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1
Merc, Jaroslav, and Augustin Varga. "Predictive Diagnostics of Wet Bottom Boilers Operational States by Calculation of Steam Coal Ash Fluid Temperature." Key Engineering Materials 669 (October 2015): 345–52. http://dx.doi.org/10.4028/www.scientific.net/kem.669.345.
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This article deals with the issue of steam coal ash fluid (or fusion) temperature evaluation by mathematical method, based on comparison of statistic values obtained by laboratory analysis. The ash fluid temperature is very important parameter for Wet Bottom Boilers operation states because of quality of slagging. The ash composition has the biggest impact to the operation effectiveness and reliability of the Wet Bottom Boilers. It can directly influence the boiler production. Importance of information on ash fluid temperature increased after more strict of NOx emission limits (below 600 mg/m3) become obliged. WBB were initially designed for optimal operation with high temperatures in combustion chamber, with a production of high amount of NOx (often about 1400 mg/m3). The ash fluid temperature is usually determined by laboratory only, but it requires certain time and costs. Authors tried to bring faster and easier way how to evaluate of ash fluid temperature with acceptable accuracy of the parameter as predictive diagnostics [6] of the future boiler operational states.
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Madejski, Paweł, and Norbert Modliński. "Numerical investigation using two different CFD codes of pulverized-coal combustion process characteristic in an industrial power plant boiler." E3S Web of Conferences 82 (2019): 01009. http://dx.doi.org/10.1051/e3sconf/20198201009.
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Steam boilers using the coal as a basic fuel are still one of the most important techniques used to generate electricity in Power Plants. Many activities connected with optimization of steam boilers operation, investigation of combustion efficiency using different fuels, control and reducing pollutants emission are observed. Numerical modeling of large steam boilers using Computational Fluid Dynamic method can be a very way to develop and verify effects of all activities regarding combustion process optimization. Numerical modeling results of the coal combustion process in the front wall coal-fired boiler are presented in the paper. The behavior of the flow of pulverized coal through the burners was analyzed, and the temperature and velocity distribution in the combustion chamber were reproduced in the simulation. Despite the fact that the attention has been focused on boiler simulation at nominal load, it is possible to perform numerical studies concerning the analysis of coal combustion at different boiler loads (minimum load and flexible boiler operation). Analysis of different fuels and their impact on the combustion process, as well as analysis of coal mills operation, coal particles size distribution and they impact on boiler operation can be performed using developed models.
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Adi Saputra, I. Nyoman Agus, I. Gusti Bagus Wijaya Kusuma, and I. Gusti Ngurah Priambadi. "Analisis Perbedaan Mesh Pada Simulasi Boiler PLTGU Tanjung Priok Berbasis CFD." Jurnal METTEK 6, no. 1 (April 30, 2020): 46. http://dx.doi.org/10.24843/mettek.2020.v06.i01.p06.
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Penelitian Analisis Perbedaan Mesh berbasis Computational Fluid Dynamic (CFD) ini dilakukan Pada Boiler PLTGU Tanjung Priok. Boiler atau reboiler dalam sistem PLTGU dikategorikan sebagai alat penukar kalor karena perpindahan panasnya dilakukan tanpa kontak langsung antara media pemanas dengan media yang dipanaskan. Fluida kerja pada boiler PLTGU Tanjung Priok berupa gas methane dan air. Penelitian ini bertujuan melihat jumlah pembagian elemen terhadap hasil simulasi dengan menggunakan dua model Studi konvergensi grid yaitu dengan grid kasar, dan yang paling optimal melalui hasil simulasi CFD. Metode yang digunakan mulai dari mendesain geometri boiler sesuai kondisi di lapangan menginput initial conditions dan boundry conditions. Data hasil penelitian yang sudah di lakukan pada simulasi boiler menunjukkan bahwa baik temperatur, tekanan dan kecepatan aliran memiliki nilai yang sama besar dan tidak di pengaruhi oleh pembagian elemen yang di lakukan pada saat proses meshing dari elemen yang paling kasar dengan jumlah total sebanyak 203.363 sampai pada tahap proses meshing dengan elemen teroptimal yang berjumlah sebanyak 1.491.428 berdasarkan hal tersebut maka proses simulasi yang dilakukan menjadi lebih efisien karena proses perhitungan data dari elemen yang lebih sedikit mendapatkan hasil yang sama dengan elemen yang lebih banyak.
The research on Mesh Difference Analysis based on Computational Fluid Dynamic (CFD) was conducted at Tanjung Priok PLTGU Boiler. Boilers or reboilers in PLTGU systems are categorized as heat exchangers because the heat transfer is done without direct contact between the heating media and the heated media. The working fluid in the Tanjung Priok gas power plant boiler is in the form of methane gas and water. This study aims to look at the number of elements divided against the simulation results by using two grid convergence study models, namely with a coarse grid, and the most optimal through CFD simulation results. The method used starts from designing the boiler geometry according to the field conditions, inputting initial conditions and boundry conditions. Data from research that has been done on boiler simulations shows that both temperature, pressure and flow velocity have the same value and are not affected by the division of elements carried out during the meshing process of the most coarse elements with a total number of 203.363 up to the meshing process stage with the optimum elements totaling 1,491,428 based on this, the simulation process carried out becomes more efficient because the process of calculating data from fewer elements gets the same results with more elements.
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Samsudin, Salmi, Nuraini Abdul Aziz, Abdul Aziz Hairuddin, and Siti Ujila Masuri. "A Study on Bituminous Coal Base Acid Ratio to the Slagging Factor at Large Scale Boiler." International Journal of Heat and Technology 39, no. 3 (June 30, 2021): 833–40. http://dx.doi.org/10.18280/ijht.390317.
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Different types of coal have different characteristics and performances. In thermal coal plant, deposition of coal ash inside the furnace causes slag formation inside the boiler rear path and consequently reduces the heat transfer process and boiler efficiency. Besides, accumulation of ash on the boiler tube surfaces form layers of slags and blocks the flue gas flow out of the boiler. Therefore, the purpose of this study is to investigate the relationship between sub-bituminous coal base acid ratio towards the heat transfer process inside large-scale boilers. The base acid ratio for sub-bituminous coal is measured before firing inside large-scale boiler of studied the thermal plant which has a generation capacity of 700 MW. This study found correlation between high furnace rear path temperature (FRPT) that is observed to be above 800℃, with the build up of ash accumulation inside the boiler, for the studied coal. Thus, a high base acid ratio causes the accumulation of coal ash, thus reducing the heat transfer process which results in high FRPT of the boiler. Therefore, it proves that a base acid ratio is an indicator for coal performance during firing inside the boiler.
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TRAN, HONGHI, and DANNY TANDRA. "Recovery boiler sootblowers: History and technological advances." January 2015 14, no. 1 (February 1, 2015): 51–60. http://dx.doi.org/10.32964/tj14.1.51.
