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Records added in 2019
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Showing records 263 to 287 of 1602. [First] Page: 1 8 9 10 11 12 13 14 15 16 Last
A Refined Self-Tuning Filter-Based Instantaneous Power Theory Algorithm for Indirect Current Controlled Three-Level Inverter-Based Shunt Active Power Filters under Non-sinusoidal Source Voltage Conditions
Yap Hoon, Mohd Amran Mohd Radzi, Mohd Khair Hassan, Nashiren Farzilah Mailah
December 10, 2019 (v1)
Keywords: current harmonics, distorted supply voltage, multilevel inverter, power electronics, power quality, reactive power compensation
In this paper, a refined reference current generation algorithm based on instantaneous power (pq) theory is proposed, for operation of an indirect current controlled (ICC) three-level neutral-point diode clamped (NPC) inverter-based shunt active power filter (SAPF) under non-sinusoidal source voltage conditions. SAPF is recognized as one of the most effective solutions to current harmonics due to its flexibility in dealing with various power system conditions. As for its controller, pq theory has widely been applied to generate the desired reference current due to its simple implementation features. However, the conventional dependency on self-tuning filter (STF) in generating reference current has significantly limited mitigation performance of SAPF. Besides, the conventional STF-based pq theory algorithm is still considered to possess needless features which increase computational complexity. Furthermore, the conventional algorithm is mostly designed to suit operation of direct curre... [more]
Relative Voltage Control of the Wind Farms Based on the Local Reactive Power Regulation
Yangyang Zhao, Jianyun Chai, Xudong Sun
December 10, 2019 (v1)
Keywords: distributed voltage control, local reactive power regulation, relative voltage observation, wind farm
The fast and coordinated voltage control of distributed nodes inside a large scale wind farm is a stringent issue. To achieve the reactive power compensation without a dedicated upper communication system, this paper proposes a relative control strategy based on the local reactive power regulation. This method can realize the voltage coordination of the key equipment and feeder line nodes, on the basis of the relative voltage observations. Firstly, the stability analysis of a certain wind farm with pre-known parameters and structure is studied under the wind power fluctuations. Secondly, the optimal capacity configurations of the reactive power compensators are discussed, with multiple nodes inside the wind farms. Simulation results of a specific wind farm in North Hebei, China, validate the effectiveness of the proposed control, which is equipped with fast and stable voltage dynamic responses, as well as local reactive power compensations without remote communication.
Fuzzy Logic-Based Operation of Battery Energy Storage Systems (BESSs) for Enhancing the Resiliency of Hybrid Microgrids
Akhtar Hussain, Van-Hai Bui, Hak-Man Kim
December 10, 2019 (v1)
Keywords: battery energy storage system (BESS), BESS operation modes, fuzzy logic, hybrid microgrid, microgrid operation, microgrid resiliency
The resiliency of power systems can be enhanced during emergency situations by using microgrids, due to their capability to supply local loads. However, precise prediction of disturbance events is very difficult rather the occurrence probability can be expressed as, high, medium, or low, etc. Therefore, a fuzzy logic-based battery energy storage system (BESS) operation controller is proposed in this study. In addition to BESS state-of-charge and market price signals, event occurrence probability is taken as crisp input for the BESS operation controller. After assessing the membership levels of all the three inputs, BESS operation controller decides the operation mode (subservient or resilient) of BESS units. In subservient mode, BESS is fully controlled by an energy management system (EMS) while in the case of resilient mode, the EMS follows the commands of the BESS operation controller for scheduling BESS units. Therefore, the proposed hybrid microgrid model can operate in normal, res... [more]
A Cyber Physical Model Based on a Hybrid System for Flexible Load Control in an Active Distribution Network
Yun Wang, Dong Liu, Chen Sun
December 10, 2019 (v1)
Keywords: active distribution system, cyber physical systems, flexible load, hybrid system model, Model Predictive Control
