WorldWideScience

Sample records for bed combustor co-firing

  1. Atmospheric fluidized-bed combustion (AFBC) co-firing of coal and hospital waste. Environmental Assessment

    Energy Technology Data Exchange (ETDEWEB)

    1993-02-01

    The proposed project involves co-firing of coal and medical waste (including infectious medical waste) in an atmospheric fluidized-bed combustor (AFBC) to safely dispose of medical waste and produce steam for hospital needs. Combustion at the design temperature and residence time (duration) in the AFBC has been proven to render infectious medical waste free of disease producing organisms. The project would be located at the Veterans Affairs (VA) Medical Center in Lebanon, Pennsylvania. The estimated cost of the proposed AFBC facility is nearly $4 million. It would be jointly funded by DOE, Veterans Affairs, and Donlee Technologies, Inc., of York, Pennsylvania, under a cooperative agreement between DOE and Donlee. Under the terms of this agreement, $3.708 million in cost-shared financial assistance would be jointly provided by DOE and the Veterans Affairs (50/50), with $278,000 provided by Donlee. The purposes of the proposed project are to: (1) provide the VA Medical Center and the Good Samaritan Hospital (GSH), also of Lebanon, Pennsylvania, with a solution for disposal of their medical waste; and (2) demonstrate that a new coal-burning technology can safely incinerate infectious medical waste, produce steam to meet hospital needs, and comply with environmental regulations.

  2. Co-firing a pressurized fluidized-bed combustion system with coal and refuse derived fuels and/or sludges. Task 16

    Energy Technology Data Exchange (ETDEWEB)

    DeLallo, M.; Zaharchuk, R.

    1994-01-01

    The co-firing of waste materials with coal in utility scale power plants has emerged as an effective approach to produce energy and manage municipal waste. Leading this approach, the atmospheric fluidized-bed combustor (AFBC) has demonstrated its commercial acceptance in the utility market as a reliable source of power burning a variety of waste and alternative fuels. The fluidized bed, with its stability of combustion, reduces the amount of thermochemical transients and provides for easier process control. The application of pressurized fluidized-bed combustor (PFBC) technology, although relatively new, can provide significant enhancements to the efficient production of electricity while maintaining the waste management benefits of AFBC. A study was undertaken to investigate the technical and economic feasibility of co-firing a PFBC with coal and municipal and industrial wastes. Focus was placed on the production of electricity and the efficient disposal of wastes for application in central power station and distributed locations. Wastes considered for co-firing include municipal solid waste (MSW), tire-derived fuel (TDF), sewage sludge, and industrial de-inking sludge. Issues concerning waste material preparation and feed, PFBC operation, plant emissions, and regulations are addressed. This paper describes the results of this investigation, presents conclusions on the key issues, and provides recommendations for further evaluation.

  3. Co-firing coal and biomass in a fluidised bed boiler

    CSIR Research Space (South Africa)

    North, BC

    2005-11-01

    Full Text Available of biomass is “CO2 Neutral”. The CSIR was approached by one of its licensees, International Combustion (Africa) Ltd (ICAL), to design the fluidised bed combustion (FBC) zone for a biomass waste and coal co-fired boiler. This boiler had been requested by a...

  4. CO-COMBUSTION OF REFUSE DERIVED FUEL WITH COAL IN A FLUIDISED BED COMBUSTOR

    Directory of Open Access Journals (Sweden)

    W. A. WAN AB KARIM GHANI

    2009-03-01

    Full Text Available Power generation from biomass is an attractive technology which utilizes municipal solid waste-based refused derived fuel. In order to explain the behavior of biomass-fired fluidized bed incinerator, biomass sources from refuse derived fuel was co-fired with coal in a 0.15 m diameter and 2.3 m high fluidized bed combustor. The combustion efficiency and carbon monoxide emissions were studied and compared with those from pure coal combustion. This study proved that the blending effect had increased the carbon combustion efficiency up to 12% as compared to single MSW-based RDF. Carbon monoxide levels fluctuated between 200-1600 ppm were observed when coal is added. It is evident from this research that efficient co-firing of biomass with coal can be achieved with minimum modification of existing coal-fired boilers.

  5. CO-FIRING COAL: FEEDLOT AND LITTER BIOMASS (CFB AND CLB) FUELS IN PULVERIZED FUEL AND FIXED BED BURNERS

    Energy Technology Data Exchange (ETDEWEB)

    Kalyan Annamalai; John Sweeten; Saqib Mukhtar; Ben Thein; Gengsheng Wei; Soyuz Priyadarsan; Senthil Arumugam; Kevin Heflin

    2003-08-28

    Intensive animal feeding operations create large amounts of animal waste that must be safely disposed of in order to avoid environmental degradation. Cattle feedlots and chicken houses are two examples. In feedlots, cattle are confined to small pens and fed a high calorie grain-diet diet in preparation for slaughter. In chicken houses, thousands of chickens are kept in close proximity. In both of these operations, millions of tons of manure are produced every year. The manure could be used as a fuel by mixing it with coal in a 90:10 blend and firing it in an existing coal suspension fired combustion systems. This technique is known as co-firing, and the high temperatures produced by the coal will allow the biomass to be completely combusted. Reburn is a process where a small percentage of fuel called reburn fuel is injected above the NO{sub x} producing, conventional coal fired burners in order to reduce NO{sub x}. The manure could also be used as reburn fuel for reducing NO{sub x} in coal fired plants. An alternate approach of using animal waste is to adopt the gasification process using a fixed bed gasifier and then use the gases for firing in gas turbine combustors. In this report, the cattle manure is referred to as feedlot biomass (FB) and chicken manure as litter biomass (LB). The report generates data on FB and LB fuel characteristics. Co-firing, reburn, and gasification tests of coal, FB, LB, coal: FB blends, and coal: LB blends and modeling on cofiring, reburn systems and economics of use of FB and LB have also been conducted. The biomass fuels are higher in ash, lower in heat content, higher in moisture, and higher in nitrogen and sulfur (which can cause air pollution) compared to coal. Small-scale cofiring experiments revealed that the biomass blends can be successfully fired, and NO{sub x} emissions will be similar to or lower than pollutant emissions when firing coal. Further experiments showed that biomass is twice or more effective than coal when

  6. Co-firing of biomass and other wastes in fluidised bed systems

    Energy Technology Data Exchange (ETDEWEB)

    Gulyurtlu, I.; Lopes, H.; Boavida, D.; Abelha, P. [INETI/DEECA, Lisboa (Portugal); Werther, J.; Hartge, E.-U.; Wischnewski, R. [TU Hamburg-Harburg (Georgia); Leckner, B.; Amand, L.-E.; Davidsson, K. [Chalmers Univ. of Technology (Sweden); Salatino, P.; Chirone, R.; Scala, F.; Urciuolo, M. [Dipartimento di Ingegneria Chimica, Universita di Napoli Frederico II and Istituto di Ricerche sulla Combustione (Italy); Oliveira, J.F.; Lapa, N.

    2006-07-01

    A project on co-firing in large-scale power plants burning coal is currently funded by the European Commission. It is called COPOWER. The project involves 10 organisations from 6 countries. The project involves combustion studies over the full spectrum of equipment size, ranging from small laboratory-scale reactors and pilot plants, to investigate fundamentals and operating parameters, to proving trials on a commercial power plant in Duisburg. The power plant uses a circulating fluidized bed boiler. The results to be obtained are to be compared as function of scale-up. There are two different coals, 3 types of biomass and 2 kinds of waste materials are to be used for blending with coal for co-firing tests. The baseline values are obtained during a campaign of one month at the power station and the results are used for comparison with those to be obtained in other units of various sizes. Future tests will be implemented with the objective to achieve improvement on baseline values. The fuels to be used are already characterized. There are ongoing studies to determine reactivities of fuels and chars produced from the fuels. Reactivities are determined not only for individual fuels but also for blends to be used. Presently pilot-scale combustion tests are also undertaken to study the effect of blending coal with different types of biomass and waste materials. The potential for synergy to improve combustion is investigated. Simultaneously, studies to verify the availability of biomass and waste materials in Portugal, Turkey and Italy have been undertaken. Techno-economic barriers for the future use of biomass and other waste materials are identified. The potential of using these materials in coal fired power stations has been assessed. The conclusions will also be reported.

  7. Measurements of dioxin emissions during co-firing in a fluidised bed

    Energy Technology Data Exchange (ETDEWEB)

    I. Gulyurtlu; A.T. Crujeira; P. Abelha; I. Cabrita [INETI, Lisbon (Portugal). Departamento de Engenharia Energetica e Controle Ambiental

    2007-09-15

    The emissions of dioxins could be considerable when fuels with high chlorine content are used, particularly in fluidised beds due to constraints to use temperatures in the range 800-900{sup o}C for other considerations. However, mixing of fuels with different characteristics may lead to a reduction in dioxin emissions. Studies are currently being undertaken at the above-mentioned department in mixing fuels of varying chlorine and sulphur contents to monitor the emissions of dioxins both in the gas and solid phases. Furthermore, the influence of certain elements like Cu in the ash in the emissions of dioxins is also studied to verify the catalytic effect. The INETI pilot-scale test facility is used for the combustion work. Two different coals, namely Colombian and Polish, are used as the base fuel. The supplementary fuels for co-firing include MBM and straw pellets. The combustion temperature is maintained at about 800-830{sup o}C range without any limestone addition. The residence time of over 2 s is respected. Results obtained by far suggest that the presence of sulphur in both fuels have a very strong effect on the eventual emissions of dioxins and the synergy regarding to reduce the dioxins below the levels permitted is possible by mixing fuels based on their characteristics. The paper reports the results obtained and evaluates the effect of fuel nature and operating conditions on the emissions of dioxins. 34 refs., 8 figs., 12 tabs.

  8. Biomass co-firing

    DEFF Research Database (Denmark)

    Yin, Chungen

    2013-01-01

    Co-firing biomass with fossil fuels in existing power plants is an attractive option for significantly increasing renewable energy resource utilization and reducing CO2 emissions. This chapter mainly discusses three direct co-firing technologies: pulverized-fuel (PF) boilers, fluidized-bed combus...

  9. Polycyclic aromatic hydrocarbon (PAH) emission from co-firing of petrochemical sludge with coal in circulating fluidized bed incinerator

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, G.; Zhao, C.S. [South East University, Nanjing (China). School of Energy & Environment

    2009-07-01

    Experimental tests of polycyclic aromatic hydrocarbon (PAH) emission characteristics from co-firing of petrochemical sludge with coal were conducted in it pilot-scale circulating fluidized bed (CFB) incinerator with the thermal input of 0.2 MW. Results showed that when the mass mixing ratio increases from 10 to 40%, PAH, especially lower molecular weight (LMW) PAH, emission increases substantially. As combustion temperature or excess air coefficient increases, PAH emission decreases at first and then increases. There is an optimum combustion temperature and excess air coefficient for inhibiting PAHs formulation. PAH emission declines significantly when the secondary air fraction is increased from 20 to 50%. The staged combustion technique of circulating fluidized beds may have the advantage of inhibiting the formation of PAHs, Some optimized operation parameters are recommended for incineration of petrochemical sludge with coal in a circulating fluidized bed incinerator.

  10. Utilisation of low grade fuels influidised bed combustors

    CSIR Research Space (South Africa)

    North, B

    2010-11-01

    Full Text Available This presentation highlights the utilisation of low grade fuels in Fluidised Bed Combustors (FBC) with regards to South African coal. It looks at types of coals and fuels tested, test facilities and examples of FBC’s at the CSIR. Benefits from...

  11. Particulate and PCDD/F emissions from coal co-firing with solid biofuels in a bubbling fluidised bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    H. Lopes; I. Gulyurtlu; P. Abelha; T. Crujeira; D. Salema; M. Freire; R. Pereira; I. Cabrita [INETI, Lisbon (Portugal). DEECA

    2009-12-15

    In the scope of the COPOWER project SES6-CT-2004 to investigate potential synergies of co-combustion of different biofuels with coal, a study of emissions of particulate matter and PCDD/F was carried out. The biofuels tested were meat and bone meal (MBM), sewage sludge biopellets (BP), straw pellets (SP), olive bagasse (OB) and wood pellets (WP). The tests performed include co-firing of 5%, 15% and 25% by weight of biofuels with coals of different origin. Both monocombustion and co-firing were carried out. Combustion tests were performed on a pilot fluidised bed, equipped with cyclones and air staging was used in order to achieve almost complete combustion of fuels with high volatile contents and to control gaseous emissions. Particulate matter emissions were isokinetically sampled in the stack and their particle size analysis was performed with a cascade impactor (Mark III). The results showed that most particles emitted were below 10 {mu}m (PM10) for all the tests, however, with the increasing share of biofuels and also during combustion of pure biofuels, especially olive bagasse, straw and MBM, very fine particles, below about 1 {mu}m were present. With the exception of sewage sludge, greater amounts of biofuels appeared to give rise to the decrease in particulate mean diameters and increase in PM percentages below 1 {mu}m. The formation of very fine particles could be related with the presence of aerosol forming elements such as K, Na (in the case of MBM) and Cl in biofuels, which even resulted in higher PM emissions when the ash content of fuels decreased. A correlation wasverified between the increase of PCDD/F with the decrease of PM mean diameter. This may be due to higher specific surface area and greater Cu concentration in the fly ashes. 33 refs., 11 figs., 4 tabs.

  12. Co-firing option of palm shell waste and Malaysian coal blends in a circulating fluidized bed

    International Nuclear Information System (INIS)

    Ahmad Hussain; Farid Nasir Ani

    2010-01-01

    Palm oil shell waste is one of the main agriculture wastes in Malaysia. In order to utilize these wastes efficiently, pyrolysis of oil-palm shell waste was first carried out using Thermogravimetric analysis (TGA). The effects of heating rate on the pyrolytic properties were investigated to evaluate its suitability for co-firing. The TGA analyses of oil palm shell waste and Malaysian coal blends suggests that there is an obvious lateral shift in the thermo grams for different heating rate. Kinetics calculations were also done using integral method. For palm shell waste powder it was found that the activation energies ranged from 112-119 kJ/mole and for the Mukah coal blends it ranged from 93.3 -100.8 kJ/mole. Combustion studies for palm shell wastes and coal blends were done in a hot circulating fluidized-bed (CFB) test rig. This is the first practical experience of using this type of rig in Malaysia. The temperature dependence on the combustion and emission behaviour were identified. The effects of variation of primary air and feed rate have also been analyzed and their influence on emissions has been established. The combustion studies of palm shell wastes were done and it was found that the emission of NO x ranged from 20-164 ppm while the CO emissions were high for some operating conditions. For the co-firing studies, the NO x and CO deceased with the percentage increase in the blending ratio of coal with palm shell waste.. The optimum blending ratio was found to be in a ratio of 40 percent coal and 60 percent Mukah coal. It was also found that Mukah coal show agglomeration behaviour with when it is blended in 80% ratio. (author)

  13. Refractory experience in circulating fluidized bed combustors, Task 7

    Energy Technology Data Exchange (ETDEWEB)

    Vincent, R.Q.

    1989-11-01

    This report describes the results of an investigation into the status of the design and selection of refractory materials for coal-fueled circulating fluidized-bed combustors. The survey concentrated on operating units in the United States manufactured by six different boiler vendors: Babcock and Wilcox, Combustion Engineering, Foster Wheeler, Keeler Dorr-Oliver, Pyropower, and Riley Stoker. Information was obtained from the boiler vendors, refractory suppliers and installers, and the owners/operators of over forty units. This work is in support of DOE's Clean Coal Technology program, which includes circulating fluidized-bed technology as one of the selected concepts being evaluated.

  14. Pulsed atmospheric fluidized-bed combustor development

    International Nuclear Information System (INIS)

    1992-05-01

    Pulsed atmospheric fluidized-bed combustion (PAFBC) is a unique and innovative coal-fueled technology that has the potential to meet these conditions and provide heat and/or process steam to small industrial, commercial, institutional and residential complexes. The potential of Pulse Atmospheric Fluidized Bed Combustion (PAFBC) technology has been amply demonstrated under the sponsorship of a previous DOE/METC contract (DE-AC21-88MC25069). The environmental performance of a coal-fired laboratory-scale system (1.5 million British Thermal Units per hour) (MMBtu/hr) significantly surpassed that of conventional bubbling and circulating fluidized-bed combustion units (see Table 1 for performance comparison). Prompted by these encouraging results in combustion, sulfur capture, emissions control, and enhanced heat transfer, Island Creek Coal Company (ICC) and Baltimore Thermal Energy Corporation expressed interest in the technology and offered to participate by providing host sites for field testing. EA's have been submitted independently for each of these field test sites. This submission addresses the preliminary testing of the PAFBC unit at Manufacturing and Technology Conversion International's (MTCI) Baltimore, MD facility

  15. Combustion of cork waste in a circulating fluidized bed combustor

    Energy Technology Data Exchange (ETDEWEB)

    Gulyurtlu, I.; Boavida, D.; Miranda, M.; Cabrita, I. [Dept. de Tecnologias de Combustao, ITE-INETI, Lisboa (Portugal); Abelha, P. [Coaltec e Ambiente, Lisboa (Portugal)

    1999-07-01

    There is currently an ongoing joint project between Portugal and Spain, which is being funded by the FAIR programme. The principal objective of the FAIR project is to investigate the application of the fluidised bed combustion (FBC) technology to burn cork wastes with the aim of overcoming the difficulties currently experienced in the cork processing industries. The combustion studies at INETI were carried out using the 300 kW{sub th} circulating fluidised bed facility. The combustor is square in cross section with each side being 0.3 m long. The combustor height is 5 m. The temperatures in the bed, the riser and that of the flue gases leaving the reactor were continuously monitored. The combustion gases leaving the reactor passed through the recycling cyclone first to capture most of particulates elutriated out of the combustor. The solid particles were intermittently collected for analysis to determine the amount of carbon present, which helped the combustion efficiency to be calculated. Instantaneous measurements of O{sub 2}, CO, CO{sub 2}, NO{sub x}, N{sub 2}O and SO{sub 2} present levels in the flue gases were also carried out. The combustion tests were done with both the cork waste dust and granular virgin cork. The difference is that cork dust gets contaminated during the process due to the use of various additives. Most of the combustion took place in the riser where the temperature was at times up to 523 K above that of the bed. The unburned carbon level was low ranging from about 1.5 to 2.% suggesting that most of the particles burned to completion in the riser. (orig.)

  16. Single particle behaviour in circulating fluidized bed combustors

    DEFF Research Database (Denmark)

    Erik Weinell, Claus

    1994-01-01

    of fuel particles in a boiler. A cold pilot scale model of a circulating fluidized bed combustor was used. Here sand was recirculated by means of air. Pressure measurements along the riser determined suspension density. A radioactive tracking facility to determined the dynamic picture of the particle...... trajectories in the simulated boiler. In the splash zone, closest to the secondary air inlet an exponential decay in the solids suspension density with the riser height was observed. A transport zone was characterized by an exponential decay in the solids suspension but with a smaller decay constant...

  17. CO-FIRING COAL, FEEDLOT, AND LITTER BIOMASS (CFB AND LFB) FUELS IN PULVERIZED FUEL AND FIXED BED BURNERS

    Energy Technology Data Exchange (ETDEWEB)

    Kalyan Annamalai; John Sweeten; Saqib Mukhtar; Ben Thien; Gengsheng Wei; Soyuz Priyadarsan

    2002-01-15

    Intensive animal feeding operations create large amounts of animal waste that must be safely disposed of in order to avoid environmental degradation. Cattle feedlots and chicken houses are two examples. In feedlots, cattle are confined to small pens and fed a high calorie grain diet in preparation for slaughter. In chicken houses, thousands of chickens are kept in close proximity. In both of these operations, millions of tons of manure are produced every year. In this project a co-firing technology is proposed which would use manure that cannot be used for fertilizer, for power generation. Since the animal manure has economic uses as both a fertilizer and as a fuel, it is properly referred to as feedlot biomass (FB) for cow manure, or litter biomass (LB) for chicken manure. The biomass will be used a as a fuel by mixing it with coal in a 90:10 blend and firing it in existing coal fired combustion devices. This technique is known as co-firing, and the high temperatures produced by the coal will allow the biomass to be completely combusted. Therefore, it is the goal of the current research to develop an animal biomass cofiring technology. A cofiring technology is being developed by performing: (1) studies on fundamental fuel characteristics, (2) small scale boiler burner experiments, (3) gasifier experiments, (4) computer simulations, and (5) an economic analysis. The fundamental fuel studies reveal that biomass is not as high a quality fuel as coal. The biomass fuels are higher in ash, higher in moisture, higher in nitrogen and sulfur (which can cause air pollution), and lower in heat content than coal. Additionally, experiments indicate that the biomass fuels have higher gas content, release gases more readily than coal, and less homogeneous. Small-scale boiler experiments revealed that the biomass blends can be successfully fired, and NO{sub x} pollutant emissions produced will be similar to or lower than pollutant emissions when firing coal. This is a surprising

  18. Bed agglomeration in fluidized combustor fueled by wood and rice straw blends

    NARCIS (Netherlands)

    Thy, P.; Jenkins, B.M.; Williams, R.B.; Lesher, C.E.; Bakker, R.R.

    2010-01-01

    Petrographic techniques have been used to examine bed materials from fluidized bed combustion experiments that utilized wood and rice straw fuel blends. The experiments were conducted using a laboratory-scale combustor with mullite sand beds, firing temperatures of 840 to 1030 °C, and run durations

  19. The Instituto de Investigaciones Electricas fluidized bed combustor; El combustor de lecho fluidizado del Instituto de Investigaciones Electricas

    Energy Technology Data Exchange (ETDEWEB)

    Milan Foressi, Julio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1991-12-31

    After synthesizing the most important aspects of the combustion technology in fluidized bed, the experimental combustor developed at the Instituto de Investigaciones Electricas (IIE) is described, as well as the test results of the experiences carried out with coal from Rio Escondido, Coahuila. [Espanol] Tras sintetizar los aspectos mas importantes de la tecnologia de combustion en lecho fluidizado, se describe el combustor experimental desarrollado en el Instituto de Investigaciones Electricas (IIE), asi como los resultados de las experiencias realizadas con carbon proveniente de Rio Escondido, Coahuila.

  20. Results of combustion and emissions testing when co-firing blends of binder-enhanced densified refuse-derived fuel (b-dRDF) pellets and coal in a 440 MW{sub e} cyclone fired combustor. Volume 3: Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Ohlsson, O.

    1994-07-01

    This report contains the data resulting from the co-firing of b-dRDF pellets and coal in a 440-MW{sub e} cyclone-fired combustor. These tests were conducted under a Collaborative Research and Development Agreement (CRADA). The CRADA partners included the U.S. Department of Energy (DOE), National Renewable Energy Laboratory (NREL), Argonne National Laboratory (ANL), Otter Tail Power Company, Green Isle Environmental, Inc., XL Recycling Corporation, and Marblehead Lime Company. The report is made up of three volumes. This volume contains other supporting information, along with quality assurance documentation and safety and test plans. With this multi-volume approach, readers can find information at the desired level of detail, depending on individual interest or need.

  1. Bed agglomeration in fluidized combustor fueled by wood and rice straw blends

    DEFF Research Database (Denmark)

    Thy, Peter; Jenkins, Brian; Williams, R.B.

    2010-01-01

    Abstract Petrographic techniques have been used to examine bed materials from fluidized bed combustion experiments that utilized wood and rice straw fuel blends. The experiments were conducted using a laboratory-scale combustor with mullite sand beds, firing temperatures of 840 to 1030 °C, and run...... areas between bed particles, ultimately led to bed agglomeration. The interfaces and the presence of gas bubbles in the cement suggest a bonding material with a high surface tension and a liquid state. The cement films originate by filling of irregularities on individual and partially agglomerated bed...

  2. Combustion of peanut shells in a cone-shaped bubbling fluidized-bed combustor using alumina as the bed material

    International Nuclear Information System (INIS)

    Arromdee, Porametr; Kuprianov, Vladimir I.

    2012-01-01

    Highlights: ► We propose burning of peanut shells in a conical fluidized bed using alumina sand. ► We examine hydrodynamic, combustion and emission characteristics of the reactor. ► High, over 99%, combustion efficiency is achievable. ► Emissions of CO and NO from the combustor meet the national emission limits. ► Composition of the bed material undergoes significant changes during the combustion. -- Abstract: This paper reports experimental studies on burning peanut shells in the conical fluidized-bed combustor using alumina sand as the fluidizing agent. Prior to combustion tests, hydrodynamic regimes and characteristics of a conical alumina–biomass bed were investigated under cold-state conditions for variable percentage of peanut shells in the mixture and static bed height. With selected particle sizes (300–500 μm) and static bed height (30 cm), alumina ensured bubbling fluidization regime of the bed at operating conditions specified for firing biomass. Combustion tests were performed at 60 kg/h and 45 kg/h fuel feed rates, while ranging excess air from 20% to 80% at a fixed combustor load. Temperature and gas concentrations (O 2 , CO, C x H y as CH 4 , and NO) were measured along radial and axial directions inside the reactor as well as at stack in order to characterize combustion and emission performance of the combustor for the ranges of operating conditions. For firing 60 kg/h peanut shells, excess air of 40% can be selected as an appropriate value ensuring high, about 99%, combustion efficiency and rather low emissions of CO and NO: 520 ppm and 125 ppm, respectively (both on a dry basis and at 6% O 2 ). With reducing combustor load, the combustion efficiency and emission characteristics were improved to a little extent. No evidence of bed agglomeration was found during 30-h combustion tests on this conical fluidized-bed combustor using alumina sand as the bed material. However, the timescale effect on the composition of the bed material was

  3. OPTIMIZATION OF DESIGN PARAMETERS OF A STIRLING GENERATOR FOR USE WITH A FLUIDIZED BED COMBUSTOR

    OpenAIRE

    Lombardi, Simone; Bizon, Katarzyna; Marra, Francesco; Continillo, Gaetano

    2012-01-01

    This work investigates the possibility to place the head of a Stirling engine, more specifically the elements of the hot side heat exchanger, in direct contact with the sand of a Fluidized Bed Combustor. This choice is primarily suggested by the heat exchange coefficients between the multiphase fluidized bed medium and the surface of the heat exchanger, much larger than those attained when the heat exchanger is located in the stream of hot flue gases. Moreover, the mechanical action exerted b...

  4. The combustion of low calorific value fuels (oil shale) by using fluidized bed combustor

    International Nuclear Information System (INIS)

    Azzam, S.M.

    1993-01-01

    The present work reports an experimental data for combustion of oil-shale in a fluidized bed combustor. The experimental set up was designed for the combustion of low calorific value fuel such as oil-shale to facilitate the variation of many parameters over a wide operating range. A cold run was firstly conducted to study the fluidization parameters. Fluidization experiment were made with different sized quartiz particles. Minimum fluidization velocities and other fluidization characteristics were determined at room temperature. Secondary a hot run was started, first studying the combustion of 'LPG' in a fluidized bed as a starting process, then studying the combustion if oil-shale with different flow rates. The experimetal results are promising and give rise to hopes that this valuable deposit can be used as a fuel source and can be burned sucessfully in a fluidized bed combustor. This study had prooved that utilization of oil-shale a fuel source is no more a complicated technical problem, this opens the way for power generation using fluidized bed combustors. (author). 17 refs., 32 figs., 3 tabs

  5. Air Distributor Designs for Fluidized Bed Combustors: A Review

    Directory of Open Access Journals (Sweden)

    A. Shukrie

    2016-06-01

    Full Text Available Fluidized bed combustion (FBC has been recognized as one of the suitable technologies for converting a wide variety of biomass fuels into energy. One of the key factors affecting the successful operation of fluidized bed combustion is its distributor plate design. Therefore, the main purpose of this article is to provide a critical overview of the published studies that are relevant to the characteristics of different fluidized bed air distributor designs. The review of available works display that the type of distributor design significantly affects the operation of the fluidized bed i.e., performance characteristics, fluidization quality, air flow dynamics, solid pattern and mixing caused by the direction of air flow through the distributors. Overall it is observed that high pressure drop across the distributor is one of the major draw backs of the current distributor designs. However, fluidization was stable in a fluidized bed operated at a low perforation ratio distributor due to the pressure drop across the distributor, adequate to provide uniform gas distribution. The swirling motion produced by the inclined injection of gas promotes lateral dispersion and significantly improves fluidization quality. Lastly, the research gaps are highlighted for future improvement consideration on the development of efficient distributor designs.

  6. Co-combustion of waste with coal in a circulating fluidised bed combustor

    Energy Technology Data Exchange (ETDEWEB)

    Gulyurtlu, I.; Boavida, D.; Abelha, P.; Lopes, H.; Cabrita, I. [DEECA-INETI, Lisboa (Portugal)

    2002-07-01

    The results of a study of cocombustion of waste with coal is described. Various wastes (biomass, sludge, and refuse derived fuel) were burned with coal in a circulating fluidised bed combustor. Conditions that prevent segregated combustion, reduce production of nitrogen oxides, and attain high combustion efficiency were studied. The effects of variations in air staging in the riser, mixing of air with volatiles, coal/biomass ratio, methods of feeding biomass, and temperature are described. 5 refs., 3 figs., 5 tabs.

  7. Combustion of peanut and tamarind shells in a conical fluidized-bed combustor: a comparative study.

    Science.gov (United States)

    Kuprianov, Vladimir I; Arromdee, Porametr

    2013-07-01

    Combustion of peanut and tamarind shells was studied in the conical fluidized-bed combustor using alumina sand as the bed material to prevent bed agglomeration. Morphological, thermogravimetric and kinetic characteristics were investigated to compare thermal and combustion reactivity between the biomass fuels. The thermogravimetric kinetics of the biomasses was fitted using the Coats-Redfern method. Experimental tests on the combustor were performed at 60 and 45 kg/h fuel feed rates, with excess air within 20-80%. Temperature and gas concentrations were measured along radial and axial directions in the reactor and at stack. The axial temperature and gas concentration profiles inside the combustor exhibited sensible effects of fuel properties and operating conditions on combustion and emission performance. High (≈ 99%) combustion efficiency and acceptable levels of CO, CxHy, and NO emissions are achievable when firing peanut shells at excess air of about 40%, whereas 60% is more preferable for burning tamarind shells. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Refractory experience in circulating fluidized bed combustors, Task 7. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Vincent, R.Q.

    1989-11-01

    This report describes the results of an investigation into the status of the design and selection of refractory materials for coal-fueled circulating fluidized-bed combustors. The survey concentrated on operating units in the United States manufactured by six different boiler vendors: Babcock and Wilcox, Combustion Engineering, Foster Wheeler, Keeler Dorr-Oliver, Pyropower, and Riley Stoker. Information was obtained from the boiler vendors, refractory suppliers and installers, and the owners/operators of over forty units. This work is in support of DOE`s Clean Coal Technology program, which includes circulating fluidized-bed technology as one of the selected concepts being evaluated.

  9. Effect of flue gas recirculation on heat transfer in a supercritical circulating fluidized bed combustor

    Directory of Open Access Journals (Sweden)

    Błaszczuk Artur

    2015-09-01

    Full Text Available This paper focuses on assessment of the effect of flue gas recirculation (FGR on heat transfer behavior in 1296t/h supercritical coal-fired circulating fluidized bed (CFB combustor. The performance test in supercritical CFB combustor with capacity 966 MWth was performed with the low level of flue gas recirculation rate 6.9% into furnace chamber, for 80% unit load at the bed pressure of 7.7 kPa and the ratio of secondary air to the primary air SA/PA = 0.33. Heat transfer behavior in a supercritical CFB furnace between the active heat transfer surfaces (membrane wall and superheater and bed material has been analyzed for Geldart B particle with Sauter mean diameters of 0.219 and 0.246 mm. Bed material used in the heat transfer experiments had particle density of 2700 kg/m3. A mechanistic heat transfer model based on cluster renewal approach was used in this work. A heat transfer analysis of CFB combustion system with detailed consideration of bed-to-wall heat transfer coefficient distributions along furnace height is investigated. Heat transfer data for FGR test were compared with the data obtained for representative conditions without recycled flue gases back to the furnace through star-up burners.

  10. Spectral methods applied to fluidized bed combustors. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R.C.; Christofides, N.J.; Junk, K.W.; Raines, T.S.; Thiede, T.D.

    1996-08-01

    The objective of this project was to develop methods for characterizing fuels and sorbents from time-series data obtained during transient operation of fluidized bed boilers. These methods aimed at determining time constants for devolatilization and char burnout using carbon dioxide (CO{sub 2}) profiles and from time constants for the calcination and sulfation processes using CO{sub 2} and sulfur dioxide (SO{sub 2}) profiles.

  11. Combustion of poultry litter in a fluidised bed combustor

    Energy Technology Data Exchange (ETDEWEB)

    P. Abelha; I. Gulyurtlu; D. Boavida; J. Seabra Barros; I. Cabrita; J. Leahy; B. Kelleher; M. Leahy [DEECA-INETI, Lisbon (Portugal)

    2003-04-01

    Combustion studies of poultry litter alone or mixed with peat by 50% on weight basis were undertaken in an atmospheric bubbling fluidised bed. Because of high moisture content of poultry litter, there was some uncertainty whether the combustion could be sustained on 100% poultry litter and as peat is very available in Ireland, its presence was considered to help to improve the combustion. However, the results showed that, as long as the moisture content of poultry litter was kept below 25%, the combustion did not need the addition of peat. The main parameters that were investigated are (i) moisture content, (ii) air staging, and (iii) variations in excess air levels along the freeboard. The main conclusions of the results are (i) combustion was influenced very much by the conditions of the fuel supply, (ii) the steady fuel supply was strongly dependent on the moisture content of the poultry litter, (iii) temperature appeared to be still very influential in reducing the levels of unburned carbon and hydrocarbons released from residues, (iv) the air staging in the freeboard improved combustion efficiency by enhancing the combustion of volatiles released from residues in the riser and (vi) NOx emissions were influenced by air staging in the freeboard. Particles collected from the bed and the two cyclones were analysed to determine the levels of heavy metals and the leachability tests were carried out with ashes collected to verify whether or not they could safely be used in agricultural lands. 8 refs., 1 fig., 8 tabs.

  12. Experimental studies on pulp and paper mill sludge ash behavior in fluidized bed combustors

    Energy Technology Data Exchange (ETDEWEB)

    Latva-Somppi, J. [VTT Chemical Technology, Espoo (Finland). Process Technology

    1998-11-01

    Ash formation during the fluidized bed combustion (FBC) of pulp and paper mill sludges has been experimentally studied on an industrial and bench scale. The methods included aerosol measurements, chemical and crystalline composition analyses, thermogravimetry and electron microscopy. Fly ash mass and number size distributions and elemental enrichment in submicron particles and bottom ash were measured. Fly ash, bottom ash and ash deposits were characterized and their formation mechanisms are discussed. During combustion the fine paper-making additives in sludge, clay minerals and calcite, sintered fanning porous agglomerates. The fly ash mass mean size was 7.5 - 15 lam and the supermicron particles included 93.6 - 97.3 % of the fly ash. Condensation of the volatilized inorganic species formed spherical submicron particles in the fly ash. Their mass concentration was almost negligible when co-firing paper mill sludges and wood. This suggests that the fraction of the volatilized inorganic species in the paper mill sludges was low. Results from pulp mill sludge and bark co-firing were different. A clear mass mode below 0.3 pm, presenting 2.2 - 5.0 weight-% of the fly ash was detected. The condensed species included K, Na, S and Cl. Their mass fraction was higher in the pulp mill sludge than in the paper mill sludge. Evidently this resulted in increased volatilization and formation of condensed particles. The following trace elements were enriched in the submicron ash during pulp mill sludge and wood co-firing: As, Cd, Rb and Pb. The main part of the volatile species was, however, captured in the bulk ash. Presumably, this was due to the high surface area concentration in the bulk ash. Sludge moisture was observed to reduce the inorganic species volatilization. Probably steam vaporization from the wet sludge through the burning layer decreased combustion temperatures on char surface and less char was produced. Hence, the volatilization of ash forming species was

  13. Staged fluidized-bed coal combustor for boiler retrofit

    International Nuclear Information System (INIS)

    Rehmat, A.; Dorfman, L.; Shibayama, G.; Waibel, R.

    1991-01-01

    The Advanced Staged Fluidized-Bed Coal Combustion System (ASC) is a novel clean coal technology for either coal-fired repowering of existing boilers or for incremental power generation using combined-cycle gas turbines. This new technology combines staged combustion for gaseous emission control, in-situ sulfur capture, and an ash agglomeration/vitrification process for the agglomeration/vitrification of ash and spent sorbent, thus rendering solid waste environmentally benign. The market for ASC is expected to be for clean coal-fired repowering of generating units up to 250 MW, especially for units where space is limited. The expected tightening of the environmental requirements on leachable solids residue by-products could considerably increase the marketability for ASC. ASC consists of modular low-pressure vessels in which coal is partially combusted and gasified using stacked fluidized-bed processes to produce low-to-medium-Btu, high-temperature gas. This relatively clean fuel gas is used to repower/refuel existing pulverized-coal, natural gas, or oil-fired boilers using bottom firing and reburning techniques. The benefits of ASC coal-fired repowering include the ability to repower boilers without obtaining additional space while meeting the more stringent environmental requirements of the future. Low NO x , SO x , and particulate levels are expected while a nonleachable solid residue with trace metal encapsulation is produced. ASC also minimizes boiler modification and life-extension expenditures. Repowered efficiencies can be restored to the initial operating plant efficiency, and the existing boiler capacity can be increased by 10%. Preliminary cost estimates indicate that ASC will have up to a $250/kW capital cost advantage over existing coal-fired repowering options. 4 figs., 4 tabs

  14. Thermo-hydrodynamic design of fluidized bed combustors estimating metal wastage

    CERN Document Server

    Lyczkowski, Robert W; Bouillard, Jacques X; Folga, Stephen M

    2012-01-01

    Thermo-Hydrodynamic Design of Fluidized Bed Combustors: Estimating Metal Wastage is a unique volume that finds that the most sensitive parameters affecting metal wastage are superficial fluidizing velocity, particle diameter, and particle sphericity.  Gross consistencies between disparate data sources using different techniques were found when the erosion rates are compared on the same basis using the concept of renormalization.  The simplified mechanistic models and correlations, when validated, can be used to renormalize any experimental data so they can be compared on a consistent basis using a master equation.

  15. Energy extraction from wine dregs by self-sustained burning with fluidized-bed combustor

    Energy Technology Data Exchange (ETDEWEB)

    Leu, J.H. [Yu-Da Inst. of Business Technology, Taiwan (China). Dept. of Marketing and Logistics Management; Chung, Y.N.; Pan, T.S.; Chen, C.S. [Dayeh Univ., Taiwan (China). Dept. of Electrical Engineering

    2005-07-01

    Wine dregs typically have moisture contents of between 70 and 80 per cent, and the disposal of wine dregs in Taiwan is both costly and time-consuming. This paper described a method of extracting energy from wine dregs through the use of a pre-drying technique with a fluidized bed technology. A bubble-type fluidized bed combustor was used to combust high moisture Chinese Kaoliang wine lees. The system consisted of an incinerator, a feeding system, a heat recovery system, and an air pollution control system. Results of the experimental study showed that 92.3 per cent combustion was achieved for the wine lees at temperatures of 860 degrees C. Sulfur oxide (SO{sub x}) emissions and nitrogen oxide (NO{sub x}) emissions were negligible. Carbon monoxide (CO) emissions were suppressed to 92 ppm by modulating operating temperatures, axial temperature distributions, and primary and excess air. 3 refs., 3 tabs., 7 figs.

  16. Synthetic sorbents for removal of sulfur dioxide in fluidized-bed coal combustors. [25 refs

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, R.B.; Wilson, W.I.; Johnson, I.; Jonke, A.A.

    1977-06-01

    Synthetic sorbents have been investigated for use in place of limestone for SO/sub 2/ emission control in fluidized-bed coal combustors. Sorbents prepared by impregnation of porous alumina with alkali metal or alkaline earth oxides were studied. The most promising sorbent was found to be calcium oxide in alumina. However, the SO/sub 2/ reactivity of this synthetic sorbent was less than that for a moderately reactive limestone. Hence, a greater quantity of synthetic sorbent would be needed to meet SO/sub 2/ emission standards. The attrition resistance of this synthetic sorbent was found to be greater than that of natural stones; therefore, a larger number of cycles of use would be expected. It is estimated that the use of this synthetic sorbent would reduce the amount of waste sorbent to about one-sixth the amount expected using a moderately reactive once-through limestone. The cost of using this synthetic sorbent is estimated to be about three and a half times the cost expected using once-through limestone. This cost is considered to be too large in view of the expected modest decrease in environmental impact. The synthetic sorbents developed in this study are therefore not considered viable alternatives for limestone in fluidized-bed coal combustors.

  17. EXPERIMENTAL STUDY OF HIGH LEVELS OF SO2 REMOVAL IN ATMOSPHERIC-PRESSURE FUIDIZED-BED COMBUSTORS

    Science.gov (United States)

    The report describes tests conducted in an atmospheric-pressure-fluidized-bed combustor (FBC) with a cross-section of 1 x 1.6 m) to demonstrate high levels of S02 removal when burning a high-sulfur coal and feeding limestone sorbent for S02 removal. The goal was to achieve 90-plu...

  18. Experimental investigations of extracted rapeseed combustion emissions in a small scale stationary fluidized bed combustor

    Energy Technology Data Exchange (ETDEWEB)

    Dinh Tung, N.; Steinbrecht, D. [Rostock University, Faculty of Mechanical Engineering and Marine Technology, Chair of Environmental Technology, Justus-von-Liebig-Weg 6, D - 18059 Rostock (Germany); Tung, N. D. [Hanoi University of Agriculture- Hanoi/Vietnam, Faculty of Mechanical Engineering, Trau Quy - Gia Lam - Hanoi (Viet Nam); Vincent, T. [Rostock University, Chair of Energy Systems, Justus-von-Liebig-Weg 6, D - 18059 Rostock (Germany)

    2009-07-01

    The objective of this study was to observe the combustion process of extracted rapeseed (ER) grist in a stationary fluidized bed combustor (SFBC) and evaluate the chemical compositions of the flue gas emissions. The experimental tests of ER combustion in the 90 to 200 kW SFB combustion test facility show that the optimal ER combustion temperature is within the range from 850 to 880 {sup o}C. Temperature and the concentration of exhausted emissions (e.g. O{sub 2}, CO, CO{sub 2}, NO, NO{sub 2}, SO{sub 2}, C{sub org}) were measured with dedicated sensors distributed within the combustor, along its height and in the flue gas duct. The experimental results showed that with respect to German emission limits the concentration of SO{sub 2} and NO{sub x} in the flue gas were high whereas that of CO was low. This study furthermore is applicable for the abundant biomass residue resources in Vietnam (rice husk, rice straw, bagasse, cassava residues, coconut shell etc.), which have similar chemical compositions to ER. (author)

  19. Experimental Investigations of Extracted Rapeseed Combustion Emissions in a Small Scale Stationary Fluidized Bed Combustor

    Directory of Open Access Journals (Sweden)

    Dieter Steinbrecht

    2009-02-01

    Full Text Available The objective of this study was to observe the combustion process of extracted rapeseed (ER grist in a stationary fluidized bed combustor (SFBC and evaluate the chemical compositions of the flue gas emissions. The experimental tests of ER combustion in the 90 to 200 kW (Kilowatt SFB combustion test facility show that the optimal ER combustion temperature is within the range from 850 to 880° C. Temperature and the concentration of exhausted emissions (e.g. O2, CO, CO2, NO, NO2, SO2, Corg were measured with dedicated sensors distributed within the combustor, along its height and in the flue gas duct. The experimental results showed that with respect to German emission limits the concentration of SO2 and NOx in the flue gas were high whereas that of CO was low. This study furthermore is applicable for the abundant biomass residue resources in Vietnam (rice husk, rice straw, bagasse, cassava residues, coconut shell etc., which have similar chemical compositions to ER.

  20. Biomass Fuel and Combustion Conditions Selection in a Fixed Bed Combustor

    Directory of Open Access Journals (Sweden)

    María E. Arce

    2013-11-01

    Full Text Available The biomass market has experienced an increase in development, leading to research and development efforts that are focused on determining optimal biofuel combustion conditions. Biomass combustion is a complex process that involves divergent parameters and thus requires the use of advanced analysis methods. This study proposes combining grey relational analysis (GRA and error propagation theory (EPT to select a biofuel and its optimal combustion conditions. This research will study three biofuels that are currently used in a region of South Europe (Spain, and the most important variables that affect combustion are the ignition front propagation speed and the highest temperature that is reached at the fixed bed combustor. The results demonstrate that a combination of both theories for the analysis of solid-state thermochemical phenomena enables a fast and simple way of choosing the best configuration for each fuel.

  1. Sampling related issues in pod-based model reduction of simplified circulating fluidised bed combustor model

    Directory of Open Access Journals (Sweden)

    Bizon Katarzyna

    2015-09-01

    Full Text Available Over the last decades the method of proper orthogonal decomposition (POD has been successfully employed for reduced order modelling (ROM in many applications, including distributed parameter models of chemical reactors. Nevertheless, there are still a number of issues that need further investigation. Among them, the policy of the collection of representative ensemble of experimental or simulation data, being a starting and perhaps most crucial point of the POD-based model reduction procedure. This paper summarises the theoretical background of the POD method and briefly discusses the sampling issue. Next, the reduction procedure is applied to an idealised model of circulating fluidised bed combustor (CFBC. Results obtained confirm that a proper choice of the sampling strategy is essential for the modes convergence however, even low number of observations can be sufficient for the determination of the faithful dynamical ROM.

  2. Coal desulfurization in a rotary kiln combustor

    Energy Technology Data Exchange (ETDEWEB)

    Cobb, J.T. Jr.

    1990-08-15

    BCR National Laboratory (BCRNL) has initiated a project aimed at evaluating the technical and economic feasibility of using a rotary kiln, suitably modified, to burn Pennsylvania anthracite wastes, co-fired with high-sulfur bituminous coal. Limestone will be injected into the kiln for sulfur control, to determine whether high sulfur capture levels can be achieved with high sorbent utilization. The principal objectives of this work are: (1) to prove the feasibility of burning anthracite refuse, with co-firing of high-sulfur bituminous coal and with limestone injection for sulfur emissions control, in a rotary kiln fitted with a Universal Energy International (UEI) air injector system; (2) to determine the emissions levels of SO{sub x} and NO{sub x} and specifically to identify the Ca/S ratios that are required to meet New Source Performance Standards; (3) to evaluate the technical and economic merits of a commercial rotary kiln combustor in comparison to fluidized bed combustors; and, (4) to ascertain the need for further work, including additional combustion tests, prior to commercial application, and to recommend accordingly a detailed program towards this end.

  3. Radiative heat transfer in strongly forward scattering media of circulating fluidized bed combustors

    Science.gov (United States)

    Ates, Cihan; Ozen, Guzide; Selçuk, Nevin; Kulah, Gorkem

    2016-10-01

    Investigation of the effect of particle scattering on radiative incident heat fluxes and source terms is carried out in the dilute zone of the lignite-fired 150 kWt Middle East Technical University Circulating Fluidized Bed Combustor (METU CFBC) test rig. The dilute zone is treated as an axisymmetric cylindrical enclosure containing grey/non-grey, absorbing, emitting gas with absorbing, emitting non/isotropically/anisotropically scattering particles surrounded by grey diffuse walls. A two-dimensional axisymmetric radiation model based on Method of Lines (MOL) solution of Discrete Ordinates Method (DOM) coupled with Grey Gas (GG)/Spectral Line-Based Weighted Sum of Grey Gases Model (SLW) and Mie theory/geometric optics approximation (GOA) is extended for incorporation of anisotropic scattering by using normalized Henyey-Greenstein (HG)/transport approximation for the phase function. Input data for the radiation model is obtained from predictions of a comprehensive model previously developed and benchmarked against measurements on the same CFBC burning low calorific value indigenous lignite with high volatile matter/fixed carbon (VM/FC) ratio in its own ash. Predictive accuracy and computational efficiency of nonscattering, isotropic scattering and forward scattering with transport approximation are tested by comparing their predictions with those of forward scattering with HG. GG and GOA based on reflectivity with angular dependency are found to be accurate and CPU efficient. Comparisons reveal that isotropic assumption leads to under-prediction of both incident heat fluxes and source terms for which discrepancy is much larger. On the other hand, predictions obtained by neglecting scattering were found to be in favorable agreement with those of forward scattering at significantly less CPU time. Transport approximation is as accurate and CPU efficient as HG. These findings indicate that negligence of scattering is a more practical choice in solution of the radiative

  4. Co-combustion of risk husk with coal in a fluidized bed

    International Nuclear Information System (INIS)

    Ghani, A.K.; Alias, A.B.; Savory, R.M.; Cliffe, K.R.

    2006-01-01

    Power generation from biomass is an attractive technology which utilizes agricultural residue waste. In order to explain the behavior of biomass-fired fluidized bed incinerator, biomass sources from agricultural residues (rice husk) was co-fired with coal in a 0.15 m diameter and 2.3 m high fluidized bed combustor. The combustion efficiency and CO emissions were studied and compared with those for pure coal combustion. Biomass waste with up to 70% mass fraction can be co-combusted in a fluidized bed combustor designed for coal combustion with a maximum drop of efficiency of 20% depending upon excess air levels. CO levels fluctuated between 200-700 ppm were observed when coal is added. It is evident from this research that efficient co-firing of rice husk with coal can be achieved with minimum modification of existing coal-fired boilers. (Author)

  5. Effect of Air Staging Ratios on the Burning Rate and Emissions in an Underfeed Fixed-Bed Biomass Combustor

    Directory of Open Access Journals (Sweden)

    Araceli Regueiro

    2016-11-01

    Full Text Available This experimental work studies a small-scale biomass combustor (5–12 kW with an underfed fixed bed using low air staging ratios (15%–30%. This document focuses on the influence of the operative parameters on the combustion process, so gaseous emissions and the distribution and concentration of particulate matter have also been recorded. The facility shows good stability and test repeatability. For the studied airflow ranges, the results show that increasing the total airflow rate does not increase the overall air excess ratio because the burning rate is proportionally enhanced (with some slight differences that depend on the air staging ratio. Consequently, the heterogeneous reactions at the bed remain in the so-called oxygen-limited region, and thus the entire bed operates under sub-stoichiometric conditions with regards of the char content of the biomass. In addition, tests using only primary air (no staging may increase the fuel consumption, but in a highly incomplete way, approaching a gasification regime. Some measured burning rates are almost 40% higher than previous results obtained in batch combustors due to the fixed position of the ignition front. The recorded concentration of particulate matter varies between 15 and 75 mg/Nm3, with a main characteristic diameter between 50 and 100 nm.

  6. Simultaneous reduction of NOx, N{sub 2}O, SO{sub 2} emissions from a fluidized bed coal combustor using alternative bed material

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, T.; Asazuma, J.; Shinkai, M.; Matsunaga, S.; Yamagiwa, K.; Fujiwara, N. [Niigata University, Niigata (Japan). Dept. of Chemistry & Chemical Engienering

    2003-07-01

    A kind of porous alumina was employed as bed material of bubbling fluidized bed coal combustion instead of non-porous silica sand. The effect of the bed material on emissions of N{sub 2}O and NOx was evaluated using a bench-scale combustor. The present porous alumina suppressed N{sub 2}O emission. This result is explained by the catalytic activity of porous alumina to decompose N{sub 2}O. In addition, NOx emission with porous bed material was nearly the same as or lower than that for the sand bed. Thus the decrease in N{sub 2}O without increasing NOx was attained. A modification of desulfurization by limestone was proposed. Fine limestone particles were employed as sorbent in order to conduct SO{sub 2} capture in the freeboard. By employing fine particles, the contact between volatile matter and limestone, which is known to increase the emission of NOx, was avoided. Thus the increase in NOx emission during limestone feed was avoided.

  7. Wall heat flux influence on the thermodynamic optimisation of irreversibilities of a circulating fluidised bed combustor

    CSIR Research Space (South Africa)

    Baloyi, J

    2016-07-01

    Full Text Available In the study the comparison of irreversibilities was done when the wall condition of the combustor was changed from adiabatic to negative heat flux, for incoming air temperature of 400 K. The reactant mixture of solid pitch pine wood fuel and air...

  8. Commercial liquid-metal MHD conversion systems coupled to LMFBR and coal-fired fluidized bed combustors

    International Nuclear Information System (INIS)

    Amend, W.E.; Brunsvold, A.; Pierson, E.S.

    1975-01-01

    The constraints imposed on two-phase liquid-metal MHD (LMMHD) when employed in commercial power plants with practical heat sources have not previously been studied. The coupling of a LMMHD power system with an LMFBR and a coal-fired fluidized bed combustor are considered. Two MHD systems are considered. The first is a dual cycle where heat is added to both the liquid metal and the gas, and the gas may expand through a gas turbine after the MHD generator. The second system, a binary cycle, differs in that a significant portion of the sensible heat in the gas entering the compression loop is converted to useful power in a steam bottoming cycle. The effect of liquid-metal vapor carry-over into the gas loop is included. The couplings of the LMMHD system with the heat sources and with the steam plants were studied in depth. The results of the study of each interface are presented parametrically for each heat source and energy conversion system. Operating points have been selected and the complete schematic of each system considered is presented along with all thermodynamic state points and fluid flow rates. All system parameters and component efficiencies were selected to be consistent with near term technology and good engineering design principles. These criteria yielded a system performance of 37 percent for an LMFBR operating with a maximum reactor coolant temperature of 1200 0 F when the pure LMMHD energy converter was used. A LMMHD/steam binary cycle is shown to be capable of achieving a thermal efficiency of 44.8 percent when used with the same heat source. Results with the coal fluidized bed combustor as a heat source show even higher performance levels (about 50 percent efficiency) since the maximum cycle temperature is increased

  9. Steam reformer with catalytic combustor

    Science.gov (United States)

    Voecks, Gerald E. (Inventor)

    1990-01-01

    A steam reformer is disclosed having an annular steam reforming catalyst bed formed by concentric cylinders and having a catalytic combustor located at the center of the innermost cylinder. Fuel is fed into the interior of the catalytic combustor and air is directed at the top of the combustor, creating a catalytic reaction which provides sufficient heat so as to maintain the catalytic reaction in the steam reforming catalyst bed. Alternatively, air is fed into the interior of the catalytic combustor and a fuel mixture is directed at the top. The catalytic combustor provides enhanced radiant and convective heat transfer to the reformer catalyst bed.

  10. Final Environmental Impact Statement for the JEA Circulating Fluidized Bed Combustor Project

    Energy Technology Data Exchange (ETDEWEB)

    N/A

    2000-06-30

    This EIS assesses environmental issues associated with constructing and demonstrating a project that would be cost-shared by DOE and JEA (formerly the Jacksonville Electric Authority) under the Clean Coal Technology Program. The project would demonstrate circulating fluidized bed (CFB) combustion technology at JEA's existing Northside Generating Station in Jacksonville, Florida, about 9 miles northeast of the downtown area of Jacksonville. The new CFB combustor would use coal and petroleum coke to generate nearly 300 MW of electricity by repowering the existing Unit 2 steam turbine, a 297.5-MW unit that has been out of service since 1983. The proposed project is expected to demonstrate emission levels of sulfur dioxide (SO{sub 2}), oxides of nitrogen (NO{sub x}), and particulate matter that would be lower than Clean Air Act limits while at the same time producing power more efficiently and at less cost than conventional coal utilization technologies. At their own risk, JEA has begun initial construction activities without DOE funding. Construction would take approximately two years and, consistent with the original JEA schedule, would be completed in December 2001. Demonstration of the proposed project would be conducted during a 2-year period from March 2002 until March 2004. In addition, JEA plans to repower the currently operating Unit 1 steam turbine about 6 to 12 months after the Unit 2 repowering without cost-shared funding from DOE. Although the proposed project consists of only the Unit 2 repowering, this EIS analyzes the Unit 1 repowering as a related action. The EIS also considers three reasonably foreseeable scenarios that could result from the no-action alternative in which DOE would not provide cost-shared funding for the proposed project. The proposed action, in which DOE would provide cost-shared finding for the proposed project, is DOE's preferred alternative. The EIS evaluates the principal environmental issues, including air quality

  11. In Developping a Bench-Scale Circulating Fluidized Bed Combustor to Burn High Ash Brazilian Coal-Dolomites Mixtures

    Science.gov (United States)

    Ramírez Behainne, Jhon Jairo; Hory, Rogério Ishikawa; Goldstein, Leonardo; Bernárdez Pécora, Araí Augusta

    This work considers some of the questions in burning high ash Brazilian coal-dolomite mixtures in a bench-scale circulating fluidized bed combustor (CFBC). Experimental tests were performed with the CE4500 coal from Santa Catarina State, in southern Brazil, with a Sauter mean diameter d p =43 μm. The coal particles were mixed with dolomite particles of d p = 111 μm and this fuel mixture was fed into the circulating fluidized reactor, previously loaded with quartz sand particles of d p =353 μm. This inert material was previously heated by the combustion of liquefied petroleum gas up to the ignition temperature of the fuel mixture. The CFBC unit has a 100mm internal diameter riser, 4.0m high, as well as a 62.8mm internal diameter downcomer. The loop has a cyclone, a sampling valve to collect particles and a 62.8mm internal diameter L-valve to recirculate the particles in the loop. A screw feeder with a rotation control system was used to feed the fuel mixture to the reactor. The operational conditions were monitored by pressure taps and thermocouples installed along the loop. A data acquisition system showed the main operational conditions to control. Experimental tests performed put in evidence the problems found during bed operation, with special attention to the solids feed device, to the L-valve operation, to particle size, solids inventory, fluidized gas velocity, fuel mixture and recirculated solids feeding positions.

  12. Metal wastage design guidelines for bubbling fluidized-bed combustors. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lyczkowski, R.W.; Podolski, W.F.; Bouillard, J.X.; Folga, S.M. [Argonne National Lab., IL (United States)

    1992-11-01

    These metal wastage design guidelines identify relationships between metal wastage and (1) design parameters (such as tube size, tube spacing and pitch, tube bundle and fluidized-bed height to distributor, and heat exchanger tube material properties) and (2) operating parameters (such as fluidizing velocity, particle size, particle hardness, and angularity). The guidelines are of both a quantitative and qualitative nature. Simplified mechanistic models are described, which account for the essential hydrodynamics and metal wastage processes occurring in bubbling fluidized beds. The empirical correlational approach complements the use of these models in the development of these design guidelines. Data used for model and guideline validation are summarized and referenced. Sample calculations and recommended design procedures are included. The influences of dependent variables on metal wastage, such as solids velocity, bubble size, and in-bed pressure fluctuations, are discussed.

  13. Study of a 30 MW bubbling fluidized bed combustor based on co ...

    Indian Academy of Sciences (India)

    Power generation based on biomass holds a considerable promise in Punjab, which has huge biomass resources from crop production system and agro industries. ... ever, there are some biomass residues concentrated at specific locations, where demand for energy also exists. Fluidized-bed combustion process seems to ...

  14. Characterisation of particulate matter emitted from cofiring of lignite and agricultural residues in a fixed-bed combustor.

    Science.gov (United States)

    Mantananont, Nattasut; Garivait, Savitri; Patumsawad, Suthum

    2012-01-01

    This study is focused on the emission of fixed bed combustor batch operated. Real-time analyser ELPI (electrical low-pressure impactor) system was used to size-segregated particulate matter emission ranging from 40 nm to 10 μm. The results show that total number concentration were 3.4 × 10(3), 1.6 × 10(4), and 1.5 × 10(5) particles/cm(3) · kg(fuel), while total mass of particles were 12.2, 8.0, and 6.5 mg/Nm(3) · kg(fuel) for combustion of lignite, rice husk and bagasse, respectively. But it can be noticed that cofiring released more particulate matter. Meanwhile it was found that the effect of ratio of over-fired air to total air supply is more pronounced, since decrease in this ratio, the amount of particles are decreased significantly. For particle size distribution, it can be observed that submicron-sized particles dominate and the most prevailing size is in the range: 50 nm particle size; 40 nm particle morphology showed that the isolate shape of submicron particle produced during lignite combustion is characterised by different geometries such as round, capsule, rod, flake-like, whereas the spherical shape is obtained with combustion of rice husk.

  15. Conceptual design of a fluidized bed combustor for volume reduction of waste

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, E.K.; Morris, G.J.; Atkinson, C.M.; Clark, N.N.; Gautam, M.; Loth, J.L.; Zhang, G.Q.; Zhang, L.M.; Kono, H.O.

    1992-06-01

    A group of research engineers was assembled to investigate novel fluidized bed combustion systems for incinerating low-level radioactive wastes. The goal of this project was to significantly reduce the volume of these wastes in an efficient and environmentally safe manner. The process is to be limited by a maximum temperature of 600 {degrees}C and the waste product was to contain a minimum of waste material produced by the process itself (refractory, absorbents, catalysts, etc.). The approach presented in this study is to evaluate: (1) a modification of the existing system, (2) a hybrid reactor concept, and (3) a fast circulating reactor concept. Carbon dioxide and oxygen were to be the only gases introduced into the reactors. The results of this study indicate that the existing system may be more efficient with gas and solids recirculation; however, two beds are required. The hybrid reactor concept involves a bubbling bed and a fast bed in one reactor. Although a simple operation is envisioned for this system, there are several technical questions which must be addressed in order to optimize the system for a final analysis. The fast circulating reactor concept also appears to represent a simple system to operate; however, it also presents several technical questions which must be addressed before a thorough evaluation of this concept may be completed. In conclusion, this report represents a first evaluation of new concepts for significant volume reduction of low-level radioactive wastes. The technical issues required for a complete evaluation of these concepts are presented. A future research effort is outlined the result of which should significantly increase our knowledge of these issues.

  16. Combustion behaviour of Olive pruning/animal manure blends in a fluidized bed combustor

    Directory of Open Access Journals (Sweden)

    Despina Vamvuka

    2017-09-01

    Both fuels burned mostly within the bed. The maximum temperature of animal manure was 50 °C lower than that of olive pruning, however efficiency was nearly 99%. CO emissions were low, SO2 emissions were negligible, whereas NOx emissions of blends exceeded legislation limits, when excess air ratio was over 1.4. Decreasing excess air from 50 to 30%, or reducing reactor loading, resulted in improved burnout. The optimum performance for the blends was achieved when the feed rate was 0.6 kg/h and excess air was 30%.

  17. Characterisation of Particulate Matter Emitted from Cofiring of Lignite and Agricultural Residues in a Fixed-Bed Combustor

    Directory of Open Access Journals (Sweden)

    Nattasut Mantananont

    2012-01-01

    Full Text Available This study is focused on the emission of fixed bed combustor batch operated. Real-time analyser ELPI (electrical low-pressure impactor system was used to size-segregated particulate matter emission ranging from 40 nm to 10 μm. The results show that total number concentration were 3.4×103, 1.6×104, and 1.5×105 particles/cm3⋅kgfuel, while total mass of particles were 12.2, 8.0, and 6.5 mg/Nm3⋅kgfuel for combustion of lignite, rice husk and bagasse, respectively. But it can be noticed that cofiring released more particulate matter. Meanwhile it was found that the effect of ratio of over-fired air to total air supply is more pronounced, since decrease in this ratio, the amount of particles are decreased significantly. For particle size distribution, it can be observed that submicron-sized particles dominate and the most prevailing size is in the range: 50 nm

  18. A simplified model of nitric oxide emission from a circulating fluidized bed combustor

    Energy Technology Data Exchange (ETDEWEB)

    Talukdar, J.; Basu, P. [Technical University of Nova Scotia, Halifax, NS (Canada)

    1995-10-01

    A simplified mathematical model leading to a closed form of solution is developed for estimation of nitric oxide emission from a coal fired circulating fluidized bed (CFB) furnace. The furnace is divided into two sections: a lower section below and an upper section above the secondary air injection level. Reactions in the cyclone and the return leg are neglected. Furnace dimensions, coal feed rate, coal composition and furnace temperature are inputs to the model which was validated against several pilot scale and commercial units. Experimental results from two pilot plants and two commercial power plants agree with model predictions. A sensitivity analysis was carried out using the model to examine the effect of different operating parameters and coal properties on the overall NO emission from the furnace. It was found that excess air and furnace temperature are most important factors influencing the NO emission level. The primary to secondary air ratio influences the NO emission level reasonably. Properties of coal are other factors which affect the NO emission to a large extent. The model, though it involves some simplification, predicts the overall emission of NO with a level of accuracy accepted in commercial operation. 27 refs., 8 figs., 2 tabs.

