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Sample records for boiler soot blowers

  1. Optimum geometry for boiler soot blowers nozzles; Geometria optima de toberas para deshollinadores de caldera

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza Garza, Jesus; Garcia Tinoco, Guillermo J.; Martinez Flores, Jose Oscar [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1989-12-31

    For boiler soot blowing converging-diverging nozzles are employed, whose function is to convert thermal energy of a gas into kinetic energy to remove the deposits that adhere to the heat exchanger surfaces. In this paper are described the experimental equipment and the methods for flow, dynamic pressure, discharge velocity and air expansion factor calculation in each nozzle, as a function of its design geometry, utilizing air from a five stage centrifugal compressor. The graphic analysis of the results, concludes that the most efficient nozzles are not the ones than develop the greatest velocity, but the ones of highest dynamic pressure at the outlet. The nozzle geometry that allows obtaining the maximum dynamic air pressure at the discharge is A{sub 2}/A{sub g}=1.3676 [Espanol] Para el deshollinado de calderas se utilizan las toberas convergentes-divergentes, cuya funcion es convertir la energia termica de un gas en energia cinetica para remover los depositos que se adhieren a las superficies de intercambio de calor. En este trabajo se describen el equipo experimental y los metodos de calculo para flujo, presion dinamica, velocidad a la descarga y factor de expansion del aire en cada tobera, como funcion de su geometria de diseno. Durante la experimentacion se evaluaron siete disenos diferentes de toberas, empleando aire de un compresor centrifugo de cinco etapas. Del analisis grafico de los resultados, se concluye que las toberas mas eficientes no son las que desarrollan mayor velocidad sino las de mayor presion dinamica de la salida. La geometria de tobera que permite obtener la maxima presion dinamica del aire a la descarga es A{sub 2}/A{sub g} = 1.3676.

  2. Optimization in the design and efficiency of retractable soot blowers; Optimacion del diseno y la eficiencia de sopladores de hollin retractiles

    Energy Technology Data Exchange (ETDEWEB)

    Diego Marin, Antonio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1987-12-31

    In this article the importance of soot blowers in the subject of design, operation and maintenance are described and the effects that its inefficient functioning causes in the steam generators. The activities and the results of a project for the evaluation of the functioning of the soot blowers in the Comision Federal de Electricidad (CFE) boilers. Finally, the scope of a new project oriented towards the retractable soot blowers efficiency optimization, and to the creation of the infra-structure to substitute the import of its components. [Espanol] En este articulo se describe la importancia de los sopladores de hollin en los aspectos de diseno, operacion y mantenimiento, y los efectos que su funcionamiento deficiente produce en los generadores de vapor. Se presentan tambien las actividades y los resultados de un proyecto para evaluar el funcionamiento de los deshollinadores de las calderas de la Comision Federal de Electricidad (CFE). Finalmente, se presenta el alcance de un nuevo proyecto que se orienta a optimar la eficiencia de los sopladores de hollin retractiles y a crear la infraestructura para sustituir las importaciones de sus componentes.

  3. Intelligent soot blowing for boilers co-firing waste and biofuel; Behovsstyrd sotblaasning foer bio- och avfallseldade pannor - inventering och teknikval

    Energy Technology Data Exchange (ETDEWEB)

    Kjoerk, Anders [S.E.P. Scandinavian Energy Project AB, Goeteborg (Sweden)

    2003-11-01

    To achieve optimum boiler operation and performance it is necessary to control the cleanliness and limit the fouling of the heat transfer surfaces. Historically, the heating surfaces in boilers firing biomass and waste are cleaned by steamblowing soot blowers on scheduled time-based and/or parameter-based intervals or by mechanical methods. With the advent of fuel switching strategies and use of mixed-in industrial waste, the control of heating surface cleanliness has become even more crucial for these boilers. Scheduled and/or parameter based approaches do not easily address operational changes. As plant operators push to achieve greater efficiency and performance from their boilers, the ability to more effectively optimize cleaning cycles has become increasingly important. If soot blowing is done only when and where it is required rather than at set intervals, unit performance can be maintained with reduced blowing, which saves steam. Two philosophical approaches toward intelligent soot blowing are currently being applied in the industry. One incorporates heat flux monitors to gather real-time heat transfer data to determine which areas of the furnace need cleaning. The other uses indirect temperature and pressure data to infer locations where soot blowing is needed, and is mainly applied for controlling soot blowers in the superheater and economiser area. The heat flux monitors are so fare used for control of the furnace wall blowers. A system using temperature, pressure and flow data does not require much additional instrumentation as compared with what is available on a standard boiler. However the blower control system must be capable of operating blowers on an individual basis. For advanced options it should also be possible to adjust the speed of the soot blower and the steam pressure. The control program could be more or less advanced but the ability to model heating surfaces and determine real-time cleanliness is crucial for an intelligent soot blowing

  4. Soot blowing methods and soot steam consumption in Swedish recovery boilers; Sotningsmetoder och sotaangfoerbrukning i svenska sodapannor

    Energy Technology Data Exchange (ETDEWEB)

    Svedin, Kristoffer; Wallin, Erik; Ahlroth, Mikael

    2008-09-15

    The aim with the report was to put together a description of the current state of the sootblowing systems at Swedish recovery boilers, and to explain differences in cleanability and sootblowing efficiency. In chapter 4 a summary of new techniques and alternative soot blowing methods is found. The report is intended for persons working in the pulp industry. To facilitate the benchmarking the recovery boilers have been divided into two groups. Group A comprises recovery boilers which only have one stop per year and the remaining recovery boilers with more than one stop are classified into group B. The following conclusions, based on the recovery boiler design specifications, are of importance to achieve high boiler availability: Low furnace load; High recovery boiler, wide furnace bottom area; Modern air ports; Small or no correlation between cross pitch division in heat surfaces and cleanability could be seen. The expectation was to identify such a relation. However there are doubts on the correctness in reported data. The amount of chlorine and potassium is assumed to affect the cleanability for a few recovery boilers, but for the majority the amounts are low and most likely do not impact the operation. Because of the large impact of the recovery boilers design data (furnace area, load etc.) on the sootblowing, it has been hard to identify the relation cleanability contra sootblowing system. The relations that could be seen are: No distinction between normally designed nozzles and 'high efficiency' nozzles could be identified. The operational conditions for the different models differ a lot and the effect of nozzle type could not be distinguished. Only a minority of the soot blowing sequences are known from the study. In the recovery boilers with problematic areas improvements can be made in the soot blowing sequence. Four recovery boilers are using intelligent soot blowing of some kind. Two of these boilers have low availability and the other two have

  5. Extension of Weighted Sum of Gray Gas Data to Mathematical Simulation of Radiative Heat Transfer in a Boiler with Gas-Soot Media

    OpenAIRE

    Samira Gharehkhani; Ali Nouri-Borujerdi; Salim Newaz Kazi; Hooman Yarmand

    2014-01-01

    In this study an expression for soot absorption coefficient is introduced to extend the weighted-sum-of-gray gases data to the furnace medium containing gas-soot mixture in a utility boiler 150 MWe. Heat transfer and temperature distribution of walls and within the furnace space are predicted by zone method technique. Analyses have been done considering both cases of presence and absence of soot particles at 100% load. To validate the proposed soot absorption coefficient, the expression is co...

  6. Boilers a practical reference

    CERN Document Server

    Rayaprolu, Kumar

    2012-01-01

    AAbrasion and Abrasion Index (see Wear)Absolute or Dynamic Viscosity (æ) (see Viscosity in Fluid Characteristics)Acid Cleaning (see Commissioning)Acid Rain (also see Air Pollution Emissions and Controls and Gas Cleaning)Acid Sludge (see Refuse Fuels from Refinery in Liquid Fuels)Acid Smuts (see Oil Ash)Acoustic Soot Blowers (see Sonic Horns)Acoustic Enclosure (see Noise Control)Acoustic Leak Detection SystemAdiabatic Flame Temperature (see Combustion)Aeroderivative (see Types of GTs in Turbines, Gas)Ageing of Boiler ComponentsAgro-Fuels and FiringAir Ducts (see Draught Plant)Air Flow Measureme

  7. Efficiency and effect of different soot blowing methods on boilers using different types of fuels; Sotningsmetodernas effektivitet och konsekvenser paa foerbraenningsanlaeggningar foer olika typer av braenslen

    Energy Technology Data Exchange (ETDEWEB)

    Eklund, Anders; Rodin, Aasa

    2004-09-01

    Increased use of recovered wood fuel, waste fuel and new types of wood fuel, have increased the amount of fouling in the superheater and economizer. Deposits in the boilers heat-absorbing banks reduces the boiler efficiency and increases the exit flue gas temperatures. Thus, efficient soot blowing practice is now in focus with the aim of reducing the amount of fouling. This report evaluates the function and efficiency of the commonly used soot blowing methods at boilers in the range of 10 to 130 MW. The investigated soot blowing methods are: steam-, acoustic-, shot-, water-, hammer- and detonation cleaning. Plant experience and data has been acquired from the following six plants: Fortum Hoegdalen, Haesselby and Brista, Stora Enso Hyltebruk, Tekniska Verken i Linkoeping, kraftvaermeverket and C4-Energi, Alloeverket. Participating plants have shown a wide variety in: different boiler designs, different design of superheater and economizer, different kinds of used fuels and different kinds of fouling problems. Soot blowing efficiency is basically a function of three parameters: 1. Characteristics of the deposit regarding to hardness, toughness, homogeneity, amount and coverage, this is often due to the characteristics of the fired fuel. 2. Design of the heat absorbing banks regarding the risk of deposit formation and clogging. 3. Characteristics of the soot blowing method regarding the cleaning effect, bank penetration, high temperature endurance and suitability in different parts of the boiler. These three parameters coincide and together they decide the performance efficiency of the soot blowing method. Used fuel can be divided in to three groups depending on the formed deposits: Firing of mainly wood fuels resulted in no or minor problem with fouling. Firing of waste fuels resulted in hard and tough deposits. Participating waste fired boilers was, however, designed with consideration to these types of deposits and, therefore, these deposits was in reality not a

  8. Needs-driven soot blowing in waste boilers; Behovsstyrd sotblaasning i avfallspannor

    Energy Technology Data Exchange (ETDEWEB)

    Niklasson, Fredrik; Davidsson, Kent

    2009-09-15

    The increased use of alternative and waste fuels has resulted in an increased number of plants having trouble with fouling and corrosion on boiler banks and superheater tubes. Frequent sootblowing will keep the surfaces relatively clean, but on the other hand, it may erode the tube material. An intelligent sootblowing system will initiate sootblowings on individual tube banks only when needed for that specific tube bank. Such a system depends on the detection of the degree of fouling of specific tube banks. In this project, the conditions for an intelligent sootblowing system at the waste fired boilers in Boraas are investigated from measured flows, temperatures and pressure drop. New thermocouples at the water tubes between the banks of the economiser have been installed and connected to the control and monitoring system of the boiler. From measured temperatures and flows, heat transfer coefficients are calculated and used to detect the fouling on the heat exchangers. A pressure transducer has been altered to measure the pressure over the boiler bank. At the superheaters, the measurements show a significant improvement of the heat transfer coefficients immediately following sootblowing. Thereafter, the heat transfer coefficients decline more slowly, almost linearly. The measurements indicate that the fouling rate is almost same for the two superheaters and do not motivate individual sootblowing sequences of the two superheaters. The pressure drop over the boiler bank was found too insensitive a measure to be used as an indicator for an intelligent sootblowing system, at least in this specific boiler. In the economiser, the decline of calculated heat transfer coefficients showed a relative rate of fouling on individual tube banks. The results show that the fouling rate is significantly higher in the top tube banks, which comes first in the direction of the flue gas, compared to downstream banks. Experiments by sootblowing the top tube bank more frequently than the

  9. Characterization and quantification of deposits build up and removal in straw suspension fired boilers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Arendt Jensen, Peter; Wedel, S.; Jappe Frandsen, F.; Dam-Johansen, K.; Shafique Bashir, M. [Technical Univ. of Denmark. CHEC Research Centre, Kgs. Lyngby (Denmark); Wadenback, J.; Thaaning Pedersen, S. [Vattenfall A/S, Copenhagen (Denmark)

    2013-07-15

    This project deals with ash deposit formation in suspension fired biomass power plant boilers. The project has been conducted in a tight collaboration between Vattenfall and the CHEC Research Centre at DTU Department of Chemical Engineering. A large part of the project has been performed by conducting advanced probe measurements at the Amagervaerkets Vattenfall owed boilers. It was the objective of the project to provide an improved understanding of ash deposit formation and removal in biomass suspension fired boilers. The project have provided a large amount of knowledge on the following issues: 1) The influence of local boiler conditions on deposit formation in suspension fired boilers using wood or co-firing straw and wood, 2) quantification of deposit removal in biomass suspension firing boilers with regards both to natural shedding and soot blower induced shedding, 3) established relations of the properties of fuel ash, fly ash and deposits, 4) use of coal ash to remedy biomass ash induced boiler deposit problems. (Author)

  10. Extension of Weighted Sum of Gray Gas Data to Mathematical Simulation of Radiative Heat Transfer in a Boiler with Gas-Soot Media

    Directory of Open Access Journals (Sweden)

    Samira Gharehkhani

    2014-01-01

    Full Text Available In this study an expression for soot absorption coefficient is introduced to extend the weighted-sum-of-gray gases data to the furnace medium containing gas-soot mixture in a utility boiler 150 MWe. Heat transfer and temperature distribution of walls and within the furnace space are predicted by zone method technique. Analyses have been done considering both cases of presence and absence of soot particles at 100% load. To validate the proposed soot absorption coefficient, the expression is coupled with the Taylor and Foster's data as well as Truelove's data for CO2-H2O mixture and the total emissivities are calculated and compared with the Truelove's parameters for 3-term and 4-term gray gases plus two soot absorption coefficients. In addition, some experiments were conducted at 100% and 75% loads to measure furnace exit gas temperature as well as the rate of steam production. The predicted results show good agreement with the measured data at the power plant site.

  11. Extension of weighted sum of gray gas data to mathematical simulation of radiative heat transfer in a boiler with gas-soot media.

    Science.gov (United States)

    Gharehkhani, Samira; Nouri-Borujerdi, Ali; Kazi, Salim Newaz; Yarmand, Hooman

    2014-01-01

    In this study an expression for soot absorption coefficient is introduced to extend the weighted-sum-of-gray gases data to the furnace medium containing gas-soot mixture in a utility boiler 150 MWe. Heat transfer and temperature distribution of walls and within the furnace space are predicted by zone method technique. Analyses have been done considering both cases of presence and absence of soot particles at 100% load. To validate the proposed soot absorption coefficient, the expression is coupled with the Taylor and Foster's data as well as Truelove's data for CO2-H2O mixture and the total emissivities are calculated and compared with the Truelove's parameters for 3-term and 4-term gray gases plus two soot absorption coefficients. In addition, some experiments were conducted at 100% and 75% loads to measure furnace exit gas temperature as well as the rate of steam production. The predicted results show good agreement with the measured data at the power plant site. PMID:25143981

  12. Characterization and quantification of deposits build up and removal in straw suspension fired boilers

    DEFF Research Database (Denmark)

    Jensen, Peter Arendt; Shafique Bashir, Muhammad; Wedel, Stig;

    This project deals with ash deposit formation in suspension fired biomass power plant boilers. The project has been conducted in a tight collaboration between Vattenfall and the CHEC Research Centre at DTU Department of Chemical Engineering. A large part of the project has been performed...... by conducting advanced probe measurements at the Amagerværkets Vattenfall owed boilers. It was the objective of the project to provide an improved understanding of ash deposit formation and removal in biomass suspension fired boilers. The project have provided a large amount of knowledge on the following issues......: 1) The influence of local boiler conditions on deposit formation in suspension fired boilers using wood or co-firing straw and wood, 2) quantification of deposit removal in biomass suspension firing boilers with regards both to natural shedding and soot blower induced shedding, 3) established...

  13. Online soot cleaning using infrasound

    Energy Technology Data Exchange (ETDEWEB)

    Torra i Fernandez, Eric; Ellebro, Martin [Infrafone AB, Stockholm (Sweden)

    2013-10-01

    The company Infrafone has been using infrasound as a soot cleaning method for more than 30 years. Infrasonic soot cleaning increases the efficiency, the availability and the lifetime of marine and industrial boilers. The properties and the description of infrasound and Infrafone's soot cleaning method are presented. Moreover, a brief comparison with audible sonic horns is carried out. The results and the savings of installing Infrafone's infrasonic cleaners are presented here with several case studies. (orig.)

  14. Size distribution and concentration of soot generated in oil and gas-fired residential boilers under different combustion conditions

    Science.gov (United States)

    Jiménez, Santiago; Barroso, Jorge; Pina, Antonio; Ballester, Javier

    2016-05-01

    In spite of the relevance of residential heating burners in the global emission of soot particles to the atmosphere, relatively little information on their properties (concentration, size distribution) is available in the literature, and even less regarding the dependence of those properties on the operating conditions. Instead, the usual procedure to characterize those emissions is to measure the smoke opacity by several methods, among which the blackening of a paper after filtering a fixed amount of gas (Bacharach test) is predominant. In this work, the size distributions of the particles generated in the combustion of a variety of gaseous and liquid fuels in a laboratory facility equipped with commercial burners have been measured with a size classifier coupled to a particle counter in a broad range of operating conditions (air excesses), with simultaneous determination of the Bacharach index. The shape and evolution of the distribution with progressively smaller oxygen concentrations depends essentially on the state of the fuel: whereas the combustion of the gases results in monomodal distributions that 'shift' towards larger diameters, in the case of the gas-oils an ultrafine mode is always observed, and a secondary mode of coarse particle grows in relevance. In both cases, there is a strong, exponential correlation between the total mass concentration and the Bacharach opacity index, quite similar for both groups of fuels. The empirical expressions proposed may allow other researchers to at least estimate the emissions of numerous combustion facilities routinely characterized by their smoke opacities.

  15. Improvement in super heater deposition of straw boiler based on numerical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Tai, Lv; Zhou, Ting-ting; Wang, Hai [Northeast Dianli Univ., Jilin (China). College of Energy and Power Engineering

    2013-07-01

    There is the problem of deposition exits generally in straw boiler super heater due to chlorine and alkalescent substance consists in the straw fuel, which agglomerate combustion material, especially for crops. Deposition does not only behave to raise the tube temperature, but also accelerate corrosion, even hide cartridge igniter trouble. This paper based on the study of some 75 t/h plant to optimize the ash removal system of super heater. According to the CFD simulation, the flue flow situation in tube bundle of super heater diverse along with the position of the tube. Based on the regular of deposit researched from the simulation outcome, this paper propose to optimize the structure of shock wave soot blower of pattern BH-100 used by the plant, which did not performance a proper role.

  16. VARIABLE SPEED INTEGRATED INTELLIGENT HVAC BLOWER

    Energy Technology Data Exchange (ETDEWEB)

    Shixiao Wang; Herman Wiegman; Wilson Wu; John Down; Luana Iorio; Asha Devarajan; Jing Wang; Ralph Carl; Charlie Stephens; Jeannine Jones; Paul Szczesny

    2001-11-14

    This comprehensive topical report discusses the key findings in the development of a intelligent integrated blower for HVAC applications. The benefits of rearward inclined blades over that of traditional forward inclined blades is well documented and a prototype blower design is presented. A comparison of the proposed blower to that of three typical units from the industry is presented. The design of the blower housing is also addressed and the impact of size limitations on static efficiency is discussed. Issues of air flow controllability in the rearward inclined blower is addressed and a solution to this problem is proposed. Several motor design options are discussed including inside-out radial flux designs and novel axial flux designs, all are focused on the various blower needs. The control of the motor-blower and airflow through the use of a high density inverter stage and modern digital signal processor is presented. The key technical challenges of the approach are discussed. The use of the motor as a sensor in the larger heating/ventilating system is also discussed. Diagnostic results for both the motor itself and the blower system are presented.

  17. VARIABLE SPEED INTEGRATED INTELLIGENT HVAC BLOWER; TOPICAL

    International Nuclear Information System (INIS)

    This comprehensive topical report discusses the key findings in the development of a intelligent integrated blower for HVAC applications. The benefits of rearward inclined blades over that of traditional forward inclined blades is well documented and a prototype blower design is presented. A comparison of the proposed blower to that of three typical units from the industry is presented. The design of the blower housing is also addressed and the impact of size limitations on static efficiency is discussed. Issues of air flow controllability in the rearward inclined blower is addressed and a solution to this problem is proposed. Several motor design options are discussed including inside-out radial flux designs and novel axial flux designs, all are focused on the various blower needs. The control of the motor-blower and airflow through the use of a high density inverter stage and modern digital signal processor is presented. The key technical challenges of the approach are discussed. The use of the motor as a sensor in the larger heating/ventilating system is also discussed. Diagnostic results for both the motor itself and the blower system are presented

  18. Air injection vacuum blower noise control

    Energy Technology Data Exchange (ETDEWEB)

    Mose, Tyler L.A.; Faszer, Andrew C. [Noise Solutions Inc. (Canada)], email: tmose@noisesolutions.com, email: afaszer@noisesolutions.com

    2011-07-01

    Air injection vacuum blowers, with applications in waste removal, central vacuum systems, and aeration systems, are widely used when high vacuum levels are required. Noise generated by those blowers must be addressed for operator health and residential disturbance. This paper describes a project led by Noise Solutions Inc., to identify noise sources in a blower, and design and test a noise mitigation system. First the predominant noise sources in the blower must be determined, this is done with a sound level meter used to quantify the contribution of each individual noise source and the dominant tonal noise from the blower. Design of a noise abatement system must take into account constraints arising from blower mobile use, blower optimal performance, and the resulting overall vibration of the structure. The design was based on calculations from the sound attenuation of a reactive expansion chamber and two prototypes of custom silencers were then tested, showing a significant noise reduction both in total sound levels and tonal noise.

  19. Regenerative Blower for EVA Suit Ventilation Fan

    Science.gov (United States)

    Izenson, Michael G.; Chen, Weibo; Paul, Heather L.

    2010-01-01

    Portable life support systems in future space suits will include a ventilation subsystem driven by a dedicated fan. This ventilation fan must meet challenging requirements for pressure rise, flow rate, efficiency, size, safety, and reliability. This paper describes research and development that showed the feasibility of a regenerative blower that is uniquely suited to meet these requirements. We proved feasibility through component tests, blower tests, and design analysis. Based on the requirements for the Constellation Space Suit Element (CSSE) Portable Life Support System (PLSS) ventilation fan, we designed the critical elements of the blower. We measured the effects of key design parameters on blower performance using separate effects tests, and used the results of these tests to design a regenerative blower that will meet the ventilation fan requirements. We assembled a proof-of-concept blower and measured its performance at sub-atmospheric pressures that simulate a PLSS ventilation loop environment. Head/flow performance and maximum efficiency point data were used to specify the design and operating conditions for the ventilation fan. We identified materials for the blower that will enhance safety for operation in a lunar environment, and produced a solid model that illustrates the final design. The proof-of-concept blower produced the flow rate and pressure rise needed for the CSSE ventilation subsystem while running at 5400 rpm, consuming only 9 W of electric power using a non-optimized, commercial motor and controller and inefficient bearings. Scaling the test results to a complete design shows that a lightweight, compact, reliable, and low power regenerative blower can meet the performance requirements for future space suit life support systems.

  20. Improved soot blowing, based on needs, using the mechanical characteristics of the steam pipe - stage 2; Foerbaettrad behovsstyrd sotning med hjaelp av vaermeoeverfoerande tubens mekaniska egenskaper - etapp 2

    Energy Technology Data Exchange (ETDEWEB)

    Blom, Elisabet; Fredoe, Claes; Gabrielsson, Lars; Eriksson, Daniel

    2011-10-15

    The detection of contamination of the boiler tubes through the tube mechanical properties has been studied. The project has carried out measurements and detection of three different boilers with different conditions in terms of sooting philosophy, combustion method and sooting method. The assembly of the detecting strain gauge takes place on a clip which is screwed and glued onto the tube.

  1. High temperature corrosion in biomass- and waste fired boilers. A status report; Kunskapslaeget betraeffande hoegtemperaturkorrosion i aangpannor foer biobraensle och avfall

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, P.; Ifwer, K.; Staalenheim, A.; Montgomery, M.; Hoegberg, J.; Hjoernhede, A.

    2006-12-15

    Many biomass- or waste-fired plants have problems with high temperature corrosion on the furnace walls or at the superheaters, especially if the steam temperature is greater than 500 deg C. An increase in the combustion of waste fuels means that an increasing number of boilers have had problems. Therefore, there is great interest from plant owners to reduce the costs associated with high temperature corrosion. At the same time there exists a considerable driving force towards improving the electrical efficiency of a plant by the use of more advanced steam data. The purpose of the work presented here was to answer three main questions: What can be done to reduce high temperature corrosion with current fuel blends and steam temperatures? How can more waste fuels be burnt without an increased risk for corrosion? What needs to be done to reach higher steam temperatures in the future? The level of knowledge of high temperature corrosion in biomass- and waste-fired boilers has been described and summarised. The following measures are recommended to reduce corrosion in existing plant: Make sure that the fuel is well mixed and improve fuel feeding to obtain a more even spread of the fuel over the cross-section of the boiler. Use combustion technology methods to stabilize the oxygen content of the flue gases near the membrane walls and other heat transfer surfaces. Experiment with additives and/or supplementary fuels which contain sulphur in some form, for example peat. Reduce the flue gas temperature at the superheaters. Review soot-blowing procedures or protect heat transfer surfaces from soot blowers. Evaluate coated membrane wall panels in parts of the furnace that experience the worst corrosion. Test more highly alloyed steels suitable for superheaters and when replacing a superheater change to a more highly alloyed steel. For the future, the following should be considered: The role of sulphur needs to be investigated more and other additives should be investigated

  2. 33 CFR 154.826 - Vapor compressors and blowers.

    Science.gov (United States)

    2010-07-01

    ...) Excessive shaft bearing temperature. (d) If a centrifugal compressor, fan, or lobe blower handles vapor in....826 Vapor compressors and blowers. (a) Each inlet and outlet to a compressor or blower which handles... system acceptable to the Commandant (CG-522). (b) If a reciprocating or screw-type compressor...

  3. Production Facility Prototype Blower Installation Report

    Energy Technology Data Exchange (ETDEWEB)

    Woloshun, Keith Albert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dale, Gregory E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dalmas, Dale Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Romero, Frank Patrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-07-28

    The roots blower in use at ANL for in-beam experiments and also at LANL for flow tests was sized for 12 mm diameter disks and significantly less beam heating.  Currently, the disks are 29 mm in diameter, with a 12 mm FWHM Gaussian beam spot at 42 MeV and 2.86 μA on each side of the target, 5.72 μA total. The target design itself is reported elsewhere.  With the increased beam heating, the helium flow requirement increased so that a larger blower was need for a mass flow rate of 400 g/s at 2.76 MPa (400 psig).  An Aerzen GM 12.4 blower was selected, and is currently being installed at the LANL facility for target and component flow testing.  This report describes this blower/motor/ppressure vessel package and the status of the facility preparations.

  4. Improved soot blowing, based on needs, through measurement of the natural frequency of the heat transferring tubes; Foerbaettrad behovsstyrd sotning genom maetning av oeverfoerande tubernas egenfrekvens

    Energy Technology Data Exchange (ETDEWEB)

    Blom, Elisabet; Ivarsson, Christofer

    2007-11-15

    The aim of the project is to develop a method for detecting soot on the transferring tubes by measuring the Eigen frequency of the tubes as a function of the soot deposit growth. The project is a pilot study independent of boiler type and it is applicable to all boilers where soot deposit on transferring tubes is a repeating issue. The report is supposed to answer two major questions. Is it possible to make use of Eigen frequencies in order to trace soot deposit on transferring tubes? What governing parameters are related to the Eigen frequency of transferring tubes? By today, soot blowing is executed after recommendations from the manufacturer in terms of number of soot blowing per time unit. The fuel type as well as boiler type has great influence on the soot deposit growth. The objective of the project is to investigate whether the mechanical properties of the transferring tube can be used to detect soot deposit. The project is divided into a theoretical and a practical part. The theoretical part covers the design of the probe and the change of its mechanical properties when soot deposit is present. Practical experiments were then carried out in a laboratory were the probes mechanical properties with and without soot deposit were investigated. It was shown that the Eigen frequency of the probe decreased with an increased mass due to soot deposit. A test was also made in a boiler at SAKAB but difficulties in attaching the probe to the inspection hatch. The results varied and the interpretation of the results become difficult. However, it was obvious that the mechanical properties of the probe changed with the amount of soot deposit. It was concluded that detection of soot deposit by studying the mechanical properties of the transferring tubes is possible. Yet, using a probe is no optimal solution, instead measurements should be done directly on the heat transferring tubes. In addition, a strategy for controlling the soot deposit has to be developed

  5. New controls spark boiler efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Engels, T. (Monsanto, University Park, IL (United States))

    1993-09-01

    Monsanto's NutraSweet plant in University Park, IL, produces aspartame, the patented NutraSweet artificial sweetener product. Until recently, boiler control was managed by a '60s-era Fireye jackshaft system in which air and natural gas were mechanically linked with an offset to compensate for oxygen trim. The interlocking devices on the Fireye system were becoming obsolete, and the boiler needed a new front end retrofitted for low emissions. In order to improve boiler control efficiency, we decided to modernize and automate the entire boiler control system. We replaced the original jackshaft system, and installed a Gordon-Piet burner system, including gas valves, air dampers, blowers, and burner. The upgrade challenges included developing a control strategy and selecting and implementing a process control system. Since our plant has standardized on the PROVOX process management information system from Fisher Controls (now Fisher-Rosemount Systems) to support most of our process, it was a natural and logical choice for boiler controls as well. 2 figs.

  6. Simplified multizone blower door techniques for multifamily buildings. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    This research focused on the applicability of (a) two-blower-door and (b) single-blower-door multi-zone pressurization techniques for estimating the air leakage characteristics of New York State multi-family apartment buildings. The research also investigated the magnitude of external leakage area in multi-family buildings and used computer simulations to estimate the effect of decreasing external and internal leakage areas on air infiltration rates. This research investigates whether two blower doors can be used to determine the ELA of the exterior envelope and the ELA of partitions. Two multi-zone versions of the single-blower-door pressurization method are also examined.

  7. Experimental investigation on a one-step centripetal blower as a model of a blower to ventilate cooling towers

    International Nuclear Information System (INIS)

    Model tests were performed on a one-step centripetal blower (impeller external diameter of 1 m) whose aim was to clarify whether this kind of blower is suitable to ventilate a cooling tower. Aside from the investigation of the general operational behaviour, it was above all important in the tests to investigate the sensitivity of the centripetal blower to rotating tearing with regular flow as well as with side wind, as the main difficulty was suspected in controlling the blower with side wind. (orig./LN)

  8. Operating experience with main blowers with variable blade angles

    Energy Technology Data Exchange (ETDEWEB)

    Bogatov, I.V.; Spivak, V.A.

    1986-05-01

    Efficiency of blowers used for ventilation in underground coal mines in the USSR in many cases is below the statistical efficiency level. Efficiency of 30% of blowers does not exceed 60%. New design of blower blades developed and tested in the USSR is an easy and economic way for increasing blower efficiency. Each blade consists of 2 sections: a stationary section and a section with a variable-incidence angle. The incidence angle depends on local conditions and requirements for ventilation. During performance tests of VTsZ-32 blowers in the PKAA mine an angle of blade incidence of 20 or 30 degrees was used. This guaranteed air pressure of 6,000 Pa and air output of 120 m/sup 3//s. Increased blade incidence angle was used in summer and during periods of increased methane emission. In winter angle of blade incidence was reduced to 10 degrees, blower output ranged from 80 to 90 m/sup 3//s, air pressure declined to 3,800 Pa. Using blower blades with variable-incidence angle reduced energy consumption, ventilation cost and investment.

  9. Liquid Cloud Responses to Soot

    Science.gov (United States)

    Koch, D. M.

    2010-12-01

    Although soot absorption warms the atmosphere, soot may cause climate cooling due to its effects on liquid clouds, including contribution to cloud condensation nuclei (CCN) and semi-direct effects. Six global models that include aerosol microphysical schemes conducted three soot experiments. The average model cloud radiative response to biofuel soot (black and organic carbon), including both indirect and semi-direct effects, is -0.12 Wm-2, comparable in size but opposite in sign to the respective direct atmospheric warming. In a more idealized fossil fuel black carbon only experiment, some models calculated a positive cloud response because the soot provided a deposition sink for sulfate, decreasing formation of more viable CCN. Biofuel soot particles were typically assumed to be larger and more hygroscopic than for fossil fuel soot and therefore caused more negative forcing, as also found in previous studies. Diesel soot (black and organic carbon) experiments had relatively smaller cloud impacts with five of the models competition of opposing effects on the CCN population make it difficult to extrapolate from idealized experiments to likely impacts of realistic potential emission changes. However, results so far suggest that soot-induced cloud-cooling effects are comparable in magnitude to the direct warming effects from soot absorption.

  10. Biomass boilers

    OpenAIRE

    Nahodil, Jiří

    2011-01-01

    Bachelor’s thesis deals with the use of biomass for heating houses and apartment houses. The first part is dedicated to biomass. Here are mentioned the possibility of energy recovery, treatment and transformation of biomass into a form suitable for burning, its properties and combustion process itself. The second part is devoted to biomass boilers, their separation and description. The last section compares the specific biomass boiler with a boiler to natural gas, particularly from an economi...

  11. Vibration and Stability of 3000-hp, Titanium Chemical Process Blower

    OpenAIRE

    2003-01-01

    This 74-in-diameter blower had an overhung rotor design of titanium construction, operating at 50 pounds per square inch gauge in a critical chemical plant process. The shaft was supported by oil-film bearings and was directdriven by a 3000-hp electric motor through a metal disk type of coupling. The operating speed was 1780 rpm. The blower shaft and motor shaft motion was monitored by Bently Nevada proximity probes and a Model 3100 monitoring system.Although the blowers showed very satisfact...

  12. Blower door method in radon diagnostics

    International Nuclear Information System (INIS)

    The idea of the radon transfer factor is commonly presented as the ratio of the building indoor radon concentration to the subsoil radon concentration. Ventilation and the pressure field over the whole building envelope, which varies in a time over a very wide range even in the same building, poses a major problem. Therefore a new approach based on the controlled conditions determining the soil air infiltration was developed. Radon in soil gas infiltrates into the building indoor environment particularly through cracks and other leakages in the structure providing the building contact with its subsoil. The infiltration is driven by the air pressure difference on the two sides of the structure. The pressure difference is caused by the stack effect and its value ranges from 1-2 Pa in family houses to some tens of Pa in higher buildings. Unfortunately, the pressure difference is very unstable under normal conditions, being affected by a host of parameters such as the height of the building, distribution and geometry of leakages, outdoor-indoor temperature difference, etc. Wind direction and velocity of the wind plays a major role. In our research the blower door method was applied in combination with a monitoring of the indoor radon concentration. The indoor-outdoor pressure difference and the pressure difference at the two sides of the screen shutter of the blower door fan are also measured. The blower door ensures a constant, evaluable air exchange rate. The fan power is regulated to provide a stable pressure difference within the range of roughly 5-100 Pa. This approach provides very well defined conditions allowing us to apply a constant ventilation-constant radon supply model. In such circumstances the dynamical changes of radon concentrations are very fast, and therefore a unique continual radon monitor was applied. The radon supply rate is evaluated from the radon steady state of the time course of radon concentration. The dependence of the radon supply rate on

  13. EC motors for blowers; EC-Motoren fuer Luefter

    Energy Technology Data Exchange (ETDEWEB)

    Sauer, Thomas; Reiff, Ellen-Christine

    2009-10-15

    There are highly flexible commercial ventilation and air conditioning systems for server rooms which combine energy savings with optimum room air quality. EC blowers contribute to this and reduce also body sound. (orig./GL)

  14. Dynamical system analysis of unstable flow phenomena in centrifugal blower

    Directory of Open Access Journals (Sweden)

    Garcia David

    2015-09-01

    Full Text Available Methods of dynamical system analysis were employed to analyze unsteady phenomena in a centrifugal blower. Pressure signals gathered at different control points were decomposed into their Principal Components (PCs by means of Singular Spectrum Analysis (SSA. Certain number of PCs was considered in the analysis based on their statistical correlation. Projection of the original signal onto its PCs allowed to draw the phase trajectory that clearly separated non-stable blower working conditions from its regular operation.

  15. Vibration and Stability of 3000-hp, Titanium Chemical Process Blower

    Directory of Open Access Journals (Sweden)

    Les Gutzwiller

    2003-01-01

    Full Text Available This 74-in-diameter blower had an overhung rotor design of titanium construction, operating at 50 pounds per square inch gauge in a critical chemical plant process. The shaft was supported by oil-film bearings and was directdriven by a 3000-hp electric motor through a metal disk type of coupling. The operating speed was 1780 rpm. The blower shaft and motor shaft motion was monitored by Bently Nevada proximity probes and a Model 3100 monitoring system.

  16. On sound generation mechanism by a centrifugal blower

    Science.gov (United States)

    Wu, Sean

    2002-05-01

    Centrifugal blower noise has often been modeled as dipoles and quadrupoles to account for the effects of fluid-structure interaction and turbulence as the impeller rotates. However, many experimental results have shown that sound powers from centrifugal blowers increase with speed to the power of 4-6, which implies the existence of a monopole [Lighthill, Proc. R. Soc., Ser. A 222, 564-587 (1952)]. This paper demonstrates that such a monopole indeed exists for a blower running inside a heating ventilation and air-conditioning (HVAC) unit of a vehicle. Tests indicate that this monopole is producible by a volumetric fluctuation due to an unsteady rotor. When the blower is operated at the voltage power input specified by the car manufacturer, the sound power increases with the speed to the power of 4. When the blower is installed on a stable shaft and running at the same voltage power input, the volumetric fluctuations are significantly reduced and the sound power increases with speed to the power of 6. This implies that the monopole sound has been effectively replaced by the dipole sound. Since dipole is less effective in generating sound at low speeds than monopole, eliminating rotor fluctuations can lower vehicle HVAC noise levels.

  17. Chemical and statistical soot modeling

    OpenAIRE

    Blanquart, Guillaume

    2008-01-01

    The combustion of petroleum based fuels like kerosene, gasoline, or diesel leads to the formation of several kind of pollutants. Among them, soot particles are particularly bad for their severe consequences on human health. Over the past decades, strict regulations have been placed on car and aircraft engines in order to limit these particulate matter emissions. Designing low emission engines requires the use of predictive soot models which can be applied to the combustion of real fuels. ...

  18. Uji Performansi Getaran Mekanis dan Kebisingan Mist Blower Yanmar MK 150-B

    OpenAIRE

    Ahmad Noval Irvani; Mad Yamin

    2012-01-01

    Mist blower is one of the mechanization tool of agriculture considered as a tool that can assist humans in fertilizer and pesticides spreading activities. Levels of motor speed in the used mist blower were 1915, 4009, and 7227 rpm. Vibration measurements were conducted on the engine and handlebar control mist blower with the three-dimensional axes namely X, Y, and Z. Mist blower noise measurements were performed on the engine, operator's right ear and left ear. Based on the analysis of vibrat...

  19. Building America Top Innovations 2013 Profile – High-Performance Furnace Blowers

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2013-09-01

    This Top Innovations profile describes Lawrence Berkeley National Laboratory's work with furnace blower design that led to the creation of a standard for rating blowers, credits for the use of good blowers in Federal tax credit programs and energy codes, and consideration in current federal rulemaking procedures.

  20. Ash fouling monitoring and key variables analysis for coal fired power plant boiler

    OpenAIRE

    Shi Yuanhao; Wang Jingcheng

    2015-01-01

    Ash deposition on heat transfer surfaces is still a significant problem in coal-fired power plant utility boilers. The effective ways to deal with this problem are accurate on-line monitoring of ash fouling and soot-blowing. In this paper, an online ash fouling monitoring model based on dynamic mass and energy balance method is developed and key variables analysis technique is introduced to study the internal behavior of soot-blowing system. In this process...

  1. The impact of biomass co-combustion on the erosion of boiler convection surfaces

    International Nuclear Information System (INIS)

    Highlights: • The lower ash content of biomass, the more quickly ash settles on boiler tubes. • The higher share of biomass, the more quickly ash settles on boiler tubes. • Operation of jet blowers involves intense fly ash erosive wear of heating surfaces • Application of acoustic or microblasting technology is advantageous. - Abstract: The erosive wear of boiler tubes caused by fly ash in coal combustion flue gases has been studied for a long time. However, there are practically no data concerning the intensity of the erosion of the heating surfaces of boilers fired with both coal and biomass, and thus it is difficult to design these particular areas appropriately. The essential problem is the tendency of the fly ash from biomass combustion to produce ash deposits on the boiler convection surfaces and to cause slagging on the radiant surfaces. In such cases, both an increase in the deposits and a shortening of the time over which the ash fouling accumulates to the maximum level are observed. Consequently, if the boiler is fitted with steam or air blowers, they are started more frequently; if not, they have to be installed. The research conducted here proves that the situation leads to serious damage to the tubes, which results from the erosion caused by ash particles carried by the blowing agent jet. The authors of this paper attempt to make a quantitative evaluation of the impact of co-firing two types of biomass (coniferous wood chips and willow wood chips) on both types of tube erosion

  2. Energy efficiency in boilers; Eficiencia energetica em caldeiras

    Energy Technology Data Exchange (ETDEWEB)

    Ponte, Ricardo Silva The [Universidade Federal do Ceara (UFCE), Fortaleza, CE (Brazil). Dept. de Engenharia Eletrica], email: ricthe@dee.ufc.br; Barbosa, Marcos Antonio Pinheiro; Rufino, Maria da Gracas [Universidade de Fortaleza (UNIFOR), CE (Brazil). Dept. de Engenharia Eletrica], emails: marcos_apb@unifor.br, gsrufino@unifor.br

    2010-07-01

    The boiler is vapor generator equipment that has been widely used in industrial milieu as in electric energy generation in thermoelectric plants. Since their first conception, the boilers have been changed in order to provide security and energetic efficiency. They can present high losses of energy if they don't be operated according to some criteria. A considerable part of boilers operation cost include fuel expenses. So, the adoption of effective steps in order to reduce fuel consumption is important to industry economy, besides it brings environmental benefits through the reduction of pollution liberation. The present article has the objective of emphasizing the effective steps for the economy of energy in boilers, such as, the regulation of combustion; the control of soot and incrustations; the installation of economizers, air heaters and super heaters; the reduction in purges and reintroduction of condensed steam. (author)

  3. Performance Enhancement of Dual-Inlet Centrifugal Blower by Optimal Design of Splitter

    International Nuclear Information System (INIS)

    The shape of an impeller splitter for a dual-inlet centrifugal blower was optimized to enhance the blower performance. Two design variable, the normalized chord and pitch of a splitter, were used to evaluate the blower performance and internal flow fields based on the three-dimensional flow analysis. The blower performance obtained using this numerical simulation had a maximum error of 4 percent compared to that in an experiment at the design flow condition. The shape optimization of the splitter successfully increased the blower efficiency and pressure by 3.65 and 1.14 percent compared to the reference values. The blower performance was increased by reducing the flow separation near the blade suction surface by optimizing the shape of the splitter, which produced a pressure increase at the outlet of the volute casing

  4. Performance Enhancement of Dual-Inlet Centrifugal Blower by Optimal Design of Splitter

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Sung; Jang, Choon Man [Korea Institute of Construction Technology, Goyang (Korea, Republic of)

    2014-12-15

    The shape of an impeller splitter for a dual-inlet centrifugal blower was optimized to enhance the blower performance. Two design variable, the normalized chord and pitch of a splitter, were used to evaluate the blower performance and internal flow fields based on the three-dimensional flow analysis. The blower performance obtained using this numerical simulation had a maximum error of 4 percent compared to that in an experiment at the design flow condition. The shape optimization of the splitter successfully increased the blower efficiency and pressure by 3.65 and 1.14 percent compared to the reference values. The blower performance was increased by reducing the flow separation near the blade suction surface by optimizing the shape of the splitter, which produced a pressure increase at the outlet of the volute casing.

  5. Design and Development of a Regenerative Blower for Space Suit Ventilation

    Science.gov (United States)

    Izenson, Mike; Chen, Weibo; Paul, Heather

    2010-01-01

    The ventilation subsystem in future space suits will require a dedicated ventilation fan. The unique requirements for the ventilation fan, including stringent safety requirements and the ability to increase output to operate in buddy mode, combine to make a regenerative blower an attractive technology choice. This paper describes progress in the design, development, and testing of a regenerative blower designed to meet requirements for a ventilation subsystem for future space suit life support. Analysis methods were developed for the blower s complex internal flows and impeller geometries were identified that enable significant improvements in blower efficiency. Performance predictions were verified by test, measuring aerodynamic efficiencies of 45% at operating conditions that correspond to the ventilation fan s design point. A compact motor/controller was developed to drive the blower efficiently at low rotating speed (4500 rpm). Finally, a low-pressure oxygen test loop was assembled to demonstrate the blower s reliability under prototypical conditions.

  6. Design and Development of a Regenerative Blower for EVA Suit Ventilation

    Science.gov (United States)

    Izenson, Michael G.; Chen, Weibo; Hill, Roger W.; Phillips, Scott D.; Paul, Heather L.

    2011-01-01

    Ventilation subsystems in future space suits require a dedicated ventilation fan. The unique requirements for the ventilation fan - including stringent safety requirements and the ability to increase output to operate in buddy mode - combine to make a regenerative blower an attractive choice. This paper describes progress in the design, development, and testing of a regenerative blower designed to meet requirements for ventilation subsystems in future space suits. We have developed analysis methods for the blower s complex, internal flows and identified impeller geometries that enable significant improvements in blower efficiency. We verified these predictions by test, measuring aerodynamic efficiencies of 45% at operating conditions that correspond to the ventilation fan s design point. We have developed a compact motor/controller to drive the blower efficiently at low rotating speed (4500 rpm). Finally, we have assembled a low-pressure oxygen test loop to demonstrate the blower s reliability under prototypical conditions.

  7. Ago Soots tuli Võrru "Peole" / Ago Soots ; intervjueerinud Kaile Kabun

    Index Scriptorium Estoniae

    Soots, Ago

    2009-01-01

    Intervjuu Võrumaalt pärit VAT Teatri näitleja ja lavastaja Ago Sootsiga, kes mängib peaosa Võru linnateatri suvelavastuses "Pidu". Slawomir Mrožeki näidendi lavastab Uku Uusberg, esietendus 17. juunil Võru vanas viinavabrikus. Ago Soots oma kooliajast, tööst VAT Teatris, huvist muusika ja spordi vastu, näitlejaametist, lavastusest

  8. Sistem Pemeliharaan Dan Cara Kerja Peralatan Blower Di Pabrik Mini PTKI – Medan

    OpenAIRE

    Manurung, Benari H.

    2012-01-01

    Pendidikan Teknologi Kimia Industri Medan memiliki suatu pabrik mini yang di dalamnya terdapat banyak peralatan – peralatan mekanik yang sering di gunakan di bidang industri, salah satu dari peralatan tersebut adalah Blower. Blower merupakan mesin atau alat yang digunakan untuk menaikkan atau memperbesar tekanan udara atau gas, yang akan dialirkan dalam suatu ruangan tertentu, juga sebagai pengisapan atau pemvakuman udara atau gas yang tertentu. Pada blower, cara kerja yang terjadi memi...

  9. Time-frequency analysis of the Surge Onset in the Centrifugal Blower

    Science.gov (United States)

    Liskiewicz, Grzegorz; Horodko, Longin

    2015-09-01

    Time frequency analysis of the surge onset was performed in the centrifugal blower. A pressure signal was registered at the blower inlet, outlet and three locations at the impeller shroud. The time-frequency scalograms were obtained by means of the Continuous Wavelet Transform (CWT). The blower was found to successively operate in four different conditions: stable working condition, inlet recirculation, transient phase and deep surge. Scalograms revealed different spectral structures of aforementioned phases and suggest possible ways of detecting the surge predecessors.

  10. Steam boiler technology

    Energy Technology Data Exchange (ETDEWEB)

    Teir, S.

    2002-07-01

    The steam boiler technology e-Book is provided by the Laboratory of Energy Engineering and Environmental Protection at Helsinki University of Technology. The book covers the basics and the history of steam generation, modern boilers types and applications, steam/water circulation design, feedwater and steam systems components, heat exchangers in steam boilers, boiler calculations, thermal design of heat exchangers.

  11. Response to centrifugal and axi-vane blowers to large pressure transients

    International Nuclear Information System (INIS)

    The effect of large pressure pulses on the operation of centrifugal and axi-vane blowers of the types found in ventilation systems used in the mining and nuclear industries was investigated using the Los Alamos National Laboratory/New Mexico State University fluid dynamics test facility. Three blowers were tested for both quasi-steady and transient pressures: a 24-in. and a 12-in. centrifugal blower and a 33-in. axi-vane blower were subjected to pressure pulses at their exhaust and inlet, which caused backflow and outrunning flow, respectively. Performance curves were obtained for the first, second, and fourth quadrants

  12. Ash fouling monitoring and key variables analysis for coal fired power plant boiler

    Directory of Open Access Journals (Sweden)

    Shi Yuanhao

    2015-01-01

    Full Text Available Ash deposition on heat transfer surfaces is still a significant problem in coal-fired power plant utility boilers. The effective ways to deal with this problem are accurate on-line monitoring of ash fouling and soot-blowing. In this paper, an online ash fouling monitoring model based on dynamic mass and energy balance method is developed and key variables analysis technique is introduced to study the internal behavior of soot-blowing system. In this process, artificial neural networks (ANN are used to optimize the boiler soot-blowing model and mean impact values method is utilized to determine a set of key variables. The validity of the models has been illustrated in a real case-study boiler, a 300MW Chinese power station. The results on same real plant data show that both models have good prediction accuracy, while the ANN model II has less input parameters. This work will be the basis of a future development in order to control and optimize the soot-blowing of the coal-fired power plant utility boilers.

  13. Gas-cooled reactor coolant circulator and blower technology

    International Nuclear Information System (INIS)

    In the previous 17 meetings held within the framework of the International Working Group on Gas-Cooled Reactors, a wide variety of topics and components have been addressed, but the San Diego meeting represented the first time that a group of specialists had been convened to discuss circulator and blower related technology. A total of 20 specialists from 6 countries attended the meeting in which 15 technical papers were presented in 5 sessions: circulator operating experience I and II (6 papers); circulator design considerations I and II (6 papers); bearing technology (3 papers). A separate abstract was prepared for each of these papers. Refs, figs and tabs

  14. Production Facility Prototype Blower Installation Report with 1000 Hour Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Woloshun, Keith Albert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dale, Gregory E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Romero, Frank Patrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dalmas, Dale Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-04-01

    The roots blower in use at ANL for in-beam experiments and also at LANL for flow tests was sized for 12 mm diameter disks and significantly less beam heating. Currently, the disks are 29 mm in diameter, with a 12 mm FWHM Gaussian beam spot at 42 MeV and 2.86 μA on each side of the target, 5.72 μA total. The target design itself is reported elsewhere. With the increased beam heating, the helium flow requirement increased so that a larger blower was needed for a mass flow rate of 400 g/s at 2.76 MPa (400 psig). An Aerzen GM 12.4 blower was selected, and is currently being installed at the LANL facility for target and component flow testing. This report describes this blower/motor/pressure vessel package and the status of the facility preparations. The blower has been operated for 1000 hours as a preliminary investigation of long term performance, operation and possible maintenance issues. The blower performed well, with no significant change in blower head or mass flow rate developed under the operating conditions. Upon inspection, some oil had leaked out of the shaft seal of the blower. The shaft seal and bearing race have been replaced. Test results and conclusions are reported.

  15. Production Facility Prototype Blower Installation Report with 1000 Hour Test Results

    International Nuclear Information System (INIS)

    The roots blower in use at ANL for in-beam experiments and also at LANL for flow tests was sized for 12 mm diameter disks and significantly less beam heating. Currently, the disks are 29 mm in diameter, with a 12 mm FWHM Gaussian beam spot at 42 MeV and 2.86 μA on each side of the target, 5.72 μA total. The target design itself is reported elsewhere. With the increased beam heating, the helium flow requirement increased so that a larger blower was needed for a mass flow rate of 400 g/s at 2.76 MPa (400 psig). An Aerzen GM 12.4 blower was selected, and is currently being installed at the LANL facility for target and component flow testing. This report describes this blower/motor/pressure vessel package and the status of the facility preparations. The blower has been operated for 1000 hours as a preliminary investigation of long term performance, operation and possible maintenance issues. The blower performed well, with no significant change in blower head or mass flow rate developed under the operating conditions. Upon inspection, some oil had leaked out of the shaft seal of the blower. The shaft seal and bearing race have been replaced. Test results and conclusions are reported.

  16. Performance and Life Tests of a Regenerative Blower for EVA Suit Ventilation

    Science.gov (United States)

    Izenson, Michael G.; Chen, Weibo; McCormick, John; Paul, Heather L.; Jennings, Mallory A.

    2012-01-01

    Ventilation fans for future space suits must meet demanding performance specifications, satisfy stringent safety requirements for operation in an oxygen atmosphere, and be able to increase output to operate in buddy mode. A regenerative blower is an attractive choice due to its ability to meet these requirements at low operating speed. This paper describes progress in the development and testing of a regenerative blower designed to meet requirements for ventilation subsystems in future space suits. The blower includes a custom-designed motor that has significantly improved its efficiency. We have measured the blower s head/flow performance and power consumption under conditions that simulate both the normal and buddy mode operating points. We have operated the blower for TBD hours and demonstrated safe operation in an oxygen test loop at prototypical pressures. We also demonstrated operation with simulated lunar dust.

  17. NASA: Black soot fuels global warming

    CERN Multimedia

    2003-01-01

    New research from NASA's Goddard Space Center scientists suggests emissions of black soot have been altering the way sunlight reflects off Earth's snow. The research indicates the soot could be responsible for as much as 25 percent of global warming over the past century (assorted news items, 1 paragraph each).

  18. Boilers, evaporators, and condensers

    International Nuclear Information System (INIS)

    This book reports on the boilers, evaporators and condensers that are used in power plants including nuclear power plants. Topics included are forced convection for single-phase side heat exchangers, heat exchanger fouling, industrial heat exchanger design, fossil-fuel-fired boilers, once through boilers, thermodynamic designs of fossil fuel-first boilers, evaporators and condensers in refrigeration and air conditioning systems (with respect to reducing CFC's) and nuclear steam generators

  19. Central heating: package boilers

    Energy Technology Data Exchange (ETDEWEB)

    Farahan, E.

    1977-05-01

    Performance and cost data for electrical and fossil-fired package boilers currently available from manufacturers are provided. Performance characteristics investigated include: unit efficiency, rated capacity, and average expected lifetime of units. Costs are tabulated for equipment and installation of various package boilers. The information supplied in this report will simplify the process of selecting package boilers required for industrial, commercial, and residential applications.

  20. Residential Forced Air System Cabinet Leakage and Blower Performance

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain S.; Dickerhoff, Darryl J.; Delp, William W.

    2010-03-01

    This project evaluated the air leakage and electric power consumption of Residential HVAC components, with a particular focus on air leakage of furnace cabinets. Laboratory testing of HVAC components indicated that air leakage can be significant and highly variable from unit to unit ? indicating the need for a standard test method and specifying maximum allowable air leakage in California State energy codes. To further this effort, this project provided technical assistance for the development of a national standard for Residential HVAC equipment air leakage. This standard is being developed by ASHRAE and is called"ASHRAE Standard 193P - Method of test for Determining the Air Leakage Rate of HVAC Equipment". The final part of this project evaluated techniques for measurement of furnace blower power consumption. A draft test procedure for power consumption was developed in collaboration with the Canadian General Standards Board: CSA 823"Performance Standard for air handlers in residential space conditioning systems".

  1. Pumping characteristics of roots blower pumps for light element gases

    International Nuclear Information System (INIS)

    The pumping speed and compression ratio of the two-stage roots blower pumping system were measured for light element gases (H2, D2 and He) and for N2, in order to assess validity of the ITER torus roughing system as an ITER R and D task (T234). The pumping system of an Edwards EH1200 (nominal pumping speed of 1200 m3/s), two EH250s (ibid. 250 m3/s) and a backing pump (ibid. 100 m3/s) in series connection was tested under PNEUROP standards. The maximum pumping speeds of the two-stage system for D2 and N2 were 1200 and 1300 m3/h, respectively at 60 Hz, which satisfied the nominal pumping speed. These experimental data support the design validity of the ITER torus roughing system. (author)

  2. Improving quality of assembly of mine ventilation blowers

    Energy Technology Data Exchange (ETDEWEB)

    Spivak, V.A.

    1984-01-01

    Results of a study by Dongiprouglemash of reasons for substandard performance of main ventilation blowers are described. Mean time between failures is 12-20 months, and this could be improved by 1.8-2.5 times. A table illustrating common faults and their consequences is given, and two examples from Donbass mines are described. Most common faults are poor alignment of bearing due e.g. to inadequate contact between concrete base and bearing shell (reduction of bearing life from 5-10 years to less than 1 year), stepped or otherwise incorrect shaping of concrete in air flow part (2-8% pressure reduction and 3-8% efficiency reduction), uneven labyrinth gaps, and incorrect setting of guide vanes (in given example leading to vibration, noise, overheating of bearings and 30% increase in electricity consumption).

  3. Enhancement of performance by blade optimization in two-stage ring blower

    Science.gov (United States)

    Jang, Choon-Man; Han, Gi-Young

    2010-10-01

    This paper describes the shape optimization of an impeller used for two-stage high pressure ring blower. Two shape variables, which are used to define an impeller shape, are introduced to increase the blower performance. The pressure of a blower is selected as an object function, and the blade optimization is performed by a response surface method. Three-dimensional Navier-Stokes equations are introduced to analyze the internal flow of the blower and to find the value of object function for the training data. Relatively good agreement between experimental measurements and numerical simulation is obtained in the present study. Throughout the shape optimization, it is found that a hub height is effective to increase pressure in the ring blower. The pressure rise for the optimal two-stage ring blower is successfully increased up to 1.86% compared with that of reference at the design flow rate. Local recirculation flow having low velocity is formed in both sides of the impeller outlet by different flow direction of the inlet and outlet of the impeller. Detailed flow field inside the ring blower is also analyzed and discussed.

  4. Effect of strain rate on sooting limits in counterflow diffusion flames of gaseous hydrocarbon fuels: Sooting temperature index and sooting sensitivity index

    KAUST Repository

    Wang, Yu

    2014-05-01

    The effect of the strain rate on the sooting limits in counterflow diffusion flames was investigated in various gaseous hydrocarbon fuels by varying the nitrogen dilution in the fuel and oxidizer streams. The sooting limit was defined as the critical fuel and oxygen mole fraction at which soot started to appear in the elastic light scattering signal. The sooting region for normal alkane fuels at a specified strain rate, in terms of the fuel and oxygen mole fraction, expanded as the number of carbon atoms increased. The alkene fuels (ethylene, propene) tested had a higher propensity for sooting as compared with alkane fuels with the same carbon numbers (ethane, propane). Branched iso-butane had a higher propensity for sooting than did n-butane. An increase in the strain rate reduced the tendency for sooting in all the fuels tested. The sensitivity of the sooting limit to the strain rate was more pronounced for less sooting fuels. When plotted in terms of calculated flame temperature, the critical oxygen mole fraction exhibited an Arrhenius form under sooting limit conditions, which can be utilized to significantly reduce the effort required to determine sooting limits at different strain rates. We found that the limiting temperatures of soot formation flames are viable sooting metrics for quantitatively rating the sooting tendency of various fuels, based on comparisons with threshold soot index and normalized smoke point data. We also introduce a sooting temperature index and a sooting sensitivity index, two quantitative measures to describe sooting propensity and its dependence on strain rate. © 2013 The Combustion Institute.

  5. Fuel sulfur and boiler fouling

    Energy Technology Data Exchange (ETDEWEB)

    Litzke, W.; Celebi, Y.; Butcher, T. [Brookhaven National Lab., Upton, NY (United States)

    1995-04-01

    Fouling of the heat transfer surfaces of boilers and furnaces by `soot` leads to reduced efficiency and increased service requirements. The average level of annual efficiency reduction as a result of fouling if generally accepted as 2% per year. Improving the efficiency of equipment in the field may be the most important oil heat conservation opportunity at present. Improvements can be realized by reducing fouling rates, promoting lower firing rates in existing equipment, and enabling excess air levels to be set lower without raising concerns about increased service requirements. In spite of the importance of efficiency in the field there is very little data available on efficiency degradation rates with modern equipment, actual field operating conditions (excess air and smoke number settings) and service problems which affect efficiency. During 1993-94 field tests were initiated to obtain such data and to obtain information that would compliment existing and current laboratory work. Experimental work conducted on a bench scale level have included tests with various advanced burners, fuel types, and different operating conditions which have been done at the BNL Rapid Fouling Test Facility. This report will focus on the field study of fouling effects on ten residential heating service problems at each site are summarized. In addition, the technical difficulties involved with conducting such a field study shall also be discussed as the findings should serve to improve future work in this area.

  6. Time-frequency analysis of the Surge Onset in the Centrifugal Blower

    Directory of Open Access Journals (Sweden)

    Liskiewicz Grzegorz

    2015-09-01

    Full Text Available Time frequency analysis of the surge onset was performed in the centrifugal blower. A pressure signal was registered at the blower inlet, outlet and three locations at the impeller shroud. The time-frequency scalograms were obtained by means of the Continuous Wavelet Transform (CWT. The blower was found to successively operate in four different conditions: stable working condition, inlet recirculation, transient phase and deep surge. Scalograms revealed different spectral structures of aforementioned phases and suggest possible ways of detecting the surge predecessors.

  7. Monte Carlo simulation for soot dynamics

    Directory of Open Access Journals (Sweden)

    Zhou Kun

    2012-01-01

    Full Text Available A new Monte Carlo method termed Comb-like frame Monte Carlo is developed to simulate the soot dynamics. Detailed stochastic error analysis is provided. Comb-like frame Monte Carlo is coupled with the gas phase solver Chemkin II to simulate soot formation in a 1-D premixed burner stabilized flame. The simulated soot number density, volume fraction, and particle size distribution all agree well with the measurement available in literature. The origin of the bimodal distribution of particle size distribution is revealed with quantitative proof.

  8. Monte carlo simulation for soot dynamics

    KAUST Repository

    Zhou, Kun

    2012-01-01

    A new Monte Carlo method termed Comb-like frame Monte Carlo is developed to simulate the soot dynamics. Detailed stochastic error analysis is provided. Comb-like frame Monte Carlo is coupled with the gas phase solver Chemkin II to simulate soot formation in a 1-D premixed burner stabilized flame. The simulated soot number density, volume fraction, and particle size distribution all agree well with the measurement available in literature. The origin of the bimodal distribution of particle size distribution is revealed with quantitative proof.

  9. Thermometric Soots on Hot Jupiters?

    CERN Document Server

    Zahnle, K; Fortney, J J

    2009-01-01

    We use a 1D thermochemical and photochemical kinetics model to predict that the stratospheric chemistry of hot Jupiters should change dramatically as temperature drops from 1200 to 1000 K. At 1200 K methane is too unstable to reach the stratosphere in significant quantities, while thermal decomposition of water is a strong source of OH radicals that oxidize any hydrocarbons that do form to CO and CO$_2$. At 1000 K methane, although very reactive, survives long enough to reach the lower stratosphere, and the greater stability of water coupled with efficient scavenging of OH by H$_2$ raise the effective C/O ratio in the reacting gases above unity. Reduced products such as ethylene, acetylene, and hydrogen cyanide become abundant; such conditions favor polymerization and possible formation of PAHs and soots. Although low temperature is the most important factor favoring hydrocarbons in hot Jupiters, higher rates of vertical mixing and generally lower metallicities also favor organic synthesis. The peculiar prope...

  10. Radiation Intensity of a Turbulent Sooting Ethylene Flame

    OpenAIRE

    Hartman, Ryan M; Gore, Jay P, PhD

    2013-01-01

    Turbulent sooting flame radiation is relevant to applications ranging from fire safety to gas turbine engines. The complex direct interactions of soot and radiation intensity are of particular importance when creating accurate soot prediction models. Previous studies have measured gas-band and broadband radiation intensity from turbulent sooting flames. The focus of the current study is the characterization of radiation intensity emanating from soot. A high-speed infrared camera (FLIR Phoenix...

  11. Electrically heated particulate matter filter soot control system

    Science.gov (United States)

    Gonze, Eugene V.; Paratore, Jr., Michael J.; Bhatia, Garima

    2016-03-15

    A regeneration system includes a particulate matter (PM) filter with an upstream end for receiving exhaust gas and a downstream end. A control module determines a current soot loading level of the PM filter and compares the current soot loading level to a predetermined soot loading level. The control module permits regeneration of the PM filter when the current soot loading level is less than the predetermined soot loading level.