To strengthen the integration of the primary and secondary systems, a concept of Cyber Physical Systems (CPS) is introduced to construct a CPS in Power Systems (Power CPS). The most basic work of the Power CPS is to build an integration model which combines both a continuous process and a discrete process. The advanced form of smart grid, the Active Distribution Network (ADN) is a typical example of Power CPS. After designing the Power CPS model architecture and its application in ADN, a Hybrid System based model and control method of Power CPS is proposed in this paper. As an application example, ADN flexible load is modeled and controlled with ADN feeder power control by a control strategy which includes the normal condition and the underpowered condition. In this model and strategy, some factors like load power consumption and load functional demand are considered and optimized. In order to make up some of the deficiencies of centralized control, a distributed control method is pres... [more]
Design and Implementation of Novel Smart Battery Management System for FPGA Based Portable Electronic Devices
Fangrong Xue, Zhi Ling, Yubing Yang, Xingpo Miao
December 10, 2019 (v1)
Keywords: battery management, FPGA, portable devices, smart charging
This paper presents the analysis and design of a smart battery management system for Field Programmable Gate Array (FPGA) based portable electronic devices. It is a novel concept of incorporating the functionality of a smart battery management system into the FPGA used by portable electronic devices, which provides the following advantages. (1) It lowers cost since the conventional commercial independent battery management circuit can be eliminated; (2) It offers more flexibility because FPGA based battery management algorithms can be specifically designed for different battery chemistries of different devices and can provide the flexibility of algorithms and functionalities updating as well. Smart battery management system concepts include four aspects: (1) smart charging; (2) battery balancing; (3) smart discharging; and (4) safety operating. One novel charging algorithm, which combines the merits of multistage charging and pulse charging, is proposed to charge a Li-ion battery pack... [more]
Circulating Current Reduction Strategy for Parallel-Connected Inverters Based IPT Systems
Ruikun Mai, Liwen Lu, Yong Li, Tianren Lin, Zhengyou He
December 10, 2019 (v1)
Keywords: circulating currents, current phasor and voltage constant control, inductive power transfer (IPT), parallel-connected inverter
Multiple inverters connected in parallel is a promising method to upgrade the power capacity of inductive power transfer (IPT) systems. Due to a slight unbalance of the control signals, the inner resistances of the inverters and other uncertainties, circulating currents exist among the parallel units which reduce the reliability of IPT systems. Firstly, the series-parallel resonant tank is employed in the multiple inverters based IPT system to eliminate the DC and harmonic circulating currents. The fundamental circulating currents in the paralleled inverter units are analyzed in detail. Then, for eliminating the fundamental circulating currents, a current decomposition method and a control diagram are proposed to avoid acquiring the phase of the current by detecting zero cross current point which increases the accuracy of the control algorithm. Finally, a 1-kW parallel-connected inverter IPT system is provided to verify the proposed approach. The experimental results show that the prop... [more]
Numerical Investigation of the Production Behavior of Methane Hydrates under Depressurization Conditions Combined with Well-Wall Heating
Xuke Ruan, Xiao-Sen Li, Chun-Gang Xu
December 10, 2019 (v1)
Keywords: depressurization, gas production, methane hydrate, numerical simulation, well-wall heating
In this study, a 2D hydrate dissociation simulator has been improved and verified to be valid in numerical simulations of the gas production behavior using depressurization combined with a well-wall heating method. A series of numerical simulations were performed and the results showed that well-wall heating had an influence enhancing the depressurization-induced gas production, but the influence was limited, and it was even gradually weakened with the increase of well-wall heating temperature. Meanwhile, the results of the sensitivity analysis demonstrated the gas production depended on the initial hydrate saturation, initial pressure and the thermal boundary conditions. The supply of heat for hydrate dissociation mainly originates from the thermal boundaries,whichcontrolthehydratedissociationandgasproductionbydepressurizationcombined with well-wall heating. However, the effect of initial temperature on the gas production could be nearly negligible under depressurization conditions combi... [more]
