p−T−x Measurements for Some Working Fluids for an Absorption Heat Transformer: 1,1,1,2-Tetrafluoroethane (R134a) + Dimethylether Diethylene Glycol (DMEDEG) and Dimethylether Triethylene Glycol (DMETrEG)

Abstract

The solubilities of 1,1,1,2-tetrafluoroethane (R134a), CF3CH2F, + dimethylether diethylene glycol (DMEDEG), CH3O(CH2CH2O)2CH3, and R134a + dimethylether triethylene glycol (DMETrEG) binary systems were measured, using the “static−analytic” method at temperatures between (303 and 353) K. This work was an opportunity to test the use of R134a as a refrigerant in combination with an organic absorbent, like DMEDEG and DMETrEG, in an absorption heat transformer (AHT), also known as a type II absorption heat pump or a reversed absorption heat pump. The experimental data were correlated using the Peng−Robinson equation of state (PR-EoS) in combination with Mathias−Copeman α function, Huron−Vidal mixing rules, and the nonrandom two-liquid (NRTL) activity coefficient model. The experimental results were compared to the predicted values obtained using the predictive Soave−Redlich−Kwong group contribution equation of state (PSRK-EoS).

p–T–x Measurements for 1,1,1,2-Tetrafluoroethane (R134a) + N,N-Dimethylacetamide (DMA) and N-Methyl-2-pyrrolidone (NMP)

“…Previous works carried out by the same present authors are reported in the literature and one can cite Zehioua et al 2,3 . who considered the modeling and experimental measurements of isothermal vapor-liquid equilibrium data for different binary systems namely 1, 1, 1, 2-Tetrafluoroethane (R134a) + Dimethylformamide (DMF) working fluids used for an Absorption Heat Transformer (AHT) 2 and R134a + 1-Methoxy-2-(2methoxyethoxy) ethane (DMEDEG) and 1,2-bis(2-ethoxyethoxy) ethane (DMETrEG) 3 . Also…”

“…Previous works carried out by the same present authors are reported in the literature, and one can cite Zehioua et al , who considered the modeling and experimental measurements of isothermal vapor–liquid equilibrium data for different binary systems, namely, 1,1,1,2-tetrafluoroethane (R134a) + dimethylformamide (DMF) working fluids used for an absorption heat transformer (AHT) and R134a + 1-methoxy-2-(2-methoxyethoxy) ethane (DMEDEG) and 1,2-bis­(2-ethoxyethoxy) ethane (DMETrEG) . Also Fatouh and Murthy considered different working fluid pairs on the basis of p – T – x – H data, with R22 as the refrigerant and six different organic absorbents: [ N , N -dimethylformamide (DMF), N , N -dimethylacetamide (DMA), N -methyl-2-pyrrolidone (NMP), dimethyl ether diethylene glycol (DMEDEG), dimethyl ether tetraethylene glycol (DMETEG), and dimethyl ether triethylene glycol (DMETrEG)] still used in AHT.…”

Measurement and Correlation of Vapor–Liquid Equilibrium for R124 (1-Chloro-1,2,2,2-Tetrafluoroethane)-NMP (N-Methyl-2-Pyrrolidone) and R124-DMF (N,N-Dimethylformamide) Mixtures

“…In order to measure the VLE data of R124-NMP and R124-DMF binary mixtures, the experimental principle given by refs , , and was adopted in this paper and a VLE measurement system showed in Figure was set. The system composed of some apparatuses which are (1) thermostatic water bath, (2) equilibrium still, (3) temperature controller, (4) refrigerator, (5) vacuum pump, (6) temperature sensors, (7) pressure sensors, (8) refrigerant cylinder, (9) refrigerant storage tank, (10) valves, (11) computer, (12) liquid injector, (13) six-way metering valve, and (14) gas chromatography (GC).…”

“…In order to replace two traditional working fluids, many efforts have been paid to research and develop new organic working fluids in which the refrigerants are hydrochlorofluorocarbons (HCFCs) or hydrofluorocarbons (HFCs), such as R22, R124, and R134a, and the absorbents are chemical solvents, such as N , N -dimethylformamide (DMF), N , N -dimethylacetamide (DMAC), N -methyl-2-pyrrolidone (NMP), dimethyl ether diethylene glycol (DMEDEG), dimethyl ether tetraethylene glycol (DMETEG), and dimethyl ether triethylene glycol (DMETrEG). − Although the ozone depletion potential (ODP) of these refrigerants may not be zero and the global warming potential (GWP) of these refrigerants may be high, the influence on the environment is comparatively small when refrigerants leak from ARSs due to most refrigerants stay in ARSs in the form of solution.…”

“…Then their thermal properties can be obtained by the VLE data. In order to explore the possibility of using R134a as a refrigerant in combination with different organic absorbents in ARSs, Zehioua et al , measured the VLE data of three binary mixtures, R134a-DMF, R134a-DMEDEG, and R134a-DMETrEG, by the static analytic method, respectively. The measured temperature range for R134a-DMF mixture was from 303.30 to 353.24 K. The range for R134a-DMEDEG and R134a-DMETrEG mixtures was from 303 to 353 K. Later, Han et al measured the solubility of R134a-DMF mixture in a wider temperature range from 263.15 to 363.15 K. Borde et al constructed p – T – x curves of R134a-DMETEG, R134a- N -methyl-epsilon-caprolactam (MCL) and R134a-dimethyl-ethylene urea (DMEU) mixtures based on VLE measurement data.…”