Dissertations / Theses on the topic 'Electric power-plants – Dust control'

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1

Yuen, Albert Wai Ling Materials Science &amp Engineering Faculty of Science UNSW. "Collector current density and dust collection in wire-plate electrostatic precipitators." Awarded by:University of New South Wales. Materials Science and Engineering, 2006. http://handle.unsw.edu.au/1959.4/28274.

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Even minimal improvements in particle collection efficiency of electrostatic precipitators significantly reduce dust emission from fossil-fuelled power stations and reduce pollution. Yet current designs rely on the Deutsch collection theory, which was developed for tubular precipitators and has been applied to wire-plate precipitators on the assumption that the inter-electrode electric fields at the same discharge distance in both were similar. Differences in geometry and associated collector electric fields and current density non-uniformity have not been taken into account, although the collector electric field and current density of the wire-plate precipitator are not uniform. And observations show that precipitated dust patterns and the distribution of collector current density are interrelated. Investigations revealed a simple square law relationship between the collector electric field and the collector current density in the space charge dominated coronas. Applying this relationship to the Deutsch collection theory led to a current-density-based collection formula that takes into account the non-uniform collector current density distribution. The current-density-based collection formula is then used to assess the impact of collector current density on collection efficiency, the results closely following published measurements. Applying the current-density-based collection formula to estimate the dust accumulation shows that most of the dust accumulates at collector locations facing the corona wires. The effect of the non-uniform precipitated dust layer on collection performance is assessed using the distributed corona impedance - the ratio of the inter-electrode voltage and the non-uniform collector current. Re-distribution of the collector current profile as dust builds up is also compatible with published measurements. Finally this is applied to optimize the wire-plate precipitator collection performance. This shows that optimal collection performance is obtained with the wire-wire spacing less than the wire-plate distance, once again confirming published experimental results. This is the first analytical approach to show better collection performance can be achieved at the ratio of wire-wire spacing/wire-plate distance not equal to unity, which has been the standard industry practice since 1960.
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2

Khaliq, Abdul. "Preventive control for the attainment of a dynamically secure power system." Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/13893.

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3

ABDULLA, ABDULLA I. M. "SOME NEW TECHNIQUES FOR THE LOAD FREQUENCY CONTROL OF MULTI-AREA POWER SYSTEMS." Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/183902.

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In this dissertation, the problem of multi-area load frequency control in large power systems is investigated. The load frequency control problem is concerned with the minimization of the deviations in the frequencies of the different areas and in the tie line power exchange between these areas, and is a problem of major importance in the satisfactory operation of large power systems. Some new techniques for designing load frequency control systems are presented through the use of concepts from singular perturbation and hierarchical system theory. To provide appropriate vehicles for the design of the new control systems, state variable models for power systems are developed. These models progress from a two-area interconnected power system model to large scale models comprising of N areas. Two centralized state feedback schemes are proposed for the load frequency control by utilizing the separation of the system models into two time scales. In the first scheme, composite controls and reduced order controls are developed to meet the required performance specifications by. The second scheme is obtained by using the theory of variable structure systems where the existence of a sliding regime leads to the design of a single discontinuous state feedback controller that meets the performance requirements. In order to further improve the performance of the closed loop system, a two level hierarchical control scheme is developed. This consists of a set of local controllers that are designed using either the singular perturbation approach or the variable structure system approach as before and a set of global control functions provided by a higher level controller that attempts to coordinate the local controllers. The interaction prediction principle is used as a tool in the design of the global controller. The performance of the presently developed control schemes is examined in detail for the illustrative cases of a two-area and a three-area power system. From this analysis, it is shown that these controllers provide an improved performance compared to the existing control schemes in reducing the frequency and tie line power deviations.
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4

Bø, Torstein Ingebrigtsen. "Dynamic Model Predictive Control for Load Sharing in Electric Power Plants for Ships." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18749.

