Silane-propane ignitor/burner

DOEpatents

Hill, Richard W.; Skinner, Dewey F.; Thorsness, Charles B.

1985-01-01

A silane propane burner for an underground coal gasification process which is used to ignite the coal and to controllably retract the injection point by cutting the injection pipe. A narrow tube with a burner tip is positioned in the injection pipe through which an oxidant (oxygen or air) is flowed. A charge of silane followed by a supply of fuel, such as propane, is flowed through the tube. The silane spontaneously ignites on contact with oxygen and burns the propane fuel.

Experimental Flow Models for SSME Flowfield Characterization

NASA Technical Reports Server (NTRS)

Abel, L. C.; Ramsey, P. E.

1989-01-01

Full scale flow models with extensive instrumentation were designed and manufactured to provide data necessary for flow field characterization in rocket engines of the Space Shuttle Main Engine (SSME) type. These models include accurate flow path geometries from the pre-burner outlet through the throat of the main combustion chamber. The turbines are simulated with static models designed to provide the correct pressure drop and swirl for specific power levels. The correct turbopump-hot gas manifold interfaces were designed into the flow models to permit parametric/integration studies for new turbine designs. These experimental flow models provide a vehicle for understanding the fluid dynamics associated with specific engine issues and also fill the more general need for establishing a more detailed fluid dynamic base to support development and verification of advanced math models.

Characterization of Particle Combustion in a Rijke Burner

DTIC Science & Technology

1988-11-01

Rijke Burner 14 3.1 Introduction 14 3.2 Acoustics 14 3.3 Eperimental Procedure 17 3.3.1 Apparatus 17 3.3.2 Data Reduction 19 3.4 Burner...response of the modified Rijke burner, 2) The experimental procedures, including design modifications of the burner and data reduction, and 3...have been modified and improved significantly. The following sections describe the major design changes made in the modified Rijke burner and its

Slurry burner for mixture of carbonaceous material and water

DOEpatents

Nodd, D.G.; Walker, R.J.

1985-11-05

The present invention is intended to overcome the limitations of the prior art by providing a fuel burner particularly adapted for the combustion of carbonaceous material-water slurries which includes a stationary high pressure tip-emulsion atomizer which directs a uniform fuel into a shearing air flow as the carbonaceous material-water slurry is directed into a combustion chamber, inhibits the collection of unburned fuel upon and within the atomizer, reduces the slurry to a collection of fine particles upon discharge into the combustion chamber, and regulates the operating temperature of the burner as well as primary air flow about the burner and into the combustion chamber for improved combustion efficiency, no atomizer plugging and enhanced flame stability.

Research in Varying Burner Tilt Angle to Reduce Rear Pass Temperature in Coal Fired Boiler

NASA Astrophysics Data System (ADS)

Thrangaraju, Savithry K.; Munisamy, Kannan M.; Baskaran, Saravanan

2017-04-01

This research shows the investigation conducted on one of techniques that is used in Manjung 700 MW tangentially fired coal power plant. The investigation conducted in this research is finding out the right tilt angle for the burners in the boiler that causes an efficient temperature distribution and combustion gas flow pattern in the boiler especially at the rear pass section. The main outcome of the project is to determine the right tilt angle for the burner to create an efficient temperature distribution and combustion gas flow pattern that able to increase the efficiency of the boiler. The investigation is carried out by using Computational Fluid Dynamics method to obtain the results by varying the burner tilt angle. The boiler model is drawn by using designing software which is called Solid Works and Fluent from Computational Fluid Dynamics is used to conduct the analysis on the boiler model. The analysis is to imitate the real combustion process in the real Manjung 700 MW boiler. The expected results are to determine the right burner tilt angle with a computational fluid analysis by obtaining the temperature distribution and combustion gas flow pattern for each of the three angles set for the burner tilt angle in FLUENT software. Three burner tilt angles are selected which are burner tilt angle at (0°) as test case 1, burner tilt angle at (+10°) as test case 2 and burner tilt angle at (-10°) as test case 3. These entire three cases were run in CFD software and the results of temperature distribution and velocity vector were obtained to find out the changes on the three cases at the furnace and rear pass section of the boiler. The results are being compared in analysis part by plotting graphs to determine the right tilting angle that reduces the rear pass temperature.

Uniform-burning matrix burner

DOEpatents

Bohn, Mark S.; Anselmo, Mark

2001-01-01

Computer simulation was used in the development of an inward-burning, radial matrix gas burner and heat pipe heat exchanger. The burner and exchanger can be used to heat a Stirling engine on cloudy days when a solar dish, the normal source of heat, cannot be used. Geometrical requirements of the application forced the use of the inward burning approach, which presents difficulty in achieving a good flow distribution and air/fuel mixing. The present invention solved the problem by providing a plenum with just the right properties, which include good flow distribution and good air/fuel mixing with minimum residence time. CFD simulations were also used to help design the primary heat exchanger needed for this application which includes a plurality of pins emanating from the heat pipe. The system uses multiple inlet ports, an extended distance from the fuel inlet to the burner matrix, flow divider vanes, and a ring-shaped, porous grid to obtain a high-temperature uniform-heat radial burner. Ideal applications include dish/Stirling engines, steam reforming of hydrocarbons, glass working, and any process requiring high temperature heating of the outside surface of a cylindrical surface.

Fuel burner and combustor assembly for a gas turbine engine

DOEpatents

Leto, Anthony

1983-01-01

A fuel burner and combustor assembly for a gas turbine engine has a housing within the casing of the gas turbine engine which housing defines a combustion chamber and at least one fuel burner secured to one end of the housing and extending into the combustion chamber. The other end of the fuel burner is arranged to slidably engage a fuel inlet connector extending radially inwardly from the engine casing so that fuel is supplied, from a source thereof, to the fuel burner. The fuel inlet connector and fuel burner coact to anchor the housing against axial movement relative to the engine casing while allowing relative radial movement between the engine casing and the fuel burner and, at the same time, providing fuel flow to the fuel burner. For dual fuel capability, a fuel injector is provided in said fuel burner with a flexible fuel supply pipe so that the fuel injector and fuel burner form a unitary structure which moves with the fuel burner.

Controlled pilot oxidizer for a gas turbine combustor

DOEpatents

Laster, Walter R.; Bandaru, Ramarao V.

2010-07-13

A combustor (22) for a gas turbine (10) includes a main burner oxidizer flow path (34) delivering a first portion (32) of an oxidizer flow (e.g., 16) to a main burner (28) of the combustor and a pilot oxidizer flow path (38) delivering a second portion (36) of the oxidizer flow to a pilot (30) of the combustor. The combustor also includes a flow controller (42) disposed in the pilot oxidizer flow path for controlling an amount of the second portion delivered to the pilot.

Characterization of a new Hencken burner with a transition from a reducing-to-oxidizing environment for fundamental coal studies

NASA Astrophysics Data System (ADS)

Adeosun, Adewale; Huang, Qian; Li, Tianxiang; Gopan, Akshay; Wang, Xuebin; Li, Shuiqing; Axelbaum, Richard L.

2018-02-01

In pulverized coal burners, coal particles usually transition from a locally reducing environment to an oxidizing environment. The locally reducing environment in the near-burner region is due to a dense region of coal particles undergoing devolatilization. Following this region, the particles move into an oxidizing environment. This "reducing-to-oxidizing" transition can influence combustion processes such as ignition, particulate formation, and char burnout. To understand these processes at a fundamental level, a system is required that mimics such a transition. Hence, we have developed and characterized a two-stage Hencken burner to evaluate the effect of the reducing-to-oxidizing transition and particle-to-particle interaction (which characterizes dense region of coal particles) on ignition and ultrafine aerosol formation. The two-stage Hencken burner allows coal particles to experience a reducing environment followed by a transition to an oxidizing environment. This work presents the results of the design and characterization of the new two-stage Hencken burner and its new coal feeder. In a unique approach to the operation of the flat-flame of the Hencken burner, the flame configurations are operated as either a normal flame or inverse flame. Gas temperatures and oxygen concentrations for the Hencken burner are measured in reducing-to-oxidizing and oxidizing environments. The results show that stable flames with well-controlled conditions, relatively uniform temperatures, and species concentrations can be achieved in both flame configurations. This new Hencken burner provides an effective system for evaluating the effect of the reducing-to-oxidizing transition and particle-to-particle interaction on early-stage processes of coal combustion such as ignition and ultrafine particle formation.

Cooling Characteristics of an Experimental Tail-pipe Burner with an Annular Cooling-air Passage

NASA Technical Reports Server (NTRS)

Kaufman, Harold R; Koffel, William K

1952-01-01

The effects of tail-pipe fuel-air ratio (exhaust-gas temperatures from approximately 3060 degrees to 3825 degrees R), radial distributiion of tail-pipe fuel flow, and mass flow of combustion gas and the inside wall were determined for an experimental tail-pipe burner cooled by air flowing through and insulated cooling-air to combustion gas mass flow from 0.066 to 0.192 were also determined.

Computational Fluid Dynamics Based Investigation of Sensitivity of Furnace Operational Conditions to Burner Flow Controls

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marc Cremer; Kirsi St. Marie; Dave Wang

2003-04-30

This is the first Semiannual Technical Report for DOE Cooperative Agreement No: DE-FC26-02NT41580. The goal of this project is to systematically assess the sensitivity of furnace operational conditions to burner air and fuel flows in coal fired utility boilers. Our approach is to utilize existing baseline furnace models that have been constructed using Reaction Engineering International's (REI) computational fluid dynamics (CFD) software. Using CFD analyses provides the ability to carry out a carefully controlled virtual experiment to characterize the sensitivity of NOx emissions, unburned carbon (UBC), furnace exit CO (FECO), furnace exit temperature (FEGT), and waterwall deposition to burner flowmore » controls. The Electric Power Research Institute (EPRI) is providing co-funding for this program, and instrument and controls experts from EPRI's Instrument and Controls (I&C) Center are active participants in this project. This program contains multiple tasks and good progress is being made on all fronts. A project kickoff meeting was held in conjunction with NETL's 2002 Sensors and Control Program Portfolio Review and Roadmapping Workshop, in Pittsburgh, PA during October 15-16, 2002. Dr. Marc Cremer, REI, and Dr. Paul Wolff, EPRI I&C, both attended and met with the project COR, Susan Maley. Following the review of REI's database of wall-fired coal units, the project team selected a front wall fired 150 MW unit with a Riley Low NOx firing system including overfire air for evaluation. In addition, a test matrix outlining approximately 25 simulations involving variations in burner secondary air flows, and coal and primary air flows was constructed. During the reporting period, twenty-two simulations have been completed, summarized, and tabulated for sensitivity analysis. Based on these results, the team is developing a suitable approach for quantifying the sensitivity coefficients associated with the parametric tests. Some of the results of the CFD simulations of the single wall fired unit were presented in a technical paper entitled, ''CFD Investigation of the Sensitivity of Furnace Operational Conditions to Burner Flow Controls,'' presented at the 28th International Technical Conference on Coal Utilization and Fuel Systems in Clearwater, FL March 9-14, 2003. In addition to the work completed on the single wall fired unit, the project team made the selection of a 580 MW opposed wall fired unit to be the subject of evaluation in this program. Work is in progress to update the baseline model of this unit so that the parametric simulations can be initiated.« less

[Industrial pulverized coal low NO{sub x} burner, Phase I] technical progress report, April 1, 1992--June 30, 1992

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-09-01

Market evaluation of industrial pulverized coal usage, and of typical industries and applications where the low-NO{sub x}, burner may be sold, was partially completed at the end of this reporting period. The study identified three coals that may adequately meet the requirements of the low-NO{sub x} burner modeling study, and of the intended industrial applications. These were: (a) Pittsburgh Seam Bituminous, (b) Pittsburgh No. 8, and (c) Utah Bituminous. The first burner design, for modeling studies, was developed for a nominal output of 5.0 million Btu/hr. All input and process parameters, and all major dimensions of the burner have beenmore » determined. Burner design sketch was developed. Standard jet pump geometry of the fuel-rich burner flow path (US Patents No. 4,445,842 and No. 3,990,831), has been modified for use with pulverized coal. Staged air was added. Staged air, in conjunction with recirculated flue gas, has been found by ADL, MIT and other researchers to be effective in NO{sub x}, reduction. No attempt has been made to achieve compactness of design. The primary and seconder, air inlets and flow passages are separate, although in the industrial burner they will be combined. Flue gas may be drawn into the burner either from the hot furnace chamber, or from the flue stack after recuperation. However, to satisfy the energy requirements for volatilizing the coal, flue gas temperature above 2000{degrees}F may be needed. With the preliminary burner design completed, and suitable coals for the modeling study selected, type project is ready to proceed to the kinetic modeling tasks at MIT.« less

[Industrial pulverized coal low NO[sub x] burner, Phase I] technical progress report, April 1, 1992--June 30, 1992

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-09-01

Market evaluation of industrial pulverized coal usage, and of typical industries and applications where the low-NO[sub x], burner may be sold, was partially completed at the end of this reporting period. The study identified three coals that may adequately meet the requirements of the low-NO[sub x] burner modeling study, and of the intended industrial applications. These were: (a) Pittsburgh Seam Bituminous, (b) Pittsburgh No. 8, and (c) Utah Bituminous. The first burner design, for modeling studies, was developed for a nominal output of 5.0 million Btu/hr. All input and process parameters, and all major dimensions of the burner have beenmore » determined. Burner design sketch was developed. Standard jet pump geometry of the fuel-rich burner flow path (US Patents No. 4,445,842 and No. 3,990,831), has been modified for use with pulverized coal. Staged air was added. Staged air, in conjunction with recirculated flue gas, has been found by ADL, MIT and other researchers to be effective in NO[sub x], reduction. No attempt has been made to achieve compactness of design. The primary and seconder, air inlets and flow passages are separate, although in the industrial burner they will be combined. Flue gas may be drawn into the burner either from the hot furnace chamber, or from the flue stack after recuperation. However, to satisfy the energy requirements for volatilizing the coal, flue gas temperature above 2000[degrees]F may be needed. With the preliminary burner design completed, and suitable coals for the modeling study selected, type project is ready to proceed to the kinetic modeling tasks at MIT.« less

The structure of evaporating and combusting sprays: Measurements and predictions

NASA Technical Reports Server (NTRS)

Shuen, J. S.; Solomon, A. S. P.; Faeth, G. M.

1984-01-01

An apparatus developed, to allow observations of monodisperse sprays, consists of a methane-fueled turbulent jet diffusion flame with monodisperse methanol drops injected at the burner exit. Mean and fluctuating-phase velocities, drop sizes, drop-mass fluxes and mean-gas temperatures were measured. Initial drop diameters of 100 and 180 microns are being considered in order to vary drop penetration in the flow and effects of turbulent dispersion. Baseline tests of the burner flame with no drops present were also conducted. Calibration tests, needed to establish methods for predicting drop transport, involve drops supported in the post-flame region of a flat-flame burner operated at various mixture ratios. Spray models which are being evaluated include: (1) locally homogeneous flow (LFH) analysis, (2) deterministic separated flow (DSF) analysis and (3) stochastic separated flow (SSF) analysis.

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

NASA Technical Reports Server (NTRS)

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.

Pulverized solid injection system. Application to laboratory burners and pyrometric temperature measurements

NASA Astrophysics Data System (ADS)

Therssen, E.; Delfosse, L.

1995-08-01

The design and setting up of a pulverized solid injection system for use in laboratory burners is presented. The original dual system consists of a screw feeder coupled to an acoustic sower. This laboratory device allows a good regularity and stability of the particle-gas mixture transported to the burner in a large scale of mass powder and gas vector rate flow. The thermal history of the particles has been followed by optical measurements. The quality of the particle cloud injected in the burner has been validated by the good agreement between experimental and modeling particle temperature.

Large eddy simulation of forced ignition of an annular bluff-body burner

DOE Office of Scientific and Technical Information (OSTI.GOV)

Subramanian, V.; Domingo, P.; Vervisch, L.

2010-03-15

The optimization of the ignition process is a crucial issue in the design of many combustion systems. Large eddy simulation (LES) of a conical shaped bluff-body turbulent nonpremixed burner has been performed to study the impact of spark location on ignition success. This burner was experimentally investigated by Ahmed et al. [Combust. Flame 151 (2007) 366-385]. The present work focuses on the case without swirl, for which detailed measurements are available. First, cold-flow measurements of velocities and mixture fractions are compared with their LES counterparts, to assess the prediction capabilities of simulations in terms of flow and turbulent mixing. Timemore » histories of velocities and mixture fractions are recorded at selected spots, to probe the resolved probability density function (pdf) of flow variables, in an attempt to reproduce, from the knowledge of LES-resolved instantaneous flow conditions, the experimentally observed reasons for success or failure of spark ignition. A flammability map is also constructed from the resolved mixture fraction pdf and compared with its experimental counterpart. LES of forced ignition is then performed using flamelet fully detailed tabulated chemistry combined with presumed pdfs. Various scenarios of flame kernel development are analyzed and correlated with typical flow conditions observed in this burner. The correlations between, velocities and mixture fraction values at the sparking time and the success or failure of ignition, are then further discussed and analyzed. (author)« less

Flame tolerant secondary fuel nozzle

DOEpatents

Khan, Abdul Rafey; Ziminsky, Willy Steve; Wu, Chunyang; Zuo, Baifang; Stevenson, Christian Xavier

2015-02-24

A combustor for a gas turbine engine includes a plurality of primary nozzles configured to diffuse or premix fuel into an air flow through the combustor; and a secondary nozzle configured to premix fuel with the air flow. Each premixing nozzle includes a center body, at least one vane, a burner tube provided around the center body, at least two cooling passages, a fuel cooling passage to cool surfaces of the center body and the at least one vane, and an air cooling passage to cool a wall of the burner tube. The cooling passages prevent the walls of the center body, the vane(s), and the burner tube from overheating during flame holding events.

Altitude Performance Characteristics of Tail-pipe Burner with Convergingconical Burner Section on J47 Turbojet Engine

NASA Technical Reports Server (NTRS)

Prince, William R; Mcaulay, John E

1950-01-01

An investigation of turbojet-engine thrust augmentation by means of tail-pipe burning was conducted in the NACA Lewis altitude wind tunnel. Performance data were obtained with a tail-pipe burner having a converging conical burner section installed on an axial-flow-compressor type turbojet engine over a range of simulated flight conditions and tail-pipe fuel-air ratios with a fixed-area exhaust nozzle. A maximum tail-pipe combustion efficiency of 0.86 was obtained at an altitude of 15,000 feet and a flight Mach number of 0.23. Tail-pipe burner operation was possible up to an altitude of 45,000 feet at a flight Mach number of 0.23.

Combustion system for hybrid solar fossil fuel receiver

DOEpatents

Mehos, Mark S.; Anselmo, Kenneth M.; Moreno, James B.; Andraka, Charles E.; Rawlinson, K. Scott; Corey, John; Bohn, Mark S.

2004-05-25

A combustion system for a hybrid solar receiver comprises a pre-mixer which combines air and fuel to form an air-fuel mixture. The mixture is introduced tangentially into a cooling jacket. A burner plenum is fluidically connected to the cooling jacket such that the burner plenum and the cooling jacket are arranged in thermal contact with one another. The air-fuel mixture flows through the cooling jacket cooling the burner plenum to reduce pre-ignition of the air-fuel mixture in the burner plenum. A combustion chamber is operatively associated with and open to the burner plenum to receive the air-fuel mixture from the burner plenum. An igniter is operatively positioned in the combustion chamber to combust the air-fuel mixture, releasing heat. A recuperator is operatively associated with the burner plenum and the combustion chamber and pre-heats the air-fuel mixture in the burner plenum with heat from the combustion chamber. A heat-exchanger is operatively associated and in thermal contact with the combustion chamber. The heat-exchanger provides heat for the hybrid solar receiver.

Indirect measurement of the thermal-acoustic efficiency spectrum of a long turbulent burner

NASA Technical Reports Server (NTRS)

Mahan, J. R.; Jones, J. D.; Blevins, L. R.; Cline, J. G.

1983-01-01

A new method is described for deducing the thermal-acoustic efficiency spectrum (defined as the fraction of combustion heat release converted to acoustic energy at a given frequency) of a long turbulent burner from the sound spectrum measured in the far field. The method, which is based on a one-dimensional model of the unsteady flow in the burner, is applied to a tubular diffusion-flame hydrogen burner whose length is large compared to its diameter. The results for thermal powers ranging from 4.5 to 22.3 kW show that the thermal-acoustic efficiency is relatively insensitive to the burner power level, decreasing from a value of around 0.0001 at 150 Hz with a slope of about 20 dB per decade. Evidence is presented indicating that acoustic agitation of the flame below 500 Hz, especially in the neighborhood of the resonant frequencies of the burner, is a significant acoustic source.

Characterization of a Combined CARS and Interferometric Rayleigh Scattering System

NASA Technical Reports Server (NTRS)

Tedder, Sarah A.; Bivolaru, Daniel; Danehy, Paul M.; Weikl, M. C.; Beyrau, F.; Seeger, T.; Cutler, Andrew D.

2007-01-01

This paper describes the characterization of a combined Coherent anti-Stokes Raman Spectroscopy and Interferometric Rayleigh Scattering (CARS-IRS) system by reporting the accuracy and precision of the measurements of temperature, species mole fraction of N2, O2, and H2, and two-components of velocity. A near-adiabatic H2-air Hencken burner flame was used to provide known properties for measurements made with the system. The measurement system is also demonstrated in a small-scale Mach 1.6 H2-air combustion-heated supersonic jet with a co-flow of H2. The system is found to have a precision that is sufficient to resolve fluctuations of flow properties in the mixing layer of the jet.

Altitude-wind-tunnel investigation of tail-pipe burning with a Westinghouse X24C-4B axial-flow turbojet engine

NASA Technical Reports Server (NTRS)

Fleming, William A; Wallner, Lewis E

1948-01-01

Thrust augmentation of an axial-flow type turbojet engine by burning fuel in the tail pipe has been investigated in the NACA Cleveland altitude wind tunnel. The performance was determined over a range of simulated flight conditions and tail-pipe fuel flows. The engine tail pipe was modified for the investigation to reduce the gas velocity at the inlet of the tail-pipe combustion chamber and to provide an adequate seat for the flame; four such modifications were investigated. The highest net-thrust increase obtained in the investigation was 86 percent with a net thrust specific fuel consumption of 2.91 and a total fuel-air ratio of 0.0523. The highest combustion efficiencies obtained with the four configurations ranged from 0.71 to 0.96. With three of the tail-pipe burners, for which no external cooling was provided, the exhaust nozzle and the rear part of the burner section were bright red during operation at high tail-pipe fuel-air ratios. With the tail-pipe burner for which fuel and water cooling were provided, the outer shell of the tail-pipe burner showed no evidence of elevated temperatures at any operating condition.

Reverberatory screen for a radiant burner

DOEpatents

Gray, Paul E.

1999-01-01

The present invention relates to porous mat gas fired radiant burner panels utilizing improved reverberatory screens. The purpose of these screens is to boost the overall radiant output of the burner relative to a burner using no screen and the same fuel-air flow rates. In one embodiment, the reverberatory screen is fabricated from ceramic composite material, which can withstand higher operating temperatures than its metallic equivalent. In another embodiment the reverberatory screen is corrugated. The corrugations add stiffness which helps to resist creep and thermally induced distortions due to temperature or thermal expansion coefficient differences. As an added benefit, it has been unexpectedly discovered that the corrugations further increase the radiant efficiency of the burner. In a preferred embodiment, the reverberatory screen is both corrugated and made from ceramic composite material.

Experimental study of the thermal-acoustic efficiency in a long turbulent diffusion-flame burner

NASA Technical Reports Server (NTRS)

Mahan, J. R.

1983-01-01

An acoustic source/propagation model is used to interpret measured noise spectra from a long turbulent burner. The acoustic model is based on the perturbation solution of the equations describing the unsteady one-dimensional flow of an inviscid ideal gas with a distributed heat source. The model assumes that the measured noise spectra are due uniquely to the unsteady component of combustion heat release. The model was applied to a long cylindrical hydrogen burner operating over a range of power levels between 4.5 kW and 22.3 kW. Acoustic impedances at the inlet to the burner and at the exit of the tube downstream of the burner were measured and are used as boundary conditions for the model. These measured impedances are also presented.

Plasma-assisted combustion technology for NOx reduction in industrial burners.

PubMed

Lee, Dae Hoon; Kim, Kwan-Tae; Kang, Hee Seok; Song, Young-Hoon; Park, Jae Eon

2013-10-01

Stronger regulations on nitrogen oxide (NOx) production have recently promoted the creation of a diverse array of technologies for NOx reduction, particularly within the combustion process, where reduction is least expensive. In this paper, we discuss a new combustion technology that can reduce NOx emissions within industrial burners to single-digit parts per million levels without employing exhaust gas recirculation or other NOx reduction mechanisms. This new technology uses a simple modification of commercial burners, such that they are able to perform plasma-assisted staged combustion without altering the outer configuration of the commercial reference burner. We embedded the first-stage combustor within the head of the commercial reference burner, where it operated as a reformer that could host a partial oxidation process, producing hydrogen-rich reformate or synthesis gas product. The resulting hydrogen-rich flow then ignited and stabilized the combustion flame apart from the burner rim. Ultimately, the enhanced mixing and removal of hot spots with a widened flame area acted as the main mechanisms of NOx reduction. Because this plasma burner acted as a low NOx burner and was able to reduce NOx by more than half compared to the commercial reference burner, this methodology offers important cost-effective possibilities for NOx reduction in industrial applications.

Performance assessment of U.S. residential cooking exhaust hoods.

PubMed

Delp, William W; Singer, Brett C

2012-06-05

This study assessed the performance of seven new residential cooking exhaust hoods representing common U.S. designs. Laboratory tests were conducted to determine fan curves relating airflow to duct static pressure, sound levels, and exhaust gas capture efficiency for front and back cooktop burners and the oven. Airflow rate sensitivity to duct flow resistance was higher for axial fan devices than for centrifugal fan devices. Pollutant capture efficiency (CE) ranged from <15% to >98%, varying across hoods and with airflow and burner position for each hood. CE was higher for back burners relative to front burners, presumably because most hoods covered only part of the front burners. Open hoods had higher CE than those with grease screen and metal-covered bottoms. The device with the highest CE--exceeding 80% for oven and front burners--had a large, open hood that covered most of the front burners. The airflow rate for this hood surpassed the industry-recommended level of 118 L·s(-1) (250 cfm) and produced sound levels too high for normal conversation. For hoods meeting the sound and fan efficacy criteria for Energy Star, CE was <30% for front and oven burners.

Lean Premixed Combustion Stabilized by Low Swirl a Promising Concept for Practical Applications

NASA Technical Reports Server (NTRS)

Cheng, R. K.

1999-01-01

Since its inception, the low-swirl burner (LSB) has shown to be a useful laboratory apparatus for fundamental studies of premixed turbulent flames. The LSB operates under wide ranges of equivalence ratios, flow rates, and turbulence intensities. Its flame is lifted and detached from the burner and allows easy access for laser diagnostics. The flame brush is axisymmetric and propagates normal to the incident reactants. Therefore, the LSB is well suited for investigating detailed flame structures and empirical coefficients such as flame speed, turbulence transport, and flame generated turbulence. Due to its capability to stabilize ultra-lean premixed turbulent flames (phi approx. = 0.55), the LSB has generated interest from the gas appliance industry for use as an economical low-NO(x) burner. Lean premixed combustion emits low levels of NO(x), due primarily to the low flame temperature. Therefore, it is a very effective NO(x) prevention method without involving selective catalytic reduction (SCR), fuel-air staging, or flue gas recirculation (FGR). En the gas turbine industry, substantial research efforts have already been undertaken and engines with lean premixed combustors are already in use. For commercial and residential applications, premixed pulsed combustors and premixed ceramic matrix burners are commercially available. These lean premixed combustion technologies, however, tend to be elaborate but have relatively limited operational flexibility, and higher capital, operating and maintenance costs. Consequently, these industries are continuing the development of lean premixed combustion technologies as well as exploring new concepts. This paper summarizes the research effects we have undertaken in the past few years to demonstrate the feasibility of applying the low-swirl flame stabilization method for a wide range of heating and power generation systems. The principle of flame stabilization by low-swirl is counter to the conventional high-swirl methods that rely on a recirculation zone to anchor the flame. In LSBS, flow recirculation is not promoted to allow the premixed turbulent flames to propagate freely. A LSB with an air-jet swirler is essentially an open tube with the swirler at its mid section. The small air-jets generate swirling motion only in the annular region and leaving the central core of the flow undisturbed, When this flow exits the burner tube, the angular momentum generates radial mean pressure gradient to diverge the non-swirling reactants stream. Consequently, the mean flow velocity decreases linearly. Propagating against this decelerating flow, the flame self-sustains at the position where the local flow velocity equals the flame speed, S(sub f). The LSB operates with a swirl number, S, between 0.02 to 0.1. This is much lower than the minimum S of 0.6 required for the high-swirl burners. We found that the swirl number needed for flame stabilization varies only slightly with fuel type, flow velocity, turbulent conditions and burner dimensions (i.e. throat diameter and swirl injection angle).

Enclosed ground-flare incinerator

DOEpatents

Wiseman, Thomas R.

2000-01-01

An improved ground flare is provided comprising a stack, two or more burner assemblies, and a servicing port so that some of the burner assemblies can be serviced while others remain in operation. The burner assemblies comprise a burner conduit and nozzles which are individually fitted to the stack's burner chamber and are each removably supported in the chamber. Each burner conduit is sealed to and sandwiched between a waste gas inlet port and a matching a closure port on the other side of the stack. The closure port can be opened for physically releasing the burner conduit and supplying sufficient axial movement room for extracting the conduit from the socket, thereby releasing the conduit for hand removal through a servicing port. Preferably, the lower end of the stack is formed of one or more axially displaced lower tubular shells which are concentrically spaced for forming annular inlets for admitting combustion air. An upper tubular exhaust stack, similarly formed, admits additional combustion air for increasing the efficiency of combustion, increasing the flow of exhausted for improved atmospheric dispersion and for cooling the upper stack.

Computational investigations of low-emission burner facilities for char gas burning in a power boiler

NASA Astrophysics Data System (ADS)

Roslyakov, P. V.; Morozov, I. V.; Zaychenko, M. N.; Sidorkin, V. T.

2016-04-01

Various variants for the structure of low-emission burner facilities, which are meant for char gas burning in an operating TP-101 boiler of the Estonia power plant, are considered. The planned increase in volumes of shale reprocessing and, correspondingly, a rise in char gas volumes cause the necessity in their cocombustion. In this connection, there was a need to develop a burner facility with a given capacity, which yields effective char gas burning with the fulfillment of reliability and environmental requirements. For this purpose, the burner structure base was based on the staging burning of fuel with the gas recirculation. As a result of the preliminary analysis of possible structure variants, three types of early well-operated burner facilities were chosen: vortex burner with the supply of recirculation gases into the secondary air, vortex burner with the baffle supply of recirculation gases between flows of the primary and secondary air, and burner facility with the vortex pilot burner. Optimum structural characteristics and operation parameters were determined using numerical experiments. These experiments using ANSYS CFX bundled software of computational hydrodynamics were carried out with simulation of mixing, ignition, and burning of char gas. Numerical experiments determined the structural and operation parameters, which gave effective char gas burning and corresponded to required environmental standard on nitrogen oxide emission, for every type of the burner facility. The burner facility for char gas burning with the pilot diffusion burner in the central part was developed and made subject to computation results. Preliminary verification nature tests on the TP-101 boiler showed that the actual content of nitrogen oxides in burner flames of char gas did not exceed a claimed concentration of 150 ppm (200 mg/m3).

Internal structure visualization of flow and flame by process tomography and PLIF data fusion

NASA Astrophysics Data System (ADS)

Liu, J.; Liu, Shi; Sun, S.; Pan, X.; Schlaberg, I. H. I.

2018-02-01

To address the increasing demands on pollution control and energy saving, the study of low-emission and high-efficiency burners has been emphasized worldwide. Swirl-induced environmental burners (EV-burners), have notable features aligned with these requirements. In this study, an EV burner is investigated by both an ECT system and an OH-PLIF system. The aim is to detect the structure of a flame and obtain more information about the combustion process in an EV burner. 3D ECT sensitivity maps are generated for the measurement and OH-PLIF images are acquired in the same combustion zone as for the ECT measurements. The experimental images of a flame by ECT are in good agreement with the OH radical distribution pictures captured by OH-PLIF, which provide a mutual verification of the visualization method.

Influence of the technique for injection of flue gas and the configuration of the swirl burner throat on combustion of gaseous fuel and formation of nitrogen oxides in the flame

NASA Astrophysics Data System (ADS)

Dvoinishnikov, V. A.; Khokhlov, D. A.; Knyaz'kov, V. P.; Ershov, A. Yu.

2017-05-01

How the points at which the flue gas was injected into the swirl burner and the design of the burner outlet influence the formation and development of the flame in the submerged space, as well as the formation of nitrogen oxides in the combustion products, have been studied. The object under numerical investigation is the flame of the GMVI combined (oil/gas) burner swirl burner fitted with a convergent, biconical, cylindrical, or divergent throat at the burner outlet with individual supply of the air and injection of the gaseous fuel through tubing. The burners of two designs were investigated; they differ by the absence or presence of an inlet for individual injection of the flue gas. A technique for numerical simulation of the flame based on the CFD methods widely used in research of this kind underlies the study. Based on the summarized results of the numerical simulation of the processes that occur in jet flows, the specific features of the aerodynamic pattern of the flame have been established. It is shown that the flame can be conventionally divided into several sections over its length in all investigations. The lengths of each of the sections, as well as the form of the fields of axial velocity, temperatures, concentrations of the fuel, oxygen, and carbon and nitrogen oxides, are different and determined by the design features of the burner, the flow rates of the agent, and the compositions of the latter in the burner ducts as well as the configuration of the burner throat and the temperature of the environment. To what degree the burner throat configuration and the techniques for injection of the flue gas at different ambient temperatures influence the formation of nitrogen oxides has been established. It is shown that the supply of the recirculation of flue gas into the fuel injection zone enables a considerable reduction in the formation of nitrogen oxides in the flame combustion products. It has been established that the locations of the zones of intensive fuel burnout and generation of nitrogen oxides do not coincide over the flame length, and the ambient temperature has a significant impact on the combustion stability at low values and on the concentration of nitrogen oxides in the combustion products at high values.

Abatement of SF{sub 6} and CF{sub 4} using an enhanced kerosene microwave plasma burner

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shin, Dong Hun; Hong, Yong Cheol; Cho, Soon Cheon

2006-11-15

A kerosene microwave plasma burner was presented as a tool for abatement of SF{sub 6} and CF{sub 4} gases, which cause global warming. The plasma burner operates by injecting kerosene as a liquid hydrocarbon fuel into a microwave plasma torch and by mixing the resultant gaseous hydrogen and carbon compounds with air or oxygen (O{sub 2}) gas. The abatement of SF{sub 6} and CF{sub 4}, by making use of the kerosene plasma burner, was conducted in terms of nitrogen (N{sub 2}) flow rates. The destruction and removal efficiency of the burner were achieved up to 99.9999% for 0.1 liters permore » minute (lpm) SF{sub 6} in 120 lpm N{sub 2} and 99.3% for 0.05 lpm CF{sub 4} in 60 lpm N{sub 2}, revealing that the microwave plasma burner can effectively eliminate perfluorocompounds emitted from the semiconductor industries.« less

Analytic prediction of unconfined boundary layer flashback limits in premixed hydrogen-air flames

NASA Astrophysics Data System (ADS)

Hoferichter, Vera; Hirsch, Christoph; Sattelmayer, Thomas

2017-05-01

Flame flashback is a major challenge in premixed combustion. Hence, the prediction of the minimum flow velocity to prevent boundary layer flashback is of high technical interest. This paper presents an analytic approach to predicting boundary layer flashback limits for channel and tube burners. The model reflects the experimentally observed flashback mechanism and consists of a local and global analysis. Based on the local analysis, the flow velocity at flashback initiation is obtained depending on flame angle and local turbulent burning velocity. The local turbulent burning velocity is calculated in accordance with a predictive model for boundary layer flashback limits of duct-confined flames presented by the authors in an earlier publication. This ensures consistency of both models. The flame angle of the stable flame near flashback conditions can be obtained by various methods. In this study, an approach based on global mass conservation is applied and is validated using Mie-scattering images from a channel burner test rig at ambient conditions. The predicted flashback limits are compared to experimental results and to literature data from preheated tube burner experiments. Finally, a method for including the effect of burner exit temperature is demonstrated and used to explain the discrepancies in flashback limits obtained from different burner configurations reported in the literature.

Experimental and numerical investigation of the iso-thermal flow characteristics within a cylindrical chamber with multiple planar-symmetric impinging jets

NASA Astrophysics Data System (ADS)

Long, Shen; Lau, Timothy C. W.; Chinnici, Alfonso; Tian, Zhao Feng; Dally, Bassam B.; Nathan, Graham J.

2017-10-01

We present a joint experimental and numerical study of the flow structure within a cylindrical chamber generated by planar-symmetric isothermal jets, under conditions of relevance to a wide range of practical applications, including the Hybrid Solar Receiver Combustor (HSRC) technology. The HSRC features a cavity with a coverable aperture to allow it to be operated as either a combustion chamber or a solar receiver, with multiple burners to direct a flame into the chamber and a heat exchanger that absorbs the heat from both energy sources. In this study, we assess the cases of two or four inlet jets (simulating the burners), configured in a planar-symmetric arrangement and aligned at an angle to the axis (αj) over the range of 0°-90°, at a constant inlet Reynolds number of ReD = 10 500. The jets were positioned in the same axial plane near the throat and interact with each other and the cavity walls. Measurements obtained with particle image velocimetry were used together with numerical modeling employing Reynolds-averaged Navier-Stokes methods to characterize the large-scale flow field within selected configurations of the device. The results reveal a significant dependence of the mean flow-field on αj and the number of inlet jets (Nj). Four different flow regimes with key distinctive features were identified within the range of αj and Nj considered here. It was also found that αj has a controlling influence on the extent of back-flow through the throat, the turbulence intensity, the flow stability, and the dominant recirculation zone, while Nj has a secondary influence on the turbulence intensity, the flow stability, and the transition between each flow regime.

Computational fluid dynamics analysis of a synthesis gas turbulent combustion in a round jet burner

NASA Astrophysics Data System (ADS)

Mansourian, Mohammad; Kamali, Reza

2017-05-01

In this study, the RNG-Large Eddy Simulation (RNG-LES) methodology of a synthesis gas turbulent combustion in a round jet burner is investigated, using OpenFoam package. In this regard, the extended EDC extinction model of Aminian et al. for coupling the reaction and turbulent flow along with various reaction kinetics mechanisms such as Skeletal and GRI-MECH 3.0 have been utilized. To estimate precision and error accumulation, we used the Smirinov's method and the results are compared with the available experimental data under the same conditions. As a result, it was found that the GRI-3.0 reaction mechanism has the least computational error and therefore, was considered as a reference reaction mechanism. Afterwards, we investigated the influence of various working parameters including the inlet flow temperature and inlet velocity on the behavior of combustion. The results show that the maximum burner temperature and pollutant emission are affected by changing the inlet flow temperature and velocity.

A high-pressure premixed flat-flame burner for chemical process studies. [of pollutant formation in hydrocarbon flames

NASA Technical Reports Server (NTRS)

Miller, I. M.

1978-01-01

A premixed flat-flame burner was designed and tested with methane-air mixtures at pressures from 1.1 to 20 atm and equivalence ratios from 0.7 to 1.1. Reactant velocity in the burner mixing chamber was used to characterize the range of stable flames at each pressure-equivalence-ratio condition. Color photographs of the flames were used to determine flame zone thickness and flame height. The results show that this burner can be used for chemical process studies in premixed high pressure methane-air flames up to 20 atm.

Effect of fuel volatility on performance of tail-pipe burner

NASA Technical Reports Server (NTRS)

Barson, Zelmar; Sargent, Arthur F , Jr

1951-01-01

Fuels having Reid vapor pressures of 6.3 and 1.0 pounds per square inch were investigated in a tail-pipe burner on an axial-flow-type turbojet engine at a simulated flight Mach number of 0.6 and altitudes from 20,000 to 45,000 feet. With the burner configuration used in this investigation, having a mixing length of only 8 inches between the fuel manifold and the flame holder, the low-vapor-pressure fuel gave lower combustion efficiency at a given tail-pipe fuel-air ratio. Because the exhaust-nozzle area was fixed, the lower efficiency resulted in lower thrust and higher specific fuel consumption. The maximum altitude at which the burner would operate was practically unaffected by the change in fuel volatility.

Effects of elliptical burner geometry on partially premixed gas jet flames in quiescent surroundings

NASA Astrophysics Data System (ADS)

Baird, Benjamin

This study is the investigation of the effect of elliptical nozzle burner geometry and partial premixing, both 'passive control' methods, on a hydrogen/hydrocarbon flame. Both laminar and turbulent flames for circular, 3:1, and 4:1 aspect ratio (AR) elliptical burners are considered. The amount of air mixed with the fuel is varied from fuel-lean premixed flames to fuel-rich partially premixed flames. The work includes measurements of flame stability, global pollutant emissions, flame radiation, and flame structure for the differing burner types and fuel conditions. Special emphasis is placed on the near-burner region. Experimentally, both conventional (IR absorption, chemiluminecent, and polarographic emission analysis,) and advanced (laser induced fluorescence, planar laser induced fluorescence, Laser Doppler Velocimetry (LDV), Rayleigh scattering) diagnostic techniques are used. Numerically, simulations of 3-dimensional laminar and turbulent reacting flow are conducted. These simulations are run with reduced chemical kinetics and with a Reynolds Stress Model (RSM) for the turbulence modeling. It was found that the laminar flames were similar in appearance and overall flame length for the 3:1 AR elliptical and the circular burner. The laminar 4:1 AR elliptical burner flame split into two sub-flames along the burner major axis. This splitting had the effect of greatly shortening the 4:1 AR elliptical burner flame to have an overall flame length about half of that of the circular and 3:1 AR elliptical burner flames. The length of all three burners flames increased with increasing burner exit equivalence ratio. The blowout velocity for the three burners increased with increase in hydrogen mass fraction of the hydrogen/propane fuel mixture. For the rich premixed flames, the circular burner was the most stable, the 3:1 AR elliptical burner, was the least stable, and the 4:1 AR elliptical burner was intermediate to the two other burners. This order of stability was due to two reasons. The elliptical burners have enhanced turbulence generation that lowers their stability when compared to the circular burner. The 4:1 AR elliptical burner had greater stability due to a greater velocity decay rate and wider OH reaction zones particularly in the region between the two jets. The 3:1 AR elliptical and circular burners produced similar carbon monoxide and nitric oxide emission indexes over the range of equivalence ratios of 0.55 to 4.0, for laminar flames. (Abstract shortened by UMI.)

Advancements in Dual-Pump Broadband CARS for Supersonic Combustion Measurements

NASA Technical Reports Server (NTRS)

Tedder, Sarah Augusta Umberger

2010-01-01

Space- and time-resolved measurements of temperature and species mole fractions of nitrogen, oxygen, and hydrogen were obtained with a dual-pump coherent anti-Stokes Raman spectroscopy (CARS) system in hydrogen-fueled supersonic combustion free jet flows. These measurements were taken to provide time-resolved fluid properties of turbulent supersonic combustion for use in the creation and verification of computational fluid dynamic (CFD) models. CFD models of turbulent supersonic combustion flow currently facilitate the design of air-breathing supersonic combustion ramjet (scramjet) engines. Measurements were made in supersonic axi-symmetric free jets of two scales. First, the measurement system was tested in a laboratory environment using a laboratory-scale burner (approx.10 mm at nozzle exit). The flow structures of the laboratory-burner were too small to be resolved with the CARS measurements volume, but the composition and temperature of the jet allowed the performance of the system to be evaluated. Subsequently, the system was tested in a burner that was approximately 6 times larger, whose length scales are better resolved by the CARS measurement volume. During both these measurements, weaknesses of the CARS system, such as sensitivity to vibrations and beam steering and inability to measure temperature or species concentrations in hydrogen fuel injection regions were indentified. Solutions were then implemented in improved CARS systems. One of these improved systems is a dual-pump broadband CARS technique called, Width Increased Dual-pump Enhanced CARS (WIDECARS). The two lowest rotational energy levels of hydrogen detectable by WIDECARS are H2 S(3) and H2 S(4). The detection of these lines gives the system the capability to measure temperature and species concentrations in regions of the flow containing pure hydrogen fuel at room temperature. WIDECARS is also designed for measurements of all the major species (except water) in supersonic combustion flows fueled with hydrogen and hydrogen/ethylene mixtures (N2, O2, H2, C2H4, CO, and CO2). This instrument can characterize supersonic combustion fueled with surrogate fuel mixtures of hydrogen and ethylene. This information can lead to a better understanding of the chemistry and performance of supersonic combustion fueled with cracked jet propulsion (JP)-type fuel.

Simplified configuration for the combustor of an oil burner using a low pressure, high flow air-atomizing nozzle

DOEpatents

Butcher, Thomas A.; Celebi, Yusuf; Fisher, Leonard

2000-09-15

The invention relates to clean burning of fuel oil with air. More specifically, to a fuel burning combustion head using a low-pressure, high air flow atomizing nozzle so that there will be a complete combustion of oil resulting in a minimum emission of pollutants. The improved fuel burner uses a low pressure air atomizing nozzle that does not result in the use of additional compressors or the introduction of pressurized gases downstream, nor does it require a complex design. Inventors:

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kiss, L.I.; Bui, R.T.; Charette, A.

The flow structure inside round furnaces with various numbers of burners, burner arrangement, and exit conditions has been studied experimentally with the purpose of improving the flow conditions and the resulting heat transfer. Small-scale transparent models were built according to the laws of geometric and dynamic similarity. Various visualization and experimental techniques were applied. The flow pattern in the near-surface regions was visualized by the fluorescent minituft and popcorn techniques; the flow structure in the bulk was analyzed by smoke injection and laser sheet illumination. For the study of the transient effects, high-speed video photography was applied. The effects ofmore » the various flow patterns, like axisymmetric and rotational flow, on the magnitude and uniformity of the residence time, as well as on the formation of stagnation zones, were discussed. Conclusions were drawn and have since been applied for the improvement of furnace performance.« less

Mechanical swirler for a low-NO{sub x}, weak-swirl burner

DOEpatents

Cheng, R.K.; Yegian, D.T.

1999-03-09

Disclosed is a mechanical swirler for generating diverging flow in lean premixed fuel burners. The swirler of the present invention includes a central passage with an entrance for accepting a feed gas, a flow balancing insert that introduces additional pressure drop beyond that occurring in the central passage in the absence of the flow balancing insert, and an exit aligned to direct the feed gas into a combustor. The swirler also has an annular passage about the central passage and including one or more vanes oriented to impart angular momentum to feed gas exiting the annular passage. The diverging flow generated by the swirler stabilizes lean combustion thus allowing for lower production of pollutants, particularly oxides of nitrogen. 16 figs.

Mechanical swirler for a low-NO.sub.x, weak-swirl burner

DOEpatents

Cheng, Robert K.; Yegian, Derek T.

1999-01-01

Disclosed is a mechanical swirler for generating diverging flow in lean premixed fuel burners. The swirler of the present invention includes a central passage with an entrance for accepting a feed gas, a flow balancing insert that introduces additional pressure drop beyond that occurring in the central passage in the absence of the flow balancing insert, and an exit aligned to direct the feed gas into a combustor. The swirler also has an annular passage about the central passage and including one or more vanes oriented to impart angular momentum to feed gas exiting the annular passage. The diverging flow generated by the swirler stabilizes lean combustion thus allowing for lower production of pollutants, particularly oxides of nitrogen.

Measurement of gas species, temperatures, coal burnout, and wall heat fluxes in a 200 MWe lignite-fired boiler with different overfire air damper openings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jianping Jing; Zhengqi Li; Guangkui Liu

Measurements were performed on a 200 MWe, wall-fired, lignite utility boiler. For different overfire air (OFA) damper openings, the gas temperature, gas species concentration, coal burnout, release rates of components (C, H, and N), furnace temperature, and heat flux and boiler efficiency were measured. Cold air experiments for a single burner were conducted in the laboratory. The double-swirl flow pulverized-coal burner has two ring recirculation zones starting in the secondary air region in the burner. As the secondary air flow increases, the axial velocity of air flow increases, the maxima of radial velocity, tangential velocity and turbulence intensity all increase,more » and the swirl intensity of air flow and the size of recirculation zones increase slightly. In the central region of the burner, as the OFA damper opening widens, the gas temperature and CO concentration increase, while the O{sub 2} concentration, NOx concentration, coal burnout, and release rates of components (C, H, and N) decrease, and coal particles ignite earlier. In the secondary air region of the burner, the O{sub 2} concentration, NOx concentration, coal burnout, and release rates of components (C, H, and N) decrease, and the gas temperature and CO concentration vary slightly. In the sidewall region, the gas temperature, O{sub 2} concentration, and NOx concentration decrease, while the CO concentration increases and the gas temperature varies slightly. The furnace temperature and heat flux in the main burning region decrease appreciably, but increase slightly in the burnout region. The NOx emission decreases from 1203.6 mg/m{sup 3} (6% O{sub 2}) for a damper opening of 0% to 511.7 mg/m{sup 3} (6% O{sub 2}) for a damper opening of 80% and the boiler efficiency decreases from 92.59 to 91.9%. 15 refs., 17 figs., 3 tabs.« less

Characterization of Liquid Fuel Evaporation of a Lifted Methanol Spray Flame in a Vitiated Coflow Burner

NASA Technical Reports Server (NTRS)

Cabra, Ricardo; Dibble, Robert W.; Chen, Jyh-Yuan

2002-01-01

An experimental investigation of lifted spray flames in a coflow of hot, vitiated gases is presented. The vitiated coflow burner is a spray flame that issues into a coaxial flow of hot combustion products from a lean, premixed H2/Air flame. The spray flame in a vitiated coflow emulates the combustion that occurs in many advanced combustors without the detailed fluid mechanics. Two commercially available laser diagnostic systems are used to characterize the spray flame and to demonstrate the vitiated coflow burner's amenability to optical investigation. The Ensemble Particle Concentration and Size (EPCS) system is used to measure the path-average droplet size distribution and liquid volume fraction at several axial locations while an extractive probe instrument named the Real-time Fuel-air Analyzer (RFA) is used to measure the air to fuel ratio downstream of the spray nozzle with high temporal and spatial resolution. The effect of coflow conditions (stoichiometry) and dilution of the fuel with water was studied with the EPCS optical system. As expected, results show that water retards the evaporation and combustion of fuels. Measurements obtained by the RFA extractive probe show that while the Delavan manufactured nozzle does distribute the fuel over the manufacturer specified spray angle, it unfortunately does not distribute the fuel uniformly, providing conditions that may result in the production of unwanted NOx. Despite some limitations due to the inherent nature of the experimental techniques, the two diagnostics can be readily applied to spray flames in the vitiated coflow environment.

Fourier and wavelet analyses of intermittent and resonant pressure components in a slot burner

NASA Astrophysics Data System (ADS)

Pagliaroli, Tiziano; Mancinelli, Matteo; Troiani, Guido; Iemma, Umberto; Camussi, Roberto

2018-01-01

In laboratory-scale burner it has been observed that the acoustic excitations change the flame topology inducing asymmetry and oscillations. Hence, an acoustic and aeroacoustic study in non reactive condition is of primary importance during the design stage of a new burner in order to avoid the development of standing waves which can force the flame. So wall pressure fluctuations inside and outside of a novel slot burner have been studied experimentally and numerically for a broad range of geometrical parameters and mass flow rates. Wall pressure fluctuations have been measured through cavity-mounted microphones, providing uni- and multi-variate pressure statistics in both the time and frequency domains. Furthermore, since the onset of combustion-driven oscillations is always presaged by intermittent bursts of high amplitude, a wavelet-based conditional sampling procedure was applied to the database in order to detect coherent signatures embedded in the pressure time signals. Since for a particular case the coherent structures identified have a multi-scale signature, a wavelet-based decomposition technique was proposed as well to separate the contribution of the large- and small-scale flow structures to the pressure fluctuation field. As a main outcome of the activity no coupling between standing waves and velocity fluctuations was observed, but only well localized pressure signatures with shape strongly affected by the neighbouring flow physics.

An experimental investigation of hybrid kerosene burner configurations for TPV applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schroeder, K.L.; Rose, M.F.; Burkhalter, J.E.

1995-01-05

A key element in thermophotovoltaic power generation is the development of a compact and efficient configuration for the thermal source and emitter. In the present work, a hybrid configuration was investigated which was composed of a liquid fueled diffusion type burner utilizing the emitting or mantle structure as the combustion chamber. The prototype burner operates on kerosene at fuel flow rates up to 1.0 kg/hr. Fuel is atomized using an 78 kHz ultrasonic nozzle with multifuel capabilities. Combustion is stabilized and heat transfer is enhanced via forced recirculation interior to the mantle structures. These structures range in size from 600more » to 1200 cm{sup 3} and are porous in nature. This paper presents an introduction to issues specific to the use of small scale liquid fueled burners for TPV applications, and burner performance data for a series of configurations, in terms of combustor surface temperature distribution, maximum mass loading and efficiency. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.« less

Swozzle based burner tube premixer including inlet air conditioner for low emissions combustion

DOEpatents

Tuthill, Richard Sterling; Bechtel, II, William Theodore; Benoit, Jeffrey Arthur; Black, Stephen Hugh; Bland, Robert James; DeLeonardo, Guy Wayne; Meyer, Stefan Martin; Taura, Joseph Charles; Battaglioli, John Luigi

2002-01-01

A burner for use in a combustion system of a heavy-duty industrial gas turbine includes a fuel/air premixer having an air inlet, a fuel inlet, and an annular mixing passage. The fuel/air premixer mixes fuel and air into a uniform mixture for injection into a combustor reaction zone. The burner also includes an inlet flow conditioner disposed at the air inlet of the fuel/air premixer for controlling a radial and circumferential distribution of incoming air. The pattern of perforations in the inlet flow conditioner is designed such that a uniform air flow distribution is produced at the swirler inlet annulus in both the radial and circumference directions. The premixer includes a swozzle assembly having a series of preferably air foil shaped turning vanes that impart swirl to the airflow entering via the inlet flow conditioner. Each air foil contains internal fuel flow passages that introduce natural gas fuel into the air stream via fuel metering holes that pass through the walls of the air foil shaped turning vanes. By injecting fuel in this manner, an aerodynamically clean flow field is maintained throughout the premixer. By injecting fuel via two separate passages, the fuel/air mixture strength distribution can be controlled in the radial direction to obtain optimum radial concentration profiles for control of emissions, lean blow outs, and combustion driven dynamic pressure activity as machine and combustor load are varied.

10 CFR 431.76 - Uniform test method for the measurement of energy efficiency of commercial warm air furnaces.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Gases), 2.5 (Test Pressures and Burner Adjustments), 2.6 (Static Pressure and Air Flow Adjustments), 2... pressure, as specified in Section 2.5.1 of ANSI Standard Z21.47-1998, (Incorporated by reference, see § 431... thermal efficiency test), 41 (Initial Test Conditions), 42 (Combustion Test—Burner and Furnace), 43.2...

10 CFR 431.76 - Uniform test method for the measurement of energy efficiency of commercial warm air furnaces.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Gases), 2.5 (Test Pressures and Burner Adjustments), 2.6 (Static Pressure and Air Flow Adjustments), 2... pressure, as specified in Section 2.5.1 of ANSI Standard Z21.47-1998, (Incorporated by reference, see § 431... thermal efficiency test), 41 (Initial Test Conditions), 42 (Combustion Test—Burner and Furnace), 43.2...

Buoyancy Effects on Flow Transition in Hydrogen Gas Jet Diffusion Flames

NASA Technical Reports Server (NTRS)

Albers, Burt W.; Agrawal, Ajay K.; Griffin, DeVon (Technical Monitor)

2000-01-01

Experiments were performed in earth-gravity to determine how buoyancy affected transition from laminar to turbulent flow in hydrogen gas jet diffusion flames. The jet exit Froude number characterizing buoyancy in the flame was varied from 1.65 x 10(exp 5) to 1.14 x 10(exp 8) by varying the operating pressure and/or burner inside diameter. Laminar fuel jet was discharged vertically into ambient air flowing through a combustion chamber. Flame characteristics were observed using rainbow schlieren deflectometry, a line-of-site optical diagnostic technique. Results show that the breakpoint length for a given jet exit Reynolds number increased with increasing Froude number. Data suggest that buoyant transitional flames might become laminar in the absence of gravity. The schlieren technique was shown as effective in quantifying the flame characteristics.

Preliminary investigation of acoustic oscillations in an H2-O2 fired Hall generator

NASA Technical Reports Server (NTRS)

Phillips, B.

1981-01-01

Burner pressure oscillations and interelectrode voltage oscillations measured in an open-cycle supersonic flow Hall generator are presented. The ionized gas for the channel was supplied by seeding the approximately 1 lb/sec of hydrogen-oxygen combustion products with cesium. Since both the burner and the channel were located within magnetic fields exceeding 4 Tesla during operation, an infinite probe pressure measurement technique was used to measure burner pressure oscillations. Calibration of the burner pressure transducer using a resonance tube technique is presented. Evidence is presented for the existence of the first longitudinal mode of oscillations (5000 Hz) within the burner. Interelectrode voltage oscillations were simultaneously measured at two separate axial stations. The magnitude change and the phase shift between the two signals was interpreted as a decaying magnetoacoustic wave driven by the burner that propagates at local gas plus sonic velocities. The amplitude of the electrical voltage oscillations at the start of the power producing region of the channel varied with the magnetic field. This variation is compared with the results of a simple perturbation analysis. Arguments are presented for using an unsteady model for analyzing wave processes in channels.

Strain-Rate-Free Diffusion Flames: Initiation, Properties, and Quenching

NASA Technical Reports Server (NTRS)

Fendell, Francis; Rungaldier, Harald; Gokoglu, Suleyman; Schultz, Donald

1997-01-01

For about a half century, the stabilization of a steady planar deflagration on a heat-sink-type flat-flame burner has been of extraordinary service for the theoretical modeling and diagnostic probing of combusting gaseous mixtures. However, most engineering devices and most unwanted fire involve the burning of initially unmixed reactants. The most vigorous burning of initially separated gaseous fuel and oxidizer is the diffusion flame. In this useful idealization (limiting case), the reactants are converted to product at a mathematically thin interface, so no interpenetration of fuel and oxidizer occurs. This limit is of practical importance because it often characterizes the condition of optimal performance (and sometimes environmentally objectionable operation) of a combustor. A steady planar diffusion flame is most closely approached in the laboratory in the counterflow apparatus. The utility of this simple-strain-rate flow for the modeling and probing of diffusion flames was noted by Pandya and Weinberg 35 years ago, though only in the last decade or so has its use become internationally common place. However, typically, as the strain rate a is reduced below about 20 cm(exp -1), and the diffusion-flame limit (reaction rate much faster than the flow rate) is approached, the burning is observed to become unstable in earth gravity. The advantageous steady planar flow is not available in the diffusion-flame limit in earth gravity. This is unfortunate because the typical spatial scale in a counterflow is (k/a)(sup 1/2), where k denotes a characteristic diffusion coefficient; thus, the length scale becomes large, and the reacting flow is particularly amenable to diagnostic probing, as the diffusion-flame limit is approached. The disruption of planar symmetry is owing the fact that, as the strain rate a decreases, the residence time (l/a) of the throughput in the counterflow burner increases. Observationally, when the residence time exceeds about 50 msec, the inevitably present convective (Rayleigh-Benard) instabilities, associated with hot-under-cold (flame-under-fresh-reactant) stratification of fluid in a gravitational field, have time to grow to finite amplitude during transit of the burner.

NOx reduction in catalytically stabilized thermal burners. Annual report, pril 1, 1988-March 31, 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pfefferle, L.D.

1989-09-01

Catalytically stabilized combustors can be designed to combine the high reaction rates of thermal combustors with low-NOx emissions. The objectives of the research are to understand why the CST burner has inherently low-NOx emissions and whether preexisting NOx can be reduced in-situ in the post-flame zone of a CST burner. Initial results indicate that reduced NOx emissions are, at least for some operating conditions, due to more than just the ability to stabilize combustion at low temperatures. The next phase of the investigation will focus on isothermal flow-tube kinetics studies to isolate catalytic and thermal effects.

