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Records with Subject: Modelling and Simulations
Showing records 1 to 25 of 189. [First] Page: 1 2 3 4 5 Last
Systems Design of a Petroleum Coke IGCC Power Plant: Technical, Economic, and Life cycle Perspectives
Ikenna Joseph Okeke, Thomas A Adams II
July 12, 2019 (v1)
Keywords: Carbon Dioxide Capture, Electricity, Gasification, IGCC, Life Cycle Analysis, Petroleum Coke
The petroleum coke gasification integrated gasification combined cycle power plant (petcoke-IGCC) is a promising avenue for disposal of the ever-growing amount of stockpiled petroleum coke. In this work, we present a novel techno-economic and life cycle assessment of the process operated with carbon capture and sequestration. The proposed petcoke-to-electricity plant is designed and simulated in Aspen Plus v10. The proposed power plant was compared against coal integrated gasification combined cycle (coal-IGCC) and supercritical pulverized coal power plants operated with carbon capture and sequestration. The results showed that although the efficiency of the coal-IGCC plant is higher than the petcoke-IGCC plant, the higher energy density of the petcoke and lower resource costs were such that the levelized cost of electricity of petcoke-IGCC was lower than coal-IGCC. Furthermore, the feed flow rate of petcoke to the petcoke-IGCC process is approximately 15% lower than the coal feed rate... [more]
Computational Fluid Dynamics (CFD) Simulations and Experimental Measurements in an Inductively-Coupled Plasma Generator Operating at Atmospheric Pressure: Performance Analysis and Parametric Study
Sangeeta B. Punjabi, Dilip N. Barve, Narendra K. Joshi, Asoka K. Das, Dushyant C. Kothari, Arijit A. Ganguli, Sunil N. Sahasrabhude, Jyeshtharaj B. Joshi
July 11, 2019 (v1)
Keywords: Energy, impedance, inductively-coupled plasma, plasma
In this article, electrical characteristics of a high-power inductively-coupled plasma (ICP) torch operating at 3 MHz are determined by direct measurement of radio-frequency (RF) current and voltage together with energy balance in the system. The variation of impedance with two parameters, namely the input power and the sheath gas flow rate for a 50 kW ICP is studied. The ICP torch system is operated at near atmospheric pressure with argon as plasma gas. It is observed that the plasma resistance increases with an increase in the RF-power. Further, the torch inductance decreases with an increase in the RF-power. In addition, plasma resistance and torch inductance decrease with an increase in the sheath gas flow rate. The oscillator efficiency of the ICP system ranges from 40% to 80% with the variation of the Direct current (DC) powers. ICP has also been numerically simulated using Computational Fluid Dynamics (CFD) to predict the impedance profile. A good agreement was found between the... [more]
Computational Evaluation of Mixing Performance in 3-D Swirl-Generating Passive Micromixers
Mahmut Burak Okuducu, Mustafa M. Aral
July 5, 2019 (v1)
Keywords: Computational Fluid Dynamics, false diffusion, finite volume method, micromixer, numerical diffusion, swirl
Computational Fluid Dynamics (CFD) tools are used to investigate fluid flow and scalar mixing in micromixers where low molecular diffusivities yield advection dominant transport. In these applications, achieving a numerical solution is challenging. Numerical procedures used to overcome these difficulties may cause misevaluation of the mixing process. Evaluation of the mixing performance of these devices without appropriate analysis of the contribution of numerical diffusion yields over estimation of mixing performance. In this study, two- and four-inlet swirl-generating micromixers are examined for different mesh density, flow and molecular diffusivity scenarios. It is shown that mesh densities need to be high enough to reveal numerical diffusion errors in scalar transport simulations. Two-inlet micromixer design was found to produce higher numerical diffusion. In both micromixer configurations, when cell Peclet numbers were around 50 and 100 for Reynolds numbers 240 and 120, the numer... [more]
Development of 3D Finite Element Method for Non-Aqueous Phase Liquid Transport in Groundwater as Well as Verification
Wei Yu, Hong Li
June 18, 2019 (v1)
Keywords: finite element method, FLAC, mixed-form formulation, non-aqueous phase liquid, two-phase flow