An N-k Analytic Method of Composite Generation and Transmission with Interval Load
Shaoyun Hong, Haozhong Cheng, Pingliang Zeng
December 10, 2019 (v1)
Keywords: interval load, minimum load shedding, mixed integer linear programming, the worst contingency of power system, transmission expansion planning
N-k contingency estimation plays a very important role in the operation and expansion planning of power systems, the method of which is traditionally based on heuristic screening. This paper stringently analyzes the best and worst states of power systems given the uncertainties of N-k contingency and interval load. For the sake of simplification and tractable computation, an approximate direct current (DC) power flow model was used. Rigorous optimization models were established for identifying the worst and best scenarios considering the contingencies of generators and transmission lines together with their uncertain loads. It is very useful to identify the worst N-k contingencies with interval loads. If the worst existing scenario meets security standards, all scenarios must satisfy it. The mathematical model established for finding the worst N-k contingency with interval load is a bi-level optimization model. In this paper, strong duality theory and mathematical linearization were ap... [more]
Forecasting Models of Electricity Prices
Javier Contreras
December 10, 2019 (v1)
This book contains the successful invited submissions [1,2,3,4,5,6,7,8,9,10,11] to a Special Issue of Energies on the subject area of “Forecasting Models of Electricity Prices”.
Effect of the Dendrimer Generation Used in the Synthesis of Pt-Ru Nanoparticles Supported on Carbon Nanofibers on the Catalytic Activity towards Methanol Oxidation
Juan Carlos Calderón, Laura Calvillo, María Jesús Lázaro, José Luis Rodríguez, Elena Pastor
December 10, 2019 (v1)
Subject: Materials
Keywords: carbon nanofibers, dendrimers, Fuel Cells, methanol electrochemical oxidation, Pt-Ru catalysts
Pt-Ru nanoparticles supported on carbon nanofibers (CNF) were synthesized by the sodium borohydride reduction method, using different generation dendrimers (zero, one, two and three generations). After the synthesis process, these materials were submitted to a heat treatment at 350 °C, in order to clean the nanoparticle surface of organic residues. TEM characterization showed that the Pt-Ru nanoparticles size ranged between 1.9 and 5.5 nm. The use of dendrimers did not totally avoid the formation of aggregates, although monodisperse sizes were observed. The heat treatment produces the desired surface cleaning, although promoted the formation of agglomerates and crystalline Ru oxides. The study of the electrochemical activity towards the methanol oxidation displayed some clues about the influence of both the dendrimer generation and the presence of Ru oxides. Moreover, the apparent activation energy Eap for this reaction was determined. The results showed a beneficial effect of the heat... [more]
Adaptive Torque Estimation for an IPMSM with Cross-Coupling and Parameter Variations
Dooyoung Yang, Hyungsoo Mok, Jusuk Lee, Soohee Han
December 10, 2019 (v1)
Keywords: adaptive torque estimation, cross-coupling, equivalent back electromotive forces (EMF), equivalent mutual inductance, interior permanent magnet synchronous motor (IPMSM), parameter variations
This paper presents a new adaptive torque estimation algorithm for an interior permanent magnet synchronous motor (IPMSM) with parameter variations and cross-coupling between d- and q-axis dynamics. All cross-coupled, time-varying, or uncertain terms that are not part of the nominal flux equations are included in two equivalent mutual inductances, which are described using the equivalent d- and q-axis back electromotive forces (EMFs). The proposed algorithm estimates the equivalent d- and q-axis back EMFs in a recursive and stability-guaranteed manner, in order to compute the equivalent mutual inductances between the d- and q-axes. Then, it provides a more accurate and adaptive torque equation by adding the correction terms obtained from the computed equivalent mutual inductances. Simulations and experiments demonstrate that torque estimation errors are remarkably reduced by capturing and compensating for the inherent cross-coupling effects and parameter variations adaptively, using th... [more]
The Impact of Shale Gas on the Cost and Feasibility of Meeting Climate Targets—A Global Energy System Model Analysis and an Exploration of Uncertainties
Sheridan Few, Ajay Gambhir, Tamaryn Napp, Adam Hawkes, Stephane Mangeon, Dan Bernie, Jason Lowe