  12. Research on soot of black smoke from ceramic furnace flue gas: Characterization of soot

    International Nuclear Information System (INIS)

    Highlights: ► The characterization of soot was comprehensively studied by various means. ► The soot was fine particle with large specific surface area. ► Heavy metals and organic compounds were also detected in soot. ► The soot was a hazardous material and could severely impact environment and human health. - Abstract: In this study, the characterizations of soot from ceramic furnace flue gas were studied using environmental scanning electron microscopy, energy dispersive spectroscopy, particle size distribution, specific surface area measurements, crystal characterizations and organic pollutant analysis. Soot particles were mainly spherical nanoparticles with diameters less than 100 nm. However, the particles could be aggregated into larger ones with a median diameter of 3.66 μm. Nanometer pores with diameters ranging 2–4 nm were also detected in the soot particles. Because of their large surface areas and pore volumes, other pollutants in the environment can be adsorbed to soot particles potentially making them more hazardous. Several elements, including C, O and Pb, were detected in the soot, but only small amounts of crystalline materials were observed. This is because most of the detected carbon and metals/metal oxides/metal salts were amorphous. Approximately 90 different organic pollutants were detected in the soot, including aromatic compounds and other hydrocarbons. Because of the carcinogenic properties of aromatic compounds and the photochemical effects of hydrocarbons, soot could have serious health and environmental impacts. The results suggest that soot particles are hazardous material and urgently need to be controlled.

  13. Non-Thermal Soot Denuder Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a non-thermal soot denuder for measuring chemical components of the nucleation mode particulate matter emissions from gas turbine engines, in...

  14. Response of centrifugal blowers to simulated tornado transients, July-September 1981

    International Nuclear Information System (INIS)

    During this quarter, quasi-steady and dynamic testing of the 24-in. centrifugal blower was completed using the blowdown facility located at New Mexico State University. The data were obtained using a new digital data-acquisition system. Software was developed at the Los Alamos National Laboratory to reduce the dynamic test data and create computer-generated movies showing the dynamic performance of the blower under simulated tornado transient pressure conditions relative to its quasi-steady-state performance. Currently, quadrant-four (outrunning flow) data have been reduced for the most severe and a less severe tornado pressure transient. The results indicate that both the quasi-steady and dynamic blower performance are very similar. Some hysteresis in the dynamic performance occurs because of rotational inertia effects in the blower rotor and drive system. Currently quadrant-two (backflow) data are being transferred to the LTSS computer system at Los Alamos and will be reduced shortly

  15. Sooting limit in counterflow diffusion flames of ethylene/propane fuels and implication to threshold soot index

    KAUST Repository

    Joo, Peter H.

    2013-01-01

    Sooting limits in counterflow diffusion flames of propane/ethylene fuels have been studied experimentally using a light scattering technique, including the effects of dilution, fuel mixing, and strain rate. The results are discussed in view of the threshold soot index (TSI). In soot-formation (SF) flames, where the flame is located on the oxidizer side of the stagnation plane, the sooting limit depends critically on fuel type and subsequently on flame temperature. The sooting limit has a non-linear dependence on the fuel-mixing ratio, which is similar to the non-linear mixing rule for TSI observed experimentally in rich premixed flames, where soot oxidation is absent for both SF and rich premixed flames. In soot-formation-oxidation (SFO) flames, where the flame is located on the fuel side, the sooting limit depends critically on flame temperature, while it is relatively independent on fuel type. This result suggests a linear mixing rule for sooting limits in SFO flames, which is similar to the TSI behavior for coflow diffusion flames. Soot oxidation takes place for both types of flames. The aerodynamic strain effect on the sooting limits has also been studied and an appreciable influence has been observed. Under sooting conditions, soot volume fraction was measured using a light extinction technique. The soot loadings in SF flames of the mixture fuels demonstrated a synergistic effect, i.e., soot production increased for certain mixture fuels as compared to the respective singlecomponent fuels. © 2012 The Combustion Institute.

  16. Using jet blowers in order to increase the intake capacity of pumping wells

    Energy Technology Data Exchange (ETDEWEB)

    Voznyy, V.R.; Goy, I.M.; Kifor, B.M.; Lotovskiy, V.N.; Yatsura, Ya.V.

    1983-01-01

    Methods for increasing the intake capacity of pumping wells are analyzed and a new technology is proposed for clearing the near shaft zone of a stratum using jet blowers. Experience in operations to restore the filtration properties of productive levels by the complex effect of acetic processing and cyclic action using the jet blowers on a stratum is described. Conclusions and recommendations for using the developed technology for clearing the near shaft zone of a stratum are given.

  17. OPTIMIZING IMPELLER GEOMETRY FOR PERFORMANCE ENHANCEMENT OF A CENTRIFUGAL BLOWER USING THE TAGUCHI QUALITY CONCEPT

    OpenAIRE

    R RAGOTH SINGH; M.Nataraj

    2012-01-01

    As the diffusion of flow process is highly complex in centrifugal blower operation, it is necessary to design / develop the geometry of impeller and casing to reduce the flow losses significantly. In the present study, the methodology to find near optimum combination of blower operating variables for performance enhancement were analyzed using computational fluid dynamics(CFD). Taguchi orthogonal array (OA) based design of experiments (DoE) technique determines the required experimental trial...

  18. NATO Workshop on Soot in Combustion Systems

    CERN Document Server

    Prado, G

    1983-01-01

    Our interest in Mulhouse for carbon black and soot began some 30 years ago when J.B. Donnet developed the concept of surface chemistry of carbon and its involvement in interactions with gas, liquid and solid phases. In the late sixties, we began to study soot formation in pyrolytic systems and later on in flames. The idea of organ1z1ng a meeting on soot formation originated some four or five years ago, through discussions among Professor J.B. Howard, Dr. A. D'Alessio and ourselves. At that time the scientific community was becoming aware of the necessity to strictly control soot formation and emission. Being involved in the study of surface properties of carbon black as well as of formation of soot, we realized that the combustion community was not always fully aware of the progress made by the physical-chemists on carbon black. Reciprocally, the carbon specialists were often ignoring the research carried out on soot in flames. One objective of this workshop was to stimulate discussions between these two scie...

  19. Aromatics Oxidation and Soot Formation in Flames

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J. B.; Richter, H.

    2005-03-29

    This project is concerned with the kinetics and mechanisms of aromatics oxidation and the growth process to polycyclic aromatic hydrocarbons (PAH) of increasing size, soot and fullerenes formation in flames. The overall objective of the experimental aromatics oxidation work is to extend the set of available data by measuring concentration profiles for decomposition intermediates such as phenyl, cyclopentadienyl, phenoxy or indenyl radicals which could not be measured with molecular-beam mass spectrometry to permit further refinement and testing of benzene oxidation mechanisms. The focus includes PAH radicals which are thought to play a major role in the soot formation process while their concentrations are in many cases too low to permit measurement with conventional mass spectrometry. The radical species measurements are used in critical testing and improvement of a kinetic model describing benzene oxidation and PAH growth. Thermodynamic property data of selected species are determined computationally, for instance using density functional theory (DFT). Potential energy surfaces are explored in order to identify additional reaction pathways. The ultimate goal is to understand the conversion of high molecular weight compounds to nascent soot particles, to assess the roles of planar and curved PAH and relationships between soot and fullerenes formation. The specific aims are to characterize both the high molecular weight compounds involved in the nucleation of soot particles and the structure of soot including internal nanoscale features indicative of contributions of planar and/or curved PAH to particle inception.

  20. Steam boiler for fytomass

    OpenAIRE

    Baláš, Jiří

    2008-01-01

    The purpose of this Diploma Thesis was the construction design of the steam boiler for fytomass. For the specified parameters of biomass have been gradually implemented stoichiometric calculations of which are further based calculation of enthalpies of combustion gas. In the next part have been dealt with heat balance of the boiler, the efficiency of the boiler, recirculation of exhaust gases and the temperature of the combustion gases in outlet from fire. Thereinafter, the proposal of partic...

  1. Are laptop ventilation-blowers a potential source of nosocomial infections for patients?

    Science.gov (United States)

    Siegmund, Katja; Hübner, Nils; Heidecke, Claus-Dieter; Brandenburg, Ronny; Rackow, Kristian; Benkhai, Hicham; Schnaak, Volker; Below, Harald; Dornquast, Tina; Assadian, Ojan; Kramer, Axel

    2010-01-01

    Inadequately performed hand hygiene and non-disinfected surfaces are two reasons why the keys and mouse-buttons of laptops could be sources of microbial contamination resulting consequently in indirect transmission of potential pathogens and nosocomial infections. Until now the question has not been addressed whether the ventilation-blowers in laptops are actually responsible for the spreading of nosocomial pathogens. Therefore, an investigational experimental model was developed which was capable of differentiating between the microorganisms originating from the external surfaces of the laptop, and from those being blown out via the ventilation-blower duct. Culture samples were taken at the site of the external exhaust vent and temperature controls were collected through the use of a thermo-camera at the site of the blower exhaust vent as well as from surfaces which were directly exposed to the cooling ventilation air projected by the laptop. Control of 20 laptops yielded no evidence of microbial emission originating from the internal compartment following switching-on of the ventilation blower. Cultures obtained at the site of the blower exhaust vent also showed no evidence of nosocomial potential. High internal temperatures on the inner surfaces of the laptops (up to 73°C) as well as those documented at the site of the blower exhaust vent (up to 56°C) might be responsible for these findings. PMID:20941339

  2. Are laptop ventilation-blowers a potential source of nosocomial infections for patients?

    Directory of Open Access Journals (Sweden)

    Siegmund, Katja

    2010-01-01

    Full Text Available Inadequately performed hand hygiene and non-disinfected surfaces are two reasons why the keys and mouse-buttons of laptops could be sources of microbial contamination resulting consequently in indirect transmission of potential pathogens and nosocomial infections. Until now the question has not been addressed whether the ventilation-blowers in laptops are actually responsible for the spreading of nosocomial pathogens. Therefore, an investigational experimental model was developed which was capable of differentiating between the microorganisms originating from the external surfaces of the laptop, and from those being blown out via the ventilation-blower duct. Culture samples were taken at the site of the external exhaust vent and temperature controls were collected through the use of a thermo-camera at the site of the blower exhaust vent as well as from surfaces which were directly exposed to the cooling ventilation air projected by the laptop. Control of 20 laptops yielded no evidence of microbial emission originating from the internal compartment following switching-on of the ventilation blower. Cultures obtained at the site of the blower exhaust vent also showed no evidence of nosocomial potential. High internal temperatures on the inner surfaces of the laptops (up to 73°C as well as those documented at the site of the blower exhaust vent (up to 56°C might be responsible for these findings.

  3. Boiler conversions for biomass

    Energy Technology Data Exchange (ETDEWEB)

    Kinni, J. [Tampella Power Inc., Tampere (Finland)

    1996-12-31

    Boiler conversions from grate- and oil-fired boilers to bubbling fluidized bed combustion have been most common in pulp and paper industry. Water treatment sludge combustion, need for additional capacity and tightened emission limits have been the driving forces for the conversion. To accomplish a boiler conversion for biofuel, the lower part of the boiler is replaced with a fluidized bed bottom and new fuel, ash and air systems are added. The Imatran Voima Rauhalahti pulverized-peat-fired boiler was converted to bubbling fluidized bed firing in 1993. In the conversion the boiler capacity was increased by 10 % to 295 MWth and NO{sub x} emissions dropped. In the Kymmene Kuusankoski boiler, the reason for conversion was the combustion of high chlorine content biosludge. The emissions have been under general European limits. During the next years, the emission limits will tighten and the boilers will be designed for most complete combustion and compounds, which can be removed from flue gases, will be taken care of after the boiler. (orig.) 3 refs.

  4. Blower Gun pellet injection system for W7-X

    International Nuclear Information System (INIS)

    Foreseen to serve for the new stellarator W7-X for pellet investigations, the former ASDEX Upgrade Blower Gun was revised and revitalized in a test bed. The gun is able now to launch cylindrical pellets of 2 mm diameter and 2 mm length, produced from frozen Deuterium (D2) or Hydrogen (H2). Pellets are accelerated by a short pulse of pressurized helium propellant gas to velocities in the range of 100-250 m/s. Delivery reliabilities at the launcher exit close to unity are achieved. For pellet transfer to the plasma vessel a first mock up guiding tube version was investigated. Transfer through this S-shaped (inner diameter 8 mm; length 6 m) stainless steel guiding tube containing two 1 m curvature radii was investigated for both H2 and D2 pellets. Tests were performed applying repetition rates from 2 Hz to 50 Hz and propellant gas pressures ranging from 1 bar to 6 bar. For both H2 and D2, low overall delivery efficiencies were observed at slow repetition rates, but stable efficiencies of about 90% above 10 Hz.

  5. SEM Investigation of Superheater Deposits from Biomass-Fired Boilers

    DEFF Research Database (Denmark)

    Jensen, Peter Arendt; Frandsen, Flemming; Hansen, Jørn;

    2004-01-01

    adopted to minimize deposit problems at the two boilers. At Masnedø the final superheater steam temperature is 520 °C, no soot blowing of the superheaters is applied and a relatively large superheater area is used. At Ensted, an external wood-fired superheater is used in order to obtain a final steam...... layer was probably generated by in-situ reaction between KCl and Si-rich ash particles, which leads to release of chlorine-containing gases. The innermost layer contained many sublayers of mainly iron oxide, KCl, and K2SO4. The Ensted deposit had a maximum thickness of a few centimeters. The...

  6. Are black carbon and soot the same?

    Directory of Open Access Journals (Sweden)

    P. R. Buseck

    2012-09-01

    Full Text Available The climate change and environmental literature, including that on aerosols, is replete with mention of black carbon (BC, but neither reliable samples nor standards exist. Thus, there is uncertainty about its exact nature. That confusion can be avoided if terms are defined and widely understood. Here we discuss an ambiguity between BC and soot and propose a more precise definition for soot as a specific material, which we call ns-soot, where "ns" refers to carbon nanospheres. We define ns-soot as particles that consist of nanospheres, typically with diameters < 100 nm, that possess distinct structures of concentrically wrapped, graphene-like layers of carbon and with grape-like (acinoform morphologies. We additionally propose that, because of their importance for climate modeling and health issues, distinctions are made among bare, coated, and embedded ns-soot. BC, on the other hand, is not a well-defined material. We propose that the term should be restricted to light-absorbing refractory carbonaceous matter of uncertain character and that the uncertainty is stated explicitly.

  7. Tribology of soot suspension in hexadecane as distinguished by the physical structure and chemistry of soot particles

    Science.gov (United States)

    Bhowmick, Hiralal; Majumdar, S. K.; Biswas, S. K.

    2012-05-01

    Ethylene gas is burnt to generate soot which is collected thermophoretically from different locations of the flame. Tribological performance of the collected soot in hexadecane suspension is compared with that of carbon black and diesel soot. The soots are analysed to yield a range of mechanical properties, physical structures and chemistry. The paper correlates these property variations with the corresponding variations in friction and wear when the soot suspended in hexadecane is used to lubricate a steel on steel sliding interaction. The particles are dispersed in hexadecane by a non-ionic surfactant, poly-isobutylene succinimide (PIBS), which is mono-functional with no free amine group. The grafting of the surfactant on the soot particles is found to have a profound effect on the dispersion of the soot, in general, while, between the different soot types, the tribology is differentiated by the physical structure and chemistry.

  8. Tribology of soot suspension in hexadecane as distinguished by the physical structure and chemistry of soot particles

    International Nuclear Information System (INIS)

    Ethylene gas is burnt to generate soot which is collected thermophoretically from different locations of the flame. Tribological performance of the collected soot in hexadecane suspension is compared with that of carbon black and diesel soot. The soots are analysed to yield a range of mechanical properties, physical structures and chemistry. The paper correlates these property variations with the corresponding variations in friction and wear when the soot suspended in hexadecane is used to lubricate a steel on steel sliding interaction. The particles are dispersed in hexadecane by a non-ionic surfactant, poly-isobutylene succinimide (PIBS), which is mono-functional with no free amine group. The grafting of the surfactant on the soot particles is found to have a profound effect on the dispersion of the soot, in general, while, between the different soot types, the tribology is differentiated by the physical structure and chemistry. (paper)

  9. Simulation of temporal and spatial soot evolution in an automotive diesel engine using the Moss–Brookes soot model

    International Nuclear Information System (INIS)

    Highlights: ► Numerical models were validated against experimental data of two diesel engines. ► Soot model constant values were calibrated to predict in-cylinder soot processes. ► Effects of split-main injection parameters on soot distributions were determined. ► Soot cloud was distributed towards cylinder wall when using large dwell period. ► Greater soot deposition expected with large dwell period and retarded injection. - Abstract: In this reported work, computational study on the formation processes of soot particles from diesel combustion is conducted using an approach where Computational Fluid Dynamics (CFD) is coupled with a chemical kinetic model. A multi-step soot model which accounts for inception, surface growth, coagulation and oxidation was applied. Model constant values in the Moss–Brookes soot formation and Fenimore–Jones soot oxidation models were calibrated, and were validated against in-cylinder soot evolution and exhaust soot density of both heavy- and light-duty diesel engines, respectively. Effects of various injection parameters such as start of injection (SOI) timing, split-main ratio and dwell period of the split-main injection strategy on in-cylinder temporal/spatial soot evolution in a light-duty diesel engine were subsequently investigated. The spatial soot distributions at each crank angle degree after start of injection were found to be insensitive to the change of values in SOI and split-main ratio when close-coupled injection was implemented. Soot cloud was also observed to be distributed towards the cylinder wall when a large separation of 20° was used, even with an advanced SOI timing of −6° after top dead centre (ATDC). The use of large separation is hence not desired for this combustion system as it potentially leads to soot deposition on surface oil film and greater tailpipe soot emissions.

  10. NOx Control Options and Integration for US Coal Fired Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Mike Bockelie; Marc Cremer; Kevin Davis; Martin Denison; Adel Sarofim; Connie Senior; Hong-Shig Shim; Dave Swenson; Bob Hurt; Eric Suuberg; Eric Eddings; Kevin Whitty; Larry Baxter; Calvin Bartholomew; William Hecker

    2006-06-30

    This is the Final Report for DOE Cooperative Agreement No: DE-FC26-00NT40753. The goal of the project was to develop cost-effective analysis tools and techniques for demonstrating and evaluating low-NOx control strategies and their possible impact on boiler performance for boilers firing US coals. The Electric Power Research Institute (EPRI) provided co-funding for this program. This project included research on: (1) In furnace NOx control; (2) Impacts of combustion modifications on boiler operation; (3) Selective Catalytic Reduction (SCR) catalyst testing and (4) Ammonia adsorption/removal on fly ash. Important accomplishments were achieved in all aspects of the project. Rich Reagent Injection (RRI), an in-furnace NOx reduction strategy based on injecting urea or anhydrous ammonia into fuel rich regions in the lower furnace, was evaluated for cyclone-barrel and PC fired utility boilers. Field tests successfully demonstrated the ability of the RRI process to significantly reduce NOx emissions from a staged cyclone-fired furnace operating with overfire air. The field tests also verified the accuracy of the Computational Fluid Dynamic (CFD) modeling used to develop the RRI design and highlighted the importance of using CFD modeling to properly locate and configure the reagent injectors within the furnace. Low NOx firing conditions can adversely impact boiler operation due to increased waterwall wastage (corrosion) and increased soot production. A corrosion monitoring system that uses electrochemical noise (ECN) corrosion probes to monitor, on a real-time basis, high temperature corrosion events within the boiler was evaluated. Field tests were successfully conducted at two plants. The Ohio Coal Development Office provided financial assistance to perform the field tests. To investigate soot behavior, an advanced model to predict soot production and destruction was implemented into an existing reacting CFD modeling tool. Comparisons between experimental data collected

  11. Microwave assisted regeneration of soot filters

    International Nuclear Information System (INIS)

    Full text: Air pollution is a 'hot' issue nowadays, especially in metropolitan and heavily industrialized areas. Vehicular emissions are the largest source of atmospheric aerosols in metropolitan areas. The strong environmental legislation on gaseous emissions, both from gasoline and diesel engines, demands an urgent solution to eliminate the particulates and soot emission by vehicles, especially Diesel engines. There are several techniques available for elimination of soot emission, such as the use of cerium based fuel additives. A more conventional approach is of soot filters. The most important issue in using this technology is the regeneration of the filters after the soot particles are trapped. Self-regeneration is not usually possible due to high ignition temperature of Diesel soot. Despite the use of catalysts, in-situ regeneration of these filter elements is not always possible at the conventional operation temperature, in which case filter or exhaust heating is required. Currently, we have assessed the feasibility of using a microwave sensitive, catalytic material as a filter coating, thus allowing in-situ regeneration of the soot filter by exposing it periodically to a dielectric field. Microwave technique has distinct advantages of instantaneous operation, direct heating and fast switch on and off. Ideal susceptor materials for the present purpose are at the same time oxidation catalysts, thereby eliminating the need for additional combustion of any hydrocarbons present in the gas phase or carbon monoxide formed during soot combustion. Therefore we have opted to use La-M-Mn (M= Ce, Mg, Ca, Sr and Ba) based perovskites, as a potentially suitable coating material. These perovskites can be represented with the general structural formula AA'BO3. The substitution of A or B metal cations can be employed to systematically change the catalytic properties and possibly also the dielectric properties et-up. The structural properties of these perovskites have been

  12. Retrofit device to improve vapor compression cooling system performance by dynamic blower speed modulation

    Science.gov (United States)

    Roth, Robert Paul; Hahn, David C.; Scaringe, Robert P.

    2015-12-08

    A device and method are provided to improve performance of a vapor compression system using a retrofittable control board to start up the vapor compression system with the evaporator blower initially set to a high speed. A baseline evaporator operating temperature with the evaporator blower operating at the high speed is recorded, and then the device detects if a predetermined acceptable change in evaporator temperature has occurred. The evaporator blower speed is reduced from the initially set high speed as long as there is only a negligible change in the measured evaporator temperature and therefore a negligible difference in the compressor's power consumption so as to obtain a net increase in the Coefficient of Performance.

  13. OPTIMIZING IMPELLER GEOMETRY FOR PERFORMANCE ENHANCEMENT OF A CENTRIFUGAL BLOWER USING THE TAGUCHI QUALITY CONCEPT

    Directory of Open Access Journals (Sweden)

    R RAGOTH SINGH

    2012-10-01

    Full Text Available As the diffusion of flow process is highly complex in centrifugal blower operation, it is necessary to design / develop the geometry of impeller and casing to reduce the flow losses significantly. In the present study, the methodology to find near optimum combination of blower operating variables for performance enhancement were analyzed using computational fluid dynamics(CFD. Taguchi orthogonal array (OA based design of experiments (DoE technique determines the required experimental trials. The experimental results are justifiedby Analysis of Variance (ANOVA and confirmed by conformation experiments. The parameters chosen for design optimization are Impeller outlet diameter, Impeller wheel width, Thickness of blade and Impeller inlet diameter. The levels for the parametric specification are chosen from the ranges where the blower will get thebest efficiency. CFD results were validated by the fine conformity between the CFD results and the experimental results.

  14. Aerosol generation by blower motors as a bias in assessing aerosol penetration into cabin filtration systems.

    Science.gov (United States)

    Heitbrink, William A; Collingwood, Scott

    2005-01-01

    In cabin filtration systems, blower motors pressurize a vehicle cabin with clean filtered air and recirculate air through an air-conditioning evaporator coil and a heater core. The exposure reduction offered by these cabins is evaluated by optical particle counters that measure size-dependent aerosol concentration inside and outside the cabin. The ratio of the inside-to-outside concentration is termed penetration. Blower motors use stationary carbon brushes to transmit an electrical current through a rotating armature that abrades the carbon brushes. This creates airborne dust that may affect experimental evaluations of aerosol penetration. To evaluate the magnitude of these dust emissions, blower motors were placed in a test chamber and operated at 12 and 13.5 volts DC. A vacuum cleaner drew 76 m3/hour (45 cfm) of air through HEPA filters, the test chamber, and through a 5 cm diameter pipe. An optical particle counter drew air through an isokinetic sampling probe and measured the size-dependent particle concentrations from 0.3 to 15 microm. The concentration of blower motor aerosol was between 2 x 10(5) and 1.8 x 10(6) particles/m3. Aerosol penetration into three stationary vehicles, two pesticide application vehicles and one tractor were measured at two conditions: low concentration (outside in the winter) and high concentration (inside repair shops and burning incense sticks used as a supplemental aerosol source). For particles smaller than 1 microm, the in-cabin concentrations can be explained by the blower motor emissions. For particles larger than 1 microm, other aerosol sources, such as resuspended dirt, are present. Aerosol generated by the operation of the blower motor and by other sources can bias the exposure reduction measured by optical particle counters. PMID:15764523

  15. ENERGY STAR Certified Boilers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Boilers that are effective as of October 1,...

  16. Charting the boiler market

    International Nuclear Information System (INIS)

    The ''boiler market'' of electricity, sometimes called unsecured transmission, is electric power consumption that in public statistics is restricted by the obligation of the customers to cut their consumption at short notice and therefore are granted some discount on the network lease. The present document is part of a project that aims to provide a better understanding of the flexibility in the Norwegian power market, limited by the power-intensive industry and the boiler market. It discusses the boiler market. It begins with a discusses of the available statistics, where different sources show very dissimilar consumption figures. Then it examines how the consumption in the boiler market developed during the winter 2002/2003. Finally, there is a description of the regulations of unsecured transmission and how the various network owners adapt to the regulations.

  17. Response of air cleaning system dampers and blowers to simulated tornado transients

    International Nuclear Information System (INIS)

    The effects of tornado-like pressure transients upon dampers and blowers in nuclear air cleaning systems were studied. For the dampers pressure drop as a function of flow rate was obtained and an empirical relationship developed. Transient response was examined for several types of dampers, as was structural integrity. Both centrifugal and axi-vane blowers were tested and transient characteristic curves were generated in outrunning and backflow situations. The transient characteristic curves do not necessarily match the quasi-steady characteristic curves

  18. Development of local air blower for removing radioactive iodine using the carbon fiber filter

    International Nuclear Information System (INIS)

    Boiling water type nuclear power plant (BWR) conducts overhaul of the condenser and the turbine regularly. The radioactive iodine dissipation in the turbine system, that occurs in the reactor during plant operation, need to implement safeguards against radioactive iodine. Carbon particle filter type local air blower is conventionally used in order to eliminate the radioactive iodine before during maintenance, but has the problem in mobility due to size of the device. We developed the new type of local air blower using carbon fiber to improve mobility of device. (author)

  19. TECHNOLOGY OF SMOKE PREVENTION AND DUST CONTROL FOR HORIZONTAL GRATE-FIRED BOILERS%卧式层状燃煤锅炉炉内消烟除尘技术

    Institute of Scientific and Technical Information of China (English)

    王擎; 孙东红; 孙佰仲; 闫跃升; 孙键

    2003-01-01

    In China, a number of horizontal grate-fired boilers have been used in industry and black soot and fly ash are emitted out of the furnace. A smoke prevention and dust control device suited for horizontal grate-fired boilers is invented so as to solve these two problems. The technical feature of the device is presented and aerodynamic field in the furnace is simulated. It shows many advantages,such as simple structure, easy arrangement, effective inhibition of soot formation and realizing dust-removal in furnace.

  20. Precursor soot synthesis of fullerenes and nanotubes without formation of carbonaceous soot

    Science.gov (United States)

    Reilly, Peter T. A.

    2007-03-20

    The present invention is a method for the synthesis of fullerenes and/or nanotubes from precursor soot without the formation of carbonaceous soot. The method comprises the pyrolysis of a hydrocarbon fuel source by heating the fuel source at a sufficient temperature to transform the fuel source to a condensed hydrocarbon. The condensed hydrocarbon is a reaction medium comprising precursor soot wherein hydrogen exchange occurs within the reaction medium to form reactive radicals which cause continuous rearrangement of the carbon skeletal structure of the condensed hydrocarbon. Then, inducing dehydrogenation of the precursor soot to form fullerenes and/or nanotubes free from the formation of carbonaceous soot by continued heating at the sufficient temperature and by regulating the carbon to hydrogen ratio within the reaction medium. The dehydrogenation process produces hydrogen gas as a by-product. The method of the present invention in another embodiment is also a continuous synthesis process having a continuous supply of the fuel source. The method of the present invention can also be a continuous cyclic synthesis process wherein the reaction medium is fed back into the system as a fuel source after extraction of the fullerenes and/or nanotube products. The method of the present invention is also a method for producing precursor soot in bulk quantity, then forming fullerenes and/or nanotubes from the precursor bulk.

  1. Steam boiler technology

    Energy Technology Data Exchange (ETDEWEB)

    Teir, S.

    2003-07-01

    This book is the published version of the e-book with the same name. The interactive lecture slides, which accompany most chapters, exist only in the online version and on the attached CD-Rom. The Steam Boiler Technology e-book is the main course book for the course on steam boiler technology provided by the Laboratory of Energy Engineering and Environmental Protection at Helsinki University of Technology. The steam boiler technology e-Book is provided by the Laboratory of Energy Engineering and Environmental Protection at Helsinki University of Technology. The book covers the basics and the history of steam generation, modern boilers types and applications, steam/water circulation design, feedwater and steam systems components, heat exchangers in steam boilers, boiler calculations, thermal design of heat exchangers. The chapters of the second edition have been corrected based on reader and reviewer comments, and four new chapters have been added. The user interface of the electronic version has also been updated. The password for the online book will be changed once a year. If you have problems accessing the online book, or need a new password, please contact sebastian.teir@hut.fi.

  2. MODELLING, SIMULATING AND OPTIMIZING BOILERS

    DEFF Research Database (Denmark)

    Sørensen, Kim; Condra, Thomas Joseph; Houbak, Niels

    In the present work a framework for optimizing the design of boilers for dynamic operation has been developed. A cost function to be minimized during the optimization has been formulated and for the present design variables related to the Boiler Volume and the Boiler load Gradient (i.e. ring rate...... on the boiler) have been dened. Furthermore a number of constraints related to: minimum and maximum boiler load gradient, minimum boiler size, Shrinking and Swelling and Steam Space Load have been dened. For dening the constraints related to the required boiler volume a dynamic model for simulating...... the boiler performance has been developed. Outputs from the simulations are shrinking and swelling of water level in the drum during for example a start-up of the boiler, these gures combined with the requirements with respect to allowable water level uctuations in the drum denes the requirements with...

  3. Thermal fragmentation and deactivation of combustion-generated soot particles

    KAUST Repository

    Raj, Abhijeet

    2014-09-01

    The effect of thermal treatment on diesel soot and on a commercial soot in an inert environment under isothermal conditions at intermediate temperatures (400-900°C) is studied. Two important phenomena are observed in both the soot samples: soot fragmentation leading to its mass loss, and loss of soot reactivity towards O2. Several experimental techniques such as high resolution transmission electron microscopy, electron energy loss spectroscopy, thermo-gravimetric analysis with mass spectrometry, elemental analysis, Fourier transform infrared spectroscopy and X-ray diffraction have been used to identify the changes in structures, functional groups such as oxygenates and aliphatics, σ and π bonding, O/C and H/C ratios, and crystallite parameters of soot particles, introduced by heat. A decrease in the size of primary particles and an increase in the average polycyclic aromatic hydrocarbon (PAH) size was observed in soots after thermal treatment. The activation energies of soot oxidation for thermally treated soot samples were found to be higher than those for the untreated ones at most conversion levels. The cyclic or acyclic aliphatics with sp3 hybridization were present in significant amounts in all the soot samples, but their concentration decreased with thermal treatment. Interestingly, the H/C and the O/C ratios of soot particles increased after thermal treatment, and thus, they do not support the decrease in soot reactivity. The increase in the concentration of oxygenates on soot surface indicate that their desorption from soot surface in the form of CO, CO2 and other oxygenated compounds may not be significant at the temperatures (400-900°C) studied in this work. © 2014 The Combustion Institute.

  4. Auxiliary bearing design and rotor dynamics analysis of blower fan for HTR-10

    International Nuclear Information System (INIS)

    The electromagnetic bearing instead of ordinary mechanical bearing was chosen to support the rotor in the blower fan system with helium of 10 MW high temperature gas-cooled test reactor (HTR-10), and the auxiliary bearing was applied in the HTR-10 as the backup protector. When the electromagnetic bearing doesn't work suddenly for the power broken, the auxiliary bearing is used to support the falling rotor with high rotating speed. The rotor system will be protected by the auxiliary bearing. The design of auxiliary bearing is the ultimate safeguard for the system. This rotor is vertically mounted to hold the blower fan. The rotor's length is about 1.5 m, its weight is about 240 kg and the rotating speed is about 5400 r/min. Auxiliary bearing design and rotor dynamics analysis are very important for the design of blower fan to make success. The research status of the auxiliary bearing was summarized in the paper. A sort of auxiliary bearing scheme was proposed. MSC.Marc was selected to analyze the vibration mode and the natural frequency of the rotor. The scheme design of auxiliary bearing and analysis result of rotor dynamics offer the important theoretical base for the protector design and control system of electromagnetic bearing of the blower fan. (authors)

  5. Velocity and turbulence measurements of impellers discharge flow for multi-stage centrifugal blower

    International Nuclear Information System (INIS)

    This paper assesses some results of an experimental investigation on a 4-stage centrifugal blower. The two-dimensional velocity and turbulence field at the exit of the first and fourth stage was measured in some working conditions of the machine, by a single hot-wire anemometer rotated twice about its own axis

  6. Development of a no-moving-part blower for difficult operating conditions

    Czech Academy of Sciences Publication Activity Database

    Tesař, Václav

    2013-01-01

    Roč. 91, č. 12 (2013), s. 2401-2411. ISSN 0263-8762 R&D Projects: GA ČR GA13-23046S Institutional research plan: CEZ:AV0Z20760514 Keywords : blower * fluidics * hazardous fluids Subject RIV: BK - Fluid Dynamics Impact factor: 2.281, year: 2013 http://www.sciencedirect.com/science/article/pii/S0263876213001081

  7. Analytical study of ventilation-system behavior using TVENT1 under simulated blower malfunctions

    International Nuclear Information System (INIS)

    A large, complex ventilation system at the Los Alamos National Laboratory's Plutonium Processing Facility was modeled and analyzed using a computer code called TVENT1. Useful information was obtained about the system's operating characteristics when subjected to potential blower malfunctions. This report provides an excellent example for a potential user of TVENT1 for application to an actual system

  8. Soot oxidation over NOx storage catalysts. Activity and deactivation

    International Nuclear Information System (INIS)

    Soot oxidation activity and deactivation of NOx storage and reduction (NSR) catalysts containing Pt, K, and Ba supported on Al2O3, are studied under a variety of reaction conditions. K-containing catalysts decrease soot oxidation temperature with O2 alone and the presence of Pt further enhance the activity due to synergetic effect. The active species responsible for synergism on Pt/K-Al2O3 are unstable and cannot be regenerated. Soot oxidation temperature decreases by about 150oC with NO+O2 exhaust feed gas and under lean conditions NSR system acts as catalysed soot filter (CSF). The reactions that are mainly responsible for decreasing soot oxidation temperature are: (1) soot oxidation with NO2 followed by NO recycles to NO2, and (2) soot oxidation with O2 assisted by NO2. Only a part of the stored NOx that is decomposed at high temperatures under lean conditions is found to be useful for soot oxidation. NOx storage capacity of NSR catalysts decreases upon ageing under soot oxidising conditions. This will lead to a decreased soot oxidation activity on stored nitrate decomposition. Pt/K-Al2O3 catalyst is more active, but least stable compared with Pt/Ba-Al2O3. (author)

  9. Review of soot measurement in hydrocarbon-air flames

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Soot,which is produced in fuel-rich parts of flames as a result of incomplete combustion of hydrocarbons,is the No.2 contributor to global warming after carbon dioxide.Developing soot measurement techniques is important to understand soot formation mechanism and control soot emission.The various soot measurement techniques,such as thermophoretic sampling par-ticles diagnostics followed by electron microscopy analysis,thermocouple particle densitometry,light extinction,laser-induced incandescence,two-color method,and emission computed tomography,are reviewed in this paper.The measurement principle and application cases of these measurement methods are described in detail.The development trend of soot measurement is to realize the on-line measurement of multi-dimensional distributions of temperature,soot volume fraction,soot particle size and other parameters in hydrocarbon-air flames.Soot measurement techniques suitable for both small flames in laboratories and large-scale flames in industrial combustion devices should be developed.Besides,in some special situations,such as high-pressure,zero gravity and micro-gravity flames,soot measurement also should be provided.

  10. Curbing Air Pollution and Greenhouse Gas Emissions from Industrial Boilers in China

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Price, Lynn K [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lu, Hongyou [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Liu, Xu [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Tsen, Katherine [Univ. of California, Berkeley, CA (United States); Xiangyang, Wei [National Energy Conservation Center (China); Yunpeng, Zhang [National Energy Conservation Center (China); Jian, Guan [China Special Equipment Inspection & Test Inst. (China); Rui, Hou [China Machinery Industry Conservation & Resource Utilization Center (China); Junfeng, Zhang [China National Offshore Oil Corp. (China); Yuqun, Zhuo [Tsinghua Univ., Beijing (China); Shumao, Xia [China Energy Conservation & Environmental Protection Group (China); Yafeng, Han [Xi' an Jiatong Univ. (China); Manzhi, Liu [China Univ. of Mining and Technology (China)

    2015-10-28

    China’s industrial boiler systems consume 700 million tons of coal annually, accounting for 18% of the nation’s total coal consumption. Together these boiler systems are one of the major sources of China’s greenhouse gas (GHG) emissions, producing approximately 1.3 gigatons (Gt) of carbon dioxide (CO2) annually. These boiler systems are also responsible for 33% and 27% of total soot and sulfur dioxide (SO2) emissions in China, respectively, making a substantial contribution to China’s local environmental degradation. The Chinese government - at both the national and local level - is taking actions to mitigate the significant greenhouse gas (GHG) emissions and air pollution related to the country’s extensive use of coal-fired industrial boilers. The United States and China are pursuing a collaborative effort under the U.S.-China Climate Change Working Group to conduct a comprehensive assessment of China’s coal-fired industrial boilers and to develop an implementation roadmap that will improve industrial boiler efficiency and maximize fuel-switching opportunities. Two Chinese cities – Ningbo and Xi’an – have been selected for the assessment. These cities represent coastal areas with access to liquefied natural gas (LNG) imports and inland regions with access to interprovincial natural gas pipelines, respectively.

  11. Sooting Characteristics and Modeling in Counterflow Diffusion Flames

    KAUST Repository

    Wang, Yu

    2013-11-01

    Soot formation is one of the most complex phenomena in combustion science and an understanding of the underlying physico-chemical mechanisms is important. This work adopted both experimental and numerical approaches to study soot formation in laminar counterfl ow diffusion flames. As polycyclic aromatic hydrocarbons (PAHs) are the precursors of soot particles, a detailed gas-phase chemical mechanism describing PAH growth upto coronene for fuels with 1 to 4 carbon atoms was validated against laminar premixed and counter- flow diffusion fl ames. Built upon this gas-phase mechanism, a soot model was then developed to describe soot inception and surface growth. This soot model was sub- sequently used to study fuel mixing effect on soot formation in counterfl ow diffusion flames. Simulation results showed that compared to the baseline case of the ethylene flame, the doping of 5% (by volume) propane or ethane in ethylene tends to increase the soot volume fraction and number density while keeping the average soot size almost unchanged. These results are in agreement with experimental observations. Laser light extinction/scattering as well as laser induced fluorescence techniques were used to study the effect of strain rate on soot and PAH formation in counterfl ow diffusion ames. The results showed that as strain rate increased both soot volume fraction and PAH concentrations decreased. The concentrations of larger PAH were more sensitive to strain rate compared to smaller ones. The effect of CO2 addition on soot formation was also studied using similar experimental techniques. Soot loading was reduced with CO2 dilution. Subsequent numerical modeling studies were able to reproduce the experimental trend. In addition, the chemical effect of CO2 addition was analyzed using numerical data. Critical conditions for the onset of soot were systematically studied in counterfl ow diffusion ames for various gaseous hydrocarbon fuels and at different strain rates. A sooting

  12. Oxidation of soot on iron oxide catalysts

    OpenAIRE

    Waglöhner, Steffen

    2012-01-01

    This thesis addresses the rational development of an iron oxide based catalyst for soot oxidation. The approach of this development process comprises three research methods, namely mechanistic and kinetic experiments, kinetic and fluid dynamic modelling and structure-activity relations of different types of iron oxides. A combination of this enables the synthesis of an advanced catalytic material, which is transferred to a real DPF system and tested under real diesel exhaust conditions.

  13. Dynamic Boiler Performance

    DEFF Research Database (Denmark)

    Sørensen, Kim

    Traditionally, boilers have been designed mainly focussing on the static operation of the plant. The dynamic capability has been given lower priority and the analysis has typically been limited to assuring that the plant was not over-stressed due to large temperature gradients. New possibilities...... developed. Analyzing boilers for dynamic operation gives rise to a number of opposing aims: shrinking and swelling, steam quality, stress levels, control system/philosophy, pressurization etc. Common for these opposing aims is that an optimum can be found for selected operation conditions. The framework has...

  14. Effects of Gas Temperature Fluctuation on the Soot Formation Reactions

    Institute of Scientific and Technical Information of China (English)

    CHEN Ying; ZHANG Jian

    2013-01-01

    The effects of gas temperature fluctuations on soot formation and oxidation reactions are investigated numerically in a reacting flow.The instantaneous variations of soot mass fraction with time are obtained under the time-averaged gas temperature of 1500 1700 K.The simulation results show that the gas temperature fluctuation has obvious influence on the instantaneous processes of soot formation and oxidation.Within the present range of gas temperature,the gas temperature fluctuation results in generally lower soot mass fraction comparing to that without gas temperature fluctuation.The increase in the fluctuation amplitude of gas temperature leads to decrease in time-averaged soot mass fraction and increase in time-averaged soot particle number density.

  15. Technical Note: The single particle soot photometer fails to detect PALAS soot nanoparticles

    Directory of Open Access Journals (Sweden)

    M. Gysel

    2012-07-01

    Full Text Available The single particle soot photometer (SP2 uses laser-induced incandescence (LII for the measurement of atmospheric black carbon (BC particles. The BC mass concentration is obtained by combining quantitative detection of BC mass in single particles with a counting efficiency of 100% above its lower detection limit (LDL. It is commonly accepted that a particle must contain at least several tenths of femtograms BC in order to be detected by the SP2.

    Here we show the unexpected result that BC particles from a PALAS spark discharge soot generator remain undetected by the SP2, even if their BC mass, as independently determined with an aerosol particle mass analyser (APM, is clearly above the typical LDL of the SP2. Comparison of counting efficiency and effective density data of PALAS soot with flame generated soot (combustion aerosol standard burner, CAST, fullerene soot and carbon black particles (Cabot Regal 400R reveals that particle morphology can affect the SP2's LDL. PALAS soot particles are fractal-like agglomerates of very small primary particles with a low fractal dimension, resulting in a very low effective density. Such loosely-packed particles behave like "the sum of individual primary particles" in the SP2's laser. Accordingly, the PALAS soot particles remain undetected as the SP2's laser intensity is insufficient to heat the primary particles to vaporisation because of their small size (primary particle diameter ~5–10 nm. It is not surprising that particle morphology can have an effect on the SP2's LDL, however, such a dramatic effect as reported here for PALAS soot was not expected. In conclusion, the SP2's LDL at a certain laser power depends on total BC mass per particle for compact particles with sufficiently high effective density. However, for fractal-like agglomerates of very small primary particles and low fractal dimension, the BC mass per primary particle determines the limit of detection, independent of the total

  16. Electrochemical supercapacitor behaviour of functionalized candle flame carbon soot

    Indian Academy of Sciences (India)

    C Justin Raj; Byung Chul Kim; Bo-Bae Cho; Won-Je Cho; Sung-Jin Kim; Sang Yeup Park; Kook Hyun Yu

    2016-02-01

    The electrochemical supercapacitor behaviour of bare, washed and nitric acid functionalized candle flame carbon soots were reported. Crystallinity and the morphology of the candle soots were recorded using X-ray diffraction analysis, scanning and transmission electron microscopy, respectively. The nitric acid functionalized candle soot showed an improved Brunauer–Emmett–Teller surface area of 137.93 from 87.495 m$^2$ g$^{−1}$ of washed candle soot. The presence of various functional groups in candle soots and the development of oxygen functionalities in the functionalized candle soot were examined through Fourier transform infrared spectroscopy and energy-dispersive X-ray analysis. Raman spectra showed the characteristic peaks corresponding to the D (diamond) and G (graphite) phase of carbon present in the candle soots. The electrochemical characterization was performed by cyclic voltammetry, galvanostatic charge/discharge test and impedance spectroscopy in 1MH2SO4 electrolyte. The functionalized candle soot electrode showed an enhanced specific capacitance value of 187 F g$^{−1}$ at 0.15 A g$^{−1}$ discharge current density, which is much higher than that of bare and washed candle soot electrodes.

  17. Measurement and Analysis of the Noise Radiated by Low Mach Number Centrifugal Blowers.

    Science.gov (United States)

    Yeager, David Marvin

    An investigation was performed of the broad band, aerodynamically generated noise in low tip-speed Mach number, centrifugal air moving devices. An interdisciplinary experimental approach was taken which involved investigation of the aerodynamic and acoustic fields, and their mutual relationship. The noise generation process was studied using two experimental vehicles: (1) a scale model of a homologous family of centrifugal blowers typical of those used to cool computer and business equipment, and (2) a single blade from a centrifugal blower impeller placed in a known, controllable flow field. The radiation characteristics of the model blower were investigated by measuring the acoustic intensity distribution near the blower inlet and comparing it with the intensity near the inlet to an axial flow fan. Results showed that the centrifugal blower is a distributed, random noise source, unlike an axial fan which exhibited the effects of a coherent, interacting source distribution. Aerodynamic studies of the flow field in the inlet and at the discharge to the rotating impeller were used to assess the mean flow distribution through the impeller blade channels and to identify regions of excessive turbulence near the rotating blade row. Both circumferential and spanwise mean flow nonuniformities were identified along with a region of increased turbulence just downstream of the scroll cutoff. The fluid incidence angle, normally taken as an indicator of blower performance, was estimated from mean flow data as deviating considerably from an ideal impeller design. An investigation of the noise radiated from the single, isolated airfoil was performed using modern correlation and spectral analysis techniques. Radiation from the single blade in flow was characterized using newly developed expressions for the correlation area and the dipole source strength per unit area, and from the relationship between the blade surface pressure and the incident turbulent flow field. Results

  18. MODELLING, SIMULATING AND OPTIMIZING BOILERS

    DEFF Research Database (Denmark)

    Sørensen, K.; Condra, T.; Houbak, Niels

    to operate a boiler plant dynamically means that the boiler designs must be able to absorb any fluctuations in water level and temperature gradients resulting from the pressure change in the boiler. On the one hand a large water-/steam space may be required, i.e. to build the boiler as big as......This paper describes the modelling, simulating and optimizing including experimental verification as being carried out as part of a Ph.D. project being written resp. supervised by the authors. The work covers dynamic performance of both water-tube boilers and fire tube boilers. A detailed dynamic...... model of the boiler has been developed and simulations carried out by means of the Matlab integration routines. The model is prepared as a dynamic model consisting of both ordinary differential equations and algebraic equations, together formulated as a Differential-Algebraic-Equation system. Being able...

  19. MODELLING, SIMULATING AND OPTIMIZING BOILERS

    DEFF Research Database (Denmark)

    Sørensen, K.; Condra, T.; Houbak, Niels

    This paper describes the modelling, simulating and optimizing including experimental verification as being carried out as part of a Ph.D. project being written resp. supervised by the authors. The work covers dynamic performance of both water-tube boilers and fire tube boilers. A detailed dynamic...... model of the boiler has been developed and simulations carried out by means of the Matlab integration routines. The model is prepared as a dynamic model consisting of both ordinary differential equations and algebraic equations, together formulated as a Differential-Algebraic-Equation system. Being able...... to operate a boiler plant dynamically means that the boiler designs must be able to absorb any fluctuations in water level and temperature gradients resulting from the pressure change in the boiler. On the one hand a large water-/steam space may be required, i.e. to build the boiler as big as...

  20. Modelling, simulating and optimizing Boilers

    DEFF Research Database (Denmark)

    Sørensen, Kim; Condra, Thomas Joseph; Houbak, Niels

    2003-01-01

    This paper describes the modelling, simulating and optimizing including experimental verication as being carried out as part of a Ph.D. project being written resp. supervised by the authors. The work covers dynamic performance of both water-tube boilers and re tube boilers. A detailed dynamic model...... of the boiler has been developed and simulations carried out by means of the Matlab integration routines. The model is prepared as a dynamic model consisting of both ordinary differential equations and algebraic equations, together formulated as a Differential-Algebraic- Equation system. Being able...... to operate a boiler plant dynamically means that the boiler designs must be able to absorb any uctuations in water level and temperature gradients resulting from the pressure change in the boiler. On the one hand a large water-/steam space may be required, i.e. to build the boiler as big as possible...

  1. Sooting Behaviour Dynamics of a Non-Bouyant Laminar Diffusion Flame

    OpenAIRE

    Fuentes, Andres; Legros, Guillaume; Rouvreau, Sebastien; Joulain, Pierre; Vantelon, Jean-Pierre; Torero, Jose L; Fernandez-Pello, Carlos

    2007-01-01

    Local soot concentrations in non-buoyant laminar diffusion flames have been demonstrated to be the outcome of two competitive processes, soot formation and soot oxidation. It was first believed that soot formation was the controlling mechanism and thus soot volume fractions could be scaled with a global residence time. Later studies showed that this is not necessarily the case and the local ratio of the soot formation and oxidation residence times is the prime variable controlling the ultimat...

  2. CHP Integrated with Burners for Packaged Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Castaldini, Carlo; Darby, Eric

    2013-09-30

    division of Sempra Energy. These match funds were provided via concurrent contracts and investments available via CMCE, Altex, and Leva Energy The project attained all its objectives and is considered a success. CMCE secured the support of GI&E from Italy to supply 100 kW Turbec T-100 microturbines for the project. One was purchased by the project’s subcontractor, Altex, and a second spare was purchased by CMCE under this project. The microturbines were then modified to convert from their original recuperated design to a simple cycle configuration. Replacement low-NOx silo combustors were designed and bench tested in order to achieve compliance with the California Air Resources Board (CARB) 2007 emission limits for NOx and CO when in CHP operation. The converted microturbine was then mated with a low NOx burner provided by Altex via an integration section that allowed flow control and heat recovery to minimize combustion blower requirements; manage burner turndown; and recover waste heat. A new fully integrated control system was designed and developed that allowed one-touch system operation in all three available modes of operation: (1) CHP with both microturbine and burner firing for boiler heat input greater than 2 MMBtu/hr; (2) burner head only (BHO) when the microturbine is under service; and (3) microturbine only when boiler heat input requirements fall below 2 MMBtu/hr. This capability resulted in a burner turndown performance of nearly 10/1, a key advantage for this technology over conventional low NOx burners. Key components were then assembled into a cabinet with additional support systems for generator cooling and fuel supply. System checkout and performance tests were performed in the laboratory. The assembled system and its support equipment were then shipped and installed at a host facility where final performance tests were conducted following efforts to secure fabrication, air, and operating permits. The installed power burner is now in commercial

  3. Study on soot formation characteristics in the diesel combustion process based on an improved detailed soot model

    International Nuclear Information System (INIS)

    Highlights: • An improved model to predict soot formation in a diesel engine has been proposed. • The physical process of PAHs deposition on the particle surface was considered. • Model validation carried out with a complete experimental matrix in two engines. • Good agreement between experimental and simulated results was found. • Particle size distribution and mass concentration in diesel engines are determined. - Abstract: Although much research has been done on soot formation in engines, the mechanisms involved in the process are poorly understood and models of the process are overly simplistic. An improved detailed soot model is developed that couples a reduced diesel surrogate fuel chemical reaction mechanism of n-heptane/toluene, implemented into KIVA-3V2 code, for the numerical investigation of soot formation, mass concentration, and size distribution in diesel engines. This detailed soot model incorporates the effects of soot precursors, including isomers of acetylene and polycyclic aromatic hydrocarbons (PAHs), and the physical processes of PAH deposition on the particle surface, soot formation, and particle surface growth. Compared with experiment results in an optical engine and a single-cylinder diesel engine, the improved detailed soot model was effective: the simulated in-cylinder combustion pressure, heat release rate, and ignition timing were in excellent agreement with the experimental results. The simulated two-dimensional, transient distribution of soot concentration was in good agreement with that obtained by using the two-color method, and the simulated changing trend of soot emission was consistent with the experimental results. Therefore, the detailed soot model can be used to accurately simulate and predict soot emission at different conditions in diesel engines. Furthermore, at the initial stage of combustion, large amounts of small-size soot particles were produced by the pyrolysis reactions and polymerization of the hydrocarbon

  4. Optimization of Load Assignment to Boilers in Industrial Boiler Plants

    Institute of Scientific and Technical Information of China (English)

    CAO Jia-cong; QIU Guang; CAO Shuang-hua; LIU Feng-qiang

    2004-01-01

    Along with the increasing importance of sustainable energy, the optimization of load assignment to boilers in an industrial boiler plant becomes one of the major projects for the optimal operation of boiler plants. Optimal load assignment for power systems has been a long-lasting subject, while it is quite new for industrial boiler plants. The existing methods of optimal load assignment for boiler plants are explained and analyzed briefly in the paper. They all need the fuel cost curves of boilers. Thanks to some special features of the curves for industrial boilers, a new model referred to as minimized departure model (MDM) of optimization of load assignment for boiler plants is developed and proposed in the paper. It merely relies upon the accessible data of two typical working conditions to build the model, viz. the working conditions with the highest efficiency of a boiler and with no-load. Explanation of the algorithm of computer program is given, and effort is made so as to determine in advance how many and which boilers are going to work. Comparison between the results using MDM and the results reported in references is carried out, which proves that MDM is preferable and practicable.

  5. Distinction of gaseous soot precursor molecules and soot precursor particles through photoionization mass spectrometry.

    Science.gov (United States)

    Happold, Joachim; Grotheer, Horst-Henning; Aigner, Manfred

    2007-01-01

    Samples were drawn from sooting premixed low-pressure ethylene oxygen flames and investigated through photoionization mass spectrometry using either KrF or ArF lasers as the radiation source. With the former, mass spectra were obtained as described in the literature and characterized through a series of signal groups, one for each C-number and extending to about m/z 1000, assigned as a PAH series. When the ArF laser was used the same series was observed with a somewhat higher sensitivity. In addition, a new series was observed overlaid on the PAH series and starting at about m/z 680. The new series exhibited abundant ions and it completely dominated the spectrum beyond m/z 1000. This series was identified as being the spectrum of soot precursor particles. Through measurement of the ionization order it was concluded that at least two photons are needed for ionization of PAHs whereas the particles need only one photon. Consequently, they can be measured with high sensitivity when an ArF laser is used as the radiation source. Furthermore, the discrimination of soot precursor molecules and soot precursor particles becomes possible through photoionization and this enables an improved understanding of the mass spectra. This should allow a particle growth mechanism to be deduced in the near future. PMID:17342787

  6. Numerical Simulation of Unsteady Discharge Flow with Fluctuation in Positive Discharge Blower

    Institute of Scientific and Technical Information of China (English)

    LIU Zhengxian; WANG Dou; XU Lianhuan

    2009-01-01

    The operating performance of positive discharge blower/s markedly influenced by the pulsation of the discharge flow, but difficult to be measured with experimental methods. The internal and discharge flow of positive discharge blower with involute type three-lobe are numerically investigated, both in air cooling and countercurrent cooling conditions by means of computational fluid dynamics (CFD). The unsteady compressible flow equations are solved using RNG κ-ε turbulent model. The finite difference method and the second order upwind difference scheme are applied into discrete equations. In the numerical simulation, the dynamic mesh techniques are used to approach the rotating displacement of cell cubage and the alterability of inlet, outlet flow area. The non-uniform mesh is applied to the rotor-stator coupled area. The reliability of the numerical method is verified by simulating the inner flow and comparing with the semi-empirical theory. The flow flux curves and the distributing of velocity vector showed obvious vortex motion in all the discharge process, both in air cooling and countercurrent cooling conditions. These vortexes with different positions, intension and numbers at different rotating angles have remarkable influences on the discharge flux. For air cooling, the vortex produced a second pulsation with big-amplitude in a cycle, and led to the early appearance of maximum of backflow. For countercurrent cooling, the frequency of pulsation increased due to the pre-inflow, but the hackflow at the outlet is prevented, also the pulsation strength has greatly decreased.

  7. Modification and Application of a Leaf Blower-vac for Field Sampling of Arthropods.

    Science.gov (United States)

    Zou, Yi; van Telgen, Mario D; Chen, Junhui; Xiao, Haijun; de Kraker, Joop; Bianchi, Felix J J A; van der Werf, Wopke

    2016-01-01

    Rice fields host a large diversity of arthropods, but investigating their population dynamics and interactions is challenging. Here we describe the modification and application of a leaf blower-vac for suction sampling of arthropod populations in rice. When used in combination with an enclosure, application of this sampling device provides absolute estimates of the populations of arthropods as numbers per standardized sampling area. The sampling efficiency depends critically on the sampling duration. In a mature rice crop, a two-minute sampling in an enclosure of 0.13 m(2) yields more than 90% of the arthropod population. The device also allows sampling of arthropods dwelling on the water surface or the soil in rice paddies, but it is not suitable for sampling fast flying insects, such as predatory Odonata or larger hymenopterous parasitoids. The modified blower-vac is simple to construct, and cheaper and easier to handle than traditional suction sampling devices, such as D-vac. The low cost makes the modified blower-vac also accessible to researchers in developing countries. PMID:27584040

  8. Construction and testing of a blower-door assembly for regulation of air pressure within structures

    International Nuclear Information System (INIS)

    The Technical Measurements Center is evaluating several methods to decrease the time required to determine an annual average radon-daughter concentration in structures. One method involves stabilizing the air pressure within the structure at a constant pressure with reference to external atmospheric or soil-gas pressure. This report describes the construction and preliminary testing of a blower-door system to maintain a constant differential air pressure within a structure. The blower-door assembly includes a collapsible frame and a large fan to occlude a doorway, a damper with an actuator to control air flow, a controller to drive the damper actuator, and a pressure transducer to measure the differential pressure. Preliminary testing of the system indicates that pressure within the structure in the range of 1 to 20 Pascals can be held to within approximately +-1 Pa of the set point. Further testing of the blower-door system is planned to provide data on the applicability of this method to short-duration tests for annual average radon-daughter concentration estimates. 13 figs., 1 tab

  9. Photoacoustic Soot Spectrometer (PASS) Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, M [Los Alamos National Laboratory; Springston, S [Brookhaven National Laboratory; Koontz, A [Pacific Northwest National Laboratory; Aiken, A [Los Alamos National Laboratory

    2013-01-17

    The photoacoustic soot spectrometer (PASS) measures light absorption by aerosol particles. As the particles pass through a laser beam, the absorbed energy heats the particles and in turn the surrounding air, which sets off a pressure wave that can be detected by a microphone. The PASS instruments deployed by ARM can also simultaneously measure the scattered laser light at three wavelengths and therefore provide a direct measure of the single-scattering albedo. The Operator Manual for the PASS-3100 is included here with the permission of Droplet Measurement Technologies, the instrument’s manufacturer.

  10. Aromatics oxidation and soot formation in flames

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J.B.; Pope, C.J.; Shandross, R.A.; Yadav, T. [Massachusetts Institute of Technology, Cambridge (United States)

    1993-12-01

    This project is concerned with the kinetics and mechanisms of aromatics oxidation and soot and fullerenes formation in flames. The scope includes detailed measurements of profiles of stable and radical species concentrations in low-pressure one-dimensional premixed flames. Intermediate species identifications and mole fractions, fluxes, and net reaction rates calculated from the measured profiles are used to test postulated reaction mechanisms. Particular objectives are to identify and to determine or confirm rate constants for the main benzene oxidation reactions in flames, and to characterize fullerenes and their formation mechanisms and kinetics.

  11. Measurement of nanotube content in pyrolytically generated carbon soot

    OpenAIRE

    Coleman, Jonathan; Blau, Werner; DRURY, ANNA

    2000-01-01

    PUBLISHED Carbon nanotubes can be efficiently separated from impurity material in carbon soot using a conjugated polymer filtration system as monitored by EPR, allowing the calculation of purity of the crude carbon soot. The authors wish to thank the Irish Higher Educational Authority for partly funding this work.

  12. Mutagenicity of diesel exhaust soot dispersed in phospholipid surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, W.; Keane, M.; Xing, S.; Harrison, J.; Gautam, M.; Ong, T.

    1994-06-01

    Organics extractable from respirable diesel exhaust soot particles by organic solvents have been known for some time to be direct acting frameshift mutagens in the Ames Salmonella typhimurium histidine reversion assay. Upon deposition in a pulmonary alveolus or respiratory bronchiole, respirable diesel soot particles will contact first the hypophase which is coated by and laden with surfactants. To model interactions of soot and pulmonary surfactant, the authors dispersed soots in vitro in the primary phospholipid pulmonary surfactant dipalmitoyl glycerophosphorylcholine (lecithin) (DPL) in physiological saline. They have shown that diesel soots dispersed in lecithin surfactant can express mutagenic activity, in the Ames assay system using S. typhimurium TA98, comparable to that expressed by equal amounts of soot extracted by dichloromethane/dimethylsulfoxide (DCM/DMSO). Here the authors report additional data on the same system using additional exhaust soots and also using two other phospholipids, dipalmitoyl glycerophosphoryl ethanolamine (DPPE), and dipalmitoyl phosphatidic acid (DPPA), with different ionic character hydrophilic moieties. A preliminary study of the surfactant dispersed soot in an eucaryotic cell test system also is reported.

  13. Fractal-like dimension of nanometer Diesel soot particles

    Energy Technology Data Exchange (ETDEWEB)

    Skillas, G.; Baltensperger, U. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Siegmann, K. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-11-01

    Measurements with a low-pressure impactor and a differential mobility analyser were conducted for Diesel soot at various engine loads. By means of these measurements a fractal-like dimension of Diesel soot particles, with diameters ranging from 55 up to 260 nm, was established. (author) 2 figs., 7 refs.

  14. Black soot and the survival of Tibetan glaciers.

    Science.gov (United States)

    Xu, Baiqing; Cao, Junji; Hansen, James; Yao, Tandong; Joswia, Daniel R; Wang, Ninglian; Wu, Guangjian; Wang, Mo; Zhao, Huabiao; Yang, Wei; Liu, Xianqin; He, Jianqiao

    2009-12-29

    We find evidence that black soot aerosols deposited on Tibetan glaciers have been a significant contributing factor to observed rapid glacier retreat. Reduced black soot emissions, in addition to reduced greenhouse gases, may be required to avoid demise of Himalayan glaciers and retain the benefits of glaciers for seasonal fresh water supplies. PMID:19996173

  15. NOx CONTROL OPTIONS AND INTEGRATION FOR US COAL FIRED BOILERS

    International Nuclear Information System (INIS)

    This is the seventh Quarterly Technical Report for DOE Cooperative Agreement No: DE-FC26-00NT40753. The goal of the project is to develop cost effective analysis tools and techniques for demonstrating and evaluating low NOx control strategies and their possible impact on boiler performance for firing US coals. The Electric Power Research Institute (EPRI) is providing co-funding for this program. This program contains multiple tasks and good progress is being made on all fronts. A series of field tests for RRI at the Ameren Sioux Unit No.1 have demonstrated that RRI can provide up to 30% NOx reduction over the use of over fire air in large scale (480MW) cyclone fired utility boilers. The field tests and modeling results are in good agreement. Final data analysis has been completed for tests performed at Eastlake Power Station of a real-time waterwall corrosion monitoring system. The tests demonstrated that corrosion could be measured accurately in real-time in normal boiler operations, and an assessment of waterwall wastage could be made without impacting boiler availability. Detailed measurements of soot volume fraction have been performed for a coal burner in a pilot scale test furnace. The measured values are in good agreement with the expected trends for soot generation and destruction. Catalysts from four commercial manufacturers have been ordered and one of the samples was received this quarter. Several in situ analyses of vanadium-based SCR catalyst systems were completed at BYU. Results to date indicate that the system produces results that represent improvements compared to literature examples of similar experiments. Construction of the catalyst characterization system (CCS) reactor is nearly complete, with a few remaining details discussed in this report. A literature review originally commissioned from other parties is being updated and will be made available under separate cover as part of this investigation. Fabrication of the multi-catalyst slipstream

  16. Emission of volatile organic compounds from oil-fired and gas-fired heating boilers

    International Nuclear Information System (INIS)

    The emissions of Volatile Organic Compounds (VOC) and nitrogen oxides (NOx) from different types of oil-fired and gas-fired boilers have been investigated. Measurements have been made at three excess air ratios for two different burners for domestic boilers using light fuel oil, as well as at larger plants using WRD, heavy fuel oil and LPG. Significant emissions of VOC, in this case methane, ethylene and acetylene, could only be found in one case with a burner for domestic boilers adjusted to a soot number of 9, according to Bacharach. However, this represents practically unrealistic operating conditions. In all other cases the concentrations of VOC were below the detection limits. The emissions of NOx varied between 26 mg NO2/MJ in one case for a burner for domestic boilers, to 183 NO2/MJ for one of the heavy fuel oil plants. In conclusion, the survey shows that the VOC emissions from oil-fired and gas-fired boiler plants are very low. (3 refs., 17 figs., 6 tabs.)