Groundwater contamination previously occurred at a broad range of locations in present-day China. There are thousands of kinds of contaminants which can be divided into soluble and insoluble categories in groundwater. In recent years, the non-aqueous phase liquid (NAPL) pollution that belongs to the multi-phase seepage flow phenomenon has become an increasingly prominent topic due to the challenge brought by groundwater purification and its treatment. Migrating with seepage flow and moving into the potable water sources, these contaminants directly endanger people’s health. Therefore, it is necessary to research how these contaminants not only migrate, but also are then accordingly remedied. First, as an analysis means, an effective numerical method is necessary to be built. A three-dimensional finite element method program for analyzing two-phase flow in porous media, which can be applied to the immiscible contaminant transport problem in subsurface flow has been developed in this pap... [more]
Numerical Simulation of the Effects of the Helical Angle on the Decaying Swirl Flow of the Hole Cleaning Device
Jingyu Qu, Tie Yan, Xiaofeng Sun, Zijian Li, Wei Li
June 18, 2019 (v1)
Keywords: Computational Fluid Dynamics, decaying swirl flow, hole cleaning device, horizontal wellbore, swirl intensity
The application of the hole cleaning device in downhole is a new technology that can improve the problem of cuttings accumulation in the annulus and improve the hole cleaning effect of the wellbore during drilling. In this paper, the Reynolds Averaged Navier⁻Stokes model, together with the Realizable k-ε turbulence model, are used to perform transient simulations. The effects of rotational speed, blade shape, and helical angle on the initial swirl intensity and its decay behavior along the flow direction are studied. The swirl number, the initial swirl intensity, the decay rate, the tangential velocity distribution, and the variation of pressure are analyzed. The results indicate that the swirl number of the swirl flow exponentially decays along the flow direction. The straight blade and V-shaped blade have different swirl flow induction mechanisms. Under specific drilling parameters, the critical helical angle is determined for both types of blades. When the selection of the helical a... [more]
The Application of a Three-Dimensional Deterministic Model in the Study of Debris Flow Prediction Based on the Rainfall-Unstable Soil Coupling Mechanism
Shuangshuang Qiao, Shengwu Qin, Junjun Chen, Xiuyu Hu, Zhongjun Ma
June 10, 2019 (v1)
Keywords: debris flow, forecasting, Jiaohe, rainfall-unstable soil coupling mechanism(R-USCM), scoops3D
As debris flow is one of the most destructive natural disasters in many parts of the world, the assessment and management of future debris flows with proper forecasting methods are crucial for the safety of life and property. So increasing attention has been paid to the forecasting methods on debris flows. A debris flow forecasting method based on the rainfall-unstable soil coupling mechanism (R-USCM) is presented in the current study. This method is based on the debris flow formation mechanism. The density of sediment is introduced as an evaluation index to determine the susceptibility of debris flow occurrence. The forecasting method includes two phases: (1) rainfall and soil coupling and (2) runoff and unstable soil coupling. Scoops3D, a three-dimensional (3D) model for analyzing slope stability, was introduced into the debris flow forecasting method. In order to test the forecasting accuracy of this method, Jiaohe County was selected as a research area, and the serious debris flow... [more]
Metabolic Modeling of Clostridium difficile Associated Dysbiosis of the Gut Microbiota
Poonam Phalak, Michael A. Henson
June 10, 2019 (v1)
Keywords: bacterial biofilms, Clostridium difficile infection, gut microbiota dysbiosis, metabolic modeling
Recent in vitro experiments have demonstrated the ability of the pathogen Clostridium difficile and commensal gut bacteria to form biofilms on surfaces, and biofilm development in vivo is likely. Various studies have reported that 3%⁻15% of healthy adults are asymptomatically colonized with C. difficile, with commensal species providing resistance against C. difficile pathogenic colonization. C. difficile infection (CDI) is observed at a higher rate in immunocompromised patients previously treated with broad spectrum antibiotics that disrupt the commensal microbiota and reduce competition for available nutrients, resulting in imbalance among commensal species and dysbiosis conducive to C. difficile propagation. To investigate the metabolic interactions of C. difficile with commensal species from the three dominant phyla in the human gut, we developed a multispecies biofilm model by combining genome-scale metabolic reconstructions of C. difficile, Bacteroides thetaiotaomicron from the p... [more]
Model for the Patterns of Salt-Spray-Induced Chloride Corrosion in Concretes under Coupling Action of Cyclic Loading and Salt Spray Corrosion
Ruixue Liu, Huiguang Yin, Lianying Zhang, Bing Li, Xianbiao Mao
June 8, 2019 (v1)
Keywords: chloride, concrete, coupling model, numerical calculation, Unsaturation
