A thermodynamic modeling of 2-bed adsorption desalination to promote main equipment performance

Abstract Adsorption desalination utilizes the discrete adsorption of the water vapor from the evaporator, and is capable of being discharged to the condenser. This study illuminated an advanced cycle of mass and heat recovery among beds, condensers, and evaporators. Morover, the thermodynamic modeling of Adsorption Desalination Systems (ADS) under different operating conditions was investigated. Furthermore, its effect on the evaporator vapor production and the water vapor adsorption and desorption in the adsorption beds were accounted for. Parenthetically, the mathematical model of ADS thermodynamics was validated with the experimental data. Besides, the advanced ADS modeling was conducted via mass and heat recovery among beds, condensers, and evaporators. In addition to the amount of the desalinated water, the time history chart of the equipment applied in the process with and without the thermal and mass recovery is also illustrated. Finally, under such operating conditions, the SDWP (Specific Daily Water Production) advanced ADS is 153% higher than conventional ADS.

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Water Vapor Adsorption and Heat Transfer Characteristics of FAPO Zeolite Adsorbent Coating Plate with Operating Conditions

Korean Journal of Air-Conditioning and Refrigeration Engineering ◽

10.6110/kjacr.2021.33.8.377 ◽

2021 ◽

Vol 33 (8) ◽

pp. 377-384

Author(s):

Kyung Jin Bae ◽

Oh Kyung Kwon

Keyword(s):

Heat Transfer ◽

Water Vapor ◽

Water Vapor Adsorption ◽

Operating Conditions ◽

Heat Transfer Characteristics ◽

Vapor Adsorption ◽

Transfer Characteristics ◽

Zeolite Adsorbent

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Sub- and Supercritical Extraction of Slovenian Hops (Humulus lupulus L.) Aurora Variety Using Different Solvents

Plants ◽

10.3390/plants10061137 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1137

Author(s):

Katja Bizaj ◽

Mojca Škerget ◽

Iztok Jože Košir ◽

Željko Knez

Keyword(s):

Sulfur Hexafluoride ◽

Total Yield ◽

Extraction Yield ◽

Operating Conditions ◽

Influence Of Process Parameters ◽

Humulus Lupulus L ◽

Bitter Acids ◽

Temperature And Pressure ◽

Carbon Dioxide Co2 ◽

The Mathematical Model

This work investigates the efficiency of supercritical fluid extraction of hops with a variety of solvents including carbon dioxide (CO2), propane, sulfur hexafluoride (SF6), and dimethyl ether (DME) at various densities (low-density and high-density). Operating parameters were 50 bar, 100 bar and 150 bar and 20 °C, 40 °C, 60 °C and 80 °C for all solvents, respectively. The influence of process parameters on the total yield of extraction and content of bitter acids in the extracts has been investigated. The mathematical model based on Fick’s second law well described the experimental extraction results. Furthermore, HPLC analysis has been used to determine α- and β-acids in extracts. The yield of bitter compounds in hop extracts was largely influenced by the type of solvent, the temperature and pressure applied during extraction. The results show that CO2 and propane were roughly equivalent to DME in solvating power, while SF6 was a poor solvent at the same conditions. The highest yield as well as the highest concentration of bitter acids in extracts were obtained by using DME, where the optimal operating conditions were 40 °C and 100 bar for the extraction of α-acids (max. concentration 9.6%), 60 °C and 50 bar for the extraction of β-acids (4.5%) and 60 °C and 150 bar for the maximum extraction yield (25.6%).

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Component-Oriented Modeling of a Micro-Scale Organic Rankine Cycle System for Waste Heat Recovery Applications

Applied Sciences ◽

10.3390/app11051984 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1984

Author(s):

Ramin Moradi ◽

Emanuele Habib ◽

Enrico Bocci ◽

Luca Cioccolanti

Keyword(s):

Electric Power ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Waste Heat ◽

Organic Rankine Cycle ◽

Rankine Cycle ◽

Operating Conditions ◽

Working Fluid ◽

Pump Efficiency ◽

Micro Scale

Organic Rankine cycle (ORC) systems are some of the most suitable technologies to produce electricity from low-temperature waste heat. In this study, a non-regenerative, micro-scale ORC system was tested in off-design conditions using R134a as the working fluid. The experimental data were then used to tune the semi-empirical models of the main components of the system. Eventually, the models were used in a component-oriented system solver to map the system electric performance at varying operating conditions. The analysis highlighted the non-negligible impact of the plunger pump on the system performance Indeed, the experimental results showed that the low pump efficiency in the investigated operating range can lead to negative net electric power in some working conditions. For most data points, the expander and the pump isentropic efficiencies are found in the approximate ranges of 35% to 55% and 17% to 34%, respectively. Furthermore, the maximum net electric power was about 200 W with a net electric efficiency of about 1.2%, thus also stressing the importance of a proper selection of the pump for waste heat recovery applications.

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