  17. Optimising boiler performance.

    Science.gov (United States)

    Mayoh, Paul

    2009-01-01

    Soaring fuel costs continue to put the squeeze on already tight health service budgets. Yet it is estimated that combining established good practice with improved technologies could save between 10% and 30% of fuel costs for boilers. Paul Mayoh, UK technical manager at Spirax Sarco, examines some of the practical measures that healthcare organisations can take to gain their share of these potential savings. PMID:19192603

  18. Measuring soot particles from automotive exhaust emissions

    Directory of Open Access Journals (Sweden)

    Andres Hanspeter

    2014-01-01

    Full Text Available The European Metrology Research Programme participating countries and the European Union jointly fund a three year project to address the need of the automotive industry for a metrological sound base for exhaust measurements. The collaborative work on particle emissions involves five European National Metrology Institutes, the Tampere University of Technology, the Joint Research Centre for Energy and Transport and the Leibniz Institute for Tropospheric Research. On one hand, a particle number and size standard for soot particles is aimed for. Eventually this will allow the partners to provide accurate and comparable calibrations of measurement instruments for the type approval of Euro 5b and Euro 6 vehicles. Calibration aerosols of combustion particles, silver and graphite proof partially suitable. Yet, a consensus choice together with instrument manufactures is pending as the aerosol choice considerably affects the number concentration measurement. Furthermore, the consortium issued consistent requirements for novel measuring instruments foreseen to replace today’s opacimeters in regulatory periodic emission controls of soot and compared them with European legislative requirements. Four partners are conducting a metrological validation of prototype measurement instruments. The novel instruments base on light scattering, electrical, ionisation chamber and diffusion charging sensors and will be tested at low and high particle concentrations. Results shall allow manufacturers to further improve their instruments to comply with legal requirements.

  19. Studies of propane flame soot acting as heterogeneous ice nuclei in conjunction with single particle soot photometer measurements

    Directory of Open Access Journals (Sweden)

    I. Crawford

    2011-04-01

    Full Text Available The ice nucleation efficiency of propane flame soot particles with and without a sulphuric acid coating was investigated using the aerosol and cloud chamber facility AIDA (Aerosol Interaction and Dynamics in the Atmosphere. The test soot for cloud formation simulations was produced using a propane flame Combustion Aerosol Standard generator (CAST, Jing-CAST Technologies. The organic carbon content (OC of the test soot was altered in a reproducible fashion by changing the fuel/air mixture of the generator. The soot content of ice nuclei was subsequently investigated using a combination of a pumped counterflow virtual impactor (PCVI to separate and evaporate the ice crystals, and a DMT single particle soot photometer (SP2 to examine the mixing state of the BC containing ice residuals.

    Ice nucleation was found to be most efficient for uncoated soot of low organic carbon content (~5% organic carbon content where deposition freezing occurred at an ice saturation ratio Sice~1.22 at a temperature T = 226.6 K with 25% of the test soot becoming active as ice nuclei. Propane flame soot of higher organic carbon content (~30% and ~70% organic carbon content showed significantly lower ice nucleation efficiency (an activated fraction of the order of a few percent in the experiments than the low organic carbon content soot, with water saturation being required for freezing to occur. Ice nucleation occurred over the range Sice = 1.22–1.70, and T = 223.2–226.6 K. Analysis of the SP2 data showed that the 5% organic carbon content soot had an undetectable OC coating whereas the 30% organic carbon content soot had a thicker or less volatile OC coating.

    The application of a sulphuric acid coating to the flame soot shifted the threshold of the onset of freezing towards that of the homogeneous freezing of sulphuric acid; for the minimum OC flame soot this inhibited nucleation since the onset of

  20. Studies of propane flame soot acting as heterogeneous ice nuclei in conjunction with single particle soot photometer measurements

    Directory of Open Access Journals (Sweden)

    I. Crawford

    2011-09-01

    Full Text Available The ice nucleation efficiency of propane flame soot particles with and without a sulphuric acid coating was investigated using the aerosol and cloud chamber facility AIDA (Aerosol Interaction and Dynamics in the Atmosphere. The test soot for cloud formation simulations was produced using a propane flame Combustion Aerosol Standard generator (CAST, Jing-CAST Technologies. The organic carbon content (OC of the test soot was altered in a reproducible fashion by changing the fuel/air mixture of the generator. The soot content of ice nuclei was subsequently investigated using a combination of a pumped counterflow virtual impactor (PCVI to separate and evaporate the ice crystals, and a DMT single particle soot photometer (SP2 to examine the mixing state of the BC containing ice residuals.

    Ice nucleation was found to be most efficient for uncoated soot of low organic carbon content (~5 % organic carbon content where deposition freezing occurred at an ice saturation ratio Sice ~ 1.22 at a temperature T = 226.6 K with 25 % of the test soot becoming active as ice nuclei. Propane flame soot of higher organic carbon content (~30 % and ~70 % organic carbon content showed significantly lower ice nucleation efficiency (an activated fraction of the order of a few percent in the experiments than the low organic carbon content soot, with water saturation being required for freezing to occur. Ice nucleation occurred over the range Sice = 1.22–1.70, and T = 223.2–226.6 K. Analysis of the SP2 data showed that the 5 % organic carbon content soot had an undetectable OC coating whereas the 30 % organic carbon content soot had a thicker or less volatile OC coating.

    The application of a sulphuric acid coating to the flame soot shifted the threshold of the onset of freezing towards that of the homogeneous freezing of sulphuric acid; for the minimum OC flame soot this inhibited nucleation since the

  1. Ice nucleation activity of diesel soot particles at Cirrus relevant conditions: Effects of hydration, secondary organics coating, hydration, soot morphology, and coagulation

    Energy Technology Data Exchange (ETDEWEB)

    Kulkarni, Gourihar R.; China, Swarup; Liu, Shang; Nandasiri, Manjula I.; Sharma, Noopur; Wilson, Jacqueline M.; Aiken, A. C.; Chand, Duli; Laskin, Alexander; Mazzoleni, Claudio; Pekour, Mikhail S.; Shilling, John E.; Shutthanandan, V.; Zelenyuk, Alla; Zaveri, Rahul A.

    2016-04-16

    The role of atmospheric relevant soot particles that are processed in the atmosphere toward ice nucleation at cirrus cloud condition is poorly understood. In this study, the ice nucleating properties of diesel soot particles subjected to various physical and chemical aging treatments were investigated at temperatures ranging from -40 to -50 °C. We show that bare soot particles nucleate ice in deposition mode, but coating with secondary organics suppresses the heterogeneous ice nucleation potential of soot particles requiring homogeneous freezing threshold conditions. However, the ice nucleation efficiency of soot particles coated with an aqueous organic layer was similar to bare soot particles. Hydration of bare soot particles slightly enhanced the ice nucleation efficiency, and the IN abilities of compact soot particles (roundness = ~ 0.6) were similar to bare lacey soot particles (roundness = ~ 0.4). These results indicate that ice nucleation properties are sensitive to the various aging treatments.

  2. Super Boiler 2nd Generation Technology for Watertube Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Mr. David Cygan; Dr. Joseph Rabovitser

    2012-03-31

    This report describes Phase I of a proposed two phase project to develop and demonstrate an advanced industrial watertube boiler system with the capability of reaching 94% (HHV) fuel-to-steam efficiency and emissions below 2 ppmv NOx, 2 ppmv CO, and 1 ppmv VOC on natural gas fuel. The boiler design would have the capability to produce >1500 F, >1500 psig superheated steam, burn multiple fuels, and will be 50% smaller/lighter than currently available watertube boilers of similar capacity. This project is built upon the successful Super Boiler project at GTI. In that project that employed a unique two-staged intercooled combustion system and an innovative heat recovery system to reduce NOx to below 5 ppmv and demonstrated fuel-to-steam efficiency of 94% (HHV). This project was carried out under the leadership of GTI with project partners Cleaver-Brooks, Inc., Nebraska Boiler, a Division of Cleaver-Brooks, and Media and Process Technology Inc., and project advisors Georgia Institute of Technology, Alstom Power Inc., Pacific Northwest National Laboratory and Oak Ridge National Laboratory. Phase I of efforts focused on developing 2nd generation boiler concepts and performance modeling; incorporating multi-fuel (natural gas and oil) capabilities; assessing heat recovery, heat transfer and steam superheating approaches; and developing the overall conceptual engineering boiler design. Based on our analysis, the 2nd generation Industrial Watertube Boiler when developed and commercialized, could potentially save 265 trillion Btu and $1.6 billion in fuel costs across U.S. industry through increased efficiency. Its ultra-clean combustion could eliminate 57,000 tons of NOx, 460,000 tons of CO, and 8.8 million tons of CO2 annually from the atmosphere. Reduction in boiler size will bring cost-effective package boilers into a size range previously dominated by more expensive field-erected boilers, benefiting manufacturers and end users through lower capital costs.

  3. DOWNSCALE APPLICATION OF BOILER THERMAL CALCULATION APPROACH

    OpenAIRE

    Zelený, Zbynĕk; Hrdlička, Jan

    2016-01-01

    Commonly used thermal calculation methods are intended primarily for large scale boilers. Hot water small scale boilers, which are commonly used for home heating have many specifics, that distinguish them from large scale boilers especially steam boilers. This paper is focused on application of thermal calculation procedure that is designed for large scale boilers, on a small scale boiler for biomass combustion of load capacity 25 kW. Special issue solved here is influence of formation of dep...

  4. Soot Reactivity in Conventional Combustion and Oxy-fuel Combustion Environments

    DEFF Research Database (Denmark)

    Abián, María; Jensen, Anker D.; Glarborg, Peter;

    2012-01-01

    of the carbon, as well as to compare the soot reactivity toward O2 and CO2. Soot samples were either oxidized in 5% O2 or gasified in 10, 50, and 90% CO2 atmospheres, during non-isothermal runs at 10 K/min. Soot oxidation was observed at temperatures of 400–500 K lower than soot gasification, showing higher...

  5. Small boiler uses waste coal

    Energy Technology Data Exchange (ETDEWEB)

    Virr, M.J. [Spinheat Ltd. (United States)

    2009-07-15

    Burning coal waste in small boilers at low emissions poses considerable problem. While larger boiler suppliers have successfully installed designs in the 40 to 80 MW range for some years, the author has been developing small automated fluid bed boiler plants for 25 years that can be applied in the range of 10,000 to 140,000 lbs/hr of steam. Development has centered on the use of an internally circulating fluid bed (CFB) boiler, which will burn waste fuels of most types. The boiler is based on the traditional D-shaped watertable boiler, with a new type of combustion chamber that enables a three-to-one turndown to be achieved. The boilers have all the advantages of low emissions of the large fluid boilers while offering a much lower height incorporated into the package boiler concept. Recent tests with a waste coal that had a high nitrogen content of 1.45% demonstrated a NOx emission below the federal limit of 0.6 lbs/mm Btu. Thus a NOx reduction on the order of 85% can be demonstrate by combustion modification alone. Further reductions can be made by using a selective non-catalytic reduction (SNCR) system and sulfur absorption of up to 90% retention is possible. The article describes the operation of a 30,000 lbs/hr boiler at the Fayette Thermal LLC plant. Spinheat has installed three ICFB boilers at a nursing home and a prison, which has been tested on poor-grade anthracite and bituminous coal. 2 figs.

  6. Modification of soot by volatile species in an urban atmosphere.

    Science.gov (United States)

    Shi, Zongbo; Zhang, Daizhou; Ji, Hezhe; Hasegawa, Shuichi; Hayashi, Masahiro

    2008-01-15

    Aerosol samples in the urban atmosphere of Kumamoto (32 degrees 48'N, 134 degrees 45'E) in southwestern Japan were collected onto aluminum foil strips. Parts of the samples were heated to 550 degrees C in pure helium gas, and oxygen (2%)-helium (98%) mixture gas. Particles in unheated and heated parts were characterized individually by their morphology and elemental composition using a scanning electron microscope equipped with an energy dispersive X-ray spectrometer. There were mainly two types of soot-containing particles according to the morphology: chain-like and sub-round. Chain-like particles were likely young soot particles because such particles in heated specimens showed similar morphology to those in unheated specimen. In contrast, the sub-round particles were composed of volatile species encapsulated with soot. The heating caused partial evaporation of such particles, and the soot inclusions could be identified only after the heating. The volatile species frequently contained sulfur compounds, but sulfur was not detected in the residues, suggesting that the volatile species were mainly produced on soot particles in the atmosphere. The sub-round soot-containing particles were approximately 3 times larger in diameter than the inclusions. These results suggest that soot particles could be substantially modified in size and composition by volatile species in the urban atmosphere. PMID:17897704

  7. COMBINED BOILER WITH TPV

    OpenAIRE

    Björk, Magnus

    2013-01-01

    A TPV-system consists of a hot surface emitting heat radiation on a solar cell with a narrow bandgap.  A unit consisting of a boiler and a TPV-system has been constructed for testing of the performance of TPV cells. The emitter is heated by a fuel consisting of RME-oil. The radiation is collected and concentrated through two reflecting cones formed like a Faberge-egg, with an edge-type optical filter between the cones. The Faberge-egg is treated with electro-polishing in order to obtain a hig...

  8. Boiler for ships; Hakuyo boira

    Energy Technology Data Exchange (ETDEWEB)

    Shimoda, F. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)

    1999-07-20

    In this paper, production and technology trend of boiler for ships in 1998 are described. The actual results of main boiler are as follows. As the main boiler for LNG ships, 4 boilers produced by Mitsui Engineering and Shipbuilding for Qatar Project, 8 produced by Kawasaki Heavy Industries for South Korea and 10 produced by Mitsubishi Heavy Industries for domestic use and South Korea. 1998 was an active year for the main boiler for ships. The auxiliary boiler of steam pressure of 16k to 25k equipping for tanker ships was 115 (4,441t/h of steam quantity in total), it greatly increased in comparison with 88 (3,172t/h) produced in the proceeding year. Donkey boilers of steam pressure of 6k to 10k equipping for container ships and bulk cargo was 147 (672t/h), and it substantially decreased in comparison with 274 (693t/h) of the proceeding year, but capacity per boiler increased. The gas exhaust economizer for turbo power generation plants was 6 produced for VLCC. (NEDO)

  9. Visualizing the mobility of silver during catalytic soot oxidation

    DEFF Research Database (Denmark)

    Gardini, Diego; Christensen, Jakob M.; Damsgaard, Christian Danvad;

    2016-01-01

    The catalytic activity and mobility of silver nanoparticles used as catalysts in temperature programmed oxidation of soot:silver (1:5 wt:wt) mixtures have been investigated by means of flow reactor experiments and in situ environmental transmission electron microscopy (ETEM). The carbon oxidation...... mobility during the soot oxidation, and this mobility, which increases the soot/catalyst contact, is expected to be an important factor for the lower oxidation temperature. In the intimate tight contact mixture the initial dispersion of the silver particles is greater,,and the onset of mobility occurs at a...

  10. Pellet wood gasification boiler / Combination boiler. Market review. 7. ed.; Scheitholzvergaser-/Kombikessel. Marktuebersicht

    Energy Technology Data Exchange (ETDEWEB)

    Uth, Joern

    2010-08-15

    In the market review under consideration on pellet wood gasification boilers and combination boilers, the Federal Ministry of Food, Agriculture and Consumer Protection (Bonn, Federal Republic of Germany) report on planning and installation of wood-fired heating systems, recommendations regarding to the technical assessment of boiler systems, buffers/combination boilers, prices of pellet wood gasification boilers, data sheets of the compared pellet wood gasification boilers, pellet wood combination boilers, prices of pellet wood combination boilers, data sheets of the compared pellet wood gasification boilers, list of providers.

  11. Market review. Pellet wood gasification boiler / combination boiler. 8. ed.; Marktuebersicht. Scheitholzvergaser-/Kombikessel

    Energy Technology Data Exchange (ETDEWEB)

    Uth, Joern

    2012-01-15

    In the market review under consideration on pellet wood gasification boilers and combination boilers, the Federal Ministry of Food, Agriculture and Consumer Protection (Bonn, Federal Republic of Germany) reports on planning and installation of wood-fired heating systems, recommendations regarding to the technical assessment of boiler systems, buffers/combination boilers, prices of pellet wood gasification boilers, data sheets of the compared pellet wood gasification boilers, pellet wood combination boilers, prices of pellet wood combination boilers, data sheets of the compared pellet wood gasification boilers, list of providers.

  12. Strain rate effects on soot evolution in turbulent nonpremixed flames

    Science.gov (United States)

    Lew, Jeffry K.; Mueller, Michael E.; Mahmoud, Saleh; Alwahabi, Zeyad T.; Dally, Bassam B.; Nathan, Graham J.

    2015-11-01

    Large Eddy Simulations (LES) of turbulent nonpremixed ethylene/hydrogen/nitrogen (2/2/1 by volume) jet flames are conducted to investigate the effects of global strain rate on soot evolution. The exit strain rate is varied by fixing the Reynolds number as the burner diameter and exit velocity are altered. A detailed integrated LES approach is employed that includes a nonpremixed flamelet model that accounts for heat losses from radiation, a transport equation model to account for unsteadiness in polycyclic aromatic hydrocarbon (PAH) evolution, a detailed soot model based on the Hybrid Method of Moments, and a novel presumed subfilter PDF model for soot-turbulence interactions. As the strain rate increases, the maximum soot volume fraction decreases due to the suppression of PAH formation. This trend with increasing strain rate is validated against experimental measurements conducted at The University of Adelaide.

  13. Ultrasensitive, Fast-Response Size-Dependent Soot Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a "black carbon" (soot) monitor for measuring non-volatile particulate emissions from gas turbine engines employing a proprietary optical...

  14. HETEROGENEOUS SOOT NANOSTRUCTURE IN ATMOSPHERIC AND COMBUSTION SOURCE AEROSOLS

    Science.gov (United States)

    Microscopic images of soot emissions from wildfire and a wide range of anthropogenic combustion sources show that the nanostructures of individual particles in these emissions are predominantly heterogeneous, decidedly influenced by the fuel composition and by the particular comb...

  15. A Computational Investigation of Sooting Limits of Spherical Diffusion Flames

    Science.gov (United States)

    Lecoustre, V. R.; Chao, B. H.; Sunderland, P. B.; Urban, D. L.; Stocker, D. P.; Axelbaum, R. L.

    2007-01-01

    Limiting conditions for soot particle inception in spherical diffusion flames were investigated numerically. The flames were modeled using a one-dimensional, time accurate diffusion flame code with detailed chemistry and transport and an optically thick radiation model. Seventeen normal and inverse flames were considered, covering a wide range of stoichiometric mixture fraction, adiabatic flame temperature, and residence time. These flames were previously observed to reach their sooting limits after 2 s of microgravity. Sooting-limit diffusion flames with residence times longer than 200 ms were found to have temperatures near 1190 K where C/O = 0.6, whereas flames with shorter residence times required increased temperatures. Acetylene was found to be a reasonable surrogate for soot precursor species in these flames, having peak mole fractions of about 0.01.

  16. Conductometric Soot Sensor for Automotive Exhausts: Initial Studies

    OpenAIRE

    Ralf Moos; Dieter Brüggemann; Andreas Heinrich; Constanze Feistkorn; Sven Wiegärtner; Gunter Hagen

    2010-01-01

    In order to reduce the tailpipe particulate matter emissions of Diesel engines, Diesel particulate filters (DPFs) are commonly used. Initial studies using a conductometric soot sensor to monitor their filtering efficiency, i.e., to detect a malfunction of the DPF, are presented. The sensors consist of a planar substrate equipped with electrodes on one side and with a heater on the other. It is shown that at constant speed-load points, the time until soot percolation occurs or the resistance i...

  17. Emission of ions and charged soot particles by aircraft engines

    OpenAIRE

    Sorokin, A.; Vancassel, X.; P. Mirabel

    2003-01-01

    In this article, a model which examines the formation and evolution of chemiions in an aircraft engine is proposed. This model which includes chemiionisation, electron thermo-emission, electron attachment to soot particles and to neutral molecules, electron-ion and ion-ion recombination, ion-soot interaction, allows the determination of the ion concentration at the exit of the combustor and at the nozzle exit of the engine. It also allows the determination ...

  18. Oxygen extended sooting index of FAME blends with aviation kerosene

    OpenAIRE

    Llamas Lois, Alberto; Canoira López, Laureano

    2013-01-01

    The use of biofuels in the aviation sector has economic and environmental benefits. Among the options for the production of renewable jet fuels, hydroprocessed esters and fatty acids (HEFA) have received predominant attention in comparison with fatty acid methyl esters (FAME), which are not approved as additives for jet fuels. However, the presence of oxygen in methyl esters tends to reduce soot emissions and therefore particulate matter emissions. This sooting tendency is quantified in this ...

  19. Phototransformation Rate Constants of PAHs Associated with Soot Particles

    OpenAIRE

    Kim, Daekyun; Young, Thomas M.; Anastasio, Cort

    2012-01-01

    Photodegradation is a key process governing the residence time and fate of polycyclic aromatic hydrocarbons (PAHs) in particles, both in the atmosphere and after deposition. We have measured photodegradation rate constants of PAHs in bulk deposits of soot particles illuminated with simulated sunlight. The photodegradation rate constants at the surface (k0p), the effective diffusion coefficients (Deff), and the light penetration depths (z0.5) for PAHs on soot layers of variable thickness were ...

  20. Optimal scheduling of sootblowers in power plant boilers

    Science.gov (United States)

    Vasquez-Urbano, Pedro Manuel

    1997-11-01

    Burning coal or other fossil fuels in a utility boiler fouls the surfaces of its heat exchangers with ash and soot residues. These deposits affect the performance of the power plant since they reduce heat transfer from the combustion gases to the water or steam. Fouling can be removed during the operation of the plant with the use of lances, called sootblowers, that direct high-pressure air or steam onto the fouled surfaces. Sootblowing operations are key to plant efficiency and boiler maintenance, but they also incur operating costs. A utility boiler may have a hundred or so sootblowers placed in fixed locations. Deciding which of these should be used at any moment is complicated by the lack of instrumentation that can monitor fouling levels. This dissertation studies the optimization problem of scheduling sootblowing activities at a utility plant. The objective is to develop an optimization approach to determine which sootblowers should be activated at any moment in order to maximize plant efficiency. To accomplish this, three issues are addressed. First, models are developed that can estimate fouling conditions indirectly during plant operation using commonly available data. The approach used relies on a sequential application of linear regression fits. Secondly, autoregressive exogenous (ARX) models are used to describe the dynamics of the fouling process and to estimate the consequences of fouling on plant efficiency. All the foregoing empirical models are developed using data from a power plant. Finally, using the empirical models, an optimization model is formulated for the sootblowing scheduling problem and different optimization approaches that combine nonlinear programming with heuristics methods are investigated for its solution. The applicability of dynamic programming to this optimization problem is also explored.

  1. The reduction of soot formation from fuels using oxygenates additives

    International Nuclear Information System (INIS)

    Highlights: ► Understanding of the performance of thermo chemical heat pump. ► Tool for storing thermal energy. ► Parameters that affect the amount of thermal stored energy. ► Lithium chloride has better effect on storing thermal energy. - Abstract: This work presents an experimental technique for the measurement of the soot formation in pure fuel, biofuel and emulsified fuel, that constitute this fuels was studied in heated shock tube and investigated the possibility of reducing soot production in locally refined diesel, locally produced biofuel and emulsified fuel. This reduction was conducted using certain oxygenated additives (methane, ethane and acetone). It was found that soot concentration is maximum when pure diesel was burned, followed by emulsified fuels and the lease concentration was obtained when biofuel was burned. Further, methanol has the most significant effect on the reduction of soot once added to each fuel, while acetone has the lease effect on soot reduction. The results gave good indication of the effect for oxygenated additives in reduction the soot formation.

  2. Isothermal Kinetics of Catalyzed Air Oxidation of Diesel Soot

    Directory of Open Access Journals (Sweden)

    R. Prasad

    2011-01-01

    Full Text Available To comply with the stringent emission regulations on soot, diesel vehicles manufacturers more and more commonly use diesel particulate filters (DPF. These systems need to be regenerated periodically by burning soot that has been accumulated during the loading of the DPF. Design of the DPF requires rate of soot oxidation. This paper describes the kinetics of catalytic oxidation of diesel soot with air under isothermal conditions. Kinetics data were collected in a specially designed mini-semi-batch reactor. Under the high air flow rate assuming pseudo first order reaction the activation energy of soot oxidation was found to be, Ea = 160 kJ/ mol. ©2010 BCREC UNDIP. All rights reserved(Received: 14th June 2010, Revised: 18th July 2010, Accepted: 9th August 2010[How to Cite: R. Prasad, V.R. Bella. (2010. Isothermal Kinetics of Catalyzed Air Oxidation of Diesel Soot. Bulletin of Chemical Reaction Engineering and Catalysis, 5(2: 95-101. doi:10.9767/bcrec.5.2.796.95-101][DOI:http://dx.doi.org/10.9767/bcrec.5.2.796.95-101 || or local:  http://ejournal.undip.ac.id/index.php/bcrec/article/view/796]Cited by in: ACS 1 |

  3. Large Eddy Simulation of a Sooting Jet Diffusion Flame

    Science.gov (United States)

    Blanquart, Guillaume; Pitsch, Heinz

    2007-11-01

    The understanding of soot particle dynamics in combustion systems is a key issue in the development of low emission engines. Of particular importance are the processes shaping the soot particle size distribution function (PSDF). However, it is not always necessary to represent exactly the full distribution, and often information about its moments only is sufficient. The Direct Quadrature Method of Moments (DQMOM) allows for an efficient and accurate prediction of the moments of the soot PSDF. This method has been validated for laminar premixed and diffusion flames with detailed chemistry and is now implemented in a semi-implicit low Mach-number Navier-Stokes solver. A Large Eddy Simulation (LES) of a piloted sooting jet diffusion flame (Delft flame) is performed to study the dynamics of soot particles in a turbulent environment. The profiles of temperature and major species are compared with the experimental measurements. Soot volume fraction profiles are compared with the recent data of Qamar et al. (2007). Aggregate properties such as the diameter and the fractal shape are studied in the scope of DQMOM.

  4. Direct Numerical Simulation of Soot Particle Dynamics using DQMOM

    Science.gov (United States)

    Blanquart, Guillaume; Pitsch, Heinz; Fox, Rodney

    2006-11-01

    The understanding of soot particle dynamics in combustion systems is a key issue in the development of low emission engines. Of particular importance are the processes shaping the soot particle size distribution function (PSDF). However, it is not always necessary to represent exactly the full distribution but rather some of its moments. The Direct Quadrature Method of Moments (DQMOM) allows for a very accurate prediction of the moments of the soot PSDF without the cost of expensive methods like Direct Simulation Monte-Carlo (DSMC). This method has been validated for laminar premixed and diffusion flames with detailed chemistry and is now implemented in a semi-implicit low Mach number Navier-Stokes solver. A Direct Numerical Simulation (DNS) of an ethylene jet diffusion flame is performed to study the dynamics of soot particles in a turbulent environment. Soot particles are formed in very rich regions of the flames and are then transported to lean regions where they get oxidized. The time evolution of the soot PSDF will be analyzed and compared to similar distributions from laminar simulations.

  5. Durable superhydrophobic carbon soot coatings for sensor applications

    Science.gov (United States)

    Esmeryan, K. D.; Radeva, E. I.; Avramov, I. D.

    2016-01-01

    A novel approach for the fabrication of durable superhydrophobic (SH) carbon soot coatings used in quartz crystal microbalance (QCM) based gas or liquid sensors is reported. The method uses modification of the carbon soot through polymerization of hexamethyldisiloxane (HMDSO) by means of glow discharge RF plasma. The surface characterization shows a fractal-like network of carbon nanoparticles with diameter of ~50 nm. These particles form islands and cavities in the nanometer range, between which the plasma polymerized hexamethyldisiloxane (PPHMDSO) embeds and binds to the carbon chains and QCM surface. Such modified surface structure retains the hydrophobic nature of the soot and enhances its robustness upon water droplet interactions. Moreover, it significantly reduces the insertion loss and dynamic resistance of the QCM compared to the commonly used carbon soot/epoxy resin approach. Furthermore, the PPHMDSO/carbon soot coating demonstrates durability and no aging after more than 40 probing cycles in water based liquid environments. In addition, the surface layer keeps its superhydrophobicity even upon thermal annealing up to 540 °C. These experiments reveal an opportunity for the development of soot based SH QCMs with improved electrical characteristics, as required for high-resolution gas or liquid measurements.

  6. Emission of ions and charged soot particles by aircraft engines

    Directory of Open Access Journals (Sweden)

    A. Sorokin

    2003-01-01

    Full Text Available In this article, a model which examines the formation and evolution of chemiions in an aircraft engine is proposed. This model which includes chemiionisation, electron thermo-emission, electron attachment to soot particles and to neutral molecules, electron-ion and ion-ion recombination, ion-soot interaction, allows the determination of the ion concentration at the exit of the combustor and at the nozzle exit of the engine. It also allows the determination of the charge of the soot particles. For the engine considered, the upper limit for the ion emission index EIi is of the order of (2-5 x1016 ions/kg-fuel if ion-soot interactions are ignored and the introduction of ion-soot interactions lead about to a 50% reduction. The results also show that most of the soot particles are either positively or negatively charged, the remaining neutral particles representing approximately 20% of the total particles. A comparison of the model results with the available ground-based experimental data obtained on the ATTAS research aircraft engines during the SULFUR experiments (Schumann, 2002 shows an excellent agreement.

  7. Measurement of Soot Deposition in Automotive Components Using Neutron Radiography

    International Nuclear Information System (INIS)

    About 40% of air pollution is generated by vehicles and transportation. The particulate matter (PM) emission significantly impacts human health. Fine particles below 2.5 μm (PM2.5) can enter the lungs and lead to respiratory problems. These particles not only influence human health, but also reduce the capability of many automobile exhaust heat exchanging devices. Neutron radiography is a non-destructive method of analyzing carbonaceous PM. While neutron radiography has been demonstrated for soot measurement in the past, the application has not considered the presence of unburned hydrocarbons, significant amounts of moisture nor examined complex geometrical configurations. The purpose of this work is to study a reliable non-destructive testing methodology using neutron radiography for measurement of soot distribution in automotive components. A soot standard (aluminium target) was designed and manufactured as a calibration tool. The standard is radiographed and used to measure the differences between various soot thickness and compositions. The radiograph images are analyzed to determine a calibration curve based upon the composition of the materials which can then be used for analysis of the automotive components. Experiments are performed using a diesel engine to produce soot deposits on exhaust piping. Soot distribution on exhaust piping is measured using neutron radiography. (authors)

  8. Response to Comment on “Modeling Maximum Adsorption Capacities of Soot and Soot-like Materials for PAHs and PCBs”

    NARCIS (Netherlands)

    Noort, van P.C.M.; Jonker, M.T.O.; Koelmans, A.A.

    2005-01-01

    A comment by John C. Fetzer on modeling maximum adsorption capacities of soot and soot-like materials for PAH and PCB and the adsorption behavior of PAH on soots and on other adsorptive materials is presented. The authors (van Noort et al.) base their model on van der Waal's forces only. This may be

  9. Determining heat loss into the environment based on comprehensive investigation of boiler performance characteristics

    Science.gov (United States)

    Lyubov, V. K.; Malygin, P. V.; Popov, A. N.; Popova, E. I.

    2015-08-01

    A refined procedure for determining heat loss into the environment from heat-generating installations is presented that takes into account the state of their lining and heat insulation quality. The fraction of radiative component in the total amount of heat loss through the outer surfaces is determined. The results from experimental investigations of the thermal engineering and environmental performance characteristics of a foreign hot-water boiler in firing wood pellets are presented. A conclusion is drawn about the possibility of using such hot-water boilers for supplying heat to low-rise buildings, especially for the conditions of the North-Arctic region. The results from a thermal engineering investigation of wood pellets and furnace residue carried out on installations of a thermal analysis laboratory are presented together with the grain-size composition of fuel and indicators characterizing the mechanical strength of wood pellets. The velocity fields, flue gas flow rates, and soot particle concentrations are determined using the external filtration methods, and the composition of combustion products is investigated using a gas analyzer. The graphs of variation with time of boiler external surface temperature from the moment of achieving the nominal mode of operation and heat loss into the environment for stationary boilers are presented.

  10. Use of EC-blowers contribute to green investment; Gebruik van EC-ventilatoren levert bijdrage aan groene investering

    Energy Technology Data Exchange (ETDEWEB)

    Huijgens, G.; Ridder, A.

    2009-07-01

    Despite their small share in the entire use, applying EC blowers (electronically commutated) in coolers and condensers can provide an interesting contribution to a sound green investment. This additional investment with EC blowers will pay off through more efficient energy use and easy operation with rpm control. [Dutch] Door gebruik te maken van EC-ventilatoren (EC staat voor 'electronically commutated') op koelers en condensors kan, ondanks het kleine aandeel in het totaalverbruik, toch een interessante bijdrage geleverd worden aan een verantwoorde groene investering. Deze meerinvestering met EC-ventilatoren betaalt zich uit in zuinig energieverbruik en eenvoudige aansturing met toerenregeling.

  11. CFB boilers in multifuel application

    International Nuclear Information System (INIS)

    Fuel flexibility characteristic for CFB boilers plays an important rule in industrial and utility size applications. Possibility to use wider range of fuels that has been long time considered as by-products or wastes and possibility to design boilers able to operate with alternative fuels is an important factor that improves fuel delivery security and plant economy. Presented article is based on similar publications that present Foster Wheeler's experience in design and delivery of the CFB boilers for wide range of coals and cofiring by- products of crude oil refining and coal processing. Aspects of biomass cofiring will be also presented. (author)

  12. Soot, unburned carbon and ultrafine particle emissions from air- and oxy-coal flames

    International Nuclear Information System (INIS)

    Oxy-coal combustion is one possible solution for the mitigation of greenhouse gases. In this process coal is burned in oxygen, rather than air, and the temperatures in the boiler are mitigated by recycling flue gases, so that the inlet mixture may contain either 27 % O2 to match adiabatic flame temperatures, or 32 % O2 to match gaseous radiation heat fluxes in the combustion chamber. However, a major issue for heat transfer from coal combustion is the radiative heat transmission from soot. For this research, air and oxy coal firing were compared regarding the emission of soot. A 100 kW down-fired laboratory combustor was used to determine effects of switching from air to oxy-firing on soot, unburned carbon and ultrafine particle emissions from practical pulverized coal flames. Of interest here were potential chemical effects of substitution of the N2 in air by CO2 in practical pulverized coal flames. The oxy-coal configuration investigated used once-through CO2, simulating cleaned flue gas recycle with all contaminants and water removed. Three coals were each burned in: a) air, b) 27 % O2/ 73 % CO2, c) 32 % O2/ 68 % CO2. Tests were conducted at (nominally) 3 %, 2 %, 1 % and 0 % O2 in the exhaust (dry basis). For each condition, particulate samples were iso kinetically withdrawn far from the radiant zone, and analyzed using a photoacoustic analyzer (PA) for black carbon, a scanning mobility particle sizer (SMPS) for ultrafine particles, and a total sample loss on ignition (LOI) method for unburned carbon in ash. Data suggest that at low stoichiometric ratios, ultrafine particles consist primarily of black carbon, which, for the bituminous coal, is produced in lesser amounts under oxy-fired conditions than under the air-fired condition, even when adiabatic flame temperatures are matched. However, significant changes in mineral matter vaporization were not observed unless the flames were hotter. These and other results are interpreted in the light of available

  13. R+D works for the further development of high temperature reactors. (1) Captive bearing experiments for active magnetic bearings. (2) Captive bearing test for HTR blowers

    International Nuclear Information System (INIS)

    When using active magnetic bearings as blower shaft bearings, blower motors and bearings must be protected against mechanical damage in case of faults (example: total electrical supply failure due to the supply cables breaking). So-called captive bearings are provided, in order to be able to shut the blowers down safely in such faults. These captive bearings are roller bearings which are additionally fitted in the area of the blower shaft bearings, to prevent mechanical contact between the blower rotor and stator. As there was little experience available for the given boundary conditions, such as - speed, - acceleration, - bearing load, - bearing dimensions, - ambient conditions, appropriate development and tests had to be carried out. It was important to determine suitable captive bearings and the necessary ambient conditions, which will make it possible to support the failures of the magnetic bearings to be expected in 40 years' operation of the reactor without damage and to meet the requirements of the captive bearings. (orig./GL)

  14. Hybrid model of steam boiler

    International Nuclear Information System (INIS)

    In the case of big energy boilers energy efficiency is usually determined with the application of the indirect method. Flue gas losses and unburnt combustible losses have a significant influence on the boiler's efficiency. To estimate these losses the knowledge of the operating parameters influence on the flue gases temperature and the content of combustible particles in the solid combustion products is necessary. A hybrid model of a boiler developed with the application of both analytical modelling and artificial intelligence is described. The analytical part of the model includes the balance equations. The empirical models express the dependence of the flue gas temperature and the mass fraction of the unburnt combustibles in solid combustion products on the operating parameters of a boiler. The empirical models have been worked out by means of neural and regression modelling.

  15. Boiler-turbine life extension

    Energy Technology Data Exchange (ETDEWEB)

    Natzkov, S. [TOTEMA, Ltd., Sofia (Bulgaria); Nikolov, M. [CERB, Sofia (Bulgaria)

    1995-12-01

    The design life of the main power equipment-boilers and turbines is about 105 working hours. The possibilities for life extension are after normatively regulated control tests. The diagnostics and methodology for Boilers and Turbines Elements Remaining Life Assessment using up to date computer programs, destructive and nondestructive control of metal of key elements of units equipment, metal creep and low cycle fatigue calculations. As well as data for most common damages and some technical decisions for elements life extension are presented.

  16. A Review on Diesel Soot Emission, its Effect and Control

    Directory of Open Access Journals (Sweden)

    R. Prasad

    2011-01-01

    Full Text Available The diesel engines are energy efficient, but their particulate (soot emissions are responsible of severe environmental and health problems. This review provides a survey on published information regarding diesel soot emission, its adverse effects on the human health, environment, vegetations, climate, etc. The legislations to limit diesel emissions and ways to minimize soot emission are also summarized. Soot particles are suspected to the development of cancer; cardiovascular and respiratory health effects; pollution of air, water, and soil; impact agriculture productivity, soiling of buildings; reductions in visibility; and global climate change. The review covers important recent developments on technologies for control of particulate matter (PM; diesel particulate filters (DPFs, summarizing new filter and catalyst materials and DPM measurement. DPF technology is in a state of optimization and cost reduction. New DPF regeneration strategies (active, passive and plasma-assisted regenerations as well as the new learning on the fundamentals of soot/catalyst interaction are described. Recent developments in diesel oxidation catalysts (DOC are also summarized showing potential issues with advanced combustion strategies, important interactions on NO2 formation, and new formulations for durability. Finally, systematic compilation of the concerned newer literature on catalytic oxidation of soot in a well conceivable tabular form is given. A total of 156 references are cited. ©2010 BCREC UNDIP. All rights reserved(Received: 2nd June 2010, Revised: 17th June 2010; Accepted: 24th June 2010[How to Cite: R. Prasad, V.R. Bella. (2010. Review on Diesel Soot Emission, its Effect and Control. Bulletin of Chemical Reaction Engineering and Catalysis, 5(2: 69-86. doi:10.9767/bcrec.5.2.794.69-86][DOI: http://dx.doi.org/10.9767/bcrec.5.2.794.69-86 || or local:   http://ejournal.undip.ac.id/index.php/bcrec/article/view/794 ]Cited by in: ACS 1 |

  17. CFD Simulation On CFBC Boiler

    Directory of Open Access Journals (Sweden)

    Amol S. Kinkar

    2015-02-01

    Full Text Available Abstract Heavy industrialization amp modernization of society demands in increasing of power cause to research amp develop new technology amp efficient utilization of existing power units. Variety of sources are available for power generation such as conventional sources like thermal hydro nuclear and renewable sources like wind tidal biomass geothermal amp solar. Out of these most common amp economical way for producing the power is by thermal power stations. Various industrial boilers plays an important role to complete the power generation cycle such as CFBC Circulating Fluidized Bed Combustion FBC Fluidized Bed Combustion AFBC Atmospheric Fluidized Bed Combustion Boiler CO Boiler RG amp WHR Boiler Waster heat recovery Boiler. This paper is intended to comprehensively give an account of knowledge related to refractory amp its failure in CFBC boiler with due effect of flue gas flow during operation on refractory by using latest technology of CAD Computer aided Design amp CAE Computer aided Engineering. By conceptual application of these technology the full scale model is able to analyze in regards the flow of flue gas amp bed material flow inside the CFBC loop via CFD Computational Fluid Dynamics software. The results obtained are helpful to understand the impact of gas amp particles on refractory in different areas amp also helped to choose suitable refractory material in different regions.

  18. Ice nucleation activity of diesel soot particles at cirrus relevant temperature conditions: Effects of hydration, secondary organics coating, soot morphology, and coagulation

    Science.gov (United States)

    Kulkarni, Gourihar; China, Swarup; Liu, Shang; Nandasiri, Manjula; Sharma, Noopur; Wilson, Jacqueline; Aiken, Allison C.; Chand, Duli; Laskin, Alexander; Mazzoleni, Claudio; Pekour, Mikhail; Shilling, John; Shutthanandan, Vaithiyalingam; Zelenyuk, Alla; Zaveri, Rahul A.

    2016-04-01

    Ice formation by diesel soot particles was investigated at temperatures ranging from -40 to -50°C. Size-selected soot particles were physically and chemically aged in an environmental chamber, and their ice nucleating properties were determined using a continuous flow diffusion type ice nucleation chamber. Bare (freshly formed), hydrated, and compacted soot particles, as well as α-pinene secondary organic aerosol (SOA)-coated soot particles at high relative humidity conditions, showed ice formation activity at subsaturation conditions with respect to water but below the homogeneous freezing threshold conditions. However, SOA-coated soot particles at dry conditions were observed to freeze at homogeneous freezing threshold conditions. Overall, our results suggest that heterogeneous ice nucleation activity of freshly emitted diesel soot particles are sensitive to some of the aging processes that soot can undergo in the atmosphere.

  19. An experimental design for the investigation of water repellent property of candle soot particles

    Energy Technology Data Exchange (ETDEWEB)

    Sahoo, Bichitra Nanda; Kandasubramanian, Balasubramanian, E-mail: meetkbs@gmail.com

    2014-11-14

    The mechanistic aspect of candle soot particles under controlled atmosphere has been reported. The soot particles were characterized using Fourier transformation Infrared Spectroscopy, Raman spectroscopy, Transmission electron microscopy and X-ray diffraction. Hydrophobicity of the candle soot particles was confirmed from the presence of C–H group which enhances water repellency and can be used as filler material for fabrication of superhydrophobic coatings. The layered soot particle on the glass slide exhibits maximum water contact angle of 168°. Roughness of soot particle and various hydrophobic groups involved for obtaining superhydrophobicity were exposed. The Raman spectrum of soot particles revealed the presence of disorder graphene which was confirmed from appearance of D1 band. The agglomeration of candle soot particles has been discussed by measuring fractal dimension (D{sub f}) of the particles. The in-depth investigation for bringing the mechanism of formation of soot particle inside the flame reveals the inception of the first particles, growth of soot particles, particle coalescence, agglomeration and oxidation. Here, we have found that the mechanism of particle formation in candle flame involves various steps, in which the sintering as well as coalescence/collision process plays a major role. - Highlights: • Mechanistic aspect for hydrophobicity of candle soot is demonstrated. • Hydrophobicity of soot particles at different exposure time is described. • Agglomeration of soot particles related to fractal dimension is reported. • Mechanism of formation of soot particles in the candle flame is also described.

  20. Ignition delay and soot oxidative reactivity of MTBE blended diesel fuel

    KAUST Repository

    Yang, Seung Yeon

    2014-04-01

    Methyl tert-butyl ether (MTBE) was added to diesel fuel to investigate the effect on ignition delay and soot oxidative reactivity. An ignition quality tester (IQT) was used to study the ignition propensity of MTBE blended diesel fuels in a reactive spray environment. The IQT data showed that ignition delay increases linearly as the MTBE fraction increases in the fuel. A four-stroke single cylinder diesel engine was used to generate soot samples for a soot oxidation study. Soot samples were pre-treated using a tube furnace in a nitrogen environment to remove any soluble organic fractions and moisture content. Non-isothermal oxidation of soot samples was conducted using a thermogravimetric analyzer (TGA). It was observed that oxidation of \\'MTBE soot\\' started began at a lower temperature and had higher reaction rate than \\'diesel soot\\' across a range of temperatures. Several kinetic analyses including an isoconversional method and a combined model fitting method were carried out to evaluate kinetic parameters. The results showed that Diesel and MTBE soot samples had similar activation energy but the pre-exponential factor of MTBE soot was much higher than that of the Diesel soot. This may explain why MTBE soot was more reactive than Diesel soot. It is suggested that adding MTBE to diesel fuel is better for DPF regeneration since an MTBE blend can significantly influence the ignition characteristics and, consequently, the oxidative reactivity of soot. Copyright © 2014 SAE International.

  1. An experimental design for the investigation of water repellent property of candle soot particles

    International Nuclear Information System (INIS)

    The mechanistic aspect of candle soot particles under controlled atmosphere has been reported. The soot particles were characterized using Fourier transformation Infrared Spectroscopy, Raman spectroscopy, Transmission electron microscopy and X-ray diffraction. Hydrophobicity of the candle soot particles was confirmed from the presence of C–H group which enhances water repellency and can be used as filler material for fabrication of superhydrophobic coatings. The layered soot particle on the glass slide exhibits maximum water contact angle of 168°. Roughness of soot particle and various hydrophobic groups involved for obtaining superhydrophobicity were exposed. The Raman spectrum of soot particles revealed the presence of disorder graphene which was confirmed from appearance of D1 band. The agglomeration of candle soot particles has been discussed by measuring fractal dimension (Df) of the particles. The in-depth investigation for bringing the mechanism of formation of soot particle inside the flame reveals the inception of the first particles, growth of soot particles, particle coalescence, agglomeration and oxidation. Here, we have found that the mechanism of particle formation in candle flame involves various steps, in which the sintering as well as coalescence/collision process plays a major role. - Highlights: • Mechanistic aspect for hydrophobicity of candle soot is demonstrated. • Hydrophobicity of soot particles at different exposure time is described. • Agglomeration of soot particles related to fractal dimension is reported. • Mechanism of formation of soot particles in the candle flame is also described

  2. Soot and Radiation Measurements in Microgravity Jet Diffusion Flames

    Science.gov (United States)

    Ku, Jerry C.

    1996-01-01

    The subject of soot formation and radiation heat transfer in microgravity jet diffusion flames is important not only for the understanding of fundamental transport processes involved but also for providing findings relevant to spacecraft fire safety and soot emissions and radiant heat loads of combustors used in air-breathing propulsion systems. Our objectives are to measure and model soot volume fraction, temperature, and radiative heat fluxes in microgravity jet diffusion flames. For this four-year project, we have successfully completed three tasks, which have resulted in new research methodologies and original results. First is the implementation of a thermophoretic soot sampling technique for measuring particle size and aggregate morphology in drop-tower and other reduced gravity experiments. In those laminar flames studied, we found that microgravity soot aggregates typically consist of more primary particles and primary particles are larger in size than those under normal gravity. Comparisons based on data obtained from limited samples show that the soot aggregate's fractal dimension varies within +/- 20% of its typical value of 1.75, with no clear trends between normal and reduced gravity conditions. Second is the development and implementation of a new imaging absorption technique. By properly expanding and spatially-filtering the laser beam to image the flame absorption on a CCD camera and applying numerical smoothing procedures, this technique is capable of measuring instantaneous full-field soot volume fractions. Results from this technique have shown the significant differences in local soot volume fraction, smoking point, and flame shape between normal and reduced gravity flames. We observed that some laminar flames become open-tipped and smoking under microgravity. The third task we completed is the development of a computer program which integrates and couples flame structure, soot formation, and flame radiation analyses together. We found good

  3. Microscopic investigation of soot and ash particulate matter derived from biofuel and diesel: implications for the reactivity of soot

    International Nuclear Information System (INIS)

    Investigation of soot and ash particulate matter deposited in diesel particulate filters (DPFs) operating with biofuel (B100) and diesel (pure diesel: B0 and diesel80/biofuel20 blend: B20) by means of optical microscopy, scanning electron microscopy, and high resolution transmission electron microscopy (HRTEM) reveals the following: the rapeseed methyl ester biofuel used for this study contributes to ash production, mainly of Ca–S– and P-bearing compounds ranging in size between 50 and 300 nm. Smaller ash particles are less common and build aggregates. Ash is deposited on the inlet DPF surface, the inlet channel walls, and in B100-DPF at the plugged ends of inlet channels. The presence of Fe–Cr–Ni fragments, down to tens of nanometers in size within the ash is attributed to engine wear. Pt particles (50–400 nm large) within the ash indicate that the diesel oxidation catalyst (DOC) upstream of the DPF shows aging effects. Radial cracks on the coating layer of the DOC confirm this assumption. The B100-DPF contains significantly less soot than B20 and B0. Based on the generally accepted view that soot reactivity correlates with the nanostructure of its primary particles, the length and curvature of graphene sheets from biofuel- and diesel-derived soot were measured and computed on the basis of HRTEM images. The results show that biofuel-derived soot can be more easily oxidized than diesel soot, not only during early formation but also during and after considerable particle growth. Differences in the graphene sheet separation distance, degree of crystalline order and size of primary soot particles between the two fuel types are in line with this inference.

  4. Changes of hygroscopicity and morphology during ageing of diesel soot

    Science.gov (United States)

    Tritscher, Torsten; Jurányi, Zsófia; Martin, Maria; Chirico, Roberto; Gysel, Martin; Heringa, Maarten F.; DeCarlo, Peter F.; Sierau, Berko; Prévôt, André S. H.; Weingartner, Ernest; Baltensperger, Urs

    2011-07-01

    Soot particles are an important component of atmospheric aerosol and their interaction with water is important for their climate effects. The hygroscopicity of fresh and photochemically aged soot and secondary organic aerosol (SOA) from diesel passenger car emissions was studied under atmospherically relevant conditions in a smog chamber at sub-and supersaturation of water vapor. Fresh soot particles show no significant hygroscopic growth nor cloud condensation nucleus (CCN) activity. Ageing by condensation of SOA formed by photooxidation of the volatile organic carbon (VOC) emission leads to increased water uptake and CCN activity as well as to a compaction of the initially non-spherical soot particles when exposed to high relative humidity (RH). It is important to consider the latter effect for the interpretation of mobility based measurements. The vehicle with oxidation catalyst (EURO3) emits much fewer VOCs than the vehicle without after-treatment (EURO2). Consequently, more SOA is formed for the latter, resulting in more pronounced effects on particle hygroscopicity and CCN activity. Nevertheless, the aged soot particles did not reach the hygroscopicity of pure SOA particles formed from diesel VOC emissions, which are similarly hygroscopic (0.06 < κH - TDMA < 0.12 and 0.09 < κCCN < 0.14) as SOA from other precursor gases investigated in previous studies.

  5. Changes of hygroscopicity and morphology during ageing of diesel soot

    Energy Technology Data Exchange (ETDEWEB)

    Tritscher, Torsten; Juranyi, Zsofia; Chirico, Roberto; Gysel, Martin; Heringa, Maarten F; DeCarlo, Peter F; Prevot, Andre S H; Weingartner, Ernest; Baltensperger, Urs [Laboratory of Atmospheric Chemistry, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Martin, Maria; Sierau, Berko, E-mail: Ernest.Weingartner@psi.ch [Institute of Atmospheric and Climate Sciences, ETH Zurich, Universitaetsstrasse 16, 8092 Zurich (Switzerland)

    2011-07-15

    Soot particles are an important component of atmospheric aerosol and their interaction with water is important for their climate effects. The hygroscopicity of fresh and photochemically aged soot and secondary organic aerosol (SOA) from diesel passenger car emissions was studied under atmospherically relevant conditions in a smog chamber at sub-and supersaturation of water vapor. Fresh soot particles show no significant hygroscopic growth nor cloud condensation nucleus (CCN) activity. Ageing by condensation of SOA formed by photooxidation of the volatile organic carbon (VOC) emission leads to increased water uptake and CCN activity as well as to a compaction of the initially non-spherical soot particles when exposed to high relative humidity (RH). It is important to consider the latter effect for the interpretation of mobility based measurements. The vehicle with oxidation catalyst (EURO3) emits much fewer VOCs than the vehicle without after-treatment (EURO2). Consequently, more SOA is formed for the latter, resulting in more pronounced effects on particle hygroscopicity and CCN activity. Nevertheless, the aged soot particles did not reach the hygroscopicity of pure SOA particles formed from diesel VOC emissions, which are similarly hygroscopic (0.06 < {kappa}{sub H-TDMA} < 0.12 and 0.09 < {kappa}{sub CCN} < 0.14) as SOA from other precursor gases investigated in previous studies.

  6. Forward-illumination light-extinction technique for soot measurement

    International Nuclear Information System (INIS)

    A forward-illumination light-extinction (FILE) soot volume fraction measurement technique was developed and tested. By using a camera and a point light source in front of the flame and a diffuser behind the flame, with this technique one can achieve a two-dimensional soot concentration measurement with only one window when one is studying confined combustion. The line-of-sight quantitative soot volume fraction is obtained by calculation of the reflected light intensity with or without the presence of soot cloud. Verification of this technique was accomplished by measurement of an axisymmetric ethylene diffusion flame. The field distribution obtained by Abel inversion is presented and matched well with previous point measurements. The FILE technique has high time resolution when a high-speed camera and a copper vapor laser are adopted. All these advantages of FILE make it suitable for line-of-sight integrated, two-dimensional soot distribution of transient combustion, e.g., in the case of in-cylinder Diesel combustion

  7. Changes of hygroscopicity and morphology during ageing of diesel soot

    International Nuclear Information System (INIS)

    Soot particles are an important component of atmospheric aerosol and their interaction with water is important for their climate effects. The hygroscopicity of fresh and photochemically aged soot and secondary organic aerosol (SOA) from diesel passenger car emissions was studied under atmospherically relevant conditions in a smog chamber at sub-and supersaturation of water vapor. Fresh soot particles show no significant hygroscopic growth nor cloud condensation nucleus (CCN) activity. Ageing by condensation of SOA formed by photooxidation of the volatile organic carbon (VOC) emission leads to increased water uptake and CCN activity as well as to a compaction of the initially non-spherical soot particles when exposed to high relative humidity (RH). It is important to consider the latter effect for the interpretation of mobility based measurements. The vehicle with oxidation catalyst (EURO3) emits much fewer VOCs than the vehicle without after-treatment (EURO2). Consequently, more SOA is formed for the latter, resulting in more pronounced effects on particle hygroscopicity and CCN activity. Nevertheless, the aged soot particles did not reach the hygroscopicity of pure SOA particles formed from diesel VOC emissions, which are similarly hygroscopic (0.06 H-TDMA CCN < 0.14) as SOA from other precursor gases investigated in previous studies.

  8. Testicular cancer trends as 'whistle blowers' of testicular developmental problems in populations

    DEFF Research Database (Denmark)

    Skakkebaek, N E; Rajpert-De Meyts, E; Jørgensen, N; Main, K M; Leffers, H; Andersson, A-M; Juul, A; Jensen, T K; Toppari, J

    2007-01-01

    Recently a worldwide rise in the incidence of testicular germ cell cancer (TGCC) has been repeatedly reported. The changing disease pattern may signal that other testicular problems may also be increasing. We have reviewed recent research progress, in particular evidence gathered in the Nordic...... countries, which shows strong associations between testicular cancer, undescended testis, hypospadias, poor testicular development and function, and male infertility. These studies have led us to suggest the existence of a testicular dysgenesis syndrome (TDS), of which TGCC, undescended testis, hypospadias...... trends in TGCC rates of a population may be 'whistle blowers' of other reproductive health problems. As cancer registries are often of excellent quality - in contrast to registries for congenital abnormalities - health authorities should consider an increase in TGCC as a warning that other reproductive...

  9. Boiler using combustible fluid

    Science.gov (United States)

    Baumgartner, H.; Meier, J.G.

    1974-07-03

    A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.

  10. Chinese Soot on a Vietnamese Soup

    Science.gov (United States)

    Mari, X.

    2015-12-01

    Black Carbon (BC) is an aerosol emitted as soot during biomass burning and fossil fuels combustion together with other carbonaceous aerosols such as organic carbon (OC) and polyaromatic hydrocarbons (PAHs). While the impacts of BC on health and climate have been studied for many years, studies about its deposition and impact on marine ecosystems are scares. This is rather surprising considering that a large fraction of atmospheric BC deposits on the surface of the ocean via dry or wet deposition. On a global scale, deposition on the ocean is about 45 Tg C per year, with higher fluxes in the northern hemisphere and in inter-tropical regions, following the occurrence of the hot-spots of concentration. In the present study conducted on shore, in Haiphong and Halong cities, North Vietnam, we measured the seasonal variations of atmospheric BC, OC and PAHs during a complete annual cycle. The presentation will discuss the atmospheric results in terms of seasonal variability and sources. Inputs to the marine system are higher during the dry season, concomitantly with the arrival of air masses enriched in BC coming from the North. However, the carbon fingerprint can significantly differ at shorter time periods depending on the air mass pathway and speed. Our work leads to the characterization and the determination of the relative contribution of more specific sources like local traffic, which includes tourism and fishing boats, coal dust emitted from the nearby mine, and long-range transported aerosols. This variable input of carbonaceous aerosols might have consequences for the cycling and the repartition of carbon and nutrients in the marine ecosystem of Halong Bay.

  11. Steady State Investigations of DPF Soot Burn Rates and DPF Modeling

    DEFF Research Database (Denmark)

    Cordtz, Rasmus Lage; Ivarsson, Anders; Schramm, Jesper

    2011-01-01

    soot mass concentrations are used as model boundary conditions. An in-house developed raw exhaust gas sampling technique is used to measure the soot concentration upstream the DPF which is also needed to find the DPF soot burn rate. The soot concentration is measured basically by filtering the soot...... characteristics are used to fit model constants of soot and filter properties. Measured DPF gas conversions and soot burn rates are used to fit model activation energies of four DPF regeneration reactions using O2 and NO2 as reactants. Modeled DPF pressure drops and soot burn rates are compared to the steady...... mass of a sample gas continuously extracted from the engine exhaust pipe for 1-2 hours while also measuring the gas flow passed through the filter. A small silicon carbide wall flow DPF protected in a sealed stainless steel filter housing is used as sample filter. Measured DPF pressure drop...

  12. Morphological effects on the radiative properties of soot aerosols in different internally mixing states with sulfate

    International Nuclear Information System (INIS)

    The radiative properties of soot aerosols largely depend on their mixing state and morphology factors. In this paper, we generated soot aggregates in four mixing states with sulfate, including bare soot, partly coated soot, heavily coated soot and soot with inclusion. The number of monomers and fractal dimension of soot were varied in each mixing state while the radius of monomers was fixed at 0.025 μm. Using the discrete dipole approximation method (DDA), we calculated optical parameters relevant for climate forcing simulation at mid-visible wavelength (0.55 μm). Internal mixing results in enhanced absorption, scattering cross sections as well as the single scattering albedo. The enhancement ratio of the absorption is largest for heavily coated soot, which ranges from 1.5 to 1.65 with a soot volume fraction of 0.15 and is larger for soot with larger fractal dimension. The scattering cross section can be dramatically increased by factors larger than 10 when soot is heavily coated. The increasing of both the scattering cross section and the single scattering albedo is larger for soot aggregates with smaller number of monomers and fractal dimension. The asymmetry parameter is insensitive to the fractal dimension for heavily coated soot and soot with inclusion. Two simplified models including the homogeneous sphere model (HS) and the core shell sphere model (CS) were examined using the DDA results as references. The performance of the HS and CS model largely depends on the morphology factors and the mixing state of soot. For bare and partly coated soot, both the HS and CS model can introduce relative errors as large as several tens percent. For heavily coated soot, the HS model predicts the absorption with relative errors within 10%, while it overestimates the absorption with relative errors no larger than 20% for soot with inclusion. The HS model predicts the single scattering albedo and the asymmetry parameter with relative errors no larger than 10% for heavily

  13. Hybrid Method of Moments for modeling soot formation and growth

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, M.E.; Blanquart, G.; Pitsch, H. [Department of Mechanical Engineering, Stanford University, Stanford, CA 94305 (United States)

    2009-06-15

    In this work, a new statistical model for soot formation and growth is developed and presented. The Hybrid Method of Moments (HMOM) seeks to combine the advantages of two moment methods, the Method of Moments with Interpolative Closure (MOMIC) and the Direct Quadrature Method of Moments (DQMOM), in an accurate and consistent formulation. MOMIC is numerically simple and easy to implement but is unable to account for bimodal soot Number Density Functions (NDF). DQMOM is accurate but is numerically ill-posed and difficult to implement. HMOM combines the best of both two methods to capture bimodal NDF while retaining ease of implementation and numerical robustness. The new hybrid method is shown to predict mean quantities nearly as accurately as DQMOM and high-fidelity Monte Carlo simulations. In addition, a model for combining particle coalescence with particle aggregation is presented and shown to accurately reproduce experimental measurements in a variety of sooting flames. (author)

  14. Laser-induced incandescence: Towards quantitative soot volume fraction measurements

    Energy Technology Data Exchange (ETDEWEB)

    Tzannis, A.P.; Wienbeucker, F.; Beaud, P.; Frey, H.-M.; Gerber, T.; Mischler, B.; Radi, P.P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Laser-Induced Incandescence has recently emerged as a versatile tool for measuring soot volume fraction in a wide range of combustion systems. In this work we investigate the essential features of the method. LII is based on the acquisition of the incandescence of soot when heated through a high power laser pulse. Initial experiments have been performed on a model laboratory flame. The behaviour of the LII signal is studied experimentally. By applying numerical calculations we investigate the possibility to obtain two-dimensional soot volume fraction distributions. For this purpose a combination of LII with other techniques is required. This part is discussed in some extent and the future work is outlined. (author) 4 figs., 3 refs.

  15. 10 CFR 431.82 - Definitions concerning commercial packaged boilers.

    Science.gov (United States)

    2010-01-01

    ... pressure boiler means a packaged boiler that is: (1) A steam boiler designed to operate at a steam pressure... steam boiler designed to operate at or below a steam pressure of 15 psig; or (2) A hot water boiler... efficiency for a commercial packaged boiler is determined using test procedures prescribed under § 431.86...

  16. New Nanotech from an Ancient Material: Chemistry Demonstrations Involving Carbon-Based Soot

    Science.gov (United States)

    Campbell, Dean J.; Andrews, Mark J.; Stevenson, Keith J.

    2012-01-01

    Carbon soot has been known since antiquity, but has recently been finding new uses as a robust, inexpensive nanomaterial. This paper describes the superhydrophobic properties of carbon soot films prepared by combustion of candle wax or propane gas and introduces some of the optical absorption and fluorescence properties of carbon soot particles.…

  17. Phototransformation rate constants of PAHs associated with soot particles

    International Nuclear Information System (INIS)

    Photodegradation is a key process governing the residence time and fate of polycyclic aromatic hydrocarbons (PAHs) in particles, both in the atmosphere and after deposition. We have measured photodegradation rate constants of PAHs in bulk deposits of soot particles illuminated with simulated sunlight. The photodegradation rate constants at the surface (kp0), the effective diffusion coefficients (Deff), and the light penetration depths (z0.5) for PAHs on soot layers of variable thickness were determined by fitting experimental data with a model of coupled photolysis and diffusion. The overall disappearance rates of irradiated low molecular weight PAHs (with 2–3 rings) on soot particles were influenced by fast photodegradation and fast diffusion kinetics, while those of high molecular weight PAHs (with 4 or more rings) were apparently controlled by either the combination of slow photodegradation and slow diffusion kinetics or by very slow diffusion kinetics alone. The value of z0.5 is more sensitive to the soot layer thickness than the kp0 value. As the thickness of the soot layer increases, the z0.5 values increase, but the kp0 values are almost constant. The effective diffusion coefficients calculated from dark experiments are generally higher than those from the model fitting method for illumination experiments. Due to the correlation between kp0 and z0.5 in thinner layers, Deff should be estimated by an independent method for better accuracy. Despite some limitations of the model used in this study, the fitted parameters were useful for describing empirical results of photodegradation of soot-associated PAHs. - Highlights: ► PAHs on soot were evaluated by a model of coupled photolysis and diffusion. ► Photodegradation rate at the surface, diffusion coefficient, and light penetration path were determined. ► Low MW PAHs were influenced by fast photodegradation and fast diffusion. ► High MW PAHs were controlled either by slow photodegradation and slow

  18. Study on soot purifying of molding shop in coking factory

    Institute of Scientific and Technical Information of China (English)

    LI Duo-song; ZHANG Hui; BAI Xiang-yu

    2006-01-01

    Exhaust gas in molding shop was complicated in component and characteristic in Iow thickness asphalt smoke, mass steam-gas and dust. It was difficult to purify the soot with common purifier. So we must consider them roundly and develop new multifunction purifier. PFP multifunction soot purifier was made on the base of design optimization and was installed at Shenhuo Coking Factory in 2004. The combined effects of multi- mechanism in purifier make purifying ratio keep in high level. The remove ratio of smut reaches at 92.8%, and asphalt smoke at 83.7%.