Firing of pulverized solvent refined coal

DOEpatents

Lennon, Dennis R.; Snedden, Richard B.; Foster, Edward P.; Bellas, George T.

1990-05-15

A burner for the firing of pulverized solvent refined coal is constructed and operated such that the solvent refined coal can be fired successfully without any performance limitations and without the coking of the solvent refined coal on the burner components. The burner is provided with a tangential inlet of primary air and pulverized fuel, a vaned diffusion swirler for the mixture of primary air and fuel, a center water-cooled conical diffuser shielding the incoming fuel from the heat radiation from the flame and deflecting the primary air and fuel steam into the secondary air, and a watercooled annulus located between the primary air and secondary air flows.

Slurry burner for mixture of carbonaceous material and water

DOEpatents

Nodd, Dennis G.; Walker, Richard J.

1987-01-01

A carbonaceous material-water slurry burner includes a high pressure tip-emulsion atomizer for directing a carbonaceous material-water slurry into a combustion chamber for burning therein without requiring a support fuel or oxygen enrichment of the combustion air. Introduction of the carbonaceous material-water slurry under pressure forces it through a fixed atomizer wherein the slurry is reduced to small droplets by mixing with an atomizing air flow and directed into the combustion chamber. The atomizer includes a swirler located immediately adjacent to where the fuel slurry is introduced into the combustion chamber and which has a single center channel through which the carbonaceous material-water slurry flows into a plurality of diverging channels continuous with the center channel from which the slurry exits the swirler immediately adjacent to an aperture in the combustion chamber. The swirler includes a plurality of slots around its periphery extending the length thereof through which the atomizing air flows and by means of which the atomizing air is deflected so as to exert a maximum shear force upon the carbonaceous material-water slurry as it exits the swirler and enters the combustion chamber. A circulating coolant system or boiler feed water is provided around the periphery of the burner along the length thereof to regulate burner operating temperature, eliminate atomizer plugging, and inhibit the generation of sparklers, thus increasing combustion efficiency. A secondary air source directs heated air into the combustion chamber to promote recirculation of the hot combustion gases within the combustion chamber.

Time-resolved characterization of primary emissions from residential wood combustion appliances.

PubMed

Heringa, M F; DeCarlo, P F; Chirico, R; Lauber, A; Doberer, A; Good, J; Nussbaumer, T; Keller, A; Burtscher, H; Richard, A; Miljevic, B; Prevot, A S H; Baltensperger, U

2012-10-16

Primary emissions from a log wood burner and a pellet boiler were characterized by online measurements of the organic aerosol (OA) using a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS) and of black carbon (BC). The OA and BC concentrations measured during the burning cycle of the log wood burner, batch wise fueled with wood logs, were highly variable and generally dominated by BC. The emissions of the pellet burner had, besides inorganic material, a high fraction of OA and a minor contribution of BC. However, during artificially induced poor burning BC was the dominating species with ∼80% of the measured mass. The elemental O:C ratio of the OA was generally found in the range of 0.2-0.5 during the startup phase or after reloading of the log wood burner. During the burnout or smoldering phase, O:C ratios increased up to 1.6-1.7, which is similar to the ratios found for the pellet boiler during stable burning conditions and higher than the O:C ratios observed for highly aged ambient OA. The organic emissions of both burners have a very similar H:C ratio at a given O:C ratio and therefore fall on the same line in the Van Krevelen diagram.

Demonstration test of burner liner strain measuring system

NASA Technical Reports Server (NTRS)

Stetson, K. A.

1984-01-01

A demonstration test was conducted for two systems of static strain measurement that had been shown to have potential for application jet engine combustors. A modified JT12D combustor was operated in a jet burner test stand while subjected simultaneously to both systems of instrumentation, i.e., Kanthal A-1 wire strain gages and laser speckle photography. A section of the burner was removed for installation and calibration of the wire gages, and welded back into the burner. The burner test rig was modified to provide a viewing port for the laser speckle photography such that the instrumented section could be observed during operation. Six out of ten wire gages survived testing and showed excellent repeatability. The extensive precalibration procedures were shown to be effective in compensating for the large apparent strains associated with these gages. Although all portions of the speckle photography system operated satisfactorily, a problem was encountered in the form of optical inhomogeneities in the hot, high-pressure gas flowing by the combustor case which generate large and random apparent strain distributions.

Anisotropic enhancement of turbulence in large-scale, low-intensity turbulent premixed propane air flames

NASA Astrophysics Data System (ADS)

Furukawa, Junichi; Noguchi, Yoshiki; Hirano, Toshisuke; Williams, Forman A.

2002-07-01

The density change across premixed flames propagating in turbulent flows modifies the turbulence. The nature of that modification depends on the regime of turbulent combustion, the burner design, the orientation of the turbulent flame and the position within the flame. The present study addresses statistically stationary turbulent combustion in the flame-sheet regime, in which the laminar-flame thickness is less than the Kolmogorov scale, for flames stabilized on a vertically oriented cylindrical burner having fully developed upward turbulent pipe flow upstream from the exit. Under these conditions, rapidly moving wrinkled laminar flamelets form the axisymmetric turbulent flame brush that is attached to the burner exit. Predictions have been made of changes in turbulence properties across laminar flamelets in such situations, but very few measurements have been performed to test the predictions. The present work measures individual velocity changes and changes in turbulence across flamelets at different positions in the turbulent flame brush for three different equivalence ratios, for comparison with theory.

Fully Premixed Low Emission, High Pressure Multi-Fuel Burner

NASA Technical Reports Server (NTRS)

Nguyen, Quang-Viet (Inventor)

2012-01-01

A low-emissions high-pressure multi-fuel burner includes a fuel inlet, for receiving a fuel, an oxidizer inlet, for receiving an oxidizer gas, an injector plate, having a plurality of nozzles that are aligned with premix face of the injector plate, the plurality of nozzles in communication with the fuel and oxidizer inlets and each nozzle providing flow for one of the fuel and the oxidizer gas and an impingement-cooled face, parallel to the premix face of the injector plate and forming a micro-premix chamber between the impingement-cooled face and the in injector face. The fuel and the oxidizer gas are mixed in the micro-premix chamber through impingement-enhanced mixing of flows of the fuel and the oxidizer gas. The burner can be used for low-emissions fuel-lean fully-premixed, or fuel-rich fully-premixed hydrogen-air combustion, or for combustion with other gases such as methane or other hydrocarbons, or even liquid fuels.

BURNER RIG TESTING OF A500 C/SiC

DTIC Science & Technology

2018-03-17

test program characterized the durability behavior of A500® C/SiC ceramic matrix composite material at room and elevated temperature . Specimens were...7 Figure 6. Typical Room- Temperature Tensile Stress-Versus-Strain Trace for As-Manufactured A500...Operation ......................................... 18 Figure 17. Example of the Burner Rig Temperature Profiles Used

Development and test of different methods to improve the description and NO{sub x} emissions in staged combustion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brink, A.; Kilpinen, P.; Hupa, M.

1996-01-01

Two methods to improve the modeling of NO{sub x} emissions in numerical flow simulation of combustion are investigated. The models used are a reduced mechanism for nitrogen chemistry in methane combustion and a new model based on regression analysis of perfectly stirred reactor simulations using detailed comprehensive reaction kinetics. The applicability of the methods to numerical flow simulation of practical furnaces, especially in the near burner region, is tested against experimental data from a pulverized coal fired single burner furnace. The results are also compared to those obtained using a commonly used description for the overall reaction rate of NO.

Large eddy simulation modelling of combustion for propulsion applications.

PubMed

Fureby, C

2009-07-28

Predictive modelling of turbulent combustion is important for the development of air-breathing engines, internal combustion engines, furnaces and for power generation. Significant advances in modelling non-reactive turbulent flows are now possible with the development of large eddy simulation (LES), in which the large energetic scales of the flow are resolved on the grid while modelling the effects of the small scales. Here, we discuss the use of combustion LES in predictive modelling of propulsion applications such as gas turbine, ramjet and scramjet engines. The LES models used are described in some detail and are validated against laboratory data-of which results from two cases are presented. These validated LES models are then applied to an annular multi-burner gas turbine combustor and a simplified scramjet combustor, for which some additional experimental data are available. For these cases, good agreement with the available reference data is obtained, and the LES predictions are used to elucidate the flow physics in such devices to further enhance our knowledge of these propulsion systems. Particular attention is focused on the influence of the combustion chemistry, turbulence-chemistry interaction, self-ignition, flame holding burner-to-burner interactions and combustion oscillations.

Numerical Simulation of an Enclosed Laminar Jet Diffusion Flame in Microgravity Environment: Comparison with ELF Data

NASA Technical Reports Server (NTRS)

Jia, Kezhong; Venuturumilli, Rajasekhar; Ryan, Brandon J.; Chen, Lea-Der

2001-01-01

Enclosed diffusion flames are commonly found in practical combustion systems, such as the power-plant combustor, gas turbine combustor, and jet engine after-burner. In these systems, fuel is injected into a duct with a co-flowing or cross-flowing air stream. The diffusion flame is found at the surface where the fuel jet and oxygen meet, react, and consume each other. In combustors, this flame is anchored at the burner (i.e., fuel jet inlet) unless adverse conditions cause the flame to lift off or blow out. Investigations of burner stability study the lift off, reattachment, and blow out of the flame. Flame stability is strongly dependent on the fuel jet velocity. When the fuel jet velocity is sufficiently low, the diffusion flame anchors at the burner rim. When the fuel jet velocity is increased, the flame base gradually moves downstream. However, when the fuel jet velocity increases beyond a critical value, the flame base abruptly jumps downstream. When this "jump" occurs, the flame is said to have reached its lift-off condition and the critical fuel jet velocity is called the lift-off velocity. While lifted, the flame is not attached to the burner and it appears to float in mid-air. Flow conditions are such that the flame cannot be maintained at the burner rim despite the presence of both fuel and oxygen. When the fuel jet velocity is further increased, the flame will eventually extinguish at its blowout condition. In contrast, if the fuel jet velocity of a lifted flame is reduced, the flame base moves upstream and abruptly returns to anchor at the burner rim. The fuel jet velocity at reattachment can be much lower than that at lift off, illustrating the hysteresis effect present in flame stability. Although there have been numerous studies of flame stability, the controlling mechanisms are not well understood. This uncertainty is described by Pitts in his review of various competing theories of lift off and blow out in turbulent jet diffusion flames. There has been some research on the stability of laminar flames, but most studies have focused on turbulent flames. It is also well known that the airflow around the fuel jet can significantly alter the lift off, reattachment and blow out of the jet diffusion flame. Buoyant convection is sufficiently strong in 1-g flames that it can dominate the flow-field, even at the burner rim. In normal-gravity testing, it is very difficult to delineate the effects of the forced airflow from those of the buoyancy-induced flow. Comparison of normal-gravity and microgravity flames provides clear indication of the influence of forced and buoyant flows on the flame stability. The overall goal of the Enclosed Laminar Flames (ELF) investigation (STS-87/USMP-4 Space Shuttle mission, November to December 1997) is to improve our understanding of the effects of buoyant convection on the structure and stability of co-flow diffusion flame, e.g., see http://zeta.lerc.nasa.gov/expr/elf.htm. The ELF hardware meets the experiment hardware limit of the 35-liter interior volume of the glovebox working area, and the 180x220-mm dimensions of the main door. The ELF experiment module is a miniature, fan-driven wind tunnel, equipped with a gas supply system. A 1.5-mm diameter nozzle is located on the duct's flow axis. The cross section of the duct is nominally a 76-mm square with rounded corners. The forced air velocity can be varied from about 0.2 to 0.9 m/s. The fuel flow can be set as high as 3 std. cubic centimeter (cc) per second, which corresponds to a nozzle exit velocity of up to 1.70 m/s. The ELF hardware and experimental procedure are discussed in detail in Brooker et al. The 1-g test results are repeated in several experiments following the STS-87 Mission. The ELF study is also relevant to practical systems because the momentum-dominated behavior of turbulent flames can be achieved in laminar flames in microgravity. The specific objectives of this paper are to evaluate the use reduced model for simulation of flame lift-off and blowout.

Effect of the fuel bias distribution in the primary air nozzle on the slagging near a swirl coal burner throat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lingyan Zeng; Zhengqi Li; Hong Cui

2009-09-15

Three-dimensional numerical simulations of slagging characteristics near the burner throat region were carried out for swirl coal combustion burners used in a 1025 tons/h boiler. The gas/particle two-phase numerical simulation results and the data measured by a particle-dynamics anemometer (PDA) show that the numeration model was reasonable. For the centrally fuel-rich swirl coal combustion burner, the coal particles move in the following way. The particles first flow into furnace with the primary air from the burner throat. After traversing a certain distance, they move back to the burner throat and then toward the furnace again. Thus, particle trajectories are extended.more » For the case with equal air mass fluxes in the inner and outer primary air/coal mixtures, as the ratio of the coal mass flux in the inner primary air/coal mixture to the total coal mass flux increased from 40 (the reference condition) to 50%, 50 to 70%, and 70 to 100%, the maximum number density declined by 22, 11, and 4%, respectively, relative to the reference condition. In addition, the sticking particle ratio declined by 13, 14, and 8%, respectively, compared to the reference condition. 22 refs., 12 figs., 3 tabs.« less

Diffusion Flame Stabilization

NASA Technical Reports Server (NTRS)

Takahashi, Fumiaki; Katta, V. R.

2006-01-01

Diffusion flames are commonly used for industrial burners in furnaces and flares. Oxygen/fuel burners are usually diffusion burners, primarily for safety reasons, to prevent flashback and explosion in a potentially dangerous system. Furthermore, in most fires, condensed materials pyrolyze, vaporize, and burn in air as diffusion flames. As a result of the interaction of a diffusion flame with burner or condensed-fuel surfaces, a quenched space is formed, thus leaving a diffusion flame edge, which plays an important role in flame holding in combustion systems and fire spread through condensed fuels. Despite a long history of jet diffusion flame studies, lifting/blowoff mechanisms have not yet been fully understood, compared to those of premixed flames. In this study, the structure and stability of diffusion flames of gaseous hydrocarbon fuels in coflowing air at normal earth gravity have been investigated experimentally and computationally. Measurements of the critical mean jet velocity (U(sub jc)) of methane, ethane, or propane at lifting or blowoff were made as a function of the coflowing air velocity (U(sub a)) using a tube burner (i.d.: 2.87 mm). By using a computational fluid dynamics code with 33 species and 112 elementary reaction steps, the internal chemical-kinetic structures of the stabilizing region of methane and propane flames were investigated. A peak reactivity spot, i.e., reaction kernel, is formed in the flame stabilizing region due to back-diffusion of heat and radical species against an oxygen-rich incoming flow, thus holding the trailing diffusion flame. The simulated flame base moved downstream under flow conditions close to the measured stability limit.

Diffusion Flame Stabilization

NASA Technical Reports Server (NTRS)

Takahashi, Fumiaki; Katta, Viswanath R.

2007-01-01

Diffusion flames are commonly used for industrial burners in furnaces and flares. Oxygen/fuel burners are usually diffusion burners, primarily for safety reasons, to prevent flashback and explosion in a potentially dangerous system. Furthermore, in most fires, condensed materials pyrolyze, vaporize, and burn in air as diffusion flames. As a result of the interaction of a diffusion flame with burner or condensed-fuel surfaces, a quenched space is formed, thus leaving a diffusion flame edge, which plays an important role in flame holding in combustion systems and fire spread through condensed fuels. Despite a long history of jet diffusion flame studies, lifting/blowoff mechanisms have not yet been fully understood, compared to those of premixed flames. In this study, the structure and stability of diffusion flames of gaseous hydrocarbon fuels in coflowing air at normal earth gravity have been investigated experimentally and computationally. Measurements of the critical mean jet velocity (U(sub jc)) of methane, ethane, or propane at lifting or blowoff were made as a function of the coflowing air velocity (U(sub a)) using a tube burner (i.d.: 2.87 mm) (Fig. 1, left). By using a computational fluid dynamics code with 33 species and 112 elementary reaction steps, the internal chemical-kinetic structures of the stabilizing region of methane and propane flames were investigated (Fig. 1, right). A peak reactivity spot, i.e., reaction kernel, is formed in the flame stabilizing region due to back-diffusion of heat and radical species against an oxygen-rich incoming flow, thus holding the trailing diffusion flame. The simulated flame base moved downstream under flow conditions close to the measured stability limit.

Effect of Secondary Jet-flow Angle on Performance of Turbine Inter-guide-vane Burner Based on Jet-vortex Flow

NASA Astrophysics Data System (ADS)

Zheng, Haifei; Tang, Hao; Xu, Xingya; Li, Ming

2014-08-01

Four different secondary airflow angles for the turbine inter-guide-vane burners with trapped vortex cavity were designed. Comparative analysis between combustion performances influenced by the variation of secondary airflow angle was carried out by using numerical simulation method. The turbulence was modeled using the Scale-Adaptive Simulation (SAS) turbulence model. Four cases with different secondary jet-flow angles (-45°, 0°, 30°, 60°) were studied. It was observed that the case with secondary jet-flows at 60° angle directed upwards (1) has good mixing effect; (2) mixing effect is the best although the flow field distributions inside both of the cavity and the main flow passage for the four models are very similar; (3) has complete combustion and symmetric temperature distribution on the exit section of guide vane (X = 70 mm), with uniform temperature distribution, less temperature gradient, and shrank local high temperature regions in the notch located on the guide vane.

Method and device for determining heats of combustion of gaseous hydrocarbons

NASA Technical Reports Server (NTRS)

Singh, Jag J. (Inventor); Sprinkle, Danny R. (Inventor); Puster, Richard L. (Inventor)

1988-01-01

A method and device is provided for a quick, accurate and on-line determination of heats of combustion of gaseous hydrocarbons. First, the amount of oxygen in the carrier air stream is sensed by an oxygen sensing system. Second, three individual volumetric flow rates of oxygen, carrier stream air, and hydrocrabon test gas are introduced into a burner. The hydrocarbon test gas is fed into the burner at a volumetric flow rate, n, measured by a flowmeter. Third, the amount of oxygen in the resulting combustion products is sensed by an oxygen sensing system. Fourth, the volumetric flow rate of oxygen is adjusted until the amount of oxygen in the combustion product equals the amount of oxygen previously sensed in the carrier air stream. This equalizing volumetric flow rate is m and is measured by a flowmeter. The heat of combustion of the hydrocrabon test gas is then determined from the ratio m/n.

Strain-induced extinction of hydrogen-air counterflow diffusion flames - Effects of steam, CO2, N2, and O2 additives to air

NASA Technical Reports Server (NTRS)

Pellett, G. L.; Northam, G. B.; Wilson, L. G.

1992-01-01

A fundamental study was performed using axisymmetric nozzle and tubular opposed jet burners to measure the effects of laminar plug flow and parabolic input velocity profiles on the extinction limits of H2-air counterflow diffusion flames. Extinction limits were quantified by 'flame strength', (average axial air jet velocity) at blowoff of the central flame. The effects of key air contaminants, on the extinction limits, are characterized and analyzed relative to utilization of combustion contaminated vitiated air in high enthalpy supersonic test facilities.

Effect of operation parameters on the slagging near swirl coal burner throat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Changfu You; Yong Zhou

2006-10-15

Fluid flow, heat transfer, coal combustion, and slagging processes had been numerically simulated near a swirl burner throat. The effect of the ratio distribution of each burner air, their swirling numbers, and the coal character on the slagging process had been analyzed. The computation results indicate that the maximal sticking-particle numbers occur at the uppermost waterwall, while the sticking-particle number at neither waterwall near the swirl burner outlet is very small. The swirling number has a significant effect on the number of the sticking particle. The sticking-particle number increases rapidly with the increment of the outer secondary air and themore » primary air-swirling numbers, respectively, because it can strengthen the flow entrainment ability to carry more particles to the waterwall. The inner secondary air has a complicated influence on the slagging process. When the inner secondary air-swirling number is about middle intensive degree (about 0.9), the sticking-particle number reaches maximum. If the inner secondary air-swirling number continues increasing, then the coal particles will combust completely and reduce the particle concentration, thus decrease the sticking-particle number. The ratio of each air has a slight influence on the sticking-particle number relative to the swirling number. The coal particles with small mean diameter combust completely, which can reduce the sticking-particle number. 13 refs., 16 figs., 1 tab.« less

Tunable Diode Laser Absorption Spectroscopy Verification Analysis for Use in the Combustion Optimization and Analysis Laser Laboratory

DTIC Science & Technology

2009-03-01

characterized experimental data by operating the system over a wide range of conditions for an H2 laminar flame produced by a Hencken burner. The TDLAS...43 3.3 Combustion System Calibration and Operation ................................... 47 3.3.1 Theoretical...51 3.3.3 Hencken Burner Operation ............................................................... 56 3.3.4 Turbulent Jet Operation

Emulation of Condensed Fuel Flames Using a Burning Rate Emulator (BRE) in Microgravity

NASA Technical Reports Server (NTRS)

Markan, A.; Quintiere, J. G.; Sunderland, P. B.; De Ris, J. L.; Stocker, D. P.

2017-01-01

The Burning Rate Emulator (BRE) is a gaseous fuel burner developed to emulate the burning of condensed phase fuels. The current study details several tests at the NASA Glenn 5-s drop facility to test the BRE technique in microgravity conditions. The tests are conducted for two burner diameters, 25 mm and 50 mm respectively, with methane and ethylene as the fuels. The ambient pressure, oxygen content and fuel flow rate are additional parameters. The microgravity results exhibit a nominally hemispherical flame with decelerating growth and quasi-steady heat flux after about 5 seconds. The BRE burner was evaluated with a transient analysis to assess the extent of steady-state achieved. The burning rate and flame height recorded at the end of the drop are correlated using two steady-state purely diffusive models. A higher burning rate for the bigger burner as compared to theory indicates the significance of gas radiation. The effect of the ambient pressure and oxygen concentration on the heat of gasification are also examined.

Digital temperature and velocity control of mach 0.3 atmospheric pressure durability testing burner rigs in long time, unattended cyclic testing

NASA Technical Reports Server (NTRS)

Deadmore, D. L.

1985-01-01

Hardware and software were developed to implement the hybrid digital control of two Jet A-1 fueled Mach 0.3 burners from startup to completion of a preset number of hot corrosion flame durability cycle tests of materials at 1652 F. This was accomplished by use of a basic language programmable microcomputer and data aquisition and control unit connected together by the IEEE-488 Bus. The absolute specimen temperature was controlled to + or - 3 F by use of digital adjustment of the fuel flow using a P-I-D (Proportional-Integral-Derivative) control algorithm. The specimen temperature was within + or - 2 F of the set point more than 90 percent of the time. Pressure control was achieved by digital adjustment of the combustion air flow using a proportional control algorithm. The burner pressure was controlled at 1.0 + or - 0.02 psig. Logic schemes were incorporated into the system to protect the test specimen from abnormal test conditions in the event of a hardware of software malfunction.

Lean Limit Phenomena

NASA Technical Reports Server (NTRS)

Law, C. K.

1983-01-01

The influence of stretch and preferential diffusion on premixed flame extinction and stability was investigated via two model flame configurations, namely the stagnation flame and the bunsen flame. Using a counterflow burner and a stagnation flow burner with a water-cooled wall, the effect of downstream heat loss on the extinction of a stretched premixed flame investigated for lean and rich propane/air and methane/air mixtures. It was demonstrated that extinction by stretch alone is possible only when the deficient reactant is the less mobile one. When it is the more mobile one, downstream heat loss or incomplete reaction is also needed to achieve extinction. The local extinction of bunsen flame tips and edges of hydrocarbon/air premixtures was investigated using a variety of burners. Results show that, while for both rich propane/air and butane/air mixtures tip opening occurs at a constant fuel equivalence ratio of 1.44 and is therefore independent of the intensity, uniformity, and configuration of the approach flow, for rich methane/air flames burning is intensified at the tip and therefore opening is not possible.

Efficiency of using direct-flow burners and nozzles in implementation of dry-bottom ash removal at the TPP-210A boiler furnace

NASA Astrophysics Data System (ADS)

Arkhipov, A. M.; Kanunnikov, A. A.; Kirichkov, V. S.; Prokhorov, V. B.; Fomenko, M. V.; Chernov, S. L.

2017-02-01

In reconstruction of operating pulverized coal-fired boilers, one of the main factors is the choice of a method for slag removal: dry bottom ash removal (DBAR) or slag-tap removal (STR). In this case, ecological and economic aspects should be taken into account, and also the early ignition of pulverized coal fuel, the reliability of operation of the furnace walls in the mode without slagging, and the stability of slag removal should be provided. In this work, issues of changeover of the pulverized coal-fired boilers of the TPP-210A type from the STR mode to the DBAR mode are considered. As of today, the main problems during the operation of these boilers are the high emissions of nitrogen oxides together with flue gases into the atmosphere and the appropriated payoffs, a small range of loads available, the necessity of stabilization of the pulverizedcoal flame sustainability by using the highly reactive fuel, large mechanical fuel underburning, etc. Results of studying aerodynamics of a furnace with DBAR obtained in the process of physical simulation are given; technical solutions and preliminary design (configuration of burners and nozzles in the boiler furnace, conceptual design of the pulverized coal burner, configuration of TPP-210A boiler with the low heat liberation of furnace cross-section and volumetric heat release) are set forth, which are associated with the optimization of aerodynamics of furnace volume, when the direct-flow burners and nozzles are used, and with organization of the efficient staged combustion of solid fuel. Two versions of possible modernization of a boiler unit are considered. Under conditions of the planned increase in the steam production capacity, the most promising measures are as follows: the DBAR implementation with reducing heat releases of the cross-section and volume of the furnace approximately by half, the installation of the direct-flow burners and nozzles with injection of recirculation gases into the active combustion zone by bleeding them from the turning chamber.

An efficient liner cooling scheme for advanced small gas turbine combustors

NASA Technical Reports Server (NTRS)

Paskin, Marc D.; Mongia, Hukam C.; Acosta, Waldo A.

1993-01-01

A joint Army/NASA program was conducted to design, fabricate, and test an advanced, small gas turbine, reverse-flow combustor utilizing a compliant metal/ceramic (CMC) wall cooling concept. The objectives of this effort were to develop a design method (basic design data base and analysis) for the CMC cooling technique and then demonstrate its application to an advanced cycle, small, reverse-flow combustor with 3000 F burner outlet temperature. The CMC concept offers significant improvements in wall cooling effectiveness resulting in a large reduction in cooling air requirements. Therefore, more air is available for control of burner outlet temperature pattern in addition to the benefits of improved efficiency, reduced emissions, and lower smoke levels. The program was divided into four tasks. Task 1 defined component materials and localized design of the composite wall structure in conjunction with development of basic design models for the analysis of flow and heat transfer through the wall. Task 2 included implementation of the selected materials and validated design models during combustor preliminary design. Detail design of the selected combustor concept and its refinement with 3D aerothermal analysis were completed in Task 3. Task 4 covered detail drawings, process development and fabrication, and a series of burner rig tests. The purpose of this paper is to provide details of the investigation into the fundamental flow and heat transfer characteristics of the CMC wall structure as well as implementation of the fundamental analysis method for full-scale combustor design.

Development of combined low-emissions burner devices for low-power boilers

NASA Astrophysics Data System (ADS)

Roslyakov, P. V.; Proskurin, Yu. V.; Khokhlov, D. A.

2017-08-01

Low-power water boilers are widely used for autonomous heat supply in various industries. Firetube and water-tube boilers of domestic and foreign manufacturers are widely represented on the Russian market. However, even Russian boilers are supplied with licensed foreign burner devices, which reduce their competitiveness and complicate operating conditions. A task of developing efficient domestic low-emissions burner devices for low-power boilers is quite acute. A characteristic property of ignition and fuel combustion in such boilers is their flowing in constrained conditions due to small dimensions of combustion chambers and flame tubes. These processes differ significantly from those in open combustion chambers of high-duty power boilers, and they have not been sufficiently studied yet. The goals of this paper are studying the processes of ignition and combustion of gaseous and liquid fuels, heat and mass transfer and NO x emissions in constrained conditions, and the development of a modern combined low-emissions 2.2 MW burner device that provides efficient fuel combustion. A burner device computer model is developed and numerical studies of its operation on different types of fuel in a working load range from 40 to 100% of the nominal are carried out. The main features of ignition and combustion of gaseous and liquid fuels in constrained conditions of the flame tube at nominal and decreased loads are determined, which differ fundamentally from the similar processes in steam boiler furnaces. The influence of the burner devices design and operating conditions on the fuel underburning and NO x formation is determined. Based on the results of the design studies, a design of the new combined low-emissions burner device is proposed, which has several advantages over the prototype.

Testing and Characterization of CMC Combustor Liners

NASA Technical Reports Server (NTRS)

Robinson, R. Craig; Verrilli, Michael J.

2003-01-01

Multiple combustor liner applications, both segmented and fully annular designs, have been configured for exposure in NASA's High Pressure Burner Rig (HPBR). The segmented liners were attached to the rig structure with SiC/SiC fasteners and exposed to simulated gas turbine conditions for nearly 200 hours. Test conditions included pressures of 6 atm., gas velocity of 42 m/s, and gas temperatures near 1450 C. The temperatures of both the cooled and combustion flow sides of the liners were measured using optical and contact measurement techniques. Minor weight loss was observed, but the liners remained structural sound, although damage was noted in some fasteners.

Influence of staged-air on airflow, combustion characteristics and NO(x) emissions of a down-fired pulverized-coal 300 MW(e) utility boiler with direct flow split burners.

PubMed

Li, Zhengqi; Kuang, Min; Zhang, Jia; Han, Yunfeng; Zhu, Qunyi; Yang, Lianjie; Kong, Weiguang

2010-02-01

Cold airflow experiments were conducted to investigate the aerodynamic field in a small-scale furnace of a down-fired pulverized-coal 300 MW(e) utility boiler arranged with direct flow split burners enriched by cyclones. By increasing the staged-air ratio, a deflected flow field appeared in the lower furnace; larger staged-air ratios produced larger deflections. Industrial-sized experiments on a full-scale boiler were also performed at different staged-air damper openings with measurements taken of gas temperatures in the burner region and near the right-side wall, wall heat fluxes, and gas components (O(2), CO, and NO(x)) in the near-wall region. Combustion was unstable at staged-air damper openings below 30%. For openings of 30% and 40%, late ignition of the pulverized coal developed and large differences arose in gas temperatures and heat fluxes between the regions near the front and rear walls. In conjunction, carbon content in the fly ash was high and boiler efficiency was low with high NO(x) emission above 1200 mg/m(3) (at 6% O(2) dry). For fully open dampers, differences in gas temperatures and heat fluxes, carbon in fly ash and NO(x) emission decreased yielding an increase in boiler efficiency. The optimal setting is fully open staged-air dampers.

Progress on Variable Cycle Engines

NASA Technical Reports Server (NTRS)

Westmoreland, J. S.; Howlett, R. A.; Lohmann, R. P.

1979-01-01

Progress in the development and future requirements of the Variable Stream Control Engine (VSCE) are presented. The two most critical components of this advanced system for future supersonic transports, the high performance duct burner for thrust augmentation, and the low jet coannular nozzle were studied. Nozzle model tests substantiated the jet noise benefit associated with the unique velocity profile possible with a coannular nozzle system on a VSCE. Additional nozzle model performance tests have established high thrust efficiency levels only at takeoff and supersonic cruise for this nozzle system. An experimental program involving both isolated component and complete engine tests has been conducted for the high performance, low emissions duct burner with good results and large scale testing of these two components is being conducted using a F100 engine as the testbed for simulating the VSCE. Future work includes application of computer programs for supersonic flow fields to coannular nozzle geometries, further experimental testing with the duct burner segment rig, and the use of the Variable Cycle Engine (VCE) Testbed Program for evaluating the VSCE duct burner and coannular nozzle technologies.

Microjet burners for molecular-beam sources and combustion studies

NASA Astrophysics Data System (ADS)

Groeger, Wolfgang; Fenn, John B.

1988-09-01

A novel microjet burner is described in which combustion is stabilized by a hot wall. The scale is so small that the entire burner flow can be passed through a nozzle only 0.2 mm or less in diameter into an evacuated chamber to form a supersonic free jet with expansion so rapid that all collisional processes in the jet gas are frozen in a microsecond or less. This burner can be used to provide high-temperature source gas for free jet expansion to produce intense beams of internally hot molecules. A more immediate use would seem to be in the analysis of combustion products and perhaps intermediates by various kinds of spectroscopies without some of the perturbation effects encountered in probe sampling of flames and other types of combustion devices. As an example of the latter application of this new tool, we present infrared emission spectra for jet gas obtained from the combustion of oxygen-hydrocarbon mixtures both fuel-rich and fuel-lean operation. In addition, we show results obtained by mass spectrometric analysis of the combustion products.

Chemical and toxicological characterization of residential oil burner emissions: I. Yields and chemical characterization of extractables from combustion of No. 2 fuel oil at different Bacharach Smoke Numbers and firing cycles.

PubMed Central

Leary, J A; Biemann, K; Lafleur, A L; Kruzel, E L; Prado, G P; Longwell, J P; Peters, W A

1987-01-01

Particulates and complex organic mixtures were sampled from the exhaust of a flame retention head residential oil burner combusting No. 2 fuel oil at three firing conditions: continuous at Bacharach Smoke No. 1, and cyclic (5 min on, 10 min off) at Smoke Nos. 1 and 5. The complex mixtures were recovered by successive Soxhlet extraction of filtered particulates and XAD-2 sorbent resin with methylene chloride (DCM) and then methanol (MeOH). Bacterial mutagenicity [see Paper II (8)] was found in the DCM extractables. Samples of DCM extracts from the two cyclic firing conditions and of the raw fuel were separated by gravity column chromatography on alumina. The resulting fractions were further characterized by a range of instrumental methods. Average yields of both unextracted particulates and of DCM extractables, normalized to a basis of per unit weight of fuel fired, were lower for continuous firing than for cyclic firing. For cyclic firing, decreasing the smoke number lowered the particulates emissions but only slightly reduced the average yield of DCM extractables. These and similar observations, here reported for two other oil burners, show that adjusting the burner to a lower smoke number has little effect on, or may actually increase, emissions of organic extractables of potential public health interest. Modifications of the burner firing cycle aimed at approaching continuous operation offer promise for reducing the amount of complex organic emissions. Unburned fuel accounted for roughly half of the DCM extractables from cyclic firing of the flame retention head burner at high and low smoke number. Large (i.e., greater than 3 ring) polycyclic aromatic hydrocarbons (PAH) were not observed in the DCM extractables from cyclic firing. However, nitroaromatics, typified by alkylated nitronaphthalenes, alkyl-nitrobiphenyls, and alkyl-nitrophenanthrenes were found in a minor subfraction containing a significant portion of the total mutagenic activity of the cyclic low smoke samples (8). Oxygen-containing PAH, typified by phenalene-1-one and its alkyl derivatives, are important mutagens from cyclic firing at high smoke conditions. Thus, oil burner effluents differ markedly from those of several other combustors, including the automotive diesel engine, where multiring PAH, typified by fluoranthene and alkylated phenanthrenes, account for a significant portion of the effluent mutagenicity. Implications for combustion and emissions source identification are discussed. PMID:3665865

Development and numerical/experimental characterization of a lab-scale flat flame reactor allowing the analysis of pulverized solid fuel devolatilization and oxidation at high heating rates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lemaire, R., E-mail: romain.lemaire@mines-douai.fr; Menanteau, S.

2016-01-15

This paper deals with the thorough characterization of a new experimental test bench designed to study the devolatilization and oxidation of pulverized fuel particles in a wide range of operating conditions. This lab-scale facility is composed of a fuel feeding system, the functioning of which has been optimized by computational fluid dynamics. It allows delivering a constant and time-independent mass flow rate of fuel particles which are pneumatically transported to the central injector of a hybrid McKenna burner using a carrier gas stream that can be inert or oxidant depending on the targeted application. A premixed propane/air laminar flat flamemore » stabilized on the porous part of the burner is used to generate the hot gases insuring the heating of the central coal/carrier-gas jet with a thermal gradient similar to those found in industrial combustors (>10{sup 5} K/s). In the present work, results issued from numerical simulations performed a priori to characterize the velocity and temperature fields in the reaction chamber have been analyzed and confronted with experimental measurements carried out by coupling particle image velocimetry, thermocouple and two-color pyrometry measurements so as to validate the order of magnitude of the heating rate delivered by such a new test bench. Finally, the main features of the flat flame reactor we developed have been discussed with respect to those of another laboratory-scale system designed to study coal devolatilization at a high heating rate.« less

Development and numerical/experimental characterization of a lab-scale flat flame reactor allowing the analysis of pulverized solid fuel devolatilization and oxidation at high heating rates

NASA Astrophysics Data System (ADS)

Lemaire, R.; Menanteau, S.

2016-01-01

This paper deals with the thorough characterization of a new experimental test bench designed to study the devolatilization and oxidation of pulverized fuel particles in a wide range of operating conditions. This lab-scale facility is composed of a fuel feeding system, the functioning of which has been optimized by computational fluid dynamics. It allows delivering a constant and time-independent mass flow rate of fuel particles which are pneumatically transported to the central injector of a hybrid McKenna burner using a carrier gas stream that can be inert or oxidant depending on the targeted application. A premixed propane/air laminar flat flame stabilized on the porous part of the burner is used to generate the hot gases insuring the heating of the central coal/carrier-gas jet with a thermal gradient similar to those found in industrial combustors (>105 K/s). In the present work, results issued from numerical simulations performed a priori to characterize the velocity and temperature fields in the reaction chamber have been analyzed and confronted with experimental measurements carried out by coupling particle image velocimetry, thermocouple and two-color pyrometry measurements so as to validate the order of magnitude of the heating rate delivered by such a new test bench. Finally, the main features of the flat flame reactor we developed have been discussed with respect to those of another laboratory-scale system designed to study coal devolatilization at a high heating rate.

Burner rig corrosion of SiC at 1000 deg C

NASA Technical Reports Server (NTRS)

Jacobson, N. S.; Stearns, C. A.; Smialek, J. L.

1985-01-01

Sintered alpha-SiC was examined in both oxidation and hot corrosion with a burner rig at 400 kPa (4 atm) and 1000 C with a flow velocity of 310 ft/sec. Oxidation tests for times to 46 hr produced virtually no attack, whereas tests with 4 ppm Na produced extensive corrosion in 13-1/2 hr. Thick glassy layers composed primarily of sodium silicate formed in the salt corrosion tests. This corrosion attack caused severe pitting of the silicon carbide substrate which led to a 32 percent strength decrease below the as-received material. Parallel furnace tests of Na2SO4/air induced attacked yielded basically similar results with some slight product composition differences. The differences are explained in terms of the continuous sulfate deposition which occurs in a burner rig.

Pulverized fuel-oxygen burner

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, Curtis; Patterson, Brad; Perdue, Jayson

A burner assembly combines oxygen and fuel to produce a flame. The burner assembly includes an oxygen supply tube adapted to receive a stream of oxygen and a solid fuel conduit arranged to extend through the oxygen tube to convey a stream of fluidized, pulverized, solid fuel into a flame chamber. Oxygen flowing through the oxygen supply tube passes generally tangentially through a first set of oxygen-injection holes formed in the solid fuel conduit and off-tangentially from a second set of oxygen-injection holes formed in the solid fuel conduit and then mixes with fluidized, pulverized, solid fuel passing through themore » solid fuel conduit to create an oxygen-fuel mixture in a downstream portion of the solid fuel conduit. This mixture is discharged into a flame chamber and ignited in the flame chamber to produce a flame.« less

Real-time combustion controller

DOEpatents

Lindner, Jeffrey S.; Shepard, W. Steve; Etheridge, John A.; Jang, Ping-Rey; Gresham, Lawrence L.

1997-01-01

A method and system of regulating the air to fuel ratio supplied to a burner to maximize the combustion efficiency. Optical means are provided in close proximity to the burner for directing a beam of radiation from hot gases produced by the burner to a plurality of detectors. Detectors are provided for sensing the concentration of, inter alia, CO, CO.sub.2, and H.sub.2 O. The differences between the ratios of CO to CO.sub.2 and H.sub.2 O to CO are compared with a known control curve based on those ratios for air to fuel ratios ranging from 0.85 to 1.30. The fuel flow is adjusted until the difference between the ratios of CO to CO.sub.2 and H.sub.2 O to CO fall on a desired set point on the control curve.

Real-time combustion controller

DOEpatents

Lindner, J.S.; Shepard, W.S.; Etheridge, J.A.; Jang, P.R.; Gresham, L.L.

1997-02-04

A method and system are disclosed for regulating the air to fuel ratio supplied to a burner to maximize the combustion efficiency. Optical means are provided in close proximity to the burner for directing a beam of radiation from hot gases produced by the burner to a plurality of detectors. Detectors are provided for sensing the concentration of, inter alia, CO, CO{sub 2}, and H{sub 2}O. The differences between the ratios of CO to CO{sub 2} and H{sub 2}O to CO are compared with a known control curve based on those ratios for air to fuel ratios ranging from 0.85 to 1.30. The fuel flow is adjusted until the difference between the ratios of CO to CO{sub 2} and H{sub 2}O to CO fall on a desired set point on the control curve. 20 figs.

A procedure for predicting internal and external noise fields of blowdown wind tunnels

NASA Technical Reports Server (NTRS)

Hosier, R. N.; Mayes, W. H.

1972-01-01

The noise generated during the operation of large blowdown wind tunnels is considered. Noise calculation procedures are given to predict the test-section overall and spectrum level noise caused by both the tunnel burner and turbulent boundary layer. External tunnel noise levels due to the tunnel burner and circular jet exhaust flow are also calculated along with their respective cut-off frequency and spectrum peaks. The predicted values are compared with measured data, and the ability of the prediction procedure to estimate blowdown-wind-tunnel noise levels is shown.

Combustion rate limits of hydrogen plus hydrocarbon fuel: Air diffusion flames from an opposed jet burner technique

NASA Technical Reports Server (NTRS)

Pellett, Gerald L.; Guerra, Rosemary; Wilson, Lloyd G.; Reeves, Ronald N.; Northam, G. Burton

1987-01-01

Combustion of H2/hydrocarbon (HC) fuel mixtures may be considered in certain volume-limited supersonic airbreathing propulsion applications. Effects of HC addition to H2 were evaluated, using a recent argon-bathed, coaxial, tubular opposed jet burner (OJB) technique to measure the extinction limits of counterflow diffusion flames. The OJB flames were formed by a laminar jet of (N2 and/or HC)-diluted H2 mixture opposed by a similar jet of air at ambient conditions. The OJB data, derived from respective binary mixtures of H2 and methane, ethylene, or propane HCs, were used to characterize BLOWOFF and RESTORE. BLOWOFF is a sudden breaking of the dish-shaped OJB flame to a stable torus or ring shape, and RESTORE marks sudden restoration of the central flame by radial inward flame propagation. BLOWOFF is a measure of kinetically-limited flame reactivity/speed under highly stretched, but relatively ideal impingement flow conditions. RESTORE measures inward radial flame propagation rate, which is sensitive to ignition processes in the cool central core. It is concluded that relatively small molar amounts of added HC greatly reduce the reactivity characteristics of counterflow hydrogen-air diffusion flames, for ambient initial conditions.

Combustion and Ignition Studies of Nanocomposite Energetic Materials

DTIC Science & Technology

2010-12-14

Characterization of a gas burner to simulate a propellant flame and evaluate aluminum particle combustion,” M. Jackson, M. L. Pantoya and W. Gill, Combustion...of a gas burner to simulate a propellant flame and evaluate aluminum particle combustion,” M. Jackson, M. L. Pantoya and W. Gill, Combustion and...changes in parameters such as particle size. The LFA measures these properties for bulk powders, consolidated pellets or even liquid mediums and is

Dampers for Natural Draft Heaters: Technical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lutz, James D.; Biermayer, Peter; King, Derek

2008-10-27

Energy required for water heating accounts for approximately 40percent of national residential natural gas consumption in California. With water heating contributing such a substantial portion of natural gas consumption, it is important to pay attention to water heater efficiencies. This paper reports on an investigation of a patented, buoyancy-operated flue damper. It is an add-on design to a standard atmospherically vented natural-draft gas-fired storage water heater. The flue damper was expected to reduce off-cycle standby losses, which would lead to improvements in the efficiency of the water heater. The test results showed that the Energy Factor of the baseline watermore » heater was 0.576. The recovery efficiency was 0.768. The standby heat loss coefficient was 10.619 (BTU/hr-oF). After the damper was installed, the test results show an Energy Factor for the baseline water heater of 0.605. The recovery efficiency was 0.786. The standby heat loss coefficient was 9.135 (BTU/hr-oF). The recovery efficiency increased 2.3percent and the standby heat loss coefficient decreased 14percent. When the burner was on, the baseline water heater caused 28.0 CFM of air to flow from the room. During standby, the flow was 12.4 CFM. The addition of the damper reduced the flow when the burner was on to 23.5 CFM. During standby, flow with the damper was reduced to 11.1 CFM. The flue damper reduced off-cycle standby losses, and improved the efficiency of the water heater. The flue damper also improved the recovery efficiency of the water heater by restricting on-cycle air flows through the flue.With or without the flue damper, off-cycle air flow upthe stack is nearly half the air flow rate as when the burner is firing.« less

Emissions of Jatropha oil-derived biodiesel blend fuels during combustion in a swirl burner

NASA Astrophysics Data System (ADS)

Norwazan, A. R.; Mohd. Jaafar, M. N.; Sapee, S.; Farouk, Hazir

2018-03-01

Experimental works on combustion of jatropha oil biodiesel blends of fuel with high swirling flow in swirl burner have been studied in various blends percentage. Jatropha oil biodiesel was produced using a two-step of esterification-transesterification process. The paper focuses on the emissions of biodiesel blends fuel using jatropha oil in lean through to rich air/fuel mixture combustion in swirl burner. The emissions performances were evaluated by using axial swirler amongst jatropha oil blends fuel including diesel fuel as baseline. The results show that the B25 has good emissions even though it has a higher emission of NOx than diesel fuel, while it emits as low as 42% of CO, 33% of SO2 and 50% of UHC emissions with high swirl number. These are due to the higher oxygen content in jatropha oil biodiesel.

Study of industry requirements that can be fulfilled by combustion experimentation aboard space station

NASA Technical Reports Server (NTRS)

Priem, Richard J.

1988-01-01

The purpose of this study is to define the requirements of commercially motivated microgravity combustion experiments and the optimal way for space station to accommodate these requirements. Representatives of commercial organizations, universities and government agencies were contacted. Interest in and needs for microgravity combustion studies are identified for commercial/industrial groups involved in fire safety with terrestrial applications, fire safety with space applications, propulsion and power, industrial burners, or pollution control. From these interests and needs experiments involving: (1) no flow with solid or liquid fuels; (2) homogeneous mixtures of fuel and air; (3) low flow with solid or liquid fuels; (4) low flow with gaseous fuel; (5) high pressure combustion; and (6) special burner systems are described and space station resource requirements for each type of experiment provided. Critical technologies involving the creation of a laboratory environment and methods for combining experimental needs into one experiment in order to obtain effective use of space station are discussed. Diagnostic techniques for monitoring combustion process parameters are identified.

Compliant Metal Enhanced Convection Cooled Reverse-Flow Annular Combustor

NASA Technical Reports Server (NTRS)

Paskin, Marc D.; Acosta, Waldo A.

1994-01-01

A joint Army/NASA program was conducted to design, fabricate, and test an advanced, reverse-flow, small gas turbine combustor using a compliant metal enhanced (CME) convection wall cooling concept. The objectives of this effort were to develop a design method (basic design data base and analysis) for the CME cooling technique and tben demonstrate its application to an advanced cycle, small, reverse-flow combustor with 3000 F (1922 K) burner outlet temperature (BOT). The CME concept offers significant improvements in wall cooling effectiveness resulting in a large reduction in cooling air requirements. Therefore, more air is available for control of burner outlet temperature pattern in addition to the benefit of improved efficiency, reduced emissions, and smoke levels. Rig test results demonstrated the benefits and viability of the CME concept meeting or exceeding the aerothermal performance and liner wall temperature characteristics of similar lower temperature-rise combustors, achieving 0.15 pattern factor at 3000 F (1922 K) BOT, while utilizing approximately 80 percent less cooling air than conventional, film-cooled combustion systems.

Characterization of a Laminate Flat Plate Diffusion Flame in Microgravity using PIV, Visible and CH Emissions

NASA Technical Reports Server (NTRS)

Joulain, P.; Cordeiro, P.; Torero, J. L.

2001-01-01

Motivated by fire safety concerns and the advent of long-term micro-gravity facilities, a cooperative program has been developed to study the mechanisms and material properties that control flow assisted (co-current) flame spread. This program has used as a common fire scenario a reacting steady-state boundary layer. Preliminary studies explored the aerodynamics of a reacting boundary layer by simulating a condensed fuel by means of a gas burner. Stability curves for ethane air flames were obtained and different burning regimes were identified. An important feature of this study was the independent identification of the different mechanisms leading to the instability of the flow. It was observed that fuel injection velocity and thermal expansion independently contributed to the separation of the flow at the leading edge of the burner. The occurrence of separation resulted in complex three-dimensional flow patterns that have a dominant effect on critical fire safety parameters such as the stand-off distance and flame length. This work was extended to a solid fuel (PMMA) leading to a Sounding Rocket experiment (Mini-Texus-6). The solid phase showed similar flow patterns, mostly present at low flow velocities (<100 mm/s) but the results clearly demonstrated that the thermal balance at the pyrolyzing fuel surface is the dominant mechanism that controls both stand-off distance and flame length. This thermal balance could be described in a global manner by means of a total mass transfer or "B" number. This "B" number incorporates surface re-radiation, radiative feedback and in-depth heat conduction as first prescribed by Emmons. The mass transfer number becomes the single parameter that determines the evolution of these fire safety variables (flame length, stand-off distance) and therefore can be used as a ranking criterion to assess the flammability of materials. The particular configuration is representative of the NASA upward flame spread test (Test 1) therefore this approach can be used in the interpretation of the results obtained from this test. Nevertheless, complete validation of this approach has not been fully achieved due, mainly because all the measurements necessary to compare with the theoretical predictions have not been obtained. Following these studies two different directions have been taken. The first attempts to elucidate the details of the gas phase combustion reaction and the associated flow field by means of quantitative and qualitative measurements. The second approach, a more practical one, is to apply this methodology to the assessment of material flammability. The former is currently being conducted with a gas burner because it allows for easier control and longer experimentation time. The results obtained so far will be presented in more detail. The latter is a new program therefore only a brief summary of the objectives will be presented.

Performance Investigation on an Ultra-compact Interstage Turbine Burner with Trapped-vortex Slot Inlet

NASA Astrophysics Data System (ADS)

Zhang, Hongtao; Luo, Guangqi; Guan, Lei; Zeng, Jianchen

2017-10-01

Ultra-Compact Combustor (UCC), which is one of mainstream design concepts of Interstage Turbine Burner (ITB), has the advantages of compact structure and high combustion efficiency. A design concept of an UCC with trapped-vortex slot inlet was proposed and numerical simulation of the stability, emissions, internal flow velocity and temperature distribution was carried out. The results indicated that the UCC with trapped-vortex slot inlet could enhance the mixing of combustion mixture and the mainstream airflow, improve the combustion efficiency, outlet temperature and the uniformity of outlet temperature field.

Advanced Combustor in the Four Burner Area

NASA Image and Video Library

1966-03-21

Engineer Frank Kutina and a National Aeronautics and Space Administration (NASA) mechanic examine the setup of an advanced combustor rig inside one of the test cells at the Lewis Research Center’s Four Burner Area in the Engine Research Building. Kutina, of the Research Operations Branch, served as go-between for the researchers and the mechanics. He helped develop the test configurations and get the hardware installed. At the time of this photograph, Lewis Center Director Abe Silverstein had just established the Airbreathing Engine Division to address the new propulsion of the 1960s. After nearly a decade of focusing almost exclusively on space, NASA Lewis began tackling issues relating to the new turbofan engine, noise reduction, energy efficiency, supersonic transport, and the never-ending quest for higher performance levels with smaller and more lightweight engines. The Airbreathing Engine Division’s Combustion Branch was dedicated to the study and mitigation of the high temperatures and pressures found in advanced combustor designs. These high temperatures and pressures could destroy engine components. The Lewis investigation included film cooling, diffuser flow, and jet mixing. Components were tested in smaller test cells, but a full-scale augmenting burner rig, seen here, was tested extensively in the Four Burner Area test cell.

Heat Transfer Model for Hot Air Balloons

NASA Astrophysics Data System (ADS)

Llado-Gambin, Adriana

A heat transfer model and analysis for hot air balloons is presented in this work, backed with a flow simulation using SolidWorks. The objective is to understand the major heat losses in the balloon and to identify the parameters that affect most its flight performance. Results show that more than 70% of the heat losses are due to the emitted radiation from the balloon envelope and that convection losses represent around 20% of the total. A simulated heating source is also included in the modeling based on typical thermal input from a balloon propane burner. The burner duty cycle to keep a constant altitude can vary from 10% to 28% depending on the atmospheric conditions, and the ambient temperature is the parameter that most affects the total thermal input needed. The simulation and analysis also predict that the gas temperature inside the balloon decreases at a rate of -0.25 K/s when there is no burner activity, and it increases at a rate of +1 K/s when the balloon pilot operates the burner. The results were compared to actual flight data and they show very good agreement indicating that the major physical processes responsible for balloon performance aloft are accurately captured in the simulation.

Scaling of cell size in cellular instabilities of nonpremixed jet flames

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lo Jacono, D.; Monkewitz, P.A.

2007-10-15

Systematic experiments have been undertaken to study the parameter dependence of cellular instability and in particular the scaling of the resulting cell size in CO{sub 2}-diluted H{sub 2}-O{sub 2} jet diffusion flames. Cellular flames are known to arise near the extinction limit when reactant Lewis numbers are relatively low. The Lewis numbers of the investigated near-extinction mixtures, based on the initial mixture strength {phi}{sub m} and ambient conditions, varied in the ranges [1.1-1.3] for oxygen and [0.25-0.29] for hydrogen ({phi}{sub m} is defined here as the fuel-to-oxygen mass ratio, normalized by the stoichiometric ratio). The experiments were carried out bothmore » in an axisymmetric jet (AJ) burner and in a two-dimensional slot burner known as a Wolfhard-Parker (WP) burner with an oxidizer co-flow (mostly 100% O{sub 2}) of fixed low velocity. First, the region of cellular flames adjacent to the extinction limit was characterized in terms of initial H{sub 2} concentration and fuel jet velocity, with all other parameters fixed. Then, the wavelength of the cellular instability, i.e., the cell size, was determined as a function of the fuel jet velocity and the initial mixture strength {phi}{sub m}. For conditions not too close to extinction, this wavelength is found to increase with the square root of the vorticity thickness of the jet shear layer and roughly the 1/5 power of {phi}{sub m}. Very close to extinction, this scaling breaks down and will likely switch to a scaling with the flame thickness, i.e., involving the Damkoehler number. (author)« less

Characteristics of sound radiation from turbulent premixed flames

NASA Astrophysics Data System (ADS)

Rajaram, Rajesh

Turbulent combustion processes are inherently unsteady and, thus, a source of acoustic radiation, which occurs due to the unsteady expansion of reacting gases. While prior studies have extensively characterized the total sound power radiated by turbulent flames, their spectral characteristics are not well understood. The objective of this research work is to measure the flow and acoustic properties of an open turbulent premixed jet flame and explain the spectral trends of combustion noise. The flame dynamics were characterized using high speed chemiluminescence images of the flame. A model based on the solution of the wave equation with unsteady heat release as the source was developed and was used to relate the measured chemiluminescence fluctuations to its acoustic emission. Acoustic measurements were performed in an anechoic environment for several burner diameters, flow velocities, turbulence intensities, fuels, and equivalence ratios. The acoustic emissions are shown to be characterized by four parameters: peak frequency (Fpeak), low frequency slope (beta), high frequency slope (alpha) and Overall Sound Pressure Level (OASPL). The peak frequency (Fpeak) is characterized by a Strouhal number based on the mean velocity and a flame length. The transfer function between the acoustic spectrum and the spectrum of heat release fluctuations has an f2 dependence at low frequencies, while it converged to a constant value at high frequencies. Furthermore, the OASPL was found to be characterized by (Fpeak mfH)2, which resembles the source term in the wave equation.

Burner rig study of variables involved in hole plugging of air cooled turbine engine vanes

NASA Technical Reports Server (NTRS)

Deadmore, D. L.; Lowell, C. E.

1983-01-01

The effects of combustion gas composition, flame temperatures, and cooling air mass flow on the plugging of film cooling holes by a Ca-Fe-P-containing deposit were investigated. The testing was performed on film-cooled vanes exposed to the combustion gases of an atmospheric Mach 0.3 burner rig. The extent of plugging was determined by measurement of the open hole area at the conclusion of the tests as well as continuous monitoring of some of the tests using stop-action photography. In general, as the P content increased, plugging rates also increased. The plugging was reduced by increasing flame temperature and cooling air mass flow rates. At times up to approximately 2 hours little plugging was observed. This apparent incubation period was followed by rapid plugging, reaching in several hours a maximum closure whose value depended on the conditions of the test.

Variable cycle engines for advanced supersonic transports

NASA Technical Reports Server (NTRS)

Howlett, R. A.; Kozlowski, H.

1975-01-01

Variable Cycle Engines being studied for advanced commercial supersonic transports show potential for significant environmental and economic improvements relative to 1st generation SST engines. The two most promising concepts are: a Variable Stream Control Engine and a Variable Cycle Engine with a rear flow-control valve. Each concept utilizes variable components and separate burners to provide independent temperature and velocity control for two coannular flow streams. Unique fuel control techniques are combined with cycle characteristics that provide low fuel consumption, similar to a turbojet engine, for supersonic operation. This is accomplished while retaining the good subsonic performance features of a turbofan engine. A two-stream coannular nozzle shows potential to reduce jet noise to below FAR Part 36 without suppressors. Advanced burner concepts have the potential for significant reductions in exhaust emissions. In total, these unique engine concepts have the potential for significant overall improvements to the environmental and economic characteristics of advanced supersonic transports.

Evaluating the influence of particulate matter on spectroscopic measurements of a combusting flow

NASA Astrophysics Data System (ADS)

Herlan, Jonathan; Murray, Nathan

2017-11-01

An adiabatic table-top burner has been used to develop a method for estimating the temperature and concentration of OH in a measurement volume of a non-premixed, hydrogen-air flame. The estimation method uses a nonlinear curve-fitting routine to compare experimental absorption spectra with a model derived, using statistical mechanics, from the Beer-Lambert law. With the aim of applying this method to the analysis of rocket exhaust plumes, this study evaluates whether or not it provides faithful estimates of temperature and OH concentration when the combusting flow contains particulate matter-such as soot or tracers used for particle image velocimetry (PIV) measurements. The hydrogen line of the table-top burner will be seeded with alumina, Al2O3, particles and their influence on spectroscopic measurements elucidated. The authors wish to thank Mr. Bernard Jansen for his support and insight in laboratory activities.

Burner ignition system

DOEpatents

Carignan, Forest J.

1986-01-21

An electronic ignition system for a gas burner is battery operated. The battery voltage is applied through a DC-DC chopper to a step-up transformer to charge a capacitor which provides the ignition spark. The step-up transformer has a significant leakage reactance in order to limit current flow from the battery during initial charging of the capacitor. A tank circuit at the input of the transformer returns magnetizing current resulting from the leakage reactance to the primary in succeeding cycles. An SCR in the output circuit is gated through a voltage divider which senses current flow through a flame. Once the flame is sensed, further sparks are precluded. The same flame sensor enables a thermopile driven main valve actuating circuit. A safety valve in series with the main gas valve responds to a control pressure thermostatically applied through a diaphragm. The valve closes after a predetermined delay determined by a time delay orifice if the pilot gas is not ignited.