In this study, the patterns of chloride ion erosion of unsaturated concrete subjected to the coupling action of cyclic loading and salt spray corrosion were experimentally studied, and Fick’s Second Law was used to fit the variation patterns of chloride concentration to obtain the chloride diffusion coefficient. Accordingly, we have established a mathematical model that describes chloride transport in unsaturated concrete and accounts for the effects of gas flow, water migration, convection diffusion, and capillary action. This model is composed of three equations—the gas flow equation, the solution flow equation, and the solute convection⁻diffusion equation. The COMSOL numerical analysis software was subsequently used to obtain solutions for this model, based on parameters such as porosity and the chloride diffusion coefficient. Subsequently, the saturation, relative permeability, and the chloride ion concentration during the first corrosion cycle were analyzed. The numerical results... [more]
Agent-Based Simulation of Value Flow in an Industrial Production Process
Luminita Parv, Bogdan Deaky, Marius Daniel Nasulea, Gheorghe Oancea
June 8, 2019 (v1)
Keywords: agent-based simulation, SME’s, sustainable production process, value stream analysis, value stream design
The current competitive environment demands companies to be more and more efficient. In order to increase manufacturing efficiency, two apparently independent approaches have emerged: lean strategies, focusing on identifying and minimizing non-added value activities, identifying wastes in the system and their elimination, and information tools for planning and controlling activities. In this paper, a manufacturing system was considered for which it was necessary to increase the production capacity in order to respond to the customer’s increased demand. A practical case study in the automotive industry for a medium-sized enterprise was considered. In order to investigate the production process parameters and to implement lean principles, Value Stream Mapping (current analysis and optimized solution) and Anylogic agent-based simulations were carried out. Based on this, the lean performances, specific for the target VSM, were evaluated in terms of key performance indicators. The benefits... [more]
The Accident Path of Coal Mine Gas Explosion Based on 24Model: A Case Study of the Ruizhiyuan Gas Explosion Accident
Gui Fu, Ziqi Zhao, Chuanbo Hao, Qiang Wu
May 16, 2019 (v1)
Keywords: 24Model, accident prevention, action path, coal mine, gas explosion accident, safety management
In order to effectively prevent coal mine accidents, we selected the most serious type of accident in coal mines—gas explosions—as the research object. Based on the accident causation model (24Model), we propose an action path and analysis steps of accidents caused by different employees in the organization. A gas explosion coal mine accident was analyzed using the 24Model and the proposed action path, and 12 unsafe actions, 3 unsafe states, 4 habitual behaviors, 10 safety management systems, and 10 safety cultures were obtained. Case analysis results show that by using the 24Model and path analysis the proposed effect can help employees to clearly identify the cause of the accident, to better understand the logical relationship with the causes of the accident, improve the effectiveness of training, and effectively prevent similar accidents. The 24Model and the proposed path can be used to comprehensively analyze the reasons for and help to effectively prevent coal mine gas explosion a... [more]
Simulation Study on the Influence of Gas Mole Fraction and Aqueous Activity under Phase Equilibrium
Weilong Zhao, Hao Wu, Jing Wen, Xin Guo, Yongsheng Zhang, Ruirui Wang
May 16, 2019 (v1)
Keywords: activity, gas mole fraction, phase equilibrium, threshold value, UNIFAC
This work explored the influence of gas mole fraction and activity in aqueous phase while predicting phase equilibrium conditions. In pure gas systems, such as CH₄, CO₂, N₂ and O₂, the gas mole fraction in aqueous phase as one of phase equilibrium conditions was proposed, and a simplified correlation of the gas mole fraction was established. The gas mole fraction threshold maintaining three-phase equilibrium was obtained by phase equilibrium data regression. The UNIFAC model, the predictive Soave-Redlich-Kwong equation and the Chen-Guo model were used to calculate aqueous phase activity, the fugacity of gas and hydrate phase, respectively. It showed that the predicted phase equilibrium pressures are in good agreement with published phase equilibrium experiment data, and the percentage of Absolute Average Deviation Pressures are given. The water activity, gas mole fraction in aqueous phase and the fugacity coefficient in vapor phase are discussed.
