Working fluids for an absorption system based on R124 (2-chloro-1,1,1,2,-tetrafluoroethane) and organic absorbents

Borde, I.; Jelínek, M.; Daltrophe, N.

doi:10.1016/s0140-7007(97)00090-x

Cited by 62 publications

(32 citation statements)

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“…Fig1a-h show the excess enthalpy variations with the refrigerant (R124) molar fraction at different temperatures in terms of molar fraction for the R124-DMAC pair considered in [1], the values of which are compared with the results obtained in the present work. Similar with those of R124 and DMAC mixture Fig2a'-h' show the excess enthalpy variations with the refrigerant (R134a) molar fraction at different temperatures in terms of molar fraction for the R134a-DMETEG pair considered in [2], the values of which are compared with the results obtained in the present work.…”

Section: Resultsmentioning

confidence: 85%

“…For the UNIQUAC model the required interaction parameters are obtained using the experimental data available in the literature [1,2], by minimizing the objective function F defined as follows:…”

Section: Optimization Of Interaction Parametersmentioning

confidence: 99%

“…Hence the thermodynamic calculation of the key operating parameters of an absorption cycle, i.e. the coefficient of performance (COP) and the circulation ratio with a possible variation of the order of 15% [1].…”

Section: Introductionmentioning

confidence: 99%

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Optimization of UNIQUAC interaction parameters for absorption refrigeration machine working fluids

Ilhem

Nardjess

Procedes

2018

2018 9th International Renewable Energy Congress (IREC)

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To be able to pre-select new working fluids for absorption refrigeration systems, it is necessary to have a good understanding in the calculation or correlation of thermophysical properties of working fluids. The choice of the most appropriate thermodynamic model for the prediction or calculation of thermodysical properties is a crucial task. Consequently the present study deals with the determination of excess properties for refrigerant mixtures which are required for the calculation of the various involved enthalpies and hence the used refrigeration machine.The present study considered the pairs (2-chloro-1,1,1,2-tétrafluoroethane) (R124) as a refrigerant in combination with an organic absorbent (N, N'-Dimethylacetamide) DMAC and (1,1,1,2-tetrafluoroethane) (R134a) as a refrigerant in combination with an organic absorbent dimethylether tetraethyleneglycol (DMETEG) by calculating the molecular interaction parameters for the UNIQUAC model using the excess enthalpy of mixing at eight different temperatures varying from 0°C to 140°C by a step of 20°C for the first pair and varying from 20°C to 140°C for the second pair.The obtained interaction parameters values led to mixing excess enthalpy results very close to experimental values, contrary to the UNIFAC model which showed huge deviations. Therefore the optimization technique based on the Simplex method proved to be very reliable in the determination of interaction parameters for the UNIQUAC model. Keywords: UNIQUAC; UNIFAC; Excess enthalpy; Refrigerant; Absorbent. RésuméPour pouvoir présélectionner de nouveaux fluides de travail pour les systèmes de réfrigération à absorption, il est nécessaire de bien comprendre le calcul ou la corrélation des propriétés thermophysiques des fluides de travail. Le choix du modèle thermodynamique le plus approprié pour la prédiction ou le calcul des propriétés thermodynamiques est une tâche cruciale. En conséquence, la présente étude traite de la détermination des propriétés excédentaires des mélanges de réfrigérants nécessaires au calcul des différentes enthalpies impliquées et donc de la machine frigorifique utilisée.La présente étude a examiné les paires (2-chloro-1,1,1,2-tétrafluoroéthane) (R124) en tant que frigorigène en combinaison avec un absorbant organique (N, N'-diméthylacétamide) DMAC et (1,1,1, 2-tétrafluoroéthane) (R134a) en tant que réfrigérant en association avec un diméthyléther éther tétraéthylèneglycol (DMETEG) absorbant organique en calculant les paramètres d'interaction moléculaire pour le modèle UNIQUAC en utilisant l'enthalpie de mélange en excès à huit températures différentes variant de 0 ° C à 140 ° C par un pas de 20 ° C pour la première paire et variant de 20 ° C à 140 ° C pour la deuxième paire.Les valeurs des paramètres d'interaction obtenues ont conduit à mélanger les résultats d'excès d'enthalpie très proches des valeurs expérimentales, contrairement au modèle UNIFAC qui présentait des écarts importants. Par conséquent, la technique d'optimisation basée sur la méthode Simplex s'est révélée très fia...