  19. Gaseous emissions from sewage sludge combustion in a moving bed combustor.

    Science.gov (United States)

    Batistella, Luciane; Silva, Valdemar; Suzin, Renato C; Virmond, Elaine; Althoff, Chrtistine A; Moreira, Regina F P M; José, Humberto J

    2015-12-01

    Substantial increase in sewage sludge generation in recent years requires suitable destination for this residue. This study evaluated the gaseous emissions generated during combustion of an aerobic sewage sludge in a pilot scale moving bed reactor. To utilize the heat generated during combustion, the exhaust gas was applied to the raw sludge drying process. The gaseous emissions were analyzed both after the combustion and drying steps. The results of the sewage sludge characterization showed the energy potential of this residue (LHV equal to 14.5 MJ kg(-1), db) and low concentration of metals, polycyclic aromatic hydrocarbons (PAH), polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF). The concentration of CO, NOx, BTEX (benzene, toluene, ethylbenzene and xylenes) emitted from the sludge combustion process were lower than the legal limits. The overall sludge combustion and drying process showed low emissions of PCDD/PCDF (0.42 ng I-TEQ N m(-3)). BTEX and PAH emissions were not detected. Even with the high nitrogen concentration in the raw feed (5.88% db), the sludge combustion process presented NOx emissions below the legal limit, which results from the combination of appropriate feed rate (A/F ratio), excess air, and mainly the low temperature kept inside the combustion chamber. It was found that the level of CO emissions from the overall sludge process depends on the dryer operating conditions, such as the oxygen content and the drying temperature, which have to be controlled throughout the process in order to achieve low CO levels. The aerobic sewage sludge combustion process generated high SO2 concentration due to the high sulfur content (0.67 wt%, db) and low calcium concentration (22.99 g kg(-1)) found in the sludge. The high concentration of SO2 in the flue gas (4776.77 mg N m(-3)) is the main factor inhibiting PCDD/PCDF formation. Further changes are needed in the pilot plant scheme to reduce SO2 and particulate matter emissions

  20. Fluid dynamic simulation of the fluidized bed using propane-air fuel; Simulacao dinamica de um combustor de leito fluidizado utilizando como combustivel o ar-propanado

    Energy Technology Data Exchange (ETDEWEB)

    Lima Junior, L.P.; Lucena, S.; Silva, D.J. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Engenharia Quimica]. E-mail: limajun@br.inter.net

    2004-07-01

    This paper has for purpose to present the modeling and simulation of the homogeneous combustion of the mixture of propane-air in a combustor of fluidized bed with inert particles, basing on a stationary model with phases in series, being taken into account the thermal changes and mass changes among the phases and it changes thermal with the wall for radiation. Computational methods are used for such simulation and CFX 4.4 as dynamic flowing computation software (CFD), kindred of more proximity with the real aspects. Being studied like this dynamic and kinetic flowing parameters of the involved components. (author)

  1. Mercury emissions during cofiring of sub-bituminous coal and biomass (chicken waste, wood, coffee residue, and tobacco stalk) in a laboratory-scale fluidized bed combustor.

    Science.gov (United States)

    Cao, Yan; Zhou, Hongcang; Fan, Junjie; Zhao, Houyin; Zhou, Tuo; Hack, Pauline; Chan, Chia-Chun; Liou, Jian-Chang; Pan, Wei-Ping

    2008-12-15

    Four types of biomass (chicken waste, wood pellets, coffee residue, and tobacco stalks) were cofired at 30 wt % with a U.S. sub-bituminous coal (Powder River Basin Coal) in a laboratory-scale fluidized bed combustor. A cyclone, followed by a quartz filter, was used for fly ash removal during tests. The temperatures of the cyclone and filter were controlled at 250 and 150 degrees C, respectively. Mercury speciation and emissions during cofiring were investigated using a semicontinuous mercury monitor, which was certified using ASTM standard Ontario Hydra Method. Test results indicated mercury emissions were strongly correlative to the gaseous chlorine concentrations, but not necessarily correlative to the chlorine contents in cofiring fuels. Mercury emissions could be reduced by 35% during firing of sub-bituminous coal using only a quartz filter. Cofiring high-chlorine fuel, such as chicken waste (Cl = 22340 wppm), could largely reduce mercury emissions by over 80%. When low-chlorine biomass, such as wood pellets (Cl = 132 wppm) and coffee residue (Cl = 134 wppm), is cofired, mercury emissions could only be reduced by about 50%. Cofiring tobacco stalks with higher chlorine content (Cl = 4237 wppm) did not significantly reduce mercury emissions. This was also true when limestone was added while cofiring coal and chicken waste because the gaseous chlorine was reduced in the freeboard of the fluidized bed combustor, where the temperature was generally below 650 degrees C without addition of the secondary air. Gaseous speciated mercury in flue gas after a quartz filter indicated the occurrence of about 50% of total gaseous mercury to be the elemental mercury for cofiring chicken waste, but occurrence of above 90% of the elemental mercury for all other cases. Both the higher content of alkali metal oxides or alkali earth metal oxides in tested biomass and the occurrence of temperatures lower than 650 degrees C in the upper part of the fluidized bed combustor seemed to be

  2. Effects of operating conditions and fuel properties on emission performance and combustion efficiency of a swirling fluidized-bed combustor fired with a biomass fuel

    International Nuclear Information System (INIS)

    Kuprianov, Vladimir I.; Kaewklum, Rachadaporn; Chakritthakul, Songpol

    2011-01-01

    This work reports an experimental study on firing 80 kg/h rice husk in a swirling fluidized-bed combustor (SFBC) using an annular air distributor as the swirl generator. Two NO x emission control techniques were investigated in this work: (1) air staging of the combustion process, and (2) firing rice husk as moisturized fuel. In the first test series for the air-staged combustion, CO, NO and C x H y emissions and combustion efficiency were determined for burning 'as-received' rice husk at fixed excess air of 40%, while secondary-to-primary air ratio (SA/PA) was ranged from 0.26 to 0.75. The effects of SA/PA on CO and NO emissions from the combustor were found to be quite weak, whereas C x H y emissions exhibited an apparent influence of air staging. In the second test series, rice husks with the fuel-moisture content of 8.4% to 35% were fired at excess air varied from 20% to 80%, while the flow rate of secondary air was fixed. Radial and axial temperature and gas concentration (O 2 , CO, NO) profiles in the reactor, as well as CO and NO emissions, are discussed for the selected operating conditions. The temperature and gas concentration profiles for variable fuel quality exhibited significant effects of both fuel-moisture and excess air. As revealed by experimental results, the emission of NO from this SFBC can be substantially reduced through moisturizing rice husk, while CO is effectively mitigated by injection of secondary air into the bed splash zone, resulting in a rather low emission of CO and high (over 99%) combustion efficiency of the combustor for the ranges of operating conditions and fuel properties.

  3. Thermodynamic optimisation and computational analysis of irreversibilities in a small-scale wood-fired circulating fluidised bed adiabatic combustor

    CSIR Research Space (South Africa)

    Baloyi, J

    2014-06-01

    Full Text Available An analysis of irreversibilities generated due to combustion in an adiabatic combustor burning wood was conducted. This was done for a reactant mixture varying from a rich to a lean mixture. A non-adiabatic non-premixed combustion model of a...

  4. Effects of acetic acid injection and operating conditions on NO emission in a vortexing fluidized bed combustor using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Fuping Qian; Chiensong Chyang; Weishen Yen [Anhui University of Technology, Ma' anshan (China). School of Civil Engineering and Architecture

    2009-07-15

    The effects of acetic acid injection and operating conditions on NO emission were investigated in a pilot scale vortexing fluidized bed combustor (VFBC), an integration of circular freeboard and a rectangular combustion chamber. Operating conditions, such as the stoichiometric oxygen in the combustion chamber, the bed temperature and the injecting location of acetic acid, were determined by means of response surface methodology (RSM), which enables the examination of parameters with a moderate number of experiments. In RSM, NO emission concentration after acetic acid injection and NO removal percentage at the exit of the VFBC are used as the objective function. The results show that the bed temperature has a more important effect on the NO emission than the injecting location of acetic acid and the stoichiometric oxygen in the combustion chamber. Meanwhile, the injecting location of acetic acid and the stoichiometric oxygen in the combustion chamber have a more important effect on the NO removal percentage than the bed temperature. NO emission can be decreased by injecting the acetic acid into the combustion chamber, and NO emission decreases with the height of the acetic acid injecting location above the distributor. On the other hand, NO removal percentage increases with the height of the acetic acid injecting location, and NO emission increases with the stoichiometric oxygen in the combustion chamber and the bed temperature. NO removal percentage increases with the stoichiometric oxygen, and increases first, then decreases with the bed temperature. Also, a higher NO removal percentage could be obtained at 850{sup o}C. 26 refs., 12 figs., 8 tabs.

  5. Coal desulfurization in a rotary kiln combustor. Quarterly report No. 1, April 16, 1990--July 15, 1990

    Energy Technology Data Exchange (ETDEWEB)

    Cobb, J.T. Jr.

    1990-08-15

    BCR National Laboratory (BCRNL) has initiated a project aimed at evaluating the technical and economic feasibility of using a rotary kiln, suitably modified, to burn Pennsylvania anthracite wastes, co-fired with high-sulfur bituminous coal. Limestone will be injected into the kiln for sulfur control, to determine whether high sulfur capture levels can be achieved with high sorbent utilization. The principal objectives of this work are: (1) to prove the feasibility of burning anthracite refuse, with co-firing of high-sulfur bituminous coal and with limestone injection for sulfur emissions control, in a rotary kiln fitted with a Universal Energy International (UEI) air injector system; (2) to determine the emissions levels of SO{sub x} and NO{sub x} and specifically to identify the Ca/S ratios that are required to meet New Source Performance Standards; (3) to evaluate the technical and economic merits of a commercial rotary kiln combustor in comparison to fluidized bed combustors; and, (4) to ascertain the need for further work, including additional combustion tests, prior to commercial application, and to recommend accordingly a detailed program towards this end.

  6. Modelling of Biomass Combustor : Final assignment energy from biomass

    NARCIS (Netherlands)

    Ammerlaan, R.; Van den Hill, E.J.; Kaas, A.W.S.; Verburg, M.W.

    2010-01-01

    In this study a 1.1 MW fluidized bed combustor is modeled. A literature study is performed on aspects which determine the characteristics of the combustor. A model is set up and calculations for the design of the Fluidized Bed Combustor (FBC) are performed. Characteristics are calculated for the

  7. Evaluating the sustainability of co-firing in the UK

    International Nuclear Information System (INIS)

    Woods, Jeremy; Tipper, Richard; Brown, Gareth; Diaz-Chavez, Rocio; Lovell, Jessica; de Groot, Peter

    2006-01-01

    The objectives of the study were: Assess the overall carbon balance for co-firing; Investigate the other sustainability issues relating to co-firing; Assess the scope for incentivising the most sustainable forms of co-firing. The main questions to be addressed were: Is the overall carbon balance for co-firing positive? What is the difference in carbon balance between energy crops and other biomass? Are some kinds of energy crops better than others? How big a factor is transport in the carbon balance? Under what circumstances (fuel, transport, process, etc.) are the greatest benefits of co-firing in terms of carbon balance and sustainability? Are there any circumstances (as above) that could raise serious carbon balance or sustainability issues? How does the carbon balance compare between co-firing, dedicated biomass, and biomass heat? Is there any scope for encouraging the most sustainable forms of co-firing - perhaps through using existing or currently in development accreditation schemes? The report concludes that: Co-firing could be expanded to make a significant and low risk contribution to Government and EU renewable energy policy targets; Real environmental and social benefits could arise from the expansion of co-firing markets, both in the UK and in poor developing countries, given responsible development policy; There is no clear environmental or social case, for an arbitrary cap on the amount of co-firing; Co-firing could expand and enhance clean coal Carbon and Capture and Sequestration (CCS). This report focuses solely on the carbon (GHG) and broader sustainability impacts of co-firing in the UK. It does not include an economic evaluation. It provides an overview of the existing materials being used as feedstocks for co-firing and a summary life-cycle assessment of the GHG balances and sustainability (environmental and social) impacts of the provision and use of those feedstocks. A clear distinction is made between the use of residues and dedicated

  8. Development of a pilot fluidized bed combustion to NOx reduction using natural gas: characterization and dimensioning; Desenvolvimento de um combustor piloto a leito fluidizado para reducao de NOx usando gas natural: caracterizacao e dimensionamento

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Douglas A.; Lucena, Sergio [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2004-07-01

    At the present time, the operation of combustion systems and the design of combustors continue being important problems in the Engineering, and don't involve just the size increase of combustors, but also changes of characteristics in the details of projects. The combustors applications are directly related to the needs, like: material transformation for heating, drying or incineration; and all have the inconvenience of emanating of pollutant gaseous (such like NOx). In combustion systems of gases, NOx is basically created in the reaction between nitrogen and oxygen to high temperatures ({approx} 1200 deg C). Below such conditions, the contribution of thermal NOx is recognisably small. The efficient reduction, safe control and economical elimination of pollutant emissions in the systems of burning are the main focuses of environmental legislation and concern to several industrialized countries, besides Brazil. Furthermore, in appeal at the Environmental Laws and at the rising consumption of combustible gases (Natural Gas), new technologies more attractive and economically viable have been studied, for example the combustion systems in fluidized bed. In this kind of system is possible to obtain high combustion efficiency at low temperatures ({approx} 900 deg C) with NOx reduction. In this work is intended of characterizing and dimensioning an industrial fluidized bed combustor that uses Natural Gas like feedstock in the combustion system, with smaller amounts of emitted NOx. (author)

  9. Base Metal Co-Fired Multilayer Piezoelectrics

    Directory of Open Access Journals (Sweden)

    Lisheng Gao

    2016-03-01

    Full Text Available Piezoelectrics have been widely used in different kinds of applications, from the automobile industry to consumer electronics. The novel multilayer piezoelectrics, which are inspired by multilayer ceramic capacitors, not only minimize the size of the functional parts, but also maximize energy efficiency. Development of multilayer piezoelectric devices is at a significant crossroads on the way to achieving low costs, high efficiency, and excellent reliability. Concerning the costs of manufacturing multilayer piezoelectrics, the trend is to replace the costly noble metal internal electrodes with base metal materials. This paper discusses the materials development of metal co-firing and the progress of integrating current base metal chemistries. There are some significant considerations in metal co-firing multilayer piezoelectrics: retaining stoichiometry with volatile Pb and alkaline elements in ceramics, the selection of appropriate sintering agents to lower the sintering temperature with minimum impact on piezoelectric performance, and designing effective binder formulation for low pO2 burnout to prevent oxidation of Ni and Cu base metal.

  10. Characterisation of polycyclic aromatic hydrocarbons in flue gas and residues of a full scale fluidized bed combustor combusting non-hazardous industrial waste.

    Science.gov (United States)

    Van Caneghem, J; Vandecasteele, C

    2014-11-01

    This paper studies the fate of PAHs in full scale incinerators by analysing the concentration of the 16 EPA-PAHs in both the input waste and all the outputs of a full scale Fluidized Bed Combustor (FBC). Of the analysed waste inputs i.e. Waste Water Treatment (WWT) sludge, Refuse Derived Fuel (RDF) and Automotive Shredder Residue (ASR), RDF and ASR were the main PAH sources, with phenanthrene, fluoranthene and pyrene being the most important PAHs. In the flue gas sampled at the stack, naphthalene was the only predominant PAH, indicating that the PAHs in FBC's combustion gas were newly formed and did not remain from the input waste. Of the other outputs, the boiler and fly ash contained no detectable levels of PAHs, whereas the flue gas cleaning residue contained only low concentrations of naphthalene, probably adsorbed from the flue gas. The PAH fingerprint of the bottom ash corresponded rather well to the PAH fingerprint of the RDF and ASR, indicating that the PAHs in this output, in contrast to the other outputs, were mainly remainders from the PAHs in the waste inputs. A PAH mass balance showed that the total PAH input/output ratio of the FBC ranged from about 100 to about 2600 depending on the waste input composition and the obtained combustion conditions. In all cases, the FBC was clearly a net PAH sink. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. In-situ laser spectroscopy of CO, Ch4, and H2O in a particle laden laboratory-scale fluidized bed combustor

    Directory of Open Access Journals (Sweden)

    Lackner Maximilian

    2002-01-01

    Full Text Available The pyrolysis, devolatilization and char combustion of bituminous coal and biomass (beechwood, firwood were investigated in a laboratory-scale fluidized bed combustor by tunable diode laser spectroscopy. Individual fuel particles were suspended in the freeboard of the unit. The bed temperature was 800 °C, the oxygen partial pressure 0 to 20 kPa (0-10 vol.%. Two Fabry Perot type tunable near infrared diode lasers were deployed for quantitative in-situ species concentration measurements. CH4 and CO were measured simultaneously during devolatilization and char combustion in-situ 10 mm above the surface of the fuel particles as well as H2O using laser spectroscopy. Sand particles were passing the probing laser beam path. Besides the resonant absorption of the laser light by CO, CH4 and H2O severe and strongly transient non-resonant attenuation by partial blocking of the beam and beam steering effects occurred. By wavelength tuning the two laser sources, species concentrations could be determined. The measured absorbances had to be corrected for the real temperature measured at the position of the probing laser beam. In addition, CO, CO2 and O2 were determined ex-situ by con ventional methods. A spatial profile inside the FBC of major species (CH4, CO, CO2, O, H, OH was calculated using a chemical kinetics program for a single fuel particle in a plug flow reactor geometry. The results were compared to the experimental findings. Good agreement was found. Tunable diode laser spectroscopy was found to be an apt method of determining quantitative species concentrations of multiple gases in a high temperature multi phase environment.

  12. Pilot fluidized bed combustor system applied to thermal energy production from light hydrocarbons - part I: description and hydrodynamics analysis; Sistema combustor piloto a leito fluidizado para producao de energia termica a partir de hidrocarbonetos leves. Parte I: descricao e analise hidrodinamica do sistema

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Leandro P. de; Souza Junior, Francisco de Assis; Alves, Stella M.A.; Estevao, Paulo [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Lucena, Sergio; Souza, Phillipi R. de O. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Lab. de Controle e Otimizacao de Processos; Santos, Douglas A. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

    2008-07-01

    During the last years, the employment of light hydrocarbons in combustion systems for power generation has been announced by Brazilian Government's like a great bet for diversification the energetic matrix in spite of the provisional crisis. As consequence, high demand and growing R and D investments caused immediate reflexes in all economical and industrial sectors of the Natural Gas chain, mainly considering the gas from Campos, Santos and Espirito Santo offshore fields offered to the market. Regarding this, Northeast Region of Brazil shows itself to be attentive to the energy market tendencies and to environmental sector, creating conditions for developing new technologies and applications for the gas consumption. Among the possible applications of the gas consumption, the fluidized bed combustion systems are highlighted, like a real alternative for energy applying of the hydrocarbons produced, considering a good safety range to effective environmental demands. Thereby, the present work aimed to perform the description of a pilot fluidized bed combustor system with sand using light hydrocarbons - specifically, natural gas and LPG. Thereby, said pilot fluidized bed combustor operates isothermically without developing flames and/or hot spots. Besides the exposed, a hydrodynamic analysis of the system was made, identifying variables and parameters onto fluidized bed combustion process. (author.

  13. Sulphur capture by co-firing sulphur containing fuels with biomass fuels - optimization

    International Nuclear Information System (INIS)

    Nordin, A.

    1992-12-01

    Previous results concerning co-firing of high sulphur fuels with biomass fuels have shown that a significant part of the sulphur can be absorbed in the ash by formation of harmless sulphates. The aim of this work has been to (i) determine the maximum reduction that can be obtained in a bench scaled fluidized bed (5 kW); (ii) determine which operating conditions will give maximum reduction; (iii) point out the importance and applicability of experimental designs and multivariate methods when optimizing combustion processes; (iv) determine if the degree of sulphur capture can be correlated to the degree of slagging, fouling or bed sintering; and (v) determine if further studies are desired. The following are some of the more important results obtained: - By co-firing peat with biomass, a total sulphur retention of 70 % can be obtained. By co-firing coal with energy-grass, the total SO 2 emissions can be reduced by 90 %. - Fuel feeding rate, amount of combustion air and the primary air ratio were the most important operating parameters for the reduction. Bed temperature and oxygen level seem to be the crucial physical parameters. - The NO emissions also decreased by the sulphur reducing measures. The CO emissions were relatively high (130 mg/MJ) compared to large scale facilities due to the small reactor and the small fluctuations in the fuel feeding rate. The SO 2 emissions could however be reduced without any increase in CO emissions. - When the reactor was fired with a grass, the bed sintered at a low temperature ( 2 SO 4 and KCl are formed no sintering problems were observed. (27 refs., 41 figs., 9 tabs., 3 appendices)

  14. Allothermal steam gasification of biomass in cyclic multi-compartment bubbling fluidized-bed gasifier/combustor - new reactor concept.

    Science.gov (United States)

    Iliuta, Ion; Leclerc, Arnaud; Larachi, Faïçal

    2010-05-01

    A new reactor concept of allothermal cyclic multi-compartment fluidized bed steam biomass gasification is proposed and analyzed numerically. The concept combines space and time delocalization to approach an ideal allothermal gasifier. Thermochemical conversion of biomass in periodic time and space sequences of steam biomass gasification and char/biomass combustion is simulated in which the exothermic combustion compartments provide heat into an array of interspersed endothermic steam gasification compartments. This should enhance unit heat integration and thermal efficiency and procure N(2)-free biosyngas with recourse neither to oxygen addition in steam gasification nor contact between flue and syngas. The dynamic, one-dimensional, multi-component, non-isothermal model developed for this concept accounts for detailed solid and gas flow dynamics whereupon gasification/combustion reaction kinetics, thermal effects and freeboard-zone reactions were tied. Simulations suggest that allothermal operation could be achieved with switch periods in the range of a minute supporting practical feasibility for portable small-scale gasification units. Copyright 2009 Elsevier Ltd. All rights reserved.

  15. Ash transformation during co-firing coal and straw

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Peter Arendt; Jensen, Anker Degn

    2007-01-01

    Co-firing straw with coal in pulverized fuel boilers can cause problems related to fly ash utilization, deposit formation, corrosion and SCR catalyst deactivation due to the high contents of Cl and K in the ash. To investigate the interaction between coal and straw ash and the effect of coal...... quality on fly ash and deposit properties, straw was co-fired with three kinds of coal in an entrained flow reactor. The compositions of the produced ashes were compared to the available literature data to find suitable scaling parameters that can be used to predict the composition of ash from straw...... and coal co-firing. Reasonable agreement in fly ash compositions regarding total K and fraction of water soluble K was obtained between co-firing in an entrained flow reactor and full-scale plants. Capture of potassium and subsequent release of HCl can be achieved by sulphation with SO2 and more...

  16. CFD simulation of coal and straw co-firing

    DEFF Research Database (Denmark)

    Junker, Helle; Hvid, Søren L.; Larsen, Ejvind

    This paper presents the results of a major R&D program with the objective to develop CFD based tools to assess the impact of biomass co-firing in suspension fired pulverized coal power plants. The models have been developed through a series of Danish research projects with the overall objective...... emissions. Results are presented for a Danish full-scale boiler that is currently co-firing biomass with coal on a commercial basis....

  17. GASIFICATION BASED BIOMASS CO-FIRING - PHASE I; SEMIANNUAL

    International Nuclear Information System (INIS)

    Babul Patel; Kevin McQuigg; Robert F. Toerne

    2001-01-01

    Biomass gasification offers a practical way to use this locally available fuel source for co-firing traditional large utility boilers. The gasification process converts biomass into a low Btu producer gas that can be fed directly into the boiler. This strategy of co-firing is compatible with variety of conventional boilers including natural gas fired boilers as well as pulverized coal fired and cyclone boilers. Gasification has the potential to address all problems associated with the other types of co-firing with minimum modifications to the existing boiler systems. Gasification can also utilize biomass sources that have been previously unsuitable due to size or processing requirements, facilitating a reduction in the primary fossil fuel consumption in the boiler and thereby reducing the greenhouse gas emissions to the atmosphere

  18. GASIFICATION BASED BIOMASS CO-FIRING - PHASE I

    Energy Technology Data Exchange (ETDEWEB)

    Babul Patel; Kevin McQuigg; Robert F. Toerne

    2001-12-01

    Biomass gasification offers a practical way to use this locally available fuel source for co-firing traditional large utility boilers. The gasification process converts biomass into a low Btu producer gas that can be fed directly into the boiler. This strategy of co-firing is compatible with variety of conventional boilers including natural gas fired boilers as well as pulverized coal fired and cyclone boilers. Gasification has the potential to address all problems associated with the other types of co-firing with minimum modifications to the existing boiler systems. Gasification can also utilize biomass sources that have been previously unsuitable due to size or processing requirements, facilitating a reduction in the primary fossil fuel consumption in the boiler and thereby reducing the greenhouse gas emissions to the atmosphere.

  19. Biomass co-firing under oxy-fuel conditions

    DEFF Research Database (Denmark)

    Álvarez, L.; Yin, Chungen; Riaza, J.

    2014-01-01

    to have favourable synergy effects in all the cases: it significantly improves the burnout and remarkably lowers NOx emissions. The reduced peak temperatures during co-firing can also help to mitigate deposition formation in real furnaces. Co-firing CO2-neutral biomass with coals under oxy-fuel conditions...... can achieve a below-zero CO2 emission if the released CO2 is captured and sequestered. The model-predicted burnout and gaseous emissions were compared against the experimental results. A very good agreement was observed, the differences in a range of ± 5–10% of the experimental values, which indicates...

  20. Low-Temperature Co-Fired Unipoled Multilayer Piezoelectric Transformers.

    Science.gov (United States)

    Gao, Xiangyu; Yan, Yongke; Carazo, Alfredo Vazquez; Dong, Shuxiang; Priya, Shashank

    2018-03-01

    The reliability of piezoelectric transformers (PTs) is dependent upon the quality of fabrication technique as any heterogeneity, prestress, or misalignment can lead to spurious response. In this paper, unipoled multilayer PTs were investigated focusing on high-power composition and co-firing profile in order to provide low-temperature synthesized high-quality device measured in terms of efficiency and power density. The addition of 0.2 wt% CuO into Pb 0.98 Sr 0.02 (Mg 1/3 Nb 2/3 ) 0.06 (Mn 1/3 Nb 2/3 ) 0.06 (Zr 0.48 Ti 0.52 ) 0.88 O 3 (PMMnN-PZT) reduces the co-firing temperature from 1240 °C to 930 °C, which allows the use of Ag/Pd inner electrode instead of noble Pt inner electrode. Low-temperature synthesized material was found to exhibit excellent piezoelectric properties ( , , %, pC/N, and °C). The performance of the PT co-fired with Ag/Pd electrode at 930 °C was similar to that co-fired at 1240 °C with Pt electrode (25% reduction in sintering temperature). Both high- and low-temperature synthesized PTs demonstrated 5-W output power with >90% efficiency and 11.5 W/cm 3 power density.

  1. Circulator Integrated in Low Temperature Co-fired Ceramics Technology

    NARCIS (Netherlands)

    Dijk, R. van; Bent, G. van der; Ashari, M.; McKay, M.

    2014-01-01

    We present a demonstration of an integrated circulator for TR modules using low temperature co-fired ceramic (LTCC) technology. Two different circulators have been realised to be used in TR modules in two different frequency bands, C-and Ku-band. The circulator is a three-port junction microstrip

  2. Co-firing coal and biomass blends and their influence on the post-combustion CO2 capture installation

    Science.gov (United States)

    Więckol-Ryk, Angelika; Smoliński, Adam

    2017-10-01

    Co-firing of biomass with coal for energy production is a well-known technology and plays an important role in the electricity sector. The post-combustion capture integrated with biomass-fired power plants (Bio-CCS) seems to be a new alternative for reducing greenhouse gas emissions. This study refers to the best known and advanced technology for post-combustion CO2 capture (PCC) based on a chemical absorption in monoethanolamine (MEA). The co-firing of hard coal with four types of biomass was investigated using a laboratory fixed bed reactor system. The comparison of gaseous products emitted from the combustion of coal and different biomass blends were determined using gas chromatography. Research proved that co-firing of biomass in fossil fuel power plants is beneficial for PCC process. It may also reduce the corrosion of CO2 capture installation. The oxygen concentration in the flue gases from hard coal combustion was comparable with the respective value for a fuel blend of biomass content of 20% w/w. It was also noted that an increase in biomass content in a sample from 20 to 40 % w/w increased the concentration of oxygen in the flue gas streams. However, this concentration should not have a significant impact on the rate of amine oxidative degradation.

  3. Analysis of biomass co-firing systems in Taiwan power markets using linear complementarity models

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Ming-Che; Lin, Chun-Hung [Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China); Chou, Chun-An [Department of Industrial and Systems Engineering, Rutgers University, 96 Frelinghuysen Rd, Piscataway, NJ 08854 (United States); Hsu, Shao-Yiu [Department of Geography and Environmental Engineering, Johns Hopkins University, 3400, N Charles St, Ames-313, Baltimore, MD 21218 (United States); Wen, Tzai-Hung, E-mail: wenthung@ntu.edu.tw [Department of Geography, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China)

    2011-08-15

    Biomass co-firing systems in power plants generate electric power by the simultaneous combustion of biomass and fossil fuels. The co-firing process reduces investment costs by converting biomass energy into electricity in existing conventional power plants. Biomass co-firing significantly reduces carbon dioxide and sulfur dioxide emissions in power generation. To meet the increase in biomass demand, this paper has considered systematic energy crop production, which is expected to increase in the near future. Our aim is to analyze biomass co-firing systems in the Taiwanese electricity market. In this paper, we study two emerging biomass feedstocks: switchgrass and Miscanthus. We focus on the impact of energy crop co-firing on carbon dioxide and sulfur dioxide emissions for electricity generation. A Nash-Cournot competition model, which simulates potential biomass co-firing scenarios, is formulated for power markets. A case study conducted in the Taiwanese electricity market showed that biomass co-firing lowers total electricity demand and sale. Miscanthus is more economical than switchgrass in terms of the production cost and the land required to generate biopower for the same levels of biomass co-firing. - Highlights: > Biomass co-firing system in electricity market is analyzed in this paper. > The research studies the impact of two energy crops in co-firing system. > This paper conducts a case study of co-firing system in Taiwan power markets.

  4. Experimental investigation and mathematical modelling of the combustion of brown coal, refuse and mixed fuels in a circulating fluidized bed combustor; Experimentelle Untersuchung und mathematische Modellierung der Verbrennung von Braunkohle, Abfallstoffen und Mischbrennstoffen in einer zirkulierenden Wirbelschichtfeuerung

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, W.; Brunne, T.; Hiller, A. [Technische Univ. Dresden (Germany). Inst. fuer Energietechnik; Albrecht, J. [Lurgi Umwelt GmbH, Frankfurt am Main (Germany); Quang, N. [Polytechnic Inst., Danang (Viet Nam)

    1998-09-01

    Extensive experiments on combustion of biological materials and residues in fluidized bed combustors and dust combustors have been carried out at the Department of Power Plant Engineering of Dresden University since the early nineties. Particular interest was taken in mixing brown coal with sewage sludge, sugar pulp and waste wood. The experiments were supplemented by modelling in a research project funded jointly by the BMBF and Messrs. Lurgi since early 1997. A combustion cell model designed by Siegen University is being modified for the new mixed fuels, and preliminary investigations were carried out on a batch reactor while the modelling work was continued. (orig.) [Deutsch] An dem Lehrstuhl fuer Kraftwerkstechnik der TU Dresden werden seit Anfang der 90-iger Jahre umfangreiche experimentelle Untersuchungen zur Verbrennung von Bio- und Reststoffen in Wirbelschicht- und Staubfeuerungen durchgefuehrt. Dabei war vor allem die Zufeuerung dieser Stoffe in Waermeerzeugeranlagen auf Braunkohlenbasis von besonderem Interesse. Experimentell konnte nachgewiesen werden, dass sowohl Biobrennstoffe als auch Abfaelle in zirkulierenden Wirbelschichtfeuerungen umweltschonend zur Waermeerzeugung eingesetzt werden koennen. Als Beispiel wird das an Hand von Braunkohle-Klaerschlammgemischen sowie Bagasse- und Holz-Braunkohlegemischen gezeigt. Neben den experimentellen Untersuchungen bietet die Modellierung der Verbrennungsvorgaenge ein geeignetes Mittel um Voraussagen zu anderen Mischungsanteilen sowie anderen geometrischen Abmessungen machen zu koennen. Seit Anfang 1997 wird dazu ein vom BMBF und der Firma Lurgi gefoerdertes Forschungsvorhaben bearbeitet. Ein von der Universitaet Gesamthochschule Siegen fuer die Braunkohleverbrennung konzipiertes Zellenmodell wird auf die neuen Brennstoffgemische erweitert. Da grundsaetzlich andere Stoffzusammensetzungen vorliegen, wurden an einem Batch-Reaktor Voruntersuchungen zum Pyrolyseverhalten der Brennstoffe durchgefuehrt. Erste

  5. Combustor and combustor screech mitigation methods

    Science.gov (United States)

    Kim, Kwanwoo; Johnson, Thomas Edward; Uhm, Jong Ho; Kraemer, Gilbert Otto

    2014-05-27

    The present application provides for a combustor for use with a gas turbine engine. The combustor may include a cap member and a number of fuel nozzles extending through the cap member. One or more of the fuel nozzles may be provided in a non-flush position with respect to the cap member.

  6. Control and reduction of NOx emissions on light hydrocarbons combustion in fluidized bed combustors: a technological prospection surveys; Controle e reducao de emissoes de NOx durante queima de hidrocarbonetos leves em combustores a leito fluidizado: um estudo de prospeccao tecnologica

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Douglas Alves; Winter, Eduardo [Instituto Nacional da Propriedade Industrial (INPI), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The present paper aims a technological prospecting study of the main technological agents involved in industrial light hydrocarbons combustion process. More specifically, the work approaches technologies applied to nitrogen oxides emissions control and reduction. Nitrogen oxides are typically known as 'NOx' (NO, N{sub 2}O, NO{sub 2}). 'NOx' are byproducts from fuel burning in combustion systems, including also in fluidized bed combustion systems. The technological prospecting study employed 'technology foresight' as tool for evaluating the technological perspectives of the thermal generation, basis on environment protection. Such technological perspectives of the thermal generation were evaluated through invention patent documents. The query methodology for obtaining of patent documents employed a free patent base, known as ESPACENET. Additionally, the documents obtained were evaluated, considering beyond the countries and the publication dates, technological perspectives employed to 'NOx' emissions control and reduction. It is very important to highlight around 70% of the industrial technological information are just found in invention patent documents. (author)

  7. Co-firing plans in the spotlight over biomass imports

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    Spurred by the renewables obligation, coal-fired power stations with a capacity of over 20GW could be co-firing with biomass by early next year. But, with little of their fuel coming from dedicated energy crops, the generators are in danger of entering a minefield. UK wood panel manufacturers fear that their raw material costs will rise in the face of subsidised competition from power stations, while the generators' growing biomass imports are stirring sensitivities about rainforest destruction and dislocation of overseas markets for agricultural by-products. 1 tab., 2 photos.

  8. Co-firing high sulfur coal with refuse derived fuels. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pan, W.P.; Riley, J.T.; Lloyd, W.G.

    1997-11-30

    This project was designed to evaluate the combustion performance of and emissions from a fluidized bed combustor during the combustion of mixtures of high sulfur and/or high chlorine coals and municipal solid waste (MSW). The project included four major tasks, which were as follows: (1) Selection, acquisition, and characterization of raw materials for fuels and the determination of combustion profiles of combination fuels using thermal analytical techniques; (2) Studies of the mechanisms for the formation of chlorinated organics during the combustion of MSW using a tube furnace; (3) Investigation of the effect of sulfur species on the formation of chlorinated organics; and (4) Examination of the combustion performance of combination fuels in a laboratory scale fluidized bed combustor. Several kinds of coals and the major combustible components of the MSW, including PVC, newspaper, and cellulose were tested in this project. Coals with a wide range of sulfur and chlorine contents were used. TGA/MS/FTIR analyses were performed on the raw materials and their blends. The possible mechanism for the formation of chlorinated organics during combustion was investigated by conducting a series of experiments in a tube furnace. The effect of sulfur dioxide on the formation of molecular chlorine during combustion processes was examined in this study.

  9. BPACK -- A computer model package for boiler reburning/co-firing performance evaluations. User`s manual, Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Wu, K.T.; Li, B.; Payne, R.

    1992-06-01

    This manual presents and describes a package of computer models uniquely developed for boiler thermal performance and emissions evaluations by the Energy and Environmental Research Corporation. The model package permits boiler heat transfer, fuels combustion, and pollutant emissions predictions related to a number of practical boiler operations such as fuel-switching, fuels co-firing, and reburning NO{sub x} reductions. The models are adaptable to most boiler/combustor designs and can handle burner fuels in solid, liquid, gaseous, and slurried forms. The models are also capable of performing predictions for combustion applications involving gaseous-fuel reburning, and co-firing of solid/gas, liquid/gas, gas/gas, slurry/gas fuels. The model package is conveniently named as BPACK (Boiler Package) and consists of six computer codes, of which three of them are main computational codes and the other three are input codes. The three main codes are: (a) a two-dimensional furnace heat-transfer and combustion code: (b) a detailed chemical-kinetics code; and (c) a boiler convective passage code. This user`s manual presents the computer model package in two volumes. Volume 1 describes in detail a number of topics which are of general users` interest, including the physical and chemical basis of the models, a complete description of the model applicability, options, input/output, and the default inputs. Volume 2 contains a detailed record of the worked examples to assist users in applying the models, and to illustrate the versatility of the codes.

  10. Nonequilibrium Sulfur Capture & Retention in an Air Cooled Slagging Coal Combustor

    Energy Technology Data Exchange (ETDEWEB)

    Bert Zauderer

    1998-04-21

    Calcium oxide injected in a slagging combustor reacts with the sulfur from coal combustion to form sulfur-bearing particles, which are deposited on the liquid slag layer on the combustor wall. Due to the low solubility of sulfur in slag, it must be rapidly drained from the combustor to limit sulfur gas re-evolution. Analysis indicated that slag mass flow rates in excess of 400 lb/hr should limit sulfur re-evolution. The objective of this 36 month project was to perform a series of tests to determine the factors that control the retention of the sulfur in the slag. 19 days of testing were completed prior to 9/30/97. In the present quarterly reporting period ending 12/31/97, 13 tests days were completed on co-firing coal and a high ash, rice husk biomass, which was selected to produce a high slag flow rate. Most of the test effort focussed on developing methods for feeding the very low density rice husks into combustor. Various levels of mineral matter from coal ash, rice husk ash, calcium sulfate, and calcium oxide was injected in the combustor during these 13 tests. The peak mineral matter, injection rate was 592 lb/hr for a period of about one-hour. No significant sulfur concentration was measured in the slag removed from the combustor. This may be due to the brief test duration, and longer duration tests are planned for the next quarter. The two major accomplishments in this quarter are the successful co-firing of coal and biomass in the slagging combustor. This is a major technical milestone due to its application to greenhouse gas emission reduction. It was not in the original project plan. Also, the total of 31 test days completed by 12/31/97 is double the number originally planned.

  11. Recycling of Sustainable Co-Firing Fly Ashes as an Alkali Activator for GGBS in Blended Cements

    Directory of Open Access Journals (Sweden)

    Yann-Hwang Wu

    2015-02-01

    Full Text Available This study investigates the feasibility of co-firing fly ashes from different boilers, circulating fluidized beds (CFB or stokers as a sustainable material in alkali activators for ground granulated blast-furnace slag (GGBS. The mixture ratio of GGBS and co-firing fly ashes is 1:1 by weight. The results indicate that only CF fly ash of CFB boilers can effectively stimulate the potential characteristics of GGBS and provide strength as an alkali activator. CF fly ash consists of CaO3 (48.5%, SiO2 (21.1%, Al2O3 (13.8%, SO3 (10.06%, Fe2O3 (2.25% and others (4.29%. SA fly ash consists of Al2O3 (19.7%, SiO2 (36.3%, Fe2O3 (28.4% and others (15.6%. SB fly ash consists of Al2O3 (15%, SiO2 (25.4%, Zn (20.6%, SO3 (10.9%, Fe2O3 (8.78% and others (19.32%. The mixtures of SA fly ash and SB fly ash with GGBS, respectively, were damaged in the compressive strength test during seven days of curing. However, the built up strength of the CF fly ash and GGBS mixture can only be maintained for 7–14 days, and the compressive strength achieves 70% of that of a controlled group (cement in hardening cement paste. The strength of blended CF fly ash and GGBS started to decrease after 28 days, and the phenomenon of ettrigite was investigated due to the high levels of sulfur content. The CaO content in sustainable co-firing fly ashes must be higher than a certain percentage in reacting GGBS to ensure the strength of blended cements.

  12. Recycling of Sustainable Co-Firing Fly Ashes as an Alkali Activator for GGBS in Blended Cements.

    Science.gov (United States)

    Wu, Yann-Hwang; Huang, Ran; Tsai, Chia-Jung; Lin, Wei-Ting

    2015-02-16

    This study investigates the feasibility of co-firing fly ashes from different boilers, circulating fluidized beds (CFB) or stokers as a sustainable material in alkali activators for ground granulated blast-furnace slag (GGBS). The mixture ratio of GGBS and co-firing fly ashes is 1:1 by weight. The results indicate that only CF fly ash of CFB boilers can effectively stimulate the potential characteristics of GGBS and provide strength as an alkali activator. CF fly ash consists of CaO₃ (48.5%), SiO₂ (21.1%), Al₂O₃ (13.8%), SO₃ (10.06%), Fe₂O₃ (2.25%) and others (4.29%). SA fly ash consists of Al₂O₃ (19.7%), SiO₂ (36.3%), Fe2O3 (28.4%) and others (15.6%). SB fly ash consists of Al₂O₃ (15%), SiO₂ (25.4%), Zn (20.6%), SO₃ (10.9%), Fe₂O₃ (8.78%) and others (19.32%). The mixtures of SA fly ash and SB fly ash with GGBS, respectively, were damaged in the compressive strength test during seven days of curing. However, the built up strength of the CF fly ash and GGBS mixture can only be maintained for 7-14 days, and the compressive strength achieves 70% of that of a controlled group (cement in hardening cement paste). The strength of blended CF fly ash and GGBS started to decrease after 28 days, and the phenomenon of ettrigite was investigated due to the high levels of sulfur content. The CaO content in sustainable co-firing fly ashes must be higher than a certain percentage in reacting GGBS to ensure the strength of blended cements.

  13. Recycling of Sustainable Co-Firing Fly Ashes as an Alkali Activator for GGBS in Blended Cements

    Science.gov (United States)

    Wu, Yann-Hwang; Huang, Ran; Tsai, Chia-Jung; Lin, Wei-Ting

    2015-01-01

    This study investigates the feasibility of co-firing fly ashes from different boilers, circulating fluidized beds (CFB) or stokers as a sustainable material in alkali activators for ground granulated blast-furnace slag (GGBS). The mixture ratio of GGBS and co-firing fly ashes is 1:1 by weight. The results indicate that only CF fly ash of CFB boilers can effectively stimulate the potential characteristics of GGBS and provide strength as an alkali activator. CF fly ash consists of CaO3 (48.5%), SiO2 (21.1%), Al2O3 (13.8%), SO3 (10.06%), Fe2O3 (2.25%) and others (4.29%). SA fly ash consists of Al2O3 (19.7%), SiO2 (36.3%), Fe2O3 (28.4%) and others (15.6%). SB fly ash consists of Al2O3 (15%), SiO2 (25.4%), Zn (20.6%), SO3 (10.9%), Fe2O3 (8.78%) and others (19.32%). The mixtures of SA fly ash and SB fly ash with GGBS, respectively, were damaged in the compressive strength test during seven days of curing. However, the built up strength of the CF fly ash and GGBS mixture can only be maintained for 7–14 days, and the compressive strength achieves 70% of that of a controlled group (cement in hardening cement paste). The strength of blended CF fly ash and GGBS started to decrease after 28 days, and the phenomenon of ettrigite was investigated due to the high levels of sulfur content. The CaO content in sustainable co-firing fly ashes must be higher than a certain percentage in reacting GGBS to ensure the strength of blended cements. PMID:28787970

  14. Comparative life cycle assessment of biomass co-firing plants with carbon capture and storage

    NARCIS (Netherlands)

    Schakel, Wouter|info:eu-repo/dai/nl/369280784; Meerman, Hans; Talaei, Alireza; Ramírez, Andrea|info:eu-repo/dai/nl/284852414; Faaij, André

    2014-01-01

    Combining co-firing biomass and carbon capture and storage (CCS) in power plants offers attractive potential for net removal of carbon dioxide (CO2) from the atmosphere. In this study, the impact of co-firing biomass (wood pellets and straw pellets) on the emission profile of power plants with

  15. Drivers of biomass co-firing in U.S. coal-fired power plants

    Science.gov (United States)

    Michael E. Goerndt; Francisco X. Aguilar; Kenneth Skog

    2013-01-01

    Substantial knowledge has been generated in the U.S. about the resource base for forest and other residue-derived biomass for bioenergy including co-firing in power plants. However, a lack of understanding regarding power plant-level operations and manager perceptions of drivers of biomass co-firing remains. This study gathered information from U.S. power plant...

  16. Camber Evolution and Stress Development of Porous Ceramic Bilayers During Co-Firing

    DEFF Research Database (Denmark)

    Ni, De Wei; Esposito, Vincenzo; Schmidt, Cristine Grings

    2013-01-01

    sintering mismatch stress in co-fired CGO-LSM/CGO bilayer laminates was significantly lower than general sintering stresses expected for free sintering conditions. As a result, no co-firing defects were observed in the bilayer laminates, illustrating an acceptable sintering compatibility of the ceramic...

  17. The effect of Co-firing with Straw and Coal on High Temperature Corrosion

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Frandsen, Flemming; Larsen, OH

    2001-01-01

    As a part of ELSAMS development programme into alternative energy sources, various concepts of straw-firing have been investigated. This paper concerns co-firing of straw with coal to reduce the corrosion rate observed in straw-fired power plants. Co-firing with coal reduces the amount of potassi...

  18. ESTABLISHMENT OF AN ENVIRONMENTAL CONTROL TECHNOLOGY LABORATORY WITH A CIRCULATING FLUIDIZED-BED COMBUSTION SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Wei-Ping Pan; Andy Wu; John T. Riley

    2005-04-30

    This report is to present the progress made on the project ''Establishment of an Environmental Control Technology Laboratory (ECTL) with a Circulating Fluidized-Bed Combustion (CFBC) System'' during the period January 1, 2005 through March 31, 2005. The following tasks have been completed. First, the renovation of the new Combustion Laboratory is nearly complete, and the construction of the Circulating Fluidized-Bed (CFB) Combustor Building is in the final stages. Second, the fabrication and manufacture of the CFBC Facility is being discussed with a potential contractor. Discussions with potential contactor regarding the availability of materials and current machining capabilities have resulted in the modification of the original designs. The selection of the fabrication contractor for the CFBC Facility is expected during the next quarter. Third, co-firing experiments conducted with coal and chicken waste have been initiated in the laboratory-scale simulated fluidized-bed facility. The experimental results from this study are presented in this report. Finally, the proposed work for the next quarter is described in this report.

  19. Variable volume combustor

    Science.gov (United States)

    Ostebee, Heath Michael; Ziminsky, Willy Steve; Johnson, Thomas Edward; Keener, Christopher Paul

    2017-01-17

    The present application provides a variable volume combustor for use with a gas turbine engine. The variable volume combustor may include a liner, a number of micro-mixer fuel nozzles positioned within the liner, and a linear actuator so as to maneuver the micro-mixer fuel nozzles axially along the liner.

  20. Dual-Mode Combustor

    Science.gov (United States)

    Trefny, Charles J (Inventor); Dippold, Vance F (Inventor)

    2013-01-01

    A new dual-mode ramjet combustor used for operation over a wide flight Mach number range is described. Subsonic combustion mode is usable to lower flight Mach numbers than current dual-mode scramjets. High speed mode is characterized by supersonic combustion in a free-jet that traverses the subsonic combustion chamber to a variable nozzle throat. Although a variable combustor exit aperture is required, the need for fuel staging to accommodate the combustion process is eliminated. Local heating from shock-boundary-layer interactions on combustor walls is also eliminated.

  1. ENVIRONMENTAL AND SUSTAINABLE TECHNOLOGY EVALUATION: BIOMASS CO-FIRING IN INDUSTRIAL BOILERS--UNIVERSITY OF IOWA

    Science.gov (United States)

    The U.S. EPA operates the Environmental and Sustainable Technology Evaluation (ESTE) program to facilitate the deployment of innovative technologies through performance verification and information dissemination. This ESTE project involved evaluation of co-firing common woody bio...

  2. Ash transformation in suspension fired boilers co-firing coal and straw

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Peter Arendt; Jensen, Anker Degn

    of flue gas cleaning equipment. This survey includes discussions on the inorganic constituents transformation during straw and coal combustion, alkali-ash and alkali sulfur reactions, a survey of power plant and test rig co-firing experiments, a discussion of equilibrium calculations, a discussion......In this literature report is provided a status for the present knowledge level on ash properties when co-firing coal and biomass. The fly ash formed in boilers using co-firing of coal and straw do have a large influence on ash deposit formation, boiler corrosion, fly ash utilization and operation...... of alkali getter experiments and a discussion of modeling of alkali reaction with kaolin. Presently there is still a need for a better understanding of especially the reaction of potassium with coal ash, thereby making better predictions of co-firing ash properties....

  3. Computational model of a whole tree combustor

    Energy Technology Data Exchange (ETDEWEB)

    Bryden, K.M.; Ragland, K.W. [Univ. of Wisconsin, Madison, WI (United States)

    1993-12-31

    A preliminary computational model has been developed for the whole tree combustor and compared to test results. In the simulation model presented hardwood logs, 15 cm in diameter are burned in a 4 m deep fuel bed. Solid and gas temperature, solid and gas velocity, CO, CO{sub 2}, H{sub 2}O, HC and O{sub 2} profiles are calculated. This deep, fixed bed combustor obtains high energy release rates per unit area due to the high inlet air velocity and extended reaction zone. The lowest portion of the overall bed is an oxidizing region and the remainder of the bed acts as a gasification and drying region. The overfire air region completes the combustion. Approximately 40% of the energy is released in the lower oxidizing region. The wood consumption rate obtained from the computational model is 4,110 kg/m{sup 2}-hr which matches well the consumption rate of 3,770 kg/m{sup 2}-hr observed during the peak test period of the Aurora, MN test. The predicted heat release rate is 16 MW/m{sup 2} (5.0*10{sup 6} Btu/hr-ft{sup 2}).

  4. The feasibility of co-firing biomass for electricity in Missouri

    International Nuclear Information System (INIS)

    Liu, Zuoming; Altman, Ira; Johnson, Thomas G.

    2014-01-01

    Bioenergy is one of the most significant energy resources with potential to serve as a partial replacement for fossil. As an agricultural state, Missouri has great potential to use biomass for energy production. In 2008, Missouri adopted a renewable portfolio standard (RPS) yet about 80% of its power supply still comes from coal. This paper describes a feasibility study of co-firing biomass in existing coal-powered plants in Missouri. Specifically, this study developed a linear programming model and simulated six scenarios to assess the economic feasibility and greenhouse gas impacts of co-firing biomass in existing qualified coal power plants in Missouri. The results of this study indicate that although co-firing can reduce the emissions of GHG and environmental pollutants, it is still not an economically feasible option for power generation without additional economic or policy incentives or regulations which could take environmental costs into account. Based on these results, strategies and policies to promote the utilization of biomass and to increase its competitiveness with fossil fuels are identified and discussed. - Highlights: • This paper reports on a study of the economic feasibility and environmental effects of co-firing biomass for electricity. • The feasibility of co-firing biomass varies by location depending on local availability of biomass and size of facility. • We apply a linear optimization model that generates economic and environmental indicators for each of several locations. • This paper will appeal to power generators, academic researchers and consultants interested in the feasibility of biopower

  5. Noise characteristics of resistors buried in low-temperature co-fired ceramics

    International Nuclear Information System (INIS)

    Kolek, A; Ptak, P; Dziedzic, A

    2003-01-01

    The comparison of noise properties of conventional thick film resistors prepared on alumina substrates and resistors embedded in low-temperature co-fired ceramics (LTCCs) is presented. Both types of resistors were prepared from commercially available resistive inks. Noise measurements of LTCC resistors below 1 kHz show Gaussian 1/f noise. This is concluded from the calculations of the second spectra as well as from studying the volume dependence of noise intensity. It has occurred that noise index of LTCC resistors on average is not worse than that of conventional resistors. A detailed study of co-fired surface resistors and co-fired buried resistors show that burying a resistor within LTCC substrate usually leads to (significant) enhancement of resistance but not of noise intensity. We interpret this behaviour as another argument in favour of tunnelling as the dominant conduction mechanism in LTCC resistors

  6. Potential high temperature corrosion problems due to co-firing of biomass and fossil fuels

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Vilhelmsen, T.; Jensen, S.A.

    2007-01-01

    Over the past years, considerable high temperature corrosion problems have been encountered when firing biomass in power plants due to the high content of potassium chloride in the deposits. Therefore to combat chloride corrosion problems co-firing of biomass with a fossil fuel has been undertaken...... significant corrosion attack was due to sulphidation attack at the grain boundaries of 18-8 steel after 3 years exposure. The corrosion mechanisms and corrosion rates are compared with biomass firing and coal firing. Potential corrosion problems due to co-firing biomass and fossil fuels are discussed....... appear such as sulphidation and hot corrosion due to sulphate deposits. At Studstrup power plant Unit 4, based on trials with exposure times of 3000 hours using 0-20% straw co-firing with coal, the plant now runs with a fuel of 10% straw + coal. After three years exposure in this environment...

  7. Ash transformation in suspension fired boilers co-firing coal and straw

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Peter Arendt; Jensen, Anker Degn

    The properties of the ash from co-firing of coal and straw have a large influence on boiler operation, flue gas cleaning equipment and appropriate utilization of the fly ash. A study on the fuel composition and local conditions influence on fly ash properties has been done by making entrained flow...... reactor experiments with co-firing of coal and straw, making mineral and alkali vapor laboratory reactor experiments and by developing a model of KCl reaction with kaolin. The results include correlations that can be used to estimate the speciation of potassium in the fly ash when co-firing straw...... and bituminous coal. The laboratory experiments indicated which mineral types and local conditions that provide the most efficient binding of potassium to species with a high melting point, and where a simultaneous release of chlorine as gaseous HCl takes place....

  8. Field test corrosion experiences when co-firing straw and coal: 10 year status within Elsam

    DEFF Research Database (Denmark)

    Frandsen, Rasmus Berg; Montgomery, Melanie; Larsen, Ole Hede

    2007-01-01

    In Denmark, straw is utilised for the generation of energy and district heating in power plants. Combustion of straw gives rise to high contents of potassium chloride and some sulphur dioxide in the flue gas. These compounds can lead to deposits with high content of potassium chloride and potassium...... sulphate on superheater tubes resulting in increased corrosion rates. From field experimental results this paper show, that by co-firing straw with coal, corrosion rates can be brought down to an acceptable level. This paper firstly deals with the results from a demonstration program co-firing coal...... and straw at the 150 MW pulverized coal fired boiler Studstrup unit 1. Two exposure series lasting 3000 hours each were performed for co-firing 10 and 20% of straw (% energy basis) with coal. Using built in test tubes in the hot end of the actual superheaters and air/water cooled corrosion probes...

  9. Energy Analysis of a Biomass Co-firing Based Pulverized Coal Power Generation System

    Directory of Open Access Journals (Sweden)

    Marc A. Rosen

    2012-03-01

    Full Text Available The results are reported of an energy analysis of a biomass/coal co-firing based power generation system, carried out to investigate the impacts of biomass co-firing on system performance. The power generation system is a typical pulverized coal-fired steam cycle unit, in which four biomass fuels (rice husk, pine sawdust, chicken litter, and refuse derived fuel and two coals (bituminous coal and lignite are considered. Key system performance parameters are evaluated for various fuel combinations and co-firing ratios, using a system model and numerical simulation. The results indicate that plant energy efficiency decreases with increase of biomass proportion in the fuel mixture, and that the extent of the decrease depends on specific properties of the coal and biomass types.

  10. Noise characteristics of resistors buried in low-temperature co-fired ceramics

    CERN Document Server

    Kolek, A; Dziedzic, A

    2003-01-01

    The comparison of noise properties of conventional thick film resistors prepared on alumina substrates and resistors embedded in low-temperature co-fired ceramics (LTCCs) is presented. Both types of resistors were prepared from commercially available resistive inks. Noise measurements of LTCC resistors below 1 kHz show Gaussian 1/f noise. This is concluded from the calculations of the second spectra as well as from studying the volume dependence of noise intensity. It has occurred that noise index of LTCC resistors on average is not worse than that of conventional resistors. A detailed study of co-fired surface resistors and co-fired buried resistors show that burying a resistor within LTCC substrate usually leads to (significant) enhancement of resistance but not of noise intensity. We interpret this behaviour as another argument in favour of tunnelling as the dominant conduction mechanism in LTCC resistors.

  11. BENEFIT COST FOR BIOMASS CO-FIRING IN ELECTRICITY GENERATION: CASE OF UTAH, U.S.

    Directory of Open Access Journals (Sweden)

    Man-Keun Kim

    2015-07-01

    Full Text Available Policy making regarding biomass co-firing is difficult. The article provides a benefit-cost analysis for decision makers to facilitate policy making process to implement efficient biomass co-firing policy. The additional cost is the sum of cost of the biomass procurement and biomass transportation. Co-benefits are sales of greenhouse gas emission credits and health benefit from reducing harmful air pollutants, especially particulate matter. The benefit-cost analysis is constructed for semi-arid U.S. region, Utah, where biomass supply is limited. Results show that biomass co-firing is not economically feasible in Utah but would be feasible when co-benefits are considered. Benefit-cost ratio is critically dependent upon biomass and carbon credit prices. The procedure to build the benefit-cost ratio can be applied for any region with other scenarios suggested in this study.

  12. Rat inhalation test with particles from biomass combustion and biomass co-firing exhaust

    OpenAIRE

    Bellmann, B.; Creutzenberg, O.; Ernst, H.; Muhle, H.

    2009-01-01

    The health effects of 6 different fly ash samples from biomass combustion plants (bark, wood chips, waste wood, and straw), and co-firing plants (coal, co-firing of coal and sawdust) were investigated in a 28-day nose-only inhalation study with Wistar WU rats. Respirable fractions of carbon black (Printex 90) and of titanium dioxide (Bayertitan T) were used as reference materials for positive and negative controls. The exposure was done 6 hours per day, 5 days per week at an aerosol concentra...

  13. NONEQUILIBRIUM SULFUR CAPTURE AND RETENTION IN AN AIR COOLED SLAGGING COAL COMBUSTOR

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Bert Zauderer

    1999-03-15

    Calcium oxide injected in a slagging combustor reacts with the sulfur from coal combustion to form sulfur-bearing particles. They are deposited on the liquid slag layer on the combustor wall. Due to the low solubility of sulfur in slag, slag must be rapidly drained from the combustor to limit sulfur gas re-evolution. Analysis indicated that slag mass flow rates in excess of 400 lb/hr should limit sulfur re-evolution. The objective of this 42-month project was to perform a series of tests to determine the factors that control the retention of the sulfur in the slag. 36 days of testing on the combustor were completed prior to the end of this reporting period, 12/31/98. This compares with 16 tests required in the original project plan. Combustor tests in early 1997 with high (37%) ash, Indian coal confirmed that high slag mass flow rates of about 500 lb/hr resulted in retention in the slag of up to 20% of the injected sulfur content mineral matter. To further increase the slag flow rate, rice husks, which contain 20% ash, and rice husk char, which contain 70% ash, were co-fired with coal in the combustor. A series of 13 combustor tests were performed in fourth quarter of 1997 and a further 6 tests were performed in January 1998 and in the summer of 1998. The test objective was to achieve slag flow rates between 500 and 1,000 lb/hr. Due to the very low bulk density of rice husk, compared to pulverized coal, almost the entire test effort focused on developing methods for feeding the rice husks into combustor. In the last test of December 1997, a peak mineral matter, injection rate of 592 lb/hr was briefly achieved by injection of coal, rice husk char, gypsum, and limestone into the combustor. However, no significant sulfur concentration was measured in the slag removed from the combustor. The peak injection rate reached with biomass in the 1997 tests was 310 lb/hr with rice husk, and 584 lb/hr with rice husk char.

  14. A better understanding of biomass co-firing by developing an advanced non-spherical particle tracking model

    DEFF Research Database (Denmark)

    Yin, Chungen; Rosendahl, Lasse Aistrup; Kær, Søren Knudsen

    2004-01-01

    Co-firing biomass with coal or gas in the existing units has gained increasing interest in the recent past to increase the production of environmentally friendly, renewable green power. In this paper, co-firing biomass with natural gas in a 10m long wall-fired burner model is studied numerically....

  15. Co-firing of biomass with coal: constraints and role of biomass pretreatment

    NARCIS (Netherlands)

    Maciejewska, A.K.; Veringa, H.; Sanders, J.P.M.; Peteves, S.D.

    2006-01-01

    This report aims at introducing the aspects of co-firing of biomass with coal. The main focus is given to problems and constraints related to utilizing biomass together with coal for power generation, and the potential of biomass pre-treatment in mitigating these constraints. The work is based on a

  16. Investigating the Energy Potential from Co-firing Coal with Municipal ...

    African Journals Online (AJOL)

    At the same time, there are several coal power plant in the country that generate both heat and power. This study was, therefore, initiated to investigate the effect of co-firing MSW and coal. Proximate and ultimate analyses were conducted on both MSW and coal. The optimum blending ratio of MSW and coal was found to be ...

  17. Cleaning of biomass derived product gas for engine applications and for co-firing in PC-boilers

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E.; Staahlberg, P.; Laatikainen-Luntama, J. [VTT Energy, Espoo (Finland). Energy Production Technologies] [and others

    1997-10-01

    The conventional fluidized-bed combustion has become commercially available also to relatively small scale (5 MWe), but this technology has rather low power-to-heat ratio and consequently it`s potential is limited to applications where district or process heat is the main product. Thus, there seems to be a real need to develop more efficient methods for small-scale power production from biomass. Gasification diesel power plant is one alternative for the small-scale power production, which has clearly higher power-to-heat ratio than can be reached in conventional steam cycles. The main technical problem in this process is the gas cleaning from condensable tars. In addition to the diesel-power plants, there are several other interesting applications for atmospheric-pressure clean gas technology. One alternative for cost-effective biomass utilization is co-firing of biomass derived product gas in existing pulverized coal fired boilers (or other types of boilers and furnaces). The aim of the project is to develop dry gas cleaning methods for gasification-diesel power plants and for other atmospheric-pressure applications of biomass and waste gasification. The technical objectives of the project are as follows: To develop and test catalytic gas cleaning methods for engine. To study the removal of problematic ash species of (CFE) gasification with regard to co-combustion of the product gas in PC boilers. To evaluate the technical and economical feasibility of different small-scale power plant concepts based on fixed-bed updraft and circulating fluidized- bed gasification of biomass and waste. (orig.)

  18. CO-FIRING COAL: FEEDLOT AND LITTER BIOMASS FUELS

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Kalyan Annamalai; Dr. John Sweeten; Dr. Sayeed Mukhtar

    2000-10-24

    The following are proposed activities for quarter 1 (6/15/00-9/14/00): (1) Finalize the allocation of funds within TAMU to co-principal investigators and the final task lists; (2) Acquire 3 D computer code for coal combustion and modify for cofiring Coal:Feedlot biomass and Coal:Litter biomass fuels; (3) Develop a simple one dimensional model for fixed bed gasifier cofired with coal:biomass fuels; and (4) Prepare the boiler burner for reburn tests with feedlot biomass fuels. The following were achieved During Quarter 5 (6/15/00-9/14/00): (1) Funds are being allocated to co-principal investigators; task list from Prof. Mukhtar has been received (Appendix A); (2) Order has been placed to acquire Pulverized Coal gasification and Combustion 3 D (PCGC-3) computer code for coal combustion and modify for cofiring Coal: Feedlot biomass and Coal: Litter biomass fuels. Reason for selecting this code is the availability of source code for modification to include biomass fuels; (3) A simplified one-dimensional model has been developed; however convergence had not yet been achieved; and (4) The length of the boiler burner has been increased to increase the residence time. A premixed propane burner has been installed to simulate coal combustion gases. First coal, as a reburn fuel will be used to generate base line data followed by methane, feedlot and litter biomass fuels.

  19. Experimental analysis of a combustion reactor under co-firing coal with biomass

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Fabyo Luiz; Bazzo, Edson; Oliveira Junior, Amir Antonio Martins de [Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil). LabCET], e-mail: ebazzo@emc.ufsc.br; Bzuneck, Marcelo [Tractebel Energia S.A., Complexo Termeletrico Jorge Lacerda, Capivari de Baixo, SC (Brazil)], e-mail: marcelob@tractebelenergia.com.br

    2010-07-01

    Mitigation of greenhouse gases emission is one of the most important issues in energy engineering. Biomass is a potential renewable source but with limited use in large scale energy production because of the relative smaller availability as compared to fossil fuels, mainly to coal. Besides, the costs concerning transportation must be well analysed to determine its economic viability. An alternative for the use of biomass as a primary source of energy is the co-firing, that is the possibility of using two or more types of fuels combined in the combustion process. Biomass can be co-fired with coal in a fraction between 10 to 25% in mass basis (or 4 to 10% in heat-input basis) without seriously impacting the heat release characteristics of most boilers. Another advantage of cofiring, besides the significant reductions in fossil CO{sub 2} emissions, is the reduced emissions of NO{sub x} and SO{sub x}. As a result, co-firing is becoming attractive for power companies worldwide. This paper presents results of some experimental analysis on co-firing coal with rice straw in a combustion reactor. The influence of biomass thermal share in ash composition is also discussed, showing that alkali and earth alkaline compounds play the most important role on the fouling and slagging behavior when co-firing. Some fusibility correlations that can assist in the elucidation of these behavior are presented and discussed, and then applied to the present study. Results show that for a biomass thermal share up to 20%, significant changes are not expected in fouling and slagging behavior of ash. (author)

  20. Self-cementitious properties of fly ashes from CFBC boilers co-firing coal and high-sulphur petroleum coke

    International Nuclear Information System (INIS)

    Sheng Guanghong; Li Qin; Zhai Jianping; Li Feihu

    2007-01-01

    Self-cementitious properties of fly ash from circulating fluidized bed combustion boiler co-firing coal and high-sulphur petroleum coke (CPFA) were investigated. CPFA was self-cementitious which was affected by its fineness and chemical compositions, especially the contents of SO 3 and free lime (f-CaO). Higher contents of SO 3 and f-CaO were beneficial to self-cementitious strength; the self-cementitious strength increases with a decrease of its 45 μm sieve residue. The expansive ratio of CPFA hardened paste was high because of generation of ettringite (AFt), which was influenced by its water to binder ratio (W/A), curing style and grinding of the ash. The paste cured in water had the highest expansive ratio, and grinding of CPFA was beneficial to its volume stability. The hydration products of CPFA detected by X-ray diffraction (XRD) and scanning electron microscopy (SEM) were portlandite, gypsum, AFt and hydrated calcium silicate (C-S-H)

  1. Co-firing coal with wood pellets for U.S. electricity generation: A real options analysis

    International Nuclear Information System (INIS)

    Xian, Hui; Colson, Gregory; Mei, Bin; Wetzstein, Michael E.

