Isothermal Vapor–Liquid Equilibrium Measurements of 1,1-Difluoroethane + N,N-Dimethylformamide and N,N-Dimethylacetamide

Abstract

Vapor–liquid equilibrium (VLE) data of working fluids play a vital role in the research and development of absorption refrigeration technology. In this paper, the VLE data of two new working fluids, 1,1-difluoroethane (R152a) + N,N-dimethylformamide (DMF) and R152a + N,N-dimethylacetamide (DMAC), were measured by the static analytical method at temperatures from (293.15 to 353.15) K. The experimental results show that R152a exhibits better solubility characteristics with DMF and DMAC, and the solubility of R152a in DMAC is slightly better than that in DMF. All experimental data were correlated by the activity coefficient model of five-parameter nonrandom two liquid (NRTL). The calculated results are in essential agreement with the experimental data, and the maximum relative deviation of pressure are 3.69 % and 3.51 %, the average relative deviation of pressure are 1.60 % and 1.11 %, for binary systems R152a + DMF and R152a + DMAC, respectively.

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

“…The temperature controller is controlled by a platinum resistance thermometer which the accuracy is ±0.15 K, the temperature stability is 0.03 K, and the resolution of digital data acquisition device is 0.01 K. In this work, the maximum experimental temperature is 90 °C. Therefore, the temperature uncertainties can be expressed , as u (1) ( T ) = 0.15/ = 0.087, u (2) ( T ) = 0.03/ = 0.017 and u (3) ( T ) = 0.5 × 0.01/ = 0.0029. Thus, the combined standard uncertainty of temperature in the range of this work is …”

“…The resolution of pressure monitor is 0.001 MPa. Therefore, the pressure uncertainties can be expressed , as u (1) ( p ) = 0.04% × 5.17/2.58 = 0.0008 in which the 2.58 denominator is the coverage factor while the confidence probability is 99%, and u (2) ( p ) = 0.5 × 0.001/ = 0.0003. Thus, the combined standard uncertainty of pressure in the range of this work is …”

Visual experimental research on the effect of nozzle orifice structure on R124–DMAC absorption process in a vertical bubble tube

“…Some organic working fluids may be applied to replace ammonia-water mixture, in which HCFCs or HFCs are used as refrigerants and DMAC, DMETEG, DMEU, DMF, DMU or NMP are used as absorbents (Arun et al, 1998;Borde et al, 1997;Meng et al, 2013;Sujatha et al, 1997b;Xiao et al, 2011). To date, a few literatures about the bubble absorption process of organic working fluids are published.…”

Optimization of UNIQUAC interaction parameters for absorption refrigeration machine working fluids

“…In many previous works, the Non-Random two-liquids (NRTL) activity coefficient model was used to correlate the vapor liquid equilibrium data of non ideality binary systems such as HFCs and organic solvents mixtures for absorption refrigeration cycles [10,11,20,21,22]. The (NRTL), Redlich-Kwong-Soave cubic equation of state (RKS), Perturbed-chain Statistical Associating fluid Theory (PC-SAFT) and UNIFAC models were studied by Hifni M Ariyadi [10] in order to select the appropriate model to be used to correlate the thermophysical properties needed to investigate the thermal performance of the absorption systems based on ammonia/ionic liquid working fluids.…”