Employment of Emergency Advanced Nurses of Turkey: A Discrete-Event Simulation Application
Abdulkadir Atalan, Cem Cagri Donmez
April 15, 2019 (v1)
Keywords: advanced nurses, discrete event simulation, emergency service resources, emergency services
In the present study, problems in emergency services (ESs) were dealt with by analyzing the working system of ESs in Turkey. The purpose of this study was to reduce the waiting times spent in hospitals by employing advanced nurses (ANs) to treat patients who are not urgent, or who may be treated as outpatients in ESs. By applying discrete-event simulation on a 1/24 (daily) and 7/24 (weekly) basis, and by employing ANs, it was determined that the number of patients that were treated increased by 26.71% on a 1/24 basis, and by 15.13% on a 7/24 basis. The waiting time that was spent from the admission to the ES until the treatment time decreased by 38.67% on a 1/24 basis and 53.66% on a 24/7 basis. Similarly, the length of stay was reduced from 82.46 min to 53.97 min in the ES. Among the findings, it was observed that the efficiency rate of the resources was balanced by the employment of ANs, although it was not possible to obtain sufficient efficiency from the resources used in the ESs p... [more]
Modeling/Simulation of the Dividing Wall Column by Using the Rigorous Model
Chi Zhai, Qinjun Liu, Jose A. Romagnoli, Wei Sun
April 15, 2019 (v1)
Keywords: gProms, rigorous DWC model, the benzene–toluene–xylene system
Dividing wall column (DWC) is an atypical distillation column with an internal, vertical WE partition wall that effectively accommodates two conventional distillation columns into one to improve the thermodynamic efficiency. In previous studies, different equivalent models by combining conventional columns are adopted to approximate the DWC modeling, which may not well describe the integration of the DWC; moreover, the computational cost increases when multiple columns are implemented to represent one DWC. In this paper, a rigorous mathematical model is proposed based on the mass balance, the energy and phase equilibrium of the DWC, where decision variables and state variables are equally treated. The model was developed in the general process modeling system (gPROMS). Based on the rigorous model, the influences of liquid split ratio and vapor split ratio are discussed, and it is shown that the heat duty is sensitive to changes on the liquid and vapor split ratio. Inappropriate liquid... [more]
2D Plane Strain Consolidation Process of Unsaturated Soil with Vertical Impeded Drainage Boundaries
Minghua Huang, Dun Li
April 9, 2019 (v1)
Keywords: consolidation process, excess pore-pressures, impeded drainage boundary, semi-analytical solution, unsaturated soil
The consolidation process of soil stratum is a common issue in geotechnical engineering. In this paper, the two-dimensional (2D) plane strain consolidation process of unsaturated soil was studied by incorporating vertical impeded drainage boundaries. The eigenfunction expansion and Laplace transform techniques were adopted to transform the partial differential equations for both the air and water phases into two ordinary equations, which can be easily solved. Then, the semi-analytical solutions for the excess pore-pressures and the soil layer settlement were derived in the Laplace domain. The final results in the time domain could be computed by performing the numerical inversion of Laplace transform. Furthermore, two comparisons were presented to verify the accuracy of the proposed semi-analytical solutions. It was found that the semi-analytical solution agreed well with the finite difference solution and the previous analytical solution from the literature. Finally, the 2D plane stra... [more]
Modeling Permeation through Mixed-Matrix Membranes: A Review
Gloria M. Monsalve-Bravo, Suresh K. Bhatia
April 8, 2019 (v1)
Keywords: effective medium approach, mixed-matrix membrane (MMM), particle-polymer interface, permeation modeling, simulation of MMM