The origin and structure of streak-like instabilities in laminar boundary layer flames

NASA Astrophysics Data System (ADS)

Gollner, Michael; Miller, Colin; Tang, Wei; Finney, Mark

2017-11-01

Streamwise streaks are consistently observed in wildland fires, at the base of pool fires, and in other heated flows within a boundary layer. This study examines both the origin of these structures and their role in influencing some of the macroscopic properties of the flow. Streaks were reproduced and characterized via experiments on stationary heated strips and liquid and gas-fueled burners in laminar boundary layer flows, providing a framework to develop theory based on both observed and measured physical phenomena. The incoming boundary layer was established as the controlling mechanism in forming streaks, which are generated by pre-existing coherent structures, while the amplification of streaks was determined to be compatible with quadratic growth of Rayleigh-Taylor Instabilities, providing credence to the idea that the downstream growth of streaks is strongly tied to buoyancy. These local instabilities were also found to affect macroscopic properties of the flow, including heat transfer to the surface, indicating that a two-dimensional assumption may fail to adequately describe heat and mass transfer during flame spread and other reacting boundary layer flows. This work was supported by NSF (CBET-1554026) and the USDA-FS (13-CS-11221637-124).

Furnace devices aerodynamics optimization for fuel combustion efficiency improvement and nitrogen oxide emission reduction

NASA Astrophysics Data System (ADS)

Volkov, E. P.; Prokhorov, V. B.; Arkhipov, A. M.; Chernov, S. L.; Kirichkov, V. S.; Kaverin, A. A.

2017-11-01

MPEI conducts researches on physical and mathematical models of furnace chambers for improvement of power-generation equipment fuel combustion efficiency and ecological safety. Results of these researches are general principles of furnace aerodynamics arrangement for straight-flow burners and various fuels. It has been shown, that staged combustion arrangement with early heating and igniting with torch distribution in all furnace volume allows to obtain low carbon in fly ash and nitrogen oxide emission and also to improve boiler operation reliability with expand load adjustment range. For solid fuel combustion efficiency improvement it is practical to use high-placed and strongly down-tilted straight-flow burners, which increases high-temperature zone residence time for fuel particles. In some cases, for this combustion scheme it is possible to avoid slag-tap removal (STR) combustion and to use Dry-bottom ash removal (DBAR) combustion with tolerable carbon in fly ash level. It is worth noting that boilers with STR have very high nitrogen oxide emission levels (1200-1800 mg/m3) and narrow load adjustment range, which is determined by liquid slag output stability, so most industrially-developed countries don’t use this technology. Final decision about overhaul of boiler unit is made with regard to physical and mathematical modeling results for furnace and zonal thermal calculations for furnace and boiler as a whole. Overhaul of boilers to provide staged combustion and straight-flow burners and nozzles allows ensuring regulatory nitrogen oxide emission levels and corresponding best available technology criteria, which is especially relevant due to changes in Russian environmental regulation.

Numerical Investigation of Fuel Distribution Effect on Flow and Temperature Field in a Heavy Duty Gas Turbine Combustor

NASA Astrophysics Data System (ADS)

Deng, Xiaowen; Xing, Li; Yin, Hong; Tian, Feng; Zhang, Qun

2018-03-01

Multiple-swirlers structure is commonly adopted for combustion design strategy in heavy duty gas turbine. The multiple-swirlers structure might shorten the flame brush length and reduce emissions. In engineering application, small amount of gas fuel is distributed for non-premixed combustion as a pilot flame while most fuel is supplied to main burner for premixed combustion. The effect of fuel distribution on the flow and temperature field related to the combustor performance is a significant issue. This paper investigates the fuel distribution effect on the combustor performance by adjusting the pilot/main burner fuel percentage. Five pilot fuel distribution schemes are considered including 3 %, 5 %, 7 %, 10 % and 13 %. Altogether five pilot fuel distribution schemes are computed and deliberately examined. The flow field and temperature field are compared, especially on the multiple-swirlers flow field. Computational results show that there is the optimum value for the base load of combustion condition. The pilot fuel percentage curve is calculated to optimize the combustion operation. Under the combustor structure and fuel distribution scheme, the combustion achieves high efficiency with acceptable OTDF and low NOX emission. Besides, the CO emission is also presented.

Understanding Kelvin-Helmholtz instability in paraffin-based hybrid rocket fuels

NASA Astrophysics Data System (ADS)

Petrarolo, Anna; Kobald, Mario; Schlechtriem, Stefan

2018-04-01

Liquefying fuels show higher regression rates than the classical polymeric ones. They are able to form, along their burning surface, a low viscosity and surface tension liquid layer, which can become unstable (Kelvin-Helmholtz instability) due to the high velocity gas flow in the fuel port. This causes entrainment of liquid droplets from the fuel surface into the oxidizer gas flow. To better understand the droplets entrainment mechanism, optical investigations on the combustion behaviour of paraffin-based hybrid rocket fuels in combination with gaseous oxygen have been conducted in the framework of this research. Combustion tests were performed in a 2D single-slab burner at atmospheric conditions. High speed videos were recorded and analysed with two decomposition techniques. Proper orthogonal decomposition (POD) and independent component analysis (ICA) were applied to the scalar field of the flame luminosity. The most excited frequencies and wavelengths of the wave-like structures characterizing the liquid melt layer were computed. The fuel slab viscosity and the oxidizer mass flow were varied to study their influence on the liquid layer instability process. The combustion is dominated by periodic, wave-like structures for all the analysed fuels. Frequencies and wavelengths characterizing the liquid melt layer depend on the fuel viscosity and oxidizer mass flow. Moreover, for very low mass flows, no wavelength peaks are detected for the higher viscosity fuels. This is important to better understand and predict the onset and development of the entrainment process, which is connected to the amplification of the longitudinal waves.

Failure mechanisms of thermal barrier coatings exposed to elevated temperatures

NASA Technical Reports Server (NTRS)

Miller, R. A.; Lowell, C. E.

1982-01-01

The failure of a ZrO2-8%Y2O3/Ni-14% Al-0.1% Zr coating system on Rene 41 in Mach 0.3 burner rig tests was characterized. High flame and metal temperatures were employed in order to accelerate coating failure. Failure by delamination was shown to precede surface cracking or spalling. This type of failure could be duplicated by cooling down the specimen after a single long duration isothermal high temperature cycle in a burner rig or a furnace, but only if the atmosphere was oxidizing. Stresses due to thermal expansion mismatch on cooling coupled with the effects of plastic deformation of the bond coat and oxidation of the irregular bond coat are the probable life limiting factors. Heat up stresses alone could not fail the coating in the burner rig tests. Spalling eventually occurs on heat up but only after the coating has already failed through delamination.

Burners and combustion apparatus for carbon nanomaterial production

DOEpatents

Alford, J. Michael; Diener, Michael D; Nabity, James; Karpuk, Michael

2013-02-05

The invention provides improved burners, combustion apparatus, and methods for carbon nanomaterial production. The burners of the invention provide sooting flames of fuel and oxidizing gases. The condensable products of combustion produced by the burners of this invention produce carbon nanomaterials including without limitation, soot, fullerenic soot, and fullerenes. The burners of the invention do not require premixing of the fuel and oxidizing gases and are suitable for use with low vapor pressure fuels such as those containing substantial amounts of polyaromatic hydrocarbons. The burners of the invention can operate with a hot (e.g., uncooled) burner surface and require little, if any, cooling or other forms of heat sinking. The burners of the invention comprise one or more refractory elements forming the outlet of the burner at which a flame can be established. The burners of the invention provide for improved flame stability, can be employed with a wider range of fuel/oxidizer (e.g., air) ratios and a wider range of gas velocities, and are generally more efficient than burners using water-cooled metal burner plates. The burners of the invention can also be operated to reduce the formation of undesirable soot deposits on the burner and on surfaces downstream of the burner.

Burners and combustion apparatus for carbon nanomaterial production

DOEpatents

Alford, J. Michael; Diener, Michael D.; Nabity, James; Karpuk, Michael

2007-10-09

The invention provides improved burners, combustion apparatus, and methods for carbon nanomaterial production. The burners of the invention provide sooting flames of fuel and oxidizing gases. The condensable products of combustion produced by the burners of this invention produce carbon nanomaterials including without limitation, soot, fullerenic soot, and fullerenes. The burners of the invention do not require premixing of the fuel and oxidizing gases and are suitable for use with low vapor pressure fuels such as those containing substantial amounts of polyaromatic hydrocarbons. The burners of the invention can operate with a hot (e.g., uncooled) burner surface and require little, if any, cooling or other forms of heat sinking. The burners of the invention comprise one or more refractory elements forming the outlet of the burner at which a flame can be established. The burners of the invention provide for improved flame stability, can be employed with a wider range of fuel/oxidizer (e.g., air) ratios and a wider range of gas velocities, and are generally more efficient than burners using water-cooled metal burner plates. The burners of the invention can also be operated to reduce the formation of undesirable soot deposits on the burner and on surfaces downstream of the burner.

Development of high performance hybrid rocket fuels

NASA Astrophysics Data System (ADS)

Zaseck, Christopher R.

In this document I discuss paraffin fuel combustion and investigate the effects of additives on paraffin entrainment and regression. In general, hybrid rockets offer an economical and safe alternative to standard liquid and solid rockets. However, slow polymeric fuel regression and low combustion efficiency have limited the commercial use of hybrid rockets. Paraffin is a fast burning fuel that has received significant attention in the 2000's and 2010's as a replacement for standard fuels. Paraffin regresses three to four times faster than polymeric fuels due to the entrainment of a surface melt layer. However, further regression rate enhancement over the base paraffin fuel is necessary for widespread hybrid rocket adoption. I use a small scale opposed flow burner to investigate the effect of additives on the combustion of paraffin. Standard additives such as aluminum combust above the flame zone where sufficient oxidizer levels are present. As a result no heat is generated below the flame itself. In small scale opposed burner experiments the effect of limited heat feedback is apparent. Aluminum in particular does not improve the regression of paraffin in the opposed burner. The lack of heat feedback from additive combustion limits the applicability of the opposed burner. In turn, the results obtained in the opposed burner with metal additive loaded hybrid fuels do not match results from hybrid rocket experiments. In addition, nano-scale aluminum increases melt layer viscosity and greatly slows the regression of paraffin in the opposed flow burner. However, the reactive additives improve the regression rate of paraffin in the opposed burner where standard metals do not. At 5 wt.% mechanically activated titanium and carbon (Ti-C) improves the regression rate of paraffin by 47% in the opposed burner. The mechanically activated Ti C likely reacts in or near the melt layer and provides heat feedback below the flame region that results in faster opposed burner regression. In order to examine paraffin/additive combustion in a motor environment, I conducted experiments on well characterized aluminum based additives. In particular, I investigate the influence of aluminum, unpassivated aluminum, milled aluminum/polytetrafluoroethylene (PTFE), and aluminum hydride on the performance of paraffin fuels for hybrid rocket propulsion. I use an optically accessible combustor to examine the performance of the fuel mixtures in terms of characteristic velocity efficiency and regression rate. Each combustor test consumes a 12.7 cm long, 1.9 cm diameter fuel strand under 160 kg/m 2s of oxygen at up to 1.4 MPa. The experimental results indicate that the addition of 5 wt.% 30 mum or 80 nm aluminum to paraffin increases the regression rate by approximately 15% compared to neat paraffin grains. At higher aluminum concentrations and nano-scale particles sizes, the increased melt layer viscosity causes slower regression. Alane and Al/PTFE at 12.5 wt.% increase the regression of paraffin by 21% and 32% respectively. Finally, an aging study indicates that paraffin can protect air and moisture sensitive particles from oxidation. The opposed burner and aluminum/paraffin hybrid rocket experiments show that additives can alter bulk fuel properties, such as viscosity, that regulate entrainment. The general effect of melt layer properties on the entrainment and regression rate of paraffin is not well understood. Improved understanding of how solid additives affect the properties and regression of paraffin is essential to maximize performance. In this document I investigate the effect of melt layer properties on paraffin regression using inert additives. Tests are performed in the optical cylindrical combustor at ˜1 MPa under a gaseous oxygen mass flux of ˜160 kg/m2s. The experiments indicate that the regression rate is proportional to mu0.08rho 0.38kappa0.82. In addition, I explore how to predict fuel viscosity, thermal conductivity, and density prior to testing. Mechanically activated Ti-C and Al/PTFE are examined in the optical combustor. I examine the effect of the reactivity by altering the mill time for the Ti-C and Al/PTFE particles. Mechanical activation of both Ti-C and Al/PTFE improve the regression rate of paraffin more than the unmilled additives. At 12.5 wt.% Al/PTFE milled for 40 minutes regresses 12% faster than the unmilled fuel. Similarly, at 12.5 wt.% 7.5 minute milled Ti C regresses 7% faster than unmilled Ti-C. The reactive particles increase heat transfer to the fuel surface and improve regression. The composition of the combustion products are examined using a particle catcher system in conjunction with visible light and electron microscopy. The exhaust products indicate that the mechanical activation of the Al/PTFE particles cause microexplosions that reduce exhaust particle size. However, the composition of the mechanically activated Al/PTFE products do not indicate more complete combustion. In addition, the mechanically activated and unmilled Ti-C showed no difference in exhaust products.

Low emission U-fired boiler combustion system

DOEpatents

Ake, Terence; Beittel, Roderick; Lisauskas, Robert A.; Reicker, Eric

2000-01-01

At least one main combustion chamber contains at least one pulverized coal burner. Each pulverized coal burner is operatively arranged for minimizing NO.sub.X production and for maintaining a predetermined operating temperature to liquefy ash within the combustion chamber. The combustion chamber includes a slag drain for removing slag from the combustion chamber. A slag screen is positioned in a generally U-shaped furnace flow pattern. The slag screen is positioned between the combustion chamber and a radiant furnace. The radiant furnace includes a reburning zone for in-furnace No.sub.X reduction. The reburning zone extends between a reburning fuel injection source and at least one overfire air injection port for injecting air.

Further development of the dynamic gas temperature measurement system. Volume 1: Technical efforts

NASA Technical Reports Server (NTRS)

Elmore, D. L.; Robinson, W. W.; Watkins, W. B.

1986-01-01

A compensated dynamic gas temperature thermocouple measurement method was experimentally verified. Dynamic gas temperature signals from a flow passing through a chopped-wheel signal generator and an atmospheric pressure laboratory burner were measured by the dynamic temperature sensor and other fast-response sensors. Compensated data from dynamic temperature sensor thermoelements were compared with fast-response sensors. Results from the two experiments are presented as time-dependent waveforms and spectral plots. Comparisons between compensated dynamic temperature sensor spectra and a commercially available optical fiber thermometer compensated spectra were made for the atmospheric burner experiment. Increases in precision of the measurement method require optimization of several factors, and directions for further work are identified.

CHP Integrated with Burners for Packaged Boilers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Castaldini, Carlo; Darby, Eric

2013-09-30

The objective of this project was to engineer, design, fabricate, and field demonstrate a Boiler Burner Energy System Technology (BBEST) that integrates a low-cost, clean burning, gas-fired simple-cycle (unrecuperated) 100 kWe (net) microturbine (SCMT) with a new ultra low-NOx gas-fired burner (ULNB) into one compact Combined Heat and Power (CHP) product that can be retrofit on new and existing industrial and commercial boilers in place of conventional burners. The Scope of Work for this project was segmented into two principal phases: (Phase I) Hardware development, assembly and pre-test and (Phase II) Field installation and demonstration testing. Phase I was dividedmore » into five technical tasks (Task 2 to 6). These tasks covered the engineering, design, fabrication, testing and optimization of each key component of the CHP system principally, ULNB, SCMT, assembly BBEST CHP package, and integrated controls. Phase I work culminated with the laboratory testing of the completed BBEST assembly prior to shipment for field installation and demonstration. Phase II consisted of two remaining technical tasks (Task 7 and 8), which focused on the installation, startup, and field verification tests at a pre-selected industrial plant to document performance and attainment of all project objectives. Technical direction and administration was under the management of CMCE, Inc. Altex Technologies Corporation lead the design, assembly and testing of the system. Field demonstration was supported by Leva Energy, the commercialization firm founded by executives at CMCE and Altex. Leva Energy has applied for patent protection on the BBEST process under the trade name of Power Burner and holds the license for the burner currently used in the product. The commercial term Power Burner is used throughout this report to refer to the BBEST technology proposed for this project. The project was co-funded by the California Energy Commission and the Southern California Gas Company (SCG), a 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 operation and has achieved all the performance goals.« less

Structure of hydrogen-rich transverse jets in a vitiated turbulent flow

DOE PAGES

Lyra, Sgouria; Wilde, Benjamin; Kolla, Hemanth; ...

2014-11-24

Our paper reports the results of a joint experimental and numerical study of the flow characteristics and flame structure of a hydrogen rich jet injected normal to a turbulent, vitiated crossflow of lean methane combustion products. Simultaneous high-speed stereoscopic PIV and OH PLIF measurements were obtained and analyzed alongside three-dimensional direct numerical simulations of inert and reacting JICF with detailed H2/COH2/CO chemistry. Both the experiment and the simulation reveal that, contrary to most previous studies of reacting JICF stabilized in low-to-moderate temperature air crossflow, the present conditions lead to a burner-attached flame that initiates uniformly around the burner edge. Significantmore » asymmetry is observed, however, between the reaction zones located on the windward and leeward sides of the jet, due to the substantially different scalar dissipation rates. The windward reaction zone is much thinner in the near field, while also exhibiting significantly higher local and global heat release than the much broader reaction zone found on the leeward side of the jet. The unsteady dynamics of the windward shear layer, which largely control the important jet/crossflow mixing processes in that region, are explored in order to elucidate the important flow stability implications arising in the inert and reacting JICF. The paper concludes with an analysis of the ignition, flame characteristics, and global structure of the burner-attached flame. FurthermoreChemical explosive mode analysis (CEMA) shows that the entire windward shear layer, and a large region on the leeward side of the jet, are highly explosive prior to ignition and are dominated by non-premixed flame structures after ignition. The predominantly mixing limited nature of the flow after ignition is examined by computing the Takeno flame index, which shows that ~70% of the heat release occurs in non-premixed regions.« less

Coal-water mixture fuel burner

DOEpatents

Brown, T.D.; Reehl, D.P.; Walbert, G.F.

1985-04-29

The present invention represents an improvement over the prior art by providing a rotating cup burner arrangement for use with a coal-water mixture fuel which applies a thin, uniform sheet of fuel onto the inner surface of the rotating cup, inhibits the collection of unburned fuel on the inner surface of the cup, reduces the slurry to a collection of fine particles upon discharge from the rotating cup, and further atomizes the fuel as it enters the combustion chamber by subjecting it to the high shear force of a high velocity air flow. Accordingly, it is an object of the present invention to provide for improved combustion of a coal-water mixture fuel. It is another object of the present invention to provide an arrangement for introducing a coal-water mixture fuel into a combustion chamber in a manner which provides improved flame control and stability, more efficient combustion of the hydrocarbon fuel, and continuous, reliable burner operation. Yet another object of the present invention is to provide for the continuous, sustained combustion of a coal-water mixture fuel without the need for a secondary combustion source such as natural gas or a liquid hydrocarbon fuel. Still another object of the present invention is to provide a burner arrangement capable of accommodating a coal-water mixture fuel having a wide range of rheological and combustion characteristics in providing for its efficient combustion. 7 figs.

Soot Formation in Freely-Propagating Laminar Premixed Flames

NASA Technical Reports Server (NTRS)

Lin, K.-C.; Hassan, M. I.; Faeth, G. M.

1997-01-01

Soot formation within hydrocarbon-fueled flames is an important unresolved problem of combustion science. Thus, the present study is considering soot formation in freely-propagating laminar premixed flames, exploiting the microgravity environment to simplify measurements at the high-pressure conditions of interest for many practical applications. The findings of the investigation are relevant to reducing emissions of soot and continuum radiation from combustion processes, to improving terrestrial and spacecraft fire safety, and to developing methods of computational combustion, among others. Laminar premixed flames are attractive for studying soot formation because they are simple one-dimensional flows that are computationally tractable for detailed numerical simulations. Nevertheless, studying soot-containing burner-stabilized laminar premixed flames is problematical: spatial resolution and residence times are limited at the pressures of interest for practical applications, flame structure is sensitive to minor burner construction details so that experimental reproducibility is not very good, consistent burner behavior over the lengthy test programs needed to measure soot formation properties is hard to achieve, and burners have poor durability. Fortunately, many of these problems are mitigated for soot-containing, freely-propagating laminar premixed flames. The present investigation seeks to extend work in this laboratory for various soot processes in flames by observing soot formation in freely-propagating laminar premixed flames. Measurements are being made at both Normal Gravity (NG) and MicroGravity (MG), using a short-drop free-fall facility to provide MG conditions.

Performance of a hydrogen burner to simulate air entering scramjet combustors. [simulation of total temperature, total pressure, and volume fraction of oxygen of air at flight conditions

NASA Technical Reports Server (NTRS)

Russin, W. R.

1974-01-01

Tests were conducted to determine the performance of a hydrogen burner used to produce a test gas that simulates air entering a scramjet combustor at various flight conditions. The test gas simulates air in that it duplicates the total temperature, total pressure, and the volume fraction of oxygen of air at flight conditions. The main objective of the tests was to determine the performance of the burner as a function of the effective exhaust port area. The conclusions were: (1) pressure oscillations of the chugging type were reduced in amplitude to plus or minus 2 percent of the mean pressure level by proper sizing of hydrogen, oxygen, and air injector flow areas; (2) combustion efficiency remained essentially constant as the exhaust port area was increased by a factor of 3.4; (3) the mean total temperature determined from integrating the exit radial gas property profiles was within plus or minus 5 percent of the theoretical bulk total temperature; (4) the measured exit total temperature profile had a local peak temperature more than 30 percent greater than the theoretical bulk total temperature; and (5) measured heat transfer to the burner liner was 75 percent of that predicted by theory based on a flat radial temperature profile.

Studies in premixed combustion. [Benjamin Levich Inst. for Physico-Chemical Hydrodynamics, City College of CUNY, New York, New York

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sivashinsky, G.I.

1993-01-01

During the period under review, significant progress was been made in studying the intrinsic dynamics of premixed flames and the problems of flame-flow interaction. (1) A weakly nonlinear model for Bunsen burner stabilized flames was proposed and employed for the simulation of three-dimensional polyhedral flames -- one of the most graphic manifestations of thermal-diffusive instability in premixed combustion. (2) A high-precision large-scale numerical simulation of Bunsen burner tip structure was conducted. The results obtained supported the earlier conjecture that the tip opening observed in low Lewis number systems is a purely optical effect not involving either flame extinction or leakagemore » of unburned fuel. (3) A one-dimensional model describing a reaction wave moving through a unidirectional periodic flow field is proposed and studied numerically. For long-wavelength fields the system exhibits a peculiar non-uniqueness of possible propagation regimes. The transition from one regime to another occurs in a manner of hysteresis.« less

Qualitative flow visualization of flame attachment on slopes

Treesearch

Torben P. Grumstrup; Sara S. McAllister; Mark A. Finney

2017-01-01

Heating of unburned fuel by attached flames and plume of a wildfire can produce high spread rates that have resulted in firefighter fatalities worldwide. Qualitative flow fields of the plume of a gas burner embedded in a table tilted to 0°, 10°, 20°, and 30° above horizontal were imaged using the retroreflective shadowgraph technique as a means to understand plume...

A novel approach to predict the stability limits of combustion chambers with large eddy simulation

NASA Astrophysics Data System (ADS)

Pritz, B.; Magagnato, F.; Gabi, M.

2010-06-01

Lean premixed combustion, which allows for reducing the production of thermal NOx, is prone to combustion instabilities. There is an extensive research to develop a reduced physical model, which allows — without time-consuming measurements — to calculate the resonance characteristics of a combustion system consisting of Helmholtz resonator type components (burner plenum, combustion chamber). For the formulation of this model numerical investigations by means of compressible Large Eddy Simulation (LES) were carried out. In these investigations the flow in the combustion chamber is isotherm, non-reacting and excited with a sinusoidal mass flow rate. Firstly a combustion chamber as a single resonator subsequently a coupled system of a burner plenum and a combustion chamber were investigated. In this paper the results of additional investigations of the single resonator are presented. The flow in the combustion chamber was investigated without excitation at the inlet. It was detected, that the mass flow rate at the outlet cross section is pulsating once the flow in the chamber is turbulent. The fast Fourier transform of the signal showed that the dominant mode is at the resonance frequency of the combustion chamber. This result sheds light on a very important source of self-excited combustion instabilities. Furthermore the LES can provide not only the damping ratio for the analytical model but the eigenfrequency of the resonator also.

FIELD EVALUATION OF LOW-EMISSION COAL BURNER TECHNOLOGY ON UTILITY BOILERS VOLUME II. SECOND GENERATION LOW-NOX BURNERS

EPA Science Inventory

The report describes tests to evaluate the performance characteristics of three Second Generation Low-NOx burner designs: the Dual Register burner (DRB), the Babcock-Hitachi NOx Reducing (HNR) burner, and the XCL burner. The three represent a progression in development based on t...

Suppression Characteristics of Cup-Burner Flames in Low Gravity

NASA Technical Reports Server (NTRS)

Takahashi, Fumiaki; Linteris, Gregory T.; Katta, Viswanath R.

2004-01-01

The structure and suppression of laminar methane-air co-flow diffusion flames formed on a cup burner have been studied experimentally and numerically using physically acting fire-extinguishing agents (CO2, N2, He, and Ar) in normal earth (lg) and zero gravity (0g). The computation uses a direct numerical simulation with detailed chemistry and radiative heat-loss models. An initial observation of the flame without agent was also made at the NASA Glenn 2.2-Second Drop Tower. An agent was introduced into a low-speed coflowing oxidizing stream by gradually replacing the air until extinguishment occurred under a fixed minimal fuel velocity. The suppression of cup-burner flames, which resemble real fires, occurred via a blowoff process (in which the flame base drifted downstream) rather than the global extinction phenomenon typical of counterflow diffusion flames. The computation revealed that the peak reactivity spot (the reaction kernel) formed in the flame base was responsible for attachment and blowoff phenomena of the trailing diffusion flame. The thermal and transport properties of the agents affected the flame extinguishment limits.

Experimental Evaluation of a Low Emissions High Performance Duct Burner for Variable Cycle Engines (VCE)

NASA Technical Reports Server (NTRS)

Lohmann, R. P.; Mador, R. J.

1979-01-01

An evaluation was conducted with a three stage Vorbix duct burner to determine the performance and emissions characteristics of the concept and to refine the configuration to provide acceptable durability and operational characteristics for its use in the variable cycle engine (VCE) testbed program. The tests were conducted at representative takeoff, transonic climb, and supersonic cruise inlet conditions for the VSCE-502B study engine. The test stand, the emissions sampling and analysis equipment, and the supporting flow visualization rigs are described. The performance parameters including the fuel-air ratio, the combustion efficiency/exit temperature, thrust efficiency, and gaseous emissions calculations are defined. The test procedures are reviewed and the results are discussed.

Integration of an Inter Turbine Burner to a Jet Turbine Engine

DTIC Science & Technology

2013-03-01

whether for electrical systems or increased thrust, improved engine efficiency must be found. An Ultra-Compact Combustor ( UCC ) is a proposed... UCC to be viable it is important to study the effects of feeding the core and circumferential flows from a common gas reservoir. This research...prediction of which flow split would produce the best results and testing of this prediction was initiated. A second important issue for UCC development

How to design low-noise burners

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sams, G.; Jordan, J.

1996-12-01

Frequently, natural draft burner designs used in indirect heaters fail to meet the low noise standard of 85 to 88 dBA three feet from the flame arrestor. Noise encountered with indirect burner designs has been shown to be related to nozzle and firetube gas velocities. Testing shows that when the nozzle velocity is sufficiently greater than the firetube velocity, the low-frequency rumble that accompanies current designs ceases. Data obtained from field testing was used to construct a relationship between burner noise level and gas volume expansion ratio, burner air-to-fuel ratio, mixture flowrate, orifice velocity, burner area, and the number ofmore » burners. The noise from a burner can be predicted if the above easily calculable variables are known.« less

Sealed, nozzle-mix burners for silica deposition

DOEpatents

Adler, Meryle D. M.; Brown, John T.; Misra, Mahendra K.

2003-07-08

Burners (40) for producing fused silica boules are provided. The burners employ a tube-in-tube (301-306) design with flats (56, 50) on some of the tubes (305, 301) being used to limit the cross-sectional area of certain passages (206, 202) within the burner and/or to atomize a silicon-containing, liquid source material, such as OMCTS. To avoid the possibility of flashback, the burner has separate passages for fuel (205) and oxygen (204, 206), i.e., the burner employs nozzle mixing, rather than premixing, of the fuel and oxygen. The burners are installed in burner holes (26) formed in the crown (20) of a furnace and form a seal with those holes so that ambient air cannot be entrained into the furnace through the holes. An external air cooled jacket (60) can be used to hold the temperature of the burner below a prescribed upper limit, e.g., 400.degree. C.

Fuel-flexible burner apparatus and method for fired heaters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zink, Darton J.; Isaacs, Rex K.; Jamaluddin, A. S.

A burner apparatus for a fired heating system and a method of burner operation. The burner provides stable operation when burning gas fuels having heating values ranging from low to high and accommodates sudden wide changes in the Wobbe value of the fuel delivered to the burner. The burner apparatus includes a plurality of exterior fuel ejectors and has an exterior notch which extends around the burner wall for receiving and combusting a portion of the gas fuel. At least a portion of the hot combustion product gas produced in the exterior notch is delivered through channels formed in themore » burner wall to the combustion area at the forward end of the burner. As the Wobbe value of the gas fuel decreases, one or more outer series of addition ejectors can be automatically activated as needed to maintain the amount of heat output desired.« less

Rhenium-Foil Witness Cylinders

NASA Technical Reports Server (NTRS)

Knight, B. L.

1992-01-01

Cylindrical portion of wall of combustion chamber replaced with rhenium foil mounted on holder. Rhenium oxidizes without melting, indicating regions of excess oxidizer in combustion-chamber flow. Rhenium witness foils also useful in detecting excess oxygen and other oxidizers at temperatures between 2,000 and 3,600 degrees F in burner cores of advanced gas-turbine engines.

Velocity Fields of Axisymmetric Hydrogen-Air Counterflow Diffusion Flames from LDV, PIV, and Numerical Computation

NASA Technical Reports Server (NTRS)

Pellett, Gerald L.; Wilson, Lloyd G.; Humphreys, William M., Jr.; Bartram, Scott M.; Gartrell, Luther R.; Isaac, K. M.

1995-01-01

Laminar fuel-air counterflow diffusion flames (CFDFs) were studied using axisymmetric convergent-nozzle and straight-tube opposed jet burners (OJBs). The subject diagnostics were used to probe a systematic set of H2/N2-air CFDFs over wide ranges of fuel input (22 to 100% Ha), and input axial strain rate (130 to 1700 Us) just upstream of the airside edge, for both plug-flow and parabolic input velocity profiles. Laser Doppler Velocimetry (LDV) was applied along the centerline of seeded air flows from a convergent nozzle OJB (7.2 mm i.d.), and Particle Imaging Velocimetry (PIV) was applied on the entire airside of both nozzle and tube OJBs (7 and 5 mm i.d.) to characterize global velocity structure. Data are compared to numerical results from a one-dimensional (1-D) CFDF code based on a stream function solution for a potential flow input boundary condition. Axial strain rate inputs at the airside edge of nozzle-OJB flows, using LDV and PIV, were consistent with 1-D impingement theory, and supported earlier diagnostic studies. The LDV results also characterized a heat-release hump. Radial strain rates in the flame substantially exceeded 1-D numerical predictions. Whereas the 1-D model closely predicted the max I min axial velocity ratio in the hot layer, it overpredicted its thickness. The results also support previously measured effects of plug-flow and parabolic input strain rates on CFDF extinction limits. Finally, the submillimeter-scale LDV and PIV diagnostics were tested under severe conditions, which reinforced their use with subcentimeter OJB tools to assess effects of aerodynamic strain, and fueVair composition, on laminar CFDF properties, including extinction.

Influence of burner form and pellet type on domestic pellet boiler performance

NASA Astrophysics Data System (ADS)

Rastvorov, D. V.; Osintsev, K. V.; Toropov, E. V.

2017-10-01

The study presents combustion and emission results obtained using two serial pellet boilers of the same heating capacity 40 kW. These boilers have been designed by producers for domestic conditions of exploitation. The principal difference between boilers was the type of the burner. The study concerns the efficiency and ecological performance difference between burners of circular and rectangular forms. The features of the combustion process in both types of burners were studied when boiler operated with different sorts of pellets. The results suggest that the burner of circular form excels the rectangular form burner. However, there is some difference of NOx emission between circular and rectangular burners.

THE CHARACTERIZATION OF A SOLID SORBENT WITH CRYSTALLITE SIZE AND STRAIN DATA FROM X-RAY DIFFRACTION LINE BROADENING

EPA Science Inventory

The paper gives results of the characterization of a solid sorbent with crystallite size and strain data from x-ray diffraction line broadening, as part of an EPA investigation of the injection of dry Ca(OH)2 into coal-fired electric power plant burners for the control of SO2 emi...

Large Eddy Simulations of the Vortex-Flame Interaction in a Turbulent Swirl Burner

NASA Astrophysics Data System (ADS)

Lu, Zhen; Elbaz, Ayman M.; Hernandez Perez, Francisco E.; Roberts, William L.; Im, Hong G.

2017-11-01

A series of swirl-stabilized partially premixed flames are simulated using large eddy simulation (LES) along with the flamelet/progress variable (FPV) model for combustion. The target burner has separate and concentric methane and air streams, with methane in the center and the air flow swirled through the tangential inlets. The flame is lifted in a straight quarl, leading to a partially premixed state. By fixing the swirl number and air flow rate, the fuel jet velocity is reduced to study flame stability as the flame approaches the lean blow-off limit. Simulation results are compared against measured data, yielding a generally good agreement on the velocity, temperature, and species mass fraction distributions. The proper orthogonal decomposition (POD) method is applied on the velocity and progress variable fields to analyze the dominant unsteady flow structure, indicating a coupling between the precessing vortex core (PVC) and the flame. The effects of vortex-flame interactions on the stabilization of the lifted swirling flame are also investigated. For the stabilization of the lifted swirling flame, the effects of convection, enhanced mixing, and flame stretching introduced by the PVC are assessed based on the numerical results. This research work was sponsored by King Abdullah University of Science and Technology (KAUST) and used computational resources at KAUST Supercomputing Laboratory.

Investigation of the effect of pilot burner on lean blow out performance of a staged injector

NASA Astrophysics Data System (ADS)

Yang, Jinhu; Zhang, Kaiyu; Liu, Cunxi; Ruan, Changlong; Liu, Fuqiang; Xu, Gang

2014-12-01

The staged injector has exhibited great potential to achieve low emissions and is becoming the preferable choice of many civil airplanes. Moreover, it is promising to employ this injector design in military engine, which requires most of the combustion air enters the combustor through injector to reduce smoke emission. However, lean staged injector is prone to combustion instability and extinction in low load operation, so techniques for broadening its stable operation ranges are crucial for its application in real engine. In this work, the LBO performance of a staged injector is assessed and analyzed on a single sector test section. The experiment was done in atmospheric environment with optical access. Kerosene-PLIF technique was used to visualize the spray distribution and common camera was used to record the flame patterns. Emphasis is put on the influence of pilot burner on LBO performance. The fuel to air ratios at LBO of six injectors with different pilot swirler vane angle were evaluated and the obtained LBO data was converted into data at idle condition. Results show that the increase of pilot swirler vane angle could promote the air assisted atomization, which in turn improves the LBO performance slightly. Flame patterns typical in the process of LBO are analyzed and attempts are made to find out the main factors which govern the extinction process with the assistance of spray distribution and numerical flow field results. It can be learned that the flame patterns are mainly influenced by structure of the flow field just behind the pilot burner when the fuel mass flow rate is high; with the reduction of fuel, atomization quality become more and more important and is the main contributing factor of LBO. In the end of the paper, conclusions are drawn and suggestions are made for the optimization of the present staged injector.

Pattern Formation in Diffusion Flames Embedded in von Karman Swirling Flows

NASA Technical Reports Server (NTRS)

Nayagam, Vedha

2006-01-01

Pattern formation is observed in nature in many so-called excitable systems that can support wave propagation. It is well-known in the field of combustion that premixed flames can exhibit patterns through differential diffusion mechanism between heat and mass. However, in the case of diffusion flames where fuel and oxidizer are separated initially there have been only a few observations of pattern formation. It is generally perceived that since diffusion flames do not possess an inherent propagation speed they are static and do not form patterns. But in diffusion flames close to their extinction local quenching can occur and produce flame edges which can propagate along stoichiometric surfaces. Recently, we reported experimental observations of rotating spiral flame edges during near-limit combustion of a downward-facing polymethylmethacrylate disk spinning in quiescent air. These spiral flames, though short-lived, exhibited many similarities to patterns commonly found in quiescent excitable media including compound tip meandering motion. Flame disks that grow or shrink with time depending on the rotational speed and in-depth heat loss history of the fuel disk have also been reported. One of the limitations of studying flame patterns with solid fuels is that steady-state conditions cannot be achieved in air at normal atmospheric pressure for experimentally reasonable fuel thickness. As a means to reproduce the flame patterns observed earlier with solid fuels, but under steady-state conditions, we have designed and built a rotating, porous-disk burner through which gaseous fuels can be injected and burned as diffusion flames. The rotating porous disk generates a flow of air toward the disk by a viscous pumping action, generating what is called the von K rm n boundary layer which is of constant thickness over the entire burner disk. In this note we present a map of the various dynamic flame patterns observed during the combustion of methane in air as a function of fuel flow rate and the burner rotational speed.

Influence of oxygen concentration, fuel composition, and strain rate on synthesis of carbon nanomaterials

NASA Astrophysics Data System (ADS)

Hou, Shuhn-Shyurng; Huang, Wei-Cheng

2015-02-01

This paper investigates the influence of flame parameters including oxygen concentration, fuel composition, and strain rate on the synthesis of carbon nanomaterials in opposed-jet ethylene diffusion flames with or without rigid-body rotation. In the experiments, a mixture of ethylene and nitrogen was introduced from the upper burner; meanwhile, a mixture of oxygen and nitrogen was supplied from the lower burner. A nascent nickel mesh was used as the catalytic metal substrate to collect deposited materials. With non-rotating opposed-jet diffusion flames, carbon nanotubes (CNTs) were successfully produced for oxygen concentrations in the range of 21-50 % at a fixed ethylene concentration of 20 %, and for ethylene concentrations ranging from 14 to 24 % at a constant oxygen concentration of 40 %. With rotating opposed-jet diffusion flames, the strain rate was varied by adjusting the angular velocities of the upper and lower burners. The strain rate governed by flow rotation greatly affects the synthesis of carbon nanomaterials [i.e., CNTs and carbon nano-onions (CNOs)] either through the residence time or carbon sources available. An increase in the angular velocity lengthened the residence time of the flow and thus caused the diffusion flame to experience a decreased strain rate, which in turn produced more carbon sources. The growth of multi-walled CNTs was achieved for the stretched flames experiencing a higher strain rate [i.e., angular velocity was equal to 0 or 1 rotations per second (rps)]. CNOs were synthesized at a lower strain rate (i.e., angular velocity was in the range of 2-5 rps). It is noteworthy that the strain rate controlled by flow rotation greatly influences the fabrication of carbon nanostructures owing to the residence time as well as carbon source. Additionally, more carbon sources and higher temperature are required for the synthesis of CNOs compared with those required for CNTs (i.e., about 605-625 °C for CNTs and 700-800 °C for CNOs).

Effects of Passive Fuel-Air Mixing Control on Burner Emissions Via Lobed Fuel Injectors

NASA Technical Reports Server (NTRS)

Mitchell, M. G.; Smith, O. I.; Karagozian, A. R.

1999-01-01

The present experimental study examines the effects of differing levels of passive fuel-air premixing on flame structures and their associated NO(x) and CO emissions. Four alternative fuel injector geometries were explored, three of which have lobed shapes. These lobed injectors mix fuel and air and strain species inter-faces to differing extents due to streamwise vorticity generation, thus creating different local or core equivalence ratios within flow regions upstream of flame ignition and stabilization. Prior experimental studies of two of these lobed injector flowfields focused on non-reactive mixing characteristics and emissions measurements for the case where air speeds were matched above and below the fuel injector, effectively generating stronger streamwise vorticity than spanwise vorticity. The present studies examine the effects of airstream mismatch (and hence additional spanwise vorticity generation), effects of confinement of the crossflow to reduce the local equivalence ratio, and the effects of altering the geometry and position of the flameholders. NO(x) and CO emissions as well as planar laser-induced fluorescence imaging (PLIF) of seeded acetone are used to characterize injector performance and reactive flow evolution.

Counterflow diffusion flames of hydrogen, and hydrogen plus methane, ethylene, propane, and silane vs. air - Strain rates at extinction

NASA Technical Reports Server (NTRS)

Pellett, G. L.; Northam, G. Burton; Wilson, L. G.

1991-01-01

Five coaxial tubular opposed jet burners (OJBs) with tube diameter D(T) of 1.8-10 mm and 5 mm conical nozzles were used to form dish-shaped counterflow diffusion flames centered by opposing laminar jets of nitrogen and hydrocarbon-diluted H2 versus air in an argon-purged chamber at 1 atm. Area-averaged air jet velocities at blowoff of the central flame, U(air), characterized extinction of the airside flame as functions of input H2 concentration on the fuelside. A master plot of extensive U(air) data at blowoff versus D(T) shows that U(air) varies linearly with D(T). This and other data sets are used to find that nozzle OJB results for U(air)/diameter average 4.24 + or - 0.28 times larger than tubular OJB results for the same fuel compositions. Critical radial velocity gradients consistent with one-dimensional stagnation point boundary theory and with plug flow inputs are estimated. The results compare favorably with published numerical results based only on potential flow.

Metal hydride and pyrophoric fuel additives for dicyclopentadiene based hybrid propellants

NASA Astrophysics Data System (ADS)

Shark, Steven C.

The purpose of this study is to investigate the use of reactive energetic fuel additives that have the potential to increase the combustion performance of hybrid rocket propellants in terms of solid fuel regression rate and combustion efficiency. Additives that can augment the combustion flame zone in a hybrid rocket motor by means of increased energy feedback to the fuel grain surface are of great interest. Metal hydrides have large volumetric hydrogen densities, which gives these materials high performance potential as fuel additives in terms of specifc impulse. The excess hydrogen and corresponding base metal may also cause an increase in the hybrid rocket solid fuel regression rate. Pyrophoric additives also have potential to increase the solid fuel regression rate by reacting more readily near the burning fuel surface providing rapid energy feedback. An experimental performance evaluation of metal hydride fuel additives for hybrid rocket motor propulsion systems is examined in this study. Hypergolic ignition droplet tests and an accelerated aging study revealed the protection capabilities of Dicyclopentadiene (DCPD) as a fuel binder, and the ability for unaided ignition. Static hybrid rocket motor experiments were conducted using DCPD as the fuel. Sodium borohydride (NabH4) and aluminum hydride (AlH3) were examined as fuel additives. Ninety percent rocket grade hydrogen peroxide (RGHP) was used as the oxidizer. In this study, the sensitivity of solid fuel regression rate and characteristic velocity (C*) efficiency to total fuel grain port mass flux and particle loading is examined. These results were compared to HTPB combustion performance as a baseline. Chamber pressure histories revealed steady motor operation in most tests, with reduced ignition delays when using NabH4 as a fuel additive. The addition of NabH4 and AlH3 produced up to a 47% and 85% increase in regression rate over neat DCPD, respectively. For all test conditions examined C* efficiency ranges between 80% and 90%. The regression rate and C* efficiency mass flux dependence indicate a shift towards a more diffusion controlled system with metal hydride particle addition. Although these types of energetic particles have potential as high performing fuel additives, they can be in low supply and expensive. An opposed flow burner was investigated as a means to screen and characterize hybrid rocket fuels prior to full scale rocket motor testing. Although this type of configuration has been investigated in the past, no comparison has been made to hybrid rocket motor operation in terms of mass flux. Polymeric fuels and low melt temperature fuels with and without additives were investigated via an opposed flow burner. The effects of laminar and turbulent flow regimes on the convective heat transfer in the opposed flow system was depicted in the regression rate trends of these fuels. Regression rate trends similar to hybrid rocket motor operation were depicted, including the entrainment mechanism for paran fuel. However, there was a shift in overall magnitude of these results. A decrease in regression rate occurred for HTPB loaded with passivated nano-aluminum, due to low resonance time in the reaction zone. Previous results have shown that pyrophoric additives can cause an increase in regression rate in the opposed flow burner configuration. It is proposed that the opposed burner is useful as a screening and characterization tool for some propellant combinations. Gaseous oxygen (GOX) was investigated as an oxidizer for similar fuels evaluated with RGHP. Specifically, combustion performance sensitivity to mass flux and MH particle size was investigated. Similar results to the RGHP experiments were observed for the regression rate tends of HTPB, DPCD, and NabH 4 addition. Kinetically limited regression rate dependence on mass flux was observed at the higher mass flux levels. No major increase in C* efficiency was observed for MH addition. The C* efficiency varied with equivalence ratio by approximately 10 percentage points, which was not observed in the RGHP experiments. A 10 percentage point decrease in C* efficiency was observed with increasing mass flux in the system. This was most likely due to poorly mixed fuel and oxidizer in center of the combustion chamber at the higher mass flux levels. Detailed measurements of the hybrid rocket combustion zone is useful for understanding the mechanisms governing performance, but can be difficult to obtain. Traditional slab burner configurations have proven useful but are operationally limited in pressure and mass flux ranges. A new optical cylindrical combustor (OCC) design is presented that allows surface and flame zone imaging and tracking during hybrid rocket motor operation at appreciable mass flux and pressure levels, > 100 kg/s/m2 and > 0.69 MPa. The flame height and regression rate sensitivity to mass flux and chamber pressure was examined for the same fuels examined in the GOX hybrid rocket motor, with the addition of DCPD fuel loaded with Al and unpassivated mechanically activated Al-PTFE. The regression rate trends were on the same order of magnitude of traditional hybrid rocket motor results. A flame height decrease was observed for increased mass flux. The flame height increased with NabH 4 addition, which is most likely a function of increased blowing at the surface. There was no appreciable flame height sensitivity to NabH4 particle size. There was no relative change in flame height or regression rate between the Al and AL-PTFE addition. The OCC allowed visualization of the hybrid rocket fuel flame zone at mass flux and pressure levels that are not known to be report for traditional slab burner configurations in literature. The OCC proved to be a new useful tool for investigated hybrid rocket propellant combustion characteristics.

DESIGN REPORT: LOW-NOX BURNERS FOR PACKAGE BOILERS

EPA Science Inventory

The report describes a low-NOx burner design, presented for residual-oil-fired industrial boilers and boilers cofiring conventional fuels and nitrated hazardous wastes. The burner offers lower NOx emission levels for these applications than conventional commercial burners. The bu...

Characterization and durability testing of plasma-sprayed zirconia-yttria and hafnia-yttria thermal barrier coatings. Part 1: Effect of spray parameters on the performance of several lots of partially stabilized zirconia-yttria powder

NASA Technical Reports Server (NTRS)

Miller, Robert A.; Leissler, George W.; Jobe, J. Marcus

1993-01-01

Initial experiments conducted on thermal barrier coatings prepared in the newly upgraded research plasma spray facility and the burner rig test facilities are discussed. Part 1 discusses experiments which establish the spray parameters for three baseline zirconia-yttria coatings. The quality of five similar coating lots was judged primarily by their response to burner rig exposure supplemented by data from other sources such as specimen characterizations and thermal diffusivity measurements. After allowing for burner rig variability, although there appears to be an optimum density (i.e., optimum microstructure) for maximum burner rig life, the distribution tends to be rather broad about the maximum. In Part 2, new hafnia-yttria-based coatings were evaluated against both baseline and alternate zirconia-yttria coatings. The hafnia-yttria coatings and the zirconia-yttria coatings that were prepared by an alternate powder vendor were very sensitive to plasma spray parameters, in that high-quality coatings were only obtained when certain parameters were employed. The reasons for this important observation are not understood. Also not understood is that the first of two replicate specimens sprayed for Part 1 consistently performed better than the second specimen. Subsequent experiments did not display this spray order affect, possibly because a chiller was installed in the torch cooling water circuit. Also, large changes in coating density were observed after switching to a new lot of electrodes. Analyses of these findings were made possible, in part, because of the development of a sensitive density measurement technique described herein in detail. The measured thermal diffusivities did not display the expected strong relationship with porosity. This surprising result was believed to have been caused by increased microcracking of the denser coatings on the stainless steel substrates.

Characterization and validation of an anechoic facility for high-temperature jet noise studies

NASA Astrophysics Data System (ADS)

Craft, Joseph

In response to the increasing demand for jet noise studies performed at realistic conditions, the Florida Center For Advanced Aero-Propulsion at Florida State University has recently brought online an upgraded Anechoic High-Temperature Jet Facility. The function of this facility is to accurately simulate and characterize the aeroacoustic properties of exhaust from jet engines at realistic temperatures and flow speeds. This new addition is a blow-down facility supplied by a 3500 kPa, 114 cubic meter compressed dry air system and a sudden-expansion ethylene burner that is capable of producing ideally expanded jets up to Mach 2.6 and stagnation temperatures up to 1500 K. The jet exhausts into a fully anechoic chamber which is equipped to acquire acoustic and flow measurements including the temperature and pressure of the jet. The facility is capable of operating under free jet as well as in various impinging jet configurations pertinent to sea- and land-based aircraft, such as the F-35B. Compared to the original facility, the updated rig is capable of longer run times at higher temperatures. In this paper we demonstrate the facility's experimental capabilities and document jet aeroacoustic characteristics at various flow and temperature conditions. The anechoic chamber was characterized using ISO (3745:2003) guidelines and the lower cutoff frequency of the chamber was determined to be 315 Hz. Aeroacoustic properties of jets operating at subsonic conditions and supersonic Mach numbers ranging from 1.2 to 2.1 at temperatures of 300 K to 1300 K are documented. Where available, very good agreement was found when the present results were compared with data in the jet noise literature.

Effect of Curved Radial Vane Cavity Arrangements on Predicted Inter-Turbine Burner (ITB) Performance

DTIC Science & Technology

2007-06-01

on for only short duration and at certain points in the conditions and with flame lengths up to 50% shorter than aircraft’s mission profile to...remaining exit parameters are as finite-rate flame length , combustion heat release, and extrapolated from the interior domain. Mass flow rates ITB exit

500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. Public design report (preliminary and final)

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-07-01

This Public Design Report presents the design criteria of a DOE Innovative Clean Coal Technology (ICCT) project demonstrating advanced wall-fired combustion techniques for the reduction of NO{sub x} emissions from coal-fired boilers. The project is being conducted at Georgia Power Company`s Plant Hammond Unit 4 (500 MW) near Rome, Georgia. The technologies being demonstrated at this site include Foster Wheeler Energy Corporation`s advanced overfire air system and Controlled Flow/Split Flame low NO{sub x} burner. This report provides documentation on the design criteria used in the performance of this project as it pertains to the scope involved with the low NO{submore » x} burners, advanced overfire systems, and digital control system.« less

Heat transfer mechanism with thin filaments including ceramic high temperature heat exchanger

DOEpatents

Im, K.H.; Ahluwalia, R.K.

1994-10-18

A radiative heat transfer mechanism in a furnace is described having burners through which pulverized coal and air are burned producing combustion gases and contaminants. A plurality of elongated conduits are positioned inside the furnace proximate to the burners generally parallel to the flow of combustion gases in the furnace. A plurality of thin filaments are inside each of the elongated hollow conduits, the filaments having diameters in the range of from about 1 micrometer to about 1,000 micrometers and having an infrared radiation cross-section sufficient to cause the filaments to heat upon exposure to infrared radiation. Blower mechanism is associated with the elongated conduits for limiting the amount of soot and ash which deposit on the conduits to preserve the radiative and convective transfer of heat energy from the combustion gases to the conduits. 7 figs.

Heat transfer mechanism with thin filaments including ceramic high temperature heat exchanger

DOEpatents

Im, Kwan H.; Ahluwalia, Rajesh K.

1994-01-01

A radiative heat transfer mechanism in a furnace having burners through which pulverized coal and air are burned producing combustion gases and contaminants. A plurality of elongated conduits are positioned inside the furnace proximate to the burners generally parallel to the flow of combustion gases in the furnace. A plurality of thin filaments are inside each of the elongated hollow conduits, the filaments having diameters in the range of from about 1 micrometer to about 1,000 micrometers and having an infrared radiation cross-section sufficient to cause the filaments to heat upon exposure to infrared radiation. Blower mechanism is associated with the elongated conduits for limiting the amount of soot and ash which deposit on the conduits to preserve the radiative and convective transfer of heat energy from the combustion gases to the conduits.

An Experimental and Numerical Study of a Supersonic Burner for CFD Model Development

NASA Technical Reports Server (NTRS)

Magnotti, G.; Cutler, A. D.

2008-01-01

A laboratory scale supersonic burner has been developed for validation of computational fluid dynamics models. Detailed numerical simulations were performed for the flow inside the combustor, and coupled with finite element thermal analysis to obtain more accurate outflow conditions. A database of nozzle exit profiles for a wide range of conditions of interest was generated to be used as boundary conditions for simulation of the external jet, or for validation of non-intrusive measurement techniques. A set of experiments was performed to validate the numerical results. In particular, temperature measurements obtained by using an infrared camera show that the computed heat transfer was larger than the measured value. Relaminarization in the convergent part of the nozzle was found to be responsible for this discrepancy, and further numerical simulations sustained this conclusion.

Low-NOx burner and SNCR retrofit experience at New England Power Salem Harbor Station

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quartucy, G.; Sload, A.; Fynan, G.

New England Power has recently installed Riley-Stoker low-NO{sub x} burners (LNB) and Nalco Fuel Tech urea-based selective non-catalytic NO{sub x} reduction (SNCR) systems on Units 1 and 3 at its Salem Harbor generating station. In addition, Unit 3 was also retrofit with a two-level overfire air (OFA) system. These two coal-fired units are front wall-fired with unequal burner spacing and have uncontrolled full-load NO{sub x} emissions of nominally 750 ppm (1.1 lb/MMBtu). Unit 1 is rated at 86 MW and has 12 burners, while Unit 3 is rated at 155 MW and has 16 burners. NO{sub x} reduction performance ofmore » the LNB, OFA and SNCR systems has been characterized both independently and in combination during the test programs while firing low-sulfur coals. Unit 1 tests showed that the LNBs provided NO{sub x} reductions of approximately 50 percent at loads above 60 MW using narrow angle coal spreaders. Corresponding ash carbon at these NO{sub x} levels varied between 16 and 35 percent. The SNCR system provided an additional 40 percent NO{sub x} reduction from the LNB baseline at a molar N/NO ratio of 1.2. The corresponding NH{sub 3} slip levels were less than 10 ppm. On Unit 3, LNB tests showed that NO{sub x} reductions of nominally 10 percent were achieved with the burners alone, using wide angle coal spreaders. The use of OFA, at design levels, provided additional NO{sub x} reductions ranging from 42 percent at full load to 4 percent a minimum load relative to the LNB baseline. Ash carbon levels doubled to levels above 30 percent when the OFA system was operated at design conditions at loads above 110 MW. The SNCR system provided NO{sub x} reductions of 33 percent relative to the LNB/OFA baseline of 0.55 lb/MMBtu, at a molar N/NO ratio of 1.3. Ammonia slip for these conditions was less than 5 ppm.« less

Flame Structure and Dynamics for an Array of Premixed Methane-Air Jets

NASA Astrophysics Data System (ADS)

Nigam, Siddharth P.; Lapointe, Caelan; Christopher, Jason D.; Wimer, Nicholas T.; Hayden, Torrey R. S.; Rieker, Gregory B.; Hamlington, Peter E.

2017-11-01

Premixed flames have been studied extensively, both experimentally and computationally, and their properties are reasonably well characterized for a range of conditions and configurations. However, the premixed combustion process is potentially much more difficult to predict when many such flames are arranged in a closely spaced array. These arrays must be better understood, in particular, for the design of industrial burners used in chemical and heat treatment processes. Here, the effects of geometric array parameters (e.g., angle and diameter of jet inlets, number of inlets and their respective orientation) and operating conditions (e.g., jet velocities, fuel-air ratio) on flame structure and dynamics are studied using large eddy simulations (LES). The simulations are performed in OpenFOAM using multi-step chemistry for a methane-air mixture, and temperature and chemical composition fields are characterized for a variety of configurations as functions of height above the array. Implications of these results for the design and operation of industrial burners are outlined.

Laboratory test methods for combustion stability properties of solid propellants

NASA Technical Reports Server (NTRS)

Strand, L. D.; Brown, R. S.

1992-01-01

An overview is presented of experimental methods for determining the combustion-stability properties of solid propellants. The methods are generally based on either the temporal response to an initial disturbance or on external methods for generating the required oscillations. The size distribution of condensed-phase combustion products are characterized by means of the experimental approaches. The 'T-burner' approach is shown to assist in the derivation of pressure-coupled driving contributions and particle damping in solid-propellant rocket motors. Other techniques examined include the rotating-valve apparatus, the impedance tube, the modulated throat-acoustic damping burner, and the magnetic flowmeter. The paper shows that experimental methods do not exist for measuring the interactions between acoustic velocity oscillations and burning propellant.

FIELD EVALUATION OF LOW-EMISSION COAL BURNER TECHNOLOGY ON UTILITY BOILERS VOLUME III. FIELD EVALUATIONS

EPA Science Inventory

The report gives results of field tests conducted to determine the emission characteristics of a Babcock and Wilcox Circular burner and Dual Register burner (DRB). The field tests were performed at two utility boilers, generally comparable in design and size except for the burner...

FIELD EVALUATION OF LOW-EMISSION COAL BURNER TECHNOLOGY ON UTILITY BOILERS. VOLUME I. DISTRIBUTED MIXING BURNER EVALUATION

EPA Science Inventory

The report gives results of a study in which NOx emissions and general combustion performance characteristics of four burners were evaluated under experimental furnace conditions. Of primary interest was the performance of a low NOx Distributed Mixing Burner (DMB), which was test...

TiCl4 as a source of TiO2 particles for laser anemometry measurements in hot gas

NASA Technical Reports Server (NTRS)

Weikle, Donald H.; Seasholtz, Richard G.; Oberle, Lawrence G.

1990-01-01

A method of reacting TiCl4 with water saturated gaseous nitrogen (GN2) at the entrance into a high temperature gas flow is described. The TiO2 particles formed are then entrained in the gas flow and used as seed particles for making laser anemometry (LA) measurements of the flow velocity distribution in the hot gas. Scanning electron microscope photographs of the TiO2 particles are shown. Data rate of the LA processor was measured to determine the amount of TiO2 formed. The TiCl4 and mixing gas flow diagram is shown. This work was performed in an open jet burner.

Process and apparatus for igniting a burner in an inert atmosphere

DOEpatents

Coolidge, Dennis W.; Rinker, Franklin G.

1994-01-01

According to this invention there is provided a process and apparatus for the ignition of a pilot burner in an inert atmosphere without substantially contaminating the inert atmosphere. The process includes the steps of providing a controlled amount of combustion air for a predetermined interval of time to the combustor then substantially simultaneously providing a controlled mixture of fuel and air to the pilot burner and to a flame generator. The controlled mixture of fuel and air to the flame generator is then periodically energized to produce a secondary flame. With the secondary flame the controlled mixture of fuel and air to the pilot burner and the combustion air is ignited to produce a pilot burner flame. The pilot burner flame is then used to ignited a mixture of main fuel and combustion air to produce a main burner flame. The main burner flame then is used to ignite a mixture of process derived fuel and combustion air to produce products of combustion for use as an inert gas in a heat treatment process.

Successful multi-technology NO{sub x} reduction project experience at New England Power Company - Salem Harbor station

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fynan, G.A.; Sload, A.; Adamson, E.J.