    2015-01-01

    In contrast to EU, U.S. electric utilities are not employing the bioenergy technology of co-firing wood pellets with coal. This difference in employment patterns is explored within a real options analysis (ROA) for possible U.S. utilization of wood pellets, considering fuel-price series from 2009 to 2014. For analysis, these series are divided into two sub-periods based on different market conditions: Infancy (2009–2011) and Substitution (2012–2014). ROA indicates co-firing wood pellets with coal is feasible considering adoption during wood pellets' infancy, under low discount rates, and long power-plant lifespans. A portfolio effect of employing multiple fuels underlies this result. However, co-firing is not currently economically feasible. The different adoption decisions are likely a consequence of recent cheap and abundant U.S. natural gas. For co-fired wood pellets to be feasible, government incentives and/or a market increase in natural gas prices appear necessary. -- Highlights: •Real options analysis indicates co-firing is not currently economically feasible within the U.S. •The recent U.S. natural-gas boom is likely hindering the adoption of co-firing. •For co-fired adoption, government incentives or an increase in natural-gas prices are necessary

  2. Potential high temperature corrosion problems due to co-firing of biomass and fossil fuels

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Vilhelmsen, T.; Jensen, S.A.

    2008-01-01

    Over the past few years, considerable high temperature corrosion problems have been encountered when firing biomass in power plants due to the high content of potassium chloride in the deposits. Therefore, to combat chloride corrosion problems cofiring of biomass with a fossil fuel has been....... However, the most significant corrosion attack was sulphidation attack at the grain boundaries of 18-8 steel after 3 years exposure. The corrosion mechanisms and corrosion rates are compared with biomass firing and coal firing. Potential corrosion problems due to co-firing biomass and fossil fuels...... corrosion mechanisms appear such as sulphidation and hot corrosion due to sulphate deposits. At Studstrup power plant Unit 4, based on trials with exposure times of 3000 h using 0–20% straw co-firing with coal, the plant now runs with a fuel mix of 10% strawþcoal. Based on results from a 3 years exposure...

  3. Co-firing straw and coal in a 150-MWe utility boiler: in situ measurements

    DEFF Research Database (Denmark)

    Hansen, P. F.B.; Andersen, Karin Hedebo; Wieck-Hansen, K.

    1998-01-01

    A 2-year demonstration program is carried out by the Danish utility I/S Midtkraft at a 150-MWe PF-boiler unit reconstructed for co-firing straw and coal. As a part of the demonstration program, a comprehensive in situ measurement campaign was conducted during the spring of 1996 in collaboration...... with the Technical University of Denmark. Six sample positions have been established between the upper part of the furnace and the economizer. The campaign included in situ sampling of deposits on water/air-cooled probes, sampling of fly ash, flue gas and gas phase alkali metal compounds, and aerosols as well...... deposition propensities and high temperature corrosion during co-combustion of straw and coal in PF-boilers. Danish full scale results from co-firing straw and coal, the test facility and test program, and the potential theoretical support from the Technical University of Denmark are presented in this paper...

  4. High Temperature Pt/Alumina Co-Fired System for 500 C Electronic Packaging Applications

    Science.gov (United States)

    Chen, Liang-Yu; Neudeck, Philip G.; Spry, David J.; Beheim, Glenn M.; Hunter, Gary W.

    2015-01-01

    Gold thick-film metallization and 96 alumina substrate based prototype packaging system developed for 500C SiC electronics and sensors is briefly reviewed, the needs of improvement are discussed. A high temperature co-fired alumina material system based packaging system composed of 32-pin chip-level package and printed circuit board is discussed for packaging 500C SiC electronics and sensors.

  5. Rat inhalation test with particles from biomass combustion and biomass co-firing exhaust

    International Nuclear Information System (INIS)

    Bellmann, B; Creutzenberg, O; Ernst, H; Muhle, H

    2009-01-01

    The health effects of 6 different fly ash samples from biomass combustion plants (bark, wood chips, waste wood, and straw), and co-firing plants (coal, co-firing of coal and sawdust) were investigated in a 28-day nose-only inhalation study with Wistar WU rats. Respirable fractions of carbon black (Printex 90) and of titanium dioxide (Bayertitan T) were used as reference materials for positive and negative controls. The exposure was done 6 hours per day, 5 days per week at an aerosol concentration of 16 mg/m 3 . The MMAD of all fly ash samples and reference materials in the inhalation unit were in the range from 1.5 to 3 μm. The investigations focused predominantly on the analysis of inflammatory effects in the lungs of rats using bronchoalveolar lavage (BAL) and histopathology. Different parameters (percentage of polymorphonuclear neutrophils (PMN), interleukin-8 and interstitial inflammatory cell infiltration in the lung tissue) indicating inflammatory effects in the lung, showed a statistically significant increase in the groups exposed to carbon black (positive control), C1 (coal) and C1+BM4 (co-firing of coal and sawdust) fly ashes. Additionally, for the same groups a statistically significant increase of cell proliferation in the lung epithelium was detected. No significant effects were detected in the animal groups exposed to BM1 (bark), BM2 (wood chips), BM3 (waste wood), BM6 (straw) or titanium dioxide.

  6. A Greenhouse Gas Balance of Electricity Production from Co-firing Palm Oil Products from Malaysia

    International Nuclear Information System (INIS)

    Wicke, B.; Dornburg, V.; Faaij, A.; Junginger, M.

    2007-05-01

    The Netherlands imports significant quantities of biomass for energy production, among which palm oil has been used increasingly for co-firing in existing gas-fired power plants for renewable electricity production. Imported biomass, however, can not simply be considered a sustainable energy source. The production and removal of biomass in other places in the world result in ecological, land-use and socio-economic impacts and in GHG emissions (e.g. for transportation). As a result of the sustainability discussions, the Cramer Commission in the Netherlands has formulated (draft) criteria and indicators for sustainable biomass production. This study develops a detailed methodology for determining the GHG balance of co-firing palm oil products in the Netherlands based on the Cramer Commission methodology. The methodology is applied to a specific bio-electricity chain: the production of palm oil and a palm oil derivative, palm fatty acid distillate (PFAD), in Northeast Borneo in Malaysia, their transport to the Netherlands and co-firing with natural gas for electricity production at the Essent Claus power plant

  7. Feasibility study of forest residue use as fuel through co-firing with pellet

    Energy Technology Data Exchange (ETDEWEB)

    Granada, E.; Lareo, G.; Miguez, J.L.; Moran, J.; Porteiro, J. [E.T.S. Ingenieros Industriales, Vigo University, Lagoas-Marcosende s/n, 36200-Vigo (Spain); Ortiz, L. [E.U. Ingenieria Tecnica Forestal, Campus A Xunqueira s/n, 36005-Pontevedra (Spain)

    2006-03-15

    Co-firing is a useful technology for reclaiming waste biomass as fuel. This article studies the use of three different forest residues (Eucalyptus, pine and pine bark) with pellet based on a mixture of fuels prior to combustion. Several combustion configurations, such as the basic configuration (only preheated primary air supply) and other especially developed configurations, such as secondary air and gas recirculation, are studied and optimized. Due to feeding problems, a co-firing feeding hopper was specially developed and honed in order to assure a precise feeding rate of different fuel materials. The experimental results suggest that the pine bark has the best feed performance. Overall, a lower efficiency was achieved compared with pellet-only combustion. Co-firing of these blends is financially viable due to the lower price of the treated pine bark. High percentages of pine bark (50%) reduce efficiency significantly. This is improved with secondary air and recirculation. Pine bark of around 25% is the most suitable configuration. (author)

  8. Rat inhalation test with particles from biomass combustion and biomass co-firing exhaust

    Science.gov (United States)

    Bellmann, B.; Creutzenberg, O.; Ernst, H.; Muhle, H.

    2009-02-01

    The health effects of 6 different fly ash samples from biomass combustion plants (bark, wood chips, waste wood, and straw), and co-firing plants (coal, co-firing of coal and sawdust) were investigated in a 28-day nose-only inhalation study with Wistar WU rats. Respirable fractions of carbon black (Printex 90) and of titanium dioxide (Bayertitan T) were used as reference materials for positive and negative controls. The exposure was done 6 hours per day, 5 days per week at an aerosol concentration of 16 mg/m3. The MMAD of all fly ash samples and reference materials in the inhalation unit were in the range from 1.5 to 3 μm. The investigations focused predominantly on the analysis of inflammatory effects in the lungs of rats using bronchoalveolar lavage (BAL) and histopathology. Different parameters (percentage of polymorphonuclear neutrophils (PMN), interleukin-8 and interstitial inflammatory cell infiltration in the lung tissue) indicating inflammatory effects in the lung, showed a statistically significant increase in the groups exposed to carbon black (positive control), C1 (coal) and C1+BM4 (co-firing of coal and sawdust) fly ashes. Additionally, for the same groups a statistically significant increase of cell proliferation in the lung epithelium was detected. No significant effects were detected in the animal groups exposed to BM1 (bark), BM2 (wood chips), BM3 (waste wood), BM6 (straw) or titanium dioxide.

  9. ENVIRONMENTAL AND SUSTAINABLE TECHNOLOGY EVALUATION: BIOMASS CO-FIRING IN INDUSTRIAL BOILERS--MINNESOTA POWER'S RAPIDS ENERGY CENTER

    Science.gov (United States)

    The U.S. EPA operates the Environmental and Sustainable Technology Evaluation (ESTE) program to facilitate the deployment of innovative technologies through performance verification and information dissemination. This ESTE project involved evaluation of co-firing common woody bio...

  10. Micro-mixer/combustor

    KAUST Repository

    Badra, Jihad Ahmad

    2014-09-18

    A micro-mixer/combustor to mix fuel and oxidant streams into combustible mixtures where flames resulting from combustion of the mixture can be sustained inside its combustion chamber is provided. The present design is particularly suitable for diffusion flames. In various aspects the present design mixes the fuel and oxidant streams prior to entering a combustion chamber. The combustion chamber is designed to prevent excess pressure to build up within the combustion chamber, which build up can cause instabilities in the flame. A restriction in the inlet to the combustion chamber from the mixing chamber forces the incoming streams to converge while introducing minor pressure drop. In one or more aspects, heat from combustion products exhausted from the combustion chamber may be used to provide heat to at least one of fuel passing through the fuel inlet channel, oxidant passing through the oxidant inlet channel, the mixing chamber, or the combustion chamber. In one or more aspects, an ignition strip may be positioned in the combustion chamber to sustain a flame without preheating.

  11. Combustor and method for distributing fuel in the combustor

    Science.gov (United States)

    Uhm, Jong Ho; Ziminsky, Willy Steve; Johnson, Thomas Edward; York, William David

    2016-04-26

    A combustor includes a tube bundle that extends radially across at least a portion of the combustor. The tube bundle includes an upstream surface axially separated from a downstream surface. A plurality of tubes extends from the upstream surface through the downstream surface, and each tube provides fluid communication through the tube bundle. A baffle extends axially inside the tube bundle between adjacent tubes. A method for distributing fuel in a combustor includes flowing a fuel into a fuel plenum defined at least in part by an upstream surface, a downstream surface, a shroud, and a plurality of tubes that extend from the upstream surface to the downstream surface. The method further includes impinging the fuel against a baffle that extends axially inside the fuel plenum between adjacent tubes.

  12. Emissions study of co-firing waste carpet in a rotary kiln.

    Science.gov (United States)

    Lemieux, Paul; Stewart, Eric; Realff, Matthew; Mulholland, James A

    2004-01-01

    Post-consumer carpet represents a high volume, high energy content waste stream. As a fuel for co-firing in cement kilns, waste carpet, like waste tires, has potential advantages. Technological challenges to be addressed include assessing potential emissions, in particular NO emissions (from nylon fiber carpets), and optimizing the carpet feed system. This paper addresses the former. Results of pilot-scale rotary kiln experiments demonstrate the potential for using post-consumer waste carpet as a fuel in cement kilns. Continuous feeding of shredded carpet fiber and ground carpet backing, at rates of up to 30% of total energy input, resulted in combustion without transient puffs and with almost no increase in CO and other products of incomplete combustion as compared to kiln firing natural gas only. NO emissions increased with carpet waste co-firing due to the nitrogen content of nylon fiber. In these experiments with shredded fiber and finely ground backing, carpet nitrogen conversion to NO ranged from 3 to 8%. Conversion increased with enhanced mixing of the carpet material and air during combustion. Carpet preparation and feeding method are controlling factors in fuel N conversion.

  13. From biomass to biocarbon : trends and tradeoffs when CO-firing

    Energy Technology Data Exchange (ETDEWEB)

    McLaughlin, H. [Alterna Energy Inc., Prince George, BC (Canada)

    2009-07-01

    This study examined current market dynamics for biomass-based fuels produced in British Columbia (BC) and consumed by utilities in Sweden. The aim of the study was to compare and develop the properties of 3 biofuels suitable for co-firing: (1) dry wood pellets; (2) torrefied wood pellets; and (3) biocarbon pellets. Biocarbon fuels are processed at higher temperatures to produce a higher energy density fuel per unit weight at a lower overall mass yield. The processing mass balances and physical properties of the pellets were investigated as well as the production and transportation costs of biofuels. Market value, profit, and maximum production costs of the pellets were examined. The study showed that the biofuel supply chain includes significant transportation costs relative to the cost of the raw biomass and biofuel conversion processes. It was concluded that higher energy density biocarbon pellets represent the most cost-effective biofuel option for co-firing with coal. 10 refs., 3 tabs., 4 figs.

  14. Co-Firing Oil Shale with Coal and Other Fuels for Improved Efficiency and Multi-Pollutant Control

    Energy Technology Data Exchange (ETDEWEB)

    Robert A. Carrington; William C. Hecker; Reed Clayson

    2008-06-01

    Oil shale is an abundant, undeveloped natural resource which has natural sorbent properties, and its ash has natural cementitious properties. Oil shale may be blended with coal, biomass, municipal wastes, waste tires, or other waste feedstock materials to provide the joint benefit of adding energy content while adsorbing and removing sulfur, halides, and volatile metal pollutants, and while also reducing nitrogen oxide pollutants. Oil shale depolymerization-pyrolysis-devolatilization and sorption scoping studies indicate oil shale particle sorption rates and sorption capacity can be comparable to limestone sorbents for capture of SO2 and SO3. Additionally, kerogen released from the shale was shown to have the potential to reduce NOx emissions through the well established “reburning” chemistry similar to natural gas, fuel oil, and micronized coal. Productive mercury adsorption is also possible by the oil shale particles as a result of residual fixed-carbon and other observed mercury capture sorbent properties. Sorption properties were found to be a function particle heating rate, peak particle temperature, residence time, and gas-phase stoichmetry. High surface area sorbents with high calcium reactivity and with some adsorbent fixed/activated carbon can be produced in the corresponding reaction zones that exist in a standard pulverized-coal or in a fluidized-bed combustor.

  15. Co-firing high sulfur coal with refuse derived fuels. Technical progress report No. 5, [October--December 1995

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Wei-Ping; Riley, J.T.; Lloyd, W.G.

    1995-11-30

    Studies involving the tubular furnace are in the process of identifying the ideal experimental coal-to-refuse derived fuel(RDF) ratio for use in the AFBC system. A series of experiments with this furnace has been performed to determine the possible chemical pathway for formation of chlorinated organic compounds during the combustion of various RDF sources. Phenol and chlorine appear to be likely reactants necessary for the formation of these compounds. The main goal of these experiment is to determine the exact experimental conditions for the formation of chlorinated organic compounds, as well as methods to inhibit their development. Work on the fluidized bed combustor has involved five combustion runs, in which a combustion efficiency of greater than 96% and with a consistent CO{sub 2} concentration of approximately 13% was obtained. Modifications responsible for these improvements include the addition of the underbed fuel feed system and revision of the flue gas sampling system. New methods of determining combustion efficiency and percentage of SO{sub 2} capture using TG techniques to analyze combustion products are being developed. The current outlook using this TGA/FTIR method is very promising, since previously obscured reactions are being studied. the analysis of combustion products is revealing a more complete picture of the combustion process within the AFBC system.

  16. THE CONCEPTUAL DESIGN ASSESSMENT FOR THE CO-FIRING OF BIO-REFINERY SUPPLIED LIGNIN PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Ted Berglund; Jeffrey T. Ranney; Carol L. Babb; Jacqueline G. Broder

    2001-07-01

    The major aspects of this project are proceeding toward completion. Prior to this quarter, design criteria, tentative site selection, facility layout, and preliminary facility cost estimates were completed and issued. Processing of bio-solids was completed, providing material for the pilot operations. Pilot facility design, equipment selection, and modification were completed during the fourth quarter of 2000. Initial pilot facility shakedown was completed during the fourth quarter. After some unavoidable delays, a suitable representative supply of MSW feed material was procured. During this first quarter of 2001, shredding of the feed material and final feed conditioning were completed. Pilot facility hydrolysis production was completed to produce lignin for co-fire testing. During this quarter, TVA completed the washing and dewatering of the lignin material produced from the MSW hydrolysis. Seven drums of lignin material were washed to recover the acid and sugar from the lignin and provide an improved fuel for steam generation. Samples of both the lignin and bio-solids fuel materials for co-fire testing were sent to the co-fire facility (EERC) for evaluation. After sample evaluation, EERC approved sending the material and all of the necessary fuel for testing was shipped to EERC. EERC has requested and will receive coal typical of the fuel to the TVA-Colbert boilers. This material will be used at EERC as baseline material and for mixing with the bio-fuel for combustion testing. EERC combustion testing of the bio based fuels is scheduled to begin in August of 2001. The TVA-Colbert facility has neared completion of the task to evaluate the co-location of the Masada facility on the operation of the power generation facility. The TVA-Colbert fossil plant is fully capable of providing a reliable steam supply. The preferred steam supply connection points and steam pipeline routing have been identified. The environmental review of the pipeline routing has been completed

  17. Fine structuration of low-temperature co-fired ceramic (LTCC) microreactors.

    Science.gov (United States)

    Jiang, Bo; Haber, Julien; Renken, Albert; Muralt, Paul; Kiwi-Minsker, Lioubov; Maeder, Thomas

    2015-01-21

    The development of microreactors that operate under harsh conditions is always of great interest for many applications. Here we present a microfabrication process based on low-temperature co-fired ceramic (LTCC) technology for producing microreactors which are able to perform chemical processes at elevated temperature (>400 °C) and against concentrated harsh chemicals such as sodium hydroxide, sulfuric acid and hydrochloric acid. Various micro-scale cavities and/or fluidic channels were successfully fabricated in these microreactors using a set of combined and optimized LTCC manufacturing processes. Among them, it has been found that laser micromachining and multi-step low-pressure lamination are particularly critical to the fabrication and quality of these microreactors. Demonstration of LTCC microreactors with various embedded fluidic structures is illustrated with a number of examples, including micro-mixers for studies of exothermic reactions, multiple-injection microreactors for ionone production, and high-temperature microreactors for portable hydrogen generation.

  18. The development of micro-fuel processor using low temperature co-fired ceramic (LTCC)

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Yeena; Kim, Okyoun; Haam, Seungjoo [Department of Chemical Engineering, Yonsei University, Shinchondong Seodaemoonku, Seoul 120-749 (Korea); Hong, Jong-Chul; Oh, Jeong-Hoon; Kim, Woo-Jae; Chung, Chan-Hwa [Department of Chemical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea)

    2006-10-15

    A micro-fuel processor system integrating steam reformer and partial oxidation reactor was manufactured using low temperature co-fired ceramic (LTCC). A CuO/ZnO/Al{sub 2}O{sub 3} catalyst and Pt-based catalyst prepared by wet impregnation were used for steam reforming and partial oxidation, respectively. The performance of the LTCC micro-fuel processor was measured at various operating conditions such as the effect of the ratio of the feed flow rate, the ratio of H{sub 2}O/CH{sub 3}OH and the operating temperature on the LTCC reformer and the CO clean-up system. The hydrogen concentration and the methanol conversion were high and stable as a durable micro-fuel processor from the feasibility test which was operated continuously for 12h. The product gas was composed of 75% hydrogen, 25% carbon dioxide and carbon monoxide (<50ppm) at 260{sup |}C, respectively. (author)

  19. Ash transformation and deposition behavior during co-firing biomass with sewage sludge

    DEFF Research Database (Denmark)

    Wang, Liang; Wu, Hao; Jensen, Peter Arendt

    In the present work, the ash transformation and deposition behavior during wheat straw and wood waste combustion were investigated by combustion experiments in an entrained flow reactor. The influence of sewage sludge addition on ash chemistry and deposition tendency was also studied. During...... deposits, which mainly contain K-silicates, K-Al-silicates and K-Ca-silicates. The sewage sludge addition significantly reduced the water soluble K and Na in the fly ash from wheat straw and wood waste combustion. Compared to pure wheat straw and wood waste, the ash deposition rates were increased due...... to sewage sludge addition. However, the ash deposition propensity decreased significantly. In addition, the content of water soluble K and Cl in the deposits reduced as a result of sewage sludge addition. The results from present work suggest co-firing of sewage sludge could alleviate deposit formation...

  20. Thermal Pretreatment of Wood for Co-gasification/co-firing of Biomass and Coal

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ping [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Howard, Bret [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Hedges, Sheila [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Morreale, Bryan [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Van Essendelft, Dirk [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Berry, David [National Energy Technology Lab. (NETL), Morgantown, WV (United States)

    2013-10-29

    Utilization of biomass as a co-feed in coal and biomass co-firing and co-gasification requires size reduction of the biomass. Reducing biomass to below 0.2 mm without pretreatment is difficult and costly because biomass is fibrous and compressible. Torrefaction is a promising thermal pretreatment process and has the advantages of increasing energy density, improving grindability, producing fuels with more homogenous compositions and hydrophobic behavior. Temperature is the most important factor for the torrefaction process. Biomass grindability is related to cell wall structure, thickness and composition. Thermal treatment such as torrefaction can cause chemical changes that significantly affect the strength of biomass. The objectives of this study are to understand the mechanism by which torrefaction improves the grindability of biomass and discuss suitable temperatures for thermal pretreatment for co-gasification/co-firing of biomass and coal. Wild cherry wood was selected as the model for this study. Samples were prepared by sawing a single tangential section from the heartwood and cutting it into eleven pieces. The samples were consecutively heated at 220, 260, 300, 350, 450 and 550⁰C for 0.5 hr under flowing nitrogen in a tube furnace. Untreated and treated samples were characterized for physical properties (color, dimensions and weight), microstructural changes by SEM, and cell wall composition changes and thermal behaviors by TGA and DSC. The morphology of the wood remained intact through the treatment range but the cell walls were thinner. Thermal treatments were observed to decompose the cell wall components. Hemicellulose decomposed over the range of ~200 to 300⁰C and resulted in weakening of the cell walls and subsequently improved grindability. Furthermore, wood samples treated above 300⁰C lost more than 39% in mass. Therefore, thermal pretreatment above the hemicelluloses decomposition temperature but below 300⁰C is probably sufficient to

  1. Modelling of Devolatilization in Fluidized Bed Combustion

    DEFF Research Database (Denmark)

    Stenseng, Mette; Lin, Weigang; Johnsson, Jan Erik

    1997-01-01

    A mathematical model is developed to describe the devolatilization process in a circulating fluidized bed combustor. The model is a combination of two submodels: single particle devolatilization and fluid dynamics. The single particle model includes the influence of both chemical kinetics and hea...

  2. Resource potential for renewable energy generation from co-firing of woody biomass with coal in the Northern U.S.

    Science.gov (United States)

    Michael E. Goerndt; Francisco X. Aguilar; Kenneth Skog

    2013-01-01

    Past studies have established measures of co-firing potential at varying spatial scales to assess opportunities for renewable energy generation from woody biomass. This study estimated physical availability, within ecological and public policy constraints, and associated harvesting and delivery costs of woody biomass for co-firing in selected power plants of the...

  3. Emissions from laboratory combustor tests of manufactured wood products

    Energy Technology Data Exchange (ETDEWEB)

    Wilkening, R.; Evans, M.; Ragland, K. [Univ. of Wisconsin, Madison, WI (United States); Baker, A. [USDA Forest Products Lab., Madison, WI (United States)

    1993-12-31

    Manufactured wood products contain wood, wood fiber, and materials added during manufacture of the product. Manufacturing residues and the used products are burned in a furnace or boiler instead of landfilling. Emissions from combustion of these products contain additional compounds from the combustion of non-wood material which have not been adequately characterized to specify the best combustion conditions, emissions control equipment, and disposal procedures. Total hydrocarbons, formaldehyde, higher aldehydes and carbon monoxide emissions from aspen flakeboard and aspen cubes were measured in a 76 mm i.d. by 1.5 m long fixed bed combustor as a function of excess oxygen, and temperature. Emissions of hydrocarbons, aldehydes and CO from flakeboard and from clean aspen were very sensitive to average combustor temperature and excess oxygen. Hydrocarbon and aldehyde emissions below 10 ppM were achieved with 5% excess oxygen and 1,200{degrees}C average temperature for aspen flakeboard and 1,100{degrees}C for clean aspen at a 0.9 s residence time. When the average temperature decreased below these levels, the emissions increased rapidly. For example, at 950{degrees}C and 5% excess oxygen the formaldehyde emissions were over 1,000 ppM. These laboratory tests reinforce the need to carefully control the temperature and excess oxygen in full-scale wood combustors.

  4. A review of oxy-fuel combustion in fluidized bed reactors

    CSIR Research Space (South Africa)

    Mathekga, HI

    2016-06-01

    Full Text Available Presently, there is no detailed review that summarizes the current knowledge status on oxy-fuel combustion in fluidized bed combustors. This paper reviewed the existing literature in heat transfer, char combustion and pollutant emissions oxy...

  5. Potassium Sodium Niobate-Based Lead-Free Piezoelectric Multilayer Ceramics Co-Fired with Nickel Electrodes

    Directory of Open Access Journals (Sweden)

    Shinichiro Kawada

    2015-11-01

    Full Text Available Although lead-free piezoelectric ceramics have been extensively studied, many problems must still be overcome before they are suitable for practical use. One of the main problems is fabricating a multilayer structure, and one solution attracting growing interest is the use of lead-free multilayer piezoelectric ceramics. The paper reviews work that has been done by the authors on lead-free alkali niobate-based multilayer piezoelectric ceramics co-fired with nickel inner electrodes. Nickel inner electrodes have many advantages, such as high electromigration resistance, high interfacial strength with ceramics, and greater cost effectiveness than silver palladium inner electrodes. However, widely used lead zirconate titanate-based ceramics cannot be co-fired with nickel inner electrodes, and silver palladium inner electrodes are usually used for lead zirconate titanate-based piezoelectric ceramics. A possible alternative is lead-free ceramics co-fired with nickel inner electrodes. We have thus been developing lead-free alkali niobate-based multilayer ceramics co-fired with nickel inner electrodes. The normalized electric-field-induced thickness strain (Smax/Emax of a representative alkali niobate-based multilayer ceramic structure with nickel inner electrodes was 360 pm/V, where Smax denotes the maximum strain and Emax denotes the maximum electric field. This value is about half that for the lead zirconate titanate-based ceramics that are widely used. However, a comparable value can be obtained by stacking more ceramic layers with smaller thicknesses. In the paper, the compositional design and process used to co-fire lead-free ceramics with nickel inner electrodes are introduced, and their piezoelectric properties and reliabilities are shown. Recent advances are introduced, and future development is discussed.

  6. Potassium Sodium Niobate-Based Lead-Free Piezoelectric Multilayer Ceramics Co-Fired with Nickel Electrodes

    Science.gov (United States)

    Kawada, Shinichiro; Hayashi, Hiroyuki; Ishii, Hideki; Kimura, Masahiko; Ando, Akira; Omiya, Suetake; Kubodera, Noriyuki

    2015-01-01

    Although lead-free piezoelectric ceramics have been extensively studied, many problems must still be overcome before they are suitable for practical use. One of the main problems is fabricating a multilayer structure, and one solution attracting growing interest is the use of lead-free multilayer piezoelectric ceramics. The paper reviews work that has been done by the authors on lead-free alkali niobate-based multilayer piezoelectric ceramics co-fired with nickel inner electrodes. Nickel inner electrodes have many advantages, such as high electromigration resistance, high interfacial strength with ceramics, and greater cost effectiveness than silver palladium inner electrodes. However, widely used lead zirconate titanate-based ceramics cannot be co-fired with nickel inner electrodes, and silver palladium inner electrodes are usually used for lead zirconate titanate-based piezoelectric ceramics. A possible alternative is lead-free ceramics co-fired with nickel inner electrodes. We have thus been developing lead-free alkali niobate-based multilayer ceramics co-fired with nickel inner electrodes. The normalized electric-field-induced thickness strain (Smax/Emax) of a representative alkali niobate-based multilayer ceramic structure with nickel inner electrodes was 360 pm/V, where Smax denotes the maximum strain and Emax denotes the maximum electric field. This value is about half that for the lead zirconate titanate-based ceramics that are widely used. However, a comparable value can be obtained by stacking more ceramic layers with smaller thicknesses. In the paper, the compositional design and process used to co-fire lead-free ceramics with nickel inner electrodes are introduced, and their piezoelectric properties and reliabilities are shown. Recent advances are introduced, and future development is discussed. PMID:28793646

  7. A low temperature co-fired ceramic power inductor manufactured using a glass-free ternary composite material system

    Science.gov (United States)

    Li, Yuanxun; Xie, Yunsong; Xie, Ru; Chen, Daming; Han, Likun; Su, Hua

    2018-03-01

    A glass-free ternary composite material system (CMS) manufactured employing the low temperature ( 890 ° C ) co-fired ceramic (LTCC) technique is reported. This ternary CMS consists of silver, NiCuZn ferrite, and Zn2SiO4 ceramic. The reported device fabricated from this ternary CMS is a power inductor with a nominal inductance of 1.0 μH. Three major highlights were achieved from the device and the material study. First, unlike most other LTCC methods, no glass is required to be added in either of the dielectric materials in order to co-fire the NiCuZn ferrite, Zn2SiO4 ceramic, and silver. Second, a successfully co-fired silver, NiCuZn, and Zn2SiO4 device can be achieved by optimizing the thermal shrinkage properties of both NiCuZn and Zn2SiO4, so that they have a very similar temperature shrinkage profile. We have also found that strong non-magnetic elemental diffusion occurs during the densification process, which further enhances the success rate of manufacturing co-fired devices. Last but not least, elemental mapping suggests that strong magnetic elemental diffusion between NiCuZn and Zn2SiO4 has been suppressed during the co-firing process. The investigation of electrical performance illustrates that while the ordinary binary CMS based power inductor can deal with 400 mA DC, the ternary CMS based power inductor is able to handle higher DC currents, 700 mA and 620 mA DC, according to both simulation and experiment demonstrations, respectively.

  8. Evaluation of a Liquid-Fueled Pulse Detonation Engine Combustor

    National Research Council Canada - National Science Library

    Forster, David

    1998-01-01

    ... for use in the combustor. The chosen atomizer was installed in the combustor geometries and then analyzed over a range of combustor conditions to measure deflagration to detonation transition (DDT...

  9. DLE combustor exceeds performance guarantees

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, John; Leonard, Gary [GE Marine and Industrial Engines, Evendale, OH (United States)

    1995-05-01

    The 50MW Gent power station in Belgium started operating in 1994 using General Electric`s high efficiency LM6000 gas turbine. This article describes performance testing of the new Dry Low Emissions (DLE) combustion system fitted to the aeroderivative gas turbine, which has allowed the combined cycle, cogeneration facility to function at full-power, with low emissions of nitrogen oxides, carbon monoxide, and unburned hydrocarbons. Conventional combustion systems are compared to the new premixed lean combustor used here. (UK)

  10. Analysis of circulating fluidized bed combustion technology

    Energy Technology Data Exchange (ETDEWEB)

    Furusawa, Takehiko; Shimizu, Tadaaki; Yang, Guilin

    1987-05-20

    Fluidized bed combustors are commercialized as a technology to combust solid fuels with higher efficiency and lower emission and have functions of both combustion and simultaneous desulfurization and NOx reduction with dense phase fluidized beds but it is not so easy to realize these problems. The technology of circulating fluidized bed coal combustion is expected to offer potential break-through of various problems. But the details are not reported so far. Quantitative analysis of present situations was conducted and future problems were shown with officially available informations. This analysis includes the circulating rate and loading of solids, heat recovery and heat transfer rate as a function of loading of solids, the design of cyclones related to high solid concentration within the combustor, sulfur retention with reduced Ca/S ratio and problems related to NOx reduction to be developed in future. (51 refs, 23 figs, 8 tabs)

  11. Processing, microstructure, and electric properties of buried resistors in low-temperature co-fired ceramics

    International Nuclear Information System (INIS)

    Yang, Pin; Rodriguez, Mark A.; Kotula, Paul; Miera, Brandon K.; Dimos, Duane

    2001-01-01

    The electrical properties of ruthenium oxide based devitrifiable resistors embedded within low-temperature co-fired ceramics were investigated from -100 o C to 100 o C. Special attention was given to the processing conditions and their effects on resistance and temperature coefficient of resistance (TCR). Results indicate that within this temperature range the conductance for these buried resistors is limited by tunneling of charge carriers through the thin glass layer between ruthenium oxide particles. A modified version of the tunneling barrier model is proposed to account for the microstructure ripening observed during thermal processing. The model parameters determined from curve fitting show that charging energy (i.e., the energy required for a charge carrier to tunnel through the glass barrier) is strongly dependent on particle size and particle--particle separation between ruthenium oxide grains. Initial coarsening of ruthenium oxide grains was found to reduce the charging energy and lower the resistance. However, when extended ripening occurs, the increase in particle--particle separation increases the charging energy, reduces the tunneling probability and gives rise to a higher resistance. The tradeoff between these two effects results in an optimum microstructure with a minimum resistance and TCR. Furthermore, the TCR of these buried resistors has been shown to be governed by the magnitude of the charging energy. Model parameters determined by our analysis appear to provide quantitative physical interpretations to the microstructural changes in the resistor, which in turn, are controlled by the processing conditions

  12. Effect of biomass on burnouts of Turkish lignites during co-firing

    International Nuclear Information System (INIS)

    Haykiri-Acma, H.; Yaman, S.

    2009-01-01

    Co-firing of some low quality Turkish lignites with woody shells of sunflower seed was investigated via non-isothermal thermogravimetric analysis method. For this purpose, Yozgat-Sorgun, Erzurum-Askale, Tuncbilek, Gediz, and Afsin-Elbistan lignites were selected, and burnouts of these lignites were compared with those of their blends. Biomass was blended as much as 10 and 20 wt.% of the lignites, and heating was performed up to 900 deg. C at a heating rate of 40 deg. C/min under dry air flow of 40 mL/min. This study revealed that the same biomass species may have different influences on the burnout yields of the lignites. Burnouts of Erzurum-Askale lignite increased at any temperature with the increasing ratio of biomass in the blend, whereas burnout yields of other lignites decreased to some extent. Nevertheless, the blends of Turkish lignites with sunflower seed shell did not behave in very different way, and it can be concluded that they are compatible in terms of burnouts for co-combustion in a combustion system. Although the presence of biomass in the lignite blends caused to some decreases in the final burnouts, the carbon dioxide neutral nature of biomass should be taken into account, and co-combustion is preferable for waste-to-energy-management.

  13. Corrosion Testing of Thermal Spray Coatings in a Biomass Co-Firing Power Plant

    Directory of Open Access Journals (Sweden)

    Maria Oksa

    2016-11-01

    Full Text Available Large-scale use of biomass and recycled fuel is increasing in energy production due to climate and energy targets. A 40% cut in greenhouse gas emission compared to 1990 levels and at least a 27% share of renewable energy consumption are set in EU Energy Strategy 2030. Burning fuels with high content of corrosive species such as chlorine and heavy metals causes deterioration of boiler components, shortened lifetime, limited availability of a plant and hence higher maintenance and investment costs and lower thermal and economic efficiency. Coatings can be applied to protect the critical boiler components against high temperature corrosion. In this study, five thermal spray coatings were tested in an actual biomass co-firing boiler for 1300 h with a measurement probe. The coatings were analyzed after the exposure by metallographic means and scanning electron microscope/energy-dispersive X-ray spectroscope (SEM/EDX. The deposits formed on the specimens were analyzed by X-ray fluorescence. At 550 °C, the coatings showed excellent corrosion performance compared to reference material ferritic steel T92. At 750 °C, tube material A263 together with NiCr and NiCrTi had the highest corrosion resistance. To conclude, thermal spray coatings can offer substantial corrosion protection in biomass and recycled fuel burning power plants.

  14. Ash transformation in suspension fired boilers co-firing coal and straw

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Peter Arendt; Jensen, Anker Degn

    Appendix C: Paper in Fuel 87 (2008) 3304-3312: A kinetic study of gaseous potassium capture by coal minerals in a high temperature fixed-bed reactor......Appendix C: Paper in Fuel 87 (2008) 3304-3312: A kinetic study of gaseous potassium capture by coal minerals in a high temperature fixed-bed reactor...

  15. X-Ray Characterization of Resistor/Dielectric Material for Low Temperature Co-Fired Ceramic Packages

    International Nuclear Information System (INIS)

    DIMOS, DUANE B.; KOTULA, PAUL G.; RODRIGUEZ, MARK A.; YANG, PIN

    1999-01-01

    High temperature XRD has been employed to monitor the devitrification of Dupont 951 low temperature co-fired ceramic (LTCC) and Dupont E84005 resistor ink. The LTCC underwent devitrification to an anorthite phase in the range of 835-875 C with activation energy of 180 kJ/mol as calculated from kinetic data. The resistor paste underwent devitrification in the 835-875 C range forming monoclinic and hexagonal celcian phases plus a phase believed to be a zinc-silicate. RuO(sub 2) appeared to be stable within this devitrified resistor matrix. X-ray radiography of a co-fired circuit indicated good structural/chemical compatibility between the resistor and LTCC

  16. Exergetic analysis of a steam power plant using coal and rice straw in a co-firing process

    Energy Technology Data Exchange (ETDEWEB)

    Restrepo, Alvaro; Miyake, Raphael Guardini; Bazzo, Edson [Federal University of Santa Catarina (UFSC), Dept. of Mechanical Engineering, Florianopolis, SC (Brazil)], e-mails: arestrep@labcet.ufsc.br, miyake@labcet.ufsc.br, ebazzo@emc.ufsc.br; Bzuneck, Marcelo [Tractebel Energia S.A., Capivari de Baixo, SC (Brazil). U.O. Usina Termeletrica Jorge Lacerda C.], e-mail: marcelob@tractebelenergia.com.br

    2010-07-01

    This paper presents an exergetic analysis concerning an existing 50 M We steam power plant, which operates with pulverized coal from Santa Catarina- Brazil. In this power plant, a co-firing rice straw is proposed, replacing up to 10% of the pulverized coal in energy basis required for the boiler. Rice straw has been widely regarded as an important source for bio-ethanol, animal feedstock and organic chemicals. The use of rice straw as energy source for electricity generation in a co-firing process with low rank coal represents a new application as well as a new challenge to overcome. Considering both scenarios, the change in the second law efficiency, exergy destruction, influence of the auxiliary equipment and the greenhouse gases emissions such as CO{sub 2} and SO{sub 2} were considered for analysis. (author)

  17. Health and environmental effects of refuse derived fuel (RDF) production and RDF/coal co-firing technologies

    Energy Technology Data Exchange (ETDEWEB)

    O' Toole, J.J.; Wessels, T.E.; Lynch, J.F.; Fassel, V.A.; Lembke, L.L.; Kniseley, R.N.; Norton, G.A.; Junk, G.A.; Richard, J.J.; Dekalb, E.L.; Dobosy, R.J.

    1981-10-01

    Six facilities, representing the scope of different co-firing techniques with their associated RDF production systems were reviewed in detail for combustion equipment, firing modes, emission control systems, residue handling/disposal, and effluent wastewater treatment. These facilities encompass all currently operational or soon to be operational co-firing plants and associated RDF production systems. Occupational health and safety risks for these plants were evaluated on the basis of fatal and nonfatal accidents and disease arising from the respective fuel cycles, coal and RDF. Occupational risks include exposure to pathogenic organisms in the workplace. Unusual events that are life threatening in the RDF processing industry (e.g., explosions) are also discussed and remedial and safety measures reviewed. 80 refs., 4 figs., 30 tabs.

  18. Development of a modeling approach to predict ash formation during co-firing of coal and biomass

    Energy Technology Data Exchange (ETDEWEB)

    Doshi, V. [School of Engineering, Monash University Sunway Campus, Jalan Lagoon Selatan, Bandar Sunway, Selangor (Malaysia); Vuthaluru, H.B. [Curtin University of Technology, Kent Street, Bentley 6104, Perth, Western Australia (Australia); Korbee, R. [HRL Technology, Ipswich, Queensland (Australia); Kiel, J.H.A. [ECN Biomass, Coal and Environmental Research, P.O. Box 1, 1755 ZG Petten (Netherlands)

    2009-09-15

    The scope of this paper includes the development of a modelling approach to predict the ash release behaviour and chemical composition of inorganics during co-firing of coal and biomass. In the present work, an advanced analytical method was developed and introduced to determine the speciation of biomass using pH extraction analysis. Biomass samples considered for the study include wood chips, wood bark and straw. The speciation data was used as an input to the chemical speciation model to predict the behaviour and release of ash. It was found that the main gaseous species formed during the combustion of biomass are KCl, NaCl, K{sub 2}SO{sub 4} and Na{sub 2}SO{sub 4}. Calculations of gas-to-particle formation were also carried out to determine the chemical composition of coal and biomass during cooling which takes place in the boiler. It was found that the heterogeneous condensation occurring on heat exchange surfaces of boilers is much more than homogeneous condensation. Preliminary studies of interaction between coal and biomass during ash formation process showed that Al, Si and S elements in coal may have a 'buffering' effect on biomass alkali metals, thus reducing the release of alkali-gases which act as precursors to ash deposition and corrosion during co-firing. The results obtained in this work are considered to be valuable and form the basis for accurately determining the ash deposition during co-firing. (author)

  19. An artificial intelligence treatment of devolatilization for pulverized coal and biomass in co-fired flames

    Energy Technology Data Exchange (ETDEWEB)

    Abbas, T.; Awais, M.M.; Lockwood, F.C. [Lahore University of Management & Science, Lahore (Pakistan)

    2003-02-01

    In most of the existing predictive procedures for devolatilization, combustion and emissions are modeled by a single-step, global chemical reaction, with the yield of volatile matter presumed to experience mixing-controlled combustion. Several more detailed multi-step coal devolatilization models have recently emerged. A common shortcoming of these models is that they require a large set of input data, involving kinetic parameters, gas precursor compositions, and additional parameters describing the coal's polymeric structure. The input data must be generated from an extensive series of experimental measurements for each coal of interest. Very significant computational expense and application restricted to coals, which have already been studied, are implied. All of these problems are exacerbated when coal blending or co-firing with renewable solid fuels, such as forest and agricultural waste, and sewage sludge, is considered. In this paper, a new approach based on neural networks is proposed; it is capable of handling a range of solid fuels. The model considers heating rate, fuel atomic ratios, and the temperature of the fuel particles to predict the volatiles released by the particles. The 'learning' properties of the model implicitly facilitate all the physical conditions, of devolatilization experiments, which were used during its training and validation phases. The neural-network model was implemented into an existing 3D CFD combustion code. The predictions for high- and low-NOx burners demonstrate improved prediction of in-flame data for reduced computational effort, one-fifth of that with the standard single-global-reaction devolatilization model. Its devolatilization predictions have also been compared with a detailed devolatilization model (FLASHCHAIN) and were found to be comparable.

  20. Logistics, Costs, and GHG Impacts of Utility-Scale Co-Firing with 20% Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Nichol, Corrie Ian [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2013-06-01

    This study analyzes the possibility that biopower in the U.S. is a cost-competitive option to significantly reduce greenhouse gas emissions. In 2009, net greenhouse gas (GHG) emitted in the United States was equivalent to 5,618 million metric tons CO2, up 5.6% from 1990 (EPA 2011). Coal-fired power generation accounted for 1,748 million metric tons of this total. Intuitively, life-cycle CO2 emissions in the power sector could be reduced by substituting renewable biomass for coal. If just 20% of the coal combusted in 2009 had been replaced with biomass, CO2 emissions would have been reduced by 350 million metric tons, or about 6% of net annual GHG emission. This would have required approximately 225 million tons of dry biomass. Such an ambitious fuel substitution would require development of a biomass feedstock production and supply system tantamount to coal. This material would need to meet stringent specifications to ensure reliable conveyance to boiler burners, efficient combustion, and no adverse impact on heat transfer surfaces and flue gas cleanup operations. Therefore, this report addresses the potential cost/benefit tradeoffs of co-firing 20% specification-qualified biomass (on an energy content basis) in large U.S. coal-fired power plants. The dependence and sensitivity of feedstock cost on source of material, location, supply distance, and demand pressure was established. Subsequently, the dependence of levelized cost of electricity (LCOE) on feedstock costs, power plant feed system retrofit, and impact on boiler performance was determined. Overall life-cycle assessment (LCA) of greenhouse gas emissions saving were next evaluated and compared to wind and solar energy to benchmark the leading alternatives for meeting renewable portfolio standards (or RPS).

  1. Investigation on minerals migration during co-firing of different straw/coal blending ratios

    International Nuclear Information System (INIS)

    Wang, Cuiping; Xu, Chenghao; Cao, Zhanmin; Di, Haisheng

    2013-01-01

    Highlights: • The blending ratios of coal/straw caused inhibited or promoted ash quantity effects. • The chlorine element had great influence on ash quantity and ash components. • The minerals coupling reaction was verified by the newborn stable compounds. • The 40 wt.% coal-blending ratio was significant in the prevention of slagging and corrosion. - Abstract: A set of experiments on biomass/coal co-combustion were performed to investigate the ashing behavior in a tube furnace and a Muffle furnace respectively. The eight blending samples in terms of coal contents were 0, 5, 15, 20, 40, 60, 90, and 100 wt.%. The blending ratios of coal/straw caused different ash quantity effects, ash quantity was inhibited when the coal ratio was from 5 wt.% to 15 wt.%, and promoted when higher coal ratios. Combined the morphology analysis, mineral analysis, and chlorine equilibrium analysis, the chlorine content in the drop-tube furnace ash rapidly decreased when the coal ratio was from 5 wt.% to 15 wt.%, and the Cl content of the fly ash from 40 wt.% coal blend was very low at 0.49%. In the ash from the 40 wt.% coal blend, the CaCO 3 and CaSO 4 contents were very low for coupling reaction between the biomass and coal minerals under high temperature, the new and stable CaAl 2 Si 2 O 8 , K 2 Fe 4 Si 12 O 30 , and KAlSi 3 O 8 minerals were produced, which accompanied the ash promotion effect. The ashing behavior of 40 wt.% coal-blending is largely significant in preventing slagging and corrosion during straw co-firing and coal plant operation

  2. Fabrication and characterization of low temperature co-fired cordierite glass–ceramics from potassium feldspar

    International Nuclear Information System (INIS)

    Wu, Jianfang; Li, Zhen; Huang, Yanqiu; Li, Fei; Yang, Qiuran

    2014-01-01

    Highlights: • Low cost cordierite glass–ceramics were fabricated from potassium feldspar. • The glass–ceramics could be highly densified below 950 °C. • The glass–ceramics exhibit extraordinary properties. • The glass–ceramics can be used as LTCC substrates. • The excess SiO 2 improved the microstructure and properties of the glass–ceramics. -- Abstract: Cordierite glass–ceramics for low temperature co-fired ceramic (LTCC) substrates were fabricated successfully using potassium feldspar as the main raw material. The sintering and crystallization behaviors of the glass–ceramics were investigated by the differential scanning calorimetry (DSC), X-ray diffraction (XRD), and field emission scanning electron microscope (FESEM). The results indicated that the glass–ceramics could be highly densified at 850 °C and the cordierite was the main crystalline phase precipitated from the glasses in the temperature range between 900 and 925 °C. The study also evaluated the physical properties including dielectric properties, thermal expansion and flexural strength of the glass–ceramics. The glass–ceramics showed low dielectric constants in the range of 6–8 and low dielectric losses in the range of 0.0025–0.01. The coefficients of thermal expansion (CTEs) are between 4.32 and 5.48 × 10 −6 K −1 and flexural strength of the glass–ceramics are 90–130 MPa. All of those qualify the glass–ceramics for further research to be used as potential LTCC substrates in the multilayer electronic substrate field. Additionally, the excess SiO 2 acted as a great role in improving the sinterability of the glasses, and the microstructure and dielectric properties of the relevant glass–ceramics

  3. CONCEPTUAL DESIGN ASSESSMENT FOR THE CO-FIRING OF BIO-REFINERY SUPPLIED LIGNIN PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Ted Berglund; Jeffrey T. Ranney; Carol L. Babb; Jacqueline G. Broder

    2001-01-01

    The major aspects of this project are proceeding toward completion. Prior to this quarter, design criteria, tentative site selection, facility layout, and preliminary facility cost estimates have been completed and issued for review. Processing of bio-solids was completed, providing material for the pilot operations. Pilot facility design, equipment selection, and modification were completed during the fourth quarter. Initial pilot facility shakedown was completed during the fourth quarter. During pilot plant shakedown operations, several production batch test runs were performed. These pilot tests were coupled with laboratory testing to confirm pilot results. In initial batches of operations, cellulose to glucose conversions of 62.5% and 64.8% were observed in laboratory hydrolysis. As part of this testing, lignin dewatering was tested using laboratory and vendor-supplied filtration equipment. Dewatering tests reported moisture contents in the lignin of between 50% and 60%. Dewatering parameters and options will continue to be investigated during lignin production. After some unavoidable delays, a suitable representative supply of MSW feed material was procured. Shredding of the feed material was completed and final drying of the feed is expected to be completed by late January. Once feed drying is completed, pilot facility production will begin to produce lignin for co-fire testing. Facility modifications are expected to continue to improve facility operations and performance during the first quarter of 2001. The TVA-Colbert facility continues to make progress in evaluating the co-location of the Masada facility on the operation of the power generation facility. The TVA-Colbert fossil plant is fully capable of providing a reliable steam supply. The preferred steam supply connection points and steam pipeline routing have been identified. The environmental review of the pipeline routing has been completed and no major impacts have been identified. Detailed

  4. Combustor deployments of femtosecond laser written fiber Bragg grating arrays for temperature measurements surpassing 1000°C

    Science.gov (United States)

    Walker, Robert B.; Ding, Huimin; Coulas, David; Mihailov, Stephen J.; Duchesne, Marc A.; Hughes, Robin W.; McCalden, David J.; Burchat, Ryan; Yandon, Robert; Yun, Sangsig; Ramachandran, Nanthan; Charbonneau, Michel

    2017-05-01

    Femtosecond Infrared (fs-IR) laser written fiber Bragg gratings (FBGs), have demonstrated great potential for extreme sensing. Such conditions are inherent to advanced power plant technologies and gas turbine engines, under development to reduce greenhouse gas emissions; and the ability to measure temperature gradients in these harsh environments is currently limited by the lack of sensors and controls capable of withstanding the high temperature, pressure and corrosive conditions present. This paper reviews our fabrication and deployment of hundreds of fs-IR written FBGs, for monitoring temperature gradients of an oxy-fuel fluidized bed combustor and an aerospace gas turbine combustor simulator.

  5. Bed agglomeration characteristics of palm shell and corncob combustion in fluidized bed

    International Nuclear Information System (INIS)

    Chaivatamaset, Pawin; Sricharoon, Panchan; Tia, Suvit

    2011-01-01

    Bed particle agglomeration was studied experimentally in an atmospheric laboratory scale fluidized bed combustor using quartz sand as bed material. Palm shell and corncob were tested. The objectives of the study were (i) to describe the contributions of the biomass ash properties and the operating conditions on the bed agglomeration tendency in term of the bed defluidization time (t def ) and the extent of potassium accumulation in the bed (K/Bed) and (ii) to further elucidate the ash inorganic behaviors and the governing bed agglomeration mechanisms. Defluidization caused by the bed agglomeration was experienced in all experiments during combustion of these biomasses, as a consequence of the presence of potassium in biomass. The experimental results indicated that biomass ash characteristics were the significant influence on the bed agglomeration. The increasing bed temperature, bed particle size and static bed height and the decreasing fluidizing air velocity enhanced the bed agglomeration tendency. The SEM/EDS analyses on the agglomerates confirmed that the agglomeration was attributed to the formation of potassium silicate liquid enriched on the surface of quartz sand particles in conjunction with the high surface temperature of the burning biomass char particles. Thermodynamic examination based on the phase diagram analysis confirmed that the molten phase formation was responsible for the agglomeration. In this study, the high molten ash fraction resulting from the high potassium content in biomass promoted the agglomeration and thus defluidization. - Highlights: → Palm shell and corncob of Thailand are tested their bed agglomeration behaviors during fluidized bed combustion. → The increase of bed temperature, bed particle size and static bed height and the decrease of air velocity enhance bed agglomeration. → The formation of ash derived potassium silicate melts enriched on sand surface is the key process. → The collision between char and sand

  6. Combustor assembly in a gas turbine engine

    Science.gov (United States)

    Wiebe, David J; Fox, Timothy A

    2013-02-19

    A combustor assembly in a gas turbine engine. The combustor assembly includes a combustor device coupled to a main engine casing, a first fuel injection system, a transition duct, and an intermediate duct. The combustor device includes a flow sleeve for receiving pressurized air and a liner disposed radially inwardly from the flow sleeve. The first fuel injection system provides fuel that is ignited with the pressurized air creating first working gases. The intermediate duct is disposed between the liner and the transition duct and defines a path for the first working gases to flow from the liner to the transition duct. An intermediate duct inlet portion is associated with a liner outlet and allows movement between the intermediate duct and the liner. An intermediate duct outlet portion is associated with a transition duct inlet section and allows movement between the intermediate duct and the transition duct.

  7. Increased electricity production from straw by co-firing with woody biomass; Oekad elproduktion med halm genom sameldning med traedbraenslen

    Energy Technology Data Exchange (ETDEWEB)

    Hedman, Henry; Nordgren, Daniel; Bostroem, Dan; Oehman, Marcus; Padban, Nader

    2011-01-15

    The use of straw in pulverised fuel-fired boiler is great technical challenge, especially when it comes to dealing with problems from slagging and fouling. Introduction of straw in the fuel mix of Swedish boilers will most likely be done by co-firing of woody biomass with straw, and this can provide a means to reduce the (well-documented) problems with fouling and slagging from straw. The project will focus on the faith of alkali metals (K and Na) as well as studies on the slagging and fouling propensity in pulverised fuel-fired boilers when straw is co-fired with woody biomass. A total of 5 different fuel mixtures has been fired in a 150 kW pilot-scale pulverised fuel-fired burner: (i) straw 100 %, (ii) straw/bark 50/50 %, (iii) straw/bark 75/25 % (iv) straw/wood 75/25 % (v) straw/wood 50/50 % (wt-%). The adding of woody biomass to straw has in all of the above-mentioned cases had some positive effect. In general, in all of the ash deposits, an increase in the concentration of Calcium (Ca) has been observed as well as a decrease in the concentrations of Potassium (K) and Silicon (Si). These general trends should be considered as a positive when combustion of straw is considered. Out of all ash deposits collected in the furnace, the characteristics of the bottom ash displayed the largest (positive) change and visual inspections and chemical analysis of the bottom ash showed that the ash had become more porous and contained more Calcium as more woody biomass was introduced in the fuel mix. The deposit build-up rate on the air cooled probes was reduced when more woody biomass was co-fired with straw. The reduction was highest in the trial where 50% woody biomass was used and the most apparent changes in composition could be seen in Calcium (increase) and Potassium (decrease). Danish experiences from introducing straw in pulverised fuel-fired boiler indicate that extra soot-blowers should be considered at the furnace walls and in connection to screen-tubes (if any

  8. Pressurized Fluidized Bed Combustion of Sewage Sludge

    Science.gov (United States)

    Suzuki, Yoshizo; Nojima, Tomoyuki; Kakuta, Akihiko; Moritomi, Hiroshi

    A conceptual design of an energy recovering system from sewage sludge was proposed. This system consists of a pressurized fluidized bed combustor, a gas turbine, and a heat exchanger for preheating of combustion air. Thermal efficiency was estimated roughly as 10-25%. In order to know the combustion characteristics of the sewage sludge under the elevated pressure condition, combustion tests of the dry and wet sewage sludge were carried out by using laboratory scale pressurized fluidized bed combustors. Combustibility of the sewage sludge was good enough and almost complete combustion was achieved in the combustion of the actual wet sludge. CO emission and NOx emission were marvelously low especially during the combustion of wet sewage sludge regardless of high volatile and nitrogen content of the sewage sludge. However, nitrous oxide (N2O) emission was very high. Hence, almost all nitrogen oxides were emitted as the form of N2O. From these combustion tests, we judged combustion of the sewage sludge with the pressurized fluidized bed combustor is suitable, and the conceptual design of the power generation system is available.

  9. The influence of transport phenomena on the fluidized bed combustion of a single carbon particle

    NARCIS (Netherlands)

    Prins, W.; van Swaaij, Willibrordus Petrus Maria

    1990-01-01

    The burning rate and temperature of the carbon particles are known to affect the efficiency of a fluidized bed combustor, and also the emission levels of undesired noxious components. The main results of an extensive study on the fluidized bed combustion behaviour of a single carbon particle [1] are

  10. The combustion of refuse derived fuel on a ''Nordfab'' biomass combustor at Leonard Ironside Ltd

    Energy Technology Data Exchange (ETDEWEB)

    Fells, A.R.

    1991-08-01

    Warren Spring Laboratory has been assessing the performance of a Nordfab biofuel combustor fitted with a Danstoker boiler rated at 4.5MW (100% MCR), when firing Easiburn refuse derived fuel. The unit is situated at Leonard Ironside Ltd, a market gardening business near Lyminge Kent. A number of operational problems were encountered with the system, namely excessive fuel consumption and intermittent production of a persistent acrid plume. A trials history is given with details of monitoring methods used. The results of the test work show the reciprocating grate to be unsuitable for continuous firing of refuse derived fuel. The performance of the Nordfab combustor when burning refuse derived fuel is compared with two other units using similar fuel bed transport systems. These are the coking stoker and the Dantrim biofuel combustor. (author).

  11. Technical, economic and environmental potential of co-firing of biomass in coal and natural gas fired power plants in the Netherlands

    International Nuclear Information System (INIS)

    Van Ree, R.; Korbee, R.; Eenkhoorn, S.; De Lange, T.; Groenendaal, B.

    2000-01-01

    In this paper the technical, economic, and environmental potential of co-firing of biomass in existing Dutch coal and natural gas fired power plants, and industrial combined-cycles (CC), is addressed. Main criteria that are considered are: the availability and contractibility of biomass for energy purposes; the (technical) operation of the conventional fossil fuel based processes may not be disturbed; the gaseous and liquid plant emissions have to comply to those applicable for power plants/CCs, the commercial applicability of the solid residues may not be negatively influenced; applicable additional biomass conversion technologies must be commercially available; the necessary additional investment costs must be acceptable from an economic point of view, and the co-firing option must result in a substantial CO 2 -emission reduction. The main result of the study described in the paper is the presentation of a clear and founded indication of the total co-firing potential of biomass in existing power plants and industrial CCs in the Netherlands. This potential is determined by considering both technical, economic, and environmental criteria. In spite of the fact that the co-firing potential for the specific Dutch situation is presented, the results of the criteria considered are more generally applicable, and therefore are also very interesting for potential co-firing initiatives outside of the Netherlands

  12. Modeling and performance analysis of CCHP (combined cooling, heating and power) system based on co-firing of natural gas and biomass gasification gas

    International Nuclear Information System (INIS)

    Wang, Jiangjiang; Mao, Tianzhi; Sui, Jun; Jin, Hongguang

    2015-01-01

    Co-firing biomass and fossil energy is a cost-effective and reliable way to use renewable energy and offer advantages in flexibility, conversion efficiency and commercial possibility. This study proposes a co-fired CCHP (combined cooling, heating and power) system based on natural gas and biomass gasification gas that contains a down-draft gasifier, ICE (internal combustion engine), absorption chiller and heat exchangers. Thermodynamic models are constructed based on a modifying gasification thermochemical equilibrium model and co-fired ICE model for electricity and heat recovery. The performance analysis for the volumetric mixture ratio of natural gas and product gas indicates that the energy and exergy efficiencies are improved by 9.5% and 13.7%, respectively, for an increasing mixture ratio of 0–1.0. Furthermore, the costs of multi-products, including electricity, chilled water and hot water, based on exergoeconomic analysis are analyzed and discussed based on the influences of the mixture ratio of the two gas fuels, investment cost and biomass cost. - Highlights: • Propose a co-fired CCHP system by natural gas and biomass gasification gas. • Modify biomass gasification and co-fired ICE models. • Present the thermodynamic analysis of the volumetric mixture ratios of two gas fuels. • Energy and exergy efficiencies are improved 9.5% and 13.7%. • Discuss multi-products’ costs influenced by investment and fuel costs.

  13. Field test corrosion experiments in Denmark with biomass fuels Part II Co-firing of straw and coal

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Larsen, OH

    2002-01-01

    In Denmark, straw is used for generating energy in power plants. However during straw combustion, potassium chloride and SO2 are released in the flue gas and through condensation and deposition processes they will result in the formation of superheater deposits rich in potassium chloride and pota......In Denmark, straw is used for generating energy in power plants. However during straw combustion, potassium chloride and SO2 are released in the flue gas and through condensation and deposition processes they will result in the formation of superheater deposits rich in potassium chloride...... and potassium sulphate. These components give rise to varying degrees of accelerated corrosion. This paper concerns co-firing of straw with coal to reduce the corrosion rate from straw to an acceptable level. A field investigation at Midtkraft Studstrup suspension-fired power plant in Denmark has been...... undertaken where coal has been co-fired with 10% straw and 20% straw (% energy basis) for up to approx. 3000 hours. Two types of exposure were undertaken to investigate corrosion: a) the exposure of metal rings on water/air cooled probes, and b) the exposure of a range of materials built into the existing...

  14. Particle motion in fluidised beds

    International Nuclear Information System (INIS)

    Stein, M.G.

    1999-07-01

    Gas fluidised beds are important components in many process industries, e.g. coal combustors and granulators, but not much is known about the movement of the solids. Positron Emission Particle Tracking (PEPT) enables the movement of a single, radioactive tracer particle to be followed rapidly and faithfully. Experiments were carried out in columns sized between 70 and 240mm. diameter, operating in the bubbling regime at ambient process conditions using particles of group B and D (Geldart Classification). Particle motion was tracked and the data applied to models for particle movement at the gas distributor as well as close to other surfaces and to models for particle circulation in beds of cohesive particles. In the light of these data, models for particle and bubble interaction, particle circulation, segregation, attrition, erosion, heat transfer and fluidised bed scale-up rules were reassessed. Particle motion is directly caused by bubble motion, and their velocities were found to be equal for particles travelling in a bubble. PEPT enables particle circulation to be measured, giving a more accurate correlation for future predictions. Particle motion follows the scale-up rules based on similarities of the bubble motion in the bed. A new group of parameters was identified controlling the amount of attrition in fluidised beds and a new model to predict attrition is proposed. (author)

  15. Performance of low-Btu fuel gas turbine combustors

    Energy Technology Data Exchange (ETDEWEB)

    Bevan, S.; Bowen, J.H.; Feitelberg, A.S.; Hung, S.L.; Lacey, M.A.; Manning, K.S.

    1995-11-01

    This reports on a project to develop low BTU gas fuel nozzle for use in large gas turbine combustors using multiple fuel nozzles. A rich-quench-lean combustor is described here which reduces the amount of NO{sub x} produced by the combustion of the low BTU gas. The combustor incorporates a converging rich stage combustor liner, which separates the rich stage recirculation zones from the quench stage and lean stage air.

  16. NOx results from two combustors tested on medium BTU coal gas

    Science.gov (United States)

    Sherlock, T. P.; Carl, D. E.; Vermes, G.; Schwab, J.; Notardonato, J. J.

    1982-01-01

    The results of tests of two combustor configurations using coal gas from a 25 ton/day fluidized bed coal gasifier are reported. The trials were run with a ceramic-lined, staged rich/lean burner and an integral, all metal multiannular swirl burner (MASB) using a range of temperatures and pressures representative of industrial turbine inlet conditions. A lean mixture was examined at 104, 197, and 254 Btu/Scf, yielding NO(x) emissions of 5, 20, and 70 ppmv, respectively. The MASB was employed only with a gas rated at 220-270 Btu/Scf, producing 80 ppmv NO(x) at rated engine conditions. The results are concluded to be transferrable to current machines. Further tests on the effects of gas composition, the scaling of combustors to utility size, and the development of improved wall cooling techniques and variable geometry are indicated.

  17. Combustion of biomass-derived, low caloric value, fuel gas in a gasturbine combustor

    Energy Technology Data Exchange (ETDEWEB)

    Andries, J.; Hoppesteyn, P.D.J.; Hein, K.R.G. [Technische Univ. Delf (Netherlands)

    1998-09-01

    The use of biomass and biomass/coal mixtures to produce electricity and heat reduces the net emissions of CO{sub 2}, contributes to the restructuring of the agricultural sector, helps to reduce the waste problem and saves finite fossil fuel reserves. Pressurised fluidised bed gasification followed by an adequate gas cleaning system, a gas turbine and a steam turbine, is a potential attractive way to convert biomass and biomass/coal mixtures. To develop and validate mathematical models, which can be used to design and operate Biomass-fired Integrated Gasification Combined Cycle (BIGCC) systems, a Process Development Unit (PPDU) with a maximum thermal capacity of 1.5 MW{sub th}, located at the Laboratory for Thermal Power Engineering of the Delft University of Technology in The Netherlands is being used. The combustor forms an integral part of this facility. Recirculated flue gas is used to cool the wall of the combustor. (orig.)

