Academic literature on the topic 'Grate steam boiler'
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Journal articles on the topic "Grate steam boiler"
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Eidensten, L., J. Yan, and G. Svedberg. "Biomass Externally Fired Gas Turbine Cogeneration." Journal of Engineering for Gas Turbines and Power 118, no. 3 (July 1, 1996): 604–9. http://dx.doi.org/10.1115/1.2816691.
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This paper is a presentation of a systematic study on externally fired gas turbine cogeneration fueled by biomass. The gas turbine is coupled in series with a biomass combustion furnace in which the gas turbine exhaust is used to support combustion. Three cogeneration systems have been simulated. They are systems without a gas turbine, with a non-top-fired gas turbine, and a top-fired gas turbine. For all systems, three types of combustion equipment have been selected: circulating fluidized bed (CFB) boiler, grate fired steam boiler, and grate fired hot water boiler. The sizes of biomass furnaces have been chosen as 20 MW and 100 MW fuel inputs. The total efficiencies based on electricity plus process heat, electrical efficiencies, and the power-to-heat ratios for various alternatives have been calculated. For each of the cogeneration systems, part-load performance with varying biomass fuel input is presented. Systems with CFB boilers have a higher total efficiency and electrical efficiency than other systems when a top-fired gas turbine is added. However, the systems with grate fired steam boilers allow higher combustion temperature in the furnace than CFB boilers do. Therefore, a top combustor may not be needed when high temperature is already available. Only one low-grade fuel system is then needed and the gas turbine can operate with a very clean working medium.
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Orang, Naz, Honghi Tran, Andy Jones, and F. Donald Jones. "Operating parameters affecting the thermal performance of biomass boilers." August 2017 16, no. 08 (2017): 453–61. http://dx.doi.org/10.32964/tj16.8.453.
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Operating data of a bubbling fluidized bed (BFB) boiler and three stoker grate (SG) biomass boilers from different pulp mills were analyzed over a 2-year period. The results show that in all cases, the thermal performance decreases markedly from 5.5 to 4 lb steam/lb dry biomass as the feedstock moisture content increases from 40% to 60%. The BFB boiler had better thermal performance, although it operated in a higher moisture content range compared with the SG boilers. Multivariate analysis was also performed on one of the SG boilers to determine operating parameters that affect thermal performance. The results show that furnace temperature, oil flow rate, and induced draft fan current positively correlate with thermal performance, while the feedstock moisture content, total air flow, and excess oxygen (O2) negatively correlate with thermal performance. This implies that when making modifications to improve thermal performance, it is important to take into account correlations among various parameters. In some cases, one positively correlated parameter might cause an increase in a negatively correlated parameter. The net effect might be a decrease in thermal performance.
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Ryabov, Georgy, Dmitry Litoun, and Eduard Dik. "Agglomeration of bed material: Influence on efficiency of biofuel fluidized bed boiler." Thermal Science 7, no. 1 (2003): 5–16. http://dx.doi.org/10.2298/tsci0301005r.
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The successful design and operation of a fluidized bed combustor requires the ability to control and mitigate ash-related problems. The main ash-related problem of biomass filing boiler is agglomeration. The fluidized bed boiler with steam capacity of 66 t/h (4 MPa, 440 ?C) was started up at the Arkhangelsk Paper-Pi dp-Plant in 2001. This boiler was manufactured by the Russian companies "Energosofin" and "Belenergomash" and installed instead of the existing boiler with mechanical grate. Some constructional elements and steam drum of existing boiler remained unchanged. The primary air fan was installed past the common air fan, which supply part of the air into 24 secondary airports. First operating period shows that the bed material is expanded and then operator should increase the primary air rate, and the boiler efficiency dramatically decreases. Tills paper presents some results of our investigations of fuel, bed and fly ash chemical compositions and other characteristics. Special experiments were carried out to optimize the bed drain flow rate. The influence of secondly air supply improvement on mixing with the main flow and boiler efficiency are given.
