Records with Subject: Process Design
Showing records 1 to 25 of 156. [First] Page: 1 2 3 4 5 Last
Model-Based Cost Optimization of Double-Effect Water-Lithium Bromide Absorption Refrigeration Systems
Sergio F. Mussati, Seyed Soheil Mansouri, Krist V. Gernaey, Tatiana Morosuk, Miguel C. Mussati
April 15, 2019 (v1)
Keywords: absorption refrigeration, cost optimization, double-effect system, H2O-LiBr working pair, nonlinear mathematical programming
This work presents optimization results obtained for a double-effect H₂O-LiBr absorption refrigeration system considering the total cost as minimization criterion, for a wide range of cooling capacity values. As a model result, the sizes of the process units and the corresponding operating conditions are obtained simultaneously. In this paper, the effectiveness factor of each proposed heat exchanger is considered as a model optimization variable which allows (if beneficial, according to the objective function to be minimized) its deletion from the optimal solution, therefore, helping us to determine the optimal configuration. Several optimization cases considering different target levels of cooling capacity are solved. Among the major results, it was observed that the total cost is considerably reduced when the solution heat exchanger operating at low temperature is deleted compared to the configuration that includes it. Also, it was found that the effect of removing this heat exchange... [more]
Application of Supergravity Technology in a TEG Dehydration Process for Offshore Platforms
Hongfang Lu, Guoguang Ma, Mohammadamin Azimi, Lingdi Fu
April 15, 2019 (v1)
Keywords: Higee, natural gas dehydration, supergravity technology, TEG
In the dehydration process of offshore natural gas production, due to the site limitation of the platform, if the conventional triethylene glycol (TEG) dehydration process is employed, the size of the absorption tower is usually small. However, in the case of fluctuations in raw material gas and large gas production, it is easy to cause a large loss of TEG and a flooding event, resulting in the water dew point of natural gas not meeting the requirements. Therefore, combined with the dehydration process of TEG and supergravity technology, a new dehydration process of natural gas suitable for offshore platforms is proposed in this paper. The principle and process of the TEG dehydration process based on supergravity technology are discussed by establishing a mass transfer model. The laboratory experiment of the new process is carried out, and the effects of TEG flow rate, super-gravity packed bed rotation speed, and gas flow rate on the air dew point are obtained. By studying the dewateri... [more]
Optimization of the Melting Performance of a Thermal Energy Storage Unit with Fractal Net Fins
Jiayi Zheng, Cheng Yu, Taotao Chen, Yanshun Yu, Fang Wang
April 15, 2019 (v1)
Keywords: fin, fractal, melting, net, phase change
In this study, fractal net fins were introduced to improve the melting performance of a thermal energy storage unit. A transient model for melting heat transfer for phase change material (PCM) was presented and numerically analyzed, to study the melting performance in a thermal energy storage unit using fractal net fins. The melting phase change process was modelled using the apparent heat capacity method. The evolutions of temperature and the liquid fraction in the thermal energy storage unit were investigated and discussed. The effects of the length and width ratios of the fractal net on melting performance were analyzed to obtain the optimal fin configuration. The results indicated that the fractal net fins significantly enhanced the melting heat transfer performance of the PCM in a thermal energy storage unit. The fractal net fins configuration was optimal when the length and width ratios of the fractal net were 0.5. The temperature response at the corner points of the fractal net... [more]
Textile Wastewater Treatment for Water Reuse: A Case Study
Hua Yin, Peiwen Qiu, Yuange Qian, Zhuwen Kong, Xiaolong Zheng, Zhihua Tang, Huafang Guo
April 15, 2019 (v1)
Keywords: ozonation, reverse osmosis, textile wastewater, ultrafiltration, water recovery rate, water reuse
The reduced natural waters and the large amount of wastewater produced by textile industry necessitate an effective water reuse treatment. In this study, a combined two-stage water reuse treatment was established to enhance the quality and recovery rate of reused water. The primary treatment incorporated a flocculation and sedimentation system, two sand filtration units, an ozonation unit, an ultrafiltration (UF) system, and a reverse osmosis (RO) system. The second treatment included an ozonation unit, a sand filtration unit, and UF and RO systems. The color removal rate increased with the increasing ozone dosage, and the relational expression between the ozone dosage and color removal rate was fitted. Ozonation greatly reduced the color by 92.59 and 97.27 times during the primary and second ozonation stages, respectively. RO had the highest removal rate. The combined processes showed good performance in water reuse treatment. The treated, reused water satisfied the reuse standard and... [more]