  18. Evaluation of AFBC co-firing of coal and hospital wastes

    Energy Technology Data Exchange (ETDEWEB)

    1991-02-01

    The purpose of this program is to expand the use of coal by utilizing CFB (circulating fluidized bed) technology to provide an environmentally safe method for disposing of waste materials. Hospitals are currently experiencing a waste management crisis. In many instances, they are no longer permitted to burn pathological and infectious wastes in incinerators. Older hospital incinerators are not capable of maintaining the stable temperatures and residence times necessary in order to completely destroy toxic substances before release into the atmosphere. In addition, the number of available landfills which can safely handle these substances is decreasing each year. The purpose of this project is to conduct necessary research investigating whether the combustion of the hospital wastes in a coal-fired circulating fluidized bed boiler will effectively destroy dioxins and other hazardous substances before release into the atmosphere. If this is proven feasible, in light of the quantity of hospital wastes generated each year, it would create a new market for coal -- possibly 50 million tons/year.

  19. Diesel engine catalytic combustor system. [aircraft engines

    Science.gov (United States)

    Ream, L. W. (Inventor)

    1984-01-01

    A low compression turbocharged diesel engine is provided in which the turbocharger can be operated independently of the engine to power auxiliary equipment. Fuel and air are burned in a catalytic combustor to drive the turbine wheel of turbine section which is initially caused to rotate by starter motor. By opening a flapper value, compressed air from the blower section is directed to catalytic combustor when it is heated and expanded, serving to drive the turbine wheel and also to heat the catalytic element. To start, engine valve is closed, combustion is terminated in catalytic combustor, and the valve is then opened to utilize air from the blower for the air driven motor. When the engine starts, the constituents in its exhaust gas react in the catalytic element and the heat generated provides additional energy for the turbine section.

  20. Variable volume combustor with aerodynamic support struts

    Science.gov (United States)

    Ostebee, Heath Michael; Johnson, Thomas Edward; Stewart, Jason Thurman; Keener, Christopher Paul

    2017-03-07

    The present application provides a combustor for use with a gas turbine engine. The combustor may include a number of micro-mixer fuel nozzles and a fuel injection system for providing a flow of fuel to the micro-mixer fuel nozzles. The fuel injection system may include a number of support struts supporting the fuel nozzles and providing the flow of fuel therethrough. The support struts may include an aerodynamic contoured shape so as to distribute evenly a flow of air to the micro-mixer fuel nozzles.

  1. An Overview of Atmospheric Fluidized Bed Combustion Systems as Applied to Army Scale Central Heat Plants

    Science.gov (United States)

    1992-11-01

    or burned in a separate fluidizcd bed combustor called a carbon burnup cell. Fuel and Sorbent Feed. To achieve high combustion efficier.cy and maximum...AFBC tecnnology is relatively new, calculating the boiler efficiency of fluidized bed boilers is not as well defined as it is for conventional boilers...paragraphs will highlight some options to improve the combustion efficiency. A carbon burnup cell (CBC) uses a separate fluidized bed operated at a much

  2. A High-Performance LC Wireless Passive Pressure Sensor Fabricated Using Low-Temperature Co-Fired Ceramic (LTCC Technology

    Directory of Open Access Journals (Sweden)

    Chen Li

    2014-12-01

    Full Text Available An LC resonant pressure sensor with improved performance is presented in this paper. The sensor is designed with a buried structure, which protects the electrical components from contact with harsh environments and reduces the resonant-frequency drift of the sensor in high-temperature environments. The pressure-sensitive membrane of the sensor is optimized according to small-deflection-plate theory, which allows the sensor to operate in high-pressure environments. The sensor is fabricated using low-temperature co-fired ceramic (LTCC technology, and a fugitive film is used to create a completed sealed embedded cavity without an evacuation channel. The experimental results show that the frequency drift of the sensor versus the temperature is approximately 0.75 kHz/°C, and the responsivity of the sensor can be up to 31 kHz/bar within the pressure range from atmospheric pressure to 60 bar.

  3. A high-performance LC wireless passive pressure sensor fabricated using low-temperature co-fired ceramic (LTCC) technology.

    Science.gov (United States)

    Li, Chen; Tan, Qiulin; Xue, Chenyang; Zhang, Wendong; Li, Yunzhi; Xiong, Jijun

    2014-12-05

    An LC resonant pressure sensor with improved performance is presented in this paper. The sensor is designed with a buried structure, which protects the electrical components from contact with harsh environments and reduces the resonant-frequency drift of the sensor in high-temperature environments. The pressure-sensitive membrane of the sensor is optimized according to small-deflection-plate theory, which allows the sensor to operate in high-pressure environments. The sensor is fabricated using low-temperature co-fired ceramic (LTCC) technology, and a fugitive film is used to create a completed sealed embedded cavity without an evacuation channel. The experimental results show that the frequency drift of the sensor versus the temperature is approximately 0.75 kHz/°C, and the responsivity of the sensor can be up to 31 kHz/bar within the pressure range from atmospheric pressure to 60 bar.

  4. Effects of laminating and co-firing conditions on the performance of anode-supported Ce0.8Sm0.201.9 film electrolyte

    Directory of Open Access Journals (Sweden)

    Li X.

    2011-01-01

    Full Text Available In order to evaluate the laminating and co-firing technique on the performance of anode-supported Ce0.8Sm0.2O1.9 (SDC film electrolyte and its single cell, NiO-YSZ and NiOSDC anode-supported SDC film electrolytes were fabricated by laminating 24 sheets of anode plus one sheet of electrolyte and co-firing. La0.4Sr0.6Co0.2Fe0.8O3-δ (LSCF-SDC cathode was coated on the SDC electrolytes to form a single cell. The lamination was tried at different laminating temperatures and pressures and the co-firing was carried out at different temperatures. The results showed that the laminating temperature should above the glass transition temperature (Tg of the binder. The laminating pressure of 70 MPa resulted in warp of the samples. The best co-firing temperature of the anode-supported SDC film electrolyte was 1400°C. The SDC film electrolyte formed well adherence to the anode. The NiO-YSZ anode had larger flexural strength than the NiO-SDC anode. The NiO-YSZ anode-supported SDC film electrolyte single cell had an open circuit voltage of 0.803 V and a maximum power density of 93.03 mW/cm2 with hydrogen as fuel at 800°C.

  5. Technical properties of biomass and solid recovered fuel (SRF) co-fired with coal: Impact on multi-dimensional resource recovery value.

    Science.gov (United States)

    Iacovidou, Eleni; Hahladakis, John; Deans, Innes; Velis, Costas; Purnell, Phil

    2018-03-01

    The power plant sector is adopting the co-firing of biomass and solid recovered fuel (SRF) with coal in an effort to reduce its environmental impact and costs. Whereas this intervention contributes to reducing carbon emissions and those of other pollutants related with the burning of fossil fuel, it may also result in hidden impacts that are often overlooked. When co-firing, the physical and chemical properties of the mixed fuels and the subsequent technical implications on the process performance and by-products are significant. Interconnections between multiple values nested within four domains of value, i.e. environmental, economic, technical and social, mean that changes in the one domain (in the co-firing case, the technical one) can have considerable implications in the other domains as well. In this study, using a systematic and flexible approach to conceptualising multi-dimensional aspects associated with the co-firing of biomass and SRF with coal, we unveil examples of such interconnections and implications on overall value delivered through the use and recovery of waste resources. Such an analysis could underpin the selection of useful metrics (quantitative or semi-quantitative descriptors) for enabling a systemic multi-dimensional value assessment, and value's distribution amongst interconnected parts of resource recovery systems; key in enabling sound analysis and decision-making. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  6. Numerical evaluation of different pulverized coal and solid recovered fuel co-firing modes inside a large-scale cement calciner

    International Nuclear Information System (INIS)

    Mikulčić, Hrvoje; Berg, Eberhard von; Vujanović, Milan; Wang, Xuebin; Tan, Houzhang; Duić, Neven

    2016-01-01

    Highlights: • Substitution of coal by alternative fuels is a method for greenhouse gas mitigation. • Alternative fuels have an impact on the performance of existing pulverized fuel furnaces. • Numerical simulations are a useful tool for studying and control of co-firing process. • Six different co-firing modes inside a cement calciner were evaluated. • The thermal share of solid recovered fuel varied from 0% to 100%. - Abstract: Partial substitution of coal by alternative solid fuels, such as waste-derived fuels and biomass, is recognized as an advantageous method for greenhouse gas mitigation. However, due to different fuel properties than that of coal, alternative fuels have a direct impact on the performance of existing pulverized coal fired furnaces. Numerical simulations currently represent a useful approach for studying and controlling the co-firing process. Early comprehensive information, parametric studies and initial conclusions that can be gained from numerical simulations are very important in handling modern combustion units. In this study modelling approach for the combustion of pulverized coal, biomass, plastic, and solid recovered fuel is presented. The purpose of the present study is to evaluate six different pulverized coal and solid recovered fuel co-firing modes inside a cement calciner. The thermal share of the solid recovered fuel in these six simulations varied from 0% to 100%. The results obtained, which include the temperature and species concentrations, provide useful conclusions regarding the maximal allowed coal substitution rate for stable cement calciner operation.

  7. Ultra-Low Carbon Emissions from Coal-Fired Power Plants through Bio-Oil Co-Firing and Biochar Sequestration.

    Science.gov (United States)

    Dang, Qi; Mba Wright, Mark; Brown, Robert C

    2015-12-15

    This study investigates a novel strategy of reducing carbon emissions from coal-fired power plants through co-firing bio-oil and sequestering biochar in agricultural lands. The heavy end fraction of bio-oil recovered from corn stover fast pyrolysis is blended and co-fired with bituminous coal to form a bio-oil co-firing fuel (BCF). Life-cycle greenhouse gas (GHG) emissions per kWh electricity produced vary from 1.02 to 0.26 kg CO2-eq among different cases, with BCF heavy end fractions ranging from 10% to 60%, which corresponds to a GHG emissions reduction of 2.9% to 74.9% compared with that from traditional bituminous coal power plants. We found a heavy end fraction between 34.8% and 37.3% is required to meet the Clean Power Plan's emission regulation for new coal-fired power plants. The minimum electricity selling prices are predicted to increase from 8.8 to 14.9 cents/kWh, with heavy end fractions ranging from 30% to 60%. A minimum carbon price of $67.4 ± 13 per metric ton of CO2-eq was estimated to make BCF power commercially viable for the base case. These results suggest that BCF co-firing is an attractive pathway for clean power generation in existing power plants with a potential for significant reductions in carbon emissions.

  8. Steam Reformer With Fibrous Catalytic Combustor

    Science.gov (United States)

    Voecks, Gerald E.

    1987-01-01

    Proposed steam-reforming reactor derives heat from internal combustion on fibrous catalyst. Supplies of fuel and air to combustor controlled to meet demand for heat for steam-reforming reaction. Enables use of less expensive reactor-tube material by limiting temperature to value safe for material yet not so low as to reduce reactor efficiency.

  9. Capture of SO2 by limestone in a 71 MWe pressurized fluidized bed boiler

    Directory of Open Access Journals (Sweden)

    Shimizu Tadaaki

    2003-01-01

    Full Text Available A 71 MWe pressurized fluidized bed coal combustor was operated. A wide variety of coals were burnt under fly ash recycle conditions. Limestone was fed to the combustor as bed material as well as sorbent. The emission of SO^ and limestone attrition rate were measured. A simple mathematical model of SO? capture by limestone with intermittent solid attrition was applied to the analysis of the present experimental results. Except for high sulfur fuel, the results of the present model agreed with the experimental results.

  10. Synergistic erosion/corrosion of superalloys in PFB coal combustor effluent

    Science.gov (United States)

    Benford, S. M.; Zellars, G. R.; Lowell, C. E.

    1981-01-01

    Two Ni-based superalloys were exposed to the high velocity effluent of a pressurized fluidized bed coal combustor. Targets were 15 cm diameter rotors operating at 40,000 rpm and small flat plate specimens. Above an erosion rate threshold, the targets were eroded to bare metal. The presence of accelerated oxidation at lower erosion rates suggests erosion/corrosion synergism. Various mechanisms which may contribute to the observed oxide growth enhancement include erosive removal of protective oxide layers, oxide and subsurface cracking, and chemical interaction with sulfur in the gas and deposits through damaged surface layers.

  11. Method for controlling incineration in combustor for radioactive wastes

    International Nuclear Information System (INIS)

    Takaoku, Y.; Uehara, A.

    1991-01-01

    This invention relates to a method for controlling incineration in a combustor for low-level radioactive wastes. In particular, it relates to a method for economizing in the consumption of supplemental fuel while maintaining a stable incineration state by controlling the amount of fuel and of radioactive wastes fed to the combustor. The amount of fuel supplied is determined by the outlet gas temperature of the combustor. (L.L.)

  12. Low NOx Fuel Flexible Combustor Integration Project Overview

    Science.gov (United States)

    Walton, Joanne C.; Chang, Clarence T.; Lee, Chi-Ming; Kramer, Stephen

    2015-01-01

    The Integrated Technology Demonstration (ITD) 40A Low NOx Fuel Flexible Combustor Integration development is being conducted as part of the NASA Environmentally Responsible Aviation (ERA) Project. Phase 2 of this effort began in 2012 and will end in 2015. This document describes the ERA goals, how the fuel flexible combustor integration development fulfills the ERA combustor goals, and outlines the work to be conducted during project execution.

  13. Selective recovery of silver from waste low-temperature co-fired ceramic and valorization through silver nanoparticle synthesis.

    Science.gov (United States)

    Swain, Basudev; Shin, Dongyoon; Joo, So Yeong; Ahn, Nak Kyoon; Lee, Chan Gi; Yoon, Jin-Ho

    2017-11-01

    Considering the value of silver metal and silver nanoparticles, the waste generated during manufacturing of low temperature co-fired ceramic (LTCC) were recycled through the simple yet cost effective process by chemical-metallurgy. Followed by leaching optimization, silver was selectively recovered through precipitation. The precipitated silver chloride was valorized though silver nanoparticle synthesis by a simple one-pot greener synthesis route. Through leaching-precipitation optimization, quantitative selective recovery of silver chloride was achieved, followed by homogeneous pure silver nanoparticle about 100nm size were synthesized. The reported recycling process is a simple process, versatile, easy to implement, requires minimum facilities and no specialty chemicals, through which semiconductor manufacturing industry can treat the waste generated during manufacturing of LTCC and reutilize the valorized silver nanoparticles in manufacturing in a close loop process. Our reported process can address issues like; (i) waste disposal, as well as value-added silver recovery, (ii) brings back the material to production stream and address the circular economy, and (iii) can be part of lower the futuristic carbon economy and cradle-to-cradle technology management, simultaneously. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. High pressure MHD coal combustors investigation, phase 2

    Science.gov (United States)

    Iwata, H.; Hamberg, R.

    1981-05-01

    A high pressure MHD coal combustor was investigated. The purpose was to acquire basic design and support engineering data through systematic combustion experiments at the 10 and 20 thermal megawatt size and to design a 50 MW/sub t/ combustor. This combustor is to produce an electrically conductive plasma generated by the direct combustion of pulverized coal with hot oxygen enriched vitiated air that is seeded with potassium carbonate. Vitiated air and oxygen are used as the oxidizer, however, preheated air will ultimately be used as the oxidizer in coal fired MHD combustors.

  15. Flame Propagation in a Dump Combustor with Shear Layer Excitation

    Data.gov (United States)

    National Aeronautics and Space Administration — This experimentation looks to investigate the use of fluidic oscillators to attenuate combustion instability in a naturally unstable rocket combustor. Since...

  16. Low pollution combustor designs for CTOL engines - Results of the Experimental Clean Combustor Program

    Science.gov (United States)

    Roberts, R.; Peduzzi, A.; Niedzwiecki, R. W.

    1976-01-01

    The NASA/Pratt & Whitney Aircraft Experimental Clean Combustor Program is a multi-year, major contract effort. Primary program objectives are the generation of combustor technology for development of advanced commercial CTOL engines with lower exhaust emissions than current aircraft and demonstration of this technology in a full-scale JT9D engine in 1976. This paper describes the pollution and performance goals, Phase I and II test results, and the Phase III combustor hardware, pollution sampling techniques, and test plans. Best results were obtained with the Vorbix concept which employs multiple burning zones and improved fuel preparation and distribution. Substantial reductions were achieved in all pollutant categories, meeting the 1979 EPA standards for NOx, THC, and smoke when extrapolated to JT9D cycle conditions. The Vorbix concept additionally demonstrated the capability for acceptable altitude relight and did not appear to have unsolvable durability or exit temperature distribution problems.

  17. Catalytic Combustor for Fuel-Flexible Turbine

    Energy Technology Data Exchange (ETDEWEB)

    W. R. Laster; E. Anoshkina

    2008-01-31

    Under the sponsorship of the U. S. Department of Energy's National Energy Technology Laboratory, Siemens Westinghouse has conducted a three-year program to develop an ultra low NOx, fuel flexible catalytic combustor for gas turbine application in IGCC. The program is defined in three phases: Phase 1 - Implementation Plan, Phase 2 - Validation Testing and Phase 3 - Field Testing. Both Phase 1 and Phase 2 of the program have been completed. In IGCC power plants, the gas turbine must be capable of operating on syngas as a primary fuel and an available back-up fuel such as natural gas. In this program the Rich Catalytic Lean (RCLTM) technology is being developed as an ultra low NOx combustor. In this concept, ultra low NOx is achieved by stabilizing a lean premix combustion process by using a catalytic reactor to oxidize a portion of the fuel, increasing the temperature of fuel/air mixture prior to the main combustion zone. In Phase 1, the feasibility of the catalytic concept for syngas application has been evaluated and the key technology issues identified. In Phase II the technology necessary for the application of the catalytic concept to IGCC fuels was developed through detailed design and subscale testing. Phase III (currently not funded) will consist of full-scale combustor basket testing on natural gas and syngas.

  18. Catalytic Combustor for Fuel-Flexible Turbine

    Energy Technology Data Exchange (ETDEWEB)

    Laster, W. R.; Anoshkina, E.

    2008-01-31

    Under the sponsorship of the U. S. Department of Energy’s National Energy Technology Laboratory, Siemens Westinghouse has conducted a three-year program to develop an ultra low NOx, fuel flexible catalytic combustor for gas turbine application in IGCC. The program is defined in three phases: Phase 1- Implementation Plan, Phase 2- Validation Testing and Phase 3 – Field Testing. Both Phase 1 and Phase 2 of the program have been completed. In IGCC power plants, the gas turbine must be capable of operating on syngas as a primary fuel and an available back-up fuel such as natural gas. In this program the Rich Catalytic Lean (RCLTM) technology is being developed as an ultra low NOx combustor. In this concept, ultra low NOx is achieved by stabilizing a lean premix combustion process by using a catalytic reactor to oxidize a portion of the fuel, increasing the temperature of fuel/air mixture prior to the main combustion zone. In Phase 1, the feasibility of the catalytic concept for syngas application has been evaluated and the key technology issues identified. In Phase II the technology necessary for the application of the catalytic concept to IGCC fuels was developed through detailed design and subscale testing. Phase III (currently not funded) will consist of full-scale combustor basket testing on natural gas and syngas.

  19. Combustion of refuse derived fuel in a fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Piao, Guilin; Aono, Shigeru; Mori, Shigekatsu; Deguchi, Seiichi; Fujima, Yukihisa [Nagoya Univ. (Japan); Kondoh, Motohiro; Yamaguchi, Masataka [Toyota Motor Corp. (Japan). Plant Engineering Dept.

    1998-12-31

    Power generation from Refuse Derived Fuel (RDF) is an attractive utilization technology of municipal solid waste. To explain the behavior of RDF-fired fluidized bed incinerator, the commercial size RDF was continuously burnt in a 30 x 30 cm bubbling type fluidized-bed combustor. It was found that 12 kg/h of RDF feed rate was too high feed for this test unit and the Co level was higher than 500 ppm. However, 10 kg/h of RDF was a proper feed rate and the Co level was kept under 150 ppm. Secondary air injection and changing air ratio from the pipe grid were effective for the complete combustion of RDE. It was also found that HCl concentration in flue gas was controlled by the calcium component contained in RDF and its level was decreased with decreasing the combustor temperature.

  20. Availability of Biomass Residues for Co-Firing in Peninsular Malaysia: Implications for Cost and GHG Emissions in the Electricity Sector

    Directory of Open Access Journals (Sweden)

    W. Michael Griffin

    2014-02-01

    Full Text Available Fossil fuels comprise 93% of Malaysia’s electricity generation and account for 36% of the country’s 2010 Greenhouse Gas (GHG emissions. The government has targeted the installation of 330 MW of biomass electricity generation capacity by 2015 to avoid 1.3 Mt of CO2 emissions annually and offset some emissions due to increased coal use. One biomass option is to co-fire with coal, which can result in reduced GHG emissions, coal use, and costs of electricity. A linear optimization cost model was developed using seven types of biomass residues for Peninsular Malaysia. Results suggest that about 12 Mt/year of residues are available annually, of which oil-palm residues contribute 77%, and rice and logging residues comprise 17%. While minimizing the cost of biomass and biomass residue transport, co-firing at four existing coal plants in Peninsular Malaysia could meet the 330 MW biomass electricity target and reduce costs by about $24 million per year compared to coal use alone and reduces GHG emissions by 1.9 Mt of CO2. Maximizing emissions reduction for biomass co-firing results in 17 Mt of CO2 reductions at a cost of $23/t of CO2 reduced.

  1. Thermal treatment of soil co-contaminated with lube oil and heavy metals in a low-temperature two-stage fluidized bed incinerator

    International Nuclear Information System (INIS)

    Samaksaman, Ukrit; Peng, Tzu-Huan; Kuo, Jia-Hong; Lu, Chien-Hsing; Wey, Ming-Yen

    2016-01-01

    Highlights: • Low-temperature two-stage fluidized bed incineration was applied for soil remediation. • Co-firing of polyethylene with co-contaminated soil was studied. • Co-firing of polyethylene in soil remediation can promote residue quality. • The leachability of heavy metals passed the regulatory threshold values. - Abstract: This study presents the application of a low-temperature two-stage fluidized bed incinerator to remediate contaminants in the soil. The system was designed to control emissions of both gaseous pollutants and heavy metals during combustion. Soil co-contaminated with lube oil and heavy metals such as cadmium, chromium, copper, and lead was examined. Experiments were conducted by estimating various parameters such as operating temperature in the first-stage reactor (500–700 °C), ratio of sand bed height/diameter in the second-stage reactor (H/D: 3, 4, 6), and gas velocity (0.21–0.29 m/s). Heavy metal and gaseous pollutant emissions were also investigated during contaminated soil co-firing with polyethylene. The experimental results indicated that the destruction and removal efficiency of lube oil in treated soil products ranged from 98.27 to 99.93%. On the other hand, leaching tests of bottom ashes illustrated that heavy metals such as chromium, copper, and lead in leachates were complied with the regulations. For gaseous emissions, carbon monoxide concentrations decreased apparently with increasing ratio of sand bed height/diameter in the second-stage reactor. The increase of gas velocity had significant potential to generate the lowest carbon monoxide and particulate matter emissions. Nevertheless, during co-firing with polyethylene, emissions of organic pollutants such as benzene, toluene, ethylbenzene, and xylene and polycyclic aromatic hydrocarbons decrease by using the low-temperature two-stage fluidized bed incineration system.

  2. Modelling of NOx emissions from pressurized fluidized bed combustion - A parameter study

    DEFF Research Database (Denmark)

    Jensen, Anker; Johnsson, Jan Erik

    1997-01-01

    Simulations with a mathematical model of a pressurized bubbling fluidized-bed combustor (PFBC) combined with a kinetic model for NO formation and reduction are reported. The kinetic model for NO formation and reduction considers NO and NH3 as the fixed nitrogen species, and includes homogeneous r...

  3. The erosion/corrosion of small superalloy turbine rotors operating in the effluent of a PFB coal combustor

    Science.gov (United States)

    Zellars, G. R.; Benford, S. M.; Rowe, A. P.; Lowell, C. E.

    1979-01-01

    The operation of a turbine in the effluent of a pressurized fluidized bed (PFB) coal combustor presents serious materials problems. Synergistic erosion/corrosion and deposition/corrosion interactions may favor the growth of erosion-resistant oxides on blade surfaces, but brittle cracking of these oxides may be an important source of damage along heavy particle paths. Integrally cast alloy 713LC and IN792 + Hf superalloy turbine rotors in a single-stage turbine with 6% partial admittance have been operated in the effluent of a PFB coal combustor for up to 164 hr. The rotor erosion pattern exhibits heavy particle separation with severe erosion at the leading edge, pressure side center, and suction side trailing edge at the tip. The erosion distribution pattern gives a spectrum of erosion/oxidation/deposition as a function of blade position. The data suggest that preferential degradation paths may exist even under the targeted lower loadings (less than 20 ppm).

  4. Prospects for co-firing of clean coal and creosote-treated waste wood at small-scale power stations

    Directory of Open Access Journals (Sweden)

    Zandersons Janis

    2006-01-01

    Full Text Available If a small-scale clean coal fueled power plant is co-fueled with 5% of creosote-treated used-up sleeper wood, the decontamination by carbonisation at 500 °C in an indirectly heated rotary kiln with the diameter 1.7 m and effective length 10 m can be realized. It should be included in the "3R Clean Coal Carbonisation Plant" system, which processes coal. It will improve the heat balance of the system, since the carbonisation of wood will deliver a lot of high caloricity pyroligneous vapour to the joint furnace of the "3R Clean Coal Carbonisation Plant". Pine wood sleeper sapwood contains 0.25% of sulphur, but the average pine sleeper wood (sapwood and heartwood 0.05% of sulphur. Most of the sulphur is lost with the pyroligneous vapour and burned in the furnace. Since the "3R Clean Coal Carbonisation Plant" is equipped with a flue gases cleaning system, the SO2 emission level will not exceed 5 mg/m3. The charcoal of the sapwood portion of sleepers and that of the average sleeper wood will contain 0.22% and 0.035% of sulphur, respectively. The increase of the carbonisation temperature does not substantially decrease the sulphur content in charcoal, although it is sufficiently low, and the charcoal can be co-fired with clean coal. The considered process is suitable for small power plants, if the biomass input in the common energy balance is 5 to 10%. If the mean distance of sleepers transportation for Central and Eastern Europe is estimated not to exceed 200 km, the co-combustion of clean coal and carbonized sleepers would be an acceptable option from the environmental and economic points of view.

  5. Importance of fragmentation on the steady state combustion of wood char in a bubbling fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Pinho, Carlos [Universidade do Porto (CEFT/FEUP), Porto (Portugal). Faculdade de Engenharia. Centro de Estudos de Fenomenos de Transporte], E-mail: ctp@fe.up.pt

    2010-07-01

    A simple mathematical model for the analysis of the steady state behavior of a bubbling fluidized bed burner is presented, with the main intention of evaluating the importance of the primary fragmentation of fuel particles on the performance of this type of burners. This model has pedagogical advantages because of its simplicity and easiness of application to the analysis of realistic situations. The model is based upon the classical models used for the study of batch combustion processes in fluidized bed reactors. Experimental data from studies of fluidized bed combustion of portuguese vegetable chars are used to support the analysis of the performance of a 1 m diameter fluidized bed combustor. (author)

  6. Combustor nozzle for a fuel-flexible combustion system

    Science.gov (United States)

    Haynes, Joel Meier [Niskayuna, NY; Mosbacher, David Matthew [Cohoes, NY; Janssen, Jonathan Sebastian [Troy, NY; Iyer, Venkatraman Ananthakrishnan [Mason, OH

    2011-03-22

    A combustor nozzle is provided. The combustor nozzle includes a first fuel system configured to introduce a syngas fuel into a combustion chamber to enable lean premixed combustion within the combustion chamber and a second fuel system configured to introduce the syngas fuel, or a hydrocarbon fuel, or diluents, or combinations thereof into the combustion chamber to enable diffusion combustion within the combustion chamber.

  7. Variable volume combustor with nested fuel manifold system

    Science.gov (United States)

    McConnaughhay, Johnie Franklin; Keener, Christopher Paul; Johnson, Thomas Edward; Ostebee, Heath Michael

    2016-09-13

    The present application provides a combustor for use with a gas turbine engine. The combustor may include a number of micro-mixer fuel nozzles, a fuel manifold system in communication with the micro-mixer fuel nozzles to deliver a flow of fuel thereto, and a linear actuator to maneuver the micro-mixer fuel nozzles and the fuel manifold system.

  8. Variable volume combustor with pre-nozzle fuel injection system

    Science.gov (United States)

    Keener, Christopher Paul; Johnson, Thomas Edward; McConnaughhay, Johnie Franklin; Ostebee, Heath Michael

    2016-09-06

    The present application provides a combustor for use with a gas turbine engine. The combustor may include a number of fuel nozzles, a pre-nozzle fuel injection system supporting the fuel nozzles, and a linear actuator to maneuver the fuel nozzles and the pre-nozzle fuel injection system.

  9. Variable volume combustor with a conical liner support

    Science.gov (United States)

    Johnson, Thomas Edward; McConnaughhay, Johnie Franklin; Keener, Chrisophter Paul; Ostebee, Heath Michael

    2017-06-27

    The present application provides a variable volume combustor for use with a gas turbine engine. The variable volume combustor may include a liner, a number of micro-mixer fuel nozzles positioned within the liner, and a conical liner support supporting the liner.

  10. System and method for reducing combustion dynamics in a combustor

    Science.gov (United States)

    Uhm, Jong Ho; Ziminsky, Willy Steve; Johnson, Thomas Edward; Srinivasan, Shiva; York, William David

    2016-11-29

    A system for reducing combustion dynamics in a combustor includes an end cap that extends radially across the combustor and includes an upstream surface axially separated from a downstream surface. A combustion chamber is downstream of the end cap, and tubes extend from the upstream surface through the downstream surface. Each tube provides fluid communication through the end cap to the combustion chamber. The system further includes means for reducing combustion dynamics in the combustor. A method for reducing combustion dynamics in a combustor includes flowing a working fluid through tubes that extend axially through an end cap that extends radially across the combustor and obstructing at least a portion of the working fluid flowing through a first set of the tubes.

  11. Pressurized fluidized-bed combustion technology exchange workshop

    Energy Technology Data Exchange (ETDEWEB)

    ,

    1980-04-01

    The pressurized fluidized-bed combustion technology exchange workshop was held June 5 and 6, 1979, at The Meadowlands Hilton Hotel, Secaucus, New Jersey. Eleven papers have been entered individually into EDB and ERA. The papers include reviews of the US DOE and EPRI programs in this area and papers by Swedish, West German, British and American organizations. The British papers concern the joint program of the USA, UK and FRG at Leatherhead. The key factor in several papers is the use of fluidized bed combustors, gas turbines, and steam turbines in combined-cycle power plants. One paper examines several combined-cycle alternatives. (LTN)

  12. Combustor nozzles in gas turbine engines

    Science.gov (United States)

    Johnson, Thomas Edward; Keener, Christopher Paul; Stewart, Jason Thurman; Ostebee, Heath Michael

    2017-09-12

    A micro-mixer nozzle for use in a combustor of a combustion turbine engine, the micro-mixer nozzle including: a fuel plenum defined by a shroud wall connecting a periphery of a forward tube sheet to a periphery of an aft tubesheet; a plurality of mixing tubes extending across the fuel plenum for mixing a supply of compressed air and fuel, each of the mixing tubes forming a passageway between an inlet formed through the forward tubesheet and an outlet formed through the aft tubesheet; and a wall mixing tube formed in the shroud wall.

  13. An investigation of co-combustion municipal sewage sludge with biomass in a 20kW BFB combustor under air-fired and oxygen-enriched condition.

    Science.gov (United States)

    Kumar, Rajesh; Singh, Ravi Inder

    2017-12-01

    The behavior of municipal sewage sludge (MSS) with biomass (Guar stalks (GS), Mustard Husk (MH), Prosopis Juliflora Wood (PJW)) has been investigated in a 20kW bubbling fluidized bed (BFB) combustor under both air-fired (A-F) and oxygen-enriched (O-E) conditions. The work presented is divided into three parts, first part cover the thermogravimetric analysis (TGA), second part cover the experimental investigation of BFB combustor, and third part covers the ash analysis. TGA was performed with a ratio of 50%MSS/50%biomass (GS, MH, PJW) and results show that 50%MSS/50%GS has highest combustion characteristic factor (CCF). The experimental investigation of BFB combustor was performed for two different ratios of MSS/biomass (50%/50% and 25%/75%) and the combustion characteristics of blends were distinctive under both A-F and O-E condition. Despite 50%MSS/50%GS showing the highest combustion performance in TGA analysis, it formed agglomerates during burning in BFB. Due to this formation of large amount of agglomerates, de-fluidization was observed in the combustor bed after 65-75min in A-F conditions. The rate of de-fluidization increased under O-E condition. The de-fluidization problem disappeared when the share of MSS was reduced to 25%, but small amounts of the agglomerate were still present in the bed. With oxygen enhancement, the combustion efficiency of BFB combustor was improved and flue gasses were found within permissible limit. The maximum conceivable combustion efficiency (97.1%) for BFB combustor was accomplished by using 50% MSS/50%PJW under O-E condition. Results show that a ratio of 25%MSS/75%biomass combusted successfully inside the BFB combustor and extensive work is required for efficient utilization of significant share of MSS with biomass. SEM/EDS analyses were performed for agglomerate produced and for the damaged heater to study the surface morphology and compositions. The elemental heterogeneity of fly ash generated during MSS/biomass combustion

  14. Substrate Integrated Waveguide Based Phase Shifter and Phased Array in a Ferrite Low Temperature Co-fired Ceramic Package

    KAUST Repository

    Nafe, Ahmed A.

    2014-03-01

    Phased array antennas, capable of controlling the direction of their radiated beam, are demanded by many conventional as well as modern systems. Applications such as automotive collision avoidance radar, inter-satellite communication links and future man-portable satellite communication on move services require reconfigurable beam systems with stress on mobility and cost effectiveness. Microwave phase shifters are key components of phased antenna arrays. A phase shifter is a device that controls the phase of the signal passing through it. Among the technologies used to realize this device, traditional ferrite waveguide phase shifters offer the best performance. However, they are bulky and difficult to integrate with other system components. Recently, ferrite material has been introduced in Low Temperature Co-fired Ceramic (LTCC) multilayer packaging technology. This enables the integration of ferrite based components with other microwave circuitry in a compact, light-weight and mass producible package. Additionally, the recent concept of Substrate Integrated Waveguide (SIW) allowed realization of synthesized rectangular waveguide-like structures in planar and multilayer substrates. These SIW structures have been shown to maintain the merits of conventional rectangular waveguides such as low loss and high power handling capabilities while being planar and easily integrable with other components. Implementing SIW structures inside a multilayer ferrite LTCC package enables monolithic integration of phase shifters and phased arrays representing a true System on Package (SoP) solution. It is the objective of this thesis to pursue realizing efficient integrated phase shifters and phased arrays combining the above mentioned technologies, namely Ferrite LTCC and SIW. In this work, a novel SIW phase shifter in ferrite LTCC package is designed, fabricated and tested. The device is able to operate reciprocally as well as non-reciprocally. Demonstrating a measured maximum

  15. The development and biocompatibility of low temperature co-fired ceramic (LTCC) for microfluidic and biosensor applications

    Science.gov (United States)

    Luo, Jin

    Low temperature co-fired ceramic (LTCC) electronic packaging materials are applied for their electrical and mechanical properties, high reliability, chemical stability and ease of fabrication. Three dimensional features can also be prepared allowing integration of microfluidic channels and cavities inside LTCC modules. Mechanical, optical, electrical, microfluidic functions have been realized in single LTCC modules. For these reasons LTCC is attractive for biomedical microfluidics and Lab-on-a-Chip systems. However, commercial LTCC systems, optimized for microelectrics applications, have unknown cytocompatibility, and are not compatible with common surface functionalization chemistries. The first goal of this work is to develop biocompatible LTCC materials for biomedical applications. In the current work, two different biocompatible LTCC substrate materials are conceived, formulated and evaluated. Both materials are based from wellknown and widely utilized biocompatible materials. The biocompatibilities of the developed LTCC materials for in-vitro applications are studied by cytotoxicity assays, including culturing endothelial cells (EC) both in LTCC leachate and directly on the LTCC substrates. The results demonstrate the developed LTCC materials are biocompatible for in-vitro biological applications involving EC. The second goal of this work is to develop functional capabilities in LTCC microfluidic systems suitable for in-vitro and biomedical applications. One proposed application is the evaluation of oxygen tension and oxidative stress in perfusion cell culture and bioreactors. A Clark-type oxygen sensor is successfully integrated with LTCC technique in this work. In the current work, a solid state proton conductive electrolyte is used to integrate an oxygen sensor into the LTCC. The measurement of oxygen concentration in Clark-type oxygen sensor is based on the electrochemical reaction between working electrode and counter electrode. Cyclic voltammetry and

  16. Fluid Mechanics of Lean Blowout Precursors in Gas Turbine Combustors

    Directory of Open Access Journals (Sweden)

    T. M. Muruganandam

    2012-03-01

    Full Text Available Understanding of lean blowout (LBO phenomenon, along with the sensing and control strategies could enable the gas turbine combustor designers to design combustors with wider operability regimes. Sensing of precursor events (temporary extinction-reignition events based on chemiluminescence emissions from the combustor, assessing the proximity to LBO and using that data for control of LBO has already been achieved. This work describes the fluid mechanic details of the precursor dynamics and the blowout process based on detailed analysis of near blowout flame behavior, using simultaneous chemiluminescence and droplet scatter observations. The droplet scatter method represents the regions of cold reactants and thus help track unburnt mixtures. During a precursor event, it was observed that the flow pattern changes significantly with a large region of unburnt mixture in the combustor, which subsequently vanishes when a double/single helical vortex structure brings back the hot products back to the inlet of the combustor. This helical pattern is shown to be the characteristic of the next stable mode of flame in the longer combustor, stabilized by double helical vortex breakdown (VBD mode. It is proposed that random heat release fluctuations near blowout causes VBD based stabilization to shift VBD modes, causing the observed precursor dynamics in the combustor. A complete description of the evolution of flame near the blowout limit is presented. The description is consistent with all the earlier observations by the authors about precursor and blowout events.

  17. Experimental study of a high-efficiency low-emission surface combustor-heater

    International Nuclear Information System (INIS)

    Xiong, Tian-yu; Khinkis, M.J.; Fish, F.F.

    1991-01-01

    The surface combustor-heater is a combined combustion/heat-transfer device in which the heat-exchange surfaces are embedded in a stationary bed of refractory material where gaseous fuel is burned. Because of intensive heat radiation from the hot solid particles and enhanced heat convection from the gas flow to the heat-exchange tubes, heat transfer is significantly intensified. Removing heat simultaneously with the combustion process has the benefit of reducing the combustion temperature, which suppresses NO x formation. A basic experimental study was conducted on a 60-kW bench-scale surface combustor-heater with two rows of water-cooled tube coils to evaluate its performance and explore the mechanism of combined convective-radiative heat transfer and its interaction with combustion in the porous matrix. Combustion stability in the porous matrix, heat-transfer rates, emissions, and pressure drop through the unit have been investigated for the variable parameters of operation and unit configurations. Experimental results have demonstrated that high combustion intensity (up to 2.5 MW/m 2 ), high heat-transfer rates (up to 310 kW/m 2 ), high density of energy conversion (up to 8 MW/m 3 ), as well as ultra-low emissions (NO x and CO as low as 15 vppm*) have been achieved. The excellent performance of the test unit and the extensive data obtained from the present experimental study provide the basis for further development of high-efficiency and ultra low-emission water heaters, boilers, and process heaters based on the surface combustor-heater concept. 4 refs., 16 figs

  18. The impact of co-firing sunflower husk pellets with coal in a boiler on the chemical composition of flue gas

    Directory of Open Access Journals (Sweden)

    Zajemska Monika

    2017-01-01

    The calculations showed that the most important influence on the composition of the flue gas from the co-firing process of coal with sunflower husk has a composition of biomass. It should be emphasized that the results of computer simulations obtained by the authors have an useful aspect and can be applied in practice, especially to the analysis of the mechanism of chloride corrosion which is possible to occur due to the chlorine content in the biomass. They may also be useful for evaluating the unburned hydrocarbons produced by combustion of rich mixtures (λ < 1.0.

  19. Analysis of the sintering stresses and shape distortion produced in co-firing of CGO-LSM/CGO bi-layer porous structures

    DEFF Research Database (Denmark)

    Ni, De Wei; Esposito, Vincenzo; Schmidt, Cristine Grings

    Gadolinium-doped cerium oxide (CGO) and lanthanum strontium manganate (LSM) are electro-ceramics materials with high potential for several electrochemical applications such as solid Oxide Fuel Cell (SOFC), gas separation membranes, and flue gas purification devices. Especially for novel...... electrochemical flue gas purification devices, multilayer structures with alternating porous layers of CGO and a LSM/CGO mixture are used to achieve specific functional requirements. In a manufacturing process of such ceramic multilayer devices, co-firing is one of the critical steps as many defects...

  20. Availability of Biomass Residues for Co-Firing in Peninsular Malaysia: Implications for Cost and GHG Emissions in the Electricity Sector

    OpenAIRE

    W. Michael Griffin; Jeremy Michalek; H. Scott Matthews; Mohd Nor Azman Hassan

    2014-01-01

    Fossil fuels comprise 93% of Malaysia’s electricity generation and account for 36% of the country’s 2010 Greenhouse Gas (GHG) emissions. The government has targeted the installation of 330 MW of biomass electricity generation capacity by 2015 to avoid 1.3 Mt of CO 2 emissions annually and offset some emissions due to increased coal use. One biomass option is to co-fire with coal, which can result in reduced GHG emissions, coal use, and costs of electricity. A linear optimization cost model wa...

  1. Co-firing Bosnian coals with woody biomass: Experimental studies on a laboratory-scale furnace and 110 MWe power unit

    Directory of Open Access Journals (Sweden)

    Smajevic Izet

    2012-01-01

    Full Text Available This paper presents the findings of research into cofiring two Bosnian cola types, brown coal and lignite, with woody biomass, in this case spruce sawdust. The aim of the research was to find the optimal blend of coal and sawdust that may be substituted for 100% coal in large coal-fired power stations in Bosnia and Herzegovina. Two groups of experimental tests were performed in this study: laboratory testing of co-firing and trial runs on a large-scale plant based on the laboratory research results. A laboratory experiment was carried out in an electrically heated and entrained pulverized-fuel flow furnace. Coal-sawdust blends of 93:7% by weight and 80:20% by weight were tested. Co-firing trials were conducted over a range of the following process variables: process temperature, excess air ratio and air distribution. Neither of the two coal-sawdust blends used produced any significant ash-related problems provided the blend volume was 7% by weight sawdust and the process temperature did not exceed 1250ºC. It was observed that in addition to the nitrogen content in the co-fired blend, the volatile content and particle size distribution of the mixture also influenced the level of NOx emissions. The brown coal-sawdust blend generated a further reduction of SO2 due to the higher sulphur capture rate than for coal alone. Based on and following the laboratory research findings, a trial run was carried out in a large-scale utility - the Kakanj power station, Unit 5 (110 MWe, using two mixtures; one in which 5%/wt and one in which 7%/wt of brown coal was replaced with sawdust. Compared to a reference firing process with 100% coal, these co-firing trials produced a more intensive redistribution of the alkaline components in the slag in the melting chamber, with a consequential beneficial effect on the deposition of ash on the superheater surfaces of the boiler. The outcome of the tests confirms the feasibility of using 7%wt of sawdust in combination

  2. ESTABLISHMENT OF AN ENVIRONMENTAL CONTROL TECHNOLOGY LABORATORY WITH A CIRCULATING FLUIDIZED-BED COMBUSTION SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Wei-Ping Pan; Andy Wu; John T. Riley

    2004-10-30

    This report is to present the progress made on the project ''Establishment of an Environmental Control Technology Laboratory (ECTL) with a Circulating Fluidized-Bed Combustion (CFBC) System'' during the period July 1, 2004 through September 30, 2004. The following tasks have been completed. First, renovation of the new Combustion Laboratory and the construction of the Circulating Fluidized-Bed (CFB) Combustor Building have started. Second, the design if the component parts of the CFBC system have been reviewed and finalized so that the drawings may be released to the manufacturers during the next quarter. Third, the experiments for solid waste (chicken litter) incineration have been conducted using a Thermogravimetric Analyzer (TGA). This is in preparation for testing in the simulated fluidized-bed combustor. The experimental results from this study are presented in this report. Finally, the proposed work for the next quarter has been outlined in this report.

  3. Combustion generated noise in gas turbine combustors

    Science.gov (United States)

    Strahle, W. C.; Shivashankara, B. N.

    1975-01-01

    Experiments are conducted for the noise power and spectra emitted from a gas turbine combustor can exhausting to the atmosphere. The theory of combustion noise is applied to the results to determine the noise generating capability of the flame in the absence of reflecting can surfaces. The results show that for a fixed fuel (JP-4) the noise output is independent of fuel/air ratio for well stabilized can-type flames and heavily dependent on airflow while the spectra are dominated by the can acoustics, primarily through sound absorption by the liner. In an installed configuration the noise output depends heavily on the enclosure acoustics. Scaling rules are presented for installed configurations.

  4. Method for operating a combustor in a fuel cell system

    Science.gov (United States)

    Chalfant, Robert W.; Clingerman, Bruce J.

    2002-01-01

    A method of operating a combustor to heat a fuel processor in a fuel cell system, in which the fuel processor generates a hydrogen-rich stream a portion of which is consumed in a fuel cell stack and a portion of which is discharged from the fuel cell stack and supplied to the combustor, and wherein first and second streams are supplied to the combustor, the first stream being a hydrocarbon fuel stream and the second stream consisting of said hydrogen-rich stream, the method comprising the steps of monitoring the temperature of the fuel processor; regulating the quantity of the first stream to the combustor according to the temperature of the fuel processor; and comparing said quantity of said first stream to a predetermined value or range of predetermined values.

  5. Mercury emissions from municipal solid waste combustors

    Energy Technology Data Exchange (ETDEWEB)

    1993-05-01

    This report examines emissions of mercury (Hg) from municipal solid waste (MSW) combustion in the United States (US). It is projected that total annual nationwide MSW combustor emissions of mercury could decrease from about 97 tonnes (1989 baseline uncontrolled emissions) to less than about 4 tonnes in the year 2000. This represents approximately a 95 percent reduction in the amount of mercury emitted from combusted MSW compared to the 1989 mercury emissions baseline. The likelihood that routinely achievable mercury emissions removal efficiencies of about 80 percent or more can be assured; it is estimated that MSW combustors in the US could prove to be a comparatively minor source of mercury emissions after about 1995. This forecast assumes that diligent measures to control mercury emissions, such as via use of supplemental control technologies (e.g., carbon adsorption), are generally employed at that time. However, no present consensus was found that such emissions control measures can be implemented industry-wide in the US within this time frame. Although the availability of technology is apparently not a limiting factor, practical implementation of necessary control technology may be limited by administrative constraints and other considerations (e.g., planning, budgeting, regulatory compliance requirements, etc.). These projections assume that: (a) about 80 percent mercury emissions reduction control efficiency is achieved with air pollution control equipment likely to be employed by that time; (b) most cylinder-shaped mercury-zinc (CSMZ) batteries used in hospital applications can be prevented from being disposed into the MSW stream or are replaced with alternative batteries that do not contain mercury; and (c) either the amount of mercury used in fluorescent lamps is decreased to an industry-wide average of about 27 milligrams of mercury per lamp or extensive diversion from the MSW stream of fluorescent lamps that contain mercury is accomplished.

  6. Feasibility study of ultra-low NOx Gas turbine combustor using the RML combustion concept

    Energy Technology Data Exchange (ETDEWEB)

    Van, Tien Giap; Hwang, Jeong Jae; Kim, Min Kuk; Ahn, Kook Young [Environment and Energy Research Division, Korea Institute of Machinery and Materials (KIMM), Daejeon (Korea, Republic of)

    2016-12-15

    A new combustion concept, the so called RML, was investigated to validate its application as a gas turbine combustor for combustor outlet temperatures over 1973 K. The feasibility study of the RML combustor was conducted with zero dimensional combustion calculations. The emission characteristics of RQL, LEAN, EGR and RML combustors were compared. The calculation results showed that the RQL combustor has lower NOx emissions than the LEAN at high outlet temperature. NOx emissions of the RML combustor at equivalence ratio of the rich chamber of 2.0 can be reduced by 30 % compared with the EGR combustor, and lower than the RQL combustor at a combustor outlet temperature over 1973 K. However, the CO emissions of the RML combustor were higher than those of the LEAN and EGR combustors. Also, the possibility of applying the RML combustor to gas turbines was discussed considering residence time, equivalence ratio of the rich chamber and recirculation rate. Although further research to design and realize the proposed RML combustor is needed, this study verified that the RML concept can be successfully used in a gas turbine combustor.

  7. Variable volume combustor with an air bypass system

    Science.gov (United States)

    Johnson, Thomas Edward; Ziminsky, Willy Steve; Ostebee, Heath Michael; Keener, Christopher Paul

    2017-02-07

    The present application provides a combustor for use with flow of fuel and a flow of air in a gas turbine engine. The combustor may include a number of micro-mixer fuel nozzles positioned within a liner and an air bypass system position about the liner. The air bypass system variably allows a bypass portion of the flow of air to bypass the micro-mixer fuel nozzles.

  8. Aerotrace. Measurement of particulates from an engine combustor

    Energy Technology Data Exchange (ETDEWEB)

    Hurley, C.D. [DRA, Farnborough (United Kingdom)

    1997-12-31

    The effect of gas turbine operating conditions, inlet temperature, pressure and overall air fuel ratio, on particulate number density has been measured. Particulate number density was found to be proportional to combustor inlet pressure and decrease with increasing combustor inlet temperature. The relationship with air fuel ratio is more complex. The mechanism of particulate loss down sample lines has been elucidated and equations are presented to predict particulate losses for stainless steel and PTFE sample lines. (author) 3 refs.

  9. Combustion of Syngas Fuel in Gas Turbine Can Combustor

    OpenAIRE

    Chaouki Ghenai

    2010-01-01

    Numerical investigation of the combustion of syngas fuel mixture in gas turbine can combustor is presented in this paper. The objective is to understand the impact of the variability in the alternative fuel composition and heating value on combustion performance and emissions. The gas turbine can combustor is designed to burn the fuel efficiently, reduce the emissions, and lower the wall temperature. Syngas mixtures with different fuel compositions are produced through different coal and biom...

  10. Pollution technology program, can-annular combustor engines

    Science.gov (United States)

    Roberts, R.; Fiorentino, A. J.; Greene, W.

    1976-01-01

    A Pollution Reduction Technology Program to develop and demonstrate the combustor technology necessary to reduce exhaust emissions for aircraft engines using can-annular combustors is described. The program consisted of design, fabrication, experimental rig testing and assessment of results and was conducted in three program elements. The combustor configurations of each program element represented increasing potential for meeting the 1979 Environmental Protection Agency (EPA) emission standards, while also representing increasing complexity and difficulty of development and adaptation to an operational engine. Experimental test rig results indicate that significant reductions were made to the emission levels of the baseline JT8D-17 combustor by concepts in all three program elements. One of the Element I single-stage combustors reduced carbon monoxide to a level near, and total unburned hydrocarbons (THC) and smoke to levels below the 1979 EPA standards with little or no improvement in oxides of nitrogen. The Element II two-stage advanced Vorbix (vortex burning and mixing) concept met the standard for THC and achieved significant reductions in CO and NOx relative to the baseline. Although the Element III prevaporized-premixed concept reduced high power NOx below the Element II results, there was no improvement to the integrated EPA parameter relative to the Vorbix combustor.

  11. Co-combustion of automotive shredder residue (ASR) and sewage sludge with a mixture of industrial and household waste in an 20MW fluidized bed combustor; Samfoerbraenning av bilfluff, roetslam och avfall i en 20 MW fluidbaeddpanna - Studier av braenslesammansaettningens paaverkan paa belaeggningsbildning

    Energy Technology Data Exchange (ETDEWEB)

    Eskilsson, David; Johansson, Andreas; Johansson, Linda; Wikstroem-Blomqvist, Evalena

    2007-07-01

    In order to prevent a further increased use of resources and to decrease the environmental impact from landfills, organic wastes are today diverted towards material and energy recovery. This creates a waste market with an increasing number of waste fractions that needs to be treated properly. As an example, in Sweden it has recently been prohibited to landfill source separated combustible waste (2002) and organic waste (2005). Wastes as automotive shredder residue (ASR) and sewage sludge can no longer be landfilled and needs to be either material or energy recovered, which challenge the waste treatment sector. This work investigates the effects of ASR and sewage sludge co-combustion in a 20 MW Energy-from-Waste plant (bubbling fluidised bed). The long term objective of the work is to increase the fuel flexibility, the boiler availability and the power production. This report focus on boiler operation and combustion performance in terms of agglomeration, deposit rates and emissions. In addition to the tests with ASR and sewage sludge, repeated measurements were performed during normal load as a reference. The results show that the co-combusted fractions of ASR and sewage sludge, which on mass basis constituted 6 % and 15 % respectively, did not increase the risk for agglomeration or deposits on heat-exchanging surfaces. Instead, compared to the two reference cases, the deposit rates decreased when sewage sludge was added. Only minor variation in the emissions was seen between the different cases. The levels of I-TEQs were far below the legislated values in all cases

  12. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. Hemant Kumar. Articles written in Sadhana. Volume 40 Issue 4 June 2015 pp 1283-1299 Mechanical Sciences. Study of a 30 MW bubbling fluidized bed combustor based on co-firing biomass and coal · Hemant Kumar S K Mohapatra Ravi Inder Singh · More Details Abstract Fulltext PDF. Today's ...

  13. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Study of a 30 MW bubbling fluidized bed combustor based on co-firing biomass and coal · Hemant Kumar S K Mohapatra Ravi Inder Singh · More Details Abstract Fulltext PDF. Today's power generation sources are largely dependent on fossil fuels due to which the future sustainable development has become a challenge.

  14. Development program on pressurized fluidized-bed combustion. Annual report, July 1, 1974--June 30, 1975

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, G.J.; Cunningham, P.; Fischer, J.

    1975-07-01

    The feasibility of using fluidized-bed combustors in power and steam plants is being evaluated. The concept involves burning fuels such as coal in a fluidized bed of either a naturally occurring, calcium-containing limestone or dolomite or in a synthetically prepared calcium-containing stone. The calcium oxide in the stone reacts with the sulfur released during combustion to form calcium sulfate, which remains in the bed, thus decreasing the level of SO/sub 2/ in the flue gas. Levels of NO/sub x/ in the flue gas are also low. The effect of operating variables and type of stone on the levels of SO/sub 2/ and NO/sub x/ is being determined. Behavior of trace elements during combustion has been preliminarily evaluated. The properties of a fluidized bed at minimum fluidization at different temperatures and pressures have been determined. The CaSO/sub 4/ produced in the combustion process is regenerated to CaO for reuse in the combustor by reductive decomposition at 1095/sup 0/C (2000/sup 0/F). The effects of operating variables on sulfur release during regeneration are being evaluated. Another regeneration process, solid-solid reaction of CaSO/sub 4/ with CaS, is also being investigated. Fundamental investigations of the kinetics of sulfation and regeneration reactions for the natural and synthetic stones are continuing. A model for the sulfation reaction is presented. The status of the new combustor andancillary regenerator equipment is discussed. (auth)

  15. Flow conditioner for fuel injector for combustor and method for low-NO.sub.x combustor

    Science.gov (United States)

    Dutta, Partha; Smith, Kenneth O.; Ritz, Frank J.

    2013-09-10

    An injector for a gas turbine combustor including a catalyst coated surface forming a passage for feed gas flow and a channel for oxidant gas flow establishing an axial gas flow through a flow conditioner disposed at least partially within an inner wall of the injector. The flow conditioner includes a length with an interior passage opening into upstream and downstream ends for passage of the axial gas flow. An interior diameter of the interior passage smoothly reduces and then increases from upstream to downstream ends.

  16. Evaluation of AFBC co-firing of coal and hospital wastes. Technical report, January 1989--August 1990

    Energy Technology Data Exchange (ETDEWEB)

    1991-02-01

    The purpose of this program is to expand the use of coal by utilizing CFB (circulating fluidized bed) technology to provide an environmentally safe method for disposing of waste materials. Hospitals are currently experiencing a waste management crisis. In many instances, they are no longer permitted to burn pathological and infectious wastes in incinerators. Older hospital incinerators are not capable of maintaining the stable temperatures and residence times necessary in order to completely destroy toxic substances before release into the atmosphere. In addition, the number of available landfills which can safely handle these substances is decreasing each year. The purpose of this project is to conduct necessary research investigating whether the combustion of the hospital wastes in a coal-fired circulating fluidized bed boiler will effectively destroy dioxins and other hazardous substances before release into the atmosphere. If this is proven feasible, in light of the quantity of hospital wastes generated each year, it would create a new market for coal -- possibly 50 million tons/year.

  17. Effects on NOx and SO2 Emissions during Co-Firing of Coal With Woody Biomass in Air Staging and Reburning

    Directory of Open Access Journals (Sweden)

    Nihad Hodžić

    2018-02-01

    Full Text Available Co-firing coal with different types of biomass is increasingly being applied in thermal power plants in Europe. The main motive for the use of biomass as the second fuel in coal-fired power plants is the reduction of CO2 emissions, and related financial benefits in accordance with the relevant international regulations and agreements. Likewise, the application of primary measures in the combustion chamber, which also includes air staging and/or reburning, results in a significant reduction in emission of polluting components of flue gases, in particular NOx emissions. In addition to being efficient and their application to new and future thermoblocks is practically unavoidable, their application and existing conventional combustion chamber does not require significant constructional interventions and is therefore relatively inexpensive. In this work results of experimental research of co-firing coals from Middle Bosnian basin with waste woody biomass are presented. Previously formed fuel test matrix is subjected to pulverized combustion under various temperatures and various technical and technological conditions. First of all it refers to the different mass ratio of fuel components in the mixture, the overall coefficient of excess air and to the application of air staging and/or reburning. Analysis of the emissions of components of the flue gases are presented and discussed. The impact of fuel composition and process temperature on the values of the emissions of components of the flue gas is determined. Additionally, it is shown that other primary measures in the combustion chamber are resulting in more or less positive effects in terms of reducing emissions of certain components of the flue gases into the environment. Thus, for example, the emission of NOx of 989 mg/ measured in conventional combustion, with the simultaneous application of air staging and reburning is reduced to 782 mg/, or by about 21%. The effects of the primary measures

  18. Pulsed atmospheric fluidized bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    1989-11-01

    In order to verify the technical feasibility of the MTCI Pulsed Atmospheric Fluidized Bed Combustor technology, a laboratory-scale system was designed, built and tested. Important aspects of the operational and performance parameters of the system were established experimentally. A considerable amount of the effort was invested in the initial task of constructing an AFBC that would represent a reasonable baseline against which the performance of the PAFBC could be compared. A summary comparison of the performance and emissions data from the MTCI 2 ft {times} 2 ft facility (AFBC and PAFBC modes) with those from conventional BFBC (taller freeboard and recycle operation) and circulating fluidized bed combustion (CFBC) units is given in Table ES-1. The comparison is for typical high-volatile bituminous coals and sorbents of average reactivity. The values indicated for BFBC and CFBC were based on published information. The AFBC unit that was designed to act as a baseline for the comparison was indeed representative of the larger units even at the smaller scale for which it was designed. The PAFBC mode exhibited superior performance in relation to the AFBC mode. The higher combustion efficiency translates into reduced coal consumption and lower system operating cost; the improvement in sulfur capture implies less sorbent requirement and waste generation and in turn lower operating cost; lower NO{sub x} and CO emissions mean ease of site permitting; and greater steam-generation rate translates into less heat exchange surface area and reduced capital cost. Also, the PAFBC performance generally surpasses those of conventional BFBC, is comparable to CFBC in combustion and NO{sub x} emissions, and is better than CFBC in sulfur capture and CO emissions even at the scaled-down size used for the experimental feasibility tests.

  19. Experimental study on fuel oil combustion in circulating fluidized bed; Estudio experimental sobre la combustion de combustoleo en lecho fluidizado circulante

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Rangel, Ricardo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    The Instituto de Investigaciones Electricas (IIE) developed a circulating fluidized bed combustor of 0.5 thermal MW unique in its type in Latin America. The Bachelor`s thesis entitled ``Experimental Study on Fuel Oil Combustion in Circulating Fluidized Bed`` was performed operating this combustor with the purpose of determining the feasibility of burning heavy fuel oil in a stable and sustained form, as well as the effect of the addition of calcium carbonate to the combustor. The results of the experimental trials showed heavy fuel oil can be burned in a circulating fluidized bed, with low sulfur dioxide emissions. During the conduction of the experiments a sulfur retention of 43% was achieved with a Ca/S relationship of 4.5. [Espanol] El Instituto de Investigaciones Electricas (IIE) desarrollo un combustor de lecho fluidizado circulante de 0.5 MW termicos de potencia, unico en su tipo en Latinoamerica. La tesis de licenciatura titulada Estudio Experimental sobre la Combustion de Combustoleo en Lecho Fluidizado Circulante se realizo operando dicho combustor, con el proposito de determinar la factibilidad de quemar combustoleo pesado en forma estable y autosostenida, asi como la influencia que tiene la adicion de carbonato de calcio al lecho. Los resultados de los ensayos experimentales mostraron que se puede quemar combustoleo pesado en un lecho fluidizado circulante, con bajas emisiones de bioxido de azufre. Durante la experimentacion se logro una retencion de azufre del 43%, con una relacion Ca/S de 4.5.

  20. Investigation on the flame dynamics of meso-combustors

    Science.gov (United States)

    Ahmed, Mahbub

    Miniature heat engines burning hydrogen and hydrocarbon fuels have significantly higher energy densities compared to conventional lithium batteries and thus will play an essential role in the portable production of power for future electronics, remote sensors, and micro aerial vehicles. Additionally, miniature heat engines will tremendously benefit next generation of environmental technologies such as steam reforming, ammonia decomposition and fuel cells. Successful miniaturization of heat engine components demand a more complete and broader understanding of micro-fluid dynamics and micro-combustion phenomena associated with the combustor design. This dissertation is aimed at investigating the details of the micro-mixing dynamics and the combustion behavior of the meso-combustor and to create fundamental understanding of physics based design methodology. The primary goals of the project are (i) to develop an understanding of fuel-air mixing inside a meso-combustor, (ii) to develop an understanding of the flame stability (flame quenching and velocity blowout) criteria of a meso-combustor, (iii) to understand the thermal behavior of the meso-combustor, and (iv) to correlate these with combustor operating conditions such as the Reynolds number, equivalent ratio, and thermal power etc. The present study shows that adequate mixing of fuel and air is achievable in millimeter scale combustors. Both computed results and experimental measurements of iso-thermal (non-burning) flows at different mixing configurations indicate that the laminar burning velocity remains higher than the local flow velocities in most of the combustor locations to support stable flame propagations. Stable flames of hydrogen are achieved for all mixing and flow configurations. The combustion of methane with air as oxidizer in the combustors is unreliable. However, highly stable combustion of methane at various mixing and flow conditions is achieved when pure oxygen is used as an oxidizer. The

  1. Combustion test of refuse derived fuel in fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Piao, Guilin; Aono, Shegeru; Yamazaki, Ryohei; Fujima, Yukihisa; Mori, Shigekatsu [Nagoya University, Aichi (Japan); Kondo, Motohiro; Yamaguchi, Masataka [Toyota Motor Corp., Aichi (Japan)

    1999-08-01

    Power generation from Refuse Derived Fuel (RFD) is a promising utilization technology for municipal municipal solid waste. To explain the combustion behaviors of RDF was fed continuously in to a 0.3 x 0.3 m x 2.73 m in height bubbling-type fluidized bed combustor and CO, NO{sub x}, SO{sub x} and HCl concentrations in the flue gas from the combustor were detected by a continuos measurement system. It is found that CO concentration in the flue gas is greatly increased by increasing the RFD feed rate, and CO concentration in the flue gas is greatly decreased by increasing the air ratio because the volatile matters rate is extremely great in combustion of RFD. It is also significantly affected by the secondary air injection and the air distribution ratio from the distributor. HCl concentration in the flue gas is effectively controlled by the calcium compound contained in RDF.HCl concentration is maintained to be less than 60 ppm when the bed temperature is 800 degree C, and the HCl removal ratio by the calcium component is higher than 70% even though under the higher bed temperature than 900 degree C. NO{sub x} concentration was among 50-150 ppm and SO{sub x} concentration is less than 0.5 ppm. (author)

  2. A low-temperature co-fired ceramic micro-reactor system for high-efficiency on-site hydrogen production

    Science.gov (United States)

    Jiang, Bo; Maeder, Thomas; Santis-Alvarez, Alejandro J.; Poulikakos, Dimos; Muralt, Paul

    2015-01-01

    A ceramic-based, meso-scale fuel processor for on-board production of syngas fuel was demonstrated for applications in micro-scale solid-oxide fuel cells (μ-SOFCs). The processor had a total dimension of 12 mm × 40 mm × 2 mm, the gas reforming micro reactor occupying the hot end of a cantilever had outer dimensions of 12 × 18 mm. The device was fabricated through a novel progressive lamination process in low-temperature co-fired ceramic (LTCC) technology. Both, heating function and desired fluidic structures were integrated monolithically into the processor. Using catalytic partial oxidation of a hydrocarbon fuel (propane) as a reaction model, a thermally self-sustaining hydrogen production was achieved. The output flow is sufficiently high to drive an optimized single membrane μSOFC cell of about the same footprint as the micro reactor. Microsystem design, fabrication, catalyst integration as well as the chemical characterization are discussed in detail.