This paper presents the successes and lessons learned during recent low NOx burner and SNCR projects on generating units at New England Power`s Salem Harbor Generating Station. The principals involved in the project were New England Power Company, New England Power Service Company, Stone and Webster Engineering Corp. and Deutsche-Babcock Riley Inc. One unit was retrofitted with 16 Riley CCV burners with an OFA system, the other with 12 low NOx burners only. In addition to the burners, a SNCR system was also installed on three units. Since each of the burner systems are interdependent (SNCR was treated separately duringmore » design phases and optimized along with the burner systems), close cooperation during the design stages was essential to ensuring a successful installation, startup and optimization. This paper will present the coordinated effort put forth by each company toward this goal with the hope of assisting others who may be planning a similar effort. A summary of the operating results will also be presented. The up front teamwork and advance planning that went into the design stages of the project resulted in a number of successful outcomes e.g. scanner reliability, properly operating oil supply system, compatibility of burners and burner front oil system with new Burner Management System (BMS), reliable first attempt burner ignition and more. Advance planning facilitated pre-outage work and factored into keeping schedules and budgets on track.« less

Fan/Ram Duct Program

DTIC Science & Technology

1973-10-01

turbofan engine shutoff scheme, the ram duct flow conditions, and the Ian duct shutoff vane area transi- tion schedule. This loss will be...airflow. The performance of the turbofan is neglected until the main engine burner is ignited. At that time it is assumed that the turbo - fan...B. Transient Operation . . .. TRANSIENT TRANSITION TEST CASES A. Turbofan to Ramjet B. Ramjet to Turbo fan CONCLUSIONS AND RECOMMENDATIONS

Microwave resonance lamp absorption technique for measuring temperature and OH number density in combustion environments

NASA Technical Reports Server (NTRS)

Lempert, Walter R.

1988-01-01

A simple technique for simultaneous determination of temperature and OH number density is described, along with characteristic results obtained from measurements using a premixed, hydrogen air flat flame burner. The instrumentation is based upon absorption of resonant radiation from a flowing microwave discharge lamp, and is rugged, relatively inexpensive, and very simple to operate.

A Parametric Cycle Analysis of a Separate-Flow Turbofan with Interstage Turbine Burner

NASA Technical Reports Server (NTRS)

Marek, C. J. (Technical Monitor); Liew, K. H.; Urip, E.; Yang, S. L.

2005-01-01

Today's modern aircraft is based on air-breathing jet propulsion systems, which use moving fluids as substances to transform energy carried by the fluids into power. Throughout aero-vehicle evolution, improvements have been made to the engine efficiency and pollutants reduction. This study focuses on a parametric cycle analysis of a dual-spool, separate-flow turbofan engine with an Interstage Turbine Burner (ITB). The ITB considered in this paper is a relatively new concept in modern jet engine propulsion. The JTB serves as a secondary combustor and is located between the high- and the low-pressure turbine, i.e., the transition duct. The objective of this study is to use design parameters, such as flight Mach number, compressor pressure ratio, fan pressure ratio, fan bypass ratio, linear relation between high- and low-pressure turbines, and high-pressure turbine inlet temperature to obtain engine performance parameters, such as specific thrust and thrust specific fuel consumption. Results of this study can provide guidance in identifying the performance characteristics of various engine components, which can then be used to develop, analyze, integrate, and optimize the system performance of turbofan engines with an ITB.

Development of a 100 kW plasma torch for plasma assisted combustion of low heating value fuels

NASA Astrophysics Data System (ADS)

Takali, S.; Fabry, F.; Rohani, V.; Cauneau, F.; Fulcheri, L.

2014-11-01

Most thermal power plants need an auxiliary power source to (i) heat-up the boiler during start up phases before reaching autonomy power and (ii) sustain combustion at low load. This supplementary power is commonly provided with high LHV fossil fuel burners which increases operational expenses and disables the use of anti-pollutant filters. A Promising alternative is under development and consists in high temperature plasma assisted AC electro-burners. In this paper, the development of a new 100 kW three phase plasma torch with graphite electrodes is detailed. This plasma torch is working at atmospheric pressure with air as plasma gas and has three-phase power supply and working at 680 Hz. The nominal air flow rate is 60 Nm3.h-1 and the outlet gas temperature is above 2 500 K. At the beginning, graphite electrodes erosion by oxidizing medium was studied and controlling parameters were identified through parametric set of experiments and tuned for optimal electrodes life time. Then, a new 3-phase plasma torch design was modelled and simulated on ANSYS platform. The characteristics of the plasma flow and its interaction with the environing elements of the torch are detailed hereafter.

Industrial Application of an Improved Multiple Injection and Multiple Staging Combustion Technology in a 600 MWe Supercritical Down-Fired Boiler.

PubMed

Song, Minhang; Zeng, Lingyan; Chen, Zhichao; Li, Zhengqi; Zhu, Qunyi; Kuang, Min

2016-02-02

To solve the water wall overheating in lower furnace, and further reduce NOx emissions and carbon in fly ash, continuous improvement of the previously proposed multiple injection and multiple staging combustion (MIMSC) technology lies on three aspects: (1) along the furnace arch breadth, changing the previously centralized 12 burner groups into a more uniform pattern with 24 burners; (2) increasing the mass ratio of pulverized coal in fuel-rich flow to that in fuel-lean flow from 6:4 to 9:1; (3) reducing the arch-air momentum by 23% and increasing the tertiary-air momentum by 24%. Industrial-size measurements (i.e., adjusting overfire air (OFA) damper opening of 20-70%) uncovered that, compared with the prior MIMSC technology, the ignition distance of fuel-rich coal/air flow shortened by around 1 m. The gas temperature in the lower furnace was symmetric and higher, the flame kernel moved upward and therefore made the temperature in near-wall region of furnace hopper decrease by about 400 °C, the water wall overheating disappeared completely. Under the optimal OFA damper opening (i.e, 55%), NOx emissions and carbon in fly ash attained levels of 589 mg/m(3) at 6% O2 and 6.18%, respectively, achieving NOx and carbon in fly ash significant reduction by 33% and 37%, respectively.

Dual-water mixture fuel burner

DOEpatents

Brown, Thomas D.; Reehl, Douglas P.; Walbert, Gary F.

1986-08-05

A coal-water mixture (CWM) burner includes a conically shaped rotating cup into which fuel comprised of coal particles suspended in a slurry is introduced via a first, elongated inner tube coupled to a narrow first end portion of the cup. A second, elongated outer tube is coaxially positioned about the first tube and delivers steam to the narrow first end of the cup. The fuel delivery end of the inner first tube is provided with a helical slot on its lateral surface for directing the CWM onto the inner surface of the rotating cup in the form of a uniform, thin sheet which, under the influence of the cup's centrifugal force, flows toward a second, open, expanded end portion of the rotating cup positioned immediately adjacent to a combustion chamber. The steam delivered to the rotating cup wets its inner surface and inhibits the coal within the CWM from adhering to the rotating cup. A primary air source directs a high velocity air flow coaxially about the expanded discharge end of the rotating cup for applying a shear force to the CWM in atomizing the fuel mixture for improved combustion. A secondary air source directs secondary air into the combustion chamber adjacent to the outlet of the rotating cup at a desired pitch angle relative to the fuel mixture/steam flow to promote recirculation of hot combustion gases within the ignition zone for increased flame stability.

Measurements and Modeling of SiCl(4) Combustion in a Low-Pressure H2/O2 Flame

DTIC Science & Technology

2006-11-10

temperature and OH concentration profiles as a function of distance from a McKenna-style burner in premixed, one-dimensional, low-pressure H2/0 2/Ar SiCl4 ...profiles for hydrogen/oxygen flames with and without SiCl4 ....... . .. . .. . . . . . 15 111,o Tables 1. Silicon Tetrachloride Proposed Combustion...studied with and without SiCI4 precursor at concentrations of 0.5% of the H 2 + 02 flow. For the experiments doped with SiCl4 , the oxygen flow exiting the

Thermocouple error correction for measuring the flame temperature with determination of emissivity and heat transfer coefficient.

PubMed

Hindasageri, V; Vedula, R P; Prabhu, S V

2013-02-01

Temperature measurement by thermocouples is prone to errors due to conduction and radiation losses and therefore has to be corrected for precise measurement. The temperature dependent emissivity of the thermocouple wires is measured by the use of thermal infrared camera. The measured emissivities are found to be 20%-40% lower than the theoretical values predicted from theory of electromagnetism. A transient technique is employed for finding the heat transfer coefficients for the lead wire and the bead of the thermocouple. This method does not require the data of thermal properties and velocity of the burnt gases. The heat transfer coefficients obtained from the present method have an average deviation of 20% from the available heat transfer correlations in literature for non-reacting convective flow over cylinders and spheres. The parametric study of thermocouple error using the numerical code confirmed the existence of a minimum wire length beyond which the conduction loss is a constant minimal. Temperature of premixed methane-air flames stabilised on 16 mm diameter tube burner is measured by three B-type thermocouples of wire diameters: 0.15 mm, 0.30 mm, and 0.60 mm. The measurements are made at three distances from the burner tip (thermocouple tip to burner tip/burner diameter = 2, 4, and 6) at an equivalence ratio of 1 for the tube Reynolds number varying from 1000 to 2200. These measured flame temperatures are corrected by the present numerical procedure, the multi-element method, and the extrapolation method. The flame temperatures estimated by the two-element method and extrapolation method deviate from numerical results within 2.5% and 4%, respectively.

Thermocouple error correction for measuring the flame temperature with determination of emissivity and heat transfer coefficient

NASA Astrophysics Data System (ADS)

Hindasageri, V.; Vedula, R. P.; Prabhu, S. V.

2013-02-01

Temperature measurement by thermocouples is prone to errors due to conduction and radiation losses and therefore has to be corrected for precise measurement. The temperature dependent emissivity of the thermocouple wires is measured by the use of thermal infrared camera. The measured emissivities are found to be 20%-40% lower than the theoretical values predicted from theory of electromagnetism. A transient technique is employed for finding the heat transfer coefficients for the lead wire and the bead of the thermocouple. This method does not require the data of thermal properties and velocity of the burnt gases. The heat transfer coefficients obtained from the present method have an average deviation of 20% from the available heat transfer correlations in literature for non-reacting convective flow over cylinders and spheres. The parametric study of thermocouple error using the numerical code confirmed the existence of a minimum wire length beyond which the conduction loss is a constant minimal. Temperature of premixed methane-air flames stabilised on 16 mm diameter tube burner is measured by three B-type thermocouples of wire diameters: 0.15 mm, 0.30 mm, and 0.60 mm. The measurements are made at three distances from the burner tip (thermocouple tip to burner tip/burner diameter = 2, 4, and 6) at an equivalence ratio of 1 for the tube Reynolds number varying from 1000 to 2200. These measured flame temperatures are corrected by the present numerical procedure, the multi-element method, and the extrapolation method. The flame temperatures estimated by the two-element method and extrapolation method deviate from numerical results within 2.5% and 4%, respectively.

A GUIDE TO FUEL PERFORMANCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

LITZKE,W.

2004-08-01

Heating oil, as its name implies, is intended for end use heating consumption as its primary application. But its identity in reference name and actual chemical properties may vary based on a number of factors. By name, heating oil is sometimes referred to as gas oil, diesel, No. 2 distillate (middle distillate), or light heating oil. Kerosene, also used as a burner fuel, is a No. 1 distillate. Due to the higher heat content and competitive price in most markets, No. 2 heating oil is primarily used in modern, pressure-atomized burners. Using No. 1 oil for heating has the advantagesmore » of better cold-flow properties, lower emissions, and better storage properties. Because it is not nearly as abundant in supply, it is often markedly more expensive than No. 2 heating oil. Given the advanced, low-firing rate burners in use today, the objective is for the fuel to be compatible and achieve combustion performance at the highest achievable efficiency of the heating systems--with minimal service requirements. Among the Oil heat industry's top priorities are improving reliability and reducing service costs associated with fuel performance. Poor fuel quality, fuel degradation, and contamination can cause burner shut-downs resulting in ''no-heat'' calls. Many of these unscheduled service calls are preventable with routine inspection of the fuel and the tank. This manual focuses on No. 2 heating oil--its performance, properties, sampling and testing. Its purpose is to provide the marketer, service manager and technician with the proper guidelines for inspecting the product, maintaining good fuel quality, and the best practices for proper storage. Up-to-date information is also provided on commercially available fuel additives, their appropriate use and limitations.« less

Pollutant Emissions and Lean Blowoff Limits of Fuel Flexible Burners Operating on Gaseous Renewable and Fossil Fuels

NASA Astrophysics Data System (ADS)

Colorado, Andres

This study provides an experimental and numerical examination of pollutant emissions and stability of gaseous fueled reactions stabilized with two premixed-fuel-flexible and ultra-low NOx burner technologies. Both burners feature lean combustion technology to control the formation of nitrogen oxides (NOx). The first fuel--flexible burner is the low-swirl burner (LSB), which features aerodynamic stabilization of the reactions with a divergent flow-field; the second burner is the surface stabilized combustion burner (SSCB), which features the stabilization of the reactions on surface patterns. For combustion applications the most commonly studied species are: NOx, carbon monoxide (CO), and unburned hydrocarbons (UHC). However these are not the only pollutants emitted when burning fossil fuels; other species such as nitrous oxide (N2O), ammonia (NH3) and formaldehyde (CH2O) can be directly emitted from the oxidation reactions. Yet the conditions that favor the emission of these pollutants are not completely understood and require further insight. The results of this dissertation close the gap existing regarding the relations between emission of pollutants species and stability when burning variable gaseous fuels. The results of this study are applicable to current issues such as: 1. Current combustion systems operating at low temperatures to control formation of NOx. 2. Increased use of alternative fuels such as hydrogen, synthetic gas and biogas. 3. Increasing recognition of the need/desire to operate combustion systems in a transient manner to follow load and to offset the intermittency of renewable power. 4. The recent advances in measurement methods allow us to quantify other pollutants, such as N 2O, NH3 and CH2O. Hence in this study, these pollutant species are assessed when burning natural gas (NG) and its binary mixtures with other gaseous fuels such as hydrogen (H2), carbon dioxide (CO2), ethane (C 2H6) and propane (C3H8) at variable operation modes including: ignition; lean blowoff; and variable air to fuel ratio. Some remarkable results of this dissertation include: • At a fixed fire rate (117kW) the addition of hydrogen to NG raises the emission of NO x for the reactions stabilized with the LSB. Under the same conditions, the addition of H2 to NG will reduce the emission levels of the reactions stabilized with the SSCB. • It was found experimentally that nitrous oxide (N2O) is emitted during ignition and blowoff events. • Ammonia (NH3) is also emitted during ignition and blowoff events. • It was found experimentally that at high concentrations of hydrogen in NG (H2>70%), reactions aerodynamically stabilized with the LSB will emit significant amounts of N2O.

40 CFR 63.6092 - Are duct burners and waste heat recovery units covered by subpart YYYY?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Are duct burners and waste heat... Stationary Combustion Turbines What This Subpart Covers § 63.6092 Are duct burners and waste heat recovery units covered by subpart YYYY? No, duct burners and waste heat recovery units are considered steam...

40 CFR 63.6092 - Are duct burners and waste heat recovery units covered by subpart YYYY?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Are duct burners and waste heat... Stationary Combustion Turbines What This Subpart Covers § 63.6092 Are duct burners and waste heat recovery units covered by subpart YYYY? No, duct burners and waste heat recovery units are considered steam...

40 CFR 63.6092 - Are duct burners and waste heat recovery units covered by subpart YYYY?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Are duct burners and waste heat... Stationary Combustion Turbines What This Subpart Covers § 63.6092 Are duct burners and waste heat recovery units covered by subpart YYYY? No, duct burners and waste heat recovery units are considered steam...

16 CFR Figure 6 to Part 1633 - Burner Assembly Showing Arms and Pivots (Shoulder Screws), in Relation to, Portable Frame...

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Burner Assembly Showing Arms and Pivots (Shoulder Screws), in Relation to, Portable Frame Allowing Burner Height Adjustment 6 Figure 6 to Part 1633... and Pivots (Shoulder Screws), in Relation to, Portable Frame Allowing Burner Height Adjustment...

16 CFR Figure 6 to Part 1633 - Burner Assembly Showing Arms and Pivots (Shoulder Screws), in Relation to, Portable Frame...

Code of Federal Regulations, 2013 CFR

2013-01-01

... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Burner Assembly Showing Arms and Pivots (Shoulder Screws), in Relation to, Portable Frame Allowing Burner Height Adjustment 6 Figure 6 to Part 1633... and Pivots (Shoulder Screws), in Relation to, Portable Frame Allowing Burner Height Adjustment...

16 CFR Figure 6 to Part 1633 - Burner Assembly Showing Arms and Pivots (Shoulder Screws), in Relation to, Portable Frame...

Code of Federal Regulations, 2014 CFR

2014-01-01

... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Burner Assembly Showing Arms and Pivots (Shoulder Screws), in Relation to, Portable Frame Allowing Burner Height Adjustment 6 Figure 6 to Part 1633... and Pivots (Shoulder Screws), in Relation to, Portable Frame Allowing Burner Height Adjustment...

Southern Woods-Burners: A Descriptive Analysis

Treesearch

M.L. Doolittle; M.L. Lightsey

1979-01-01

About 40 percent of the South's nearly 60,000 wildfires yearly are set by woods-burners. A survey of 14 problem areas in four southern States found three distinct sets of woods-burners. Most active woods-burners are young, white males whose activities are supported by their peers. An older but less active group have probably retired from active participation but...

Method and apparatus for operating a self-starting air heating system

DOEpatents

Heinrich, Charles E.

1983-12-06

A self-starting, fuel fired, air heating system including a fuel burner fired vapor generator, a turbine, and a condenser connected in a closed circuit such that the vapor output from the vapor generator is conducted to the turbine and then to the condenser where it is condensed for return to the vapor generator. The turbine drives an air blower which passes air over the condenser for cooling the condenser and heating the air. Also, a condensate pump is driven by the turbine. The disclosure is particularly concerned with a method and apparatus which on start-up prevents the vapor generator's vapor output from being conducted to the turbine until a predetermined pressure differential has been achieved. However, after the vapor flow is once permitted, it cannot again be prevented until after the fuel burner has been shut off and restarted.

Deposition of Na2SO4 from salt-seeded combustion gases of a high velocity burner rig

NASA Astrophysics Data System (ADS)

Santoro, G. J.; Gokoglu, S. A.; Kohl, F. J.; Stearns, C. A.; Rosner, D. E.

The mechanism of deposition of Na2SO4 was studied under controlled laboratory conditions and the results have been compared to a recently developed comprehensive theory of vapor deposition. Thus Na2SO4, NaCl, NaNO3 and simulated sea salt solutions were injected into the combustor of a nominal Mach 0.3 burner rig burning jet fuel at constant fuel/air ratios. The deposits formed on inert collectors, rotation in the cross flow of the combustion gases, were weighed and analyzed. Collector temperature was uniform and could be varied over a large range by internal air cooling. Deposition rates and dew point temperatures were determined. Supplemental testing included droplet size measurements of the atomized salt solutions. These tests along with thermodynamic and transport calculations were utilized in the interpretation of the deposition results.

Influence of firebed temperature on inorganic particle emissions in a residential wood pellet boiler

NASA Astrophysics Data System (ADS)

Gehrig, Matthias; Jaeger, Dirk; Pelz, Stefan K.; Weissinger, Alexander; Groll, Andreas; Thorwarth, Harald; Haslinger, Walter

2016-07-01

The temperature-dependent release of inorganic elements is the first step of the main formation pathway of particle emissions in automatically fired biomass burners. To investigate this step, a residential pellet boiler with an underfeed-burner was equipped with a direct firebed cooling. This test setup enabled decreased firebed temperatures without affecting further parameters like air flow rates or oxygen content in the firebed. A reduction of particle emissions in PM1-fraction at activated firebed cooling was found by impactor measurement and by optical particle counter. The affected particles were found in the size range <0.3 μm and have been composed mainly of potassium chloride (KCl). The chemical analysis of PM1 and boiler ash showed no statistically significant differences due to the firebed cooling. Therefore, our results indicate that the direct firebed cooling influenced the release of potassium (K) without affecting other chemical reactions.

Deposition of Na2SO4 from salt-seeded combustion gases of a high velocity burner rig

NASA Technical Reports Server (NTRS)

Santoro, G. J.; Gokoglu, S. A.; Kohl, F. J.; Stearns, C. A.; Rosner, D. E.

1984-01-01

The mechanism of deposition of Na2SO4 was studied under controlled laboratory conditions and the results have been compared to a recently developed comprehensive theory of vapor deposition. Thus Na2SO4, NaCl, NaNO3 and simulated sea salt solutions were injected into the combustor of a nominal Mach 0.3 burner rig burning jet fuel at constant fuel/air ratios. The deposits formed on inert collectors, rotation in the cross flow of the combustion gases, were weighed and analyzed. Collector temperature was uniform and could be varied over a large range by internal air cooling. Deposition rates and dew point temperatures were determined. Supplemental testing included droplet size measurements of the atomized salt solutions. These tests along with thermodynamic and transport calculations were utilized in the interpretation of the deposition results.

Validation of structural analysis methods using the in-house liner cyclic rigs

NASA Technical Reports Server (NTRS)

Thompson, R. L.

1982-01-01

Test conditions and variables to be considered in each of the test rigs and test configurations, and also used in the validation of the structural predictive theories and tools, include: thermal and mechanical load histories (simulating an engine mission cycle; different boundary conditions; specimens and components of different dimensions and geometries; different materials; various cooling schemes and cooling hole configurations; several advanced burner liner structural design concepts; and the simulation of hot streaks. Based on these test conditions and test variables, the test matrices for each rig and configurations can be established to verify the predictive tools over as wide a range of test conditions as possible using the simplest possible tests. A flow chart for the thermal/structural analysis of a burner liner and how the analysis relates to the tests is shown schematically. The chart shows that several nonlinear constitutive theories are to be evaluated.

40 CFR 63.6092 - Are duct burners and waste heat recovery units covered by subpart YYYY?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 12 2011-07-01 2009-07-01 true Are duct burners and waste heat... Combustion Turbines What This Subpart Covers § 63.6092 Are duct burners and waste heat recovery units covered by subpart YYYY? No, duct burners and waste heat recovery units are considered steam generating units...

40 CFR 63.6092 - Are duct burners and waste heat recovery units covered by subpart YYYY?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Are duct burners and waste heat... Combustion Turbines What This Subpart Covers § 63.6092 Are duct burners and waste heat recovery units covered by subpart YYYY? No, duct burners and waste heat recovery units are considered steam generating units...

Shaft kilns for firing of refractory raw material on a model of operation of a firing system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Utenkov, A.F.; Strekalova, L.V.

1986-09-01

This paper attempts to develop a design of gas burner for providing uniform high-temperature firing of refractory material in shaft kilns. On the model the influence of the following factors on the processes of mass exchange and the character of the gasdynamics was studied: the ratio of the diamters of the gas and air orifices of tube-in-tube type burners and their absolute values with a constant gas consumption; the depth of the gas orifice in relation to the tip of the burner; the form of the initial profile of the velocity of the gasair jet at the outlet from themore » burner; the angle of slope of the burners to the shaft housing; the ratio of the consumption of gas supplied under the shaft and to the gas burners; and the static pressure in the working space at the level of the gas burners.« less

Burner (Stinger)

MedlinePlus

... and a loss of sensation. Who Gets Burners? Football players are most at risk for burners. But ... any athletic activity. Use protective gear (like a football neck collar or specially designed shoulder pads). Use ...

Investigations on the self-excited oscillations in a kerosene spray flame

DOE Office of Scientific and Technical Information (OSTI.GOV)

de la Cruz Garcia, M.; Mastorakos, E.; Dowling, A.P.

2009-02-15

A laboratory scale gas turbine type burner at atmospheric pressure and with air preheat was operated with aviation kerosene Jet-A1 injected from a pressure atomiser. Self-excited oscillations were observed and analysed to understand better the relationship between the spray and thermo-acoustic oscillations. The fluctuations of CH{sup *} chemiluminescence measured simultaneously with the pressure were used to determine the flame transfer function. The Mie scattering technique was used to record spray fluctuations in reacting conditions with a high speed camera. Integrating the Mie intensity over the imaged region gave a temporal signal acquired simultaneously with pressure fluctuations and the transfer functionmore » between the light scattered from the spray and the velocity fluctuations in the plenum was evaluated. Phase Doppler anemometry was used for axial velocity and drop size measurements at different positions downstream the injection plane and for various operating conditions. Pressure spectra showed peaks at a frequency that changed with air mass flow rate. The peak for low air mass flow rate operation was at 220 Hz and was associated with a resonance of the supply plenum. At the same global equivalence ratio but at high air mass flow rates, the pressure spectrum peak was at 323 Hz, a combustion chamber resonant frequency. At low air flow rates, the spray fluctuation motion was pronounced and followed the frequency of the pressure oscillation. At high air flow rates, more effective evaporation resulted in a complete disappearance of droplets at an axial distance of about 1/3 burner diameters from the injection plane, leading to a different flame transfer function and frequency of the self-excited oscillation. The results highlight the sensitivity of the self-excited oscillation to the degree of mixing achieved before the main recirculation zone. (author)« less

Fracture analysis of tube boiler for physical explosion accident.

PubMed

Kim, Eui Soo

2017-09-01

Material and failure analysis techniques are key tools for determining causation in case of explosive and bursting accident result from material and process defect of product in the field of forensic science. The boiler rupture generated by defect of the welding division, corrosion, overheating and degradation of the material have devastating power. If weak division of boiler burner is fractured by internal pressure, saturated vapor and water is vaporized suddenly. At that time, volume of the saturated vapor and water increases up to thousands of volume. This failure of boiler burner can lead to a fatal disaster. In order to prevent an explosion and of the boiler, it is critical to introduce a systematic investigation and prevention measures in advance. In this research, the cause of boiler failure is investigated through forensic engineering method. Specifically, the failure mechanism will be identified by fractography using scanning electron microscopes (SEM) and Optical Microscopes (OM) and mechanical characterizations. This paper presents a failure analysis of household welding joints for the water tank of a household boiler burner. Visual inspection was performed to find out the characteristics of the fracture of the as-received material. Also, the micro-structural changes such as grain growth and carbide coarsening were examined by optical microscope. Detailed studies of fracture surfaces were made to find out the crack propagation on the weld joint of a boiler burner. It was concluded that the rupture may be caused by overheating induced by insufficient water on the boiler, and it could be accelerated by the metal temperature increase. Copyright © 2017 Elsevier B.V. All rights reserved.

16 CFR Figure 6 to Part 1633 - Burner Assembly Showing Arms and Pivots (Shoulder Screws) in Relation to Portable Frame Allowing...

Code of Federal Regulations, 2011 CFR

2011-01-01

... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Burner Assembly Showing Arms and Pivots (Shoulder Screws) in Relation to Portable Frame Allowing Burner Height Adjustment 6 Figure 6 to Part 1633... and Pivots (Shoulder Screws) in Relation to Portable Frame Allowing Burner Height Adjustment ER15MR06...

16 CFR Figure 6 to Part 1633 - Burner Assembly Showing Arms and Pivots (Shoulder Screws) in Relation to, Portable Frame Allowing...

Code of Federal Regulations, 2012 CFR

2012-01-01

... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Burner Assembly Showing Arms and Pivots (Shoulder Screws) in Relation to, Portable Frame Allowing Burner Height Adjustment 6 Figure 6 to Part 1633... and Pivots (Shoulder Screws) in Relation to, Portable Frame Allowing Burner Height Adjustment ER15MR06...

Rotational and vibrational Raman spectroscopy for thermochemistry measurements in supersonic flames

NASA Astrophysics Data System (ADS)

Bayeh, Alexander Christian

High speed chemically reacting flows are important in a variety of aerospace applications, namely ramjets, scramjets, afterburners, and rocket exhausts. To study flame extinction under similar high Mach number conditions, we need access to thermochemistry measurements in supersonic environments. In the current work a two-stage miniaturized combustor has been designed that can produce open supersonic methane-air flames amenable to laser diagnostics. The first stage is a vitiation burner, and was inspired by well-known principles of jet combustors. We explored the salient parameters of operation experimentally, and verified flame holding computationally using a well-stirred reactor model. The second stage of the burner generates an external supersonic flame, operating in premixed and partially premixed modes. The very high Mach numbers present in the supersonic flames should provide a useful test bed for the examination of flame suppression and extinction using laser diagnostics. We also present the development of new line imaging diagnostics for thermochemistry measurements in high speed flows. A novel combination of vibrational and rotational Raman scattering is used to measure major species densities (O 2, N2, CH4, H2O,CO2, CO, & H2) and temperature. Temperature is determined by the rotational Raman technique by comparing measured rotational spectra to simulated spectra based on the measured chemical composition. Pressure is calculated from density and temperature measurements through the ideal gas law. The independent assessment of density and temperature allows for measurements in environments where the pressure is not known a priori. In the present study we applied the diagnostics to laboratory scale supersonic air and vitiation jets, and examine the feasibility of such measurements in reacting supersonic flames. Results of full thermochemistry were obtained for the air and vitiation jets that reveal the expected structure of an under-expanded jet. Centerline traces of density, temperature, and pressure of the air jet agree well with computations, while measurements of chemical composition for the vitiation flow also agree well with predicted equilibrium values. Finally, we apply the new diagnostics to the exhaust of the developed burner, and show the first ever results for density, temperature, and pressure, as well as chemical composition in a supersonic flame.

Electrical Aspects of Impinging Flames

NASA Astrophysics Data System (ADS)

Chien, Yu-Chien

This dissertation examines the use of electric fields as one mechanism for controlling combustion as flames are partially extinguished when impinging on nearby surfaces. Electrical aspects of flames, specifically, the production of chemi-ions in hydrocarbon flames and the use of convective flows driven by these ions, have been investigated in a wide range of applications in prior work but despite this fairly comprehensive effort to study electrical aspects of combustion, relatively little research has focused on electrical phenomena near flame extinguishment, nor for flames near impingement surfaces. Electrical impinging flames have complex properties under global influences of ion-driven winds and flow field disturbances from the impingement surface. Challenges of measurements when an electric field is applied in the system have limited an understanding of changes to the flame behavior and species concentrations caused by the field. This research initially characterizes the ability of high voltage power supplies to respond on sufficiently short time scales to permit real time electrical flame actuation. The study then characterizes the influence of an electric field on the impinging flame shape, ion current and flow field of the thermal plume associated with the flame. The more significant further examinations can be separated into two parts: 1) the potential for using electric fields to control the release of carbon monoxide (CO) from surface-impinging flames, and 2) an investigation of controlling electrically the heat transfer to a plate on which the flame impinges. Carbon monoxide (CO) results from the incomplete oxidation of hydrocarbon fuels and, while CO can be desirable in some syngas processes, it is usually a dangerous emission from forest fires, gas heaters, gas stoves, or furnaces where insufficient oxygen in the core reaction does not fully oxidize the fuel to carbon dioxide and water. Determining how carbon monoxide is released and how heat transfer from the flame to the plate can be controlled using the electric field are the two main goals of this research. Multiple diagnostic techniques are employed such as OH chemiluminescence to identify the reaction zone, OH PLIF to characterize the location of this radical species, CO released from the flame, IR imaging and OH PLIF thermometry to understand the surface and gas temperature distribution, respectively. The principal finding is that carbon monoxide release from an impinging diffusion flame results from the escape of carbon monoxide created on the fuel side of the flame along the boundary layer near the surface where it avoids oxidation by OH, which sits to the air side of the reaction sheet interface. In addition, the plate proximity to the flame has a stronger influence on the emission of toxic carbon monoxide than does the electric field strength. There is, however, a narrow region of burner to surface distance where the electric field is most effective. The results also show that heat transfer can be spatially concentrated effectively using an electric field driven ion wind, particularly at some burner to surface distances.

A high turndown, ultra low emission low swirl burner for natural gas, on-demand water heaters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rapp, Vi H.; Cheng, Robert K.; Therkelsen, Peter L.

Previous research has shown that on-demand water heaters are, on average, approximately 37% more efficient than storage water heaters. However, approximately 98% of water heaters in the U.S. use storage water heaters while the remaining 2% are on-demand. A major market barrier to deployment of on-demand water heaters is their high retail cost, which is due in part to their reliance on multi-stage burner banks that require complex electronic controls. This project aims to research and develop a cost-effective, efficient, ultra-low emission burner for next generation natural gas on-demand water heaters in residential and commercial buildings. To meet these requirements,more » researchers at the Lawrence Berkeley National Laboratory (LBNL) are adapting and testing the low-swirl burner (LSB) technology for commercially available on-demand water heaters. In this report, a low-swirl burner is researched, developed, and evaluated to meet targeted on-demand water heater performance metrics. Performance metrics for a new LSB design are identified by characterizing performance of current on-demand water heaters using published literature and technical specifications, and through experimental evaluations that measure fuel consumption and emissions output over a range of operating conditions. Next, target metrics and design criteria for the LSB are used to create six 3D printed prototypes for preliminary investigations. Prototype designs that proved the most promising were fabricated out of metal and tested further to evaluate the LSB’s full performance potential. After conducting a full performance evaluation on two designs, we found that one LSB design is capable of meeting or exceeding almost all the target performance metrics for on-demand water heaters. Specifically, this LSB demonstrated flame stability when operating from 4.07 kBTU/hr up to 204 kBTU/hr (50:1 turndown), compliance with SCAQMD Rule 1146.2 (14 ng/J or 20 ppm NOX @ 3% O2), and lower CO emissions than state-of-the art water heaters. Overall, the results from this research show that the LSB could provide a simple, low cost burner solution for significantly extending operating range of on-demand water heaters while providing low NOX and CO emissions.« less

A small porous-plug burner for studies of combustion chemistry and soot formation

NASA Astrophysics Data System (ADS)

Campbell, M. F.; Schrader, P. E.; Catalano, A. L.; Johansson, K. O.; Bohlin, G. A.; Richards-Henderson, N. K.; Kliewer, C. J.; Michelsen, H. A.

2017-12-01

We have developed and built a small porous-plug burner based on the original McKenna burner design. The new burner generates a laminar premixed flat flame for use in studies of combustion chemistry and soot formation. The size is particularly relevant for space-constrained, synchrotron-based X-ray diagnostics. In this paper, we present details of the design, construction, operation, and supporting infrastructure for this burner, including engineering attributes that enable its small size. We also present data for charactering the flames produced by this burner. These data include temperature profiles for three premixed sooting ethylene/air flames (equivalence ratios of 1.5, 1.8, and 2.1); temperatures were recorded using direct one-dimensional coherent Raman imaging. We include calculated temperature profiles, and, for one of these ethylene/air flames, we show the carbon and hydrogen content of heavy hydrocarbon species measured using an aerosol mass spectrometer coupled with vacuum ultraviolet photoionization (VUV-AMS) and soot-volume-fraction measurements obtained using laser-induced incandescence. In addition, we provide calculated mole-fraction profiles of selected gas-phase species and characteristic profiles for seven mass peaks from AMS measurements. Using these experimental and calculated results, we discuss the differences between standard McKenna burners and the new miniature porous-plug burner introduced here.

A small porous-plug burner for studies of combustion chemistry and soot formation.

PubMed

Campbell, M F; Schrader, P E; Catalano, A L; Johansson, K O; Bohlin, G A; Richards-Henderson, N K; Kliewer, C J; Michelsen, H A

2017-12-01

We have developed and built a small porous-plug burner based on the original McKenna burner design. The new burner generates a laminar premixed flat flame for use in studies of combustion chemistry and soot formation. The size is particularly relevant for space-constrained, synchrotron-based X-ray diagnostics. In this paper, we present details of the design, construction, operation, and supporting infrastructure for this burner, including engineering attributes that enable its small size. We also present data for charactering the flames produced by this burner. These data include temperature profiles for three premixed sooting ethylene/air flames (equivalence ratios of 1.5, 1.8, and 2.1); temperatures were recorded using direct one-dimensional coherent Raman imaging. We include calculated temperature profiles, and, for one of these ethylene/air flames, we show the carbon and hydrogen content of heavy hydrocarbon species measured using an aerosol mass spectrometer coupled with vacuum ultraviolet photoionization (VUV-AMS) and soot-volume-fraction measurements obtained using laser-induced incandescence. In addition, we provide calculated mole-fraction profiles of selected gas-phase species and characteristic profiles for seven mass peaks from AMS measurements. Using these experimental and calculated results, we discuss the differences between standard McKenna burners and the new miniature porous-plug burner introduced here.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lunden, Melissa M.; Delp, William W.

Effective exhaust hoods can mitigate the indoor air quality impacts of pollutant emissions from residential cooking. This study reports capture efficiencies (CE) measured for cooking generated particles for scripted cooking procedures in a 121-m3 chamber with kitchenette. CEs also were measured for burner produced CO2 during cooking and separately for pots and pans containing water. The study used four exhaust hoods previously tested by Delp and Singer (Environ. Sci. Technol., 2012, 46, 6167-6173). For pan-frying a hamburger over medium heat on the back burner, CEs for particles were similar to those for burner produced CO2 and mostly above 80percent. Formore » stir-frying green beans in a wok (high heat, front burner), CEs for burner CO2 during cooking varied by hood and airflow: CEs were 34-38percent for low (51?68 L s-1) and 54?72percent for high (109?138 L s-1) settings. CEs for 0.3?2.0 ?m particles during front burner stir-frying were 3?11percent on low and 16?70percent on high settings. Results indicate that CEs measured for burner CO2 are not predictive of CEs of cooking-generated particles under all conditions, but they may be suitable to identify devices with CEs above 80percent both for burner combustion products and for cooking-related particles.« less

Micronized coal burner facility

NASA Technical Reports Server (NTRS)

Calfo, F. D.; Lupton, M. W. (Inventor)

1984-01-01

A combustor or burner system in which the ash resulting from burning a coal in oil mixture is of submicron particle size is described. The burner system comprises a burner section, a flame exit nozzle, a fuel nozzle section, and an air tube by which preheated air is directed into the burner section. Regulated air pressure is delivered to a fuel nozzle. Means are provided for directing a mixture of coal particles and oil from a drum to a nozzle at a desired rate and pressure while means returns excess fuel to the fuel drum. Means provide for stable fuel pressure supply from the fuel pump to the fuel nozzle.

Characterization and durability testing of plasma-sprayed zirconia-yttria and hafnia-yttria thermal barrier coatings. Part 2: Effect of spray parameters on the performance of several hafnia-yttria and zirconia-yttria coatings

NASA Technical Reports Server (NTRS)

Miller, Robert A.; Leissler, George W.

1993-01-01

This is the second of two reports which discuss initial experiments on thermal barrier coatings prepared and tested in newly upgraded plasma spray and burner rig test facilities at LeRC. The first report, part 1, describes experiments designed to establish the spray parameters for the baseline zirconia-yttria coating. Coating quality was judged primarily by the response to burner rig exposure, together with a variety of other characterization approaches including thermal diffusivity measurements. That portion of the study showed that the performance of the baseline NASA coating was not strongly sensitive to processing parameters. In this second part of the study, new hafnia-yttria coatings were evaluated with respect to both baseline and alternate zirconia-yttria coatings. The hafnia-yttria and the alternate zirconia-yttria coatings were very sensitive to plasma-spray parameters in that high-quality coatings were obtained only when specific parameters were used. The reasons for this important observation are not understood.

Numerical study of flow, combustion and emissions characteristics in a 625 MWe tangentially fired boiler with composition of coal 70% LRC and 30% MRC

NASA Astrophysics Data System (ADS)

Sa'adiyah, Devy; Bangga, Galih; Widodo, Wawan; Ikhwan, Nur

2017-08-01

Tangential fired boiler is one of the methods that can produce more complete combustion. This method applied in Suralaya Power Plant, Indonesia. However, the boiler where supposed to use low rank coal (LRC), but at a given time must be mixed with medium rank coal (MRC) from another unit because of lack of LRC coal. Accordingly to the situation, the study about choosing the right position of LRC and MRC in the burner elevation must be investigated. The composition of coal is 70%LRC / 30%MRC where MRC will be placed at the lower (A & C - Case I)) or higher (E & G - Case II) elevation as the cases in this study. The study is carried out using Computational Fluid Dynamics (CFD) method. The simulation with original case (100%LRC) has a good agreement with the measurement data. As the results, MRC is more recommended at the burner elevation A & C rather than burner elevation E & G because it has closer temperature (880 K) compared with 100%LRC and has smaller local heating area between upper side wall and front wall with the range of temperature 1900 - 2000 K. For emissions, case I has smaller NOx and higher CO2 with 104 ppm and 15,6%. Moreover, it has samller O2 residue with 5,8% due to more complete combustion.

Dish/stirling hybrid-receiver

DOEpatents

Mehos, Mark S.; Anselmo, Kenneth M.; Moreno, James B.; Andraka, Charles E.; Rawlinson, K. Scott; Corey, John; Bohn, Mark S.

2002-01-01

A hybrid high-temperature solar receiver is provided which comprises a solar heat-pipe-receiver including a front dome having a solar absorber surface for receiving concentrated solar energy, a heat pipe wick, a rear dome, a sidewall joining the front and the rear dome, and a vapor and a return liquid tube connecting to an engine, and a fossil fuel fired combustion system in radial integration with the sidewall for simultaneous operation with the solar heat pipe receiver, the combustion system comprising an air and fuel pre-mixer, an outer cooling jacket for tangentially introducing and cooling the mixture, a recuperator for preheating the mixture, a burner plenum having an inner and an outer wall, a porous cylindrical metal matrix burner firing radially inward facing a sodium vapor sink, the mixture ignited downstream of the matrix forming combustion products, an exhaust plenum, a fossil-fuel heat-input surface having an outer surface covered with a pin-fin array, the combustion products flowing through the array to give up additional heat to the receiver, and an inner surface covered with an extension of the heat-pipe wick, a pin-fin shroud sealed to the burner and exhaust plenums, an end seal, a flue-gas diversion tube and a flue-gas valve for use at off-design conditions to limit the temperature of the pre-heated air and fuel mixture, preventing pre-ignition.

Analytical screening of low emissions, high performance duct burners for supersonic cruise aircraft engines

NASA Technical Reports Server (NTRS)

Lohmann, R. A.; Riecke, G. T.

1977-01-01

An analytical screening study was conducted to identify duct burner concepts capable of providing low emissions and high performance in advanced supersonic engines. Duct burner configurations ranging from current augmenter technology to advanced concepts such as premix-prevaporized burners were defined. Aerothermal and mechanical design studies provided the basis for screening these configurations using the criteria of emissions, performance, engine compatibility, cost, weight and relative risk. Technology levels derived from recently defined experimental low emissions main burners are required to achieve both low emissions and high performance goals. A configuration based on the Vorbix (Vortex burning and mixing) combustor concept was analytically determined to meet the performance goals and is consistent with the fan duct envelope of a variable cycle engine. The duct burner configuration has a moderate risk level compatible with the schedule of anticipated experimental programs.

Cold start characteristics of ethanol as an automobile fuel

DOEpatents

Greiner, Leonard

1982-01-01

An alcohol fuel burner and decomposer in which one stream of fuel is preheated by passing it through an electrically heated conduit to vaporize the fuel, the fuel vapor is mixed with air, the air-fuel mixture is ignited and combusted, and the combustion gases are passed in heat exchange relationship with a conduit carrying a stream of fuel to decompose the fuel forming a fuel stream containing hydrogen gas for starting internal combustion engines, the mass flow of the combustion gas being increased as it flows in heat exchange relationship with the fuel carrying conduit, is disclosed.

Internal Flow and Burning Characteristics of 16-inch Ram Jet Operating in a Free Jet at Mach Numbers of 1.35 and 1.73

NASA Technical Reports Server (NTRS)

Perchonok, Eugene; Farley, John M

1951-01-01

The effects of mass-flow ratio on the additive drag and normal-shock position of a single oblique-shock diffuser are presented. Also evaluated is the variation with operating condition of the velocity distribution at the combustion-chamber inlet. A comparison with connected-pipe data is included. Burner performance with a corrugated gutter-grid flame holder is discussed. It is shown that the total-pressure drop across the combustion chamber can be predicted with reasonable accuracy from the computed flame holder and combustion momentum pressure losses.

The influence of combustion liner holes on noise production by ducted burners

NASA Technical Reports Server (NTRS)

Mahan, J. R.; Jones, J. D.

1984-01-01

The thermoacoustic energy conversion process in a turbulent flame is not yet sufficiently well understood to allow accurate prediction of the sound pressure field of even the simplest of laboratory burners. The present contribution is intended to be a step toward fuller understanding of this process. In particular, the possibility is explored that the source structure, in the form of the thermoacoustic efficiency spectrum, might be influenced by the acoustic response of the burner itself. Experimental results are presented which seem to establish that, at least for the gas-fueled laboratory burner studied, source activity is not affected by the addition of downstream combustion liner holes which otherwise alter the acoustic response of the burner.

Pulverized coal burner

DOEpatents

Sivy, J.L.; Rodgers, L.W.; Koslosy, J.V.; LaRue, A.D.; Kaufman, K.C.; Sarv, H.

1998-11-03

A burner is described having lower emissions and lower unburned fuel losses by implementing a transition zone in a low NO{sub x} burner. The improved burner includes a pulverized fuel transport nozzle surrounded by the transition zone which shields the central oxygen-lean fuel devolatilization zone from the swirling secondary combustion air. The transition zone acts as a buffer between the primary and the secondary air streams to improve the control of near-burner mixing and flame stability by providing limited recirculation regions between primary and secondary air streams. These limited recirculation regions transport evolved NO{sub x} back towards the oxygen-lean fuel pyrolysis zone for reduction to molecular nitrogen. Alternate embodiments include natural gas and fuel oil firing. 8 figs.

Pulverized coal burner

DOEpatents

Sivy, Jennifer L.; Rodgers, Larry W.; Koslosy, John V.; LaRue, Albert D.; Kaufman, Keith C.; Sarv, Hamid

1998-01-01

A burner having lower emissions and lower unburned fuel losses by implementing a transition zone in a low NO.sub.x burner. The improved burner includes a pulverized fuel transport nozzle surrounded by the transition zone which shields the central oxygen-lean fuel devolatilization zone from the swirling secondary combustion air. The transition zone acts as a buffer between the primary and the secondary air streams to improve the control of near-burner mixing and flame stability by providing limited recirculation regions between primary and secondary air streams. These limited recirculation regions transport evolved NO.sub.x back towards the oxygen-lean fuel pyrolysis zone for reduction to molecular nitrogen. Alternate embodiments include natural gas and fuel oil firing.

10 CFR 431.76 - Uniform test method for the measurement of energy efficiency of commercial warm air furnaces.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Arrangements), 2.3 (Test Ducts and Plenums), 2.4 (Test Gases), 2.5 (Test Pressures and Burner Adjustments), 2.6 (Static Pressure and Air Flow Adjustments), 2.39 (Thermal Efficiency) (note, this is 2.38 in ANSI Z21.47... test must be conducted only at the normal inlet test pressure, as specified in section 2.5.1 of ANSI...

10 CFR 431.76 - Uniform test method for the measurement of energy efficiency of commercial warm air furnaces.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Arrangements), 2.3 (Test Ducts and Plenums), 2.4 (Test Gases), 2.5 (Test Pressures and Burner Adjustments), 2.6 (Static Pressure and Air Flow Adjustments), 2.39 (Thermal Efficiency) (note, this is 2.38 in ANSI Z21.47... test must be conducted only at the normal inlet test pressure, as specified in section 2.5.1 of ANSI...

X-ray Fluorescence Measurements of Turbulent Methane-Oxygen Shear Coaxial Flames

DTIC Science & Technology

2015-05-01

The shear coaxial jet injector is a typical injector design in liquid rocket engines, used as the main chamber element for Space Shuttle Main...current study. (b) Representation of the injector tip of the shear coaxial burner with propellant streams and dimensions labeled. (c) Picture of flame...integrated with the Air Force Research Laboratories’ (AFRL) Mobile Flow Laboratory (MFL). This facility is designed to allow aerospace-propulsion injector

The Effects of Gravity on Wrinkled Laminar Flames

NASA Technical Reports Server (NTRS)

Kostiuk, Larry W.; Zhou, Liming; Cheng, Robert K.

1993-01-01

The effects of gravity are significant to the dynamics of idealized unconfined open premixed flames. Moderate to low turbulence Reynolds number flames, i.e., wrinkled laminar flames, of various unconfined geometries have been used extensively for investigating fundamental processes of turbulent flame propagation and to validate theoretical models. Without the wall constraints, the flames are free to expand and interact with surrounding ambient air. The flow field in which the flame exists is determined by a coupling of burner geometry, flame orientation and the gravity field. These complex interactions raise serious questions regarding the validity of comparing the experimental data of open flames with current theoretical and numerical models that do not include the effects of gravity nor effects of the larger aerodynamic flowfield. Therefore, studies of wrinkled laminar flame in microgravity are needed for a better understanding of the role of gravity on flame characteristics such as the orientation, mean aerodynamics stretch, flame wrinkle size and burning rate. Our approach to characterize and quantify turbulent flame structures under microgravity is to exploit qualitative and quantitative flow visualization techniques coupled with video recording and computer controlled image analysis technologies. The experiments will be carried out in the 2.2 second drop tower at the NASA Lewis Research Center. The longest time scales of typical wrinkled laminar flames in the geometries considered here are in the order of 10 msec. Hence, the duration of the drop is sufficient to obtain the amount of statistical data necessary for characterize turbulent flame structures.

Gas fired boilers: Perspective for near future fuel composition and impact on burner design process

NASA Astrophysics Data System (ADS)

Schiro, Fabio; Stoppato, Anna; Benato, Alberto

2017-11-01

The advancements on gas boiler technology run in parallel with the growth of renewable energy production. The renewable production will impact on the fuel gas quality, since the gas grid will face an increasing injection of alternative fuels (biogas, biomethane, hydrogen). Biogas allows producing energy with a lower CO2 impact; hydrogen production by electrolysis can mitigate the issues related to the mismatch between energy production by renewable and energy request. These technologies will contribute to achieve the renewable production targets, but the impact on whole fuel gas production-to-consumption chain must be evaluated. In the first part of this study, the Authors present the future scenario of the grid gas composition and the implications on gas fed appliances. Given that the widely used premixed burners are currently designed mainly by trial and error, a broader fuel gas quality range means an additional hitch on this design process. A better understanding and structuring of this process is helpful for future appliance-oriented developments. The Authors present an experimental activity on a premixed condensing boiler setup. A test protocol highlighting the burners' flexibility in terms of mixture composition is adopted and the system fuel flexibility is characterized around multiple reference conditions.

Device to lower NOx in a gas turbine engine combustion system

DOEpatents

Laster, Walter R; Schilp, Reinhard; Wiebe, David J

2015-02-24

An emissions control system for a gas turbine engine including a flow-directing structure (24) that delivers combustion gases (22) from a burner (32) to a turbine. The emissions control system includes: a conduit (48) configured to establish fluid communication between compressed air (22) and the combustion gases within the flow-directing structure (24). The compressed air (22) is disposed at a location upstream of a combustor head-end and exhibits an intermediate static pressure less than a static pressure of the combustion gases within the combustor (14). During operation of the gas turbine engine a pressure difference between the intermediate static pressure and a static pressure of the combustion gases within the flow-directing structure (24) is effective to generate a fluid flow through the conduit (48).

Burners

MedlinePlus

... bruise the nerves. If you play a contact sport, you can get a burner when you tackle, block, or run into another player. There are 3 ways a burner injury can happen: Your shoulder is pushed down at the same time that your head is forced to the opposite ...

Syngas formation in methane flames and carbon monoxide release during quenching

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weinberg, Felix; Carleton, Fred; Houdmont, Raphael

Following a recent investigation into chemi-ionization and chemiluminescence during gradual aeration of small, laminar methane flames, we proposed that partial oxidation products, or syngas constituents, formed in the pre-flame zone well below the luminous region, were responsible for the observed effects. We therefore map temperature, CO, and H{sub 2} for geometries and conditions relevant to burners in domestic boiler systems, to assess the potential hazard of CO release into the ambient atmosphere, should any partial quenching occur. CO concentrations peaks of 5.5 volume % are recorded in the core surrounding the axis. Appreciable CO concentrations are also found in themore » absence of added air. Experiments on various burner port geometries and temperatures suggest that this is not due to air entrainment at the flame base but to diffusion from zones closer to the flame. Next, quenching surfaces such as grids, perforated plates and flame trap matrices of different metals are progressively lowered into the flame. To avoid flow line distortion, suction aspirates the quenched products. The highest emission rate occurs with the quenching plane some 4 mm above the burner; further lowering of the quenching surface causes flame extinction. The maximum CO release is close to converting 10% of the CH{sub 4} feed, with some variation with quenching material. Expressing this potential release in terms of, e.g. boiler power, predicts a potentially serious hazard. Results of numerical simulations adequately parallel the experimental sampling profiles and provide insights into local concentrations, as well as the spatially resolved CO flux, which is calculated for a parabolic inlet flow profile. Integration across the stream implies, on the basis of the simulation, a possible tripling of the experimental CO release, were quenching simply to release the local gas composition into the atmosphere. Comparison with experiment suggests some chemical interaction with the quenching surface. (author)« less

Pollutant Concentrations and Emission Rates from Scripted Natural Gas Cooking Burner Use in Nine Northern California Homes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singer, Brett C.; Delp, William W.; Lorenzetti, David M.

METHODS: Combustion pollutant concentrations were measured during the scripted operation of natural gas cooking burners in nine homes. In addition to a base condition of closed windows, no forced air unit (FAU) use, and no mechanical exhaust, additional experiments were conducted while operating an FAU and/or vented range hood. Test homes included a 26m2 two-room apartment, a 134m2 first floor flat, and seven detached homes of 117–226m2. There were four single-story, four two-story and one 1.5 story homes. Cooktop use entailed boiling and simmering activities, using water as a heat sink. Oven and broiler use also were simulated. Time-resolved concentrationsmore » of carbon dioxide (CO2), nitric oxide (NO), nitrogen oxides (NOX), nitrogen dioxide (NO2), particles with diameters of 6 nm or larger (PN), carbon monoxide (CO), and fine particulate matter (PM2.5) were measured in the kitchen (K) and bedroom area (BR) of each home. CO2, NO, NO2, and PN data from sequential experiments were analyzed to quantify the contribution of burner use to the highest 1h and 4h time-integrated concentrations in each room. RESULTS: Four of the nine homes had kitchen 1h NO2 exceed the national ambient air quality standard (100 ppb). Two other homes had 1h NO2 exceed 50 ppb in the kitchen, and three had 1h NO2 above 50 ppb in the bedroom, suggesting substantial exposures to anyone at home when burners are used for a single substantial event. In all homes, the highest 1h kitchen PN exceeded 2 x105 cm-3-h, and the highest 4h PN exceeded 3 x105 cm-3-hr in all homes. The lowest 1h kitchen/bedroom ratios were 1.3–2.1 for NO in the apartment and two open floor plan homes. The largest K/BR ratios of 1h NO2 were in a two-story 1990s home retrofitted for deep energy savings: ratios in this home were 3.3 to 6.6. Kitchen 1h ratios of NO, NO2 and PN to CO2 were used to calculate fuel normalized emission factors (ng J-1). Range hood use substantially reduced cooking burner pollutant concentrations both in the kitchen and bedroom of several homes. A hood with large capture volume and a measured flow of 108 L/s reduced concentrations 80-95%. IMPLICATIONS: These measurements demonstrate that operation of natural gas cooking burners without venting can cause short-term kitchen concentrations of NO2 to exceed the US outdoor health standard, and can elevate concentrations of NO, NO2, and ultrafine particles throughout the home. Results are generally consistent with a recent simulation study that estimated widespread 1h NO2 exposures exceeding 100 ppb in homes that use gas burners without venting. While operating a venting range hood can greatly reduce pollutant levels from burner use (and presumably from cooking as well), performance varies widely across hoods. Increased awareness of the need to ventilate when cooking would substantially reduce in-home exposure to NO2 and ultrafine particles in California homes. Helping consumers select effective hoods, for example by publishing capture efficiency performance ratings, also would help reduce exposure.« less

DEMONSTRATION BULLETIN: CELLO PULSE COMBUSTION BURNER SYSTEM/SONOTECH INC.

EPA Science Inventory

Sonotech, Inc. (Sonotech), of Atlanta, GA, the developer of the Cello® pulse combustion burner, claims that its burner system can be beneficial to a variety of combustion processes. The system incorporates a combustor that can be tuned to induce large amplitude sonic pulsation...

A critical review of noise production models for turbulent, gas-fueled burners

NASA Technical Reports Server (NTRS)

Mahan, J. R.

1984-01-01

The combustion noise literature for the period between 1952 and early 1984 is critically reviewed. Primary emphasis is placed on past theoretical and semi-empirical attempts to predict or explain observed direct combustion noise characteristics of turbulent, gas-fueled burners; works involving liquid-fueled burners are reviewed only when ideas equally applicable to gas-fueled burners are pesented. The historical development of the most important contemporary direct combustion noise theories is traced, and the theories themselves are compared and criticized. While most theories explain combustion noise production by turbulent flames in terms of randomly distributed acoustic monopoles produced by turbulent mixing of products and reactants, none is able to predict the sound pressure in the acoustic farfield of a practical burner because of the lack of a proven model which relates the combustion noise source strenght at a given frequency to the design and operating parameters of the burner. Recommendations are given for establishing a benchmark-quality data base needed to support the development of such a model.

Capture efficiency of cooking-related fine and ultrafine particles by residential exhaust hoods.

PubMed

Lunden, M M; Delp, W W; Singer, B C

2015-02-01

Effective exhaust hoods can mitigate the indoor air quality impacts of pollutant emissions from residential cooking. This study reports capture efficiencies (CE) measured for cooking-generated particles for scripted cooking procedures in a 121-m3 chamber with kitchenette. CEs also were measured for burner produced CO2 during cooking and separately for pots and pans containing water. The study used four exhaust hoods previously tested by Delp and Singer (Environ. Sci. Technol., 2012, 46, 6167-6173). For pan-frying a hamburger over medium heat on the back burner, CEs for particles were similar to those for burner produced CO2 and mostly above 80%. For stir-frying green beans in a wok (high heat, front burner), CEs for burner CO2 during cooking varied by hood and airflow: CEs were 34-38% for low (51-68 l/s) and 54-72% for high (109-138 l/s) settings. CEs for 0.3-2.0 μm particles during front burner stir-frying were 3-11% on low and 16-70% on high settings. Results indicate that CEs measured for burner CO2 are not predictive of CEs of cooking-generated particles under all conditions, but they may be suitable to identify devices with CEs above 80% both for burner combustion products and for cooking-related particles. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Effects of Buoyancy on Laminar and Turbulent Premixed V-Flame

NASA Technical Reports Server (NTRS)

Cheng, Robert K.; Bedat, Benoit

1997-01-01

Turbulent combustion occurs naturally in almost all combustion systems and involves complex dynamic coupling of chemical and fluid mechanical processes. It is considered as one of the most challenging combustion research problems today. Though buoyancy has little effect on power generating systems operating under high pressures (e.g., IC engines and turbines), flames in atmospheric burners and the operation of small to medium furnaces and boilers are profoundly affected by buoyancy. Changes in burner orientation impacts on their blow-off, flash-back and extinction limits, and their range of operation, burning rate, heat transfer, and emissions. Theoretically, buoyancy is often neglected in turbulent combustion models. Yet the modeling results are routinely compared with experiments of open laboratory flames that are obviously affected by buoyancy. This inconsistency is an obstacle to reconciling experiments and theories. Consequently, a fundamental understanding of the coupling between turbulent flames and buoyancy is significant to both turbulent combustion science and applications. The overall effect of buoyancy relates to the dynamic interaction between the flame and its surrounding, i.e., the so-called elliptical problem. The overall flame shape, its flowfield, stability, and mean and local burning rates are dictated by both upstream and downstream boundary conditions. In steady propagating premixed flames, buoyancy affects the products region downstream of the flame zone. These effects are manifested upstream through the mean and fluctuating pressure fields to influence flame stretch and flame wrinkling. Intuitively, the effects buoyancy should diminish with increasing flow momentum. This is the justification for excluding buoyancy in turbulent combustion models that treats high Reynolds number flows. The objectives of our experimental research program is to elucidate flame-buoyancy coupling processes in laminar and turbulent premixed flames, and to characterize microgravity (micro g) premixed flames. The results are used to derive appropriate scaling parameters for guiding the development of theoretical models to include the effects of buoyancy. Knowledge gain from the analysis will also contribute to further understanding of the elliptical nature of premixed flames. Our current emphasis is to examine the momentum limit above which the effects of buoyancy would become insignificant. This is accomplished by comparing the flowfields and the mean properties of normal gravity flames (+g), and reversed gravity flames (-g, up-side-down flames) at different flow velocities and turbulence intensities. Microgravity (micro g) flames experiments provide the key reference data to reconcile the differences between flames in +g and -g. As flame configuration has significant impact on premixed flames characteristics we have studied axi-symmetric conical flames and plane-symmetric rod-stabilized v-flames. The two configurations produce distinct features that dictates how the flames couple with buoyancy. In a conical flame, the hot products plume completely envelopes the flame cone and shields the flame from direct interaction with the ambient air. The plume originates at the burner rim and generates a divergent flowfield. In comparison, the products region of v-flames forms between the twin flame sheets and it is convergent towards the center-plane. Interaction with ambient air is limited to the two end regions of the stabilized rod and beyond the flame sheets.