  19. Boiler Retrofit for the Utilization of Biodiesel

    OpenAIRE

    Leily Nurul Komariah; Marwani Marwani

    2016-01-01

    Fuel oil used in the boiler is able to substitute with biodiesel. In lower blends, there are no engine modification needed, but some researchers recommended some technical adjustments in order to maintain the boiler's performance and equipment durability. This study consists of the comparison between the performance of boiler before and after retrofitting on the use of biodiesel. The diesel oil was introduced in biodiesel blends of 10% (B10), 20% (B20) and 25% (B25). A fire tube boiler was us...

  20. 49 CFR 230.47 - Boiler number.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Boiler number. 230.47 Section 230.47... Steam Gauges § 230.47 Boiler number. (a) Generally. The builder's number of the boiler, if known, shall be stamped on the steam dome or manhole flange. If the builder's number cannot be obtained,...

  1. 29 CFR 1915.162 - Ship's boilers.

    Science.gov (United States)

    2010-07-01

    ... Ship's boilers. (a) Before work is performed in the fire, steam, or water spaces of a boiler where employees may be subject to injury from the direct escape of a high temperature medium such as steam, or... dead boiler with the live system or systems shall be secured, blanked, and tagged indicating...

  2. Sootblowing optimization for improved boiler performance

    Science.gov (United States)

    James, John Robert; McDermott, John; Piche, Stephen; Pickard, Fred; Parikh, Neel J

    2013-07-30

    A sootblowing control system that uses predictive models to bridge the gap between sootblower operation and boiler performance goals. The system uses predictive modeling and heuristics (rules) associated with different zones in a boiler to determine an optimal sequence of sootblower operations and achieve boiler performance targets. The system performs the sootblower optimization while observing any operational constraints placed on the sootblowers.

  3. Sootblowing optimization for improved boiler performance

    Energy Technology Data Exchange (ETDEWEB)

    James, John Robert; McDermott, John; Piche, Stephen; Pickard, Fred; Parikh, Neel J.

    2012-12-25

    A sootblowing control system that uses predictive models to bridge the gap between sootblower operation and boiler performance goals. The system uses predictive modeling and heuristics (rules) associated with different zones in a boiler to determine an optimal sequence of sootblower operations and achieve boiler performance targets. The system performs the sootblower optimization while observing any operational constraints placed on the sootblowers.

  4. Cracking and corrosion recovery boiler

    Energy Technology Data Exchange (ETDEWEB)

    Suik, H. [Tallinn Technical University, Horizon Pulp and Paper, Tallinn (Estonia)

    1998-12-31

    The corrosion of heat surfaces and the cracking the drums are the main problems of the recovery boiler. These phenomena have been appeared during long-term operation of boiler `Mitsubishi - 315` erected at 1964. Depth of the crack is depending on the number of shutdowns and on operation time. Corrosion intensity of different heat surfaces is varying depend on the metal temperature and the conditions at place of positioning of tube. The lowest intensity of corrosion is on the bank tubes and the greatest is on the tubes of the second stage superheater and on the tubes at the openings of air ports. (orig.) 5 refs.

  5. Dynamics of flow–soot interaction in wrinkled non-premixed ethylene–air flames

    KAUST Repository

    Arias, Paul G.

    2015-08-17

    A two-dimensional simulation of a non-premixed ethylene–air flame was conducted by employing a detailed gas-phase reaction mechanism considering polycyclic aromatic hydrocarbons, an aerosol-dynamics-based soot model using a method of moments with interpolative closure, and a grey gas and soot radiation model using the discrete transfer method. Interaction of the sooting flame with a prescribed decaying random velocity field was investigated, with a primary interest in the effects of velocity fluctuations on the flame structure and the associated soot formation process for a fuel-strip configuration and a composition with mature soot growth. The temporally evolving simulation revealed a multi-layered soot formation process within the flame, at a level of detail not properly described by previous studies based on simplified soot models utilizing acetylene or naphthalene precursors for initial soot inception. The overall effect of the flame topology on the soot formation was found to be consistent with previous experimental studies, while a unique behaviour of localised strong oxidation was also noted. The imposed velocity fluctuations led to an increase of the scalar dissipation rate in the sooting zone, causing a net suppression in the soot production rate. Considering the complex structure of the soot formation layer, the effects of the imposed fluctuations vary depending on the individual soot reactions. For the conditions under study, the soot oxidation reaction was identified as the most sensitive to the fluctuations and was mainly responsible for the local suppression of the net soot production. © 2015 Taylor & Francis

  6. NOx CONTROL OPTIONS AND INTEGRATION FOR US COAL FIRED BOILERS

    Energy Technology Data Exchange (ETDEWEB)

    Mike Bockelie; Marc Cremer; Kevin Davis; Temi Linjewile; Connie Senior; Hong-Shig Shim; Bob Hurt; Eric Eddings; Larry Baxter

    2003-01-30

    This is the tenth Quarterly Technical Report for DOE Cooperative Agreement No: DE-FC26-00NT40753. The goal of the project is to develop cost effective analysis tools and techniques for demonstrating and evaluating low NO{sub x} control strategies and their possible impact on boiler performance for firing US coals. The Electric Power Research Institute (EPRI) is providing cofunding for this program. This program contains multiple tasks and good progress is being made on all fronts. During this quarter, progress was made on the computational simulation of a full-scale boiler with the purpose of understanding the potential impacts of burner operating conditions on soot and NO{sub x} generation. Sulfation tests on both the titania support and vanadia/titania catalysts were completed using BYU's in situ spectroscopy reactor this quarter. These experiments focus on the extent to which vanadia and titania sulfate in an SO{sub 2}-laden, moist environment. Construction of the CCS reactor system is essentially complete and the control hardware and software are largely in place. A large batch of vanadia/titania catalyst in powder form has been prepared for use in poisoning tests. During this quarter, minor modifications were made to the multi-catalyst slipstream reactor and to the control system. The slipstream reactor was installed at AEP's Rockport plant at the end of November 2002. In this report, we describe the reactor system, particularly the control system, which was created by REI specifically for the reactor, as well as the installation at Rockport.

  7. Ceria Prepared by Flame Spray Pyrolysis as an Efficient Catalyst for Oxidation of Diesel Soot

    DEFF Research Database (Denmark)

    Christensen, Jakob Munkholt; Deiana, Davide; Grunwaldt, Jan-Dierk;

    2014-01-01

    Ceria has been prepared by flame spray pyrolysis and tested for activity in catalytic soot oxidation. In tight contact with soot the oxidation activity (measured in terms of the temperature of maximal oxidation rate, Tmax) of the flame made ceria is among the highest reported for CeO2. This can to...... a significant degree be ascribed to the large surface area achieved with the flame spray pyrolysis method. The importance of the inherent soot reactivity for the catalytic oxidation was studied using various soot samples, and the reactivity of the soot was found to have a significant impact, as the...

  8. Laser-saturated fluorescence measurements in laminar sooting diffusion flames

    Science.gov (United States)

    Wey, Changlie

    1993-01-01

    The hydroxyl radical is known to be one of the most important intermediate species in the combustion processes. The hydroxyl radical has also been considered a dominant oxidizer of soot particles in flames. In this investigation the hydroxyl concentration profiles in sooting diffusion flames were measured by the laser-saturated fluorescence (LSF) method. The temperature distributions in the flames were measured by the two-line LSF technique and by thermocouple. In the sooting region the OH fluorescence was too weak to make accurate temperature measurements. The hydroxyl fluorescence profiles for all four flames presented herein show that the OH fluorescence intensities peaked near the flame front. The OH fluorescence intensity dropped sharply toward the dark region of the flame and continued declining to the sooting region. The OH fluorescence profiles also indicate that the OH fluorescence decreased with increasing height in the flames for all flames investigated. Varying the oxidizer composition resulted in a corresponding variation in the maximum OH concentration and the flame temperature. Furthermore, it appears that the maximum OH concentration for each flame increased with increasing flame temperature.

  9. Soot particle disintegration and detection using two laserELFFS

    Energy Technology Data Exchange (ETDEWEB)

    Stipe, Christopher B.; Lucas, Donald; Koshland, Catherine P.; Sawyer, Robert F.

    2004-11-17

    A two laser technique is used to study laser-particle interactions and the disintegration of soot by high power UV light. Two separate 20 ns laser pulses irradiate combustion generated soot nanoparticles with 193 nm photons. The first laser pulse, from 0 to 14.7 J/cm{sup 2}, photofragments the soot particles and electronically excites the liberated carbon atoms. The second laser pulse, held constant at 13 J/cm{sup 2}, irradiates the remaining particle fragments and other products of the first laser pulse. The atomic carbon fluorescence at 248 nm produced by the first laser pulse increases linearly with laser fluence from 1 to 6 J/cm{sup 2}. At higher fluences, the signal from atomic carbon signal saturates. The carbon fluorescence from the second laser pulse decreases as the fluence from the first laser increases, ultimately approaching zero as first laser fluence approaches 10 J/cm{sup 2}, suggesting that the particles fully disintegrate at high laser fluences. We use an energy balance parameter, called the photon-atom ratio (PAR), to aid in understanding laser-particle interactions. These results help define the regimes where photofragmentation fluorescence methods quantitatively measure total soot concentrations.

  10. Nanoparticle production by UV irradiation of combustion generated soot particles

    International Nuclear Information System (INIS)

    Laser ablation of surfaces normally produce high temperature plasmas that are difficult to control. By irradiating small particles in the gas phase, we can better control the size and concentration of the resulting particles when different materials are photofragmented. Here, we irradiate soot with 193 nm light from an ArF excimer laser. Irradiating the original agglomerated particles at fluences ranging from 0.07 to 0.26 J/cm2 with repetition rates of 20 and 100 Hz produces a large number of small, unagglomerated particles, and a smaller number of spherical agglomerated particles. Mean particle diameters from 20 to 50 nm are produced from soot originally having a mean electric mobility diameter of 265 nm. We use a non-dimensional parameter, called the photon-atom ratio (PAR), to aid in understanding the photofragmentation process. This parameter is the ratio of the number of photons striking the soot particles to the number of the carbon atoms contained in the soot particles, and is a better metric than the laser fluence for analyzing laser-particle interactions. These results suggest that UV photofragmentation can be effective in controlling particle size and morphology, and can be a useful diagnostic for studying elements of the laser ablation process

  11. Nanoparticle production by UV irradiation of combustion generated soot particles

    International Nuclear Information System (INIS)

    Laser ablation of surfaces normally produce high temperature plasmas that are difficult to control. By irradiating small particles in the gas phase, we can better control the size and concentration of the resulting particles when different materials are photofragmented. Here, we irradiate soot with 193 nm light from an ArF excimer laser. Irradiating the original agglomerated particles at fluences ranging from 0.07 to 0.26 J/cm2 with repetition rates of 20 and 100 Hz produces a large number of small, unagglomerated particles, and a smaller number of spherical agglomerated particles. Mean particle diameters from 20 to 50 nm are produced from soot originally having a mean electric mobility diameter of 265nm. We use a non-dimensional parameter, called the photon/atom ratio (PAR), to aid in understanding the photofragmentation process. This parameter is the ratio of the number of photons striking the soot particles to the number of the carbon atoms contained in the soot particles, and is a better metric than the laser fluence for analyzing laser-particle interactions. These results suggest that UV photofragmentation can be effective in controlling particle size and morphology, and can be a useful diagnostic for studying elements of the laser ablation process

  12. Soot Combustion over Nanostructured Ceria with Different Morphologies

    Science.gov (United States)

    Zhang, Wen; Niu, Xiaoyu; Chen, Liqiang; Yuan, Fulong; Zhu, Yujun

    2016-01-01

    In this study, nano-structure ceria with three different morphologies (nanorod, nanoparticle and flake) have been prepared by hydrothermal and solvothermal methods. The ceria samples were deeply characterized by XRD, SEM, TEM, H2-TPR, XPS and in-situ DRIFTS, and tested for soot combustion in absence/presence NO atmospheres under loose and tight contact conditions. The prepared ceria samples exhibit excellent catalytic activities, especially, the CeO2 with nanorod (Ce-R) shows the best catalytic activity, for which the peak temperature of soot combustion (Tm) is about 500 and 368 °C in loose and tight contact conditions, respectively. The catalytic activity for Ce-R is higher than that of the reported CeO2 catalysts and reaches a level that of precious metals. The characterization results reveal that the maximal amounts of adsorbed oxygen species on the surface of the nanostructure Ce-R catalyst should be the crucial role to decide the catalytic soot performance. High BET surface area may also be a positive effect on soot oxidation activity under loose contact conditions. PMID:27353143

  13. Investigations into effects of blade number in a booster blower for forced ventilation on noise level caused by stream heterogeneity

    Energy Technology Data Exchange (ETDEWEB)

    Sowa, A.

    1985-09-01

    Noise level is analyzed caused by WLE-603A booster mine blowers used for local ventilation in underground coal mines in Poland. The blowers have two impellers rotating in opposite directions. One impeller is equipped with 10 or 11 blades, the other with 9, 8, 7, 6 or 5 blades. Revolution rate of 2940 rpm is used. A formula for optimizing blade number on two impellers and the relation of impeller number is derived. Effects of optimizing blade number on the air streams produced by two impellers and their interaction are analyzed. Effects of stream heterogeneity on noise level are determined. Recommendations for the optimum blade number which reduces noise level are made. 3 references.

  14. Cosmet'eau-Changes in the personal care product consumption practices: from whistle-blowers to impacts on aquatic environments.

    Science.gov (United States)

    Bressy, Adèle; Carré, Catherine; Caupos, Émilie; de Gouvello, Bernard; Deroubaix, José-Frédéric; Deutsch, Jean-Claude; Mailler, Romain; Marconi, Anthony; Neveu, Pascale; Paulic, Laurent; Pichon, Sébastien; Rocher, Vincent; Severin, Irina; Soyer, Mathilde; Moilleron, Régis

    2016-07-01

    The Cosmet'eau project (2015-2018) investigates the "changes in the personal care product (PCP) consumption practices: from whistle-blowers to impacts on aquatic environments." In this project, the example of PCPs will be used to understand how public health concerns related to micropollutants can be addressed by public authorities-including local authorities, industries, and consumers. The project aims to characterize the possible changes in PCP consumption practices and to evaluate the impact of their implementation on aquatic contamination. Our goals are to study the whistle-blowers, the risk perception of consumers linked with their practices, and the contamination in parabens and their substitutes, triclosan, and triclocarban from wastewater to surface water. The project investigates the following potential solutions: modifications of industrial formulation or changes in consumption practices. The final purpose is to provide policy instruments for local authorities aiming at building effective strategies to fight against micropollutants in receiving waters. PMID:27179812

  15. Structural Effects of Biodiesel on Soot Volume Fraction in a Laminar Co-Flow Diffusion Flame

    Science.gov (United States)

    Weingarten, Jason

    An experimental study was performed to determine the structural effects of biodiesel on soot volume fraction in a laminar co-flow diffusion flame. These include the effects of the ester function group, the inclusion of a double bond, and its positional effect. The soot volume fraction and temperature profiles of a biodiesel surrogate, n-Decane, 1-Decene, and 5-Decene fuels were measured. Improvements were made to existing laser extinction and rapid thermocouple insertion apparatus and were used to measure soot volume fraction and temperature profiles respectively. Flow rates of each fuel were determined in order to keep the temperature effects on soot negligible. Using n-Decane as a baseline, the double bond increased soot production and was further increased with a more centrally located double bond. The ester function group containing oxygen decreased soot production. The order of most to least sooting fuels were as follows 5-Decene > 1-Decene > n-Decane > Biodiesel Surrogate.

  16. Adaptive controlling of power boiler

    OpenAIRE

    Wojcik, W.; Kalita, M; Smolarz, A.

    2004-01-01

    This paper presents research on adaptive control (AC) of combastion process in in¬dustry. Results were obtained from research conducted in laboratory combustion chamber with usage of Fiber Optical Measurement System (FOMS) with electronic block. Simulation proved that implementing AC and FOMS to burning process improves flue gasses parameters -direct measure of power boiler ecologic and economical quality of work.

  17. Cosmet'eau -Changes in the personal care product consumption practices: from whistle-blowers to impacts on aquatic environments

    OpenAIRE

    Bressy, Adèle; Carré, Catherine; Caupos, Émilie; De Gouvello, Bernard; Deroubaix, José-Frédéric; Deutsch, Jean-Claude; Mailler, Romain; Marconi, Anthony; Neveu, Pascale; Paulic, Laurent; Pichon, Sébastien; Rocher, Vincent; Severin, Irina; SOYER, Mathilde; Moilleron, Régis

    2016-01-01

    International audience The Cosmet'eau project (2015-2018) investigates the " changes in the personal care product (PCP) consumption practices: from whistle-blowers to impacts on aquatic environments. " In this project, the example of PCPs will be used to understand how public health concerns related to micropollutants can be addressed by public authorities – including local authorities –, industries and consumers. The project aims to characterize the possible changes in PCP consumption pra...

  18. Modelling thermal radiation and soot formation in buoyant diffusion flames

    International Nuclear Information System (INIS)

    The radiative heat transfer plays an important role in fire problems since it is the dominant mode of heat transfer between flames and surroundings. It controls the pyrolysis, and therefore the heat release rate, and the growth rate of the fire. In the present work a numerical study of buoyant diffusion flames is carried out, with the main objective of modelling the thermal radiative transfer and the soot formation/destruction processes. In a first step, different radiative property models were tested in benchmark configurations. It was found that the FSCK coupled with the Modest and Riazzi mixing scheme was the best compromise in terms of accuracy and computational requirements, and was a good candidate to be implemented in CFD codes dealing with fire problems. In a second step, a semi-empirical soot model, considering acetylene and benzene as precursor species for soot nucleation, was validated in laminar co flow diffusion flames over a wide range of hydrocarbons (C1-C3) and conditions. In addition, the optically-thin approximation was found to produce large discrepancies in the upper part of these small laminar flames. Reliable predictions of soot volume fractions require the use of an advanced radiation model. Then the FSCK and the semi-empirical soot model were applied to simulate laboratory-scale and intermediate-scale pool fires of methane and propane. Predicted flame structures as well as the radiant heat flux transferred to the surroundings were found to be in good agreement with the available experimental data. Finally, the interaction between radiation and turbulence was quantified. (author)

  19. Fragmentation and bond strength of airborne diesel soot agglomerates

    Directory of Open Access Journals (Sweden)

    Messerer Armin

    2008-06-01

    Full Text Available Abstract Background The potential of diesel soot aerosol particles to break up into smaller units under mechanical stress was investigated by a direct impaction technique which measures the degree of fragmentation of individual agglomerates vs. impact energy. Diesel aerosol was generated by an idling diesel engine used for passenger vehicles. Both the aerosol emitted directly and aerosol that had undergone additional growth by Brownian coagulation ("aging" was investigated. Optionally a thermo-desoption technique at 280°C was used to remove all high-volatility and the majority of low-volatility HC adsorbates from the aerosol before aging. Results It was found that the primary soot agglomerates emitted directly from the engine could not be fragmented at all. Soot agglomerates permitted to grow additionally by Brownian coagulation of the primary emitted particles could be fragmented to a maximum of 75% and 60% respectively, depending on whether adsorbates were removed from their surface prior to aging or not. At most, these aged agglomerates could be broken down to roughly the size of the agglomerates from the primary emission. The energy required for a 50% fragmentation probability of all bonds within an agglomerate was reduced by roughly a factor of 2 when aging "dry" agglomerates. Average bond energies derived from the data were 0.52*10-16 and 1.2*10-16 J, respectively. This is about 2 orders of magnitude higher than estimates for pure van-der-Waals agglomerates, but agrees quite well with other observations. Conclusion Although direct conclusions regarding the behavior of inhaled diesel aerosol in contact with body fluids cannot be drawn from such measurements, the results imply that highly agglomerated soot aerosol particles are unlikely to break up into units smaller than roughly the size distribution emitted as tail pipe soot.

  20. Developing Boiler Concepts as Integrated Units

    DEFF Research Database (Denmark)

    Sørensen, Kim; Condra, Thomas Joseph; Houbak, Niels

    2004-01-01

    With the objective to be able to optimize the design and operation of steam boiler concepts Aalborg Industries A/S [1] has together with Aalborg University, Institute of Energy Technology [9] carried out a development project paying special attention to the boiler concept as an integrated unit......, emissions and to obtain long time operation experiences with the boiler concept, a full scale prototype has been built and these tests have been accomplished on the prototype. By applying this integrated unit approach to the boiler concept development it has been possible to optimize the different building...... bricks in the boiler concept to each other and hereby obtain signicant reductions in the boiler concepts weight and foot-print . The actual development project has focused on an heavy fuel oil-red boiler for the marine market with a capacity in the range 1-10 t/h saturated steam. The development project...

  1. Failure Analysis of 600 MW Supercritical Boiler Water Wall

    OpenAIRE

    Fu Huilin; Cai Zhengchun; Yan Xiaozhong; He Jinqiao; Zhou Yucai

    2013-01-01

    Boiler tube often causes abnormal boiler outage, bringing greater economic losses. This thesis mainly comes from the dynamics of boiler water, boiler furnace accident location of wall temperature distribution to explore the cause of the accident boiler. Calculation results show that the deformation will seriously reduce the boiler allowable maximum temperature difference between the screens. And the boiler is not over-temperature, low temperature difference between the screens, which have bur...

  2. Safety demonstration tests on pressure rise in ventilation system and blower integrity of a fuel-reprocessing plant

    International Nuclear Information System (INIS)

    In JAERI, the demonstration test was carried out as a part of safety researches of the fuel-reprocessing plant using a large-scale facility consist of cells, ducts, dumpers, HEPA filters and a blower, when an explosive burning due to a rapid reaction of thermal decomposition for solvent/nitric acid occurs in a cell of the reprocessing plant. In the demonstration test, pressure response propagating through the facility was measured under a blowing of air from a pressurized tank into the cell in the facility to elucidate an influence of pressure rise in the ventilation system. Consequently, effective pressure decrease in the facility was given by a configuration of cells and ducts in the facility. In the test, transient responses of HEPA filters and the blower by the blowing of air were also measured to confirm the integrity. So that, it is confirmed that HEPA filters and the blower under pressure loading were sufficient to maintain the integrity. The content described in this report will contribute to safety assessment of the ventilation system in the event of explosive burning in the reprocessing plant. (author)

  3. Effects of inlet radius and bell mouth radius on flow rate and sound quality of centrifugal blower

    International Nuclear Information System (INIS)

    The effect of inlet radius and bell mouth radius on flow rate of centrifugal blower were numerically simulated using a commercial CFD program, FLUENT. In this research, a total of eight numerical models were prepared by combining different values of bell mouth radii and inlet radii (the cross section of bell mouth was chosen as a circular arc in this research). The frozen rotor method combined with a realizable k-epsilon turbulence model and non-equilibrium wall function was used to simulate the three-dimensional flow inside the centrifugal blowers. The inlet radius was then revealed to have significant impact on flow rate with the maximum difference between analyzed models was about 4.5% while the bell mouth radius had about 3% impact on flow rate. Parallel experiments were carried out to confirm the results of CFD analysis. The CFD results were thereafter validated owning to the good agreement between CFD results and the parallel experiment results. In addition to performance analysis, noise experiments were carried out to analyze the dependence of sound quality on inlet radius and bell mouth radius with different flow rate. The noise experiment results showed that the loudness and sharpness value of different models were quite similar, which mean the inlet radius and the bell mouth radius didn't have a clear impact on sound quality of centrifugal blower

  4. Effects of inlet radius and bell mouth radius on flow rate and sound quality of centrifugal blower

    Energy Technology Data Exchange (ETDEWEB)

    Son, Pham Ngoc; Kim, Jae Won; Byun, S. M. [Sunmoon University, Asan (Korea, Republic of); Ahn, E. Y. [Hanbat National University, Daejeon (Korea, Republic of)

    2012-05-15

    The effect of inlet radius and bell mouth radius on flow rate of centrifugal blower were numerically simulated using a commercial CFD program, FLUENT. In this research, a total of eight numerical models were prepared by combining different values of bell mouth radii and inlet radii (the cross section of bell mouth was chosen as a circular arc in this research). The frozen rotor method combined with a realizable k-epsilon turbulence model and non-equilibrium wall function was used to simulate the three-dimensional flow inside the centrifugal blowers. The inlet radius was then revealed to have significant impact on flow rate with the maximum difference between analyzed models was about 4.5% while the bell mouth radius had about 3% impact on flow rate. Parallel experiments were carried out to confirm the results of CFD analysis. The CFD results were thereafter validated owning to the good agreement between CFD results and the parallel experiment results. In addition to performance analysis, noise experiments were carried out to analyze the dependence of sound quality on inlet radius and bell mouth radius with different flow rate. The noise experiment results showed that the loudness and sharpness value of different models were quite similar, which mean the inlet radius and the bell mouth radius didn't have a clear impact on sound quality of centrifugal blower.

  5. Coordination of nuclear safety regulations and corporate compliance activities. Desirable implementation of the whistle-blower protection scheme in Japan

    International Nuclear Information System (INIS)

    Recently, scandals and incidents associated with development and utilization of nuclear energy have attracted social concerns widely. However, there are limitations in preventing nuclear operators from illegal or unethical conduct only through reinforcement and expanding the nuclear safety regulations. From this viewpoint, it has turned out a real issue to develop a desirable coordination between the regulatory system and corporate compliance activities to maintain and further improve nuclear safety. Whistle-blower protection scheme (as depicted 'Declaration to the Competent Minister' in The Law for the Regulation of Nuclear Source Material, Nuclear Fuel Material and Reactors') reveals itself as a promising scheme to promote such coordination of nuclear safety regulations and corporate compliance activities. This study demonstrates that introduction of whistle-blower protection system in the U.S. federal nuclear safety regulations has encouraged developments of Employee Concerns Programs as corporate allegation programs at the U.S. based utility companies, and thereby indicates concrete improvement proposals of whistle-blower protection system enforcement in nuclear safety regulation in Japan that encourages corporate compliance activities. The principal aspects are as follows; (1) Development of compensatory scheme for employees who were discriminated on ground of the declaration, and (2) Clear rulemaking for existing private corporate allegation programs to be compatible with the official whistle-blowing procedure by Nuclear and Industrial Safety Agency, the Japanese safety regulatory authority. (author)

  6. Soot modeling of counterflow diffusion flames of ethylene-based binary mixture fuels

    KAUST Repository

    Wang, Yu

    2015-03-01

    A soot model was developed based on the recently proposed PAH growth mechanism for C1-C4 gaseous fuels (KAUST PAH Mechanism 2, KM2) that included molecular growth up to coronene (A7) to simulate soot formation in counterflow diffusion flames of ethylene and its binary mixtures with methane, ethane and propane based on the method of moments. The soot model has 36 soot nucleation reactions from 8 PAH molecules including pyrene and larger PAHs. Soot surface growth reactions were based on a modified hydrogen-abstraction-acetylene-addition (HACA) mechanism in which CH3, C3H3 and C2H radicals were included in the hydrogen abstraction reactions in addition to H atoms. PAH condensation on soot particles was also considered. The experimentally measured profiles of soot volume fraction, number density, and particle size were well captured by the model for the baseline case of ethylene along with the cases involving mixtures of fuels. The simulation results, which were in qualitative agreement with the experimental data in the effects of binary fuel mixing on the sooting structures of the measured flames, showed in particular that 5% addition of propane (ethane) led to an increase in the soot volume fraction of the ethylene flame by 32% (6%), despite the fact that propane and ethane are less sooting fuels than is ethylene, which is in reasonable agreement with experiments of 37% (14%). The model revealed that with 5% addition of methane, there was an increase of 6% in the soot volume fraction. The average soot particle sizes were only minimally influenced while the soot number densities were increased by the fuel mixing. Further analysis of the numerical data indicated that the chemical cross-linking effect between ethylene and the dopant fuels resulted in an increase in PAH formation, which led to higher soot nucleation rates and therefore higher soot number densities. On the other hand, the rates of soot surface growth per unit surface area through the HACA mechanism were

  7. A noninvasive high frequency oscillation ventilator: Achieved by utilizing a blower and a valve

    Science.gov (United States)

    Yuan, YueYang; Sun, JianGuo; Wang, Baicun; Feng, Pei; Yang, ChongChang

    2016-02-01

    After the High Frequency Oscillatory Ventilation (HFOV) has been applied in the invasive ventilator, the new technique of noninvasive High Frequency Oscillatory Ventilation (nHFOV) which does not require opening the patient's airway has attracted much attention from the field. This paper proposes the design of an experimental positive pressure-controlled nHFOV ventilator which utilizes a blower and a special valve and has three ventilation modes: spontaneous controlled ventilation combining HFOV, time-cycled ventilation combining HFOV (T-HFOV), and continuous positive airway pressure ventilation combining HFOV. Experiments on respiratory model are conducted and demonstrated the feasibility of using nHFOV through the control of fan and valve. The experimental ventilator is able to produce an air flow with small tidal volume (VT) and a large minute ventilation volume (MV) using regular breath tubes and nasal mask (e.g., under T-HFOV mode, with a maximum tidal volume of 100 ml, the minute ventilation volume reached 14 400 ml). In the process of transmission, there is only a minor loss of oscillation pressure. (Under experimental condition and with an oscillation frequency of 2-10 Hz, peak pressure loss was around 0%-50% when it reaches the mask.)

  8. An investigation of late-combustion soot burnout in a DI diesel engine using simultaneous planar imaging of soot and OH radical

    Energy Technology Data Exchange (ETDEWEB)

    John E. Dec; Peter L. Kelly-Zion

    1999-10-01

    Diesel engine design continues to be driven by the need to improve performance while at the same time achieving further reductions in emissions. The development of new designs to accomplish these goals requires an understanding of how the emissions are produced in the engine. Laser-imaging diagnostics are uniquely capable of providing this information, and the understanding of diesel combustion and emissions formation has been advanced considerably in recent years by their application. However, previous studies have generally focused on the early and middle stages of diesel combustion. These previous laser-imaging studies do provide important insight into the soot formation and oxidation processes during the main combustion event. They indicate that prior to the end of injection, soot formation is initiated by fuel-rich premixed combustion (equivalence ratio > 4) near the upstream limit of the luminous portion of the reacting fuel jet. The soot is then oxidized at the diffusion flame around the periphery of the luminous plume. Under typical diesel engine conditions, the diffusion flame does not burn the remaining fuel and soot as rapidly as it is supplied, resulting in an expanding region of rich combustion products and soot. This is evident in natural emission images by the increasing size of the luminous soot cloud prior to the end of injection. Hence, the amount of soot in the combustion chamber typically increases until shortly after the end of fuel injection, at which time the main soot formation period ends and the burnout phase begins. Sampling valve and two-color pyrometry data indicate that the vast majority (more than 90%) of the soot formed is oxidized before combustion ends; however, it is generally thought that a small fraction of this soot from the main combustion zones is not consumed and is the source of tail pipe soot emissions.

  9. T-Matrix Modeling of Linear Depolarization by Morphologically Complex Soot and Soot-Containing Aerosols

    Science.gov (United States)

    Mishchenko, Michael I.; Liu, Li; Mackowski, Daniel W.

    2013-01-01

    We use state-of-the-art public-domain Fortran codes based on the T-matrix method to calculate orientation and ensemble averaged scattering matrix elements for a variety of morphologically complex black carbon (BC) and BC-containing aerosol particles, with a special emphasis on the linear depolarization ratio (LDR). We explain theoretically the quasi-Rayleigh LDR peak at side-scattering angles typical of low-density soot fractals and conclude that the measurement of this feature enables one to evaluate the compactness state of BC clusters and trace the evolution of low-density fluffy fractals into densely packed aggregates. We show that small backscattering LDRs measured with groundbased, airborne, and spaceborne lidars for fresh smoke generally agree with the values predicted theoretically for fluffy BC fractals and densely packed near-spheroidal BC aggregates. To reproduce higher lidar LDRs observed for aged smoke, one needs alternative particle models such as shape mixtures of BC spheroids or cylinders.

  10. Simultaneous measurement of the concentrations of soot particles and gas species in light hydrocarbon flames using mass spectrometry

    International Nuclear Information System (INIS)

    Besides gas species concentrations, soot volume fractions are also important data in the study of flames. This work describes the simultaneous measurement of the concentrations of soot and gas species in light hydrocarbon flames by in situ sampling and mass spectrometry (MS).The reaction medium was frozen by sampling into a very low-pressure tube, and the soot selectivity (proportion of carbon atoms in the reactant converted to soot) was determined from the C and H mass balances using the measured concentrations of the gas species and the mass of soot present per unit gas volume. The H/C ratio of the soot was measured by a thermogravimetry–mass spectrometry combination. The soot volume fraction was calculated from the soot selectivity and density of the soot. The soot selectivity measured by this reduced pressure sampling mass spectrometry (RPSMS) method was verified by measurements using the gravimetric sampling technique where the mass of soot collected in a volume of gas was weighed by a high precision balance. For most of the measurements, the uncertainty in the soot volume fraction was ±5%, but this would be larger when the soot volume fractions are less than 1 ppm. For demonstration, the RPSMS method was used to study a methane fuel-rich flame where the soot volume fractions were 1–5 ppm. The simultaneous measurement of concentrations of soot and gas species is useful for the quantitative study of flames. (paper)

  11. On the formation and early evolution of soot in turbulent nonpremixed flames

    KAUST Repository

    Bisetti, Fabrizio

    2012-01-01

    A Direct Numerical Simulation (DNS) of soot formation in an n-heptane/air turbulent nonpremixed flame has been performed to investigate unsteady strain effects on soot growth and transport. For the first time in a DNS of turbulent combustion, Polycyclic Aromatic Hydrocarbons (PAH) are included via a validated, reduced chemical mechanism. A novel statistical representation of soot aggregates based on the Hybrid Method of Moments is used [M.E. Mueller, G. Blanquart, H. Pitsch, Combust. Flame 156 (2009) 1143-1155], which allows for an accurate state-of-the-art description of soot number density, volume fraction, and morphology of the aggregates. In agreement with previous experimental studies in laminar flames, Damköhler number effects are found to be significant for PAH. Soot nucleation and growth from PAH are locally inhibited by high scalar dissipation rate, thus providing a possible explanation for the experimentally observed reduction of soot yields at increasing levels of mixing in turbulent sooting flames. Furthermore, our data indicate that soot growth models that rely on smaller hydrocarbon species such as acetylene as a proxy for large PAH molecules ignore or misrepresent the effects of turbulent mixing and hydrodynamic strain on soot formation due to differences in the species Damköhler number. Upon formation on the rich side of the flame, soot is displaced relative to curved mixture fraction iso-surfaces due to differential diffusion effects between soot and the gas-phase. Soot traveling towards the flame is oxidized, and aggregates displaced away from the flame grow primarily by condensation of PAH on the particle surface. In contrast to previous DNS studies based on simplified soot and chemistry models, surface reactions are found to contribute barely to the growth of soot, for nucleation and condensation processes occurring in the fuel stream are responsible for the most of soot mass generation. Furthermore, the morphology of the soot aggregates is

  12. Effect of Dimethyl Ether Mixing on Soot Size Distribution in Premixed Ethylene Flame

    KAUST Repository

    Li, Zepeng

    2016-04-21

    As a byproduct of incomplete combustion, soot attracts increasing attentions as extensive researches exploring serious health and environmental effects from soot particles. Soot emission reduction requires a comprehensive understanding of the mechanism for polycyclic aromatic hydrocarbons and of soot formation and aging processes. Therefore, advanced experimental techniques and numerical simulations have been conducted to investigate this procedure. In order to investigate the effects of dimethyl ether (DME) mixing on soot particle size distribution functions (PSDFs), DME was mixed in premixed ethylene/oxygen/argon at flames at the equivalence ratio of 2.0 with a range of mixing ratio from 0% to 30% of the total carbon fed. Two series of atmospheric pressure flames were tested in which cold gas velocity was varied to obtain different flame temperatures. The evolution of PSDFs along the centerline of the flame was determined by burner stabilized stagnation probe and scanning mobility particle sizer (SMPS) techniques, yielding the PSDFs for various separation distances above the burner surface. Meanwhile, the flame temperature profiles were carefully measured by a thermocouple and the comparison to that of simulated laminar premixed burner-stabilized stagnation flame was satisfactory. Additionally, to understand the chemical role of DME mixing in soot properties, characterization measurements were conducted on soot samples using thermo-gravimetric analysis (TGA) and elemental analysis (EA). Results of the evolution of PSDFs and soot volume fraction showed that adding DME into ethylene flame could reduce soot yield significantly. The addition of DME led to the decrease of both the soot nucleation rate and the particle mass growth rate. To explain the possible mechanism for the observation, numerical simulations were performed. Although DME addition resulted in the slight increase of methyl radicals from pyrolysis, the decrease in acetylene and propargyl radicals

  13. Strain rate effect on sooting characteristics in laminar counterflow diffusion flames

    KAUST Repository

    Wang, Yu

    2016-01-20

    The effects of strain rate, oxygen enrichment and fuel type on the sooting characteristics of counterflow diffusion flames were studied. The sooting structures and relative PAH concentrations were measured with laser diagnostics. Detailed soot modeling using recently developed PAH chemistry and surface reaction mechanism was performed and the results were compared with experimental data for ethylene flames, focusing on the effects of strain rates. The results showed that increase in strain rate reduced soot volume fraction, average size and peak number density. Increase in oxygen mole fraction increased soot loading and decreased its sensitivity on strain rate. The soot volume fractions of ethane, propene and propane flames were also measured as a function of global strain rate. The sensitivity of soot volume fraction to strain rate was observed to be fuel dependent at a fixed oxygen mole fraction, with the sensitivity being higher for more sooting fuels. However, when the soot loadings were matched at a reference strain rate for different fuels by adjusting oxygen mole fraction, the dependence of soot loading on strain rate became comparable among the tested fuels. PAH concentrations were shown to decrease with increase in strain rate and the dependence on strain rate is more pronounced for larger PAHs. Soot modeling was performed using detailed PAH growth chemistry with molecular growth up to coronene. A qualitative agreement was obtained between experimental and simulation results, which was then used to explain the experimentally observed strain rate effect on soot growth. However, quantitatively, the simulation result exhibits higher sensitivity to strain rate, especially for large PAHs and soot volume fractions.

  14. Molecular mechanics and quantum mechanical modeling of hexane soot structure and interactions with pyrene

    Directory of Open Access Journals (Sweden)

    Kubicki JD

    2000-09-01

    Full Text Available Molecular simulations (energy minimizations and molecular dynamics of an n-hexane soot model developed by Smith and co-workers (M. S. Akhter, A. R. Chughtai and D. M. Smith, Appl. Spectrosc., 1985, 39, 143; ref. 1 were performed. The MM+ (N. L. Allinger, J. Am. Chem. Soc., 1977, 395, 157; ref. 2 and COMPASS (H. Sun, J. Phys. Chem., 1998, 102, 7338; ref. 3 force fields were tested for their ability to produce realistic soot nanoparticle structure. The interaction of pyrene with the model soot was simulated. Quantum mechanical calculations on smaller soot fragments were carried out. Starting from an initial 2D structure, energy minimizations are not able to produce the observed layering within soot with either force field. Results of molecular dynamics simulations indicate that the COMPASS force field does a reasonably accurate job of reproducing observations of soot structure. Increasing the system size from a 683 to a 2732 atom soot model does not have a significant effect on predicted structures. Neither does the addition of water molecules surrounding the soot model. Pyrene fits within the soot structure without disrupting the interlayer spacing. Polycyclic aromatic hydrocarbons (PAH, such as pyrene, may strongly partition into soot and have slow desorption kinetics because the PAH-soot bonding is similar to soot–soot interactions. Diffusion of PAH into soot micropores may allow the PAH to be irreversibly adsorbed and sequestered so that they partition slowly back into an aqueous phase causing dis-equilibrium between soil organic matter and porewater.

  15. Impacts of fuel formulation and engine operating parameters on the nanostructure and reactivity of diesel soot

    Science.gov (United States)

    Yehliu, Kuen

    This study focuses on the impacts of fuel formulations on the reactivity and nanostructure of diesel soot. A 2.5L, 4-cylinder, turbocharged, common rail, direct injection light-duty diesel engine was used in generating soot samples. The impacts of engine operating modes and the start of combustion on soot reactivity were investigated first. Based on preliminary investigations, a test condition of 2400 rpm and 64 Nm, with single and split injection strategies, was chosen for studying the impacts of fuel formulation on the characteristics of diesel soot. Three test fuels were used: an ultra low sulfur diesel fuel (BP15), a pure soybean methyl-ester (B100), and a synthetic Fischer-Tropsch fuel (FT) produced in a gas-to-liquid process. The start of injection (SOI) and fuel rail pressures were adjusted such that the three test fuels have similar combustion phasing, thereby facilitating comparisons between soots from the different fuels. Soot reactivity was investigated by thermogravimetric analysis (TGA). According to TGA, B100 soot exhibits the fastest oxidation on a mass basis followed by BP15 and FT derived soots in order of apparent rate constant. X-ray photoelectron spectroscopy (XPS) indicates no relation between the surface oxygen content and the soot reactivity. Crystalline information for the soot samples was obtained using X-ray diffraction (XRD). The basal plane diameter obtained from XRD was inversely related to the apparent rate constants for soot oxidation. For comparison, high resolution transmission electron microscopy (HRTEM) provided images of the graphene layers. Quantitative image analysis proceeded by a custom algorithm. B100 derived soot possessed the shortest mean fringe length and greatest mean fringe tortuosity. This suggests soot (nano)structural disorder correlates with a faster oxidation rate. Such results are in agreement with the X-ray analysis, as the observed fringe length is a measure of basal plane diameter. Moreover the relation

  16. CFD Simulation On CFBC Boiler

    OpenAIRE

    Amol S. Kinkar; G. M. Dhote; R.R. Chokkar

    2015-01-01

    Abstract Heavy industrialization amp modernization of society demands in increasing of power cause to research amp develop new technology amp efficient utilization of existing power units. Variety of sources are available for power generation such as conventional sources like thermal hydro nuclear and renewable sources like wind tidal biomass geothermal amp solar. Out of these most common amp economical way for producing the power is by thermal power stations. Various industrial boilers plays...

  17. Scandinavian baffle boiler design revisited

    OpenAIRE

    Stepanov Borivoj Lj.; Pešenjanski Ivan K.; Spasojević Momčilo Đ.

    2015-01-01

    The aim of this paper is to examine whether the use of baffles in a combustion chamber, one of the well-known low-cost methods for the boiler performance improvement, can be enhanced. Modern day tools like computational fluid dynamics were not present at the time when these measures were invented, developed and successfully applied. The objective of this study is to determine the influence of location and length of a baffle in a furnace, for different mass ...

  18. Chaotic map models of soot fluctuations in turbulent diffusion flames

    Energy Technology Data Exchange (ETDEWEB)

    Mukerji, S.; McDonough, J.M.; Menguec, M.P.; Manickavasagam, S. [Univ. of Kentucky, Lexington, KY (United States). Dept. of Mechanical Engineering; Chung, S. [Univ. of Illinois, Urbana, IL (United States). Dept. of Chemical Engineering

    1998-10-01

    In this paper, the authors introduce a methodology to characterize time-dependent soot volume fraction fluctuations in turbulent diffusion flames via chaotic maps. The approach is based on the hypothesis that fluctuations of properties in turbulent flames are deterministic in nature, rather than statistical. The objective is to develop models of these fluctuations to be used in comprehensive algorithms to study the nature of turbulent flames and the interaction of turbulence with radiation. To this end the authors measured the time series of soot scattering coefficient in an ethylene diffusion flame from light scattering experiments and fit these data to linear combinations of chaotic maps of the unit interval. Both time series and power spectra can be modeled with reasonable accuracy in this way.

  19. Conductometric Soot Sensor for Automotive Exhausts: Initial Studies

    Directory of Open Access Journals (Sweden)

    Ralf Moos

    2010-03-01

    Full Text Available In order to reduce the tailpipe particulate matter emissions of Diesel engines, Diesel particulate filters (DPFs are commonly used. Initial studies using a conductometric soot sensor to monitor their filtering efficiency, i.e., to detect a malfunction of the DPF, are presented. The sensors consist of a planar substrate equipped with electrodes on one side and with a heater on the other. It is shown that at constant speed-load points, the time until soot percolation occurs or the resistance itself are reproducible means that can be well correlated with the filtering efficiency of a DPF. It is suggested to use such a sensor setup for the detection of a DPF malfunction.

  20. Soot in the atmosphere and snow surface of Antarctica

    International Nuclear Information System (INIS)

    Samples of snow collected near the south pole during January and February 1986 were analyzed for the presence of light-absorbing particles by passing the melted snow through a nuclepore filter. Transmission of light through the filter showed that snow far from the station contains the equivalent of 0.1-0.3 ng of carbon per gram of snow (ng/g). Samples of ambient air were filtered and found to contain about 1-2 ng of carbon per kilogram of air, giving a scavenging ratio of about 150. The snow downwind of the station exhibited a well-defined plume of soot due to the burning of diesel fuel, but even in the center of the plume 1 km downwind, the soot concentration was only 3 ng/g, too small to affect snow albedo significantly. Measurements of snow albedo near large inland stations are therefore probably representative of their surrounding regions

  1. Single Particle Soot Photometer intercomparison at the AIDA chamber

    Directory of Open Access Journals (Sweden)

    M. Laborde

    2012-12-01

    Full Text Available Soot particles, consisting of black carbon (BC, organic carbon (OC, inorganic salts, and trace elements, are emitted into the atmosphere during incomplete combustion. Accurate measurements of atmospheric BC are important as BC particles cause adverse health effects and impact the climate.

    Unfortunately, the accurate measurement of the properties and mass concentrations of BC particles remains difficult. The Single Particle Soot Photometer (SP2 can contribute to improving this situation by measuring the mass of refractory BC in individual particles as well as its mixing state.

    Here, the results of the first detailed SP2 intercomparison, involving 6 SP2s from 6 different research groups, are presented, including the most evolved data products that can presently be calculated from SP2 measurements.

    It was shown that a detection efficiency of almost 100% down to 1 fg BC per particle can readily be achieved, and that this limit can be pushed down to ∼0.2 fg BC with optimal SP2 setup. Number and mass size distributions of BC cores agreed within ±5% and ±10%, respectively, in between the SP2s, with larger deviations in the range below 1 fg BC.

    The accuracy of the SP2's mass concentration measurement depends on the calibration material chosen. The SP2 has previously been shown to be equally sensitive to fullerene soot and ambient BC from sources where fossil fuel was dominant and less sensitive to fullerene soot than to Aquadag. Fullerene soot was therefore chosen as the standard calibration material by the SP2 user community; however, many data sets rely solely on Aquadag calibration measurements. The difference in SP2 sensitivity was found to be almost equal (fullerene soot to Aquadag response ratio of ∼0.75 at 8.9 fg BC for all SP2s. This allows the calculation of a fullerene soot equivalent calibration curve from a measured Aquadag calibration, when no fullerene soot calibration is available. It could be

  2. Single Particle Soot Photometer intercomparison at the AIDA chamber

    Directory of Open Access Journals (Sweden)

    M. Laborde

    2012-05-01

    Full Text Available Soot particles, consisting of black carbon (BC, organic carbon (OC, inorganic salts, and trace elements, are emitted into the atmosphere during incomplete combustion. Accurate measurements of atmospheric BC are important as BC particles cause adverse health effects and impact the climate.

    Unfortunately, the accurate measurement of the properties and mass concentrations of BC particles remains difficult. The Single Particle Soot Photometer (SP2 can contribute to improving this situation by measuring the mass of refractory BC in individual particles as well as its mixing state.

    Here, the results of the first detailed SP2 intercomparison, involving 6 SP2s from 6 different research groups, are presented, including the most evolved data products that can presently be calculated from SP2 measurements.

    It was shown that a detection efficiency of almost 100% down to 1 fg BC per particle can readily be achieved, and that this limit can be pushed down to ~0.3 fg BC with optimal SP2 setup. Number and mass size distributions of BC cores agreed within ±5% and ±10%, respectively, in between the SP2s, with larger deviations in the range below 1 fg BC.

    The accuracy of the SP2's mass concentration measurement depends on the calibration material chosen. The SP2 has previously been shown to be equally sensitive to fullerene soot and ambient BC from sources where fossil fuel were dominant and less sensitive to fullerene soot than to Aquadag. Fullerene soot was therefore chosen as the standard calibration material by the SP2 user community, however many datasets rely solely on Aquadag calibration measurements. The difference in SP2 sensitivity was found to be almost equal (fullerene soot to Aquadag response ratio of ~0.75 at 8.9 fg BC for all SP2s. This allows the calculation of a fullerene soot equivalent calibration curve from a measured Aquadag calibration, when no fullerene soot calibration is available. It could be shown

  3. Further development of recovery boiler; Soodakattilan kehitystyoe

    Energy Technology Data Exchange (ETDEWEB)

    Janka, K.; Siiskonen, P.; Sundstroem, K. [Tampella Power Oy, Tampere (Finland)] [and others

    1996-12-01

    The global model of a recovery boiler was further developed. The aim is to be able to model the velocity, temperature and concentration fields in a boiler. At this moment the model includes submodels for: droplet drying, pyrolysis, char burning, gas burning and for droplet trajectory. The preliminary study of NO{sub x} and fly ash behaviour in a boiler was carried out. The study concerning flow field in the superheater area was carried out a 2-dimensional case in which the inflow parameters were taken from global model of a recovery boiler. Further the prediction methods of fouling in a recovery boiler were developed based on theoretical calculations of smelting behaviour of multicomponent mixtures and measurements at operating recovery boilers. (author)

  4. Inception report and gap analysis. Boiler inspection

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-06-01

    This inception and gap analysis report on boilers in Latvia, has been prepared in the framework of the 'Implementation of the EU directive on energy performance of buildings: development of the Latvian Scheme for energy auditing of building and inspection of boilers'. The report is the basis for the establishment of training of boiler inspectors; it develops a gap analysis for better understanding and estimating the number of installations in Latvia and develops suggestions for the institutional set up. In particular includes information on existing standard and regulation on boiler, suggestion for the content of the training material of experts for boiler inspections and a syllabus of the training course. A specific section is dedicated to the suggestion for certification system of trained boiler inspectors. (au)

  5. Lanthanum-promoted copper-based hydrotalcites derived mixed oxides for NO{sub x} adsorption, soot combustion and simultaneous NO{sub x}-soot removal

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhongpeng [School of Resources and Environment, University of Jinan, 106 Jiwei Road, Jinan 250022 (China); Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR (United Kingdom); Yan, Xiaotong; Bi, Xinlin; Wang, Liguo [School of Resources and Environment, University of Jinan, 106 Jiwei Road, Jinan 250022 (China); Zhang, Zhaoliang, E-mail: chm_zhangzl@ujn.edu.cn [School of Resources and Environment, University of Jinan, 106 Jiwei Road, Jinan 250022 (China); Jiang, Zheng; Xiao, Tiancun [Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR (United Kingdom); Umar, Ahmad [Department of Chemistry, College of Science and Arts, Najran University, P.O. Box 1988, Najran 11001 (Saudi Arabia); Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, P.O. Box 1988, Najran 11001 (Saudi Arabia); Wang, Qiang, E-mail: qiang.wang.ox@gmail.com [College of Environmental Science and Engineering, Beijing Forestry University, 35 Tsinghua East Road, Beijing 100083 (China)

    2014-03-01

    Graphical abstract: - Highlights: • The addition of La in Cu-based oxides increased the types of active oxygen. • NO{sub x} adsorption, soot oxidation and simultaneous NO{sub x}-soot removal were enhanced. • The possible catalytic mechanism was studied via in situ FTIR analysis. • Soot oxidation was promoted by the NO{sub 2} intermediate. - Abstract: La-promoted Cu-based hydrotalcites derived mixed oxides were prepared and their catalytic activities for NO{sub x} adsorption, soot oxidation, and simultaneous NO{sub x}-soot removal were investigated. The catalysts were characterized by XRD, DTG, BET, FTIR, H2-TPR, TPD and TPO techniques. The oxides catalysts exhibited mesoporous properties with specific surface area of 45–160 m{sup 2}/g. The incorporation of La and Cu decreased the amount of basic sites due to the large decrease in surface areas. Under O{sub 2} atmosphere, La incorporation is dominant for soot oxidation activity, while Cu favors high selectivity to CO{sub 2} formation. A synergetic effect between La and Cu for catalyzed soot oxidation lies in the improved redox property and suitable basicity. The presence of NO in O{sub 2} significantly promoted soot oxidation on the catalysts with the ignition temperature decreased to about 300 °C. In O{sub 2}/NO atmosphere, NO{sub 2} acts as an intermediate which oxidizes soot to CO{sub 2} at a lower temperature with itself reduced to NO or N{sub 2}, contributing to the high catalytic performance in simultaneous removal of NO{sub x} and soot.

  6. Business opportunities in boiler control systems

    Energy Technology Data Exchange (ETDEWEB)

    McHale, A.P.

    1988-03-01

    Each year some Pound 4.5 billion is spent on fuel to fire the UK non-domestic boiler stock. The average age of the 500 000 population of boilers is more than 10 years and in that time great advances have been made in the capacity and capability of microprocessor controls. There is undoubtedly an enormous potential to retrofit existing boilers with the latest controls both to improve efficiency of production and utilisation.

  7. Trace and minor element characterization of diesel soot

    International Nuclear Information System (INIS)

    Concentrations of 20 trace and minor components, such as metals, nitrogen and sulphur, were determined in representative diesel soot samples corresponding to various driving patterns of an old and a new type of Mercedes-Benz diesel engine for passenger cars. The samples were analysed by instrumental neutron activation analysis, and after decomposition, by flame and graphite furnace atomic absorption spectrometry. The content of sulphur was determined by a method based on the formation of hydrogen sulphide and precipitation micro-titrimetry. The concentrations of the elements Au, La, Sb, Sc and V were at the sub-μg/g level; As, Ba, Cd, Co, Cr, Mn, Ni and Se were at the lower μg/g level; and Ca, Cu, Fe, N, Na, Pb, S, and Zn ranged from the upper μg/g to lower percent levels. The emission of several elements was likely the result of different factors such as utilization of organometallic additives (Ca, Na, Zn) in diesel fuel or lubrication oil, contamination of diesel fuel by alkyllead compounds, wear and corrosion of the engine and exhaust system parts. The concentration of elemental components in diesel soot, generally, varied with operating conditions, which affected fuel and oil consumption, combustion efficiency (soot production), and mechanical strain. (orig.)

  8. Conductometric Sensor for Soot Mass Flow Detection in Exhausts of Internal Combustion Engines

    Directory of Open Access Journals (Sweden)

    Markus Feulner

    2015-11-01

    Full Text Available Soot sensors are required for on-board diagnostics (OBD of automotive diesel particulate filters (DPF to detect filter failures. Widely used for this purpose are conductometric sensors, measuring an electrical current or resistance between two electrodes. Soot particles deposit on the electrodes, which leads to an increase in current or decrease in resistance. If installed upstream of a DPF, the “engine-out” soot emissions can also be determined directly by soot sensors. Sensors were characterized in diesel engine real exhausts under varying operation conditions and with two different kinds of diesel fuel. The sensor signal was correlated to the actual soot mass and particle number, measured with an SMPS. Sensor data and soot analytics (SMPS agreed very well, an impressing linear correlation in a double logarithmic representation was found. This behavior was even independent of the used engine settings or of the biodiesel content.

  9. Conductometric Sensor for Soot Mass Flow Detection in Exhausts of Internal Combustion Engines.

    Science.gov (United States)

    Feulner, Markus; Hagen, Gunter; Müller, Andreas; Schott, Andreas; Zöllner, Christian; Brüggemann, Dieter; Moos, Ralf

    2015-01-01

    Soot sensors are required for on-board diagnostics (OBD) of automotive diesel particulate filters (DPF) to detect filter failures. Widely used for this purpose are conductometric sensors, measuring an electrical current or resistance between two electrodes. Soot particles deposit on the electrodes, which leads to an increase in current or decrease in resistance. If installed upstream of a DPF, the "engine-out" soot emissions can also be determined directly by soot sensors. Sensors were characterized in diesel engine real exhausts under varying operation conditions and with two different kinds of diesel fuel. The sensor signal was correlated to the actual soot mass and particle number, measured with an SMPS. Sensor data and soot analytics (SMPS) agreed very well, an impressing linear correlation in a double logarithmic representation was found. This behavior was even independent of the used engine settings or of the biodiesel content. PMID:26580621

  10. Investigation of Chemical Kinetics on Soot Formation Event of n-Heptane Spray Combustion

    DEFF Research Database (Denmark)

    Pang, Kar Mun; Jangi, Mehdi; Bai, Xue-Song;

    2014-01-01

    In this reported work, 2-dimsensional computational fluid dynamics studies of n-heptane combustion and soot formation processes in the Sandia constant-volume vessel are carried out. The key interest here is to elucidate how the chemical kinetics affects the combustion and soot formation events....... Numerical computation is performed using OpenFOAM and chemistry coordinate mapping (CCM) approach is used to expedite the calculation. Three n-heptane kinetic mechanisms with different chemistry sizes and comprehensiveness in oxidation pathways and soot precursor formation are adopted. The three examined...... chemical models use acetylene (C2H2), benzene ring (A1) and pyrene (A4) as soot precursor. They are henceforth addressed as nhepC2H2, nhepA1 and nhepA4, respectively for brevity. Here, a multistep soot model is coupled with the spray combustion solver to simulate the soot formation/oxidation processes...

  11. Comparison of Three Soot Models Applied to Multi-Dimensional Diesel Combustion Simulations

    Science.gov (United States)

    Tao, Feng; Srinivas, Sukhin; Reitz, Rolf D.; Foster, David E.

    In this paper, three soot models previously proposed for diesel combustion and soot formation studies are briefly reviewed and compared. The three models are (1) two-step empirical soot model, (2) eight-step phenomenological soot model, and (3) complex-chemistry coupled phenomenological soot model. All three models have been implemented into the KIVA-3V simulation code. For comparison, a heavy-duty DI diesel engine case with fuel injection typical of standard DI diesel operating conditions was studied. Flame structures of a single diesel spray predicted using these three models were compared, and the results offer our perspective on the application of these three models to soot modeling in diesel engines.

  12. Modeling of fire-tube boilers

    OpenAIRE

    Ortiz, F.J. Gutiérrez

    2011-01-01

    Abstract In fire-tube boilers, the flue gas passes inside boiler tubes, and heat is transferred to water on the shell side. A dynamic model has been developed for the analysis of boiler performance, and Matlab has been applied for integrating it. The mathematical model developed is based on the first principles of mass, energy and momentum conservations. In the model, the two parts of the boiler (fire/gas and water/steam sides), the economizer, the superheater and the heat recovery...

  13. Boiler plants completed in record time

    International Nuclear Information System (INIS)

    Bubbling fluidised bed (BFB) combustion has steadily increased its share of the boiler market in recent years, particularly in the Nordic region, where it is particularly well-suited to handling the high moisture content biofuels produced and used by the forest products industry. Foster Wheeler is the world's leading supplier of fluidised bed combustion technology. Over 200 of the more than 300 fluidised bed boilers supplied by the company are circulating fluidised bed (CFB) designs, a market in which Foster Wheeler has more than a 40% share. Foster Wheeler Energia Oy supplied the Myllykoski project at Anjalankoski with a fluidised bed boiler, auxiliary steam boilers, and flue gas scrubber systems

  14. Stress-Assisted Corrosion in Boiler Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Preet M Singh; Steven J Pawel

    2006-05-27

    A number of industrial boilers, including in the pulp and paper industry, needed to replace their lower furnace tubes or decommission many recovery boilers due to stress-assisted corrosion (SAC) on the waterside of boiler tubes. More than half of the power and recovery boilers that have been inspected reveal SAC damage, which portends significant energy and economic impacts. The goal of this project was to clarify the mechanism of stress-assisted corrosion (SAC) of boiler tubes for the purpose of determining key parameters in its mitigation and control. To accomplish this in-situ strain measurements on boiler tubes were made. Boiler water environment was simulated in the laboratory and effects of water chemistry on SAC initiation and growth were evaluated in terms of industrial operations. Results from this project have shown that the dissolved oxygen is single most important factor in SAC initiation on carbon steel samples. Control of dissolved oxygen can be used to mitigate SAC in industrial boilers. Results have also shown that sharp corrosion fatigue and bulbous SAC cracks have similar mechanism but the morphology is different due to availability of oxygen during boiler shutdown conditions. Results are described in the final technical report.

  15. 49 CFR 230.30 - Lap-joint seam boilers.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Inspection and Repair § 230.30 Lap-joint seam boilers. Every boiler having lap-joint longitudinal...

  16. Hygroscopic growth and droplet activation of soot particles: uncoated, succinic or sulfuric acid coated

    Directory of Open Access Journals (Sweden)

    S. Henning

    2012-05-01

    Full Text Available The hygroscopic growth and droplet activation of uncoated soot particles and such coated with succinic acid and sulfuric acid were investigated during the IN-11 campaign at the Aerosol Interaction and Dynamics in the Atmosphere (AIDA facility. A GFG-1000 soot generator applying either nitrogen or argon as carrier gas and a miniCAST soot generator were utilized to generate soot particles. Different organic carbon (OC to black carbon (BC ratios were adjusted for the CAST-soot by varying the fuel to air ratio. The hygroscopic growth was investigated by means of the mobile Leipzig Aerosol Cloud Interaction Simulator (LACIS-mobile and two different Hygroscopicity Tandem Differential Mobility Analyzers (HTDMA, VHTDMA. Two Cloud Condensation Nucleus Counter (CCNC were applied to measure the activation of the particles. For the untreated soot particles neither hygroscopic growth nor activation was observed at a supersaturation of 1%, with exception of a partial activation of GFG-soot generated with argon as carrier gas. Coatings of succinic acid lead to a detectable hygroscopic growth of GFG-soot and enhanced the activated fraction of GFG- (carrier gas: argon and CAST-soot, whereas no hygroscopic growth of the coated CAST-soot was found. Sulfuric acid coatings led to an OC-content dependent hygroscopic growth of CAST-soot. Such a dependence was not observed for activation measurements. Coating with sulfuric acid decreased the amount of Polycyclic Aromatic Hydrocarbons (PAH, which were detected by AMS-measurements in the CAST-soot, and increased the amount of substances with lower molecular weight than the initial PAHs. We assume that these reaction products increased the hygroscopicity of the coated particles in addition to the coating substance itself.

  17. Hygroscopic growth and droplet activation of soot particles: uncoated, succinic or sulfuric acid coated

    Directory of Open Access Journals (Sweden)

    S. Henning

    2011-10-01

    Full Text Available The hygroscopic growth and droplet activation of uncoated soot particles and such coated with succinic acid and sulfuric acid were investigated during the IN-11 campaign at the Aerosol Interaction and Dynamics in the Atmosphere (AIDA facility. A GFG-1000 soot generator applying nitrogen, respectively argon as carrier gas and a miniCAST soot generator were utilized to generate soot particles. Different organic carbon (OC to black carbon (BC ratios were adjusted for the CAST-soot by varying the fuel to air ratio. The hygroscopic growth was investigated by means of the mobile Leipzig Aerosol Cloud Interaction Simulator (LACIS-mobile and two different Hygroscopicity Tandem Differential Mobility Analyzers (HTDMA, VHTDMA. Two Cloud Condensation Nucleus Counter (CCNC were applied to measure the activation of the particles. For the untreated soot particles neither hygroscopic growth nor activation was observed, with exception of a partial activation of GFG-soot generated with argon as carrier gas. Coatings of succinic acid lead to a detectable hygroscopic growth of GFG-soot and enhanced the activated fraction of GFG- (carrier gas: argon and CAST-soot, whereas no hygroscopic growth of the coated CAST-soot was found. Sulfuric acid coatings lead to an OC-content dependent hygroscopic growth of CAST-soot. Such a dependence was not observed for activation measurements. Coating with sulfuric acid decreased the amount of Polycyclic Aromatic Hydrocarbons (PAH, which were detected by AMS-measurements in the CAST-soot, and increased the amount of substances with lower molecular weight than the initial PAHs. We assume, that these reaction products increased the hygroscopicity of the coated particles in addition to the coating substance itself.

  18. Measurement of Fuel Concentration Distribution in a Sooting Flame through Raman Scattering

    OpenAIRE

    HAYASHIDA, Kazuhiro; AMAGAI, Kenji; SATOH, Keiji; Arai, Masataka

    2006-01-01

    Spontaneous Raman spectroscopy with KrF excimer laser was applied to obtain a fuel concentration distribution in a sooting flame. In the case of sooting flame, fluorescence from polycyclic aromatic hydrocarbons (PAH) and laser-induced incandescence (LII) from soot particles appeared with Raman scattering. These background emissions overlapped on the Raman scattering. In order to separate the Raman scattering and the background emissions, polarization property of laser-induced emissions was ut...

  19. Laser Soot-Scattering Imaging of a Large Buoyant Diffusion Flame

    OpenAIRE

    Miake-Lye, Richard C.; Toner, Stephen J.