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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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Duo, Wenli, Ibrahim Karidio, Larry Cross, and Bob Ericksen. "Combustion and Emission Performance of a Hog Fuel Fluidized Bed Boiler With Addition of Tire Derived Fuel." Journal of Energy Resources Technology 129, no. 1 (March 1, 2006): 42–49. http://dx.doi.org/10.1115/1.2424958.
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Salt-laden hog fuel (wood waste) is burnt in a fluidized bed boiler converted from a traveling grate boiler to generate steam for a specialty paper mill. The converted boiler has a design capacity of 156t∕h of steam from hog and actual generation has varied from 76% to 107% of the design capacity. The conversion has resulted in more stable operation, more complete combustion, less ash production, reduced boiler maintenance, and lower fossil fuel consumption. Tire derived fuel (TDF) is used as a supplementary fuel. With an energy content of 31GJ∕t for TDF, as compared to 8GJ∕t for wet hog, addition of 2%–5% TDF by weight increased the bed temperature by an average of 55°C, stabilized and improved the combustion of low quality hog and high moisture content sludge. The impact of TDF addition was studied in detail. Stack emissions were tested and bottom and flyash samples were analyzed. Although TDF contains an average of 1.6% zinc and 9.2% steel wire by weight, addition of TDF did not affect total particulate emissions from the boiler. SO2 emissions were increased due to the high sulfur content of TDF (1.4%), while NOx emissions were reduced. A good correlation was obtained from the test results, showing that the addition of TDF resulted in a reduction in both the total formation and the stack emissions of dioxins and furans.
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Chang, Chia-Chi, Yen-Hau Chen, Wei-Ren Chang, Chao-Hsiung Wu, Yi-Hung Chen, Ching-Yuan Chang, Min-Hao Yuan, et al. "The emissions from co-firing of biomass and torrefied biomass with coal in a chain-grate steam boiler." Journal of the Air & Waste Management Association 69, no. 12 (October 28, 2019): 1467–78. http://dx.doi.org/10.1080/10962247.2019.1668871.
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Saari, Jussi, Ekaterina Sermyagina, Juha Kaikko, Markus Haider, Marcelo Hamaguchi, and Esa Vakkilainen. "Evaluation of the Energy Efficiency Improvement Potential through Back-End Heat Recovery in the Kraft Recovery Boiler." Energies 14, no. 6 (March 11, 2021): 1550. http://dx.doi.org/10.3390/en14061550.
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Sustainability and energy efficiency have become important factors for many industrial processes, including chemical pulping. Recently complex back-end heat recovery solutions have been applied to biomass-fired boilers, lowering stack temperatures and recovering some of the latent heat of the moisture by condensation. Modern kraft recovery boiler flue gas offers still unutilized heat recovery possibilities. Scrubbers have been used, but the focus has been on gas cleaning; heat recovery implementations remain simple. The goal of this study is to evaluate the potential to increase the power generation and efficiency of chemical pulping by improved back-end heat recovery from the recovery boiler. Different configurations of heat recovery schemes and different heat sink options are considered, including heat pumps. IPSEpro simulation software is used to model the boiler and steam cycle of a modern Nordic pulp mill. When heat pumps are used to upgrade some of the recovered low-grade heat, up to +23 MW gross and +16.7 MW net power generation increase was observed when the whole pulp mill in addition to the boiler and steam cycle is considered as heat consumer. Combustion air humidification proved to yield a benefit only when assuming the largest heat sink scenario for the pulp mill.
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Kander, Ladislav, Karel Matocha, and Jaromír Sobotka. "Relationships between Microstructural Parameters and Properties of 15NiCuMoNb5 Grade Steel Used for Special Industry Applications." Materials Science Forum 567-568 (December 2007): 381–84. http://dx.doi.org/10.4028/www.scientific.net/msf.567-568.381.
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This article is focused on optimization of fundamental utility properties and technological process of advanced low alloy steel 15NiCuMoNb5 used for power engineering mainly for production of large capacity steam boilers. Consequently problem critical locality in weld after post weld heat treatment is studied. Optimization of welding technology is proposed. Fracture behaviour of welded joint made from boiler plates 80 mm in thickness of 15NiCuMoNb5 type steel after N + T PWHT regime after welding procedure were studied. Stable crack growth measurement and evaluation of fracture toughness of base material as well as weld metal in temperature region from 0 up 350°C were carried out. Unstable cleavage fracture and fracture toughness KJc of both parts of welded joint at test temperatures cover the transition region were evaluated. The reference temperature T0 approach was used for evaluation of temperature dependence of fracture toughness in transition range.