Building Block-Based Synthesis and Intensification of Work-Heat Exchanger Networks (WHENS)
Jianping Li, Salih Emre Demirel, M. M. Faruque Hasan
April 15, 2019 (v1)
Keywords: building blocks, MINLP, superstructure, WHENS, work and heat integration
We provide a new method to represent all potential flowsheet configurations for the superstructure-based simultaneous synthesis of work and heat exchanger networks (WHENS). The new representation is based on only two fundamental elements of abstract building blocks. The first design element is the block interior that is used to represent splitting, mixing, utility cooling, and utility heating of individual streams. The second design element is the shared boundaries between adjacent blocks that permit inter-stream heat and work transfer and integration. A semi-restricted boundary represents expansion/compression of streams connected to either common (integrated) or dedicated (utility) shafts. A completely restricted boundary with a temperature gradient across it represents inter-stream heat integration. The blocks interact with each other via mass and energy flows through the boundaries when assembled in a two-dimensional grid-like superstructure. Through observation and examples from l... [more]
New Technical Parameters and Operational Improvements of the Metal Oxide Varistors Manufacturing Process
Flaviu Mihai Frigura-Iliasa, Sorin Musuroi, Ciprian Sorandaru, Doru Vatau
April 15, 2019 (v1)
Keywords: composition, manufacturing process, Metal Oxide Varistors, sintering pressure, sintering temperature
At the beginning, this article details the manufacturing procedures for varistor materials. Starting from the initial composition of two large series of varistors (those with two additive oxides and those with five additive oxides), there is a major overview of the main stages of the technological process and the equipment used for the production, emphasizing the technological changes that were made. The article continues with the study of the influence of the sintering pressure and the sintering temperature on the electrical properties of the varistor materials made before. There were two experimental series of 7 varistors, one series based on 2 additive oxides and one based on 5 additive oxides. Each varistor of these series was sintered at another temperature, the fundamental purpose being to determine an optimal sintering temperature for each chemical composition. A second activity consisted of manufacturing two more series of varistors with the same chemical composition (2 oxides... [more]
Energy Analysis of the S-CO₂ Brayton Cycle with Improved Heat Regeneration
Muhammad Ehtisham Siddiqui, Khalid H. Almitani
April 9, 2019 (v1)
Keywords: energy analysis, heat exchanger effectiveness, improved heat regeneration, partial cooling, recompression Brayton cycle, supercritical carbon dioxide, thermal efficiency
Supercritical carbon dioxide (S-CO₂) Brayton cycles (BC) are promising alternatives for power generation. Many variants of S-CO₂ BC have already been studied to make this technology economically more viable and efficient. In comparison to other BC and Rankine cycles, S-CO₂ BC is less complex and more compact, which may reduce the overall plant size, maintenance, and the cost of operation and installation. In this paper, we consider one of the configurations of S-CO₂ BC called the recompression Brayton cycle with partial cooling (RBC-PC) to which some modifications are suggested with an aim to improve the overall cycle’s thermal efficiency. The type of heat source is not considered in this study; thus, any heat source may be considered that is capable of supplying temperature to the S-CO₂ in the range from 500 °C to 850 °C, like solar heaters, or nuclear and gas turbine waste heat. The commercial software Aspen HYSYS V9 (Aspen Technology, Inc., Bedford, MA, USA) is used for simulations.... [more]
Integration of Process Modeling, Design, and Optimization with an Experimental Study of a Solar-Driven Humidification and Dehumidification Desalination System
Mohammed Alghamdi, Faissal Abdel-Hady, A. K. Mazher, Abdulrahim Alzahrani
April 8, 2019 (v1)
Keywords: dehumidification, desalination, design, experimental, humidification