December 10, 2019 (v1)
Subject: Energy Policy
Keywords: climate change mitigation, energy economics, energy scenarios, energy system analysis, fugitive methane emissions, Natural Gas, shale gas, supply curves, TIMES Integrated Assessment Model (TIAM)
There exists considerable uncertainty over both shale and conventional gas resource availability and extraction costs, as well as the fugitive methane emissions associated with shale gas extraction and its possible role in mitigating climate change. This study uses a multi-region energy system model, TIAM (TIMES integrated assessment model), to consider the impact of a range of conventional and shale gas cost and availability assessments on mitigation scenarios aimed at achieving a limit to global warming of below 2 °C in 2100, with a 50% likelihood. When adding shale gas to the global energy mix, the reduction to the global energy system cost is relatively small (up to 0.4%), and the mitigation cost increases by 1%⁻3% under all cost assumptions. The impact of a “dash for shale gas”, of unavailability of carbon capture and storage, of increased barriers to investment in low carbon technologies, and of higher than expected leakage rates, are also considered; and are each found to have t... [more]
Improvement of Wind Energy Production through HVDC Systems
Morris Brenna, Federica Foiadelli, Michela Longo, Dario Zaninelli
December 10, 2019 (v1)
Subject: Energy Policy
Keywords: HVDC transmission system, Italian power system, renewables integration, wind curtailment
Variable and non-programmable resources, such as solar and wind, have undergone a stunning growth in recent years and are likely to gain even more importance in the future. Their strong presence in the national electricity mix has created issues in many countries regarding the secure operation of the power system. In order to guarantee the stability of the system, several TSOs have resorted to wind energy curtailment, which represents a waste of clean energy and an economic loss. In order to analyze this issue, a model of the Italian power system was developed, a program able to simulate the electricity dispatching mechanism. The model was, then, used to evaluate possible solutions to reduce wind curtailment. In particular, a proposal for the construction of an HVDC line linking Southern and Northern Italy was studied.
Impact of Distributed Generation Grid Code Requirements on Islanding Detection in LV Networks
Fabio Bignucolo, Alberto Cerretti, Massimiliano Coppo, Andrea Savio, Roberto Turri
December 10, 2019 (v1)
Keywords: distributed generation (DG), fast voltage support (FVS), inertia emulation, interface protection system (IPS), islanding detection, power regulation, unintentional islanding
The recent growing diffusion of dispersed generation in low voltage (LV) distribution networks is entailing new rules to make local generators participate in network stability. Consequently, national and international grid codes, which define the connection rules for stability and safety of electrical power systems, have been updated requiring distributed generators and electrical storage systems to supply stabilizing contributions. In this scenario, specific attention to the uncontrolled islanding issue has to be addressed since currently required anti-islanding protection systems, based on relays locally measuring voltage and frequency, could no longer be suitable. In this paper, the effects on the interface protection performance of different LV generators’ stabilizing functions are analysed. The study takes into account existing requirements, such as the generators’ active power regulation (according to the measured frequency) and reactive power regulation (depending on the local m... [more]
A Methodological Approach to Assess the Impact of Smarting Action on Electricity Transmission and Distribution Networks Related to Europe 2020 Targets
Andrea Bonfiglio, Federico Delfino, Marco Invernizzi, Renato Procopio
December 10, 2019 (v1)
Keywords: electricity transmission and distribution, Energy Efficiency, environmental impact, power systems, renewable generation integration
The achievement of the so-called 2020 targets requested by the European Union (EU) has determined a significant growth of proposals of solutions and of technical projects aiming at reducing the CO₂ emissions and increasing the energy efficiency, as well as the penetration of Renewable Energy Sources (RES) in the electric network. As many of them ask for funding from the EU itself, there is the necessity to define a methodology to rank them and decide which projects should be sponsored to obtain the maximum effect on the EU 2020 targets. The present paper aims at (i) defining a set of Key Performance Indicators (KPIs) to compare different proposals, (ii) proposing an analytical methodology to evaluate the defined KPIs and (iii) evaluating the maximum impact that the considered action is capable of producing. The proposed methodology is applied to a set of possible interventions performed on a benchmark transmission network test case, in order to show that the defined indicators can be e... [more]
