Solar Flash Desalination Under Hydrostatically Sustained Vacuum

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Mohammad Abutayeh ◽  
D. Yogi Goswami
Keyword(s):  
Atmospheric Pressure ◽  
Saline Water ◽  
Ground Level ◽  
Water Tank ◽  
Operational Parameters ◽  
Detailed Model ◽  
Theoretical Simulation ◽  
Proposed Model ◽  
Fundamental Physical ◽  
Chamber Size

A new desalination scheme has been proposed. The system consists of a saline water tank, a concentrated brine tank, and a fresh water tank placed on ground level plus an evaporator and a condenser located several meters above the ground. The evaporator-condenser assembly, or flash chamber, is initially filled with saline water that later drops by gravity, creating a vacuum above the water surface in the unit without a vacuum pump. The vacuum is maintained by the internal hydrostatic pressure balanced by the atmospheric pressure. The ground tanks are open to the atmosphere, while the flash chamber is insulated and sealed to retain both heat and vacuum. A theoretical simulation of the proposed model was carried out using a detailed model built by employing the fundamental physical and thermodynamic relationships to describe the process and was complimented by reliable empirical correlations to estimate the physical properties of the involved species and the operational parameters of the proposed system. The simulation results show that running the system at higher flash temperatures with a fixed flash chamber size will result in faster vacuum erosion leading to less overall evaporation.

Sustainable Desalination Process Simulation

2010 ◽  
Author(s):  
Mohammad Abutayeh ◽  
D. Yogi Goswami ◽  
Elias K. Stefanakos
Keyword(s):  
Atmospheric Pressure ◽  
Energy Efficient ◽  
Computer Code ◽  
Operational Parameters ◽  
Theoretical Simulation ◽  
Detailed Computer ◽  
Solar Heater ◽  
Hydrostatic Balance ◽  
Theoretical Simulations ◽  
Fundamental Physical

Experimental and theoretical simulations of a novel sustainable desalination process have been carried out. The simulated process consists of pumping seawater through a solar heater before flashing it under vacuum in an elevated chamber. The vacuum is passively created and then maintained by the hydrostatic balance between pressure inside the elevated flash chamber and outdoor atmospheric pressure. The experimental simulations were carried out using a pilot unit built to depict the proposed desalination system. Theoretical simulations were performed using a detailed computer code employing fundamental physical and thermodynamic laws to describe the separation process, complimented by experimentally based correlations to estimate physical properties of the involved species and operational parameters of the proposed system setting it apart from previous empirical desalination models. Experimental and theoretical simulation results matched well with one another, validating the developed model. Feasibility of the proposed system rapidly increased with flash temperature due to increased fresh water production and improved heat recovery. In addition, the proposed desalination system is naturally sustainable by solar radiation and gravity, making it very energy efficient.

Solar Flash Desalination Under Hydrostatically Sustained Vacuum

2008 ◽  
Author(s):  
Mohammad Abutayeh ◽  
Yogi Goswami
Keyword(s):  
Hydrostatic Pressure ◽  
Fresh Water ◽  
Atmospheric Pressure ◽  
Water Surface ◽  
Saline Water ◽  
Ground Level ◽  
Vacuum Pump ◽  
Low Grade ◽  
Water Tank ◽  
Produce Water

Creating vacuum conditions above liquids increases their evaporation rates. This phenomenon can be integrated into a practical continuous desalination process by repeatedly flashing seawater in vacuumed chambers to produce water vapor that condenses afterwards producing fresh water. Gravity can be used to balance the hydrostatic pressure inside the flash chambers with the outdoor atmospheric pressure to maintain that vacuum, while low grade solar radiation can be used to add heat to seawater before flashing. The proposed desalination system consists of a saline water tank, a concentrated brine tank, and a fresh water tank placed on ground level plus an evaporator and a condenser located several meters above ground. The evaporator-condenser assembly, or flash chamber, is initially filled with saline water that later drops by gravity creating a vacuum above the water surface in the unit without a vacuum pump. The vacuum is maintained by the internal hydrostatic pressure balanced by the atmospheric pressure. The ground tanks are open to the atmosphere, while the flash chamber is insulated and sealed to retain both heat and vacuum.

scholarly journals Theoretical and Experimental Simulation of Passive Vacuum Solar Flash Desalination

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Mohammad Abutayeh ◽  
D. Yogi Goswami ◽  
Elias K. Stefanakos
Keyword(s):  
Atmospheric Pressure ◽  
Computer Code ◽  
Experimental Simulation ◽  
Operational Parameters ◽  
Theoretical Simulation ◽  
Detailed Computer ◽  
Solar Heater ◽  
Hydrostatic Balance ◽  
Theoretical Simulations ◽  
Fundamental Physical

Experimental and theoretical simulations of a novel sustainable desalination process have been carried out. The simulated process consists of pumping seawater through a solar heater before flashing it under vacuum in an elevated chamber. Vacuum is passively created and then maintained by the hydrostatic balance between pressure inside the elevated flash chamber and outdoor atmospheric pressure. Experimental simulations were carried out using a pilot unit built to depict the proposed desalination system. Theoretical simulations were performed using a detailed computer code employing fundamental physical and thermodynamic laws to describe the separation process, complimented by experimentally based correlations to estimate physical properties of the involved species and operational parameters of the proposed system setting it apart from previous empirical desalination models. Experimental and theoretical simulation results matched well, validating the developed model. Feasibility of the proposed system rapidly increased with flash temperature due to increased fresh water production and improved heat recovery. In addition, the proposed desalination system is naturally sustainable by solar radiation and gravity, making it very energy efficient.

scholarly journals Decoupling of ground level pressures observed in Italian volcanoes: are they driven by space weather geo-effectiveness?

