scholarly journals Modeling and Assessment of a Biomass Gasification Integrated System for Multigeneration Purpose

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Shoaib Khanmohammadi ◽  
Kazem Atashkari ◽  
Ramin Kouhikamali
Keyword(s):  
Optimal Design ◽  
Objective Function ◽  
Electrical Power ◽  
Clean Energy ◽  
Biomass Gasification ◽  
Integrated System ◽  
Design Parameters ◽  
Base Case ◽  
Cost Rate ◽  
Gasification Process

The use of biomass due to the reduction in greenhouse gas emissions and environmental impacts has attracted many researchers’ attention in the recent years. Access to an energy conversion system which is able to have the optimum performance for applying valuable low heating value fuels has been considered by many practitioners and scholars. This paper focuses on the accurate modeling of biomass gasification process and the optimal design of a multigeneration system (heating, cooling, electrical power, and hydrogen as energy carrier) to take the advantage of this clean energy. In the process of gasification modeling, a thermodynamic equilibrium model based on Gibbs energy minimization is used. Also, in the present study, a detailed parametric analysis of multigeneration system for undersigning the behavior of objective functions with changing design parameters and obtaining the optimal design parameters of the system is done as well. The results show that with exergy efficiency as an objective function this parameter can increase from 19.6% in base case to 21.89% in the optimized case. Also, for the total cost rate of system as an objective function it can decrease from 154.4 $/h to 145.1 $/h.

scholarly journals Novel Design for a Diffusive Solar Cell Window

2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
Ruei-Tang Chen ◽  
Chih-Chieh Kang ◽  
Jeng-Feng Lin ◽  
Sheng-Wei Chiou ◽  
Hung-Hsiang Cheng ◽  
...  
Keyword(s):  
Solar Cell ◽  
Optimal Design ◽  
Layer Structure ◽  
Electrical Power ◽  
Design Parameters ◽  
Glass Thickness ◽  
Building Integrated Photovoltaics ◽  
Natural Lighting ◽  
Cell Window

Building integrated photovoltaics (BIPV) are an important application of future solar energy development. The incorporation of solar cells into windows must not only maintain indoor natural lighting but also generate electrical power at the same time. In our continuing effort to improve the design of diffusion solar window, a more fundamental and efficient three-layer structure—glass/EVA with TiO2nanoparticles embedded/glass—was proposed. In this work, a well-established ASAP ray-tracing model for a diffusive solar cell window was implemented to validate the outperformance of three-layer structure over primitive five-layer structure. Optical simulations were also implemented to perform its primary design for the determination of the optimal design parameters, such as the glass thickness, the EVA thickness, and the weight concentration of TiO2nanoparticles. Based on the simulation results, an optimal design for a three-layer diffusive solar cell window prototype was proposed. And the influence of both EVA thickness and glass thickness on the power edge-exitance (solar cell power generation efficiency) of a DSCW was thoroughly investigated.

scholarly journals Numerical Assessment of a One-Mass Spring-Based Electromagnetic Energy Harvester on a Vibrating Object

2016 ◽  
Vol 41 (1) ◽  
pp. 119-131 ◽  
Author(s):  
Min-Chie Chiu ◽  
Ying-Chun Chang ◽  
Long-Jyi Yeh ◽  
Chiu-Hung Chung
Keyword(s):  
Optimal Design ◽  
Energy Harvester ◽  
Damping Ratio ◽  
Electrical Power ◽  
Electromagnetic Energy ◽  
Design Parameters ◽  
Helical Springs ◽  
Spring Wire ◽  
Excitation Period ◽  
Mass Spring

Abstract The paper is an exploration of the optimal design parameters of a space-constrained electromagnetic vibration-based generator. An electromagnetic energy harvester is composed of a coiled polyoxymethylen circular shell, a cylindrical NdFeB magnet, and a pair of helical springs. The magnet is vertically confined between the helical springs that serve as a vibrator. The electrical power connected to the coil is actuated when the energy harvester is vibrated by an external force causing the vibrator to periodically move through the coil. The primary factors of the electrical power generated from the energy harvester include a magnet, a spring, a coil, an excited frequency, an excited amplitude, and a design space. In order to obtain maximal electrical power during the excitation period, it is necessary to set the system’s natural frequency equal to the external forcing frequency. There are ten design factors of the energy harvester including the magnet diameter (Dm), the magnet height (Hm), the system damping ratio (ζsys), the spring diameter (Ds), the diameter of the spring wire (ds), the spring length (ℓs), the pitch of the spring (ps), the spring’s number of revolutions (Ns), the coil diameter (Dc), the diameter of the coil wire (dc), and the coil’s number of revolutions (Nc). Because of the mutual effects of the above factors, searching for the appropriate design parameters within a constrained space is complicated. Concerning their geometric allocation, the above ten design parameters are reduced to four (Dm, Hm, ζsys, and Nc). In order to search for optimal electrical power, the objective function of the electrical power is maximized by adjusting the four design parameters (Dm, Hm, ζsys, and Nc) via the simulated annealing method. Consequently, the optimal design parameters of Dm, Hm, ζsys, and Nc that produce maximum electrical power for an electromagnetic energy harvester are found.