Solar energy is becoming a promising source of heat and power for electrical generation and desalination plants. In this work, an integrated study of modeling, optimization, and experimental work is undertaken for a parabolic trough concentrator combined with a humidification and dehumidification desalination unit. The objective is to study the design performance and economic feasibility of a solar-driven desalination system. The design involves the circulation of a closed loop of synthetic blend motor oil in the concentrators and the desalination unit heat input section. The air circulation in the humidification and dehumidification unit operates in a closed loop, where the circulating water runs during the daytime and requires only makeup feed water to maintain the humidifier water level. Energy losses are reduced by minimizing the waste of treated streams. The process is environmentally friendly, since no significant chemical treatment is required. Design, construction, and operatio... [more]
Systematic and Model-Assisted Process Design for the Extraction and Purification of Artemisinin from Artemisia annua L.—Part I: Conceptual Process Design and Cost Estimation
Maximilian Sixt, Axel Schmidt, Fabian Mestmäcker, Maximilian Johannes Huter, Lukas Uhlenbrock, Jochen Strube
April 8, 2019 (v1)
Keywords: artemisinin, cost estimation, miniplant, piloting, process design
The article summarizes a systematic process design for the extraction and purification of artemisinin from annual mugwort (Artemisia annua L.). Artemisinin serves as an anti-malaria drug, therefore, resource-efficient and economic processes for its production are needed. The process design was based on lab-scale experiments and afterwards piloted on miniplant-scale at the institute. In this part of the article, a detailed economic feasibility studies including a reference process as a benchmark the lab-scale process and the pilot-scale process is given. Relevant differences between the different scales are discussed. The details of the respective unit operations (solid-liquid extraction, liquid-liquid extraction, chromatography and crystallization) are presented in dedicated articles. The study showed that even miniaturized lab-scale experiments are able to deliver data detailed enough for scale-up calculations on a theoretical basis. To our knowledge, a comparable systematic process d... [more]
Effect of the Length-to-Width Aspect Ratio of a Cuboid Packed-Bed Device on Efficiency of Chromatographic Separation
Guoqiang Chen, Raja Ghosh
April 8, 2019 (v1)
Keywords: bioseparation, chromatography, chromatography box, cuboid packed-bed, protein, separation efficiency
In recent papers we have discussed the use of cuboid packed-bed devices as alternative to columns for chromatographic separations. These devices address some of the major flow distribution challenges faced by preparative columns used for process-scale purification of biologicals. Our previous studies showed that significant improvements in separation metrics such as the number of theoretical plates, peak shape, and peak resolution in multi-protein separation could be achieved. However, the length-to-width aspect ratio of a cuboid packed-bed device could potentially affect its performance. A systematic comparison of six cuboid packed-bed devices having different length-to-width aspect ratios showed that it had a significant effect on separation performance. The number of theoretical plates per meter in the best-performing cuboid packed-bed device was about 4.5 times higher than that in its equivalent commercial column. On the other hand, the corresponding number in the worst-performing... [more]
Energy and Exergy Analysis of the S-CO₂ Brayton Cycle Coupled with Bottoming Cycles
Muhammad Ehtisham Siddiqui, Aqeel Ahmad Taimoor, Khalid H. Almitani
April 8, 2019 (v1)
Keywords: combined cycle, efficiency, exergy loss, organic Rankine cycle, recompression cycle, second law efficiency, supercritical carbon dioxide
Supercritical carbon dioxide (S-CO₂) Brayton cycles (BC) are soon to be a competitive and environment friendly power generation technology. Progressive technological developments in turbo-machineries and heat exchangers have boosted the idea of using S-CO₂ in a closed-loop BC. This paper describes and discusses energy and exergy analysis of S-CO₂ BC in cascade arrangement with a secondary cycle using CO₂, R134a, ammonia, or argon as working fluids. Pressure drop in the cycle is considered, and its effect on the overall performance is investigated. No specific heat source is considered, thus any heat source capable of providing temperature in the range from 500 °C to 850 °C can be utilized, such as solar energy, gas turbine exhaust, nuclear waste heat, etc. The commercial software ‘Aspen HYSYS version 9’ (Aspen Technology, Inc., Bedford, MA, USA) is used for simulations. Comparisons with the literature and simulation results are discussed first for the standalone S-CO₂ BC. Energy analys... [more]
Valorization of Shale Gas Condensate to Liquid Hydrocarbons through Catalytic Dehydrogenation and Oligomerization
Taufik Ridha, Yiru Li, Emre Gençer, Jeffrey J. Siirola, Jeffrey T. Miller, Fabio H. Ribeiro, Rakesh Agrawal
April 8, 2019 (v1)