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Rao, M. Venkateswara. "Application of Small Punch Test to Evaluate Tensile Properties of SA213T22 Grade Boiler Steel." Materials Science Forum 830-831 (September 2015): 191–94. http://dx.doi.org/10.4028/www.scientific.net/msf.830-831.191.
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Conventional tensile test methods are used for service exposed high temperature boiler tubes to evaluate the deterioration in mechanical properties such as tensile strength, yield strength and percentage elongation. The mechanical properties are required to be evaluated periodically as the boiler components undergo material degradation due to aging phenomena. The aging phenomena occurs due to continuous exposure of tubes to high temperature & pressure steam prevailing inside the tubes and high temperature exposure to corrosive combustible gases from the external surfaces within the boiler.A recent developed new technique called small punch testing has been used to evaluate the tensile properties of SA 213T22 grade steel predominantly exists in super-heater and re-heater sections of boiler. The small punch tests have been carried out on the miniature disk shaped specimens of diameter of 8.0 mm and 0.5 mm thickness extracted from both the new and service exposed tubes. Conventional uniaxial tensile tests on standard specimens from the same tube material have also been performed for comparison. The service exposed tubes showed considerable loss in mechanical properties in both the conventional and small punch test results. Correlations of tensile properties have been obtained based on the comparative analysis of both small punch and uniaxial tensile test results. Further, the study showed that an appropriate empirical relation could be generated for new and service exposed materials between both the techniques. Conventional test methods require large quantity of material removal for test samples from in-service components whereas small punch test method needs only a miniature sample extraction. This small punch test technique could also be extended to evaluate the thicker section boiler components such as pipelines and headers in the boiler as a part of remaining life assessment study. Also this technique could be a useful tool to any metallic component where large quantity of sample removal may be difficult or may not be feasible.
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Trojan, Marcin. "Computer modeling of a convective steam superheater." Archives of Thermodynamics 36, no. 1 (March 1, 2015): 125–37. http://dx.doi.org/10.1515/aoter-2015-0009.
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Abstract Superheater is for generating superheated steam from the saturated steam from the evaporator outlet. In the case of pulverized coal fired boiler, a relatively small amount of ash causes problems with ash fouling on the heating surfaces, including the superheaters. In the convection pass of the boiler, the flue gas temperature is lower and ash deposits can be loose or sintered. Ash fouling not only reduces heat transfer from the flue gas to the steam, but also is the cause of a higher pressure drop on the flue gas flow path. In the case the pressure drop is greater than the power consumed by the fan increases. If the superheater surfaces are covered with ash than the steam temperature at the outlet of the superheater stages falls, and the flow rates of the water injected into attemperator should be reduced. There is also an increase in flue gas temperature after the different stages of the superheater. Consequently, this leads to a reduction in boiler efficiency. The paper presents the results of computational fluid dynamics simulations of the first stage superheater of both the boiler OP-210M using the commercial software. The temperature distributions of the steam and flue gas along the way they flow together with temperature of the tube walls and temperature of the ash deposits will be determined. The calculated steam temperature is compared with measurement results. Knowledge of these temperatures is of great practical importance because it allows to choose the grade of steel for a given superheater stage. Using the developed model of the superheater to determine its degree of ash fouling in the on-line mode one can control the activation frequency of steam sootblowers.
Dissertations / Theses on the topic "Grate steam boiler"
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Soľár, Slavomír. "Roštový parní kotel s přirozenou cirkulací na spalování slámy z pšenice,žita a ječmene." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-232154.
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The main aim of this diploma thesis is to proceed a design of grate steam boiler for grain straw combustion with 15,6 MJ/kg of fuel efficiency. Steam power of boiler is 15 t/h, pressure of overheated steam is 5 MPa, temperature of overheated steam is 415 °C and temperature of inlet water is 125 °C. The estimation is based on proportioning of draughts and segments of boiler and on thermal computation. Verification of divergence of thermal balance is going to constate accuracy of boiler design.