Over the past three decades, mixed-matrix membranes (MMMs), comprising an inorganic filler phase embedded in a polymer matrix, have emerged as a promising alternative to overcome limitations of conventional polymer and inorganic membranes. However, while much effort has been devoted to MMMs in practice, their modeling is largely based on early theories for transport in composites. These theories consider uniform transport properties and driving force, and thus models for the permeability in MMMs often perform unsatisfactorily when compared to experimental permeation data. In this work, we review existing theories for permeation in MMMs and discuss their fundamental assumptions and limitations with the aim of providing future directions permitting new models to consider realistic MMM operating conditions. Furthermore, we compare predictions of popular permeation models against available experimental and simulation-based permeation data, and discuss the suitability of these models for pr... [more]
Numerical Investigation of the Failure Mechanism of Transversely Isotropic Rocks with a Particle Flow Modeling Method
Xu-Xu Yang, Hong-Wen Jing, Wei-Guo Qiao
April 8, 2019 (v1)
Keywords: failure mechanism, interface, particle flow modeling, transversely isotropic rocks
Transversely isotropic rocks are commonly encountered in rock engineering practices, and their strength and failure behavior is often governed by the property of anisotropy. The particle flow modeling method was utilized to investigate the failure mechanism of transversely isotropic rocks subject to uniaxial compressive loading. The details for establishing transversely isotropic rock models were first presented, and then a parametric study was carried out to look into the effect of interface properties on the failure mode and strength of transversely isotropic rock models by varying the interface dip angle. The smooth joint model was incorporated to create interfaces for the completeness of establishing transversely isotropic rock models with the particle flow modeling method. Accordingly, three failure modes observed in transversely isotropic rock models with varying dip angles were tensile failure across interfaces, shear failure along interfaces, and tensile failure along interface... [more]
Population Balance Modeling and Opinion Dynamics—A Mutually Beneficial Liaison?
Michael Kuhn, Christoph Kirse, Heiko Briesen
April 8, 2019 (v1)
Keywords: Deffuant-Weisbuch model, interdisciplinarity, mass transfer, opinion dynamics, population balance model, social sciences
In this contribution, we aim to show that opinion dynamics and population balance modeling can benefit from an exchange of problems and methods. To support this claim, the Deffuant-Weisbuch model, a classical approach in opinion dynamics, is formulated as a population balance model. This new formulation is subsequently analyzed in terms of moment equations, and conservation of the first and second order moment is shown. Exemplary results obtained by our formulation are presented and agreement with the original model is found. In addition, the influence of the initial distribution is studied. Subsequently, the Deffuant-Weisbuch model is transferred to engineering and interpreted as mass transfer between liquid droplets which results in a more flexible formulation compared to alternatives from the literature. On the one hand, it is concluded that the transfer of opinion-dynamics problems to the domain of population balance modeling offers some interesting insights as well as stimulating... [more]
Model Development and Validation of Fluid Bed Wet Granulation with Dry Binder Addition Using a Population Balance Model Methodology
Shashank Venkat Muddu, Ashutosh Tamrakar, Preetanshu Pandey, Rohit Ramachandran
April 8, 2019 (v1)
Keywords: binder dissolution, fluid bed granulation, heat and mass balance, kernel development, population balance model
An experimental study in industry was previously carried out on a batch fluid bed granulation system by varying the inlet fluidizing air temperature, binder liquid spray atomization pressure, the binder liquid spray rate and the disintegrant composition in the formulation. A population balance model framework integrated with heat transfer and moisture balance due to liquid addition and evaporation was developed to simulate the fluid bed granulation system. The model predictions were compared with the industry data, namely, the particle size distributions (PSDs) and geometric mean diameters (GMDs) at various time-points in the granulation process. The model also predicted the trends for binder particle dissolution in the wetting liquid and the temperatures of the bed particles in the fluid bed granulator. Lastly, various process parameters were varied and extended beyond the region studied in the aforementioned experimental study to identify optimal regimes for granulation.