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Sootblowing technology used in recovery boilers originated from that used in coal-fired boilers. It started with manual cleaning with hand lancing and hand blowing, and evolved slowly into online sootblowing using retractable sootblowers. Since 1991, intensive research and development has focused on sootblowing jet fundamentals and deposit removal in recovery boilers. The results have provided much insight into sootblower jet hydrodynamics, how a sootblower jet interacts with tubes and deposits, and factors influencing its deposit removal efficiency, and have led to two important innovations: fully-expanded sootblower nozzles that are used in virtually all recovery boilers today, and the low pressure sootblowing technology that has been implemented in several new recovery boilers. The availability of powerful computing systems, superfast microprocessors and data acquisition systems, and versatile computational fluid dynamics (CFD) modeling capability in the past two decades has also contributed greatly to the advancement of sootblowing technology. High quality infrared inspection cameras have enabled mills to inspect the deposit buildup conditions in the boiler during operation, and helped identify problems with sootblower lance swinging and superheater platens and boiler bank tube vibrations. As the recovery boiler firing capacity and steam parameters have increased markedly in recent years, sootblowers have become larger and longer, and this can present a challenge in terms of both sootblower design and operation.
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Stoppato, Anna, and Alberto Benato. "Life Cycle Assessment of a Commercially Available Organic Rankine Cycle Unit Coupled with a Biomass Boiler." Energies 13, no. 7 (April 10, 2020): 1835. http://dx.doi.org/10.3390/en13071835.
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Organic Rankine Cycle (ORC) turbogenerators are a well-established technology to recover from medium to ultra-low grade heat and generate electricity, or heat and work as cogenerative units. High firmness, good reliability and acceptable efficiency guarantee to ORCs a large range of applications: from waste heat recovery of industrial processes to the enhancement of heat generated by renewable resources like biomass, solar or geothermal. ORC unit coupled with biomass boiler is one of the most adopted arrangements. However, despite biomass renewability, it is mandatory to evaluate the environmental impact of systems composed by boilers and ORCs taking into account the entire life cycle. To this purpose, the authors perform a life cycle assessment of a commercially available 150 kW cogenerative ORC unit coupled with a biomass boiler to assess the global environmental performance. The system is modelled in SimaPro using different approaches. Results show that the most impacting processes in terms of CO2 equivalent emissions are the ones related to biomass production and organic fluid leakages with 71% and 19% of the total. Therefore, being fluid release in the environment high impacting, a comparison among three fluids is also performed. Analysis shows that adopting a hydrofluoroolefin fluid with a low global warming potential instead of the hydrocarbon fluid as already used in the cycle guarantees a significant improvement of the environmental performance.
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MAAKALA, VILJAMI, and PASI MIIKKULAINEN. "Dimensioning a recovery boiler furnace using mathematical optimization." February 2015 14, no. 2 (March 1, 2015): 119–29. http://dx.doi.org/10.32964/tj14.2.119.
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Capacities of the largest new recovery boilers are steadily rising, and there is every reason to expect this trend to continue. However, the furnace designs for these large boilers have not been optimized and, in general, are based on semiheuristic rules and experience with smaller boilers. We present a multiobjective optimization code suitable for diverse optimization tasks and use it to dimension a high-capacity recovery boiler furnace. The objective was to find the furnace dimensions (width, depth, and height) that optimize eight performance criteria while satisfying additional inequality constraints. The optimization procedure was carried out in a fully automatic manner by means of the code, which is based on a genetic algorithm optimization method and a radial basis function network surrogate model. The code was coupled with a recovery boiler furnace computational fluid dynamics model that was used to obtain performance information on the individual furnace designs considered. The optimization code found numerous furnace geometries that deliver better performance than the base design, which was taken as a starting point. We propose one of these as a better design for the high-capacity recovery boiler. In particular, the proposed design reduces the number of liquor particles landing on the walls by 37%, the average carbon monoxide (CO) content at nose level by 81%, and the regions of high CO content at nose level by 78% from the values obtained with the base design. We show that optimizing the furnace design can significantly improve recovery boiler performance.
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Jiang, Yu, Kyeong-Hoon Park, and Chung-Hwan Jeon. "Feasibility Study of Co-Firing of Torrefied Empty Fruit Bunch and Coal through Boiler Simulation." Energies 13, no. 12 (June 12, 2020): 3051. http://dx.doi.org/10.3390/en13123051.
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Torrefied empty fruit bunch (EFB) co-firing is a promising technology to reduce emissions from coal-fired power plants. However, co-firing can influence the combustion and heat transfer characteristics in a coal boiler. In order to study the feasibility of co-firing application of torrefied EFB (T-EFB) in boilers, the combustion characteristics, gas emissions and heat flux distribution were analyzed, respectively. First, the kinetic parameters of T-EFB devolatilization and char oxidation were obtained by experimental analysis. Second, the computational fluid dynamics (CFD) analysis was applied to the actual 500 MWe boiler simulation to further evaluate the differences in the co-firing performance parameters (combustion characteristics and emissions) of the T-EFB and the heat transfer characteristics within the boiler. Numerical results show that T-EFB co-firing can improve the ignition characteristics of pulverized coal, reduce the formation of unburned particles. When the blending ratio was increased from 10% to 50%, significantly NOx (oxides of nitrogen) reduction (levels from 170 to 98 ppm at 6% O2) was achieved. At a blending ratio above 40%, boiler combustion efficiency decreases as the total heat flux of the boiler decreases due to an increase in the amount of unburned carbon. In addition, T-EFB co-firing can affect the heat transfer characteristics of the boiler.
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Aguilar Vizcarra, Duilio, Doris Esenarro, and Ciro Rodriguez. "Three Steps Mixed (Fire Tube–Water Tube) Vertical Boiler to Optimize Thermal Performance." Fluids 6, no. 3 (February 25, 2021): 93. http://dx.doi.org/10.3390/fluids6030093.
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The research aims to design and construct a new mixed vertical boiler (fire tube – water tube) with three gas passes. The strength of this technological innovation is in the best use of the thermic transmission receiving fluid (hot water, steam, thermal oil), this due to its multipurpose function of three steps using alternative fuels (Diesel, Liquid Petroleum Gas LPG, natural gas), by improving the thermal efficiency of the boiler its temperature is reduced with gases at low temperatures, which in turn also reduce environmental pollution. The methodology focuses on calculating the transfer area with the calculation method that will allow dimensioning the boiler, considering the calculation of losses and the fluid speed, with two defined procedures, the first for fire tube and water tube boilers. And another alternative. The results obtained allowed optimizing the thermal efficiency level, achieving very significant thermal efficiency results: With LPG 92.4% for hot water and 92.42% to generate steam in the same way with natural gas 90.25% for hot water and 90.24% to generate steam as well with Diesel 2; 89.21% for hot water and 89.31% to generate steam.
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Okumura, Koji. "Field Operation of Circulating Fluid Red Boiler." JAPAN TAPPI JOURNAL 46, no. 1 (1992): 168–73. http://dx.doi.org/10.2524/jtappij.46.168.
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Kosugi, Minoru. "Operating Experience of Circulating Fluid Bed Boiler." JAPAN TAPPI JOURNAL 51, no. 1 (1997): 111–22. http://dx.doi.org/10.2524/jtappij.51.111.
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Wajs, Jan, Dariusz Mikielewicz, Michał Bajor, and Zbigniew Kneba. "Experimental investigation of domestic micro-CHP based on the gas boiler fitted with ORC module." Archives of Thermodynamics 37, no. 3 (September 1, 2016): 79–93. http://dx.doi.org/10.1515/aoter-2016-0021.