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Kozák, Tomáš. "Roštový kotel s přirozenou cirkulací na spalování dřevní štěpky." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-232155.
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The thesis is dedicated to the design of the steam boiler which burns wood chips, with a natural circulation of the water. It is a grate boiler, which produces 20 t/h of the steam. The output parameters of the steam are 420 °C and 5 MPa. The feedwater temperature is 125 ° C .The thesis gradually deals with stoichiometric calculations and determines the efficiency of the boiler. Then it describes the design of the fireplace and thermal calculations of each heat transfer surfaces. The appendix includes drawings of the boiler.
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Pecháček, Michal. "Parní kotel na dřevní štěpku 25t/h, 5,5MPa, 475°C." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230874.
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The work deals with design of steam grate boiler with a output of 25 t/h, parameters of steam output p = 5.5 MPa, t = 475 °C and a temperature of feed water 105 °C. It is a boiler with natural water circulation by evaporation surfaces. Wood biomass is boiler fuel. The proposal consists of stoichiometric calculations, determination of boiler efficiency, thermal calculations and determinion geometric parameters of the boiler and its heat transfer surfaces. The boiler drawing is a part of the work.
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Szegedi, Peter. "Výroba tepla a elektrické energie ve spalovně směsného komunálního odpadu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-230117.
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This diploma thesis deals with a design of steam boiler used to incineration of mixed municipal waste. Based on the specified fuel and the required output parameters of the steam from a steam boiler is calculated stoichiometry of incineration, thermal losses and overall boiler efficiency. Other chapters of thesis are focused on construction and thermal calculation of boiler moves. Finally, this thesis is to check heat balance of the boiler.
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Lauš, Ladislav. "Roštový kotel s přirozenou cirkulací na spalování směsi dřeva a hnědého uhlí." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-232156.
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The work deals with the constructional and calculation design of the boiler for burning wood and combustion coal in scale (30/70-coal), in load 50 t/h, parameters of steam output p=7,5 MPa, t=480 °C and a temperature of feed water 105 °C. It is a boiler with natural water circulation by evaporation surfaces. In proposal first steichiometric calculations and enthalpic calculations of air and flue gas are performed. Then it is calculated heat balance, the boiler losses and the thermal efficiency is determined. After designing the combustion chamber and dimensions of pulls are determined. In last chapter the overall energy balance are checked. Drawing documentation of steam boiler is a part of the work.
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Nechvátal, Ondřej. "Kotle na spalování biomasy." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-227929.
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The aim of this diploma thesis is the construction design of the steam boiler burning biomass according to the set parametres (450°C, 5,2MPa, 5,83kg/s).There are main parts to solve and design: stoichiometry, energy balance, combustion chamber, heat-delivery surface and strenght calculation output chest of superheater.
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Malíková, Veronika. "Roštový kotel na spalování dřevní štěpky a tříděného odpadu 50t/h." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417551.
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The diploma thesis deals with the design of a grate boiler for the combustion of a mixture of RDF and wood chips with the specified output and parameters of superheated steam. The introduction consists of stoichiometric calculations and determination of the thermal efficiency of the boiler. The thesis is devoted to determining the dimensions of the boiler, heat transfer calculations, determining pressure losses, checking the heat balance and chlorine corrosion.
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Vítámvás, Zdeněk. "Parní kotel na spalování tříděného odpadu 85t/h." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229411.
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This thesis deals with a project of steam boiler to combustion of refused-derived fuel. With respect of required fuel and output parameters of the steam was worked out stoichiometry, energy loss and boiler efficiency, heat flows was allocate to individual heat exchange surfaces. The heat exchange surfaces was calculate and project in detail.
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Suchánková, Lenka. "Parní kotel na biomasu menších výkonů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-443182.
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The master's thesis describes the design of the steam boiler, which burns biomass with heat output of 6 MW. The required parameters of the steam are a temperature of 300 °C and a pressure of 2,5 MPa. The thesis is gradually devoted to stoichiometric calculations through heat losses and boiler efficiency, to the design of the combustion chambre, heat exchangers and pressure losses. Part of the thesis is drawing documentation of the boiler.