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The main contribution of this thesis is an investigation of model predictive control(MPC) for marine diesel electric power plants. Recommendations and new ideasfor further development are emphasized.The motivation of the thesis is to develop a controller for diesel electric power plantsthat can control the plant in a more efficient way. This includes reducing wear andtear, fuel consumption, and emissions. However, the safety aspect is always themost important factor and must be handled with care.The case plant to be studied is a diesel electrical power plant consisting of severaldiesel driven generators (genset). These gensets produce electrical power to servethe electrical demands on a marine vessel. The consumers can be propulsion units,heave compensators, drilling equipment, and hotel loads. These highly dynamicconsumers are large compared with the producers. This gives unwanted fluctuationof frequency. In some vessels this effect is so large that more gensets are requiredfor transients than for peak demands. This can be avoided with better controlstrategies.The controller developed in this thesis adjusts the local controllers on the dieselengines. The objective is to keep the genset at a given load sharing, while keepingthe frequency within rules and regulations. In addition is the plant controlled to astate where a single point failure does not lead to blackout.Blackout is prevented by calculating a failure case in addition to the normal case.The failure case may be a disconnection of the largest genset on the power bussegment. The case is calculated in the controller to make sure that if the caseoccurs the plant is able to handle the failure without a blackout. A normal case,where everything goes as normal, is calculated to optimize the current operation.The controller is verified by simulation done in MATLAB/Simulink. Theimplemented controller performs well during all of the simulated cases. However,the predictions made by the controller are in some cases conservative. This is dueto the choice of the fuel rate constraints. Lastly, suggestions for how to improvethe performance of the controller are included. The most important suggestionsare to include a model of the turbocharger in the control plant model and toinclude more failure cases.
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5

Du, Zhaobin. "Area COI-based slow frequency dynamics modeling, analysis and emergency control for interconnected power systems." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B4175783X.

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6

Yilmaz, Oguz. "Participation Of Combined Cycle Power Plants To Power System Frequency Control: Modeling And Application." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607228/index.pdf.

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This thesis proposes a method and develops a model for the participation of a combined cycle power plant to power system frequency control. Through the period of integration to the UCTE system, (Union for Coordination of Transmission of Electricity in Europe) frequency behavior of Turkey&rsquo
s grid and studies related to its improvement had been a great concern, so is the reason that main subject of my thesis became as &ldquo
Power System Frequency Control&rdquo
. Apart from system-wide global control action (secondary control)
load control loops at power plants, reserve power and its provision even at the minimum capacity generation stage, (primary control) are the fundamental concerns of this subject. The adjustment of proper amount of reserve at the power plants, and correct system response to any kind of disturbance, in the overall, are measured by the quality of the frequency behaviour of the system. A simulator that will simulate a dynamic gas turbine and its control system model, together with a combined cycle power plant load controller is the outcome of this thesis.
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7

Thapa, Ravi Chandra. "Damping Interarea Oscillations in Power Systems with DFIG." Thesis, North Dakota State University, 2011. https://hdl.handle.net/10365/29173.

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With rapid depletion of fossil fuels and increasing environmental concerns, the trend to capture renewable energy, especially through wind energy resources, is increasing. The doubly fed induction generator (DFIG) is the most widely used generator for wind energy conversion because of its various advantages over other types of generators. In a DFIG, the rotor is fed through back to back converters via slip rings. The converters enable the generation control. This control property can be used to support reliable operation of a grid network system. Interarea oscillation has been a major factor in limiting power transfers in interconnected power systems. Poorly damped modes can trigger oscillatory instability, potentially leading to cascading blackouts in such systems. We consider a two-area system where DFIG based wind generation is integrated with conventional synchronous generators. A simple controller is proposed for the DFIG to improve damping of interarca oscillations. To support the proposition, case studies are conducted in Matlab/Simulink. The effectiveness of the proposed controller is then analyzed by eigenvalue analysis and verified with time domain simulation results. The results show that a properly tuned controller can increase the damping of dominant oscillatory mode by nearly 5% while improving the area transfer by about 200 MW of wind power. The results further show that with the proposed control strategy, damping of dominant oscillatory mode increased by more than 10%.
North Dakota State University. Graduate School
North Dakota State University. Department of Electrical and Computer Engineering
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8

Fleshman, Muller Eunamia. "Development of a supplier quality assessment system in Eskom." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97323.