  3. Combustion aerosols from co-firing of coal and solid recovered fuel in a 400 mw pf-fired power plant

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Wu, Hao; Jappe Frandsen, Flemming

    2010-01-01

    In this work, combustion aerosols (i.e. fine particles coal-fired power plant was sampled with a low-pressure impactor, and analysed by transmission and scanning electron microscopy. The power plant was operated at both dedicated coal combustion conditions...... and under conditions with cofiring of up to 10% (thermal basis) of solid recovered fuel (SRF). The SRFs were characterized by high contents of Cl, Ca, Na and trace metals, while the coal had relatively higher S, Al, Fe and K content. The mass-based particle size distribution of the aerosols was found...... to be bi-modal, with an ultrafine (vaporization) mode centered around 0.1 μm, and a coarser (finefragmentation) mode above 2 μm. Co-firing of SRF tended to increase the formation of ultrafine particles as compared with dedicated coal combustion, while the coarse mode tended to decrease. The increased...

  4. Microfabrication of a Novel Ceramic Pressure Sensor with High Sensitivity Based on Low-Temperature Co-Fired Ceramic (LTCC Technology

    Directory of Open Access Journals (Sweden)

    Chen Li

    2014-06-01

    Full Text Available In this paper, a novel capacitance pressure sensor based on Low-Temperature Co-Fired Ceramic (LTCC technology is proposed for pressure measurement. This approach differs from the traditional fabrication process for a LTCC pressure sensor because a 4J33 iron-nickel-cobalt alloy is applied to avoid the collapse of the cavity and to improve the performance of the sensor. Unlike the traditional LTCC sensor, the sensitive membrane of the proposed sensor is very flat, and the deformation of the sensitivity membrane is smaller. The proposed sensor also demonstrates a greater responsivity, which reaches as high as 13 kHz/kPa in range of 0–100 kPa. During experiments, the newly fabricated sensor, which is only about 6.5 cm2, demonstrated very good performance: the repeatability error, hysteresis error, and nonlinearity of the sensor are about 4.25%, 2.13%, and 1.77%, respectively.

  5. Simulation modeling of fluidized bed coal gasifier for new topping cycle system

    Energy Technology Data Exchange (ETDEWEB)

    Piao, Guilin; Yamazaki, Ryohei; Mori, Shigekatsu; Fujima, Yukihisa [Nagoya Univ. (Japan). Dept. of Chemical Engineering

    1997-12-31

    A new topping cycle coal power generation process is to be developed as a Japanese national project of high efficiency power generation process of coal. This process consists of a combination system of a pressurized bubbling fluidized-bed coal gasifier and a pressurized bubbling fluidized-bed combustor in series. To evaluate the performances and also to determine specifications and operation parameters of this process, it is extremely important to analyze the behavior and the performance of this system by a reasonable simulation model. A simulation model of this new process is developed in this paper. It is demonstrated by calculated results from this model that the carbon conversion in the gasifier, the composition and the heating value of produced gas are strongly dependent on operating conditions. Heat recovery by the steam in the combustor is also estimated as the function of coal feed rate.

  6. Simultaneous determination of devolatilization and char burnout times during fluidized bed combustion of coal

    International Nuclear Information System (INIS)

    Christofiedes, N.; Brown, R.C.

    1992-01-01

    In this paper, the authors investigate a method for simultaneous determination of devolatilization and char burnout times based on the analysis of CO 2 emissions from a fluidized bed combustor. The technique is non-intrusive and can be performed under realistic combustion conditions. The authors' method involves batching single-size coal samples in a fluidized bed combustor that is heated with propane gas or other fuel. Carbon dioxide profiles versus time for the batch tests are analyzed with a linear model to obtain characteristic time constants for coal devolatilization and char combustion which can be related to total devolatilization time and burnout time for a coal sample. The authors' approach does not require special sample preparation, can be performed in actual combustion equipment and employs standard boiler instrumentation

  7. Advanced low emissions catalytic combustor program at General Electric

    Science.gov (United States)

    Dodds, W. J.

    1979-01-01

    The Advanced Low Emissions Catalytic Combustors Program (ALECC) is being undertaken to evaluate the feasibility of employing catalytic combustion technology in aircraft gas turbine engines as a means to control emission of oxides of nitrogen during subsonic stratospheric cruise operation. The ALECC Program is being conducted in three phases. The first phase, which was completed in November, 1978, consisted of a design study to identify catalytic combustor designs having the greatest potential to meet the emissions and performance goals specified. The primary emissions goal of this program was to obtain cruise NO emissions of less than 1g/kg (compared with levels of 15 to 20 g/x obtained with current designs)/ However, good overall performance and feasibility for engine development were heavily weighted in the evaluation of combustor designs.

  8. Design and evaluation of combustors for reducing aircraft engine pollution

    Science.gov (United States)

    Jones, R. E.; Grobman, J.

    1973-01-01

    Various techniques and test results are briefly described and referenced for detail. The effort arises from the increasing concern for the measurement and control of emissions from gas turbine engines. The greater part of this research is focused on reducing the oxides of nitrogen formed during takeoff and cruise in both advanced CTOL, high pressure ratio engines, and advanced supersonic aircraft engines. The experimental approaches taken to reduce oxides of nitrogen emissions include the use of: multizone combustors incorporating reduced dwell time, fuel-air premixing, air atomization, fuel prevaporization, water injection, and gaseous fuels. In the experiments conducted to date, some of these techniques were more successful than others in reducing oxides of nitrogen emissions. Tests are being conducted on full-annular combustors at pressures up to 6 atmospheres and on combustor segments at pressures up to 30 atmospheres.

  9. Analytical fuel property effects: Small combustors, phase 2

    Science.gov (United States)

    Hill, T. G.; Monty, J. D.; Morton, H. L.

    1985-01-01

    The effects of non-standard aviation fuels on a typical small gas turbine combustor were studied and the effectiveness of design changes intended to counter the effects of these fuels was evaluated. The T700/CT7 turboprop engine family was chosen as being representative of the class of aircraft power plants desired for this study. Fuel properties, as specified by NASA, are characterized by low hydrogen content and high aromatics levels. No. 2 diesel fuel was also evaluated in this program. Results demonstrated the anticipated higher than normal smoke output and flame radiation intensity with resulting increased metal temperatures on the baseline T700 combustor. Three new designs were evaluated using the non standard fuels. The three designs incorporated enhanced cooling features and smoke reduction features. All three designs, when burning the broad specification fuels, exhibited metal temperatures at or below the baseline combustor temperatures on JP-5. Smoke levels were acceptable but higher than predicted.

  10. Effect of ramp-cavity on hydrogen fueled scramjet combustor

    Directory of Open Access Journals (Sweden)

    J.V.S. Moorthy

    2014-03-01

    Full Text Available Sustained combustion and optimization of combustor are the two challenges being faced by combustion scientists working in the area of supersonic combustion. Thorough mixing, lower stagnation pressure losses, positive thrust and sustained combustion are the key issues in the field of supersonic combustion. Special fluid mechanism is required to achieve good mixing. To induce such mechanisms in supersonic inflows, the fuel injectors should be critically shaped incurring less flow losses. Present investigations are focused on the effect of fuel injection scheme on a model scramjet combustor performance. Ramps at supersonic flow generate axial vortices that help in macro-mixing of fuel with air. Interaction of shocks generated by ramps with the fuel stream generates boro-clinic torque at the air & liquid fuel interface, enhancing micro-mixing. Recirculation zones present in cavities increase the residence time of the combustible mixture. Making use of the advantageous features of both, a ramp-cavity combustor is designed. The combustor has two sections. First, constant height section consists of a backward facing step followed by ramps and cavities on both the top and bottom walls. The ramps are located alternately on top and bottom walls. The complete combustor width is utilized for the cavities. The second section of the combustor is diverging area section. This is provided to avoid thermal choking. In the present work gaseous hydrogen is considered as fuel. This study was mainly focused on the mixing characteristics of four different fuel injection locations. It was found that injecting fuel upstream of the ramp was beneficial from fuel spread point of view.

  11. Combustor with two stage primary fuel assembly

    Science.gov (United States)

    Sharifi, Mehran; Zolyomi, Wendel; Whidden, Graydon Lane

    2000-01-01

    A combustor for a gas turbine having first and second passages for pre-mixing primary fuel and air supplied to a primary combustion zone. The flow of fuel to the first and second pre-mixing passages is separately regulated using a single annular fuel distribution ring having first and second row of fuel discharge ports. The interior portion of the fuel distribution ring is divided by a baffle into first and second fuel distribution manifolds and is located upstream of the inlets to the two pre-mixing passages. The annular fuel distribution ring is supplied with fuel by an annular fuel supply manifold, the interior portion of which is divided by a baffle into first and second fuel supply manifolds. A first flow of fuel is regulated by a first control valve and directed to the first fuel supply manifold, from which the fuel is distributed to first fuel supply tubes that direct it to the first fuel distribution manifold. From the first fuel distribution manifold, the first flow of fuel is distributed to the first row of fuel discharge ports, which direct it into the first pre-mixing passage. A second flow of fuel is regulated by a second control valve and directed to the second fuel supply manifold, from which the fuel is distributed to second fuel supply tubes that direct it to the second fuel distribution manifold. From the second fuel distribution manifold, the second flow of fuel is distributed to the second row of fuel discharge ports, which direct it into the second pre-mixing passage.

  12. Flashback behavior in a model swirl combustor at elevated pressure

    Science.gov (United States)

    Ranjan, Rakesh; Ebi, Dominik; Clemens, Noel

    2014-11-01

    Understanding of combustion physics at high pressure is essential for safe and efficient operation of gas turbine combustors. A new optically-accessible elevated pressure combustion facility has been developed for this purpose. The modular design of the chamber allows applying various optical diagnostic techniques and the installation of different types of combustors. In the current study, the effect of pressure on boundary layer flashback in lean-premixed swirl flames is investigated. Mixtures of hydrogen and methane at different equivalence ratios are tested. High-speed chemiluminescence imaging is employed to study the upstream flame propagation inside the mixing tube, which allows comparison to previous results of flashback at atmospheric pressure.

  13. Variable volume combustor with aerodynamic fuel flanges for nozzle mounting

    Science.gov (United States)

    McConnaughhay, Johnie Franklin; Keener, Christopher Paul; Johnson, Thomas Edward; Ostebee, Heath Michael

    2016-09-20

    The present application provides a combustor for use with a gas turbine engine. The combustor may include a number of micro-mixer fuel nozzles and a fuel injection system for providing a flow of fuel to the micro-mixer fuel nozzles. The fuel injection system may include a number of support struts supporting the fuel nozzles and for providing the flow of fuel therethrough. The fuel injection system also may include a number of aerodynamic fuel flanges connecting the micro-mixer fuel nozzles and the support struts.

  14. Cleaning of biomass derived product gas for engine applications and for co-firing in PC-boilers

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E.; Staahlberg, P. [VTT Energy, Espoo (Finland). Energy Production Technologies

    1997-12-01

    The main constituents rendering the engine use of gas produced from biomass are the tar content of the gases (condensing hydrocarbons), which cause problems for pipings, nozzles, and control of combustion. Purification methods, based on catalytic cracking of tars are investigated in the research in order to eliminate these problems. The target of the project is to demonstrate the developed gasification/gas purification process with engine test using PDU-scale equipment. Impurities of biomasses and biomass wastes (alkalis, chlorine, heavy metals), and the ash melting properties restrict in many cases the combined utilisation of biomasses and coal in power plant boilers. The second main task of this research is to investigate the removal of the problematic gas and ash components from the product gas. The sufficient degree of purification should be achieved by as simple and as cheap purification methods as possible. The main tasks of the first year of the project were (a) determination of the dimensioning characteristics of ambient pressure PDU scale cell-catalyst reactor (tests with laboratory-scale equipment), designing and construction of the reactor, (b) to investigate the operation of a cell-catalyst in purification of pre-cracked down-draft gasification gas, (c) acquisition of dimensioning data for dolomite-cracker based on fluidized bed principle, and (d) gasification of the Dutch building demolition waste and Danish straw, and the purification tests with the gases

  15. Turbine combustor with fuel nozzles having inner and outer fuel circuits

    Science.gov (United States)

    Uhm, Jong Ho; Johnson, Thomas Edward; Kim, Kwanwoo

    2013-12-24

    A combustor cap assembly for a turbine engine includes a combustor cap and a plurality of fuel nozzles mounted on the combustor cap. One or more of the fuel nozzles would include two separate fuel circuits which are individually controllable. The combustor cap assembly would be controlled so that individual fuel circuits of the fuel nozzles are operated or deliberately shut off to provide for physical separation between the flow of fuel delivered by adjacent fuel nozzles and/or so that adjacent fuel nozzles operate at different pressure differentials. Operating a combustor cap assembly in this fashion helps to reduce or eliminate the generation of undesirable and potentially harmful noise.

  16. Thermal performance of a micro-combustor for micro-gas turbine system

    International Nuclear Information System (INIS)

    Cao, H.L.; Xu, J.L.

    2007-01-01

    Premixed combustion of hydrogen gas and air was performed in a stainless steel based micro-annular combustor for a micro-gas turbine system. Micro-scale combustion has proved to be stable in the micro-combustor with a gap of 2 mm. The operating range of the micro-combustor was measured, and the maximum excess air ratio is up to 4.5. The distribution of the outer wall temperature and the temperature of exhaust gas of the micro-combustor with excess air ratio were obtained, and the wall temperature of the micro-combustor reaches its maximum value at the excess air ratio of 0.9 instead of 1 (stoichiometric ratio). The heat loss of the micro-combustor to the environment was calculated and even exceeds 70% of the total thermal power computed from the consumed hydrogen mass flow rate. Moreover, radiant heat transfer covers a large fraction of the total heat loss. Measures used to reduce the heat loss were proposed to improve the thermal performance of the micro-combustor. The optimal operating status of the micro-combustor and micro-gas turbine is analyzed and proposed by analyzing the relationship of the temperature of the exhaust gas of the micro-combustor with thermal power and excess air ratio. The investigation of the thermal performance of the micro-combustor is helpful to design an improved micro-combustor

  17. Multiscale Software Tool for Controls Prototyping in Supersonic Combustors

    National Research Council Canada - National Science Library

    Pindera, M

    2004-01-01

    .... In Phase I we have developed a proof-of-concept version of such a tool. We have developed a model-free direct control strategy with on-line training and demonstrated its capabilities in controlling isolator unstart in a hypersonic combustor...

  18. Combustion of Syngas Fuel in Gas Turbine Can Combustor

    Directory of Open Access Journals (Sweden)

    Chaouki Ghenai

    2010-01-01

    Full Text Available Numerical investigation of the combustion of syngas fuel mixture in gas turbine can combustor is presented in this paper. The objective is to understand the impact of the variability in the alternative fuel composition and heating value on combustion performance and emissions. The gas turbine can combustor is designed to burn the fuel efficiently, reduce the emissions, and lower the wall temperature. Syngas mixtures with different fuel compositions are produced through different coal and biomass gasification process technologies. The composition of the fuel burned in can combustor was changed from natural gas (methane to syngas fuel with hydrogen to carbon monoxide (H2/CO volume ratio ranging from 0.63 to 2.36. The mathematical models used for syngas fuel combustion consist of the k-ε model for turbulent flow, mixture fractions/PDF model for nonpremixed gas combustion, and P-1 radiation model. The effect of syngas fuel composition and lower heating value on the flame shape, gas temperature, mass of carbon dioxide (CO2 and nitrogen oxides (NOx per unit of energy generation is presented in this paper. The results obtained in this study show the change in gas turbine can combustor performance with the same power generation when natural gas or methane fuel is replaced by syngas fuels.

  19. DEVELOPMENT OF A VORTEX CONTAINMENT COMBUSTOR FOR COAL COMBUSTION SYTEMS

    Science.gov (United States)

    The report describes the development of a vortex containment combustor (VCC) for coal combustion systems, designed to solve major problems facing the conversion of oil- and gas-fired boilers to coal (e.g., derating, inorganic impurities in coal, and excessive formation of NOx and...

  20. Non-linear dynamics in pulse combustor: A review

    Indian Academy of Sciences (India)

    tages, lack of thorough understanding of the dynamics complicates the design of pulse combustors and is one of the main ... engineering community. Many researchers have investigated the dynamic behaviour of .... substantiated the qualitative observations similar to that in figure 1 with quantitative esti- mates based on ...

  1. Non-linear dynamics in pulse combustor: A review

    Indian Academy of Sciences (India)

    the regime of periodic behaviour, and (iii) using the dynamic characteristics to predict events like extinction. 2. Dynamic characterization using mathematical model. Pulse combustor consists of a combustion chamber that is often modelled as a well- stirred reactor due to intense mixing with a tailpipe extending from one end.

  2. Devolatilization and ash comminution of two different sewage sludges under fluidized bed combustion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Solimene, R.; Urciuolo, M.; Cammarota, A.; Chirone, R. [Istituto di Ricerche sulla Combustione (IRC) - CNR, Napoli (Italy); Salatino, P. [Istituto di Ricerche sulla Combustione (IRC) - CNR, Napoli (Italy); Dipartimento di Ingegneria Chimica Universita degli Studi di Napoli Federico II, Napoli (Italy); Damonte, G.; Donati, C.; Puglisi, G. [ECODECO Gruppo A2A, Giussago (PV) (Italy)

    2010-04-15

    Two different wet sewage sludges have been characterized under fluidized bed combustion conditions with reference to their devolatilization behavior and ash comminution with the aid of different and complementary experimental protocols. Analysis of the devolatilization process allowed to determine the size of fuel particle able to achieve effective lateral spreading of the volatile matter across the cross-section of medium-scale combustors. Primary fragmentation and primary ash particle characterization pointed out the formation of a significant amount of relatively large fragments. The mechanical properties of these fragments have been characterized by means of elutriation/abrasion tests using both quartz and sludge ash beds. (author)

  3. Development of a bench-scale fluidized bed combustor (FBC) for ...

    African Journals Online (AJOL)

    The high technological level of equipment for combustion of fuels, as well as the necessity for rational and efficient use of non-renewable energy resources, has resulted demanding requirements that must be fulfilled by equipment for energy production, via combustion. These requirements form the characteristics of ...

  4. Study of a 30 MW bubbling fluidized bed combustor based on co ...

    Indian Academy of Sciences (India)

    As the demand for electricity is growing rapidly, emissions of carbon dioxide and other pollutants from this sector can be expected to increase unless other alternatives are made available. Among the energy sources that can substitute fossil fuels, biomass fuels appear as one of the options with a high worldwide potential.

  5. Study of a 30 MW bubbling fluidized bed combustor based on co ...

    Indian Academy of Sciences (India)

    viable because of the huge investments required for collection, transportation and storage. How- ever, there are .... proximate analysis of various biomass fuels used has been done and shown in table 3 and table 4 .... estimated based on the carbon content as obtained from the elemental analysis of the fuel and the excess ...

  6. Optimum diameter of a circulating fluidised bed combustor with negative wall heat flux

    CSIR Research Space (South Africa)

    Baloyi, J

    2015-07-01

    Full Text Available The focus of the world is the reduction of greenhouse gases like carbon dioxide, which contribute to the global warming currently experienced. Since most of the carbon dioxide emitted into the atmosphere is from fossil fuel combustion, alternative...

  7. Thermal stability in a newly designed columnar-conical fluidized bed for combustion of rice husk

    Energy Technology Data Exchange (ETDEWEB)

    Rozainee, M.; Salema, A.A.; Ngo, S.P.; Chye, G.B. [Malaysian Technological Univ., Johor Bahru (Malaysia). Dept. of Chemical Engineering

    2006-07-01

    The effects of fluidizing and liquid propane gas (LPG) flow rates on thermal stability of a fluidized bed were examined. The aim of the study was to hybridize a columnar and conical fluidized bed (CCFB) in order to encourage the combustion of low-calorific fuels such as rice husks. Experiments were conducted to examine the thermal stability of the CCFB. Premixed primary air and liquid propane gas (LPG) was fed into the bed in order to verify its thermal stability. Temperature profiles of the combustor and bed were measured. The impact of the fluidizing velocity and LPG flow rate on the temperature profile was examined in order to analyze the influence of the fluidizing velocity and LPG rate on combustion rates. Results of the study showed that the combustion of the CCFB was sustained at a fluidizing velocity of 1.5 U{sub mf} and at an LPG flow rate of 8 liters per minute. Results of the study showed that fluidizing velocity played an important role on the thermal stability of the bed. It was concluded that the thermal stability of the combustor is sufficient for the CCFB. 13 refs., 2 tabs., 5 figs.

  8. Fluidized bed combustion: mixing and pollutant limitation

    Energy Technology Data Exchange (ETDEWEB)

    Leckner, B. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Energy Conversion

    1997-10-01

    Fluidized bed combustion (FBC) has been applied commercially during a few decades, and sufficient knowledge is gained to design boilers with sizes of up to several hundreds of megawatt thermal power (MW{sub th}). The knowledge of what goes on inside a large combustion chamber is still limited, however, and this impedes further optimization and efficient solution of problems that might occur. Despite this lack of knowledge the present survey deals with combustion chamber processes and discusses mixing and distribution of fuel and air in the combustion chamber and its importance for sulphur capture and reduction of emissions of nitrogen oxides. It is desirable to present the material in a general way and to cover the entire field of FBC. However, the scarce openly published information deals mostly with coal combustion in atmospheric circulating fluidized bed (CFB) combustors, and therefore this application will receive most attention, but reference is also made to pressurized combustion and to other fuels than coal. In this context the important work made in the LIEKKI project on the analysis of different fuels and on the influence of pressure should be especially pointed out. (orig.)

  9. Strategies for 2nd generation biofuels in EU - Co-firing to stimulate feedstock supply development and process integration to improve energy efficiency and economic competitiveness

    Energy Technology Data Exchange (ETDEWEB)

    Berndes, Goeran; Hansson, Julia; Egeskog, Andrea [Department of Energy and Environment, Division of Physical Resource Theory, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden); Johnsson, Filip [Department of Energy and Environment, Division of Energy Technology, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden)

    2010-02-15

    The present biofuel policies in the European Union primarily stimulate 1st generation biofuels that are produced based on conventional food crops. They may be a distraction from lignocellulose based 2nd generation biofuels - and also from biomass use for heat and electricity - by keeping farmers' attention and significant investments focusing on first generation biofuels and the cultivation of conventional food crops as feedstocks. This article presents two strategies that can contribute to the development of 2nd generation biofuels based on lignocellulosic feedstocks. The integration of gasification-based biofuel plants in district heating systems is one option for increasing the energy efficiency and improving the economic competitiveness of such biofuels. Another option, biomass co-firing with coal, generates high-efficiency biomass electricity and reduces CO{sub 2} emissions by replacing coal. It also offers a near-term market for lignocellulosic biomass, which can stimulate development of supply systems for biomass also suitable as feedstock for 2nd generation biofuels. Regardless of the long-term priorities of biomass use for energy, the stimulation of lignocellulosic biomass production by development of near term and cost-effective markets is judged to be a no-regrets strategy for Europe. Strategies that induce a relevant development and exploit existing energy infrastructures in order to reduce risk and reach lower costs, are proposed an attractive complement the present and prospective biofuel policies. (author)

  10. Strategies for 2nd generation biofuels in EU - Co-firing to stimulate feedstock supply development and process integration to improve energy efficiency and economic competitiveness

    International Nuclear Information System (INIS)

    Berndes, Goeran; Hansson, Julia; Egeskog, Andrea; Johnsson, Filip

    2010-01-01

    The present biofuel policies in the European Union primarily stimulate 1st generation biofuels that are produced based on conventional food crops. They may be a distraction from lignocellulose based 2nd generation biofuels - and also from biomass use for heat and electricity - by keeping farmers' attention and significant investments focusing on first generation biofuels and the cultivation of conventional food crops as feedstocks. This article presents two strategies that can contribute to the development of 2nd generation biofuels based on lignocellulosic feedstocks. The integration of gasification-based biofuel plants in district heating systems is one option for increasing the energy efficiency and improving the economic competitiveness of such biofuels. Another option, biomass co-firing with coal, generates high-efficiency biomass electricity and reduces CO 2 emissions by replacing coal. It also offers a near-term market for lignocellulosic biomass, which can stimulate development of supply systems for biomass also suitable as feedstock for 2nd generation biofuels. Regardless of the long-term priorities of biomass use for energy, the stimulation of lignocellulosic biomass production by development of near term and cost-effective markets is judged to be a no-regrets strategy for Europe. Strategies that induce a relevant development and exploit existing energy infrastructures in order to reduce risk and reach lower costs, are proposed an attractive complement the present and prospective biofuel policies. (author)

  11. DEVELOPMENT OF A VALIDATED MODEL FOR USE IN MINIMIZING NOx EMISSIONS AND MAXIMIZING CARBON UTILIZATION WHEN CO-FIRING BIOMASS WITH COAL

    Energy Technology Data Exchange (ETDEWEB)

    Larry G. Felix; P. Vann Bush

    2002-01-31

    This is the fifth Quarterly Technical Report for DOE Cooperative Agreement No. DE-FC26-00NT40895. A statement of the project objectives is included in the Introduction of this report. One additional biomass co-firing test burn was conducted during this quarter. In this test (Test 9), up to 20% by weight dry hardwood sawdust and switchgrass was injected through the center of the single-register burner with Jacobs Ranch coal. Jacobs Ranch coal is a low-sulfur Powder River Basin coal ({approx} 0.5% S). The results from Test 9 as well as for Test 8 (conducted late last quarter) are presented in this quarterly report. Significant progress has been made in implementing a modeling approach to combine reaction times and temperature distributions from computational fluid dynamic models of the pilot-scale combustion furnace with char burnout and chemical reaction kinetics to predict NO{sub x} emissions and unburned carbon levels in the furnace exhaust. Additional results of CFD modeling efforts have been received and preparations are under way for continued pilot-scale combustion experiments with the dual-register burner. Finally, a project review was held at NETL in Pittsburgh, on November 13, 2001.

  12. DEVELOPMENT OF A VALIDATED MODEL FOR USE IN MINIMIZING NOx EMISSIONS AND MAXIMIZING CARBON UTILIZATION WHEN CO-FIRING BIOMASS WITH COAL

    Energy Technology Data Exchange (ETDEWEB)

    Larry G. Felix; P. Vann Bush

    2002-10-26

    This is the eighth Quarterly Technical Report for DOE Cooperative Agreement No. DE-FC26-00NT40895. A statement of the project objectives is included in the Introduction of this report. The final biomass co-firing test burn was conducted during this quarter. In this test (Test 14), up to 20% by weight dry switchgrass was comilled with Jim Walters No.7 mine coal and injected through the single-register burner. Jim Walters No.7 coal is a low-volatility, low-sulfur ({approx}0.7% S) Eastern bituminous coal. The results of this test are presented in this quarterly report. Progress has continued to be made in implementing a modeling approach to combine reaction times and temperature distributions from computational fluid dynamic models of the pilot-scale combustion furnace with char burnout and chemical reaction kinetics to predict NO{sub x} emissions and unburned carbon levels in the furnace exhaust. The REI Configurable Fireside Simulator (CFS) is now in regular use. Presently, the CFS is being used to generate CFD calculations for completed tests with Powder River Basin coal and low-volatility (Jim Walters No.7 Mine) coal. Niksa Energy Associates will use the results of these CFD simulations to complete their validation of the NOx/LOI predictive model. Work has started on the project final report.

  13. Materials support for EPRI Fluidized-Bed Combustion Program

    International Nuclear Information System (INIS)

    Sethi, V.K.; Wright, I.G.

    1993-05-01

    This research project was intended to provide technical support for materials aspects of EPRI's U.C. Fluidized Bed Combustor Program. The scope of this support included participation in the EPRI FBC materials oversight panel, inspection of fluidized beds during forced or planned outages, analysis of materials failures and of associated deposits, participation in technical meetings involving fluidized bed materials. Volume I describes the results of exposing for approximately 5,000 hours in the Georgetown AFBC a number of surface modifications that had been reported to have promise in combating in-bed evaporator tube wastage. Some measures were applied to sample lengths of carbon-steel tubing, and installed as part of the in-bed evaporator tube bundle at Georgetown. These tubes are inspected periodically while still installed in the unit, and were finally cut out and subjected to detailed measurements and metallographic evaluation. The exposure at regular intervals throughout the bed of plain carbon-steel tubes that were honed and surface-ground allowed a baseline measurement of the wastage potential of this bed, which was high. Qualitatively, all but one of the protective measures tested reduced wastage. The unprotected tubes showed that wastage occurred mainly on the underside of the tubes, with maximum wear at the tube bottom. The protective measures that were exposed were densely studded tubes, fins and flow separators, fins and studs on the underside of the tube, and longitudinal rods. These surface modifications were exposed in the chromized and unchromized conditions, together with plain carbon-steel tubes that had been chromized. The tubes with fins and flow separators exhibited continued wastage on the underside between the flow separators, which was attributed in part to the steep inclination of the tubes in the bed. The plain, chromized tubes, together with the armored, chromized tubes, exhibited virtually no wastage of the tube surface nor of the armor

  14. Pressurized fluidized-bed combustion part-load behavior. Volume I. Summary report

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, A. G.; Pillai, K. K.; Raven, P.; Wood, P.

    1981-09-01

    Tests performed during 1980 to determine the part-load characteristics of a pressurized fluidized-bed combustor for a combined-cycle power plant and to examine its behavior during load changing are discussed. Part-load operation was achieved by varying the bed temperature by amounts between 200 to 300/sup 0/F and the bed depth from between 9 and 10 ft at rates varying between 0.2 ft/min and 0.5 ft/min. The performance at part-load steady-state conditions and during transient conditions is reported with information on combustion efficiency (99% at full-load with 9 ft bed depth and 1650/sup 0/F bed temperature; 95% with 4 ft depth and 1390/sup 0/F); sulfur retention (95/sup 0/ at full load to 80% at low bed depth and low bed temperature); sulfur emissions (no definitive results); NO/sub x/ emissions (tendency for increase as bed temperature was reduced); alkali emissions (no bed temperature effect detected); and heat transfer. It was demonstrated that load can be altered in a rapid and controlled manner by changing combinations of bed depth temperature and pressure. The most important practical change was the reduction in O/sub 2/ concentration which occurred when the bed height was increased at a rapid rate. The extra energy required to reheat the incoming bed material resulted (in the most extreme case) in a temporary drop in excess air from 65% to 12%. In a full-scale plant the loss of heat from the stored bed material would be much lower and the excess air trough when increasing load would not be as pronounced. Nevertheless, it seems prudent to design full-scale plant for a full load excess air of not less than about 50% when using bed depth as a load control parameter.

  15. Considerations on valorization of biomass origin materials in co-combustion with coal in fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    I. Gulyurtlu; P. Abelha; H. Lopes; A. Crujeira; I. Cabrita [DEECA-INETI, Lisbon (Portugal)

    2007-07-01

    Co-combustion of biomass materials with coal is currently gaining increasing importance, in order to meet the targets on greenhouse gas emissions, defined in the Kyoto protocol. Co-firing of coal with biomass materials could be the short-term solution in reducing CO{sub 2} emissions from power stations. The work undertaken studied co-firing of meat and bone meal (MBM), olive cake and straw pellets with bituminous coals from Colombia (CC) and Poland (PC), which are commonly used in European power stations. The co-combustion studies were carried out on the pilot fluidized bed installation of INETI. Gaseous pollutants and solid concentration in flue gases and ashes from different locations were monitored. Results obtained indicate that the co-feeding of biomass materials did not present any problem and ensured stable combustion conditions and high efficiency. However, for temperatures above 800{sup o}C, bed agglomeration could be observed for all biomass species studied. Most of the combustion of biomass material, contrary to that of coal, was observed to take place in the riser where the temperature was as high as 150-250{sup o}C above that of the bed. SO{sub 2} and NOx levels were found to be lower. The emissions of dioxins could be considerable with fuels with high Cl as is the case with straw. However, mixing of fuels with high S content could lead to a strong reduction in dioxin emissions. Ashes produced from biomass combustion may be considered for further reutilization or landfilling. Other options depend on their characteristics, chemical composition and leaching behaviour. This was evaluated in this study.

  16. Study of toxic metals during combustion of RDF in a fluidized bed pilot

    Energy Technology Data Exchange (ETDEWEB)

    Crujeira, T.; Lopes, H.; Abelha, P.; Sargaco, C.; Goncalves, R.; Freire, M.; Cabrita, I.; Gulyurtlu, I. [DEECA, INETI, Lisbon (Portugal)

    2005-04-01

    The study of the behavior of heavy metals during combustion of refuse-derived fuel (RDF) in a pilot fluidized bed was performed. The results of co-combustion were compared with coal combustion and RDF monocombustion. The amounts of heavy metals retained by the ash were different during co-firing in comparison with monocombustion due to the mechanisms leading to different partitioning of ash. It was verified that heavy metal emissions increased with introduction of RDF, but remained below regulated levels, with the exception of chromium (Cr) and nickel (Ni). For RDF monocombustion the emissions were, however, more severe, especially for cadmium (Cd), lead (Pb), and copper (Cu). This seems to be related not only to larger input amounts, but also to higher volatilisation during monocombustion caused by the presence of higher chlorine and lower sulphur contents in the RDF. Hence, as far as heavy metals are concerned, the utilization of RDF as a co-firing combustible for coal seems to be more environmental favorable than when RDF is fired alone.

  17. International seminar on biomass and fossil fuels co-firing in power plants and heating plants in Europe; Seminaire international sur la cocombustion de biomasse et d'energies fossiles dans les centrales electriques et les chaufferies en Europe

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The aim of the European commission which has fixed to 12% the share of renewable energies in the total energy consumption up to 2010, is to develop the biomass sector. Co-firing is a solution that allows to increase significantly the use of biomass because it does not require important investments. Today, about 150 power plants in Europe use co-firing. An Altener project named 'Cofiring' has ben settled in order to bring together and analyze the European experience in this domain and to sustain and rationalize the design of future projects. The conclusions of this study, coordinated by VTT Energy and which involves CARMEN (Germany), CBE (Portugal), the Danish centre for landscape and planning, ITEBE (France), KOBA (Italy), SLU (Sweden), and EVA (Austria), were presented during this international seminar. (J.S.)

  18. Computational Analysis of Dynamic SPK(S8)-JP8 Fueled Combustor-Sector Performance

    Science.gov (United States)

    Ryder, R.; Hendricks, Roberts C.; Huber, M. L.; Shouse, D. T.

    2010-01-01

    Civil and military flight tests using blends of synthetic and biomass fueling with jet fuel up to 50:50 are currently considered as "drop-in" fuels. They are fully compatible with aircraft performance, emissions and fueling systems, yet the design and operations of such fueling systems and combustors must be capable of running fuels from a range of feedstock sources. This paper provides Smart Combustor or Fuel Flexible Combustor designers with computational tools, preliminary performance, emissions and particulates combustor sector data. The baseline fuel is kerosene-JP-8+100 (military) or Jet A (civil). Results for synthetic paraffinic kerosene (SPK) fuel blends show little change with respect to baseline performance, yet do show lower emissions. The evolution of a validated combustor design procedure is fundamental to the development of dynamic fueling of combustor systems for gas turbine engines that comply with multiple feedstock sources satisfying both new and legacy systems.

  19. Vortex combustor for low NOX emissions when burning lean premixed high hydrogen content fuel

    Science.gov (United States)

    Steele, Robert C; Edmonds, Ryan G; Williams, Joseph T; Baldwin, Stephen P

    2012-11-20

    A trapped vortex combustor. The trapped vortex combustor is configured for receiving a lean premixed gaseous fuel and oxidant stream, where the fuel includes hydrogen gas. The trapped vortex combustor is configured to receive the lean premixed fuel and oxidant stream at a velocity which significantly exceeds combustion flame speed in a selected lean premixed fuel and oxidant mixture. The combustor is configured to operate at relatively high bulk fluid velocities while maintaining stable combustion, and low NOx emissions. The combustor is useful in gas turbines in a process of burning synfuels, as it offers the opportunity to avoid use of diluent gas to reduce combustion temperatures. The combustor also offers the possibility of avoiding the use of selected catalytic reaction units for removal of oxides of nitrogen from combustion gases exiting a gas turbine.

  20. Co-combustion of coal and non-recyclable paper and plastic waste in a fluidised bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    D. Boavida; P. Abelha; I. Gulyurtlu; I. Cabrita [DEECA-INETI, Lisbon (Portugal)

    2003-10-01

    Co-combustion of waste with coal was carried out using a fluidised bed combustor with the aim of achieving a fuel mixture with little variations in its heating value and simultaneously reducing the accumulation of non-toxic waste material by upgrading them for energy purposes. Results obtained indicate that the feeding of waste materials plays an important role to achieve conditions for a stable combustion. The form in which the fuel is fed to the combustor makes a significant contribution to achieve desirable combustion performance and differences were observed in results regarding the combustion efficiency and emissions when waste was fed densified or in a fluffy state when it was burned mixed with coal. Part of the combustion of waste material, contrary to that of coal, was observed to take place in the freeboard where the temperature was as much as 150{sup o}C above that of the bed. 15 refs., 8 figs., 8 tabs.

  1. Experimental study on the heavy-duty gas turbine combustor

    International Nuclear Information System (INIS)

    Antonovsky, V.; Ahn, Kook Young

    2000-01-01

    The results of stand and field testing of a combustion chamber for a heavy-duty 150 MW gas turbine are discussed. The model represented one of 14 identical segments of a tubular multican combustor constructed in the scale 1:1. The model experiments were executed at a pressure smaller than in the real gas turbine. The combustion efficiency, pressure loss factor, pattern factor, liner wall temperature, flame radiation, fluctuating pressure, and NOx emission were measured at partial and full load for both model and on-site testing. The comparison of these items of information, received on similar modes in the stand and field tests, has allowed the development of a method of calculation and the improvement of gas turbine combustors

  2. Pulse Combustor CRADA PC91-001 Final Report

    Energy Technology Data Exchange (ETDEWEB)

    none

    1992-08-31

    As outlined in the Cooperative Research and Development Agreement (CRADA) between BO Technical Developments, Ltd. (BO Tech) and the Pittsburgh Energy Technology Center (PETC) Coal Combustion Division, a BO Tech designed pulse-blade combustor was studied at PETC. Phase 1 involved limited tests of a single-blade pulsed-combustor module to evaluate the suitability of a gas-designed unit for firing coal for use in residential, commercial, or industrial sectors. During the course of the project, three different pulsed blade burners were designed and fabricated by BO Tech and subsequently delivered to PETC for evaluation. These units were designed to allow modification of the furnace dimensions, which would give PETC a means to take simple steps to improve coal firing performance is required. No major furnace design changes were to be included as part of the phase 1 activities.

  3. Coal-Fired MHD Combustor Development Project, Phase 3D

    Science.gov (United States)

    1985-02-01

    The Coal-Fired MHD Combustor Development Project (phase 3D) is reported. The scope encompasses development work on the 50 MW/sub t/ combustor related to test support at the CDIF, fabrication and assembly of first and second stage hardware, plans for second stage design verification testing and power testing, and designs for a continuous slag rejector and low preheat inlet section. Progress includes the following: (1) operational verification testing of the first stage at the CDIF was completed; (2) assembly and checkout of the second first stage, two second stages, and PEM is 75 to 90% completed; (3) conceptual designs for a continuous slag rejector and low preheat inlet section are completed and low preheat preliminary design work is 75% completed; and (4) revision of the users' manual to include the second stage is 75% completed and a draft Test Plan for power train testing is reviewed.

  4. Systems and methods for preventing flashback in a combustor assembly

    Science.gov (United States)

    Johnson, Thomas Edward; Ziminsky, Willy Steve; Stevenson, Christian Xavier

    2016-04-05

    Embodiments of the present application include a combustor assembly. The combustor assembly may include a combustion chamber, a first plenum, a second plenum, and one or more elongate air/fuel premixing injection tubes. Each of the elongate air/fuel premixing injection tubes may include a first length at least partially disposed within the first plenum and configured to receive a first fluid from the first plenum. Moreover, each of the elongate air/fuel premixing injection tubes may include a second length disposed downstream of the first length and at least partially disposed within the second plenum. The second length may be formed of a porous wall configured to allow a second fluid from the second plenum to enter the second length and create a boundary layer about the porous wall.

  5. System for supporting bundled tube segments within a combustor

    Energy Technology Data Exchange (ETDEWEB)

    Melton, Patrick Benedict

    2016-03-01

    A system for supporting bundled tube segments within a combustor includes an annular sleeve that extends circumferentially and axially within the combustor, a support lug that extends radially inward from the annular sleeve and an annular support frame that is disposed within the annular sleeve. The annular support frame includes an inner ring portion, an outer ring portion and a plurality of spokes that extend radially between the inner and outer ring portions. The inner ring portion, the outer ring portion and the plurality of spokes define an annular array of openings for receiving a respective bundled tube segment. The inner ring portion is connected to each bundled tube segment and the outer ring portion is coupled to the support lug.

  6. Analytical fuel property effects, small combustors, phase 1

    Science.gov (United States)

    Cohen, J. D.

    1983-01-01

    The effects of nonstandard aviation fuels on a typical small gas turbine combustor was analyzed. The T700/CT7 engine family was chosen as being representative of the class of aircraft power plants desired. Fuel properties, as specified by NASA, are characterized by low hydrogen content and high aromatics levels. Higher than normal smoke output and flame radiation intensity for the current T700 combustor which serves as a baseline were anticipated. It is, therefore, predicted that out of specification smoke visibility and higher than normal shell temperatures will exist when using NASA ERBS fuels with a consequence of severe reduction in cyclic life. Three new designs are proposed to compensate for the deficiencies expected with the existing design. They have emerged as the best of the eight originally proposed redesigns or combinations thereof. After the five choices that were originally made by NASA on the basis of competing performance factors, General Electric narrowed the field to the three proposed.

  7. Numerical optimization of laboratory combustor geometry for NO suppression

    International Nuclear Information System (INIS)

    Mazaheri, Karim; Shakeri, Alireza

    2016-01-01

    Highlights: • A five-step kinetics for NO and CO prediction is extracted from GRI-3.0 mechanism. • Accuracy and applicability of this kinetics for numerical optimization were shown. • Optimized geometry for a combustor was determined using the combined process. • NO emission from optimized geometry is found 10.3% lower than the basis geometry. - Abstract: In this article, geometry optimization of a jet stirred reactor (JSR) combustor has been carried out for minimum NO emissions in methane oxidation using a combined numerical algorithm based on computational fluid dynamics (CFD) and differential evolution (DE) optimization. The optimization algorithm is also used to find a fairly accurate reduced mechanism. The combustion kinetics is based on a five-step mechanism with 17 unknowns which is obtained using an optimization DE algorithm for a PSR–PFR reactor based on GRI-3.0 full mechanism. The optimization design variables are the unknowns of the five-step mechanism and the cost function is the concentration difference of pollutants obtained from the 5-step mechanism and the full mechanism. To validate the flow solver and the chemical kinetics, the computed NO at the outlet of the JSR is compared with experiments. To optimize the geometry of a combustor, the JSR combustor geometry is modeled using three parameters (i.e., design variables). An integrated approach using a flow solver and the DE optimization algorithm produces the lowest NO concentrations. Results show that the exhaust NO emission for the optimized geometry is 10.3% lower than the original geometry, while the inlet temperature of the working fluid and the concentration of O 2 are operating constraints. In addition, the concentration of CO pollutant is also much less than the original chamber.

  8. Combustion and direct energy conversion inside a micro-combustor

    International Nuclear Information System (INIS)

    Lei, Yafeng; Chen, Wei; Lei, Jiang

    2016-01-01

    Highlights: • The flammability range of micro-combustor was broadened with heat recirculation. • The quenching diameter decreased with heat recirculation compared to without recirculation. • The surface areas to volume ratio was the most important parameter affecting the energy conversion efficiency. • The maximum conversion efficiency (3.15%) was achieved with 1 mm inner diameter. - Abstract: Electrical energy can be generated by employing a micro-thermophotovoltaic (TPV) cell which absorbs thermal radiation from combustion taking place in a micro-combustor. The stability of combustion in a micro-combustor is essential for operating a micro-power system using hydrogen and hydrocarbon fuels as energy source. To understand the mechanism of sustaining combustion within the quenching distance of fuel, this study proposed an annular micro combustion tube with recirculation of exhaust heat. To explore the feasibility of combustion in the micro annular tube, the parameters influencing the combustion namely, quenching diameter, and flammability were studied through numerical simulation. The results indicated that combustion could be realized in micro- combustor using heat recirculation. Following results were obtained from simulation. The quenching diameter reduced from 1.3 mm to 0.9 mm for heat recirculation at equivalence ratio of 1; the lean flammability was 2.5%–5% lower than that of without heat recirculation for quenching diameters between 2 mm and 5 mm. The overall energy conversion efficiency varied at different inner diameters. A maximum efficiency of 3.15% was achieved at an inner diameter of 1 mm. The studies indicated that heat recirculation is an effective strategy to maintain combustion and to improve combustion limits in micro-scale system.

  9. Nonintrusive transceiver and method for characterizing temperature and velocity fields in a gas turbine combustor

    Energy Technology Data Exchange (ETDEWEB)

    DeSilva, Upul P.; Claussen, Heiko

    2017-09-05

    An acoustic transceiver is implemented for measuring acoustic properties of a gas in a turbine engine combustor. The transceiver housing defines a measurement chamber and has an opening adapted for attachment to a turbine engine combustor wall. The opening permits propagation of acoustic signals between the gas in the turbine engine combustor and gas in the measurement chamber. An acoustic sensor mounted to the housing receives acoustic signals propagating in the measurement chamber, and an acoustic transmitter mounted to the housing creates acoustic signals within the measurement chamber. An acoustic measurement system includes at least two such transceivers attached to a turbine engine combustor wall and connected to a controller.

  10. Flame dynamics of a meso-scale heat recirculating combustor

    Energy Technology Data Exchange (ETDEWEB)

    Vijayan, V.; Gupta, A.K. [Department of Mechanical Engineering, University of Maryland, College Park, MD 20742 (United States)

    2010-12-15

    The dynamics of premixed propane-air flame in a meso-scale ceramic combustor has been examined here. The flame characteristics in the combustor were examined by measuring the acoustic emissions and preheat temperatures together with high-speed cinematography. For the small-scale combustor, the volume to surface area ratio is small and hence the walls have significant effect on the global flame structure, flame location and flame dynamics. In addition to the flame-wall thermal coupling there is a coupling between flame and acoustics in the case of confined flames. Flame-wall thermal interactions lead to low frequency flame fluctuations ({proportional_to}100 Hz) depending upon the thermal response of the wall. However, the flame-acoustic interactions can result in a wide range of flame fluctuations ranging from few hundred Hz to few kHz. Wall temperature distribution is one of the factors that control the amount of reactant preheating which in turn effects the location of flame stabilization. Acoustic emission signals and high-speed flame imaging confirmed that for the present case flame-acoustic interactions have more significant effect on flame dynamics. Based on the acoustic emissions, five different flame regimes have been identified; whistling/harmonic mode, rich instability mode, lean instability mode, silent mode and pulsating flame mode. (author)

  11. Recurrence networks to study dynamical transitions in a turbulent combustor

    Science.gov (United States)

    Godavarthi, V.; Unni, V. R.; Gopalakrishnan, E. A.; Sujith, R. I.

    2017-06-01

    Thermoacoustic instability and lean blowout are the major challenges faced when a gas turbine combustor is operated under fuel lean conditions. The dynamics of thermoacoustic system is the result of complex nonlinear interactions between the subsystems—turbulent reactive flow and the acoustic field of the combustor. In order to study the transitions between the dynamical regimes in such a complex system, the time series corresponding to one of the dynamic variables is transformed to an ɛ-recurrence network. The topology of the recurrence network resembles the structure of the attractor representing the dynamics of the system. The transitions in the thermoacoustic system are then captured as the variation in the topological characteristics of the network. We show the presence of power law degree distribution in the recurrence networks constructed from time series acquired during the occurrence of combustion noise and during the low amplitude aperiodic oscillations prior to lean blowout. We also show the absence of power law degree distribution in the recurrence networks constructed from time series acquired during the occurrence of thermoacoustic instability and during the occurrence of intermittency. We demonstrate that the measures derived from recurrence network can be used as tools to capture the transitions in the turbulent combustor and also as early warning measures for predicting impending thermoacoustic instability and blowout.

  12. Optimal planning of co-firing alternative fuels with coal in a power plant by grey nonlinear mixed integer programming model.

    Science.gov (United States)

    Ko, Andi Setiady; Chang, Ni-Bin

    2008-07-01

    Energy supply and use is of fundamental importance to society. Although the interactions between energy and environment were originally local in character, they have now widened to cover regional and global issues, such as acid rain and the greenhouse effect. It is for this reason that there is a need for covering the direct and indirect economic and environmental impacts of energy acquisition, transport, production and use. In this paper, particular attention is directed to ways of resolving conflict between economic and environmental goals by encouraging a power plant to consider co-firing biomass and refuse-derived fuel (RDF) with coal simultaneously. It aims at reducing the emission level of sulfur dioxide (SO(2)) in an uncertain environment, using the power plant in Michigan City, Indiana as an example. To assess the uncertainty by a comparative way both deterministic and grey nonlinear mixed integer programming (MIP) models were developed to minimize the net operating cost with respect to possible fuel combinations. It aims at generating the optimal portfolio of alternative fuels while maintaining the same electricity generation simultaneously. To ease the solution procedure stepwise relaxation algorithm was developed for solving the grey nonlinear MIP model. Breakeven alternative fuel value can be identified in the post-optimization stage for decision-making. Research findings show that the inclusion of RDF does not exhibit comparative advantage in terms of the net cost, albeit relatively lower air pollution impact. Yet it can be sustained by a charge system, subsidy program, or emission credit as the price of coal increases over time.

  13. DEVELOPMENT OF A VALIDATED MODEL FOR USE IN MINIMIZING NOx EMISSIONS AND MAXIMIZING CARBON UTILIZATION WHEN CO-FIRING BIOMASS WITH COAL

    Energy Technology Data Exchange (ETDEWEB)

    Larry G. Felix; P. Vann Bush

    2002-04-30

    This is the sixth Quarterly Technical Report for DOE Cooperative Agreement No. DE-FC26-00NT40895. A statement of the project objectives is included in the Introduction of this report. Two additional biomass co-firing test burns were conducted during this quarter. In the first test (Test 10), up to 20% by weight dry hardwood sawdust and switchgrass was compiled with Galatia coal and injected through the dual-register burner. Galatia coal is a medium-sulfur Illinois Basin coal ({approx}1.0% S). The dual-register burner is a generic low-NO{sub x} burner that incorporates two independent wind boxes. In the second test (Test 11), regular ({approx}70% passing 200 mesh) and finely ground ({approx}90% passing 200 mesh) Pratt Seam coal was injected through the single-register burner to determine if coal grind affects NO{sub x} and unburned carbon emissions. The results of these tests are presented in this quarterly report. Significant progress has been made in implementing a modeling approach to combine reaction times and temperature distributions from computational fluid dynamic models of the pilot-scale combustion furnace with char burnout and chemical reaction kinetics to predict NO{sub x} emissions and unburned carbon levels in the furnace exhaust. No additional results of CFD modeling have been received as delivery of the Configurable Fireside Simulator is expected during the next quarter. Preparations are under way for continued pilot-scale combustion experiments with the single-register burner and a low-volatility bituminous coal. Some delays have been experienced in the acquisition and processing of biomass. Finally, a project review was held at the offices of Southern Research in Birmingham, on February 27, 2002.

  14. DEVELOPMENT OF A VALIDATED MODEL FOR USE IN MINIMIZING NOx EMISSIONS AND MAXIMIZING CARBON UTILIZATION WHEN CO-FIRING BIOMASS WITH COAL

    International Nuclear Information System (INIS)

    Larry G. Felix; P. Vann Bush

    2002-01-01

    This is the sixth Quarterly Technical Report for DOE Cooperative Agreement No. DE-FC26-00NT40895. A statement of the project objectives is included in the Introduction of this report. Two additional biomass co-firing test burns were conducted during this quarter. In the first test (Test 10), up to 20% by weight dry hardwood sawdust and switchgrass was compiled with Galatia coal and injected through the dual-register burner. Galatia coal is a medium-sulfur Illinois Basin coal ((approx)1.0% S). The dual-register burner is a generic low-NO(sub x) burner that incorporates two independent wind boxes. In the second test (Test 11), regular ((approx)70% passing 200 mesh) and finely ground ((approx)90% passing 200 mesh) Pratt Seam coal was injected through the single-register burner to determine if coal grind affects NO(sub x) and unburned carbon emissions. The results of these tests are presented in this quarterly report. Significant progress has been made in implementing a modeling approach to combine reaction times and temperature distributions from computational fluid dynamic models of the pilot-scale combustion furnace with char burnout and chemical reaction kinetics to predict NO(sub x) emissions and unburned carbon levels in the furnace exhaust. No additional results of CFD modeling have been received as delivery of the Configurable Fireside Simulator is expected during the next quarter. Preparations are under way for continued pilot-scale combustion experiments with the single-register burner and a low-volatility bituminous coal. Some delays have been experienced in the acquisition and processing of biomass. Finally, a project review was held at the offices of Southern Research in Birmingham, on February 27, 2002

  15. Emissions and performance of catalysts for gas turbine catalytic combustors. [automobile engines

    Science.gov (United States)

    Anderson, D. N.

    1977-01-01

    Three noble-metal monolithic catalysts were tested in a 12-cm-dia. combustion test rig to obtain emissions and performance data at conditions simulating the operation of a catalytic combustor for an automotive gas turbine engine. Tests with one of the catalysts at 800 K inlet mixture temperature, 3 x 10 to the 5th Pa pressure, and a reference velocity (catalyst bed inlet velocity) of 10 m/sec demonstrated greater than 99 percent combustion efficiency for reaction temperatures higher than 1300 K. With a reference velocity of 25 m/sec the reaction temperature required to achieve the same combustion-efficiency increased to 1380 K. The exit temperature pattern factors for all three catalysts were below 0.1 when adiabatic reaction temperatures were higher than 1400 K. The highest pressure drop was 4.5 percent at 25 m/sec reference velocity. Nitrogen oxides emissions were less than 0.1 g NO2/kg fuel for all test conditions.

  16. Atmospheric fluidized bed combustion of municipal solid waste: test program results

    Energy Technology Data Exchange (ETDEWEB)

    Preuit, L C; Wilson, K B

    1980-05-01

    Air classified municipal solid waste (MSW) was fired in an atmospheric fluidized bed combustor at low excess air to simulate boiler conditions. The 7 ft/sup 2/ combustor at Combustion Power Company's energy laboratory in Menlo Park, CA, incorporates water tubes for heat extraction and recycles elutriated particles to the bed. System operation was stable while firing processed MSW for the duration of a 300-h test. Low excess air, low exhaust gas emissions, and constant bed temperature demonstrated feasibility of steam generation from fluidized bed combustion of MSW. During the 300-h test, combustion efficiency averaged 99%. Excess air was typically 44% while an average bed temperature of 1400/sup 0/F and an average superficial gas velocity of 4.6 fps were maintained. Typical exhaust emission levels were 30 ppM SO/sub 2/, 160 ppM NO/sub x/, 200 ppM CO, and 25 ppM hydrocarbons. No agglomeration of bed material or detrimental change in fluidization properties was experienced. A conceptual design study of a full scale plant to be located at Stanford University was based on process conditions from the 300-h test. The plant would produce 250,000 lb/hr steam at the maximum firing rate of 1000 tons per day (TPD) processed MSW. The average 800 TPD firing rate would utilize approximately 1200 TPD raw MSW from surrounding communities. The Stanford Solid Waste energy Program was aimed at development of a MSW-fired fluidized bed boiler and cogeneration plant to supply most of the energy needs of Stanford University.

  17. Fluid-bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, G.; Schoebotham, N.

    1981-02-01

    In Energy Equipment Company's two-stage fluidized bed system, partial combustion in a fluidized bed is followed by burn-off of the generated gases above the bed. The system can be retrofitted to existing boilers, and can burn small, high ash coal efficiently. It has advantages when used as a hot gas generator for process drying. Tests on a boiler at a Cadbury Schweppes plant are reported.

  18. The preliminary design of an annular combustor for a mini gas turbine

    CSIR Research Space (South Africa)

    Meyers, Bronwyn C

    2015-10-01

    Full Text Available This study involves the redesign of the combustor liner for a 200N mini gas turbine engine using first principles and the design methods of the NREC series as shown in Figure 1. The combustor design was performed using five different operating...

  19. Three-dimensional particle image velocimetry in a generic can-type gas turbine combustor

    CSIR Research Space (South Africa)

    Meyers, BC

    2009-09-01

    Full Text Available The three-dimensional flow field inside a generic can-type, forward flow, experimental combustor was measured. A stereoscopic Particle Image Velocimetry (PIV) system was used to obtain the flow field of the combustor in the non-reacting condition...

  20. DEVELOPMENT OF A VALIDATED MODEL FOR USE IN MINIMIZING NOx EMISSIONS AND MAXIMIZING CARBON UTILIZATION WHEN CO-FIRING BIOMASS WITH COAL

    Energy Technology Data Exchange (ETDEWEB)

    Larry G. Felix; P. Vann Bush

    2002-07-01

    This is the seventh Quarterly Technical Report for DOE Cooperative Agreement No. DE-FC26-00NT40895. A statement of the project objectives is included in the Introduction of this report. Two additional biomass co-firing test burns were conducted during this quarter. In the first test (Test 12), up to 20% by weight dry hardwood sawdust and switchgrass was comilled with Galatia coal and injected through the single-register burner. Liquid ammonia was intermittently added to the primary air stream to increase fuel-bound nitrogen and simulate cofiring with chicken litter. Galatia coal is a medium-sulfur ({approx} 1.2% S), high chlorine ({approx}0.5%) Illinois Basin coal. In the second test (Test 13), up to 20% by weight dry hardwood sawdust and switchgrass was comilled with Jim Walters No.7 mine coal and injected through the single-register burner. Jim Walters No.7 coal is a low-volatility, low-sulfur ({approx} 0.7% S) Eastern bituminous coal. The results of these tests are presented in this quarterly report. Progress has continued to be made in implementing a modeling approach to combine reaction times and temperature distributions from computational fluid dynamic models of the pilot-scale combustion furnace with char burnout and chemical reaction kinetics to predict NO{sub x} emissions and unburned carbon levels in the furnace exhaust. The Configurable Fireside Simulator has been delivered from REI, Inc. and is being tested with exiting CFD solutions. Preparations are under way for a final pilot-scale combustion experiment using the single-register burner fired with comilled mixtures of Jim Walters No.7 low-volatility bituminous coal and switchgrass. Because of the delayed delivery of the Configurable Fireside Simulator, it is planned to ask for a no-cost time extension for the project until the end of this calendar year. Finally, a paper describing this project that included preliminary results from the first four cofiring tests was presented at the 12th European

  1. Parametric Study of Pulse-Combustor-Driven Ejectors at High-Pressure

    Science.gov (United States)

    Yungster, Shaye; Paxson, Daniel E.; Perkins, Hugh D.

    2015-01-01

    Pulse-combustor configurations developed in recent studies have demonstrated performance levels at high-pressure operating conditions comparable to those observed at atmospheric conditions. However, problems related to the way fuel was being distributed within the pulse combustor were still limiting performance. In the first part of this study, new configurations are investigated computationally aimed at improving the fuel distribution and performance of the pulse-combustor. Subsequent sections investigate the performance of various pulse-combustor driven ejector configurations operating at highpressure conditions, focusing on the effects of fuel equivalence ratio and ejector throat area. The goal is to design pulse-combustor-ejector configurations that maximize pressure gain while achieving a thermal environment acceptable to a turbine, and at the same time maintain acceptable levels of NOx emissions and flow non-uniformities. The computations presented here have demonstrated pressure gains of up to 2.8%.

  2. The pollution reduction technology program for can-annular combustor engines - Description and results

    Science.gov (United States)

    Roberts, R.; Fiorentino, A. J.; Diehl, L.

    1976-01-01

    Pollutant reduction and performance characteristics were determined for three successively more advanced combustor concepts. Program Element I consisted of minor modifications to the current production JT8D combustor and fuel system to evaluate means of improved fuel preparation and changes to the basic airflow distribution. Element II addressed versions of the two-staged Vorbix (vortex burning and mixing) combustor and represented a moderate increase in hardware complexity and difficulty of development. The concept selected for Element III employed vaporized fuel as a means of achieving minimum emission levels and represented the greatest difficulty of development and adaptation to the JT8D engine. Test results indicate that the Element I single-stage combustors were capable of dramatic improvement in idle pollutants. The multistage combustors evaluated in Program Elements II and III simultaneously reduced CO, THC and NOx emissions, but were unable to satisfy the current 1979 EPA standards.

  3. Development and testing of pulsed and rotating detonation combustors

    Science.gov (United States)

    St. George, Andrew C.

    Detonation is a self-sustaining, supersonic, shock-driven, exothermic reaction. Detonation combustion can theoretically provide significant improvements in thermodynamic efficiency over constant pressure combustion when incorporated into existing cycles. To harness this potential performance benefit, countless studies have worked to develop detonation combustors and integrate these devices into existing systems. This dissertation consists of a series of investigations on two types of detonation combustors: the pulse detonation combustor (PDC) and the rotating detonation combustor (RDC). In the first two investigations, an array of air-breathing PDCs is integrated with an axial power turbine. The system is initially operated with steady and pulsed cold air flow to determine the effect of pulsed flow on turbine performance. Various averaging approaches are employed to calculate turbine efficiency, but only flow-weighted (e.g., mass or work averaging) definitions have physical significance. Pulsed flow turbine efficiency is comparable to steady flow efficiency at high corrected flow rates and low rotor speeds. At these conditions, the pulse duty cycle expands and the variation of the rotor incidence angle is constrained to a favorable range. The system is operated with pulsed detonating flow to determine the effect of frequency, fill fraction, and rotor speed on turbine performance. For some conditions, output power exceeds the maximum attainable value from steady constant pressure combustion due to a significant increase in available power from the detonation products. However, the turbine component efficiency estimated from classical thermodynamic analysis is four times lower than the steady design point efficiency. Analysis of blade angles shows a significant penalty due to the detonation, fill, and purge processes simultaneously imposed on the rotor. The latter six investigations focus on fundamental research of the RDC concept. A specially-tailored RDC data

  4. Fluidized bed incinerator development

    International Nuclear Information System (INIS)

    Ziegler, D.L.; Johnson, A.J.

    1976-01-01

    A fluidized bed incinerator is being developed for burning rad contaminated solid and liquid waste materials. In situ neutralization of acid gases by the bed material, catalytic afterburning, and gas filtration are used to produce a clean flue gas without the use of aqueous scrubbing

  5. Active Combustion Control for Aircraft Gas-Turbine Engines-Experimental Results for an Advanced, Low-Emissions Combustor Prototype

    Science.gov (United States)

    DeLaat, John C.; Kopasakis, George; Saus, Joseph R.; Chang, Clarence T.; Wey, Changlie

    2012-01-01

    Lean combustion concepts for aircraft engine combustors are prone to combustion instabilities. Mitigation of instabilities is an enabling technology for these low-emissions combustors. NASA Glenn Research Center s prior activity has demonstrated active control to suppress a high-frequency combustion instability in a combustor rig designed to emulate an actual aircraft engine instability experience with a conventional, rich-front-end combustor. The current effort is developing further understanding of the problem specifically as applied to future lean-burning, very low-emissions combustors. A prototype advanced, low-emissions aircraft engine combustor with a combustion instability has been identified and previous work has characterized the dynamic behavior of that combustor prototype. The combustor exhibits thermoacoustic instabilities that are related to increasing fuel flow and that potentially prevent full-power operation. A simplified, non-linear oscillator model and a more physics-based sectored 1-D dynamic model have been developed to capture the combustor prototype s instability behavior. Utilizing these models, the NASA Adaptive Sliding Phasor Average Control (ASPAC) instability control method has been updated for the low-emissions combustor prototype. Active combustion instability suppression using the ASPAC control method has been demonstrated experimentally with this combustor prototype in a NASA combustion test cell operating at engine pressures, temperatures, and flows. A high-frequency fuel valve was utilized to perturb the combustor fuel flow. Successful instability suppression was shown using a dynamic pressure sensor in the combustor for controller feedback. Instability control was also shown with a pressure feedback sensor in the lower temperature region upstream of the combustor. It was also demonstrated that the controller can prevent the instability from occurring while combustor operation was transitioning from a stable, low-power condition to

  6. Nondestructive Evaluation of Ceramic Matrix Composite Combustor Components

    Science.gov (United States)

    Sun, Jiangang G.; Verrilli, Michael J.; Stephan, Robert R.; Barnett, Terry R.; Ojard, Greg C.

    2003-01-01

    Combustor liners fabricated from a SiC/SiC composite (silicon carbide fibers in a silicon carbide matrix) were nondestructively interrogated before and after combustion rig testing by x-ray, ultrasonic, and thermographic techniques. In addition, mechanical test results were obtained from witness coupons, representing the as-manufactured liners, and from coupons machined from the components after combustion exposure. Thermography indications correlated with reduced material properties obtained after rig testing. The thermography indications in the SiC/SiC liners were delaminations and damaged fiber tows, as determined through microstructural examinations.