Keywords: process synthesis and design, shale gas condensate, shale gas condensate-to-heavier liquids, Technoeconomic Analysis
The recent shale gas boom has transformed the energy landscape of the United States. Compared to natural gas, shale resources contain a substantial amount of condensate and natural gas liquids (NGLs). Many shale basin regions located in remote areas are lacking the infrastructure to distribute the extracted NGLs to other regions—particularly the Gulf Coast, a major gas processing region. Here we present a shale gas transformation process that converts NGLs in shale resources into liquid hydrocarbons, which are easier to transport from these remote basins than NGL or its constituents. This process involves catalytic dehydrogenation followed by catalytic oligomerization. Thermodynamic process analysis shows that this process has the potential to be more energy efficient than existing NGL-to-liquid fuel (NTL) technologies. In addition, our estimated payback period for this process is within the average lifetime of shale gas wells. The proposed process holds the promise to be an energy eff... [more]
Finding the Signal in the Noise: Determining North America’s best path forward for sustainable energy
Thomas A Adams II
March 31, 2019 (v2)
Keywords: Calcium Looping, Carbon Dioxide Capture, Chemical Looping, Life Cycle Analysis, Meta-Study, Oxyfuels, Postcombustion Capture, Solid Oxide Fuel Cells, Technoeconomic Analysis
One of the largest engineering challenges of our time is finding technical solutions that permit the use of our energy resources in a sustainable way. In order to achieve meaningful and positive change, new energy systems must adhere to the triple bottom line of sustainability. This means that new technical solutions must be economically, socio-politically, and environmentally sustainable, such that they can be rapidly adopted and accepted. The engineering literature is full of a great many technical proposals for new energy systems, but it turns out to be quite hard to objectively look at them all, see through the hype, and decide which are the best and most promising technologies in which to invest our research and development dollars. In this talk, I will present a case study with the results of our recent meta-study covering over 100 candidate electricity generation systems with carbon dioxide capture, in order to determine which are the most promising classes of technologies. I wi... [more]
Thermo-Economic Comparison and Parametric Optimizations among Two Compressed Air Energy Storage System Based on Kalina Cycle and ORC
Ruixiong Li, Huanran Wang, Erren Yao, Shuyu Zhang
March 15, 2019 (v1)
Keywords: CAES, integrated energy storage system, Kalina cycle, ORC, thermo-economic
The compressed air energy storage (CAES) system, considered as one method for peaking shaving and load-levelling of the electricity system, has excellent characteristics of energy storage and utilization. However, due to the waste heat existing in compressed air during the charge stage and exhaust gas during the discharge stage, the efficient operation of the conventional CAES system has been greatly restricted. The Kalina cycle (KC) and organic Rankine cycle (ORC) have been proven to be two worthwhile technologies to fulfill the different residual heat recovery for energy systems. To capture and reuse the waste heat from the CAES system, two systems (the CAES system combined with KC and ORC, respectively) are proposed in this paper. The sensitivity analysis shows the effect of the compression ratio and the temperature of the exhaust on the system performance: the KC-CAES system can achieve more efficient operation than the ORC-CAES system under the same temperature of exhaust gas; mea... [more]
Design of an Energy Efficient Future Base Station with Large-Scale Antenna System
Byung Moo Lee, Youngok Kim
February 27, 2019 (v1)
Keywords: base station (BS), energy efficiency (EE), large-scale (LS) antenna system
Due to the continuous increase in data demanded by end-users, an energy-efficient base station (BS) is a vital topic of interest that would not only result in a substantial economic impact on service providers, but would also reduce the carbon footprint of operating a network. In this regard, we propose the structure and systematic operation of a BS with a large-scale (LS) antenna system that can increase the energy efficiency (EE) of cellular systems. The proposed BS structure includes various power-related units, such as a central management apparatus, power controller, EE calculator, radio site-dependent parameter space (RSD-PS) and determiner. With the information provided from each unit, the decision unit determines how to adjust each component of the BS in order to maximize the EE. Extensive simulations show that the proposed BS improves the EE performance by about 83.05% relative to the reference BS.