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AbstractThe results of investigations conducted on the prototype of vapour driven micro-CHP unit integrated with a gas boiler are presented. The system enables cogeneration of heat and electric energy to cover the energy demand of a household. The idea of such system is to produce electricity for own demand or for selling it to the electric grid – in such situation the system user will became the prosumer. A typical commercial gas boiler, additionally equipped with an organic Rankine cycle (ORC) module based on environmentally acceptable working fluid can be regarded as future generation unit. In the paper the prototype of innovative domestic cogenerative ORC system, consisting of a conventional gas boiler and a small size axial vapour microturbines (in-house designed for ORC and the commercially available for Rankine cycle (RC)), evaporator and condenser were scrutinised. In the course of study the fluid working temperatures, rates of heat, electricity generation and efficiency of the whole system were obtained. The tested system could produce electricity in the amount of 1 kWe. Some preliminary tests were started with water as working fluid and the results for that case are also presented. The investigations showed that domestic gas boiler was able to provide the saturated/superheated ethanol vapour (in the ORC system) and steam (in the RC system) as working fluids.
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Manic, Nebojsa, Vladimir Jovanovic, Dragoslava Stojiljkovic, and Zagorka Brat. "Application of different turbulence models for improving construction of small-scale boiler fired by solid fuel." Thermal Science 21, suppl. 3 (2017): 809–23. http://dx.doi.org/10.2298/tsci160627017m.
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Due to the rapid progress in computer hardware and software, CFD became a powerful and effective tool for implementation turbulence modeling in defined combustion mathematical models in the complex boiler geometries. In this paper the commercial CFD package, ANSYS FLUENT was used to model fluid flow through the boiler, in order to define velocity field and predict pressure drop. Mathematical modeling was carried out with application of Standard, RNG, and Realizable k-? turbulence model using the constants presented in literature. Three boilers geometry were examined with application of three different turbulence models with variants, which means consideration of 7 turbulence model arrangements in FLUENT. The obtained model results are presented and compared with data collected from experimental tests. All experimental tests were performed according to procedures defined in the standard SRPS EN 303-5 and obtained results are presented in this paper for all three examined geometries. This approach was used for improving construction of boiler fired by solid fuel with heat output up to 35 kW and for selection of the most convenient construction.
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Stecco, S. S., and U. Desideri. "Considerations on the Design Principles for a Binary Mixture Heat Recovery Boiler." Journal of Engineering for Gas Turbines and Power 114, no. 4 (October 1, 1992): 701–6. http://dx.doi.org/10.1115/1.2906645.
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The use of a binary mixture as a working fluid in bottoming cycles has in recent years been recognized as a means of improving combined cycle efficiency. There is, however, quite a number of studies dealing with components of plants that employ fluids other than water, and particularly binary mixtures. Due to different specific volume, viscosity, thermal conductivity, and Prandtl number, heat recovery boilers designed to work with water require certain modifications before they can be used with binary mixtures. Since a binary mixture is able to recover more heat from the exhaust fumes than water, the temperature difference between the hot and the cold fluids is generally lower over the whole recovery boiler; this necessitates greater care in sizing the tube bundles in order to avoid an excessive heat transfer surface per unit of thermal power exchanged. The aim of this paper is to provide some general criteria for the design of a heat recovery boiler for a binary mixture, by showing the influence of various dimensional parameters on the heat surface and pressure drop both in the cold and the hot side. Heat transfer coefficients and pressure drops in the hot side were computed by means of correlations found in the literature. A particular application was studied for an ammonia-water mixture, used in the Kalina cycles, which represents one of the most interesting binary cycles proposed so far.
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Lee, Jong-Sun. "Structural Analysis of Synthetic Heat Transfer Fluid Boiler." Journal of the Korea Academia-Industrial cooperation Society 13, no. 8 (August 31, 2012): 3352–57. http://dx.doi.org/10.5762/kais.2012.13.8.3352.
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Motyl, Przemysław, Danuta Król, Sławomir Poskrobko, and Marek Juszczak. "Numerical Modelling and Experimental Verification of the Low-Emission Biomass Combustion Process in a Domestic Boiler with Flue Gas Flow around the Combustion Chamber." Energies 13, no. 21 (November 9, 2020): 5837. http://dx.doi.org/10.3390/en13215837.
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The paper presents the results of numerical and experimental studies aimed at developing a new design of a 10 kW low-emission heating boiler fired with wood pellets. The boiler is to meet stringent requirements in terms of efficiency (η > 90%) and emissions per 10% O2: CO < 500 mg/Nm3, NOx ≤ 200 mg/Nm3, and dust ≤ 20 mg/Nm3; these emission restrictions are as prescribed in the applicable ECODESIGN Directive in the European Union countries. An innovative aspect of the boiler structure (not yet present in domestic boilers) is the circular flow of exhaust gases around the centrally placed combustion chamber. The use of such a solution ensures high-efficiency, low-emission combustion and meeting the requirements of ECODESIGN. The results of the numerical calculations were verified and confirmed experimentally, obtaining average emission values of the limited gases CO = 91 mg/Nm3, and NOx = 197 mg/Nm3. The temperature measured in the furnace is 450–500 °C and in the flue it was 157–197 °C. The determined boiler efficiency was 92%. Numerical calculations were made with the use of an advanced CFD (Computational Fluid Dynamics) workshop in the form of the Ansys programming and a computing environment with the dominant participation of the Fluent module. It was shown that the results obtained in both experiments are sufficiently convergent.
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Ibraheem, Amjd, and Ferenc Szodrai. "Numerical Model Analysis of Natural Gas Combustion Burners." International Journal of Engineering and Management Sciences 4, no. 1 (March 3, 2019): 67–71. http://dx.doi.org/10.21791/ijems.2019.1.9.
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Traditional power plants still the dominating power source for all the major industries and powerdemanding facilities, the most crucial facility for the whole plant operations is the industrial boiler which generatessteam, heating energy or electrical power. Boilers generate energy by combustion. The improvement of combustion efficiency could greatly influence the energy consumption and will make the boiler more efficient and cleaner (less emissions), that’s why it is important to understand the combustion and thermal flow behaviours inside the boiler. Beside experimental testing, computational work nowadays becoming more and more important due to lower cost and acceptable accuracy with minimum error. With numerical calculations method, the computational model created by a Computational Fluid Dynamics (CFD) software could reduce a lot of trial and error on experimental work. In this paper utilizing the ANSYS FLUENT 19.1 software to make crate the combustion model. The ratio of air to fuel mixture, the equivalency factor, mass flow rate of the mixture, velocity, mass fractions of the mixture components (fuel and air) and their temperatures will serve as the input parameter while the exhaust gase component mass fraction, temperature, mass flow and velocity will be monitored.
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Stepanov, Borivoj, Ivan Pesenjanski, and Momcilo Spasojevic. "Scandinavian baffle boiler design revisited." Thermal Science 19, no. 1 (2015): 305–16. http://dx.doi.org/10.2298/tsci130508070s.
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The aim of this paper is to examine whether the use of baffles in a combustion chamber, one of the well-known low-cost methods for the boiler performance improvement, can be enhanced. Modern day tools like computational fluid dynamics were not present at the time when these measures were invented, developed and successfully applied. The objective of this study is to determine the influence of location and length of a baffle in a furnace, for different mass flows, on gas residence time. The numerical simulations have been performed of a simple Scandinavian stove like furnace. The isothermal model is used, while air is used as a medium and turbulence is modeled by realizable k-epsilon model. The Lagrange particle tracking is used for the residence time distribution determination. The statistical analysis yielded the average residence time. The results of the computational fluid dynamics studies for different baffle positions, dimensions and flow rates show from up to 17% decrease to up to 13 % increase of residence time. The conclusion is that vertical position of the baffle is the most important factor, followed by the length of the baffle, while the least important showed to be the mass flow.