2014 ◽  
Vol 57 (3) ◽  
Author(s):  
Paolo Madonia ◽  
Paolo Romano ◽  
Salvatore Inguaggiato
Keyword(s):  
Space Weather ◽  
Atmospheric Pressure ◽  
Pressure Field ◽  
Ground Level ◽  
Total Solar Irradiance ◽  
Weather Parameters ◽  
Sun Activity ◽  
Fft Analysis ◽  
Sunspot Groups

<p>Investigations on correlation drops between near-ground atmospheric pressures measured at sea level and at higher altitudes on Italian volcanoes have been carried out. We looked for perturbations of the atmospheric pressure field driven by volcanic activity, but not excluding possible external triggers for the observed anomalies. Decorrelations between atmospheric pressures measured at Stromboli Island in stations located at different altitudes (years 2002-10) have been analysed and compared with data from other volcanic (Vesuvius) and non volcanic (Mt. Soro) orographic structures. We investigated as their possible triggers volcanic, meteorological and space weather parameters, with particular attention to Total Solar Irradiance (TSI), Kp index and Forbush decreases. Pressure decorrelations seems to be driven by astronomic cycles, with maxima in summer and minima in winter. A further contribution was found, seemingly assignable to TSI anomalies, with correlation minima occurring 12 hours after these but only during phases of high Sun activity. Moreover, during the same phases a main periodicity of about 27 days in pressure decorrelations was revealed by FFT analysis. This period is the same of the Sun Carrington rotation, expressing the periodic reappearance of sunspot groups on Sun’s surface. The strong similarity between recurrences of sunspot number and atmospheric pressure anomalies further supports the role of the former as a possible trigger for the latter.</p>

Parametric evaluation of ambient desorption optical emission spectroscopy utilizing a liquid sampling-atmospheric pressure glow discharge microplasma

2017 ◽  
Vol 32 (5) ◽  
pp. 931-941 ◽  
Author(s):  
Htoo W. Paing ◽  
R. Kenneth Marcus
Keyword(s):  
Glow Discharge ◽  
Atmospheric Pressure ◽  
Emission Spectroscopy ◽  
Optical Emission Spectroscopy ◽  
Optical Emission ◽  
Atmospheric Pressure Glow Discharge ◽  
Operational Parameters ◽  
Pressure Glow Discharge ◽  
Liquid Sampling

The operational parameters of the AD-LS-APGD-OES microplasma have been evaluated in terms of understanding their roles in analyte response.

Probabilistic model predictive control for extended prediction horizons

2021 ◽  
Vol 69 (9) ◽  
pp. 759-770
Author(s):  
Tim Brüdigam ◽  
Johannes Teutsch ◽  
Dirk Wollherr ◽  
Marion Leibold ◽  
Martin Buss
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Prediction Models ◽  
Computational Effort ◽  
Probabilistic Constraints ◽  
Detailed Model ◽  
Control Approach ◽  
Proposed Model ◽  
Sampling Times

Abstract Detailed prediction models with robust constraints and small sampling times in Model Predictive Control yield conservative behavior and large computational effort, especially for longer prediction horizons. Here, we extend and combine previous Model Predictive Control methods that account for prediction uncertainty and reduce computational complexity. The proposed method uses robust constraints on a detailed model for short-term predictions, while probabilistic constraints are employed on a simplified model with increased sampling time for long-term predictions. The underlying methods are introduced before presenting the proposed Model Predictive Control approach. The advantages of the proposed method are shown in a mobile robot simulation example.

scholarly journals Thermal behavior of ceramic particles in a gaseous medium at high temperature

2020 ◽  
Vol 307 ◽  
pp. 01056
Author(s):  
Abderrahmane AISSA ◽  
Abdel-Nour ZAIM ◽  
M SAHNOUN ◽  
Redouane FARES ◽  
M ABDELOUHAB ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Spherical Particle ◽  
Atmospheric Pressure ◽  
Computational Analysis ◽  
Gaseous Medium ◽  
Plasma Jet ◽  
Spray Process ◽  
Plasma Spray Process ◽  
Proposed Model ◽  
Computational Fluid Dynamics Cfd

Numerical simulation of the interaction between the spherical particle and plasma gas is carried out. The aim of this study is to investigatethermal transfer between the plasma gas and solid particle during the plasma spray process and to validate the well-known empirical correlation of the Ranz and Marshall. In the conditions of molten or semi-molten states of prepared substrate, the medium (plasma jet) can affect the high velocities of particles. On the basis of direct numerical simulation, the computational analysis has been carried out by using computational fluid dynamics (CFD) of heat transfer in atmospheric pressure and mid-temperature range (3000k–12000k) of a plasma flow over a spherical particle. Our proposed model improves correlation with experiments compared to the existing approaches in the literature.