    1987-01-01

    A novel diagnostic technique, which makes use of laser light scattered by soot particles, was used in an effort to identify the flame sheets within a natural gas diffusion flame. Soot particles, inherently created and consumed in the flame, were used as the scattering medium, which obviated the need for externally supplied seed material. Since no foreign material was added to the flame, the current technique can be considered truly nonintrusive. The soot distribution within a large buoyant...

  20. Dynamics of very small soot particles during soot burnout in diesel engines; Dynamik kleinster Russteilchen waehrend der Russausbrandphase im Dieselmotor

    Energy Technology Data Exchange (ETDEWEB)

    Bockhorn, H. [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Chemische Technik; Peters, N. [RWTH Aachen (DE). Institut fuer Technische Mechanik (ITM); Pittermann, R. [WTZ fuer Motoren- und Maschinenforschung Rosslau gGmbH (Germany); Hentschel, J.; Weber, J.

    2003-07-01

    The investigations used advanced laser-optical methods for measuring soot particle size distributions, temporally and spectrally resolved measurements of engine combustion, measurements of composition and size distribution of particles in exhaust, and further development and validation of reaction-kinetic models. In all, it can be stated that mixing will affect not only soot particle formation but also soot particle emissions. Mixing can be influenced by using a fuel-water emulsion and by CR injection. Experiments and models both showed the advantageous effects of water added to the diesel fuels and of CR injection. The higher OH radical concentrations in the later combustion stages also serve to ensure faster oxidation of soot. (orig.) [German] Ziel des Projektes war es, Informationen ueber die Bildung und Oxidation von Russ sowie die Teilchendynamik der Russteilchen waehrend der Ausbrandphase zu erhalten. Dies wurde erreicht durch die Weiterentwicklung laseroptischer Methoden zur Bestimmung der Groessenverteilung von Russpartikeln, durch zeit- und spektral aufgeloeste Erfassung der motorischen Verbrennung, durch die Bestimmung von Zusammensetzung und Groessenverteilung von Partikeln im Abgas sowie durch die Weiterentwicklung und Validierung von reaktionskinetischen Modellen. Zusammenfassend laesst sich sagen, dass sich die Gemischbildung im Dieselmotor nicht nur auf die Bildung der Russpartikel sondern auch auf die Russpartikelemission auswirkt. Die Verwendung einer Kraftstoff-Wasser-Emulsion und die Common-Rail-Einspritzung stellen zwei Verfahren zur Beeinflussung der Gemischbildung dar. Sowohl die experimentellen Untersuchungen als auch die Modellierung zeigen den die Gemischbildung foerdernden Einfluss des Zusatzes von Wasser zum Dieselbrennstoff. Ein erhoehter Anteil an vorgemischter Verbrennung, wie er auch durch die Verwendung hoher Einspritzdruecke bei der Common-Rail-Einspritzung erreicht werden kann, verringert die waehrend der Verbrennung entstehende

  1. Soot formation characteristics of gasoline surrogate fuels in counterflow diffusion flames

    KAUST Repository

    Choi, Byungchul

    2011-01-01

    The characteristics of polycyclic aromatic hydrocarbon (PAH) and soot for gasoline surrogate fuels have been investigated in counterflow diffusion flames by adopting laser-induced fluorescence (LIF) and laser-induced incandescence (LII) techniques for both soot formation and soot formation/oxidation flames. Tested fuels were three binary mixtures from the primary reference fuels of n-heptane, iso-octane, and toluene. The result showed that PAH and soot maintained near zero level for all mixtures of n-heptane/iso-octane case under present experimental conditions. For n-heptane/toluene and iso-octane/toluene mixtures, PAH initially increased and then decreased with the toluene ratio, exhibiting a synergistic effect. The soot formation increased monotonically with the toluene ratio, however the effect of toluene on soot formation was minimal for relatively small toluene ratios. These results implied that even though toluene had a dominant role in soot and PAH formations, small amount of toluene had a minimal effect on soot formation. Numerical simulations have also been conducted by adopting recently proposed two kinetic mechanisms. The synergistic behavior of aromatic rings was predicted similar to the experimental PAH measurement, however, the degree of the synergistic effect was over-predicted for the soot formation flame, indicating the need for refinements in the kinetic mechanisms. © 2010 Published by Elsevier Inc. on behalf of The Combustion Institute. All rights reserved.

  2. Morphology Of Diesel Soot Residuals From Supercooled Water Droplets And Ice Crystals: Implications For Optical Properties

    Energy Technology Data Exchange (ETDEWEB)

    China, Swarup; Kulkarni, Gourihar R.; Scarnatio, Barbara; Sharma, Noopur; Pekour, Mikhail S.; Shilling, John E.; Wilson, Jacqueline M.; Zelenyuk, Alla; Chand, Duli; Liu, Shang; Aiken, Allison; Dubey, Manvendra K.; Laskin, Alexander; Zaveri, Rahul A.; Mazzoleni, Claudio

    2015-11-04

    Freshly emitted soot particles are fractal-like aggregates, but atmospheric processing often transforms their morphology. Morphology of soot particles plays an important role in determining their optical properties, life cycle and hence their effect on Earth’s radiative balance. However, little is known about the morphology of soot particles that participated in cold cloud processes. Here we report results from laboratory experiments that simulate cold cloud processing of diesel soot particles by allowing them to form supercooled droplets and ice crystals at -20 and -40°C, respectively. Electron microscopy revealed that soot residuals from ice crystals were more compact (roundness~0.55) than those from supercooled droplets (roundness ~0.45), while nascent soot particles were the least compact (roundness~0.41). Optical simulations using the discrete dipole approximation showed that the more compact structure enhances soot single scattering albedo by a factor up to 1.4, thereby reducing the top-of-the-atmosphere direct radiative forcing by ~63%. These results underscore that climate models should consider the morphological evolution of soot particles due to cold cloud processing to improve the estimate of direct radiative forcing of soot.

  3. Soot reduction under DC electric fields in counterflow non-premixed laminar ethylene flames

    KAUST Repository

    Park, Daegeun

    2014-04-23

    The effects of DC electric fields on non-premixed ethylene flames in a counterflow burner were studied experimentally with a focus on the reduction of soot particles. The experiment was conducted by connecting a high voltage terminal and a ground terminal to a lower (fuel) and upper (oxidizer) nozzle, respectively. We applied direct current (DC) potentials in a range of -5 kV < Vdc < 5 kV. Uniform electric fields were then generated in the gap between the two nozzles. The experimental conditions were selected to cover both soot formation (SF) and soot formation oxidation (SFO) flames. The flames subjected to the negative electric fields moved toward the fuel nozzle because of an ionic wind due to the Lorentz force acting on the positive ions in the flames. In addition, the yellow luminosity significantly decreased, indicating changes in the sooting characteristics. To analyze the sooting characteristics under the electric fields, planar laser induced incandescence (PLII) and fluorescence (PLIF) techniques were used to visualize the soot, polycyclic aromatic hydrocarbons (PAHs), and OH radicals. The sooting limits in terms of the fuel and oxygen mole fractions were measured. No substantial soot formation due to the effects of the DC electric fields for the tested range of voltages and reactant mole fractions could be identified. The detailed flame behaviors and sooting characteristics under the DC electric fields are discussed. Copyright © Taylor & Francis Group, LLC.

  4. Soot Reference Materials for instrument calibration and intercomparisons: a workshop summary with recommendations

    Directory of Open Access Journals (Sweden)

    D. Baumgardner

    2012-03-01

    Full Text Available Soot, which is produced from biomass burning and the incomplete combustion of fossil and biomass fuels, has been linked to regional and global climate change and to negative health problems. Scientists measure soot using a variety of methods in order to quantify source emissions and understand its atmospheric chemistry, reactivity under emission conditions, interaction with solar radiation, influence on clouds, and health impacts. A major obstacle currently limiting progress is the absence of established standards or reference materials for calibrating the many instruments used to measure the various properties of soot.

    The current state of availability and practicability of soot standard reference materials (SRMs was reviewed by a group of 50 international experts during a workshop in June of 2011. The workshop was convened to summarize the current knowledge on soot measurement techniques, identify the measurement uncertainties and limitations related to the lack of SRMs, and identify attributes of SRMs that, if developed, would reduce measurement uncertainties. The workshop established that suitable SRMs are available for calibrating some, but not all, measurement methods. The community of single-particle sootphotometer (SP2 users identified a suitable SRM, fullerene soot, but users of instruments that measure light absorption by soot collected on filters did not. Similarly, those who use thermal optical analysis (TOA to analyze the organic and elemental carbon components of soot were not satisfied with current SRMs. The workshop produced recommendations for the development of new SRMs that would be suitable for the different soot measurement methods.

  5. Optical absorption under total internal reflection in the characterization of soot in diesel engine oils

    International Nuclear Information System (INIS)

    Optical absorption of infrared radiation under total internal reflection in a novel sensor has been utilized to investigate the soot contamination of diesel engine oil by response surface methodology in factorial experiments. Sensor response showed highly significant dependence on oil soot concentration and temperature, in which the effect of the soot was greatest. The soot contamination of the optical rod in engine oil was found to be a surface phenomenon which showed little or no dependence on bulk oil shearing displacement below 500 rpm. The quadratic effect of sensor response to soot concentration was very high due to the agglomeration of soot particles, derived from the high surface energy of carbon soot. Test results of this optical absorption technique were in conformance with those other oil analysis techniques such as UV spectrophotometry, total acid number, viscosimetry, optical microscopy and EPMA. The technique proved to be more reliable than RDE emission spectrometry which showed ambiguous results due to colloidal suspension of soot particles in oil. Optical absorption proved to be an effective criterion in characterizing the soot contamination of diesel engine oil

  6. Blower door tests of a group of identical flats in a new student accommodation in the Arctic

    OpenAIRE

    Kotol, Martin; Rode, Carsten; Vahala, Jan

    2012-01-01

    A new student accommodation for engineering students “Apisseq” was built in the town of Sisimiut, Greenland in 2010. Its purpose is not only to provide accommodation for students. Thanks to its complex monitoring system it enables researchers to evaluate the building’s energy performance and indoor air quality (IAQ) as well as performance of some single components. In summer 2012 a blower door test was performed on all 37 living units out of which 33 are identical single room flats and 4 are ...

  7. 46 CFR 109.555 - Propulsion boilers.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Propulsion boilers. 109.555 Section 109.555 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.555 Propulsion boilers. The master or person in charge and the engineer in charge...

  8. Seeking for total efficiency on boiler operation

    International Nuclear Information System (INIS)

    In this paper, as for the boiler in the private power generation plant which has been in operation since July, 1974 based on the production increase project of the factory, the measures for energy conservation considered from the planning and design stage, the countermeasures to the low loading of the boiler by the epoch-making effect of the energy conservation in the production system since the oil crisis in 1973, and the cost management of the boiler are described. The outline of the private power generation plant is shown. The boiler facilities are the boiler for power generation of 81 kg/cm2, 433degC, 65 t/h, the saturation boiler of 30 kg/cm2, 211degC, 47 t/h, and the waste heat boiler of 22 kg/cm2, 211 degC, 4.2 t/h. As the measures for energy conservation, tangential corner firing-two stage combustion process was adopted, and the total heat of recovered drain has been utilized. The remodeling and the effect of improvement of the boiler and the turbine as the countermeasures to low loading are reported. The examples of other energy conservation in the waste tire incinerator, air compressor, exhaust desulfurizer and air preheater are described. (K.I.)

  9. Effects of atmospheric water on the optical properties of soot aerosols with different mixing states

    International Nuclear Information System (INIS)

    Soot aerosols have become the second most important contributor to global warming after carbon dioxide in terms of direct forcing, which is the dominant absorber of visible solar radiation. The optical properties of soot aerosols depend strongly on the mixing mechanism of black carbon with other aerosol components and its hygroscopic properties. In this study, the effects of atmospheric water on the optical properties of soot aerosols have been investigated using a superposition T-matrix method that accounts for the mixing mechanism of soot aerosols with atmospheric water. The dramatic changes in the optical properties of soot aerosols were attributed to its different mixing states with atmospheric water (externally mixed, semi-embedded mixed, and internally mixed). Increased absorption is accompanied by a larger increase in scattering, which is reflected by the increased single scattering albedo. The asymmetry parameter also increased when increasing the atmospheric water content. Moreover, atmospheric water intensified the radiative absorption enhancement attributed to the mixing states of the soot aerosols, with values ranging from 1.5 to 2.5 on average at 0.870 μm. The increased absorption and scattering ability of soot aerosols, which is attributed to atmospheric water, exerted an opposing effect on climate change. These findings should improve our understanding of the effects of atmospheric water on the optical properties of soot aerosols and their effects on climate. The mixing mechanism for soot aerosols and atmospheric water is important when evaluating the climate effects of soot aerosols, which should be explicitly considered in radiative forcing models. - Highlights: • Effects of atmospheric water on optical properties of soot aerosols are investigated. • Increased absorption is accompanied by a larger increase in scattering. • Atmospheric water intensified the absorption enhancement due the mixing states

  10. Soot reference materials for instrument calibration and intercomparisons: a workshop summary with recommendations

    Directory of Open Access Journals (Sweden)

    D. Baumgardner

    2012-08-01

    Full Text Available Soot, which is produced from biomass burning and the incomplete combustion of fossil and biomass fuels, has been linked to regional and global climate change and to negative health problems. Scientists measure the properties of soot using a variety of methods in order to quantify source emissions and understand its atmospheric chemistry, reactivity under emission conditions, interaction with solar radiation, influence on clouds, and health impacts. A major obstacle currently limiting progress is the absence of established standards or reference materials for calibrating the many instruments used to measure the various properties of soot.

    The current state of availability and practicability of soot standard reference materials (SRMs was reviewed by a group of 50 international experts during a workshop in June of 2011. The workshop was convened to summarize the current knowledge on soot measurement techniques, identify the measurement uncertainties and limitations related to the lack of soot SRMs, and identify attributes of SRMs that, if developed, would reduce measurement uncertainties. The workshop established that suitable SRMs are available for calibrating some, but not all, measurement methods. The community of users of the single-particle soot-photometer (SP2, an instrument using laser-induced incandescence, identified a suitable SRM, fullerene soot, but users of instruments that measure light absorption by soot collected on filters did not. Similarly, those who use thermal optical analysis (TOA to analyze the organic and elemental carbon components of soot were not satisfied with current SRMs. The workshop, and subsequent, interactive discussions, produced a number of recommendations for the development of new SRMs, and their implementation, that would be suitable for the different soot measurement methods.

  11. A computational study of ethylene–air sooting flames: Effects of large polycyclic aromatic hydrocarbons

    KAUST Repository

    Selvaraj, Prabhu

    2015-11-05

    An updated reduced gas-phase kinetic mechanism was developed and integrated with aerosol models to predict soot formation characteristics in ethylene nonpremixed and premixed flames. A primary objective is to investigate the sensitivity of the soot formation to various chemical pathways for large polycyclic aromatic hydrocarbons (PAH). The gas-phase chemical mechanism adopted the KAUST-Aramco PAH Mech 1.0, which utilized the AramcoMech 1.3 for gas-phase reactions validated for up to C2 fuels. In addition, PAH species up to coronene (C24H12 or A7) were included to describe the detailed formation pathways of soot precursors. In this study, the detailed chemical mechanism was reduced from 397 to 99 species using directed relation graph with expert knowledge (DRG-X) and sensitivity analysis. The method of moments with interpolative closure (MOMIC) was employed for the soot aerosol model. Counterflow nonpremixed flames at low strain rate sooting conditions were considered, for which the sensitivity of soot formation characteristics to different nucleation pathways were investigated. Premixed flame experiment data at different equivalence ratios were also used for validation. The findings show that higher PAH concentrations result in a higher soot nucleation rate, and that the total soot volume and average size of the particles are predicted in good agreement with experimental results. Subsequently, the effects of different pathways, with respect to pyrene- or coronene-based nucleation models, on the net soot formation rate were analyzed. It was found that the nucleation processes (i.e., soot inception) are sensitive to the choice of PAH precursors, and consideration of higher PAH species beyond pyrene is critical for accurate prediction of the overall soot formation.

  12. Optimizing the integrated design of boilers - simulation

    DEFF Research Database (Denmark)

    Sørensen, Kim; Karstensen, Claus M. S.; Condra, Thomas Joseph;

    2004-01-01

    Boilers can be considered as consisting of three main components: (i) the pressure part, (ii) the burner and (iii) the control system. To be able to develop the boilers of the future (i.e. the boilers with the lowest emissions, the highest efciency, the best dynamic performance etc.) it is...... important to see the 3 components as an integrated unit and optimize these as such. This means that the burner must be designed and optimized exactly to the pressure part where it is utilized, the control system must have a conguration optimal for the pressure part and burner where it is utilized etc....... Traditionally boiler control systems have been designed in a rather simple manner consisting of a feed water controller and a pressure controller; two controllers which, in principle, operated without any interaction - for more details on boiler control see [4]. During the last year Aalborg Industries A/S has...

  13. PAH emission from the industrial boilers.

    Science.gov (United States)

    Li, C; Mi, H; Lee, W; You, W; Wang, Y

    1999-10-01

    Polycyclic aromatic hydrocarbons (PAHs) emitted from 25 industrial boilers were investigated. The fuels used for these 25 boilers included 21 heavy oil, two diesel, a co-combustion of heavy oil and natural gas (HO+NG) and a co-combustion of coke oven gas and blast furnace gas (COG+BFG) boilers. PAH samples from the stack flue gas (gas and particle phases) of these 25 boilers were collected by using a PAH stack sampling system. Twenty one individual PAHs were analyzed primarily by a gas chromatography/mass spectrometer (GC/MS). Total-PAH concentration in the flue gas of 83 measured data for these 25 boiler stacks ranged between 29.0 and 4250 microg/m(3) and averaged 488 microg/m(3). The average of PAH-homologue mass (F%) counted for the total-PAH mass was 54.7%, 9.47% and 15.3% for the 2-ring, 3-ring and 4-ring PAHs, respectively. The PAHs in the stack flue gas were dominant in the lower molecular weight PAHs. The emission factors (EFs) of total-PAHs were 13,300, 2920, 2880 and 208 microg/kg-fuel for the heavy oil, diesel, HO+NG and COG+BFG fueled-boiler, respectively. Nap was the most predominant PAH occurring in the stack flue gas. In addition, the EF of 21 individual PAHs in heavy-oil boiler were almost the highest among the four various fueled-boilers except for those of FL and BkF in the diesel boiler. Furthermore, the EF of total-PAHs or BaP for heavy oil were both one order of magnitude higher than that for the diesel-fueled boiler. PMID:10502602

  14. Computer system for monitoring power boiler operation

    Energy Technology Data Exchange (ETDEWEB)

    Taler, J.; Weglowski, B.; Zima, W.; Duda, P.; Gradziel, S.; Sobota, T.; Cebula, A.; Taler, D. [Cracow University of Technology, Krakow (Poland). Inst. for Process & Power Engineering

    2008-02-15

    The computer-based boiler performance monitoring system was developed to perform thermal-hydraulic computations of the boiler working parameters in an on-line mode. Measurements of temperatures, heat flux, pressures, mass flowrates, and gas analysis data were used to perform the heat transfer analysis in the evaporator, furnace, and convection pass. A new construction technique of heat flux tubes for determining heat flux absorbed by membrane water-walls is also presented. The current paper presents the results of heat flux measurement in coal-fired steam boilers. During changes of the boiler load, the necessary natural water circulation cannot be exceeded. A rapid increase of pressure may cause fading of the boiling process in water-wall tubes, whereas a rapid decrease of pressure leads to water boiling in all elements of the boiler's evaporator - water-wall tubes and downcomers. Both cases can cause flow stagnation in the water circulation leading to pipe cracking. Two flowmeters were assembled on central downcomers, and an investigation of natural water circulation in an OP-210 boiler was carried out. On the basis of these measurements, the maximum rates of pressure change in the boiler evaporator were determined. The on-line computation of the conditions in the combustion chamber allows for real-time determination of the heat flowrate transferred to the power boiler evaporator. Furthermore, with a quantitative indication of surface cleanliness, selective sootblowing can be directed at specific problem areas. A boiler monitoring system is also incorporated to provide details of changes in boiler efficiency and operating conditions following sootblowing, so that the effects of a particular sootblowing sequence can be analysed and optimized at a later stage.

  15. Effects of Biomass Feedstock on the Yield and Reactivity of Soot from Fast Pyrolysis at High Temperatures

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Jensen, Peter A.; Glarborg, Peter;

    that of beechwood soot (from 33.2 to 102 nm) and wheat straw soot (from 11.5 to 165.3 nm). In addition, pinewood soot particles contained mainly multi-core structures at 1250°C. The potassium content played a more important role on the soot reactivity than the particle size and nanostructure.......This study investigated the effect of feedstock on the yield, nanostructure and reactivity of soot. Woody and herbaceous biomass were pyrolyzed at high heating rates and temperatures of 1250 and 1400°C in a drop tube furnace. The collected solid residues were structurally characterized by electron...... respect to the alkali content, particle size and nanostructure. Potassium was incorporated in the soot matrix and to a significant extent influenced the soot reactivity. The particle size distribution of pinewood soot produced at 1250°C was in the range from 27.2 to 263 nm which was broader compared to...

  16. Automation of the control system and reform of the COSIPA no. 3 turbo blower; Automacao dos sistema de controle e reforma do turbo soprador n. 3 da Cosipa

    Energy Technology Data Exchange (ETDEWEB)

    Kobukloski, Sandro; Martins, Marcos Rogerio S.; Garcia, Jose Eduardo da S.; Reis, Joao de Paula; Romao Junior, Wilson; Vilarinho, Joao Clovis; Spinassi, Luiz Carlos; Florencio, Aurelio Freire; Rocha, Jose Olimpio Castro Pereira da [Companhia Siderurgica Paulista (COSIPA), Cubatao, SP (Brazil)

    2001-07-01

    The turbo blower no. 3 (TS no. 3) start operation in 1976 blowing for the COSIPA blast furnace no. 2. Since 1993 the equipment was dedicated to the blast furnace no. 1, which is smaller than the previous one, consequently releasing the excess air to the atmosphere. Due to some modifications and for safety of the equipment, an operational conditional has been introducing with higher energy consumption. Due to operational requests a complete machine control system reformation was decided, blower stator and rotor blade replacement, and installation of a self-cleaning pre-filtering system. (author)

  17. Key role of organic carbon in the sunlight-enhanced atmospheric aging of soot by O2

    OpenAIRE

    Han, Chong; Liu, Yongchun; Ma, Jinzhu; He, Hong

    2012-01-01

    Soot particles are ubiquitous in the atmosphere and have important climatic and health effects. The aging processes of soot during long-range transport result in variability in its morphology, microstructure, and hygroscopic and optical properties, subsequently leading to the modification of soot’s climatic and health effects. In the present study the aging process of soot by molecular O2 under simulated sunlight irradiation is investigated. Organic carbon components on the surface of soot ar...

  18. Effects of Large Polycyclic Aromatic Hydrocarbons on the Soot Formation in Ethylene-Air Nonpremixed Flames

    KAUST Repository

    Prabhu, S.

    2015-03-30

    This study presents updated comprehensive gas-phase kinetic mechanism and aerosol models to predict soot formation characteristics in ethylene-air nonpremixed flames. A main objective is to investigate the sensitivity of the soot formation rate to various chemical pathways for large polycyclic aromatic hydrocarbons (PAH). In this study, the detailed chemical mechanism was reduced from 397 to 99 species using directed relation graph (DRG) and sensitivity analysis. The method of moments with interpolative closure (MOMIC) was employed for the soot aerosol model. Counterflow nonpremixed flames of pure ethylene at low strain rate sooting conditions are considered, for which the sensitivity of soot formation characteristics with respect to hetrogeneous nucleation is investigated. Results show that higher PAH concentrations result in higher soot nucleation rate, and that the average size of the particles are in good agreement with experimental results. It is found that the nucleation processes (i.e., soot inception) from higher PAH precursors, coronene in particular, is critical for accurate prediction of the overall soot formation.

  19. Microwave-assisted in-situ regeneration of a perovskite coated diesel soot filter

    NARCIS (Netherlands)

    Y. Zhang-Steenwinkel; L.M. van der Zande; H.L. Castricum; A. Bliek; R.W. van den Brink; G.D. Elzinga

    2005-01-01

    Dielectric heating may be used as an in situ technique for the periodic regeneration of soot filters, as those used in Diesel engines. As generally the Diesel exhaust temperatures are below the soot light-off temperature, passive regeneration is not possible. Presently, we have investigated the diel

  20. Extraction of polycyclic aromatic hydrocarbons from soot and sediment : solvent selection and implications for sorption mechanism

    NARCIS (Netherlands)

    Jonker, M.T.O.; Koelmans, A.A.

    2002-01-01

    Soot contains high levels of toxic compounds such as polycyclic aromatic hydrocarbons (PAHs). Extraction of PAHs from soot for quantitative analysis is difficult because the compounds are extremely tightly bound to the sorbent matrix. This study was designed to investigate the effect of solvent type

  1. Simulations of sooting turbulent jet flames using a hybrid flamelet/stochastic Eulerian field method

    Science.gov (United States)

    Consalvi, Jean-Louis; Nmira, Fatiha; Burot, Daria

    2016-03-01

    The stochastic Eulerian field method is applied to simulate 12 turbulent C1-C3 hydrocarbon jet diffusion flames covering a wide range of Reynolds numbers and fuel sooting propensities. The joint scalar probability density function (PDF) is a function of the mixture fraction, enthalpy defect, scalar dissipation rate and representative soot properties. Soot production is modelled by a semi-empirical acetylene/benzene-based soot model. Spectral gas and soot radiation is modelled using a wide-band correlated-k model. Emission turbulent radiation interactions (TRIs) are taken into account by means of the PDF method, whereas absorption TRIs are modelled using the optically thin fluctuation approximation. Model predictions are found to be in reasonable agreement with experimental data in terms of flame structure, soot quantities and radiative loss. Mean soot volume fractions are predicted within a factor of two of the experiments whereas radiant fractions and peaks of wall radiative fluxes are within 20%. The study also aims to assess approximate radiative models, namely the optically thin approximation (OTA) and grey medium approximation. These approximations affect significantly the radiative loss and should be avoided if accurate predictions of the radiative flux are desired. At atmospheric pressure, the relative errors that they produced on the peaks of temperature and soot volume fraction are within both experimental and model uncertainties. However, these discrepancies are found to increase with pressure, suggesting that spectral models describing properly the self-absorption should be considered at over-atmospheric pressure.

  2. Soot microphysical effects on liquid clouds, a multi-model investigation

    Science.gov (United States)

    Koch, D.; Balkanski, Y.; Bauer, S. E.; Easter, R. C.; Ferrachat, S.; Ghan, S. J.; Hoose, C.; Iversen, T.; Kirkevåg, A.; Kristjansson, J. E.; Liu, X.; Lohmann, U.; Menon, S.; Quaas, J.; Schulz, M.; Seland, Ø.; Takemura, T.; Yan, N.

    2011-02-01

    We use global models to explore the microphysical effects of carbonaceous aerosols on liquid clouds. Although absorption of solar radiation by soot warms the atmosphere, soot may cause climate cooling due to its contribution to cloud condensation nuclei (CCN) and therefore cloud brightness. Six global models conducted three soot experiments; four of the models had detailed aerosol microphysical schemes. The average cloud radiative response to biofuel soot (black and organic carbon), including both indirect and semi-direct effects, is -0.11 Wm-2, comparable in size but opposite in sign to the respective direct effect. In a more idealized fossil fuel black carbon experiment, some models calculated a positive cloud response because soot provides a deposition sink for sulfuric and nitric acids and secondary organics, decreasing nucleation and evolution of viable CCN. Biofuel soot particles were also typically assumed to be larger and more hygroscopic than for fossil fuel soot and therefore caused more negative forcing, as also found in previous studies. Diesel soot (black and organic carbon) experiments had relatively smaller cloud impacts with five of the models competition of opposing effects on the CCN population make it difficult to extrapolate from idealized experiments to likely impacts of realistic potential emission changes.

  3. Dexpler: Converting Android Dalvik Bytecode to Jimple for Static Analysis with Soot

    CERN Document Server

    Bartel, Alexandre; Monperrus, Martin; Traon, Yves Le

    2012-01-01

    This paper introduces Dexpler, a software package which converts Dalvik bytecode to Jimple. Dexpler is built on top of Dedexer and Soot. As Jimple is Soot's main internal rep- resentation of code, the Dalvik bytecode can be manipu- lated with any Jimple based tool, for instance for performing point-to or flow analysis.

  4. Reconstruction of atmospheric soot history in inland regions from lake sediments over the past 150 years

    Science.gov (United States)

    Han, Y. M.; Wei, C.; Huang, R.-J.; Bandowe, B. A. M.; Ho, S. S. H.; Cao, J. J.; Jin, Z. D.; Xu, B. Q.; Gao, S. P.; Tie, X. X.; An, Z. S.; Wilcke, W.

    2016-01-01

    Historical reconstruction of atmospheric black carbon (BC, in the form of char and soot) is still constrained for inland areas. Here we determined and compared the past 150-yr records of BC and polycyclic aromatic compounds (PACs) in sediments from two representative lakes, Huguangyan (HGY) and Chaohu (CH), in eastern China. HGY only receives atmospheric deposition while CH is influenced by riverine input. BC, char, and soot have similar vertical concentration profiles as PACs in both lakes. Abrupt increases in concentrations and mass accumulation rates (MARs) of soot have mainly occurred since ~1950, the establishment of the People’s Republic of China, when energy usage changed to more fossil fuel contributions reflected by the variations in the concentration ratios of char/soot and individual PACs. In HGY, soot MARs increased by ~7.7 times in the period 1980-2012 relative to the period 1850-1950. Similar increases (~6.7 times) were observed in CH. The increase in soot MARs is also in line with the emission inventory records in the literature and the fact that the submicrometer-sized soot particles can be dispersed regionally. The study provides an alternative method to reconstruct the atmospheric soot history in populated inland areas.

  5. Carbon Nanostructure: Its Evolution During its Impact Upon Soot Growth and Oxidation

    Science.gov (United States)

    2001-01-01

    The proposed work is a ground-based study to define and quantify soot nanostructural changes in response to growth conditions, thermal and oxidative treatments and to quantify their impact upon further oxidation and growth of highly ordered carbon materials. Experimental data relating soot oxidation rates to multiple oxidizing species concentrations will directly test for additive or synergistic soot oxidation rates. Such validation is central for assessing the applicability of individual soot oxidation rates and designing oxidative strategies for controlling soot loadings in and emissions from turbulent combustion processes. Through these experiments, new insights into soot nanostructure evolution during and its impact upon oxidation by O2 and OH will be realized. It is expected that the results of this effort will spawn new research directions in future microgravity and 1g environments. Issues raised by positive or even negative demonstration of the hypotheses of this proposal have direct bearing on modelling and controlling soot formation and its destruction in nearly every combustion process producing soot.

  6. A mechanistic study on the simultaneous elimination of soot and nitric oxide from engine exhaust

    KAUST Repository

    Raj, Abhijeet

    2011-04-01

    The non-catalytic interaction between soot and nitric oxide (NO) resulting in their simultaneous elimination was studied on different types of reactive site present on soot. The reaction mechanism proposed previously was extended by including seven new reaction pathways for which the reaction energetics and kinetics were studied using density functional theory and transition state theory. This has led to the calculation of a new rate for the removal of carbon monoxide (CO) from soot. The new pathways have been added to our polycyclic aromatic hydrocarbon (PAH) growth model and used to simulate the NO-soot interaction to form CO, N2 and N2O. The simulation results show satisfactory agreement with experiment for the new CO removal rate. The NO-soot reaction was found to depend strongly on the soot site type and temperature. For a set of temperatures, computed PAH structures were analysed to determine the functional groups responsible for the decrease in the reactivity of soot with NO with increasing reaction time. In isothermal conditions, it was found that as temperature is increased, the number of oxygen atoms remaining on the soot surface decreases, while the number of nitrogen atoms increases for a given reaction time. © 2010 Elsevier Ltd. All rights reserved.

  7. Physical and chemical characterization of residential oil boiler emissions.

    Science.gov (United States)

    Hays, Michael D; Beck, Lee; Barfield, Pamela; Lavrich, Richard J; Dong, Yuanji; Vander Wal, Randy L

    2008-04-01

    The toxicity of emissions from the combustion of home heating oil coupled with the regional proximity and seasonal use of residential oil boilers (ROB) is an important public health concern. Yet scant physical and chemical information about the emissions from this source is available for climate and air quality modeling and for improving our understanding of aerosol-related human health effects. The gas- and particle-phase emissions from an active ROB firing distillate fuel oil (commonly known as diesel fuel) were evaluated to address this deficiency. Ion chromatography of impactor samples showed that the ultrafine ROB aerosol emissions were approximately 45% (w/w) sulfate. Gas chromatography-mass spectrometry detected various n-alkanes at trace levels, sometimes in accumulation mode particles, and out of phase with the size distributions of aerosol mass and sulfate. The carbonaceous matter in the ROB aerosol was primarily light-adsorbing elemental carbon. Gas chromatography-atomic emission spectroscopy measured a previously unrecognized organosulfur compound group in the ROB aerosol emissions. High-resolution transmission electron microscopy of ROB soot indicated the presence of a highly ordered primary particle nanostructure embedded in larger aggregates. Organic gas emissions were measured using EPA Methods TO-15 and TO-11A. The ROB emitted volatile oxygenates (8 mg/(kg of oil burned)) and olefins (5 mg/(kg of oil burned)) mostly unrelated to the base fuel composition. In the final analysis, the ROB tested was a source of numerous hazardous air pollutants as defined in the Clean Air Act Amendments. Approximations conducted using emissions data from the ROB tests show relatively low contributions to a regional-level anthropogenic emissions inventory for volitile organic compounds, PM2.5, and SO2 mass. PMID:18504987

  8. Measurements of soot formation and hydroxyl concentration in near critical equivalence ratio premixed ethylene flame

    Science.gov (United States)

    Inbody, Michael Andrew

    1993-01-01

    The testing and development of existing global and detailed chemical kinetic models for soot formation requires measurements of soot and radical concentrations in flames. A clearer understanding of soot particle inception relies upon the evaluation and refinement of these models in comparison with such measurements. We present measurements of soot formation and hydroxyl (OH) concentration in sequences of flat premixed atmospheric-pressure C2H4/O2/N2 flames and 80-torr C2H4/O2 flames for a unique range of equivalence ratios bracketting the critical equivalence ratio (phi(sub c)) and extending to more heavily sooting conditions. Soot volume fraction and number density profiles are measured using a laser scattering-extinction apparatus capable of resolving a 0.1 percent absorption. Hydroxyl number density profiles are measured using laser-induced fluorescence (LIF) with broadband detection. Temperature profiles are obtained from Rayleigh scattering measurements. The relative volume fraction and number density profiles of the richer sooting flames exhibit the expected trends in soot formation. In near-phi(sub c) visibility sooting flames, particle scattering and extinction are not detected, but an LIF signal due to polycyclic aromatic hydrocarbons (PAH's) can be detected upon excitation with an argon-ion laser. A linear correlation between the argon-ion LIF and the soot volume fraction implies a common mechanistic source for the growth of PAH's and soot particles. The peak OH number density in both the atmospheric and 80-torr flames declines with increasing equivalence ratio, but the profile shape remains unchanged in the transition to sooting, implying that the primary reaction pathways for OH remain unchanged over this transition. Chemical kinetic modeling is demonstrated by comparing predictions using two current reaction mechanisms with the atmospheric flame data. The measured and predicted OH number density profiles show good agreement. The predicted benzene

  9. 46 CFR 61.05-20 - Boiler safety valves.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Boiler safety valves. 61.05-20 Section 61.05-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PERIODIC TESTS AND INSPECTIONS Tests and Inspections of Boilers § 61.05-20 Boiler safety valves. Each safety valve for a drum, superheater, or reheater of a boiler shall...

  10. Scattering and propagation of terahertz pulses in random soot aggregate systems

    International Nuclear Information System (INIS)

    Scattering and propagation of terahertz pulses in random soot aggregate systems are studied by using the generalized multi-particle Mie-solution (GMM) and the pulse propagation theory. Soot aggregates are obtained by the diffusion-limited aggregation (DLA) model. For a soot aggregate in soot aggregate systems, scattering characteristics are analyzed by using the GMM. Scattering intensities versus scattering angles are given. The effects of different positions of the aggregate on the scattering intensities, scattering cross sections, extinction cross sections, and absorption cross sections are computed and compared. Based on pulse propagation in random media, the transmission of terahertz pulses in random soot aggregate systems is determined by the two-frequency mutual coherence function. Numerical simulations and analysis are given for terahertz pulses (0.7956 THz). (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  11. Pyrene measurements in sooting low pressure methane flames by jet-cooled laser-induced fluorescence.

    Science.gov (United States)

    Wartel, M; Pauwels, J-F; Desgroux, P; Mercier, X

    2011-12-15

    This paper presents in detail the study we carried out concerning the pyrene measurement by jet-cooled laser-induced fluorescence (JCLIF) in different sooting low pressure methane flames. The aim of this paper is both to demonstrate the potentialities of this technique for the measurement of such moderately sized polycyclic aromatic hydrocarbons under sooting flame conditions and to provide new experimental data for the understanding and the development of chemical models of the soot formation processes. Several concentration profiles of pyrene measured in different sooting flame (various pressure and equivalence ratio) are presented. The validation of the JCLIF method for pyrene measurements is explained in detail as well as the calibration procedure, based on the standard addition method, which has been implemented for the quantification of the concentration profiles. Sensitivity lower than 1 ppb was obtained for the measurement of this species under sooting flame conditions. PMID:22029528

  12. Laboratory measurements in a turbulent, swirling flow. [measurement of soot inside a flame-tube burner

    Science.gov (United States)

    Hoult, D. P.

    1979-01-01

    Measurements of soot inside a flame-tube burner using a special water-flushed probe are discussed. The soot is measured at a series of points at each burner, and upon occasion gaseous constitutents NO, CO, hydrocarbons, etc., were also measured. Four geometries of flame-tube burners were studied, as well as a variety of different fuels. The role of upstream geometry on the downstream pollutant formation was studied. It was found that the amount of soot formed in particularly sensitive to how aerodynamically clean the configuration of the burner is upstream of the injector swirl vanes. The effect of pressure on soot formation was also studied. It was found that beyond a certain Reynolds number, the peak amount of soot formed in the burner is constant.

  13. A Progress Review on Soot Experiments and Modeling in the Engine Combustion Network (ECN)

    KAUST Repository

    Skeen, Scott A.

    2016-04-05

    The 4th Workshop of the Engine Combustion Network (ECN) was held September 5-6, 2015 in Kyoto, Japan. This manuscript presents a summary of the progress in experiments and modeling among ECN contributors leading to a better understanding of soot formation under the ECN “Spray A” configuration and some parametric variants. Relevant published and unpublished work from prior ECN workshops is reviewed. Experiments measuring soot particle size and morphology, soot volume fraction (fv), and transient soot mass have been conducted at various international institutions providing target data for improvements to computational models. Multiple modeling contributions using both the Reynolds Averaged Navier-Stokes (RANS) Equations approach and the Large-Eddy Simulation (LES) approach have been submitted. Among these, various chemical mechanisms, soot models, and turbulence-chemistry interaction (TCI) methodologies have been considered.

  14. High-Energy-Density Fuel Blending Strategies and Drop Dispersion for Fuel Cost Reduction and Soot Propensity Control

    Science.gov (United States)

    Bellan, J.; Harstad, K.

    1998-01-01

    The idea that low soot propensity of high-energy-density (HED) liquid sooting fuels and cost reduction of a multicomponent energetic fuel can be achieved by doping a less expensive, less sooting liquid fuel with HED is tested through numerical simulations.

  15. Electrical design requirements for electrode boilers for nuclear plants

    International Nuclear Information System (INIS)

    Medium-voltage steam electrode boilers, in the 20- to 50-MW range, have become an attractive alternative to comparable fossil-fueled boilers as a source of auxiliary steam during the startup and normal shutdown of nuclear power plants. The electrode boiler represents a favorable option because of environmental, fire protection, and licensing considerations. However, this electrical option brings some difficult design problems for which solutions are required in order to integrate the electrode boiler into the plant low resistance grounded power system. These considerations include the effects of an unbalanced electrode boiler on the performance of polyphase induction motors, boiler grounding for personnel safety, boiler neutral grounding, and ground relaying

  16. Soot particles at an elevated site in eastern China during the passage of a strong cyclone

    International Nuclear Information System (INIS)

    Atmospheric particles larger than 0.2 μm were collected at the top of Mt. Tai (36.25°N, 117.10°E, 1534 m a.s.l.) in eastern China in May 2008 during the passage of a strong cyclone. The particles were analyzed with electron microscopes and characterized by morphology, equivalent diameter and elemental composition. Soot particles with coating (coated soot particles) and those without apparent coating (naked soot particles) were predominant in the diameter range smaller than 0.6 μm in all samples. The number–size distribution of the relative abundance of naked soot particles in the prefrontal air was similar to that in the postfrontal air and their size modes were around 0.2–0.3 μm. However, the distribution of inclusions of coated soot particles showed a mode in the range of 0.1–0.3 μm. The coating degree of coated soot particles, which was defined by the ratio of the diameter of inclusion to the diameter of particle body, showed a mode around 0.5 with the range of 0.3–0.6. These results indicate that the status of soot particles in the prefrontal and postfrontal air was similar although air pollution levels were dramatically different. In addition, the relative abundance of accumulation mode particles increased with the decrease of soot particles after the front passage. - Highlights: ► Particles at an elevated site in eastern China in a strong cyclone were studied. ► Aged status of soot particles in the prefrontal and postfrontal air was similar. Soot particles in elevated layers could be considered as aged ones.

  17. Boiler Retrofit for the Utilization of Biodiesel

    Directory of Open Access Journals (Sweden)

    Leily Nurul Komariah

    2016-02-01

    Full Text Available Fuel oil used in the boiler is able to substitute with biodiesel. In lower blends, there are no engine modification needed, but some researchers recommended some technical adjustments in order to maintain the boiler's performance and equipment durability. This study consists of the comparison between the performance of boiler before and after retrofitting on the use of biodiesel. The diesel oil was introduced in biodiesel blends of 10% (B10, 20% (B20 and 25% (B25. A fire tube boiler was used for the test with pressure of 3 bar and heat input capacity of 60,000 kcal. The boiler retrofit is conducted by fine tuning the fan damper scale (FDS and adding a heating feature on fuel system. It was specifically intended to maintain the quality of combustion and boiler efficiency as well as to avoid an increase in fuel consumption. The combustion behaviour was monitored by exhaust emissions of CO, NOx, and SO2. The fan damper scale (FDS and fuel temperature is adjusted by the increasing portion of biodiesel used. The fuel heating apparatus was set at temperature of 40oC for the use of B10, and 60oC for B20 and B25. The FDS adjustment was successfully resulted a reduction in rate of combustion air by average of 9.2%. The boiler retrofitting for the utilization of B10, B20 and B25 showed an increase in boiler efficiency by 0.64%, 0.42% and 2.6% respectively. The boiler retrofitting is surprisingly reduced the fuel consumption by average of 11.2%.

  18. Power for the industrial age: a brief history of boilers

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, S.E.

    1996-02-01

    Boilers were first designed in Greece during the Hellenistic period by Hero, but they were regarded purely as a novelty and no industrial application was found for these toys until the seventeenth century when mining engineers used them for steam-powered pumps. By the end of the 17th century the early shell boilers were replaced by tube boilers, the direct ancestors of the modern boiler. Among the best known of the early boiler manufacturers was Babcock and Wilcox, and they supplied boilers to one of the first electric power plants. In the early 20th century superheaters, economizers, stokers and pulverizers were added to the design of the utility boiler. Fusion-welded boiler drums added to safety. More recently environmental concerns have initiated a new generation of boilers, such as the pressurised fluidised bed combustion boilers and their advanced versions. 5 refs., 3 figs.

  19. Low excess air operations of oil boilers

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, T.A.; Celebi, Y.; Litzke, Wai Lin [Brookhaven National Labs., Upton, NY (United States)

    1997-09-01

    To quantify the benefits which operation at very low excess air operation may have on heat exchanger fouling BNL has recently started a test project. The test allows simultaneous measurement of fouling rate, flue gas filterable soot, flue gas sulfuric acid content, and flue gas sulfur dioxide.

  20. Candle soot nanoparticles-polydimethylsiloxane composites for laser ultrasound transducers

    Science.gov (United States)

    Chang, Wei-Yi; Huang, Wenbin; Kim, Jinwook; Li, Sibo; Jiang, Xiaoning

    2015-10-01

    Generation of high power laser ultrasound strongly demands the advanced materials with efficient laser energy absorption, fast thermal diffusion, and large thermoelastic expansion capabilities. In this study, candle soot nanoparticles-polydimethylsiloxane (CSNPs-PDMS) composite was investigated as the functional layer for an optoacoustic transducer with high-energy conversion efficiency. The mean diameter of the collected candle soot carbon nanoparticles is about 45 nm, and the light absorption ratio at 532 nm wavelength is up to 96.24%. The prototyped CSNPs-PDMS nano-composite laser ultrasound transducer was characterized and compared with transducers using Cr-PDMS, carbon black (CB)-PDMS, and carbon nano-fiber (CNFs)-PDMS composites, respectively. Energy conversion coefficient and -6 dB frequency bandwidth of the CSNPs-PDMS composite laser ultrasound transducer were measured to be 4.41 × 10-3 and 21 MHz, respectively. The unprecedented laser ultrasound transduction performance using CSNPs-PDMS nano-composites is promising for a broad range of ultrasound therapy applications.

  1. Chemical cleaning of UK AGR boilers

    International Nuclear Information System (INIS)

    For a number of years, the waterside pressure drops across the advanced gas-cooled reactor (AGR) pod boilers have been increasing. The pressure drop increases have accelerated with time, which is the converse behaviour to that expected for rippled magnetite formation (rapid initial increase slowing down with time). Nonetheless, magnetite deposition remains the most likely cause for the increasing boiler resistances. A number of potential countermeasures have been considered in response to the boiler pressure drop increases. However, there was no detectable reduction in the rate of pressure drop increase. Chemical cleaning was therefore considered and a project to substantiate and then implement chemical cleaning was initiated. (authors)

  2. Boiler efficiency methodology for solar heat applications

    Science.gov (United States)

    Maples, D.; Conwell, J. C.; Pacheco, J. E.

    1992-08-01

    This report contains a summary of boiler efficiency measurements which can be applied to evaluate the performance of steam-generating boilers via both the direct and indirect methods. This methodology was written to assist industries in calculating the boiler efficiency for determining the applicability and value of thermal industrial heat, as part of the efforts of the Solar Thermal Design Assistance Center (STDAC) funded by Sandia National Laboratories. Tables of combustion efficiencies are enclosed as functions of stack temperatures and the amount of carbon dioxide and carbon monoxide in the gas stream.

  3. Changes in radiative properties of soot contaminated maize canopy

    Science.gov (United States)

    Illes, B.; Anda, A.

    2012-04-01

    The effect of particle (Black Carbon, BC) on certain radiative characteristics of maize plants was studied over 2011 growing season in a field experiment carried out in Keszthely Agrometeorological Research Station. As the main constituent of BC, the soot that is almost exclusively responsible for light absorption by particles in the atmosphere, thus changing the radiation balance of the Earth and contributing to global warming. Maize hybrid Perlona (FAO 340) with short-season was applied as test plant. Of the two water supply treatments, the rainfed variant was sown in field plots, while compensation evapotranspirometers of the Thornthwaite type were used for the "ad libitum" treatment. The BC applied as pollutant was coming from the Hankook Tyre Company (Dunaújváros, Hungary), where it is used to improve the wear resistance of the tyres. The black carbon was chemically "pure", i.e. it is free of other contaminants (heavy metals etc.), so the reproducibility of the experiment is not problematic, unlike that of tests on other atmospheric air pollutants. Road traffic was simulated by using frequent low particle rates (3 g m-2 week-1) with a motorised sprayer of SP 415 type, during the season. The leaf area index was measured each week on the same 12 sample plants in each treatment using an LI 3000A automatic planimeter (LI-COR, Lincoln, NE). The impact of black carbon on plant radiative properties were analysed in the field (about 0.3 ha/treatment). Pyranometers of the CMA-11 type (Kipp & Zonen, Vaisala) were installed on columns of adjustable height in the centre of the 0.3 ha plots designated for albedo measurements. Data were collected using a Logbox SD (Kipp & Zonen, Vaisala) datalogger in the form of 10-minute means of samples taken every 6 seconds. BC pollution had no effect on maize growth and development. Compared with soot contaminated and control plants, we concluded that the LAI was a few percent higher in polluted plants, but this increment was not

  4. Development of Filter-Blower Unit for use in the Advanced Nuclear Biological Chemical Protection System (ANBCPS) Helicopter/Transport-aircraft version

    NARCIS (Netherlands)

    Sabel, R.; Reffeltrath, P.A.; Jonkman, A.; Post, T.

    2006-01-01

    As a participant in the three-nation partnership for development of the ANBCP-S for use in Helicopters, Transport Aircraft and Fast Jet, the Royal Netherlands Airforce (RNLAF) picked up the challenge to design a Filter- Blower-Unit (FBU). Major Command (MajCom) of the RNLAF set priority to develop a

  5. EC blowers for school building ventilation. Wholesome climate and high energy efficiency; EC-Ventilatoren fuer Schullueftungskonzepte. Gesundes Klima bei hoher Energieeffizienz

    Energy Technology Data Exchange (ETDEWEB)

    Salig, Andreas [ebm-papst, Mulfingen (Germany). Verkauf Inland; Grohmann, Erwin [Grohmann Lueftungstechnik GmbH, Forchtenberg (Germany); Reiff, Ellen-Christine [Redaktionsbuero Stutensee (Germany)

    2009-07-01

    Government funds of several thousands of millions were provided in 2009 for the modernisation of school buildings. There are highly flexible commercial ventilation and air conditioning systems for this type of buildings which combine energy savings with optimum room air quality. EC blowers contribute to this. (orig.)

  6. Emission, Structure and Optical Properties of Overfire Soot from Buoyant Turbulent Diffusion Flames

    Science.gov (United States)

    Koylu, Umit Ozgur

    The present study investigated soot and carbon monoxide emissions, and evaluated the optical properties of soot, in the overfire region of buoyant turbulent diffusion flames burning in still air. Soot and carbon monoxide emissions, and the corresponding correlation between these emissions, were studied experimentally. The optical properties of soot were investigated both experimentally and theoretically. The experiments involved gas (acetylene, propylene, ethylene, propane, methane) and liquid (toluene, benzene, n-heptane, iso-propanol, ethanol, methanol) fuels. The investigation was limited to the fuel-lean (overfire) region of buoyant turbulent diffusion flames burning in still air. Measurements included flame heights, characteristic flame residence times, carbon monoxide and soot concentrations, mixture fractions, ex-situ soot structure parameters (primary particle sizes, number of primary particles in aggregates, fractal dimensions), and in-situ optical cross sections (differential scattering, total scattering, and absorption) of soot in the overfire region of buoyant turbulent diffusion flames, emphasizing conditions in the long residence time regime where these properties are independent of position in the overfire region and flame residence time. The predictions of optical cross sections for polydisperse aggregates were based on Rayleigh-Debye-Gans theory for fractal aggregates; the predictions of this theory were evaluated by combining the TEM structure and the light scattering/extinction measurements. Carbon monoxide concentrations and mixture fractions were correlated in the overfire region of gas- and liquid -fueled turbulent diffusion flames. Soot volume fraction state relationships were observed for liquid fuels, supporting earlier observations for gas fuels. A strong correlation between carbon monoxide and soot concentrations was established in the fuel-lean region of both gas- and liquid-fueled turbulent diffusion flames. The structure and emission

  7. Understanding and predicting soot generation in turbulent non-premixed jet flames.

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hai (University of Southern California, Los Angeles, CA); Kook, Sanghoon; Doom, Jeffrey; Oefelein, Joseph Charles; Zhang, Jiayao; Shaddix, Christopher R.; Schefer, Robert W.; Pickett, Lyle M.

    2010-10-01

    This report documents the results of a project funded by DoD's Strategic Environmental Research and Development Program (SERDP) on the science behind development of predictive models for soot emission from gas turbine engines. Measurements of soot formation were performed in laminar flat premixed flames and turbulent non-premixed jet flames at 1 atm pressure and in turbulent liquid spray flames under representative conditions for takeoff in a gas turbine engine. The laminar flames and open jet flames used both ethylene and a prevaporized JP-8 surrogate fuel composed of n-dodecane and m-xylene. The pressurized turbulent jet flame measurements used the JP-8 surrogate fuel and compared its combustion and sooting characteristics to a world-average JP-8 fuel sample. The pressurized jet flame measurements demonstrated that the surrogate was representative of JP-8, with a somewhat higher tendency to soot formation. The premixed flame measurements revealed that flame temperature has a strong impact on the rate of soot nucleation and particle coagulation, but little sensitivity in the overall trends was found with different fuels. An extensive array of non-intrusive optical and laser-based measurements was performed in turbulent non-premixed jet flames established on specially designed piloted burners. Soot concentration data was collected throughout the flames, together with instantaneous images showing the relationship between soot and the OH radical and soot and PAH. A detailed chemical kinetic mechanism for ethylene combustion, including fuel-rich chemistry and benzene formation steps, was compiled, validated, and reduced. The reduced ethylene mechanism was incorporated into a high-fidelity LES code, together with a moment-based soot model and models for thermal radiation, to evaluate the ability of the chemistry and soot models to predict soot formation in the jet diffusion flame. The LES results highlight the importance of including an optically-thick radiation

  8. Soot measurements for diesel and biodiesel spray combustion under high temperature highly diluted ambient conditions

    KAUST Repository

    Zhang, Ji

    2014-11-01

    This paper presents the soot temperature and KL factor for biodiesel, namely fatty acid methyl ester (FAME) and diesel fuel combustion in a constant volume chamber using a two-color technique. The KL factor is a parameter for soot concentration, where K is an absorption coefficient and proportional to the number density of soot particles, L is the geometric thickness of the flame along the optical detection axis, and KL factor is proportional to soot volume fraction. The main objective is to explore a combustion regime called high-temperature and highly-diluted combustion (HTHDC) and compare it with the conventional and low-temperature combustion (LTC) modes. The three different combustion regimes are implemented under different ambient temperatures (800 K, 1000 K, and 1400 K) and ambient oxygen concentrations (10%, 15%, and 21%). Results are presented in terms of soot temperature and KL factor images, time-resolved pixel-averaged soot temperature, KL factor, and spatially integrated KL factor over the soot area. The time-averaged results for these three regimes are compared for both diesel and biodiesel fuels. Results show complex combined effects of the ambient temperature and oxygen concentration, and that two-color temperature for the HTHDC mode at the 10% oxygen level can actually be lower than the conventional mode. Increasing ambient oxygen and temperature increases soot temperature. Diesel fuel results in higher soot temperature than biodiesel for all three regimes. Results also show that diesel and biodiesel fuels have very different burning and sooting behavior under the three different combustion regimes. For diesel fuel, the HTHDC regime offers better results in terms of lower soot than the conventional and LTC regimes, and the 10% O2, 1400 K ambient condition shows the lowest soot concentration while maintaining a moderate two-color temperature. For biodiesel, the 15% O2, 800 K ambient condition shows some advantages in terms of reducing soot

  9. Characterization of Oxy-combustion Impacts in Existing Coal-fired Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Bradley; Davis, Kevin; Senior, Constance; Shim, Hong Shim; Otten, Brydger; Fry, Andrew; Wendt, Jost; Eddings, Eric; Paschedag, Alan; Shaddix, Christopher; Cox, William; Tree, Dale

    2013-09-30

    Reaction Engineering International (REI) managed a team of experts from University of Utah, Siemens Energy, Praxair, Vattenfall AB, Sandia National Laboratories, Brigham Young University (BYU) and Corrosion Management Ltd. to perform multi-scale experiments, coupled with mechanism development, process modeling and CFD modeling, for both applied and fundamental investigations. The primary objective of this program was to acquire data and develop tools to characterize and predict impacts of CO{sub 2} flue gas recycle and burner feed design on flame characteristics (burnout, NO{sub x}, SO{sub x}, mercury and fine particle emissions, heat transfer) and operational concerns (fouling, slagging and corrosion) inherent in the retrofit of existing coal-fired boilers for oxy-coal combustion. Experimental work was conducted at Sandia National Laboratories’ Entrained Flow Reactor, the University of Utah Industrial Combustion Research Facility, and Brigham Young University. Process modeling and computational fluid dynamics (CFD) modeling was performed at REI. Successful completion of the project objectives resulted in the following key deliverables: 1) Multi-scale test data from 0.1 kW bench-scale, 100 kW and 200 kW laboratory-scale, and 1 MW semi-industrial scale combustors that describe differences in flame characteristics, fouling, slagging and corrosion for coal combustion under air-firing and oxygen-firing conditions, including sensitivity to oxy-burner design and flue gas recycle composition. 2) Validated mechanisms developed from test data that describe fouling, slagging, waterwall corrosion, heat transfer, char burnout and sooting under coal oxy-combustion conditions. The mechanisms were presented in a form suitable for inclusion in CFD models or process models. 3) Principles to guide design of pilot-scale and full-scale coal oxy-firing systems and flue gas recycle configurations, such that boiler operational impacts from oxy-combustion retrofits are minimized. 4

  10. Modelling and simulating fire tube boiler performance

    DEFF Research Database (Denmark)

    Sørensen, K.; Condra, T.; Houbak, Niels; Karstensen, C.

    2003-01-01

    A model for a flue gas boiler covering the flue gas and the water-/steam side has been formulated. The model has been formulated as a number of sub models that are merged into an overall model for the complete boiler. Sub models have been defined for the furnace, the convection zone (split in 2: a...... zone submerged in water and a zone covered by steam), a model for the material in the boiler (the steel) and 2 models for resp. the water/steam zone (the boiling) and the steam. The dynamic model has been developed as a number of Differential-Algebraic-Equation system (DAE). Subsequently Mat......Lab/Simulink has been applied for carrying out the simulations. To be able to verify the simulated results experiments has been carried out on a full scale boiler plant....

  11. Modelling and simulating fire tube boiler performance

    DEFF Research Database (Denmark)

    Sørensen, Kim; Karstensen, Claus; Condra, Thomas Joseph; Houbak, Niels

    2003-01-01

    A model for a ue gas boiler covering the ue gas and the water-/steam side has been formulated. The model has been formulated as a number of sub models that are merged into an overall model for the complete boiler. Sub models have been dened for the furnace, the convection zone (split in 2: a zone...... submerged in water and a zone covered by steam), a model for the material in the boiler (the steel) and 2 models for resp. the water/steam zone (the boiling) and the steam. The dynamic model has been developed as a number of Differential-Algebraic- Equation system (DAE). Subsequently MatLab/Simulink has...... been applied for carrying out the simulations. To be able to verify the simulated results an experiments has been carried out on a full scale boiler plant....

  12. Application of a compliant foil bearing for the thrust force estimation in the single stage radial blower

    Science.gov (United States)

    Łagodzinski, Jakub; Miazga, Kacper; Musiał, Izabela

    2015-08-01

    The paper presents the application of a compliant foil bearing for estimation of the thrust force in a single stage radial blower under operational conditions. The bump foil of the thrust bearing behaves as a nonlinear spring. The knowledge of the spring deflection curve allows estimation of the actual thrust force for a measured bump deflection at the given rotational speed. To acquire the deflection curve, static calibration of the axial shaft displacement sensor was performed. During the calibration, the information about voltage signals of the sensor for the given loading force was collected. The measured voltage values at different speeds and loadswere then converted into the thrust force. The results were verified by comparison to the thrust force resulting from the pressure distribution on the impeller.

  13. Dewetting Process of Blast Furnace Blower%高炉鼓风机前脱湿技术

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      高炉脱湿鼓风是高炉节能的重要措施,并对高炉的稳定生产具有重要作用。对高炉鼓风机前脱湿的工艺和特点进行说明,并简述其在钢铁企业推广的意义。%Blast furnace dewetting blast is an important measure for energy conservation of blast furnace and it plays an important role in stabilizing production of blast furnace. The dewetting process and features of blast blower are described. The significance to popularize the process in steel enterprises is introduced briefly.

  14. Ecological boiler modernization, feasible energy solutions

    International Nuclear Information System (INIS)

    Alstom Power, s.r.o., ALSTOM GROUP in Brno, Czech Republic is a successor of PBS (First Brno Machine Works). PBS was a well-known company in Bulgaria - mainly as Heating Power Plant (HPP) and Industrial Plant supplier of boilers, industrial steam turbines, milling systems, heat exchangers Btc. PBS has been privatised in two stages starting at1993 year. Alstom recently deals with boiler and heat exchanger products. Industrial turbine but has been sold to Siemens in 2004

  15. Gas fired boilers and atmospheric pollution

    International Nuclear Information System (INIS)

    A general analysis concerning atmospheric pollution is presented: chemical composition and vertical distribution of atmosphere and pollutants, chemical reactions, ozone destruction and production cycles, COx, NOx and SOx pollutions. The gas fired boiler number and repartition in France are presented and the associated pollution is analyzed (CO2, CO, NOx) and quantified. Various pollution control technics concerning gas fired boiler pollutants are described and a pollution criterion for clean gas fired generators is proposed

  16. Removal of External Deposits on Boiler Tubes

    Directory of Open Access Journals (Sweden)

    C. P. De

    1970-07-01

    Full Text Available The superheater tubes in Port and Starboard boilers were found to have completely clogged by heavy deposits, which on analysis mainly vanadium pentoxide and sodium sulphmatter. The cleaning of the deposits was accomplished by alternate spraying with 15-20 per cent hydrogen peroxide and washing with hot water jets. Over the past two years, since the date of cleaning, the IN ship is operating without any trouble in the boilers.

  17. Boiler burden reduced at Bedford site.

    Science.gov (United States)

    Horsley, Chris

    2011-10-01

    With the NHS aiming to reduce its 2007 carbon footprint by 10% by 2015, Chris Horsley, managing director of Babcock Wanson UK, a provider of industrial boilers and burners, thermal oxidisers, air treatment, water treatment, and associated services, looks at how one NHS Trust has approached the challenge, and considerably reduced its carbon emissions, by refurbishing its boiler house and moving from oil to gas-fired steam generation. PMID:22049674

  18. Transients in a circulating fluidized bed boiler

    OpenAIRE

    Baskakov, A. P.; Munts, V. A.; Pavlyuk, E. Yu.

    2013-01-01

    Transients in a circulating fluidized bed boiler firing biomass are considered. An attempt is made to describe transients with the use of concepts applied in the automatic control theory. The parameters calculated from an analysis of unsteady heat balance equations are compared with the experimental data obtained in the 12-MW boiler of the Chalmers University of Technology. It is demonstrated that these equations describe the transient modes of operation with good accuracy. Dependences for ca...

  19. Laser-induced incandescence measurements of soot in turbulent pool fires

    International Nuclear Information System (INIS)

    We present what we believe to be the first application of the laser-induced incandescence (LII) technique to large-scale fire testing. The construction of an LII instrument for fire measurements is presented in detail. Soot volume fraction imaging from 2 m diameter pool fires burning blended toluene/methanol liquid fuels is demonstrated along with a detailed report of measurement uncertainty in the challenging pool fire environment. Our LII instrument relies upon remotely located laser, optical, and detection systems and the insertion of water-cooled, fiber-bundle-coupled collection optics into the fire plume. Calibration of the instrument was performed using an ethylene/air laminar diffusion flame produced by a Santoro-type burner, which allowed for the extraction of absolute soot volume fractions from the LII images. Single-laser-shot two-dimensional images of the soot layer structure are presented with very high volumetric spatial resolution of the order of 10-5 cm3. Probability density functions of the soot volume fraction fluctuations are constructed from the large LII image ensembles. The results illustrate a highly intermittent soot fluctuation field with potentially large macroscale soot structures and clipped soot probability densities.

  20. Numerical study on soot removal in partial oxidation of methane to syngas reactors

    Institute of Scientific and Technical Information of China (English)

    Weisheng; Wei; Tao; Zhang; Jian; Xu; Wei; Du

    2014-01-01

    The serious carbon deposition existing in catalytic partial oxidation of methane(CPOM) to syngas process is one of the key problems that impede its industrialization. In this study, 3-dimensional unsteady numerical simulations of the soot formation and oxidation in oxidation section in a heat coupling reactor were carried out by computational fluid dynamics(CFD) approach incorporating the Moss-Brookes model for soot formation. The model has been validated and proven to be in good agreement with experiment results. Effects of nozzle type,nozzle convergence angle, channel spacing, number of channels, radius/height ratio, oxygen/carbon ratio, preheat temperature and additional introduction of steam on the soot formation were simulated. Results show that the soot formation in oxidation section of the heat coupling reactor depends on both nozzle structures and operation conditions, and the soot concentration can be greatly reduced by optimization with the maximum mass fraction of soot inside the oxidation reactor from 2.28% to 0.0501%, and so that the soot mass fraction at the exit reduces from0.74% to 0.03%.

  1. Soot formation, transport, and radiation in unsteady diffusion flames : LDRD final report.

    Energy Technology Data Exchange (ETDEWEB)

    Suo-Anttila, Jill Marie (Sandia National Laboratories, Albuquerque, NM); Williams, Timothy C.; Shaddix, Christopher R.; Jensen, Kirk A. (Sandia National Laboratories, Albuquerque, NM); Blevins, Linda Gail; Kearney, Sean Patrick (Sandia National Laboratories, Albuquerque, NM); Schefer, Robert W.

