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Records with Subject: Modelling and Simulations
Showing records 1 to 25 of 179. [First] Page: 1 2 3 4 5 Last
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]
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]
Improved Battery Parameter Estimation Method Considering Operating Scenarios for HEV/EV Applications
Jufeng Yang, Bing Xia, Yunlong Shang, Wenxin Huang, Chris Mi
March 15, 2019 (v1)
Keywords: equivalent circuit modeling, lithium-ion battery, operating scenario, parameter estimation
This paper presents an improved battery parameter estimation method based on typical operating scenarios in hybrid electric vehicles and pure electric vehicles. Compared with the conventional estimation methods, the proposed method takes both the constant-current charging and the dynamic driving scenarios into account, and two separate sets of model parameters are estimated through different parts of the pulse-rest test. The model parameters for the constant-charging scenario are estimated from the data in the pulse-charging periods, while the model parameters for the dynamic driving scenario are estimated from the data in the rest periods, and the length of the fitted dataset is determined by the spectrum analysis of the load current. In addition, the unsaturated phenomenon caused by the long-term resistor-capacitor (RC) network is analyzed, and the initial voltage expressions of the RC networks in the fitting functions are improved to ensure a higher model fidelity. Simulation and ex... [more]
Performance of a Predictive Model for Calculating Ascent Time to a Target Temperature
Jin Woo Moon, Min Hee Chung, Hayub Song, Se-Young Lee
February 27, 2019 (v1)
Keywords: artificial neural network (ANN), ascending time, heating system, predictive controls, setback temperature
The aim of this study was to develop an artificial neural network (ANN) prediction model for controlling building heating systems. This model was used to calculate the ascent time of indoor temperature from the setback period (when a building was not occupied) to a target setpoint temperature (when a building was occupied). The calculated ascent time was applied to determine the proper moment to start increasing the temperature from the setback temperature to reach the target temperature at an appropriate time. Three major steps were conducted: (1) model development; (2) model optimization; and (3) performance evaluation. Two software programs—Matrix Laboratory (MATLAB) and Transient Systems Simulation (TRNSYS)—were used for model development, performance tests, and numerical simulation methods. Correlation analysis between input variables and the output variable of the ANN model revealed that two input variables (current indoor air temperature and temperature difference from the targe... [more]
Modeling of a Field-Modulated Permanent-Magnet Machine
Xianglin Li, K. T. Chau, Yubin Wang
February 27, 2019 (v1)
Keywords: d-q frame, field-modulated permanent magnet (FMPM) machine, finite element analysis (FEA), Modelling
In this work, an effective field-modulated permanent-magnet (FMPM) machine was investigated, in which the spoke-magnet outer rotor and open-slot stator were employed. The objective of this paper is to provide the mathematical modeling analysis that was performed for the purpose of control research on this type of FMPM machine. The simulation results by means of finite element analysis (FEA) are given to verify the theoretical analysis and the validity of mathematical model. A prototype machine was also fabricated for experimentation. Both the analytical model and the FEA results are validated by experimental tests on the prototype machine.
Laboratory Experiment and Numerical Analysis of a New Type of Solar Tower Efficiently Generating a Thermal Updraft
Yuji Ohya, Masaki Wataka, Koichi Watanabe, Takanori Uchida
February 27, 2019 (v1)
Keywords: computational fluid dynamics (CFD), diffuser, laboratory experiment, solar tower, thermal updraft
A new type of solar tower was developed through laboratory experiments and numerical analyses. The solar tower mainly consists of three components. The transparent collector area is an aboveground glass roof, with increasing height toward the center. Attached to the center of the inside of the collector is a vertical tower within which a wind turbine is mounted at the lower entry to the tower. When solar radiation heats the ground through the glass roof, ascending warm air is guided to the center and into the tower. A solar tower that can generate electricity using a simple structure that enables easy and less costly maintenance has considerable advantages. However, conversion efficiency from sunshine energy to mechanical turbine energy is very low. Aiming to improve this efficiency, the research project developed a diffuser-type tower instead of a cylindrical tower, and investigated a suitable diffuser shape for practical use. After changing the tower height and diffuser open angle, w... [more]
Numerical Simulation of a Vortex Combustor Based on Aluminum and Steam
Xianhe Chen, Zhixun Xia, Liya Huang, Likun Ma
February 27, 2019 (v1)
Keywords: aluminum particle, diffusion flame, numerical simulation, steam, vortex combustor
In this paper we report a new development in the numerical model for aluminum-steam combustion. This model is based on the diffusion flame of the continuum regime and the thermal equilibrium between the particle and the flow field, which can be used to calculate the aluminum particle combustion model for two phase calculation conditions. The model prediction is in agreement with the experimental data. A new type of vortex combustor is proposed to increase the efficiency of the combustion of aluminum and steam, and the mathematical model of the two phase reacting flow in this combustor is established. The turbulence effects are modeled using the Reynolds Stress Model (RSM) with Linear Pressure-Strain approach, and the Eddy-Dissipation model is used to simulate the gas phase combustion. Aluminum particles are injected into the vortex combustor, forming a swirling flow around the chamber, whose trajectories are traced using the Discrete Phase Model (DPM). The simulation results show that... [more]
An Analysis Based on SD Model for Energy-Related CO₂ Mitigation in the Chinese Household Sector
Xingpeng Chen, Guokui Wang, Xiaojia Guo, Jinxiu Fu