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Thesis (MBA)--Stellenbosch University, 2015.
ENGLISH ABSTRACT: Eskom, the South Africa and trans-Africa electrical power utility, has a capacity expansion project that is estimated to cost roughly R340 billion. The programme is anticipated to continue through 2018. Eskom will be contracting with a multitude of suppliers and it is imperative that the projects delivered under the capacity expansion programme meet Eskom’s required quality standards. The question then arises whether the set quality standards are sufficiently comprehensive to provide confidence that suppliers will achieve high quality standards. This aim of this research was to examine supplier assessment programmes to determine the criteria that will best provide supplier assurance. The researcher consulted a vast range of literature available on supplier quality assessment programmes. From the literature consulted, there appeared to be some recurring themes from the range of assessment tools. It also becomes apparent that the assessment tool cannot only focus on a quality system, but a balance of strategic and operational focus was needed to fully understand suppliers’ ability to deliver. One of the key considerations was establishing longer-term collaborative relationships with key suppliers. Long-term relations encourage trust, transparency and innovation. It was equally important to ensure that operational assessments provided insight on suppliers’ capability. Based on the literature reviewed, a proposed framework was tested against the current methodology for supplier evaluation. From these comparisons, some gaps were identified and recommendations were suggested to improve the supplier evaluation programme.
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9

Du, Zhaobin, and 杜兆斌. "Area COI-based slow frequency dynamics modeling, analysis and emergency control for interconnected power systems." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B4175783X.

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10

Tomilson, Andrew G. "Frequency and voltage control of a high-penetration, no-storage wind-diesel system." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0023/MQ36186.pdf.

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11

Gencoglu, Cihangir. "Assessment Of The Effect Of Hydroelectric Power Plants&#039." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612165/index.pdf.

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The Turkish TSO (TEIAS) has been leading a project that aims the synchronous interconnected operation of the Turkish Power System and the ENTSO-E CESA (former UCTE) System. For this purpose, this study concentrates on the specific problems related to the electromechanical systems of large size hydroelectric power plants regarding low frequency inter area oscillations, which are prone to occur once the interconnected operation is established. The expected frequency of inter area oscillations after interconnected operation is close to 0.15 Hz, which is in the frequency range of the speed governing structures of turbines, as explained in the first two sections of the thesis. In the third section, the nonlinear turbine governor model used throughout the study is explained. In the following part, the governor parameter tuning study with regard to the defined performance objectives is explained. Afterwards, the effect of the retuned governor settings of the sample hydroelectric power plants on a simple multi machine power system is shown. Following that, the system wide effect of removing the sources of negative damping, which are strongly dependent on the governor settings of the major hydroelectric power plants of the Turkish Power System, is shown. In the final part, conclusions are made on the operation of the hydroelectric power plants regarding the frequency stability of the system after synchronous interconnected operation of the Turkish Power System and the ENTSO-E CESA System.
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12

Vijapur, Santosh H. "Design optimization and experimental study of a wet laminar electrostatic precipitator for enchancing collection efficiency of aerosols." Ohio : Ohio University, 2008. http://www.ohiolink.edu/etd/view.cgi?ohiou1227020758.

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13

Raab, Andreas Franz Alois [Verfasser], Kai [Akademischer Betreuer] Strunz, Antonello [Gutachter] Monti, and Olav B. [Gutachter] Fosso. "Operational planning, modeling and control of virtual power plants with electric vehicles / Andreas Franz Alois Raab ; Gutachter: Antonello Monti, Olav B. Fosso ; Betreuer: Kai Strunz." Berlin : Technische Universität Berlin, 2018. http://d-nb.info/115618522X/34.

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14

Sheblé, Gerald B. "Unit commitment for operations." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/49977.