    2004-10-01

    Fires pose the dominant risk to the safety and security of nuclear weapons, nuclear transport containers, and DOE and DoD facilities. The thermal hazard from these fires primarily results from radiant emission from high-temperature flame soot. Therefore, it is necessary to understand the local transport and chemical phenomena that determine the distributions of soot concentration, optical properties, and temperature in order to develop and validate constitutive models for large-scale, high-fidelity fire simulations. This report summarizes the findings of a Laboratory Directed Research and Development (LDRD) project devoted to obtaining the critical experimental information needed to develop such constitutive models. A combination of laser diagnostics and extractive measurement techniques have been employed in both steady and pulsed laminar diffusion flames of methane, ethylene, and JP-8 surrogate burning in air. For methane and ethylene, both slot and coannular flame geometries were investigated, as well as normal and inverse diffusion flame geometries. For the JP-8 surrogate, coannular normal diffusion flames were investigated. Soot concentrations, polycyclic aromatic hydrocarbon (PAH) laser-induced fluorescence (LIF) signals, hydroxyl radical (OH) LIF, acetylene and water vapor concentrations, soot zone temperatures, and the velocity field were all successfully measured in both steady and unsteady versions of these various flames. In addition, measurements were made of the soot microstructure, soot dimensionless extinction coefficient (&), and the local radiant heat flux. Taken together, these measurements comprise a unique, extensive database for future development and validation of models of soot formation, transport, and radiation.

  2. Soot properties and species measurements in a two-meter diameter JP-8 pool fire.

    Energy Technology Data Exchange (ETDEWEB)

    Shaddix, Christopher R.; Murphy, Jeffrey J.

    2003-06-01

    A tunable diode laser absorption spectroscopy probe was used to measure in situ soot properties and species concentrations in two-meter diameter JP-8 pool fires. Twelve tests were performed at the Lurance Canyon Bum Site operated by Sandia in Albuquerque, New Mexico. Seven of the tests were conducted with the probe positioned close to the centerline at heights above the pool surface ranging from 0.5 m to 2.0 mm in 0.25 m increments. For the remaining five tests, the probe was positioned at two heights 0.3 m from the centerline and at three heights 0.5 m from the centerline. Soot concentration was determined using a soot absorption measurement based on the transmission of a solid-state red laser (635 nm) through the 3.7 cm long probe volume. Soot temperature and a second estimate of soot concentration were measured using two-color optical pyrometry at 850 nm and la00 nm. The effective data rate for these measurements was 10 Mz. Finally, tunable diode laser absorption spectroscopy was used to qualitatively estimate water concentration at a rate of 1 kHz. To improve signal-to-noise, these data were averaged to an effective rate of 2 Hz. The results presented include the statistics, probability density functions, and spectral density functions of soot concentration, soot temperature, and approximate water concentrations at the different measurement locations throughout the fire.

  3. Optimizing electro-thermo Helds for soot oxidation using microwave heating and metal

    Science.gov (United States)

    Al-Wakeel, Haitham B.; Karim, Z. A. Abdul; Al-Kayiem, Hussain H.

    2015-04-01

    Soot is produced by incomplete combustion of various carbon-containing compounds. Soot is one of the main environmental pollutants and has become an important environmental and specific objective. To reduce soot from exhaust emission of diesel engine, a new technique is proposed and implemented by using metal inserted in the soot exposed to electromagnetic radiation. This paper presents a simulation to obtain optimum metal length and shape that give optimum electric field for attaining temperature enough for soot oxidation using microwave heating and a thin metal rod. Four cases were numerically examined to investigate the electric field and temperature distributions in a mono-mode TE10 microwave cavity having closed surfaces of perfect electric conductors. The operating frequency is 2.45 GHz, and power supply is 1500 W. The simulation methodology is coupling the absorbed electromagnetic energy with heat transfer energy. The absorbed electromagnetic energy is found from the electric field within the soot. The simulation was run using ANSYS based on finite element method. The results of the four simulation cases show that the optimum simulation is represented by case 2 where the value of electric field is 39000 V/m and heating time to arrive at the oxidation temperature (873 K) is 35 s using cylindrical metal rod of 8 mm length. It is revealed that the concept of achieving high temperature for soot oxidation by using thin metal rod inside a microwave cavity can be applied.

  4. Asymptotic analysis soot model and experiment for a directed injection engine

    Science.gov (United States)

    Liu, Yongfeng; Pei, Pucheng; Xiong, Qinghui; Lu, Yong

    2012-09-01

    The existing soot models are either too complex and can not be applied to the internal combustion engine, or too simple to make calculation errors. Exploring the soot model becomes the pursuit of the goal of many researchers within the error range in the current computer speed. On the basis of the latest experimental results, TP (temperature phases) model is presented as a new soot model to carry out optimization calculation for a high-pressure common rail diesel engine. Temperature and excess air factor are the most important two parameters in this model. When zone temperature T0.6, only the soot precursors—polycyclic aromatic hydrocarbons(PAH) is created and there is no soot emission. When zone temperature T ⩾ 1 500 K and excess air factor ΦKIVA code instead of original model to carry out optimizing. KIVA standard model and experimental data are analyzed for the results of cylinder pressures, the corresponding heat release rates, and soot with variation of injection time, variation of rail pressure and variation of speed among TP models. The experimental results indicate that the TP model can carry out optimization and computational fluid dynamics can be a tool to calculate for a high-pressure common rail directed injection diesel engine. The TP model result is closer than the use of the original KIVA-3V results of soot model accuracy by about 50% and TP model gives a new method for engine researchers.

  5. Quantifying uncertainty in soot volume fraction estimates using Bayesian inference of auto-correlated laser-induced incandescence measurements

    Science.gov (United States)

    Hadwin, Paul J.; Sipkens, T. A.; Thomson, K. A.; Liu, F.; Daun, K. J.

    2016-01-01

    Auto-correlated laser-induced incandescence (AC-LII) infers the soot volume fraction (SVF) of soot particles by comparing the spectral incandescence from laser-energized particles to the pyrometrically inferred peak soot temperature. This calculation requires detailed knowledge of model parameters such as the absorption function of soot, which may vary with combustion chemistry, soot age, and the internal structure of the soot. This work presents a Bayesian methodology to quantify such uncertainties. This technique treats the additional "nuisance" model parameters, including the soot absorption function, as stochastic variables and incorporates the current state of knowledge of these parameters into the inference process through maximum entropy priors. While standard AC-LII analysis provides a point estimate of the SVF, Bayesian techniques infer the posterior probability density, which will allow scientists and engineers to better assess the reliability of AC-LII inferred SVFs in the context of environmental regulations and competing diagnostics.

  6. Assessment of physical workload in boiler operations.

    Science.gov (United States)

    Rodrigues, Valéria Antônia Justino; Braga, Camila Soares; Campos, Julio César Costa; Souza, Amaury Paulo de; Minette, Luciano José; Sensato, Guilherme Luciano; Moraes, Angelo Casali de; Silva, Emília Pio da

    2012-01-01

    The use of boiler wood-fired is fairly common equipment utilized in steam generation for energy production in small industries. The boiler activities are considered dangerous and heavy, mainly due to risks of explosions and the lack of mechanization of the process. This study assessed the burden of physical labor that operators of boilers are subjected during the workday. Assessment of these conditions was carried out through quantitative and qualitative measurements. A heart rate monitor, a wet-bulb globe thermometer (WBGT), a tape-measure and a digital infrared camera were the instruments used to collect the quantitative data. The Nordic Questionnaire and the Painful Areas Diagram were used to relate the health problems of the boiler operator with activity. With study, was concluded that the boiler activity may cause pains in the body of intensity different, muscle fatigue and diseases due to excessive weight and the exposure to heat. The research contributed to improve the boiler operator's workplace and working conditions. PMID:22316759

  7. Experimental and numerical study on soot formation and oxidation by using diesel fuel in constant volume chamber with various ambient oxygen concentrations

    International Nuclear Information System (INIS)

    Highlights: • Improved soot model reproduced soot formation/oxidation at various O2 concentrations. • C2H2, precursor and soot mass increased with decreasing O2 but decreased at 12% O2. • The total area of soot reaction zone shrank remarkably at 12% oxygen. • Higher soot was from stronger formation at 18% O2 but from weaker oxidation at 15%. • The suppressed soot inception at lower O2 led to the retarded and reduced soot mass. - Abstract: The study on effects of exhaust gas recirculation (EGR) on soot behavior is very important to reduce soot emissions and control the low temperature combustion process in diesel engines. In this work, high time-resolved quantitative soot measurements were experimented on a constant volume chamber by using European low-sulfur diesel fuel at three ambient oxygen concentrations (21%, 18%, 15%). Meanwhile, an improved semi-empirical soot model was coupled into computational fluid dynamics (KIVA-3V Release 2) code for in-depth understanding the soot formation and oxidation processes. Results demonstrated that numerical results of the improved semi-empirical soot model showed good agreement with experimental data in the whole processes of soot formation/oxidation and soot distribution under different oxygen concentrations. The mass concentration of acetylene, soot precursor species and soot mass initially increased with decreasing ambient oxygen concentrations from 21% to 15% and then began to decrease at 12% oxygen, while OH radicals reduced monotonically from 21% oxygen to 12%. At 12% oxygen, the concentrations of local rich sooty zone, acetylene and soot precursor species were as high as those under higher oxygen concentrations, but the total area of soot zone shrank remarkably at 12% oxygen. Compared to 21% ambient oxygen concentration, both soot formation and oxidation rates were increased under 18% oxygen, while the higher soot mass under 18% oxygen was the result of stronger soot formation mechanism. At 15% oxygen, both

  8. Damköhler number effects on soot formation and growth in turbulent nonpremixed flames

    KAUST Repository

    Attili, Antonio

    2015-01-01

    The effect of Damköhler number on turbulent nonpremixed sooting flames is investigated via large scale direct numerical simulation in three-dimensional n-heptane/air jet flames at a jet Reynolds number of 15,000 and at three different Damköhler numbers. A reduced chemical mechanism, which includes the soot precursor naphthalene, and a high-order method of moments are employed. At the highest Damköhler number, local extinction is negligible, while flames holes are observed in the two lowest Damköhler number cases. Compared to temperature and other species controlled by fuel oxidation chemistry, naphthalene is found to be affected more significantly by the Damköhler number. Consequently, the overall soot mass fraction decreases by more than one order of magnitude for a fourfold decrease of the Damköhler number. On the contrary, the overall number density of soot particles is approximately the same, but its distribution in mixture fraction space is different in the three cases. The total soot mass growth rate is found to be proportional to the Damköhler number. In the two lowest Da number cases, soot leakage across the flame is observed. Leveraging Lagrangian statistics, it is concluded that soot leakage is due to patches of soot that cross the stoichiometric surface through flame holes. These results show the leading order effects of turbulent mixing in controlling the dynamics of soot in turbulent flames. © 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

  9. The Influences of Electric Fields on Soot Formation and Flame Structure of Diffusion Flames

    Institute of Scientific and Technical Information of China (English)

    LinXie; TakeyukiKishi; 等

    1993-01-01

    The influences of DC and AC electric fields,at frequencies up to 1.48 MHz and the maximum strength of about 6 kV/cm,on soot formation and flame structure were investigated using a counterflow type acetylene diffusion flame.The distributioons of flame luminosity,soot volume fraction,Flame temperature and OH concentration in flame were measured by non-invasive detection methods.Under the influence of electric fields,the changes in distribution of the soot volume fraction were confirmed.Electric fields of high frequency and high intensity reduced the soot volume fraction.whereas other electric fields increased it.The maximum values of flame temperature and OH concentration decreased.In the relationship between the maximum value of the soot volume fraction and the maximum temperature,the maximum soot volum fraction showed toth increase and decrease with maximum temperatures depending on the frequencies and intensities of the electric fields,and both of them occurred at temperatures lower than 1990 K.The production of the incipient particles seemed to be the dominant process controlling the soot volume fraction due to the electric fields.The luminosity of a sooting diffusion flame was found to depend on the volume fraction and temperature of the soot particles in the flame,As for the behavior of the flame in the electric fields.the ionic wind effect was not found to be dominant in the present work,and the result of the precious simulation based on the ionic wind theory was not consistent with the present experimental results.

  10. Simultaneous removal of soot and nitrogen oxides from diesel engine exhausts

    Energy Technology Data Exchange (ETDEWEB)

    Pisarello, M.L.; Milt, V.; Peralta, M.A.; Querini, C.A.; Miro, E.E. [INCAPE, CONICET, Fac. Ingenieria Quimica, UNL, Santiago del Estero 2829, 3000 Santa Fe (Argentina)

    2002-07-03

    In this paper, previously reported findings and new results presented here are discussed with the main objective of establishing the reaction mechanism for soot oxidation on different supports and catalysts formulations. Catalysts containing Co, K and/or Ba supported on MgO, La{sub 2}O{sub 3} and CeO{sub 2} have been studied for diesel soot catalytic combustion. Among them, K/La{sub 2}O{sub 3} and K/CeO{sub 2} showed the best activity and stability for the combustion of soot with oxygen. A reaction mechanism involving the redox sites and the surface-carbonate species takes place on these catalysts. On the other hand, Co,K/La{sub 2}O{sub 3} and Co,K/CeO{sub 2} catalysts display activity for the simultaneous removal of soot and nitric oxide. The soot-catalyst contacting phenomenon was also addressed. A synergic La-K effect was observed in which the mechanical mixtures of soot with K-La{sub 2}O{sub 3} showed higher combustion rates than those observed when K and La were directly deposited on the soot surface. The effect of the addition of Ba was explored with the aim of promoting the interaction of the solid with NO{sub 2}, thus combining the NO{sub x} catalytic trap concept with the soot combustion for filter regeneration. Ba/CeO{sub 2} and Ba,K/CeO{sub 2} were effective in NO{sub x} absorption as shown in the microbalance experiments. However, the formation of stable nitrate species inhibits the soot combustion reaction.

  11. Is Carbon Black a Suitable Model Colloidal Substrate for Diesel Soot?

    Science.gov (United States)

    Growney, David J; Mykhaylyk, Oleksandr O; Middlemiss, Laurence; Fielding, Lee A; Derry, Matthew J; Aragrag, Najib; Lamb, Gordon D; Armes, Steven P

    2015-09-29

    Soot formation in diesel engines is known to cause premature engine wear. Unfortunately, genuine diesel soot is expensive to generate, so carbon blacks are often used as diesel soot mimics. Herein, the suitability of a commercial carbon black (Regal 250R) as a surrogate for diesel soot dispersed in engine base oil is examined in the presence of two commonly used polymeric lubricant additives. The particle size, morphology, and surface composition of both substrates are assessed using BET surface area analysis, TEM, and XPS. The extent of adsorption of a poly(ethylene-co-propylene) (dOCP) statistical copolymer or a polystyrene-block-poly(ethylene-co-propylene) (PS-PEP) diblock copolymer onto carbon black or diesel soot from n-dodecane is compared indirectly using a supernatant depletion assay technique via UV spectroscopy. Thermogravimetric analysis is also used to directly determine the extent of copolymer adsorption. Degrees of dispersion are examined using optical microscopy, TEM, and analytical centrifugation. SAXS studies reveal some structural differences between carbon black and diesel soot particles. The mean radius of gyration determined for the latter is significantly smaller than that calculated for the former, and in the absence of any copolymer, diesel soot suspended in n-dodecane forms relatively loose mass fractals compared to carbon black. SAXS provides evidence for copolymer adsorption and indicates that addition of either copolymer transforms the initially compact agglomerates into relatively loose aggregates. Addition of dOCP or PS-PEP does not significantly affect the structure of the carbon black primary particles, with similar results being observed for diesel soot. In favorable cases, remarkably similar data can be obtained for carbon black and diesel soot when using dOCP and PS-PEP as copolymer dispersants. However, it is not difficult to identify simple copolymer-particle-solvent combinations for which substantial differences can be observed

  12. Visualization of sooting field in an emulsion droplet flame by using microgravity environment; Bisho juryoku kankyo wo riyoshita nyuka nenryo ekiteki kaennai susu nodoba no kashika

    Energy Technology Data Exchange (ETDEWEB)

    Segawa, D.; Kadota, T. [University of Osaka Prefecture, Osaka (Japan). Faculty of Engineering; Tsue, M.; Kono, M. [The University of Tokyo, Tokyo (Japan); Yamasaki, H. [Ehime Univ., Ehime (Japan). Faculty of Education

    1999-07-25

    Sooting field in a flame formed around a suspended droplet was visualized under microgravity using the planar laser light scattering technique. The soot concentration and the instantaneous soot amount were approximately estimated from the intensity of the scattered light using the image analysis system. The fuels employed were water-in-oil emulsions composed of n-dodecane, water and surfactant. The water content was varied from 0 to 0.2 in volume. A soot layer which was concentric with the droplet was observed inside the luminous flame. The results show the unsteadiness of the sooting behavior as well as the flame behavior. The maximum of the soot concentration is located near the inner edge of the soot layer. The time history of the instantaneous soot amount is similar to that of the instantaneous flame radius. The maximum of the soot concentration does not vary with the water content, while the soot amount decreases significantly with the water emulsification. (author)

  13. Subsonic aircraft soot. A tracer documenting barriers to inter-hemispheric mixing

    Energy Technology Data Exchange (ETDEWEB)

    Pueschel, R.F. [NASA Ames Research Center, Moffett Field, CA (United States)

    1997-12-31

    Meridional observations of soot aerosols and radioactive {sup 14}C, and models of the geographic distribution of nuclear bomb-released {sup 14}C and aircraft-emitted NO{sub x}, all show strong gradients between the hemispheres. Reason for it are decade-long inter-hemispheric mixing times which are much in excess of yearlong stratospheric residence times of tracers. Vertical mixing of soot aerosol is not corroborated by {sup 14}C observations. The reason could be radiometric forces that act on strongly absorbing soot. (author) 10 refs.

  14. Effect of aging on morphology, hygroscopicity, and optical properties of soot aerosol

    Science.gov (United States)

    Khalizov, A. F.; Xue, H.; Pagels, J.; McMurry, P. H.; Zhang, R.

    2009-12-01

    Soot from incomplete combustion represents one of the major forms of particulate matter pollution, profoundly impacting human health, air quality, and climate. The direct and indirect radiative effects of soot aerosol depend on particle composition and morphology, which may vary significantly when aerosol is subjected to atmospheric aging. We will present an overview of a comprehensive set of experimental measurements performed in our laboratory at Texas A&M to study the effect of internal mixing with atmospheric species on morphology, hygroscopicity, and optical properties of combustion soot. In our experiments, size-classified soot aerosol was exposed to 0.1 - 1000 ppb (part per billion) mixing ratios of sulfuric acid and dicarboxylic organic acids and resulting changes particle morphology and mixing state under dry and humid conditions were characterized through mass-mobility measurements by aerosol particle mass analyzer (APM) and tandem differential mobility analyzer (TDMA). Light absorption and scattering cross-sections for well-characterized fresh and coated soot aerosol were derived using a cavity ring-down spectrometer and an integrating nephelometer in order to assess the effect of atmospheric processing on the radiative properties of atmospheric soot. Internally mixed soot shows significant changes in particle morphology, increasing with the mass fraction of the coating material and relative humidity. Restructuring was the strongest for aggregates coated by sulfuric and glutaric acids whereas succinic acid coating did not result in observable morphology change. Sulfuric acid - coated particles experienced large hygroscopic growth at sub-saturated conditions and activated to cloud droplets at atmospherically relevant supersaturations. Furthermore, coating and subsequent hygroscopic growth considerably altered the optical properties of soot aerosol, increasing light scattering and absorption cross-sections. We found that irreversible restructuring of soot

  15. Study of diesel combustion and soot formation as observed by high-speed photography; Kosokudo satsuei ni yoru diesel kikan no nensho oyobi soot seisei ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Shioji, M.; Yamane, K.; Ikegami, M. [Kyoto University, Kyoto (Japan). Faculty of Engineering; Ito, S. [Nippon Steel Corp., Tokyo (Japan)

    1995-01-25

    In order to contribute to reduction of soot formation in diesel engines, processes of combustion and the soot formation at a low engine speed were studied, especially surveying the effectiveness of high-pressure injection in detail. The experiment was performed by a direct-injection engine and a specially designed injection system with a high-pressure device by fast hydraulic acceleration of spool. The behavior of flames was observed by high-speed photographs, and the processes of combustion and soot formation were compared with the rates of heat release. The distribution of soot particles in the combustion space was observed by the photograph and a laser-light sheet method at various injection pressures and nozzle diameters. The results obtained were as follows: On the condition of high injection pressure and explosive combustion, luminosity of flames over the combustion space is stronger and the luminosity fluctuation becomes less as the injection pressure increases. On the condition of high pressure and small nozzle diameter, soot clouds are observed only in the middle part of combustion process but disappear in the latter. 8 refs., 9 figs.

  16. Research and design of 330 MW circulating fluidized bed boiler

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xianbin; Shi, Zhenghai; Huang, Zhong [Thermal Power Research Institute, Xi' an (China); Jiang, Minhua [China Huaneg Group, Beijing (China); Yu, Long; Zhang, Yanjun; Wang, Fengjun; Zhang, Man [Harbin Boiler CO., Ltd, Harbin (China)

    2013-07-01

    Based on research and manufacture of 210MW circulating fluidized bed (CFB) boiler, the key technologies of large CFB boiler have been Research, the plan design of 330MW CFB boiler have been performed, construction design of key components and scaling up characteristics were analysed, The 330MW CFB boiler designed demonstration project has been put into commercial operation, It is the largest capacity CFB boiler operated in china now, Operation of 330MW CFB boiler was stable and good performance has been proved.

  17. Characterization of model boiler specimens

    International Nuclear Information System (INIS)

    This paper describes the general results of an investigation of three crevice corrosion samples provided by Westinghouse from the S112-1 Model Boiler Program. These samples had all been formed under essentially the same initial chemical conditions, but two had been treated with inhibitors at the end of the experimental runs. The first received no neutralization during the model runs, the second was treated with Ca(OH)2 and the third was treated with boric acid. The samples were prepared for examination in several different ways. The samples were characteristic of dented intersections and had the general conformation of a thin-walled inner Inconel cylinder within a thick-walled carbon steel cylinder. An original 12-mil inter-cylinder gap had been packed with powdered magnetite. This magnetite had been augmented by further growth of magnetite during the model runs, making the oxide layer considerably thicker than the original 12-mils in some areas of the samples. The cylinders were sectioned and polished perpendicular to their long axes and the resulting surfaces examined

  18. Facile preparation of superhydrophobic candle soot coating and its wettability under condensation

    Science.gov (United States)

    Yuan, Zhiqing; Huang, Juan; Peng, Chaoyi; Wang, Menglei; Wang, Xian; Bin, Jiping; Xing, Suli; Xiao, Jiayu; Zeng, Jingcheng; Xiao, Ximei; Fu, Xin; Gong, Huifang; Zhao, Dejian; Chen, Hong

    2016-02-01

    A facile method was developed to prepare a superhydrophobic candle soot coating by burning candle and simple deposition on a low-density polyethylene substrate. The water contact angle and sliding angle of the as-prepared superhydrophobic candle soot coating were, respectively, 160 ± 2° and 1° under common condition. ESEM images showed that the superhydrophobic candle soot coating was comprised of many nanoparticles with the size range of about 30-50 nm. After condensation for 30 min, the average contact angle of the condensed water droplets was 150° ± 2°, showing excellent superhydrophobicity under condensation. The mechanism of the candle soot coating remaining superhydrophobicity under condensation was analyzed. This work is helpful for the design and preparation of superhydrophobic surface which can remain superhydrophobicity in future.

  19. The influence of gravity levels on soot formation for the combustion of ethylene-air mixture

    Science.gov (United States)

    Zhang, Y.; Liu, D.; Li, S.; Li, Y.; Lou, C.

    2014-12-01

    The reduced mechanism coupled with 2D flame code using CHEMKIN II to investigate the effect of gravity on flame structure and soot formation in diffusion flames. The results show that the gravity has a rather significant effect on flame structure and soot formation. The visible flame height and peak soot volume fraction in general increases with the gravity from 1 g decreased to 0 g. The peak flame temperature decreases with decreasing gravity level. Comparing the calculated results from 1 g to 0 g, the flame shape becomes wider, the high temperature zone becomes shorter, the mixture velocity has a sharp decrease, the soot volume fraction has a sharp increase and CO and unprovided species distribution becomes wider along radial direction. At normal and half gravity, the flame is buoyancy controlled and the axial velocity is largely independent of the coflow air velocity. At microgravity (0 g), the flame is momentum controlled.

  20. The effect of oxygenate molecular structure on soot production in direct-injection diesel engines.

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, Charles K. (Lawrence Livermore National Laboratory, Livermore, CA); Pitz, William J. (Lawrence Livermore National Laboratory, Livermore, CA); Mueller, Charles J.; Martin, Glen M.; Pickett, Lyle M.

    2003-06-01

    A combined experimental and kinetic modeling study of soot formation in diesel engine combustion has been used to study the addition of oxygenated species to diesel fuel to reduce soot emissions. This work indicates that the primary role of oxygen atoms in the fuel mixture is to reduce the levels of carbon atoms available for soot formation by fixing them in the form of CO or COz. When the structure of the oxygenate leads to prompt and direct formation of CO2, the oxygenate is less effective in reducing soot production than in cases when all fuel-bound 0 atoms produce only CO. The kinetic and molecular structure principles leading to this conclusion are described.

  1. Soot Formation Modeling of n-dodecane and Diesel Sprays under Engine-Like Conditions

    DEFF Research Database (Denmark)

    Pang, Kar Mun; Poon, Hiew Mun; Ng, Hoon Kiat; Gan, Suyin; Schramm, Jesper

    2015-01-01

    This work concerns the modelling of soot formation process in diesel spray combustion under engine-like conditions. The key aim is to investigate the soot formation characteristics at different ambient temperatures. Prior to simulating the diesel combustion, numerical models including a revised...... multi-step soot model is validated by comparing to the experimental data of n-dodecane fuel in which the associated chemistry is better understood. In the diesel spray simulations, a single component n-heptane mechanism and the multi-component Diesel Oil Surrogate (DOS) model are adopted. A newly...... without toluene chemistry is approximately two-fold. Improvement is observed when toluene chemistry is considered, producing ratios of greater than 3.7. This can be attributed to the higher amount of soot precursor and surface growth species formed through the toluene oxidation pathways in the 1000 K case...

  2. Laser-Induced Emissions Sensor for Soot Mass in Rocket Plumes Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A method is proposed to measure soot mass concentration non-intrusively from a distance in a rocket engine exhaust stream during ground tests using laser-induced...

  3. Time-resolved LII signals from aggregates of soot particles levitated in room temperature air

    CERN Document Server

    Mitrani, James M

    2015-01-01

    We observed and modeled time-resolved laser-induced incandescence (LII) signals from soot aggregates. Time-resolved LII signals were observed from research-grade soot particles, levitated in room temperature air. We were able to measure sizes and structural properties of our soot particles ex situ, and use those measurements as input parameters when modeling the observed LII signals. We showed that at low laser fluences, aggregation significantly influences LII signals by reducing conductive cooling to the ambient air. At moderate laser fluences, laser-induced disintegration of aggregates occurs, so the effects of aggregation on LII signals are negligible. These results can be applied to extend LII for monitoring formation of soot and nanoparticle aggregates.

  4. Instabilities and soot formation in spherically expanding, high pressure, rich, iso-octane-air flames

    Energy Technology Data Exchange (ETDEWEB)

    Lockett, R D [School of Engineering and Mathematical Sciences, City University, Northampton Square, London EC1V OHB (United Kingdom)

    2006-07-15

    Flame instabilities, cellular structures and soot formed in high pressure, rich, spherically expanding iso-octane-air flames have been studied experimentally using high speed Schlieren cinematography, OH fluorescence, Mie scattering and laser induced incandescence. Cellular structures with two wavelength ranges developed on the flame surface. The larger wavelength cellular structure was produced by the Landau-Darrieus hydrodynamic instability, while the short wavelength cellular structure was produced by the thermal-diffusive instability. Large negative curvature in the short wavelength cusps caused local flame quenching and fracture of the flame surface. In rich flames with equivalence ratio {phi} > 1.8, soot was formed in a honeycomb-like structure behind flame cracks associated with the large wavelength cellular structure induced by the hydrodynamic instability. The formation of soot precursors through low temperature pyrolysis was suggested as a suitable mechanism for the initiation of soot formation behind the large wavelength flame cracks.

  5. Soot Structure and Reactivity Analysis by Raman Microspectroscopy, Temperature-Programmed Oxidation, and High-Resolution Transmission Electron Microscopy

    Science.gov (United States)

    Knauer, Markus; Schuster, Manfred E.; Su, Dangsheng; Schlögl, Robert; Niessner, Reinhard; Ivleva, Natalia P.

    2009-11-01

    Raman microspectroscopy (RM), temperature-programmed oxidation (TPO), high-resolution transmission electron microscopy (HRTEM), and electron energy loss spectroscopy (EELS) were combined to get comprehensive information on the relationship between structure and reactivity of soot in samples of spark discharge (GfG), heavy duty engine diesel (EURO VI and IV) soot, and graphite powder upon oxidation by oxygen at increasing temperatures. GfG soot and graphite powder represent the higher and lower reactivity limits. Raman microspectroscopic analysis was conducted by determination of spectral parameters using a five band fitting procedure (G, D1-D4) as well as by evaluation of the dispersive character of the D mode. The analysis of spectral parameters shows a higher degree of disorder and a higher amount of molecular carbon for untreated GfG soot samples than for samples of untreated EURO VI and EURO IV soot. The structural analysis based on the dispersive character of the D mode revealed substantial differences in ordering descending from graphite powder, EURO IV, VI to GfG soot. HRTEM images and EELS analysis of EURO IV and VI samples indicated a different morphology and a higher structural order as compared to GfG soot in full agreement with the Raman analysis. These findings are also confirmed by the reactivity of soot during oxidation (TPO), where GfG soot was found to be the most reactive and EURO IV and VI soot samples exhibited a moderate reactivity.

  6. Influence of thermal radiation on soot production in Laminar axisymmetric diffusion flames

    International Nuclear Information System (INIS)

    The aim of this paper is to study the effect of radiative heat transfer on soot production in laminar axisymmetric diffusion flames. Twenty-four C1–C3 hydrocarbon–air flames, consisting of normal (NDF) and inverse (IDF) diffusion flames at both normal gravity (1 g) and microgravity (0 g), and covering a wide range of conditions affecting radiative heat transfer, were simulated. The numerical model is based on the Steady Laminar Flamelet (SLF) model, a semi-empirical two-equation acetylene/benzene based soot model and the Statistical Narrow Band Correlated K (SNBCK) model coupled to the Finite Volume Method (FVM) to compute thermal radiation. Predictions relative to velocity, temperature, soot volume fraction and radiative losses are on the whole in good agreement with the available experimental data. Model results show that, for all the flames considered, thermal radiation is a crucial process with a view to providing accurate predictions for temperatures and soot concentrations. It becomes increasingly significant from IDFs to NDFs and its influence is much greater as gravity is reduced. The radiative contribution of gas prevails in the weakly-sooting IDFs and in the methane and ethane NDFs, whereas soot radiation dominates in the other flames. However, both contributions are significant in all cases, with the exception of the 1 g IDFs investigated where soot radiation can be ignored. The optically-thin approximation (OTA) was also tested and found to be applicable as long as the optical thickness, based on flame radius and Planck mean absorption coefficient, is less than 0.05. The OTA is reasonable for the IDFs and for most of the 1 g NDFs, but it fails to predict the radiative heat transfer for the 0 g NDFs. The accuracy of radiative-property models was then assessed in the latter cases. Simulations show that the gray approximation can be applied to soot but not to combustion gases. Both the non-gray and gray soot versions of the Full Spectrum Correlated k

  7. Physicochemical properties and atmospheric ageing of soot - investigated though aerosol mass spectrometry

    OpenAIRE

    Eriksson, Axel

    2015-01-01

    Aerosol particles contribute significantly to the global burden of disease, and remain the main source of uncertainty in assessments of human-induced climate change. The microphysical characterization of particles is necessary to understand the roles they play in the detrimental effects of air pollution on human health, and in the energy budget of our planet. Soot particles are especially relevant for climate and health, but the main component of soot – black carbon – is uniquely challengi...

  8. The excited states of the neutral and ionized carbon in the regenerative sooting discharges

    International Nuclear Information System (INIS)

    We report the mechanisms of production and the state of excitation of the neutral and singly charged monatomic carbon in the regenerative soot as a function of the discharge parameters in graphite hollow cathode (HC) sources. Two distinctly different source configurations have been investigated. Comparisons of the level densities of various charged states of C1 have identified the regenerative properties of the C radicals in graphite HC soot

  9. Effect of fractal parameters on absorption properties of soot in the infrared region

    International Nuclear Information System (INIS)

    Absorption coefficient of soot aggregates in the infrared region is investigated using multi-sphere T matrix algorithm. As the refractive index of soot is relatively high, the interaction between neighboring particles is important and Rayleigh approximation is invalid. The absorption cross section of soot is much higher than the Rayleigh approximation prediction. The effect of fractal parameters, dimension Df and prefactor kf, on absorption can be substantial and varies strongly with optical size parameter x and refractive index m. Families of fractal structures having similar absorption cross sections have been identified. It is noted that the fractal structures from the same family have similar particle distance correlation functions. Following this, an empirical model for absorption of soot as a function of m, x and fractal parameters has been developed. The model successfully predicts the absorption within ±5% for various fractal structures. Compared to Rayleigh approximation, the absorption enhancement can be as high as 200% at low temperatures and 120% at high temperatures. Effects of fractal parameters on absorption enhancement are important for low temperature applications but are not significant at high temperatures. This is mainly due to high refractive indices of soot at long wavelengths and shift of emitted radiation towards short wavelengths with increase in temperature. - Highlights: • Absorption of soot in the IR is investigated using MSTM method. • Absorption properties are discussed in terms of morphology of soot aggregates. • An empirical model for absorption of soot in the IR has been developed. • The model predicts absorption within ±5% for various fractal parameters

  10. Soot microphysical effects on liquid clouds, a multi-model investigation

    Energy Technology Data Exchange (ETDEWEB)

    Koch, D; Balkanski, Y; Bauer, S; Easter, Richard C; Ferrachat, S; Ghan, Steven J; Hoose, C; Iversen, T; Kirkevag, A; Kristjansson, J E; Liu, Xiaohong; Lohmann, U; Menon, Surabi; Quaas, J; Schulz, M; Seland, O; Takemura, T; Yan, N

    2011-02-10

    We use global models to explore the microphysical effects of carbonaceous aerosols on liquid clouds. Although absorption of solar radiation by soot warms the atmosphere, soot may cause climate cooling due to its contribution to cloud condensation nuclei (CCN) and therefore cloud brightness. Six global models conducted three soot experiments; four of the models had detailed aerosol microphysical schemes. The average cloud radiative response to biofuel soot (black and organic carbon), including both indirect and semi-direct effects, is -0.11Wm-2, comparable in size but opposite in sign to the respective direct effect. In a more idealized fossil fuel black carbon experiment, some models calculated a positive cloud response because soot provides a deposition sink for sulfuric and nitric acids and secondary organics, decreasing nucleation and evolution of viable CCN. Biofuel soot particles were also typically assumed to be larger and more hygroscopic than for fossil fuel soot and therefore caused more negative forcing, as also found in previous studies. Diesel soot (black and organic carbon) experiments had relatively smaller cloud impacts with five Correspondence to: D. Koch (dorothy.koch@science.doe.gov) of the models <±0.06Wm-2 from clouds. The results are subject to the caveats that variability among models, and regional and interrannual variability for each model, are large. This comparison together with previously published results stresses the need to further constrain aerosol microphysical schemes. The non-linearities resulting from the competition of opposing effects on the CCN population make it difficult to extrapolate from idealized experimen

  11. Measurements of Soot Mass Absorption Coefficients from 300 to 660 nm

    Science.gov (United States)

    Renbaum-Wolff, Lindsay; Fisher, Al; Helgestad, Taylor; Lambe, Andrew; Sedlacek, Arthur; Smith, Geoffrey; Cappa, Christopher; Davidovits, Paul; Onasch, Timothy; Freedman, Andrew

    2016-04-01

    Soot, a product of incomplete combustion, plays an important role in the earth's climate system through the absorption and scattering of solar radiation. In particular, the assumed mass absorption coefficient (MAC) of soot and its variation with wavelength presents a significant uncertainty in the calculation of radiative forcing in global climate change models. As part of the fourth Boston College/Aerodyne soot properties measurement campaign, we have measured the mass absorption coefficient of soot produced by an inverted methane diffusion flame over a spectral range of 300-660 nm using a variety of optical absorption techniques. Extinction and absorption were measured using a dual cavity ringdown photoacoustic spectrometer (CRD-PAS, UC Davis) at 405 nm and 532 nm. Scattering and extinction were measured using a CAPS PMssa single scattering albedo monitor (Aerodyne) at 630 nm; the absorption coefficient was determined by subtraction. In addition, the absorption coefficients in 8 wavelength bands from 300 to 660 nm were measured using a new broadband photoacoustic absorption monitor (UGA). Soot particle mass was quantified using a centrifugal particle mass analyzer (CPMA, Cambustion), mobility size with a scanning mobility particle sizer (SMPS, TSI) and soot concentration with a CPC (Brechtel). The contribution of doubly charged particles to the sample mass was determined using a Single Particle Soot Photometer (DMT). Over a mass range of 1-8 fg, corresponding to differential mobility diameters of ~150 nm to 550 nm, the value of the soot MAC proved to be independent of mass for all wavelengths. The wavelength dependence of the MAC was best fit to a power law with an Absorption Ångstrom Coefficient slightly greater than 1.

  12. Effects of ambient oxygen concentration on soot temperature and concentration for biodiesel and diesel spray combustion

    KAUST Repository

    Zhang, Ji

    2015-06-01

    Ambient oxygen concentration, a key variable directly related to exhaust gas recirculation (EGR) levels in diesel engines, plays a significant role in particulate matter (PM) and nitrogen oxides (NOx) emissions. The utilization of biodiesel in diesel engines has been investigated over the last decades for its renewable characteristics and lower emissions compared to diesel. In an earlier work, we demonstrated that the soot temperature and concentration of biodiesel were lower than diesel under regular diesel engine conditions without EGR. Soot concentration was quantified by a parameter called KL factor. As a continuous effort, this paper presents an experimental investigation of the ambient oxygen concentration on soot temperature and KL factor during biodiesel and diesel spray combustion. The experiment was implemented in a constant volume chamber system, where the ambient oxygen concentration varied from 21 to 10% and the ambient temperature was kept to 1,000 K. A high speed two-color pyrometry technique was used to measure transient soot temperature and the KL factor of the spray flame. The soot temperature of biodiesel is found to be lower than that of diesel under the same conditions, which follows the same trend from our previous results found when the ambient temperature changes to 21% oxygen conditions. A reduction in ambient oxygen concentration generally reduces the soot temperature for both fuels. However, this is a complicated effect on soot processes as the change of oxygen concentration greatly affects the balance between soot formation and oxidation. The KL factor is observed to be the highest at 12% O2 for diesel and 18% O2 for biodiesel, respectively. On the other hand, the 10% O2 condition shows the lowest KL factor for both fuels. These results can provide quantitative experimental evidences to optimize the ambient oxygen concentration for diesel engines using different fuels for better emissions characteristics. © 2014 American Society of

  13. Impacts of vehicle exhaust black soot on germination of gram seed (Cicer arietinum L.)

    OpenAIRE

    Naba Kumar Mondal; Debopriya Panja; Chittaranjan Das; Uttiya Dey; Kousik Das

    2014-01-01

    An investigation was initiated to examine the effects of carbon soot collected from exhaust tube of 15 years old petrol and diesel operated vehicles on gram seed germination and biochemical changes of seedling. In view of the widespread cultivation of gram seed in India and long-term impact of black carbon is the warming of the atmosphere as per the recommendation of IPCC (2007). Black soot were separately treated with different doses and the effects of these treatment had on seed germination...

  14. Quantitative Measurement of Soot Concentration by Two-Wavelength Correction of Laser-Induced Incandescence Signals

    Energy Technology Data Exchange (ETDEWEB)

    Jung, J. S. [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

    1997-05-01

    To quantify the L II signals from soot particle of flames in diesel engine cylinder, a new method has been proposed for correcting L II signal attenuated by soot particles between the measuring point and the detector. It has been verified by an experiment on a laminar jet ethylene-air diffusion flame. Being proportional to the attenuation, the ratio of L II signal at two different detection wavelengths can be used to correct the measured L II signal and obtain the unattenuated L II signal, from which the soot volume fraction in the flame can be estimated. Both the 1064-nm and frequency-doubled 532-nm beams from the Nd : YAG laser are used. Single-shot, one-dimensional(1-D) line images are recorded on the intensified CCD camera, with the rectangular-profile laser beam using 1-mm-diameter pinhole. Two broadband optical interference filters having the center wavelengths of 647 nm and 400nm respectively and a bandwidth of 10 nm are used. This two wavelength correction has been applied to the ethylene-air coannular laminar diffusion flame, previously studied on soot formation by the laser extinction method in this laboratory. The results by the L II measurement technique and the conventional laser extinction method at the height of 40 nm above the jet exit agreed well with each other except around outside of the peaks of soot concentration, where the soot concentration was relatively high and resulting attenuation of the L II signal was large. The radial profile shape of soot concentration was not changed a lot, but the absolute value of the soot volume fraction around outside edge changed from 4 ppm to 6.5 ppm at r=2.8 mm after correction. This means that the attenuation of L II signal was approximately 40% at this point, which is higher than the average attenuation rate of this flame, 10 {approx} 15%. (author). 15 refs., 8 figs.

  15. Ceria-catlyzed soot oxidation studied by environmental transmission electron microscopy

    DEFF Research Database (Denmark)

    Simonsen, S.B.; Dahl, S.; Johnson, Erik;

    2008-01-01

    Environmental tranmission electron microscopy (ETEM) was used to monitor in situ ceria-catalyzed oxidation of soot in relation to diesel engine emission control.  From time-lapsed ETEM image series of soot particles in contact with CeO2. or with Al2O3 as inert reference, mechanistic and kinetic i...... insight into the catalytic and noncatalytic ozidation mechanisms was obtained....

  16. Processing of soot in an urban environment: case study from the Mexico City Metropolitan Area

    Directory of Open Access Journals (Sweden)

    K. S. Johnson

    2005-01-01

    Full Text Available Chemical composition, size, and mixing state of atmospheric particles are critical in determining their effects on the environment. There is growing evidence that soot aerosols play a particularly important role in both climate and human health, but still relatively little is known of their physical and chemical nature. In addition, the atmospheric residence times and removal mechanisms for soot are neither well understood nor adequately represented in regional and global climate models. To investigate the effect of locality and residence time on properties of soot and mixing state in a polluted urban environment, particles of diameter 0.2–2.0 μm were collected in the Mexico City Metropolitan Area (MCMA during the MCMA-2003 Field Campaign from various sites within the city. Individual particle analysis by different electron microscopy methods coupled with energy dispersed x-ray spectroscopy, and secondary ionization mass spectrometry show that freshly-emitted soot particles become rapidly processed in the MCMA. Whereas fresh particulate emissions from mixed-traffic are almost entirely carbonaceous, consisting of soot aggregates with liquid coatings suggestive of unburned lubricating oil and water, ambient soot particles which have been processed for less than a few hours are heavily internally mixed, primarily with ammonium sulfate. Single particle analysis suggests that this mixing occurs through several mechanisms that require further investigation. In light of previously published results, the internally-mixed nature of processed soot particles is expected to affect heterogeneous chemistry on the soot surface, including interaction with water during wet-removal.

  17. Cloud droplet activity changes of soot aerosol upon smog chamber ageing

    OpenAIRE

    Wittbom, C.; Pagels, J. H.; J. Rissler; A. C. Eriksson; J. E. Carlsson; Roldin, P.; E. Z. Nordin; Nilsson, P. T.; E. Swietlicki; B. Svenningsson

    2014-01-01

    Particles containing soot, or black carbon, are generally considered to contribute to global warming. However, large uncertainties remain in the net climate forcing resulting from anthropogenic emissions of black carbon (BC), to a large extent due to the fact that BC is co-emitted with gases and primary particles, both organic and inorganic, and subject to atmospheric ageing processes. In this study, diesel exhaust particles and particles from a flame soot g...

  18. Cloud droplet activity changes of soot aerosol upon smog chamber ageing

    OpenAIRE

    Wittbom, C.; A. C. Eriksson; J. Rissler; J. E. Carlsson; Roldin, P.; E. Z. Nordin; Nilsson, P. T.; E. Swietlicki; Pagels, J. H.; B. Svenningsson

    2014-01-01

    Particles containing soot, or black carbon, are generally considered to contribute to global warming. However, large uncertainties remain in the net climate forcing resulting from anthropogenic emissions of black carbon (BC), to a large extent due to the fact that BC is co-emitted with gases and primary particles, both organic and inorganic, and subject to atmospheric ageing processes. In this study, diesel exhaust particles and particles from a flame soot generator spiked w...

  19. Biomass Gasification Behavior in an Entrained Flow Reactor: Gas Product Distribution and Soot Formation

    DEFF Research Database (Denmark)

    Qin, Ke; Jensen, Peter Arendt; Lin, Weigang;

    2012-01-01

    Biomass gasification and pyrolysis were studied in a laboratory-scale atmospheric pressure entrained flow reactor. Effects of operating parameters and biomass types on the syngas composition were investigated. In general, the carbon conversion during biomass gasification was higher than 90% at th...... increased both the H2 and CO yields. Wood, straw, and dried lignin had similar gasification behavior, except with regard to soot formation. The soot yield was lowest during straw gasification possibly because of its high potassium content....

  20. Comparison of Preparation Methods of Copper Based PGMFree Diesel-Soot Oxidation Catalysts

    Directory of Open Access Journals (Sweden)

    R. Prasad

    2011-05-01

    Full Text Available CuO-CeO2 systems have been proposed as a promising catalyst for low temperature diesel-soot oxidation. CuO-CeO2 catalysts prepared by various methods were examined for air oxidation of the soot in a semi batch tubular flow reactor. The air oxidation of soot was carried out under tight contact with soot/catalyst ratio of 1/10. Air flow rate was 150 ml/min, soot-catalyst mixture was 110 mg, heating rate was 5 0C/min. Prepared catalysts were calcined at 500 0C and their stability was examined by further heating to 800 0C for 4 hours. It was found that the selectivity of all the catalysts was nearly 100% to CO2 production. It was observed that the activity and stability of the catalysts greatly influenced by the preparation methods. The strong interaction between CuO and CeO2 is closely related to the preparation route that plays a crucial role in the soot oxidation over the CuO-CeO2 catalysts. The ranking order of the preparation methods of the catalysts in the soot oxidation performance is as follows: sol-gel > urea nitrate combustion > Urea gelation method > thermal decomposition > co-precipitation. Copyright © 2011 BCREC UNDIP. All rights reserved.(Received: 27th June 2010, Revised: 7th August 2010; Accepted: 13rd October 2010[How to Cite: R. Prasad, V.R. Bella. (2011. Comparison of Preparation Methods of Copper Based PGMFree Diesel-Soot Oxidation Catalysts. Bulletin of Chemical Reaction Engineering and Catalysis, 6(1: 15-21. doi:10.9767/bcrec.6.1.822.15-21][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.6.1.822.15-21 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/822 | View in 

  1. Boiler house modernization through shared savings program

    Energy Technology Data Exchange (ETDEWEB)

    Breault, R.W. [Tecogen, Waltham, MA (United States)

    1995-12-31

    Throughout Poland as well as the rest of Eastern Europe, communities and industries rely on small heat only boilers to provide district and process heat. Together these two sectors produce about 85,000 MW from boilers in the 2 to 35 MW size range. The bulk of these units were installed prior to 1992 and must be completely overhauled to meet the emission regulations which will be coming into effect on January 1, 1998. Since the only practical fuel is coal in most cases, these boilers must be either retrofit with emission control technology or be replaced entirely. The question that arises is how to accomplish this given the current tight control of capital in Poland and other East European countries. A solution that we have for this problem is shared savings. These boilers are typically operating with a quiet low efficiency as compared to western standards and with excessive manual labor. Installing modernization equipment to improve the efficiency and to automate the process provides savings. ECOGY provides the funds for the modernization to improve the efficiency, add automation and install emission control equipment. The savings that are generated during the operation of the modernized boiler system are split between the client company and ECOGY for a number of years and then the system is turned over in entirety to the client. Depending on the operating capacity, the shared savings agreement will usually span 6 to 10 years.

  2. Evaluation of surrogate boilers for steam generators

    International Nuclear Information System (INIS)

    Steam generator damage in pressurized water reactors is a continuing problem which results from a combination of factors including mechanical design, thermal hydraulics, materials selection, fabrication techniques, water chemistry, and system design and operation. A wide variety of steam generator damage mechanisms has been identified in operating PWRs including intergranular attack, thinning, stress corrosion cracking, erosion, denting, fatigue cracking, pitting, and fretting. Model boilers operated in parallel to the steam generators, i.e., surrogate boilers, may provide a useful tool in the study of these damage mechanisms, their causative factors, and the effects of corrosion actions. To evaluate the applicability of surrogate boilers to such studies, Steam Generator Owners Group I project S111-2 was established. Evaluation of numerous surrogate boiler design alternates led to identification of several possible acceptable approaches. The appropriate surrogate feedwater was identified as plant feedwater. Capability to operate with a tube-side temperature similar to the hot-leg temperature was considered necessary as was the ability to provide mechanical, thermal, and chemical corrosion acceleration. Practical and economically feasible surrogate boiler designs were developed in response to these design requirements

  3. Boiler MACT Technical Assistance (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-03-01

    Fact sheet describing the changes to Environmental Protection Act process standards. The DOE will offer technical assistance to ensure that major sources burning coal and oil have information on cost-effective, clean energy strategies for compliance, and to promote cleaner, more efficient boiler burning to cut harmful pollution and reduce operational costs. The U.S. Environmental Protection Agency (EPA) is expected to finalize the reconsideration process for its Clean Air Act pollution standards National Emissions Standards for Hazardous Air Pollutants for Major Sources: Industrial, Commercial, and Institutional Boilers and Process Heaters (known as Boiler Maximum Achievable Control Technology (MACT)), in Spring 2012. This rule applies to large and small boilers in a wide range of industrial facilities and institutions. The U.S. Department of Energy (DOE) will offer technical assistance to ensure that major sources burning coal or oil have information on cost-effective clean energy strategies for compliance, including combined heat and power, and to promote cleaner, more efficient boilers to cut harmful pollution and reduce operational costs.

  4. Internally mixed soot, sulfates, and organic matter in aerosol particles from Mexico City

    Science.gov (United States)

    Adachi, K.; Buseck, P. R.

    2008-05-01

    Soot particles are major aerosol constituents that result from emissions of burning of fossil fuel and biomass. Because they both absorb sunlight and contribute to cloud formation, they are an influence on climate on local, regional, and global scales. It is therefore important to evaluate their optical and hygroscopic properties and those effects on the radiation budget. Those properties commonly change through reaction with other particles or gases, resulting in complex internal mixtures. Using transmission electron microscopy, we measured ~8000 particles (25 samples) with aerodynamic diameters from 0.05 to 0.3 μm that were collected in March 2006 from aircraft over Mexico City (MC) and adjacent areas. More than 50% of the particles consist of internally mixed soot, organic matter, and sulfate. Imaging combined with chemical analysis of individual particles show that many are coated, consist of aggregates, or both. Coatings on soot particles can amplify their light absorption, and coagulation with sulfates changes their hygroscopic properties, resulting in shorter lifetime. Our results suggest that a mixture of materials from multiple sources such as vehicles, power plants, and biomass burning occurs in individual particles, thereby increasing their complexity. Through changes in their optical and hygroscopic properties, internally mixed soot particles have a greater effect on the regional climate than uncoated soot particles. Moreover, soot occurs in more than 60% of all particles in the MC plumes, suggesting its important role in the formation of secondary aerosol particles.

  5. A multi-probe thermophoretic soot sampling system for high-pressure diffusion flames

    Science.gov (United States)

    Vargas, Alex M.; Gülder, Ömer L.

    2016-05-01

    Optical diagnostics and physical probing of the soot processes in high pressure combustion pose challenges that are not faced in atmospheric flames. One of the preferred methods of studying soot in atmospheric flames is in situ thermophoretic sampling followed by transmission electron microscopy imaging and analysis for soot sizing and morphology. The application of this method of sampling to high pressures has been held back by various operational and mechanical problems. In this work, we describe a rotating disk multi-probe thermophoretic soot sampling system, driven by a microstepping stepper motor, fitted into a high-pressure chamber capable of producing sooting laminar diffusion flames up to 100 atm. Innovative aspects of the sampling system design include an easy and precise control of the sampling time down to 2.6 ms, avoidance of the drawbacks of the pneumatic drivers used in conventional thermophoretic sampling systems, and the capability to collect ten consecutive samples in a single experimental run. Proof of principle experiments were performed using this system in a laminar diffusion flame of methane, and primary soot diameter distributions at various pressures up to 10 atm were determined. High-speed images of the flame during thermophoretic sampling were recorded to assess the influence of probe intrusion on the flow field of the flame.

  6. Diffusion air effects on the soot axial distribution concentration in a premixed acetylene/air flame

    Energy Technology Data Exchange (ETDEWEB)

    Fassani, Fabio Luis; Santos, Alex Alisson Bandeira; Goldstein Junior, Leonardo [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Engenharia Termica e de Fluidos]. E-mails: fassani@fem.unicamp.br; absantos@fem.unicamp.br; leonardo@fem.unicamp.br; Ferrari, Carlos Alberto [Universidade Estadual de Campinas, SP (Brazil). Inst. de Fisica. Dept. de Eletronica Quantica]. E-mail: ferrari@ifi.unicamp.br

    2000-07-01

    Soot particles are produced during the high temperature pyrolysis or combustion of hydrocarbons. The emission of soot from a combustor, or from a flame, is determined by the competition between soot formation and its oxidation. Several factors affect these processes, including the type of fuel, the air-to-fuel ratio, flame temperature, pressure, and flow pattern. In this paper, the influence of the induced air diffusion on the soot axial distribution concentration in a premixed acetylene/air flame was studied. The flame was generated in a vertical axis burner in which the fuel - oxidant mixture flow was surrounded by a nitrogen discharge coming from the annular region between the burner tube and an external concentric tube. The nitrogen flow provided a shield that protected the flame from the diffusion of external air, enabling its control. The burner was mounted on a step-motor driven, vertical translation table. The use of several air-to-fuel ratios made possible to establish the sooting characteristics of this flame, by measuring soot concentration along the flame height with a non-intrusive laser light absorption technique. (author)

  7. Tribology of ethylene-air diffusion flame soot under dry and lubricated contact conditions

    International Nuclear Information System (INIS)

    Soot particles are generated in a flame caused by burning ethylene gas. The particles are collected thermophoretically at different locations of the flame. The particles are used to lubricate a steel/steel ball on flat reciprocating sliding contact, as a dry solid lubricant and also as suspended in hexadecane. Reciprocating contact is shown to establish a protective and low friction tribo-film. The friction correlates with the level of graphitic order of the soot, which is highest in the soot extracted from the mid-flame region and is low in the soot extracted from the flame root and flame tip regions. Micro-Raman spectroscopy of the tribo-film shows that the a priori graphitic order, the molecular carbon content of the soot and the graphitization of the film as brought about by tribology distinguish between the frictions of soot extracted from different regions of the flame, and differentiate the friction associated with dry tribology from that recorded under lubricated tribology. (paper)

  8. Ice Nucleation and Droplet Formation by Bare and Coated Soot Particles

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, Beth J.; Kulkarni, Gourihar R.; Beranek, Josef; Zelenyuk, Alla; Thornton, Joel A.; Cziczo, Daniel J.

    2011-09-13

    We have studied ice formation at temperatures relevant to homogeneous and heterogeneous ice nucleation, as well as droplet activation and hygroscopicity, of soot particles of variable size and composition. Coatings of adipic, malic, and oleic acid were applied to span an atmospherically relevant range of solubility, and both uncoated and oleic acid coated soot particles were exposed to ozone to simulate atmospheric oxidation. The results are interpreted in terms of onset ice nucleation, with a comparison to a mineral dust particle that acts as an efficient ice nucleus, and particle hygroscopicity. At 253K and 243K, we found no evidence of heterogeneous ice nucleation occurring above the level of detection for our experimental conditions. Above water saturation, only droplet formation was observed. At 233K, we observe the occurrence of homogeneous ice nucleation for all particles studied. Coatings also did not significantly alter the ice nucleation behavior of soot particles, but aided in the uptake of water. Hygroscopicity studies confirmed that pure soot particles were hydrophobic, and coated soot particles activated as droplets at high water supersaturations. A small amount of heterogeneous ice nucleation either below the detection limit of our instrument or concurrent with droplet formation and/or homogeneous freezing cannot be precluded, but we are able to set limits for its frequency. We conclude that both uncoated and coated soot particles representative of those generated in our studies are unlikely to significantly contribute to the global budget of heterogeneous ice nuclei at temperatures between 233K and 253K.

  9. Development of high fidelity soot aerosol dynamics models using method of moments with interpolative closure

    KAUST Repository

    Roy, Subrata P.

    2014-01-28

    The method of moments with interpolative closure (MOMIC) for soot formation and growth provides a detailed modeling framework maintaining a good balance in generality, accuracy, robustness, and computational efficiency. This study presents several computational issues in the development and implementation of the MOMIC-based soot modeling for direct numerical simulations (DNS). The issues of concern include a wide dynamic range of numbers, choice of normalization, high effective Schmidt number of soot particles, and realizability of the soot particle size distribution function (PSDF). These problems are not unique to DNS, but they are often exacerbated by the high-order numerical schemes used in DNS. Four specific issues are discussed in this article: the treatment of soot diffusion, choice of interpolation scheme for MOMIC, an approach to deal with strongly oxidizing environments, and realizability of the PSDF. General, robust, and stable approaches are sought to address these issues, minimizing the use of ad hoc treatments such as clipping. The solutions proposed and demonstrated here are being applied to generate new physical insight into complex turbulence-chemistry-soot-radiation interactions in turbulent reacting flows using DNS. © 2014 Copyright Taylor and Francis Group, LLC.

  10. Internally mixed soot, sulfates, and organic matter in aerosol particles from Mexico City

    Directory of Open Access Journals (Sweden)

    K. Adachi

    2008-05-01

    Full Text Available Soot particles are major aerosol constituents that result from emissions of burning of fossil fuel and biomass. Because they both absorb sunlight and contribute to cloud formation, they are an influence on climate on local, regional, and global scales. It is therefore important to evaluate their optical and hygroscopic properties and those effects on the radiation budget. Those properties commonly change through reaction with other particles or gases, resulting in complex internal mixtures. Using transmission electron microscopy, we measured ~8000 particles (25 samples with aerodynamic diameters from 0.05 to 0.3 μm that were collected in March 2006 from aircraft over Mexico City (MC and adjacent areas. More than 50% of the particles consist of internally mixed soot, organic matter, and sulfate. Imaging combined with chemical analysis of individual particles show that many are coated, consist of aggregates, or both. Coatings on soot particles can amplify their light absorption, and coagulation with sulfates changes their hygroscopic properties, resulting in shorter lifetime. Our results suggest that a mixture of materials from multiple sources such as vehicles, power plants, and biomass burning occurs in individual particles, thereby increasing their complexity. Through changes in their optical and hygroscopic properties, internally mixed soot particles have a greater effect on the regional climate than uncoated soot particles. Moreover, soot occurs in more than 60% of all particles in the MC plumes, suggesting its important role in the formation of secondary aerosol particles.

  11. Establishment of Optimum Ecological System for Monitoring Boiler Units

    OpenAIRE

    V. I. Nazarov

    2014-01-01

    A mathematical model has been proposed for ecological monitoring of a boiler unit. This model makes it possible to obtain maximum decrease in effluents at minimum reduction in economical operational efficiency of the boiler unit.

  12. Computer simulation of the fire-tube boiler hydrodynamics

    Directory of Open Access Journals (Sweden)

    Khaustov Sergei A.

    2015-01-01

    Full Text Available Finite element method was used for simulating the hydrodynamics of fire-tube boiler with the ANSYS Fluent 12.1.4 engineering simulation software. Hydrodynamic structure and volumetric temperature distribution were calculated. The results are presented in graphical form. Complete geometric model of the fire-tube boiler based on boiler drawings was considered. Obtained results are suitable for qualitative analysis of hydrodynamics and singularities identification in fire-tube boiler water shell.

  13. Application of GPRS and GIS in Boiler Remote Monitoring System

    OpenAIRE

    Hongchao Wang; Yifeng Wu

    2012-01-01

    Application of GPRS and GIS in boiler remote monitoring system was designed in this paper by combining the advantage of GPRS and GIS in remote data transmission with configuration monitoring technology. The detail information of the operating conditions of the industrial boiler can be viewed by marking the location of boiler on the electronic map dynamically which can realize the unified management for industrial boiler of a region or city conveniently. Experimental application show that the ...

  14. Modelling and predictive control of a drum-type boiler

    OpenAIRE

    Molloy, Barbara

    1997-01-01

    Boilers generate steam continuously and on a large scale. Controlling the boiler process is extremely difficult - it is a highly nonlinear process, its dynamics vary with load and it is strongly multivariable. It is also inherently unstable due to the integrator effect of the drum. In addition, boilers are commonly used in situations where the load can change suddenly and without prior warning. Traditionally, boilers have been controlled by Single-Input, Single-Output (SISO) Proportional ...

  15. Computer simulation of the fire-tube boiler hydrodynamics

    OpenAIRE

    Khaustov Sergei A.; Zavorin Alexander S.; Buvakov Konstantin V.; Sheikin Vyacheslav A.

    2015-01-01

    Finite element method was used for simulating the hydrodynamics of fire-tube boiler with the ANSYS Fluent 12.1.4 engineering simulation software. Hydrodynamic structure and volumetric temperature distribution were calculated. The results are presented in graphical form. Complete geometric model of the fire-tube boiler based on boiler drawings was considered. Obtained results are suitable for qualitative analysis of hydrodynamics and singularities identification in fire-tube boiler water shell.

  16. Experimental installation with pressurized fluidized bed boiler

    Energy Technology Data Exchange (ETDEWEB)

    Dobrzanski, W.; Szwarc, W.; Jurek, K.; Prokop, A. (Politechnika Warszawska (Poland). Instytut Techniki Cieplnej)

    1990-01-01

    Describes a test installation with a 3 MW pressurized fluidized bed boiler. The installation was commissioned at the Institute of Heat Engineering at the Technical University in Warsaw. Predesign assumptions and the lay-out of the installation are given. A schematic diagram of the pressurized (0.6 MPa) fluidized bed boiler with an inner diameter of 1.4 m and a total height of 5.45 m is shown. The fuel feeding system consists of a coal and adsorbent container, two feeders and an air jet pump for pneumatic transport. A water type boiler is integrated into the pressure vessel. Flue gas cyclones are also integrated into a separate pressure vessel. The computerized control system and instrumentation are described. Temperatures, pressures, pressure differences, rotational speeds and the chemical composition of gases are monitored.

  17. Evaluation of thermal overload in boiler operators.

    Science.gov (United States)

    Braga, Camila Soares; Rodrigues, Valéria Antônia Justino; Campos, Julio César Costa; de Souza, Amaury Paulo; Minette, Luciano José; de Moraes, Angêlo Casali; Sensato, Guilherme Luciano

    2012-01-01

    The Brazilians educational institutions need a large energy demand for the operation of laundries, restaurants and accommodation of students. Much of that energy comes from steam generated in boilers with wood fuel. The laboral activity in boiler may present problems for the operator's health due to exposure to excessive heat, and its operation has a high degree of risk. This paper describes an analysis made the conditions of thermal environment in the operation of a B category boiler, located at a Higher Education Institution, located in the Zona da Mata Mineira The equipments used to collect data were Meter WBGT of the Heat Index; Meter of Wet Bulb Index and Globe Thermometer (WBGT); Politeste Instruments, an anemometer and an Infrared Thermometer. By the application of questionnaires, the second phase consisted of collecting data on environmental factors (temperature natural environment, globe temperature, relative humidity and air velocity). The study concluded that during the period evaluated, the activity had thermal overload. PMID:22316768

  18. Analysis of natural circulation in the in-core structure test section (T2) in the case of a blower trip

    International Nuclear Information System (INIS)

    When a blower trip occurs in an abnormal condition of the in-core structure test section (T2), natural circulation will develop in the two flow channels which are formed by the gap between the fixed reflector and the side shield and the gap between the side shield and the core barrel. The natural circulation heats up the structures of T2, such as a core restraint mechanism and a core barrel and others. Moreover, the radiation emitted from the heated core barrel enhances markably heating-up of the pressure vessel. This report deals with an analysis of the natural circulation accurred after a blower trip, and with the effect on the temperature rise of the structures of T2. Possible countermeasures are also discussed. (author)

  19. Optimization of Boiler Heat Load in Water-Heating Boiler-House

    OpenAIRE

    B. A. Bayrashevsky; N. P. Borushko

    2014-01-01

    An analytical method for optimization of water-heating boiler loads has been developed on the basis of approximated semi-empirical dependences pertaining to changes of boiler gross efficiency due to its load. A complex (∂tух/∂ξ)Δξ is determined on the basis of a systematic analysis (monitoring) of experimental data and the Y. P. Pecker’s formula for calculation of balance losses q2. This complex makes it possible to set a corresponding correction to a standard value of the boiler gross effici...