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Parker, Kevin. "Fixing a Boiler with CFD." Mechanical Engineering 120, no. 04 (April 1, 1998): 59–61. http://dx.doi.org/10.1115/1.1998-apr-2.
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This article focuses on carryover at a paper mill that had been solved using computational fluid dynamics (CFD) to visualize flow within the boiler. Technicians had tried adjusting airflow and firing arrangements without success. They turned the problem over to analysts who simulated the airflow within the boiler using CFD. An animated sequence of streamlines showing airflow provided engineers with a clear understanding of exactly what was happening inside the boiler, making it relatively easy to adjust operating conditions and solve the problem. McDermott analysts use FIELDVIEW, a commercial post-processing program from Intelligent Light in Lyndhurst, NJ. With the software, the analyst can create three-dimensional perspective views with hidden-line removal and light shading. She or He can trace the path of a marker traveling along with the fluid through a series of animated views. The analysts made a second FIELDVIEW movie of the airflow conditions with the new arrangement, showing the elimination of the center core. They played the two movies simultaneously on two monitors set side-by-side to demonstrate for the customer’s engineers how the recommended changes would solve the problem.
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Jo, Hyunbin, Kiseop Kang, Jongkeun Park, Changkook Ryu, Hyunsoo Ahn, and Younggun Go. "Optimization of Air Distribution to Reduce NOx Emission and Unburned Carbon for the Retrofit of a 500 MWe Tangential-Firing Coal Boiler." Energies 12, no. 17 (August 26, 2019): 3281. http://dx.doi.org/10.3390/en12173281.
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The use of separated overfire air (SOFA) has become a standard technique of air staging for NOx reduction in the coal-fired boiler and can also be applied to existing boilers by retrofit. This study was to optimize the air distribution for the proposed SOFA installation in a 500 MWe tangential-firing boiler that has 20 identical units in Korea. Using computational fluid dynamics (CFD) incorporating advanced coal combustion submodels, the reference case was established in good agreement with the design data, and different flow ratios of burner secondary air, close-coupled OFA (CCOFA), and SOFA were evaluated. Increasing the total OFA ratio effectively suppressed NO formation within the burner zone but had a negative impact on the boiler performance. With moderate air staging, NO reduction became active between the CCOFA and SOFA levels and, therefore, the OFA distribution could be optimized for the overall boiler performance. For total OFA ratios of 25% and 30% with respective burner zone stoichiometric ratios of 0.847 and 0.791, increasing the SOFA ratio to 15% and 20%, respectively, was ideal for decreasing the unburned carbon release and ash slagging as well as NO emission. Too high or low SOFA ratios rapidly increased the unburned carbon because of inefficient mixing between the strong air jets and char particles. Based on these ideal cases, the actual air distribution can be adjusted depending on the coal properties such as the ash slagging propensity.
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Kolat, Pavel, and Zdeněk Kadlec. "Sewage sludge as a biomass energy source." Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 61, no. 1 (2013): 85–91. http://dx.doi.org/10.11118/actaun201361010085.
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The major part of the dry matter content of sewage sludge consists of nontoxic organic compounds, in general a combination of primary sludge and secondary microbiological sludge. The sludge also contains a substantive amount of inorganic material and a small amount of toxic components. There are many sludge-management options in which production of energy is one of the key treatment steps. The most important options are anaerobic digestion, co-digestion, incineration in combination with energy recovery and co-incineration in coal-fired power plants. The goal of our applied research is to verify, if the sludge from waste water treatment plants may be used as a biomass energy source in respect of the EU legislation, which would comply with emission limits or the proposal of energy process optimizing the preparation of coal/sludge mixture for combustion in the existing fluid bed boilers in the Czech Republic. The paper discusses the questions of thermal usage of mechanically drained stabilized sewage sludge from the waste water treatment plants in the boiler with circulated fluid layer. The paper describes methods of thermal analysis of coal, sewage sludge and its mixtures, mud transport to the circulating fluidised bed boiler, effects on efficiency, operational reliability of the combustion equipment, emissions and solid combustion residues.
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LEPPÄNEN, AINO, ERKKI VÄLIMÄKI, ANTTI OKSANEN, and HONGHI TRAN. "CFD-modeling of fume formation in kraft recovery boilers." March 2013 12, no. 3 (April 1, 2013): 25–32. http://dx.doi.org/10.32964/tj12.3.25.
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A computational fluid dynamics (CFD) model was developed to simulate alkali metal chemistry and fume particle formation in a kraft recovery boiler. The modeling results were partially validated against previously obtained field measurements. The model provides information about fume composition, chlorine and potassium enrichment factors, and particle mass concentration at different locations in the boiler.
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Yeh, Chun Lang. "SOx Reduction by Feedwater in an Industrial Boiler." Applied Mechanics and Materials 619 (August 2014): 135–41. http://dx.doi.org/10.4028/www.scientific.net/amm.619.135.
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This paper discusses the SOx reduction by feedwater in an industrial boiler. The combustion and fluid flow in the boiler is examined with emphasis on the effect of feedwater on SOx reduction. The simulation results indicate that feedwater injected into the DeSOx section has little influence on the heat absorption of the cooling pipes in the flue gas cooling section. The boiler exit temperature and the exit concentrations of SOx, NOx and CO are reduced by the feedwater. When the feedwater flowrate is increased to 1000 times the original value, the boiler exit temperature and the exit concentrations of SOx, NOx and CO are reduced to 1/2, 1/13, 1/13 and 1/20 of the original values.
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Liao, Hong Kai, Yue Xi Yu, Yan Ling Wu, and Wei Zhong. "Model and Algorithm for Thermal Performance Calculation of Power Station Boiler Based on Process Steady-State Simulation Theory." Applied Mechanics and Materials 483 (December 2013): 587–93. http://dx.doi.org/10.4028/www.scientific.net/amm.483.587.
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Thermal performance calculation is the core task of designing power station boiler. By abstracting generalized components and generalized fluid nodes, and defining the process unit and process section at the logic level, the universal physical model of boiler was built in a particular form of flowsheet. Meanwhile, a sequential modular approach was proposed as the main algorithm for boiler thermal calculation based on process system steady-state simulation theory. Two key problems in the algorithm, i.e., module calculations and the logics of calling the modules calculations were explained. Finally, a practically developed system BESS, which has excellent flexibility and extensibility was presented. It turns out that the model and algorithm can be successfully employed in developing the general-purpose software for boiler thermal calculation.
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Yeh, Chun Lang. "Chemical Reaction and Fluid Flow in a Carbon Monoxide Boiler(II) Chemical Reaction Analysis." Advanced Materials Research 581-582 (October 2012): 19–26. http://dx.doi.org/10.4028/www.scientific.net/amr.581-582.19.
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Performance of a CO boiler has a detrimental influence on the operation and production of related industries. In this paper, the reacting flow in a Carbon Monoxide boiler is investigated. The influence of insertion of an ellipsoidal cone is discussed. It is found that insertion of an ellipsoidal cone can lower the temperature in the DeNOx section. There is a larger skin friction coefficient with a larger ellipsoidal cone angle. It is also found that NOx formation in the DeNOx section can be alleviated by insertion of an ellipsoidal cone.
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BRINK, ANDERS, TOR LAURÉN, MIKKO HUPA, RALF KOSCHACK, and CHRISTIAN MUELLER. "In-furnace temperature and heat flux mapping in a kraft recovery boiler." September 2010 9, no. 9 (October 1, 2010): 7–11. http://dx.doi.org/10.32964/tj9.9.7.
