Experimental assessment of an ammonia/lithium nitrate absorption cooler operated on low temperature geothermal energy

Ayala, R.; Frías, J.L.; Lam, Lisa Steigerwalt; Heard, C.L.; Holland, F.A.

doi:10.1016/0890-4332(94)90047-7

Cited by 18 publications

(3 citation statements)

References 3 publications

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“…Experimental data obtained with absorption cooling prototypes designed initially to operate with the ammonia/water working pair (Ayala et al [12], Infante Ferreira [13], Heard [14]) and loaded with the ammonia/lithium nitrate working pair showed poor performance results. The authors of these experimental studies concluded that the main reason for the poor performance lay in the absorber and was due to the high viscosity of the fluid mixture compared with that of the ammonia/water mixture.…”

Section: Introductionmentioning

confidence: 99%

Boiling heat transfer and pressure drop of NH3/LiNO3 and NH3/(LiNO3 + H2O) in a plate heat exchanger

Táboas

Bourouis

Vallès

2016

International Journal of Thermal Sciences

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Section: Introductionmentioning

confidence: 99%

Boiling heat transfer and pressure drop of NH3/LiNO3 and NH3/(LiNO3 + H2O) in a plate heat exchanger

Táboas

Bourouis

Vallès

2016

International Journal of Thermal Sciences

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“…However, Infante Ferreira offers equations for the estimation of more thermodynamic properties. Therefore, these equations have been widely used (Wang et al, 1998;Thioye, 1997b;Altamush Siddiqui, 1994;Ayala et al, 1994;Kaushik and Kumar, 1985), thus they will be also used in the present work.…”

Section: Thermodynamic Propertiesmentioning

confidence: 98%

Thermodynamic study of multistage absorption cycles using low-temperature heat

Venegas

Izquierdo

Vega

et al. 2002

Int. J. Energy Res.

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SUMMARYThe use of low-temperature heat (between 50 and 908C) is studied to drive absorption systems in two different applications: refrigeration and heat pump cycles. Double-and triple-stage absorption systems are modelled and simulated, allowing a comparison between the absorbent-refrigerant solutions H 2 O-NH 3 , LiNO 3 -NH 3 and NaSCN-NH 3 . The results obtained for the double-stage cycle show that in the refrigeration cycle the LiNO 3 -NH 3 solution operates with a COP of 0.32, the H 2 O-NH 3 pair with a COP of 0.29 and the NaSCN-NH 3 solution with a COP of 0.27, when it evaporates at À158C, condenses and absorbs refrigerant at 408C and generates vapour at 908C. The results are presented for double-and triplestage absorption systems with evaporation temperatures ranging between À40 and 08C and condensation temperatures ranging from 158C to 458C.The results obtained for the double-stage heat pump cycle show that the LiNO 3 -NH 3 solution reaches a COP of 1.32, the NaSCN-NH 3 pair a COP of 1.30 and the H 2 O-NH 3 mixture a COP of 1.24, when it condenses and absorbs refrigerant at 508C, evaporates at 08C and generates vapour at 908C. For the double-and triple-stage cycles, the results are presented for evaporation temperatures ranging between 0 and 158C. The minimum temperature required in the generators to operate the refrigeration and heat pump cycles are also presented.

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“…In addition, systems with a NH 3 /LiNO 3 mixture do not require rectification of the refrigerant vapor emitted from the generator because the absorbent is a salt, and these systems can operate at lower activation temperatures compared to ammonia/water (NH 3 /H 2 O) systems. Nevertheless, former experimental investigations have shown that the major limiting aspect of the NH 3 /LiNO 3 mixture is its elevated viscosity, which restricts heat and mass transfer, primarily in the absorber, in comparison to the NH 3 /H 2 O mixture [4][5][6][7]. This limitation has motivated studies aimed at enhancing the absorption process with NH 3 /LiNO 3 by employing passive techniques [8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Performance Assessment of an NH3/LiNO3 Bubble Plate Absorber Applying a Semi-Empirical Model and Artificial Neural Networks

et al. 2020

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In this study, ammonia vapor absorption with NH3/LiNO3 was assessed using correlations derived from a semi-empirical model, and artificial neural networks (ANNs). The absorption process was studied in an H-type corrugated plate absorber working in bubble mode under the conditions of an absorption chiller machine driven by low-temperature heat sources. The semi-empirical model is based on discretized heat and mass balances, and heat and mass transfer correlations, proposed and developed from experimental data. The ANN model consists of five trained artificial neurons, six inputs (inlet flows and temperatures, solution pressure, and concentration), and three outputs (absorption mass flux, and solution heat and mass transfer coefficients). The semi-empirical model allows estimation of temperatures and concentration along the absorber, in addition to overall heat and mass transfer. Furthermore, the ANN design estimates overall heat and mass transfer without the need for internal details of the absorption phenomenon and thermophysical properties. Results show that the semi-empirical model predicts the absorption mass flux and heat flow with maximum errors of 15.8% and 12.5%, respectively. Maximum errors of the ANN model are 10.8% and 11.3% for the mass flux and thermal load, respectively.

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Experimental assessment of an ammonia/lithium nitrate absorption cooler operated on low temperature geothermal energy

Cited by 18 publications

References 3 publications

Boiling heat transfer and pressure drop of NH3/LiNO3 and NH3/(LiNO3 + H2O) in a plate heat exchanger

Boiling heat transfer and pressure drop of NH3/LiNO3 and NH3/(LiNO3 + H2O) in a plate heat exchanger

Thermodynamic study of multistage absorption cycles using low-temperature heat

Performance Assessment of an NH3/LiNO3 Bubble Plate Absorber Applying a Semi-Empirical Model and Artificial Neural Networks

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