  7. Pulsed atmospheric fluidized bed combustion. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1989-11-01

    In order to verify the technical feasibility of the MTCI Pulsed Atmospheric Fluidized Bed Combustor technology, a laboratory-scale system was designed, built and tested. Important aspects of the operational and performance parameters of the system were established experimentally. A considerable amount of the effort was invested in the initial task of constructing an AFBC that would represent a reasonable baseline against which the performance of the PAFBC could be compared. A summary comparison of the performance and emissions data from the MTCI 2 ft {times} 2 ft facility (AFBC and PAFBC modes) with those from conventional BFBC (taller freeboard and recycle operation) and circulating fluidized bed combustion (CFBC) units is given in Table ES-1. The comparison is for typical high-volatile bituminous coals and sorbents of average reactivity. The values indicated for BFBC and CFBC were based on published information. The AFBC unit that was designed to act as a baseline for the comparison was indeed representative of the larger units even at the smaller scale for which it was designed. The PAFBC mode exhibited superior performance in relation to the AFBC mode. The higher combustion efficiency translates into reduced coal consumption and lower system operating cost; the improvement in sulfur capture implies less sorbent requirement and waste generation and in turn lower operating cost; lower NO{sub x} and CO emissions mean ease of site permitting; and greater steam-generation rate translates into less heat exchange surface area and reduced capital cost. Also, the PAFBC performance generally surpasses those of conventional BFBC, is comparable to CFBC in combustion and NO{sub x} emissions, and is better than CFBC in sulfur capture and CO emissions even at the scaled-down size used for the experimental feasibility tests.

  8. Thermal performance of a meso-scale liquid-fuel combustor

    International Nuclear Information System (INIS)

    Vijayan, V.; Gupta, A.K.

    2011-01-01

    Research highlights: → Demonstrated successful combustion of liquid fuel-air mixtures in a novel meso-scale combustor. → Flame quenching was eliminated using heat recirculation in a swiss roll type combustor that also extended the flammability limits. → Liquid fuel was rapidly vaporized with the use of hot narrow channel walls that eliminated the need of a fuel atomizer. → Maximum power density of the combustor was estimated to be about 8.5 GW/m3 and heat load in the range of 50-280W. → Overall efficiency of the combustor was estimated in the range of 12 to 20%. - Abstract: Combustion in small scale devices poses significant challenges due to the quenching of reactions from wall heat losses as well as the significantly reduced time available for mixing and combustion. In the case of liquid fuels there are additional challenges related to atomization, vaporization and mixing with the oxidant in the very short time-scale liquid-fuel combustor. The liquid fuel employed here is methanol with air as the oxidizer. The combustor was designed based on the heat recirculating concept wherein the incoming reactants are preheated by the combustion products through heat exchange occurring via combustor walls. The combustor was fabricated from Zirconium phosphate, a ceramic with very low thermal conductivity (0.8 W m -1 K -1 ). The combustor had rectangular shaped double spiral geometry with combustion chamber in the center of the spiral formed by inlet and exhaust channels. Methanol and air were introduced immediately upstream at inlet of the combustor. The preheated walls of the inlet channel also act as a pre-vaporizer for liquid fuel which vaporizes the liquid fuel and then mixes with air prior to the fuel-air mixture reaching the combustion chamber. Rapid pre-vaporization of the liquid fuel by the hot narrow channel walls eliminated the necessity for a fuel atomizer. Self-sustained combustion of methanol-air was achieved in a chamber volume as small as 32.6 mm 3

  9. Technical evaluation: pressurized fluidized-bed combustion technology

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S A; Vogel, G J; Gehl, S M; Hanway, Jr, J E; Henry, R F; Parker, K M; Smyk, E B; Swift, W M; Podolski, W F

    1982-04-01

    The technology of pressurized fluidized-bed combustion, particularly in its application to a coal-burning combined-cycle plant, is evaluated by examining the technical status of advanced-concept plant components - boiler system (combustor, air-handling and air-injection equipment, and heat exchangers); solids handling, injection, and ejection system; hot-gas cleanup equipment; instrumentation/control system; and the gas turbine - along with materials of plant construction. Environmental performance as well as energy efficiency are examined, and economic considerations are reviewed briefly. The evaluation concludes with a broad survey of the principal related research and development programs in the United States and other countries, a foreview of the most likely technological developments, and a summary of unresolved technical issues and problems.

  10. Advances in measurements and simulation of gas-particle flows and coal combustion in burners/combustors

    International Nuclear Information System (INIS)

    Zhou, L X

    2009-01-01

    Innovative coal combustors were developed, and measurement and simulation of gas-particle flows and coal combustion in such combustors were done in the Department of Engineering Mechanics, Tsinghua University. LDV/PDPA measurements are made to understand the behavior of turbulent gas-particle flows in coal combustors. Coal combustion test was done for the non-slagging cyclone coal combustor. The full two-fluid model developed by the present author was used to simulate turbulent gas-particle flows, coal combustion and NO x formation. It is found by measurements and simulation that the optimum design can give large-size recirculation zones for improving the combustion performance for all the combustors. The combustion test shows that the nonslagging coal combustor can burn 3-5mm coal particles with good combustion efficiency and low NO emission. Simulation in comparison with experiments indicates that the swirl number can significantly affect the NO formation in the swirl coal combustor.

  11. Experimental and numerical simulation for swirl flow in a combustor

    Science.gov (United States)

    Dulin, V. M.; Markovich, D. M.; Minakov, A. V.; Hanjalic, K.; Chikishev, L. M.

    2013-12-01

    Results of the experimental and numerical simulation for swirl flow in combustion of a lean methane-air mixture in a model combustor at atmospheric pressure are represented. The panoramic method for the flow velocity measurement and the calculation by a large eddy method were used for the investigation of the nonstationary turbulent flow. The numerical modeling for the breakdown of the vortex core of the flow and the topology of large-scale vortex structures forming in it showed the close fit to the experiment. The analysis of obtained data showed that for the case of the intensive swirl of the flow as well as in the case of the flow without combustion, dynamics of the flow with combustion was determined by the global azimuthal instability mode corresponding to the intensive precession of the vortex core. The flame had the similar characteristics of the stability and compactness in the case of stabilization by the low swirl; however, velocity pulsations in the flow corresponded to the development of only local instability modes. Thus, the other kind of vortex breakdown in the case of the low swirl, for which the central recirculation zone is lacking, is not only favorable in view of the reduction of the NO x emission, but also remains a possibility for the effective use of the active control method for the flow and combustion. In particular, the given result may be used for the elimination of the thermoacoustic resonance in combustors.

  12. Coal-fired MHD combustor development project: Phase 3D

    Science.gov (United States)

    1985-05-01

    This fourth quarterly technical progress report of the Coal-Fired MHD Combustor Development Project (Phase 3D) presents the accomplishments during the period February 1 to April 30, 1985. The scope of work covered by this quarterly report encompasses development work on the 50 MW/sub t/ combustor related to test support at the CDIF, assembly and checkout of first and second stage hardware, second stage design verification testing, designs for a continuous slag rejector and low preheat inlet section, and planning for power train testing. Progress includes the following: assembly and checkout of the second first stage, two second stages, and PEM was completed and the hardware was shipped to CDIF and FETS; integration of first and second stage hardware on the FETS Cell No. 2 test stand was completed, cold flow functional tests were performed, and hot fire checkout testing was initiated; assembly of the continuous slag rejector test set-up was 70% completed; the low preheat air inlet section Preliminary Design Review was held (work on the detail design was initiated and is 85% complete); and the Users' Manual was updated to include material for the second stage and final revisions to the power train test plan were made.

  13. Three Dimensional CFD Analysis of the GTX Combustor

    Science.gov (United States)

    Steffen, C. J., Jr.; Bond, R. B.; Edwards, J. R.

    2002-01-01

    The annular combustor geometry of a combined-cycle engine has been analyzed with three-dimensional computational fluid dynamics. Both subsonic combustion and supersonic combustion flowfields have been simulated. The subsonic combustion analysis was executed in conjunction with a direct-connect test rig. Two cold-flow and one hot-flow results are presented. The simulations compare favorably with the test data for the two cold flow calculations; the hot-flow data was not yet available. The hot-flow simulation Indicates that the conventional ejector-ramjet cycle would not provide adequate mixing at the conditions tested. The supersonic combustion ramjet flowfield was simulated with frozen chemistry model. A five-parameter test matrix was specified, according to statistical design-of-experiments theory. Twenty-seven separate simulations were used to assemble surrogate models for combustor mixing efficiency and total pressure recovery. Scramjet injector design parameters (injector angle, location, and fuel split) as well as mission variables (total fuel mass flow and freestream Mach number) were included in the analysis. A promising injector design has been identified that provides good mixing characteristics with low total pressure losses. The surrogate models can be used to develop performance maps of different injector designs. Several complex three-way variable interactions appear within the dataset that are not adequately resolved with the current statistical analysis.

  14. Sintering in Biofuel and Coal-Biofuel Fired FBC's

    DEFF Research Database (Denmark)

    Lin, Weigang; Dam-Johansen, Kim

    1998-01-01

    This report presents the results of systematic experiments conducted in a laboratory scale fluidized bed combustor in order to study agglomeration phenomena during firing straw and co-firing straw with coal. The influence of operating conditions on ag-glomeration was investigated. The effect of co......-firing straw with coal on agglomeration was also examined. The results show that temperature has the most pronounced effect on the agglomeration tendency. As bed temperature increases, the defluidiza-tion time decreases sharply, which indicates an increasing tendency of agglomera-tion. When co-firing straw...... with coal, the defluidization time can be extended signifi-cantly. Examination of the agglomerates sampled during combustion by various analytical techniques indicates that the high potassium content in straw is the main cause for the formation of agglomerates. In the combustion process, potassium...

  15. Technical and economic assessment of fluidized-bed-augmented compressed-air energy-storage system: system load following capability

    Energy Technology Data Exchange (ETDEWEB)

    Lessard, R.D.; Blecher, W.A.; Merrick, D.

    1981-09-01

    The load-following capability of fluidized bed combustion-augmented compressed air energy storage systems was evaluated. The results are presented in two parts. The first part is an Executive Summary which provides a concise overview of all major elements of the study including the conclusions, and, second, a detailed technical report describing the part-load and load following capability of both the pressurized fluid bed combustor and the entire pressurized fluid bed combustor/compressed air energy storage system. The specific tasks in this investigation were to: define the steady-state, part-load operation of the CAES open-bed PFBC; estimate the steady-state, part-load performance of the PFBC/CAES system and evaluate any possible operational constraints; simulate the performance of the PFBC/CAES system during transient operation and assess the load following capability of the system; and establish a start-up procedure for the open-bed PFBC and evaluate the impact of this procedure. The conclusions are encouraging and indicate that the open-bed PFBC/CAES power plant should provide good part-load and transient performance, and should have no major equipment-related constraints, specifically, no major problems associated with the performance or design of either the open-end PFBC or the PFBC/CAES power plant in steady-state, part-load operation are envisioned. The open-bed PFBC/CAES power plant would have a load following capability which would be responsive to electric utility requirements for a peak-load power plant. The open-bed PFBC could be brought to full operating conditions within 15 min after routine shutdown, by employing a hot-start mode of operation. The PFBC/CAES system would be capable of rapid changes in output power (12% of design load per minute) over a wide output power range (25% to 100% of design output). (LCL)

  16. Combustion Dynamics in Multi-Nozzle Combustors Operating on High-Hydrogen Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Santavicca, Dom; Lieuwen, Tim

    2013-09-30

    Actual gas turbine combustors for power generation applications employ multi-nozzle combustor configurations. Researchers at Penn State and Georgia Tech have extended previous work on the flame response in single-nozzle combustors to the more realistic case of multi-nozzle combustors. Research at Georgia Tech has shown that asymmetry of both the flow field and the acoustic forcing can have a significant effect on flame response and that such behavior is important in multi-flame configurations. As a result, the structure of the flame and its response to forcing is three-dimensional. Research at Penn State has led to the development of a three-dimensional chemiluminescence flame imaging technique that can be used to characterize the unforced (steady) and forced (unsteady) flame structure of multi-nozzle combustors. Important aspects of the flame response in multi-nozzle combustors which are being studied include flame-flame and flame-wall interactions. Research at Penn State using the recently developed three-dimensional flame imaging technique has shown that spatial variations in local flame confinement must be accounted for to accurately predict global flame response in a multi-nozzle can combustor.

  17. Experimental and Computational Study of Trapped Vortex Combustor Sector Rig with High-Speed Diffuser Flow

    Directory of Open Access Journals (Sweden)

    R. C. Hendricks

    2001-01-01

    Full Text Available The Trapped Vortex Combustor (TVC potentially offers numerous operational advantages over current production gas turbine engine combustors. These include lower weight, lower pollutant emissions, effective flame stabilization, high combustion efficiency, excellent high altitude relight capability, and operation in the lean burn or RQL modes of combustion. The present work describes the operational principles of the TVC, and extends diffuser velocities toward choked flow and provides system performance data. Performance data include EINOx results for various fuel-air ratios and combustor residence times, combustion efficiency as a function of combustor residence time, and combustor lean blow-out (LBO performance. Computational fluid dynamics (CFD simulations using liquid spray droplet evaporation and combustion modeling are performed and related to flow structures observed in photographs of the combustor. The CFD results are used to understand the aerodynamics and combustion features under different fueling conditions. Performance data acquired to date are favorable compared to conventional gas turbine combustors. Further testing over a wider range of fuel-air ratios, fuel flow splits, and pressure ratios is in progress to explore the TVC performance. In addition, alternate configurations for the upstream pressure feed, including bi-pass diffusion schemes, as well as variations on the fuel injection patterns, are currently in test and evaluation phases.

  18. Electrodialytic treatment for metal removal from sewage sludge ash from fluidized bed combustion

    DEFF Research Database (Denmark)

    Pazos, Marta; Kirkelund, Gunvor Marie; Ottosen, Lisbeth M.

    2010-01-01

    Sewage sludge contains several potentially hazardous compounds such as heavy metals, PCBs, PAHs, etc. However, elements with high agricultural value (P, K or Ca) are also present. During the last years, the fluidized bed sludge combustor (FBSC) is considered an effective and novel alternative...... of electrodialytic treatment, the Cd concentration was reduced to values below the limiting concentration. In all experiments the concentrations of other metals were under limiting values of the Danish legislation. It can be concluded that the electrodialytic treatment is an adequate alternative to reduce the Cd...

  19. Design Optimization of a Micro-Combustor for Lean, Premixed Fuel-Air Mixtures

    Science.gov (United States)

    Powell, Leigh Theresa

    Present technology has been shifting towards miniaturization of devices for energy production for portable electronics. Micro-combustors, when incorporated into a micro-power generation system, provide the energy desired in the form of hot gases to power such technology. This creates the need for a design optimization of the micro-combustor in terms of geometry, fuel choice, and material selection. A total of five micro-combustor geometries, three fuels, and three materials were computationally simulated in different configurations in order to determine the optimal micro-combustor design for highest efficiency. Inlet velocity, equivalence ratio, and wall heat transfer coefficient were varied in order to test a comprehensive range of micro-combustor parameters. All simulations completed for the optimization study used ANSYS Fluent v16.1 and post-processing of the data was done in CFD Post v16.1. It was found that for lean, premixed fuel-air mixtures (φ = 0.6 - 0.9) ethane (C 2H6) provided the highest flame temperatures when ignited within the micro-combustor geometries. An aluminum oxide converging micro-combustor burning ethane and air at an equivalence ratio of 0.9, an inlet velocity of 0.5 m/s, and heat transfer coefficient of 5 W/m2-K was found to produce the highest combustor efficiency, making it the optimal choice for a micro-combustor design. It is proposed that this geometry be experimentally and computationally investigated further in order to determine if additional optimization can be achieved.

  20. NONEQUILIBRIUM SULFUR CAPTURE & RETENTION IN AN AIR COOLED SLAGGING COAL COMBUSTOR

    Energy Technology Data Exchange (ETDEWEB)

    Bert Zauderer

    2003-04-21

    Calcium oxide injected in a slagging combustor reacts with the sulfur from coal combustion to form sulfur-bearing particles. The reacted particles impact and melt in the liquid slag layer on the combustor wall by the centrifugal force of the swirling combustion gases. Due to the low solubility of sulfur in slag, it must be rapidly drained from the combustor to limit sulfur gas re-evolution. Prior analyses and laboratory scale data indicated that for Coal Tech's 20 MMBtu/hour, air-cooled, slagging coal combustor slag mass flow rates in excess of 400 lb/hr should limit sulfur re-evolution. The objective of this 42-month project was to validate this sulfur-in-slag model in a group of combustor tests. A total of 36 days of testing on the combustor were completed during the period of performance of this project. This was more that double the 16 test days that were required in the original work statement. The extra tests were made possible by cost saving innovations that were made in the operation of the combustor test facility and in additional investment of Coal Tech resources in the test effort. The original project plan called for two groups of tests. The first group of tests involved the injection of calcium sulfate particles in the form of gypsum or plaster of Paris with the coal into the 20 MMBtu/hour-combustor. The second group of tests consisted of the entire two-step process, in which lime or limestone is co-injected with coal and reacts with the sulfur gas released during combustion to form calcium sulfate particles that impact and dissolve in the slag layer. Since this sulfur capture process has been validated in numerous prior tests in this combustor, the primary effort in the present project was on achieving the high slag flow rates needed to retain the sulfur in the slag.

  1. Bed rest during pregnancy

    Science.gov (United States)

    ... Belizán JM, Bergel E. Bed rest in singleton pregnancies for preventing preterm birth. Cochrane Database ... and Gynecology, Loma Linda University School of Medicine, Loma Linda Center for Fertility, ...

  2. Enuresis (Bed-Wetting)

    Science.gov (United States)

    ... Symptoms of enuresis Enuresis is when an older child (age 7 or older) wets the bed at night ... feel guilt and embarrassment. It’s true that your child should take responsibility for bedwetting. He or she could do this ...

  3. Particle fuel bed tests

    International Nuclear Information System (INIS)

    Horn, F.L.; Powell, J.R.; Savino, J.M.

    1985-01-01

    Gas-cooled reactors, using packed beds of small diameter coated fuel particles have been proposed for compact, high-power systems. The particulate fuel used in the tests was 800 microns in diameter, consisting of a thoria kernel coated with 200 microns of pyrocarbon. Typically, the bed of fuel particles was contained in a ceramic cylinder with porous metallic frits at each end. A dc voltage was applied to the metallic frits and the resulting electric current heated the bed. Heat was removed by passing coolant (helium or hydrogen) through the bed. Candidate frit materials, rhenium, nickel, zirconium carbide, and zirconium oxide were unaffected, while tungsten and tungsten-rhenium lost weight and strength. Zirconium-carbide particles were tested at 2000 K in H 2 for 12 hours with no visible reaction or weight loss

  4. Hydrogen injection scheme influence on flow structure in supersonic combustor of constant cross-section

    Science.gov (United States)

    Starov, A. V.; Goldfeld, M. A.

    2017-10-01

    The efficiency of using two variants of hydrogen injection (distributed and non-distributed injection from vertical pylons) is experimentally investigated. The tests are performed in the attached pipeline regime with the Mach number at the model combustor entrance M=2. The combustion chamber has a backward-facing step at the entrance and slotted channels for combustion stabilization. The tested variants of injection differ basically by the shapes of the fuel jets and, correspondingly, by the hydrogen distribution over the combustor. As a result, distributed injection is found to provide faster ignition, upstream displacement of the elevated pressure region, and more intense combustion over the entire combustor volume.

  5. Design and preliminary results of a fuel flexible industrial gas turbine combustor

    Science.gov (United States)

    Novick, A. S.; Troth, D. L.; Yacobucci, H. G.

    1981-01-01

    The design characteristics are presented of a fuel tolerant variable geometry staged air combustor using regenerative/convective cooling. The rich/quench/lean variable geometry combustor is designed to achieve low NO(x) emission from fuels containing fuel bound nitrogen. The physical size of the combustor was calculated for a can-annular combustion system with associated operating conditions for the Allison 570-K engine. Preliminary test results indicate that the concept has the potential to meet emission requirements at maximum continuous power operation. However, airflow sealing and improved fuel/air mixing are necessary to meet Department of Energy program goals.

  6. Quiet Clean Short-haul Experimental Engine (QCSEE). Double-annular clean combustor technology development report

    Science.gov (United States)

    Bahr, D. W.; Burrus, D. L.; Sabla, P. E.

    1979-01-01

    A sector combustor technology development program was conducted to define an advanced double annular dome combustor sized for use in the quiet clean short haul experimental engine (QCSEE). A design which meets the emission goals, and combustor performance goals of the QCSEE engine program was developed. Key design features were identified which resulted in substantial reduction in carbon monoxide and unburned hydrocarbon emission levels at ground idle operating conditions, in addition to very low nitric oxide emission levels at high power operating conditions. Their significant results are reported.

  7. Flame stabilization and mixing characteristics in a Stagnation Point Reverse Flow combustor

    Science.gov (United States)

    Bobba, Mohan K.

    A novel combustor design, referred to as the Stagnation Point Reverse-Flow (SPRF) combustor, was recently developed that is able to operate stably at very lean fuel-air mixtures and with low NOx emissions even when the fuel and air are not premixed before entering the combustor. The primary objective of this work is to elucidate the underlying physics behind the excellent stability and emissions performance of the SPRF combustor. The approach is to experimentally characterize velocities, species mixing, heat release and flame structure in an atmospheric pressure SPRF combustor with the help of various optical diagnostic techniques: OH PLIF, chemiluminescence imaging, PIV and Spontaneous Raman Scattering. Results indicate that the combustor is primarily stabilized in a region downstream of the injector that is characterized by low average velocities and high turbulence levels; this is also the region where most of the heat release occurs. High turbulence levels in the shear layer lead to increased product entrainment levels, elevating the reaction rates and thereby enhancing the combustor stability. The effect of product entrainment on chemical timescales and the flame structure is illustrated with simple reactor models. Although reactants are found to burn in a highly preheated (1300 K) and turbulent environment due to mixing with hot product gases, the residence times are sufficiently long compared to the ignition timescales such that the reactants do not autoignite. Turbulent flame structure analysis indicates that the flame is primarily in the thin reaction zones regime throughout the combustor, and it tends to become more flamelet like with increasing distance from the injector. Fuel-air mixing measurements in case of non-premixed operation indicate that the fuel is shielded from hot products until it is fully mixed with air, providing nearly premixed performance without the safety issues associated with premixing. The reduction in NOx emissions in the SPRF

  8. Development of an analytical model to assess fuel property effects on combustor performance

    Science.gov (United States)

    Sutton, R. D.; Troth, D. L.; Miles, G. A.; Riddlebaugh, S. M.

    1987-01-01

    A generalized first-order computer model has been developed in order to analytically evaluate the potential effect of alternative fuels' effects on gas turbine combustors. The model assesses the size, configuration, combustion reliability, and durability of the combustors required to meet performance and emission standards while operating on a broad range of fuels. Predictions predicated on combustor flow-field determinations by the model indicate that fuel chemistry, as defined by hydrogen content, exerts a significant influence on flame retardation, liner wall temperature, and smoke emission.

  9. Innovative rock bed construction

    Energy Technology Data Exchange (ETDEWEB)

    Cook, J.

    1983-06-01

    A general discussion of the use of rock beds for heating and cooling thermal storage is particularized for design and construction in Phoenix, Arizona. The rock bed parameters for three two-story condominium apartments constructed in 1982 are discussed, including sizing criteria and original construction details. A revised construction method using gabions that are self-supporting chain link cylinders provided a much more economical construction method as well as other advantages of speed and structural flexibility.

  10. Flame dynamics in a micro-channeled combustor

    International Nuclear Information System (INIS)

    Hussain, Taaha; Balachandran, Ramanarayanan; Markides, Christos N.

    2015-01-01

    The increasing use of Micro-Electro-Mechanical Systems (MEMS) has generated a significant interest in combustion-based power generation technologies, as a replacement of traditional electrochemical batteries which are plagued by low energy densities, short operational lives and low power-to-size and power-to-weight ratios. Moreover, the versatility of integrated combustion-based systems provides added scope for combined heat and power generation. This paper describes a study into the dynamics of premixed flames in a micro-channeled combustor. The details of the design and the geometry of the combustor are presented in the work by Kariuki and Balachandran [1]. This work showed that there were different modes of operation (periodic, a-periodic and stable), and that in the periodic mode the flame accelerated towards the injection manifold after entering the channels. The current study investigates these flames further. We will show that the flame enters the channel and propagates towards the injection manifold as a planar flame for a short distance, after which the flame shape and propagation is found to be chaotic in the middle section of the channel. Finally, the flame quenches when it reaches the injector slots. The glow plug position in the exhaust side ignites another flame, and the process repeats. It is found that an increase in air flow rate results in a considerable increase in the length (and associated time) over which the planar flame travels once it has entered a micro-channel, and a significant decrease in the time between its conversion into a chaotic flame and its extinction. It is well known from the literature that inside small channels the flame propagation is strongly influenced by the flow conditions and thermal management. An increase of the combustor block temperature at high flow rates has little effect on the flame lengths and times, whereas at low flow rates the time over which the planar flame front can be observed decreases and the time of

  11. Near-zero emissions combustor system for syngas and biofuels

    International Nuclear Information System (INIS)

    Yongho, Kim; Rosocha, Louis

    2010-01-01

    A multi-institutional plasma combustion team was awarded a research project from the DOE/NNSA GIPP (Global Initiative for Prolifereation Prevention) office. The Institute of High Current Electronics (Tomsk, Russia); Leonardo Technologies, Inc. (an American-based industrial partner), in conjunction with the Los Alamos National Laboratory are participating in the project to develop novel plasma assisted combustion technologies. The purpose of this project is to develop prototypes of marketable systems for more stable and cleaner combustion of syngas/biofuels and to demonstrate that this technology can be used for a variety of combustion applications - with a major focus on contemporary gas turbines. In this paper, an overview of the project, along with descriptions of the plasma-based combustors and associated power supplies will be presented. Worldwide, it is recognized that a variety of combustion fuels will be required to meet the needs for supplying gas-turbine engines (electricity generation, propulsion), internal combustion engines (propulsion, transportation), and burners (heat and electricity generation) in the 21st Century. Biofuels and biofuel blends have already been applied to these needs, but experience difficulties in modifications to combustion processes and combustor design and the need for flame stabilization techniques to address current and future environmental and energy-efficiency challenges. In addition, municipal solid waste (MSW) has shown promise as a feedstock for heat and/or electricity-generating plants. However, current combustion techniques that use such fuels have problems with achieving environmentally-acceptable air/exhaust emissions and can also benefit from increased combustion efficiency. This project involves a novel technology (a form of plasma-assisted combustion) that can address the above issues. Plasma-assisted combustion (PAC) is a growing field that is receiving worldwide attention at present. The project is focused on

  12. Parametric Design of Injectors for LDI-3 Combustors

    Science.gov (United States)

    Ajmani, Kumud; Mongia, Hukam; Lee, Phil

    2015-01-01

    Application of a partially calibrated National Combustion Code (NCC) for providing guidance in the design of the 3rd generation of the Lean-Direct Injection (LDI) multi-element combustion configuration (LDI-3) is summarized. NCC was used to perform non-reacting and two-phase reacting flow computations on several LDI-3 injector configurations in a single-element and a five-element injector array. All computations were performed with a consistent approach for mesh-generation, turbulence, spray simulations, ignition and chemical kinetics-modeling. Both qualitative and quantitative assessment of the computed flowfield characteristics of the several design options led to selection of an optimal injector LDI- 3 design that met all the requirements including effective area, aerodynamics and fuel-air mixing criteria. Computed LDI-3 emissions (namely, NOx, CO and UHC) will be compared with the prior generation LDI- 2 combustor experimental data at relevant engine cycle conditions.

  13. Analysis of a high-temperature coal combustor according to a one-dimensional flow model

    Energy Technology Data Exchange (ETDEWEB)

    Chung, P M; Smith, R S

    1977-10-01

    A steady state, one-dimensional analysis for a high temperature coal combustor is presented. An existing solution of solid fuel ignition is employed to describe the ignition of the coal particles. A one-dimensional flow model with radiative heat loss is then constructed to describe the subsequent vaporization of ash and devolatilization, combustion, and gasification of the coal. Combustion is considered to take place either at a flame sheet in the diffusion layer surrounding each particle or at the particle surface. The combustion products are considered to be redistributed in the main gas stream of the combustor according to simplified chemical equilibrium criteria. A simplified devolatilization rate law is formulated, which incorporates in a tractable manner the various competing reactions within the coal particle. Data are presented for the variation of temperatures and mass fractions with position in the combustor and for the influence of various parameters on combustor performance.

  14. Ignition improvement by injector arrangement in a multi-fuel combustor for micro gas turbine

    Science.gov (United States)

    Antoshkiv, O.; Poojitganont, T.; Jeansirisomboon, S.; Berg, H. P.

    2018-01-01

    The novel combustor design also has an impact on the ignitor arrangement. The conventional ignitor system cannot guarantee optimal ignition performance in the usual radial position. The difficult ignitability of gaseous fuels was the main challenge for the ignitor system improvement. One way to improve the ignition performance significantly is a torch ignitor system in which the gaseous fuel is directly mixed with a large amount of the combustor air. To reach this goal, the ignition process was investigated in detail. The micro gas turbine (MGT) ignition was optimised considering three main procedures: torch ignitor operation, burner ignition and flame propagation between the neighbour injectors. A successful final result of the chain of ignition procedures depends on multiple aspects of the combustor design. Performed development work shows an important step towards designing modern high-efficiency low-emission combustors.

  15. Thermoacoustic analysis of the dynamic pressure inside a model combustor during limit cycle oscillations

    NARCIS (Netherlands)

    Alemela, P.R.; Roman Casado, J.C.; Tarband Veeraraghavan, S.K.; Kok, Jacobus B.W.

    2013-01-01

    In this work comprehensive experimental and numerical studies incorporating the most relevant physical mechanisms causing limit cycle pressure and combustion rate oscillations (LCO) in a laboratory scale combustor will be discussed. The strong interaction between the aerodynamics-combustion-acoustic

  16. System and method for reducing combustion dynamics and NO.sub.x in a combustor

    Science.gov (United States)

    Uhm, Jong H.; Johnson, Thomas Edward

    2015-11-20

    A system for reducing combustion dynamics and NO.sub.x in a combustor includes a tube bundle that extends radially across at least a portion of the combustor, wherein the tube bundle comprises an upstream surface axially separated from a downstream surface. A shroud circumferentially surrounds the upstream and downstream surfaces. A plurality of tubes extends through the tube bundle from the upstream surface through the downstream surface, wherein the downstream surface is stepped to produce tubes having different lengths through the tube bundle. A method for reducing combustion dynamics and NO.sub.x in a combustor includes flowing a working fluid through a plurality of tubes radially arranged between an upstream surface and a downstream surface of an end cap that extends radially across at least a portion of the combustor, wherein the downstream surface is stepped.

  17. Effect of Surface Impulsive Thermal Loads on Fatigue Behavior of Constant Volume Propulsion Engine Combustor Materials

    National Research Council Canada - National Science Library

    Zhu, Dongming

    2004-01-01

    .... In this study, a simulated engine test rig has been established to evaluate thermal fatigue behavior of a candidate engine combustor material, Haynes 188, under superimposed CO2 laser surface impulsive thermal loads (30 to 100 Hz...

  18. An Engineering Model for Prediction of Waste Incineration in a Dump Combustor

    National Research Council Canada - National Science Library

    Arunajatesan, S

    1997-01-01

    An engineering model that can be used to obtain predictions of axial distributions of temperature and species concentrations in complex flows has been formulated and applied to waste incineration in a dump combustor...

  19. Thermal Performance of a Scramjet Combustor Operating at Mach 5.6 Flight Conditions

    National Research Council Canada - National Science Library

    Stouffer, Scott

    1997-01-01

    .... The objective of the thermal loads testing was to map the thermal and mechanical loads, including heat transfer, dynamic and static pressures, and skin friction in a scramjet combustor during direct...

  20. The Performance of Hydrocarbon Fuels with H2O2 in a Uni-element Combustor

    National Research Council Canada - National Science Library

    Muss, Jeffrey

    2003-01-01

    .... The combustor used decomposed 90% hydrogen peroxide as the oxidizer. The water-cooled combustion chamber included significant fuel film cooling, with the overall mixture ratio (MR) ranging from 3.75 to 7.4...

  1. Investigation of soot and carbon formation in small gas turbine combustors

    Science.gov (United States)

    Rosfjord, T. J.

    1982-01-01

    An investigation of hardware configurations which attempt to minimize carbon and soot-production without sacrificing performance in small gas turbine combustors was conducted. Four fuel injectors, employing either airblast atomization, pressure atomization, or fuel vaporization techniques were combined with nozzle air swirlers and injector sheaths. Eight configurations were screened at sea-level takeoff and idle test conditions. Selected configurations were focused upon in an attempt to quantify the influence of combustor pressure, inlet temperature, primary zone operation, and combustor loading on soot and carbon formation. Cycle tests were also performed. It was found that smoke emission levels depended on the combustor fluid mechanics, the atomization quality of the injector and the fuel hydrogen content.

  2. Characterization of Centrifugally-Loaded Flame Migration for Ultra-Compact Combustors

    Science.gov (United States)

    2011-10-01

    with the Alstom GT24 and GT26 commercial engines [35]. Hiddeman used the term ”sequential combustion” rather than ITB and demonstrated that the benefit...of the new Alstom engines was increased power gen- eration for similar turbine temperatures via distribution of the combustion process between the main...combustor and second combustor, located in between the HPT and LPT [35]. While the Alstom engines demonstrate the ITB cycle benefits, realization of

  3. Investigation and demonstration of a rich combustor cold-start device for alcohol-fueled engines

    Energy Technology Data Exchange (ETDEWEB)

    Hodgson, J W; Irick, D K [Univ. of Tennessee, Knoxville, TN (United States)

    1998-04-01

    The authors have completed a study in which they investigated the use of a rich combustor to aid in cold starting spark-ignition engines fueled with either neat ethanol or neat methanol. The rich combustor burns the alcohol fuel outside the engine under fuel-rich conditions to produce a combustible product stream that is fed to the engine for cold starting. The rich combustor approach significantly extends the cold starting capability of alcohol-fueled engines. A design tool was developed that simulates the operation of the combustor and couples it to an engine/vehicle model. This tool allows the user to determine the fuel requirements of the rich combustor as the vehicle executes a given driving mission. The design tool was used to design and fabricate a rich combustor for use on a 2.8 L automotive engine. The system was tested using a unique cold room that allows the engine to be coupled to an electric dynamometer. The engine was fitted with an aftermarket engine control system that permitted the fuel flow to the rich combustor to be programmed as a function of engine speed and intake manifold pressure. Testing indicated that reliable cold starts were achieved on both neat methanol and neat ethanol at temperatures as low as {minus}20 C. Although starts were experienced at temperatures as low as {minus}30 C, these were erratic. They believe that an important factor at the very low temperatures is the balance between the high mechanical friction of the engine and the low energy density of the combustible mixture fed to the engine from the rich combustor.

  4. A Design Methodology for Rapid Implementation of Active Control Systems Across Lean Direct Injection Combustor Platforms

    Science.gov (United States)

    Baumann, William T.; Saunders, William R.; Vandsburger, Uri; Saus, Joseph (Technical Monitor)

    2003-01-01

    The VACCG team is comprised of engineers at Virginia Tech who specialize in the subject areas of combustion physics, chemical kinetics, dynamics and controls, and signal processing. Currently, the team's work on this NRA research grant is designed to determine key factors that influence combustion control performance through a blend of theoretical and experimental investigations targeting design and demonstration of active control for three different combustors. To validiate the accuracy of conclusions about control effectiveness, a sequence of experimental verifications on increasingly complex lean, direct injection combustors is underway. During the work period January 1, 2002 through October 15, 2002, work has focused on two different laboratory-scale combustors that allow access for a wide variety of measurements. As the grant work proceeds, one key goal will be to obtain certain knowledge about a particular combustor process using a minimum of sophisticated measurements, due to the practical limitations of measurements on full-scale combustors. In the second year, results obtained in the first year will be validated on test combustors to be identified in the first quarter of that year. In the third year, it is proposed to validate the results at more realistic pressure and power levels by utilizing the facilities at the Glenn Research Center.

  5. Sludge combustion in fluidized bed reactors at laboratory scale

    International Nuclear Information System (INIS)

    Chirone, R.; Cammarota, A.

    2001-01-01

    The combustion of a dried sewage sludge in laboratory scale fluidized bed has been studied in Naples by the Istituto di ricerche sulla combustione (Irc) in the framework of a National project named Thermal Process with Energy Recovery to be used in laboratory and pre-pilot scale apparatus. The attention has been focused on emissions of unreacted carbon as elutriated fines, on the emissions of pollutant gases and on the assessment of the inventory of fly- and bottom ashes. The combustion behaviour of sewage sludge has been compared with those of a market available Tyre Derived Fuel (TDF) and a biomass from Mediterranean area (Robinia Pseudoacacia) and with that of a South African bituminous coal. Stationary combustion tests were carried out at 850 0 C by feeding particles in the size range 0-1 mm into a bed of silica sand without any sorbent addition. The fluidized bed combustor has been operated, at a superficial gas velocity of 0.4 m/s and different excesses of air ranging between 14 and 98%. Relatively high combustion efficiency, larger than 98.9% has been obtained in experiments carried out with sewage sludge and excess of air larger than 20%. These values, are comparable with those obtained in previously experimental activity carried out under similar operative conditions with a South Africa Bituminous coal (97-98%). It is larger than those obtained by using a Tyre Derived Fuel (89-90%) and the Robinia Pseudoacacia Biomass (93-93%). The relative importance of carbon fines elutriation, CO emissions and volatile bypassing the bed in determining the loss of combustion efficiency has been evaluated for the different fuels tested [it

  6. Bed bug deterrence

    Directory of Open Access Journals (Sweden)

    Haynes Kenneth F

    2010-09-01

    Full Text Available Abstract A recent study in BMC Biology has determined that the immature stage of the bed bug (the nymph signals its reproductive status to adult males using pheromones and thus avoids the trauma associated with copulation in this species. The success of this nymphal strategy of deterrence is instructive. Against the background of increasing problems with bed bugs, this research raises the question whether pheromones might be used to control them. See research article http://www.biomedcentral.com/1741-7007/8/121

  7. The Safety of Hospital Beds

    Science.gov (United States)

    Gervais, Pierre; Pooler, Charlotte; Merryweather, Andrew; Doig, Alexa K.; Bloswick, Donald

    2015-01-01

    To explore the safety of the standard and the low hospital bed, we report on a microanalysis of 15 patients’ ability to ingress, move about the bed, and egress. The 15 participants were purposefully selected with various disabilities. Bed conditions were randomized with side rails up or down and one low bed with side rails down. We explored the patients’ use of the side rails, bed height, ability to lift their legs onto the mattress, and ability to turn, egress, and walk back to the chair. The standard bed was too high for some participants, both for ingress and egress. Side rails were used by most participants when entering, turning in bed, and exiting. We recommend that side rails be reconsidered as a means to facilitate in-bed movement, ingress, and egress. Furthermore, single deck height settings for all patients are not optimal. Low beds as a safety measure must be re-evaluated. PMID:28462302

  8. The Use of an Ultra-Compact Combustor as an Inter-Turbine Burner for Improved Engine Performance

    Science.gov (United States)

    2014-03-27

    Alstom , formally known as ABB Power Generation, developed a line of SCgas turbines for the power generation industry [12]. The Alstom GT24 and GT26...consist of a primary combustor a turbine and a reheat combustor, with the aim of achieving high efficiency while delivering low emissions. Alstom has been...utilizing the SC concepts since the 1940’s using diffusion type combustors. In 1995 Alstom developed their modern line SC gas turbines shown in Figure

  9. Release of alkali salts and coal volatiles affecting internal components in fluidized bed combustion systems

    Directory of Open Access Journals (Sweden)

    Arias del Campo, E.

    2003-12-01

    Full Text Available In spite of the potential advantages of atmospheric fluidized bed systems, experience has proved that, under certain environments and operating conditions, a given material employed for internal components could lead to catastrophic events. In this study, an attempt is made to establish material selection and operational criteria that optimize performance and availability based on theoretical considerations of the bed hydrodynamics, thermodynamics and combustion process. The theoretical results may indicate that, for high-volatile coals with particle diameters (dc of 1-3 mm and sand particle size (ds of 0.674 mm, a considerable proportion of alkali chlorides may be transferred into the freeboard region of fluidized bed combustors as vapor phase, at bed temperatures (Tb < 840 °C, excess air (XSA ≤ 20 %, static bed height (Hs ≤ 0.2 m and fluidizing velocity (Uo < 1 m/s. Under these operating conditions, a high alkali deposition may be expected to occur in heat exchange tubes located above the bed. Conversely, when the combustors operate at Tb > 890 °C and XSA > 30 %, a high oxidation rate of the in-bed tubes may be present. Nevertheless, for these higher Tb values and XSA < 10 %, corrosion attack of metallic components, via sulfidation, would occur since the excessive gas-phase combustion within the bed induced a local oxygen depletion.

    A pesar de las ventajas potenciales de los sistemas atmosféricos de lecho fluidizado, la experiencia ha demostrado que, bajo ciertas atmósferas y condiciones de operación, un material que se emplea como componente interno podría experimentar una falla y conducir a eventos catastróficos. En este estudio, se intenta establecer un criterio tanto operativo como de selección del material que permita optimizar su disponibilidad y funcionalidad basados en consideraciones teóricas de la hidrodinámica del lecho, la termodin

  10. Combustion characteristics of Athabasca froth treatment tailings in a simulated fluidilized bed

    Energy Technology Data Exchange (ETDEWEB)

    Esmaeili, P.; Ghosh, M.; Speirs, B. C. [Imperial Oil Resources (Canada); Leon, M. A.; Rao, S.; Dutta, A.; Basu, P. [Greenfield Research Inc. (Canada)

    2011-07-01

    In surface-mined oil sands, a stream of water, asphaltenes, solids and residual bitumen/solvent, known as PFT tailings, is created during the bitumen production process. The aim of this study was to investigate the use of this PFT tailings stream as a fuel source for combustion in a fluidized bed for energy recovery. To do so, physical and fluidization characteristics of the fuel as well as combustion kinetics were assessed through laboratory analysis. In addition, the fuel's combustion characteristics were investigated through experiments in a quartz wool matrix tubular reactor and theoretical calculations at various moisture contents. Results showed that this fuel can be burned in a fluidized bed with a reactivity comparable to that of coal samples. This research found that PFT tailings could be used to generate energy during disposal but further work will have to be undertaken in a hot CFB combustor to confirm this.

  11. N2 O A greenhouse gas released from the combustion of coals in fluidized beds

    International Nuclear Information System (INIS)

    Boavida, D.; Lobo, L. S.; Gulyurtlu, I.; Cabrita, I.

    1996-01-01

    This paper discusses the results of the experimental work investigating the formation of N-2 O and NO during fluidized bed combustion of coals, and of chars and volatiles produced from the pyrolysis of these coals. Ammonia (N H 3 ) and hydrogen cyanide (HCN) are shown to play important roles as gas phase precursors of both NO and N 2 O. The conversion of fuel-N through N H 3 and HCN to N 2 O and NO was studied using a fluidized bed combustor in the temperature range between 973 K and 1273 K, for two different coals. The results suggest that the principal contribution to N 2 O emission Originated from volatile-N, however, char-N could also have an important role, depending upon the temperature. 1 fig., 8 tabs

  12. An experimental study of heat transfer to a horizontal tube in a large particle fluidized bed at elevated temperature

    Science.gov (United States)

    George, A. H.

    Experimental data for the time-average local heat transfer coefficient to a single horizontal tube in a large particle fluidized bed at elevated temperature, are presented. Refractory particles with surface mean diameter 2.14 mm and 3.23 mm were fluidized by combustion products of propane at bed temperatures of 810 K and 1053 K. The particle sizes are near the largest presently used in pilot plant fluidized bed coal combustors. The superficial gas velocity ranged from that required for minimum fluidization, or slightly packed, to the velocity where slugging first occurred, or the highest velocity air blower capacity would allow. Heat transfer results indicate that a stack of defluidized particles remain on top of the tube at low superficial gas velocities. A very low local heat transfer coefficient was obtained under these conditions. There was less than 10 percent difference in the maximum spatial average heat transfer coefficients for the two particle sizes considered.

  13. Bed Prism Spectacles

    Science.gov (United States)

    Ribeiro, Jair Lúcio Prados

    2018-01-01

    We only became aware of the existence of bed prism spectacles when a student brought them to the classroom and asked us about how they work. The device proved to be a fertile source of curiosity among the students, and, to be properly understood, it required us to develop a comparison between reflection in a typical mirror and total internal…

  14. Practice Hospital Bed Safety

    Science.gov (United States)

    ... the mattress end Subscribe: FDA Consumer Health Information "Hospital beds are found in nearly all patient care settings or environments," says Joan Ferlo Todd, RN, a senior nurse-consultant at the Food and Drug Administration’s (FDA) Center for Devices and Radiological Health (CDRH). " ...

  15. Combustion characteristics and retention-emission of selenium during co-firing of torrefied biomass and its blends with high ash coal.

    Science.gov (United States)

    Ullah, Habib; Liu, Guijian; Yousaf, Balal; Ali, Muhammad Ubaid; Abbas, Qumber; Zhou, Chuncai

    2017-12-01

    The combustion characteristics, kinetic analysis and selenium retention-emission behavior during co-combustion of high ash coal (HAC) with pine wood (PW) biomass and torrefied pine wood (TPW) were investigated through a combination of thermogravimetric analysis (TGA) and laboratory-based circulating fluidized bed combustion experiment. Improved ignition behavior and thermal reactivity of HAC were observed through the addition of a suitable proportion of biomass and torrefied. During combustion of blends, higher values of relative enrichment factors in fly ash revealed the maximum content of condensing volatile selenium on fly ash particles, and depleted level in bottom ash. Selenium emission in blends decreased by the increasing ratio of both PW and TPW. Higher reductions in the total Se volatilization were found for HAC/TPW than individual HAC sample, recommending that TPW have the best potential of selenium retention. The interaction amongst selenium and fly ash particles may cause the retention of selenium. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. FY 1989 report on the results of the development of the entrained bed coal gasification power plant. Part 1. Element study; 1989 nendo seika hokokusho. Funryusho sekitan gaska hatsuden plant kaihatsu - Sono 1. Yoso kenkyu hen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1990-03-01

    For the purpose of establishing the technology of integrated coal gasification combined cycle power generation, element study was conducted of a 200t/d entrained bed coal gasification pilot plant, and the FY 1989 results were summarized. In the gasification test using 2t/d gasifier equipment, the following were carried out: test on gasification of the coal proposed for pilot plant, test on changes in coal feed ratio, analysis of trace gas elements in coal, study of the fixed bed gas refining system, etc. In the study of large gas turbine combustor for demonstration machine, development of combustor which makes stable combustion in the low load region possible, development of low NOx combustor which controls the conversion of nitrogen compounds such as ammonia in coal gasification gas to NOx, development of combustor which makes the optimum and effective cooling possible by combining film cooling, impingement cooling, etc. In the study of simulation of the combined power generation total system, verification tests on the control mode switching function of the general load pressure control system, movement to meet anomaly of the control system, integrated cooperation control system, etc. (NEDO)

  17. Low NO sub x heavy fuel combustor concept program. Phase 1A: Combustion technology generation coal gas fuels

    Science.gov (United States)

    Sherlock, T. P.

    1982-01-01

    Combustion tests of two scaled burners using actual coal gas from a 25 ton/day fluidized bed coal gasifier are described. The two combustor configurations studied were a ceramic lined, staged rich/lean burner and an integral, all metal multiannual swirl burner (MASB). The tests were conducted over a range of temperature and pressures representative of current industrial combustion turbine inlet conditions. Tests on the rich lean burner were conducted at three levels of product gas heating values: 104, 197 and 254 btu/scf. Corresponding levels of NOx emissions were 5, 20 and 70 ppmv. Nitrogen was added to the fuel in the form of ammonia, and conversion efficiencies of fuel nitrogen to NOx were on the order of 4 percent to 12 percent, which is somewhat lower than the 14 percent to 18 percent conversion efficiency when src-2 liquid fuel was used. The MASB was tested only on medium btu gas (220 to 270 btu/scf), and produced approximately 80 ppmv NOx at rated engine conditions. Both burners operated similarly on actual coal gas and erbs fuel, and all heating values tested can be successfully burned in current machines.

  18. VA National Bed Control System

    Data.gov (United States)

    Department of Veterans Affairs — The VA National Bed Control System records the levels of operating, unavailable and authorized beds at each VAMC, and it tracks requests for changes in these levels....

  19. Life assessment of combustor liner using unified constitutive models

    Science.gov (United States)

    Tong, M. T.; Thompson, R. L.

    1988-01-01

    Hot section components of gas turbine engines are subject to severe thermomechanical loads during each mission cycle. Inelastic deformation can be induced in localized regions leading to eventual fatigue cracking. Assessment of durability requires reasonably accurate calculation of the structural response at the critical location for crack initiation. In recent years nonlinear finite element computer codes have become available for calculating inelastic structural response under cyclic loading. NASA-Lewis sponsored the development of unified constitutive material models and their implementation in nonlinear finite element computer codes for the structural analysis of hot section components. These unified models were evaluated with regard to their effect on the life prediction of a hot section component. The component considered was a gas turbine engine combustor liner. A typical engine mission cycle was used for the thermal and structural analyses. The analyses were performed on a CRAY computer using the MARC finite element code. The results were compared with laboratory test results, in terms of crack initiation lives.

  20. Fuel burner and combustor assembly for a gas turbine engine

    Science.gov (United States)

    Leto, Anthony

    1983-01-01

    A fuel burner and combustor assembly for a gas turbine engine has a housing within the casing of the gas turbine engine which housing defines a combustion chamber and at least one fuel burner secured to one end of the housing and extending into the combustion chamber. The other end of the fuel burner is arranged to slidably engage a fuel inlet connector extending radially inwardly from the engine casing so that fuel is supplied, from a source thereof, to the fuel burner. The fuel inlet connector and fuel burner coact to anchor the housing against axial movement relative to the engine casing while allowing relative radial movement between the engine casing and the fuel burner and, at the same time, providing fuel flow to the fuel burner. For dual fuel capability, a fuel injector is provided in said fuel burner with a flexible fuel supply pipe so that the fuel injector and fuel burner form a unitary structure which moves with the fuel burner.

  1. Nail bed onychomatricoma.

    Science.gov (United States)

    Wang, Lei; Gao, Tianwen; Wang, Gang

    2014-10-01

    Onychomatricoma is a rare tumor originating from the nail matrix, and, in rare conditions, from the ventral aspect of the proximal nailfold. Here we report a rare case of a 51-year-old man presenting with melanonychia mainly involving the distal nail plate. Histopathologic examination showed typical findings of onychomatricoma mainly involving the nail bed, while the nail matrix was largely uninvolved. We also identified fungal infection in a focal area of the distal nail plate. Our findings indicate that onychomatricoma can develop in the surrounding epithelial tissue of the nail unit, including the nail bed, and suggest that fungal infection may represent a secondary phenomenon of onychomatricoma. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Geomechanics of bedded salt

    International Nuclear Information System (INIS)

    Serata, S.; Milnor, S.W.

    1979-01-01

    Creep data from the literature search is reinterpreted by SGI, resulting in a better understanding of the temperature and stress state dependence of the octahedral creep rate and the octahedral shear strength. The concept of a transition strength between the elastic and the plastic states is in agreement with the data. The elastic and rheological properties of salt are described, and a set of constitutive equations is presented. The dependence of material properties on parameters such as temperature is considered. Findings on the permeability of salt are summarized, and the in-situ behavior of openings in bedded salt is described based on extensive engineering experience. A stress measuring system utilizing a finite element computer code is discussed. Geological factors affecting the stability of salt openings are considered, and the Stress Control Technique for designing stable openings in bedded salt formations is explained

  3. The effect of inlet conditions on lean premixed gas turbine combustor performance

    Science.gov (United States)

    Vilayanur, Suresh Ravi

    The combustion community is today faced with the goal to reduce NOx at high efficiencies. This requirement has directed attention to the manner by which air and fuel are treated prior to and at the combustor inlet. This dissertation is directed to establishing the role of combustor inlet conditions on combustor performance, and to deriving an understanding of the relationship between inlet conditions and combustion performance. To investigate the complex effect of inlet parameters on combustor performance, (1) a test facility was designed and constructed, (2) hardware was designed and fabricated, (3) a statistically based technique was designed and applied, and (4) detailed in-situ measurements were acquired. Atmospheric tests were performed at conditions representative of industrial combustors: 670 K inlet preheat and an equivalence ratio of 0.47, and make the study immediately relevant to the combustion community. The effects of premixing length, fuel distribution, swirl angle, swirl vane thickness and swirl solidity were investigated. The detailed in-situ measurements were performed to form the database necessary to study the responsible mechanisms. A host of conventional and advanced diagnostics were used for the investigation. In situ measurements included the mapping of the thermal and velocity fields of the combustor, obtaining species concentrations inside the combustor, and quantifying the fuel-air mixing entering the combustor. Acoustic behavior of the combustor was studied, including the application of high speed videography. The results reveal that the principal statistically significant effect on NOx production is the inlet fuel distribution, and the principal statistically significant effect on CO production is the swirl strength. Elevated levels of NOx emission result when the fuel is weighted to the centerline. Eddies shedding off the swirler hub ignite as discrete packets, and due to the elevated concentrations of fuel, reach higher temperatures

  4. An experimental study of the stable and unstable operation of an LPP gas turbine combustor

    Science.gov (United States)

    Dhanuka, Sulabh Kumar

    A study was performed to better understand the stable operation of an LPP combustor and formulate a mechanism behind the unstable operation. A unique combustor facility was developed at the University of Michigan that incorporates the latest injector developed by GE Aircraft Engines and enables operation at elevated pressures with preheated air at flow-rates reflective of actual conditions. The large optical access has enabled the use of a multitude of state-of-the-art laser diagnostics such as PIV and PLIF, and has shed invaluable light not only into the GE injector specifically but also into gas turbine combustors in general. Results from Particle Imaging Velocimetry (PIV) have illustrated the role of velocity, instantaneous vortices, and key recirculation zones that are all critical to the combustor's operation. It was found that considerable differences exist between the iso-thermal and reacting flows, and between the instantaneous and mean flow fields. To image the flame, Planar Laser Induced Fluorescence (PLIF) of the formaldehyde radical was successfully utilized for the first time in a Jet-A flame. Parameters regarding the flame's location and structure have been obtained that assist in interpreting the velocity results. These results have also shown that some of the fuel injected from the main fuel injectors actually reacts in the diffusion flame of the pilot. The unstable operation of the combustor was studied in depth to obtain the stability limits of the combustor, behavior of the flame dynamics, and frequencies of the oscillations. Results from simultaneous pressure and high speed chemiluminescence images have shown that the low frequency dynamics can be characterized as flashback oscillations. The results have also shown that the stability of the combustor can be explained by simple and well established premixed flame stability mechanisms. This study has allowed the development of a model that describes the instability mechanism and accurately

  5. Parametric Modeling Investigation of a Radially-Staged Low-Emission Aviation Combustor

    Science.gov (United States)

    Heath, Christopher M.

    2016-01-01

    Aviation gas-turbine combustion demands high efficiency, wide operability and minimal trace gas emissions. Performance critical design parameters include injector geometry, combustor layout, fuel-air mixing and engine cycle conditions. The present investigation explores these factors and their impact on a radially staged low-emission aviation combustor sized for a next-generation 24,000-lbf-thrust engine. By coupling multi-fidelity computational tools, a design exploration was performed using a parameterized annular combustor sector at projected 100% takeoff power conditions. Design objectives included nitrogen oxide emission indices and overall combustor pressure loss. From the design space, an optimal configuration was selected and simulated at 7.1, 30 and 85% part-power operation, corresponding to landing-takeoff cycle idle, approach and climb segments. All results were obtained by solution of the steady-state Reynolds-averaged Navier-Stokes equations. Species concentrations were solved directly using a reduced 19-step reaction mechanism for Jet-A. Turbulence closure was obtained using a nonlinear K-epsilon model. This research demonstrates revolutionary combustor design exploration enabled by multi-fidelity physics-based simulation.

  6. Influence of the burner swirl on the azimuthal instabilities in an annular combustor

    Science.gov (United States)

    Mazur, Marek; Nygård, Håkon; Worth, Nicholas; Dawson, James

    2017-11-01

    Improving our fundamental understanding of thermoacoustic instabilities will aid the development of new low emission gas turbine combustors. In the present investigation the effects of swirl on the self-excited azimuthal combustion instabilities in a multi-burner annular annular combustor are investigated experimentally. Each of the burners features a bluff body and a swirler to stabilize the flame. The combustor is operated with an ethylene-air premixture at powers up to 100 kW. The swirl number of the burners is varied in these tests. For each case, dynamic pressure measurements at different azimuthal positions, as well as overhead imaging of OH* of the entire combustor are conducted simultaneously and at a high sampling frequency. The measurements are then used to determine the azimuthal acoustic and heat release rate modes in the chamber and to determine whether these modes are standing, spinning or mixed. Furthermore, the phase shift between the heat release rate and pressure and the shape of these two signals are analysed at different azimuthal positions. Based on the Rayleigh criterion, these investigations allow to obtain an insight about the effects of the swirl on the instability margins of the combustor. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant agreement n° 677931 TAIAC).

  7. Study on the Effect of Air Throttling on Flame Stabilization of an Ethylene Fueled Scramjet Combustor

    Directory of Open Access Journals (Sweden)

    Ye Tian

    2015-01-01

    Full Text Available The effect of air throttling on flame stabilization of an ethylene fueled scramjet combustor was investigated by numerical simulation and experiments in this paper. The results were obtained under the inflow condition with Mach number of 2.0, total temperature of 900 K, total pressure of 0.8 MPa, and total equivalence ratio of 0.5. The shock train generated by air throttling had a big effect on the flow structure of the scramjet combustor. Compared with the combustor without air throttling, the flow field with air throttling had a lower velocity and higher pressure, temperature, and vortices intensity. Air throttling was an effective way to achieve flame stabilization; the combustion in the combustor without air throttling was nearly blowout. In the experiment, the combustion was nearly blowout with air throttling location of 745 mm, and the fuel/air mixture in the combustor with air throttling location of 875 mm was burned intensively. It was important to choose the location and time sequence of air throttling for fuel ignition and flame stabilization. The numerical simulation results agreed well with experimental measurements.

  8. Combustion oscillation study in a kerosene fueled rocket-based combined-cycle engine combustor

    Science.gov (United States)

    Huang, Zhi-Wei; He, Guo-Qiang; Qin, Fei; Xue, Rui; Wei, Xiang-Geng; Shi, Lei

    2016-12-01

    This study reports the combustion oscillation features in a three-dimensional (3D) rocket-based combined-cycle (RBCC) engine combustor under flight Mach number (Mflight) 3.0 conditions both experimentally and numerically. Experiment is performed on a direct-connect ground test facility, which measures the wall pressure along the flow-path. High-speed imaging of the flame luminosity and schlieren is carried out at exit of the primary rocket. Compressible reactive large eddy simulation (LES) with reduced chemical kinetics of a surrogate model for kerosene is performed to further understand the combustion oscillation mechanisms in the combustor. LES results are validated with experimental data by the time-averaged and root mean square (RMS) pressure values, and show acceptable agreement. Effects of the primary rocket jet on pressure oscillation in the combustor are analyzed. Relation of the high speed rocket jet oscillation, which is thought to among the most probable sources of combustion oscillation, with the RBCC combustor is recognized. Results reveal that the unsteady over-expanded rocket jet has significant impacts on the combustion oscillation feature of the RBCC combustor, which is different from a thermo-acoustics type oscillation. The rocket jet/air inflow physical interactions under different rocket jet expansion degrees are experimentally studied.

  9. Effects of Cavity Configurations on Flameholding and Performances of Kerosene Fueled Scramjet Combustor

    Science.gov (United States)

    Shi, Deyong; Song, Wenyan; Wang, Yuhang; Wang, Yanhua

    2017-08-01

    In this work, the effects of cavity flameholder configurations on flameholding and performances of kerosene fueled scramjet combustor were studied experimentally and numerically. For experiments, a directly connected ground facility was used and clean high enthalpy air, with a total temperature of 800 K and a total pressure of 800 Kpa, was provided by an electricity resistance heater. To investigate the effects of cavity configurations on flameholding capacity and reacting-flow characteristics, three different flameholders, one single cavity flameholder and two tandem cavity flameholders, were used in experiments. For the two combustors with tandem cavity flameholders, the location and configurations of its up-stream cavity were same with the single cavity flameholder, and the length-to-depth ratios for down-stream cavities were 9 and 11 respectively. The experimental results showed that stabilize kerosene combustion were achieved for combustor with tandem cavity flameholders mounted, and none for that with single cavity flameholder. The none-reacting and reacting flows of combustor models with tandem cavity flameholders were compared and studied with numerical and experimental results. The results showed that higher combustion efficiencies and pressure recovery ratios were achieved for the combustor with down-stream cavity length-to-depth ratio of 9.

  10. Combustion Dynamic Characteristics Identification in a 9-point LDI Combustor Under Choked Outlet Boundary Conditions

    Science.gov (United States)

    He, Zhuohui J.; Chang, Clarence T.

    2017-01-01

    Combustion dynamics data were collected at the NASA Glenn Research Center's CE-5 flame tube test facility under combustor outlet choked conditions. Two 9-point Swirl-Venturi Lean Direct Injection (SV-LDI) configurations were tested in a rectangular cuboid combustor geometry. Combustion dynamic data were measured at different engine operational conditions up to inlet air pressure and temperature of 24.13 bar and 828 K, respectively. In this study, the effects of acoustic cavity resonance, precessing vortex core (PVC), and non-uniform thermal expansion on the dynamic noise spectrum are identified by comparing the dynamic data that collected at various combustor inlet conditions along with combustor geometric calculations. The results show that the acoustic cavity resonance noises were seen in the counter-rotating pilot configuration but not in the co-rotating pilot configuration. Dynamic pressure noise band at around 0.9 kHz was only detected at the P'41 location (9.8 cm after fuel injector face) but not at the P'42 location (29 cm after the fuel injector face); the amplitude of this noise band depended on the thermal expansion ratio (T4/T3). The noise band at around 1.8 kHz was found to depend on the inlet air pressure or the air density inside the combustor. The PVC frequency was not observed in these two configurations.

  11. CFD analysis of a scramjet combustor with cavity based flame holders

    Science.gov (United States)

    Kummitha, Obula Reddy; Pandey, Krishna Murari; Gupta, Rajat

    2018-03-01

    Numerical analysis of a scramjet combustor with different cavity flame holders has been carried out using ANSYS 16 - FLUENT tool. In this research article the internal fluid flow behaviour of the scramjet combustor with different cavity based flame holders have been discussed in detail. Two dimensional Reynolds-Averaged Navier-Stokes governing(RANS) equations and shear stress turbulence (SST) k - ω model along with finite rate/eddy dissipation chemistry turbulence have been considered for modelling chemical reacting flows. Due to the advantage of less computational time, global one step reaction mechanism has been used for combustion modelling of hydrogen and air. The performance of the scramjet combustor with two different cavities namely spherical and step cavity has been compared with the standard DLR scramjet. From the comparison of numerical results, it is found that the development of recirculation regions and additional shock waves from the edge of cavity flame holder is increased. And also it is observed that with the cavity flame holder the residence time of air in the scramjet combustor is also increased and achieved stabilized combustion. From this research analysis, it has been found that the mixing and combustion efficiency of scramjet combustor with step cavity design is optimum as compared to other models.

  12. Fuel property effects on USAF gas turbine engine combustors and afterburners

    Science.gov (United States)

    Reeves, C. M.

    1984-01-01

    Since the early 1970s, the cost and availability of aircraft fuel have changed drastically. These problems prompted a program to evaluate the effects of broadened specification fuels on current and future aircraft engine combustors employed by the USAF. Phase 1 of this program was to test a set of fuels having a broad range of chemical and physical properties in a select group of gas turbine engine combustors currently in use by the USAF. The fuels ranged from JP4 to Diesel Fuel number two (DF2) with hydrogen content ranging from 14.5 percent down to 12 percent by weight, density ranging from 752 kg/sq m to 837 kg/sq m, and viscosity ranging from 0.830 sq mm/s to 3.245 sq mm/s. In addition, there was a broad range of aromatic content and physical properties attained by using Gulf Mineral Seal Oil, Xylene Bottoms, and 2040 Solvent as blending agents in JP4, JP5, JP8, and DF2. The objective of Phase 2 was to develop simple correlations and models of fuel effects on combustor performance and durability. The major variables of concern were fuel chemical and physical properties, combustor design factors, and combustor operating conditions.

  13. Bioenergy originating from biomass combustion in a fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Crujeira, T.; Gulyurtlu, I.; Lopes, H.; Abelha, P.; Cabrita, I. [INETI/DEECA, Lisboa (Portugal)

    2008-07-01

    Bioenergy could significantly contribute to reducing and controlling greenhouse emissions (GHG) and to replace fossil fuels in large power plants. Although the use of biomass, originating from forests, could be beneficial, particularly in preventing fires, there are obstacles to achieve a sustainable supply chain of biomass in most European countries. In addition, there are also technical barriers as requirements of biomass combustion may differ from those of coal, which could mean significant retrofitting of existing installations. The combustion behaviour of different biomass materials were studied on a pilot fluidised bed combustor, equipped with two cyclones for particulate matter removal. The gaseous pollutants leaving the stack were sampled under isokinetic conditions for particulate matter, chlorine compounds, heavy metals and dioxins and furans (PCDD/F). The results obtained indicated that the combustion of these materials did not present any operational problem, although for temperatures above 800{sup o}C, bed agglomeration could be observed for all biomass materials studied. Most of the combustion of biomass, contrary to what is observed for coal, takes place in the riser where the temperature was as much as 150{sup o}C above that of the bed. Stable combustion conditions were achieved as well as high combustion efficiency. When compared with the emissions of bituminous coal, the most used fossil fuel, the emissions of CO and SO2 were found to be lower and NOx emissions were similar to those of coal. HCl and PCDD/F could be considerable with biomasses containing high chlorine levels, as in the case of straw. It was observed that the nature of ash could give rise serious operating problems.