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Horký, Lukáš. "Kotle na spalování biomasy." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-227924.
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The topic of this thesis is the calculation of the steam-boiler on biomass. This thesis deals with stoichiometry, the calculation of enthalpies of combustion gas, the heat balance of the boiler and the results in fixing the efficiency of the boiler, the calculation of fire and the balance heat calculation of component parts of the boiler. Onward follow detailed calculations of particular heating surfaces. The output parametres are temperature, pressure and the amount of steam.
Conference papers on the topic "Grate steam boiler"
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Eidensten, Lars, Jinyue Yan, and Gunnar Svedberg. "Biomass Externally Fired Gas Turbine Cogeneration." In ASME 1994 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1994. http://dx.doi.org/10.1115/94-gt-345.
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This paper is a presentation of systematic study on externally fired gas turbine cogeneration fueled by biomass. The gas turbine is coupled in series with a biomass combustion furnace in which the gas turbine exhaust is used to support combustion. Three cogeneration systems have been simulated. They are systems without a gas turbine, with a non top-fired gas turbine, and a top-fired gas turbine. For all systems, three types of combustion equipment have been selected: circulating fluidized bed (CFB) boiler, grate fired steam boiler and grate fired hot water boiler. The sizes of biomass furnaces have been chosen 20 MW and 100 MW fuel inputs. The total efficiencies based on electricity plus process heat, electrical efficiencies, and the power-to-heat ratios for various alternatives have been calculated. For each of the cogeneration systems, part load performance with varying biomass fuel input is presented. Systems with CFB boilers have a higher total efficiency and electrical efficiency than other systems when a top-fired gas turbine is added. However, the systems with grate fired steam boilers allow higher combustion temperature in the furnace than CFB boilers do. Therefore, a top combustor may not be needed when high temperature is already available. Only one low grade fuel system is then needed and the gas turbine can operate with very clean working medium.
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Sohnemann, Jens, Walter Schäfers, and Armin Main. "Waste Combustion Technology Developments for Large Scale Plants." In 20th Annual North American Waste-to-Energy Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/nawtec20-7035.
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For the waste disposal of urban areas and major cities at the North American market place rather large scale energy from waste (EfW) plants are needed. This implies a mechanical input of approx. 40 Mg/h [39.36 tn l./h] and thermal input by waste per unit of 110 MW [375.3 MBTU/h] and more. There are basic design criteria that feature large scale EfW plants: - Layout of boiler with horizontal or vertical orientation of convective part. - Top or bottom suspension of boiler. - Flexible design of stoker regarding large throughput figures and heating values of waste with water or air cooled grate bars. - Design and geometry of combustion furnace in order to optimize the flow pattern. - Optimization of boiler steel structure: integrated steel structure for boiler and boiler house enclosure. - Optimization of corrosion protection and maintainability of large scale boilers: cladding versus refractory lining. - Maintenance aspects of the boiler. The paper gives information on the pros and cons regarding the design features with special focus on optimized solutions for large scale EfW plants. For the core component of the combustion system — the grate — Fisia Babcock Environment (FBE) is using forward moving grates as well as roller grates. The moving grate in STEINMÜLLER design, which is used in the great majority of all our plants, has specific characteristics for providing uniform combustion and optimal burnout. The automatic combustion rate control system is the key component in the combustion process in order to receive good burn out quality in slag and flue gas as well as constant steam production and oxygen content of flue gas. This paper includes a detailed report on a modern control system with focus on a simple and efficient control structure. Besides these measures regarding the combustion process, this paper also reports about the respective aspects and concepts for the flue gas cleaning systems. In this field the FBE CIRCUSORB® process was presented in previous papers and is now compared with a multistage wet flue gas cleaning system. The latter is relevant in case of very low emission requirements.
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Pethe, Samit J., Chris Dayton, Marcel D. Berz, and Tim Peterson. "Elements of a Successful Waste-to-Energy Boiler Upgrade." In 17th Annual North American Waste-to-Energy Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/nawtec17-2373.