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The topic of unit commitment has been and continues to be of interest to many researchers and is a primary operation for most utilities. Past research has utilized integer programming, dynamic programming, linear programming, gradient, and heuristic techniques. This research combines both linear programming and dynamic programming for unit commitment decisions within a weekly time frame. The result provides most of the advantages of linear programming and dynamic programming with less stringent requirements on the pre solution information needed for unit transition sequences. Further, the research yields a new tool for the solution of the Transaction Evaluation problem.
Ph. D.
incomplete_metadata
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15

Van, Reenen Olaf Pieter. "Eskom nuclear generation : risk mitigation through quality management development of small suppliers." Thesis, Cape Peninsula University of Technology, 2009. http://hdl.handle.net/20.500.11838/1223.

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Thesis (MTech (Quality)--Cape Peninsula University of Technology, 2009
There is a South African Government initiative to use State-owned Enterprises (SOE’s) to roll out a programme for the development and stimulation of local small businesses in South Africa. The state has requested SOE’s to set targets on a voluntary basis to increase trade with small businesses, with the purpose of developing small enterprises to eventually enhance skills transfer, training and employment. However, when large customers such as Eskom Nuclear Generation require ISO certification as a prerequisite for a supplier to provide goods and/or services to them, most small businesses are unable to comply. The requirement of ISO9000 compliance inhibits the ability of most small businesses to compete with their larger counterparts. Small businesses constitute as much as 90% of most world economies. They have many advantages to offer customers, such as a high level of flexibility, innovation and responsiveness to customer needs. These attributes can introduce healthy competition to the supply chain. Small businesses, by their very nature experience more risks, such as a higher vulnerability to volatile market forces and skills loss. In addition, they are generally less specialised. They are under continuous competitive pressure, and are generally not able to provide assurance of a sustainable product over a longer period. Although there is an imperative to develop and use small suppliers, they introduce higher risk to the supply chain. The primary research objective of this dissertation is to develop a robust model to identify risks inherent to small businesses, and to propose measures to mitigate such risks. A classification of problems with small suppliers that have occurred at Koeberg Nuclear Power Station over a period of 3 years (from June 2005 to May 2008), will form the basis of the research methodology. The anticipated findings of the research include the following. _ Several common critical issues of failure will be identified in the internal processes of small suppliers, with variations between types of suppliers, which will indicate which elements within the context of ISO9000 can be applied to address shortcoming in the suppliers’ processes. _ A matrix will be compiled from this by which the customer can identify the type of supplier, the types of risks inherent to that supplier, and which elements of ISO9000 the customer should insist upon to be adopted into an elementary quality management system of that small supplier. This should be executed as part of a larger supplier development programme.
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16

Reddy, Shailendra N. "A mathematical simulation of ETS' limestone emission control (LEC) process using a moving bed configuration." Ohio : Ohio University, 1991. http://www.ohiolink.edu/etd/view.cgi?ohiou1183736591.

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17

Almeida, José Leandro Casa Nova. "Análise da viabilidade técnica e econômica de implantação de uma microusina hidrelétrica /." Guaratinguetá : [s.n.], 2007. http://hdl.handle.net/11449/99288.