February 27, 2019 (v1)
Keywords: CO2 emissions, household sector, system dynamics
Reducing carbon dioxide (CO₂) emissions has become a global consensus in response to global warming and climate change, especially to China, the largest CO₂ emitter in the world. Most studies have focused on CO₂ emissions from the production sector, however, the household sector plays an important role in the total energy-related CO₂ emissions. This study formulates an integrated model based on logarithmic mean Divisia index methodology and a system dynamics model to dynamically simulate household energy consumption and CO₂ emissions under different conditions. Results show the following: (1) the integrated model performs well in calculating the contribution of influencing factors on household CO₂ emissions and analyzing the options for CO₂ emission mitigation; (2) the increase in income is the dominant driving force of household CO₂ emissions, and as a result of the improved standard of living in China a sustained increase in household CO₂ emissions can be expected; (3) with decreasin... [more]
Validation of Generic Models for Variable Speed Operation Wind Turbines Following the Recent Guidelines Issued by IEC 61400-27
Andrés Honrubia-Escribano, Francisco Jiménez-Buendía, Emilio Gómez-Lázaro, Jens Fortmann
February 27, 2019 (v1)
Keywords: doubly-fed induction machine (DFIG), full-scale converter (FSC), generic model, IEC 61400-27, model validation, power system stability, standard model
Considerable efforts are currently being made by several international working groups focused on the development of generic, also known as simplified or standard, wind turbine models for power system stability studies. In this sense, the first edition of International Electrotechnical Commission (IEC) 61400-27-1, which defines generic dynamic simulation models for wind turbines, was published in February 2015. Nevertheless, the correlations of the IEC generic models with respect to specific wind turbine manufacturer models are required by the wind power industry to validate the accuracy and corresponding usability of these standard models. The present work conducts the validation of the two topologies of variable speed wind turbines that present not only the largest market share, but also the most technological advances. Specifically, the doubly-fed induction machine and the full-scale converter (FSC) topology are modeled based on the IEC 61400-27-1 guidelines. The models are simulated... [more]
Design and Output Performance Model of Turbodrill Blade Used in a Slim Borehole
Yu Wang, Bairu Xia, Zhiqiao Wang, Liguang Wang, Qin Zhou
February 27, 2019 (v1)
Keywords: granite section, multistage simulation models, output performances prediction, slim borehole, turbodrill
Small-diameter turbodrills have great potential for use in slim boreholes because of their lower cost and higher efficiency when used in geothermal energy and other underground resource applications. Multistage hydraulic components consisting of stators and rotors are key aspects of turbodrills. This study aimed to develop a suitable blade that can be used under high temperature in granite formations. First, prediction models for single- and multi-stage blades were established based on Bernoulli’s Equation. The design requirement of the blade for high-temperature geothermal drilling in granite was proposed. A Φ89 blade was developed based on the dimensionless parameter method and Bezier curve; the parameters of the blade, including its radial size, symotric parameters, and blade profiles, were input into ANASYS and CFX to establish a calculation model of the single-stage blade. The optimization of the blade structure of the small-diameter turbodrill enabled a multistage turbodrill mode... [more]
Assessment of the Usability and Accuracy of the Simplified One-Diode Models for Photovoltaic Modules
Vincenzo Franzitta, Aldo Orioli, Alessandra Di Gangi
February 27, 2019 (v1)
Keywords: four-parameter model, I-V characteristics, one-diode equivalent circuit, photovoltaic modules, solar energy, three-parameter model
Models for photovoltaic (PV) cells and panels, based on the diode equivalent circuit, have been widely used because they are effective tools for system design. Many authors have presented simplified one-diode models whose three or four parameters are calculated using the data extracted from the datasheets issued by PV panel manufactures and adopting some simplifying hypotheses and numerical solving techniques. Sometimes it may be difficult to make a choice among so many models. To help researchers and designers working in the area of photovoltaic systems in selecting the model that is fit for purpose, a criterion for rating both the usability and accuracy of simplified one-diode models is proposed in this paper. The paper minutely describes the adopted hypotheses, analytical procedures and operative steps to calculate the parameters of the most famous simplified one-diode equivalent circuits. To test the achievable accuracy of the models, a comparison between the characteristics of som... [more]
Hydraulic Hybrid Excavator—Mathematical Model Validation and Energy Analysis
Paolo Casoli, Luca Riccò, Federico Campanini, Andrea Bedotti
February 27, 2019 (v1)
Keywords: energy analysis, fuel saving, hydraulic hybrid excavator, numerical modeling
Recent demands to reduce pollutant emissions and improve energy efficiency have driven the implementation of hybrid solutions in mobile machinery. This paper presents the results of a numerical and experimental analysis conducted on a hydraulic hybrid excavator (HHE). The machinery under study is a middle size excavator, whose standard version was modified with the introduction of an energy recovery system (ERS). The proposed ERS layout was designed to recover the potential energy of the boom, using a hydraulic accumulator as a storage device. The recovered energy is utilized through the pilot pump of the machinery which operates as a motor, thus reducing the torque required from the internal combustion engine (ICE). The analysis reported in this paper validates the HHE model by comparing numerical and experimental data in terms of hydraulic and mechanical variables and fuel consumption. The mathematical model shows its capability to reproduce the realistic operating conditions of the... [more]
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