Technology and Reliability of Normally-Off GaN HEMTs with p-Type Gate
Matteo Meneghini, Oliver Hilt, Joachim Wuerfl, Gaudenzio Meneghesso
December 10, 2019 (v1)
Keywords: degradation, gallium nitride, normally-off, p-GaN, reliability, transistor
GaN-based transistors with p-GaN gate are commonly accepted as promising devices for application in power converters, thanks to the positive and stable threshold voltage, the low on-resistance and the high breakdown field. This paper reviews the most recent results on the technology and reliability of these devices by presenting original data. The first part of the paper describes the technological issues related to the development of a p-GaN gate, and the most promising solutions for minimizing the gate leakage current. In the second part of the paper, we describe the most relevant mechanisms that limit the dynamic performance and the reliability of GaN-based normally-off transistors. More specifically, we discuss the following aspects: (i) the trapping effects specific for the p-GaN gate; (ii) the time-dependent breakdown of the p-GaN gate during positive gate stress and the related physics of failure; (iii) the stability of the electrical parameters during operation at high drain vo... [more]
Application of Meta-Heuristic Techniques for Optimal Load Shedding in Islanded Distribution Network with High Penetration of Solar PV Generation
Mohammad Dreidy, Hazlie Mokhlis, Saad Mekhilef
December 10, 2019 (v1)
Keywords: Binary Evolutionary Programming (BEP), Binary Genetic Algorithm (BGA), Binary Particle Swarm Optimization (BPSO), Distribution Generation (DG), Renewable Energy Resources (RESs), Under Frequency Load Shedding (UFLS)
Recently, several environmental problems are beginning to affect all aspects of life. For this reason, many governments and international agencies have expressed great interest in using more renewable energy sources (RESs). However, integrating more RESs with distribution networks resulted in several critical problems vis-à-vis the frequency stability, which might lead to a complete blackout if not properly treated. Therefore, this paper proposed a new Under Frequency Load Shedding (UFLS) scheme for islanding distribution network. This scheme uses three meta-heuristics techniques, binary evolutionary programming (BEP), Binary genetic algorithm (BGA), and Binary particle swarm optimization (BPSO), to determine the optimal combination of loads that needs to be shed from the islanded distribution network. Compared with existing UFLS schemes using fixed priority loads, the proposed scheme has the ability to restore the network frequency without any overshooting. Furthermore, in terms of ex... [more]
Influence of Tip Clearance on Pressure Fluctuation in Low Specific Speed Mixed-Flow Pump Passage
Wenwu Zhang, Zhiyi Yu, Baoshan Zhu
December 10, 2019 (v1)
Subject: Other
Keywords: low specific speed, mixed-flow pump, pressure fluctuation, rotor-stator interaction, tip clearance
To explore the influence of tip clearance on pressure fluctuation in a low specific speed mixed-flow pump, tip clearances δ of 0.25 mm, 0.75 mm and 1.00 mm, along with no tip clearance, were selected. The reliability of the simulation was verified by comparison with the experimental data of external characteristics and fluctuation in the guide vane passage. Through ANSYS-CFX, MATLAB code and fast Fourier transform (FFT) algorithm, pressure fluctuation characteristics in this pump were obtained. The results show that pressure fluctuation exists in all conditions due to the rotor-stator interaction. Under the no tip clearance and tip clearance conditions, the maximum fluctuation value was located near the guide inlet and impeller outlet, respectively. Clearance leakage had less influence on pressure fluctuation at the impeller inlet and central regions within a certain range of the clearance; beyond this range, fluctuations in the whole flow passage increased significantly, while the cle... [more]
A System Dynamics Analysis of Investment, Technology and Policy that Affect Natural Gas Exploration and Exploitation in China
Jianzhong Xiao, Jinhua Cheng, Jun Shen, Xiaolin Wang