scholarly journals OPTIMAL DESIGN OF CYLINDRICAL GEARS WITH CONVEX-CONCAVE CONTACT: OBJECTIVE FUNCTION AND VARIABLES PLANNING

2021 ◽  
pp. 129-134
Author(s):  
Oleksandr Ustynenko ◽  
Nickita Levin ◽  
Oleksiy Bondarenko ◽  
Miroslav Bošanský ◽  
Roman Protasov ◽  
...  
Keyword(s):  
Optimal Design ◽  
Objective Function ◽  
Optimality Criterion ◽  
Extreme Points ◽  
Optimality Criteria ◽  
Contact Stresses ◽  
Design Parameters ◽  
Curvature Radius ◽  
Cylindrical Gears ◽  
Test Points

Reducing the mass and dimensions of gears is an actual task of modern mechanical engineering. One of the perspective ways to solve it is the use of gearing with a convex-concave contact of the teeth. Therefore, the study is devoted to the development of methods for the optimal design of cylindrical gears with convex-concave contact of the working surfaces. Optimality criteria: minimum contact stresses and (or) minimum relative sliding velocities, taking into account design, geometrical and technological constraints. C-C gearing was chosen as the object of research. It was proposed by the Slovak scientists M. Boshanski and M. Veresh. An objective function is constructed for the case of minimizing contact stresses. The optimality criterion is formulated as follows: contact stresses σH in the mesh must take the minimum possible value when all constraints are met. An objective function is also constructed for the case of minimizing the relative sliding velocities of profiles. The optimality criterion is formulated as follows: the relative sliding s velocities of profiles λ at the extreme points of mesh must take the minimum possible value when all the constraints are met. Variables planning are defined. These are pressure angle at the pole αС, the curvature radius at the upper part of contact path rkh, and the curvature radius at the lower part of contact path rkd. A method for solving the problem of optimal design is chosen. The method of probing the space of design parameters was chosen from all the variety. The points of the LPτ-sequence are used as test points. The method allows you to operate with a significant number of parameters – up to 51, provides a sufficiently large number of evenly distributed test points – up to 220. In further studies, it is planned to form a system of constraints on variables planning, to develop methods and algorithms for solving the problem. Also carry out test and verification calculations to confirm and evaluate the theoretical results. Keywords: gear, convex-concave contact, optimal design, objective function, variables planning

Optimal Design of a Vibration-Based Electromagnetic Energy Harvester Using a Simulated Annealing Algorithm

2012 ◽  
Vol 28 (4) ◽  
pp. 691-700 ◽  
Author(s):  
M.-C. Chiu ◽  
Y.-C. Chang ◽  
L.-J. Yeh ◽  
C.-H. Chung
Keyword(s):  
Simulated Annealing ◽  
Optimal Design ◽  
Permanent Magnet ◽  
Simulated Annealing Algorithm ◽  
Vibrational Energy ◽  
Electrical Power ◽  
Wire Diameter ◽  
Design Parameters ◽  
Input Amplitude ◽  
Specific Frequency

ABSTRACTThis paper presents the optimal design of an electromagnetic vibration-based generator using the simulated annealing method (SA). To optimally extract the vibrational energy of a system vibrating at a specific frequency, the selected mass and spring stiffness of a resonant vibration is required. The relationship between induced energy and the generator's structure, its permanent magnet height and diameter, number of turns, and wire diameter in a single air coil are discussed. Also, a prototype of the vibrationbased electrical generator is built and tested via a shaker excited at resonance frequency and input amplitude of 0.06mm. Consequently, results reveal that the design parameters (permanent magnet height and diameter, number of turns, and wire diameter) play essential roles in maximizing electrical power.