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Resumo: A proposta desta dissertação foi a de apresentar o desempenho de uma microcentral hidrelétrica, instalada no Centro de Energias Renováveis da Unesp, Campus Guaratinguetá. As análises apresentadas são de desempenho elétrico e mecânico. A microcentral hidrelétrica utiliza roda Pelton com 0,4m de diâmetro no ponto de incidência do jato de água. O gerador utilizado foi com rotor de ímãs permanentes de ferrite. Tanto o gerador quanto a microusina são de baixo custo de aquisição e instalação. Foram feitos os testes em bancada com o gerador aproximando o máximo possível das condições ideais de funcionamento. Também foram realizadas algumas alterações físicas na microhidrelétrica para manter a rotação constante com a variação de carga. Utilizaram-se cargas resistivas e não-lineares. Os resultados contribuíram para a melhoria da qualidade da energia e o controle do fluxo de água no processo de geração de energia. O conjunto composto de gerador e a turbina Pelton, durante o experimento, apresentaram rendimentos eletromecânicos da ordem de 20% a 30% comparados com a teoria.
Abstract: This proposal of this work is to demonstrate the performance of a Micro- Hydroelectrical Powerplant (MHP), which has been installed at the UNESP – FEG - Renewable Energy Center, in Guaratinguetá-SP. The present analysis refers to the electrical and mechanical performances. The micro-hydroelectrical powerplant employs a Pelton turbine with a diameter of 0,4m at the incidence of water flow. The generator is provided with permanent ferrite magnet rotor. Costs were low for both the acquisition of parts and installation of the generator and the micro-hydroelectrical powerplant. Bench tests carried out with the generator reached the maximum possible ideal functioning conditions. Some physical modifications were necessary to maintain constant rotation with load variations. Resistive and non-linear loads were used in the essays. The results contributed for an improvement in the quality of energy and the control of water flow in the process of generating energy. The assembly composed of the generator and the Pelton turbine presented an electro-mechanical revenue between 20% to 30%.
Orientador: Teófilo Miguel de Souza.
Coorientador: Pedro Magalhães Sobrinho.
Banca: Samuel Euzedice de Lucena.
Banca: Osiris Cancigliere Junior.
Mestre
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18

Almeida, José Leandro Casa Nova [UNESP]. "Análise da viabilidade técnica e econômica de implantação de uma microusina hidrelétrica." Universidade Estadual Paulista (UNESP), 2007. http://hdl.handle.net/11449/99288.

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Made available in DSpace on 2014-06-11T19:29:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-03Bitstream added on 2014-06-13T20:00:00Z : No. of bitstreams: 1 almeida_jlcn_me_guara.pdf: 1246383 bytes, checksum: bca809ae8bb8fe32b7de24055d2e53d7 (MD5)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A proposta desta dissertação foi a de apresentar o desempenho de uma microcentral hidrelétrica, instalada no Centro de Energias Renováveis da Unesp, Campus Guaratinguetá. As análises apresentadas são de desempenho elétrico e mecânico. A microcentral hidrelétrica utiliza roda Pelton com 0,4m de diâmetro no ponto de incidência do jato de água. O gerador utilizado foi com rotor de ímãs permanentes de ferrite. Tanto o gerador quanto a microusina são de baixo custo de aquisição e instalação. Foram feitos os testes em bancada com o gerador aproximando o máximo possível das condições ideais de funcionamento. Também foram realizadas algumas alterações físicas na microhidrelétrica para manter a rotação constante com a variação de carga. Utilizaram-se cargas resistivas e não-lineares. Os resultados contribuíram para a melhoria da qualidade da energia e o controle do fluxo de água no processo de geração de energia. O conjunto composto de gerador e a turbina Pelton, durante o experimento, apresentaram rendimentos eletromecânicos da ordem de 20% a 30% comparados com a teoria.
This proposal of this work is to demonstrate the performance of a Micro- Hydroelectrical Powerplant (MHP), which has been installed at the UNESP FEG - Renewable Energy Center, in Guaratinguetá-SP. The present analysis refers to the electrical and mechanical performances. The micro-hydroelectrical powerplant employs a Pelton turbine with a diameter of 0,4m at the incidence of water flow. The generator is provided with permanent ferrite magnet rotor. Costs were low for both the acquisition of parts and installation of the generator and the micro-hydroelectrical powerplant. Bench tests carried out with the generator reached the maximum possible ideal functioning conditions. Some physical modifications were necessary to maintain constant rotation with load variations. Resistive and non-linear loads were used in the essays. The results contributed for an improvement in the quality of energy and the control of water flow in the process of generating energy. The assembly composed of the generator and the Pelton turbine presented an electro-mechanical revenue between 20% to 30%.
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19

Do, Khoa Dang. "Reconfigurable control in electric utility power plants." 2012. http://hdl.handle.net/2152/19469.