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Gas temperatures, incident heat flux, and surface temperatures were measured in a large kraft recovery boiler. The measurements were a part of an extensive campaign planned and carried out to support validation of models based on computational fluid dynamics. The gas temperatures were measured with three different techniques: infrared (IR) pyrometer, suction pyrometer, and unshielded thermocouples. In addition to the temperature measurements, the radiative heat flux was measured in a number of locations in the boiler using a portable heat flux probe, and the surface temperatures inside the boiler were measured using a portable single-band IR camera.
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Yeh, Chun Lang. "Numerical Study of the Influence of Refractory Thickening on the Reacting Flow and DeNOx Effect in a CO Boiler." Applied Mechanics and Materials 284-287 (January 2013): 861–66. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.861.
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Performance of a CO boiler has a detrimental influence on the operation and production of related industries. In a previous study, we have presented a numerical study of the influence of refractory thickening on the heat transfer and fluid flow in a CO boiler. In this paper, the influence of refractory thickening on the reacting flow and DeNOx effect in a CO boiler is discussed. It is found that refractory thickening can reduce the temperature and the skin friction in the DeNOx section. Furthermore, NOx formation in the DeNOx section is also alleviated by refractory thickening.
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Krzywanski, Jaroslaw, Karol Sztekler, Mateusz Szubel, Tomasz Siwek, Wojciech Nowak, and Łukasz Mika. "A Comprehensive Three-Dimensional Analysis of a Large-Scale Multi-Fuel CFB Boiler Burning Coal and Syngas. Part 1. The CFD Model of a Large-Scale Multi-Fuel CFB Combustion." Entropy 22, no. 9 (August 31, 2020): 964. http://dx.doi.org/10.3390/e22090964.
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The paper is focused on the idea of multi-fuel combustion in a large-scale circulating fluidized bed (CFB) boiler. The article discusses the concept of simultaneous coal and syngas combustion. A comprehensive three-dimensional computational fluid dynamics (CFD) model is developed, which allows us to describe complex phenomena that occur in the combustion chamber of the CFB boiler burning coal and syngas produced from coal sludge.
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Yeh, Chun Lang. "Analysis of DeNOx by SNCR in a Carbon Monoxide Boiler." Applied Mechanics and Materials 764-765 (May 2015): 413–17. http://dx.doi.org/10.4028/www.scientific.net/amm.764-765.413.
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This study investigates numerically the NOx reduction by SNCR in a CO boiler. The combustion and fluid flow in the FPC CO boiler is examined with emphasis on the influence of the injection position of reducing agent on NOx reduction. Simulation results indicate that NOx is formed mainly in the high temperature region near the boiler inlet where the mixing caused by swirler is strong. Among the reducing agent injection positions investigated, the boiler inlet has the best NOx reduction efficiency, while 0.5m behind the boiler inlet is the worst. When reducing agent is injected from the boiler inlet, a NOx reduction efficiency of 51% is achieved if default amount of reducing agent is injected. When reducing agent is injected from 3.6m behind the boiler inlet, the NOx reduction efficiency is 14% for default amount of reducing agent. The injection position of reducing agent has a siginificant influence on the NOx reduction efficiency. Better injection positions for NOx reduction should be where reducing agent can pass through a region where temperature is suitable for the SNCR reaction or residence time of reducing agent in the SNCR reaction region can be longer, e.g., the boiler inlet or the downstream region of the oxidizer lower portion where recirculation exists.
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Hosanova, Rindra. "Simulasi Numerik Karakteristik Pembakaran Pada Tangentially Fired Boiler Dengan Variasi Sudut Yaw." SPECTA Journal of Technology 3, no. 3 (December 31, 2019): 44–56. http://dx.doi.org/10.35718/specta.v3i3.57.
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Coal is one of the energy sources that widely used for electricity, the age of coal reserves only remain 56 years, so it is necessary to make a study to reduce the consumption rate of coal with make an improvement on boiler efficiency which use tangentially fired boiler because it has good combustion. There are a problem in this type of boiler such as unbalance temperature and temperature deviation in superheaters and reheaters of the boiler. This research is made to study the effect of yaw angle modification to temperature in boiler. Method that used in this research is Computational Fluid Dynamic (CFD). Coal yaw angle modification in this research are +5º, 0º, -5º, -10º, dan -15º. Coal yaw angle modification have an effect to temperature distribution, wider yaw angle then larger the temperature deviation. The best coal yaw angle configuration is at -5º because it has the least temperature deviation on the upper furnace which minimize the risk of overheat on superheaters and reheaters.
Keywords: CFD, yaw angle, tangentially fired boiler
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Zeng, Guang, Sen Lin Zhao, Lai Wei, Run Ze Huang, and Modiri Badirwang. "Experimental Study on Technical Difficulties of Botswana First Circulating Fluidized Bed Boiler during Loading Process." Advanced Materials Research 721 (July 2013): 357–62. http://dx.doi.org/10.4028/www.scientific.net/amr.721.357.
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For study of technical difficulties that make Botswana first CFB (Circulating Fluidized Bed) boiler can’t reach full load at beginning of loading process, first experiments were carried out as awful experimental cases to analyze influencing factors; Second experiments were carried out as tentative experimental cases to select useful solutions; Third experiments were carried out as targeted experimental cases to execute chose solutions. Results indicate that one prominent difficulty during CFB boiler reaching full load is that boiler operation bed temperature was too high which was a comprehensive effect with some other influencing factors. CFB boiler bed temperature MFT (Main Fuel Trip) set point slight increasing, grain size changing of both start-up material and feeding coal, limestone injecting, fluidizing air of seal pot and FBHE appropriate controlling and FBHE (Fluid Bed Heat Exchanger) gradually start working are taken simultaneously, all these effective solutions solve the technical difficulties and accelerate the boiler reach full load, but attentions still need to be paid for the boiler stable operation permanently in future.
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Elmaryami, Abdlmanam, Hafied M. B. Khalid, Abdulssalam M. Abdulssalam, Alaa A. Abdulssalam, Mohamed M. Alssafi, Abdullateef S. Abdullateef, and Ziadan A. Mohamed. "Design of a Simple Model of S. P. P. to Study the Effect of Increasing the Boiler Pressure on the Efficiency of the Model." Engineering & Technology Review 2, no. 1 (January 1, 2021): 1–7. http://dx.doi.org/10.47285/etr.v2i1.60.
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The Rankine cycle is one example of vapor power cycles. One important application of it is in steam power plants. In this paper, a simple model of the steam power plant is designed to study the effect of increasing boiler's pressures (3, 4, 5, and 6 bar respectively) on the efficiency and the dryness friction of the Model. Properties of the important points in the cycle were calculated consequently the losses in the pump, the losses in the condenser, expansion of the working fluid through the turbine, and the heat transfer to the working fluid through the boiler were determined. From the results, it was found that with the increasing of the boiler's operating pressure the thermal efficiency of the model cycle increases due to a substantial increase in network. Thus net-effect is marked increases in the thermal efficiency of the cycle on account of these measures.
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O'Doherty, T., D. Froud, C. J. Bates, and N. Syred. "Characteristics of a Power Station Boiler." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 208, no. 2 (May 1994): 89–101. http://dx.doi.org/10.1243/pime_proc_1994_208_018_02.