Simulation-based search for optimal designs of accelerated life tests through response surface methodology

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Daniel Ayasse ◽  
Kangwon Seo
Keyword(s):  
Response Surface Methodology ◽  
Optimal Design ◽  
Objective Function ◽  
Response Surface ◽  
Failure Time ◽  
Simulated Data ◽  
Accelerated Life Test ◽  
Design Parameters ◽  
Content Type ◽  
Accelerated Life

PurposePlanning an accelerated life test (ALT) for a product is an important task for reliability practitioners. Traditional methods to create an optimal design of an ALT are often computationally burdensome and numerically difficult. In this paper, the authors introduce a practical method to find an optimal design of experiments for ALTs by using simulation and empirical model building.Design/methodology/approachInstead of developing the Fisher information matrix-based objective function and analytic optimization, the authors suggest “experiments for experiments” approach to create optimal planning. The authors generate simulated data to evaluate the quantity of interest, e.g. 10th percentile of failure time and apply the response surface methodology (RSM) to find an optimal solution with respect to the design parameters, e.g. test conditions and test unit allocations. The authors illustrate their approach applied to the thermal ALT with right censoring and lognormal failure time distribution.FindingsThe design found by the proposed approach shows substantially improved statistical performance in terms of the standard error of estimates of 10th percentile of failure time. In addition, the approach provides useful insights about the sensitivity of each decision variable to the objective function.Research limitations/implicationsMore comprehensive experiments might be needed to test its scalability of the method.Practical implicationsThis method is practically useful to find a reasonably efficient optimal ALT design. It can be applied to any quantities of interest and objective functions as long as those quantities can be computed from a set of simulated datasets.Originality/valueThis is a novel approach to create an optimal ALT design by using RSM and simulated data.

Simulation Analysis of the System Integrating Oxy-Fuel Combustion and Char Gasification

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Ruochen Liu ◽  
Martin Graebner ◽  
Remi Tsiava ◽  
Ting Zhang ◽  
Shenqi Xu
Keyword(s):  
Flue Gas ◽  
Simulation Analysis ◽  
Co2 Reduction ◽  
Biomass Gasification ◽  
Integrated System ◽  
Char Gasification ◽  
Gasification Process ◽  
The Government ◽  
Gas Recirculation ◽  
The Impact

Abstract To explore the feasibility of converting hot flue gas into valuable syngas through char gasification process, Aspen Plus is applied to evaluate the performance of the integrated system including oxy-combustion, pyrolysis, gasification, and flue gas recirculation. The impact of feedstock type (reed straw and municipal solid waste (MSW)), feeding rate (0.1–1 t/h), and flue gas recycle ratio (FGR) (10%–30%) is investigated. The economic analysis of the integrated system is also performed. The results indicate that higher oxygen consumption is required for biomass gasification to reach the same temperature as MSW gasification. The gasification temperature is 750 °C–950 °C under 10%–30% FGR. The CO + H2 content in syngas from biomass gasification is slightly higher than that from MSW gasification. For the integrated system, more natural gas (NG) can be saved and more fossil CO2 can be reduced under biomass gasification. When the feedstock input is 1 t/h, the fossil CO2 emission can be reduced by 70% when taking biomass, the CO2 reduction is double of that when taking MSW. The total OPEX cost can be 26% saved by biomass and 62% saved by MSW due to the government subsidy. If CO2 tax is considered, the advantage of biomass for saving OPEX cost will be more obvious.

scholarly journals Optimization of a two-mass vibration-based electromagnetic energy harvester using simulated annealing method

2018 ◽  
Vol 37 (1) ◽  
pp. 90-106 ◽  
Author(s):  
Min-Chie Chiu ◽  
Ying-Chun Chang ◽  
Long-Jyi Yeh ◽  
Chiu-Hung Chung
Keyword(s):  
Optimal Design ◽  
Energy Harvester ◽  
Electrical Power ◽  
Mode Shapes ◽  
Design Parameters ◽  
Generation Model ◽  
Mass Energy ◽  
The One ◽  
Electrical Generation ◽  
The Revolution

In this paper, a theoretical mathematical model in conjunction with an electrical generation model is examined. Using a simulated algorithm, the optimal design of a two-mass energy harvester that finds the maximal electrical power will be assessed. Before the optimal design is performed, the influence of the electrical power with respect to design parameters such as the magnet’s height, the diameter, the stiffness of the lower springs, the stiffness of the upper springs, the revolution of the lower coil, the revolution of the upper coil, the diameter of the coil’s wire, and the electrical resistance of the loading will be analyzed. Results reveal that the design parameters play essential roles in maximizing electrical power. The two mode shapes of the two-mass energy harvester also occur at the targeted forcing frequencies. The electrical power is optimally extracted at the two primary forcing frequencies, i.e. 12 and 30 Hz. Moreover, it is obvious that the induced electrical power of the two-mass energy harvester will be superior to that of the one-mass energy harvester.