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Great River Energy operates a waste-to-energy plant in Elk River, Minnesota. The plant burns 850 tons per day of refuse derived fuel (RDF) in three boilers, and its three steam turbines can produce 32 MW of electricity. In the largest of the three units, the No. 3 Boiler, steam generation was restricted by carbon monoxide (CO) and nitrogen oxides (NOx) emission limits. The plant had an interest in improving the combustion performance of the unit, thereby allowing higher average RDF firing rates while staying within emissions compliance. The project was initiated by an engineering site visit and evaluation. The boiler had a history of unstable burning on the stoker grate, which required periodic natural gas co-firing to reduce CO levels. As an outcome to the evaluation, it was decided to install a new overfire air (OFA) system to improve burnout of combustible gases above the grate. Current and new OFA arrangements were evaluated via Computational Fluid Dynamics (CFD) modeling. The results illustrated the limitations of the original OFA system (comprised of multiple rows of small OFA ports on the front and rear furnace walls), which generated inadequate mixing of air and combustible gases in the middle of the boiler. The modeling illustrated the advantages of large and fewer OFA nozzles placed on the side walls in an interlaced pattern, a configuration that has given excellent performance on over 45 biomass-fired boilers of similar design upgraded by Jansen Combustion and Boiler Technologies, Inc. (JANSEN). Installation of the new OFA system was completed in April of 2008. Subsequent testing of the No. 3 Boiler showed that it could reliably meet the state emission levels for CO and NOx (200 ppm and 250 ppm, respectively, corrected to 7% dry flue gas oxygen) while generating 24% more steam than a representative five month period prior to the upgrade. This paper describes the elements that led to a successful project, including: data collection, engineering analyses, CFD modeling, system design, equipment supply, installation, operator training, and startup assistance.
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Bektache Abdeldjebar and Benmahammed Khier. "Modeling, identification for the grate boiler a comparison fuzzy logic, PID and application of overheat steam temperature." In 2007 International Conference on Control, Automation and Systems. IEEE, 2007. http://dx.doi.org/10.1109/iccas.2007.4406918.
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Pethe, Samit J., Michael L. Britt, and Scott A. Morrison. "Carbon Monoxide Emission Improvements From Combustion System Upgrades at the Wheelabrator Portsmouth Refuse Derived Fuel Plant." In 20th Annual North American Waste-to-Energy Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/nawtec20-7003.
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Wheelabrator Technologies Inc. (WTI) operates a waste-to-energy facility in Portsmouth, Virginia. At full capacity, a total of 2,000 tons/day of refuse derived fuel (RDF) can be fired in four identical boilers to generate a total of 600,000 lb/hr of steam and 60 MW of electricity. The boilers were originally designed to co-fire RDF and coal; however, coal burning capability was removed a few years after commissioning. The plant provides all of the process/heating steam and the majority of the electrical power to the nearby Norfolk Naval Shipyard. Historically, the boilers had not been able to reliably achieve carbon monoxide (CO) emissions compliance. CO emissions experienced during normal boiler operation would be more than twice the mandated emission limit. WTI’s goal was to improve the boilers’ CO emissions performance while achieving sustained boiler operation at higher steam generation and RDF firing rates. WTI contracted Jansen Combustion and Boiler Technologies, Inc. (JANSEN) to evaluate the operation of the boilers, to assess the overall feasibility of meeting WTI’s goals, and to develop design concepts to overcome boiler limitations. The project was initiated by an engineering site visit where boiler operating data was collected and evaluated to develop a baseline of boiler operation. Current and new combustion system arrangements were evaluated with Computational Fluid Dynamics (CFD) modeling. The results confirmed that the root cause of the poor CO emissions performance was the inadequate penetration and mixing of the original overfire air (OFA) system (comprised of multiple rows of small ports on the front and rear furnace walls). CFD modeling also showed increased CO emissions to result from non-uniform RDF delivery profiles generated by the original fuel distributors that were installed at a high elevation over the grate. Modeling of the furnace with larger and fewer OFA nozzles placed on the side walls in an interlaced pattern, and the installation of “new-style” RDF distributors at a lower elevation where the boiler’s original coal distributors formerly were located was shown to significantly improve CO burnout. From December 2010 to May 2011, the new combustion systems were installed on all four boilers. Subsequent testing has shown that CO levels have been lowered by more than 70% and boiler availability has been significantly improved. Nitrogen oxides (NOx) emissions, although slightly higher following the upgrade, are still within the NOx compliance limit. This paper describes the process that led to a successful project, including: data collection and analyses, CFD modeling, equipment design and supply, operator training, and start-up assistance.