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An experimental investigation of the flow patterns in a model of a power station boiler has been carried out under isothermal conditions, to produce data for computational fluid dynamic code validation. Measurements were made in three dimensions on a single swirl burner in isolation, in two dimensions on a bank of 12 burners in a 4 × 3 grid and in the model boiler with this bank installed. The single burner exhibited a central reverse flow zone with high levels of turbulence at its boundaries. The general flow pattern found in the single burner was greatly distorted when interaction with surrounding burners in the bank occurred. Several unexpected secondary flows occurred. The model boiler displayed a complex flow arrangement with recirculation zones and two stagnation points.
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Peretyatko, M. A., P. V. Yakovlev, and S. A. Peretyatko. "Improving the heat transfer efficiency of a direct-flow recycling boiler using organic fluid." E3S Web of Conferences 266 (2021): 04009. http://dx.doi.org/10.1051/e3sconf/202126604009.
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This paper considers the problem of studying the heat transfer exchange during boiling in a direct-flow recycling boiler using an organic coolant. The study was conducted using numerical modelling in the ANSYS software package. Asaresultofthestudyavisual picture eofvaporphasedistributionwasobtained. This picture shows that the studied heat-exchange surface can be conditionally divided into two areas: the area of intense vaporization and the area in which the degree of dry vapor varies insignificantly. Analysis of changes in the heat transfer coefficient along the length of the heat-exchange surface led to the conclusion that heat transfer in the second area is inefficient. Based on the results of the study, it was concluded that intensification of heat transfer is necessary, for which it is proposed to install a separator at the boundary between the selected areas. The subject of the study is the dependence of the variationin the heat transfer coefficient along the length of the pipe and the determination of the boundary between the selected areas at various values of the defining parameters. Numerical simulation for therange of variationofthe defining parameters corresponding to the actual temperature regimeof power steam boilers and the conditions for the implementation of heat recovery in organic Rankine cycle unitswas performed.
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LEPPÄNEN, AINO, ERKKI VÄLIMÄKI, and ANTTI OKSANEN. "Modeling fine particles and alkali metal compound behavior in a kraft recovery boiler." July 2012 11, no. 7 (August 1, 2012): 9–14. http://dx.doi.org/10.32964/tj11.7.9.
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Under certain conditions, ash in black liquor forms a locally corrosive environment in a kraft recovery boiler. The ash also might cause efficiency losses and even boiler shutdown because of plugging of the flue gas passages. The most troublesome compounds in a fuel such as black liquor are potassium and chlorine because they change the melting behavior of the ash. Fouling and corrosion of the kraft recovery boiler have been researched extensively, but few computational models have been developed to deal with the subject. This report describes a computational fluid dynamics-based method for modeling the reactions between alkali metal compounds and for the formation of fine fume particles in a kraft recovery boiler furnace. The modeling method is developed from ANSYS/FLUENT software and its Fine Particle Model extension. We used the method to examine gaseous alkali metal compound and fine fume particle distributions in a kraft recovery boiler furnace. The effect of temperature and the boiler design on these variables, for example, can be predicted with the model. We also present some preliminary results obtained with the model. When the model is developed further, it can be extended to the superheater area of the kraft recovery boiler. This will give new insight into the variables that increase or decrease fouling and corrosion
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Shen, Xin, Li Jia, Yanlin Wang, Baihe Guo, Haodong Fan, Xiaolei Qiao, Man Zhang, and Yan Jin. "Study on Dynamic Characteristics of Residual Char of CFB Boiler Based on CPFD Method." Energies 13, no. 22 (November 11, 2020): 5883. http://dx.doi.org/10.3390/en13225883.
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When the load of Circulating Fluidized Bed (CFB) boiler changes dynamically, the accumulation and consumption of residual char causes a large inertia and hysteresis in the boiler combustion system. Therefore, accurate estimation of the residual char in the boiler is of great significance to the control system and improve the combustion efficiency. Based on the Computational Particles Fluid Dynamics (CPFD) method, a numerical simulation of the variable load process of CFB boiler was carried out, and the dynamic changes of the residual char inventory were analyzed by combining the coal feed, ash discharge, and furnace calorific value. The results showed that after CFB boiler reached stable operation, the residual char fluctuated from 11,000 kg to 16,000 kg, accounting for about 3.7% of the total bed material, and the residual char was in a dynamic balance. During the load-up phase, the average residual char was 17,500 kg, and during the load-down phase, the average residual char was 15,000 kg. In the process of load dynamic change, reasonable residual char stock can ensure the boiler load from one steady state to another steady state rapid transition.
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P. Adamczyk, Wojciech, Pawel Kozolub, Gabriel Węcel, and Arkadiusz Ryfa. "Simulations of the PC boiler equipped with complex swirling burners." International Journal of Numerical Methods for Heat & Fluid Flow 24, no. 4 (April 29, 2014): 845–60. http://dx.doi.org/10.1108/hff-02-2013-0067.
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Purpose – The purpose of this paper is to show possible approaches which can be used for modeling complex flow phenomena caused by swirl burners combined with simulating coal combustion process using air- and oxy-combustion technologies. Additionally, the response of exist boiler working parameter on changing the oxidizer composition from air to a mixture of the oxygen and recirculated flue gases is investigated. Moreover, the heat transfer in the superheaters section of the boiler was taken into account by modeling of the heat exchange process between continuum phase and three stages of the steam superheaters. Design/methodology/approach – An accurate solution of the flow field is required in order to predict combustion phenomena correctly for numerical simulations of the industrial pulverized coal (PC) boilers. Nevertheless, it is a very demanding task due to the complicated swirl burner construction and complex character of the flow. The presented simulations were performed using the discrete phase model for tracking particles and combustion phenomena in a dispersed phase, whereas the Eulerian approach was applied for the volatile combustion process modeling in a gaseous phase. Findings – Applying the air- to oxy-combustion technology the temperature in the combustion chamber, decreased for investigated oxidizer compositions. This was caused by the higher heat capacity of flue gases which also influences on the level of the heat flux at the boiler walls. Simulations shows that increasing the O2 concentration to 30 percent of volume base in the oxidizer mixture provided the similar combustion conditions as those for the conventional air firing. Moreover, the evaluated results give a good overview of differences between approaches used for complex swirl burners simulations. Practical implications – Nowadays, the numerical techniques such as computational fluid dynamic (CFD) can be seen as an useful engineering tool for design and processes optimization purposes. The application of the CFD gives a possibility to predict the combustion phenomena in a large industrial PC boiler and investigate the impact of changing the combustion technology from a conventional air firing to oxy-fuel combustion. Originality/value – This paper gives good overview on existing technique, approaches used for modeling PC boiler equipped with complex swirl burners. Additionally, the novelty of this work is application of the heat exchanger model for predicting heat loses in convective section of the boiler. This usually is not taken into account during simulations. The reader can also find basic concept of oxy-combustion technology, and their impact on boiler working conditions.
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Lv, Tai, and Shi Ze Zhao. "Numerical Simulation Analysis of the Optimized and Transformed 200MW Pulverized Coal Fired Boiler Burner." Applied Mechanics and Materials 672-674 (October 2014): 1524–27. http://dx.doi.org/10.4028/www.scientific.net/amm.672-674.1524.