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Section: Resultsmentioning

confidence: 85%

Section: Optimization Of Interaction Parametersmentioning

confidence: 99%

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Optimization of UNIQUAC interaction parameters for absorption refrigeration machine working fluids

Ilhem

Nardjess

Procedes

2018

2018 9th International Renewable Energy Congress (IREC)

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“…In practice, the pair LiBr/H 2 O used in air-conditioning systems and the pair NH 3 ⁄ H 2 O used in refrigerating plants have found the widest application. In the literature, however, are publications in which new pairs of working fluids -organic heat-transfer materials -are described [12][13][14]. The chief advantage of the absorption heat pumps compared to the adsorption ones is the organization of the time-invariant processes of sorption/desorption, which upgrades the thermodynamic efficiency (COP) of the heat pump.…”

Section: Thermodynamics and Heat And Mass Exchange In Sorption Heatmentioning

confidence: 99%

Prospects for employing heat pumps in the Republic of Belarus

Васильев

2005

J Eng Phys Thermophys

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ev UDC 621.577A brief analysis of the possibilities of employing sorption heat pumps in the Republic of Belarus is given. Primary consideration is given to the light-duty heat pumps used for air-conditioning systems with automatic switching from the heating to the cooling state (air/water). One important component of sorption heat pumps is the low-temperature power source, which strongly influences the design of the heat pump in terms of economy and environmental protection.The Republic of Belarus is situated in a geographical zone where the average summer temperature exceeds 20 o C and in winter it is close to 0 o C. Therefore, the application of heat pumps is economically sound mainly for heating, although in a certain period of the summertime they can also be used for air/water cooling. It is known that 90% of the global population need heat pumps for the purposes of heating and cooling. In the present paper, primary consideration is given to the light-duty heat pumps used for air-conditioning systems with automatic switching from the heating to the cooling state (air/water). In international practice, to achieve the above purpose, electrically operated steam compression heat pumps [1], in which, instead of the ecologically dangerous coolant R22, coolants R410A and R407C, as well as propane, propylene, ammonia, and CO 2 are used, are widely used. However, in the last few years, publications devoted to the development and implementation of sorption (absorption and adsorption) gas-operated (flame, gas burners) heat pumps have appeared. Unfortunately, quantity production of sorption heat pumps has been set up so far only in Japan and in the USA, while two or three years ago China began their quantity production as a part of air-conditioning systems for industrial enterprises (absorption heat pumps: heat-transfer material -lithium bromide/water) [2]. At present, of the 9 million heat pumps installed throughout the world, Europe has only 450 thousand, and they are used mainly on the basis of the gas-gas cycle for the purposes of heating in winter and cooling in summer. Of these, 135 thousand heat pumps operate in Central Europe only for air and water heating. The demands for heat pumps are satisfied mainly due to their importation from the USA and Japan. Therefore, national programs of production of heat pumps are welcomed and stimulated in every way. In Switzerland, 40% of new one-and two-family houses are equipped with heat pumps. A similar situation occurs in Austria. For private homes, of great interest are light-duty adsorption heat pumps (zeolites/water, silica gels+salts/water; active carbons/alcohol, etc.) [3][4][5][6]. One important component of sorption heat pumps is the low-temperature energy source, which strongly influences their design in terms of economy and environmental protection. Consequently, the design of a heat source depends in many respects on the chosen low-temperature energy source: atmospheric air, outflowing air of rooms (ventilation release), waters of rivers and lakes and ground waters...

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“…Recently, Jelinek and Borde (1998) have shown that a single-stage ARU can only operate with a few refrigerant-absorbent pairs based on R22 and R124 Jelinek 1988, 1987a,b;Borde et al, 1997) while the thermodynamic cycle with the refrigerant-absorbent pairs based on R134a or R32 (Borde et al, 1995a,b) do not exist. Many of the previous authors and Fatouh and Murthy (1996) have shown that the mixture R22-E181 may be one of the most promising with high solubility, chemical stability, safe operation far from the crystallization line and low generator cut-off temperature.…”

Section: Introductionmentioning

confidence: 99%

R22-E181 absorption water chilling package thermodynamics and performance in the range of ARI 560-2000 standard rating conditions

Rogdakis

2003

Int. J. Energy Res.

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SUMMARYThe purpose of this work is the thermodynamic analysis and the performance prediction of R22-E181 absorption water chilling package for standard rating conditions according to ARI 560-2000. The analysis is based on the description of the exact thermodynamic cycle plotting the enthalpy-mass fraction and the temperature-enthalpy charts. The thermodynamic properties of the R22-E181 are given in a new set of equations using extended experimental data from the literature.A step-by-step calculation model was established in order to predict the characteristic points of the thermodynamic cycle of the R22-E181 ARU and to simulate its performance.The influence of the ambient conditions on the operation of the ARU is shown graphically when the saturated condensing temperature ranges from 30 to 458C. Regression analysis is carried out to express the actual coefficient of performance and the cooling load as functions of the condenser temperature and the absorber-condenser temperature difference.According to ARI Standard 560-2000 for an absorption water chilling package, it has been found that the integrated part-load value of the COP ranges from 53 to 60%. When the saturated condensing temperature is 41.18C, the saturated evaporating temperature is 48C and the ABS/COND temperature difference ranges from 6 to 98C. The decrease of the chilled water temperature passing through evaporator is 5.68C.

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Working fluids for an absorption system based on R124 (2-chloro-1,1,1,2,-tetrafluoroethane) and organic absorbents

Cited by 62 publications

References 2 publications

Optimization of UNIQUAC interaction parameters for absorption refrigeration machine working fluids

Optimization of UNIQUAC interaction parameters for absorption refrigeration machine working fluids

Prospects for employing heat pumps in the Republic of Belarus

R22-E181 absorption water chilling package thermodynamics and performance in the range of ARI 560-2000 standard rating conditions

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