  14. 40 CFR 62.14103 - Emission limits for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Science.gov (United States)

    2010-07-01

    ... combustor metals, acid gases, organics, and nitrogen oxides. 62.14103 Section 62.14103 Protection of... combustor metals, acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste... nitrogen oxides in excess of the emission limits listed in table 2 of this subpart for affected facilities...

  15. 40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Science.gov (United States)

    2010-07-01

    ... combustor metals, acid gases, organics, and nitrogen oxides. 60.33b Section 60.33b Protection of Environment..., acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals... oxygen. (d) For approval, a State plan shall include emission limits for nitrogen oxides at least as...

  16. 40 CFR Appendix to Subpart Eee of... - Quality Assurance Procedures for Continuous Emissions Monitors Used for Hazardous Waste Combustors

    Science.gov (United States)

    2010-07-01

    ... determination and adjustment of CEMS. 4. Integration of CEMS with the automatic waste feed cutoff (AWFCO) system... Continuous Emissions Monitors Used for Hazardous Waste Combustors Appendix to Subpart EEE of Part 63... Hazardous Air Pollutants from Hazardous Waste Combustors Pt. 63, Subpt. EEE, App. Appendix to Subpart EEE of...

  17. Experimental results showing the internal three-component velocity field and outlet temperature contours for a model gas turbine combustor

    CSIR Research Space (South Africa)

    Meyers, BC

    2011-09-01

    Full Text Available A three-component flow field inside a can-type, forward flow experimental combustor was measured under non-reacting conditions. The combustor was run at atmospheric conditions with the air flow supplied from a fan and the outlet was straight...

  18. The importance of ash for the favourable properties of sewage sludge in co-firing; Askans betydelse foer roetslams goda samfoerbraenningsegenskaper

    Energy Technology Data Exchange (ETDEWEB)

    Davidsson, K.; Jones, F.; Niklasson, F.; Ryde, D. [SP Sveriges Tekniska Forskningsinstitut, Boraas, (Sweden); Gustafsson, G. [Boraas Energi och Miljoe, Boraas (Sweden); Herstad Svaerd, S. [WSP Kraft and Vaerme, Goeteborg (Sweden)

    2012-11-01

    Sewage sludge has been shown to have positive properties during cofiring with difficult fuels. The sludge mitigates deposition and corrosion which occur because of the fuels content of chlorine and alkali. The reason for the positive properties of sludge are its content of sulphur, phosphorus and aluminium silicates. Its high content of ash has also been discussed because the fly ash would constitute a large surface for alkali chlorides to condensate on and thereby avoid condensation on e.g. superheater surfaces. The ash could also blast the surface and thereby keeping them clean. The present project aims at testing the hypothesis that the ash in the sludge mitigates the deposition. Tests have been performed with synthetically produced waste pellets of which some were doped with inert particles in form of aluminium oxide. The tests were done in a lab-scale bubbling fluidised bed. Deposit probes collected deposits during the combustion of doped and un-doped waste pellets, and the deposits were chemically analysed. The result shows that the inert particles do not have any effect on the amount of hard attached deposits. The particles ended up on the lee side of the probe where they deposited because of gravitation, but they could be easily removed. The remaining deposit was analysed and the effect of inert particles was a small decrease of the content of chlorine. Tests were also performed with pellets doped with sludge. In this case the amount of deposit and its content of chlorine decreased significantly. Different sewage sludges have different properties. The present results show that sludge for cofiring should not be chosen for its amount of ash but rather for its content of sulphur, phosphorous and aluminium.

  19. The importance of ash for the favourable properties of sewage sludge in co-firing; Askans betydelse foer roetslams goda samfoerbraenningsegenskaper

    Energy Technology Data Exchange (ETDEWEB)

    Davidsson, K.; Jones, F.; Niklasson, F.; Ryde, D. [SP Sveriges Tekniska Forskningsinstitut, Boraas (Sweden); Gustafsson, G. [Boraas Energi och Miljoe, Boraas (Sweden); Herstad Svaerd, S. [WSP Kraft and Vaerme, Stockholm (Sweden)

    2012-07-01

    Sewage sludge has been shown to have positive properties during cofiring with difficult fuels. The sludge mitigates deposition and corrosion which occur because of the fuels content of chlorine and alkali. The reason for the positive properties of sludge are its content of sulphur, phosphorus and aluminium silicates. Its high content of ash has also been discussed because the fly ash would constitute a large surface for alkali chlorides to condensate on and thereby avoid condensation on e.g. superheater surfaces. The ash could also blast the surface and thereby keeping them clean. The present project aims at testing the hypothesis that the ash in the sludge mitigates the deposition. Tests have been performed with synthetically produced waste pellets of which some were doped with inert particles in form of aluminium oxide. The tests were done in a lab-scale bubbling fluidised bed. Deposit probes collected deposits during the combustion of doped and un-doped waste pellets, and the deposits were chemically analysed. The result shows that the inert particles do not have any effect on the amount of hard attached deposits. The particles ended up on the lee side of the probe where they deposited because of gravitation, but they could be easily removed. The remaining deposit was analysed and the effect of inert particles was a small decrease of the content of chlorine. Tests were also performed with pellets doped with sludge. In this case the amount of deposit and its content of chlorine decreased significantly. Different sewage sludges have different properties. The present results show that sludge for cofiring should not be chosen for its amount of ash but rather for its content of sulphur, phosphorous and aluminium.

  20. Emissions of nitrogen oxides from an experimental hydrogen-fueled gas turbine combustor

    Science.gov (United States)

    Norgren, C. T.; Ingebo, R. D.

    1974-01-01

    The effect of operating variables of a hydrogen fueled combustor on exhaust concentrations of total oxides of nitrogen was determined at inlet-air temperature levels up to 810 K, pressure of 414,000N/sa m, and reference velocity of 21.3 m/sec. The combustor, which was originally designed for hydrocarbon fuel produced a NO(x) concentration of 380 ppm with hydrogen at 810 K inlet-air temperature. A reduction in NO(x) of about 30 % was obtained by modification to a lean or rich primary zone. The lowest NO(x) levels obtained with hydrogen were equivalent to those of the reference combustor burning hydrocarbon fuels.

  1. Experimental and analytical separation of hydrodynamic, entropy and combustion noise in a gas turbine combustor

    Science.gov (United States)

    Muthukrishnan, M.; Strahle, W. C.; Neale, D. H.

    1977-01-01

    This paper deals with noise sources which are central to the problem of core engine noise in turbopropulsion systems. The sources dealt with are entropy noise and direct combustion noise, as well as a non-propagating psuedosound which is hydrodynamic noise. It is shown analytically and experimentally that a transition can occur from a combustion noise dominant situation to an entropy noise dominant case if the contraction of a terminating nozzle to the combustor is high enough. In the combustor tested, entropy noise is the dominant source for propagational noise if the combustor is choked at the exit. Analysis techniques include spectral, cross spectral, cross correlation, and ordinary and partial coherence analysis. Measurements include exterior and interior fluctuating and mean pressures and temperatures.

  2. An emissions audit of a biomass combustor burning treated wood waste

    International Nuclear Information System (INIS)

    Jackson, P.M.; Jones, H.H.; King, P.G.

    1993-01-01

    This report describes the Emissions Audit carried out on a Biomass Combustor burning treated wood waste at the premises of a furniture manufacturer. The Biomass Combustor was tested in two firing modes; continuous fire and modulating fire. Combustion chamber temperatures and gas residence times were not measured. Boiler efficiencies were very good at greater than 75% in both tests. However, analysis of the flue gases indicated that improved efficiencies are possible. The average concentrations of CO (512mgm -3 ) and THC (34mgm -3 ) for Test 1 were high, indicating that combustion was poor. The combustor clearly does not meet the requirements of the Guidance Note for the Combustion of Wood Waste. CO 2 and O 2 concentrations were quite variable showing that combustion conditions were fairly unstable. Improved control of combustion should lead to acceptable emission concentrations. (Author)

  3. Investigation of combustion in miniaturised combustor for application to micro gas turbines

    Science.gov (United States)

    Guidez, J.; Roux, P.; Poirson, N.; Jourdanneau, E.; Orain, M.; Grisch, F.

    2009-09-01

    Assessing the feasibility of combustion in miniaturised combustors (volume less than 1 cm3) is a key point for the development of micro gas turbines. This paper presents the results obtained in a combustion chamber operating with a hydrogen-air mixture. A stable combustion was obtained with an output power between 100 and 1200 W, for air mass flow rate from 0.1 to 0.5 g/s, and equivalence ratio between 0.3 and 0.7. Experimental results were obtained using thermocouples to measure temperature of the burnt gases at the outlet of the combustor, and information on combustion efficiency and output power was derived. In addition, laser-based measurements were performed using spontaneous Raman spectroscopy and Rayleigh scattering to determine radial profiles of temperature and main species concentrations at the outlet of the combustor.

  4. The design and testing of a can-type combustor in a compressor test rig

    CSIR Research Space (South Africa)

    Meyers, Bronwyn C

    2017-09-01

    Full Text Available : Start-up Design point Unit Compressor outlet data p3 221627 548506 [Pa] P3 222000 550000 [Pa] T3 295 300 [K] ?̇?𝟑 0.32 1 [kg/s] ?̇?𝒇 0.0071 0.0133 [kg/s] Turbine inlet data T4 - 800 [K] pf 20 20 [%] Combustor 𝑷𝟑𝟒 𝑷𝟑 0.053 0.053 - 𝑷𝟒... would pose little to no effect on the performance of the combustor. Table 2 The revised input values for the preliminary combustor design Condition No.: 1 2 Condition: Start-up Design point Unit Compressor outlet data p3 221627 548506 [Pa] P3...

  5. Utility gas turbine combustor viewing system: Volume 1, Conceptual design and initial field testing: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Morey, W.W.

    1988-12-01

    This report summarizes the development and field testing of a combustor viewing probe (CVP) as a flame diagnostic monitor for utility gas turbine engines. The prototype system is capable of providing a visual record of combustor flame images, recording flame spectral data, analyzing image and spectral data, and diagnosing certain engine malfunctions. The system should provide useful diagnostic information to utility plant operators, and reduce maintenance costs. The field tests demonstrated the ability of the CVP to monitor combustor flame condition and to relate changes in the engine operation with variations in the flame signature. Engine light off, run up to full speed, the addition of load, and the effect of water injection for NO/sub x/ control could easily be identified on the video monitor. The viewing probe was also valuable in identifying hard startups and shutdowns, as well as transient effects that can seriously harm the engine. 11 refs.

  6. Utility gas turbine combustor viewing system: Volume 2, Engine operating envelope test: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Morey, W.W.

    1988-12-01

    This report summarizes the development and field testing of a combustor viewing probe (CVP) as a flame diagnostic monitor for utility gas turbine engines. The prototype system is capable of providing a visual record of combustor flame images, recording flame spectral data, analyzing image and spectral data, and diagnosing certain engine malfunctions. The system should provide useful diagnostic information to utility plant operators, and reduced maintenance costs. The field tests demonstrated the ability of the CVP to monitor combustor flame condition and to relate changes in the engine operation with variations in the flame signature. Engine light off, run up to full speed, the addition of load, and the effect of water injection for NO/sub x/ control could easily be identified on the video monitor. The viewing probe was also valuable in identifying hard startups and shutdowns, as well as transient effects that can seriously harm the engine.

  7. Computational simulation of multi-strut central lobed injection of hydrogen in a scramjet combustor

    Directory of Open Access Journals (Sweden)

    Gautam Choubey

    2016-09-01

    Full Text Available Multi-strut injection is an approach to increase the overall performance of Scramjet while reducing the risk of thermal choking in a supersonic combustor. Hence computational simulation of Scramjet combustor at Mach 2.5 through multiple central lobed struts (three struts have been presented and discussed in the present research article. The geometry and model used here is slight modification of the DLR (German Aerospace Center scramjet model. Present results show that the presence of three struts injector improves the performance of scramjet combustor as compared to single strut injector. The combustion efficiency is also found to be highest in case of three strut fuel injection system. In order to validate the results, the numerical data for single strut injection is compared with experimental result which is taken from the literature.

  8. Design and Performance of a Low Btu Fuel Rich-Quench-Lean Gas Turbine Combustor

    Energy Technology Data Exchange (ETDEWEB)

    Feitelberg, A.S.; Jackson, M.R.; Lacey, M.A.; Manning, K.S.; Ritter, A.M.

    1996-12-31

    General Electric Company is developing gas turbines and a high temperature desulfurization system for use in integrated gasification combined cycle (IGCC) power plants. High temperature desulfurization, or hot gas cleanup (HGCU), offers many advantages over conventional low temperature desulfurization processes, but does not reduce the relatively high concentrations of fuel bound nitrogen (FBN) that are typically found in low Btu fuel. When fuels containing bound nitrogen are burned in conventional gas turbine combustors, a significant portion of the FBN is converted to NO{sub x}. Methods of reducing the NO{sub x} emissions from IGCC power plants equipped with HGCU are needed. Rich-quench-lean (RQL) combustion can decrease the conversion of FBN to NO{sub x} because a large fraction of the FBN is converted into non-reactive N{sub 2} in a fuel rich stage. Additional air, required for complete combustion, is added in a quench stage. A lean stage provides sufficient residence time for complete combustion. Objectives General Electric has developed and tested a rich-quench-lean gas turbine combustor for use with low Btu fuels containing FBN. The objective of this work has been to design an RQL combustor that has a lower conversion of FBN to N{sub x} than a conventional low Btu combustor and is suitable for use in a GE heavy duty gas turbine. Such a combustor must be of appropriate size and scale, configuration (can-annular), and capable of reaching ``F`` class firing conditions (combustor exit temperature = 2550{degrees}F).

  9. Understanding and predicting bed humidity in fluidized bed granulation.

    Science.gov (United States)

    Hu, Xinhui; Cunningham, John; Winstead, Denita

    2008-04-01

    Bed humidity is a critical parameter that needs to be controlled in a fluidized bed granulation to ensure reliability. To predict and control the bed humidity during the fluidized bed granulation process, a simple model based on the mass conservation of moisture was developed. The moisture mass balance model quantitatively simulates the effects of spray rate, binder solution concentration, airflow rate, inlet air temperature, and dew point on the bed humidity. The model was validated by a series of granulations performed in different scale granulators including Glatt GPCG-1, GPCG-15, and GPCG-60. Good agreement was observed between the theoretical prediction and the measured loss on drying (LOD). The model developed in the current work enables us to choose the appropriate parameters for the fluidized bed granulation and can be used as a valuable tool in process scaling-up. 2007 Wiley-Liss, Inc

  10. Shock-tunnel combustor testing for hypersonic vehicles

    Science.gov (United States)

    Loomis, Mark P.

    1994-01-01

    Proposed configurations for the next generation of transatmospheric vehicles will rely on air breathing propulsion systems during all or part of their mission. At flight Mach numbers greater than about 7 these engines will operate in the supersonic combustion ramjet mode (scramjet). Ground testing of these engine concepts above Mach 8 requires high pressure, high enthalpy facilities such as shock tunnels and expansion tubes. These impulse, or short duration facilities have test times on the order of a millisecond, requiring high speed instrumentation and data systems. One such facility ideally suited for scramjet testing is the NASA-Ames 16-Inch shock tunnel, which over the last two years has completed a series of tests for the NASP (National Aero-Space Plane) program at simulated flight Mach numbers ranging from 12-16. The focus of the experimental programs consisted of a series of classified tests involving a near-full scale hydrogen fueled scramjet combustor model in the semi-free jet method of engine testing whereby the compressed forebody flow ahead of the cowl inlet is reproduced (see appendix A). The AIMHYE-1 (Ames Integrated Modular Hypersonic Engine) test entry for the NASP program was completed in April 1993, while AIMHYE-2 was completed in May 1994. The test entries were regarded as successful, resulting in some of the first data of its kind on the performance of a near full scale scramjet engine at Mach 12-16. The data was distributed to NASP team members for use in design system verification and development. Due to the classified nature of the hardware and data, the data reports resulting from this work are classified and have been published as part of the NASP literature. However, an unclassified AIAA paper resulted from the work and has been included as appendix A. It contains an overview of the test program and a description of some of the important issues.

  11. Formed platelet combustor liner construction feasibility, phase A

    Science.gov (United States)

    Hayes, W. A.; Janke, D. E.

    1992-09-01

    Environments generated in high pressure liquid rocket engines impose severe requirements on regeneratively cooled combustor liners. Liners fabricated for use in high chamber pressures using conventional processes suffer from limitations that can impair operational cycle life and can adversely affect wall compatibility. Chamber liners fabricated using formed platelet technology provide an alternative to conventional regeneratively cooled liners (an alternative that has many attractive benefits). A formed platelet liner is made from a stacked assembly of platelets with channel features. The assembly is diffusion bonded into a flat panel and then three-dimensionally formed into a section of a chamber. Platelet technology permits the liner to have very precisely controlled and thin hot gas walls and therefore increased heat transfer efficiency. Further cooling efficiencies can be obtained through enhanced design flexibility. These advantages translate into increased cycle life and enhanced wall compatibility. The increased heat transfer efficiency can alternately be used to increase engine performance or turbopump life as a result of pressure drop reductions within the regeneratively cooled liner. Other benefits can be obtained by varying the materials of construction within the platelet liner to enhance material compatibility with operating environment or with adjoining components. Manufacturing cost savings are an additional benefit of a formed platelet liner. This is because of reduced touch labor and reduced schedule when compared to conventional methods of manufacture. The formed platelet technology is not only compatible with current state-of-the art combustion chamber structural support and manifolding schemes, it is also an enabling technology that allows the use of other high performance and potentially low cost methods of construction for the entire combustion chamber assembly. The contract under which this report is submitted contains three phases: (1) phase

  12. Coal Bed Methane Primer

    Energy Technology Data Exchange (ETDEWEB)

    Dan Arthur; Bruce Langhus; Jon Seekins

    2005-05-25

    During the second half of the 1990's Coal Bed Methane (CBM) production increased dramatically nationwide to represent a significant new source of income and natural gas for many independent and established producers. Matching these soaring production rates during this period was a heightened public awareness of environmental concerns. These concerns left unexplained and under-addressed have created a significant growth in public involvement generating literally thousands of unfocused project comments for various regional NEPA efforts resulting in the delayed development of public and fee lands. The accelerating interest in CBM development coupled to the growth in public involvement has prompted the conceptualization of this project for the development of a CBM Primer. The Primer is designed to serve as a summary document, which introduces and encapsulates information pertinent to the development of Coal Bed Methane (CBM), including focused discussions of coal deposits, methane as a natural formed gas, split mineral estates, development techniques, operational issues, producing methods, applicable regulatory frameworks, land and resource management, mitigation measures, preparation of project plans, data availability, Indian Trust issues and relevant environmental technologies. An important aspect of gaining access to federal, state, tribal, or fee lands involves education of a broad array of stakeholders, including land and mineral owners, regulators, conservationists, tribal governments, special interest groups, and numerous others that could be impacted by the development of coal bed methane. Perhaps the most crucial aspect of successfully developing CBM resources is stakeholder education. Currently, an inconsistent picture of CBM exists. There is a significant lack of understanding on the parts of nearly all stakeholders, including industry, government, special interest groups, and land owners. It is envisioned the Primer would being used by a variety of

  13. Bed Rest Muscular Atrophy

    Science.gov (United States)

    Greenleaf, John E.

    2000-01-01

    A major debilitating response from prolonged bed rest (BR) is muscle atrophy, defined as a "decrease in size of a part of tissue after full development has been attained: a wasting away of tissue as from disuse, old age, injury or disease". Part of the complicated mechanism for the dizziness, increased body instability, and exaggerated gait in patients who arise immediately after BR may be a result of not only foot pain, but also of muscular atrophy and associated reduction in lower limb strength. Also, there seems to be a close association between muscle atrophy and bone atrophy. A discussion of many facets of the total BR homeostatic syndrome has been published. The old adage that use determines form which promotes function of bone (Wolff's law) also applies to those people exposed to prolonged BR (without exercise training) in whom muscle atrophy is a consistent finding. An extreme case involved a 16-year-old boy who was ordered to bed by his mother in 1932: after 50 years in bed he had "a lily-white frame with limbs as thin as the legs of a ladder-back chair". These findings emphasize the close relationship between muscle atrophy and bone atrophy. In addition to loss of muscle mass during deconditioning, there is a significant loss of muscle strength and a decrease in protein synthesis. Because the decreases in force (strength) are proportionately greater than those in fiber size or muscle cross-sectional area, other contributory factors must be involved; muscle fiber dehydration may be important.

  14. Development program on pressurized fluidized-bed combustion. Annual report, July 1975--June 1976

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, G.J.; Johnson, I.; Cunningham, P.T.

    1976-07-01

    The feasibility of using fluidized-bed combustors in power and steam plants is being evaluated. The concept involves burning fuels such as coal in a fluidized bed of either a limestone (CaCO/sub 3/) or a synthetically prepared calcium-containing stone. The calcium reacts with the sulfur to form CaSO/sub 4/, which remains in the bed, thus decreasing the level of SO/sub 2/ in the flue gas. Levels of NO/sub x/ in the flue gas are low. In a separate step, the CaSO/sub 4/ is regenerated to CaO by reductive decomposition at Ca/sub solar/ 1100/sup 0/C for reuse in the combustor. Progress is reported on the following: the effect of regeneration operating variables on extent of regeneration and SO/sub 2/ concentration in the off-gas using coal as the source of reducing agent and of heat; the alternate combustion and regeneration behavior of stone; the rate and extent of sulfation of agents impregnated on Al/sub 2/O/sub 3/; the effect of variables on sorption and release of sulfur for CaO-impregnated stone; attrition resistance of stone; the kinetic and structural changes occurring during half-calcination of dolomite; the CaS-CaSO/sub 4/ regeneration reaction; and the volatility of trace elements when heating coal ash. Procurement and disposal of regenerated stone, minimum fluidization studies, modeling of a gas-solid combustion reaction and of the regeneration process, combustion studies using different sizes of coal and additive and also using lignite are reported.

  15. Particle bed reactor modeling

    Science.gov (United States)

    Sapyta, Joe; Reid, Hank; Walton, Lew

    The topics are presented in viewgraph form and include the following: particle bed reactor (PBR) core cross section; PBR bleed cycle; fuel and moderator flow paths; PBR modeling requirements; characteristics of PBR and nuclear thermal propulsion (NTP) modeling; challenges for PBR and NTP modeling; thermal hydraulic computer codes; capabilities for PBR/reactor application; thermal/hydralic codes; limitations; physical correlations; comparison of predicted friction factor and experimental data; frit pressure drop testing; cold frit mask factor; decay heat flow rate; startup transient simulation; and philosophy of systems modeling.

  16. Flow aerodynamics modeling of an MHD swirl combustor - calculations and experimental verification

    International Nuclear Information System (INIS)

    Gupta, A.K.; Beer, J.M.; Louis, J.F.; Busnaina, A.A.; Lilley, D.G.

    1981-01-01

    This paper describes a computer code for calculating the flow dynamics of constant density flow in the second stage trumpet shaped nozzle section of a two stage MHD swirl combustor for application to a disk generator. The primitive pressure-velocity variable, finite difference computer code has been developed to allow the computation of inert nonreacting turbulent swirling flows in an axisymmetric MHD model swirl combustor. The method and program involve a staggered grid system for axial and radial velocities, and a line relaxation technique for efficient solution of the equations. Tue produces as output the flow field map of the non-dimensional stream function, axial and swirl velocity. 19 refs

  17. Simulations of NOx Emissions from Low Emissions Discrete Jet Injector Combustor Tests

    Science.gov (United States)

    Ajmani, Kumud; Breisacher, Kevin

    2014-01-01

    An experimental and computational study was conducted to evaluate the performance and emissions characteristics of a candidate Lean Direct Injection (LDI) combustor configuration with a mix of simplex and airblast injectors. The National Combustion Code (NCC) was used to predict the experimentally measured EINOx emissions for test conditions representing low power, medium power, and high-power engine cycle conditions. Of the six cases modeled with the NCC using a reduced-kinetics finite-rate mechanism and lagrangian spray modeling, reasonable predictions of combustor exit temperature and EINOx were obtained at two high-power cycle conditions.

  18. System for reducing combustion dynamics and NO.sub.x in a combustor

    Science.gov (United States)

    Uhm, Jong Ho; Ziminsky, Willy Steve; Johnson, Thomas Edward; Hughes, Michael John; York, William David

    2016-05-31

    A combustor includes an end cap that extends radially across at least a portion of the combustor. The end cap includes an upstream surface axially separated from a downstream surface. A plurality of tubes extend from the upstream surface through the downstream surface of the end cap to provide fluid communication through the end cap. Each tube in a first set of the plurality of tubes has an inlet proximate to the upstream surface and an outlet downstream from the downstream surface. Each outlet has a first portion that extends a different axial distance from the inlet than a second portion.

  19. Parametric performance of a turbojet engine combustor using jet A and A diesel fuel

    Science.gov (United States)

    Butze, H. F.; Humenik, F. M.

    1979-01-01

    The performance of a single-can JT8D combustor was evaluated with Jet A and a high-aromatic diesel fuel over a parametric range of combustor-inlet conditions. Performance parameters investigated were combustion efficiency, emissions of CO, unburned hydrocarbons, and NOx, as well as liner temperatures and smoke. At all conditions the use of diesel fuel instead of Jet A resulted in increases in smoke numbers and liner temperatures; gaseous emissions, on the other hand, did not differ significantly between the two fuels.

  20. Circulating fluidized bed tehnology in biomass combustion-performance, advances and experiences

    Energy Technology Data Exchange (ETDEWEB)

    Mutanen, K.I. [A. Ahlstrom Corporation, Varkaus (Finland)

    1995-11-01

    Development of fluidized bed combustion (FBC) was started both in North America and in Europe in the 1960`s. In Europe and especially in Scandinavia the major driving force behind the development was the need to find new more efficient technologies for utilization of low-grade fuels like different biomasses and wastes. Both bubbling fluidized bed (BFB) and circulating fluidized bed (CFB) technologies were under intensive R&D,D efforts and have now advanced to dominating role in industrial and district heating power plant markets in Europe. New advanced CFB designs are now entering the markets. In North America and especially in the US the driving force behind the FBC development was initially the need to utilize different types of coals in a more efficient and environmentally acceptable way. The present and future markets seem to be mainly in biomass and multifuel applications where there is benefit from high combustion efficiency, high fuel flexibility and low emissions such as in the pulp and paper industry. The choice between CFB technology and BFB technology is based on selected fuels, emission requirements, plant size and on technical and economic feasibility. Based on Scandinavian experience there is vast potential in the North American industry to retrofit existing oil fired, pulverized coal fired, chemical recovery or grate fired boilers with FBC systems or to build a new FBC based boiler plant. This paper will present the status of CFB technologies and will compare technical and economic feasibility of CFB technology to CFB technology to BFB and also to other combustion methods. Power plant projects that are using advanced CFB technology e.g. Ahlstrom Pyroflow Compact technology for biomass firing and co-firing of biomass with other fuels will also be introduced.

  1. Variability of Bed Drag on Cohesive Beds under Wave Action

    Directory of Open Access Journals (Sweden)

    Ilgar Safak

    2016-04-01

    Full Text Available Drag force at the bed acting on water flow is a major control on water circulation and sediment transport. Bed drag has been thoroughly studied in sandy waters, but less so in muddy coastal waters. The variation of bed drag on a muddy shelf is investigated here using field observations of currents, waves, and sediment concentration collected during moderate wind and wave events. To estimate bottom shear stress and the bed drag coefficient, an indirect empirical method of logarithmic fitting to current velocity profiles (log-law, a bottom boundary layer model for combined wave-current flow, and a direct method that uses turbulent fluctuations of velocity are used. The overestimation by the log-law is significantly reduced by taking turbulence suppression due to sediment-induced stratification into account. The best agreement between the model and the direct estimates is obtained by using a hydraulic roughness of 10 - 4 m in the model. Direct estimate of bed drag on the muddy bed is found to have a decreasing trend with increasing current speed, and is estimated to be around 0.0025 in conditions where wave-induced flow is relatively weak. Bed drag shows an increase (up to fourfold with increasing wave energy. These findings can be used to test the bed drag parameterizations in hydrodynamic and sediment transport models and the skills of these models in predicting flows in muddy environments.

  2. Prediction of bed level variations in nonuniform sediment bed channel

    Indian Academy of Sciences (India)

    B R Andharia

    2018-04-12

    Apr 12, 2018 ... have been undertaken for measurements of bed and water levels in an aggrading channel due to overloading of nonuniform sediments ..... 2.4 Thickness of active bed layer. The mixing zone of sediment remaining in contact with the flow is referred as active layer (ABL). The thickness and particle size ...

  3. Variability of bed drag on cohesive beds under wave action

    Science.gov (United States)

    Safak, Ilgar

    2016-01-01

    Drag force at the bed acting on water flow is a major control on water circulation and sediment transport. Bed drag has been thoroughly studied in sandy waters, but less so in muddy coastal waters. The variation of bed drag on a muddy shelf is investigated here using field observations of currents, waves, and sediment concentration collected during moderate wind and wave events. To estimate bottom shear stress and the bed drag coefficient, an indirect empirical method of logarithmic fitting to current velocity profiles (log-law), a bottom boundary layer model for combined wave-current flow, and a direct method that uses turbulent fluctuations of velocity are used. The overestimation by the log-law is significantly reduced by taking turbulence suppression due to sediment-induced stratification into account. The best agreement between the model and the direct estimates is obtained by using a hydraulic roughness of 10 -4">−4 m in the model. Direct estimate of bed drag on the muddy bed is found to have a decreasing trend with increasing current speed, and is estimated to be around 0.0025 in conditions where wave-induced flow is relatively weak. Bed drag shows an increase (up to fourfold) with increasing wave energy. These findings can be used to test the bed drag parameterizations in hydrodynamic and sediment transport models and the skills of these models in predicting flows in muddy environments.

  4. Fuel Flexible Gas Turbine Combustor Flametube Facility Upgraded

    Science.gov (United States)

    Little, James E.; Nemets, Steve A.; Tornabene, Robert T.; Smith, Timothy D.; Frankenfeld, Bruce J.

    2004-01-01

    In fiscal year 2003, test cell 23 of the Research Combustion Laboratory (RCL 23) at the NASA Glenn Research Center was upgraded with the addition of gaseous hydrogen as a working propellant and the addition of a 450-psig air-supply system. Test flexibility was further enhanced by upgrades to the facility control systems. RCL 23 can now test with gaseous hydrogen flow rates up to 0.05 lbm/sec and jet fuel flow rates up to 0.62 lbm/sec. Research airflow rates up to 3 lbm/sec are possible with the 450-psig supply system over a range of inlet temperatures. Nonvitiated, heated air is supplied from a shell and tube heat exchanger. The maximum nonvitiated facility air temperature is 1100 F at 1.5 lbm/sec. Research-section exhaust temperatures are limited to 3200 F because of material and cooling capacity limits. A variety of support systems are available depending on the research hardware configuration. Test section ignition can be provided via either a hydrogen air torch system or an electronic spark system. Emissions measurements are obtained with either pneumatically or electromechanically actuated gas sample probes, and the electromechanical system allows for radial measurements at a user-specified axial location for measurement of emissions profiles. Gas analysis data can be obtained for a variety of species, including carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NO and NOx), oxygen (O2), unburnt hydrocarbons, and unburnt hydrogen. Facility control is accomplished with a programmable logic control system. Facility operations have been upgraded to a system based on graphical user interface control screens. A data system is available for real-time acquisition and monitoring of both measurements in engineering units and performance calculations. The upgrades have made RCL 23 a highly flexible facility for research into low emissions gas turbine combustor concepts, and the flame tube configuration inherently allows for a variety of fuel nozzle

  5. Investigation of Combustion Control in a Dump Combustor Using the Feedback Free Fluidic Oscillator

    Science.gov (United States)

    Meier, Eric J.; Casiano, Matthew J.; Anderson, William E.; Heister, Stephen D.

    2015-01-01

    A feedback free fluidic oscillator was designed and integrated into a single element rocket combustor with the goal of suppressing longitudinal combustion instabilities. The fluidic oscillator uses internal fluid dynamics to create an unsteady outlet jet at a specific frequency. An array of nine fluidic oscillators was tested to mimic modulated secondary oxidizer injection into the combustor dump plane. The combustor has a coaxial injector that uses gaseous methane and decomposed hydrogen peroxide with an overall O/F ratio of 11.7. A sonic choke plate on an actuator arm allows for continuous adjustment of the oxidizer post acoustics enabling the study of a variety of instability magnitudes. The fluidic oscillator unsteady outlet jet performance is compared against equivalent steady jet injection and a baseline design with no secondary oxidizer injection. At the most unstable operating conditions, the unsteady outlet jet saw a 67% reduction in the instability pressure oscillation magnitude when compared to the steady jet and baseline data. Additionally, computational fluid dynamics analysis of the combustor gives insight into the flow field interaction of the fluidic oscillators. The results indicate that open loop high frequency propellant modulation for combustion control can be achieved through fluidic devices that require no moving parts or electrical power to operate.

  6. Large Engine Technology Program. Task 22: Variable Geometry Concepts for Rich-Quench-Lean Combustors

    Science.gov (United States)

    Tacina, Robert R. (Technical Monitor); Cohen, J. M.; Padget, F. C.; Kwoka, D.; Wang, Q.; Lohmann, R. P.

    2005-01-01

    The objective of the task reported herein was to define, evaluate, and optimize variable geometry concepts suitable for use with a Rich-Quench-Lean (RQL) combustor. The specific intent was to identify approaches that would satisfy High Speed Civil Transport (HSCT) cycle operational requirements with regard to fuel-air ratio turndown capability, ignition, and stability margin without compromising the stringent emissions, performance, and reliability goals that this combustor would have to achieve. Four potential configurations were identified and three of these were refined and tested in a high-pressure modular RQL combustor rig. The tools used in the evolution of these concepts included models built with rapid fabrication techniques that were tested for airflow characteristics to confirm sizing and airflow management capability, spray patternation, and atomization characterization tests of these models and studies that were supported by Computational Fluid Dynamics analyses. Combustion tests were performed with each of the concepts at supersonic cruise conditions and at other critical conditions in the flight envelope, including the transition points of the variable geometry system, to identify performance, emissions, and operability impacts. Based upon the cold flow characterization, emissions results, acoustic behavior observed during the tests and consideration of mechanical, reliability, and implementation issues, the tri-swirler configuration was selected as the best variable geometry concept for incorporation in the RQL combustor evolution efforts for the HSCT.

  7. Compact Combustor Integrated (CI) with Compressor and Turbine for Perspective Turbojet Engine

    Science.gov (United States)

    Strokin, V. N.; Volkov, S. A.; Ljashenko, V. P.; Popov, V. I.; Startzev, A. N.; Nigmatullin, R. Z.; Shilova, T. V.; Belikov, U. V.

    2017-11-01

    For several years, CIAM has conducted comprehensive work on the development the combustor integrated (CI) with air swirling. This project involved an integrated development of three components: diffuser, combustion chamber and nozzle guide vanes of turbine to reduce their length and, respectively, the length of the engine and obtain high performance elements with low emissions of harmful substances. The new frontal device was proposed for CI combustor. The design optimization of this type combustor was conducted in the compartments and in a full-size combustion chamber. It was shown the possibility of obtaining high combustion efficiency and low NOx emissions at a short length on cruise condition. By a simplified model of the frontal device it was shown experimentally that the proposed device provided a lighting-up and flame spreading in a wide range of equivalence ratio ER (ER > 0.014) at idling. It was shown that short vane diffuser with moderate swirling ensured high parameters of the combustion chamber. The use of residual swirling of the combustion products at the exit of combustor allows reducing the size, or the number of nozzle guide vanes of the turbine. In General, the use of the swirling of the air stream gives a possibility of total length reduction for all three elements by about 20 – 25 %.

  8. Experimental evaluation of sorbents for sulfur control in a coal-fueled gas turbine slagging combustor

    International Nuclear Information System (INIS)

    Cowell, L.H.; Wen, C.S.; LeCren, R.T.

    1992-01-01

    This paper reports on a slagging combustor that has been used to evaluate three calcium-based sorbents for sulfur capture efficiency in order to assess their applicability for use in a oil-fueled gas turbine. Testing is competed in a bench-scale combustor with one-tenth the heat input needed for the full-scale gas turbine. The bench-scale rig is a two-stage combustor featuring a fuel-rich primary zone an a fuel-lean secondary zone. The combustor is operated at 6.5 bars with inlet air preheated to 600 K. Gas temperatures of 1840 K are generated in the primary zone and 1280 K in the secondary zone. Sorbents are either fed into the secondary zone or mixed with the coal-water mixture and fed into the primary zone. Dry powered sorbents are fed into the secondary zone by an auger into one of six secondary air inlet ports. The three sorbents tested in the secondary zone include dolomite, pressure-hydrated dolomitic lime, and hydrated lime. Sorbents have been tested while burning coal-water mixtures with coal sulfur loadings of 0.56 to 3.13 weight percent sulfur. Sorbents are injected into the secondary zone at varying flow rates such that the calcium/sulfur ratio varies from 0.5 to 10.0

  9. Bioethanol combustion in an industrial gas turbine combustor: simulations and experiments

    NARCIS (Netherlands)

    Sallevelt, J.L.H.P.; Pozarlik, Artur Krzysztof; Beran, Martin; Axelsson, L.; Brem, Gerrit

    2014-01-01

    Combustion tests with bioethanol and diesel as a reference have been performed in OPRA's 2 MWe class OP16 gas turbine combustor. The main purposes of this work are to investigate the combustion quality of ethanol with respect to diesel and to validate the developed CFD model for ethanol spray

  10. Experimental and numerical studies of a lean-burn internally-staged combustor

    Directory of Open Access Journals (Sweden)

    Fu Zhenbo

    2014-06-01

    Full Text Available A lean-burn internally-staged combustor for low emissions that can be used in civil aviation gas turbines is introduced in this paper. The main stage is designed and optimized in terms of fuel evaporation ratio, fuel/air pre-mixture uniformity, and particle residence time using commercial computational fluid dynamics (CFD software. A single-module rectangular combustor is adopted in performance tests including lean ignition, lean blowout, combustion efficiency, emissions, and combustion oscillation using aviation kerosene. Furthermore, nitrogen oxides (NOx emission is also predicted using CFD simulation to compare with test results. Under normal inlet temperature, this combustor can be ignited easily with normal and negative inlet pressures. The lean blowout fuel/air ratio (LBO FAR at the idle condition is 0.0049. The fuel split proportions between the pilot and main stages are determined through balancing emissions, combustion efficiency, and combustion oscillation. Within the landing and take-off (LTO cycle, this combustor enables 42% NOx reduction of the standard set by the 6th Committee on Aviation Environmental Protection (CAEP/6 with high combustion efficiency. The maximum board-band pressure oscillations of inlet air and fuel are below 1% of total pressure during steady-state operations at the LTO cycle specific conditions.

  11. Genetic algorithm to optimize the design of main combustor and gas generator in liquid rocket engines

    Science.gov (United States)

    Son, Min; Ko, Sangho; Koo, Jaye

    2014-06-01

    A genetic algorithm was used to develop optimal design methods for the regenerative cooled combustor and fuel-rich gas generator of a liquid rocket engine. For the combustor design, a chemical equilibrium analysis was applied, and the profile was calculated using Rao's method. One-dimensional heat transfer was assumed along the profile, and cooling channels were designed. For the gas-generator design, non-equilibrium properties were derived from a counterflow analysis, and a vaporization model for the fuel droplet was adopted to calculate residence time. Finally, a genetic algorithm was adopted to optimize the designs. The combustor and gas generator were optimally designed for 30-tonf, 75-tonf, and 150-tonf engines. The optimized combustors demonstrated superior design characteristics when compared with previous non-optimized results. Wall temperatures at the nozzle throat were optimized to satisfy the requirement of 800 K, and specific impulses were maximized. In addition, the target turbine power and a burned-gas temperature of 1000 K were obtained from the optimized gas-generator design.

  12. EMISSION TEST REPORT- FIELD TEST OF CARBON INJECTION FOR MERCURY CONTROL, CAMDEN COUNTY MUNICIPAL WASTE COMBUSTOR

    Science.gov (United States)

    The report gives results of parametric test to evaluate the injection powdered activated carbon to control volatile pollutants in municipal waste combustor (MWC) flue gas. he tests were conducted at a spray dryer absorber/electrostatic precipitator (SD/ESP)-equipped MWC in Camden...

  13. 3D Measurements of Ignition Processes at 20 kHz in a Supersonic Combustor

    Science.gov (United States)

    2015-03-05

    Wehe, 3D Flame Measurements at 5 kHz on a Jet Fueled Aviation Combustor. ASME Turbo Expo 2015 (2014) 10. M. Kang, Q. Lei, L. Ma, Characterization of...Geipel, A.M. Kempf, Computed tomography of chemiluminescence (CTC): instantaneous 3D measurements and phantom studies of a turbulent opposed jet

  14. Overview of experimental measurements in a generic can-type gas turbine combustor

    CSIR Research Space (South Africa)

    Meyers, BC

    2009-11-01

    Full Text Available Due to CFD Shortfalls, experimental data on gas turbine combustors is required to obtain insight into the combustion and flow mechanisms as well as for simulation and model validation and evaluation. The temperature and velocity fields of a generic...

  15. Evaluation of fuel injection configurations to control carbon and soot formation in small GT combustors

    Science.gov (United States)

    Rosfjord, T. J.; Briehl, D.

    1982-01-01

    An experimental program to investigate hardware configurations which attempt to minimize carbon formation and soot production without sacrificing performance in small gas turbine combustors has been conducted at the United Technologies Research Center. Four fuel injectors, embodying either airblast atomization, pressure atomization, or fuel vaporization techniques, were combined with nozzle air swirlers and injector sheaths, and evaluated at test conditions which included and extended beyond standard small gas turbine combustor operation. Extensive testing was accomplished with configurations embodying either a spill return or a T-vaporizer injector. Minimal carbon deposits were observed on the spill return nozzle for tests using either Jet A or ERBS test fuel. A more extensive film of soft carbon was observed on the vaporizer after operation at standard engine conditions, with large carbonaceous growths forming on the device during off-design operation at low combustor inlet temperature. Test results indicated that smoke emission levels depended on the combustor fluid mechanics (especially the mixing rates near the injector), the atomization quality of the injector and the fuel hydrogen content.

  16. Simulation Investigation on Combustion Characteristics in a Four-Point Lean Direct Injection Combustor with Hydrogen/Air

    Directory of Open Access Journals (Sweden)

    Jianzhong Li

    2017-06-01

    Full Text Available To investigate the combustion characteristics in multi-point lean direct injection (LDI combustors with hydrogen/air, two swirl–venturi 2 × 2 array four-point LDI combustors were designed. The four-point LDI combustor consists of injector assembly, swirl–venturi array and combustion chamber. The injector, swirler and venturi together govern the rapid mixing of hydrogen and air to form the mixture for combustion. Using clockwise swirlers and anticlockwise swirlers, the co-swirling and count-swirling swirler arrays LDI combustors were achieved. Using Reynolds-Averaged Navier–Stokes (RANS code for steady-state reacting flow computations, the four-point LDI combustors with hydrogen/air were simulated with an 11 species and 23 lumped reaction steps H2/Air reaction mechanism. The axial velocity, turbulence kinetic energy, total pressure drop coefficient, outlet temperature, mass fraction of OH and emission of pollutant NO of four-point LDI combustors, with different equivalence ratios, are here presented and discussed. As the equivalence ratios increased, the total pressure drop coefficient became higher because of increasing heat loss. Increasing equivalence ratios also corresponded with the rise in outlet temperature of the four-point LDI combustors, as well as an increase in the emission index of NO EINO in the four-point LDI combustors. Along the axial distance, the EINO always increased and was at maximum at the exit of the dump. Along the chamber, the EINO gradually increased, maximizing at the exit of chamber. The total temperature of four-point LDI combustors with different equivalence ratios was identical to the theoretical equilibrium temperature. The EINO was an exponential function of the equivalence ratio.

  17. Co-combustion of coal and non-recyclable paper & plastic waste in a fluidised bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Boavida, D.; Abelha, P.; Gulyurtlu, I.; Cabrita, I. [DEECA-INETI, Lisbon (Portugal)

    2002-07-01

    Co-combustion of waste with coal was carried out using a fluidised bed combustor with the aim of achieving a fuel mixture with little variations in its heating value and simultaneously reducing the accumulation of non-toxic waste material by upgrading them for energy purposes. Results obtained indicate that the feeding of waste materials could present serious problems which could render conditions for a stable combustion difficult to achieve. The waste was fed mixed with coal and there was some difference observed in results regarding the combustion efficiency and emissions. Part of the combustion of waste material, contrary to that of coal, was observed to take place in the freeboard where the temperature was as much as 150{degree}C above that of the bed. 6 refs., 8 figs., 8 tabs.

  18. The development of an integrated multistaged fluid-bed retorting process. Final report, September 1990--August 1994

    Energy Technology Data Exchange (ETDEWEB)

    Carter, S.D.; Taulbee, D.N.; Stehn, J.L.; Vego, A.; Robl, T.L.

    1995-02-01

    This summarizes the development of the KENTORT II retorting process, which includes integral fluidized bed zones for pyrolysis, gasification, and combustion of oil shale. Purpose was to design and test the process at the 50-lb/hr scale. The program included bench- scale studies of coking and cracking reactions of shale oil vapors over processed shale particles to address issues of scaleup associated with solid-recycle retorting. The bench-scale studies showed that higher amounts of carbon coverage reduce the rate of subsequent carbon deposition by shale oil vapors onto processed shale particles; however carbon-covered materials were also active in terms of cracking and coking. Main focus was the 50-lb/hr KENTORT II PDU. Cold-flow modeling and shakedown were done before the PDU was made ready for operation. Seven mass-balanced, steady-state runs were completed within the window of design operating conditions. Goals were achieved: shale feedrate, run duration (10 hr), shale recirculation rates (4:1 to pyrolyzer and 10:1 to combustor), bed temperatures (pyrolyzer 530{degree}C, gasifier 750{degree}C, combustor 830{degree}C), and general operating stability. Highest oil yields (up to 109% of Fischer assay) were achieved for runs lasting {ge} 10 hours. High C content of the solids used for heat transfer to the pyrolysis zone contributed to the enhanced oil yield achieved.

  19. Effectiveness of Bed Bug Pesticides

    Science.gov (United States)

    Before EPA allows a bed bug claim on a label, the product must be supported by data showing it will kill bed bugs when applied according to the label. Also consider factors such as extent of infestation, site preparation, and insect life stages.

  20. Turning patients over in bed

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000426.htm Turning patients over in bed To use the sharing features on this page, ... Patient The following steps should be followed when turning a patient: If you can, raise the bed to a level that reduces back strain for ...

  1. Characterisation of Interaction between Combustion Dynamics and Equivalence Ratio Oscillations in a Pressurised Combustor

    Directory of Open Access Journals (Sweden)

    Jaap F. van Kampen

    2010-09-01

    Full Text Available In regular operation, all gas turbine combustors have a significant spontaneous noise level induced by the turbulent high power flame. This noise is characteristic for the operation as it is the result of the interaction between turbulence and combustion. Pressure fluctuations may also be generated by thermoacoustic instabilities induced by amplification by the flame of the acoustic field in the combustor. This paper focuses on the characterisation of the latter process, the combustion dynamics, in a pressurized premixed natural gas combustor. In order to predict the thermo-acoustically unstable operating ranges of modern gas-turbines with the use of an acoustic network model, it is essential to determine accurately the flame transfer function. This transfer function gives the relationship between a perturbation upstream of the flame and its combustion response, leading to acoustic forcing. In this paper, the flame transfer function is obtained by experimental means in a combustor test rig. This test rig was built in the framework of the European DESIRE project, and has the ability to perform thermo-acoustic measurements up to an absolute pressure of 5 bars. The maximum power of the setup is 500 kW. The paper presents a method to determine the flame transfer function by factorizing it in six subfunctions. Systematically these subfunctions are determined. With the method presented, acoustic measurements on the steady, unperturbed flame and on the unsteady, actively perturbed flame are performed. The effect of pressure is investigated. The steady measurements are used to provide an acousto-combustion finger print of the combustor. In the unsteady measurements, the flame transfer function is reconstructed from the measured acoustic pressures. These flame transfer functions are compared to transfer functions obtained from a numerical experiment in CFD. Good agreement is obtained.

  2. Thermal characteristics of various biomass fuels in a small-scale biomass combustor

    International Nuclear Information System (INIS)

    Al-Shemmeri, T.T.; Yedla, R.; Wardle, D.

    2015-01-01

    Biomass combustion is a mature and reliable technology, which has been used for heating and cooking. In the UK, biomass currently qualifies for financial incentives such as the Renewable Heat Incentive (RHI). Therefore, it is vital to select the right type of fuel for a small-scale combustor to address different types of heat energy needs. In this paper, the authors attempt to investigate the performance of a small-scale biomass combustor for heating, and the impact of burning different biomass fuels on useful output energy from the combustor. The test results of moisture content, calorific value and combustion products of various biomass samples were presented. Results from this study are in general agreement with published data as far as the calorific values and moisture contents are concerned. Six commonly available biomass fuels were tested in a small-scale combustion system, and the factors that affect the performance of the system were analysed. In addition, the study has extended to examine the magnitude and proportion of useful heat, dissipated by convection and radiation while burning different biomass fuels in the small-scale combustor. It is concluded that some crucial factors have to be carefully considered before selecting biomass fuels for any particular heating application. - Highlights: • Six biomass materials combustion performance in a small combustor was examined. • Fuel combustion rate and amount of heat release has varied between materials. • Heat release by radiation, convection and flue gasses varied between materials. • Study helps engineers and users of biomass systems to select right materials

  3. Investigation of Methane Oxy-Fuel Combustion in a Swirl-Stabilised Gas Turbine Model Combustor

    Directory of Open Access Journals (Sweden)

    Mao Li

    2017-05-01

    Full Text Available CO2 has a strong impact on both operability and emission behaviours in gas turbine combustors. In the present study, an atmospheric, preheated, swirl-stabilised optical gas turbine model combustor rig was employed. The primary objectives were to analyse the influence of CO2 on the fundamental characteristics of combustion, lean blowout (LBO limits, CO emission and flame structures. CO2 dilution effects were examined with three preheating temperatures (396.15, 431.15, and 466.15 K. The fundamental combustion characteristics were studied utilising chemical kinetic simulations. To study the influence of CO2 on the operational range of the combustor, equivalence ratio (Ф was varied from stoichiometric conditions to the LBO limits. CO emissions were measured at the exit of the combustor using a water-cooled probe over the entire operational range. The flame structures and locations were characterised by performing CH chemiluminescence imaging. The inverse Abel transformation was used to analyse the CH distribution on the axisymmetric plane of the combustor. Chemical kinetic modelling indicated that the CO2 resulted in a lower reaction rate compared with the CH4/air flame. Fundamental combustion properties such as laminar flame speed, ignition delay time and blowout residence time were found to be affected by CO2. The experimental results revealed that CO2 dilution resulted in a narrower operational range for the equivalence ratio. It was also found that CO2 had a strong inhibiting effect on CO burnout, which led to a higher concentration of CO in the combustion exhaust. CH chemiluminescence showed that the CO2 dilution did not have a significant impact on the flame structure.

  4. The combustion of coal blends in a fluidised bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Boavida, Dulce; Abelha, Pedro; Gulyurtlu, Ibrahim; Cabrita, Isabel

    1999-07-01

    Combustion studies of five coals of different origin were carried out in a laboratory scale fluidised bed combustor. Five blends prepared by mixing two coals based on their petrological characterisation, in varying amounts, were selected to study the possibility of reduction NO{sub x}, N{sub 2}O and SO{sub 2} emissions. The results showed that some blends had the opposite behaviour concerning the release of NO{sub x} and SO{sub 2} in relation to parent coals, and the emissions were higher than expected. The N{sub 2}O amounts observed were, however, in almost all blends tested, lower than predicted values. With some blends, the mixing levels intended to reduce SO{sub 2} were not always found to correspond to those for simultaneous decrease of Nox. Most of the blends studied showed some evidence of interaction between them. Varying the proportion of the blend components was observed to alter the temperatures at which interactions were stronger.

  5. FY 1992 report on the results of the development of an entrained bed coal gasification power plant. Part 1. Element study/Technical survey; 1992 nendo seika hokokusho. Funryusho sekitan gaska hatsuden plant kaihatsu - Sono 1. Youso kenkyu hen, gijutsu chosa hen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-02-01

    For the purpose of establishing the technology of the integrated coal gasification combined cycle power generation, element study of a 200 t/d entrained bed coal gasification pilot plant was made, and the FY 1992 results were summarized. In the gasification test using a 2 t/d furnace equipment, study was made of the extraction of subjects on the operation, performance of gasification, slagging characteristics and characteristics of flux addition. In the study of slag utilization technology, chemical analysis, test on fine aggregate and test on fine particle were carried out to study applicability of the slag discharged from the entrained bed coal gasification power plant to various materials. In the study of a large gas turbine combustor for the demonstrative machine, the demonstrative machine use large gas turbine combustor testing equipment was installed at actual pressure/actual size combustion testing facilities in the pilot plant and further the test use combustor was integrated into them. By using them, the real gas combustion test was made using the adjusted coal for evaluation of combustion performance of the test use combustor. In the simulation study of the total pilot plant system, the comparative study was made between the data on the test using the actual machine and the results of the simulation. (NEDO)

  6. Investigation of combustion of coal briquettes in a fluidized bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Boavida, Dulce; Abelha, Pedro; Gulyurtlu, Ibrahim; Cabrita, Isabel

    1999-07-01

    This paper discusses the results obtained from an experimental combustion work undertaken to investigate the behaviour of multicomponent briquettes, prepared by mixing two different particle sizes of coal and two different types of binder species. single briquettes were burned over a wide range of temperatures in a laboratory scale fluidised bed combustor facility. Nitrogen (NO{sub x}, and N{sub 2}O) and Sulphur (SO{sub 2}) oxides emissions resulting from the combustion of these briquettes were constantly monitored during the time of burning. The levels of O{sub 2}, CO{sub 2} and CO were also recorded during the same period. Experimental results showed that coal particle size influenced burn-out times and emissions levels of some of gaseous species. The hinder type was also found to have a major influence on the emissions of different pollutants.The temperature was observed to significantly influence the extent of the effects of the other operating parameters studied.

  7. Reduction of calcium sulfate in a coal-fired circulating fluidized bed furnace

    Energy Technology Data Exchange (ETDEWEB)

    Talukdar, J.; Basu, P.; Greenblatt, J.H. [Technical University of Nova Scotia, Halifax, NS (Canada). Mechanical Engineering Dept.

    1996-07-01

    The overall utilisation of limestone for sulphur capture in a CFB combustor depends on the reactivity of the various calcium species in the bed. To study the re-emission of SO{sub 2} the reactivity of partially sulfated CaO was studied. The material used was bottom ash drained from a 165 MWe commercial CFB boiler furnace. The tests were performed in an electrically heated furnace. Reactivity rate constants were determined from the experimental results. The release of SO{sub 2} from CaSO{sub 4} increases with temperature as well as with the concentration of the reducing agents CO, char and graphite. Of the reducing agents considered, CO is most reactive, followed by char and then graphite. 12 refs., 17 figs., 5 tabs.

  8. SPECIFIC FEATURES OF THE OXYFUEL COMBUSTION CONDITIONS IN A BUBBLING FLUIDIZED BED

    Directory of Open Access Journals (Sweden)

    Pavel Skopec

    2016-08-01

    Full Text Available Oxyfuel combustion is a promising approach for capturing CO2 from power plants. This technology produces a flue gas with a high concentration of CO2. Our paper presents a verification of the oxyfuel combustion conditions in a bubbling fluidized bed combustor. It presents a theoretical analysis of oxyfuel combustion and makes a comparison with combustion using air. It is important to establish a proper methodology for stoichiometric calculations and for computing the basic characteristic fluidization properties. The methodology presented here has been developed for general purposes, and can be applied to calculations for combustion with air and with oxygen-enriched air, and also for full oxyfuel conditions. With this methodology, we can include any water vapour condensation during recirculation of the flue gas when dry flue gas recirculation is used. The paper contains calculations for a lignite coal, which is taken as a reference fuel for future research and for the experiments.

  9. Investigations on the Influence of the In-Stream Pylon and Strut on the Performance of a Scramjet Combustor

    Directory of Open Access Journals (Sweden)

    Hao Ouyang

    2014-01-01

    Full Text Available The influence of the in-stream pylon and strut on the performance of scramjet combustor was experimentally and numerically investigated. The experiments were conducted with a direct-connect supersonic model combustor equipped with multiple cavities. The entrance parameter of combustor corresponds to scramjet flight Mach number 4.0 with a total temperature of 947 K. The research results show that, compared with the scramjet combustor without pylon and strut, the wall pressure and the thrust of the scramjet increase due to the improvement of mixing and combustion effect due to the pylon and strut. The total pressure loss caused by the strut is considerable whereas pylon influence is slight.

  10. Diode Laser Sensor for Gas Temperature and H2O Concentration in a Scramjet Combustor Using Wavelength Modulation Spectroscopy (Postprint)

    National Research Council Canada - National Science Library

    Rieker, Gregory B; Li, Jonathan T; Jeffries, Jay B; Mathur, Tarun; Gruber, Mark R; Carter, Campbell D

    2005-01-01

    A diode laser absorption sensor which probes three spectral features of water vapor in the near infrared region to infer gas temperature and water vapor concentration near the exit of a scramjet combustor is presented...

  11. Experimental study on combustion modes and thrust performance of a staged-combustor of the scramjet with dual-strut

    Science.gov (United States)

    Yang, Qingchun; Chetehouna, Khaled; Gascoin, Nicolas; Bao, Wen

    2016-05-01

    To enable the scramjet operate in a wider flight Mach number, a staged-combustor with dual-strut is introduced to hold more heat release at low flight Mach conditions. The behavior of mode transition was examined using a direct-connect model scramjet experiment along with pressure measurements. The typical operating modes of the staged-combustor are analyzed. Fuel injection scheme has a significant effect on the combustor operating modes, particularly for the supersonic combustion mode. Thrust performances of the combustor with different combustion modes and fuel distributions are reported in this paper. The first-staged strut injection has a better engine performance in the operation of subsonic combustion mode. On the contrast, the second-staged strut injection has a better engine performance in the operation of supersonic combustion mode.

  12. Measurement of alkali-vapor emission from pressurized fluidized-bed combustion of Illinois coals

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.H.D.; Teats, F.G.; Swift, W.M. (Argonne National Lab., IL (United States)); Banerjee, D.D. (Illinois Clean Coal Inst., Carterville, IL (United States))

    1993-01-01

    Two Illinois Herrin No. 6 coals and one Illinois Springfield No. 5 coal were separately combusted in a laboratory-scale (15-cm dia) pressurized fluidized-bed combustor (PFBC) combined with an alkali sorber. These coals were combusted in a fluidized bed of Tymochtee dolomite at temperatures ranging from 910 to 950[degree]C and a system pressure of 9.2 atm absolute. Alkali-vapor emission (Na and K) in the PFBC flue gas was determined by the analytical activated-bauxite sorber bed technique developed at Argonne National Laboratory. The test results showed that sodium is the major alkali-vapor species present in the PFBC flue gas, and that the level of sodium-vapor emission increases linearly with both Na and Cl contents in the coals. This suggests that the sodium-vapor emission results from direct vaporization of NaCl present in the coals. The measured alkali-vapor concentration (Na + K), 67 to 190 ppbW, is more than 2.5 times greater than the allowable alkali limit of 24 ppb for an industrial gas turbine. Combusting these coals in a PFBC for power generation may require developing a method to control alkali vapors.

  13. Measurement of alkali-vapor emission from pressurized fluidized-bed combustion of Illinois coals

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.H.D.; Teats, F.G.; Swift, W.M. [Argonne National Lab., IL (United States); Banerjee, D.D. [Illinois Clean Coal Inst., Carterville, IL (United States)

    1993-04-01

    Two Illinois Herrin No. 6 coals and one Illinois Springfield No. 5 coal were separately combusted in a laboratory-scale (15-cm dia) pressurized fluidized-bed combustor (PFBC) combined with an alkali sorber. These coals were combusted in a fluidized bed of Tymochtee dolomite at temperatures ranging from 910 to 950{degree}C and a system pressure of 9.2 atm absolute. Alkali-vapor emission (Na and K) in the PFBC flue gas was determined by the analytical activated-bauxite sorber bed technique developed at Argonne National Laboratory. The test results showed that sodium is the major alkali-vapor species present in the PFBC flue gas, and that the level of sodium-vapor emission increases linearly with both Na and Cl contents in the coals. This suggests that the sodium-vapor emission results from direct vaporization of NaCl present in the coals. The measured alkali-vapor concentration (Na + K), 67 to 190 ppbW, is more than 2.5 times greater than the allowable alkali limit of 24 ppb for an industrial gas turbine. Combusting these coals in a PFBC for power generation may require developing a method to control alkali vapors.

  14. ESTABLISHMENT OF AN ENVIRONMENTAL CONTROL TECHNOLOGY LABORATORY WITH A CIRCULATING FLUIDIZED-BED COMBUSTION SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Wei-Ping Pan; Andy Wu; John T. Riley

    2005-07-30

    This purpose of this report is to present the progress made on the project ''Establishment of an Environmental Control Technology Laboratory (ECTL) with a Circulating Fluidized-Bed Combustion (CFBC) System'' during the period April 1, 2005 through June 30, 2005. The following tasks have been completed. First, the new Combustion Laboratory was occupied on June 15, 2005, and the construction of the Circulating Fluidized-Bed (CFB) Combustor Building is in the final painting stage. Second, the fabrication and manufacturing contract for the CFBC Facility was awarded to Sterling Boiler & Mechanical, Inc. of Evansville, Indiana. Sterling is manufacturing the assembly and component parts of the CFBC system. The erection of the CFBC system is expected to start September 1, 2005. Third, mercury emissions from the cofiring of coal and chicken waste was studied experimentally in the laboratory-scale simulated fluidized-bed combustion facility. The experimental results from this study are presented in this report. Finally, the proposed work for the next quarter is described.

  15. International evaluation of the programme on fluid bed combustion and gasification

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, H. [Ruhr Univ., Bochum (Germany); Magnusson, B.F. [Norwegian Univ. of Science and Technology, Trondheim (Norway); Reed, T. [Colorado School of Mines (United States)

    1996-12-31

    This report on the Swedish National Program on Fluid Bed Combustion and Gasification is part of the on-going evaluation process adopted by the funding organization NUTEK. This agency has invited the undersigned to act as members of an international panel responsible for evaluating the progress made in 9 projects initiated between 1993-1996. The output of this evaluation procedure is given in this report. The main aim of the Fluid Bed Combustion and Gasification Program is to develop industrially relevant knowledge and competence in experimental and computational techniques capable of characterizing the flow, heat transfer, combustion, gasification, ash formation and deposition and emissions in fluid bed gasifiers and combustors. To achieve this aim NUTEK is sponsoring research in a number of universities and encourages close cooperation between universities and industry. In the evaluation of the various sponsored research programs, the evaluation committee has considered the following key points: relevance of research to industrial needs; originality of research; program management; adequacy of resources; degree of collaboration between industry and academia; international standing of research. In this report comments and recommendations are made on individual projects as well as on the programme in general and they express the unanimous view of the panel members

  16. Torsion testing of bed joints

    DEFF Research Database (Denmark)

    Hansen, Klavs Feilberg; Pedersen, Carsten Mørk

    2008-01-01

    be carried out directly in a normal testing machine. The torsion strength is believed to be the most important parameter in out-of-plane resistance of masonry walls subjected to bending about an axis perpendicular to the bed joints. The paper also contains a few test results from bending of small walls about...... an axis perpendicular to the bed joints, which indicate the close connection between these results and results from torsion tests. These characteristics make the torsion strength well suited to act as substitute parameter for the bending strength of masonry about an axis perpendicular to the bed joints....

  17. The study of partitioning of heavy metals during fluidized bed combustion of sewage sludge and coal

    Energy Technology Data Exchange (ETDEWEB)

    Gulyurtlu, I.; Lopes, M.H.; Abelha, P.; Cabrita, I.; Oliveira, J.F.S. [INETI, Lisbon (Portugal)

    2006-06-15

    The behavior of Cd, Cr, Cu, Co, Mn, Ni, Pb, Zn, and Hg during the combustion tests of a dry granular sewage sludge on a fluidized bed combustor pilot (FBC) of about 0.3 MW was evaluated. The emissions of these heavy metals from mono-combustion were compared with those of co-combustion of the sludge with a bituminous coal. The effect of the addition of limestone was also studied in order to retain sulphur compounds and to verify its influence on the retention of heavy metals (HM). Heavy metals were collected and analyzed from different locations of the installation, which included the stack, the two cyclones, and the material removed from the bed. The results showed that the volatility of metals was rather low, resulting in emissions below the legal limits of the new directive on incineration, with the exception of Hg during the mono-combustion tests. The partitioning of metals, except for Hg, appeared to follow that of ashes, amounting to levels above 90% in the bed streams in the mono-combustion case. For co-combustion, there was a lower fixation of HM in the bed ashes, mostly originating essentially from the sewage sludge, ranging between 40% and 80%. It is believed that in this latter case, a slightly higher temperature could have enhanced the volatilization, especially of Cd and Pb. However these metals were then retained in fly ashes captured in the cyclones. In the case of Hg, the volatilisation was complete. The bed ashes were free of Hg and part of Hg was retained in the cyclones and the rest was emitted either with fine ash particles or in gaseous forms. In mono-combustion the Hg emissions from the stack (particles and gas) accounted, for about 50%. This appeared to have significantly decreased in the case of co-combustion, as only about 75% has been emitted, due to the retention effect of cyclone ashes.