Design Guidelines for Heating Aircraft Hangars with Radiant Heaters.

DTIC Science & Technology

1983-12-01

required for gas-fired radiant heaters. Building mate- rials that are contiguous to the exterior (e.g., glass skylights ) are potential collection points...for use in aircraft hangars * when the burners glow a dull red, a malfunctioning burner would be visually apparent by intermittent burner incandescence

A numerical study of axisymmetric compressible non-isothermal and reactive swirling flow

NASA Astrophysics Data System (ADS)

Tavernetti, William E.; Hafez, Mohamed M.

2017-09-01

Non-linear dynamical phenomena in combustion processes is an active area of experimental and theoretical research. This is in large part due to increasingly strict environmental pressures to make gas turbine engines and industrial burners more efficient. Using numerical methods, for steady and unsteady confined and unconfined compressible flow, this study examines the modeling influence of compressibility for axisymmetric swirling flow. The compressible reactive Navier-Stokes equations in terms of stream function, vorticity, circulation are used. Results, details of the numerical algorithms, as well as numerical verification techniques and validation with sources from the literature will be presented. Understanding how vortex breakdown phenomena are affected by modeling reactant consumption with compressibility effect is the main goal of this study.

The Use of an Ultra-Compact Combustor as an Inter-Turbine Burner for Improved Engine Performance

DTIC Science & Technology

2014-03-27

27 25 NPSS Mixed Flow Turbofan Model - Element and Link Names . . . . . . . . . 30 26 VCE with Variable Components Labeled...the power generation, Vogeler proposed the Sequential Combustion Cycle (SCC) for use in aircraft engines [13]. For a conventional turbofan with a...single combustor, thrust is a function of bypass ratio and maximum pressure and temperature in the cycle. Considering a twin spool turbofan engine as

JPRS Report, Science & Technology, Japan.

DTIC Science & Technology

1988-05-04

360 tons of HAP ( hydroxyapatite ) for medical applications, as food additives, and for use in tooth pastes is imported. There are plenty of raw...pressure ratio (qr = PjUj 2/pmum 2, equal to about 1.5) of the jet to the mainflow are chosen for the operating parameters of the jet. Quartz glass for...intermediate flow. The parameters which affect self-ignition and flame maintenance in an actual supersonic burner are the size of the recirculation

Plasma Assisted Combustion: Flame Regimes and Kinetic Studies

DTIC Science & Technology

2015-01-05

Kinetic model Fuel: Dimethyl ether Oxidizer= (1-x)O2 + xO3, x=0 - 0.1, p=1 atm Ozone chemistry & Dimethyl ether model ...diffusional cool flames • A heated counterflow burner integrated with vaporization system1 • n-heptane/nitrogen vs. oxygen/ ozone • Ozone generator...micro-DBD) produces 2- 5 % of ozone in oxygen stream, depending on oxygen flow rate • Speciation profiles by using a micro-probe sampling with a

Flow-Turning Losses in Solid Rocket Motors.

DTIC Science & Technology

1988-03-01

0041 with the Air Force Astronautics Laboratory (AFAL), Edwards AFB, CA. AFAL Project Manager was Gary Vogt. This report has been reviewed and is...associated with the injection of fluid into a chamber containing sound. Flandro , using an admittance correction acoustic "boundary-layer" type approach...apparently negligible. Flandro estimated the contribution of the acoustic losses from both his and Culick’s model to T-Burner stability data and found that

Firing of pulverized solvent refined coal

DOEpatents

Derbidge, T. Craig; Mulholland, James A.; Foster, Edward P.

1986-01-01

An air-purged burner for the firing of pulverized solvent refined coal is constructed and operated such that the solvent refined coal can be fired without the coking thereof on the burner components. The air-purged burner is designed for the firing of pulverized solvent refined coal in a tangentially fired boiler.

14 CFR 31.47 - Burners.

Code of Federal Regulations, 2012 CFR

2012-01-01

... emergency operation. (d) The burner system (including the burner unit, controls, fuel lines, fuel cells...) Five hours at the maximum fuel pressure for which approval is sought, with a burn time for each one... intermediate fuel pressure, with a burn time for each one minute cycle of three to ten seconds. An intermediate...

14 CFR 31.47 - Burners.

Code of Federal Regulations, 2013 CFR

2013-01-01

... emergency operation. (d) The burner system (including the burner unit, controls, fuel lines, fuel cells...) Five hours at the maximum fuel pressure for which approval is sought, with a burn time for each one... intermediate fuel pressure, with a burn time for each one minute cycle of three to ten seconds. An intermediate...

14 CFR 31.47 - Burners.

Code of Federal Regulations, 2010 CFR

2010-01-01

... emergency operation. (d) The burner system (including the burner unit, controls, fuel lines, fuel cells...) Five hours at the maximum fuel pressure for which approval is sought, with a burn time for each one... intermediate fuel pressure, with a burn time for each one minute cycle of three to ten seconds. An intermediate...

14 CFR 31.47 - Burners.

Code of Federal Regulations, 2011 CFR

2011-01-01

... emergency operation. (d) The burner system (including the burner unit, controls, fuel lines, fuel cells...) Five hours at the maximum fuel pressure for which approval is sought, with a burn time for each one... intermediate fuel pressure, with a burn time for each one minute cycle of three to ten seconds. An intermediate...

14 CFR 31.47 - Burners.

Code of Federal Regulations, 2014 CFR

2014-01-01

... emergency operation. (d) The burner system (including the burner unit, controls, fuel lines, fuel cells...) Five hours at the maximum fuel pressure for which approval is sought, with a burn time for each one... intermediate fuel pressure, with a burn time for each one minute cycle of three to ten seconds. An intermediate...

KINETIC STUDIES RELATED TO THE LIMB (LIMESTONE INJECTION MULTISTAGE BURNER) BURNER

EPA Science Inventory

The report gives results of theoretical and experimental studies of subjects related to the limestone injection multistage burner (LIMB). The main findings include data on the rate of evolution of H2S from different coals and on the dependence of the rate of evolution on the dist...

Burner Rig Hot Corrosion of a Single Crystal Ni-48Al-Ti-Hf-Ga Alloy

NASA Technical Reports Server (NTRS)

Nesbitt, James A.; Darolia, Ram; Cuy, Michael D.

1998-01-01

The hot corrosion resistance of a single crystal Ni-48Al-1Ti-0.5Hf-0.2Ga alloy was examined in a Mach 0.3 burner rig at 900 C for 300 hours. The combustion chamber was doped with 2 ppmw synthetic sea salt. The hot corrosion attack produced a random mound morphology on the surface. Microstructurally, the hot corrosion attack appeared to initiate with oxide-filled pits which were often broad and shallow. At an intermediate stage, the pits increased in size to incorporate unoxidized Ni islands in the corrosion product. The rampant attack stage, which was observed only at sharp sample corners, was characterized by rapid inward growth of alumina in finger-like protrusions incorporating significant amounts of Al-depleted Ni islands. Aluminum consumption in the oxide fingers resulted in the growth of a gamma' layer ahead of the advancing oxide fingers.

Down-flow moving-bed gasifier with catalyst recycle

DOEpatents

Halow, John S.

1999-01-01

The gasification of coal and other carbonaceous materials by an endothermic gasification reaction is achieved in the presence of a catalyst in a down-flow, moving-bed gasifier. Catalyst is removed along with ash from the gasifier and is then sufficiently heated in a riser/burner by the combustion of residual carbon in the ash to volatilize the catalyst. This volatilized catalyst is returned to the gasifier where it uniformly contacts and condenses on the carbonaceous material. Also, the hot gaseous combustion products resulting from the combustion of the carbon in the ash along with excess air are introduced into the gasifier for providing heat energy used in the endothermic reaction.

Measurements of axisymmetric temperature and H2O concentration distributions on a circular flat flame burner based on tunable diode laser absorption tomography

NASA Astrophysics Data System (ADS)

Xia, Huihui; Kan, Ruifeng; Xu, Zhenyu; Liu, Jianguo; He, Yabai; Yang, Chenguang; Chen, Bing; Wei, Min; Yao, Lu; Zhang, Guangle

2016-10-01

In this paper, the reconstruction of axisymmetric temperature and H2O concentration distributions in a flat flame burner is realized by tunable diode laser absorption spectroscopy (TDLAS) and filtered back-projection (FBP) algorithm. Two H2O absorption transitions (7154.354/7154.353 cm-1 and 7467.769 cm-1) are selected as line pair for temperature measurement, and time division multiplexing technology is adopted to scan this two H2O absorption transitions simultaneously at 1 kHz repetition rate. In the experiment, FBP algorithm can be used for reconstructing axisymmetric distributions of flow field parameters with only single view parallel-beam TDLAS measurements, and the same data sets from the given parallel beam are used for other virtual projection angles and beams scattered between 0° and 180°. The real-time online measurements of projection data, i.e., integrated absorbance both for pre-selected transitions on CH4/air flat flame burner are realized by Voigt on-line fitting, and the fitting residuals are less than 0.2%. By analyzing the projection data from different views based on FBP algorithm, the distributions of temperature and concentration along radial direction can be known instantly. The results demonstrate that the system and the proposed innovative FBP algorithm are capable for accurate reconstruction of axisymmetric temperature and H2O concentration distribution in combustion systems and facilities.

A Burning Rate Emulator (BRE) for Study in Microgravity

NASA Technical Reports Server (NTRS)

Markan, A.; Sunderland, P. B.; Quintiere, J. G.; DeRis, J.; Stocker, D. P.

2015-01-01

A gas-fueled burner, the Burning Rate Emulator (BRE), is used to emulate condensed-phase fuel flames. The design has been validated to easily measure the burning behavior of condensed-phase fuels by igniting a controlled stream of gas fuel and diluent. Four properties, including the heat of combustion, the heat of gasification, the surface temperature, and the laminar smoke point, are assumed to be sufficient to define the steady burning rate of a condensed-phase fuel. The heat of gasification of the fuel is determined by measuring the heat flux and the fuel flow rate. Microgravity BRE tests in the NASA 5.2 s drop facility have examined the burning of pure methane and ethylene (pure and 50 in N2 balance). Fuel flow rates, chamber oxygen concentration and initial pressure have been varied. Two burner sizes, 25 and 50 mm respectively, are chosen to examine the nature of initial microgravity burning. The tests reveal bubble-like flames that increase within the 5.2s drop but the heat flux received from the flame appears to asymptotically approach steady state. Portions of the methane flames appear to locally detach and extinguish at center, while its shape remains fixed, but growing. The effective heat of gasification is computed from the final measured net heat flux and the fuel flow rate under the assumption of an achieved steady burning. Heat flux (or mass flux) and flame position are compared with stagnant layer burning theory. The analysis offers the prospect of more complete findings from future longer duration ISS experiments.

Demonstration test of burner liner strain measurements using resistance strain gages

NASA Technical Reports Server (NTRS)

Grant, H. P.; Anderson, W. L.

1984-01-01

A demonstration test of burner liner strain measurements using resistance strain gages as well as a feasibility test of an optical speckle technique for strain measurement are presented. The strain gage results are reported. Ten Kanthal A-1 wire strain gages were used for low cycle fatigue strain measurements to 950 K and .002 apparent strain on a JT12D burner can in a high pressure (10 atmospheres) burner test. The procedure for use of the strain gages involved extensive precalibration and postcalibration to correct for cooling rate dependence, drift, and temperature effects. Results were repeatable within + or - .0002 to .0006 strain, with best results during fast decels from 950 K. The results agreed with analytical prediction based on an axisymmetric burner model, and results indicated a non-uniform circumferential distribution of axial strain, suggesting temperature streaking.

Elimination of dimethyl methylphosphonate by plasma flame made of microwave plasma and burning hydrocarbon fuel

NASA Astrophysics Data System (ADS)

Cho, S. C.; Uhm, H. S.; Hong, Y. C.; Park, Y. G.; Park, J. S.

2008-06-01

Elimination of dimethyl methylphosphonate (DMMP) in liquid phase was studied by making use of a microwave plasma burner, exhibiting a safe removal capability of stockpiled chemical weapons. The microwave plasma burner consisted of a fuel injector and a plasma flame exit connected in series to a microwave plasma torch. The burner flames were sustained by injecting hydrocarbon fuels into the microwave plasma torch in air discharge. The Fourier transform infrared spectra indicated near perfect elimination of DMMP in the microwave plasma burner. This was confirmed by gas chromatography spectra as supporting data, revealing the disappearance of even intermediary compounds in the process of DMMP destruction. The experimental results and the physical configuration of the microwave plasma burner may provide an effective means of on-site removal of chemical warfare agents found on a battlefield.

Temperature and number density measurements using Raman scattering in turbulent-supersonic-combusting flows

NASA Astrophysics Data System (ADS)

Jeyashekar, Nigil Satish

Scramjet engines propelled at hypersonic velocities have the potential to replace existing rocket launchers. Commercializing the vehicle is an arduous task, owing to issues relating to low combustion efficiency. The performance, thrust, and speed of the engine can be improved by optimizing: turbulence-chemistry interaction to provide mixing conditions favorable for the chemistry, pressure buildup, and re-circulation of hydrogen throughout the engine. The performance of the engine can be measured, flow and chemical dynamics can be evaluated when all three variables in the transport equations are known. The variables are instantaneous flow velocity, static temperature (refers to the macroscopic temperature and not the molecular species temperature), and total number density at a point in the flow. The motive is to build a non-intrusive tool to measure thermodynamic quantities (static temperature and total number density). This can be integrated with a velocity measurement tool, in the future, to obtain all three variables simultaneously and instantaneously. The dissertation describes in detail the motivation for the proposed work, with introduction to the formalism involved, with a concise literature review, followed by mathematical perspective to obtain the working equations for temperature and number density. The design of the adiabatic burner and the experimental setup used for calibration is discussed with the uncertainty involved in measurements. The measurements are made for a certain set of flow conditions in the laminar burner by Raman scattering and is validated by comparing it to the theoretical/adiabatic flame temperature and mole fraction plots, in lean and rich regime. This technique is applied to turbulent, supersonic, hydrogen-air flame of an afterburning rocket nozzle. The statistics of temperature and total number density versus the corresponding values at adiabatic conditions gives the departure from thermal and chemical equilibrium. The extent of mixing and combustion can be concluded from such statistics. The future work will involve experimental modifications to make line and planar measurements in combusting jets.

Development of 3 and 5kW Fuel Cell Power Plants

DTIC Science & Technology

1985-12-12

automotive type air -cooled (cross-flow) copper heat exchanger (Figure 7.7) was used for water reclamation. A 48V, 0.5A brushless DC blower was used to...and the balance is combusted in ’a burner to supply heat required for the endothermic reforming process. The phosphoric acid fuel cell stack is air ...the use of inter- changeable power conditioners . A microprocessor based con- troller provides event sequencing and system. control during startup

Correlation of combustor acoustic power levels inferred from internal fluctuating pressure measurements

NASA Technical Reports Server (NTRS)

Vonglahn, U. H.

1978-01-01

Combustion chamber acoustic power levels inferred from internal fluctuating pressure measurements are correlated with operating conditions and chamber geometries over a wide range. The variables include considerations of chamber design (can, annular, and reverse-flow annular) and size, number of fuel nozzles, burner staging and fuel split, airflow and heat release rates, and chamber inlet pressure and temperature levels. The correlated data include those obtained with combustion component development rigs as well as engines.

41 CFR 101-26.602-3 - Procurement of gasoline, fuel oil (diesel and burner), kerosene, and solvents.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 41 Public Contracts and Property Management 2 2014-07-01 2012-07-01 true Procurement of gasoline... § 101-26.602-3 Procurement of gasoline, fuel oil (diesel and burner), kerosene, and solvents. (a... capability to procure locally. Item Minimum annual requirement (gallons) Gasoline 10,000 Burner fuel oil 10...

41 CFR 101-26.602-3 - Procurement of gasoline, fuel oil (diesel and burner), kerosene, and solvents.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 41 Public Contracts and Property Management 2 2013-07-01 2012-07-01 true Procurement of gasoline... § 101-26.602-3 Procurement of gasoline, fuel oil (diesel and burner), kerosene, and solvents. (a... capability to procure locally. Item Minimum annual requirement (gallons) Gasoline 10,000 Burner fuel oil 10...

41 CFR 101-26.602-3 - Procurement of gasoline, fuel oil (diesel and burner), kerosene, and solvents.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 41 Public Contracts and Property Management 2 2011-07-01 2007-07-01 true Procurement of gasoline... § 101-26.602-3 Procurement of gasoline, fuel oil (diesel and burner), kerosene, and solvents. (a... capability to procure locally. Item Minimum annual requirement (gallons) Gasoline 10,000 Burner fuel oil 10...

41 CFR 101-26.602-3 - Procurement of gasoline, fuel oil (diesel and burner), kerosene, and solvents.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 41 Public Contracts and Property Management 2 2012-07-01 2012-07-01 false Procurement of gasoline... § 101-26.602-3 Procurement of gasoline, fuel oil (diesel and burner), kerosene, and solvents. (a... capability to procure locally. Item Minimum annual requirement (gallons) Gasoline 10,000 Burner fuel oil 10...

41 CFR 101-26.602-3 - Procurement of gasoline, fuel oil (diesel and burner), kerosene, and solvents.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Procurement of gasoline... § 101-26.602-3 Procurement of gasoline, fuel oil (diesel and burner), kerosene, and solvents. (a... capability to procure locally. Item Minimum annual requirement (gallons) Gasoline 10,000 Burner fuel oil 10...

Ultra clean burner for an AMTEC system suitable for hybrid electric vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mital, R.; Sievers, R.K.; Hunt, T.K.

1997-12-31

High power Alkali Metal Thermal to Electric Converter (AMTEC) systems have the potential to make the hybrid electric vehicle (HEV) program a success by meeting the challenging standards put forth by the EPA for the automobile industry. The premise of the whole concept of using AMTEC cells, as discussed by Hunt et al. (1995), for power generation in HEV`s is based on the utilization of a high efficiency external combustion system. The key requirement being a burner which will produce extremely low quantities of carbon monoxide and oxides of nitrogen, emit minimal amounts of hydrocarbon, will have high radiative andmore » convective efficiencies and at least a 4:1 turndown ratio. This work presents one such burner which has the potential to meet all of these demands and more. After investigation of a number of burners, including, metal fiber, ported metal, ceramic fiber and ported ceramic, it is believed that cellular ceramic burners will be the best candidates for integration with AMTEC cells for a high power system suitable for hybrid electric vehicles. A detailed study which includes the operating range, radiation efficiency, total heat transfer efficiency, spectral intensity, exit gas temperature and pollutant emission indices measurement has been carried out on circular and square shaped burners. Total heat transfer efficiencies as high as 65--70% have been measured using a water calorimeter. With efficient recuperation, a burner/recuperator efficiency of 80% at peak power and 90% at peak efficiency operating points are conceivable with this burner. Establishment of combustion within the porous matrix leads to low peak temperatures and hence lower NO{sub x}. The emission indices of CO and HC are also quite low. The stability range measurements show a 6:1 turndown ratio at an equivalence ratio of 0.9.« less

Experimental apparatus with full optical access for combustion experiments with laminar flames from a single circular nozzle at elevated pressures.

PubMed

Joo, Peter H; Gao, Jinlong; Li, Zhongshan; Aldén, Marcus

2015-03-01

The design and features of a high pressure chamber and burner that is suitable for combustion experiments at elevated pressures are presented. The high pressure combustion apparatus utilizes a high pressure burner that is comprised of a chamber burner module and an easily accessible interchangeable burner module to add to its flexibility. The burner is well suited to study both premixed and non-premixed flames. The optical access to the chamber is provided through four viewports for direct visual observations and optical-based diagnostic techniques. Auxiliary features include numerous access ports and electrical connections and as a result, the combustion apparatus is also suitable to work with plasmas and liquid fuels. Images of methane flames at elevated pressures up to 25 atm and preliminary results of optical-based measurements demonstrate the suitability of the high pressure experimental apparatus for combustion experiments.

Development of strand burner for solid propellant burning rate studies

NASA Astrophysics Data System (ADS)

Aziz, A.; Mamat, R.; Ali, W. K. Wan

2013-12-01

It is well-known that a strand burner is an apparatus that provides burning rate measurements of a solid propellant at an elevated pressure in order to obtain the burning characteristics of a propellant. This paper describes the facilities developed by author that was used in his studies. The burning rate characteristics of solid propellant have be evaluated over five different chamber pressures ranging from 1 atm to 31 atm using a strand burner. The strand burner has a mounting stand that allows the propellant strand to be mounted vertically. The strand was ignited electrically using hot wire, and the burning time was recorded by electronic timer. Wire technique was used to measure the burning rate. Preliminary results from these techniques are presented. This study shows that the strand burner can be used on propellant strands to obtain accurate low pressure burning rate data.

Micronized-Coal Burner Facility

NASA Technical Reports Server (NTRS)

Calfo, F. D.; Lupton, M. W.

1986-01-01

Micronized-coal (coal-in-oil mix) burner facility developed to fulfill need to generate erosion/corrosion data on series of superalloy specimens. In order to successfully operate gas turbine using COM, two primary conditions must be met. First, there must be adequate atomization of COM and second, minimization of coking of burner. Meeting these conditions will be achieved only by clean burning and flame stability.

Space Experiment Concepts: Cup-Burner Flame Extinguishment

NASA Technical Reports Server (NTRS)

Takahashi, Fumiaki

2004-01-01

Space Fire Suppression Processes & Technology. Space experiment concepts of cup-burner flame extinguishment have been conceived to address to the key issues (i.e., organizing questions) in space fire suppression. Cup-burner flame extinguishment experiment can reveal physical and chemical suppression processes and provide agent effectiveness data useful for technology development of space fire suppression systems in various reduced-gravity platforms.

Flame quality monitor system for fixed firing rate oil burners

DOEpatents

Butcher, Thomas A.; Cerniglia, Philip

1992-01-01

A method and apparatus for determining and indicating the flame quality, or efficiency of the air-fuel ratio, in a fixed firing rate heating unit, such as an oil burning furnace, is provided. When the flame brightness falls outside a preset range, the flame quality, or excess air, has changed to the point that the unit should be serviced. The flame quality indicator output is in the form of lights mounted on the front of the unit. A green light indicates that the flame is about in the same condition as when the burner was last serviced. A red light indicates a flame which is either too rich or too lean, and that servicing of the burner is required. At the end of each firing cycle, the flame quality indicator goes into a hold mode which is in effect during the period that the burner remains off. A yellow or amber light indicates that the burner is in the hold mode. In this mode, the flame quality lights indicate the flame condition immediately before the burner turned off. Thus the unit can be viewed when it is off, and the flame condition at the end of the previous firing cycle can be observed.

DEVELOPMENT AND DEMONSTRATION OF NOVEL LOW-NOx BURNERS IN THE STEEL INDUSTRY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cygan, David

Gas Technology Institute (GTI), together with Hamworthy Peabody Combustion Incorporated (formerly Peabody Engineering Corporation), the University of Utah, and Far West Electrochemical have developed and demonstrated an innovative combustion system suitable for natural gas and coke-oven gas firing within the steel industry. The combustion system is a simple, low-cost, energy-efficient burner that can reduce NOx by more than 75%. The U.S. steel industry needs to address NOx control at its steelmaking facilities. A significant part of NOx emissions comes from gas-fired boilers. In steel plants, byproduct gases – blast furnace gas (BFG) and coke-oven gas (COG) – are widely usedmore » together with natural gas to fire furnaces and boilers. In steel plants, natural gas can be fired together with BFG and COG, but, typically, the addition of natural gas raises NOx emissions, which can already be high because of residual fuel-bound nitrogen in COG. The Project Team has applied its expertise in low-NOx burners to lower NOx levels for these applications by combining advanced burner geometry and combustion staging with control strategies tailored to mixtures of natural gas and byproduct fuel gases. These methods reduce all varieties of NOx – thermal NOx produced by high flame temperatures, prompt NOx produced by complex chain reactions involving radical hydrocarbon species and NOx from fuel-bound nitrogen compounds such as ammonia found in COG. The Project Team has expanded GTI’s highly successful low-NOx forced internal recirculation (FIR) burner, previously developed for natural gas-fired boilers, into facilities that utilize BFG and COG. For natural gas firing, these burners have been shown to reduce NOx emissions from typical uncontrolled levels of 80-100 vppm to single-digit levels (9 vppm). This is done without the energy efficiency penalties incurred by alternative NOx control methods, such as external flue gas recirculation (FGR), water injection, and selective non-catalytic reduction. The FIR burner was previously demonstrated on firetube and watertube boilers, and these units are still operating at several industrial and commercial boiler sites in sizes ranging from 2.5 to 60 million Btu/h. This report covers the development of an innovative combustion system suitable for natural gas or coke-oven gas firing within the steel industry. The prototype FIR burner was evaluated on a 20 million Btu/h watertube boiler. Acceptable burner performance was obtained when firing natural gas and simulated coke-oven gas doped with ammonia. The laboratory data reveals a direct relationship between NOx formation and the ammonia concentration in the fuel. In addition, NOx formation increases as the primary stoichiometric ratio (PSR) increases. Representative ammonia concentrations, as documented in the steel industry, ranged from 200 to 500 vppm. When the laboratory burner/boiler was operated with 500 vppm ammonia in the fuel, NOx emissions ranged from 50 to 75 vppm. This, conservatively, is 75% less than state-of-the-art burner performance. When the burner is operated with 200 vppm ammonia in the fuel, the corresponding NOx emissions would range from 30 to 45 vppm, 84% less than present burner technology. During field evaluation on a 174 million Btu/h industrial prototype burner both natural gas and actual COG from on-site generation were tested. Despite the elevated hydrogen cyanide and ammonia content in the COG throughout the test program, the FIR burner showed an improvement over baseline emissions. At full load; 167 million Btu/h, NOx emissions were relatively low at 169 vppm. This represents a 30% reduction compared to baseline emissions not accounting for the higher hydrogen cyanide content in the COG. CO emissions remained below 20 vppm and were stable across the firing range. This represents a 68% reduction compared to baseline CO emissions. When firing natural gas, emissions were stable as firing rate increased over the range. At low fire; 45 million Btu/h, NOx emissions where 33 vppm and increased at full load; 144 million Btu/h, to 49 vppm. CO emissions fluctuated with the oxygen content and remained below 135 vppm during all tests. The boiler’s maximum output was not achieved due to a limitation dictated by the host site natural gas supply. The FIR burner benefits the public by simultaneously addressing the problems of air pollution and energy conservation through a low-NOx combustion technology that does not increase energy consumption. Continuing activities include the negotiation of a license with Hamworthy Peabody Combustion, Incorporated (Hamworthy Peabody) to commercialize the FIR burner for steel industry applications. Hamworthy Peabody is one of the largest U.S. manufacturers of combustion equipment for boilers in the Steel Industry, and has stated their intention to commercialize the FIR burner.« less

Environmental assessment of an enhanced-oil-recovery steam generator equipped with a low-NOx burner. Volume 1. Technical results. Final report, January 1984-January 1985

DOE Office of Scientific and Technical Information (OSTI.GOV)

Castaldini, C.; Waterland, L.R.; Lips, H.I.

1986-02-01

The report discusses results from sampling flue gas from an enhanced-oil-recovery steam generator (EOR steamer) equipped with an MHI PM low-NOx burner. The tests included burner performance/emission mapping tests, comparative testing of an identical steamer equipped with a conventional burner, and comprehensive testing of the low-NOx-burner-equipped steamer. Comprehensive test measurements included continuous flue-gas monitoring; source assessment sampling system testing with subsequent laboratory analysis to give total flue-gas organics in two boiling point ranges and specific quantitation on the semivolatile organic priority pollutants; C1 to C6 hydrocarbon sampling; Methods 5/8 sampling for particulate and SO/sub 2/ and SO/sub 3/ emissions; andmore » emitted particle size distribution tests using Andersen impactors. Full-load NOx emissions of 110 ppm (3% O/sub 2/) could be maintained from the low-NOx burner at acceptable CO and smoke emissions, compared to about 300 ppm (3% O/sub 2/) from the conventional-burner-equipped steamer. At the low-NOx condition, CO, SO/sub 2/, and SO/sub 3/ emissions were 93, 594, and 3.1 ppm, respectively. Particulate emissions were 39 mg/dscm with a mean particle diameter of 3 to 4 micrometers. Total organic emissions were 11.1 mg/dscm, almost exclusively volatile (C1 to C6) organics. Three PAHs were detected at from 0.1 to 1.4 micrograms/dscm.« less

Burner Rig with an Unattached Duct for Evaluating the Erosion Resistance of Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Miller, Robert A.; Kuczmarski, Maria A.; Zhu, Dongming

2011-01-01

Extensive computational fluid dynamics (CFD) modeling backed by experimental observation has demonstrated the feasibility of using an unattached duct to increase the velocity and spatial spread of erodent particles exiting from a burner rig. It was shown that gas velocity and temperature are mostly retained if the inner diameter of the unattached duct equaled the exit diameter of the burner rig nozzle. For particles having a mean diameter of 550 millimeters, the modeled velocity attained at a distance 2.0 in. (50.8 millimeters) beyond the exit of a 12 in. (305 millimeters) long duct was approximately twice as large as the velocity the same distance from the nozzle when the duct was not present. For finer particles, the relative enhancement was somewhat less approximately 1.5 times greater. CFD modeling was also used to guide the construction of a device for slowing down the velocity of the particles being injected into the burner rig. This device used a simple 45 degree fitting to slow the particle velocity in the feed line from 20 meters per second, which is in the range needed to convey the particles, to about 3 meters per second just as they are injected into the burner. This lower injection velocity would lessen the severity of the collision of large particles with the wall of the burner liner opposite the injection port, thereby reducing potential damage to the burner liner by high-velocity particles.

16 CFR Figure 5 to Part 1633 - Details of Burner Stand-off

Code of Federal Regulations, 2011 CFR

2011-01-01

... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Details of Burner Stand-off 5 Figure 5 to Part 1633 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY (OPEN FLAME) OF MATTRESS SETS Pt.1633, Fig. 5 Figure 5 to Part 1633—Details of Burner Stand-off ER15MR06.00...

16 CFR Figure 5 to Part 1633 - Details of Burner Stand-off

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Details of Burner Stand-off 5 Figure 5 to Part 1633 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY (OPEN FLAME) OF MATTRESS SETS Pt.1633, Fig. 5 Figure 5 to Part 1633—Details of Burner Stand-off ER15MR06.00...

16 CFR Figure 5 to Part 1633 - Details of Burner Stand-off

Code of Federal Regulations, 2014 CFR

2014-01-01

... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Details of Burner Stand-off 5 Figure 5 to Part 1633 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY (OPEN FLAME) OF MATTRESS SETS Pt. 1633, Fig. 5 Figure 5 to Part 1633—Details of Burner Stand-off ER15MR06.00...

16 CFR Figure 5 to Part 1633 - Details of Burner Stand-off

Code of Federal Regulations, 2013 CFR

2013-01-01

... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Details of Burner Stand-off 5 Figure 5 to Part 1633 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY (OPEN FLAME) OF MATTRESS SETS Pt. 1633, Fig. 5 Figure 5 to Part 1633—Details of Burner Stand-off   ER15MR06.00...

16 CFR Figure 5 to Part 1633 - Details of Burner Stand-off

Code of Federal Regulations, 2012 CFR

2012-01-01

... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Details of Burner Stand-off 5 Figure 5 to Part 1633 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY (OPEN FLAME) OF MATTRESS SETS Pt.1633, Fig. 5 Figure 5 to Part 1633—Details of Burner Stand-off ER15MR06.00...

Down-flow moving-bed gasifier with catalyst recycle

DOEpatents

Halow, J.S.

1999-04-20

The gasification of coal and other carbonaceous materials by an endothermic gasification reaction is achieved in the presence of a catalyst in a down-flow, moving-bed gasifier. Catalyst is removed along with ash from the gasifier and is then sufficiently heated in a riser/burner by the combustion of residual carbon in the ash to volatilize the catalyst. This volatilized catalyst is returned to the gasifier where it uniformly contacts and condenses on the carbonaceous material. Also, the hot gaseous combustion products resulting from the combustion of the carbon in the ash along with excess air are introduced into the gasifier for providing heat energy used in the endothermic reaction. 1 fig.

Development of heat flux sensors for turbine airfoils

NASA Astrophysics Data System (ADS)

Atkinson, William H.; Cyr, Marcia A.; Strange, Richard R.

1985-10-01

The objectives of this program are to develop heat flux sensors suitable for installation in hot section airfoils of advanced aircraft turbine engines and to experimentally verify the operation of these heat flux sensors in a cylinder in a cross flow experiment. Embedded thermocouple and Gardon gauge sensors were developed and fabricated into both blades and vanes. These were then calibrated using a quartz lamp bank heat source and finally subjected to thermal cycle and thermal soak testing. These sensors were also fabricated into cylindrical test pieces and tested in a burner exhaust to verify heat flux measurements produced by these sensors. The results of the cylinder in cross flow tests are given.

Development of heat flux sensors for turbine airfoils

NASA Technical Reports Server (NTRS)

Atkinson, William H.; Cyr, Marcia A.; Strange, Richard R.

1985-01-01

The objectives of this program are to develop heat flux sensors suitable for installation in hot section airfoils of advanced aircraft turbine engines and to experimentally verify the operation of these heat flux sensors in a cylinder in a cross flow experiment. Embedded thermocouple and Gardon gauge sensors were developed and fabricated into both blades and vanes. These were then calibrated using a quartz lamp bank heat source and finally subjected to thermal cycle and thermal soak testing. These sensors were also fabricated into cylindrical test pieces and tested in a burner exhaust to verify heat flux measurements produced by these sensors. The results of the cylinder in cross flow tests are given.

Experimental and Analytical Studies of Shielding Concepts for Point Sources and Jet Noise.

DTIC Science & Technology

1983-05-01

proximnity of the turbulent jet flow to the The Spectral Dynamics DSP 360 is a two channel real time analyzer incor- shielding surface, the edge will interact...However, this is achieved with a very long shield length equal to 190 unorthodox configurations. The emphasis is placed on the concept, times the slit...16 dB/dec. .Vn With this solid-gaseous combination, a 10 0 diameter shield of length 14 DVf =- sin 0 with a burner attached to the trailing edge

1982 AFOSR Research Meeting on Diagnostics of Reacting Flow, 25-26 February 1982.

DTIC Science & Technology

1982-02-01

wing of the Na 589.0 nm line is achieved with a piezo-electrically tuned Fabry - Perot interferometer combined with an interference filter. A second...air burner seeded to -0.01% with NaCl. Oscilloscope traces of the detector signal as the Fabry - Perot is scanned over the wavelength range of interest...lamp, SG from the gas and SL+G transmitted from the lamp through the gas. Following electronic demodulation (Fig. Ib) the three signals are used to

The Mission Defines the Cycle: Turbojet, Turbofan and Variable Cycle Engines for High Speed Propulsion

DTIC Science & Technology

2010-09-01

RTO-EN-AVT-185 2 - 1 The Mission Defines the Cycle: Turbojet, Turbofan and Variable Cycle Engines for High Speed Propulsion Joachim Kurzke...following turbine parts 1 %. With T4=2000K the amounts of cooling air are 10% and 6% respectively. Burner pressure ratio is taken into account with 0.97 and...Figure 2 . Figure 3 shows specific thrust (i.e. thrust per unit of air flow) and specific fuel consumption SFC for three altitude / Mach number

Apparatus for the pulverization and burning of solid fuels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sayler, W.H.; White, J.C.

1988-06-07

This patent describes an apparatus for pulverizing coarsely-divided, solid fuel, such as coal, and for feeding the pulverized fuel to a burner. It comprises an upstanding housing having side, bottom and top walls; an upstanding shaft axially mounted for rotation within the housing; means for rotating the shaft; a slinger having an annular opening therethrough concentric with and closely encircling the shaft; fan means secured to the shaft immediately below the top wall of the housing; air-turbulating means comprising a pair of spiders; air-inlet means in the housing below the slinger so that air will flow upwardly through the annularmore » opening as well as peripherally of the slinger, entraining fine solid fuel particles during passage through the housing interior for further pulverization by size attrition between the spiders; outlet means provided through the side of the housing adjacent to the fan means; and outlet means being adapted for connection with the burner; and solid fuel input mans leading into the housing and positioned to feed coarsely-divided solid fuel onto the slinger.« less

A ring stabilizer for lean premixed turbulent flames

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, M.R.; Kostiuk, L.W.; Cheng, R.K.

1998-08-01

In previous experiments on conical flame behavior in microgravity, which were conducted in drop-towers and in airplanes, the use of a pilot flame was not an option. To permit combustion of stable lean premixed conical flames without a pilot, a ring stabilizer was developed. Although similar types of bluff-body stabilization have been used in the past, the ring stabilizer is somewhat unique. It is designed to fit inside the burner exit port and has demonstrated to be highly effective in stabilizing flames over a very wide range of conditions (including ultra-lean flames at high flow-rates) without adversely affecting flame emissions.more » Unlike a simple rod stabilizer or a stagnation flame system, the benefit of having the stabilizer conform to the burner port is that there is very little leakage of the unburned fuel. The purpose of this brief communication is to offer this simple and highly useful device to the combustion research community. Presented are highlights of a parametric study that measured the stabilization limits and pollutant emissions of several different rings, and demonstrated their potential for use in practical systems.« less

Modeling, simulation and optimization of a no-chamber solid oxide fuel cell operated with a flat-flame burner

NASA Astrophysics Data System (ADS)

Vogler, Marcel; Horiuchi, Michio; Bessler, Wolfgang G.

A detailed computational model of a direct-flame solid oxide fuel cell (DFFC) is presented. The DFFC is based on a fuel-rich methane-air flame stabilized on a flat-flame burner and coupled to a solid oxide fuel cell (SOFC). The model consists of an elementary kinetic description of the premixed methane-air flame, a stagnation-point flow description of the coupled heat and mass transport within the gas phase, an elementary kinetic description of the electrochemistry, as well as heat, mass and charge transport within the SOFC. Simulated current-voltage characteristics show excellent agreement with experimental data published earlier (Kronemayer et al., 2007 [10]). The model-based analysis of loss processes reveals that ohmic resistance in the current collection wires dominates polarization losses, while electronic loss currents in the mixed conducting electrolyte have only little influence on the polarized cell. The model was used to propose an optimized cell design. Based on this analysis, power densities of above 200 mW cm -2 can be expected.

Blue nano titania made in diffusion flames.

PubMed

Teleki, Alexandra; Pratsinis, Sotiris E

2009-05-21

Blue titanium suboxide nanoparticles (including Magneli phases) were formed directly without any post-processing or addition of dopants by combustion of titanium-tetra-isopropoxide (TTIP) vapor at atmospheric pressure. Particle size, phase composition, rutile and anatase crystal sizes as well as the blue coloration were controlled by rapid quenching of the flame with a critical flow nozzle placed at various heights above the burner. The particles showed a broad absorption in the near-infrared region and retained their blue color upon storage in ambient atmosphere. A high concentration of paramagnetic Ti3+ centres was found in the substoichiometric particles by electron paramagnetic resonance (EPR) spectroscopy. Furthermore particles with controlled band gap energy from 3.2 to 3.6 eV were made by controlling the burner-nozzle-distance from 10 to 1 cm, respectively. The color robustness and extent of suboxidation could be further enhanced by co-oxidation of TTIP with hexamethyldisiloxane in the flame resulting in SiO2-coated titanium suboxide particles. The process is cost-effective and green while the particles produced can replace traditional blue colored, cobalt-containing pigments.

Gravitational Effects on Cellular Flame Structure

NASA Technical Reports Server (NTRS)

Dunsky, C. M.; Fernandez-Pello, A. C.

1991-01-01

An experimental investigation has been conducted of the effect of gravity on the structure of downwardly propagating, cellular premixed propane-oxygen-nitrogen flames anchored on a water-cooled porous-plug burner. The flame is subjected to microgravity conditions in the NASA Lewis 2.2-second drop tower, and flame characteristics are recorded on high-speed film. These are compared to flames at normal gravity conditions with the same equivalence ratio, dilution index, mixture flow rate, and ambient pressure. The results show that the cellular instability band, which is located in the rich mixture region, changes little under the absence of gravity. Lifted normal-gravity flames near the cellular/lifted limits, however, are observed to become cellular when gravity is reduced. Observations of a transient cell growth period following ignition point to heat loss as being an important mechanism in the overall flame stability, dominating the stabilizing effect of buoyancy for these downwardly-propagating burner-anchored flames. The pulsations that are observed in the plume and diffusion flame generated downstream of the premixed flame in the fuel rich cases disappear in microgravity, verifying that these fluctuations are gravity related.

Ablation in the slit in combustion

NASA Astrophysics Data System (ADS)

Tairova, A. A.; Belyakov, G. V.; Chervinchuk, S. Yu.

2017-12-01

The understanding of the patterns of the front of exothermic reaction propagation in permeable media is necessary for a correct description of both natural and technological processes. The study of mechanisms of combustion and filtration flow in the slit consists in determining the conditions of propagation of melting waves and evaporation in a cocurrent gas flow as well the associated mass loss of the surface material. This paper presents the heat flow effect on the hydrocarbon reservoir model. The poly methyl methacrylate with the boiling point Tboil = 200°C and sublimation heat ΔHsubl = 40.29 kJ/mol was chosen as the model of the hydrocarbon layer, which on heating becomes liquid and gaseous (ethers and methyl methacrylate pairs). Heated gas flows along the slit preliminary created. The flow was maintained by a pump. The gas burner was installed at the entrance to the slit. The heat flow was constant. The impulse of gas flow and the mass loss of the material from the surface of the gap were continuously measured with scales. The pressure in the flow was controlled by the manometer.

Flow Velocity Computation, from Temperature and Number Density Measurements using Spontaneous Raman Scattering, for Supersonic Chemically Reacting Flows.

NASA Astrophysics Data System (ADS)

Satish Jeyashekar, Nigil; Seiner, John

2006-11-01

The closure problem in chemically reacting turbulent flows would be solved when velocity, temperature and number density (transport variables) are known. The transport variables provide input to momentum, heat and mass transport equations leading to analysis of turbulence-chemistry interaction, providing a pathway to improve combustion efficiency. There are no measurement techniques to determine all three transport variables simultaneously. This paper shows the formulation to compute flow velocity from temperature and number density measurements, made from spontaneous Raman scattering, using kinetic theory of dilute gases coupled with Maxwell-Boltzmann velocity distribution. Temperature and number density measurements are made in a mach 1.5 supersonic air flow with subsonic hydrogen co-flow. Maxwell-Boltzmann distribution can be used to compute the average molecular velocity of each species, which in turn is used to compute the mass-averaged velocity or flow velocity. This formulation was validated by Raman measurements in a laminar adiabatic burner where the computed flow velocities were in good agreement with hot-wire velocity measurements.

Reynolds number effects in combustion noise

NASA Technical Reports Server (NTRS)

Seshan, P. K.

1981-01-01

Acoustic emission spectra have been obtained for non-premixed turbulent combustion from two small diameter laboratory gas burners, two commercial gas burners and a large gas burner in the firebox of a Babcock-Wilcox Boiler (50,000 lb steam/hr). The changes in burner size and firing rate represent changes in Reynolds number and changes in air/fuel ratio represent departure from stoichiometric proportions. The combustion efficiency was measured independently through gas analysis. The acoustic spectra obtained from the various burners exhibit a persistent shape over the Reynolds number range of 8200-82,000. The spectra were analyzed for identification of a predictable frequency domain that is most responsive to, and readily correlated with, combustion efficiency. A simple parameter (consisting of the ratio of the average acoustic power output in the most responsive frequency bandwidth to the acoustic power level of the loudest frequency) is proposed whose value increases significantly and unmistakably as combustion efficiency approaches 100%. The dependence of the most responsive frequency domain on the various Reynolds numbers associated with turbulent jets is discussed.

Tomographic data fusion with CFD simulations associated with a planar sensor

NASA Astrophysics Data System (ADS)

Liu, J.; Liu, S.; Sun, S.; Zhou, W.; Schlaberg, I. H. I.; Wang, M.; Yan, Y.

2017-04-01

Tomographic techniques have great abilities to interrogate the combustion processes, especially when it is combined with the physical models of the combustion itself. In this study, a data fusion algorithm is developed to investigate the flame distribution of a swirl-induced environmental (EV) burner, a new type of burner for low NOx combustion. An electric capacitance tomography (ECT) system is used to acquire 3D flame images and computational fluid dynamics (CFD) is applied to calculate an initial distribution of the temperature profile for the EV burner. Experiments were also carried out to visualize flames at a series of locations above the burner. While the ECT images essentially agree with the CFD temperature distribution, discrepancies exist at a certain height. When data fusion is applied, the discrepancy is visibly reduced and the ECT images are improved. The methods used in this study can lead to a new route where combustion visualization can be much improved and applied to clean energy conversion and new burner development.

Evaluation of the low-temperature heat-exchanger fouling problem. Phase I report. Literature review and work plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Butcher, T.A.

1983-05-01

This report describes Phase I of a study of the fouling of condensing heat exchangers in residential oil-fired boiler and furnaces. The first phase consists of a review of available information on soot information in residential systems and the preparation of a work plan for Phase II. In the literature review the effects of burner type, startup and shutdown, time from tuning, fuel quality, combustion chambers, nozzles, and fuel additives are discussed. While data are available on soot emissions with current burners and fuels there are limited data available on advanced burners and degraded fuels with modern burners. The Phasemore » II work will provide an evaluation of the need for the development of advanced burner concepts for oil-fired condensing systems. Planned experimental work includes a furnace draft optimization study, extended fouling tests, a blue flame/yellow flame comparative test, and some degraded fuel teste.« less

Research and Development of Natural Draft Ultra-Low Emissions Burners for Gas Appliances

DOE Office of Scientific and Technical Information (OSTI.GOV)

Therkelsen, Peter; Cheng, Robert; Sholes, Darren

Combustion systems used in residential and commercial cooking appliances must be robust and easy to use while meeting air quality standards. Current air quality standards for cooking appliances are far greater than other stationary combustion equipment. By developing an advanced low emission combustion system for cooking appliances, the air quality impacts from these devices can be reduced. This project adapted the Lawrence Berkeley National Laboratory (LBNL) Ring-Stabilizer Burner combustion technology for residential and commercial natural gas fired cooking appliances (such as ovens, ranges, and cooktops). LBNL originally developed the Ring-Stabilizer Burner for a NASA funded microgravity experiment. This natural draftmore » combustion technology reduces NOx emissions significantly below current SCAQMD emissions standards without post combustion treatment. Additionally, the Ring-Stabilizer Burner technology does not require the assistance of a blower to achieve an ultra-low emission lean premix flame. The research team evaluated the Ring-Stabilizer Burner and fabricated the most promising designs based on their emissions and turndown.« less

Design and Development of Tilting Rotary Furnace

NASA Astrophysics Data System (ADS)

Sai Varun, V.; Tejesh, P.; Prashanth, B. N.

2018-02-01

Casting is the best and effective technique used for manufacturing products. The important accessory for casting is furnace. Furnace is used to melt the metal. A perfect furnace is one that reduces the wastage of material, reduces the cost of manufacturing and there by reduces the cost of production. Of all the present day furnaces there may be wastage of material, and the chances of increasing the time of manufacturing as the is continuous need of tilting of the furnace for every mould and then changing the moulds. Considering these aspects, a simple and least expensive tilting rotary furnace is designed and developed. The Tilting and Rotary Furnace consists of mainly melting chamber and the base. The metal enters the melting chamber through the input door that is provided on the top of the melting chamber. Inside the melting chamber there is a graphite furnace. The metal is melted in the graphite crucible. An insulation of ceramic fibre cloth is provided inside the furnace. The metal is melted using Propane gas. The propane gas is easily available and economic. The gas is burned using a pilot burner. The pilot burner is more efficient that other burners. The pilot burner is lit with a push button igniter. The pilot burner is located at the bottom of the combustion chamber. This enables the uniform heating of the metal inside the crucible. The temperature inside the melting chamber is noted using a temperature sensor. The gas input is cut-off if the temperature is exceeding a specific temperature. After the melting of the metal is done the furnace is tilted and after the mould is filled it is rotated. The external gears are used to controlling the tilting. The results of studies carried out for the design & development of low cost, simple furnace that can be mounted anywhere on the shop floor and this can be very much useful for the education purposes and small scale manufacturing. The furnace can be rotated in 360 degrees and can help in reducing the time taken in manufacturing. The furnace is provided with a rotation motion to the base which helps in providing a uniform distribution of molten metal to various moulds and can be used to fill a number of moulds with minimal wastage of the molten material. Due to the tilting action provided to the combustion chamber, the flow of metal can be controlled easily during pouring of molten metal into the moulds.

40 CFR Appendix A to Part 76 - Phase I Affected Coal-Fired Utility Units With Group 1 or Cell Burner Boilers

Code of Federal Regulations, 2011 CFR

2011-07-01

... Units With Group 1 or Cell Burner Boilers A Appendix A to Part 76 Protection of Environment... 1 or Cell Burner Boilers Table 1—Phase I Tangentially Fired Units State Plant Unit Operator ALABAMA... TOWER 9 CEN ILLINOIS PUB SER. INDIANA CULLEY 2 STHERN IND GAS & EL. INDIANA CULLEY 3 STHERN IND GAS & EL...

NATURAL GAS VARIABILITY IN CALIFORNIA: ENVIRONMENTAL IMPACTS AND DEVICE PERFORMANCE EXPERIMENTAL EVALUATION OF POLLUTANT EMISSIONS FROM RESIDENTIAL APPLIANCES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singer, Brett C.; Apte, Michael G.; Black, Douglas R.

2009-12-01

The effect of liquefied natural gas on pollutant emissions was evaluated experimentally with used and new appliances in the laboratory and with appliances installed in residences, targeting information gaps from previous studies. Burner selection targeted available technologies that are projected to comprise the majority of installed appliances over the next decade. Experiments were conducted on 13 cooktop sets, 12 ovens, 5 broiler burners, 5 storage water heaters, 4 forced air furnaces, 1 wall furnace, and 6 tankless water heaters. Air-free concentrations and fuel-based emission factors were determined for carbon monoxide, nitrogen oxides, nitrogen dioxide, and the number of (predominantly ultrafine)more » particles over complete burns?including transient effects (device warm-up and intermittent firing of burners) following ignition--and during more stable end-of-burn conditions. Formaldehyde was measured over multi-burn cycles. The baseline fuel was Northern California line gas with Wobbe number (a measure of fuel energy delivery rate) of 1320-1340; test fuels had Wobbe numbers of roughly 1390 and 1420, and in some cases 1360. No ignition or operational problems were observed during test fuel use. Baseline emissions varied widely across and within burner groups and with burner operational mode. Statistically significant emissions changes were observed for some pollutants on some burners.« less

Prediction of the Ignition Phases in Aeronautical and Laboratory Burners using Large Eddy Simulations

NASA Astrophysics Data System (ADS)

Gicquel, L. Y. M.; Staffelbach, G.; Sanjose, M.; Boileau, M.

2009-12-01

Being able to ignite or reignite a gas turbine engine in a cold and rarefied atmosphere is a critical issue for many aeronautical gas turbine manufacturers. From a fundamental point of view, the ignition of the first burner and the flame propagation from one burner to another are two phenomena that are usually not studied. The present work presents on-going and past Large Eddy Simulations (LES) on this specific subject and as investigated at CERFACS (European Centre for Research and Advanced Training in Scientific Computation) located in Toulouse, France. Validation steps and potential difficulties are underlined to ensure reliability of LES for such problems. Preliminary LES results on simple burners are then presented, followed by simulations of a complete ignition sequence in an annular helicopter chamber. For all cases and when possible, two-phase or purely gaseous LES have been applied to the experimentally simplified or the full geometries. For the latter, massively parallel computing (700 processors on a Cray XT3 machine) was essential to perform the computation. Results show that liquid fuel injection has a strong influence on the ignition times and the rate at which the flame progresses from burner to burner. The propagation speed characteristic of these phenomena is much higher than the turbulent flame speed. Based on an in-depth analysis of the computational data, the difference in speed is mainly identified as being due to thermal expansion and the flame speed is strongly modified by the main burner aerodynamics issued by the swirled injection.

Oxy-combustion of high water content fuels

NASA Astrophysics Data System (ADS)

Yi, Fei

As the issues of global warming and the energy crisis arouse extensive concern, more and more research is focused on maximizing energy efficiency and capturing CO2 in power generation. To achieve this, in this research, we propose an unconventional concept of combustion - direct combustion of high water content fuels. Due to the high water content in the fuels, they may not burn under air-fired conditions. Therefore, oxy-combustion is applied. Three applications of this concept in power generation are proposed - direct steam generation for the turbine cycle, staged oxy-combustion with zero flue gas recycle, and oxy-combustion in a low speed diesel-type engine. The proposed processes could provide alternative approaches to directly utilize fuels which intrinsically have high water content. A large amount of energy to remove the water, when the fuels are utilized in a conventional approach, is saved. The properties and difficulty in dewatering high water content fuels (e.g. bioethanol, microalgae and fine coal) are summarized. These fuels include both renewable and fossil fuels. In addition, the technique can also allow for low-cost carbon capture due to oxy-combustion. When renewable fuel is utilized, the whole process can be carbon negative. To validate and evaluate this concept, the research focused on the investigation of the flame stability and characteristics for high water content fuels. My study has demonstrated the feasibility of burning fuels that have been heavily diluted with water in a swirl-stabilized burner. Ethanol and 1-propanol were first tested as the fuels and the flame stability maps were obtained. Flame stability, as characterized by the blow-off limit -- the lowest O2 concentration when a flame could exist under a given oxidizer flow rate, was determined as a function of total oxidizer flow rate, fuel concentration and nozzle type. Furthermore, both the gas temperature contour and the overall ethanol concentration in the droplets along the spray were measured in the chamber for a stable flame. The experimental results indicate significant preferential vaporization of ethanol over water. Modeling results support this observation and indicate that the vaporization process is best described as the distillation limit mode with enhanced mass transfer by convection. Further, the influence of preferential vaporization on flame stability was investigated. A procedure was developed to evaluate the extent of preferential vaporization and subsequent flame stability of a fuel in aqueous solution. Various water soluble fuels were analyzed via this procedure in order to identify a chemical fuel showing strong preferential vaporization. t-Butanol was identified as having excellent physical and chemical properties, indicating stronger preferential vaporization than ethanol. Flame stability tests were run for aqueous solutions of both t-butanol and ethanol under identical flow conditions. Flame stability was characterized by the blow-off limit. In each comparison, the energy contents in the two solutions were kept the same. For the experiments under high swirl flow conditions (100% swirl flow), 12.5 wt% t-butanol has slightly lower blow-off limits than 15 wt% ethanol, and 8.3 wt% t-butanol has much lower blow-off limits than 10 wt% ethanol. For the experiments under a low swirl flow condition (50% swirl/50% axial flow), 12.5 wt% t-butanol has a much lower blow-off limit than 15 wt% ethanol. The time to release the fuel from a droplet was also calculated for both ethanol and t-butanol. For the same size droplet, the time to release t-butanol is much shorter than that of ethanol under the same conditions. Faster release of the fuel from water enhances flame stability, which is consistent with the experimental results. For the oxy-combustion characteristics of low-volatility fuel with high water content, glycerol was chosen as the fuel to study. It is found that self-sustained flame can be obtained for glycerol solution with concentration as high as 60 wt%, when burned in pure O2. However, the flame is lifted far away from the nozzle. To obtain a stable flame for a low glycerol concentration solution, t-butanol or ethanol was added as an additive. Experiments showed that an attached flame can be obtained by burning a mixture of 8.3 wt% t-butanol, 30 wt% glycerol and 61.7 wt% water (B8.3/G30) or 10 wt% ethanol, 30 wt% glycerol and 60 wt% water (E10/G30) under oxy-fired condition. The flame stability for B8.3/G30 and E10/G30 was characterized under 100% and 85% swirl flow conditions. Under 100% swirl flow condition, the blow-off limits are approximately the same for both cases. Under 85% swirl, the blow-off limits for B8.3/G30 are much lower in the low flow rate region. Additionally, the lift-off limits for B8.3/G30 are lower than those for E10/G30, which means the flame stability for B8.3/G30 is better. To study the flame structure, contours of temperature across the chamber's centerline were obtained for four attached flames. It was found that the flame becomes narrower as the swirl intensity decreases. A high temperature zone in the inner recirculation zone (IRZ) is formed for the four flames. This hot zone is critical to provide heat to vaporize the glycerol in near burner region, so that flame can be attached on the nozzle. For practical purposes, a PRB coal water slurry was studied in terms of preparation, characterization, atomization and combustion. A procedure to prepare stable coal water slurry from PRB coal was developed. Triton X-100 is a good nonionic surfactant for PRB coal. On the contrary, PSS, which is ionic, is not effective for PRB coal. Due to the hydrophilic surface property of PRB coal, the maximum loading of the coal in slurry can only reach 50 wt%. The viscosities of slurries containing various concentrations of Triton X-100 were measured. To deliver the slurry in a burner, two types of two fluid nozzles -- internal mixing and external mixing -- were investigated and both nozzles were able to generate a spray with good quality. Preliminary oxy-combustion experiments were successfully conducted. Due to the high swirl flow in the combustor, the nozzle overheated which caused clogging. Additional research is needed to solve this issue and characterize the flame systematically.

Aging of Diesel and Wood Burning Emissions in Smogchamber Experiments

NASA Astrophysics Data System (ADS)

Prevot, Andre S. H.

2010-05-01

Photochemical aging experiments were performed for emissions of a diesel passenger car and logwood-burner at the smogchamber at the Paul Scherrer Institute in Switzerland. The measurements include black carbon measurements (with Aethalometer, Multi-Angle Absorption Photometer, Single Particle Soot Photometer (SP-2), and Photoacoustic Spectrometer), organic mass measurements with the Aerodyne high-resolution Aerosol mass spectrometer and off-line GC-MS measurements. Single particle composition was measured with the TSI-Aerosol time-of-flight mass spectrometer. The size distribution is characterized with a scanning mobility particle sizer, and the hygroscopicity with a hygroscopicity tandem differential mobility analyzer. The given overview of the results of experiments during the last 1.5 years will focus on the formation secondary organic aerosol and include the oxidation of primary organic aerosols and the change of optical and hygroscopic properties. A considerable variability of most results is found for different after treatment systems of diesel cars and for different burning conditions of the log-wood burner which will be discussed in detail.

Nitramine smokeless propellant research

NASA Technical Reports Server (NTRS)

Cohen, N. S.; Strand, L. P.

1977-01-01

A transient ballistics and combustion model is derived to represent the closed vessel experiment that is widely used to characterize propellants. A computer program is developed to solve the time-dependent equations, and is applied to explain aspects of closed vessel behavior. In the case of nitramine propellants the cratering of the burning surface associated with combustion above break-point pressures augments the effective burning rate as deduced from the closed vessel experiment. Low pressure combustion is significantly affected by the ignition process and, in the case of nitramine propellants, by the developing and changing surface structure. Thus, burning rates deduced from the closed vessel experiment may or may not agree with those measured in the equilibrium strand burner. Series of T burner experiments are performed to compare the combustion instability characteristics of nitramine (HMX) containing propellants and ammonium perchlorate (AP)propellants. Although ash produced by more fuel rich propellants could have provided mechanical suppression, results from clean-burning propellants permit the conclusion that HMX reduces the acoustic driving.

Numerical analysis of an entire ceramic kiln under actual operating conditions for the energy efficiency improvement.