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Ryabov, Georgy A., Dmitry S. Litoun, and Eduard P. Dik. "Agglomeration of Bed Material: Influence on Efficiency of Biofuel Fluidized Bed Boiler." In 17th International Conference on Fluidized Bed Combustion. ASMEDC, 2003. http://dx.doi.org/10.1115/fbc2003-037.
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The successful design and operation of a fluidized bed combustor requires the ability to control and mitigate ash-related problems. The main ash-related problem of biomass firing boiler is agglomeration. The fluidized bed boiler with steam capacity of 66 t/h (4 MPa, 440 °C) was started up at the Archangelsk Paper-Pulp-Plant in 2001. This boiler was manufactured by the Russian companies “Energosofin” and “Belenergomash” and installed instead of the existing boiler with mechanical grate. Some constructional elements and steam drum of existing boiler remained unchanged. The primary air fan was installed past the common air fan, which supply part of the air into 24 secondary air ports. First operating period shows that the bed material is expanded and then operator should increase the primary air rate, and the boiler efficiency dramatically decreases. This paper presents some results of our investigations of fuel, bed and fly ash chemical compositions and other characteristics. Special experiments were carried out to optimize the bed drain flow rate. The influence of secondary air supply improvement on mixing with the main flow and boiler efficiency are given.
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Richter, Ron. "2003 Upgrades at the GVRD Waste-to-Energy Facility." In 12th Annual North American Waste-to-Energy Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/nawtec12-2203.
Full textAbstract:
Montenay Inc. has operated the Greater Vancouver Regional District’s (GVRD) Waste-to-Energy Facility since it began commercial operation in 1988. The facility has a throughput of 720 tonnes (800 tons) per day in three lines. It utilizes Martin grate technology and dry lime injection with a reverse pulse jet fabric filter. The original facility design did not include a steam turbogenerator for energy recovery. The facility produced process steam at near saturation temperature to supply a recycle paper mill. The aging mill has reduced the fraction of steam used in recent years. This caused the GVRD and Montenay Inc. to cooperate in a major facility upgrade that began in 2001 and was completed in August of 2003. The complete project includes a turbogenerator, major boiler improvements and modernization of the boiler controls, while continuing to service the recycle paper mill.
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Main, Armin, and Thomas Maghon. "Concepts and Experiences for Higher Plant Efficiency With Modern Advanced Boiler and Incineration Technology." In 18th Annual North American Waste-to-Energy Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/nawtec18-3541.
Full textAbstract:
The efforts for reducing CO2 Emissions into atmosphere and increasing costs for fossil fuels concepts are the drivers for Energy from Waste (EfW) facilities with higher plant efficiency. In the past steam parameters for EfW were requested mainly at 40 bars and 400 °C (580 psi and 752 F). In case of coal fired power plants at the same location as the EfW facilities higher steam parameters at 90 bar, 520 °C (1305 psi, 968 F) have been used for the design of stoker and boiler. This long-term experience with higher steam parameters is the platform for the todays and future demand in higher plant efficiency. Increase in EfW plant efficiency is achievable by increasing temperature and pressure of live steam going along with optimized combustion conditions when using well proven grate technology for waste incineration. On the other hand higher steam parameters result in higher corrosion rates on the boiler tubes and the optimization of the combustion conditions are limited by the burn out quality requirements of slag and flue gas. Advantages and disadvantages have therefore to be balanced carefully. This paper will present different measures for optimized boiler and combustion conditions compared to an EfW plant with live steam at 40 bars and 400 °C (580 psi and 752 F) and 60% excess of combustion air. Plants operated at these conditions have very low maintenance costs created by corrosion of boiler tubes and show performance with very high availability. The following parameters and experiences will be evaluated: - reduction of excess air; - flue gas temperature at boiler outlet; - higher steam parameters (pressure and temperature); - heating surfaces for steam superheating in the radiation boiler section; - steam reheating; - external superheaters using auxiliary fuels. The comparison of the different methods for increasing the efficiency together with resulting technology challenges incorporates the experiences from modern EfW reference facilities built in Naples/Italy, Ruedersdorf (Berlin)/Germany and Heringen/Germany.
