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.

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

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.

The Effect of Thermal Contact Resistance on Heat Management in a Shuttling PCR System

2013 ◽  
Vol 284-287 ◽  
pp. 1941-1945
Author(s):  
Jyh Jian Chen ◽  
Wei Hua Chen ◽  
Yi Shiang Shie
Keyword(s):  
Pid Controller ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Computer Code ◽  
Reaction Chamber ◽  
Operational Parameters ◽  
Heat Management ◽  
Dna Templates ◽  
Polymerase Chain ◽  
The Stability

A novel shuttling polymerase chain reaction (PCR) system is assembled to make temperature uniform in the reaction chamber. The chamber is oscillated by a servo motor and contacted with three different isothermal zones to complete several thermal cycles. The home-made computer code is utilized to investigate the influences of operational parameters on the temperature inside the chamber. Numerical results show that the contact resistances between the heating blocks and the reaction chamber dominate the temperatures inside the PCR chamber. In this work a PCR system that is composed of the PID controller, the moving stage, three aluminum blocks for three different isothermal zones and a reaction chamber is also developed. Experimental results demonstrated that the stability of this shuttling PCR system is confirmed. And results show that DNA templates provided with the yT&A® cloning vector are amplified successfully in this PCR system.

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.

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%.

Study of the Effects of Environment in the Fatigue Analysis on Existing LWR as Proposed in USNRC RG 1.207

2009 ◽  
Author(s):  
Eugene Tom ◽  
Milton Dong ◽  
Hong Ming Lee
Keyword(s):  
Fatigue Life ◽  
Correction Factor ◽  
Environmental Effects ◽  
Environmental Parameters ◽  
Computer Code ◽  
Cyclic Behavior ◽  
Simplified Approach ◽  
Asme Code ◽  
Detailed Computer ◽  
Fatigue Evaluation

US NRC Regulatory Guide 1.207 Rev. 0 provides guidance for use in determining the acceptable fatigue life of ASME pressure boundary components, with consideration of the light-water reactor (LWR) environment. Because of significant conservatism in quantifying other plant-related variables (such as cyclic behavior, including stress and loading rates) involved in cumulative fatigue life calculations, the design of the current fleet of reactors is satisfactory. For new plants under design and current operating plants considering applying for License Renewal, the environment effects may need to be considered in the design. RG 1.207 proposes using an environmental correction factor (Fen) to account for LWR environments by correcting the fatigue usage calculated with the ASME “air” curves. The Fen method is presented in NUREG/CR-6909, “Effect of LWR Coolant Environments on the Fatigue Life of Reactor Materials”. By definition, Fen is the ratio of fatigue life of the component material at room temperature air environments to its fatigue life in LWR coolant at operating temperature. To incorporate environmental effects into the fatigue evaluation, the fatigue usage is calculated using provisions set forth in Section III of the ASME Code, and is adjusted by multiplying a correction factor. The calculated Fen values are then used to incorporate environmental effects into ASME fatigue usage factor evaluation. Once the environmental correction factors have been determined, the previously calculated allowable number of cycles for each load set pair based on the current Code fatigue design curve can be adjusted to determine the new fatigue usage factors for environmental effects. This paper presents a study of the effect of the Regulatory Guide if it is to be implemented on the current fleet of LWR. A quick assessment of the sensitivity of the various environmental parameters is also included in this paper. The comparison of environmental effects between the simplified approach in this paper and the results with detailed computer analyses, such as Unisont’s propriety computer code UPIPENB (Ref. 4), will be our next research project to be presented in the future conference.

Design Considerations of an Airborne Free Piston Compressor

1987 ◽  
Vol 201 (3) ◽  
pp. 177-184 ◽  
Author(s):  
E Sher
Keyword(s):  
Ambient Pressure ◽  
Pressure Ratio ◽  
Combustion Process ◽  
Piston Compressor ◽  
Computer Code ◽  
Thermodynamic Efficiency ◽  
Atmospheric Conditions ◽  
Ambient Conditions ◽  
Free Piston ◽  
Detailed Computer

The effect of the atmospheric conditions on the performance of a spark ignition free piston engine has been investigated. A detailed computer code has been developed to simulate the unit cycle and was used to evaluate the effect of its geometrical proportions and the ambient conditions on the cycle performances. The model includes a semi-empirical model for the scavenging process, calculations of the flows into and out of the cylinders, empirical expressions for the combustion process and a practical approach for the heat transfer. The model has been calibrated by using experimental results of a conventional two-stroke engine having identical cylinder and port assemblies. It was concluded that the thermodynamic efficiency of the unit is strongly dependent on the receiver to the atmospheric pressure ratio, the compression ratio of the compressor, the compressor aspect ratio and the ambient pressure. It was shown that the thermodynamic efficiency varies insignificantly with the ambient temperature.

Theoretical simulation of the picosecond runaway-electron beam in coaxial diode filled with SF 6 at atmospheric pressure

2016 ◽  
Vol 114 (4) ◽  
pp. 45001 ◽  
Author(s):  
Andrey Kozyrev ◽  
Vasily Kozhevnikov ◽  
Mikhail Lomaev ◽  
Dmitry Sorokin ◽  
Natalia Semeniuk ◽  
...  
Keyword(s):  
Electron Beam ◽  
Atmospheric Pressure ◽  
Runaway Electron ◽  
Runaway Electron Beam ◽  
Theoretical Simulation

INTRAMOLECULAR ENERGY BAND DISPERSION IN ORIENTED THIN FILM OF n-CF3(CF2)22CF3 STUDIED BY ANGLE-RESOLVED UPS AND THEORETICAL SIMULATION

2002 ◽  
Vol 09 (01) ◽  
pp. 407-412 ◽  
Author(s):  
DAISUKE YOSHIMURA ◽  
KAZUHIKO SEKI ◽  
TAKAYUKI MIYAMAE ◽  
HISAO ISHII ◽  
SHINJI HASEGAWA ◽  
...  
Keyword(s):  
Energy Band ◽  
Emission Spectra ◽  
Photoemission Spectroscopy ◽  
Surface Films ◽  
Theoretical Simulation ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Band Dispersion ◽  
Chain Axis ◽  
Theoretical Simulations ◽  
Long Chain

Electronic structure of perfluorotetracosane [n- CF 3 ( CF 2)22 CF 3; PFT], which is an oligomer of poly(tetrafluoroethylene) (PTFE), was investigated by angle-resolved photoemission spectroscopy (ARUPS) with synchrotron radiation. Theoretical simulations of ARUPS spectra were also performed by the independent atomic center (IAC) approximation combined with ab initio molecular orbital (MO) calculations. Measured normal-emission spectra for end-on oriented (the long-chain axis of PFT is perpendicular to the surface) films showed an incident photon energy dependence due to the intramolecular energy band dispersion. The energy band structure along the long-chain direction of PFT obtained from measured and calculated spectra is also discussed.

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