Evaluation of Strategies to Improve the Thermal Performance of Steel Frames in Curtain Wall Systems
Ji Hyun Oh, Hyun Jung Yoo, Sun Sook Kim
February 27, 2019 (v1)
Keywords: curtain wall, hot-box test, steel frame, thermal transmittance, U-value
Recently, metal curtain wall systems have been widely used in high-rise buildings due to many advantages, including being lightweight, rapid construction, and aesthetic features. Since the metal frame may lead to lower energy performance, thermal discomfort, and condensation risk due to the high thermal conductivity, its thermal performance can be important for the improvement of the overall thermal performance of the curtain wall system, as well as the energy efficiency of the building envelope. This study aims to evaluate variety of design strategies to improve the thermal performance of steel curtain wall frames. Five base cases and three further steps were selected for two different head profile shapes based on a state-of-the art technology review, and their thermal transmittances were calculated through simulations according to the ISO 12631 standard which is an international standard for calculating thermal transmittance of curtain wall system. Measured results that were obtained... [more]
Comparison of Two Processes Forming CaCO₃ Precipitates by Electrolysis
Hyun Sic Park, JunYoung Han, Ju Sung Lee, Kwang-Mo Kim, Hyung Jun Jo, Byoung Ryul Min
February 27, 2019 (v1)
Keywords: CaCO3, electrolysis, mineral carbonation
As one of the carbon capture and utilization (CCU) technologies, mineral carbonation which has been introduced to reduce the carbon dioxide (CO₂) concentration in the atmosphere is a technology that makes it possible to capture CO₂ and recycle byproducts as resources. However, existing mineral carbonation requires additional energy and costs, as it entails high temperature and high pressure reaction conditions. This study compared two processes which electrolyze NaCl and CaCl₂ solution to produce CO₂ absorbent needed to generate CaCO₃, and which were conducted at room temperature and pressure unlike existing mineral carbonation. As a result, high-purity calcite was obtained through Process 1 using NaCl solution, and aragonite and portlandite were obtained in addition to calcite through Process 2 (two steps) using CaCl₂ solution.
Comparative Study of Shell and Helically-Coiled Tube Heat Exchangers with Various Dimple Arrangements in Condensers for Odor Control in a Pyrolysis System
Sun-Min Kim, Jun-Ho Jo, Ye-Eun Lee, Yeong-Seok Yoo
February 27, 2019 (v1)
Keywords: condenser, dimple, heat exchanger, heat transfer, odor control, pyrolysis, RANS, shell and tube
This study performed evaluations of the shell and helically-coiled tube heat exchangers with various dimple arrangements, that is, flat, inline, staggered, and bulged, at different Dean numbers (De) and inlet temperatures of a hot channel. Conjugated heat transfer was analyzed to evaluate the heat transfer performance of the exchangers through temperature difference between the inlet and outlet, Nusselt number inside the coiled tube, and pressure drop of the coiled tube by using 3-D Reynolds-averaged Navier⁻Stokes (RANS) equations with shear stress transport turbulence closure. A grid dependency test was performed to determine the optimal number of the grid system. The numerical results were validated using the experimental data, and showed good agreement. The inline and staggered arrangements show the highest temperature differences through all De. The staggered arrangement shows the best heat transfer performance, whereas the inline arrangement shows the second highest performance wi... [more]
Inverse Aerodynamic Optimization Considering Impacts of Design Tip Speed Ratio for Variable-Speed Wind Turbines
Zhiqiang Yang, Minghui Yin, Yan Xu, Yun Zou, Zhao Yang Dong, Qian Zhou
February 27, 2019 (v1)
Keywords: aerodynamic optimization, design tip speed ratio (TSR), inverse design, maximum power point tracking (MPPT), variable-speed wind turbine (VSWT)