December 10, 2019 (v1)
Subject: Energy Policy
Keywords: China, exploitation and exploration, natural gas industry, system dynamics modeling
Natural gas has an increasing role in Chinese energy transformation. We present a system dynamics model of the natural gas industry in China. A new system dynamics model for natural gas companies based on reserve exploration and well construction as well as investment dynamics is proposed. The contribution of the paper is to analyze the influence of technology, investment and policy factors on the natural gas industry. We found that the dynamics of the main variables, including gas policy, cost of investment, accounting depreciation and exploitation technology, are sensitive to the sustainable development of resources. The simulations and results presented here will be helpful for government to reform policies, and for upstream companies to make decisions.
Phase Change Material Based Accumulation Panels in Combination with Renewable Energy Sources and Thermoelectric Cooling
Jan Skovajsa, Martin Koláček, Martin Zálešák
December 10, 2019 (v1)
Keywords: accumulation, phase change material (PCM), photovoltaic (PV), renewable energy source, solar collector, thermoelectric cooling
The article deals with the use of modern materials and technologies that can improve the thermal comfort in buildings. The article describes the design and usage of a special accumulation device, which is composed of thermal panels based on phase change materials (PCMs). The thermal panels have an integrated tube heat exchanger and heating foils. The technology can be used as a passive or active system for heating and cooling. It is designed as a “green technology”, so it is able to use renewable energy sources, e.g., photovoltaic (PV) panels, solar thermal collectors and heat pumps. Moreover, an interesting possibility is the ability to use thermoelectric coolers. In the research, measurements of the different operating modes were made, and the results are presented in the text. The measurement approves that the technology improves the thermal capacity of the building, and it is possible to use it for active heating and cooling.
Implementation and Assessment of a Decentralized Load Frequency Control: Application to Power Systems with High Wind Energy Penetration
Irene Muñoz-Benavente, Emilio Gómez-Lázaro, Tania García-Sánchez, Antonio Vigueras-Rodríguez, Angel Molina-García
December 10, 2019 (v1)
Keywords: frequency response, load frequency control, wind power integration
This paper describes and assesses a decentralized solution based on a wireless sensor-actuator network to provide primary frequency control from demand response in power systems with high wind energy penetration and, subsequently, with relevant frequency excursions. The proposed system is able to modify the electrical power demand of a variety of thermostatically-controlled loads, maintaining minimum comfort levels and minimizing both infrastructure requirements and primary reserves from the supply side. This low-cost hardware solution avoids any additional wiring, extending the wireless sensor-actuator network technology towards small customers, which account for over a 30% share of the current power demand. Frequency excursions are collected by each individual load controller, considering not only the magnitude of the frequency deviation, but also their evolution over time. Based on these time-frequency excursion characteristics, controllers are capable of modifying the power consump... [more]
Fault Tolerant and Optimal Control of Wind Turbines with Distributed High-Speed Generators
Urs Giger, Patrick Kühne, Horst Schulte
December 10, 2019 (v1)
Keywords: actuators, fault tolerant systems, power system control, wind energy system
In this paper, the control scheme of a distributed high-speed generator system with a total amount of 12 generators and nominal generator speed of 7000 min − 1 is studied. Specifically, a fault tolerant control (FTC) scheme is proposed to keep the turbine in operation in the presence of up to four simultaneous generator faults. The proposed controller structure consists of two layers: The upper layer is the baseline controller, which is separated into a partial load region with the generator torque as an actuating signal and the full-load operation region with the collective pitch angle as the other actuating signal. In addition, the lower layer is responsible for the fault diagnosis and FTC characteristics of the distributed generator drive train. The fault reconstruction and fault tolerant control strategy are tested in simulations with several actuator faults of different types.