Single Spur Gear Reducer Optimization Design Mathematical Modeling

2013 ◽  
Vol 273 ◽  
pp. 198-202
Author(s):  
Yu Xia Wang
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Optimal Design ◽  
Objective Function ◽  
Optimization Design ◽  
Spur Gear ◽  
Design Parameters ◽  
Constraint Function ◽  
Design Variables ◽  
The Mathematical Model

In a given power P, number of teeth than u, input speed and other technical conditions and requirements, find out a set of used a economic and technical indexes reach the optimal design parameters, realize the optimization design of the reducer, This paper determined unipolar standard spur gear reducer design optimization of the design variables, and then determine the objective function, determining constraint function, so as to establish the mathematical model.

Optimal Design of Disk Springs

1985 ◽  
Vol 107 (4) ◽  
pp. 477-481
Author(s):  
S. M. Metwalli ◽  
G. S. A. Shawki ◽  
A. A. Elzoghby
Keyword(s):  
Optimal Design ◽  
Objective Function ◽  
Design Parameters ◽  
Disk Spring ◽  
Maximum Utilization

In this paper the optimal disk spring is defined. Spring resilience is used as an objective function in order to attain maximum utilization of material. Various constraints on stress and/or deflection are considered. Results indicate that the radially tapered section represents the optimal realistic disk spring which maximizes the objective function and satisfies stipulated constraints. Optimal design parameters for radially tapered disk springs are thus considered and compared with those for uniform-section disk springs.

Integrated Power Take-Off and Virtual Oscillator System for the VIVACE Converter: VCK System Identification

2009 ◽  
Author(s):  
Jonghun Lee ◽  
Che-Chun Chang ◽  
Nikolaos I. Xiros ◽  
Michael M. Bernitsas
Keyword(s):  
Mechanical Energy ◽  
Electrical Power ◽  
Electrical Energy ◽  
Clean Energy ◽  
Integrated System ◽  
Mechanical Transmission ◽  
Virtual Mass ◽  
Mechanical Component ◽  
Vortex Induced Vibrations ◽  
Physical Elements

The first step in the development of an integrated system encompassing Power Take-Off (PTO) with virtual Mass-Damping-Spring (VMCK) for the VIVACE Converter (Vortex Induced Vibration for Aquatic Clean Energy) is achieved. VIVACE converts hydrokinetic energy of ocean/river currents to mechanical energy using Vortex Induced Vibrations (VIV). Subsequently, its PTO converts the mechanical energy to electricity. The objective integrated system acts as VMCK to support the hydro-mechanical component of VIVACE. The second function of the system is to act as PTO to implement the electro-mechanical component converting the harnessed mechanical energy to electrical energy without suppressing the hydro-mechanical energy harnessing mechanism of VIV. Vortex Induced Vibrations (VIV) are motions induced on long elastic bodies with bluff cross-section placed with their long axis perpendicular to a fluid flow due to periodic irregularities in this fluid-structure interaction phenomenon. In this paper, a single cylinder of VIVACE is considered. Even in this simplest case, the underlying physics of this phenomenon is strongly nonlinear. Special care is needed in designing systems that either support or enhance VIV or harvest the energy of VIV oscillations. In the first physical model of VIVACE, a mass-damper-spring arrangement was employed in the Marine Renewable Energy Laboratory (MRELab) of the University of Michigan to transmit mechanically the power to an electrical generator, which converted it to useful electrical power. A Virtual mass-damping-spring (VMCK) mechanism is intended to substitute the existing physical elements in the MRELab consisting of an electric motor driven by a power electronic converter allowing for programmable mass, stiffness and damping values. The integrated VMCK system enables improved control of the mechanism originally generating and supporting VIV as well as improved power take-off efficiency and capability. The VMCK system employs advanced switching control of the power transfer process so that VIV for a given damping is not affected. The first step taken in this paper towards development of the integrated system consists of the identification of the VCK system. The mechanical transmission system consists of a belt and two pulleys. The cylinder in VIV is attached to one side of the belt causing it to oscillate and in turn drive the pulleys.

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