Because of the slow dynamic behavior of the large-inertia wind turbine rotor, variable-speed wind turbines (VSWTs) are actually unable to keep operating at the design tip speed ratio (TSR) during the maximum power point tracking (MPPT) process. Moreover, it has been pointed out that although a larger design TSR can increase the maximum power coefficient, it also greatly prolongs the MPPT process of VSWTs. Consequently, turbines spend more time operating at the off-design TSRs and the wind energy capture efficiency is decreased. Therefore, in the inverse aerodynamic design of VSWTs, the static aerodynamic performance (i.e., the maximum power coefficient) and the dynamic process of MPPT should be comprehensively modeled for determining an appropriate design TSR. In this paper, based on the inverse design method, an aerodynamic optimization method for VSWTs, fully considering the impacts of the design TSR on the static and dynamic behavior of wind turbines is proposed. In this method, to... [more]
Research on a Household Dual Heat Source Heat Pump Water Heater with Preheater Based on ASPEN PLUS
Xiang Gou, Yang Fu, Imran Ali Shah, Yamei Li, Guoyou Xu, Yue Yang, Enyu Wang, Liansheng Liu, Jinxiang Wu
February 27, 2019 (v1)
Keywords: Aspen Plus, coefficient of performance (COP), dual heat source, heat pump, household water heater, preheater
This article proposes a dual heat source heat pump bathroom unit with preheater which is feasible for a single family. The system effectively integrates the air source heat pump (ASHP) and wastewater source heat pump (WSHP) technologies, and incorporates a preheater to recover shower wastewater heat and thus improve the total coefficient of performance (COP) of the system, and it has no electric auxiliary heating device, which is favorable to improve the security of the system operation. The process simulation software ASPEN PLUS, widely used in the design and optimization of thermodynamic systems, was used to simulate various cases of system use and to analyze the impact of the preheater on the system. The average COP value of a system with preheater is 6.588 and without preheater it is 4.677. Based on the optimization and analysis, under the standard conditions of air at 25 °C, relative humidity of 70%, wastewater at 35 °C, wastewater flow rate of 0.07 kg/s, tap water at 15 °C, and c... [more]
Development of Correlations for Windage Power Losses Modeling in an Axial Flux Permanent Magnet Synchronous Machine with Geometrical Features of the Magnets
Alireza Rasekh, Peter Sergeant, Jan Vierendeels
February 27, 2019 (v1)
Keywords: AFPMSM, Computational Fluid Dynamics, magnet parameters, windage losses
In this paper, a set of correlations for the windage power losses in a 4 kW axial flux permanent magnet synchronous machine (AFPMSM) is presented. In order to have an efficient machine, it is necessary to optimize the total electromagnetic and mechanical losses. Therefore, fast equations are needed to estimate the windage power losses of the machine. The geometry consists of an open rotor⁻stator with sixteen magnets at the periphery of the rotor with an annular opening in the entire disk. Air can flow in a channel being formed between the magnets and in a small gap region between the magnets and the stator surface. To construct the correlations, computational fluid dynamics (CFD) simulations through the frozen rotor (FR) method are performed at the practical ranges of the geometrical parameters, namely the gap size distance, the rotational speed of the rotor, the magnet thickness and the magnet angle. Thereafter, two categories of formulations are defined to make the windage losses dim... [more]
Experimental and Potential Analysis of a Single-Valve Expander for Waste Heat Recovery of a Gasoline Engine
Wenzhi Gao, Wangbo He, Lifeng Wei, Guanghua Li, Ziqi Liu
February 27, 2019 (v1)
Keywords: gasoline engine, intake valve timing, piston expander, Rankine cycle, waste heat recovery
In this paper, a Rankine cycle test system is established to recover exhaust energy from a 2.0 L gasoline engine. Experiments on the system’s performance are carried out under various working conditions. The experimental results indicate that the recovery power of the expander is strongly related to the load and speed of the gasoline engine. It is found that when the output power of the gasoline engine is 39.8⁻76.6 kW, the net power of the expander is 1.8⁻2.97 kW, which is equivalent to 3.9%⁻4.9% of the engine power. The performance simulation shows that the mass flow rate, power output, and isentropic efficiency of the piston expander are directly determined by the intake valve timing. Selecting a suitable intake valve timing can optimize the performance of the expander. The simulation results show that a 1 kW increment in power can be obtained only by selecting an optimum intake open timing. The experimental results further verify that the single-valve piston expander, because of its... [more]