Analytical Solution of Hydrostatic Pocket Tilting

2016 ◽  
Vol 821 ◽  
pp. 113-119 ◽  
Author(s):  
Eduard Stach ◽  
Jiří Falta ◽  
Matěj Sulitka
Keyword(s):  
Computational Models ◽  
Load Capacity ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Detailed Model ◽  
Limit Values ◽  
Inertia Effects ◽  
Proposed Model ◽  
Machine Tool Structure

Tilting (parallelism error) of guiding surfaces may cause reduction of load capacity of hydrostatic (HS) guideways and bearings in machine tools (MT). Using coupled finite element (FE) computational models of MT structures, it is nowadays possible to determine the extent of guiding surfaces deformation caused by thermal effects, gravitational force, cutting forces and inertia effects. Assessment of maximum allowable tilt has so far been based merely on experience. The paper presents a detailed model developed for description of the effect of HS bearing tilt on the load capacity characteristics of HS guideways. The model allows an evaluation of the tilt influence on the change of the characteristics as well as determination of the limit values of allowable tilt in interaction with compliant machine tool structure. The proposed model is based on the model of flow over the land of the HS pocket under extended Navier-Stokes equation. The model is verified using an experimental test rig.

scholarly journals Towards the Development of Syngas/Biomethane Electrolytic Production, Using Liquefied Biomass and Heterogeneous Catalyst

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3787 ◽  
Author(s):  
Gonçalves ◽  
Puna ◽  
Guerra ◽  
Rodrigues ◽  
Gomes ◽  
...  
Keyword(s):  
Synthesis Gas ◽  
Atmospheric Pressure ◽  
Zeolite Y ◽  
Gaseous Mixture ◽  
Operational Parameters ◽  
Synthetic Fuels ◽  
Volumetric Concentration ◽  
2Nd Generation ◽  
Different Temperatures ◽  
Generation Biofuel

This paper presents results on the research currently being carried out with the objective of developing new electrochemistry-based processes to produce renewable synthetic fuels from liquefied biomass. In the current research line, the gas mixtures obtained from the typical electrolysis are not separated into their components but rather are introduced into a reactor together with liquefied biomass, at atmospheric pressure and different temperatures, under acidified zeolite Y catalyst, to obtain synthesis gas. This gaseous mixture has several applications, like the production of synthetic 2nd generation biofuel (e. g., biomethane, biomethanol, bio-dimethyl ether, formic acid, etc.). The behaviour of operational parameters such as biomass content, temperature and the use of different amounts of acidified zeolite HY catalyst were investigated. In the performed tests, it was found that, in addition to the synthesis gas (hydrogen, oxygen, carbon monoxide and carbon dioxide), methane was also obtained. Therefore, this research is quite promising, and the most favourable results were obtained by carrying out the biomass test at 300 °C, together with 4% of acidified zeolite Y catalyst, which gives a methane volumetric concentration equal to 35%.

scholarly journals Comparative approach to seismic vulnerability of an elevated steel tank within a reinforced concrete chimney

2016 ◽  
Author(s):  
Yaniv Cohen ◽  
Arkady Livshits ◽  
Roberto Nascimbene
Keyword(s):  
Seismic Vulnerability ◽  
Ground Level ◽  
Comparative Approach ◽  
Water Tank ◽  
Design Procedures ◽  
Standard Procedures ◽  
Reinforced Concrete Chimney ◽  
Steel Tank ◽  
Tank Design ◽  
Dynamic Amplification

This study provides a framework for investigating the seismicresponse of an elevated steel water tank within a reinforcedconcrete chimney, to assist optimal tank placement and analysedifferent tank geometries. Elevated tank design procedures indifferent guidelines and codes are adequate for specific cases,none of which meets the exact requirements of this case study,in which the supporting structure mass is large relative to thestorage tank. The tank is located at an elevation 63 m belowthe mid-height of the 200 m chimney, resulting in a differentbehavior than a simple cantilever. Furthermore, for certainH/R ratios, coupling effects may exist between the fundamentalperiod of the chimney and that of the sloshing wave. An equivalentmodel is examined that is simple enough yet able to accuratelyproduce the design acceleration, dynamic amplification,damping and torsional effects at the chosen tank location, andto capture site effects. An analysis of the tank at ground level isconducted according to AWWA D100-11. Then, the tank at elevation63 m is analysed within the framework of three existingmethods using code spectra and site-specific spectra. A novelfourth method is then proposed which, contrary to the existingmethods, can accurately capture the conditions of this casestudy by combining the benefits of all methods. The workflowdescribed here can be readily applied to other cases of elevatedtanks for which the standard procedures are inadequate.

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