Quantitative Estimates of Nonlinear Flow Characteristics of Deformable Rough-Walled Rock Fractures with Various Lithologies
Qian Yin, Lixin He, Hongwen Jing, Dong Zhu
April 8, 2019 (v1)
Keywords: confining pressure, critical Reynolds number, lithology, nonlinear flow, rough-walled fractures, transmissivity
The existence of surface roughness, various contact conditions and the occurrence of flow nonlinearity make the flow process in natural rock fractures more complicated. To evaluate the fluid flow regimes in deformable rough-walled rock fractures, a great many hydromechanical tests were conducted on nine real fractures artificially produced from a wide range of lithological diversity. For fractures with a certain JRC (fracture roughness coefficient) value, the confining pressure varied from 5 to 20 MPa, and the hydraulic pressure was increased from 0.4 to 6.0 MPa. The experimental results display that (i) regression analyses of the raw experimental data indicate that the Forchheimer’s law provides a perfect description for flow process through the fractures. The coefficients of viscous and inertial pressure drops undergo a growth of 2⁻3 orders of magnitude with an increase in the confining pressure; (ii) the hydraulic aperture decreases by approximately 87.41⁻92.81% as the confining pre... [more]
A Numerical Study of Stress Distribution and Fracture Development above a Protective Coal Seam in Longwall Mining
Chunlei Zhang, Lei Yu, Ruimin Feng, Yong Zhang, Guojun Zhang
April 8, 2019 (v1)
Keywords: gas drainage, gob behaviors, longwall mining, permeability, stress relief
Coal and gas outbursts are serious safety concerns in the Chinese coal industry. Mining of the upper or lower protective coal seams has been widely used to minimize this problem. This paper presents new findings from longwall mining-induced fractures, stress distribution changes in roof strata, strata movement and gas flow dynamics after the lower protective coal seam is extracted in a deep underground coal mine in Jincheng, China. Two Flac3D models with varying gob loading characteristics as a function of face advance were analyzed to assess the effect of gob behavior on stress relief in the protected coal seam. The gob behavior in the models is incorporated by applying variable force to the floor and roof behind the longwall face to simulate gob loading characteristics in the field. The influence of mining height on the stress-relief in protected coal seam is also incorporated. The stress relief coefficient and relief angle were introduced as two essential parameters to evaluate the... [more]
Challenges in Nanofluidics—Beyond Navier⁻Stokes at the Molecular Scale
Peter J. Daivis, Billy D. Todd
April 8, 2019 (v1)
Keywords: hydrodynamics, molecular dynamics, nanofluidics, non-local constitutive equations, slip, spin-coupling
The fluid dynamics of macroscopic and microscopic systems is well developed and has been extensively validated. Its extraordinary success makes it tempting to apply Navier⁻Stokes fluid dynamics without modification to systems of ever decreasing dimensions as studies of nanofluidics become more prevalent. However, this can result in serious error. In this paper, we discuss several ways in which nanoconfined fluid flow differs from macroscopic flow. We give particular attention to several topics that have recently received attention in the literature: slip, spin angular momentum coupling, nonlocal stress response and density inhomogeneity. In principle, all of these effects can now be accurately modelled using validated theories. Although the basic principles are now fairly well understood, much work remains to be done in their application.