  18. Ecological characteristics of the fluidized bed boilers burning low-rank lignite coal

    International Nuclear Information System (INIS)

    Fett, F.N.; Heinbockel, I.; Dersch, J.

    1996-01-01

    The performance simulation of fluidized bed coal plants with Bulgarian low-rank coal has been made. Fluidized bed models, developed in the Institute of Energy Technology, UGN - Siegen, based on one-dimensional compartment-in-series model have been used. The parameters of each data block can be optimized according to criteria chosen in advance. The 'quality of coal - pollution characteristics of the boilers' channel has been chosen as a channel of priority importance. The input information on coal quality characteristics reflects the regression connections between ash content and the other quality components. The wide range of ash value variations of the coal (26 - 44%) causes a lot of problems. Two different models - Atmospheric Bubbling Fluidized Bed Model (ABFB) and Atmospheric Circulated Fluidized Bed Model - have been applied. Some results of computer experiments with ABFB model are given presenting the influence of coal quality on temperature profile in the combustor and on ecological characteristics of the gases. The following interconnections are marked: 1) ash content increase (connected with a net calorific value diminution) leading to a decrease in the temperature along the height of the furnace; 2) dependence of SO 2 concentration on the ash value connected with the 'temperature - NO x ' relationship; 3) decrease in SO 2 concentration caused by the augmentation of Ca/S ratio and the increase in the ash content of the coal. It is concluded that the fluidized bed technology is reliable enough for the Bulgarian low rank lignite because of the low rate of the environmental pollutants. 4 figs., 3 refs

  19. Bed Bugs: The Australian Response

    Directory of Open Access Journals (Sweden)

    Richard C. Russell

    2011-04-01

    Full Text Available Australia has experienced a sudden and unexpected resurgence in bed bug infestations from both Cimex lectularius L. and Cimex hemipterus F. A survey in 2006 revealed that infestations had increased across the nation by an average of 4,500% since the start of the decade. In response, a multi-disciplinary approach to combat the rise of this public health pest was implemented and involved the coordinated efforts of several organizations. The key components of the strategy included the introduction of a pest management standard ‘A Code of Practice for the Control of Bed Bug Infestations in Australia’ that defines and promotes ‘best practice’ in bed bug eradication, the development of a policy and procedural guide for accommodation providers, education of stakeholders in best management practices, and research. These strategies continue to evolve with developments that lead to improvements in ‘best practice’ while bed bugs remain problematic in Australia.

  20. Getting Rid of Bed Bugs

    Science.gov (United States)

    ... control is very important whether you are considering hiring a professional or planning to do it yourself. Controlling bed ... control methods, as others may cause serious harm. Hiring a pest management professional is a good option in many cases, but ...

  1. Sea bed mapping and inspection

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    The conference has 24 presentations on the topics: Sea bed mapping, inspection, positioning, hydrography, marine archaeology, remote operation vehicles and computerized simulation technologies, oil field activities and plans, technological experiences and problems. (tk)

  2. Operating characteristics of rotating beds

    Energy Technology Data Exchange (ETDEWEB)

    Keyvani, M.; Gardner, N.C.

    1988-01-01

    Vapor-liquid contacting in high gravitational fields offers prospects for significant reductions in the physical size, capital, and operating costs of packed towers. Pressure drops, power requirements, mass transfer coefficients and liquid residence time distributions are reported for a rotating bed separator. The beds studied were rigid, foamed aluminum, with specific surface areas ranging from 650 to 3000 m{sup 2}/m{sup 2}. Gravitational fields were varied from 50 to 300g.

  3. Large Eddy Simulations and Experimental Investigation of Flow in a Swirl Stabilized Combustor

    KAUST Repository

    Kewlani, Gaurav

    2012-01-09

    Swirling flows are the preferred mode of flame stabilization in lean premixed gas turbine engine combustors. Developing a fundamental understanding of combustion dynamics and flame stability in such systems requires a detailed investigation of the complex interactions between fluid mechanics and combustion. The turbulent reacting flow in a sudden expansion swirl combustor is studied using compressible large eddy simulations (LES) and compared with experimental data measured using PIV. Different vortex breakdown structures are observed, as the mixture equivalence ratio is reduced, that progressively diminish the stability of the flame. Sub-grid scale combustion models such as the artificially thickened flame method and the partially stirred reactor approach, along with appropriate chemical schemes, are implemented to describe the flame. The numerical predictions for average velocity correspond well with experimental results, and higher accuracy is obtained using the more detailed reaction mechanism. Copyright © 2012 American Institute of Aeronautics and Astronautics, Inc.

  4. Experiments and computations on coaxial swirling jets with centerbody in an axisymmetric combustor

    International Nuclear Information System (INIS)

    Chao, Y.C.; Ho, W.C.; Lin, S.K.

    1987-01-01

    Experiments and computations of turbulent, confined, coannular swirling flows have been performed in a model combustor. Numerical results are obtained by means of a revised two-equation model of turbulence. The combustor consists of two confined, concentric, swirling jets and a centerbody at the center of the inlet. Results are reported for cold flow conditions under co- and counter-swirl. The numerical results agree with the experimental data under both conditions. The size of the central recirculation zone is dominated by the strength of the outer swirl. A two-cell recirculation zone may be formed due to the presence of the swirler hub. The mechanism of interaction between the separation bubble at the hub of the swirler and the central recirculation zone due to vortex breakdown is also investigated. 18 references

  5. Ultra low injection angle fuel holes in a combustor fuel nozzle

    Science.gov (United States)

    York, William David

    2012-10-23

    A fuel nozzle for a combustor includes a mixing passage through which fluid is directed toward a combustion area and a plurality of swirler vanes disposed in the mixing passage. Each swirler vane of the plurality of swirler vanes includes at least one fuel hole through which fuel enters the mixing passage in an injection direction substantially parallel to an outer surface of the plurality of swirler vanes thereby decreasing a flameholding tendency of the fuel nozzle. A method of operating a fuel nozzle for a combustor includes flowing a fluid through a mixing passage past a plurality of swirler vanes and injecting a fuel into the mixing passage in an injection direction substantially parallel to an outer surface of the plurality of swirler vanes.

  6. Diffuse interfacelets in transcritical flows of propellants into high-pressure combustors

    Science.gov (United States)

    Urzay, Javier; Jofre, Lluis

    2017-11-01

    Rocket engines and new generations of high-power jet engines and diesel engines oftentimes involve the injection of one or more reactants at subcritical temperatures into combustor environments at high pressures, and more particularly, at pressures higher than those corresponding to the critical points of the individual components of the mixture, which typically range from 13 to 50 bars for most propellants. This class of trajectories in the thermodynamic space has been traditionally referred to as transcritical. Under particular conditions often found in hydrocarbon-fueled chemical propulsion systems, and despite the prevailing high pressures, the flow in the combustor may contain regions close to the injector where a diffuse interface is formed in between the fuel and oxidizer streams that is sustained by surface-tension forces as a result of the elevation of the critical pressure of the mixture. This talk describes progress towards modeling these effects in the conservation equations. Funded by the US Department of Energy.

  7. Numerical analysis of lean premixed combustor fueled by propane-hydrogen mixture

    Directory of Open Access Journals (Sweden)

    Mahjoub Mustafa Makhzoum Ali

    2017-01-01

    Full Text Available A numerical investigation of combustion of propane-hydrogen mixture in a swirl premixed micro gas turbine combustor is presented. The effects of hydrogen addition into propane on temperature distribution in the combustor, reaction rates of propane and hydrogen and NOx emissions for different equivalence ratios and swirl numbers are given. The propane-hydrogen mixture of 90/10% by volume was assumed. The numerical results and measurements of NOx emissions for pure propane are compared. Excellent agreements are found for all equivalence ratios and swirl numbers, except for the highest swirl number (1.13. It is found that the addition of hydrogen into propane increases NOx emission. On the other hand, the increase of swirl number and the decrease of equivalence ratio decrease the NOx emissions.

  8. Parameterised Model of 2D Combustor Exit Flow Conditions for High-Pressure Turbine Simulations

    Directory of Open Access Journals (Sweden)

    Marius Schneider

    2017-12-01

    Full Text Available An algorithm is presented generating a complete set of inlet boundary conditions for Reynolds-averaged Navier–Stokes computational fluid dynamics (RANS CFD of high-pressure turbines to investigate their interaction with lean and rich burn combustors. The method shall contribute to understanding the sensitivities of turbine aerothermal performance in a systematic approach. The boundary conditions are based on a set of input parameters controlling velocity, temperature, and turbulence fields. All other quantities are derived from operating conditions and additional modelling assumptions. The algorithm is coupled with a CFD solver by applying the generated profiles as inlet boundary conditions. The successive steps to derive consistent flow profiles are described and results are validated against flow fields extracted from combustor CFD.

  9. Effects of the reacting flowfield on combustion processes in a Stagnation Point Reverse Flow combustor

    Science.gov (United States)

    Gopalakrishnan, Priya

    The performance of dry, low NOx gas turbines, which employ lean premixed (or partially premixed) combustors, is often limited by static and dynamic combustor stability, and they require complicated mixing hardware. To overcome these issues, a novel design, referred to as a Stagnation Point Reverse Flow (SPRF) combustor, has been recently demonstrated. The SPRF combustor has been shown to operate with ultra low NOx emissions in premixed and nonpremixed modes with gaseous and liquid fuels. The objective of this thesis is to elucidate the interactions between the flowfield and combustion processes in this novel combustor for gas- and liquid-fueled operation. This is achieved with experimental measurements employing various optical diagnostic techniques, which include Particle Image Velocimetry (PIV), chemiluminescence imaging, Planar Laser-Induced Fluorescence (PLIF) of OH radicals and elastic laser scattering from liquid droplets. The velocity measurements obtained during gas-fueled operation show that both nonreacting and reacting flows exhibit a "stagnation" region with low mean velocity and high RMS fluctuations. In nonreacting flow, it has been shown that the decay rate of the jet can be modeled as a combination of a free jet and a jet in a uniform opposed flow. The high shear between the forward and reverse flows causes significant recirculation, resulting in enhanced entrainment and mixing of the returning hot product gases into the incoming reactant jet for the reacting flow cases, which enables stable operation of the combustor at very lean equivalence ratios. Nonpremixed operation produces a flowfield similar to that of the premixed case except in the near-field region. The coaxial injector design results in high turbulence intensities close to the injector exit leading to significant fuel-air premixing before combustion occurs. The operation of the SPRF combustor fueled with liquid Jet-A is also experimentally investigated. The results indicate that while

  10. Flow structures in a lean-premixed swirl-stabilized combustor with microjet air injection

    KAUST Repository

    LaBry, Zachary A.

    2011-01-01

    The major challenge facing the development of low-emission combustors is combustion instability. By lowering flame temperatures, lean-premixed combustion has the potential to nearly eliminate emissions of thermally generated nitric oxides, but the chamber acoustics and heat release rate are highly susceptible to coupling in ways that lead to sustained, high-amplitude pressure oscillations, known as combustion instability. At different operating conditions, different modes of instability are observed, corresponding to particular flame shapes and resonant acoustic modes. Here we show that in a swirl-stabilized combustor, these instability modes also correspond to particular interactions between the flame and the inner recirculation zone. Two stable and two unstable modes are examined. At lean equivalence ratios, a stable conical flame anchors on the upstream edge of the inner recirculation zone and extends several diameters downstream along the wall. At higher equivalence ratios, with the injection of counter-swirling microjet air flow, another stable flame is observed. This flame is anchored along the upstream edge of a stronger recirculation zone, extending less than one diameter downstream along the wall. Without the microjets, a stationary instability coupled to the 1/4 wave mode of the combustor shows weak velocity oscillations and a stable configuration of the inner and outer recirculation zones. Another instability, coupled to the 3/4 wave mode of the combustor, exhibits periodic vortex breakdown in which the core flow alternates between a columnar mode and a vortex breakdown mode. © 2010 Published by Elsevier Inc. on behalf of The Combustion Institute. All rights reserved.

  11. Experimental investigation of open cavity as flame holder of supersonic combustor

    Directory of Open Access Journals (Sweden)

    Goldfeld Marat

    2017-01-01

    Full Text Available The results of a study of combustion stabilization in a supersonic combustor for Mach numbers 2, 2.5, and 3 are presented. It was shown that the choice of the fuel injection scheme has decisive influence on the mixing efficiency and flame holding. It has been established that the efficiency of combustion stabilization depends essentially on Mach number and total temperature at the channel entrance.

  12. Numerical Investigation of Detonation Combustion Wave in Pulse Detonation Combustor with Ejector

    OpenAIRE

    P. Debnath; K. M. Pandey

    2017-01-01

    Detonation combustion based engines are more efficient compared to conventional deflagration based engines. Pulse detonation engine is the new concept in propulsion technology for future propulsion system. In this contrast, an ejector was used to modify the detonation wave propagation structure in pulse detonation engine combustor. In this paper k-ε turbulence model was used for detonation wave shock pattern simulation in PDE with ejectors at Ansys 14 Fluent platform. The unsteady Euler equat...

  13. Pulse Combustor Driven Pressure Gain Combustion for High Efficiency Gas Turbine Engines

    KAUST Repository

    Lisanti, Joel

    2017-02-01

    The gas turbine engine is an essential component of the global energy infrastructure which accounts for a significant portion of the total fossil fuel consumption in transportation and electric power generation sectors. For this reason there is significant interest in further increasing the efficiency and reducing the pollutant emissions of these devices. Conventional approaches to this goal, which include increasing the compression ratio, turbine inlet temperature, and turbine/compressor efficiency, have brought modern gas turbine engines near the limits of what may be achieved with the conventionally applied Brayton cycle. If a significant future step increase in gas turbine efficiency is to be realized some deviation from this convention is necessary. The pressure gain gas turbine concept is a well established new combustion technology that promises to provide a dramatic increase in gas turbine efficiency by replacing the isobaric heat addition process found in conventional technology with an isochoric process. The thermodynamic benefit of even a small increase in stagnation pressure across a gas turbine combustor translates to a significant increase in cycle efficiency. To date there have been a variety of methods proposed for achieving stagnation pressure gains across a gas turbine combustor and these concepts have seen a broad spectrum of levels of success. The following chapter provides an introduction to one of the proposed pressure gain methods that may be most easily realized in a practical application. This approach, known as pulse combustor driven pressure gain combustion, utilizes an acoustically resonant pulse combustor to approximate isochoric heat release and thus produce a rise in stagnation pressure.

  14. Coupling between Hydrodynamics, Acoustics, and Heat Release in a Self-Excited Unstable Combustor

    Science.gov (United States)

    2015-04-07

    and K. N. Bray, “Self-excited oscillations in combustors with Spray atomizers,” J. Eng. Gas Turbines Power 4, 779-786 (2001). 23 Z. Yao, Y. Gao, M. Zhu...of the k-ω turbulence model revisited,” AIAA J. 46(11), 2823-2838 (2008). 56 C. Westbrook and F. Dryer , “Simplified reaction mechanisms for the

  15. The development of an ultra-low-emission gas-fired cyclonic combustor

    International Nuclear Information System (INIS)

    Xiong, Tian-yu; Khinkis, M.J.; Coppin, W.P.

    1991-01-01

    A gas-fired cyclonic combustor has been developed for relatively low-temperature direct-air heating applications that require ultra-low pollutant emissions. High-lean premixed combustion with a flame stabilizer is adopted to achieve ultra-low emissions and high turndown operation. On the basis of analytical studies and cold modeling, a 350-kW test combustor was designed and successfully tested. Experimental results obtained using natural gas and ambient air demonstrated that the test combustor can operate steadily at high excess air up to 80% to 100% over a large turndown range up to 40:1. At design operating conditions, NO x emissions as low as 0.6 vppm and CO and total hydrocarbon (THC) emissions below 3 vppm were achieved. Over the full operating range, NO x emissions from 0.3 to 1.0 vppm and CO and THC emissions below 4 vppm were demonstrated. In all tests, concentrations of NO 2 were less than 40% of the total NO x emissions -- lower than the level of NO 2 emissions from combustion processes required for good indoor air quality (0.5 vppm). This paper presents the concept of high-lean premixed ultra-low-emission cyclonic combustion, design specifications for the combustion system, and the major experimental results, including flame stability, emissions, and turndown performance. 13 refs., 12 figs., 1 tab

  16. The development of an ultra-low-emission gas-fired combustor for space heaters

    International Nuclear Information System (INIS)

    Xiong, Tian-yu; Khinkis, M.J.; Coppin, W.P.

    1991-01-01

    An ultra-low-emission as-fired combustor has been developed for relatively low-temperature direct-air heating applications. High-lean premixed cyclonic combustion with a flame stabilizer is employed to achieve ultra-low emissions and high turndown operation. On the basis of analytical studies and cold modeling a 350-kW test combustor was designed and successfully tested. Experimental results obtained using natural gas and ambient air demonstrated that the test combustor can operate steadily at high excess air up to 80% to 100% over a large turndown range up to 40:1. At design operating conditions, NO x emissions as low as 0.6 vppm and CO and total hydrocarbon (THC) emissions below 3 vppm were achieved. Over the full operating range, NO x emissions from 0.3 to 1.0 vppm and CO and THC emissions below 4 vppm were demonstrated. In all tests, concentrations of NO 2 were less than 40% of the total NO 2 emissions from combustion processes required for good indoor air quality (0.5 vppm). This paper presents the concept of high-lean premixed ultra-low-emission cyclonic combustion, design specifications for the combustion system, and the major experimental results, including flame stability, emissions, and turndown performance. 15 refs., 10 figs., 1 tab

  17. A numerical study of mixing and combustion in hypervelocity flows through a scramjet combustor model

    Science.gov (United States)

    Krishamurthy, Ramesh

    1993-01-01

    Interest in high speed, air-breathing propulsion systems such as scramjets has revived in recent years fueled to a large extent by the National Aerospace Plane (NASP) program. These vehicles are expected to fly trans-atmospheric and as a consequence, the Mach number level within the engine/combustor would be rather high (M greater than 5). Ground based testing of such scramjet engines requires a facility that can not only achieve the right Mach number, but also have the proper pressures and temperatures to simulate the combustion processes. At present, only pulse type facilities can provide such high enthalpy flows. The newest of these is the free-piston shock tunnel, T5 located at GALCIT. Recently, a generic combustor model was tested in T5, and the experimental data from that study is analyzed in the present report. The available experimental data from T5 are essentially the static pressures on the injection wall and the one opposite to it. Thus, a principal aim of the present study was to validate the available experimental data by using a proven CFD tool and then investigate the performance characteristics of the combustor model, such as, the mixing efficiency and combustion efficiency. For this purpose, in this study, the code GASP has been used.

  18. NASA One-Dimensional Combustor Simulation--User Manual for S1D_ML

    Science.gov (United States)

    Stueber, Thomas J.; Paxson, Daniel E.

    2014-01-01

    The work presented in this paper is to promote research leading to a closed-loop control system to actively suppress thermo-acoustic instabilities. To serve as a model for such a closed-loop control system, a one-dimensional combustor simulation composed using MATLAB software tools has been written. This MATLAB based process is similar to a precursor one-dimensional combustor simulation that was formatted as FORTRAN 77 source code. The previous simulation process requires modification to the FORTRAN 77 source code, compiling, and linking when creating a new combustor simulation executable file. The MATLAB based simulation does not require making changes to the source code, recompiling, or linking. Furthermore, the MATLAB based simulation can be run from script files within the MATLAB environment or with a compiled copy of the executable file running in the Command Prompt window without requiring a licensed copy of MATLAB. This report presents a general simulation overview. Details regarding how to setup and initiate a simulation are also presented. Finally, the post-processing section describes the two types of files created while running the simulation and it also includes simulation results for a default simulation included with the source code.

  19. User's manual for rocket combustor interactive design (ROCCID) and analysis computer program. Volume 1: User's manual

    Science.gov (United States)

    Muss, J. A.; Nguyen, T. V.; Johnson, C. W.

    1991-01-01

    The user's manual for the rocket combustor interactive design (ROCCID) computer program is presented. The program, written in Fortran 77, provides a standardized methodology using state of the art codes and procedures for the analysis of a liquid rocket engine combustor's steady state combustion performance and combustion stability. The ROCCID is currently capable of analyzing mixed element injector patterns containing impinging like doublet or unlike triplet, showerhead, shear coaxial, and swirl coaxial elements as long as only one element type exists in each injector core, baffle, or barrier zone. Real propellant properties of oxygen, hydrogen, methane, propane, and RP-1 are included in ROCCID. The properties of other propellants can easily be added. The analysis model in ROCCID can account for the influence of acoustic cavities, helmholtz resonators, and radial thrust chamber baffles on combustion stability. ROCCID also contains the logic to interactively create a combustor design which meets input performance and stability goals. A preliminary design results from the application of historical correlations to the input design requirements. The steady state performance and combustion stability of this design is evaluated using the analysis models, and ROCCID guides the user as to the design changes required to satisfy the user's performance and stability goals, including the design of stability aids. Output from ROCCID includes a formatted input file for the standardized JANNAF engine performance prediction procedure.

  20. Emissions control of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans at municipal waste combustors

    International Nuclear Information System (INIS)

    Tseng, S.C.; Jozewicz, W.; Sedman, C.B.

    1991-01-01

    This paper gives the results of an analysis of available emission data of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDF) from municipal waste combustors (MWCs) to evaluate the effectiveness of various air pollution control devices on PCDD/PCDF removal. The effects of flue gas temperature, recycling fabric filter ash, and process additives such as ammonia and Tesisorb powder were also analyzed. The analysis shows that MWCs equipped with a spray dryer followed by fabric filters can achieve PCDD/PCDF removal efficiencies (REs) of 97% and higher. A RE of 94% has been achieved at a combustor equipped with a Thermal DeNO x system followed by a spray dryer and fabric filters. MWCs equipped with a duct sorbent injection system followed by fabric filters can potentially achieve a RE of 99%. A combustor equipped with a spray dryer followed by electrostatic precipitators (ESPs) has achieved a RE of 64%. Neither a duct sorbent injection system followed by ESPs nor a furnace sorbent injection system followed by ESPs could effectively remove PCDD/PCDF. PCDD/PCDF were not effectively removed from MWCs equipped with ESPs as the only devices to control air pollution

  1. Microjet Injection Strategies for Mitigating Dynamics in a Lean Premixed Swirl-Stabilized Combustor

    KAUST Repository

    LaBry, Zachary

    2011-01-04

    Combustion dynamics remain a challenge in the development of low-emission, air-breathing combustors for power generation and aircraft propulsion. In this paper, we presenta parametric study on the use of microjet injectors for suppressing or mitigating the combustion dynamics that energize the thermoacoustic instability in a swirl-stabilized, premixed combustor. Microjet injectors consist of small inlet ports intended to inject flow with high momentum at relatively low mass flow rates into the flame-anchoring region. The microjets were configured to inject flow either axially, into the outer recirculation zone, or radially into the inner recirculation zone. Additionally, different injectors were tested with different relative senses of swirl (signs of angular momentum)with respect to the main flow: co-swirling, not swirling, or counter-swirling. We observed that injecting air or premixed fuel/air into the inner recirculation zone via counter-swirling radial microjets, we were able to reduce the overall sound pressure level in the combustor by over 20 dB in the lean end of the operating range. Other injector configurations were not observed to positively influence the combust or stability. Detailed PIV measurements are used to examine possible mechanisms of how the microjets impact the combustion dynamics, and the technology implications of our experiments are discussed.

  2. Operability of an Ejector Enhanced Pulse Combustor in a Gas Turbine Environment

    Science.gov (United States)

    Paxson, Daniel E.; Dougherty, Kevin

    2008-01-01

    A pressure-gain combustor comprised of a mechanically valved, liquid fueled pulsejet, an ejector, and an enclosing shroud, was coupled to a small automotive turbocharger to form a self-aspirating, thrust producing gas turbine engine. The system was constructed in order to investigate issues associated with the interaction of pulsed combustion devices and turbomachinery. Installed instrumentation allowed for sensing of distributed low frequency pressure and temperature, high frequency pressure in the shroud, fuel flow rate, rotational speed, thrust, and laboratory noise. The engine ran successfully and reliably, achieving a sustained thrust of 5 to 6 lbf, and maintaining a rotor speed of approximately 90,000 rpm, with a combustor pressure gain of approximately 4 percent. Numerical simulations of the system without pressure-gain combustion indicated that the turbocharger would not operate. Thus, the new combustor represented a substantial improvement in system performance. Acoustic measurements in the shroud and laboratory indicated turbine stage sound pressure level attenuation of 20 dB. This is consistent with published results from detonative combustion experiments. As expected, the mechanical reed valves suffered considerable damage under the higher pressure and thermal loading characteristics of this system. This result underscores the need for development of more robust valve systems for this application. The efficiency of the turbomachinery components did not appear to be significantly affected by unsteadiness associated with pulsed combustion, though the steady component efficiencies were already low, and thus not expected to be particularly sensitive.

  3. Ignition and flame stabilization of a strut-jet RBCC combustor with small rocket exhaust.

    Science.gov (United States)

    Hu, Jichao; Chang, Juntao; Bao, Wen

    2014-01-01

    A Rocket Based Combined Cycle combustor model is tested at a ground direct connected rig to investigate the flame holding characteristics with a small rocket exhaust using liquid kerosene. The total temperature and the Mach number of the vitiated air flow, at exit of the nozzle are 1505 K and 2.6, respectively. The rocket base is embedded in a fuel injecting strut and mounted in the center of the combustor. The wall of the combustor is flush, without any reward step or cavity, so the strut-jet is used to make sure of the flame stabilization of the second combustion. Mass flow rate of the kerosene and oxygen injected into the rocket is set to be a small value, below 10% of the total fuel when the equivalence ratio of the second combustion is 1. The experiment has generated two different kinds of rocket exhaust: fuel rich and pure oxygen. Experiment result has shown that, with a relative small total mass flow rate of the rocket, the fuel rich rocket plume is not suitable for ignition and flame stabilization, while an oxygen plume condition is suitable. Then the paper conducts a series of experiments to investigate the combustion characteristics under this oxygen pilot method and found that the flame stabilization characteristics are different at different combustion modes.

  4. A Comparison of Combustion Dynamics for Multiple 7-Point Lean Direct Injection Combustor Configurations

    Science.gov (United States)

    Tacina, K. M.; Hicks, Y. R.

    2017-01-01

    The combustion dynamics of multiple 7-point lean direct injection (LDI) combustor configurations are compared. LDI is a fuel-lean combustor concept for aero gas turbine engines in which multiple small fuel-air mixers replace one traditionally-sized fuel-air mixer. This 7-point LDI configuration has a circular cross section, with a center (pilot) fuel-air mixer surrounded by six outer (main) fuel-air mixers. Each fuel-air mixer consists of an axial air swirler followed by a converging-diverging venturi. A simplex fuel injector is inserted through the center of the air swirler, with the fuel injector tip located near the venturi throat. All 7 fuel-air mixers are identical except for the swirler blade angle, which varies with the configuration. Testing was done in a 5-atm flame tube with inlet air temperatures from 600 to 800 F and equivalence ratios from 0.4 to 0.7. Combustion dynamics were measured using a cooled PCB pressure transducer flush-mounted in the wall of the combustor test section.

  5. Dual-Pump CARS Thermometry and Species Concentration Measurements in a Supersonic Combustor

    Science.gov (United States)

    OByrne, Sean; Danehy, Paul M.; Cutler, Andrew D.

    2004-01-01

    The dual-pump coherent anti-Stokes Raman spectroscopy (CARS) method was used to measure temperature and the absolute mole fractions of N2, O2 and H2 in a supersonic combustor. Experiments were conducted in NASA Langley Research Center's Direct Connect Supersonic Combustion Test Facility. In this facility, hydrogen and air bum to increase the enthalpy of the test gas; O2 is then added to simulate air. This gas is expanded through a Mach 2 nozzle and into a combustor model consisting of a short constant-area section followed by a small rearward facing step and another constant area section. At the end of this straight section H2 fuel is then injected at Mach 2 and at 30 deg. angle with respect to the freestream. One wall of the duct then expands at a 3 deg. angle for over 1 meter. The ensuing combustion is monitored optically through ports in the side of the combustor. CARS measurements were performed at the nozzle exit and at four different planes downstream fuel injection. Maps were obtained of the mean temperature, as well as quantitative N2 and O2 and qualitative H2 mean mole fraction fields. Correlations between fluctuations of the different measured parameters are presented for one of the planes of data.

  6. Dual-Pump CARS Temperature and Species Concentration Measurements in a Supersonic Combustor

    Science.gov (United States)

    O'Byrne, S.; Danehy, P. M.; Tedder, S. A.; Cutler, A. D.

    2007-01-01

    The dual-pump coherent anti-Stokes Raman scattering (CARS) method was used to measure temperature and the mole fractions of N2 and O2 in a supersonic combustor. Experiments were conducted in NASA Langley Research Center s Direct Connect Supersonic Combustion Test Facility. In this facility, H2 and oxygen-enriched air burn to increase the enthalpy of the simulated air test gas. This gas is expanded through a Mach 2 nozzle and into a combustor model consisting of a short constant-area section followed by a small rearward-facing step and another constant-area section. At the end of this straight section, H2 fuel is injected at Mach 2 and at a 30 angle with respect to the freestream. One wall of the duct then expands at a 3 angle for over 1 meter. The ensuing combustion is probed optically through ports in the side of the combustor. Dual-pump CARS measurements were performed at the facility nozzle exit and at four planes downstream of fuel injection. Maps are presented of the mean temperature, as well as N2 and O2 mean mole fraction fields. Correlations between fluctuations of the different measured parameters are also presented.

  7. Assessment of an atmospheric fluidized-bed coal-combustion gas-turbine cogeneration system for industrial application

    Energy Technology Data Exchange (ETDEWEB)

    Graves, R. L.; Holcomb, R. S.; Tallackson, J. R.

    1979-10-01

    This study was initiated to provide information on the future potential industrial market for a cogeneration system consisting of a fluidized-bed coal combustor coupled to a gas-turbine (Brayton cycle) power system that uses air as the working fluid. In assessing the potential applications for the system, the process heat energy consumption by industry is identified, with special detail included on the six most energy-intensive industries. The potential impact on the nation's oil and natural gas consumption that would result from wide-spread utilization of coal for process heat is also estimated. The fraction of industrial process heat that the system could feasibly satisfy from a thermodynamic viewpoint is estimated, and the performance (potential fuel efficiency and heat/power ratio) of the atmospheric fluidized-bed gas-turbine system is calculated. Also treated are several specific case studies of industries in which the system could be incorporated. Major parameters are specified, and flow sheets are derived for systems that would satisfy the heat and power requirements of the process or industry. The overall fuel utilization efficiency, thermal power rating, and potential number of installations are specified for these case studies. The findings of the study indicate that there is a sizable potential market for the system, with over 1000 possible installations disclosed after reviewing only 8 specific industries from 6 major Standard Industrial Classification (SIC) groups. The potential displacement of oil and gas by coal in process heating is shown to be about 1.60 m/sup 3//sec (870,000 bbl/d) of oil and 4590 m/sup 3//sec (14.0 billion ft/sup 3//d) of natural gas for all industries combined. Continued development of the fluidized-bed coal combustor and power system is recommended so that this potential may be at least partially realized.

  8. Modeling the integration of thermoelectrics in anode exhaust combustors for waste heat recovery in fuel cell systems

    Science.gov (United States)

    Maghdouri Moghaddam, Anita

    Recently developed small-scale hydrocarbon-fueled fuel cell systems for portable power under 1 kW have overall system efficiencies typically no higher than 30-35%. This study explores the possibility of using of thermoelectric waste heat recovery in anode exhaust combustors to improve the fuel cell system efficiencies by as much as 4-5% points and further to reduce required battery power during system start-up. Two models were used to explore this. The first model simulated an integrated SOFC system with a simplified catalytic combustor model with TEs integrated between the combustor and air preheating channels for waste heat recovery. This model provided the basis for assessing how much additional power can achieve during SOFC operation as a function of fuel cell operating conditions. Results for the SOFC system indicate that while the TEs may recover as much as 4% of the total fuel energy into the system, their benefit is reduced in part because they reduce the waste heat transferred back to the incoming air stream and thereby lower the SOFC operating temperatures and operating efficiencies. A second model transient model of a TE-integrated catalytic combustor explored the performance of the TEs during transient start-up of the combustor. This model incorporated more detailed catalytic combustion chemistry and enhanced cooling air fin heat transfer to show the dynamic heating of the integrated combustor. This detailed model provided a basis for exploring combustor designs and showed the importance of adequate reactant preheating when burning exhaust from a reformer during start-up for the TEs to produce significant power to reduce the size of system batteries for start-up.

  9. Clinical physiology of bed rest

    Science.gov (United States)

    Greenleaf, John E.

    1993-01-01

    Maintenance of optimal health in humans requires the proper balance between exercise, rest, and sleep as well as time in the upright position. About one-third of a lifetime is spent sleeping; and it is no coincidence that sleeping is performed in the horizontal position, the position in which gravitational influence on the body is minimal. Although enforced bed rest is necessary for the treatment of some ailments, in some cases it has probably been used unwisely. In addition to the lower hydrostatic pressure with the normally dependent regions of the cardiovascular system, body fuid compartments during bed rest in the horizontal body position, and virtual elimination of compression on the long bones of the skeletal system during bed rest (hypogravia), there is often reduction in energy metabolism due to the relative confinement (hypodynamia) and alteration of ambulatory circadian variations in metabolism, body temperature, and many hormonal systems. If patients are also moved to unfamiliar surroundings, they probably experience some feelings of anxiety and some sociopsychological problems. Adaptive physiological responses during bed rest are normal for that environment. They are attempts by the body to reduce unnecessary energy expenditure, to optimize its function, and to enhance its survival potential. Many of the deconditioning responses begin within the first day or two of bed rest; these early responses have prompted physicians to insist upon early resumption of the upright posture and ambulation of bedridden patients.

  10. Combustion Noise at Elevated Pressures in a Liquid-Fueled Premixed Combustor

    Science.gov (United States)

    Darling, Douglas; Radhakrishnan, Krishnan; Oyediran, Ayo

    1997-01-01

    Noise generated in gas turbine combustors can exist in several forms-broadband noise, sharp resonant peaks, and regular or intermittent nonlinear pulsing. In the present study, dynamic pressure measurements were made in several JP-5-fueled combustor configurations, at various mean pressures and temperatures. The fluctuating pressure was measured at mean pressures from 6 to 14 atm and inlet temperatures from 550 K to 850 K. The goal of the present work was to study the effect of changes in mean flow conditions on combustor noise: both broadband noise and sharp tones were considered. In general, the shape of the broadband noise spectrum was consistent from one configuration to another. The shape of the spectrum was influenced by the acoustic filtering of the combustion zone. This filtering ensured the basic consistency of the spectra. In general, the trends in broadband noise observed at low mean pressures were also seen at high mean pressures; that is, the total sound level decreased with both increasing equivalence ratio and increasing inlet temperature. The combustor configurations without a central pilot experienced higher broadband noise levels and were more susceptible to narrow peak resonances than configurations with a central pilot. The sharp peaks were more sensitive to the mean flow than was the broadband noise, and the effects were not always the same. In some situations, increasing the equivalence ratio made the sharp peaks grow, while at other conditions, increasing the equivalence ratio made the sharp peaks shrink. Thus, it was difficult to predict when resonances would occur; however, they were reproducible. Acoustic coupling between the upstream and downstream regions of the combustor may play a role in the sharp-peaked oscillations. Noise was also observed near lean blow out. As with other types of noise, lean blow out noise was affected by the combustion chamber acoustics, which apparently maintains the fluctuations at a uniform frequency. However

  11. Development of the control and ignition systems on a high pressure gas turbine combustor

    Science.gov (United States)

    Valdez, Carlos Alejandro

    The ignition and control systems of a laboratory scale high-pressure gas turbine combustor were developed in the present work. This work provides a detailed description of the design, development and testing of the remote control system developed for a High Pressure Gas Turbine Combustor (HPTC). The combustor has the capability to operate at pressures up to 1.5 MPa and temperatures up to 2400 K. It is also designed for a maximum air and fuel flow rates of 81.93 g/s and 35.77 g/s respectively. The fuel used will be CH4 for the early experiments but it is designed to operate using a mixture of H2-CO with a hydrogen fuel composition variation of up to 30 percent. The HPTC also has optical accessibility capabilities in its combustion chamber with a converging nozzle that restricts the exhaust flow. It also has three circular ports that can be used as instrumentation ports to obtain real time data from the combustion chamber. LabVIEW was used as the controlling interface for the user. A detailed outline of the LabVIEW programming is also described. LabVIEW controlled the proportional valves (ball valves), and solenoid valves; it also provided the user with data from mass flow meters as well as pressure transducers. Both proportional and solenoid valves are 1.91 cm and can withstand pressures of up to 1551 kPa. Thermal mass flow meters were used to obtain the flow in the lines with a range from 200-1000 L/min with an accuracy of 1.5 percent. Pressure transducers with a range from 0 to 2068 kPa were also positioned on the lines in order to know the line pressures. The ignition system design, development and testing is also described with its integration to the High Pressure Gas Turbine Combustor. A modified spark plug was used to provide the igniter with an ignition source. A diffusion flame was used to ignite the main line using methane as the fuel that utilizes the air in the combustion chamber as the oxidizer. Testing included a functional test of the equipment, and

  12. An analysis of the pull strength behaviors of fine-pitch, flip chip solder interconnections using a Au-Pt-Pd thick film conductor on Low-Temperature, Co-fired Ceramic (LTCC) substrates.

    Energy Technology Data Exchange (ETDEWEB)

    Uribe, Fernando R.; Kilgo, Alice C.; Grazier, John Mark; Vianco, Paul Thomas; Zender, Gary L.; Hlava, Paul Frank; Rejent, Jerome Andrew

    2008-09-01

    The assembly of the BDYE detector requires the attachment of sixteen silicon (Si) processor dice (eight on the top side; eight on the bottom side) onto a low-temperature, co-fired ceramic (LTCC) substrate using 63Sn-37Pb (wt.%, Sn-Pb) in a double-reflow soldering process (nitrogen). There are 132 solder joints per die. The bond pads were gold-platinum-palladium (71Au-26Pt-3Pd, wt.%) thick film layers fired onto the LTCC in a post-process sequence. The pull strength and failure modes provided the quality metrics for the Sn-Pb solder joints. Pull strengths were measured in both the as-fabricated condition and after exposure to thermal cycling (-55/125 C; 15 min hold times; 20 cycles). Extremely low pull strengths--referred to as the low pull strength phenomenon--were observed intermittently throughout the product build, resulting in added program costs, schedule delays, and a long-term reliability concern for the detector. There was no statistically significant correlation between the low pull strength phenomenon and (1) the LTCC 'sub-floor' lot; (2) grit blasting the LTCC surfaces prior to the post-process steps; (3) the post-process parameters; (4) the conductor pad height (thickness); (5) the dice soldering assembly sequence; or (5) the dice pull test sequence. Formation of an intermetallic compound (IMC)/LTCC interface caused by thick film consumption during either the soldering process or by solid-state IMC formation was not directly responsible for the low-strength phenomenon. Metallographic cross sections of solder joints from dice that exhibited the low pull strength behavior, revealed the presence of a reaction layer resulting from an interaction between Sn from the molten Sn-Pb and the glassy phase at the TKN/LTCC interface. The thick film porosity did not contribute, explicitly, to the occurrence of reaction layer. Rather, the process of printing the very thin conductor pads was too sensitive to minor thixotropic changes to ink, which resulted in

  13. Pull strength evaluation of Sn-Pb solder joints made to Au-Pt-Pd and Au thick film structures on low-temperature co-fired ceramic -final report for the MC4652 crypto-coded switch (W80).

    Energy Technology Data Exchange (ETDEWEB)

    Uribe, Fernando; Vianco, Paul Thomas; Zender, Gary L.

    2006-06-01

    A study was performed that examined the microstructure and mechanical properties of 63Sn-37Pb (wt.%, Sn-Pb) solder joints made to thick film layers on low-temperature co-fired (LTCC) substrates. The thick film layers were combinations of the Dupont{trademark} 4596 (Au-Pt-Pd) conductor and Dupont{trademark} 5742 (Au) conductor, the latter having been deposited between the 4596 layer and LTCC substrate. Single (1x) and triple (3x) thicknesses of the 4596 layer were evaluated. Three footprint sizes were evaluated of the 5742 thick film. The solder joints exhibited excellent solderability of both the copper (Cu) lead and thick film surface. In all test sample configurations, the 5742 thick film prevented side wall cracking of the vias. The pull strengths were in the range of 3.4-4.0 lbs, which were only slightly lower than historical values for alumina (Al{sub 2}O{sub 3}) substrates. General (qualitative) observations: (a) The pull strength was maximized when the total number of thick film layers was between two and three. Fewer that two layers did not develop as strong of a bond at the thick film/LTCC interface; more than three layers and of increased footprint area, developed higher residual stresses at the thick film/LTCC interface and in the underlying LTCC material that weakened the joint. (b) Minimizing the area of the weaker 4596/LTCC interface (e.g., larger 5742 area) improved pull strength. Specific observations: (a) In the presence of vias and the need for the 3x 4596 thick film, the preferred 4596:5742 ratio was 1.0:0.5. (b) For those LTCC components that require the 3x 4596 layer, but do not have vias, it is preferred to refrain from using the 5742 layer. (c) In the absence of vias, the highest strength was realized with a 1x thick 5742 layer, a 1x thick 4596 layer, and a footprint ratio of 1.0:1.0.

  14. Particle Bed Reactor scaling relationships

    International Nuclear Information System (INIS)

    Slovik, G.; Araj, K.; Horn, F.L.; Ludewig, H.; Benenati, R.

    1987-01-01

    Scaling relationships for Particle Bed Reactors (PBRs) are discussed. The particular applications are short duration systems, i.e., for propulsion or burst power. Particle Bed Reactors can use a wide selection of different moderators and reflectors and be designed for such a wide range of power and bed power densities. Additional design considerations include the effect of varying the number of fuel elements, outlet Mach number in hot gas channel, etc. All of these variables and options result in a wide range of reactor weights and performance. Extremely light weight reactors (approximately 1 kg/MW) are possible with the appropriate choice of moderator/reflector and power density. Such systems are very attractive for propulsion systems where parasitic weight has to be minimized

  15. Fluidized-bed nuclear reactor

    International Nuclear Information System (INIS)

    Grimmett, E.S.; Kunze, J.F.

    1975-01-01

    A reactor vessel containing a fluidized-bed region of particulate material including both a neutron-moderating and a fertile substance is described. A gas flow including fissile material passes through the vessel at a sufficient rate to fluidize the particulate material and at a sufficient density to support a thermal fission reaction within the fluidized-bed region. The high-temperature portion of a heat transfer system is located within the fluidized-bed region of the reactor vessel in direct contact with the fluidized particles. Heat released by fission is thereby transferred at an enhanced rate to a coolant circulating within the heat transfer system. Fission products are continuously removed from the gas flow and supplemental fissile material added during the reactor operation. (U.S.)

  16. Better backs by better beds?

    DEFF Research Database (Denmark)

    Bergholdt, Kim; Fabricius, Rasmus N; Bendix, Tom

    2008-01-01

    STUDY DESIGN: A "randomized"/stratified, single-blinded, parallel-group study. OBJECTIVE.: To evaluate 3 structurally different mattresses relative influence on patients with chronic low back pain (CLBP). SUMMARY OF BACKGROUND DATA: In several advertisements, it is proclaimed that certain...... using the probably most relevant "worst case" data. There were no relevant difference between the effects of the water bed and the foam bed. CONCLUSION: The Waterbed and foam mattress' did influence back symptoms, function and sleep more positively as apposed to the hard mattress, but the differences...

  17. Effects of Combustion-Induced Vortex Breakdown on Flashback Limits of Syngas-Fueled Gas Turbine Combustors

    Energy Technology Data Exchange (ETDEWEB)

    Ahsan Choudhuri

    2011-03-31

    Turbine combustors of advanced power systems have goals to achieve very low pollutants emissions, fuel variability, and fuel flexibility. Future generation gas turbine combustors should tolerate fuel compositions ranging from natural gas to a broad range of syngas without sacrificing operational advantages and low emission characteristics. Additionally, current designs of advanced turbine combustors use various degrees of swirl and lean premixing for stabilizing flames and controlling high temperature NOx formation zones. However, issues of fuel variability and NOx control through premixing also bring a number of concerns, especially combustor flashback and flame blowout. Flashback is a combustion condition at which the flame propagates upstream against the gas stream into the burner tube. Flashback is a critical issue for premixed combustor designs, because it not only causes serious hardware damages but also increases pollutant emissions. In swirl stabilized lean premixed turbine combustors onset of flashback may occur due to (i) boundary layer flame propagation (critical velocity gradient), (ii) turbulent flame propagation in core flow, (iii) combustion instabilities, and (iv) upstream flame propagation induced by combustion induced vortex breakdown (CIVB). Flashback due to first two foregoing mechanisms is a topic of classical interest and has been studied extensively. Generally, analytical theories and experimental determinations of laminar and turbulent burning velocities model these mechanisms with sufficient precision for design usages. However, the swirling flow complicates the flashback processes in premixed combustions and the first two mechanisms inadequately describe the flashback propensity of most practical combustor designs. The presence of hydrogen in syngas significantly increases the potential for flashback. Due to high laminar burning velocity and low lean flammability limit, hydrogen tends to shift the combustor operating conditions towards

  18. Ash and heavy metals in fluidized-bed combustion of wood wastes; Tuhka ja raskasmetallit puuperaeisen jaetteen kerrosleijupoltossa

    Energy Technology Data Exchange (ETDEWEB)

    Kaessi, T.; Aittoniemi, P. [IVO Power Engineering, Vantaa (Finland); Kauppinen, E.; Latva-Somppi, J.; Kurkela, J. [VTT Chemical Technology, Espoo (Finland); Partanen, J. [IVO Technology Centre, Vantaa (Finland)

    1997-10-01

    Ash formation and deposition mechanisms during co-combustion of pulp mill sludge and bark in industrial bubbling fluidized bed (BFB) combustor have been studied. Similar fuels were used in a bench-scale BFB for co-combustion of sludge and bark pellets and comparative studies with separate combustion of these fuels. Results indicated that in industrial scale unit significant fraction of ash had vaporization. About 14 mass-% of the total fly ash was found in the particle size below 0.2 {mu}m. The vaporized species consisted of potassium (K), sulfur (S), chlorine (Cl) and also of minor quantities of sodium (Na). In the benchscale similar vaporization fractions during co-combustion were measured, about 11 mass-%. During the combustion of bark this ratio, about 20 mass-%, was higher than during sludge combustion. The vaporized ash fraction was in the case of dried sludge combustion about 7 mass-%, but with wet sludge the vaporization rate was remarkably lower, about 1-2 mass-%. An increase in the bed temperature increased also ash vaporization. Test run period without combustion at elevated temperatures produced very low quantities of vaporized ash. The vaporized species in bench-scale test during bark pellet combustion were K, S and Cl, for sludge combustion also Na was clearly detected. No condensation of the vaporized species in bed area or furnace walls was observed. Bed defluidization was studied in the bench-scale unit. During bark pellet combustion the bed-agglomeration proceeded via small ash particle, below 2 {mu}m, coating on sand particle surface and consequent bonding between the ash layers. In the case of sludge combustion the accumulation of large ash particles and sintering of these porous agglomerates was observed to cause bed coarsening and defluidization. (orig.)

  19. The emissions of VOCs during co-combustion of coal with different waste materials in a fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    I. Gulyurtlu; P. Abelha; A. Gregorio; A. Garcia-Garcia; D. Boavida; A. Crujeira; I. Cabrita [DEECA-INETI, Lisbon (Portugal)

    2004-06-01

    The combustion of different fuels gives rise to the formation of small but appreciable amounts of volatile organic compounds (VOCs). They basically result from incomplete combustion and their emissions have negative repercussions on health and on the environment in general. As their measurement is difficult, costly, and very time-consuming, very little is reported on the emissions of VOCs from combustion installations. In this study, various blends of two different coals with several wastes were burned in a pilot-scale fluidized bed combustor and measurements of VOCs at several locations along the combustor height as well as just before the stack were carried out. The results demonstrate that the parameters important for the formation of VOCs are temperature, excess air levels, and the effectiveness of the mixing of air with fuel. Furthermore, it was observed that coal was the principal source of VOCs, but the combustion of volatiles from fuels such as biomass, occurring in the freeboard, was important in reducing the emissions of VOCs to almost zero. 8 refs., 6 figs., 6 tabs.

  20. Apparatus and process for controlling fluidized beds

    Science.gov (United States)

    Rehmat, Amirali G.; Patel, Jitendra G.

    1985-10-01

    An apparatus and process for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance.

  1. Physiology Of Prolonged Bed Rest

    Science.gov (United States)

    Greenleaf, John E.

    1991-01-01

    Report describes physiological effects of prolonged bed rest. Rest for periods of 24 hours or longer deconditions body to some extent; healing proceeds simultaneously with deconditioning. Report provides details on shifts in fluid electrolytes and loss of lean body mass, which comprises everything in body besides fat - that is, water, muscle, and bone. Based on published research.

  2. Co-combustion of tannery sludge in a commercial circulating fluidized bed boiler.

    Science.gov (United States)

    Dong, Hao; Jiang, Xuguang; Lv, Guojun; Chi, Yong; Yan, Jianhua

    2015-12-01

    Co-combusting hazardous wastes in existing fluidized bed combustors is an alternative to hazardous waste treatment facilities, in shortage in China. Tannery sludge is a kind of hazardous waste, considered fit for co-combusting with coal in fluidized bedboilers. In this work, co-combustion tests of tannery sludge and bituminous coal were conducted in a power plant in Jiaxing, Zhejiang province. Before that, the combustion behavior of tannery sludge and bituminous were studied by thermogravimetric analysis. Tannery sludge presented higher reactivity than bituminous coal. During the co-combustion tests, the emissions of harmful gases were monitored. The results showed that the pollutant emissions met the Chinese standard except for NOx. The Concentrations of seven trace elements (As, Cr, Cd, Ni, Cu, Pb, Mn) in three exit ash flows (bottom ash in bed, fly ash in filter, and submicrometer aerosol in flue gas) were analyzed. The results of mono-combustion of bituminous coal were compared with those of co-combustion with tannery sludge. It was found that chromium enriched in fly ash. At last, the leachability of fly ash and bottom ash was analyzed. The results showed that most species were almost equal to or below the limits except for As in bottom ashes and Cr in the fly ash of co-combustion test. The concentrations of Cr in leachates of co-combustion ashes are markedly higher than that of coal mono-combustion ashes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Analysis of the impact of the use of broad specification fuels on combustors for commercial aircraft gas turbine engines

    Science.gov (United States)

    Szetela, E. J.; Lehmann, R. P.; Smith, A. L.

    1979-01-01

    An analytical study was conducted to assess the impact of the use of broad specification fuels with reduced hydrogen content on the design, performance, durability, emissions and operational characteristics of combustors for commercial aircraft gas turbine engines. The study was directed at defining necessary design revisions to combustors designed for use of Jet A when such are operated on ERBS (Experimental Referee Broad Specification Fuel) which has a nominal hydrogen content of 12.8 percent as opposed to 13.7 percent in current Jet A. The results indicate that improvements in combustor liner cooling, and/or materials, and methods of fuel atomization will be required if the hydrogen content of aircraft gas turbine fuel is decreased.

  4. Design and fabrication of a meso-scale stirling engine and combustor.

    Energy Technology Data Exchange (ETDEWEB)

    Echekki, Tarek (Sandia National Laboratories, Livermore, CA); Haroldsen, Brent L. (Sandia National Laboratories, Livermore, CA); Krafcik, Karen L. (Sandia National Laboratories, Livermore, CA); Morales, Alfredo Martin (Sandia National Laboratories, Livermore, CA); Mills, Bernice E. (Sandia National Laboratories, Livermore, CA); Liu, Shiling (Sandia National Laboratories, Livermore, CA); Lee, Jeremiah C. (Sandia National Laboratories, Livermore, CA); Karpetis, Adionos N. (Sandia National Laboratories, Livermore, CA); Chen, Jacqueline H. (Sandia National Laboratories, Livermore, CA); Ceremuga, Joseph T. (Sandia National Laboratories, Livermore, CA); Raber, Thomas N. (Sandia National Laboratories, Livermore, CA); Hekmuuaty, Michelle A. (Sandia National Laboratories, Livermore, CA)

    2005-05-01

    Power sources capable of supplying tens of watts are needed for a wide variety of applications including portable electronics, sensors, micro aerial vehicles, and mini-robotics systems. The utility of these devices is often limited by the energy and power density capabilities of batteries. A small combustion engine using liquid hydrocarbon fuel could potentially increase both power and energy density by an order of magnitude or more. This report describes initial development work on a meso-scale external combustion engine based on the Stirling cycle. Although other engine designs perform better at macro-scales, we believe the Stirling engine cycle is better suited to small-scale applications. The ideal Stirling cycle requires efficient heat transfer. Consequently, unlike other thermodynamic cycles, the high heat transfer rates that are inherent with miniature devices are an advantage for the Stirling cycle. Furthermore, since the Stirling engine uses external combustion, the combustor and engine can be scaled and optimized semi-independently. Continuous combustion minimizes issues with flame initiation and propagation. It also allows consideration of a variety of techniques to promote combustion that would be difficult in a miniature internal combustion engine. The project included design and fabrication of both the engine and the combustor. Two engine designs were developed. The first used a cylindrical piston design fabricated with conventional machining processes. The second design, based on the Wankel rotor geometry, was fabricated by through-mold electroforming of nickel in SU8 and LIGA micromolds. These technologies provided the requisite precision and tight tolerances needed for efficient micro-engine operation. Electroformed nickel is ideal for micro-engine applications because of its high strength and ductility. A rotary geometry was chosen because its planar geometry was more compatible with the fabrication process. SU8 lithography provided rapid

  5. Protecting Your Home from Bed Bugs

    Science.gov (United States)

    ... your home: Inspect the luggage rack in your hotel room for bed bugs. Check secondhand furniture, beds, ... Grants January 19, 2017 Web Snapshot No FEAR Act Data Privacy Privacy and Security Notice Connect. Data. ...

  6. Videos, Webinars, Blogs Related to Bed Bugs

    Science.gov (United States)

    These tools provide practical insight on issues such as integrated pest management (IPM) for schools, bed bug bites, how carpet beetles can help, bed bugs as hitchhikers, and preventing and controlling infestations.

  7. EPA-Registered Bed Bug Products

    Science.gov (United States)

    ... treat your bed bug infestation. Foggers and bug bombs should not be used as the only method ... effective but take some time to kill the population); or Bed bugs’ becoming resistant to a specific ...

  8. Establishment of an Environmental Control Technology Laboratory with a Circulating Fluidized-Bed Combustion System

    Energy Technology Data Exchange (ETDEWEB)

    Wei-Ping Pan; Yan Cao; John Smith

    2008-05-31

    On February 14, 2002, President Bush announced the Clear Skies Initiative, a legislative proposal to control the emissions of nitrogen oxides (NO{sub x}), sulfur dioxide (SO{sub 2}), and mercury from power plants. In response to this initiative, the National Energy Technology Laboratory organized a Combustion Technology University Alliance and hosted a Solid Fuel Combustion Technology Alliance Workshop. The workshop identified multi-pollutant control; improved sorbents and catalysts; mercury monitoring and capture; and improved understanding of the underlying reaction chemistry occurring during combustion as the most pressing research needs related to controlling environmental emissions from fossil-fueled power plants. The Environmental Control Technology Laboratory will help meet these challenges and offer solutions for problems associated with emissions from fossil-fueled power plants. The goal of this project was to develop the capability and technology database needed to support municipal, regional, and national electric power generating facilities to improve the efficiency of operation and solve operational and environmental problems. In order to effectively provide the scientific data and the methodologies required to address these issues, the project included the following aspects: (1) Establishing an Environmental Control Technology Laboratory using a laboratory-scale, simulated fluidized-bed combustion (FBC) system; (2) Designing, constructing, and operating a bench-scale (0.6 MW{sub th}), circulating fluidized-bed combustion (CFBC) system as the main component of the Environmental Control Technology Laboratory; (3) Developing a combustion technology for co-firing municipal solid waste (MSW), agricultural waste, and refuse-derived fuel (RDF) with high sulfur coals; (4) Developing a control strategy for gaseous emissions, including NO{sub x}, SO{sub 2}, organic compounds, and heavy metals; and (5) Developing new mercury capturing sorbents and new

  9. Radial flow fuel nozzle for a combustor of a gas turbine

    Science.gov (United States)

    Means, Gregory Scott; Boardman, Gregory Allen; Berry, Jonathan Dwight

    2016-07-05

    A combustor for a gas turbine generally includes a radial flow fuel nozzle having a fuel distribution manifold, and a fuel injection manifold axially separated from the fuel distribution manifold. The fuel injection manifold generally includes an inner side portion, an outer side portion, and a plurality of circumferentially spaced fuel ports that extend through the outer side portion. A plurality of tubes provides axial separation between the fuel distribution manifold and the fuel injection manifold. Each tube defines a fluid communication path between the fuel distribution manifold and the fuel injection manifold.

  10. On the sensitivity of a helicopter combustor wall temperature to convective and radiative thermal loads

    International Nuclear Information System (INIS)

    Berger, S.; Richard, S.; Duchaine, F.; Staffelbach, G.; Gicquel, L.Y.M.

    2016-01-01

    Highlights: • Coupling of LES, DOM and conduction is applied to an industrial combustor. • Thermal sensitivity of the combustor to convection and radiation is investigated. • CHT based on LES is feasible in an industrial context with acceptable CPU costs. • Radiation heat fluxes are of the same order of magnitude that the convective ones. • CHT with radiation are globally in good agreement with thermocolor test. - Abstract: The design of aeronautical engines is subject to many constraints that cover performance gain as well as increasingly sensitive environmental issues. These often contradicting objectives are currently being answered through an increase in the local and global temperature in the hot stages of the engine. As a result, hot spots could appear causing a premature aging of the combustion chamber. Today, the characterization of wall temperatures is performed experimentally by complex thermocolor tests in advanced phases of the design process. To limit such expensive experiments and integrate the knowledge of the thermal environment earlier in the design process, efforts are currently performed to provide high fidelity numerical tools able to predict the combustion chamber wall temperature including the main physical phenomena: combustion, convection and mixing of hot products and cold flows, radiative transfers as well as conduction in the solid parts. In this paper, partitioned coupling approaches based on a Large Eddy Simulation (LES) solver, a Discrete Ordinate Method radiation solver and an unsteady conduction code are used to investigate the sensitivity of an industrial combustor thermal environment to convection and radiation. Four computations including a reference adiabatic fluid only simulation, Conjugate Heat Transfer, Radiation-Fluid Thermal Interaction and fully coupled simulations are performed and compared with thermocolor experimental data. From the authors knowledge, such comparative study with LES has never been published. It

  11. Spatially-resolved measurements of soot size and population in a swirl-stabilized combustor

    OpenAIRE

    Wood, CP; Smith, RA; Samuelsen, GS

    1985-01-01

    Isooctane, and mixtures of isooctane with various ring and aromatic compounds blended to yield the same smoke point were separately injected through a twin-fluid atomizer into a turbulent, swirl-stabilized model combustor. A nonintrusive optical probe based on larege angle (60°, 20°) intensity ratio scattering was used to yield a point measurement of soot particulate in the size range of 0.08 to 0.38 μm. The velocity and temperature fields were characterized by a two-color laser anemometer an...

  12. Turbomachine combustor nozzle including a monolithic nozzle component and method of forming the same

    Science.gov (United States)

    Stoia, Lucas John; Melton, Patrick Benedict; Johnson, Thomas Edward; Stevenson, Christian Xavier; Vanselow, John Drake; Westmoreland, James Harold

    2016-02-23

    A turbomachine combustor nozzle includes a monolithic nozzle component having a plate element and a plurality of nozzle elements. Each of the plurality of nozzle elements includes a first end extending from the plate element to a second end. The plate element and plurality of nozzle elements are formed as a unitary component. A plate member is joined with the nozzle component. The plate member includes an outer edge that defines first and second surfaces and a plurality of openings extending between the first and second surfaces. The plurality of openings are configured and disposed to register with and receive the second end of corresponding ones of the plurality of nozzle elements.

  13. Effects of chemical equilibrium on turbine engine performance for various fuels and combustor temperatures

    Science.gov (United States)

    Tran, Donald H.; Snyder, Christopher A.

    1992-01-01

    A study was performed to quantify the differences in turbine engine performance with and without the chemical dissociation effects for various fuel types over a range of combustor temperatures. Both turbojet and turbofan engines were studied with hydrocarbon fuels and cryogenic, nonhydrocarbon fuels. Results of the study indicate that accuracy of engine performance decreases when nonhydrocarbon fuels are used, especially at high temperatures where chemical dissociation becomes more significant. For instance, the deviation in net thrust for liquid hydrogen fuel can become as high as 20 percent at 4160 R. This study reveals that computer central processing unit (CPU) time increases significantly when dissociation effects are included in the cycle analysis.

  14. Continuous spin detonation of a syngas-air mixture in a plane-radial vortex combustor

    Science.gov (United States)

    Bykovskii, F. A.; Zhdan, S. A.; Vedernikov, E. F.

    2017-09-01

    Continuous spin detonation in syngas-air mixtures with three different syngas compositions [CO]/[H2] = 1/3, 1/2, and 1/1 is experimentally studied in a flow-type radial vortex combustor 500 mm in diameter. It is found that all these mixtures with three syngas compositions can be effectively burned in air in the detonation regime. Transverse detonation waves of identical structure are detected. The limits of existence of continuous detonation in terms of the specific flow rates of the mixtures (minimum values) are determined.

  15. A micro fuel reformer integrated with a combustor and a microchannel evaporator

    Science.gov (United States)

    Yoshida, Kazushi; Tanaka, Shuji; Hiraki, Hisashi; Esashi, Masayoshi

    2006-09-01

    This paper describes the development of a micro fuel reformer integrated with a combustor and an evaporator. Fuel reforming tests were performed by using a mixture of methanol and water as reforming fuel and hydrogen as combustion fuel. It was found that the design of the microchannel evaporator is critical to obtain larger hydrogen output. Hydrogen output and CO concentration were investigated by varying the input combustion power at different fuel feeding rates. 32.9 sccm of hydrogen, which is equivalent to 5.9 W in lower heating value, was produced, when input combustion power was 11 W.

  16. Drag and distribution measurements of single-element fuel injectors for supersonic combustors

    Science.gov (United States)

    Povinelli, L. A.

    1974-01-01

    The drag caused by several vortex generating fuel injectors for scramjet combustors was measured in a Mach 2 to 3.5 airstream. Injector drag was found to be strongly dependent on injector thickness ratio. The distribution of helium injected into the stream was measured both in the near field and the far field of the injectors for a variety of pressure ratios. The far field results differed appreciably from measurements in the near field. Injection pressure ratio was found to profoundly influence the penetration. One of the aerowing configurations tested yielded low drag consistent with desirable penetration and spreading characteristics.

  17. Effect of increased fuel temperature on emissions of oxides of nitrogen from a gas turbine combustor burning natural gas

    Science.gov (United States)

    Marchionna, N. R.

    1973-01-01

    An annular gas turbine combustor was tested with heated natural gas fuel to determine the effect of increasing fuel temperature on the formation of oxides of nitrogen. Fuel temperatures ranged from ambient to 800 K (980 F). Combustor pressure was 6 atmospheres and the inlet air temperature ranged from 589 to 894 K (600 to 1150 F). The NOx emission index increased with fuel temperature at a rate of 4 to 9 percent per 100 K (180 F), depending on the inlet air temperature. The rate of increase in NOx was lowest at the highest inlet air temperature tested.

  18. Fluidization quality analyzer for fluidized beds

    Science.gov (United States)

    Daw, C.S.; Hawk, J.A.

    1995-07-25

    A control loop and fluidization quality analyzer for a fluidized bed utilizes time varying pressure drop measurements. A fast-response pressure transducer measures the overall bed pressure drop, or over some segment of the bed, and the pressure drop signal is processed to produce an output voltage which changes with the degree of fluidization turbulence. 9 figs.

  19. Designing a CR Test bed

    DEFF Research Database (Denmark)

    Cattoni, Andrea Fabio; Buthler, Jakob Lindbjerg; Tonelli, Oscar

    2014-01-01

    with their own set up, since the potential costs and efforts could not pay back in term of expected research results. Software Defined Radio solutions offer an easy way to communication researchers for the development of customized research test beds. While several hardware products are commercially available......Research on intelligent and reconfigurable wireless systems is in continuous evolution. Nevertheless, in order to fix some keystones, more and more researchers are entering the idea of research-oriented test beds. Unfortunately, it is very difficult for a wide number of research groups to start......, the software is most of the times open source and ready to use for third party users. Even though the software solution developers claim complete easiness in the development of custom applications, in reality there are a number of practical hardware and software issues that research groups need to face, before...

  20. Review of acute cancer beds.

    LENUS (Irish Health Repository)

    Evans, D S

    2012-01-01

    A review of admissions to cancer services at University Hospital Galway (UHG) was undertaken to assess the appropriateness of hospital usage. All cancer specialty patients admitted from 26-28 May 2009 were reviewed (n = 82). Chi square tests, Exact tests, and One-way ANOVA were utilised to analyse key issues emerging from the data. Fifty (61%) were classified as emergencies. Twenty three (67%) occupied a designated cancer bed with 24 (30%) in outlying non-oncology wards. The mean length of stay was 29.3 days. Possible alternatives to admission were identified for 15 (19%) patients. There was no evidence of discharge planning for 50 (60%) admissions. There is considerable potential to make more appropriate utilisation of UHG for cancer patients, particularly in terms of reducing bed days and length of stay and the proportion of emergency cancer admissions, and further developing integrated systems of discharge planning.