PubMed

Milani, Massimo; Montorsi, Luca; Stefani, Matteo; Saponelli, Roberto; Lizzano, Maurizio

2017-12-01

The paper focuses on the analysis of an industrial ceramic kiln in order to improve the energy efficiency and thus the fuel consumption and the corresponding carbon dioxide emissions. A lumped and distributed parameter model of the entire system is constructed to simulate the performance of the kiln under actual operating conditions. The model is able to predict accurately the temperature distribution along the different modules of the kiln and the operation of the many natural gas burners employed to provide the required thermal power. Furthermore, the temperature of the tiles is also simulated so that the quality of the final product can be addressed by the modelling. Numerical results are validated against experimental measurements carried out on a real ceramic kiln during regular production operations. The developed numerical model demonstrates to be an efficient tool for the investigation of different design solutions for the kiln's components. In addition, a number of control strategies for the system working conditions can be simulated and compared in order to define the best trade off in terms of fuel consumption and product quality. In particular, the paper analyzes the effect of a new burner type characterized by internal heat recovery capability aimed at improving the energy efficiency of the ceramic kiln. The fuel saving and the relating reduction of carbon dioxide emissions resulted in the order of 10% when compared to the standard burner. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of a Prototype Military Field Space Heater

DTIC Science & Technology

1983-04-01

COMBUSTION HEATERS TENT HEATERS LIQUID FUELS LIQUID FUEL BURNERS 2&< ABSTRACT rCamrtbmum «o rarerem ataT» ft namteaamry mod Identity by block...M1941 heater. This prototype features a large triple stage burner obtained from Holland that uses staged combustion to achieve clean burning with...M1941. This Dutch burner features staged combustion , which results in complete and very clean burning of diesel fuel. This report covers fabrication and

Effects of surface chemistry on hot corrosion life

NASA Technical Reports Server (NTRS)

Fryxell, R. E.; Leese, G. E.

1985-01-01

This program has its primary objective: the development of hot corrosion life prediction methodology based on a combination of laboratory test data and evaluation of field service turbine components which show evidence of hot corrosion. The laboratory program comprises burner rig testing by TRW. A summary of results is given for two series of burner rig tests. The life prediction methodology parameters to be appraised in a final campaign of burner rig tests are outlined.

Kerosene space heaters--combustion technology and kerosene characteristics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kubayashi, k.; I Wasaki, N.

1984-07-01

This paper describes kerosene combustion technology. Unvented wick-type kerosene space heaters are very popular in Japan because of their economy and convenience. In recent years new vaporized kerosene burners having premixed combustion systems have been developed to solve some of the problems encountered in the older portable type. Some of the features of the new burners are instantaneous ignition, no vaporizing deposit on the burner and a wide range heating capacity. These new kerosene heaters have four major components: an air supply fan, a fuel supply assembly, a burner assembly and a control assembly. These heaters are designed to bemore » highly reliable, have stable combustion characteristics, yield minimum carbon deposit. Finally, they are simple and inexpensive to operate.« less

Basic research on radiant burners. Semi-annual report, through July 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sullivan, J.D.

1991-10-01

Basic performance characteristics of radiant burners are explored in the broad-based study combining theoretical modeling and experimental validation of predictions. The work included fabrication of catalyzed substrates and fibers; incorporation of the catalysts into burners; testing of catalysts; and investigation of new catalyst sources. The progress of the study is detailed and further plans are outlined. A report on the preparation of palladium catalysts by Andre Blaise Kooh is included in the appendix.

On the effects of fuel leakage on CO production from household burners as revealed by LIF and CARS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van der Meij, C.E.; Mokhov, A.V.; Jacobs, R.A.A.M.

Measurements of the distributions of CO, OH, and temperature in flames from two commonly used, commercially available household burners are presented. The local mole fractions of CO and relative distribution of OH have been obtained using laser-induced fluorescence, while the local temperatures have, been determined by coherent anti-Stokes Raman scattering (CARS). For both burners, burning in the open air, CO formation outside the main flames has been observed and attributed to the leakage of fuel-air mixture at the edges of the flame, where the fuel is subsequently converted to CO in the boundary layer between the flame and the surroundings.more » For a rich-premixed, multiblade burner, which gives Bunsen-like flames, the CO produced by the leaking fuel appears to be oxidized by OH arising from the outer cones of adjacent flames, and burns out to low concentrations. In the case of a lean-premixed burner, the CO produced by fuel leakage remains in the cool boundary layer without adequate burnout. Possible consequences for appliance behavior are discussed.« less

Homogeneous Iron Phosphate Nanoparticles by Combustion of Sprays

PubMed Central

Rudin, Thomas; Pratsinis, Sotiris E.

2013-01-01

Low-cost synthesis of iron phosphate nanostructured particles is attractive for large scale fortification of basic foods (rice, bread, etc.) as well as for Li-battery materials. This is achieved here by flame-assisted and flame spray pyrolysis (FASP and FSP) of inexpensive precursors (iron nitrate, phosphate), solvents (ethanol), and support gases (acetylene and methane). The iron phosphate powders produced here were mostly amorphous and exhibited excellent solubility in dilute acid, an indicator of relative iron bioavailability. The amorphous and crystalline fractions of such powders were determined by X-ray diffraction (XRD) and their cumulative size distribution by X-ray disk centrifuge. Fine and coarse size fractions were obtained also by sedimentation and characterized by microscopy and XRD. The coarse size fraction contained maghemite Fe2O3 while the fine was amorphous iron phosphate. Furthermore, the effect of increased production rate (up to 11 g/h) on product morphology and solubility was explored. Using increased methane flow rates through the ignition/pilot flame of the FSP-burner and inexpensive powder precursors resulted in also homogeneous iron phosphate nanoparticles essentially converting the FSP to a FASP process. The powders produced by FSP at increased methane flow had excellent solubility in dilute acid as well. Such use of methane or even natural gas might be economically attractive for large scale flame-synthesis of nanoparticles. PMID:23407874

Fire Suppression in Low Gravity Using a Cup Burner

NASA Technical Reports Server (NTRS)

Takahashi, Fumiaki; Linteris, Gregory T.; Katta, Viswanath R.

2004-01-01

Longer duration missions to the moon, to Mars, and on the International Space Station increase the likelihood of accidental fires. The goal of the present investigation is to: (1) understand the physical and chemical processes of fire suppression in various gravity and O2 levels simulating spacecraft, Mars, and moon missions; (2) provide rigorous testing of numerical models, which include detailed combustion suppression chemistry and radiation sub-models; and (3) provide basic research results useful for advances in space fire safety technology, including new fire-extinguishing agents and approaches. The structure and extinguishment of enclosed, laminar, methane-air co-flow diffusion flames formed on a cup burner have been studied experimentally and numerically using various fire-extinguishing agents (CO2, N2, He, Ar, CF3H, and Fe(CO)5). The experiments involve both 1g laboratory testing and low-g testing (in drop towers and the KC-135 aircraft). The computation uses a direct numerical simulation with detailed chemistry and radiative heat-loss models. An agent was introduced into a low-speed coflowing oxidizing stream until extinguishment occurred under a fixed minimal fuel velocity, and thus, the extinguishing agent concentrations were determined. The extinguishment of cup-burner flames, which resemble real fires, occurred via a blowoff process (in which the flame base drifted downstream) rather than the global extinction phenomenon typical of counterflow diffusion flames. The computation revealed that the peak reactivity spot (the reaction kernel) formed in the flame base was responsible for attachment and blowoff of the trailing diffusion flame. Furthermore, the buoyancy-induced flame flickering in 1g and thermal and transport properties of the agents affected the flame extinguishment limits.

Fire Suppression in Low Gravity Using a Cup Burner

NASA Technical Reports Server (NTRS)

Takahashi, Fumiaki; Linteris, Gregory T.; Katta, Viswanath R.

2004-01-01

Longer duration missions to the moon, to Mars, and on the International Space Station increase the likelihood of accidental fires. The goal of the present investigation is to: (1) understand the physical and chemical processes of fire suppression in various gravity and O2 levels simulating spacecraft, Mars, and moon missions; (2) provide rigorous testing of numerical models, which include detailed combustion-suppression chemistry and radiation sub-models; and (3) provide basic research results useful for advances in space fire safety technology, including new fire-extinguishing agents and approaches.The structure and extinguishment of enclosed, laminar, methane-air co-flow diffusion flames formed on a cup burner have been studied experimentally and numerically using various fire-extinguishing agents (CO2, N2, He, Ar, CF3H, and Fe(CO)5). The experiments involve both 1g laboratory testing and low-g testing (in drop towers and the KC-135 aircraft). The computation uses a direct numerical simulation with detailed chemistry and radiative heat-loss models. An agent was introduced into a low-speed coflowing oxidizing stream until extinguishment occurred under a fixed minimal fuel velocity, and thus, the extinguishing agent concentrations were determined. The extinguishment of cup-burner flames, which resemble real fires, occurred via a blowoff process (in which the flame base drifted downstream) rather than the global extinction phenomenon typical of counterflow diffusion flames. The computation revealed that the peak reactivity spot (the reaction kernel) formed in the flame base was responsible for attachment and blowoff of the trailing diffusion flame. Furthermore, the buoyancy-induced flame flickering in 1g and thermal and transport properties of the agents affected the flame extinguishment limits.

The effect of oxygen enrichment on soot formation and thermal radiation in turbulent, non-premixed methane flames

DOE PAGES

Shaddix, Christopher R.; Williams, Timothy C.

2016-07-12

Non-premixed oxy-fuel combustion of natural gas is used in industrial applications where high-intensity heat is required, such as glass manufacturing and metal forging and shaping. In these applications, the high flame temperatures achieved by oxy-fuel combustion increase radiative heat transfer to the surfaces of interest and soot formation within the flame is desired for further augmentation of radiation. However, the high cost of cryogenic air separation has limited the penetration of oxy-fuel combustion technologies. New approaches to air separation are being developed that may reduce oxygen production costs, but only for intermediate levels of oxygen enrichment of air. To determinemore » the influence of oxygen enrichment on soot formation and radiation, we developed a non-premixed coannular burner in which oxygen concentrations and oxidizer flow rates can be independently varied, to distinguish the effects of turbulent mixing intensity from oxygen enrichment on soot formation and flame radiation. Local radiation intensities, soot concentrations, and soot temperatures have been measured using a thin-film thermopile, planar laser-induced incandescence (LII), and two-color imaging pyrometry, respectively. The measurements show that soot formation increases as the oxygen concentration decreases from 100% to 50%, helping to moderate a decrease in overall flame radiation. An increase in turbulence intensity has a marked effect on flame height, soot formation and thermal radiation, leading to decreases in all of these. The soot temperature decreases with a decrease in the oxygen concentration and increases with an increase in turbulent mixing intensity. Altogether, the results suggest that properly designed oxygen-enriched burners that enhance soot formation for intermediate levels of oxygen purity may be able to achieve thermal radiation intensities as high as 85% of traditional oxy-fuel burners utilizing high-purity oxygen.« less

The effect of oxygen enrichment on soot formation and thermal radiation in turbulent, non-premixed methane flames

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shaddix, Christopher R.; Williams, Timothy C.

Non-premixed oxy-fuel combustion of natural gas is used in industrial applications where high-intensity heat is required, such as glass manufacturing and metal forging and shaping. In these applications, the high flame temperatures achieved by oxy-fuel combustion increase radiative heat transfer to the surfaces of interest and soot formation within the flame is desired for further augmentation of radiation. However, the high cost of cryogenic air separation has limited the penetration of oxy-fuel combustion technologies. New approaches to air separation are being developed that may reduce oxygen production costs, but only for intermediate levels of oxygen enrichment of air. To determinemore » the influence of oxygen enrichment on soot formation and radiation, we developed a non-premixed coannular burner in which oxygen concentrations and oxidizer flow rates can be independently varied, to distinguish the effects of turbulent mixing intensity from oxygen enrichment on soot formation and flame radiation. Local radiation intensities, soot concentrations, and soot temperatures have been measured using a thin-film thermopile, planar laser-induced incandescence (LII), and two-color imaging pyrometry, respectively. The measurements show that soot formation increases as the oxygen concentration decreases from 100% to 50%, helping to moderate a decrease in overall flame radiation. An increase in turbulence intensity has a marked effect on flame height, soot formation and thermal radiation, leading to decreases in all of these. The soot temperature decreases with a decrease in the oxygen concentration and increases with an increase in turbulent mixing intensity. Altogether, the results suggest that properly designed oxygen-enriched burners that enhance soot formation for intermediate levels of oxygen purity may be able to achieve thermal radiation intensities as high as 85% of traditional oxy-fuel burners utilizing high-purity oxygen.« less

46 CFR 62.35-20 - Oil-fired main boilers.

Code of Federal Regulations, 2012 CFR

2012-10-01

... to prevent pocketing and explosive accumulations of combustible gases. (iii) The burner igniter must... of automatic detection of unsafe trip conditions. (h) Burner safety trip control system. (1) Each...

46 CFR 62.35-20 - Oil-fired main boilers.

Code of Federal Regulations, 2014 CFR

2014-10-01

... to prevent pocketing and explosive accumulations of combustible gases. (iii) The burner igniter must... of automatic detection of unsafe trip conditions. (h) Burner safety trip control system. (1) Each...

46 CFR 62.35-20 - Oil-fired main boilers.

Code of Federal Regulations, 2011 CFR

2011-10-01

... to prevent pocketing and explosive accumulations of combustible gases. (iii) The burner igniter must... of automatic detection of unsafe trip conditions. (h) Burner safety trip control system. (1) Each...

46 CFR 62.35-20 - Oil-fired main boilers.

Code of Federal Regulations, 2010 CFR

2010-10-01

... to prevent pocketing and explosive accumulations of combustible gases. (iii) The burner igniter must... of automatic detection of unsafe trip conditions. (h) Burner safety trip control system. (1) Each...

46 CFR 62.35-20 - Oil-fired main boilers.

Code of Federal Regulations, 2013 CFR

2013-10-01

... to prevent pocketing and explosive accumulations of combustible gases. (iii) The burner igniter must... of automatic detection of unsafe trip conditions. (h) Burner safety trip control system. (1) Each...

NOx Control for Utility Boiler OTR Compliance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamid Farzan

Under sponsorship of the Department of Energy's National Energy Technology Laboratory (NETL), the Babcock and Wilcox Company (B and W), and Fuel Tech teamed together to investigate an integrated solution for NO{sub x} control. The system is comprised of B and W's DRB-4Z{trademark} ultra low-NO{sub x} pulverized coal (PC) burner technology and Fuel Tech's NOxOUT{reg_sign}, a urea-based selective non-catalytic reduction (SNCR) technology. Development of the low-NO{sub x} burner technology has been a focus in B and W's combustion program. The DRB-4Z{trademark} burner is B and W's newest low-NO{sub x} burner capable of achieving very low NO{sub x}. The burner ismore » designed to reduce NO{sub x} by controlled mixing of the fuel and air. Based on data from several 500 to 600 MWe boilers firing PRB coal, NOx emissions levels of 0.15 to 0.20 lb/ 106 Btu have been achieved from the DRB-4Z{trademark} burners in combination with overfire air ports. Although NOx emissions from the DRB-4Z{trademark} burner are nearing the Ozone Transport Rule (OTR) level of 0.15 lb NO{sub x}/106 Btu, the utility boiler owners can still benefit from the addition of an SNCR and/or SCR system in order to comply with the stringent NO{sub x} emission levels facing them. Large-scale testing is planned in B and W's 100-million Btu/hr Clean Environment Development Facility (CEDF) that simulates the conditions of large coal-fired utility boilers. The objective of the project is to achieve a NO{sub x} level below 0.15 lb/106 Btu (with ammonia slip of less than 5 ppm) in the CEDF using PRB coal and B and W's DRB-4Z{trademark} low-NO{sub x} pulverized coal (PC) burner in combination with dual zone overfire air ports and Fuel Tech's NO{sub x}OUT{reg_sign}. During this period B and W prepared and submitted the project management plan and hazardous substance plan to DOE. The negotiation of a subcontract for Fuel Tech has been started.« less

Dielectric-barrier-discharge plasma-assisted hydrogen diffusion flame. Part 1: Temperature, oxygen, and fuel measurements by one-dimensional fs/ps rotational CARS imaging

DOE PAGES

Retter, Jonathan E.; Elliott, Gregory S.; Kearney, Sean P.

2018-02-21

One-dimensional hybrid fs/ps CARS imaging provides single-laser-shot measurements of temperature, oxygen, and hydrogen in a plasma-assisted hydrogen diffusion flame. The coaxial dielectric-barrier-discharge burner collapses the Re ~50 hydrogen diffusion flame to within ~5 mm of the burner surface at an applied AC potential of 8.75 kV at 18 kHz, coinciding nicely with the full spatial extent of the 1D CARS measurements. Translating the burner through the measurement volume allowed for measurements at numerous radial locations in increments of 1 mm with a resolution of 140 µm × 30 µm × 600 µm, sufficient to resolve spatial gradients in this unsteadymore » flame. Longer probe delays, required for improved dynamic range in regions of high temperature fluctuations, proved difficult to model as a result of a nontrivial decay in the O 2 Raman coherence arising from complexities associated with the triplet ground electronic state of the O 2 molecule. Oxygen linewidths were treated empirically using the observed O 2 coherence decay in spectra acquired from the product gases of lean, near-adiabatic H 2/air flames stabilized on a Hencken flat-flame burner. While still leading to errors up to 10% at worst, the empirically determined Raman linewidth factors eliminated any systematic error in the O 2/N 2 measurements with probe delay. Temperature measurements in the Hencken Burner flames proved to be insensitive to probe pulse delay, providing robust thermometry. Here, demonstration of this technique in both the canonical Hencken burner flames and a new DBD burner validates its effectiveness in producing multiple spatially resolved measurements in combustion environments. Measurements in the DBD burner revealed an unsteady, counterflow flattened flame structure near the fuel orifice which became unsteady as the reaction zone curves towards the surface for larger radial positions. Lastly, fluctuations in the fuel concentration were largest at the source, as the large, plasma-generated, unsteady external toroidal vortex that dominates the transport in this flame provides enhanced ventilation of the flame surface in close proximity to the fuel tube.« less

Dielectric-barrier-discharge plasma-assisted hydrogen diffusion flame. Part 1: Temperature, oxygen, and fuel measurements by one-dimensional fs/ps rotational CARS imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Retter, Jonathan E.; Elliott, Gregory S.; Kearney, Sean P.

One-dimensional hybrid fs/ps CARS imaging provides single-laser-shot measurements of temperature, oxygen, and hydrogen in a plasma-assisted hydrogen diffusion flame. The coaxial dielectric-barrier-discharge burner collapses the Re ~50 hydrogen diffusion flame to within ~5 mm of the burner surface at an applied AC potential of 8.75 kV at 18 kHz, coinciding nicely with the full spatial extent of the 1D CARS measurements. Translating the burner through the measurement volume allowed for measurements at numerous radial locations in increments of 1 mm with a resolution of 140 µm × 30 µm × 600 µm, sufficient to resolve spatial gradients in this unsteadymore » flame. Longer probe delays, required for improved dynamic range in regions of high temperature fluctuations, proved difficult to model as a result of a nontrivial decay in the O 2 Raman coherence arising from complexities associated with the triplet ground electronic state of the O 2 molecule. Oxygen linewidths were treated empirically using the observed O 2 coherence decay in spectra acquired from the product gases of lean, near-adiabatic H 2/air flames stabilized on a Hencken flat-flame burner. While still leading to errors up to 10% at worst, the empirically determined Raman linewidth factors eliminated any systematic error in the O 2/N 2 measurements with probe delay. Temperature measurements in the Hencken Burner flames proved to be insensitive to probe pulse delay, providing robust thermometry. Here, demonstration of this technique in both the canonical Hencken burner flames and a new DBD burner validates its effectiveness in producing multiple spatially resolved measurements in combustion environments. Measurements in the DBD burner revealed an unsteady, counterflow flattened flame structure near the fuel orifice which became unsteady as the reaction zone curves towards the surface for larger radial positions. Lastly, fluctuations in the fuel concentration were largest at the source, as the large, plasma-generated, unsteady external toroidal vortex that dominates the transport in this flame provides enhanced ventilation of the flame surface in close proximity to the fuel tube.« less

Numerical Modeling of Fuel Injection into an Accelerating, Turning Flow with a Cavity

NASA Astrophysics Data System (ADS)

Colcord, Ben James

Deliberate continuation of the combustion in the turbine passages of a gas turbine engine has the potential to increase the efficiency and the specific thrust or power of current gas-turbine engines. This concept, known as a turbine-burner, must overcome many challenges before becoming a viable product. One major challenge is the injection, mixing, ignition, and burning of fuel within a short residence time in a turbine passage characterized by large three-dimensional accelerations. One method of increasing the residence time is to inject the fuel into a cavity adjacent to the turbine passage, creating a low-speed zone for mixing and combustion. This situation is simulated numerically, with the turbine passage modeled as a turning, converging channel flow of high-temperature, vitiated air adjacent to a cavity. Both two- and three-dimensional, reacting and non-reacting calculations are performed, examining the effects of channel curvature and convergence, fuel and additional air injection configurations, and inlet conditions. Two-dimensional, non-reacting calculations show that higher aspect ratio cavities improve the fluid interaction between the channel flow and the cavity, and that the cavity dimensions are important for enhancing the mixing. Two-dimensional, reacting calculations show that converging channels improve the combustion efficiency. Channel curvature can be either beneficial or detrimental to combustion efficiency, depending on the location of the cavity and the fuel and air injection configuration. Three-dimensional, reacting calculations show that injecting fuel and air so as to disrupt the natural motion of the cavity stimulates three-dimensional instability and improves the combustion efficiency.

Database Assessment of Pollution Control in the Military Explosives and Propellants Production Industry.

DTIC Science & Technology

1986-02-01

published by the Electric Power Research Institute (EPRI 1982ab). The status of spray-dryer flue gas desulfurization and the DOWA process developed by...cooled by spray aeration and recirculated to the quencher and scrubber. The gas flow through the system is controlled by an induced draft fan. All...Figure 9.6). The flue gas from the MHF is composed of SO C8,CO,ILRO, CHS and NO . It passes through an after- 2, 2 2 ’ 2 x burner where H S is

The development of reactive fuel grains for pyrophoric relight of in-space hybrid rocket thrusters

NASA Astrophysics Data System (ADS)

Steiner, Matthew Wellington

This study presents and investigates a novel hybrid fuel grain that reacts pyrophorically with gaseous oxidizer to achieve restart of a hybrid rocket motor propulsion system while reducing cost and handling concerns. This reactive fuel grain (RFG) relies on the pyrophoric nature of finely divided metal particles dispersed in a solid dicyclopentadiene (DCPD) binder, which has been shown to encapsulate air-sensitive additives until they are exposed to combustion gases. An RFG is thus effectively inert in open air in the absence of an ignition source, though the particles encapsulated within remain pyrophoric. In practice, this means that an RFG that is ignited in the vacuum of space and then extinguished will expose unoxidized pyrophoric particles, which can be used to generate sufficient heat to relight the propellant when oxidizer is flowed. The experiments outlined in this work aim to develop a suitable pyrophoric material for use in an RFG, demonstrate pyrophoric relight, and characterize performance under conditions relevant to a hybrid rocket thruster. Magnesium, lithium, calcium, and an alloy of titanium, chromium, and manganese (TiCrMn) were investigated to determine suitability of pure metals as RFG additives. Additionally, aluminum hydride (AlH3), lithium aluminum hydride (LiAlH4), lithium borohydride (LiBH4), and magnesium hydride (MgH2) were investigated to determine suitability of metals hydrides as RFG additives or as precursors for pure-metal RFG additives. Pyrophoric metals have been previously investigated as additives for increasing the regression rate of hybrid fuels, but to the author's knowledge, these materials have not been specifically investigated for their ability to ignite a propellant pyrophorically. Commercial research-grade metals were obtained as coarse powders, then ball-milled to attempt to reduce particle size below a critical diameter needed for pyrophoricity. Magnesium hydride was ball-milled and then cycled in a hydride cycling apparatus to attempt to fracture the particles through hydrogen sorption and thermal stresses. These powders were then tested for pyrophoricity with atmospheric and pure concentrations of oxygen. The TiCrMn powder was chosen as the material for evaluation of propellant performance, and was mixed with DCPD in various weight ratios to determine the required additive loading needed for pyrophoricity of the bulk propellant. Weight percentages of 10, 20, 30, and 50 wt.% TiCrMn were used to evaluate relight capability and propellant performance, and weight loadings of 50, 70, and 90 wt.% TiCrMn were used to evaluate approximate maximum loading possible without rendering the propellant structurally unsound. Propellant tests were conducted in an opposed flow burner apparatus for sub-scale regression rate and relight experiments, and an optically accessible cylindrical combustion chamber (OCC) that allows high speed cameras to record the regressing propellant surface during combustion. Gaseous oxygen (GOX) was used as an oxidizer for all tests due to its ready availability and common use as a hybrid rocket oxidizer. Opposed flow burner experiments are an inexpensive means of rapidly testing various propellant formulations at different conditions, whereas OCC tests are useful for obtaining realistic data on how an RFG would likely operate as part of a propulsion system. Relight in the opposed flow burner was attempted by cycling oxygen and nitrogen flows with carefully timed solenoid valves to initiate and extinguish combustion, and to control the slow diffusion of oxygen to the surface of the propellant, which would render the TiCrMn non-pyrophoric. The opposed flow burner experiments did not conclusively demonstrate the pyrophoric relight capability of the RFG propellant due in part to the persistence of hot spots between oxygen and purge nitrogen cycles, as determined by high-speed imaging in the near infrared range. An opposed flow burner apparatus was then constructed within a vacuum chamber assembly thus preventing atmospheric oxygen from diffusing to the propellant surface, but these tests did not demonstrate pyrophoric relight. Future work is proposed to evaluate the effect of pyrophoric particle size in order to determine the role ignition delay of each particle has in the relight capability of RFGs. OCC experiments were conducted at a low and high GOX mass flux of approximately 150 and 300 kg/s/m2, respectively, at a nominal chamber pressure of 150 psia. Four strand compositions were used: pure DCPD, 30 wt.% pyrophoric TiCrMn powder with average particle diameters of approximately 1-10 microns, 30 wt.% oxidized TiCrMn powder with average particle diameters of approximately 1-10 microns, and 30 wt.% TiCrMn powder with average particle diameters of approximately 1-4 mm. Regression rate was measure by weight loss, average web thickness change at three axial locations on the strand, and through time-resolved tracking of the regressing propellant surface via high speed video. While visual observations suggest that the addition of TiCrMn significantly increases regression rate, initial data do not show a significant trend. Additionally, it is observed that the oxidized TiCrMn strands regress at the same rate as those loaded with pyrophoric TiCrMn, suggesting that erosive burning and heat addition of the added metal may be the cause of the observed increase in regression rate. The data are too sparse to make conclusions about the effect of particle size on regression rate, so further tests are recommended to develop a significant data set for the effect of pyrophoricity and particle size on regression rate. The test article was damaged at the end of the regression rate experimental campaign, which precluded the collection of relight data that was planned for strands loaded with 50 wt.% TiCrMn particles with an average diameter of approximately 1-4 mm. Though further tests are needed to demonstrate pyrophoric relight of an RFG, the current work establishes a baseline for RFG performance and suggests that pyrophoric relight is possible by tailoring the particle size of the pyrophoric metal additive to control heat release and ignition delay.

30 CFR 18.65 - Flame test of hose.

Code of Federal Regulations, 2013 CFR

2013-07-01

... MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Inspections and Tests § 18.65 Flame... wire gauze. (2) A Pittsburgh-Universal Bunsen-type burner (inside diameter of burner tube 11 mm.), or...

30 CFR 18.65 - Flame test of hose.

Code of Federal Regulations, 2011 CFR

2011-07-01

... MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Inspections and Tests § 18.65 Flame... wire gauze. (2) A Pittsburgh-Universal Bunsen-type burner (inside diameter of burner tube 11 mm.), or...

30 CFR 18.65 - Flame test of hose.

Code of Federal Regulations, 2014 CFR

2014-07-01

... MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Inspections and Tests § 18.65 Flame... wire gauze. (2) A Pittsburgh-Universal Bunsen-type burner (inside diameter of burner tube 11 mm.), or...

30 CFR 18.65 - Flame test of hose.

Code of Federal Regulations, 2012 CFR

2012-07-01

... MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Inspections and Tests § 18.65 Flame... wire gauze. (2) A Pittsburgh-Universal Bunsen-type burner (inside diameter of burner tube 11 mm.), or...

Continuous Liquid-Sample Introduction for Bunsen Burner Atomic Emission Spectrometry.

ERIC Educational Resources Information Center

Smith, Gregory D.; And Others

1995-01-01

Describes a laboratory-constructed atomic emission spectrometer with modular instrumentation components and a simple Bunsen burner atomizer with continuous sample introduction. A schematic diagram and sample data are provided. (DDR)

30 CFR 56.7803 - Lighting the burner.

Code of Federal Regulations, 2010 CFR

2010-07-01

... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Rotary Jet Piercing § 56.7803 Lighting the burner. A suitable means of protection shall be...

30 CFR 56.7803 - Lighting the burner.

Code of Federal Regulations, 2011 CFR

2011-07-01

... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Rotary Jet Piercing § 56.7803 Lighting the burner. A suitable means of protection shall be...

33. LOOKING EAST AT SPARE BUTTERFLY VALVE FOR BURNER CONNECTION ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

33. LOOKING EAST AT SPARE BUTTERFLY VALVE FOR BURNER CONNECTION ON HOT BLAST STOVES. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

Experimental and Numerical Research of a Novel Combustion Chamber for Small Gas Turbine Engines

NASA Astrophysics Data System (ADS)

Tuma, J.; Kubata, J.; Betak, V.; Hybl, R.

2013-04-01

New combustion chamber concept (based on burner JETIS-JET Induced Swirl) for small gas turbine engine (up to 200kW) is presented in this article. The combustion chamber concept is based on the flame stabilization by the generated swirl swirl generated by two opposite tangentially arranged jet tubes in the intermediate zone, this arrangement replaces air swirler, which is very complicated and expensive part in the scope of small gas turbines with annular combustion chamber. The mixing primary jets are oriented partially opposite to the main exhaust gasses flow, this enhances hot product recirculation and fuel-air mixing necessary for low NOx production and flame stability. To evaluate the designed concept a JETIS burner demonstrator (methane fuel) was manufactured and atmospheric experimental measurements of CO, NOx for various fuel nozzles and jet tubes the configuration were done. Results of these experiments and comparison with CFD simulation are presented here. Practical application of the new chamber concept in small gas turbine liquid fuel combustor was evaluated (verified) on 3 nozzles planar combustor sector test rig at atmospheric conditions results of the experiment and numerical simulation are also presented.

Gravity Effects Observed In Partially Premixed Flames

NASA Technical Reports Server (NTRS)

Puri, Ishwar K.; Aggarwal, Suresh K.; Lock, Andrew J.; Gauguly, Ranjan; Hegde, Uday

2003-01-01

Partially premixed flames (PPFs) contain a rich premixed fuel air mixture in a pocket or stream, and, for complete combustion to occur, they require the transport of oxidizer from an appropriately oxidizer-rich (or fuel-lean) mixture that is present in another pocket or stream. Partial oxidation reactions occur in fuel-rich portions of the mixture and any remaining unburned fuel and/or intermediate species are consumed in the oxidizer-rich portions. Partial premixing, therefore, represents that condition when the equivalence ratio (phi) in one portion of the flowfield is greater than unity, and in another section its value is less than unity. In general, for combustion to occur efficiently, the global equivalence ratio is in the range fuel-lean to stoichiometric. These flames can be established by design by placing a fuel-rich mixture in contact with a fuel-lean mixture, but they also occur otherwise in many practical systems, which include nonpremixed lifted flames, turbulent nonpremixed combustion, spray flames, and unwanted fires. Other practical applications of PPFs are reported elsewhere. Although extensive experimental studies have been conducted on premixed and nonpremixed flames under microgravity, there is a absence of previous experimental work on burner stabilized PPFs in this regard. Previous numerical studies by our group employing a detailed numerical model showed gravity effects to be significant on the PPF structure. We report on the results of microgravity experiments conducted on two-dimensional (established on a Wolfhard-Parker slot burner) and axisymmetric flames (on a coannular burner) that were investigated in a self-contained multipurpose rig. Thermocouple and radiometer data were also used to characterize the thermal transport in the flame.

Low NO sub x heavy fuel combustor concept program. Phase 1A: Combustion technology generation coal gas fuels

NASA Technical Reports Server (NTRS)

Sherlock, T. P.

1982-01-01

Combustion tests of two scaled burners using actual coal gas from a 25 ton/day fluidized bed coal gasifier are described. The two combustor configurations studied were a ceramic lined, staged rich/lean burner and an integral, all metal multiannual swirl burner (MASB). The tests were conducted over a range of temperature and pressures representative of current industrial combustion turbine inlet conditions. Tests on the rich lean burner were conducted at three levels of product gas heating values: 104, 197 and 254 btu/scf. Corresponding levels of NOx emissions were 5, 20 and 70 ppmv. Nitrogen was added to the fuel in the form of ammonia, and conversion efficiencies of fuel nitrogen to NOx were on the order of 4 percent to 12 percent, which is somewhat lower than the 14 percent to 18 percent conversion efficiency when src-2 liquid fuel was used. The MASB was tested only on medium btu gas (220 to 270 btu/scf), and produced approximately 80 ppmv NOx at rated engine conditions. Both burners operated similarly on actual coal gas and erbs fuel, and all heating values tested can be successfully burned in current machines.

Development of the Radiation Stabilized Distributed Flux Burner. Phase 1, final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sullivan, J.D.; Duret, M.J.

1997-06-01

The RSB was first developed for Thermally Enhanced Oil Recovery steamers which fire with a single 60 MMBtu/hr burner; the California Energy Commission and Chevron USA were involved in the burner development. The burner has also since found applications in refinery and chemical plant process heaters. All Phase I goals were successfully met: the RSB achieved sub-9 ppM NOx and sub-50 ppM CO emissions using high excess air, external flue gas recirculation (FGR), and fuel staging in the 3 MMBtu/hr laboratory watertube boiler. In a test in a 50,000 lb/hr oil field steamer with fuel staging, it consistently achieved sub-20more » ppM NOx and as low as 10 ppM NOx. With high CO{sub 2} casing gas in this steamer, simulating external FGR, sub-20 ppM NOx and as low as 5 ppM NOx were achieved. Burner material cost was reduced by 25% on a per Btu basis by increasing the effective surface firing rate at the burner; further reductions will occur in Phase II. The market for 30 ppM and 9 ppM low NOx burners has been identified as package boilers in the 50,000 to 250,000 lb/hr size range (the 30 ppM is for retrofit, the 9 ppM for the new boiler market). Alzeta and Babcock & Wilcox have teamed to sell both boiler retrofits and new boilers; they have identified boiler designs which use the compact flame shape of the RSB and can increase steam capacity while maintaining the same boiler footprint. Alzeta, Chevron, and B & W have teamed to identify sites to demonstrate the RSB in Phases II and III. In Phase II, the RSB will be demonstrated in a 100,000 lb/hr industrial watertube boiler.« less

Model-based development of low-level control strategies for transient operation of solid oxide fuel cell systems

NASA Astrophysics Data System (ADS)

Sorrentino, Marco; Pianese, Cesare

The exploitation of an SOFC-system model to define and test control and energy management strategies is presented. Such a work is motivated by the increasing interest paid to SOFC technology by industries and governments due to its highly appealing potentialities in terms of energy savings, fuel flexibility, cogeneration, low-pollution and low-noise operation. The core part of the model is the SOFC stack, surrounded by a number of auxiliary devices, i.e. air compressor, regulating pressure valves, heat exchangers, pre-reformer and post-burner. Due to the slow thermal dynamics of SOFCs, a set of three lumped-capacity models describes the dynamic response of fuel cell and heat exchangers to any operation change. The dynamic model was used to develop low-level control strategies aimed at guaranteeing targeted performance while keeping stack temperature derivative within safe limits to reduce stack degradation due to thermal stresses. Control strategies for both cold-start and warmed-up operations were implemented by combining feedforward and feedback approaches. Particularly, the main cold-start control action relies on the precise regulation of methane flow towards anode and post-burner via by-pass valves; this strategy is combined with a cathode air-flow adjustment to have a tight control of both stack temperature gradient and warm-up time. Results are presented to show the potentialities of the proposed model-based approach to: (i) serve as a support to control strategies development and (ii) solve the trade-off between fast SOFC cold-start and avoidance of thermal-stress caused damages.

A study of burning processes of fossil fuels in straitened conditions of furnaces in low capacity boilers by an example of natural gas

NASA Astrophysics Data System (ADS)

Roslyakov, P. V.; Proskurin, Y. V.; Khokhlov, D. A.; Zaichenko, M. N.

2018-03-01

The aim of this work is to research operations of modern combined low-emission swirl burner with a capacity of 2.2 MW for fire-tube boiler type KV-GM-2.0, to ensure the effective burning of natural gas, crude oil and diesel fuel. For this purpose, a computer model of the burner and furnace chamber has been developed. The paper presents the results of numerical investigations of the burner operation, using the example of natural gas in a working load range from 40 to 100%. The basic features of processes of fuel burning in the cramped conditions of the flame tube have been identified to fundamentally differ from similar processes in the furnaces of steam boilers. The influence of the design of burners and their operating modes on incomplete combustion of fuel and the formation of nitrogen oxides has been determined.

Low NO.sub.x burner system

DOEpatents

Kitto, Jr., John B.; Kleisley, Roger J.; LaRue, Albert D.; Latham, Chris E.; Laursen, Thomas A.

1993-01-01

A low NO.sub.x burner system for a furnace having spaced apart front and rear walls, comprises a double row of cell burners on each of the front and rear walls. Each cell burner is either of the inverted type with a secondary air nozzle spaced vertically below a coal nozzle, or the non-inverted type where the coal nozzle is below the secondary air port. The inverted and non-inverted cells alternate or are provided in other specified patterns at least in the lower row of cells. A small percentage of the total air can be also provided through the hopper or hopper throat forming the bottom of the furnace, or through the boiler hopper side walls. A shallow angle impeller design also advances the purpose of the invention which is to reduce CO and H.sub.2 S admissions while maintaining low NO.sub.x generation.

Experimental study of the thermal-acoustic efficiency in a long turbulent diffusion-flame burner

NASA Technical Reports Server (NTRS)

Mahan, J. R.

1983-01-01

A two-year study of noise production in a long tubular burner is described. The research was motivated by an interest in understanding and eventually reducing core noise in gas turbine engines. The general approach is to employ an acoustic source/propagation model to interpret the sound pressure spectrum in the acoustic far field of the burner in terms of the source spectrum that must have produced it. In the model the sources are assumed to be due uniquely to the unsteady component of combustion heat release; thus only direct combustion-noise is considered. The source spectrum is then the variation with frequency of the thermal-acoustic efficiency, defined as the fraction of combustion heat release which is converted into acoustic energy at a given frequency. The thrust of the research was to study the variation of the source spectrum with the design and operating parameters of the burner.

Characterization of the non axial thrust generated by large solid propellant rocket motors in three axis stabilized ascent

NASA Technical Reports Server (NTRS)

Kosmann, W. J.; Dionne, E. R.; Klemetson, R. W.

1978-01-01

Nonaxial thrusts produced by solid rocket motors during three-axis stabilized attitude control have been determined from ascent experience on twenty three Burner II, Burner IIA and Block 5D-1 upper stage vehicles. A data base representing four different rocket motor designs (three spherical and one extended spherical) totaling twenty five three-axis stabilized firings is generated. Solid rocket motor time-varying resultant and lateral side force vector magnitudes, directions and total impulses, and roll torque couple magnitudes, directions, and total impulses are tabulated in the appendix. Population means and three sigma deviations are plotted. Existing applicable ground test side force and roll torque magnitudes and total impulses are evaluated and compared to the above experience data base. Within the spherical motor population, the selected AEDC ground test data consistently underestimated experienced motor side forces, roll torques and total impulses. Within the extended spherical motor population, the selected AEDC test data predicted experienced motor side forces, roll torques, and total impulses, with surprising accuracy considering the very small size of the test and experience populations.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, Bradley; Davis, Kevin; Senior, Constance

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 inmore » 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) Assessment of oxy-combustion impacts in two full-scale coal-fired utility boiler retrofits based on computational fluid dynamics (CFD) modeling of air-fired and oxygen-fired operation. This research determined that it is technically feasible to retrofit the combustion system in an air-fired boiler for oxy-fired operation. The impacts of CO{sub 2} flue gas recycle and burner 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) were minimal, with the exception of high sulfur levels resulting from untreated flue gas recycle with medium and high-sulfur coals. This work focused on combustion in the radiant and convective sections of the boiler and did not address boiler system integration issues, plant efficiencies, impacts on downstream air pollution control devices, or CO{sub 2} capture and compression. The experimental data, oxy-firing system principles and oxy-combustion process mechanisms provided by this work can be used by electric utilities, boiler OEMs, equipment suppliers, design firms, software vendors, consultants and government agencies to assess retrofit applications of oxy-combustion technologies to existing boilers and to guide development of new designs.« less

Trajectory, Development, and Temperature of Spark Kernels Exiting into Quiescent Air (Preprint)

DTIC Science & Technology

2012-04-01

spark is an electrical discharge in which a portion of the energy is transferred to plasma and the surrounding fluid and the remaining portion is lost...integrated radiation intensity, λα λ λ λλλ dII ∫=∆ 2 1 . (1) αλ is the spectral absorption coefficient which accounts for variations...premixed hydrogen flame anchored to a Hencken burner. This flame has been well characterized by CARS measurements26,27. A temperature profile26 was assumed

SITE PROGRAM EVALUATION OF THE SONOTECH PULSE COMBUSTION BURNER TECHNOLOGY - TECHNICAL RESULTS

EPA Science Inventory

A series of demonstration tests was performed at the Environmental Protection Agency's (EPA's) Incineration Research Facility (IRF) under the Superfund Innovative Technology Evaluation (SITE) program. These tests, twelve in all, evaluated a pulse combustion burner technology dev...

A CFD-Based Study of the Feasibility of Adapting an Erosion Burner Rig for Examining the Effect of CMAS Deposition Corrosion on Environmental Barrier Coatings

NASA Technical Reports Server (NTRS)

Miller, Robert A.; Kuczmarski, Maria A.

2015-01-01

Thermodynamic and computational fluid dynamics modeling has been conducted to examine the feasibility of adapting the NASA-Glenn erosion burner rigs for use in studies of corrosion of environmental barrier coatings by the deposition of molten CMAS. The effect of burner temperature, Mach number, particle preheat, duct heating, particle size, and particle phase (crystalline vs. glass) were analyzed. Detailed strategies for achieving complete melting of CMAS particles were developed, thereby greatly improving the probability of future successful experimental outcomes.

Feasibility Study of Regenerative Burners in Aluminum Holding Furnaces

NASA Astrophysics Data System (ADS)

Hassan, Mohamed I.; Al Kindi, Rashid

2014-09-01

Gas-fired aluminum holding reverberatory furnaces are currently considered to be the lowest efficiency fossil fuel system. A considerable volume of gas is consumed to hold the molten metal at temperature that is much lower than the flame temperature. This will lead to more effort and energy consumption to capture the excessive production of the CO2. The concern of this study is to investigate the feasibility of the regenerative-burners' furnaces to increase the furnace efficiency to reduce gas consumption per production and hence result in less CO2 production. Energy assessments for metal holding furnaces are considered at different operation conditions. Onsite measurements, supervisory control and data acquisition data, and thermodynamics analysis are performed to provide feasible information about the gas consumption and CO2 production as well as area of improvements. In this study, onsite measurements are used with thermodynamics modeling to assess a 130 MT rectangular furnace with two regenerative burners and one cold-air holding burner. The assessment showed that the regenerative burner furnaces are not profitable in saving energy, in addition to the negative impact on the furnace life. However, reducing the holding and door opening time would significantly increase the operation efficiency and hence gain the benefit of the regenerative technology.

Experimental Study of High-Pressure Rotating Detonation Combustion in Rocket Environments

NASA Astrophysics Data System (ADS)

Stechmann, David Paul

Rotating Detonation Engines (RDEs) represent a promising pressure-gain combustion technology for improving the performance of existing rocket engines. While ample theoretical evidence exists for these benefits in ideal scenarios, additional research is needed to characterize the operational behavior of these devices at high pressure and validate the expected performance gains in practice. To this end, Purdue University developed a high-pressure experimental staged-combustion RDE with a supersonic plug expansion nozzle and conducted four test campaigns using this engine. The first two campaigns employed gaseous hydrogen fuel in conjunction with a liquid oxygen pre-burner. The final two campaigns employed methane and natural gas fuels. Propellant mass flows ranged from 0.47 lbm/s (0.21 Kg/s) to 8.41 lbm/s (3.8 kg/s) while mean chamber pressures ranged from 61 psia (4.1 atm) to 381 psia (25.9 atm). Results from tests conducted with hydrogen were mixed. Detonation briefly appeared at shutdown in some configurations, but the combustor behavior was generally dominated by flame holding instead of detonation. Injector erosion and instrumentation damage were also persistent challenges. Results from tests conducted with natural gas and methane were much more successful. Overall, several different types of detonation wave behavior were observed depending on test configuration and operating conditions. In all configurations, the engine thrust, chamber pressure, wave speed, and wave behavior were characterized for differences in injector orifice area, injection location, chamber width, pre-burner operating temperature, equivalence ratio, mass flow, and throat configuration. General aspects of the plume structure, startup behavior, and dynamic oxidizer manifold response were also characterized. Two configurations were also tested with a transparent combustor to characterize wave height and profile. These observations and measurements provided insight into the effects that high-pressures and rocket propellants have on RDE operating behavior. One of the more intriguing results from the experimental campaigns described above was the simple fact that natural gas and methane behaved so differently from hydrogen despite similar operating pressures, flow rates, and injector geometry. Simplified analysis and modeling of the injector dynamic response, mixing processes, and chemical kinetics provided insight into these differences and the scalability of these processes with pressure. In particular, the chemical kinetic analysis suggests that heat release during the injection and mixing phase can dominate the chamber behavior and prevent stable limit cycle detonation from occurring with certain propellant combinations above certain pressures. These results support the observed differences in engine operating behavior, and they provide insight into potential operability limits of gas-phase RDEs. In addition to the contrast between natural gas and hydrogen, several other important observations were made during the experimental RDE evaluation process. In particular, the installation of a convergent throat appeared to suppress detonation behavior. The number of waves was also invariant with respect to the mass flow and chamber pressure, and a natural transition into limit-cycle detonation modes (i.e. self-excited instabilities) appeared despite using a torch igniter with no initial detonation. Significant manifold interaction and an overall destabilizing effect in the limit-cycle detonation cycle tended to occur at low injector pressure ratios. The relationship between pressure, wave speed, and thrust did not follow the expected correlation and instead displayed a more complex configuration-dependent relationship. While the delivered thrust did not exceed theoretical values for a constant pressure cycle, thrust performance greater than 90% was achieved in configurations with simple injector geometries, simple expansion nozzle geometries and a chamber L* of only 2.75 inches. This suggests that further improvements are possible when heat loss into the wall is considered and improved injector designs are implemented. While heat flux was not measured during any experimental test cases, post-test analysis of the chamber environment using available data suggests that heat flux may be moderately higher in RDEs than in constant pressure combustors operating at the same mean flow conditions. Nevertheless, the computed heat flux was based on limited data and may have been affected by localized conditions near the injector face, so uncertainty remains in this area. Since appreciable uncertainty exists in the theoretical performance benefits relative to the measured experimental values, a detonation engine performance model was developed using modifications to existing zero-dimensional rocket performance relations. This approach made it possible to rapidly characterize the effects of different engine operating parameters on expected performance gains including propellant choice, equivalence ratio, initial propellant temperature, chamber pressure, nozzle configuration, nozzle expansion area, and ambient pressure. While the model was relatively simple, it captured the expected "DC shift" in mean chamber pressure between constant pressure combustors and combustors with steep-fronted non-linear instabilities. (Abstract shortened by ProQuest.).

Process for oil shale retorting using gravity-driven solids flow and solid-solid heat exchange

DOEpatents

Lewis, A.E.; Braun, R.L.; Mallon, R.G.; Walton, O.R.

1983-09-21

A cascading bed retorting process and apparatus are disclosed in which cold raw crushed shale enters at the middle of a retort column into a mixer stage where it is rapidly mixed with hot recycled shale and thereby heated to pyrolysis temperature. The heated mixture then passes through a pyrolyzer stage where it resides for a sufficient time for complete pyrolysis to occur. The spent shale from the pyrolyzer is recirculated through a burner stage where the residual char is burned to heat the shale which then enters the mixer stage.

Process for oil shale retorting using gravity-driven solids flow and solid-solid heat exchange

DOEpatents

Lewis, Arthur E.; Braun, Robert L.; Mallon, Richard G.; Walton, Otis R.

1986-01-01

A cascading bed retorting process and apparatus in which cold raw crushed shale enters at the middle of a retort column into a mixer stage where it is rapidly mixed with hot recycled shale and thereby heated to pyrolysis temperature. The heated mixture then passes through a pyrolyzer stage where it resides for a sufficient time for complete pyrolysis to occur. The spent shale from the pyrolyzer is recirculated through a burner stage where the residual char is burned to heat the shale which then enters the mixer stage.

System Study for Axial Vane Engine Technology

NASA Technical Reports Server (NTRS)

Badley, Patrick R.; Smith, Michael R.; Gould, Cedric O.

2008-01-01

The purpose of this engine feasibility study was to determine the benefits that can be achieved by incorporating positive displacement axial vane compression and expansion stages into high bypass turbofan engines. These positive-displacement stages would replace some or all of the conventional compressor and turbine stages in the turbine engine, but not the fan. The study considered combustion occurring internal to an axial vane component (i.e., Diesel engine replacing the standard turbine engine combustor, burner, and turbine); and external continuous flow combustion with an axial vane compressor and an axial vane turbine replacing conventional compressor and turbine systems.

Heating Systems Specialist.

ERIC Educational Resources Information Center

Air Force Training Command, Sheppard AFB, TX.

This instructional package is intended for use in training Air Force personnel enrolled in a program for apprentice heating systems specialists. Training includes instruction in fundamentals and pipefitting; basic electricity; controls, troubleshooting, and oil burners; solid and gas fuel burners and warm air distribution systems; hot water…

THE SITE DEMONSTRATION OF THE AMERICAN COMBUSTION PYRETRON OXYGEN-ENHANCED BURNER

EPA Science Inventory

A demonstration of the American Combustion Pyretron^TM oxygen-enhanced burner ws conducted under the Superfund Innovative Technology Evaluation (SITE) program. The Demonstration was conducted at the U.S. EPA's Combustion Research Facility (CRF) in Jefferson, Arkansas....

SOX OUT ON A LIMB (LIMESTONE INJECTION MULTISTAGE BURNER)

EPA Science Inventory

The paper describes the most recent results from the Limestone Injection Multistage Burner (LIMB) program, covering results from the wall-fired demonstration. Tests were conducted to determine the efficacy of commercial calcium hydroxide (Ca(OH)2) and of calcium-lignosulfonate-mo...

DEVELOPMENTS IN LIMB (LIMESTONE INJECTION MULTISTAGE BURNER) TECHNOLOGY

EPA Science Inventory

The paper describes the most recent results from the Limestone Injection Multistage Burner (LIMB) program, results from the wall-fired demonstration. Tests were conducted to determine the efficacy of commercial calcium hydroxide--Ca(OH)2--supplied by Marblehead Lime Co. and of ca...

Emissions from gas fired agricultural burners

USDA-ARS?s Scientific Manuscript database

Because of the Federal Clean Air Act, the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) began defining Best Available Control Technology (BACT) for NOx emissions from cotton gin drying system gas fired burners in its jurisdiction. The NOx emission levels of conventionally used...

Low NOx combustion and SCR flow field optimization in a low volatile coal fired boiler.

PubMed

Liu, Xing; Tan, Houzhang; Wang, Yibin; Yang, Fuxin; Mikulčić, Hrvoje; Vujanović, Milan; Duić, Neven

2018-08-15

Low NO x burner redesign and deep air staging have been carried out to optimize the poor ignition and reduce the NO x emissions in a low volatile coal fired 330 MW e boiler. Residual swirling flow in the tangentially-fired furnace caused flue gas velocity deviations at furnace exit, leading to flow field unevenness in the SCR (selective catalytic reduction) system and poor denitrification efficiency. Numerical simulations on the velocity field in the SCR system were carried out to determine the optimal flow deflector arrangement to improve flow field uniformity of SCR system. Full-scale experiment was performed to investigate the effect of low NO x combustion and SCR flow field optimization. Compared with the results before the optimization, the NO x emissions at furnace exit decreased from 550 to 650 mg/Nm³ to 330-430 mg/Nm³. The sample standard deviation of the NO x emissions at the outlet section of SCR decreased from 34.8 mg/Nm³ to 7.8 mg/Nm³. The consumption of liquid ammonia reduced from 150 to 200 kg/h to 100-150 kg/h after optimization. Copyright © 2018. Published by Elsevier Ltd.

Design and field demonstration of a low-NOx burner for TEOR (thermally enhanced oil recovery) steamers

DOE Office of Scientific and Technical Information (OSTI.GOV)

England, G.C.; Kwan, Y.; Payne, R.

1984-10-01

The paper discusses a program that addresses the need for advanced NOx control technology for thermally enhanced oil recovery (TEOR) steam generators. A full-scale (60 million Btu/hr) burner system has been developed and tested, the concept for which was based on fundamental studies. Test results are included for full-scale burner performance in an experimental test furnace, and in a field-operating steam generator which was subsequently retrofitted in a Kern County, California, oilfield. (NOTE: NOx control techniques including low-NOx burners, postflame NH/sub 3/ injection, or other postflame treatment methods--e.g., selective catalytic reduction--have been considered in order to comply with regulations. Themore » level of NOx control required to meet both growth and air quality goals has typically been difficult to achieve with available technology while maintaining acceptable CO and particulate emissions as well as practical flame conditions within the steamer.)« less

Experimental gas-fired pulse-combustion studies

NASA Technical Reports Server (NTRS)

Blomquist, C. A.

1982-01-01

Experimental studies conducted at Argonne National Laboratory on a gas-fired, water-cooled, Helmholtz-type pulse combustion burner are discussed. In addition to the experimental work, information is presented on the evolution of pulse combustion, the types of pulse combustion burners and their applications, and the types of fuels used. Also included is a survey of other pertinent studies of gas-fired pulse combustion. The burner used in the Argonne research effort was equipped with adjustable air and gas flapper valves and was operated stably over a heat-input range of 30,000 to 200,000 Btu/h. The burner's overall heat transfer in the pulsating mode was 22 to 31% higher than when the unit was operated in the steady mode. Important phenomena discussed include (1) effects on performance produced by inserting a corebustor to change tailpipe diameter, (2) effects observed following addition of an air-inlet decoupling chamber to the unit, and (3) occurrence of carbon monoxide in the exhaust gas.

Enhanced Combustion Low NOx Pulverized Coal Burner

DOE Office of Scientific and Technical Information (OSTI.GOV)

David Towle; Richard Donais; Todd Hellewell

2007-06-30

For more than two decades, Alstom Power Inc. (Alstom) has developed a range of low cost, infurnace technologies for NOx emissions control for the domestic U.S. pulverized coal fired boiler market. This includes Alstom's internally developed TFS 2000{trademark} firing system, and various enhancements to it developed in concert with the U.S. Department of Energy. As of the date of this report, more than 270 units representing approximately 80,000 MWe of domestic coal fired capacity have been retrofit with Alstom low NOx technology. Best of class emissions range from 0.18 lb/MMBtu for bituminous coal to 0.10 lb/MMBtu for subbituminous coal, withmore » typical levels at 0.24 lb/MMBtu and 0.13 lb/MMBtu, respectively. Despite these gains, NOx emissions limits in the U.S. continue to ratchet down for new and existing boiler equipment. On March 10, 2005, the Environmental Protection Agency (EPA) announced the Clean Air Interstate Rule (CAIR). CAIR requires 25 Eastern states to reduce NOx emissions from the power generation sector by 1.7 million tons in 2009 and 2.0 million tons by 2015. Low cost solutions to meet such regulations, and in particular those that can avoid the need for a costly selective catalytic reduction system (SCR), provide a strong incentive to continue to improve low NOx firing system technology to meet current and anticipated NOx control regulations. The overall objective of the work is to develop an enhanced combustion, low NOx pulverized coal burner, which, when integrated with Alstom's state-of-the-art, globally air staged low NOx firing systems will provide a means to achieve: Less than 0.15 lb/MMBtu NOx emissions when firing a high volatile Eastern or Western bituminous coal, Less than 0.10 lb/MMBtu NOx emissions when firing a subbituminous coal, NOx reduction costs at least 25% lower than the costs of an SCR, Validation of the NOx control technology developed through large (15 MWt) pilot scale demonstration, and Documentation required for economic evaluation and commercial application. During the project performance period, Alstom performed computational fluid dynamics (CFD) modeling and large pilot scale combustion testing in its Industrial Scale Burner Facility (ISBF) at its U.S. Power Plant Laboratories facility in Windsor, Connecticut in support of these objectives. The NOx reduction approach was to optimize near-field combustion to ensure that minimum NOx emissions are achieved with minimal impact on unburned carbon in ash, slagging and fouling, corrosion, and flame stability/turn-down. Several iterations of CFD and combustion testing on a Midwest coal led to an optimized design, which was extensively combustion tested on a range of coals. The data from these tests were then used to validate system costs and benefits versus SCR. Three coals were evaluated during the bench-scale and large pilot-scale testing tasks. The three coals ranged from a very reactive subbituminous coal to a moderately reactive Western bituminous coal to a much less reactive Midwest bituminous coal. Bench-scale testing was comprised of standard ASTM properties evaluation, plus more detailed characterization of fuel properties through drop tube furnace testing and thermogravimetric analysis. Bench-scale characterization of the three test coals showed that both NOx emissions and combustion performance are a strong function of coal properties. The more reactive coals evolved more of their fuel bound nitrogen in the substoichiometric main burner zone than less reactive coal, resulting in the potential for lower NOx emissions. From a combustion point of view, the more reactive coals also showed lower carbon in ash and CO values than the less reactive coal at any given main burner zone stoichiometry. According to bench-scale results, the subbituminous coal was found to be the most amenable to both low NOx, and acceptably low combustibles in the flue gas, in an air staged low NOx system. The Midwest bituminous coal, by contrast, was predicted to be the most challenging of the three coals, with the Western bituminous coal predicted to behave in-between the subbituminous coal and the Midwest bituminous coal. CFD modeling was used to gain insight into the mechanisms governing nozzle tip performance with respect to NOx emissions. The CFD simulations were run as steady state, turbulent, non-reacting flow with heat transfer and focused on predicting the near field mixing and particle dispersion rates. CFD results were used to refine the proposed tip concepts before they were built, as well as to help identify and evaluate possible improvements to the tips for subsequent test weeks.« less

Ensemble Diffraction Measurements of Spray Combustion in a Novel Vitiated Coflow Turbulent Jet Flame Burner

NASA Technical Reports Server (NTRS)

Cabra, R.; Hamano, Y.; Chen, J. Y.; Dibble, R. W.; Acosta, F.; Holve, D.

2000-01-01

An experimental investigation is presented of a novel vitiated coflow spray flame burner. The vitiated coflow emulates the recirculation region of most combustors, such as gas turbines or furnaces; additionally, since the vitiated gases are coflowing, the burner allows exploration of the chemistry of recirculation without the corresponding fluid mechanics of recirculation. As such, this burner allows for chemical kinetic model development without obscurations caused by fluid mechanics. The burner consists of a central fuel jet (droplet or gaseous) surrounded by the oxygen rich combustion products of a lean premixed flame that is stabilized on a perforated, brass plate. The design presented allows for the reacting coflow to span a large range of temperatures and oxygen concentrations. Several experiments measuring the relationships between mixture stoichiometry and flame temperature are used to map out the operating ranges of the coflow burner. These include temperatures as low 300 C to stoichiometric and oxygen concentrations from 18 percent to zero. This is achieved by stabilizing hydrogen-air premixed flames on a perforated plate. Furthermore, all of the CO2 generated is from the jet combustion. Thus, a probe sample of NO(sub X) and CO2 yields uniquely an emission index, as is commonly done in gas turbine engine exhaust research. The ability to adjust the oxygen content of the coflow allows us to steadily increase the coflow temperature surrounding the jet. At some temperature, the jet ignites far downstream from the injector tube. Further increases in the coflow temperature results in autoignition occurring closer to the nozzle. Examples are given of methane jetting into a coflow that is lean, stoichiometric, and even rich. Furthermore, an air jet with a rich coflow produced a normal looking flame that is actually 'inverted' (air on the inside, surrounded by fuel). In the special case of spray injection, we demonstrate the efficacy of this novel burner with a methanol spray in a vitiated coflow. As a proof of concept, an ensemble light diffraction (ELD) optical instrument was used to conduct preliminary measurements of droplet size distribution and liquid volume fraction.