Decentralized Electric Vehicle Charging Strategies for Reduced Load Variation and Guaranteed Charge Completion in Regional Distribution Grids
Weige Zhang, Di Zhang, Biqiang Mu, Le Yi Wang, Yan Bao, Jiuchun Jiang, Hugo Morais
December 10, 2019 (v1)
Keywords: battery storage system, decentralized charging strategy, distribution grid, electric vehicle, load variation
A novel, fully decentralized strategy to coordinate charge operation of electric vehicles is proposed in this paper. Based on stochastic switching control of on-board chargers, this strategy ensures high-efficiency charging, reduces load variations to the grid during charging periods, achieves charge completion with high probability, and accomplishes approximate “valley-filling”. Further improvements on the core strategy, including individualized power management, adaptive strategies, and battery support systems, are introduced to further reduce power fluctuation variances and to guarantee charge completion. Stochastic analysis is performed to establish the main properties of the strategies and to quantitatively show the performance improvements. Compared with the existing decentralized charging strategies, the strategies proposed in this paper can be implemented without any information exchange between grid operators and electric vehicles (EVs), resulting in a communications cost redu... [more]
Biogas Purification: A Comparison of Adsorption Performance in D4 Siloxane Removal Between Commercial Activated Carbons and Waste Wood-Derived Char Using Isotherm Equations
Davide Papurello, Marta Gandiglio, Jalal Kafashan, Andrea Lanzini
December 10, 2019 (v1)
Subject: Materials
Keywords: adsorption equilibrium isotherms, biogas, circular economy, siloxanes, waste materials
Biogas production from organic waste could be an option to reduce landfill and pollutant emissions into air, water, and soil. These fuels contain several trace compounds that are crucial for highly efficient energy generators or gas injection into the grid. The ability of adsorbents to physically remove such adsorbates was investigated using adsorption isotherms at a constant temperature. We experimentally modelled isotherms for siloxane removal. Siloxanes were considered due to their high impact on energy generators performance even at low concentrations. Octamethylcyclotetrasiloxane was selected as a model compound and was tested using commercially available carbon and char derived from waste materials. The results show that recyclable material can be used in an energy production site and that char must be activated to improve its removal performance. The adsorption capacity is a function of specific surface area and porous volume rather than the elemental composition. The most commo... [more]
Comparison of Temperature Control and Temperature Difference Control for a Kaibel Dividing Wall Column
Xing Qian, Rui Liu, Kejin Huang, Haisheng Chen, Yang Yuan, Liang Zhang, Shaofeng Wang
December 10, 2019 (v1)
Keywords: dividing wall column (DWC), Kaibel column, process simulation, temperature control, temperature difference control
A dividing wall column (DWC) effectively intensifies the distillation process with a reduced energy consumption, capital investment, and space. The three-product DWC has been investigated intensively and extensively; however, the four-product Kaibel DWC has received scarce attention. This study aimed to propose feasible control structures for the Kaibel DWC using only temperature sensors in order to promote its industrialization. Two temperature control structures, two temperature difference control structures, and two double temperature difference control structures were studied. The feasibility of the six proposed control structures was verified with a wide variety of feed disturbances. In most cases, temperature difference control was better than temperature control to maintain product purities. The dynamic performances proved that the inserted feed disturbances were handled well. These results help to promote the industrialization of the Kaibel DWC.
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