A New Design Optimization Method for Permanent Magnet Synchronous Linear Motors
Juncai Song, Fei Dong, Jiwen Zhao, Siliang Lu, Le Li, Zhenbao Pan
February 27, 2019 (v1)
Keywords: 3D finite element analysis (3D-FEA), gravity center neighborhood algorithm (GCNA), multiple support vector machine (multi-SVM), non-parametric quick calculation model, permanent magnet linear synchronous motors (PMSLM), thrust, thrust ripple
This study focused on the design optimization of permanent magnet synchronous linear motors (PMSLM) that are applied in microsecond laser cutting machines. A new design optimization method was introduced to enhance PMSLM performances in terms of motor thrust, thrust ripple, and inductive electromotive force (EMF). Based on accurate 3D finite element analysis (3D-FEA), a multiple support vector machine (multi-SVM) was proposed to build a non-parametric quick calculation model by mapping the relation between multivariate structure parameters and multivariate operation performances. The gravity center neighborhood algorithm (GCNA) was also applied to search the global optimal combination of the structure parameters by locating the gravity center of the multi-SVM model. The superiority and validity of this method are verified by experiments.
Strategy Design of Hybrid Energy Storage System for Smoothing Wind Power Fluctuations
Jingyu Liu, Lei Zhang
February 27, 2019 (v1)
Keywords: battery, hybrid energy storage system (HESS), power allocation, state-of-charge (SOC), supercapacitor, wind power, wind power regulation system
With the increasing contribution of wind power plants, the reliability and security of modern power systems have become a huge challenge due to the uncertainty and intermittency of wind energy sources. In this paper, a hybrid energy storage system (HESS) consisting of battery and supercapacitor is built to smooth the power fluctuations of wind power. A power allocation strategy is proposed to give full play to the respective advantages of the two energy storage components. In the proposed strategy, the low-frequency and high-frequency components of wind power fluctuations are absorbed by battery groups and supercapacitor groups, respectively. By inhibiting the low-frequency components of supercapacitor current, the times of charging-discharging of battery groups can be significantly reduced. A DC/AC converter is applied to achieve the power exchange between the HESS and the grid. Adjustment rules for regulating state-of-charge (SOC) of energy storage elements are designed to avoid over... [more]
Multi-Objective Optimization of a Solar Chimney Power Plant with Inclined Collector Roof Using Genetic Algorithm
Ehsan Gholamalizadeh, Man-Hoe Kim
February 5, 2019 (v1)
Keywords: inclined collector roof, multi-objective genetic algorithm, Renewable and Sustainable Energy, solar chimney power plant
This paper presents an optimization of a solar chimney power plant with an inclined collector roof using genetic algorithms. Five design parameters that affect the system performance are the collector radius, collector inlet height, collector outlet height, chimney height and diameter. A multi-objective design to simultaneously optimize three conflicting objectives including system efficiency, power output and expenditure is used. Based on this approach, obtaining the best combination of the possible geometrical parameters, performance of two built pilot power plants in Kerman (Iran) and Manzanares (Spain) are optimized thermo-economically. The heights of the zero-slope collectors of the Kerman and Manzanares systems are 2 m and 1.85 m, respectively. The results show that in the Kerman pilot the optimal collector inlet and outlet heights are 1.5 m and 2.95 m, respectively, while those optimal heights in the Manzanares prototype are 1.5 m and 4.6 m, respectively. It is found that select... [more]
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