Burner rig hot corrosion of silicon carbide and silicon nitride

NASA Technical Reports Server (NTRS)

Fox, Dennis S.; Smialek, James L.

1990-01-01

A number of commercially available SiC and Si3N4 materials were exposed to 1000 C for 40 h in a high-velocity, pressurized burner rig as a simulation of an aircraft turbine environment. Na impurities (2 ppm) added to the burner flame resulted in molten Na2SO4 deposition, attack of the SiC and Si3N4, and formation of substantial Na2O+x(SiO2) corrosion product. Room-temperature strength of the materials decreased as a result of the formation of corrosion pits in SiC and grain-boundary dissolution and pitting in Si3N4.

A burner for plasma-coal starting of a boiler

NASA Astrophysics Data System (ADS)

Peregudov, V. S.

2008-04-01

Advanced schemes of a plasma-coal burner with single-and two-stage chambers for thermochemical preparation of fuel are described. The factors causing it becoming contaminated with slag during oil-free starting of a boiler are considered, and methods for preventing this phenomenon are pointed out.

Improvement of fire-tube boilers calculation methods by the numerical modeling of combustion processes and heat transfer in the combustion chamber

NASA Astrophysics Data System (ADS)

Komarov, I. I.; Rostova, D. M.; Vegera, A. N.

2017-11-01

This paper presents the results of study on determination of degree and nature of influence of operating conditions of burner units and flare geometric parameters on the heat transfer in a combustion chamber of the fire-tube boilers. Change in values of the outlet gas temperature, the radiant and convective specific heat flow rate with appropriate modification of an expansion angle and a flare length was determined using Ansys CFX software package. Difference between values of total heat flow and bulk temperature of gases at the flue tube outlet calculated using the known methods for thermal calculation and defined during the mathematical simulation was determined. Shortcomings of used calculation methods based on the results of a study conducted were identified and areas for their improvement were outlined.

Efficient Nonlinear Atomization Model for Thin 3D Free Liquid Films

NASA Astrophysics Data System (ADS)

Mehring, Carsten

2007-03-01

Reviewed is a nonlinear reduced-dimension thin-film model developed by the author and aimed at the prediction of spray formation from thin films such as those found in gas-turbine engines (e.g., prefilming air-blast atomizers), heavy-fuel-oil burners (e.g., rotary-cup atomizers) and in the paint industry (e.g., flat-fan atomizers). Various implementations of the model focusing on different model-aspects, i.e., effect of film geometry, surface tension, liquid viscosity, coupling with surrounding gas-phase flow, influence of long-range intermolecular forces during film rupture are reviewed together with a validation of the nonlinear wave propagation characteristics predicted by the model for inviscid planar films using a two-dimensional vortex- method. An extension and generalization of the current nonlinear film model for implementation into a commercial flow- solver is outlined.

Thermodynamic Cycle Analysis of Magnetohydrodynamic-Bypass Airbreathing Hypersonic Engines

NASA Technical Reports Server (NTRS)

Litchford, Ron J.; Bityurin, Valentine A.; Lineberry, John T.

1999-01-01

Established analyses of conventional ramjet/scramjet performance characteristics indicate that a considerable decrease in efficiency can be expected at off-design flight conditions. This can be explained, in large part, by the deterioration of intake mass flow and limited inlet compression at low flight speeds and by the onset of thrust degradation effects associated with increased burner entry temperature at high flight speeds. In combination, these effects tend to impose lower and upper Mach number limits for practical flight. It has been noted, however, that Magnetohydrodynamic (MHD) energy management techniques represent a possible means for extending the flight Mach number envelope of conventional engines. By transferring enthalpy between different stages of the engine cycle, it appears that the onset of thrust degradation may be delayed to higher flight speeds. Obviously, the introduction of additional process inefficiencies is inevitable with this approach, but it is believed that these losses are more than compensated through optimization of the combustion process. The fundamental idea is to use MHD energy conversion processes to extract and bypass a portion of the intake kinetic energy around the burner. We refer to this general class of propulsion system as an MHD-bypass engine. In this paper, we quantitatively assess the performance potential and scientific feasibility of MHD-bypass airbreathing hypersonic engines using ideal gasdynamics and fundamental thermodynamic principles.

Static and dynamic cyclic oxidation of 12 nickel-, cobalt-, and iron-base high-temperature alloys

NASA Technical Reports Server (NTRS)

Barrett, C. A.; Johnston, J. R.; Sanders, W. A.

1978-01-01

Twelve typical high-temperature nickel-, cobalt-, and iron-base alloys were tested by 1 hr cyclic exposures at 1038, 1093, and 1149 C and 0.05 hr exposures at 1093 C. The alloys were tested in both a dynamic burner rig at Mach 0.3 gas flow and in static air furnace for times up to 100 hr. The alloys were evaluated in terms of specific weight loss as a function of time, and X-ray diffraction analysis and metallographic examination of the posttest specimens. A method previously developed was used to estimate specific metal weight loss from the specific weight change of the sample. The alloys were then ranked on this basis. The burner-rig test was more severe than a comparable furnace test and resulted in an increased tendency for oxide spalling due to volatility of Cr in the protective scale and the more drastic cooling due to the air-blast quench of the samples. Increased cycle frequency also increased the tendency to spall for a given test exposure. The behavior of the alloys in both types of tests was related to their composition and their tendency to form scales. The alloys with the best overall behavior formed alpha-Al2O3 aluminate spinels.

Low NO.sub.x multistage combustor

DOEpatents

Becker, Frederick E.; Breault, Ronald W.; Litka, Anthony F.; McClaine, Andrew W.; Shukla, Kailash

2000-01-01

A high efficiency, Vortex Inertial Staged Air (VIStA) combustor provides ultra-low NO.sub.X production of about 20 ppmvd or less with CO emissions of less than 50 ppmvd, both at 3% O.sub.2. Prompt NO.sub.X production is reduced by partially reforming the fuel in a first combustion stage to CO and H.sub.2. This is achieved in the first stage by operating with a fuel rich mixture, and by recirculating partially oxidized combustion products, with control over stoichiometry, recirculation rate and residence time. Thermal NO.sub.X production is reduced in the first stage by reducing the occurrence of high temperature combustion gas regions. This is achieved by providing the first stage burner with a thoroughly pre-mixed fuel/oxidant composition, and by recirculating part of the combustion products to further mix the gases and provide a more uniform temperature in the first stage. In a second stage combustor thermal NO.sub.X production is controlled by inducing a large flow of flue gas recirculation in the second stage combustion zone to minimize the ultimate temperature of the flame. One or both of the first and second stage burners can be cooled to further reduce the combustion temperature and to improve the recirculation efficiency. Both of these factors tend to reduce production of NO.sub.X.

SONOTECH, INC. FREQUENCY-TUNABLE PULSE COMBUSTION SYSTEM (CELLO PULSE BURNER) - INNOVATIVE TECHNOLOGY EVALUATION REPORT

EPA Science Inventory

Sonotech, Inc. (Sonotech) of Atlanta, Georgia, has developed a pulse combustion burner technology that claims to offer benefits when applied in a variety of combustion processes. The technology incorporates a combustor that can be tuned to induce large-amplitude acoustic or soni...

Making a Low-Cost Soda Can Ethanol Burner for Out-of-Laboratory Flame Test Demonstrations and Experiments

ERIC Educational Resources Information Center

Yu, Henson L. Lee; Domingo, Perfecto N., Jr.; Yanza, Elliard Roswell S.; Guidote, Armando M., Jr.

2015-01-01

This article demonstrates how to make a low-cost ethanol burner utilizing soda cans. It burns with a light blue flame suitable for out-of-laboratory flame test demonstrations where interference from a yellow flame needs to be avoided.

40 CFR 52.1783 - Original identification of plan section.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Residual Oil Burners 15 NCAC 2D.0902, Applicability (Volatile Organic Compounds) 15 NCAC 2H.0603... or Residual Oil Burners 15 NCAC 2D.0939, Determination of Volatile Organic Compound Emissions (B) The... 2D.0943, Synthetic Organic Chemical and Polymer Manufacturing 15 NCAC 2D.0944, Manufacturing of...

SITE PROGRAM APPLICATIONS ANALYSIS ASSESSMENT OF SUPERFUND APPLICATIONS FOR THE AMERICAN COMBUSTION INC. PYRETRON OXYGEN ENHANCED BURNER

EPA Science Inventory

Incineration is widely used to clean up Superfund sites. Modifications which improve the efficiency with which waste can be incinerated are therefore of interest to EPA. Oxygen/air burners are of interest because their installation on conventional incinerators can allow for signi...

DEMONSTRATION BULLETIN: THE PYRETRON OXYGEN BURNER, AMERICAN COMBUSTION TECHNOLOGIES, INC.

EPA Science Inventory

The Pyretron is a burner which is designed to allow for the injection of oxygen into the combustion air stream for the purpose of increasing the efficiency of a hazardous waste incinerator. The SITE demonstration of the Pyretron took place at the U.S. EPA's Combustion Re...

INITIAL TEST RESULTS OF THE LIMESTONE INJECTION MULTISTAGE BURNER (LIMB) DEMONSTRATION PROJECT

EPA Science Inventory

The paper discusses SO2 removal efficiency and low-NOx burner performance obtained during short term tests, as well as the impact of LIMB ash on electrostatic precipitator (ESP) performance at Ohio Edison's Edgewater Station. Project goals are to demonstrate 50% or more SO2 remov...

Co-firing straw with coal in a swirl-stabilized dual-feed burner: modelling and experimental validation.

PubMed

Yin, Chungen; Kaer, Søren K; Rosendahl, Lasse; Hvid, Søren L

2010-06-01

This paper presents a comprehensive computational fluid dynamics (CFD) modelling study of co-firing wheat straw with coal in a 150kW swirl-stabilized dual-feed burner flow reactor, in which the pulverized straw particles (mean diameter of 451microm) and coal particles (mean diameter of 110.4microm) are independently fed into the burner through two concentric injection tubes, i.e., the centre and annular tubes, respectively. Multiple simulations are performed, using three meshes, two global reaction mechanisms for homogeneous combustion, two turbulent combustion models, and two models for fuel particle conversion. It is found that for pulverized biomass particles of a few hundred microns in diameter the intra-particle heat and mass transfer is a secondary issue at most in their conversion, and the global four-step mechanism of Jones and Lindstedt may be better used in modelling volatiles combustion. The baseline CFD models show a good agreement with the measured maps of main species in the reactor. The straw particles, less affected by the swirling secondary air jet due to the large fuel/air jet momentum and large particle response time, travels in a nearly straight line and penetrate through the oxygen-lean core zone; whilst the coal particles are significantly affected by secondary air jet and swirled into the oxygen-rich outer radius with increased residence time (in average, 8.1s for coal particles vs. 5.2s for straw particles in the 3m high reactor). Therefore, a remarkable difference in the overall burnout of the two fuels is predicted: about 93% for coal char vs. 73% for straw char. As the conclusion, a reliable modelling methodology for pulverized biomass/coal co-firing and some useful co-firing design considerations are suggested. Copyright 2010 Elsevier Ltd. All rights reserved.

Soot Aerosol Properties in Laminar Soot-Emitting Microgravity Nonpremixed Flames

NASA Technical Reports Server (NTRS)

Konsur, Bogdan; Megaridis, Constantine M.; Griffin, Devon W.

1999-01-01

The spatial distributions and morphological properties of the soot aerosol are examined experimentally in a series of 0-g laminar gas-jet nonpremixed flames. The methodology deploys round jet diffusion flames of nitrogen-diluted acetylene fuel burning in quiescent air at atmospheric pressure. Full-field laser-light extinction is utilized to determine transient soot spatial distributions within the flames. Thermophoretic sampling is employed in conjunction with transmission electron microscopy to define soot microstructure within the soot-emitting 0-g flames. The microgravity tests indicate that the 0-g flames attain a quasi-steady state roughly 0.7 s after ignition, and sustain their annular structure even beyond their luminous flame tip. The measured peak soot volume fractions show a complex dependence on burner exit conditions, and decrease in a nonlinear fashion with decreasing characteristic flow residence times. Fuel preheat by approximately 140 K appears to accelerate the formation of soot near the flame axis via enhanced fuel pyrolysis rates. The increased soot presence caused by the elevated fuel injection temperatures triggers higher flame radiative losses, which may account for the premature suppression of soot growth observed along the annular region of preheated-fuel flames. Electron micrographs of soot aggregates collected in 0-g reveal the presence of soot precursor particles near the symmetry axis at midflame height, The observations also verify that soot primary particle sizes are nearly uniform among aggregates present at the same flame location, but vary considerably with radius at a fixed distance from the burner. The maximum primary size in 0-g is found to be by 40% larger than in 1-g, under the same burner exit conditions. Estimates of the number concentration of primary particles and surface area of soot particulate phase per unit volume of the combustion gases are also made for selected in-flame locations.

Fully-Enclosed Ceramic Micro-burners Using Fugitive Phase and Powder-based Processing

NASA Astrophysics Data System (ADS)

Do, Truong; Shin, Changseop; Kwon, Patrick; Yeom, Junghoon

2016-08-01

Ceramic-based microchemical systems (μCSs) are more suitable for operation under harsh environments such as high temperature and corrosive reactants compared to the more conventional μCS materials such as silicon and polymers. With the recent renewed interests in chemical manufacturing and process intensification, simple, inexpensive, and reliable ceramic manufacturing technologies are needed. The main objective of this paper is to introduce a new powder-based fabrication framework, which is a one-pot, cost-effective, and versatile process for ceramic μCS components. The proposed approach employs the compaction of metal-oxide sub-micron powders with a graphite fugitive phase that is burned out to create internal cavities and microchannels before full sintering. Pure alumina powder has been used without any binder phase, enabling more precise dimensional control and less structure shrinkage upon sintering. The key process steps such as powder compaction, graphite burnout during partial sintering, machining in a conventional machine tool, and final densification have been studied to characterize the process. This near-full density ceramic structure with the combustion chamber and various internal channels was fabricated to be used as a micro-burner for gas sensing applications.

Fully-Enclosed Ceramic Micro-burners Using Fugitive Phase and Powder-based Processing

PubMed Central

Do, Truong; Shin, Changseop; Kwon, Patrick; Yeom, Junghoon

2016-01-01

Ceramic-based microchemical systems (μCSs) are more suitable for operation under harsh environments such as high temperature and corrosive reactants compared to the more conventional μCS materials such as silicon and polymers. With the recent renewed interests in chemical manufacturing and process intensification, simple, inexpensive, and reliable ceramic manufacturing technologies are needed. The main objective of this paper is to introduce a new powder-based fabrication framework, which is a one-pot, cost-effective, and versatile process for ceramic μCS components. The proposed approach employs the compaction of metal-oxide sub-micron powders with a graphite fugitive phase that is burned out to create internal cavities and microchannels before full sintering. Pure alumina powder has been used without any binder phase, enabling more precise dimensional control and less structure shrinkage upon sintering. The key process steps such as powder compaction, graphite burnout during partial sintering, machining in a conventional machine tool, and final densification have been studied to characterize the process. This near-full density ceramic structure with the combustion chamber and various internal channels was fabricated to be used as a micro-burner for gas sensing applications. PMID:27546059

Boiler using combustible fluid

DOEpatents

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.

Technology Being Developed at Lawrence Berkeley National Laboratory: Ultra-Low- Emission Combustion Technologies for Heat and Power Generation

NASA Technical Reports Server (NTRS)

Cheng, Robert K.

2001-01-01

The Combustion Technologies Group at Lawrence Berkeley National Laboratory has developed simple, low-cost, yet robust combustion technologies that may change the fundamental design concept of burners for boilers and furnaces, and injectors for gas turbine combustors. The new technologies utilize lean premixed combustion and could bring about significant pollution reductions from commercial and industrial combustion processes and may also improve efficiency. The technologies are spinoffs of two fundamental research projects: An inner-ring burner insert for lean flame stabilization developed for NASA- sponsored reduced-gravity combustion experiments. A low-swirl burner developed for Department of Energy Basic Energy Sciences research on turbulent combustion.

High-heat transfer low-NO.sub.x combustion system

DOEpatents

Abbasi, Hamid A.; Hobson, Jr., William J.; Rue, David M.; Smirnov, Valeriy

2005-09-06

A combustion apparatus comprising a pre-combustor stage and a primary combustion stage, the pre-combustor stage having two co-axial cylinders, one for oxidant and one for fuel gas, in which the fuel gas is preheated and the primary combustion stage having rectangular co-axial passages through which fuel and oxidant are admitted into a refractory burner block. Both passages converge in the vertical plane and diverge in the horizontal plane. The passage through the refractory burner block also has a rectangular profile and diverges in the horizontal plane. The outlets to the primary combustion stage are recessed in the refractory burner block at a distance which may be varied.

Development and Characterization of a High Speed Mid-IR Tunable Diode Laser Absorption Spectrometer for CO and CO2 Detection in Detonation Events

DTIC Science & Technology

2014-03-27

through a four step process. First, the I0 data was adjusted in the vertical direction. Because there were small effects due to the luminescence of...for a calibrated diffusion burner, the data showed that at 5 mm above the flame front the reaction was nearly complete. The small variation in...of collecting data at a 10 kHz repetition rate near 4.5 µm, was developed. This system was made feasible in recent years due to the development of

How Efficient is a Laboratory Burner in Heating Water?

ERIC Educational Resources Information Center

Jansen, Michael P.

1997-01-01

Describes an experiment in which chemistry students determine the efficiency of a laboratory burner used to heat water. The reaction is assumed to be the complete combustion of methane, CH4. The experiment is appropriate for secondary school chemistry students familiar with heats of reaction and simple calorimetry. Contains pre-laboratory and…

40 CFR 279.64 - Used oil storage.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 28 2013-07-01 2013-07-01 false Used oil storage. 279.64 Section 279... for Energy Recovery § 279.64 Used oil storage. Used oil burners are subject to all applicable Spill.... Used oil burners are also subject to the Underground Storage Tank (40 CFR part 280) standards for used...

40 CFR 279.64 - Used oil storage.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 27 2014-07-01 2014-07-01 false Used oil storage. 279.64 Section 279... for Energy Recovery § 279.64 Used oil storage. Used oil burners are subject to all applicable Spill.... Used oil burners are also subject to the Underground Storage Tank (40 CFR part 280) standards for used...

40 CFR 279.64 - Used oil storage.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 28 2012-07-01 2012-07-01 false Used oil storage. 279.64 Section 279... for Energy Recovery § 279.64 Used oil storage. Used oil burners are subject to all applicable Spill.... Used oil burners are also subject to the Underground Storage Tank (40 CFR part 280) standards for used...

76 FR 80747 - Approval and Promulgation of Implementation Plans; Oregon: New Source Review/Prevention of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-27

... 340-228--Requirements for Fuel Burning Equipment and Fuel Sulfur Content 0020 Definitions 11/8/2007 0200 General Emission Standards for Fuel 11/8/2007 Burning Equipment, Sulfur Dioxide Standards. 0210... reduced sulfur (TRS) emission-related definitions. 0100 Wigwam Waste Burners, Wigwam Waste Burners 11/8...

The effects of chemical kinetics and wall temperature on performance of porous media burners

NASA Astrophysics Data System (ADS)

mohammadi, Iman; Hossainpour, Siamak

2013-06-01

This paper reports a two-dimensional numerical prediction of premixed methane-air combustion in inert porous media burner by using of four multi-step mechanisms: GRI-3.0 mechanism, GRI-2.11 mechanism and the skeletal and 17 Species mechanisms. The effects of these models on temperature, chemical species and pollutant emissions are studied. A two-dimensional axisymmetric model for premixed methane-air combustion in porous media burner has developed. The finite volume method has used to solve the governing equations of methane-air combustion in inert porous media burner. The results indicate that the present four models have the same accuracy in predicting temperature profiles and the difference between these profiles is not more than 2 %. In addition, the Gri-3.0 mechanism shows the best prediction of NO emission in comparison with experimental data. The 17 Species mechanism shows good agreement in prediction of temperature and pollutant emissions with GRI-3.0, GRI-2.11 and the skeletal mechanisms. Also the effects of wall temperature on the gas temperature and mass fraction of species such as NO and CH4 are studied.

Diode laser-based thermometry using two-line atomic fluorescence of indium and gallium

NASA Astrophysics Data System (ADS)

Borggren, Jesper; Weng, Wubin; Hosseinnia, Ali; Bengtsson, Per-Erik; Aldén, Marcus; Li, Zhongshan

2017-12-01

A robust and relatively compact calibration-free thermometric technique using diode lasers two-line atomic fluorescence (TLAF) for reactive flows at atmospheric pressures is investigated. TLAF temperature measurements were conducted using indium and, for the first time, gallium atoms as temperature markers. The temperature was measured in a multi-jet burner running methane/air flames providing variable temperatures ranging from 1600 to 2000 K. Indium and gallium were found to provide a similar accuracy of 2.7% and precision of 1% over the measured temperature range. The reliability of the TLAF thermometry was further tested by performing simultaneous rotational CARS measurements in the same experiments.

Sooting turbulent jet flame: characterization and quantitative soot measurements

NASA Astrophysics Data System (ADS)

Köhler, M.; Geigle, K. P.; Meier, W.; Crosland, B. M.; Thomson, K. A.; Smallwood, G. J.

2011-08-01

Computational fluid dynamics (CFD) modelers require high-quality experimental data sets for validation of their numerical tools. Preferred features for numerical simulations of a sooting, turbulent test case flame are simplicity (no pilot flame), well-defined boundary conditions, and sufficient soot production. This paper proposes a non-premixed C2H4/air turbulent jet flame to fill this role and presents an extensive database for soot model validation. The sooting turbulent jet flame has a total visible flame length of approximately 400 mm and a fuel-jet Reynolds number of 10,000. The flame has a measured lift-off height of 26 mm which acts as a sensitive marker for CFD model validation, while this novel compiled experimental database of soot properties, temperature and velocity maps are useful for the validation of kinetic soot models and numerical flame simulations. Due to the relatively simple burner design which produces a flame with sufficient soot concentration while meeting modelers' needs with respect to boundary conditions and flame specifications as well as the present lack of a sooting "standard flame", this flame is suggested as a new reference turbulent sooting flame. The flame characterization presented here involved a variety of optical diagnostics including quantitative 2D laser-induced incandescence (2D-LII), shifted-vibrational coherent anti-Stokes Raman spectroscopy (SV-CARS), and particle image velocimetry (PIV). Producing an accurate and comprehensive characterization of a transient sooting flame was challenging and required optimization of these diagnostics. In this respect, we present the first simultaneous, instantaneous PIV, and LII measurements in a heavily sooting flame environment. Simultaneous soot and flow field measurements can provide new insights into the interaction between a turbulent vortex and flame chemistry, especially since soot structures in turbulent flames are known to be small and often treated in a statistical manner.

Prospects for Nonlinear Laser Diagnostics in the Jet Noise Laboratory

NASA Technical Reports Server (NTRS)

Herring, Gregory C.; Hart, Roger C.; Fletcher, mark T.; Balla, R. Jeffrey; Henderson, Brenda S.

2007-01-01

Two experiments were conducted to test whether optical methods, which rely on laser beam coherence, would be viable for off-body flow measurement in high-density, compressible-flow wind tunnels. These tests measured the effects of large, unsteady density gradients on laser diagnostics like laser-induced thermal acoustics (LITA). The first test was performed in the Low Speed Aeroacoustics Wind Tunnel (LSAWT) of NASA Langley Research Center's Jet Noise Laboratory (JNL). This flow facility consists of a dual-stream jet engine simulator (with electric heat and propane burners) exhausting into a simulated flight stream, reaching Mach numbers up to 0.32. A laser beam transited the LSAWT flow field and was imaged with a high-speed gated camera to measure beam steering and transverse mode distortion. A second, independent test was performed on a smaller laboratory jet (Mach number < 1.2 and mass flow rate < 0.1 kg/sec). In this test, time-averaged LITA velocimetry and thermometry were performed at the jet exit plane, where the effect of unsteady density gradients is observed on the LITA signal. Both experiments show that LITA (and other diagnostics relying on beam overlap or coherence) faces significant hurdles in the high-density, compressible, and turbulent flow environments similar to those of the JNL.

An Insidious Mode of Oxidative Degradation in a SiC-SiC Composite

NASA Technical Reports Server (NTRS)

Ogbuji, Linus U. J. T.

1997-01-01

The oxidative durability of a SiC-SiC composite with Hi-Nicalon fiber and BN interphase was investigated at 800 C (where pesting is known to occur in SiC-SiC composites) for exposure durations of up to 500 hours and in a variety of oxidant mixes and flow rates, ranging from quasi-stagnant room air, through slow flowing O2 containing 30-90% H2O, to the high-velocity flame of a burner rig. Degradation of the composite was determined from residual strength and fracture strain in post-exposure mechanical tests and correlated with microstructural evidence of damage to fiber and interphase. The severest degradation of composite behavior was found to occur in the bumer rig, and is shown to be connected with the high oxidant velocity and substantial moisture content, as well as a thin sublayer of carbon indicated to form between fiber and interphase during composite processing.

46 CFR 56.50-65 - Burner fuel-oil service systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... service systems. (a) All discharge piping from the fuel oil service pumps to burners must be seamless steel with a thickness of at least Schedule 80. If required by § 56.07-10(e) of this part or paragraph... than Schedule 80. Short lengths of steel, or annealed copper nickel, nickel copper, or copper pipe and...

46 CFR 56.50-65 - Burner fuel-oil service systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... service systems. (a) All discharge piping from the fuel oil service pumps to burners must be seamless steel with a thickness of at least Schedule 80. If required by § 56.07-10(e) of this part or paragraph... than Schedule 80. Short lengths of steel, or annealed copper nickel, nickel copper, or copper pipe and...

46 CFR 56.50-65 - Burner fuel-oil service systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... service systems. (a) All discharge piping from the fuel oil service pumps to burners must be seamless steel with a thickness of at least Schedule 80. If required by § 56.07-10(e) of this part or paragraph... than Schedule 80. Short lengths of steel, or annealed copper nickel, nickel copper, or copper pipe and...

46 CFR 56.50-65 - Burner fuel-oil service systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... service systems. (a) All discharge piping from the fuel oil service pumps to burners must be seamless steel with a thickness of at least Schedule 80. If required by § 56.07-10(e) of this part or paragraph... than Schedule 80. Short lengths of steel, or annealed copper nickel, nickel copper, or copper pipe and...

46 CFR 56.50-65 - Burner fuel-oil service systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... service systems. (a) All discharge piping from the fuel oil service pumps to burners must be seamless steel with a thickness of at least Schedule 80. If required by § 56.07-10(e) of this part or paragraph... than Schedule 80. Short lengths of steel, or annealed copper nickel, nickel copper, or copper pipe and...

40 CFR 76.5 - NOX emission limitations for Group 1 boilers.

Code of Federal Regulations, 2010 CFR

2010-07-01

... wall-fired boiler (other than units applying cell burner technology) shall not discharge, or allow to... input on an annual average basis for tangentially fired boilers. (2) 0.50 lb/mmBtu of heat input on an annual average basis for dry bottom wall-fired boilers (other than units applying cell burner technology...

Experimental verification of vapor deposition rate theory in high velocity burner rigs

NASA Technical Reports Server (NTRS)

Gokoglu, Suleyman A.; Santoro, Gilbert J.

1985-01-01

The main objective has been the experimental verification of the corrosive vapor deposition theory in high-temperature, high-velocity environments. Towards this end a Mach 0.3 burner-rig appartus was built to measure deposition rates from salt-seeded (mostly Na salts) combustion gases on the internally cooled cylindrical collector. Deposition experiments are underway.

Camping Burner-Based Flame Emission Spectrometer for Classroom Demonstrations

ERIC Educational Resources Information Center

Ne´el, Bastien; Crespo, Gasto´n A.; Perret, Didier; Cherubini, Thomas; Bakker, Eric

2014-01-01

A flame emission spectrometer was built in-house for the purpose of introducing this analytical technique to students at the high school level. The aqueous sample is sprayed through a homemade nebulizer into the air inlet of a consumer-grade propane camping burner. The resulting flame is analyzed by a commercial array spectrometer for the visible…

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

NASA Astrophysics Data System (ADS)

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.

Effect of cycled combustion ageing on a cordierite burner plate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garcia, Eugenio; Gancedo, J. Ramon; Gracia, Mercedes, E-mail: rocgracia@iqfr.csic.es

2010-11-15

A combination of {sup 57}Fe-Moessbauer spectroscopy and X-ray Powder Diffraction analysis has been employed to study modifications in chemical and mechanical stability occurring in a cordierite burner aged under combustion conditions which simulate the working of domestic boilers. Moessbauer study shows that Fe is distributed into the structural sites of the cordierite lattice as Fe{sup 2+} and Fe{sup 3+} ions located mostly at octahedral sites. Ferric oxide impurities, mainly hematite, are also present in the starting cordierite material accounting for {approx_equal}40% of the total iron phases. From Moessbauer and X-ray diffraction data it can be deduced that, under the combustionmore » conditions used, new crystalline phases were formed, some of the substitutional Fe{sup 3+} ions existing in the cordierite lattice were reduced to Fe{sup 2+}, and ferric oxides underwent a sintering process which results in hematite with higher particle size. All these findings were detected in the burner zone located in the proximity of the flame and were related to possible chemical reactions which might explain the observed deterioration of the burner material. Research Highlights: {yields}Depth profile analyses used as a probe to understand changes in refractory structure. {yields}All changes take place in the uppermost surface of the burner, close to the flame. {yields}Reduction to Fe{sup 2+} of substitutional Fe{sup 3+} ions and partial cordierite decomposition. {yields}Heating-cooling cycling induces a sintering of the existing iron oxide particles. {yields}Chemical changes can explain the alterations observed in the material microstructure.« less

Increasing the efficiency of the condensing boiler

NASA Astrophysics Data System (ADS)

Zaytsev, O. N.; Lapina, E. A.

2017-11-01

Analysis of existing designs of boilers with low power consumption showed that the low efficiency of the latter is due to the fact that they work in most cases when the heating period in the power range is significantly less than the nominal power. At the same time, condensing boilers do not work in the most optimal mode (in condensing mode) in the central part of Russia, a significant part of their total operating time during the heating season. This is due to existing methods of equipment selection and joint operation with heating systems with quantitative control of the coolant. It was also revealed that for the efficient operation of the heating system, it is necessary to reduce the inertia of the heat generating equipment. Theoretical patterns of thermal processes in the furnace during combustion gas at different radiating surfaces location schemes considering the influence of the very furnace configuration, characterized in that to reduce the work condensing boiler in conventional gas boiler operation is necessary to maintain a higher temperature in the furnace (in the part where spiral heat exchangers are disposed), which is possible when redistributing heat flow - increase the proportion of radiant heat from the secondary burner emitter allow Perey For the operation of the condensing boiler in the design (condensation) mode practically the entire heating period.

Sensor for Individual Burner Control of Coal Firing Rate, Fuel-Air Ratio and Coal Fineness Correlation

DOE Office of Scientific and Technical Information (OSTI.GOV)

R. Demler

2006-04-01

Accurate, cost-efficient monitoring instrumentation has long been considered essential to the operation of power plants. Nonetheless, for the monitoring of coal flow, such instrumentation has been sorely lacking and technically difficult to achieve. With more than half of the electrical power in the United States currently supplied by coal, energy generated by this resource is critical to the US economy. The demand for improvement in this area has only increased as a result of the following two situations: First, deregulation has produced a heightened demand for both reduced electrical cost and improved grid connectivity. Second, environmental concerns have simultaneously resultedmore » in a need for both increased efficiency and reduced carbon and NOx emissions. A potential approach to addressing both these needs would be improvement in the area of combustion control. This would result in a better heat rate, reduced unburned carbon in ash, and reduced NOx emissions. However, before feedback control can be implemented, the ability to monitor coal flow to the burners in real-time must be established. While there are several ''commercially available'' products for real-time coal flow measurement, power plant personnel are highly skeptical about the accuracy and longevity of these systems in their current state of development. In fact, following several demonstration projects of in-situ coal flow measurement systems in full scale utility boilers, it became obvious that there were still many unknown influences on these instruments during field applications. Due to the operational environment of the power plant, it has been difficult if not impossible to sort out what parameters could be influencing the various probe technologies. Additionally, it has been recognized for some time that little is known regarding the performance of coal flow splitters, even where rifflers are employed. Often the coal flow distribution from these splitters remains mal-distributed. There have been mixed results in the field using variable orifices in coal pipes. Development of other coal flow control devices has been limited. An underlying difficulty that, to date, has hindered the development of an accurate instrument for coal flow measurements is the fact that coal flow is characterized by irregular temporal and spatial variation. However, despite the inherent complexity of the dynamic system, the system is in fact deterministic. Therefore, in principle, the coal flow can be deduced from the dynamics it exhibits. Nonetheless, the interactions are highly nonlinear, rendering standard signal processing approaches, which rely on techniques such as frequency decomposition, to be of little value. Foster-Miller, Inc. has developed a methodology that relates the complex variation in such systems to the information of interest. This technology will be described in detail in Section 2. A second concern regarding the current measurement systems is installation, which can be labor-intensive and cost-prohibitive. A process that does not require the pulverizer to be taken off line would be highly desirable. Most microwave and electrostatic methods require drilling up to 20 holes in the pipe, all with a high degree of precision so as to produce a proper alignment of the probes. At least one electrostatic method requires a special spool piece to be fitted into each existing coal pipe. Overall, these procedures are both difficult and very expensive. An alternative approach is pursued here, namely the development of an instrument that relies on an acoustic signal captured by way of a commercial accelerometer. The installation of this type of sensor is both simpler and less invasive than other techniques. An accelerometer installed in a pipe wall need not penetrate through the wall, which means that the system may be able to remain on line during the installation. Further, due to the fact that the Dynamical Instruments technology, unlike other systems, does not rely on uniformity of the air or coal profile, the installation location need not be on a long, straight run of pipe. In fact, an optimal signal is obtained near a pipe elbow. This is fortuitous, as bends are often more accessible on pipes in a power plant than straight sections. In contrast to measurement systems that rely on the uniformity of the air and coal profile, the accuracy of the system under development will not compromised by varying levels of flow uniformity.« less

Structure of diffusion flames from a vertical burner

Treesearch

Mark A. Finney; Dan Jimenez; Jack D. Cohen; Isaac C. Grenfell; Cyle Wold

2010-01-01

Non-steady and turbulent flames are commonly observed to produce flame contacts with adjacent fuels during fire spread in a wide range of fuel bed depths. A stationary gas-fired burner (flame wall) was developed to begin study of flame edge variability along an analagous vertical fuel source. This flame wall is surrogate for a combustion interface at the edge of a deep...

6. View, flare and oxygen burner pad near southwest side ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. View, flare and oxygen burner pad near southwest side of Components Test Laboratory (T-27), looking northeast. Uphill and to the left of the flare is the Oxidizer Conditioning Structure (T-28D) and the Long-Term Oxidizer Silo (T-28B). - Air Force Plant PJKS, Systems Integration Laboratory, Waterton Canyon Road & Colorado Highway 121, Lakewood, Jefferson County, CO

Confronting the "Bra-Burners": Teaching Radical Feminism with a Case Study

ERIC Educational Resources Information Center

Kreydatus, Beth

2008-01-01

In many of the U.S. History courses the author has taught, she has encountered students who refer to the second-wave feminists of the 1960s and 1970s as "bra-burners." Unsurprisingly, these students know very little about the origin of this epithet, and frequently, they know even less about the women's movement generally. Second-wave feminism, and…

30 CFR 14.21 - Laboratory-scale flame test apparatus.

Code of Federal Regulations, 2012 CFR

2012-07-01

... other and the flame from each jet impinges upon each other in pairs. The burner fuel must be at least 98... test chamber. (c) A U-shaped gas-fueled impinged jet burner ignition source, measuring 12 inches (30.5 cm) long and 4 inches (10.2 cm) wide, with two parallel rows of 6 jets each. Each jet is spaced...

30 CFR 14.21 - Laboratory-scale flame test apparatus.

Code of Federal Regulations, 2013 CFR

2013-07-01

... other and the flame from each jet impinges upon each other in pairs. The burner fuel must be at least 98... test chamber. (c) A U-shaped gas-fueled impinged jet burner ignition source, measuring 12 inches (30.5 cm) long and 4 inches (10.2 cm) wide, with two parallel rows of 6 jets each. Each jet is spaced...

30 CFR 14.21 - Laboratory-scale flame test apparatus.

Code of Federal Regulations, 2014 CFR

2014-07-01

... other and the flame from each jet impinges upon each other in pairs. The burner fuel must be at least 98... test chamber. (c) A U-shaped gas-fueled impinged jet burner ignition source, measuring 12 inches (30.5 cm) long and 4 inches (10.2 cm) wide, with two parallel rows of 6 jets each. Each jet is spaced...

High Pressure Burner Rig Testing of Advanced Environmental Barrier Coatings for Si3N4 Turbine Components

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Fox, Dennis S.; Pastel, Robert T.

2007-01-01

Advanced thermal and environmental barrier coatings are being developed for Si3N4 components for turbine engine propulsion applications. High pressure burner rig testing was used to evaluate the coating system performance and durability. Test results demonstrated the feasibility and durability of the coating component systems under the simulated engine environments.

Comparison of heat transfer and soil impacts of air curtain burner burning and slash pile burning

Treesearch

Woongsoon Jang; Deborah S. Page-Dumroese; Han-Sup Han

2017-01-01

We measured soil heating and subsequent changes in soil properties between two forest residue disposal methods: slash pile burning (SPB) and air curtain burner (ACB). The ACB consumes fuels more efficiently and safely via blowing air into a burning container. Five burning trials with different fuel sizes were implemented in northern California, USA. Soil temperature...

Turbulent flame spreading mechanisms after spark ignition

NASA Astrophysics Data System (ADS)

Subramanian, V.; Domingo, Pascale; Vervisch, Luc

2009-12-01

Numerical simulation of forced ignition is performed in the framework of Large-Eddy Simulation (LES) combined with a tabulated detailed chemistry approach. The objective is to reproduce the flame properties observed in a recent experimental work reporting probability of ignition in a laboratory-scale burner operating with Methane/air non premixed mixture [1]. The smallest scales of chemical phenomena, which are unresolved by the LES grid, are approximated with a flamelet model combined with presumed probability density functions, to account for the unresolved part of turbulent fluctuations of species and temperature. Mono-dimensional flamelets are simulated using GRI-3.0 [2] and tabulated under a set of parameters describing the local mixing and progress of reaction. A non reacting case was simulated at first, to study the unsteady velocity and mixture fields. The time averaged velocity and mixture fraction, and their respective turbulent fluctuations, are compared against the experimental measurements, in order to estimate the prediction capabilities of LES. The time history of axial and radial components of velocity and mixture fraction is cumulated and analysed for different burner regimes. Based on this information, spark ignition is mimicked on selected ignition spots and the dynamics of kernel development analyzed to be compared against the experimental observations. The possible link between the success or failure of the ignition and the flow conditions (in terms of velocity and composition) at the sparking time are then explored.

Comparisons of Gas-phase Temperature Measurements in a Flame Using Thin-Filament Pyrometry and Thermocouples

NASA Technical Reports Server (NTRS)

Struk, Peter; Dietrich, Daniel; Valentine, Russell; Feier, Ioan

2003-01-01

Less-intrusive, fast-responding, and full-field temperature measurements have long been a desired tool for the research community. Recently, the emission of a silicon-carbide (SiC) fiber placed in a flowing hot (or reacting) gas has been used to measure the temperature profile along the length of the fiber. The relationship between the gas and fiber temperature comes from an energy balance on the fiber. In the present work, we compared single point flame temperature measurements using thin-filament pyrometry (TFP) and thermocouples. The data was from vertically traversing a thermocouple and a SiC fiber through a methanol/air diffusion flame of a porous-metal wick burner. The results showed that the gas temperature using the TFP technique agreed with the thermocouple measurements (25.4 m diameter wire) within 3.5% for temperatures above 1200 K. Additionally, we imaged the entire SiC fiber (with a spatial resolution of 0.14 mm) while it was in the flame using a high resolution CCD camera. The intensity level along the fiber length is a function of the temperature. This results in a one-dimensional temperature profiles at various heights above the burner wick. This temperature measurement technique, while having a precision of less than 1 K, showed data scatter as high as 38 K. Finally, we discuss the major sources of uncertainty in gas temperature measurement using TFP.

Deposition of Na2SO4 from salt-seeded combustion gases of a high velocity burner rig

NASA Technical Reports Server (NTRS)

Santoro, G. J.; Kohl, F. J.; Stearns, C. A.; Gokoglu, S. A.; Rosner, D. A.

1985-01-01

With a view to developing simulation criteria for the laboratory testing of high-temperature materials for gas turbine engines, the deposition rates of sodium sulfate from sodium salt-seeded combustion gases were determined experimentally using a well instrumented high-velocity burner. In the experiments, Na2SO4, NaCl, NaNO3, and simulated sea salt solutions were injected into the combustor of the Mach 0.3 burner rig operating at constant fuel/air ratios. The deposits formed on an inert rotating collector were then weighed and analyzed. The experimental results are compared to Rosner's vapor diffusion theory. Some additional test results, including droplet size distribution of an atomized salt spray, are used in interpreting the deposition rate data.

VCE testbed program planning and definition study

NASA Technical Reports Server (NTRS)

Westmoreland, J. S.; Godston, J.

1978-01-01

The flight definition of the Variable Stream Control Engine (VSCE) was updated to reflect design improvements in the two key components: (1) the low emissions duct burner, and (2) the coannular exhaust nozzle. The testbed design was defined and plans for the overall program were formulated. The effect of these improvements was evaluated for performance, emissions, noise, weight, and length. For experimental large scale testing of the duct burner and coannular nozzle, a design definition of the VCE testbed configuration was made. This included selecting the core engine, determining instrumentation requirements, and selecting the test facilities, in addition to defining control system and assembly requirements. Plans for a comprehensive test program to demonstrate the duct burner and nozzle technologies were formulated. The plans include both aeroacoustic and emissions testing.

Self-inflicted Firearm Discharge from Heating Using a Gas Burner.

PubMed

Osawa, Motoki; Matsushima, Yutaka; Kumar, Alok; Tsuboi, Akio; Kakimoto, Yu; Satoh, Fumiko

2016-05-01

A male in his 70s was found lying dead in the living room of his house. A gunshot entrance wound was observed in the left orbit, with a lead slug and wadding left in the skull, which exhibited fatal cranio-cerebral trauma. A cartridge had been discharged from a handmade launcher, or zip gun, that had been fixed to a spare gun barrel on a pipe chair, by heating the launcher from the side using a gas burner. The deceased had owned guns for hunting in the past and had returned the license, but he had retained a spare barrel and live cartridges at home. In this unique case of suicide, a zip gun was discharged by heating with a gas burner. © 2016 American Academy of Forensic Sciences.

An experimental and numerical study of gas jet diffusion flames enveloped by a cascade of venturis

NASA Astrophysics Data System (ADS)

Qubbaj, Ala Rafat

1999-06-01

A new technique to control carbon monoxide, nitric oxide, and soot emissions of a propane diffusion flame by modifying the air infusion rate into the flame was developed. In this study, the effectiveness of the ``venturi-cascading'' technique was experimentally as well numerically investigated. Propane jet diffusion flames at three burner-exit Reynolds numbers ( 3600, 5100 and 6500) corresponding to burner-rim-attached, undergoing transition from attached to lifted, and fully-lifted configurations were examined with several sets of venturis of different sizes and spacing arrangements. Temperature, and the concentrations of carbon dioxide, oxygen, carbon monoxide and nitric oxide in the exhaust products were measured before and after the modification, and optimal conditions to minimize pollutant emissions were obtained. The optimal value of venturi throat/burner-exit diameter ratio (D/d) was 32 +/- 3, which corresponded to an approximate clearance of 5 +/- 2 mm between the venturi throat and the burning jet width at the mid-flame height. The venturi-cascading technique at its optimal conditions resulted in a decrease of 87% and 33% in CO and NO emission indices along with a 24% decrease in soot emission from a propane jet flame, compared to the baseline condition (same flame without venturis). The reduction of NO without increasing CO was the main attraction of this technique. The temperature and composition measurements, at the optimal conditions, showed that, in the near-burner region, the venturi-cascaded flame had lower temperature and CO2 concentration by an average of 5% and 7%, respectively, than the baseline flame. However, in the mid-flame and far-burner regions, it has higher temperature by 13% and 12%, and higher CO2 concentration by 16% and 13%, in average values, respectively. Laser Induced Fluorescence (LIF) measurements, in the near-burner region of the venturi-cascaded flame, indicated an average decrease of 18%, 24% and 12% in OH, CH and CN radical species, respectively, along with 11% drop in soot precursors (PAR), from their baseline values. The thermal and composition fields of the baseline and venturi-cascaded flames were numerically simulated using CFD-ACE+, an advanced computational environment software package. The CO and NO concentrations were determined through CFD-POST, a post processing utility program for CFD-ACE+. The final simulated results were compared with the experimental data. Good agreement was found in the near-burner region. (Abstract shortened by UMI.)

Metal-supported solid oxide fuel cells operated in direct-flame configuration

DOE PAGES

Tucker, Michael C.; Ying, Andrew S.

2017-08-19

Metal-supported solid oxide fuel cells (MS-SOFC) with infiltrated catalysts on both anode and cathode side are operated in direct-flame configuration, with a propane flame impinging on the anode. Placing thermal insulation on the cathode dramatically increases cell temperature and performance. The optimum burner-to-cell gap height is a strong function of flame conditions. Cell performance at the optimum gap is determined within the region of stable non-coking conditions, with equivalence ratio from 1 to 1.9 and flow velocity from 100 to 300 cm s -1. In this region, performance is most strongly correlated to flow velocity and open circuit voltage. Themore » highest peak power density achieved is 633 mW cm -2 at 833°C, for equivalence ratio of 1.8 and flow velocity of 300 cm s -1. The cell starts to produce power within 10 s of being placed in the flame, and displays stable performance over 10 extremely rapid thermal cycles. The cell provides stable performance for >20 h of semi-continuous operation.« less

Quantitative holographic interferometry applied to combustion and compressible flow research

NASA Astrophysics Data System (ADS)

Bryanston-Cross, Peter J.; Towers, D. P.

1993-03-01

The application of holographic interferometry to phase object analysis is described. Emphasis has been given to a method of extracting quantitative information automatically from the interferometric fringe data. To achieve this a carrier frequency has been added to the holographic data. This has made it possible, firstly to form a phase map using a fast Fourier transform (FFT) algorithm. Then to `solve,' or unwrap, this image to give a contiguous density map using a minimum weight spanning tree (MST) noise immune algorithm, known as fringe analysis (FRAN). Applications of this work to a burner flame and a compressible flow are presented. In both cases the spatial frequency of the fringes exceed the resolvable limit of conventional digital framestores. Therefore, a flatbed scanner with a resolution of 3200 X 2400 pixels has been used to produce very high resolution digital images from photographs. This approach has allowed the processing of data despite the presence of caustics, generated by strong thermal gradients at the edge of the combustion field. A similar example is presented from the analysis of a compressible transonic flow in the shock wave and trailing edge regions.

Investigation of turbulent swirling jet-flames by PIV / OH PLIF / HCHO PLIF

NASA Astrophysics Data System (ADS)

Lobasov, A. S.; Chikishev, L. M.

2018-03-01

The present paper reports on the investigation of fuel-lean and fuel-rich turbulent combustion in a high-swirl jet. Swirl rate of the flow exceeded a critical value for breakdown of the swirling jet’s vortex core and formation of the recirculation zone at the jet axis. The measurements were performed by the stereo PIV, OH PLIF and HCHO PLIF techniques, simultaneously. The Reynolds number based on the flow rate and viscosity of the air was fixed as 5 000 (the bulk velocity was U 0 = 5 m/s). Three cases of the equivalence ratio ϕ of the mixture issuing from the nozzle-burner were considered, viz., 0.7, 1.4 and 2.5. The latter case corresponded to a lifted flame of fuel-rich swirling jet flow, partially premixed with the surrounding air. In all cases the flame front was subjected to deformations due to large-scale vortices, which rolled-up in the inner (around the central recirculation zone) and outer (between the annular jet core and surrounding air) mixing layers.

Fabrication of High-Temperature Heat Exchangers by Plasma Spraying Exterior Skins on Nickel Foams

NASA Astrophysics Data System (ADS)

Hafeez, P.; Yugeswaran, S.; Chandra, S.; Mostaghimi, J.; Coyle, T. W.

2016-06-01

Thermal-sprayed heat exchangers were tested at high temperatures (750 °C), and their performances were compared to the foam heat exchangers made by brazing Inconel sheets to their surface. Nickel foil was brazed to the exterior surface of 10-mm-thick layers of 10 and 40 PPI nickel foam. A plasma torch was used to spray an Inconel coating on the surface of the foil. A burner test rig was built to produce hot combustion gases that flowed over exposed face of the heat exchanger. Cooling air flowed through the foam heat exchanger at rates of up to 200 SLPM. Surface temperature and air inlet/exit temperature were measured. Heat transfer to air flowing through the foam was significantly higher for the thermally sprayed heat exchangers than for the brazed heat exchangers. On an average, thermally sprayed heat exchangers show 36% higher heat transfer than conventionally brazed foam heat exchangers. At low flow rates, the convective resistance is large (~4 × 10-2 m2 K/W), and the effect of thermal contact resistance is negligible. At higher flow rates, the convective resistance decreases (~2 × 10-3 m2 K/W), and the lower contact resistance of the thermally sprayed heat exchanger provides better performance than the brazed heat exchangers.

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCarty, Jon; Berry, Brian; Lundberg, Kare

This final report describes a 2000-2003 program for the development of components and processes to enhance the commercialization of ultra-low emissions catalytic combustion in industrial gas turbines. The range of project tasks includes: development of more durable, lower-cost catalysts and catalytic combustor components; development and design of a catalytic pre-burner and a catalytic pilot burner for gas turbines, and on-site fuel conversion processing for utilization of liquid fuel.

Room fire test for fire growth modeling : a sensitivity study

Treesearch

H. C. Tran; M. L. Janssens

1989-01-01

A room test designed according to the ASTM draft standard was used to investigate the effect of various parameters on the contribution of wall and corner fires to compartment fire growth. Location of the burner (against a wall or in a corner), power program of the gas burner ignition source, and combination of wall linings were varied, An initial series of calibration...

Flame interactions and burning characteristics of two live leaf samples

Treesearch

Brent M. Pickett; Carl Isackson; Rebecca Wunder; Thomas H. Fletcher; Bret W. Butler; David R. Weise

2009-01-01

Combustion experiments were performed over a flat-flame burner that provided the heat source for multiple leaf samples. Interactions of the combustion behavior between two leaf samples were studied. Two leaves were placed in the path of the flat-flame burner, with the top leaf 2.5 cm above the bottom leaf. Local gas and particle temperatures, as well as local oxygen...

16 CFR Figure 10 to Part 1633 - Jig for Setting Burners at Proper Distances From Mattress/Foundation

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Jig for Setting Burners at Proper Distances From Mattress/Foundation 10 Figure 10 to Part 1633 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY (OPEN FLAME) OF MATTRESS SETS Pt.1633, Fig. 10 Figure 10 to Part 1633—Jig for...

16 CFR Figure 10 to Part 1633 - Jig for Setting Burners at Proper Distances From Mattress/Foundation

Code of Federal Regulations, 2011 CFR

2011-01-01

... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Jig for Setting Burners at Proper Distances From Mattress/Foundation 10 Figure 10 to Part 1633 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY (OPEN FLAME) OF MATTRESS SETS Pt.1633, Fig. 10 Figure 10 to Part 1633—Jig for...

16 CFR Figure 10 to Part 1633 - Jig for Setting Burners at Proper Distances From Mattress/Foundation

Code of Federal Regulations, 2012 CFR

2012-01-01

... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Jig for Setting Burners at Proper Distances From Mattress/Foundation 10 Figure 10 to Part 1633 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY (OPEN FLAME) OF MATTRESS SETS Pt.1633, Fig. 10 Figure 10 to Part 1633—Jig for...

16 CFR Figure 10 to Part 1633 - Jig for Setting Burners at Proper Distances From Mattress/Foundation

Code of Federal Regulations, 2014 CFR

2014-01-01

... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Jig for Setting Burners at Proper Distances From Mattress/Foundation 10 Figure 10 to Part 1633 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY (OPEN FLAME) OF MATTRESS SETS Pt. 1633, Fig. 10 Figure 10 to Part 1633—Jig for...

16 CFR Figure 10 to Part 1633 - Jig for Setting Burners at Proper Distances From Mattress/Foundation

Code of Federal Regulations, 2013 CFR

2013-01-01

... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Jig for Setting Burners at Proper Distances From Mattress/Foundation 10 Figure 10 to Part 1633 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY (OPEN FLAME) OF MATTRESS SETS Pt. 1633, Fig. 10 Figure 10 to Part 1633—Jig for...

Turbine airfoil deposition models and their hot corrosion implications

NASA Technical Reports Server (NTRS)

Rosner, D. E.; Nagarajan, R.

1985-01-01

This research project deals with the prediction of single- and multi-component salt(-solution) deposition, flow and oxide dissolution and their effects on the lifetime of turbine blades. Goals include rationalizing and helping to predict corrosion patterns on operational gas turbine (GT) rotor blades and stator vanes, and ultimately providing some of the tools required to design laboratory simulators and future corrosion resistant high-performance engines. Necessary background developments are reviewed. Results and tentative conclusions for single species (Na sub 2 SO sub 4 (1)) condensation, binary salt-solution (Na sub 2 SO sub 4-K sub 2 SO sub 4) condensation, and burner-rig testing of alloy materials are outlined.

Numerical Simulation And Experimental Investigation Of The Lift-Off And Blowout Of Enclosed Laminar Flames

NASA Technical Reports Server (NTRS)

Venuturmilli, Rajasekhar; Zhang, Yong; Chen, Lea-Der

2003-01-01

Enclosed flames are found in many industrial applications such as power plants, gas-turbine combustors and jet engine afterburners. A better understanding of the burner stability limits can lead to development of combustion systems that extend the lean and rich limits of combustor operations. This paper reports a fundamental study of the stability limits of co-flow laminar jet diffusion flames. A numerical study was conducted that used an adaptive mesh refinement scheme in the calculation. Experiments were conducted in two test rigs with two different fuels and diluted with three inert species. The numerical stability limits were compared with microgravity experimental data. Additional normal-gravity experimental results were also presented.

Pollutant exposures from natural gas cooking burners: a simulation-based assessment for Southern California.

PubMed

Logue, Jennifer M; Klepeis, Neil E; Lobscheid, Agnes B; Singer, Brett C

2014-01-01

Residential natural gas cooking burners (NGCBs) can emit substantial quantities of pollutants, and they are typically used without venting range hoods. We quantified pollutant concentrations and occupant exposures resulting from NGCB use in California homes. A mass-balance model was applied to estimate time-dependent pollutant concentrations throughout homes in Southern California and the exposure concentrations experienced by individual occupants. We estimated nitrogen dioxide (NO2), carbon monoxide (CO), and formaldehyde (HCHO) concentrations for 1 week each in summer and winter for a representative sample of Southern California homes. The model simulated pollutant emissions from NGCBs as well as NO2 and CO entry from outdoors, dilution throughout the home, and removal by ventilation and deposition. Residence characteristics and outdoor concentrations of NO2 and CO were obtained from available databases. We inferred ventilation rates, occupancy patterns, and burner use from household characteristics. We also explored proximity to the burner(s) and the benefits of using venting range hoods. Replicate model executions using independently generated sets of stochastic variable values yielded estimated pollutant concentration distributions with geometric means varying by <10%. The simulation model estimated that-in homes using NGCBs without coincident use of venting range hoods-62%, 9%, and 53% of occupants are routinely exposed to NO2, CO, and HCHO levels that exceed acute health-based standards and guidelines. NGCB use increased the sample median of the highest simulated 1-hr indoor concentrations by 100, 3,000, and 20 ppb for NO2, CO, and HCHO, respectively. Reducing pollutant exposures from NGCBs should be a public health priority. Simulation results suggest that regular use of even moderately effective venting range hoods would dramatically reduce the percentage of homes in which concentrations exceed health-based standards.

Altitude Test Cell in the Four Burner Area

NASA Image and Video Library

1947-10-21

One of the two altitude simulating-test chambers in Engine Research Building at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. The two chambers were collectively referred to as the Four Burner Area. NACA Lewis’ Altitude Wind Tunnel was the nation’s first major facility used for testing full-scale engines in conditions that realistically simulated actual flight. The wind tunnel was such a success in the mid-1940s that there was a backlog of engines waiting to be tested. The Four Burner chambers were quickly built in 1946 and 1947 to ease the Altitude Wind Tunnel’s congested schedule. The Four Burner Area was located in the southwest wing of the massive Engine Research Building, across the road from the Altitude Wind Tunnel. The two chambers were 10 feet in diameter and 60 feet long. The refrigeration equipment produced the temperatures and the exhauster equipment created the low pressures present at altitudes up to 60,000 feet. In 1947 the Rolls Royce Nene was the first engine tested in the new facility. The mechanic in this photograph is installing a General Electric J-35 engine. Over the next ten years, a variety of studies were conducted using the General Electric J-47 and Wright Aeronautical J-65 turbojets. The two test cells were occasionally used for rocket engines between 1957 and 1959, but other facilities were better suited to the rocket engine testing. The Four Burner Area was shutdown in 1959. After years of inactivity, the facility was removed from the Engine Research Building in late 1973 in order to create the High Temperature and Pressure Combustor Test Facility.

The zero age main sequence of WIMP burners

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fairbairn, Malcolm; Scott, Pat; Edsjoe, Joakim

2008-02-15

We modify a stellar structure code to estimate the effect upon the main sequence of the accretion of weakly-interacting dark matter onto stars and its subsequent annihilation. The effect upon the stars depends upon whether the energy generation rate from dark matter annihilation is large enough to shut off the nuclear burning in the star. Main sequence weakly-interacting massive particles (WIMP) burners look much like proto-stars moving on the Hayashi track, although they are in principle completely stable. We make some brief comments about where such stars could be found, how they might be observed and more detailed simulations whichmore » are currently in progress. Finally we comment on whether or not it is possible to link the paradoxically hot, young stars found at the galactic center with WIMP burners.« less

Method for reducing NOx during combustion of coal in a burner

DOEpatents

Zhou, Bing [Cranbury, NJ; Parasher, Sukesh [Lawrenceville, NJ; Hare, Jeffrey J [Provo, UT; Harding, N Stanley [North Salt Lake, UT; Black, Stephanie E [Sandy, UT; Johnson, Kenneth R [Highland, UT

2008-04-15

An organically complexed nanocatalyst composition is applied to or mixed with coal prior to or upon introducing the coal into a coal burner in order to catalyze the removal of coal nitrogen from the coal and its conversion into nitrogen gas prior to combustion of the coal. This process leads to reduced NOx production during coal combustion. The nanocatalyst compositions include a nanoparticle catalyst that is made using a dispersing agent that can bond with the catalyst atoms. The dispersing agent forms stable, dispersed, nano-sized catalyst particles. The catalyst composition can be formed as a stable suspension to facilitate storage, transportation and application of the catalyst nanoparticles to a coal material. The catalyst composition can be applied before or after pulverizing the coal material or it may be injected directly into the coal burner together with pulverized coal.

Method and apparatus for afterburning flue gases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sikander, A.; Bjorkman, A.; Jonsson, G.

1984-11-13

A method of afterburning flue gases comprises passing impure gases from, for example, an incineration plant such as a destructor, process furnace, crematory furnace or heating boiler, through a burner in an afterburner where through enforced mixture with combustion gas they undergo complete combustion. The combustion gas, depending on the composition of the flue gases, may comprise air or oxygen or either mixed with petroleum gas. In apparatus for implementation of the method, the flue gases and the combustion gas are introduced into a burner which blows the gas mixture into a flame bowl where temperatures in the range ofmore » from 1,500/sup 0/-2,000/sup 0/ C. can be achieved. In one embodiment, the burner produces a conical basket-shaped flame in which the flue gases undergo complete combustion.« less

Apparatus for producing nanoscale ceramic powders

DOEpatents

Helble, Joseph J.; Moniz, Gary A.; Morse, Theodore F.