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With the use of computational fluid mechanics software – FLUENT, the numerical simulation computation of combustion process inside a certain 200MW corner tangential firing boiler whose combustor is transformed by the multi-grade efficient low-nitrogen combustion technology was conducted, thus the furnace temperature, velocity, mixture and NOx concentration field at rated conditions before and after the transformation were obtained. The calculation results were highly identical with the industrial test results. The results show that after using the multi-grade efficient low-nitrogen combustion technology, the NOx emissions significantly lowered down with the drop of about 40% compared with the emissions before transformation, while the furnace coking and high temperature corrosion were effectively controlled, achieving good economic and social benefits and providing a reference to the design and transformation of the same types of boilers.
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Kaczmarczyk, Tomasz, Grzegorz Żywica, and Eugeniusz Inhatowicz. "Experimental research on the domestic ORC micro power plant with a commercial biomass boiler." E3S Web of Conferences 46 (2018): 00021. http://dx.doi.org/10.1051/e3sconf/20184600021.
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The purpose of the work was to experimentally evaluate the operation of the domestic ORC micro power plant that uses a commercial biomass boiler fueled with wood pellets. The boiler, with a maximum thermal power output of 45kWt, uses a heating jacket and thermal oil as a working medium. The prototypical domestic ORC micro power plant was equipped with a multistage radial-flow microturbine that can generate electricity (2.5kWe at a rotational speed of 24,000 rpm). The microturbine is a key component of the turbogenerator, which was manufactured in oilfree technology. The turbogenerator’s high-speed bearings are lubricated with the low-boiling medium’s vapour. The HFE7100 fluid was used as a working medium in the ORC installation. The paper discusses the thermodynamic conditions to be met for effective operation of the boiler and the results of experimental research. The operating characteristics of the ORC installation and the biomass boiler were presented. Problems that occurred while testing the micro-cogeneration power plant with the boiler and their impact on the electric and thermal efficiency of the cycle were discussed.
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Mešić, Amel, Izudin Delić, and Nedim Ganibegović. "Numerical modeling of multiphase flow inside aeromixture channel and low emission burner of boiler OB-650." Technium: Romanian Journal of Applied Sciences and Technology 2, no. 7 (September 30, 2020): 94–106. http://dx.doi.org/10.47577/technium.v2i7.1649.
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Determination of multiphase flow inside PC boiler plant is of particular importance for the process control of the boiler and its efficient operation. Nowadays numerical modeling is used as an advanced tool in improvement of this or similar process. Separation of coal particle in aero-mixture channel, after pulverization, represent an important process which has a big effect on boiler efficiency, and its determination represents an important step. In this paper, numerical modeling of multiphase flow inside aero-mixture channel and low emission burner of boiler OB-650 are exposed in several steps from 3D modeling, discretization of fluid domain, setting the physical and mathematical model to validation of same model. Main goals of the same process is to obtain valid numerical model of observed problematic, that will give us data about model parameters that can be used for modeling of the same process with different inlet boundary conditions, and also to obtain appropriate specific process parameters that can be used for rising of level of efficiency and utility of boiler plant in some steady operating modes.
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Hamid, Naim. "STUDI OF SREAM DISTRIBUTION AND BOILER PERFORMANCE INDOMARINE AT PT. EASTERN PEARL FLOUR MILLS." Journal of Industrial Engineering Management 5, no. 2 (November 22, 2020): 21–30. http://dx.doi.org/10.33536/jiem.v5i2.729.
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The process of making pellets at PT. Estren Pear flour Millss require hot steam generated from the Indomarine boiler. This study aims to determine the performance of Boier Indomrine. The research method used is to collect measured data on instruments and stored in the control documents of PT. Eastern Pearl Flour Mills. The results of the calculation show that the heat energy loss in the distribution pipe installation is 32.5 kW, while the available fuel energy from the combustion process is 2334311 kJ / hour. mass balance of the working fluid that occurs is the mass rate of feed water used is 1126.35 kg / hour, the mass rate of steam produced is 934.35 kg / hour. While the rest came out through the blow down process of 192 kg / hour.
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Xue, Min, Zhu Ma, Yan Jun Li, Long Bin Yang, and Fang Zhu. "Based on the Principle of Approximate Model Established Model Test Rig Simulation of the Actual Test Bench." Advanced Materials Research 614-615 (December 2012): 14–19. http://dx.doi.org/10.4028/www.scientific.net/amr.614-615.14.
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For Marine pressurization boiler dynamic system, when the boiler provide steam for air storage, boiler drum pressure and steam pressure will have produced a wave phenomenon; In order to research this a wave phenomenon, considering similar principles , establish the model experiments to simulate the wave process. Due to boiler provide steam for air storage that involves in many complex physical processes, including two phase flow, heat transfer, braising physical phenomena. By a simple analysis, to be completely similar to the model, model must be the same as the real situation; it will lose the small model experimental significance. According to this problem, we consider use approximate modeling method which usually used in engineering, seize the pressure fluctuations of the main contradictions; Put forward in the process of considering only reflect pressure fluctuations of local fluid dynamic field project of similar approximation, Finally we get the fluctuation relationship of the actual conditions and small model experiment of main steam pressure.
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PETHE, SAMIT J., PAUL W. CLONINGER, RYAN R. SHORTREED, and KEN M. HARDISON. "Boiler retrofit improves efficiency and increases biomass firing rates." March 2021 20, no. 3 (April 1, 2021): 173–84. http://dx.doi.org/10.32964/tj20.3.173.
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Domtar’s fluff pulp mill in Plymouth, NC, USA, operates two biomass/hog fuel fired boilers (HFBs). For energy consolidation and reliability improvement, Domtar wanted to decommission the No. 1 HFB and refurbish/retrofit the No. 2 HFB. The No. 2 HFB was designed to burn pulverized coal and/or biomass on a traveling grate. The steaming capacity was 500,000 lb/h from coal and 400,000 lb/h from biomass. However, it had never sustained this design biomass steaming rate. As the sole power boiler, the No. 2 HFB would need to sustain 400,000 lb/h of biomass steam during peak loads. An extensive evaluation by a combustion and boiler technologies supplier was undertaken. The evaluation involved field testing, analysis, and computational fluid dynamics (CFD) modeling, and it identified several bottle-necks and deficiencies to achieving the No. 2 HFB’s biomass steam goal. These bottlenecks included an inadequate combustion system; insufficient heat capture; excessive combustion air temperature; inadequate sweetwater con-denser (SWC) capacity; and limited induced draft fan capacity. To address the identified deficiencies, various upgrades were engineered and implemented. These upgrades included modern pneumatic fuel distributors; a modern sidewall, interlaced overfire air (OFA) system; a new, larger economizer; modified feedwater piping to increase SWC capacity; replacement of the scrubber with a dry electro-static precipitator; and upgraded boiler controls. With the deployment of these upgrades, the No. 2 HFB achieved the targeted biomass steaming rate of 400,000 lb/h, along with lowered stack gas and combustion air temperatures. All mandated emissions limit tests at 500,000 lb/h of steam with 400,000 lb/h of biomass steam were passed, and Domtar reports a 10% reduction in fuel firing rates, which represents significant fuel savings. In addition, the mill was able to decommission the No. 1 HFB, which has substantially lowered operating and maintenance costs.
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Sucahyo, Lilis. "PERFORMANCE ANALYSIS OF WORKING FLUIDS ON ORGANIC RANKIE CYCLE (ORC) MODEL WITH BIOMASS ENERGY AS A HEAT SOURCES." Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering) 8, no. 3 (September 30, 2019): 175. http://dx.doi.org/10.23960/jtep-l.v8i3.175-186.