  20. Saturation curves of two-color laser-induced incandescence measurements for the investigation of soot optical properties

    Science.gov (United States)

    Migliorini, F.; De Iuliis, S.; Maffi, S.; Zizak, G.

    2015-09-01

    Two-color laser-induced incandescence (LII) measurements are carried out in diffusion flames and at the exhaust of a homemade soot generator, both fueled with ethylene and methane. Two-color prompt LII signals, their ratio and the corresponding temperature have been analyzed as a function of laser fluence. In particular, the effect of fuel, soot load and gas/particle initial temperature on LII measurements have been investigated. LII spectral measurements have also been performed in all conditions for validation. The results suggest that the incandescence is sensitive to both optical and non-optical physical properties of the particles. Moreover, soot volume fraction measurements are dependent on the laser fluence used, indicating that the soot temperature influences the refractive index absorption function. Such issues can be overcome by working at high laser fluences, where the saturation curves are independent from the experimental conditions if the soot absorption function near soot sublimation threshold is known.

  1. The use of liquid latex for soot removal from fire scenes and attempted fingerprint development with Ninhydrin.

    Science.gov (United States)

    Clutter, Susan Wright; Bailey, Robert; Everly, Jeff C; Mercer, Karl

    2009-11-01

    Throughout the United States, clearance rates for arson cases remain low due to fire's destructive nature, subsequent suppression, and a misconception by investigators that no forensic evidence remains. Recent research shows that fire scenes can yield fingerprints if soot layers are removed prior to using available fingerprinting processes. An experiment applying liquid latex to sooted surfaces was conducted to assess its potential to remove soot and yield fingerprints after the dried latex was peeled. Latent fingerprints were applied to glass and drywall surfaces, sooted in a controlled burn, and cooled. Liquid latex was sprayed on, dried, and peeled. Results yielded usable prints within the soot prior to removal techniques, but no further fingerprint enhancement was noted with Ninhydrin. Field studies using liquid latex will be continued by the (US) Virginia Fire Marshal Academy but it appears that liquid latex application is a suitable soot removal method for forensic applications. PMID:19732277

  2. 46 CFR 109.205 - Inspection of boilers and machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Inspection of boilers and machinery. 109.205 Section 109... OPERATIONS Tests, Drills, and Inspections § 109.205 Inspection of boilers and machinery. The chief engineer or engineer in charge, before he assumes charge of the boilers and machinery of a unit shall...

  3. 46 CFR 56.50-30 - Boiler feed piping.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Boiler feed piping. 56.50-30 Section 56.50-30 Shipping... APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-30 Boiler feed piping. (a) General... least two separate means of supplying feed water for the boilers. All feed pumps shall be fitted...

  4. 49 CFR 230.36 - Hydrostatic testing of boilers.

    Science.gov (United States)

    2010-10-01

    ... Appurtenances Pressure Testing of Boilers § 230.36 Hydrostatic testing of boilers. (a) Time of test. The... following any hydrostatic test where the pressure exceeds MAWP. ... 49 Transportation 4 2010-10-01 2010-10-01 false Hydrostatic testing of boilers. 230.36 Section...

  5. Lower price for solar boilers must improve market penetration

    International Nuclear Information System (INIS)

    The Dutch government aims at 1.7 PJ thermal energy for the year 2007 to be supplied by solar water heaters. For that target the number of installed solar boilers must increase seven times the number of installed solar boilers in 1998. This can be stimulated by a considerable reduction of the market price for such boilers

  6. Aspects of new material application for boilers construction

    International Nuclear Information System (INIS)

    Review of steel types commonly used for energetic boilers construction has been done. The worldwide trends in new materials application for improvement of boilers quality have been discussed. The mechanical properties of boiler construction steels have been shown and compared. 3 refs, 5 figs, 1 tab

  7. Central heating: fossil-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Blazek, C.F.; Baker, N.R.; Tison, R.R.

    1979-05-01

    This evaluation provides performance and cost data for fossil-fuel-fired steam boilers, hot-water generators, and thermal fluid generators currently available from manufacturers. Advanced-technology fluidized-bed boilers also are covered. Performance characteristics investigated include unit efficiencies, turndown capacity, and pollution requirements. Costs are tabulated for equipment and installation of both field-erected and packaged units. The information compiled in this evaluation will assist in the process of selecting energy-conversion units required for industrial, commercial, and residential applications.

  8. Planning Annual Shutdown Inspection for BFB Boiler

    OpenAIRE

    Sorsa, Tatu

    2014-01-01

    The goal of this thesis was to create an illustrative guidebook of annual inspection planning for BFB boiler to help power plant operator when planning of annual inspection is topical. This thesis was made for Andritz Oy and it is based on inspection reports and experiences of BFB boiler’s maintenance and inspection staff. In this thesis it is shown how to plan an annual inspection for BFB boiler and thesis gives good tools and hints for operator to manage inspection from the beginning ...

  9. The level control of the boiler drum

    OpenAIRE

    He, Chenhui

    2014-01-01

    Level control uses the boiler drum as a controlled object, and uses the level as a controller value. By making sure the level control is attached accurately we get better dynamic performance. I use the cascade control to make the difference to the traditional control. In this thesis, I summarize many problems with the level control in the steam boiler field as the false level phenomenon. I design three methods for the level control process system with different ways. I make the final choi...

  10. Transients in a circulating fluidized bed boiler

    Science.gov (United States)

    Baskakov, A. P.; Munts, V. A.; Pavlyuk, E. Yu.

    2013-11-01

    Transients in a circulating fluidized bed boiler firing biomass are considered. An attempt is made to describe transients with the use of concepts applied in the automatic control theory. The parameters calculated from an analysis of unsteady heat balance equations are compared with the experimental data obtained in the 12-MW boiler of the Chalmers University of Technology. It is demonstrated that these equations describe the transient modes of operation with good accuracy. Dependences for calculating the time constants of unsteady processes are obtained.

  11. Effect of fuel formulation on soot properties and regeneration of diesel particulate filters

    Science.gov (United States)

    Song, Juhun

    A critical requirement for implementation of particulate filters on diesel applications is having a low "break even temperature" (BET), defined as the exhaust temperature at which particulate removal occurs at roughly the same rate as particulate deposition. This needs to occur at sufficiently low temperatures either to fit within the exhaust temperature range of the typical duty cycle for a diesel vehicle or to require a minimum of active regeneration. Since catalytic coating on the diesel particulate filter was used in this study, one important factor in lowering the BET is catalyst activity for NO conversion to NO2, which can be adversely affected by sulfur content in the fuel, because the sulfur dioxide generated during diesel combustion can poison catalyst activity. However, a second important factor that significantly affects DPF regeneration behavior is particulate reactivity, which is related to the chemical and physical properties of diesel particulates. Differences in diesel combustion characteristics and fuel formulation can be a source of variation in these soot properties. The first phase of this work considered low sulfur diesel fuel (325 ppm sulfur), ultra low sulfur fuel (15 ppm sulfur) and 20 wt.% biodiesel blends. The lowest break even temperature was observed for the 325 ppm sulfur fuel blended with 20 wt.% biodiesel, due in part to increased engine-out NOx emissions with the B20 blend, which shows that engine-out exhaust composition can be as or more important than sulfur content. Furthermore, examination of the soot generated with these fuels shows a variation in the nanostructure and the oxidative reactivity for soots derived from the different fuels. The second phase of work has been performed by adding neat alternative fuels such as Biodiesel (B100) and Fisch-Tropsch (FT) fuel. B100 soot displays a similar initial soot structure as soot from three other fuels, ultra low sulfur diesel, B20 (a 20 wt.% blend of biodiesel and ultra low sulfur

  12. 旋涡风机叶片侧边型线的研究%Research on the Shape of Blade Side of Vortex Blower

    Institute of Scientific and Technical Information of China (English)

    唐照付; 聂波; 张俊林; 满建楠

    2013-01-01

    旋涡风机叶轮叶片侧边型线影响流体进出叶轮流道的速度三角形,对风机的性能有一定的影响.本文从试验和数值计算的角度对径向直叶片侧边倒角情况进行了研究,发现叶片侧边吸力面倒角比压力面倒角更能提高风机的性能,小流量区更为明显.本文用理论分析了该现象的原因,并推断前弯和后弯叶片也具有同样的性质.%The shape of impeller blade side of vortex blower can influence velocity triangle of fluid flowing in and out of impeller , so as to influence the performance of blower. The chamfer of radial side blade was studied by using methods of experiment and numerical simulation,and It finds that chamfer on the suction side is the best situation for improving the performance of vortex blower specially when little flux. The paper explains the roots of such phenomenon by theoretical analysis, and deduces that forward and backward bending blades own the same properties.

  13. Sulfuric Acid and Soot Particle Formation in Aircraft Exhaust

    Science.gov (United States)

    Pueschel, Rudolf F.; Verma, S.; Ferry, G. V.; Howard, S. D.; Vay, S.; Kinne, S. A.; Baumgardner, D.; Dermott, P.; Kreidenweis, S.; Goodman, J.; Gore, Waren J. Y. (Technical Monitor)

    1997-01-01

    A combination of CN counts, Ames wire impactor size analyses and optical particle counter data in aircraft exhaust results in a continuous particle size distribution between 0.01 micrometer and 1 micrometer particle radius sampled in the exhaust of a Boeing 757 research aircraft. The two orders of magnitude size range covered by the measurements correspond to 6-7 orders of magnitude particle concentration. CN counts and small particle wire impactor data determine a nucleation mode, composed of aircraft-emitted sulfuric acid aerosol, that contributes between 62% and 85% to the total aerosol surface area and between 31% and 34% to its volume. Soot aerosol comprises 0.5% of the surface area of the sulfuric acid aerosol. Emission indices are: EIH2SO4 = 0.05 g/kgFUEL and (0.2-0.5) g/kgFUEL (for 75 ppmm and 675 ppmm fuel-S, respectively), 2.5E4sulfur (gas) to H2SO4 (particle) conversion efficiency is between 10% and 25%.

  14. Optimal DO Setpoint Decision and Electric Cost Saving in Aerobic Reactor Using Respirometer and Air Blower Control

    International Nuclear Information System (INIS)

    Main objects for wastewater treatment operation are to maintain effluent water quality and minimize operation cost. However, the optimal operation is difficult because of the change of influent flow rate and concentrations, the nonlinear dynamics of microbiology growth rate and other environmental factors. Therefore, many wastewater treatment plants are operated for much more redundant oxygen or chemical dosing than the necessary. In this study, the optimal control scheme for dissolved oxygen (DO) is suggested to prevent over-aeration and the reduction of the electric cost in plant operation while maintaining the dissolved oxygen (DO) concentration for the metabolism of microorganisms in oxic reactor. The oxygen uptake rate (OUR) is real-time measured for the identification of influent characterization and the identification of microorganisms' oxygen requirement in oxic reactor. Optimal DO set-point needed for the micro-organism is suggested based on real-time measurement of oxygen uptake of micro-organism and the control of air blower. Therefore, both stable effluent quality and minimization of electric cost are satisfied with a suggested optimal set-point decision system by providing the necessary oxygen supply requirement to the micro-organisms coping with the variations of influent loading

  15. Optimal DO Setpoint Decision and Electric Cost Saving in Aerobic Reactor Using Respirometer and Air Blower Control

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kwang Su; Yoo, Changkyoo [Kyung Hee University, Yongin (Korea, Republic of); Kim, Minhan [Pangaea21 Ltd., Seongnam (Korea, Republic of); Kim, Jongrack [UnUsoft Ltd., Seoul (Korea, Republic of)

    2014-10-15

    Main objects for wastewater treatment operation are to maintain effluent water quality and minimize operation cost. However, the optimal operation is difficult because of the change of influent flow rate and concentrations, the nonlinear dynamics of microbiology growth rate and other environmental factors. Therefore, many wastewater treatment plants are operated for much more redundant oxygen or chemical dosing than the necessary. In this study, the optimal control scheme for dissolved oxygen (DO) is suggested to prevent over-aeration and the reduction of the electric cost in plant operation while maintaining the dissolved oxygen (DO) concentration for the metabolism of microorganisms in oxic reactor. The oxygen uptake rate (OUR) is real-time measured for the identification of influent characterization and the identification of microorganisms' oxygen requirement in oxic reactor. Optimal DO set-point needed for the micro-organism is suggested based on real-time measurement of oxygen uptake of micro-organism and the control of air blower. Therefore, both stable effluent quality and minimization of electric cost are satisfied with a suggested optimal set-point decision system by providing the necessary oxygen supply requirement to the micro-organisms coping with the variations of influent loading.

  16. Super Boiler: Packed Media/Transport Membrane Boiler Development and Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Liss, William E; Cygan, David F

    2013-04-17

    Gas Technology Institute (GTI) and Cleaver-Brooks developed a new gas-fired steam generation system the Super Boiler for increased energy efficiency, reduced equipment size, and reduced emissions. The system consists of a firetube boiler with a unique staged furnace design, a two-stage burner system with engineered internal recirculation and inter-stage cooling integral to the boiler, unique convective pass design with extended internal surfaces for enhanced heat transfer, and a novel integrated heat recovery system to extract maximum energy from the flue gas. With these combined innovations, the Super Boiler technical goals were set at 94% HHV fuel efficiency, operation on natural gas with <5 ppmv NOx (referenced to 3%O2), and 50% smaller than conventional boilers of similar steam output. To demonstrate these technical goals, the project culminated in the industrial demonstration of this new high-efficiency technology on a 300 HP boiler at Clement Pappas, a juice bottler located in Ontario, California. The Super Boiler combustion system is based on two stage combustion which combines air staging, internal flue gas recirculation, inter-stage cooling, and unique fuel-air mixing technology to achieve low emissions rather than external flue gas recirculation which is most commonly used today. The two-stage combustion provides lower emissions because of the integrated design of the boiler and combustion system which permit precise control of peak flame temperatures in both primary and secondary stages of combustion. To reduce equipment size, the Super Boiler's dual furnace design increases radiant heat transfer to the furnace walls, allowing shorter overall furnace length, and also employs convective tubes with extended surfaces that increase heat transfer by up to 18-fold compared to conventional bare tubes. In this way, a two-pass boiler can achieve the same efficiency as a traditional three or four-pass firetube boiler design. The Super Boiler is consequently

  17. Optimization of Boiler Heat Load in Water-Heating Boiler-House

    Directory of Open Access Journals (Sweden)

    B. A. Bayrashevsky

    2014-06-01

    Full Text Available An analytical method for optimization of water-heating boiler loads has been developed on the basis of approximated semi-empirical dependences pertaining to changes of boiler gross efficiency due to its load. A complex (∂tух/∂ξΔξ is determined on the basis of a systematic analysis (monitoring of experimental data and the Y. P. Pecker’s formula for calculation of balance losses q2. This complex makes it possible to set a corresponding correction to a standard value of the boiler gross efficiency due to contamination of heating surfaces.Software means for optimization of water-heating boilers has been developed and it is recommended to be applied under operational conditions.

  18. Catalytic combustion of soot over Ru-doped mixed oxides catalysts

    Institute of Scientific and Technical Information of China (English)

    LF Nascimento; RF Martins; OA Serra

    2014-01-01

    We employed modified substrates as outer heterogeneous catalysts to reduce the soot originating from the incomplete die-sel combustion. Here, we proposed that ceria (CeO2)-based catalysts could lower the temperature at which soot combustion occurred from 610 ºC to values included in the operation range of diesel exhausts (270-400 ºC). Here, we used the sol-gel method to synthesize catalysts based on mixed oxides (ZnO:CeO2) deposited on cordierite substrates, and modified by ruthenium nanoparticles. The presence of ZnO in these mixed oxides produced defects associated with oxygen vacancies, improving thermal stability, redox potential, sulfur resistance, and oxygen storage. We evaluated the morphological and structural properties of the material by X-ray diffraction (XRD), Brumauer-emmett-teller method (BET), temperature programmed reduction (H2-TPR), scanning electron micros-copy (SEM), and transmission electron microscopy (TEM). We investigated how the addition of Ru (0.5 wt.%) affected the catalytic activity of ZnO:CeO2 in terms of soot combustion. Thermogravimetric analysis (TG/DTA) revealed that presence of the catalyst de-creased the soot combustion temperature by 250 ºC, indicating that the oxygen species arose at low temperatures, which was the main reason for the high reactivity of the oxidation reactions. Comparative analysis of soot emission by diffuse reflectance spectroscopy (DRS) showed that the catalyst containing Ru on the mixed oxide-impregnated cordierite samples efficiently oxidized soot in a diesel stationary motor:soot emission decreased 80%.

  19. Subchronic oral toxicity in guinea pigs of soot from a polychlorinated biphenyl-containing transformer fire

    Energy Technology Data Exchange (ETDEWEB)

    DeCaprio, A.P.; McMartin, D.N.; Silkworth, J.B.; Rej, R.; Pause, R.; Kaminsky, L.S.

    1983-04-01

    The soot was determined to contain polychlorinated biphenyls, biphenylenes, dibenzodioxins, and dibenzofurans. The present study evaluates soot toxicity in guinea pigs receiving 0, 0.2, 1.9, 9.3, or 46.3 ppm soot in the feed for 90 days or 231.5 ppm for 32 days. At 231.5 ppm, body weight loss, thymic atrophy, bone marrow depletion, skeletal muscle and gastrointestinal tract epithelial degeneration, and fatty infiltration of hepatocytes were observed. Mortality had reached 35% by Day 32 (when survivors were killed), with total soot consumption of approximately 400 mg/kg. At 46.3 or 9.3 ppm soot, a reduced rate of body weight gain was observed, and at 46.3 ppm, the mortality by Day 90 was 30%. Relative (to body) thymus weights were decreased in both groups, while relative spleen weights were increased at 46.3 ppm soot only. Salivary gland interlobular duct squamous metaplasia and focal lacrimal gland adenitis were detected histopathologically, while bone marrow depletion was noted only in females at the higher dose. Diminished serum alanine aminotransferase (ALT) activity in both sexes and decreased serum sodium levels in male and potassium levels in female animals were detected at both dose levels. No effectse were noted in animals receiving 0.2 ppm soot for 90 days. Salivary gland duct metaplasia has not been previously reported. Toxic effects of this subchronic exposure were observed at lower total doses than with acute exposure, although variations in absorption due to the effects of different vehicles (aqueous in the acute study versus the feed in this study) could account for some or all of this difference.

  20. Effect of morphology on the optical properties of soot aggregated with spheroidal monomers

    Science.gov (United States)

    Wu, Yu; Cheng, Tianhai; Zheng, Lijuan; Chen, Hao

    2016-01-01

    The monomers of fractal aggregated soot particles are usually considered to be standard spheres in simulations, but a number of less regular shapes may be found in some burning conditions. In this paper, we simulated and investigated the optical properties of fresh dry soot particles as the aggregations of spheroidal monomers with different aspect ratios. Their optical properties were calculated using the numerically exact discrete dipole approximation (DDA) method. The simulated results indicated that the optical properties of soot aggregates composed of spheroidal monomers with highly nonspherical morphologies were considerably different from those composed of spherical monomers. The soot aggregates composed of the oblate spheroids with larger aspect ratios or the prolate spheroids with smaller aspect ratios may have led to larger cross sections of extinction, absorption and scattering. In extreme cases with Ra /Rb = 3 and Ra /Rb = 1 / 3 for the soot spheroidal monomers, the relative deviations compared to spherical monomers models reached up to 15% for the absorption cross sections, 10% for the single scattering albedo (SSA) and -25% for the asymmetry parameter (ASY). Moreover, by assuming a soot refractive index of 1.95+0.79i, a mass density of 1.8 g/cm3 and a mean volume-equivalent spherical monomer radius of 0.02 μm, the estimated mass absorption cross sections (MAC) of soot aggregates composed of the oblate spheroidal monomers with large aspect ratios (Ra /Rb = 3) reached up to 7.5 m2/g, which was closer to the measurements of 7.5±1.2 m2/g than the ~6.5 m2/g determined by the spherical monomers models. For future research with this type of small aggregated aerosol particles, it would be valuable to consider the monomer morphologies used in this paper for their optical simulations.

  1. On the radiative properties of soot aggregates part 1: Necking and overlapping

    International Nuclear Information System (INIS)

    There is a strong interest in accurately modelling the radiative properties of soot aggregates (also known as black carbon particles) emitted from combustion systems and fires to gain improved understanding of the role of black carbon to global warming. This study conducted a systematic investigation of the effects of overlapping and necking between neighbouring primary particles on the radiative properties of soot aggregates using the discrete dipole approximation. The degrees of overlapping and necking are quantified by the overlapping and necking parameters. Realistic soot aggregates were generated numerically by constructing overlapping and necking to fractal aggregates formed by point-touch primary particles simulated using a diffusion-limited cluster aggregation algorithm. Radiative properties (differential scattering, absorption, total scattering, specific extinction, asymmetry factor and single scattering albedo) were calculated using the experimentally measured soot refractive index over the spectral range of 266–1064 nm for 9 combinations of the overlapping and necking parameters. Overlapping and necking affect significantly the absorption and scattering properties of soot aggregates, especially in the near UV spectrum due to the enhanced multiple scattering effects within an aggregate. By using correctly modified aggregate properties (fractal dimension, prefactor, primary particle radius, and the number of primary particle) and by accounting for the effects of multiple scattering, the simple Rayleigh–Debye–Gans theory for fractal aggregates can reproduce reasonably accurate radiative properties of realistic soot aggregates. - Highlights: • We determine the radiative properties of realistic virtual soot aggregates. • We consider the primary sphere polydispersity, their necking and overlapping. • Scattering and absorption are decreased by considering these effects in the UV. • The single scattering albedo and asymmetry factor are also deeply

  2. Optimization of Bed Material Consumption in a CFBC Boiler

    Directory of Open Access Journals (Sweden)

    Ashish M. Pullekunnel

    2015-01-01

    Full Text Available The proposed Case-Study is to identify the scope of energy conservation and cost saving through optimization of bed material in a CFBC Boiler during plant start up. The study was undertaken at Abhijeet MADC Nagpur Energy Pvt. Ltd (AMNEPL, a 4X61.5 MW power plant at MIHAN, Khairy Khurd, Hingna, Nagpur. The scope of the study covers the savings achieved during light up of 4X250 TPH boiler and the effect of the application of the proposed method on the energy conservation possibilities and efficiency of boiler operation. The proposed method is an alternative to the conventional boiler light up of a CFBC boiler

  3. Dynamic Boiler Performance:Modelling, simulating and optimizing boilers for dynamic operation

    OpenAIRE

    Sørensen, Kim

    2004-01-01

    Traditionally, boilers have been designed mainly focussing on the static operation of the plant. The dynamic capability has been given lower priority and the analysis has typically been limited to assuring that the plant was not over-stressed due to large temperature gradients.New possibilities for buying and selling energy has increased the focus on the dynamic operation capability, efciency, emissions etc. For optimizing the design of boilers for dynamic operation a quantication of the dyna...

  4. Thermal Analysis of Superheater Platen Tubesin Boilers

    Directory of Open Access Journals (Sweden)

    Shahram Falahatkar

    2014-01-01

    Full Text Available Superheaters are among the most important components of boilers and have major importance due to this operation in high temperatures and pressures. Turbines are sensitive to the fluctuation of superheaterstemperature;therefore even the slightest fluctuation in the outlet vapor temperature from the superheaters does damage the turbine axis and fins. Examining the potential damages of combustion in the boilers and components such as the superheaters can have a vital contribution to the progression of the productivity of boiler, turbine and the power plant altogether it solutions are to be fund to improve such systems. In this study, the focus is on the nearest tube set of superheaters to the combustion chamber.These types of tubes are exposed to a wide range ofcombustion flames such that the most heat transfer to them is radiation type.Here, the 320 MW boiler of Isfahan power plant (Iran, the combustion chamber, 16 burners and the platensuperheater tubes were remodeled by CFD technique. The fluid motion, the heat transfer and combustion processes are analyzed. The two-equation turbulence model of k-εis adopted to measure the eddy viscosity. The eddy dissipation model is used to calculate the combustion as well as the P-1 radiation model to quantify the radiation. The overheated zones of superheater tubes and the combustion chamber are identified in order toimprove this problem by applying the radiation thermal shields and knees with porous crust which are introduced as the new techniques.

  5. Environmental control during steam boiler washing

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Marcio A.B.; Abreu Pereira, Vera L. de [Companhia Petroquimica do Nordeste (COPENE), Camacari, BA (Brazil). Div. de Engenharia Ambiental; Ringler, Ulrich E.S. [PROMON Engenharia Ltda., Salvador, BA (Brazil)

    1993-12-31

    The washing and chemical cleaning of boilers, activities of a high polluting potential, are responsible for the generation of wastewater of high contents of heavy metals, suspended solids and chemical oxygen demand (COD). This paper describes the actions carried out by COPENE - Petroquimica do Nordeste S/A - in order to reduce this problem. (author). 10 refs., 3 figs., 2 tabs.

  6. REBURN TECHNOLOGY FOR BOILER NOX CONTROL

    Science.gov (United States)

    The paper reports the progress principally of design-relate phases of a demonstration of reburning on a large cyclone-fired boiler, for which coal is the primary fuel and natural gas, the reburn fuel. Reburn system design criteria are presented, as well as the methodology and res...

  7. The investigation of the locomotive boiler material

    International Nuclear Information System (INIS)

    In the paper, the history of narrow-gauge railway system is described. The other information about the steam locomotive construction, as well as the technical regulations of its construction and exploitation are also done. The results of the studies of the locomotive boiler material are presented. (authors)

  8. New thinking for the boiler room.

    Science.gov (United States)

    Rose, Wayne

    2008-09-01

    Wayne Rose, marketing manager at integrated plant room manufacturer Armstrong Integrated Systems, explains how increasing use of off-site manufacture, the latest 3D modelling technology, and advances in control technology, are revolutionising boiler room design and construction. PMID:18822819

  9. Model boiler studies on deposition and corrosion

    International Nuclear Information System (INIS)

    Deposit formation was studied in a model boiler, with sea-water injections to simulate the in-leakage which could occur from sea-water cooled condensers. When All Volatile Treatment (AVT) was used for chemistry control the deposits consisted of the sea-water salts and corrosion products. With sodium phosphate added to the boiler water, the deposits also contained the phosphates derived from the sea-water salts. The deposits were formed in layers of differing compositions. There was no significant corrosion of the Fe-Ni-Cr alloy boiler tube under deposits, either on the open area of the tube or in crevices. However, carbon steel that formed a crevice around the tube was corroded severely when the boiler water did not contain phosphate. The observed corrosion of carbon steel was caused by the presence of acidic, highly concentrated chloride solution produced from the sea-water within the crevice. Results of theoretical calculations of the composition of the concentrated solution are presented. (author)

  10. Infrared imaging of fossil fuel power plant boiler interiors

    Science.gov (United States)

    Howard, James W.; Cranton, Brian W.; Armstrong, Karen L.; Hammaker, Robert G.

    1997-08-01

    Fossil fuel power plant boilers operate continuously for months at a time, typically shutting down only for routine maintenance or to address serious equipment failures. These shutdowns are very costly, and diagnostic tools and techniques which could be used to minimize shutdown duration and frequency are highly desirable. Due to the extremely hostile environment in these boilers, few tools exist to inspect and monitor operating boiler interiors. This paper presents the design of a passively cooled, infrared borescope used to inspect the interior of operating boilers. The borescope operates at 3.9 micrometer, where flame is partially transparent. The primary obstacles overcome in the instrument design were the harsh industrial environment surrounding the boilers and the high temperatures encountered inside the boilers. A portable yet durable lens system and enclosure was developed to work with a scanning radiometer to address these two problems by both shielding the radiometer from the environment and by extending the optical train into a snout designed to be inserted into access ports on the sides of the boiler. In this manner, interior images of the boiler can be made while keeping the radiometer safely outside the boiler. The lens views a 40 degree field of view through any 2.5' or larger opening in a foot thick boiler wall. Three of these borescopes have been built, and high resolution images of boiler interiors have been obtained.

  11. Mixing state of regionally transported soot particles and the coating effect on their size and shape at a mountain site in Japan

    Science.gov (United States)

    Adachi, Kouji; Zaizen, Yuji; Kajino, Mizuo; Igarashi, Yasuhito

    2014-05-01

    Soot particles influence the global climate through interactions with sunlight. A coating on soot particles increases their light absorption by increasing their absorption cross section and cloud condensation nuclei activity when mixed with other hygroscopic aerosol components. Therefore, it is important to understand how soot internally mixes with other materials to accurately simulate its effects in climate models. In this study, we used a transmission electron microscope (TEM) with an auto particle analysis system, which enables more particles to be analyzed than a conventional TEM. Using the TEM, soot particle size and shape (shape factor) were determined with and without coating from samples collected at a remote mountain site in Japan. The results indicate that ~10% of aerosol particles between 60 and 350 nm in aerodynamic diameters contain or consist of soot particles and ~75% of soot particles were internally mixed with nonvolatile ammonium sulfate or other materials. In contrast to an assumption that coatings change soot shape, both internally and externally mixed soot particles had similar shape and size distributions. Larger aerosol particles had higher soot mixing ratios, i.e., more than 40% of aerosol particles with diameters >1 µm had soot inclusions, whereas <20% of aerosol particles with diameters <1 µm included soot. Our results suggest that climate models may use the same size distributions and shapes for both internally and externally mixed soot; however, changing the soot mixing ratios in the different aerosol size bins is necessary.

  12. Insights on postinjection-associated soot emissions in direct injection diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Arregle, Jean; Pastor, Jose V.; Lopez, J. Javier; Garcia, Antonio [CMT-Motores Termicos, Universidad Politecnica de Valencia, Camino de Vera, s/n 46022, Valencia (Spain)

    2008-08-15

    A comprehensive study was carried out in order to better understand combustion behavior in a direct injection diesel engine when using postinjections. More specifically, the aim of the study is twofold: (1) to better understand the mechanism of a postinjection to reduce soot and (2) to improve the understanding of the contribution of the postinjection combustion on the total soot emissions by looking at the effect of the postinjection timing variation and the postinjection mass variation on the soot emissions associated with the postinjection. The study is focused only on far postinjections, and the explored operating conditions include the use of EGR. The first objective was fulfilled analyzing some results from a previous work adding only a few complementary results. Concerning the second objective, the basic idea behind the analysis performed is the search of appropriate parameters physically linked to the processes under analysis. These parameters are found based on the state-of-the-art of diesel combustion. For the effect of the postinjection timing, the physical parameter found was the temperature of the unburned gases at the end of injection, T{sub ug{sub E}}{sub oI}. It was checked that a threshold level of T{sub ug{sub E}}{sub oI} ({proportional_to}700 K for the cases explored here) exists below which soot is unable to be formed, independently of the postinjection size, and the amount of soot increases as the temperature increases beyond this threshold. For the effect of the postinjection size, the physical parameter that was found was DoI/ACT (the ratio between the actual duration of injection and the time necessary for mixing - the apparent combustion time). This parameter can quantify when the postinjection is able to produce soot (the threshold value is {proportional_to}0.37 for the cases explored here), and the amount of soot produced increases as this parameter increases beyond this threshold value. A function containing these two parameters has been

  13. Structural effects on the oxidation of soot particles by O2: Experimental and theoretical study

    KAUST Repository

    Raj, Abhijeet

    2013-09-01

    Soot particles are composed of polycyclic aromatic hydrocarbons (PAHs), which have either planar or curved structures. The oxidation behaviors of soot particles differ depending on their structures, arrangement of PAHs, and the type of surface functional groups. The oxidation rate of curved PAHs in soot is thought to be higher than that of planar ones. To understand the role that PAH structure plays in soot reactivity towards O2, experimental studies are conducted on two types of commercially produced soot, Printex-U and Fullerene soot, using high resolution transmission electron microscopy, electron energy loss spectroscopy, thermo-gravimetric analysis and elemental analysis. The relative concentrations of active sites, oxygenated functional groups, aliphatics and aromatics present in soots are evaluated. The activation energies for soot oxidation at different conversion levels are determined. The average activation energies of the two soots are found to differ by 26kJ/mol. To understand the reason for this difference, quantum calculations using density functional (B3LYP) and Hartree-Fock theories are conducted to study the reaction pathways of the oxidation by O2 of planar and curved PAHs using 4-pyrenyl and 1-corannulenyl as their model molecules, respectively. The energetically preferred channels for curved PAH oxidation differ from the planar one. The addition of O2 on a radical site of a six-membered ring to form a peroxyl radical is found to be barrierless for both the model PAHs. For peroxyl decomposition, three pathways are suggested, each of which involve the activation energies of 108, 170 and 121kJ/mol to form stable molecules in the case of planar PAH, and 94, 155 and 125kJ/mol in the case of curved PAH. During the oxidation of a five-membered ring, to form stable molecules, the activation energies of 90kJ/mol for the curved PAH and 169kJ/mol for the planar PAH relative to the energy of the peroxyl radical are required. The low activation barriers of

  14. Cloud droplet activity changes of soot aerosol upon smog chamber ageing

    Science.gov (United States)

    Wittbom, C.; Eriksson, A. C.; Rissler, J.; Carlsson, J. E.; Roldin, P.; Nordin, E. Z.; Nilsson, P. T.; Swietlicki, E.; Pagels, J. H.; Svenningsson, B.

    2014-09-01

    Particles containing soot, or black carbon, are generally considered to contribute to global warming. However, large uncertainties remain in the net climate forcing resulting from anthropogenic emissions of black carbon (BC), to a large extent due to the fact that BC is co-emitted with gases and primary particles, both organic and inorganic, and subject to atmospheric ageing processes. In this study, diesel exhaust particles and particles from a flame soot generator spiked with light aromatic secondary organic aerosol (SOA) precursors were processed by UV radiation in a 6 m3 Teflon chamber in the presence of NOx. The time-dependent changes of the soot nanoparticle properties were characterised using a Cloud Condensation Nuclei Counter, an Aerosol Particle Mass Analyzer and a Soot Particle Aerosol Mass Spectrometer. The results show that freshly emitted soot particles do not activate into cloud droplets at supersaturations ≤2%, i.e. the BC core coated with primary organic aerosol (POA) from the exhaust is limited in hygroscopicity. Before the onset of UV radiation it is unlikely that any substantial SOA formation is taking place. An immediate change in cloud-activation properties occurs at the onset of UV exposure. This change in hygroscopicity is likely attributed to SOA formed from intermediate volatility organic compounds (IVOCs) in the diesel engine exhaust. The change of cloud condensation nuclei (CCN) properties at the onset of UV radiation implies that the lifetime of soot particles in the atmosphere is affected by the access to sunlight, which differs between latitudes. The ageing of soot particles progressively enhances their ability to act as cloud condensation nuclei, due to changes in: (I) organic fraction of the particle, (II) chemical properties of this fraction (e.g. primary or secondary organic aerosol), (III) particle size, and (IV) particle morphology. Applying κ-Köhler theory, using a κSOA value of 0.13 (derived from independent input

  15. Cloud droplet activity changes of soot aerosol upon smog chamber ageing

    Directory of Open Access Journals (Sweden)

    C. Wittbom

    2014-04-01

    Full Text Available Particles containing soot, or black carbon, are generally considered to contribute to global warming. However, large uncertainties remain in the net climate forcing resulting from anthropogenic emissions of black carbon (BC, to a large extent due to the fact that BC is co-emitted with gases and primary particles, both organic and inorganic, and subject to atmospheric ageing processes. In this study, diesel exhaust particles and particles from a flame soot generator spiked with light aromatic secondary organic aerosol (SOA precursors were processed by UV-radiation in a 6 m3 Teflon chamber in the presence of NOx. The time-dependent changes of the soot nanoparticle properties were characterised using a Cloud Condensation Nuclei Counter, an Aerosol Particle Mass Analyzer and a Soot Particle Aerosol Mass Spectrometer. The results show that freshly emitted soot particles do not activate into cloud droplets at supersaturations ≤ 2%, i.e. the black carbon core coated with primary organic aerosol (POA from the exhaust is limited in hygroscopicity. Before the onset of UV radiation it is unlikely that any substantial SOA formation is taking place. An immediate change in cloud-activation properties occurs at the onset of UV exposure. This change in hygroscopicity is likely attributed to SOA formed from intermediate volatile organic compounds (IVOC in the diesel engine exhaust. The change of cloud condensation nuclei (CCN properties at the onset of UV radiation implies that the lifetime of soot particles in the atmosphere is affected by the access to sunlight, which differs between latitudes. The ageing of soot particles progressively enhances their ability to act as cloud condensation nuclei, due to changes in: (I organic fraction of the particle, (II chemical properties of this fraction (POA or SOA, (III particle size, and (IV particle morphology. Applying κ-Köhler theory, using a κSOA value of 0.13 (derived from independent input parameters

  16. Simulation on Soot Oxidation with NO2 and O2 in a Diesel Particulate Filter

    Science.gov (United States)

    Yamamoto, Kazuhiro; Satake, Shingo; Yamashita, Hiroshi; Obuchi, Akira; Uchisawa, Junko

    Although diesel engines have an advantage of low fuel consumption in comparison with gasoline engines, exhaust gas has more particulate matters (PM) including soot. As one of the key technologies, a diesel particulate filter (DPF) has been developed to reduce PM. When the exhaust gas passes its porous filter wall, the soot particles are trapped. However, the filter would readily be plugged with particles, and the accumulated particles must be removed to prevent filter clogging and a rise in backpressure, which is called filter regeneration process. In this study, we have simulated the flow in the wall-flow DPF using the lattice Boltzmann method. Filters of different length, porosity, and pore size are used. The soot oxidation for filter regeneration process is considered. Especially, the effect of NO2 on the soot oxidation is examined. The reaction rate has been determined by previous experimental data. Results show that, the flow along the filter monolith is roughly uniform, and the large pressure drop across the filter wall is observed. The soot oxidation rate becomes ten times larger when NO2 is added. These are useful information to construct the future regeneration system.

  17. Simulation of an electrostatic soot-filter with continuous electrochemical conversion during the stages of development

    International Nuclear Information System (INIS)

    The dissertation describes the simulation of an electrostatic Diesel-Soot-Converter during its stages of development. This simulation is not only necessary for the interpretation of the experimental results, it also shows results for assumptions that cannot be received experimentally. The Diesel-Soot-Converter consists of a charging electrode, which charges the particles by a high-voltage and a ceramic monolith, where the particles are precipitated in the open channels because of an electric field created also by a high-voltage. Afterwards the particles are burned by a plasma. The filter-function of the Diesel-Soot-Converter was formulated and the efficiency for a vehicle was calculated. In the first part of the calculation the mass flow of a BMW 318tds and a BMW 325tds was determined for an US-FTP75-testcycle and for fuel load. In the second part the efficiency of different Diesel-Soot-Converter-types was calculated for the US-FTP75-testcycle and for full load. The use of the program with other testcycles is possible. The results of the calculations show the best configuration of the Diesel-Soot-Converter for the corresponding vehicle. Therefore with the help of this program time and money for the production of the ceramic can be saved. (author)

  18. Sensing the soot load in automotive diesel particulate filters by microwave methods

    Science.gov (United States)

    Fischerauer, Gerhard; Förster, Martin; Moos, Ralf

    2010-03-01

    Modern vehicles with diesel engines need to be equipped with particulate filters (DPFs) to meet today's and tomorrow's stringent emission regulations. Such filters must be regenerated on a regular basis to burn off the soot adsorbed in the course of time. As the regeneration processes consume fuel, they must be kept to the bare minimum which requires a detailed knowledge of the actual soot load in the filter. We have investigated if the soot load can be determined in situ by the cavity perturbation method at operating frequencies in the low GHz range. We will show that, indeed, current microwave technology as used, for instance, in cellular phones is capable of detecting the soot load in a diesel particulate filter. Experimentally observed sensitivities of cavity resonance frequencies to soot load (adsorbed mass) were as high as 3 MHz g-1. This contribution reports on the measurement approach, experimental results obtained in industrial dynamometer test benches and the conclusions to be drawn from the results.

  19. Comparison of the tribology performance of nano-diesel soot and graphite particles as lubricant additives

    International Nuclear Information System (INIS)

    The tribology behavior of exhaust diesel soot as a lubricant additive was investigated and then compared with that of a selection of commercial nano-graphite particles. Specifically, 0.01 wt% particles were dispersed in PAO4 oil with 1 wt% sorbitan monooleate (Span 80) as a dispersing agent, and wear tests based on the ball against plate mode were conducted at various temperatures. Different analytical techniques (e.g. transmission electron, scanning electron and infrared microscopy; energy dispersive x-ray and Raman spectroscopy; and charge measurement) were employed to characterize the chemistry and morphology of the additives and their tribology performance. The oil containing only 0.01 wt% diesel soot clearly improved wear resistance over 60 °C. In particular, at 100 °C the wear rate decreased by approximately 90% compared to the function of base oil. In the same test conditions, diesel soot exhibited better anti-wear performance than nano-graphite at high temperatures. The potential measure showed that the nano-graphite had positive charge and the diesel soot had negative charge. Electrochemical action may play an important role in the lubricant mechanisms of diesel soot and graphite as oil additives. (paper)

  20. Comparison of the tribology performance of nano-diesel soot and graphite particles as lubricant additives

    Science.gov (United States)

    Zhang, Zu-chuan; Cai, Zhen-bing; Peng, Jin-fang; Zhu, Min-hao

    2016-02-01

    The tribology behavior of exhaust diesel soot as a lubricant additive was investigated and then compared with that of a selection of commercial nano-graphite particles. Specifically, 0.01 wt% particles were dispersed in PAO4 oil with 1 wt% sorbitan monooleate (Span 80) as a dispersing agent, and wear tests based on the ball against plate mode were conducted at various temperatures. Different analytical techniques (e.g. transmission electron, scanning electron and infrared microscopy; energy dispersive x-ray and Raman spectroscopy; and charge measurement) were employed to characterize the chemistry and morphology of the additives and their tribology performance. The oil containing only 0.01 wt% diesel soot clearly improved wear resistance over 60 °C. In particular, at 100 °C the wear rate decreased by approximately 90% compared to the function of base oil. In the same test conditions, diesel soot exhibited better anti-wear performance than nano-graphite at high temperatures. The potential measure showed that the nano-graphite had positive charge and the diesel soot had negative charge. Electrochemical action may play an important role in the lubricant mechanisms of diesel soot and graphite as oil additives.

  1. Sensing the soot load in automotive diesel particulate filters by microwave methods

    International Nuclear Information System (INIS)

    Modern vehicles with diesel engines need to be equipped with particulate filters (DPFs) to meet today's and tomorrow's stringent emission regulations. Such filters must be regenerated on a regular basis to burn off the soot adsorbed in the course of time. As the regeneration processes consume fuel, they must be kept to the bare minimum which requires a detailed knowledge of the actual soot load in the filter. We have investigated if the soot load can be determined in situ by the cavity perturbation method at operating frequencies in the low GHz range. We will show that, indeed, current microwave technology as used, for instance, in cellular phones is capable of detecting the soot load in a diesel particulate filter. Experimentally observed sensitivities of cavity resonance frequencies to soot load (adsorbed mass) were as high as 3 MHz g−1. This contribution reports on the measurement approach, experimental results obtained in industrial dynamometer test benches and the conclusions to be drawn from the results

  2. Laboratory Studies of the Effects of Ambient Conditions, Soot Emissions, and Fuel Properties on Contrail Formation

    Science.gov (United States)

    Beyersdorf, A. J.; Anderson, B. E.; Bulzan, D.; Miake-Lye, R. C.; Tacina, K.; Thornhill, K. L.; Winstead, E.; Wong, H.; Ziemba, L. D.

    2010-12-01

    Contrail formation by aircraft can affect the global radiation budget and is the most uncertain component of aviation impacts on climate change. Field campaigns studying contrail formation have given insight into their formation pathways. However in order to improve simulations of contrail production, laboratory studies of the initial processes of contrail formation from aircraft-emitted soot are needed. As part of the Aviation Climate Change Research Initiative (ACCRI), laboratory studies of contrail formation from simulated aircraft emissions were performed at the particulate aerosol laboratory (PAL) at the NASA Glenn Research Center. The facility consists of a controlled soot source connected to a flow-through chamber which can simulate atmospheric conditions at altitudes up to 45,000 ft. Soot was made by a propane-fueled CAST generator and allowed to mix with water vapor and sulfuric acid to simulate aircraft emissions. Optical particle counters were employed at two distances from the nozzle tip that provided number concentration and size distributions of newly formed ice particles. The formation of ice particles is presented for chamber temperatures and pressures simulating altitudes between 15,000 and 40,000 feet. Initial results show the role of soot concentration, soot size, concentration of co-emitted pollutants and ambient conditions in ice particle formation.

  3. Molecular characterization of organic content of soot along the centerline of a coflow diffusion flame.

    Science.gov (United States)

    Cain, Jeremy; Laskin, Alexander; Kholghy, Mohammad Reza; Thomson, Murray J; Wang, Hai

    2014-12-21

    High-resolution mass spectrometry coupled with nanospray desorption electrospray ionization was used to probe chemical constituents of young soot particles sampled along the centerline of a coflow diffusion flame of a three-component Jet-A1 surrogate. In lower positions where particles are transparent to light extinction (λ = 632.8 nm), peri-condensed polycyclic aromatic hydrocarbons (PAHs) are found to be the major components of the particle material. These particles become enriched with aliphatic components as they grow in mass and size. Before carbonization occurs, the constituent species in young soot particles are aliphatic and aromatic compounds 200-600 amu in mass, some of which are oxygenated. Particles dominated by PAHs or mixtures of PAHs and aliphatics can exhibit liquid-like appearance observed by electron microscopy and be transparent to visible light. The variations in chemical composition observed here indicate that the molecular processes of soot formation in coflow diffusion flames may be more complex than previously thought. For example, the mass growth and enrichment of aliphatic components in an initial mostly aromatic structure region of the flame that is absent of H atoms or other free radicals indicates that there must exist at least another mechanism of soot mass growth in addition to the hydrogen abstraction-carbon addition mechanism currently considered in fundamental models of soot formation. PMID:25354231

  4. MINIMIZATION OF NO EMISSIONS FROM MULTI-BURNER COAL-FIRED BOILERS; FINAL

    International Nuclear Information System (INIS)

    The focus of this program is to provide insight into the formation and minimization of NO(sub x) in multi-burner arrays, such as those that would be found in a typical utility boiler. Most detailed studies are performed in single-burner test facilities, and may not capture significant burner-to-burner interactions that could influence NO(sub x) emissions. Thus, investigations of such interactions were made by performing a combination of single and multiple burner experiments in a pilot-scale coal-fired test facility at the University of Utah, and by the use of computational combustion simulations to evaluate full-scale utility boilers. In addition, fundamental studies on nitrogen release from coal were performed to develop greater understanding of the physical processes that control NO formation in pulverized coal flames-particularly under low NO(sub x) conditions. A CO/H(sub 2)/O(sub 2)/N(sub 2) flame was operated under fuel-rich conditions in a flat flame reactor to provide a high temperature, oxygen-free post-flame environment to study secondary reactions of coal volatiles. Effects of temperature, residence time and coal rank on nitrogen evolution and soot formation were examined. Elemental compositions of the char, tar and soot were determined by elemental analysis, gas species distributions were determined using FTIR, and the chemical structure of the tar and soot was analyzed by solid-state(sup 13)C NMR spectroscopy. A laminar flow drop tube furnace was used to study char nitrogen conversion to NO. The experimental evidence and simulation results indicated that some of the nitrogen present in the char is converted to nitric oxide after direct attack of oxygen on the particle, while another portion of the nitrogen, present in more labile functionalities, is released as HCN and further reacts in the bulk gas. The reaction of HCN with NO in the bulk gas has a strong influence on the overall conversion of char-nitrogen to nitric oxide; therefore, any model that

  5. MINIMIZATION OF NO EMISSIONS FROM MULTI-BURNER COAL-FIRED BOILERS

    Energy Technology Data Exchange (ETDEWEB)

    E.G. Eddings; A. Molina; D.W. Pershing; A.F. Sarofim; T.H. Fletcher; H. Zhang; K.A. Davis; M. Denison; H. Shim

    2002-01-01

    The focus of this program is to provide insight into the formation and minimization of NO{sub x} in multi-burner arrays, such as those that would be found in a typical utility boiler. Most detailed studies are performed in single-burner test facilities, and may not capture significant burner-to-burner interactions that could influence NO{sub x} emissions. Thus, investigations of such interactions were made by performing a combination of single and multiple burner experiments in a pilot-scale coal-fired test facility at the University of Utah, and by the use of computational combustion simulations to evaluate full-scale utility boilers. In addition, fundamental studies on nitrogen release from coal were performed to develop greater understanding of the physical processes that control NO formation in pulverized coal flames--particularly under low NO{sub x} conditions. A CO/H{sub 2}/O{sub 2}/N{sub 2} flame was operated under fuel-rich conditions in a flat flame reactor to provide a high temperature, oxygen-free post-flame environment to study secondary reactions of coal volatiles. Effects of temperature, residence time and coal rank on nitrogen evolution and soot formation were examined. Elemental compositions of the char, tar and soot were determined by elemental analysis, gas species distributions were determined using FTIR, and the chemical structure of the tar and soot was analyzed by solid-state {sup 13}C NMR spectroscopy. A laminar flow drop tube furnace was used to study char nitrogen conversion to NO. The experimental evidence and simulation results indicated that some of the nitrogen present in the char is converted to nitric oxide after direct attack of oxygen on the particle, while another portion of the nitrogen, present in more labile functionalities, is released as HCN and further reacts in the bulk gas. The reaction of HCN with NO in the bulk gas has a strong influence on the overall conversion of char-nitrogen to nitric oxide; therefore, any model that

  6. Effects of diluents on soot surface temperature and volume fraction in diluted ethylene diffusion flames at pressure

    KAUST Repository

    Kailasanathan, Ranjith Kumar Abhinavam

    2014-05-20

    Soot surface temperature and volume fraction are measured in ethylene/air coflowing laminar diffusion flames at high pressures, diluted with one of four diluents (argon, helium, nitrogen, and carbon dioxide) using a two-color technique. Both temperature and soot measurements presented are line-of-sight averages. The results aid in understanding the kinetic and thermodynamic behavior of the soot formation and oxidation chemistry with changes in diluents, ultimately leading to possible methods of reducing soot emission from practical combustion hardware. The diluted fuel and coflow exit velocities (top-hat profiles) were matched at all pressures to minimize shear effects. In addition to the velocity-matched flow rates, the mass fluxes were held constant for all pressures. Addition of a diluent has a pronounced effect on both the soot surface temperature and volume fraction, with the helium diluted flame yielding the maximum and carbon dioxide diluted flame yielding minimum soot surface temperature and volume fraction. At low pressures, peak soot volume fraction exists at the tip of the flame, and with an increase in pressure, the location shifts lower to the wings of the flame. Due to the very high diffusivity of helium, significantly higher temperature and volume fraction are measured and explained. Carbon dioxide has the most dramatic soot suppression effect. By comparing the soot yield with previously measured soot precursor concentrations in the same flame, it is clear that the lower soot yield is a result of enhanced oxidation rates rather than a reduction in precursor formation. Copyright © 2014 Taylor & Francis Group, LLC.

  7. Health effects of combustion-generated soot and polycyclic aromatic hydrocarbons. Progress report, May 1, 1979-April 30, 1980. [Lead abstract

    Energy Technology Data Exchange (ETDEWEB)

    Thilly, W. G.

    1980-05-01

    Mutagen studies on soot and soot components are reported in aspects dealing from quantitative chemical analyses of samples and mutagenesis of cells and microorganisms exposed to mutagens, to bioassay developments and techniques. Several polycyclic aromatic hydrocarbons are characterized and discussed.

  8. Candle soot-based super-amphiphobic coatings resist protein adsorption.

    Science.gov (United States)

    Schmüser, Lars; Encinas, Noemi; Paven, Maxime; Graham, Daniel J; Castner, David G; Vollmer, Doris; Butt, Hans Jürgen; Weidner, Tobias

    2016-01-01

    Super nonfouling surfaces resist protein adhesion and have a broad field of possible applications in implant technology, drug delivery, blood compatible materials, biosensors, and marine coatings. A promising route toward nonfouling surfaces involves liquid repelling architectures. The authors here show that soot-templated super-amphiphobic (SAP) surfaces prepared from fluorinated candle soot structures are super nonfouling. When exposed to bovine serum albumin or blood serum, x-ray photoelectron spectroscopy and time of flight secondary ion mass spectrometry analysis showed that less than 2 ng/cm(2) of protein was adsorbed onto the SAP surfaces. Since a broad variety of substrate shapes can be coated by soot-templated SAP surfaces, those are a promising route toward biocompatible materials design. PMID:27460261

  9. Soot formation and radiation in turbulent jet diffusion flames under normal and reduced gravity conditions

    Science.gov (United States)

    Ku, Jerry C.; Tong, LI; Sun, Jun; Greenberg, Paul S.; Griffin, Devon W.

    1993-01-01

    Most practical combustion processes, as well as fires and explosions, exhibit some characteristics of turbulent diffusion flames. For hydrocarbon fuels, the presence of soot particles significantly increases the level of radiative heat transfer from flames. In some cases, flame radiation can reach up to 75 percent of the heat release by combustion. Laminar diffusion flame results show that radiation becomes stronger under reduced gravity conditions. Therefore, detailed soot formation and radiation must be included in the flame structure analysis. A study of sooting turbulent diffusion flames under reduced-gravity conditions will not only provide necessary information for such practical issues as spacecraft fire safety, but also develop better understanding of fundamentals for diffusion combustion. In this paper, a summary of the work to date and of future plans is reported.

  10. Effects of C/O Ratio and Temperature on Sooting Limits of Spherical Diffusion Flames

    Science.gov (United States)

    Lecoustre, V. R.; Sunderland, P. B.; Chao, B. H.; Urban, D. L.; Stocker, D. P.; Axelbaum, R. L.

    2008-01-01

    Limiting conditions for soot particle inception in spherical diffusion flames were investigated numerically. The flames were modeled using a one-dimensional, time accurate diffusion flame code with detailed chemistry and transport and an optically thick radiation model. Seventeen normal and inverse flames were considered, covering a wide range of stoichiometric mixture fraction, adiabatic flame temperature, residence time and scalar dissipation rate. These flames were previously observed to reach their sooting limits after 2 s of microgravity. Sooting-limit diffusion flames with scalar dissipation rate lower than 2/s were found to have temperatures near 1400 K where C/O = 0.51, whereas flames with greater scalar dissipation rate required increased temperatures. This finding was valid across a broad range of fuel and oxidizer compositions and convection directions.

  11. Oxy-Combustion Boiler Material Development

    Energy Technology Data Exchange (ETDEWEB)

    Gagliano, Michael; Seltzer, Andrew; Agarwal, Hans; Robertson, Archie; Wang, Lun

    2012-01-31

    Under U.S. Department of Energy Cooperative Agreement No. DE-NT0005262 Foster Wheeler North America Corp conducted a laboratory test program to determine the effect of oxy-combustion on boiler tube corrosion. In this program, CFD modeling was used to predict the gas compositions that will exist throughout and along the walls of air-fired and oxy-fired boilers operating with low to high sulfur coals. Test coupons of boiler tube materials were coated with deposits representative of those coals and exposed to the CFD predicted flue gases for up to 1000 hours. The tests were conducted in electric tube furnaces using oxy-combustion and air-fired flue gases synthesized from pressurized cylinders. Following exposure, the test coupons were evaluated to determine the total metal wastage experienced under air and oxy-combustions conditions and materials recommendations were made. Similar to air-fired operation, oxy-combustion corrosion rates were found to vary with the boiler material, test temperature, deposit composition, and gas composition. Despite this, comparison of air-fired and oxy-fired corrosion rates showed that oxy-firing rates were, for the most part, similar to, if not lower than those of air-firing; this finding applied to the seven furnace waterwall materials (wrought and weld overlay) and the ten superheater/reheater materials (wrought and weld overlay) that were tested. The results of the laboratory oxy-combustion tests, which are based on a maximum bulk flue gas SO2 level of 3200 ppmv (wet) / 4050 ppmv (dry), suggest that, from a corrosion standpoint, the materials used in conventional subcritical and supercritical, air-fired boilers should also be suitable for oxy-combustion retrofits. Although the laboratory test results are encouraging, they are only the first step of a material evaluation process and it is recommended that follow-on corrosion tests be conducted in coal-fired boilers operating under oxy-combustion to provide longer term (one to two year

  12. Oxy-Combustion Boiler Material Development

    Energy Technology Data Exchange (ETDEWEB)

    Michael Gagliano; Andrew Seltzer; Hans Agarwal; Archie Robertson; Lun Wang

    2012-01-31

    Under U.S. Department of Energy Cooperative Agreement No. DE-NT0005262 Foster Wheeler North America Corp conducted a laboratory test program to determine the effect of oxy-combustion on boiler tube corrosion. In this program, CFD modeling was used to predict the gas compositions that will exist throughout and along the walls of air-fired and oxy-fired boilers operating with low to high sulfur coals. Test coupons of boiler tube materials were coated with deposits representative of those coals and exposed to the CFD predicted flue gases for up to 1000 hours. The tests were conducted in electric tube furnaces using oxy-combustion and air-fired flue gases synthesized from pressurized cylinders. Following exposure, the test coupons were evaluated to determine the total metal wastage experienced under air and oxy-combustions conditions and materials recommendations were made. Similar to air-fired operation, oxy-combustion corrosion rates were found to vary with the boiler material, test temperature, deposit composition, and gas composition. Despite this, comparison of air-fired and oxy-fired corrosion rates showed that oxy-firing rates were, for the most part, similar to, if not lower than those of air-firing; this finding applied to the seven furnace waterwall materials (wrought and weld overlay) and the ten superheater/reheater materials (wrought and weld overlay) that were tested. The results of the laboratory oxy-combustion tests, which are based on a maximum bulk flue gas SO{sub 2} level of 3200 ppmv (wet) / 4050 ppmv (dry), suggest that, from a corrosion standpoint, the materials used in conventional subcritical and supercritical, air-fired boilers should also be suitable for oxy-combustion retrofits. Although the laboratory test results are encouraging, they are only the first step of a material evaluation process and it is recommended that follow-on corrosion tests be conducted in coal-fired boilers operating under oxy-combustion to provide longer term (one to

  13. X-ray scattering and spectroscopy studies on diesel soot from oxygenated fuel under various engine load conditions

    Science.gov (United States)

    Braun, Andreas; Shah, N.; Huggins, Frank E.; Kelly, K.E.; Sarofim, A.; Jacobsen, C.; Wirick, S.; Francis, H.; Ilavsky, J.; Thomas, G.E.; Huffman, G.P.

    2005-01-01

    Diesel soot from reference diesel fuel and oxygenated fuel under idle and load engine conditions was investigated with X-ray scattering and X-ray carbon K-edge absorption spectroscopy. Up to five characteristic size ranges were found. Idle soot was generally found to have larger primary particles and aggregates but smaller crystallites, than load soot. Load soot has a higher degree of crystallinity than idle soot. Adding oxygenates to diesel fuel enhanced differences in the characteristics of diesel soot, or even reversed them. Aromaticity of idle soot from oxygenated diesel fuel was significantly larger than from the corresponding load soot. Carbon near-edge X-ray absorption fine structure (NEXAFS) spectroscopy was applied to gather information about the presence of relative amounts of carbon double bonds (CC, CO) and carbon single bonds (C-H, C-OH, COOH). Using scanning X-ray transmission microspectroscopy (STXM), the relative amounts of these carbon bond states were shown to vary spatially over distances approximately 50 to 100 nm. The results from the X-ray techniques are supported by thermo-gravimetry analysis and high-resolution transmission electron microscopy. ?? 2005 Elsevier Ltd. All rights reserved.

  14. Guide to Low-Emission Boiler and Combustion Equipment Selection

    Energy Technology Data Exchange (ETDEWEB)

    Oland, CB

    2002-05-06

    Boiler owners and operators who need additional generating capacity face a number of legal, political, environmental, economic, and technical challenges. Their key to success requires selection of an adequately sized low-emission boiler and combustion equipment that can be operated in compliance with emission standards established by state and federal regulatory agencies. Recognizing that many issues are involved in making informed selection decisions, the U.S. Department of Energy (DOE), Office of Industrial Technologies (OIT) sponsored efforts at the Oak Ridge National Laboratory (ORNL) to develop a guide for use in choosing low-emission boilers and combustion equipment. To ensure that the guide covers a broad range of technical and regulatory issues of particular interest to the commercial boiler industry, the guide was developed in cooperation with the American Boiler Manufacturers Association (ABMA), the Council of Industrial Boiler Owners (CIBO), and the U.S. Environmental Protection Agency (EPA). The guide presents topics pertaining to industrial, commercial, and institutional (ICI) boilers. Background information about various types of commercially available boilers is provided along with discussions about the fuels that they burn and the emissions that they produce. Also included are discussions about emissions standards and compliance issues, technical details related to emissions control techniques, and other important selection considerations. Although information in the guide is primarily applicable to new ICI boilers, it may also apply to existing boiler installations.

  15. Catalytic soot oxidation over Ce- and Cu-doped hydrotalcites-derived mesoporous mixed oxides.

    Science.gov (United States)

    Wang, Zhongpeng; Wang, Liguo; He, Fang; Jiang, Zheng; Xiao, Tiancun; Zhang, Zhaoliang

    2014-09-01

    Ce- and Cu-doped hydrotalcites derived mixed oxides were prepared through co-precipitation and calcination method, and their catalytic activities for soot oxidation with O2 and O2/NO were investigated. The solids were characterized by XRD, TG-DTG, BET, H2-TPR, in situ FTIR and TPO techniques. All the catalysts precursors showed the typical diffraction patterns of hydrotalcite-like materials having layered structure. The derived mixed oxides exhibited mesoporous properties with specific surface area of 45-160 m2/g. After both Ce and Cu incorporated, mixed crystalline phases of CuO (tenorite), CeO2 (fluorite) and MgAl2O4 (spinel) were formed. As a result, the NO(x) adsorption capacity of this catalyst was largely increased to 201 μmol/g, meanwhile, it was also the most effective to convert NO into NO2 in the sorption process due to the enhanced reducibility. The in situ FTIR spectra revealed that NO(x) were stored mainly as chelating bidentate and monodentate nitrate. The interaction effect between Cu and Ce in the mixed oxide resulted in different NO(x) adsorption behavior. Compared with the non-catalyzed soot oxidation, soot conversion curves over the mixed oxides catalysts shift to low temperature in O2. The presence of NO in the gas phase significantly enhanced the soot oxidation activity with ignition temperature decreased to about 320 degrees C, which is due to NO conversion to NO2 over the catalyst followed by the reaction of NO2 with soot. This explains the cooperative effect of Ce and Cu in the mixed oxide on soot oxidation with high activity and 100% selectivity to CO2 formation. PMID:25924375

  16. Experimental and Numerical Studies for Soot Formation in Laminar Coflow Diffusion Flames of Jet A-1 and Synthetic Jet Fuels

    Science.gov (United States)

    Saffaripour, Meghdad

    In the present doctoral thesis, fundamental experimental and numerical studies are conducted for the laminar, atmospheric pressure, sooting, coflow diffusion flames of Jet A-1 and synthetic jet fuels. The first part of this thesis presents a comparative experimental study for Jet A-1, which is a widely used petroleum-based fuel, and four synthetically produced alternative jet fuels. The main goals of this part of the thesis are to compare the soot emission levels of the alternative fuels to those of a standard fuel, Jet A-1, and to determine the effect of fuel chemical composition on soot formation characteristics. To achieve these goals, experimental measurements are constructed and performed for flame temperature, soot concentration, soot particle size, and soot aggregate structure in the flames of pre-vaporized jet fuels. The results show that a considerable reduction in soot production, compared to the standard fuel, can be obtained by using synthetic fuels which will help in addressing future regulations. A strong correlation between the aromatic content of the fuels and the soot concentration levels in the flames is observed. The second part of this thesis presents the development and experimental validation of a fully-coupled soot formation model for laminar coflow jet fuel diffusion flames. The model is coupled to a detailed kinetic mechanism to predict the chemical structure of the flames and soot precursor concentrations. This model also provides information on size and morphology of soot particles. The flames of a three-component surrogate for Jet A-1, a three-component surrogate for a synthetic jet fuel, and pure n-decane are simulated using this model. Concentrations of major gaseous species and flame temperatures are well predicted by the model. Soot volume fractions are predicted reasonably well everywhere in the flame, except near the flame centerline where soot concentrations are underpredicted by a factor of up to five. There is an excellent

  17. A Chemical Kinetic Modeling Study of the Effects of Oxygenated Hydrocarbons on Soot Emissions from Diesel Engines

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, C K; Pitz, W J; Curran, H J

    2005-11-14

    A detailed chemical kinetic modeling approach is used to examine the phenomenon of suppression of sooting in diesel engines by addition of oxygenated hydrocarbon species to the fuel. This suppression, which has been observed experimentally for a few years, is explained kinetically as a reduction in concentrations of soot precursors present in the hot products of a fuel-rich diesel ignition zone when oxygenates are included. Oxygenates decrease the overall equivalence ratio of the igniting mixture, producing higher ignition temperatures and more radical species to consume more soot precursor species, leading to lower soot production. The kinetic model is also used to show how different oxygenates, ester structures in particular, can have different soot-suppression efficiencies due to differences in molecular structure of the oxygenated species.