Simulation and Analysis of Oleic Acid Pretreatment for Microwave-Assisted Biodiesel Production
Weiquan Ma, Tao Hong, Tian Xie, Fengxia Wang, Bin Luo, Jie Zhou, Yang Yang, Huacheng Zhu, Kama Huang
April 8, 2019 (v1)
Keywords: biodiesel, coupling, microwave heating, multiphysics calculation, oleic acid
Oleic acid needs to be heated when it is utilized for biodiesel production, but, as a low-loss solution, oleic acid is difficult to heat by microwave. An efficient heating method for oleic acid is designed. A high loss material porous media is placed in a quartz tube, and a microwave directly heats the porous medium of the high loss material. The oleic acid flows through the pores of porous media so that the oleic acid exchanges heat during this process and rapid heating of oleic acid is achieved. A coupling model, based on the finite element method, is used to analyze the microwave heating process. The multiphysics model is based on a single mode cavity operating at 2450 MHz. An elaborate experimental system is developed to validate the multiphysics model through temperature measurements carried out for different flow velocities of oleic acid and different microwave power levels. The computational results are in good agreement with the experimental data. Based on the validated model,... [more]
Simulation, calculation, and supporting data files for the paper: Design and Optimization of a Novel Coke Oven Gas and Blast Furnace Gas to Methanol Process with Carbon Dioxide Capture and Utilization
Lingyan Deng, Thomas Adams II
June 14, 2019 (v2)
Keywords: Aspen Capital Cost Estimator, Aspen Plus Simulation, blast furnace gas, CO2 emission reduction, coke oven gas, economic and sensitivity analysis, methanol production
This submission includes Excel, MATLAB code, Aspen Plus simulation, and Aspen Capital Cost Estimator files for the paper entitled "Design and Optimization of a Novel Coke Oven Gas and Blast Furnace Gas to Methanol Process with Carbon Dioxide Capture and Utilization".
Lobatto-Milstein Numerical Method in Application of Uncertainty Investment of Solar Power Projects
Mahmoud A. Eissa, Boping Tian
March 26, 2019 (v1)
Keywords: Egypt, numerical simulation, real option, Renewable and Sustainable Energy, stochastic differential equation
Recently, there has been a growing interest in the production of electricity from renewable energy sources (RES). The RES investment is characterized by uncertainty, which is long-term, costly and depends on feed-in tariff and support schemes. In this paper, we address the real option valuation (ROV) of a solar power plant investment. The real option framework is investigated. This framework considers the renewable certificate price and, further, the cost of delay between establishing and operating the solar power plant. The optimal time of launching the project and assessing the value of the deferred option are discussed. The new three-stage numerical methods are constructed, the Lobatto3C-Milstein (L3CM) methods. The numerical methods are integrated with the concept of Black⁻Scholes option pricing theory and applied in option valuation for solar energy investment with uncertainty. The numerical results of the L3CM, finite difference and Monte Carlo methods are compared to show the ef... [more]
Experimental Investigation on a Thermal Model for a Basin Solar Still with an External Reflector
Masoud Afrand, Rasool Kalbasi, Arash Karimipour, Somchai Wongwises
March 15, 2019 (v1)
Keywords: basin solar still, desalination, external reflector, still efficiency, thermal model
In this study, a thermal model for estimating the efficiency of a basin solar still with an external reflector was introduced using the energy balance equations of different parts of the solar still. Then, in order to verify the precision and accuracy of this model, a basin solar still with an external reflector was constructed and some experiments were performed. The hourly temperature values for different places of the still and amount of distilled water were calculated using the thermal model and compared with experimental measurements. Comparisons show that the thermal model of the still is in good agreement with the experimental results. Therefore, it can be concluded that the introduced thermal model can be used reliably to estimate the amount of distilled water and efficiency of the basin solar still with an external reflector. Results also revealed that the efficiency of the solar still is low in the early hours, while it was enhanced 44% in the afternoon. Furthermore, it was c... [more]
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