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Organic Rankine Cycle (ORC) is an electricity power technology particularly suitable for medium-low temperature heat sources and/or for small available termal power. This paper presents the simulation and performance analysis of working fluids R-134a, R-414B, R-404A and R-407C on ORC with biomass energy as a heat source. Simulation of the ORC system using Cycle Tempo software. The property of working fluids is obtained by using Reference Fluid Properties (Refprop). The best result performance of ORC was shown by working fluid R-404A with thermal efficiency 7.54 % and electric power output ranges between 0.075 kW. This condition operated on turbine inlet temperature at 60 oC, difference turbine working temperature of 15 oC, condensing temperature 25 oC and water boiler mass flow rate 3 lpm.
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Cihan, Ertugrul, and Barıs Kavasogullari. "Energy and exergy analysis of a combined refrigeration and waste heat driven organic Rankine cycle system." Thermal Science 21, no. 6 Part A (2017): 2621–31. http://dx.doi.org/10.2298/tsci150324002c.
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Energy and exergy analysis of a combined refrigeration and waste heat driven organic Rankine cycle system were studied theoretically in this paper. In order to complete refrigeration process, the obtained kinetic energy was supplied to the compressor of the refrigeration cycle. Turbine, in power cycle, was driven by organic working fluid that exits boiler with high temperature and pressure. Theoretical performances of proposed system were evaluated employing five different organic fluids which are R123, R600, R245fa, R141b, and R600a. Moreover, the change of thermal and exergy efficiencies were examined by changing the boiling, condensing, and evaporating temperatures. As a result of energy and exergy analysis of the proposed system, most appropriate organic working fluid was determined as R141b.
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Yang, Yongxiang, Ari Jokilaakso, Pekka Taskinen, and Markku Kytö. "Using computational fluid dynamics to modify a waste-heat boiler design." JOM 51, no. 5 (May 1999): 36–40. http://dx.doi.org/10.1007/s11837-999-0040-8.
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Naď, Martin, Zdeněk Jegla, Tomáš Létal, Pavel Lošák, and Jiří Buzík. "Thermal load non-uniformity estimation for superheater tube bundle damage evaluation." MATEC Web of Conferences 157 (2018): 02033. http://dx.doi.org/10.1051/matecconf/201815702033.
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Industrial boiler damage is a common phenomenon encountered in boiler operation which usually lasts several decades. Since boiler shutdown may be required because of localized failures, it is crucial to predict the most vulnerable parts. If damage occurs, it is necessary to perform root cause analysis and devise corrective measures (repairs, design modifications, etc.). Boiler tube bundles, such as those in superheaters, preheaters and reheaters, are the most exposed and often the most damaged boiler parts. Both short-term and long-term overheating are common causes of tube failures. In these cases, the design temperatures are exceeded, which often results in decrease of remaining creep life. Advanced models for damage evaluation require temperature history, which is available only in rare cases when it has been measured and recorded for the whole service life. However, in most cases it is necessary to estimate the temperature history from available operation history data (inlet and outlet pressures and temperatures etc.). The task may be very challenging because of the combination of complex flow behaviour in the flue gas domain and heat transfer phenomena. This paper focuses on estimating thermal load non-uniformity on superheater tubes via Computational Fluid Dynamics (CFD) simulation of flue gas flow including heat transfer within the domain consisting of a furnace and a part of the first stage of the boiler.
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Khramshina, Ekaterina A., Alexander S. Karandaev, and Rifkhat R. Khramshin. "Improving Energy Efficiency of the Variable Frequency Drive of the Forced-Draught Fan with the Two-Speed Asynchronous Motor." Applied Mechanics and Materials 792 (September 2015): 128–33. http://dx.doi.org/10.4028/www.scientific.net/amm.792.128.
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Based on the example of forced-draught fans of the GOFHWB-100 series hot water boilers (gas and oil fired hot water boilers) power supply reserves of the electric drive with two-speed asynchronous motor have been determined. The structural chart of the developed control system of the electric drive with winding changeover depending on the boiler performance is provided. The paper considers power consumption of electric drive in the variable frequency speed control mode at the motor operation on the high and low speed windings. It presents methods for calculation of energy performance based on computing the equivalent efficiency of the fluid-handling application. The analysis of the efficiency change has proved that the variable frequency control enables electric power savings at the low speed winding by 5 to 6%. The results obtained are recommended to be widely applied at the change-over of the electric drives with two-speed asynchronous motors to the variable frequency control of performance.
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Han, Jiade, Lingbo Zhu, Yiping Lu, Yu Mu, Azeem Mustafa, and Yajun Ge. "Numerical Simulation of Combustion in 35 t/h Industrial Pulverized Coal Furnace with Burners Arranged on Front Wall." Processes 8, no. 10 (October 10, 2020): 1272. http://dx.doi.org/10.3390/pr8101272.
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Coal-fired industrial boilers should operate across a wide range of loads and with a higher reduction of pollutant emission in China. In order to achieve these tasks, a physical model including two swirling burners on the front wall and boiler furnace was established for a 35 t/h pulverized coal-fired boiler. Based on Computational Fluid Dynamics (CFD) theory and the commercial software ANSYS Fluent, mathematical modeling was used to simulate the flow and combustion processes under 75% and 60% load operating conditions. The combustion characteristics in the furnace were obtained. The flue gas temperature simulation results were in good agreement with experimental data. The simulation results showed that there was a critical distance L along the direction of the furnace depth (x) and Hc along the direction of the furnace height (y) on the burner axis. When x < L, the concentration of NO decreased sharply as the height increased. When y < Hc, the NO concentration decreased sharply with an increase in the y coordinate, while increasing dramatically with an area-weighted average gas temperature increase in the swirl combustion zone. This study provides a basis for optimizing the operation of nitrogen-reducing combustion and the improvement of burner structures.
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Ovsyannik, A. V., and V. P. Kliuchinski. "Turbo-Expander Units on Low Boiling Working Fluids." ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations 64, no. 1 (February 8, 2021): 65–77. http://dx.doi.org/10.21122/1029-7448-2021-64-1-65-77.
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The article examines the possibility of increasing the efficiency of the turbo-expander cycles on low-boiling working fluids using those methods that are used for steam turbines, viz. increasing the parameters of the working fluid before the turbo-expander and using secondary overheating. Thus, four schemes of the turbo-expander cycle are considered: the one without overheating of the low-boiling working fluid, the one with single overheating of low-boiling fluid, the one with double overheating and the one with double overheating at supercritical parameters. All the studied cycles were considered with a heat exchanger at the outlet of the turbo expander, designed to heat the condensate of a low-boiling working fluid formed in the condenser of the turbo expander unit. Cycles inP–hcoordinates were built for the studied schemes. The method of thermodynamic analysis of the studied cycles based on the exergetic efficiency has been developed. The results of the research are presented in the form of Grassman-Shargut diagrams, which show exergy losses in the elements of the studied cycles on a scale, and also show the positive effect of the operation of the turbo-expander cycle in the form of electrical power. The analysis of the obtained results showed that the main losses that have a significant impact on the exergy efficiency are the losses of exergy in the recovery boiler. The increase of parameters of low-boiling working body, and the use of intermediate superheating reduce losses in the waste heat boiler and, consequently, increases exergetic efficiency of turbo-expander cycle. The turbo-expander cycle with double overheating at supercritical parameters of the low-boiling fluid is of the largest exergetic efficiency out of the schemes that have been examined.