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Duo, Wenli, Ibrahim Karidio, Larry Cross, and Bob Ericksen. "Combustion and Emission Performance of a Hog Fuel Fluidized Bed Boiler With Addition of Tire Derived Fuel." In 17th International Conference on Fluidized Bed Combustion. ASMEDC, 2003. http://dx.doi.org/10.1115/fbc2003-016.
Full textAbstract:
Salt-laden hog fuel (wood waste) is burnt in a fluidized bed boiler converted from a travelling grate boiler to generate steam for a specialty paper mill. The converted boiler has a design capacity of 156 t/h of steam from hog and actual generation has varied from 76 to 107% of the design capacity. The conversion has resulted in more stable operation, more complete combustion, less ash production, reduced boiler maintenance, and lower fossil fuel consumption. Tire derived fuel (TDF) is used as a supplementary fuel. With an energy content of 33 GJ/t for TDF, as compared to 8 GJ/t for wet hog, addition of 2–5% TDF by weight increased the bed temperature by an average of 55°C, stabilized and improved the combustion of low quality hog and high moisture content sludge. The impact of TDF addition was studied in detail. Stack emissions were tested and bottom and fly ash samples were analyzed. Although TDF contains 1% zinc and 5 to 7% steel wire, addition of TDF did not affect total particulate emissions from the boiler. SO2 emissions were increased due to the high sulfur content of TDF (1.6%). A good correlation was obtained from the test results, showing that the addition of TDF resulted in a reduction in both the total formation and the stack emissions of dioxins and furans.
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Koralewska, Ralf. "Innovative Concepts of Conversion and High Efficiency Using MARTIN Technology." In 2013 21st Annual North American Waste-to-Energy Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/nawtec21-2706.
Full textAbstract:
Thermal treatment of waste using grate-based systems has gained world-wide acceptance as the preferred method for sustainable management of residual waste. However, in order to maintain this position and respond to new challenges and/or priorities, it is necessary to further develop innovative concepts that use safe process engineering technology in terms of climate and resource protection as well as reduction of environmental impacts. MARTIN, in collaboration with research institutes, successfully developed and optimized a multi-stage combustion process in the 1990s. Various pilot and full-scale studies and tests followed. Based on this knowledge, MARTIN and its cooperation partners COVANTA ENERGY (USA), CNIM (F) and Mitsubishi Heavy Industries (JP) developed the Very Low NOx (VLN) process as a large-scale primary measure for NOx reduction. MARTIN’s next step was to develop the Very Low NOx gasification mode (VLN-GM) process. This process has been implemented directly in continuous operation at an industrial-scale Energy-from-Waste (EfW) plant in Switzerland. In VLN-GM operation, the excess air rate in the gas above the grate is decreased from λ = 1.2 to about 0.8. The characteristics of municipal solid waste make it suitable for the generation of heat and power. While boiler concepts implemented in the past often focused on factors such as high availability, reduced downtimes and minimized maintenance costs, measures to increase the efficiency of the overall process are also growing in importance. Energy efficiency can be increased by optimizing boiler efficiency itself on the one hand, and on the other hand by improving peripheral plant devices, in particular by improving energy recovery through changes in the steam parameters. MARTIN has developed corrosion-protected wall and radiant superheater solutions, located in the upper furnace area, and installed these as prototypes in full-scale plants. As a result, steam can be heated about 35 °C (90 °F) in excess of the current state-of-the-art parameters without adversely affecting plant operation due to superheater corrosion. This paper documents that innovative concepts using MARTIN technology successfully provide solutions for a grate-based conversion technology (VLN-GM) as well as measures for increasing the energy efficiency of Energy-from-Waste plants.