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In high-level automation industrial processes where maintenance or repair can not be carried out immediately, it is important to design autonomous controllers capable of maintaining the performance, reliability and safety of plants operating under sensor, actuator faults and failures, equipment fouling, feedstock variation. Advanced control strategies such as Active Fault Tolerant Control (AFTC) have been used to accommodate system failures automatically. This research presents an AFTC methodology using model predictive control (MPC) combined with a bank of Kalman Filters. This hybrid fault tolerant control system are testing in a linearized 14-order boiler-turbine unit to deal with sensor faults and actuator faults. When sensor fault occurs, the virtual sensor techniques, which uses both a bank of Kalman Filter and a reconfigured Kalman Filter is applied to estimate the plant state and corrupted sensor value. The reconfigured MPC controller, which has naturally ability in dealing with output and actuator constraints, is equipped with some advanced capabilities such as online parameter tuning mechanism, the stability improvement techniques, the feasibility improvement techniques and reference management technique to handle the plant actuator faults. In case of some specific actuator faults, the MPC controller is restructured to deal with the faults better. The proposed fault tolerant control successfully recovers the system performance in the sensor fault cases and some of the actuator cases. In other fault cases, where the system performance recovery is impossible due to faults, the fault tolerant control degrades the system performance to keep the system stable.
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Simonis, Victor A. "A probabilistic and economic analysis of a major component shared among electric utilities." 1985. http://hdl.handle.net/2097/27543.

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Swisher, Joel Nelson. "Prospects for International trade in environmental services an analysis of international carbon emission offsets /." 1991. http://catalog.hathitrust.org/api/volumes/oclc/26246172.html.

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22

Janse, van Rensburg Jacobus Johannes. "Advanced modelling of porous screens in aerodynamic diffusers using variable resistance factors." Thesis, 2014. http://hdl.handle.net/10352/247.

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Thesis (M. Tech. Mechanical engineering -- Vaal University of Technology
Strict emission legislation has forced industry in general to seriously consider the negative impact it has on the environment, specifically concerning emissions from burning fossil fuel into the atmosphere. In cases where emission levels exceed the allowable limit, companies are forced to operate at lower operating conditions and these load losses can result in a significant loss of revenue. This has forced companies to improve their ash filtering capabilities by optimising electrostatic precipitation systems. One of the main factors impacting on the efficiency of such a system is the distribution of the flow across the collection plates. The design of the inlet diffuser plays a major role in the ultimate distribution of the flow through the precipitator. Porous screens are positioned in the diffuser in order to distribute the flow across the total flow area with the aim to achieve a uniform distribution of the flow. CFD is widely used in industry to simulate the flow through precipitators in order to optimise the flow distribution and thus increase the efficiency of the system. It was found however that the current methods used to simulate these screens in CFD models were not well researched and employed fixed resistance values that could not reliably compensate for changes in the resistance coefficient due to a change in the angle of incidence. This study investigates advanced numerical methods for the simulation of porous screens in applications where the angle of incidence changes continuously across the face of the screen. New methods are introduced where the resistance of the screen is calculated as a function of the changing angle of incidence. The methods currently used are also investigated and compared with results from the new methods. Extensive experimental work was required to supply empirical data for the validation of the numerical methods that are proposed. For this reason, the first part of this study focused on the design construction and commissioning of a low speed wind tunnel. Results are presented and discussed for flow profiles through wide-angle diffusers at different angles and also for a number of different screens positioned in the centre of the diffuser. This study also investigates the sensitivity of a CFD simulation code to factors such as numerical discretisation schemes, turbulence models and solution relaxation specifically for wide-angle diffusers. These factors were tested for diffusers at different angles and included tests on open diffusers and also with screens positioned inside the diffuser. It was concluded that the current methods used are not adequate to capture the true flow profiles for a range of different screen geometries. Although the proposed models did improve on the limitations of the current methods, it was found that the applicability of these models is still limited and that further research would be required to develop numerical methods that are valid for a wide range of applications.
Vaal University of Technology, The National Research Foundation (NRF) and Eskom TSI
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