots-clés : Évaporateur; Film tombant; Faisceau; Modélisation; Simulation; Transfert de chaleur Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : The performance of the horizontal heat transfer tube bundles in falling film evaporators in large compression refrigeration systems was investigated with numerical simulation in this paper. Four types of tubes, including plain tubes, and enhanced surface tubes of Turbo-B, Turbo-BII and Turbo-EHP, were employed in the simulation. Some factors, such as tube kind, tube pass arrangement, dry patch area on tube surface, liquid refrigerant flow rate, and number of flooded tubes, were analyzed based on simulated results. In the study, the maldistribution of liquid refrigerant flow caused by the distributor apparatus was discussed, which severely affects the performance of falling film evaporators according to the simulation. Some calculated results were verified by the experiment. These discussions and results can be used to guide the design of falling film evaporators under realistic flow conditions.

Analytical solution for the simultaneous heat and mass transfer problem in air washers in Revue internationale du froid, vol 34, issue 1 (janvier 2011)

Public ISBD [article]  inRevue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 353-361 Titre : Analytical solution for the simultaneous heat and mass transfer problem in air washers Titre original : Solution analytique du problème de transfert simultané de chaleur et de masse dans un laveur d'air Type de document : texte imprimé Année de publication : 2012 Article en page(s) : pp. 353-361 Langues : Anglais (eng) Français (fre) Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Conditionnement d'air; Laveur d'air; Système évaporatif; Calcul; Transfert de chaleur; Transfert de masse Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : An analytical solution approach for the simultaneous heat and mass transfer problem in air washers operating as evaporative coolers is presented. A one-dimensional model using the coupled mass and energy balance equations in the air washer is presented. Then, starting from a linear approach for the experimental curve of the air saturation, an analytical solution for the model was derived. The solution showed an excellent agreement with the available results found in the literature. The influence of several important parameters for the cooling process such as temperature and ambient air humidity, air flow rate and feeding water temperature, in the air cooling rate was investigated. The efficacy of the process can be greatly increased by reducing the cooling water temperature and the applied air flow rate. The analytical solution can be easily included into the models used for simulating desiccant air-conditioning systems operating in conjunction with air washers. [article] Analytical solution for the simultaneous heat and mass transfer problem in air washers = Solution analytique du problème de transfert simultané de chaleur et de masse dans un laveur d'air [texte imprimé] . - 2012 . - pp. 353-361. Langues : Anglais (eng) Français (fre) in Revue internationale du froid > vol 34, issue 1 (janvier 2011) . - pp. 353-361 Catégories : 621.5 : Technique pneumatique, du vide, des basses températures Mots-clés : Conditionnement d'air; Laveur d'air; Système évaporatif; Calcul; Transfert de chaleur; Transfert de masse Index. décimale : 621.56 Technique des basses températures : réfrigération, pompe à chaleur Résumé : An analytical solution approach for the simultaneous heat and mass transfer problem in air washers operating as evaporative coolers is presented. A one-dimensional model using the coupled mass and energy balance equations in the air washer is presented. Then, starting from a linear approach for the experimental curve of the air saturation, an analytical solution for the model was derived. The solution showed an excellent agreement with the available results found in the literature. The influence of several important parameters for the cooling process such as temperature and ambient air humidity, air flow rate and feeding water temperature, in the air cooling rate was investigated. The efficacy of the process can be greatly increased by reducing the cooling water temperature and the applied air flow rate. The analytical solution can be easily included into the models used for simulating desiccant air-conditioning systems operating in conjunction with air washers.