  18. Modelling and performance evaluation of a soot cyclone separator / by L.D.J. Bieldt

    OpenAIRE

    Bieldt, Lodewyk Dominico Jacobus

    2009-01-01

    This mini-dissertation reports on the performance of a cyclone separator used to remove excess soot that is typically formed during the production of pebble fuel for High Temperature Gas-cooled Reactors. A chemical vapour deposition process is used to manufacture TRISO-coated fuel particles and during this process soot is formed that needs to be removed. This removal process uses cyclone separators as pre-filters and a bag filter as the final means of preventing unwanted particles from bei...

  19. Measurements and Modeling of Soot Formation and Radiation in Microgravity Jet Diffusion Flames. Volume 4

    Science.gov (United States)

    Ku, Jerry C.; Tong, Li; Greenberg, Paul S.

    1996-01-01

    This is a computational and experimental study for soot formation and radiative heat transfer in jet diffusion flames under normal gravity (1-g) and microgravity (0-g) conditions. Instantaneous soot volume fraction maps are measured using a full-field imaging absorption technique developed by the authors. A compact, self-contained drop rig is used for microgravity experiments in the 2.2-second drop tower facility at NASA Lewis Research Center. On modeling, we have coupled flame structure and soot formation models with detailed radiation transfer calculations. Favre-averaged boundary layer equations with a k-e-g turbulence model are used to predict the flow field, and a conserved scalar approach with an assumed Beta-pdf are used to predict gaseous species mole fraction. Scalar transport equations are used to describe soot volume fraction and number density distributions, with formation and oxidation terms modeled by one-step rate equations and thermophoretic effects included. An energy equation is included to couple flame structure and radiation analyses through iterations, neglecting turbulence-radiation interactions. The YIX solution for a finite cylindrical enclosure is used for radiative heat transfer calculations. The spectral absorption coefficient for soot aggregates is calculated from the Rayleigh solution using complex refractive index data from a Drude- Lorentz model. The exponential-wide-band model is used to calculate the spectral absorption coefficient for H20 and C02. It is shown that when compared to results from true spectral integration, the Rosseland mean absorption coefficient can provide reasonably accurate predictions for the type of flames studied. The soot formation model proposed by Moss, Syed, and Stewart seems to produce better fits to experimental data and more physically sound than the simpler model by Khan et al. Predicted soot volume fraction and temperature results agree well with published data for a normal gravity co-flow laminar

  20. NO_x-assisted soot oxidation over K/CuCe catalyst

    Institute of Scientific and Technical Information of China (English)

    翁端; 李佳; 吴晓东; 司知蠢

    2010-01-01

    CeO2 and CuOx-CeO2 supported potassium catalysts were synthesized by wetness impregnation method. The catalysts were characterized by BET, NO-TPO, NOx-TPD and soot-TPO measurements. By the decoration of potassium and copper, the maximum soot combustion temperature of the ceria-based catalyst decreased to 338 and 379 °C in the presence and absence of NO under a loose contact mode, re- spectively. The pronouncedly enhanced NO oxidation ability by copper introduction and NOx storage capacity by potassium modif...

  1. Soot formation in a blast furnace - Prediction via a parametric study, using detailed kinetic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Nordstroem, T.; Kilpinen, P.; Hupa, M. [Aabo Akademi, Turku (Finland). Combustion Chemistry Group

    1996-12-31

    The objective of this work has been to investigate the soot formation in a blast furnace fired with heavy fuel oil, using detailed kinetic modelling. This work has been concentrated on parameter studies that could explain under which conditions soot is formed and how that formation could be avoided. The parameters investigated were temperature, pressure, stoichiometric ratio, pyrolysis gas composition and reactor model. The calculations were based on a reaction mechanism that consists of 100 species and 446 reactions including polyaromatic hydrocarbons (PAM) up to 7 aromatic rings SULA 2 Research Programme; 4 refs.

  2. Control Properties of Bottom Fired Marine Boilers

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Karstensen, Claus M. S.

    2005-01-01

    This paper focuses on model analysis of a dynamic model of a bottom fired one-pass smoke tube boiler. Linearised versions of the model are analysed to determine how gain, time constants and right half plane zeros (caused by the shrink-and-swell phenomenon) depend on the steam flow load. Furthermore...... the interactions in the system are inspected to analyse potential benefit from using a multivariable control strategy in favour of the current strategy based on single loop theory. An analysis of the nonlinear model is carried out to further determine the nonlinear characteristics of the boiler system...... and to verify whether nonlinear control is needed. Finally a controller based on single loop theory is used to analyse if input constraints become active when rejecting transient behaviour from the disturbance steam flow. The model analysis shows large variations in system gains at steady state as...

  3. Maximising safety in the boiler house.

    Science.gov (United States)

    Derry, Carr

    2013-03-01

    Last month's HEJ featured an article, the second in our new series of guidance pieces aimed principally at Technician-level engineers, highlighting some of the key steps that boiler operators can take to maximise system performance and efficiency, and thus reduce running both costs and carbon footprint. In the third such article, Derry Carr, C.Env, I.Eng, BSc (Hons), M.I.Plant.E., M.S.O.E., technical manager & group gas manager at Dalkia, who is vice-chairman of the Combustion Engineering Association, examines the key regulatory and safety obligations for hospital energy managers and boiler technicians, a number of which have seen changes in recent years with revision to guidance and other documentation. PMID:23573684

  4. Recovery boiler model; Soodakattilan kehitystyoe III

    Energy Technology Data Exchange (ETDEWEB)

    Janka, K.; Ylitalo, M.; Sundstroem, K.; Helke, R.; Heinola, M. [Kvaerner Pulping Oy, Tampere (Finland)

    1997-10-01

    The recovery boiler model was further tested and developed. At this moment the model includes submodels for: droplet drying, pyrolysis, char burning, gas burning and for droplet trajectory. During 1996 the formation of CH{sub 4} during pyrolysis and release of sulfur was included to the model. Further the formation of NO from fuel nitrogen and formation of thermal- NO were included to the model using Arrhenius type reaction rate equations. The calculated results are realistic and the model is used as a tool to find out methods to increase the efficiency and availability and decrease the emissions. Analysing the results of the earlier field study of 8 boilers showed that the furnace heat load, fuming rate, find the black liquor composition have influence on the enrichment of the potassium to the fly ash. (orig.)

  5. The effect of ethanol blending on mixture formation, combustion and soot emission studied in an optical DISI engine

    International Nuclear Information System (INIS)

    Highlights: • Catalyst heating points were analyzed using optical measurement techniques. • E20 shows stronger soot radiation and higher soot concentration as isooctane. • Different mixing formation of isooctane and E20 was determined. • Strong mixture stratification was identified for both fuels. • Remaining droplets and fuel rich regions are the main source for soot formation. - Abstract: In various research studies, ethanol blended fuels have shown reduced particulate matter (PM) emissions in comparison to gasoline and its surrogate fuels in direct-injection spark-ignition (DISI) engines. However, there are also studies reporting increased particulate concentration for fuels with low ethanol content. In this work the mixture formation and sooting combustion behavior of isooctane and the mixture E20 (20 vol% of ethanol in isooctane) is analyzed for catalyst heating operation. These operating conditions are critical as they strongly contribute to overall soot emissions in driving cycles. Simultaneous high speed imaging of OH∗–chemiluminescence and natural soot luminosity measurements are performed in combination with primary particle concentration measurements using a laser induced incandescence (LII) sensor in the engine exhaust duct. At these operating conditions E20 exhibits a higher sooting tendency as compared to isooctane. In order to identify the reason for increased soot formation, the mixture formation process is analyzed by planar laser induced fluorescence (LIF) measurements. The results show that soot was formed in fuel rich regions with incomplete evaporated fuel droplets remaining from the injection event. A different evaporation process of E20 fuel spray and mixing behavior is indicated showing a more compact rich mixture cloud with surrounding lean areas near the spark plug region. This mixture stratification is characterized by higher cyclic variations and constitutes a significant source of soot formation

  6. Study of Corrosion in a Biomass Boiler

    OpenAIRE

    Berlanga, C.; Ruiz, J. A.

    2013-01-01

    Biomass plants, apart from producing energy, help to reduce CO2(g) emissions. One of the biggest problems for their development is superheater corrosion due to fuel corrosivity, especially of the straw. This limits both the temperature of the vapour and also the effectiveness of the plant. In order to know more about the reactions which happen inside the boiler of biomass, thermodynamic calculations using software (HSC Chemistry) have been carried out. Field tests have been carried out in the...

  7. Boiler Modelling of Simple Combustion Processes

    OpenAIRE

    Radovan Nosek; Jozef Jandacka; Andrzej Szlek

    2012-01-01

    The aim of the work is to investigate coal combustion in fixed bed reactor. The experimental results were worked out in the form of approximation functions describing gas composition at the exit of fixed bed reactor. Furthermore, developed functions were applied for defining the boundary conditions at the interface between the fixed bed and gas phase using FLUENT. The simulations of a domestic boiler have been done and the relative effects of different factors in CFD code were evaluated by se...

  8. Incidence of cancer among Norwegian boiler welders.

    OpenAIRE

    Danielsen, T E; Langård, S; Andersen, A.

    1996-01-01

    OBJECTIVES: The cancer incidence among 2957 boiler welders was investigated. The subjects were registered electrical welders from 1942 to 1981. A subcohort of 606 stainless steel welders was studied separately. METHODS: The investigation was a historical prospective cohort study based on a national registry. The loss of follow up was 4.9%. RESULTS: There were 625 deaths (659 expected). There were 269 cancer cases (264 expected). An excess of lung cancer was found; 50 cases v 37.5 expected. Th...

  9. Circulating fluidized bed boilers design and operations

    CERN Document Server

    Basu, Prabir

    1991-01-01

    This book provides practicing engineers and students with insight into the design and operation of circulating fluidized bed (CFB) boilers. Through a combination of theoretical concepts and practical experience, this book gives the reader a basic understanding of the many aspects of this subject.Important environmental considerations, including solid waste disposal and predicted emissions, are addressed individually in separate chapters. This book places an emphasis on combustion, hydrodynamics, heat transfer, and material issues, and illustrates these concepts with numerous examples of pres

  10. Gas mixing processes in nuclear AGR boilers

    International Nuclear Information System (INIS)

    To ensure the safe operation and control of Nuclear (A.G.R.) boilers, 2-D computational models are currently under development. The aim of these models is to predict the flow and temperature distribution of the gas and water side under different operational conditions. These models are based on numerical solutions of the 2-D flow and heat transfer equations for turbulent flow in boilers. Measurements on a closely pitched tube bank with water cooling have demonstrated considerable discrepancies between experimental results and computer predictions. This investigation is therefore being carried out to study theoretically and experimentally the flow and heat transfer process under such a boiler condition. A two dimensional computer model has been developed which incorporates the effects of gas mixing and the interactions between the gas and water side. To cover the complete heat exchanger the governing equations are written in the lumped parameter form. The governing equations have been solved by a computer code written in FORTRAN-77. To test the validity of this model, the computer predictions have been compared with experimental results. Results to date indicate reasonable agreement with experiment and a further refinement of the computer model is indicated. (author)

  11. BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    R. Viswanathan; K. Coleman; R.W. Swindeman; J. Sarver; J. Blough; W. Mohn; M. Borden; S. Goodstine; I. Perrin

    2003-10-20

    The principal objective of this project is to develop materials technology for use in ultrasupercritical (USC) plant boilers capable of operating with 760 C (1400 F), 35 MPa (5000 psi) steam. This project has established a government/industry consortium to undertake a five-year effort to evaluate and develop of advanced materials that allow the use of advanced steam cycles in coal-based power plants. These advanced cycles, with steam temperatures up to 760 C, will increase the efficiency of coal-fired boilers from an average of 35% efficiency (current domestic fleet) to 47% (HHV). This efficiency increase will enable coal-fired power plants to generate electricity at competitive rates (irrespective of fuel costs) while reducing CO{sub 2} and other fuel-related emissions by as much as 29%. Success in achieving these objectives will support a number of broader goals. First, from a national prospective, the program will identify advanced materials that will make it possible to maintain a cost-competitive, environmentally acceptable coal-based electric generation option. High sulfur coals will specifically benefit in this respect by having these advanced materials evaluated in high-sulfur coal firing conditions and from the significant reductions in waste generation inherent in the increased operational efficiency. Second, from a national prospective, the results of this program will enable domestic boiler manufacturers to successfully compete in world markets for building high-efficiency coal-fired power plants.

  12. Particulate emission abatement for Krakow boiler houses

    Energy Technology Data Exchange (ETDEWEB)

    Wysk, R.

    1995-12-31

    Among the many strategies for improving air quality in Krakow, one possible method is to adapt new and improved emission control technology. This project focuses on such a strategy. In order to reduce dust emissions from coal-fueled boilers, a new device called a Core Separator has been introduced in several boiler house applications. This advanced technology has been successfully demonstrated in Poland and several commercial units are now in operation. Particulate emissions from the Core Separator are typically 3 to 5 times lower than those from the best cyclone collectors. It can easily meet the new standard for dust emissions which will be in effect in Poland after 1997. The Core Separator is a completely inertial collector and is based on a unique recirculation method. It can effectively remove dust particles below 10 microns in diameter, the so-called PM-10 emissions. Its performance approaches that of fabric filters, but without the attendant cost and maintenance. It is well-suited to the industrial size boilers located in Krakow. Core Separators are now being marketed and sold by EcoInstal, one of the leading environmental firms in Poland, through a cooperative agreement with LSR Technologies.

  13. BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    R. Viswanathan; K. Coleman; R.W. Swindeman; J. Sarver; J. Blough; W. Mohn; M. Borden; S. Goodstine; I. Perrin

    2003-08-04

    The principal objective of this project is to develop materials technology for use in ultrasupercritical (USC) plant boilers capable of operating with 760 C (1400 F), 35 MPa (5000 psi) steam. This project has established a government/industry consortium to undertake a five-year effort to evaluate and develop of advanced materials that allow the use of advanced steam cycles in coal-based power plants. These advanced cycles, with steam temperatures up to 760 C, will increase the efficiency of coal-fired boilers from an average of 35% efficiency (current domestic fleet) to 47% (HHV). This efficiency increase will enable coal-fired power plants to generate electricity at competitive rates (irrespective of fuel costs) while reducing CO{sub 2} and other fuel-related emissions by as much as 29%. Success in achieving these objectives will support a number of broader goals. First, from a national prospective, the program will identify advanced materials that will make it possible to maintain a cost-competitive, environmentally acceptable coal-based electric generation option. High sulfur coals will specifically benefit in this respect by having these advanced materials evaluated in high-sulfur coal firing conditions and from the significant reductions in waste generation inherent in the increased operational efficiency. Second, from a national prospective, the results of this program will enable domestic boiler manufacturers to successfully compete in world markets for building high-efficiency coal-fired power plants.

  14. Field Test of Boiler Primary Loop Temperature Controller

    Energy Technology Data Exchange (ETDEWEB)

    Glanville, P. [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States); Rowley, P. [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States); Schroeder, D. [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States); Brand, L. [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States)

    2014-09-01

    Beyond these initial system efficiency upgrades are an emerging class of Advanced Load Monitoring (ALM) aftermarket controllers that dynamically respond to the boiler load, with claims of 10% to 30% of fuel savings over a heating season. For hydronic boilers specifically, these devices perform load monitoring, with continuous measurement of supply and, in some cases, return water temperatures. Energy savings from these ALM controllers are derived from dynamic management of the boiler differential, where a microprocessor with memory of past boiler cycles prevents the boiler from firing for a period of time, to limit cycling losses and inefficient operation during perceived low load conditions. These differ from OTR controllers, which vary boiler setpoint temperatures with ambient conditions while maintaining a fixed differential.

  15. Life extension of boilers using weld overlay protection

    Energy Technology Data Exchange (ETDEWEB)

    Lai, G.; Hulsizer, P. [Welding Services Inc., Norcross, GA (United States); Brooks, R. [Welding Services Inc., Welding Services Europe, Spijkenisse (Netherlands)

    1998-12-31

    The presentation describes the status of modern weld overlay technology for refurbishment, upgrading and life extension of boilers. The approaches to life extension of boilers include field overlay application, shop-fabricated panels for replacement of the worn, corroded waterwall and shop-fabricated overlay tubing for replacement of individual tubes in superheaters, generating banks and other areas. The characteristics of weld overlay products are briefly described. Also discussed are successful applications of various corrosion-resistant overlays for life extension of boiler tubes in waste-to-energy boilers, coal-fired boilers and chemical recovery boilers. Types of corrosion and selection of weld overlay alloys in these systems are also discussed. (orig.) 14 refs.

  16. A Rule-Based Industrial Boiler Selection System

    Science.gov (United States)

    Tan, C. F.; Khalil, S. N.; Karjanto, J.; Tee, B. T.; Wahidin, L. S.; Chen, W.; Rauterberg, G. W. M.; Sivarao, S.; Lim, T. L.

    2015-09-01

    Boiler is a device used for generating the steam for power generation, process use or heating, and hot water for heating purposes. Steam boiler consists of the containing vessel and convection heating surfaces only, whereas a steam generator covers the whole unit, encompassing water wall tubes, super heaters, air heaters and economizers. The selection of the boiler is very important to the industry for conducting the operation system successfully. The selection criteria are based on rule based expert system and multi-criteria weighted average method. The developed system consists of Knowledge Acquisition Module, Boiler Selection Module, User Interface Module and Help Module. The system capable of selecting the suitable boiler based on criteria weighted. The main benefits from using the system is to reduce the complexity in the decision making for selecting the most appropriate boiler to palm oil process plant.

  17. Behavioral study solar boilers 1994. Summary. Part 2 (households)

    International Nuclear Information System (INIS)

    The aim of the Dutch national solar boiler campaign of NOVEM and Holland Solar is to realize the installation of 300,000 solar boilers in the Netherlands in the year 2010. In 1995 10,000 boilers were installed. More knowledge of the decision making process and the backgrounds and motives of (potential) buyers is required. From September 1994 to March 1995 a survey has been carried out of the decision making processes in households and housing corporations. The most important results, conclusions and recommendations of the survey are summarized in this report. The parameters that can influence the decision whether to purchase a solar boiler or not are knowledge about the solar boiler, the attitude towards the solar boiler and towards the use of energy and the environment, risk perception, social aspects, information retrieval behavior, constraints, and socio-economic aspects. 44 tabs

  18. Modelling, simulating and optimizing boiler heating surfaces and evaporator circuits

    DEFF Research Database (Denmark)

    Sørensen, K.; Condra, T.; Houbak, Niels

    2003-01-01

    A model for optimizing the dynamic performance of boiler have been developed. Design variables related to the size of the boiler and its dynamic performance have been defined. The object function to be optimized takes the weight of the boiler and its dynamic capability into account. As constraints...... for the optimization a dynamic model for the boiler is applied. Furthermore a function for the value of the dynamic performance is included in the model. The dynamic models for simulating boiler performance consists of a model for the flue gas side, a model for the evaporator circuit and a model for...... the drum. The dynamic model has been developed for the purpose of determining boiler material temperatures and heat transfer from the flue gas side to the water-/steam side in order to simulate the circulation in the evaporator circuit and hereby the water level fluctuations in the drum. The dynamic...

  19. The behavior of ash species in suspension fired biomass boilers

    DEFF Research Database (Denmark)

    Jensen, Peter Arendt

    to generate ash particles typically in the size range of 50 to 200 μm on biomass suspension fired power plant boilers. A fragmentation rate of fuel particles of 3 have been used to describe both the residual ash formation process in laboratory entrained flow reactors and in full scale boilers.A range...... coal fly ash with a high content of Si and Al isused as an additive on wood fired plants to reduce the problems with alkali salt de-activationof SCR catalysts. While the fundamental chemistry of the additives are well known detailed reaction models of the interaction of salts and additive particles......While fluid bed and grate fired boilers initially was the choice of boilers used for power production from both wood and herbaceous biomass, in recent years suspension fired boilers have been increasingly used for biomass based power production. In Denmark several large pulverized fuel boilers have...

  20. Catalytic soot oxidation by platinum on sintered metal filters. Influence of the platinum quantity, particle size and location, and investigation of the platinum-soot contact

    OpenAIRE

    Hinot, Karelle

    2007-01-01

    The great challenge for next years concerning the emission of diesel engines is to develop diesel particle filters (DPF) with catalytic regeneration systems. This work is focused on the global understanding of the diesel soot oxidation on sintered metal filters (SMF). Platinum is studied as reference catalyst. The first objective is to determine which of platinum quantity, platinum particle size, or platinum location exhibits the preponderant influence on the catalytic.

  1. Deposit Probe Measurements in Large Biomass-Fired Grate Boilers and Pulverized-Fuel Boilers

    DEFF Research Database (Denmark)

    Hansen, Stine Broholm; Jensen, Peter Arendt; Jappe Frandsen, Flemming;

    2014-01-01

    build-up increased with the K-content of the fuel ash and fly ash for grate-fired boilers. For suspension-fired boilers, deposition rates are comparatively low for wood-firing and increase with increasing fuel straw shares. Shedding of deposits occurs by melting during straw-firing on a grate at high......A number of full-scale deposit probe measuring campaigns conducted in grate-fired and suspension-fired boilers, fired with biomass, have been reviewed and compared. The influence of operational parameters on the chemistry of ash and deposits, on deposit build-up rates, and on shedding behavior has...... been examined. The firing technology and the fuel utilized influence the fly ash and deposit chemical composition. In grate-firing, K, Cl, and S are enriched in the fly ash compared to the fuel ash, while the fly ash in suspension-firing is relatively similar to the fuel ash. The chemical composition...

  2. Fuel to the nuclear debate : [Rezension von:] Nuclear power in crisis, Andrew Blowers and David Pepper (editors), New York, Nichols; London ..., Croom Helm, 1987

    OpenAIRE

    Renn, Ortwin

    1988-01-01

    Nuclear energy is one of the most popular topics of today’s publication market. The literature about the pros and cons of nuclear power may easily fill a whole library. Is there anything new to add to this voluminous body of arguments and contra-arguments that would justify editing another book on nuclear energy? Andrew Blowers and David Pepper obviously felt that way and published a reader on Nuclear Power in Crisis. The book consists of 13 articles covering mainly the political, social and ...

  3. 降低罗茨风机噪声的消声器研制%The noise depressing measures for Roots blower

    Institute of Scientific and Technical Information of China (English)

    程勒

    2001-01-01

    论述了自制消声器的设计计算及制造方法,举例说明这种降低罗茨风机噪声措施取得的明显效果,以及在石化企业中的应用。%The noise depressing measures for Roots blower,design,calculation and fabrication of the muffler are described.It shows that the m easures obtain obvious effect and can be applied in oil chemical plant.

  4. JOYO MK-III performance test report. Blower start-up test (PT-303), power-increase test (PT-301), rated power operation test (PT-302)

    International Nuclear Information System (INIS)

    In the MK-III performance test for the experimental fast reactor JOYO, the reactor thermal power was raised gradually with steps at about 20%, 50%, 75%, 90%, and 100% (140 MWt). The rated power of 140 MWt for the MK-III reactor core was reached on October 28, 2003. Then, it was operated continuously by rated power for 100 hours or more. The major results of the tests are as follows. (1) From standby states (sodium temperature of 250degC, isothermal condition), the rated power of 140 MWt for the MK-III reactor core was reached on October 28, 2003 by the usual power-increase operation (a power-up rate of about 5 MWt/20 min, where the power was held for about 10 minutes every 5 MWt). It was confirmed that the temperature and flow of sodium were the alarm setting values or less at each steps. (2) The blower start-up operation of which the parameter was the reactor thermal power was done, and the influence which it was on coolant temperature was confirmed. As a result, the optimal reactor thermal power to start up the blower from a natural ventilation cooling state was set to about 18 MWt, and the starting procedure was made into a method (order of 1A->2A->1B->2B) which starts four sets of one blower at a time one by one. (3) The reactor shutdown operation was confirmed by two simultaneous control-rod insertions at 35 MWt. It was confirmed to be carried out by a series of operations from the control rod insertion to the blower shutdown with enough time margin. By adopting this reactor shutdown operation, operation complexity was mitigated and plant characteristics also improved. (4) The rated power of 140 MWt was reached on November 14. It was operated continuously by rated power for 100 hours or more on November 20, 10:30. The detailed plant data was acquired at intervals of 24 hours, and was confirmed to be less than the alarm setting values. (author)

  5. Evaluation of surrogate boilers for steam generators. Final report

    International Nuclear Information System (INIS)

    Corrosion in PWR systems is a continuing problem that can result in significant expenditures for inspection, repair, and replacement of steam generators as well as for power replacement during outages. Model boilers operated in parallel to the steam generator may provide a useful tool for monitoring and studying steam generator corrosion and corrosion prevention processes. The potential benefits of such boilers as well as several conceptual boiler design alternatives are described, and approximate costs for fabrication and operation of such systems are presented

  6. Optimal Combustion Conditions for a Small-scale Biomass Boiler

    OpenAIRE

    Viktor Plaček; Cyril Oswald; Jan Hrdlička

    2012-01-01

    This paper reports on an attempt to achieve maximum efficiency and lowest possible emissions for a small-scale biomass boiler. This aim can be attained only by changing the control algorithm of the boiler, and in this way not raising the acquisition costs for the boiler. This paper describes the experimental facility, the problems that arose while establishing the facility, and how we have dealt with them. The focus is on discontinuities arising after periodic grate sweeping, and on finding t...

  7. Investigations of operation problems at a 200 MWe PF boiler

    OpenAIRE

    Peta Sandile; Toit Chris du; Naidoo Reshendren; Schmitz Walter; Jestin Louis

    2015-01-01

    To minimize oxides of nitrogen (NOx) emission, maximize boiler combustion efficiency, achieve safe and reliable burner combustion, it is crucial to master global boiler and at-the-burner control of fuel and air flows. Non-uniform pulverized fuel (PF) and air flows to burners reduce flame stability and pose risk to boiler safety by risk of reverse flue gas and fuel flow into burners. This paper presents integrated techniques implemented at pilot ESKOM power plants for the determination of glob...

  8. PERANCANGAN pH METER PADA BOILER HRSG BERBASIS ARDUINO

    OpenAIRE

    Yuliza .; Gatot Susanto

    2015-01-01

    Air merupakan zat yang sangat dibutuhkan pada setiap sektor industri, termasuk pemanfaatan untuk kebutuhan energi dan pemanasan. Kebutuhan energi dan pemanasan di industri umumnya dipenuhi dengan cara memanfaatkan steam yang dibangkitkan dalam suatu ketel (boiler). Air yang digunakan sebagai umpan boiler dapat diperoleh dari berbagai sumber yaitu danau, sungai, laut, maupun sumur. Kandungan  air ini sangat mempengaruhi Harga pH pada air umpan boiler, penting untuk diperhatikan untuk mencegah ...

  9. Formation, growth, and transport of soot in a three-dimensional turbulent non-premixed jet flame

    KAUST Repository

    Attili, Antonio

    2014-07-01

    The formation, growth, and transport of soot is investigated via large scale numerical simulation in a three-dimensional turbulent non-premixed n-heptane/air jet flame at a jet Reynolds number of 15,000. For the first time, a detailed chemical mechanism, which includes the soot precursor naphthalene and a high-order method of moments are employed in a three-dimensional simulation of a turbulent sooting flame. The results are used to discuss the interaction of turbulence, chemistry, and the formation of soot. Compared to temperature and other species controlled by oxidation chemistry, naphthalene is found to be affected more significantly by the scalar dissipation rate. While the mixture fraction and temperature fields show fairly smooth spatial and temporal variations, the sensitivity of naphthalene to turbulent mixing causes large inhomogeneities in the precursor fields, which in turn generate even stronger intermittency in the soot fields. A strong correlation is apparent between soot number density and the concentration of naphthalene. On the contrary, while soot mass fraction is usually large where naphthalene is present, pockets of fluid with large soot mass are also frequent in regions with very low naphthalene mass fraction values. From the analysis of Lagrangian statistics, it is shown that soot nucleates and grows mainly in a layer close to the flame and spreads on the rich side of the flame due to the fluctuating mixing field, resulting in more than half of the total soot mass being located at mixture fractions larger than 0.6. Only a small fraction of soot is transported towards the flame and is completely oxidized in the vicinity of the stoichiometric surface. These results show the leading order effects of turbulent mixing in controlling the dynamics of soot in turbulent flames. Finally, given the difficulties in obtaining quantitative data in experiments of turbulent sooting flames, this simulation provides valuable data to guide the development of

  10. The behavior of ash species in suspension fired biomass boilers

    OpenAIRE

    Jensen, Peter Arendt

    2015-01-01

    While fluid bed and grate fired boilers initially was the choice of boilers used for power production from both wood and herbaceous biomass, in recent years suspension fired boilers have been increasingly used for biomass based power production. In Denmark several large pulverized fuel boilers have been converted from coal to biomass combustion in the last 15 years. This have included co-firing of coal and straw, up to 100% firing of wood or straw andthe use of coal ash as an additive to reme...

  11. Relocation of boilers to Gulbene, Latvia. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    This report describes the relocation of two coal-fired boilers from Hoeje-Taastrup, Denmark to the City of Gulbene, Latvia and the conversion of one of these boilers to combustion of wood chips. The selection of Gulbene DHE as recipient of the two boilers was made by the Danish Energy Agency. The selection was based on e feasibility study, `Small Boilers Fuel Conversion Study` prepared by the Consulting Engineering Company Birch and Krogeoe/Esbensen in 1994. The recommendations regarding the relocation and conversion of the former coal-fired boilers to use wood chips have been given in a study performed by dk-TEKNIK in the year 1994. The objectives of the Consultant`s project can be summarized as follows: Prequalification of Contractors for the boiler relocation; Preparation of Tender Documents for relocation of two formerly coal-fired boilers placed in Hoeje-Taastrup to Gulbene and conversion of the boilers to combustion of wood fuel; Evaluation and Contracting; Site supervision; Handing-over. The scope of the report describes the final reporting of the boiler relocation to Gulbene. This includes: The process of the relocation; Financial calculations; Experience gained through the project. (EG)

  12. Field Test of Boiler Primary Loop Temperature Controller

    Energy Technology Data Exchange (ETDEWEB)

    Glanville, P.; Rowley, P.; Schroeder, D.; Brand, L.

    2014-09-01

    Beyond these initial system efficiency upgrades are an emerging class of Advanced Load Monitoring (ALM) aftermarket controllers that dynamically respond to the boiler load, with claims of 10% to 30% of fuel savings over a heating season. For hydronic boilers specifically, these devices perform load monitoring, with continuous measurement of supply and in some cases return water temperatures. Energy savings from these ALM controllers are derived from dynamic management of the boiler differential, where a microprocessor with memory of past boiler cycles prevents the boiler from firing for a period of time, to limit cycling losses and inefficient operation during perceived low load conditions. These differ from OTR controllers, which vary boiler setpoint temperatures with ambient conditions while maintaining a fixed differential. PARR installed and monitored the performance of one type of ALM controller, the M2G from Greffen Systems, at multifamily sites in the city of Chicago and its suburb Cary, IL, both with existing OTR control. Results show that energy savings depend on the degree to which boilers are over-sized for their load, represented by cycling rates. Also savings vary over the heating season with cycling rates, with greater savings observed in shoulder months. Over the monitoring period, over-sized boilers at one site showed reductions in cycling and energy consumption in line with prior laboratory studies, while less over-sized boilers at another site showed muted savings.

  13. Thermal power of small scale manually fed boiler

    OpenAIRE

    Janić Todor V.; Igić Saša M.; Dedović Nebojša M.; Pavlović Darijan B.; Turan Jan J.; Sedlar Aleksandar D.

    2015-01-01

    This study reviews test results of the combustion of square soybean straw bales used as fuel in manually fed boiler with nominal thermal power of 120 kWth. The influence of the mass flow rate (180, 265, 350, 435, and 520 kg h-1) of inlet air and flue gas recirculation (0%, 16.5%, and 33%) fed to the boiler furnace was continuously monitored. Direct method was used for determination of the boiler thermal power. Correlation between boiler thermal power and ba...

  14. Between the boiler and buffer tank; Zwischen Kessel und Speicher

    Energy Technology Data Exchange (ETDEWEB)

    Ertmer, Katharina

    2013-08-06

    Some manufacturers offer new heating pump groups for return temperature raising for solid-fuel boilers. [German] Einige Hersteller bieten neue Heizungspumpengruppen zur Ruecklauftemperaturanhebung bei Festbrennstoffkesseln an.

  15. Thermomechanical finite element analysis of hot water boiler structure

    OpenAIRE

    Živković Dragoljub S.; Milčić Dragan S.; Banić Milan S.; Milosavljević Peđa M.

    2012-01-01

    The paper presents an application of the Finite Elements Method for stress and strain analysis of the hot water boiler structure. The aim of the research was to investigate the influence of the boiler scale on the thermal stresses and strains of the structure of hot water boilers. Results show that maximum thermal stresses appear in the zone of the pipe carrying wall of the first reversing chamber. This indicates that the most critical part of the boiler are weld spots of the smoke pipe...

  16. 46 CFR 52.20-17 - Opening between boiler and safety valve (modifies PFT-44).

    Science.gov (United States)

    2010-10-01

    ... ENGINEERING POWER BOILERS Requirements for Firetube Boilers § 52.20-17 Opening between boiler and safety valve (modifies PFT-44). When a discharge pipe is used, it must be installed in accordance with the...

  17. Full-spectrum k-distribution look-up table for nonhomogeneous gas-soot mixtures

    Science.gov (United States)

    Wang, Chaojun; Modest, Michael F.; He, Boshu

    2016-06-01

    Full-spectrum k-distribution (FSK) look-up tables provide great accuracy combined with outstanding numerical efficiency for the evaluation of radiative transfer in nonhomogeneous gaseous media. However, previously published tables cannot be used for gas-soot mixtures that are found in most combustion scenarios since it is impossible to assemble k-distributions for a gas mixed with nongray absorbing particles from gas-only full-spectrum k-distributions. Consequently, a new FSK look-up table has been constructed by optimizing the previous table recently published by the authors and then adding one soot volume fraction to this optimized table. Two steps comprise the optimization scheme: (1) direct calculation of the nongray stretching factors (a-values) using the k-distributions (k-values) rather than tabulating them; (2) deletion of unnecessary mole fractions at many thermodynamic states. Results show that after optimization, the size of the new table is reduced from 5 GB (including the k-values and the a-values for gases only) to 3.2 GB (including the k-values for both gases and soot) while both accuracy and efficiency remain the same. Two scaled flames are used to validate the new table. It is shown that the new table gives results of excellent accuracy for those benchmark results together with cheap computational cost for both gas mixtures and gas-soot mixtures.

  18. Optical measurements of soot in premixed flames. Ph.D. Thesis - California Univ.

    Science.gov (United States)

    Lyons, Valerie J.

    1988-01-01

    Two laser diagnostic techniques were used to measure soot volume fractions, number densities and soot particle radii in premixed propane/oxygen flat flames. The two techniques were two wavelength extinction, using 514.5 to 632.8 nm and 457.9 to 632.8 nm wavelength combinations, and extinction/scattering using 514.5 nm light. The flames were fuel rich and had cold gas velocities varying from 3.4 to 5.5 cm/s. Measurements were made at various heights above the sintered bronze, water colored flat flame burner with the equivalence ratio and cold gas velocity fixed. Also, measurements were made at a fixed height above the burner and fixed cold gas velocity while varying the equivalence ratio. Both laser techniques are based on the same underlying assumptions of particle size distribution and soot optical properties. Full Mie theory was used to determine the extinction coefficients and the scattering efficiencies. Temperature measurements in the flame were made using infrared radiometry and fine wire thermocouples. Good agreement between the two techniques in terms of soot particle radii, number density and volume fraction was found for intensity ratios between 0.1 and 0.8.

  19. Rapid synthesis of inherently robust and stable superhydrophobic carbon soot coatings

    Science.gov (United States)

    Esmeryan, Karekin D.; Castano, Carlos E.; Bressler, Ashton H.; Abolghasemibizaki, Mehran; Mohammadi, Reza

    2016-04-01

    The fabrication of superhydrophobic coatings using a candle flame or rapeseed oil has become very attractive as a novel approach for synthesis of water repellent surfaces. Here, we report an improved, simplified and time-efficient method for the preparation of robust superhydrophobic carbon soot that does not require any additional stabilizers or chemical treatment. The soot's inherent stabilization is achieved using a specially-designed cone-shaped aluminum chimney, mounted over an ignited paper-based wick immersed in a rapeseed oil. Such configuration decreases the level of oxygen during the process of combustion; altering the ratio of chemical bonds in the soot. As a result, the fractal-like network of the carbon nanoparticles is converted into dense and fused carbon chains, rigidly coupled to the substrate surface. The modified carbon coating shows thermal sustainability and retains superhydrophobicity up to ∼300 °C. Furthermore, it demonstrates a low contact angle hysteresis of 0.7-1.2° accompanied by enhanced surface adhesion and mechanical durability under random water flows. In addition, the soot's deposition rate of ∼1.5 μm/s reduces the exposure time of the substrate to heat and consequently minimizes the thermal effects, allowing the creation of superhydrophobic coatings on materials with low thermal stability (e.g. wood or polyethylene).

  20. Soot aggregate restructuring due to coatings of secondary organic aerosol derived from aromatic precursors.

    Science.gov (United States)

    Schnitzler, Elijah G; Dutt, Ashneil; Charbonneau, André M; Olfert, Jason S; Jäger, Wolfgang

    2014-12-16

    Restructuring of monodisperse soot aggregates due to coatings of secondary organic aerosol (SOA) derived from hydroxyl radical-initiated oxidation of toluene, p-xylene, ethylbenzene, and benzene was investigated in a series of photo-oxidation (smog) chamber experiments. Soot aggregates were generated by combustion of ethylene using a McKenna burner, treated by denuding, size-selected by a differential mobility analyzer, and injected into a smog chamber, where they were exposed to low vapor pressure products of aromatic hydrocarbon oxidation, which formed SOA coatings. Aggregate restructuring began once a threshold coating mass was reached, and the degree of the subsequent restructuring increased with mass growth factor. Although significantly compacted, fully processed aggregates were not spherical, with a mass-mobility exponent of 2.78, so additional SOA was required to fill indentations between collapsed branches of the restructured aggregates before the dynamic shape factor of coated particles approached 1. Trends in diameter growth factor, effective density, and dynamic shape factor with increasing mass growth factor indicate distinct stages in soot aggregate processing by SOA coatings. The final degree and coating mass dependence of soot restructuring were found to be the same for SOA coatings from all four aromatic precursors, indicating that the surface tensions of the SOA coatings are similar. PMID:25390075

  1. Alumina supported Co-K-Mo based catalytic material for diesel soot oxidation

    Czech Academy of Sciences Publication Activity Database

    Dhakad, M.; Joshi, A.G.; Rayalu, S.; Tanwar, P.; Bassin, J.K.; Kumar, R.; Lokhande, S.; Šubrt, Jan; Mitsuhashi, T.; Labhsetwar, N.

    2009-01-01

    Roč. 52, 13-20 (2009), s. 2070-2075. ISSN 1022-5528 Institutional research plan: CEZ:AV0Z40320502 Keywords : soot oxidation * diesel particulate filter * catalyst carbon oxidation Subject RIV: CA - Inorganic Chemistry Impact factor: 2.379, year: 2009

  2. Low cost, ceria promoted perovskite type catalysts for diesel soot oxidation

    Czech Academy of Sciences Publication Activity Database

    Dhakad, M.; Rayalu, S.; Kumar, R.; Doggali, P.; Bakardjieva, Snejana; Šubrt, Jan; Mitsuhashi, T.; Haneda, H.; Labhsetwar, N.

    2008-01-01

    Roč. 121, 1-2 (2008), s. 137-143. ISSN 1011-372X Institutional research plan: CEZ:AV0Z40320502 Keywords : soot oxidation * perovskite * diesel emissions Subject RIV: CA - Inorganic Chemistry Impact factor: 1.867, year: 2008

  3. Influence of complex component and particle polydispersity on radiative properties of soot aggregate in atmosphere

    International Nuclear Information System (INIS)

    The effects of morphological structure, water coating, dust mixing and primary particle size distribution on the radiative properties of soot fractal aggregates in atmosphere are investigated using T-matrix method. These fractal aggregates are numerically generated using a combination of the particle-cluster and cluster-cluster aggregation algorithms with fractal parameters representing soot aggregate in atmosphere. The radiative properties of compact aggregate notably deviate from that of the branched one, and the effect of morphology changes on the radiative properties in wet air cannot be neglected. However it is reasonable to use realization-averaged radiative properties to represent that of the aggregates with certain morphology. In wet air, the scattering, absorption and extinction cross-section and symmetry parameter of soot aggregates coated with water notably increase with water shell thickness. The mixing structures of dust have little effect on radiative properties of aggregates, but the volume fraction of dust has an obvious effect on extinction, scattering and absorption cross-section of aggregates when the size parameters are above the Rayleigh limit. Although the primary particle size distribution of soot aggregate has mild effect on the scattering albedo and asymmetry parameter, the deviations of the extinction, scattering, absorption cross-section among the three size distributions are significant in this study. The size distribution has a significant effect on forward scattering of phase function, while the effect can be neglected as the size parameter approaches to the Rayleigh limit.

  4. Investigation of soot by two-color four-wave mixing

    Energy Technology Data Exchange (ETDEWEB)

    Hemmerling, B.; Stampanoni-Panariello, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    A novel, non-intrusive technique has been used for the temporally resolved investigation of the interaction of laser radiation and soot in a flame. While there is a fairly good agreement between measurement and simulation remaining discrepancies indicate some shortcomings of the model employed. (author) 2 figs., 2 refs.

  5. Kinetics of structural change and properties of fullerene soots on conservation at atmospheric conditions

    International Nuclear Information System (INIS)

    By using X-ray Scattering method the long time change of structure and properties of fullerene soots take place with together decreasing of dissolvant process of fullerenes are shown. It is proposed the provenance of these phenomena connected with oxidation and hydro oxidation processes of fullerenes on conservation at atmospheric conditions. (author)

  6. Analysis of error in soot characterization using scattering-based techniques

    Institute of Scientific and Technical Information of China (English)

    Lin Ma

    2011-01-01

    The increasing concern of the health and environmental effects of ultrafine soot particles emitted by modern combustion devices calls for new techniques to monitor such particles. Techniques based on light scattering represent one possible monitoring method. In this study, numerical simulations were conducted to examine the errors involved in soot characterization using light scattering techniques.Specifically, this study focused on examining the error caused by the approximate fractal scattering models based on the Rayleigh-Deybe-Gans theory (the RDG-FA model). When the angular scattering properties were used to retrieve parameters of soot aggregates (the radius of gyration and the fractal dimension), the RDG-FA method was observed to cause a relative error of ~10% for a representative set of soot parameters. The effects of measurement uncertainties were also investigated. Our results revealed the pattern of the errors: the errors consisted of a relatively constant baseline error caused by the RDG-FA approximation and an error increasing with the measurement uncertainties. These results are expected to be useful in the analysis and interpretation of experimental data, and also in the determination of the accuracy and applicable range of scattering techniques.

  7. Investigation of potassium containing glass coatings as diesel soot oxidation catalysts

    Science.gov (United States)

    Zokoe, James, Jr.

    Diesel engines provide superior fuel economy to gasoline engines, but their emissions contain harmful compounds that endanger human health and the environment. Because of this, government regulations have demanded increasingly cleaner exhaust from diesel engines. Diesel engines are now being fitted with additional "Exhaust aftertreatment units" which utilize catalysts in various components in the exhaust stream to eliminate the unsafe compounds. One harmful diesel exhaust component that has proven difficult to eliminate is solid carbonaceous particulate matter. Diesel particulate filters (DPFs) are currently required of all engines to remove the solid PM, also termed soot, from the exhaust. One means for reducing cost of the aftertreatment unit is to lower the required temperature for soot oxidation (DPF regeneration) by implementing a low cost, low temperature soot oxidation catalysts. Potassium based catalysts provide the low temperature oxidation of soot, but quickly degrade in the harsh conditions of the diesel exhaust. Novel K-glass catalysts have recently been shown to stabilize the K within a silicate matrix and initial degradation studies have shown promise with soot oxidation as low as 380°C in loose catalyst-soot contact conditions. To further the study of these K-glass catalysts, this dissertation will delve into the measurement and characterization of the prolonged degradation mechanisms experienced by the glasses that fall into two categories termed as follows: combustion (K loss) and chemical (hydrothermal) degradation. K-glass catalyst samples were used to measure end of useful lifetime (EUL) testing for an estimated 100,000 mi of engine use. A baseline glass compound (KCS-1) was found to sustain acceptable soot oxidation temperatures after this lifetime (T50 < 500°C). Catalytic degradation was caused by the creation of K-rich carbonate or sulfate precipitates. These precipitates deplete the surrounding glass of active K and also mask active

  8. Experiments and Model Development for the Investigation of Sooting and Radiation Effects in Microgravity Droplet Combustion

    Science.gov (United States)

    Choi, Mun Young; Yozgatligil, Ahmet; Dryer, Frederick L.; Kazakov, Andrei; Dobashi, Ritsu

    2001-01-01

    Today, despite efforts to develop and utilize natural gas and renewable energy sources, nearly 97% of the energy used for transportation is derived from combustion of liquid fuels, principally derived from petroleum. While society continues to rely on liquid petroleum-based fuels as a major energy source in spite of their finite supply, it is of paramount importance to maximize the efficiency and minimize the environmental impact of the devices that burn these fuels. The development of improved energy conversion systems, having higher efficiencies and lower emissions, is central to meeting both local and regional air quality standards. This development requires improvements in computational design tools for applied energy conversion systems, which in turn requires more robust sub-model components for combustion chemistry, transport, energy transport (including radiation), and pollutant emissions (soot formation and burnout). The study of isolated droplet burning as a unidimensional, time dependent model diffusion flame system facilitates extensions of these mechanisms to include fuel molecular sizes and pollutants typical of conventional and alternative liquid fuels used in the transportation sector. Because of the simplified geometry, sub-model components from the most detailed to those reduced to sizes compatible for use in multi-dimensional, time dependent applied models can be developed, compared and validated against experimental diffusion flame processes, and tested against one another. Based on observations in microgravity experiments on droplet combustion, it appears that the formation and lingering presence of soot within the fuel-rich region of isolated droplets can modify the burning rate, flame structure and extinction, soot aerosol properties, and the effective thermophysical properties. These observations led to the belief that perhaps one of the most important outstanding contributions of microgravity droplet combustion is the observation that in the

  9. Experimental study on thermophoretic deposition of soot particles in laminar diffusion flames along a solid wall in microgravity

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jae-Hyuk; Chung, Suk Ho [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742 (Korea); Fujita, Osamu; Tsuiki, Takafumi [Division of Mechanical and Space Engineering, Hokkaido University, Sapporo 060-8628 (Japan); Kim, Junhong [Laboratoire E.M2.C., UPR 288 C.N.R.S Ecole Centrale Paris, Grande Voie des Vignes 92295 (France)

    2008-09-15

    Soot deposition process in diffusion flames along a solid wall has been investigated experimentally under a microgravity environment. An ethylene (C{sub 2}H{sub 4}) diffusion flame was formed around a cylindrical rod-burner with the surrounding air velocities of V{sub a} = 2.5, 5, and 10 cm/s, the oxygen concentration of 35%, and the burner wall temperature of 300 K. A laser extinction method was adopted to measure the distribution of soot volume fraction. The experiments determined the trace of maximum soot concentration together with the relative distance of the trace of flame. Results showed that the distance was about 2-5 mm. As the surrounding air velocity increased, the region of the soot particle distribution moved closer to the burner wall. The soot particles near the flame zone tended to move away from the flame zone because of the thermophoretic force and to concentrate at a certain narrow region inside the flame. Because of the simultaneous effects of convection and the thermophoresis, soot particles finally adhered to the burner wall. It has been found that there existed an optimal air velocity for the early deposition of soot on the furnace wall. (author)

  10. Ultra-small-angle X-ray scattering characterization of diesel/gasoline soot: sizes and particle-packing conditions

    International Nuclear Information System (INIS)

    Regulations on particulate emissions from internal combustion engines tend to become more stringent, accordingly the importance of particulate filters in the after-treatment system has been increasing. In this work, the applicability of ultra-small-angle X-ray scattering (USAXS) to diesel soot cake and gasoline soot was investigated. Gasoline-direct-injection engine soot was collected at different fuel injection timings. The unified fits method was applied to analyze the resultant scattering curves. The validity of analysis was supported by comparing with carbon black and taking the sample images using a transmission electron microscope, which revealed that the primary particle size ranged from 20 to 55 nm. In addition, the effects of particle-packing conditions on the USAXS measurement were demonstrated by using samples suspended in acetone. Then, the investigation was extended to characterization of diesel soot cake deposited on a diesel particulate filter (DPF). Diesel soot was trapped on a small piece of DPF at different deposition conditions which were specified using the Peclet number. The dependence of scattering curve on soot-deposition conditions was demonstrated. To support the interpretation of the USAXS results, soot cake samples were observed using a scanning electron microscope and the influence of particle-packing conditions on scattering curve was discussed

  11. Th effectiveness of soot removal techniques for the recovery of fingerprints on glass fire debris in petrol bomb cases

    International Nuclear Information System (INIS)

    The increased use of petrol bombs as an act of vengeance in Malaysia has heightened awareness for the need of research relating physical evidence found at the crime scene to the perpetrator of the crime. A study was therefore carried out to assess the effectiveness of soot removal techniques on glass fire debris without affecting the fingerprints found on the evidence. Soot was removed using three methods which were brushing, 2 % NaOH solution and tape lifting. Depending on the visibility of prints recovered, prints which were visible after soot removal were lifted directly while prints that were not visible were subjected to enhancement. Glass microscope slides were used in laboratory experiment and subjected to control burn for the formation of soot. Soot was later removed following enhancement of the prints over time (within 1 day, within 2 days and after 2 days). While in simulated petrol bomb ground experiment, petrol bombs were hurled in glass bottles and the fragments were collected. Favorable results were obtained in varying degrees using each soot removal methods. In laboratory testing, brushing and 2 % NaOH solution revealed fingerprints that were visible after removal of excess soot and were lifted directly. As for tape lifting technique, some prints were visible and were successfully lifted while those that were not visible were subjected to super glue fuming for effective fingerprint identification. (author)

  12. Optical measurements of soot and temperature profiles in premixed propane-oxygen flames

    Science.gov (United States)

    Lyons, V. J.; Pagni, P. J.

    1988-01-01

    Two laser diagnostic techniques were used to measure soot volume fractions, number densities and soot particle radii in premixed propane/oxygen flat flames. The two techniques used were two wavelength extinction, using 514.5 nm to 632.8 nm and 457.9 nm to 632.8 nm wavelength combinations, and extinction/scattering using 514.5 nm light. The flames were fuel-rich (equivalence ratios from 2.1 to 2.8) and had cold gas velocities varying from 3.4 to 5.5 cm/s. Measurements were made at various heights above the sintered-bronze, water-cooled flat flame burner with the equivalence ratio and cold gas velocity fixed. Also, measurements were made at a fixed height above the burner and fixed cold gas velocity while varying the equivalence ratio. Both laser techniques are based on the same underlying assumptions of particle size distribution and soot optical properties. Full Mie theory was used to determine the extinction coefficients K sub ext, and the scattering efficiencies, Q sub vv. Temperature measurements in the flames were made using infrared radiometry. Good agreement between the two techniques in terms of soot particle radii, number density and volume fraction was found for intensity ratios (I/I sub o) between 0.1 and 0.8. For intensity ratios higher or lower than this range, the differences in extinction coefficients at the wavelengths chosen for the two-wavelength method are too small to give accurate results for comparing particle radii and number densities. However, when comparing only soot volume fractions, the agreement between the two techniques continued to be good for intensity ratios up to 0.95.

  13. Effect of diluents on soot precursor formation and temperature in ethylene laminar diffusion flames

    KAUST Repository

    Abhinavam Kailasanathan, Ranjith Kumar

    2013-03-01

    Soot precursor species concentrations and flame temperature were measured in a diluted laminar co-flow jet diffusion flame at pressures up to eight atmospheres while varying diluent type. The objective of this study was to gain a better understanding of soot production and oxidation mechanisms, which could potentially lead to a reduction in soot emissions from practical combustion devices. Gaseous samples were extracted from the centerline of an ethylene-air laminar diffusion flame, which was diluted individually with four diluents (argon, helium, nitrogen, and carbon dioxide) to manipulate flame temperature and transport properties. The diluted fuel and co-flow exit velocities (top-hat profiles) were matched at all pressures to minimize shear-layer effects, and the mass fluxes were fixed over the pressure range to maintain constant Reynolds number. The flame temperature was measured using a fine gauge R-type thermocouple at pressures up to four atmospheres. Centerline concentration profiles of major non-fuel hydrocarbons collected via extractive sampling with a quartz microprobe and quantification using GC/MS+FID are reported within. The measured hydrocarbon species concentrations are vary dramatically with pressure and diluent, with the helium and carbon dioxide diluted flames yielding the largest and smallest concentrations of soot precursors, respectively. In the case of C2H2 and C6H6, two key soot precursors, helium diluted flames had concentrations more than three times higher compared with the carbon dioxide diluted flame. The peak flame temperature vary with diluents tested, as expected, with carbon dioxide diluted flame being the coolest, with a peak temperature of 1760K at 1atm, and the helium diluted flame being the hottest, with a peak temperature of 2140K. At four atmospheres, the helium diluted flame increased to 2240K, but the CO2 flame temperature increased more, decreasing the difference to approximately 250K. © 2012 The Combustion Institute.

  14. Effect of intrinsic organic carbon on the optical properties of fresh diesel soot.

    Science.gov (United States)

    Adler, Gabriella; Riziq, Ali Abo; Erlick, Carynelisa; Rudich, Yinon

    2010-04-13

    This study focuses on the retrieval of the normalized mass absorption cross section (MAC) of soot using theoretical calculations that incorporate new measurements of the optical properties of organic carbon (OC) intrinsic to fresh diesel soot. Intrinsic OC was extracted by water and an organic solvent, and the complex refractive index of the extracted OC was derived at 532 and 355-nm wavelengths using cavity ring-down aerosol spectrometry. The extracted OC was found to absorb weakly in the visible wavelengths and moderately at blue wavelengths. The mass ratio of OC and elemental carbon (EC) in the collected particles was evaluated using a thermo-optical method. The measured EC/OC ratio in the soot exhibited substantial variability from measurement to measurement, ranging between 2 and 5. To test the sensitivity of the MAC to this variability, three different EC/OC ratios (21, 11, and 12) were chosen as representative. Particle size and spherule morphology were estimated using scanning electron microscopy, and the soot was found to be primarily in the form of aggregates with a dominant aggregate diameter mode in the range 200-250 nm. The measured refractive index of the extracted OC was used with a variety of theoretical models to calculate the MAC of internally mixed diesel soot at 532 and 355 nm. We conclude that Rayleigh-Debye-Gans theory on clusters of coated spherules and T-matrix of a solid EC spheroid coated by intrinsic OC are both consistent with previous measurements; however, Rayleigh-Debye-Gans theory provides a more realistic physical model for the calculation. PMID:20018649

  15. Adsorption of Organic Compounds to Diesel Soot: Frontal Analysis and Polyparameter Linear Free-Energy Relationship.

    Science.gov (United States)

    Lu, Zhijiang; MacFarlane, John K; Gschwend, Philip M

    2016-01-01

    Black carbons (BCs) dominate the sorption of many hydrophobic organic compounds (HOCs) in soils and sediments, thereby reducing the HOCs' mobilities and bioavailabilities. However, we do not have data for diverse HOCs' sorption to BC because it is time-consuming and labor-intensive to obtain isotherms on soot and other BCs. In this study, we developed a frontal analysis chromatographic method to investigate the adsorption of 21 organic compounds with diverse functional groups to NIST diesel soot. This method was precise and time-efficient, typically taking only a few hours to obtain an isotherm. Based on 102 soot-carbon normalized sorption coefficients (KsootC) acquired at different sorbate concentrations, a sorbate-activity-dependent polyparameter linear free-energy relationship was established: logKsootC = (3.74 ± 0.11)V + ((-0.35 ± 0.02)log ai)E + (-0.62 ± 0.10)A + (-3.35 ± 0.11)B + (-1.45 ± 0.09); (N = 102, R(2) = 0.96, SE = 0.18), where V, E, A, and B are the sorbate's McGowan's characteristic volume, excess molar refraction, and hydrogen acidity and basicity, respectively; and ai is the sorbate's aqueous activity reflecting the system's approach to saturation. The difference in dispersive interactions with the soot versus with the water was the dominant factor encouraging adsorption, and H-bonding interactions discouraged this process. Using this relationship, soot-water and sediment-water or soil-water adsorption coefficients of HOCs of interest (PAHs and PCBs) were estimated and compared with the results reported in the literature. PMID:26587648

  16. Numerical Modelling of Soot Formation in Laminar Axisymmetric Ethylene-Air Coflow Flames at Atmospheric and Elevated Pressures

    KAUST Repository

    Rakha, Ihsan Allah

    2015-05-01

    The steady coflow diffusion flame is a widely used configuration for studying combustion kinetics, flame dynamics, and pollutant formation. In the current work, a set of diluted ethylene-air coflow flames are simulated to study the formation, growth, and oxidation of soot, with a focus on the effects of pressure on soot yield. Firstly, we assess the ability of a high performance CFD solver, coupled with detailed transport and kinetic models, to reproduce experimental measurements, like the temperature field, the species’ concentrations and the soot volume fraction. Fully coupled conservation equations for mass, momentum, energy, and species mass fractions are solved using a low Mach number formulation. Detailed finite rate chemistry describing the formation of Polycyclic Aromatic Hydrocarbons up to cyclopenta[cd]pyrene is used. Soot is modeled using a moment method and the resulting moment transport equations are solved with a Lagrangian numerical scheme. Numerical and experimental results are compared for various pressures. Reasonable agreement is observed for the flame height, temperature, and the concentrations of various species. In each case, the peak soot volume fraction is predicted along the centerline as observed in the experiments. The predicted integrated soot mass at pressures ranging from 4-8 atm, scales as P2.1, in satisfactory agreement with the measured integrated soot pressure scaling (P2.27). Significant differences in the mole fractions of benzene and PAHs, and the predicted soot volume fractions are found, using two well-validated chemical kinetic mechanisms. At 4 atm, one mechanism over-predicts the peak soot volume fraction by a factor of 5, while the other under-predicts it by a factor of 5. A detailed analysis shows that the fuel tube wall temperature has an effect on flame stabilization.

  17. An Experimental and Computational Study on Soot Formation in a Coflow Jet Flame Under Microgravity and Normal Gravity

    Science.gov (United States)

    Ma, Bin; Cao, Su; Giassi, Davide; Stocker, Dennis P.; Takahashi, Fumiaki; Bennett, Beth Anne V.; Smooke, Mitchell D.; Long, Marshall B.

    2014-01-01

    Upon the completion of the Structure and Liftoff in Combustion Experiment (SLICE) in March 2012, a comprehensive and unique set of microgravity coflow diffusion flame data was obtained. This data covers a range of conditions from weak flames near extinction to strong, highly sooting flames, and enabled the study of gravitational effects on phenomena such as liftoff, blowout and soot formation. The microgravity experiment was carried out in the Microgravity Science Glovebox (MSG) on board the International Space Station (ISS), while the normal gravity experiment was performed at Yale utilizing a copy of the flight hardware. Computational simulations of microgravity and normal gravity flames were also carried out to facilitate understanding of the experimental observations. This paper focuses on the different sooting behaviors of CH4 coflow jet flames in microgravity and normal gravity. The unique set of data serves as an excellent test case for developing more accurate computational models.Experimentally, the flame shape and size, lift-off height, and soot temperature were determined from line-of-sight flame emission images taken with a color digital camera. Soot volume fraction was determined by performing an absolute light calibration using the incandescence from a flame-heated thermocouple. Computationally, the MC-Smooth vorticity-velocity formulation was employed to describe the chemically reacting flow, and the soot evolution was modeled by the sectional aerosol equations. The governing equations and boundary conditions were discretized on an axisymmetric computational domain by finite differences, and the resulting system of fully coupled, highly nonlinear equations was solved by a damped, modified Newtons method. The microgravity sooting flames were found to have lower soot temperatures and higher volume fraction than their normal gravity counterparts. The soot distribution tends to shift from the centerline of the flame to the wings from normal gravity to

  18. A comparison of chemical structures of soot precursor nanoparticles from liquid fuel combustion in flames and engine

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Bireswar; Datta, Amitava, E-mail: amdatta_ju@yahoo.com [Jadavpur University, Department of Power Engineering (India); Datta, Aparna; Saha, Abhijit [UGC-DAE Consortium for Scientific Research, Kolkata Centre (India)

    2013-04-15

    A comparative study of the chemical structures of soot precursor nanoparticles from the liquid fuel flame and engine exhaust has been performed in this work to establish an association between the particles from both the sources. Different ex-situ measurement techniques have been used to characterize the nanoparticles in samples collected from the laboratory petrol/air and iso-octane/air flames, as well as from a gasoline engine. The TEM images of the sampled material along with the EDS spectra corroborate the existence of carbonaceous nanoparticles. The nature of the UV absorption and fluorescence spectra of the samples from the iso-octane flame environment further confirms the sampled materials to be soot precursor nanoparticles. The DLS size distribution of the particles shows them to be below 10 nm size. FTIR spectrum of the precursor nanoparticles collected form the non-sooting zone of the flame and that of fully grown soot particles show few similarities and dissimilarities among them. The soot particles are found to be much more aromatized as compared to its precursor nanoparticles. The presence of carbonyl functional group (C=O) at around 1,720 cm{sup -1} has been observed in soot precursor nanoparticles, while such oxygenated functional groups are not prominent in soot structure. The absorption (UV and IR) and fluorescence spectra of the carbonaceous material collected from the gasoline engine exhaust show many resemblances with those of soot precursor nanoparticles from flames. These spectroscopic resemblances of the soot precursor nanoparticles from the flame environment and engine exhaust gives the evidence that the in-cylinder combustion is the source of these particles in the engine exhaust.

  19. Application of 1-hydroxyethylidene-1, 1-diphosphonic acid in boiler water for industrial boilers.

    Science.gov (United States)

    Zeng, Bin; Li, Mao-Dong; Zhu, Zhi-Ping; Zhao, Jun-Ming; Zhang, Hui

    2013-01-01

    The primary method used for boiler water treatment is the addition of chemicals to industrial boilers to prevent corrosion and scaling. The static scale inhibition method was used to evaluate the scale inhibition performance of 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDP). Autoclave static experiments were used to study the corrosion inhibition properties of the main material for industrial boilers (20# carbon steel) with an HEDP additive in the industrial boiler water medium. The electrochemical behavior of HEDP on carbon steel corrosion control was investigated using electrochemical impedance spectroscopy and Tafel polarization techniques. Experimental results indicate that HEDP can have a good scale inhibition effect when added at a quantity of 5 to 7 mg/L at a test temperature of not more than 100 °C. To achieve a high scale inhibition rate, the HEDP dosage must be increased when the test temperature exceeds 100 °C. Electrochemical and autoclave static experimental results suggest that HEDP has a good corrosion inhibition effect on 20# carbon steel at a concentration of 25 mg/L. HEDP is an excellent water treatment agent. PMID:23552243

  20. Comparison of soot formation for diesel and jet-a in a constant volume combustion chamber using two-color pyrometry

    KAUST Repository

    Jing, Wei

    2014-04-01

    The measurement of the two-color line of sight soot and KL factor for NO.2 diesel and jet-A fuels was conducted in an optical constant volume combustion chamber by using a high speed camera under 1000 K ambient temperature and varied oxygen concentration conditions. The ambient conditions were set as follows: four oxygen cases including 10%, 15%, 18% and 21% at 1000 K ambient temperature. KL factor and soot temperature were determined based on the two-color pyrometry technique using two band-pass filters with wavelengths of 650 nm and 550 nm. The results show that low soot temperature is observed in the upstream inner flame along the centerline, which is surrounded by high soot temperature regions, and a high KL factor is found in the same region with a low soot temperature. The results under different times suggest that soot temperature is higher for high O2 conditions during the entire flame development; meanwhile, both integrated KL factor and soot area decrease with the increase of O2 concentration. The two fuels share a similar trend of soot temperature and KL factor, however, diesel flame has a higher soot temperature and a larger high soot temperature area compared to jet-A flame. On the other hand, diesel flame shows a lower soot level during the quasi-steady state with a higher total soot level at the end of the combustion under low O2 conditions. A lower O2 concentration range from 10% to 15% is expected to have the possibility to achieve a simultaneous reduction of soot and NOx in sooting flames under the 1000 K ambient temperature condition. Copyright © 2014 SAE International.