1997-02-04

An apparatus provides high temperature and short residence time conditions for the production of nanoscale ceramic powders. The apparatus includes a confinement structure having a multiple inclined surfaces for confining flame located between the surfaces so as to define a flame zone. A burner system employs one or more burners to provide flame to the flame zone. Each burner is located in the flame zone in close proximity to at least one of the inclined surfaces. A delivery system disposed adjacent the flame zone delivers an aerosol, comprising an organic or carbonaceous carrier material and a ceramic precursor, to the flame zone to expose the aerosol to a temperature sufficient to induce combustion of the carrier material and vaporization and nucleation, or diffusion and oxidation, of the ceramic precursor to form pure, crystalline, narrow size distribution, nanophase ceramic particles.

Apparatus for producing nanoscale ceramic powders

DOEpatents

Helble, Joseph J.; Moniz, Gary A.; Morse, Theodore F.

1995-09-05

An apparatus provides high temperature and short residence time conditions for the production of nanoscale ceramic powders. The apparatus includes a confinement structure having a multiple inclined surfaces for confining flame located between the surfaces so as to define a flame zone. A burner system employs one or more burners to provide flame to the flame zone. Each burner is located in the flame zone in close proximity to at least one of the inclined surfaces. A delivery system disposed adjacent the flame zone delivers an aerosol, comprising an organic or carbonaceous carrier material and a ceramic precursor, to the flame zone to expose the aerosol to a temperature sufficient to induce combustion of the carrier material and vaporization and nucleation, or diffusion and oxidation, of the ceramic precursor to form pure, crystalline, narrow size distribution, nanophase ceramic particles.

From Bunsen Burners to Fuel Cells: Invoking Energy Transducers to Exemplify "Paths" and Unify the Energy-Related Concepts of Thermochemistry and Thermodynamics

ERIC Educational Resources Information Center

Hladky, Paul W.

2009-01-01

The conversion of chemical energy entirely into thermal energy by Bunsen burners and into thermal energy and electrical energy by fuel cells of varying efficiencies illustrates different paths by which a chemical reaction can occur. Using the efficiency of producing electrical energy as a path label allows all of the energy-related quantities to…

Burner Rig Laboratory

NASA Image and Video Library

2015-05-12

The Fuel Burner Rig is a test laboratory at NASA Glenn, which subjects new jet engine materials, treated with protective coatings, to the hostile, high temperature, high velocity environment found inside aircraft turbine engines. These samples face 200-mile per hour flames to simulate the temperatures of aircraft engines in flight. The rig can also simulate aircraft carrier and dusty desert operations where salt and sand can greatly reduce engine life and performance.

High efficiency gas burner

DOEpatents

Schuetz, Mark A.

1983-01-01

A burner assembly provides for 100% premixing of fuel and air by drawing the air into at least one high velocity stream of fuel without power assist. Specifically, the nozzle assembly for injecting the fuel into a throat comprises a plurality of nozzles in a generally circular array. Preferably, swirl is imparted to the air/fuel mixture by angling the nozzles. The diffuser comprises a conical primary diffuser followed by a cusp diffuser.

EVALUATION OF INTERNALLY STAGED COAL BURNERS AND SORBENT JET AERODYNAMICS FOR COMBINED SO2/NOX CONTROL IN UTILITY BOILERS, VOLUME 1, TESTING IN A 10 MILLION BTU/HR EXPERIMENTAL FURNACE

EPA Science Inventory

The document gives results of tests conducted in a 2 MWt experimental furnace to: (1) investigate ways to reduce NOx emissions from utility coal burners without external air ports (i.e., with internal fuel/air staging); and (2) improve the performance of calcium-based sorbents fo...

ASU nitrogen sweep gas in hydrogen separation membrane for production of HRSG duct burner fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Panuccio, Gregory J.; Raybold, Troy M.; Jamal, Agil

2013-04-02

The present invention relates to the use of low pressure N2 from an air separation unit (ASU) for use as a sweep gas in a hydrogen transport membrane (HTM) to increase syngas H2 recovery and make a near-atmospheric pressure (less than or equal to about 25 psia) fuel for supplemental firing in the heat recovery steam generator (HRSG) duct burner.

Flame quenching by a variable-width rectangular-slot burner as a function of pressure for various propane-oxygen-nitrogen mixtures

NASA Technical Reports Server (NTRS)

Berlad, Abraham L

1954-01-01

Flame quenching by a variable-width rectangular-slot burner as a function of pressure for various propane-oxygen-nitrogen mixtures was investigated. It was found that for cold gas temperatures of 27 degrees C, pressures of 0.1 ro 1.0 atmosphere, and volumetric oxygen reactions of the oxidant of 0.17, 0.21, 0.30, 0.50, and 0.70, the relation between pressure p and quenching distance d is approximately given by d (unity) p (superscript -r) with r = 1, for equivalence ratios approximately equal to one. The quenching equation of Simon and Belles was tested. For equivalence ratios less than or equal to unity, this equation may by used, together with one empirical constant, to predict the observed quenching distance within 4.2 percent. The equation in it's present form does not appear to be suitable for values of the equivalence ratio greater than unity. A quantitative theoretical investigation has also been made of the error implicit in the assumption that flame quenching by plane parallel plates of infinite extent is equivalent to that of a rectangular burner. A curve is presented which relates the magnitude of this error to the length-to-width ratio of the rectangular burner.

Experimental studies of the emissions characteristics of nonpremixed gas-air flames of various configurations

NASA Astrophysics Data System (ADS)

Bandaru, Ramarao Venkat

2000-10-01

Flow structure plays an important role in the mixing and chemical reaction processes in turbulent jet diffusion flames, which in turn influence the formation of pollutants. Fundamental studies on pollutant formation have mainly focussed on vertical, straight jet, turbulent flames. However, in many practical combustion systems such as boilers and furnaces, flames of various configurations are used. In the present study, along with vertical straight jet flames, pollutant emissions characteristics of crossflow flames and precessing jet flames are studied. In vertical, straight jet flames, in-flame temperature and NO concentration measurements were made to ascertain the influence of flame radiation on NO x emissions observed in earlier studies. Radiation affects flame temperatures and this is seen in the measured temperature fields in, undiluted and diluted, methane and ethylene flames. Measured NO distribution fields in undiluted methane and ethylene flames inversely correlated with the temperature, and thereby explaining the observed relationship between flame radiation and NO x emissions. Flames in most practical combustion devices have complex mixing characteristics. One such configuration is the crossflow flame, where the flame is subjected to a crossflow stream. The presence of twin counter-rotating vortices in the flames leading to increased entrainment rates and shorter residence times (i.e. shorter flame lengths). The variation of NOx emissions characteristics of crossflow flames from those of straight jet flames depends on the sooting propensity of the fuel used. Additionally, the nearfield region of the flame (i.e., region near the burner exit) has a strong influence on the CO and unburned hydrocarbon emissions, and on the NO2-to-NO x ratios. Another flame configuration used in the present study is the precessing jet flame. In the practical implementation of this unique flame configuration, the fuel jet precesses about the burner axis due to natural fluid mechanical instability occurring inside the burner at a sudden expansion. Studies have shown that these flames emit up to 70% less NOx than straight jet flames. In precessing jet flames, the turbulent mixing scales are several times larger than those of straight jet flames.

Characterizing the Chemical Stability of High Temperature Materials for Application in Extreme Environments

NASA Technical Reports Server (NTRS)

Opila, Elizabeth

2005-01-01

The chemical stability of high temperature materials must be known for use in the extreme environments of combustion applications. The characterization techniques available at NASA Glenn Research Center vary from fundamental thermodynamic property determination to material durability testing in actual engine environments. In this paper some of the unique techniques and facilities available at NASA Glenn will be reviewed. Multiple cell Knudsen effusion mass spectrometry is used to determine thermodynamic data by sampling gas species formed by reaction or equilibration in a Knudsen cell held in a vacuum. The transpiration technique can also be used to determine thermodynamic data of volatile species but at atmospheric pressures. Thermodynamic data in the Si-O-H(g) system were determined with this technique. Free Jet Sampling Mass Spectrometry can be used to study gas-solid interactions at a pressure of one atmosphere. Volatile Si(OH)4(g) was identified by this mass spectrometry technique. A High Pressure Burner Rig is used to expose high temperature materials in hydrocarbon-fueled combustion environments. Silicon carbide (SiC) volatility rates were measured in the burner rig as a function of total pressure, gas velocity and temperature. Finally, the Research Combustion Lab Rocket Test Cell is used to expose high temperature materials in hydrogen/oxygen rocket engine environments to assess material durability. SiC recession due to rocket engine exposures was measured as a function of oxidant/fuel ratio, temperature, and total pressure. The emphasis of the discussion for all techniques will be placed on experimental factors that must be controlled for accurate acquisition of results and reliable prediction of high temperature material chemical stability.

Two-dimensional concentration and temperature measurements in extended flames of industrial burners using PLIF

NASA Astrophysics Data System (ADS)

Mueller, Dirk; Triebel, Wolfgang; Bochmann, Arne; Schmidl, Gabriele; Eckardt, Daniel; Burkert, Alfons; Roeper, Juergen; Schwerin, Malte

2003-11-01

Concentration profiles of OH, O2 and NO as well as temperature fields in diffusion flames of a length of approx. 300 mm and 40 mm in diameter used for gas-phase synthesis of fused silica have been determined by Planar Laser Induced Fluorescence (PLIF). The measurements have been carried out using a tunable spectrally narrowed KrF laser, whose wavelengths could be switched pulse-to-pulse. The laser beam was shaped as a light sheet into the flame at a fixed position. The flame area under investigation was monitored by moving the burner mounted on a stepper motor. By adapted synchronization the laser induced fluorescence was continuously recorded over the height of the flame perpendicular to the laser light sheet with an intensified CCD camera (10 fps, 8 bit dynamic range, 768 x 576 pixels). By image processing the spatial offset between images was corrected and superposed images were averaged and analyzed. This method allows to investigate the flame by recording 2D-fluorescence images including an automatic correction of intensity inhomogeneities of the laser light sheet. Based on the excited radical or molecule the fluorescence images were used to determine concentration and temperature distributions to build up a 2D-map of the flame. The PLIF experiment was calibrated with precise determination of the temperature at one coordinate of the flame by Spontaneous Vibrational Raman Scattering (VRS) of N2. As a result temperatures up to 3200 K could be determined with an accuracy better than 3% and a spatial resolution better than 1 mm. Temperature variations in the flame at different gas flows of fuel and oxidizer could be monitored sensitively. Also, the influence of different carrier gases like N2, Ar and He on the temperature distribution was investigated. Fluctuations in gas flow caused by turbulence could be monitored as well.

Effect of rice husk ash mass on sustainability pyrolysis zone of fixed bed downdraft gasifier with capacity of 10 kg/hour

NASA Astrophysics Data System (ADS)

Surjosatyo, Adi; Haq, Imaduddin; Dafiqurrohman, Hafif; Gibran, Felly Rihlat

2017-03-01

The formation of pyrolysis sustainability (Sustainable Pyrolysis) is the objective of the gasification process. Pyrolysis zone in the gasification process is the result of the endothermic reaction that get heat from oxidation (combustion) of the fuel with oxygen, where cracking biomass rice husk result of such as charcoal, water vapor, steam tar, and gas - gas (CO, H 2, CH 4, CO 2 and N 2) and must be maintained at a pyrolysis temperature to obtain results plentiful gas (producer gas) or syngas (synthetic gas). Obtaining continuously syngas is indicated by flow rate (discharge) producer gas well and the consistency of the flame on the gas burner, it is highly influenced by the gasification process and the operation of the gasifier and the mass balance (mass balance) between the feeding rate of rice husk with the disposal of ash (ash removal). In experiments conducted is using fixed bed gasifier type downdraft capacity of 10 kg/h. Besides setting the mass of rice husks into the gasifier and disposal arrangements rice husk ash may affect the sustainability of the pyrolysis process, but tar produced during the gasification process causes sticky rice husk ash in the plenum gasifier. Modifications disposal system rice husk ash can facilitate the arrangement of ash disposal then could control the temperature pyrolysis with pyrolysis at temperatures between 500-750 ° C. The experimental study was conducted to determine the effect of mass quantities of rice husk ash issued against sustainability pyrolysis temperature which is obtained at each time disposal of rice husk ash to produce 60-90 grams of ash issued. From some experimental phenomena is expected to be seen pyrolysis and its effect on the flow rate of syngas and the stability of the flame on the gas burner so that this research can find a correlation to obtain performance (performance) gasifier optimal.

Enhancing the use of coals by gas reburning-sorbent injection: Volume 3 -- Gas reburning-sorbent injection at Edwards Unit 1, Central Illinois Light Company. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-03-01

Design work has been completed for a Gas Reburning-Sorbent Injection (GR-SI) system to reduce emissions of NO{sub x} and SO{sub 2} from a wall fired unit at Central Illinois Light Company`s Edwards Station Unit 1, located in Bartonville, Illinois. The goal of the project was to reduce emissions of NO{sub x} by 60%, from the as found baseline of 0.98 lb/MBtu and to reduce emissions of SO{sub 2} by 50%. Since the unit currently fires a blend of high sulfur Illinois coal and low sulfur Kentucky coal to meet an SO{sub 2} limit of 1.8 lb/MBtu, the goal at thismore » site was amended to meeting this limit while increasing the fraction of high sulfur coal to 57% from the current 15% level. GR-SI requires injection of natural gas into the furnace at the level of the top burner row, creating a fuel-rich zone in which NO{sub x} formed in the coal zone is reduced to N{sub 2}. Recycled flue gas is used to increase the reburning fuel jet momentum, resulting in enhanced mixing. Recycled flue gas is also used to cool the top row of burners which would not be in service during GR operation. Dry hydrated lime sorbent is injected into the upper furnace to react with SO{sub 2}, forming solid CaSO{sub 4} and CaSO{sub 3}, which are collected by the ESP. The system was designed to inject sorbent at a rate corresponding to a calcium (sorbent) to sulfur (coal) molar ratio of 2.0. The SI system design was optimized with respect to gas temperature, injection air flow rate, and sorbent dispersion. Sorbent injection air flow is equal to 3% of the combustion air. The design includes modifications of the ESP, sootblowing, and ash handling systems.« less

Korean Waste Management Law, Presidential Decree Number 13480, and Prime Minister Order Number 397

DTIC Science & Technology

1994-06-01

radioactive waste or substances that are contaminated by radioactivity and medical waste (which is regulated by Medical Law), wastewater (which is regulated...be exceeded when the domestic waste is disposed a. In case where water polutant , pursuant to Table 1 of toe Enforcement Regulaton in the Water...combustion burner and extra burner * Normal operation of safety facilities • Normal operation of preventive facilities * Density of polutant out of

Precipitation-Static-Reduction Research

DTIC Science & Technology

1943-03-31

if» 85 z \\ PRECIPITATION-STATIC-REDUCTION RESEARCH study of the effects of flame length , flame spacing, and burner spacing on B shows that there...unod: Flame length *. The visual length of the flame from the burner tip to the flame tip when examined in a darkened room against a black background...Postlve and Negative Flames The use of the second flame-conduction coefficient, B, facilitates considerably the study of the effect of flame length , spacing

Air Emissions Inventory Guidance Document for Stationary Sources at Air Force Installations.

DTIC Science & Technology

1999-05-01

small stoker-fired boilers). sox Change to lower sulfur coal, Coal Cleaning, Flue Gas Desulfurization (e.g., wet scrubbing, spray drying, furnace...Multiclone Collector. SOx Flue Gas Desulfurization (e.g., wet , semi-dry, or dry scrubbers) NOx Low Excess Air, Burners out of Service, Biased Burner...both flue gas desulfurization spray dryer adsorber (FGD-SDA) and a fabric filter (FF). d Factors apply to boilers equipped with an electrostatic

A computer simulation of the transient response of a 4 cylinder Stirling engine with burner and air preheater in a vehicle

NASA Technical Reports Server (NTRS)

Martini, W. R.

1981-01-01

A series of computer programs are presented with full documentation which simulate the transient behavior of a modern 4 cylinder Siemens arrangement Stirling engine with burner and air preheater. Cold start, cranking, idling, acceleration through 3 gear changes and steady speed operation are simulated. Sample results and complete operating instructions are given. A full source code listing of all programs are included.

Experimental clean combustor program: Noise study

NASA Technical Reports Server (NTRS)

Sofrin, T. G.; Riloff, N., Jr.

1976-01-01

Under a Noise Addendum to the NASA Experimental Clean Combustor Program (ECCP) internal pressure fluctuations were measured during tests of JT9D combustor designs conducted in a burner test rig. Measurements were correlated with burner operating parameters using an expression relating farfield noise to these parameters. For a given combustor, variation of internal noise with operating parameters was reasonably well predicted by this expression but the levels were higher than farfield predictions and differed significantly among several combustors. For two burners, discharge stream temperature fluctuations were obtained with fast-response thermocouples to allow calculation of indirect combustion noise which would be generated by passage of the temperature inhomogeneities through the high pressure turbine stages of a JT9D turbofan engine. Using a previously developed analysis, the computed indirect combustion noise was significantly lower than total low frequency core noise observed on this and several other engines.

TPV Power Source Using Infrared-Sensitive Cells with Commercially Available Radiant Tube Burner

NASA Astrophysics Data System (ADS)

Fraas, Lewis; Minkin, Leonid; Hui, She; Avery, James; Howells, Christopher

2004-11-01

Over the last several years, JX Crystals has invented and systematically developed the key components for thermophotovoltaic systems. These key components include GaSb infrared sensitive cells, high power density shingle circuits, dielectric filters, and hydrocarbon-fueled radiant tube burners. Most recently, we invented and demonstrated an antireflection (AR)-coated tungsten IR emitter which when integrated with the other key components should make TPV systems with efficiencies over 10% practical. However, the use of the AR tungsten emitter requires an oxygen-free hermetic seal enclosure. During a 2003 Small Business Innovative Research (SBIR) Phase I contract, we integrated a tungsten emitter foil and a commercial SiC radiant tube burner within an emitter thermos and successfully demonstrated its operation at high temperature. We also designed a complete stand alone 500 W TPV generator. During the upcoming SBIR Phase II, we plan to implement this design in hardware.

Rapid ignition of fluidized bed boiler

DOEpatents

Osborn, Liman D.

1976-12-14

A fluidized bed boiler is started up by directing into the static bed of inert and carbonaceous granules a downwardly angled burner so that the hot gases cause spouting. Air is introduced into the bed at a rate insufficient to fluidize the entire bed. Three regions are now formed in the bed, a region of lowest gas resistance, a fluidized region and a static region with a mobile region at the interface of the fluidized and static regions. Particles are transferred by the spouting action to form a conical heap with the carbonaceous granules concentrated at the top. The hot burner gases ignite the carbonaceous matter on the top of the bed which becomes distributed in the bed by the spouting action and bed movement. Thereafter the rate of air introduction is increased to fluidize the entire bed, the spouter/burner is shut off, and the entire fluidized bed is ignited.

Performance of laser glazed Zr02 TBCs in cyclic oxidation and corrosion burner test rigs

NASA Technical Reports Server (NTRS)

Zaplatynsky, I.

1982-01-01

The performance of laser glazed zirconia thermal barrier coatings (TBCs) was evaluated in cyclic oxidation and cyclic corrosion tests. Plasma sprayed zirconia coatings of two thicknesses were partially melted with a CO2 laser. The power density of the focused laser beam was varied from 35 to 75 W/sq mm, while the scanning speed was about 80 cm per minute. In cyclic oxidation tests, the specimens were heated in a burner rig for 6 minutes and cooled for 3 minutes. It is indicated that the laser treated samples have the same life as the untreated ones. However, in corrosion tests, in which the burner rig flame contained 100 PPM sodium fuel equivalent, the laser treated samples exhibit nearly a fourfold life improvement over that of the reference samples vary. In both tests, the lives of the samples inversely with the thickness of the laser melted layer of zirconia.

DOE Office of Scientific and Technical Information (OSTI.GOV)

BRISC is a developmental prototype for a nextgeneration “systems-level” integrated performance and safety code (IPSC) for nuclear reactors. Its development served to demonstrate how a lightweight multi-physics coupling approach can be used to tightly couple the physics models in several different physics codes (written in a variety of languages) into one integrated package for simulating accident scenarios in a liquid sodium cooled “burner” nuclear reactor. For example, the RIO Fluid Flow and Heat transfer code developed at Sandia (SNL: Chris Moen, Dept. 08005) is used in BRISC to model fluid flow and heat transfer, as well as conduction heat transfermore » in solids. Because BRISC is a prototype, its most practical application is as a foundation or starting point for developing a true production code. The sub-codes and the associated models and correlations currently employed within BRISC were chosen to cover the required application space and demonstrate feasibility, but were not optimized or validated against experimental data within the context of their use in BRISC.« less

Transient analysis of a pulsed detonation combustor using the numerical propulsion system simulation

NASA Astrophysics Data System (ADS)

Hasler, Anthony Scott

The performance of a hybrid mixed flow turbofan (with detonation tubes installed in the bypass duct) is investigated in this study and compared with a baseline model of a mixed flow turbofan with a standard combustion chamber as a duct burner. Previous studies have shown that pulsed detonation combustors have the potential to be more efficient than standard combustors, but they also present new challenges that must be overcome before they can be utilized. The Numerical Propulsion System Simulation (NPSS) will be used to perform the analysis with a pulsed detonation combustor model based on a numerical simulation done by Endo, Fujiwara, et. al. Three different cases will be run using both models representing a take-off situation, a subsonic cruise and a supersonic cruise situation. Since this study investigates a transient analysis, the pulse detonation combustor is run in a rig setup first and then its pressure and temperature are averaged for the cycle to obtain quasi-steady results.

Solid oxide fuel cell power plant having a bootstrap start-up system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lines, Michael T

The bootstrap start-up system (42) achieves an efficient start-up of the power plant (10) that minimizes formation of soot within a reformed hydrogen rich fuel. A burner (48) receives un-reformed fuel directly from the fuel supply (30) and combusts the fuel to heat cathode air which then heats an electrolyte (24) within the fuel cell (12). A dilute hydrogen forming gas (68) cycles through a sealed heat-cycling loop (66) to transfer heat and generated steam from an anode side (32) of the electrolyte (24) through fuel processing system (36) components (38, 40) and back to an anode flow field (26)more » until fuel processing system components (38, 40) achieve predetermined optimal temperatures and steam content. Then, the heat-cycling loop (66) is unsealed and the un-reformed fuel is admitted into the fuel processing system (36) and anode flow (26) field to commence ordinary operation of the power plant (10).« less

Flow field and scalar measurements in a series of turbulent partially-premixed dimethyl ether/air jet flames

DOE PAGES

Coriton, Bruno; Im, Seong -Kyun; Gamba, Mirko; ...

2017-03-12

Here, we present a series of benchmark flames consisting of six partially-premixed piloted dimethyl ether (DME)/air jet flames. These flames provide an opportunity to understand turbulence-flame interactions for oxygenated fuels and to develop predictive models for these interactions using a canonical burner geometry. The development of accurate models for DME/air flames would establish a foundation for studies of more complex oxygenated fuels. The flames are stabilized on a piloted jet burner similar to that of the partially-premixed methane/air jet flames that have been studied extensively within the context of the TNF Workshop. This series of six jet flames spans jetmore » exit Reynolds numbers, ReD, from 29,300 to 73,300 and stoichiometric mixture fractions, ξ st, from 0.35 to 0.60. Flame conditions range from very low probability of localized extinction to a high probability of localized extinction and subsequent re-ignition. Measurements in the flames are compared at downstream locations from 5 to 25 diameters above the nozzle exit. Mean and fluctuating velocity components are measured using stereo particle image velocimetry (SPIV). Simultaneous laser-induced fluorescence (LIF) imaging of OH and CH 2O provides insights into the distribution of these intermediate species in partially-premixed DME/air flames. OH LIF imaging is also combined with SPIV to investigate the strain rate field across the reaction zone.« less

Numerical Simulation of the Thermal Process in a W-Shape Radiant Tube Burner

NASA Astrophysics Data System (ADS)

Wang, Yi; Li, Jiyong; Zhang, Lifeng; Ling, Haitao; Li, Yanlong

2014-07-01

In the current work, three-dimensional mathematical models were developed for the heat transfer and combustion in a W-shape radiant tube burner (RTB) and were solved using Fluent software (ANSYS Inc., Canonsburg, PA). The standard k- ɛ model, nonpremixed combustion model, and the discrete ordinate model were used for the modeling of turbulence, combustion, and radiant heat transfer, respectively. In addition, the NO x postprocessor was used for the prediction of the NO emission. A corresponding experiment was performed for the validation of mathematical models. The details of fluid flow, heat transfer, and combustion in the RTB were investigated. Moreover, the effect of the air/fuel ratio (A/F) and air staging on the performance of RTB was studied with the reference indexes including heat efficiency, maximum temperature difference on shell wall, and NO emission at the outlet. The results indicated that a low speed zone formed in the vicinity of the combustion chamber outlet, and there were two relative high-temperature zones in the RTB, one in combustion chamber that favored the flame stability and the other from the main flame in the RTB. The maximum temperature difference was 95.48 K. As the A/F increased, the temperature increased first and then decreased. As the ratio of the primary to secondary air increased, the recirculation zone at the outlet of combustion chamber shrank gradually to disappear, and the flame length was longer and the temperature in flame decreased correspondingly.

Simulation on an optimal combustion control strategy for 3-D temperature distributions in tangentially pc-fired utility boiler furnaces.

PubMed

Wang, Xi-fen; Zhou, Huai-chun

2005-01-01

The control of 3-D temperature distribution in a utility boiler furnace is essential for the safe, economic and clean operation of pc-fired furnace with multi-burner system. The development of the visualization of 3-D temperature distributions in pc-fired furnaces makes it possible for a new combustion control strategy directly with the furnace temperature as its goal to improve the control quality for the combustion processes. Studied in this paper is such a new strategy that the whole furnace is divided into several parts in the vertical direction, and the average temperature and its bias from the center in every cross section can be extracted from the visualization results of the 3-D temperature distributions. In the simulation stage, a computational fluid dynamics (CFD) code served to calculate the 3-D temperature distributions in a furnace, then a linear model was set up to relate the features of the temperature distributions with the input of the combustion processes, such as the flow rates of fuel and air fed into the furnaces through all the burners. The adaptive genetic algorithm was adopted to find the optimal combination of the whole input parameters which ensure to form an optimal 3-D temperature field in the furnace desired for the operation of boiler. Simulation results showed that the strategy could soon find the factors making the temperature distribution apart from the optimal state and give correct adjusting suggestions.

Flow field and scalar measurements in a series of turbulent partially-premixed dimethyl ether/air jet flames

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coriton, Bruno; Im, Seong -Kyun; Gamba, Mirko

Here, we present a series of benchmark flames consisting of six partially-premixed piloted dimethyl ether (DME)/air jet flames. These flames provide an opportunity to understand turbulence-flame interactions for oxygenated fuels and to develop predictive models for these interactions using a canonical burner geometry. The development of accurate models for DME/air flames would establish a foundation for studies of more complex oxygenated fuels. The flames are stabilized on a piloted jet burner similar to that of the partially-premixed methane/air jet flames that have been studied extensively within the context of the TNF Workshop. This series of six jet flames spans jetmore » exit Reynolds numbers, ReD, from 29,300 to 73,300 and stoichiometric mixture fractions, ξ st, from 0.35 to 0.60. Flame conditions range from very low probability of localized extinction to a high probability of localized extinction and subsequent re-ignition. Measurements in the flames are compared at downstream locations from 5 to 25 diameters above the nozzle exit. Mean and fluctuating velocity components are measured using stereo particle image velocimetry (SPIV). Simultaneous laser-induced fluorescence (LIF) imaging of OH and CH 2O provides insights into the distribution of these intermediate species in partially-premixed DME/air flames. OH LIF imaging is also combined with SPIV to investigate the strain rate field across the reaction zone.« less

Effect of Adventitious Carbon on the Environmental Degradation of SiC/BN/SiC Composites

NASA Technical Reports Server (NTRS)

Ogbuji, L. U. J. T.; Yun, H. M.; DiCarlo, J.

2002-01-01

Pesting remains a major obstacle to the application of SiC/SiC composites in engine service and selective degradation of the boron nitride interphase at intermediate temperatures is of primary concern. However, significant progress has been made on interphase improvement recently and we now know more about the phenomenon and ways to suppress it. By screening SiC/BN/SiC materials through characterization of strength and microstructures after exposure in a burner rig, some factors that control pesting in these composites have been determined. A key precaution is careful control of elemental carbon presence in the interphase region.

Nitramine smokeless propellant research

NASA Technical Reports Server (NTRS)

1977-01-01

A transient ballistics and combustion model was derived to represent the closed vessel experiment that is widely used to characterize propellants. The model incorporates the nitramine combustion mechanisms. A computer program was developed to solve the time dependent equations, and was applied to explain aspects of closed vessel behavior. It is found that the rate of pressurization in the closed vessel is insufficient at pressures of interest to augment the burning rate by time dependent processes. Series of T-burner experiments were performed to compare the combustion instability characteristics of nitramine (HMX) containing propellants and ammonium perchlorate (AP) propellants. It is found that the inclusion of HMX consistently renders the propellant more stable.

Single-cell isolation using a DVD optical pickup

PubMed Central

Kasukurti, A.; Potcoava, M.; Desai, S.A.; Eggleton, C.; Marr, D. W. M.

2011-01-01

A low-cost single-cell isolation system incorporating a digital versatile disc burner (DVD RW) optical pickup has been developed. We show that these readily available modules have the required laser power and focusing optics to provide a steady Gaussian beam capable of optically trapping micron-sized colloids and red blood cells. Utility of the pickup is demonstrated through the non-destructive isolation of such particles in a laminar-flow based microfluidic device that captures and translates single microscale objects across streamlines into designated channel exits. In this, the integrated objective lens focusing coils are used to steer the optical trap across the channel, resulting in the isolation of colloids and red blood cells using a very inexpensive off-the-shelf optical component. PMID:21643294

Effects of water-contaminated air on blowoff limits of opposed jet hydrogen-air diffusion flames

NASA Technical Reports Server (NTRS)

Pellett, Gerald L.; Jentzen, Marilyn E.; Wilson, Lloyd G.; Northam, G. Burton

1988-01-01

The effects of water-contaminated air on the extinction and flame restoration of the central portion of N2-diluted H2 versus air counterflow diffusion flames are investigated using a coaxial tubular opposed jet burner. The results show that the replacement of N2 contaminant in air by water on a mole for mole basis decreases the maximum sustainable H2 mass flow, just prior to extinction, of the flame. This result contrasts strongly with the analogous substitution of water for N2 in a relatively hot premixed H2-O2-N2 flame, which was shown by Koroll and Mulpuru (1986) to lead to a significant, kinetically controlled increase in laminar burning velocity.

Combustion of liquid fuels in a flowing combustion gas environment at high pressures

NASA Technical Reports Server (NTRS)

Canada, G. S.; Faeth, G. M.

1975-01-01

The combustion of fuel droplets in gases which simulate combustion chamber conditions was considered both experimentally and theoretically. The fuel droplets were simulated by porous spheres and allowed to gasify in combustion gases produced by a burner. Tests were conducted for pressures of 1-40 atm, temperatures of 600-1500 K, oxygen concentrations of 0-13% (molar) and approach Reynolds numbers of 40-680. The fuels considered in the tests included methanol, ethanol, propanol-1, n-pentane, n-heptane and n-decane. Measurements were made of both the rate of gasification of the droplet and the liquid surface temperature. Measurements were compared with theory, involving various models of gas phase transport properties with a multiplicative correction for the effect of forced convection.

Cook stove assembly

DOEpatents

DeFoort, Morgan W; Willson, Bryan D; Lorenz, Nathan; Brady, Michael P; Marchese, Anthony; Miller-Lionberg, Daniel D

2014-12-02

A combustion chamber, having an upper part and a lower part, may include an annular constriction, in combination with the combustion chamber, to aid in directing partially combusted gases such as carbon monoxide away from the periphery of the combustion chamber back toward its center, and into the flame front. The annular constriction may also impede the flow of partially combusted gases located at the periphery, thus increasing the time these gases spend within the combustion chamber and increasing the likelihood that any products of incomplete combustion will undergo combustion. The combustion chamber may further comprise a dual burner cooktop for directing combustion gases and exhaust to multiple cooking vessels. In further embodiments, the combustion chamber may be made of, lined, or clad with a metal alloy comprising iron, chromium, and aluminum.

Studies on Decomposition and Combustion Mechanism of Solid Fuel Rich Propellants

DTIC Science & Technology

2010-08-30

thrust to cruise at supersonic speed. This was followed by the test of large diameter ramjet called burner test vehicle (BTV). Advanced low volume...propellant surface. Vernekar et al (43) found that in pressed AP-Al pellets , maximum burn rate is obtained at intermediate metal content. Jain et al...conjunction with high pressure window strand burner . They found that the propellant combustion was irregular and regression rate varied from 0.3 to 3

Aerolization During Boron Nanoparticle Multi-Component Fuel Group Burning Studies

DTIC Science & Technology

2014-02-03

Anderson, University of Utah). …………………… 14 Figure 2. Photograph of group burning facility showing benchtop flat flame burner unit with injector nozzle ...and (B) aerosol generator. 16 Figure 6. Diagram of benchtop flat flame burner unit showing injector nozzle assembly with VOAG orifice, fuel and...translation stage, variable fuel and gas supply rates, and injector nozzles that can be configured to investigate diffusion and premixed flames (Fig. 2 & 3

Increase in the efficiency of electric melting of pellets in an arc furnace with allowance for the energy effect of afterburning of carbon oxide in slag using fuel-oxygen burners

NASA Astrophysics Data System (ADS)

Stepanov, V. A.; Krakht, L. N.; Merker, E. E.; Sazonov, A. V.; Chermenev, E. A.

2015-12-01

The problems of increasing the efficiency of electric steelmaking using fuel-oxygen burners to supply oxygen for the afterburning of effluent gases in an arc furnace are considered. The application of a new energy-saving regime based on a proposed technology of electric melting is shown to intensify the processes of slag formation, heating, and metal decarburization.

Environmental control implications of generating electric power from coal. 1977 technology status report. Appendix D. Assessment of NO/sub x/ control technology for coal fired utility boilers. [Low-excess-air, staged combustion, flu gas recirculation and burner design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1977-12-01

An NOx control technology assessment study was conducted to examine the effectiveness of low-excess-air firing, staged combustion, flue gas recirculation, and current burner/boiler designs as applied to coal-fired utility boilers. Significant variations in NOx emissions exist with boiler type, firing method, and coal type, but a relative comparison of emissions control performance, cost, and operational considerations is presented for each method. The study emphasized the numerous operational factors that are of major importance to the user in selecting and implementing a combustion modification technique. Staged combustion and low-excess-air operation were identified as the most cost-effective methods for existing units. Closemore » control of local air/fuel ratios and rigorous combustion equipment maintenance are essential to the success of both methods. Flue gas recirculation is relatively ineffective and has the added concern of tube erosion. More research is needed to resolve potential corrosion concerns with low-NOx operating modes. Low-NOx burners in conjunction with a compartmentalized windbox are capable of meeting a 0.6-lb/million Btu emission level on new units. Advanced burner designs are being developed to meet research emission goals of approximately 0.25 lb/MBtu.« less

Effect of the superposition of a dielectric barrier discharge onto a premixed gas burner flame

NASA Astrophysics Data System (ADS)

Zaima, Kazunori; Takada, Noriharu; Sasaki, Koichi

2011-10-01

We are investigating combustion control with the help of nonequilibrium plasma. In this work, we examined the effect of dielectric barrier discharge (DBD) on a premixed burner flame with CH4/O2/Ar gas mixture. The premixed burner flame was covered with a quartz tube. A copper electrode was attached on the outside of the quartz tube, and it was connected to a high-voltage power supply. DBD inside the quartz tube was obtained between the copper electrode and the grounded nozzle of the burner which was placed at the bottom of the quartz tube. We clearly observed that the flame length was shortened by superposing DBD onto the bottom part of the flame. The shortened flame length indicates the enhancement of the burning velocity. We measured the optical emission spectra from the bottom region of the flame. As a result, we observed clear line emissions from Ar, which were never observed from the flame without DBD. We evaluated the rotational temperatures of OH and CH radicals by spectral fitting. As a result, the rotational temperature of CH was not changed, and the rotational temperature of OH was decreased by the superposition of DBD. According to these results, it is considered that the enhancement of the burning velocity is not caused by gas heating. New reaction pathways are suggested.

Tensile Behavior of As-Fabricated and Burner-Rig Exposed SiC/SiC Composites with Hi-Nicalon Type-S Fibers

NASA Technical Reports Server (NTRS)

Yun, H. M.; Dicarlo, J. A.; Ogbuji, L. T.; Chen, Y. L.

2002-01-01

Tensile stress-strain curves were measured at room temperature and 1315 C for 2D-woven SiC/BN/SiC ceramic matrix composites (CMC) reinforced by two variations of Hi-Nicalon Type-S SiC fibers. These fibers, which contained a thin continuous carbon-rich layer on their as-produced surface, provided the as-fabricated CMC with good composite behavior and an ultimate strength and strain of -350 MPa and -0.5%, respectively. However, after un-stressed burner-rig exposure at 815 C for -100 hrs, CMC tensile specimens with cut edges and exposed interphases showed a significant decrease in ultimate properties with effectively no composite behavior. Microstructural observations show that the degradation was caused by internal fiber-fiber oxide bonding after removal of the carbon-rich fiber surface layer by the high-velocity combustion gases. On the other hand, SiC/BN/SiC CMC with Sylramic-iBN fibers without carbon-rich surfaces showed higher as-fabricated strength and no loss in strength after the same burner rig exposure. Based on the strong role of the carbon layer in these observations, a process method was developed and demonstrated for achieving better strength retention of Hi-Nicalon Type-S CMC during burner rig exposure. Other general approaches for minimizing this current deficiency with as-produced Type-S fibers are discussed.

Influence of the burner swirl on the azimuthal instabilities in an annular combustor

NASA Astrophysics Data System (ADS)

Mazur, Marek; Nygård, Håkon; Worth, Nicholas; Dawson, James

2017-11-01

Improving our fundamental understanding of thermoacoustic instabilities will aid the development of new low emission gas turbine combustors. In the present investigation the effects of swirl on the self-excited azimuthal combustion instabilities in a multi-burner annular annular combustor are investigated experimentally. Each of the burners features a bluff body and a swirler to stabilize the flame. The combustor is operated with an ethylene-air premixture at powers up to 100 kW. The swirl number of the burners is varied in these tests. For each case, dynamic pressure measurements at different azimuthal positions, as well as overhead imaging of OH* of the entire combustor are conducted simultaneously and at a high sampling frequency. The measurements are then used to determine the azimuthal acoustic and heat release rate modes in the chamber and to determine whether these modes are standing, spinning or mixed. Furthermore, the phase shift between the heat release rate and pressure and the shape of these two signals are analysed at different azimuthal positions. Based on the Rayleigh criterion, these investigations allow to obtain an insight about the effects of the swirl on the instability margins of the combustor. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant agreement n° 677931 TAIAC).

Real-Time Thermographic-Phosphor-Based Temperature Measurements of Thermal Barrier Coating Surfaces Subjected to a High-Velocity Combustor Burner Environment

NASA Technical Reports Server (NTRS)

Eldridge, Jeffrey I.; Jenkins, Thomas P.; Allison, Stephen W.; Cruzen, Scott; Condevaux, J. J.; Senk, J. R.; Paul, A. D.

2011-01-01

Surface temperature measurements were conducted on metallic specimens coated with an yttria-stabilized zirconia (YSZ) thermal barrier coating (TBC) with a YAG:Dy phosphor layer that were subjected to an aggressive high-velocity combustor burner environment. Luminescence-based surface temperature measurements of the same TBC system have previously been demonstrated for specimens subjected to static furnace or laser heating. Surface temperatures were determined from the decay time of the luminescence signal of the YAG:Dy phosphor layer that was excited by a pulsed laser source. However, the furnace and laser heating provides a much more benign environment than that which exists in a turbine engine, where there are additional challenges of a highly radiant background and high velocity gases. As the next step in validating the suitability of luminescence-based temperature measurements for turbine engine environments, new testing was performed where heating was provided by a high-velocity combustor burner rig at Williams International. Real-time surface temperature measurements during burner rig heating were obtained from the decay of the luminescence from the YAG:Dy surface layer. The robustness of several temperature probe designs in the sonic velocity, high radiance flame environment was evaluated. In addition, analysis was performed to show whether the luminescence decay could be satisfactorily extracted from the high radiance background.

Annual Research Briefs

NASA Technical Reports Server (NTRS)

Spinks, Debra (Compiler)

1997-01-01

This report contains the 1997 annual progress reports of the research fellows and students supported by the Center for Turbulence Research (CTR). Titles include: Invariant modeling in large-eddy simulation of turbulence; Validation of large-eddy simulation in a plain asymmetric diffuser; Progress in large-eddy simulation of trailing-edge turbulence and aeronautics; Resolution requirements in large-eddy simulations of shear flows; A general theory of discrete filtering for LES in complex geometry; On the use of discrete filters for large eddy simulation; Wall models in large eddy simulation of separated flow; Perspectives for ensemble average LES; Anisotropic grid-based formulas for subgrid-scale models; Some modeling requirements for wall models in large eddy simulation; Numerical simulation of 3D turbulent boundary layers using the V2F model; Accurate modeling of impinging jet heat transfer; Application of turbulence models to high-lift airfoils; Advances in structure-based turbulence modeling; Incorporating realistic chemistry into direct numerical simulations of turbulent non-premixed combustion; Effects of small-scale structure on turbulent mixing; Turbulent premixed combustion in the laminar flamelet and the thin reaction zone regime; Large eddy simulation of combustion instabilities in turbulent premixed burners; On the generation of vorticity at a free-surface; Active control of turbulent channel flow; A generalized framework for robust control in fluid mechanics; Combined immersed-boundary/B-spline methods for simulations of flow in complex geometries; and DNS of shock boundary-layer interaction - preliminary results for compression ramp flow.

Emission Modeling of an Interturbine Burner Based on Flameless Combustion

PubMed Central

2017-01-01

Since its discovery, the flameless combustion (FC) regime has been a promising alternative to reduce pollutant emissions of gas turbine engines. This combustion mode is characterized by well-distributed reaction zones, which potentially decreases temperature gradients, acoustic oscillations, and NOx emissions. Its attainment within gas turbine engines has proved to be challenging because previous design attempts faced limitations related to operational range and combustion efficiency. Along with an aircraft conceptual design, the AHEAD project proposed a novel hybrid engine. One of the key features of the proposed hybrid engine is the use of two combustion chambers, with the second combustor operating in the FC mode. This novel configuration would allow the facilitation of the attainment of the FC regime. The conceptual design was adapted to a laboratory scale combustor that was tested at elevated temperature and atmospheric pressure. In the current work, the emission behavior of this scaled combustor is analyzed using computational fluid dynamics (CFD) and chemical reactor network (CRN). The CFD was able to provide information with the flow field in the combustor, while the CRN was used to model and predict emissions. The CRN approach allowed the analysis of the NOx formation pathways, indicating that the prompt NOx was the dominant pathway in the combustor. The combustor design can be improved by modifying the mixing between fuel and oxidizer as well as the split between combustion and dilution air. PMID:29910533

Overview of thermal conductivity models of anisotropic thermal insulation materials

NASA Astrophysics Data System (ADS)

Skurikhin, A. V.; Kostanovsky, A. V.

2017-11-01

Currently, the most of existing materials and substances under elaboration are anisotropic. It makes certain difficulties in the study of heat transfer process. Thermal conductivity of the materials can be characterized by tensor of the second order. Also, the parallelism between the temperature gradient vector and the density of heat flow vector is violated in anisotropic thermal insulation materials (TIM). One of the most famous TIM is a family of integrated thermal insulation refractory material («ITIRM»). The main component ensuring its properties is the «inflated» vermiculite. Natural mineral vermiculite is ground into powder state, fired by gas burner for dehydration, and its precipitate is then compressed. The key feature of thus treated batch of vermiculite is a package structure. The properties of the material lead to a slow heating of manufactured products due to low absorption and high radiation reflection. The maximum of reflection function is referred to infrared spectral region. A review of current models of heat propagation in anisotropic thermal insulation materials is carried out, as well as analysis of their thermal and optical properties. A theoretical model, which allows to determine the heat conductivity «ITIRM», can be useful in the study of thermal characteristics such as specific heat capacity, temperature conductivity, and others. Materials as «ITIRM» can be used in the metallurgy industry, thermal energy and nuclear power-engineering.

Experimental study on NOx emission and unburnt carbon of a radial biased swirl burner for coal combustion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shan Xue; Shi'en Hui; Qulan Zhou

Pilot tests were carried out on a 1 MW thermal pulverized coal fired testing furnace. Symmetrical combustion was implemented by use of two whirl burners with dual air adjustment. The burnout air device was installed in various places at the top of the main burner, which consists of a primary air pipe with a varying cross-section and an impact ring. In the primary air pipe, the air pulverized coal (PC) stream was separated into a whirling stream that was thick inside and thin outside, thus realizing the thin-thick distribution at the burner nozzle in the radial direction. From the comparativemore » combustion tests of three coals with relatively great characteristic differences, Shaanbei Shenhua high rank bituminous coal (SH coal), Shanxi Hejin low rank bituminous coal (HJ coal), and Shanxi Changzhi meager coal (CZ coal), were obtained such test results as the primary air ratio, inner secondary air ratio, outer secondary air ratio, impact of the change of outer secondary air, change of the relative position for the layout of burnout air, change of the swirling intensity of the primary air and secondary air, etc., on the NOx emission, and unburnt carbon content in fly ash (CFA). At the same time, the relationship between the NOx emission and burnout ratio and affecting factors of the corresponding test items on the combustion stability and economic results were also acquired. The results may provide a vital guiding significance to engineering designs and practical applications. According to the experimental results, the influence of each individual parameter on NOx formation and unburned carbon in fly ash agrees well with the existing literature. In this study, the influences of various combinations of these parameters are also examined, thus providing some reference for the design of the radial biased swirl burner, the configuration of the furnace, and the distribution of the air. 23 refs., 14 figs., 2 tabs.« less

Utility experience of Phase I compliance on Chalk Point Unit 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eberhardt, W.H.; Henry, R.J.

1995-03-01

Potomac Electric Power Company`s Chalk Point Generating Station Unit 2 has recently undergone a retrofit to comply with Phase I of the 1990 Clean Air Act Amendments (CAAA) Title IV requirements. The approach taken was to install low NOx burners and overfire air to reduce NOx emissions and switch to lower sulfur coal to comply with Phase I sulfur dioxide (SO{sub 2}) emission limits. This approach was chosen based on a unique combination of sophisticated tools, boiler modeling, experience, testing, and cooperation between the Owners, Engineers, and the equipment Manufacturers. The result was a project performed at a reasonable costmore » and minimum risk to plant reliability and performance while meeting the specified requirements of the regulations. The Unit 2 retrofit will be followed by the retrofit of its identical sister unit, Unit 1, in the late fall of 1994. In addition to the Low NOx system retrofit and coal switching, a new distributed control system (DCS), burner management system (BMS), new ignitors, and the capability to fire natural gas on both main burners and ignitors was added. A four month outage was followed by a series of optimization tests which were designed to reduce the emissions to the compliance limit while minimizing impacts on the boiler operation. After boiler startup, burner and pulverizer performance adjustments were required resulting in dramatic improvement in both boiler and burner performance. This paper describes the approach towards achieving CAAA compliance and the net results: impacts of the Low NOx system and the Phase I coal on the boiler and auxiliary plant equipment and the adjustments which had to be made to eliminate initial operating problems. Results of months of optimization testing are presented as related to emissions, furnace slagging, flame shape, unburned carbon, steam temperatures, and tube metal temperatures.« less

Influence of G-jitter on the characteristics of a non-premixed flame: Experimental approach

NASA Astrophysics Data System (ADS)

Joulain, Pierre; Cordeiro, Pierre; Rouvreau, Sébastien; Legros, Guillaume; Fuentes, Andres; Torero, José L.

2005-03-01

The combustion of a flat plate in a boundary layer under microgravity conditions, which was first described by Emmons, is studied using a gas burner. Magnitude of injection and blowing velocities are chosen to be characteristic of pyrolyzing velocity of solid fuels, and of ventilation systems in space stations. These velocities are about 0.1 m/s for oxidiser flow and 0.004m/s for fuel flow. In this configuration, flame layout results from a coupled interaction between oxidiser flow, fuel flow and thermal expansion. Influences of these parameters are studied experimentally by means of flame length and standoff distance measurements using CH* chemiluminescence's and visible emission of the flame. Flow was also studied with Particle Image Velocimetry (PIV). Inert flows, with and without injection, and reacting flow in a microgravity environment were considered to distinguish aerodynamic from thermal effect. Thermal expansion effects have been shown by means of the acceleration of oxidiser flow. Three-dimensional effects, which are strongly marked for high injection velocities were studied. Three-dimensional tools adaptability to parabolic flights particular conditions were of concern. Flame sensitivity to g-jitters was investigated according to g-jitters frequency and range involved by parabolic flights. It appears that flame location (standoff distance), flame characteristics (length, thickness, brightness) and the aerodynamic field of the low velocity reacting flow are very much affected by the fluctuation of the gravity level or g-jitter. The lower the g-jitter frequency is, the higher the perturbation. Consequently it is difficult to perform relevant experiments for a main flow velocity lower than 0.05m/s. DNS calculations confirm the present observations, but most of the results are presented elsewhere.

Development of burners for afterburning chambers of heat-recovery boilers at cogeneration stations equipped with combined-cycle plants

NASA Astrophysics Data System (ADS)

Khomenok, L. A.

2007-09-01

Problems related to efficient afterburning of fuel in the medium of gas-turbine unit exhaust gases, as well as new design arrangements of gas-jet burners used in the chambers for afterburning fuel in heat-recovery boilers at cogeneration stations equipped with combined-cycle plants, are considered. Results obtained from comparative experimental investigations of different gas-jet flame stabilizers at a test facility are presented, and the advantages of jet-ejector stabilizers are demonstrated.

Severe Sunburn After a Hot Air Balloon Ride: A Case Report and Literature Review.

PubMed

Ozturk, Sinan; Karagoz, Huseyin

2015-01-01

Hot air balloon tours are very popular among travelers worldwide. Preventable burn injuries associated with hot air balloon rides have been reported during crashes into power lines, in propane burner explosions, and following contact with the propane burner tanks. We present a case of severe repeated sunburn, which poses another risk of preventable injury during hot air balloon rides, and briefly discuss the injury epidemiology of hot air balloon rides. © 2015 International Society of Travel Medicine.

Novel burn device for rapid, reproducible burn wound generation.

PubMed

Kim, J Y; Dunham, D M; Supp, D M; Sen, C K; Powell, H M

2016-03-01

Scarring following full thickness burns leads to significant reductions in range of motion and quality of life for burn patients. To effectively study scar development and the efficacy of anti-scarring treatments in a large animal model (female red Duroc pigs), reproducible, uniform, full-thickness, burn wounds are needed to reduce variability in observed results that occur with burn depth. Prior studies have proposed that initial temperature of the burner, contact time with skin, thermal capacity of burner material, and the amount of pressure applied to the skin need to be strictly controlled to ensure reproducibility. The purpose of this study was to develop a new burner that enables temperature and pressure to be digitally controlled and monitored in real-time throughout burn wound creation and compare it to a standard burn device. A custom burn device was manufactured with an electrically heated burn stylus and a temperature control feedback loop via an electronic microstat. Pressure monitoring was controlled by incorporation of a digital scale into the device, which measured downward force. The standard device was comprised of a heat resistant handle with a long rod connected to the burn stylus, which was heated using a hot plate. To quantify skin surface temperature and internal stylus temperature as a function of contact time, the burners were heated to the target temperature (200±5°C) and pressed into the skin for 40s to create the thermal injuries. Time to reach target temperature and elapsed time between burns were recorded. In addition, each unit was evaluated for reproducibility within and across three independent users by generating burn wounds at contact times spanning from 5 to 40s at a constant pressure and at pressures of 1 or 3lbs with a constant contact time of 40s. Biopsies were collected for histological analysis and burn depth quantification using digital image analysis (ImageJ). The custom burn device maintained both its internal temperature and the skin surface temperature near target temperature throughout contact time. In contrast, the standard burner required more than 20s of contact time to raise the skin surface temperature to target due to its quickly decreasing internal temperature. The custom burner was able to create four consecutive burns in less than half the time of the standard burner. Average burn depth scaled positively with time and pressure in both burn units. However, the distribution of burn depth within each time-pressure combination in the custom device was significantly smaller than with the standard device and independent of user. The custom burn device's ability to continually heat the burn stylus and actively control pressure and temperature allowed for more rapid and reproducible burn wounds. Burns of tailored and repeatable depths, independent of user, provide a platform for the study of anti-scar and other wound healing therapies without the added variable of non-uniform starting injury. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Novel burn device for rapid, reproducible burn wound generation

PubMed Central

Kim, J.Y.; Dunham, D.M.; Supp, D.M.; Sen, C.K.; Powell, H.M.

2016-01-01

Introduction Scarring following full thickness burns leads to significant reductions in range of motion and quality of life for burn patients. To effectively study scar development and the efficacy of anti-scarring treatments in a large animal model (female red Duroc pigs), reproducible, uniform, full-thickness, burn wounds are needed to reduce variability in observed results that occur with burn depth. Prior studies have proposed that initial temperature of the burner, contact time with skin, thermal capacity of burner material, and the amount of pressure applied to the skin need to be strictly controlled to ensure reproducibility. The purpose of this study was to develop a new burner that enables temperature and pressure to be digitally controlled and monitored in real-time throughout burn wound creation and compare it to a standard burn device. Methods A custom burn device was manufactured with an electrically heated burn stylus and a temperature control feedback loop via an electronic microstat. Pressure monitoring was controlled by incorporation of a digital scale into the device, which measured downward force. The standard device was comprised of a heat resistant handle with a long rod connected to the burn stylus, which was heated using a hot plate. To quantify skin surface temperature and internal stylus temperature as a function of contact time, the burners were heated to the target temperature (200 ± 5 °C) and pressed into the skin for 40 s to create the thermal injuries. Time to reach target temperature and elapsed time between burns were recorded. In addition, each unit was evaluated for reproducibility within and across three independent users by generating burn wounds at contact times spanning from 5 to 40 s at a constant pressure and at pressures of 1 or 3 lbs with a constant contact time of 40 s. Biopsies were collected for histological analysis and burn depth quantification using digital image analysis (ImageJ). Results The custom burn device maintained both its internal temperature and the skin surface temperature near target temperature throughout contact time. In contrast, the standard burner required more than 20 s of contact time to raise the skin surface temperature to target due to its quickly decreasing internal temperature. The custom burner was able to create four consecutive burns in less than half the time of the standard burner. Average burn depth scaled positively with time and pressure in both burn units. However, the distribution of burn depth within each time-pressure combination in the custom device was significantly smaller than with the standard device and independent of user. Conclusions The custom burn device's ability to continually heat the burn stylus and actively control pressure and temperature allowed for more rapid and reproducible burn wounds. Burns of tailored and repeatable depths, independent of user, provide a platform for the study of anti-scar and other wound healing therapies without the added variable of non-uniform starting injury. PMID:26803369

A New Method to Measure Temperature and Burner Pattern Factor Sensing for Active Engine Control

NASA Technical Reports Server (NTRS)

Ng, Daniel

1999-01-01

The determination of the temperatures of extended surfaces which exhibit non-uniform temperature variation is very important for a number of applications including the "Burner Pattern Factor" (BPF) of turbine engines. Exploratory work has shown that use of BPF to control engine functions can result in many benefits, among them reduction in engine weight, reduction in operating cost, increase in engine life, while attaining maximum engine efficiency. Advanced engines are expected to operate at very high temperature to achieve high efficiency. Brief exposure of engine components to higher than design temperatures due to non-uniformity in engine burner pattern can reduce engine life. The engine BPF is a measure of engine temperature uniformity. Attainment of maximum temperature uniformity and high temperatures is key to maximum efficiency and long life. A new approach to determine through the measurement of just one radiation spectrum by a multiwavelength pyrometer is possible. This paper discusses a new temperature sensing approach and its application to determine the BPF.

Multi-ported, internally recuperated burners for direct flame impingement heating applications

DOEpatents

Abbasi, Hamid A.; Kurek, Harry; Chudnovsky, Yaroslav; Lisienko, Vladimir G.; Malikov, German K.

2010-08-03

A direct flame impingement method and apparatus employing at least one multi-ported, internally recuperated burner. The burner includes an innermost coaxial conduit having a first fluid inlet end and a first fluid outlet end, an outermost coaxial conduit disposed around the innermost coaxial conduit and having a combustion products outlet end proximate the first fluid inlet end of the innermost coaxial conduit and a combustion products inlet end proximate the first fluid outlet end of the innermost coaxial conduit, and a coaxial intermediate conduit disposed between the innermost coaxial conduit and the outermost coaxial conduit, whereby a second fluid annular region is formed between the innermost coaxial conduit and the intermediate coaxial conduit and a combustion products annular region is formed between the intermediate coaxial conduit and the outermost coaxial conduit. The intermediate coaxial conduit has a second fluid inlet end proximate the first fluid inlet end of the innermost coaxial conduit and a second fluid outlet end proximate the combustion products inlet end of the outermost coaxial conduit.

Contributions of burner, pan, meat and salt to PM emission during grilling.

PubMed

Amouei Torkmahalleh, Mehdi; Ospanova, Saltanat; Baibatyrova, Aknur; Nurbay, Shynggys; Zhanakhmet, Gulaina; Shah, Dhawal

2018-07-01

Grilling ground beef meat was conducted in two locations at Nazarbayev University, Kazakhstan. The experiments were designed such that only particles from beef meat were isolated. A similar experimental protocol was applied at both locations. The average particle number and mass emission rates for grilling pure meat itself (excluding particles from pan and burner) were found to be 9.4 × 10 12 (SD = 7.2 × 10 12 particle min -1 and 7.6 × 10 (SD = 6.3 × 10) mg.min -1 , respectively. The PM emissions (number and mass) from the burner were found to be negligible compared to the pan and meat emissions. Ultrafine particle (UFP) concentrations from the heated pan itself were comparable to those of grilled meat. However, the particle mass concentrations from the pan itself were negligible. Approximately an hour of continuous heating resulted in zero emissions from the pan. Copyright © 2018 Elsevier Inc. All rights reserved.

Thermal barrier coating life prediction model development, phase 2

NASA Technical Reports Server (NTRS)

Meier, Susan Manning; Sheffler, Keith D.; Nissley, David M.

1991-01-01

The objective of this program was to generate a life prediction model for electron-beam-physical vapor deposited (EB-PVD) zirconia thermal barrier coating (TBC) on gas turbine engine components. Specific activities involved in development of the EB-PVD life prediction model included measurement of EB-PVD ceramic physical and mechanical properties and adherence strength, measurement of the thermally grown oxide (TGO) growth kinetics, generation of quantitative cyclic thermal spallation life data, and development of a spallation life prediction model. Life data useful for model development was obtained by exposing instrumented, EB-PVD ceramic coated cylindrical specimens in a jet fueled burner rig. Monotonic compression and tensile mechanical tests and physical property tests were conducted to obtain the EB-PVD ceramic behavior required for burner rig specimen analysis. As part of that effort, a nonlinear constitutive model was developed for the EB-PVD ceramic. Spallation failure of the EB-PVD TBC system consistently occurred at the TGO-metal interface. Calculated out-of-plane stresses were a small fraction of that required to statically fail the TGO. Thus, EB-PVD spallation was attributed to the interfacial cracking caused by in-plane TGO strains. Since TGO mechanical properties were not measured in this program, calculation of the burner rig specimen TGO in-plane strains was performed by using alumina properties. A life model based on maximum in-plane TGO tensile mechanical strain and TGO thickness correlated the burner rig specimen EB-PVD ceramic spallation lives within a factor of about plus or minus 2X.

Iso-thermal flow characteristics of rotationally symmetric jets generating a swirl within a cylindrical chamber

NASA Astrophysics Data System (ADS)

Long, Shen; Lau, Timothy C. W.; Chinnici, Alfonso; Tian, Zhao Feng; Dally, Bassam B.; Nathan, Graham J.

2018-05-01

We present a systematic experimental study of the interaction between four rotationally symmetric jets within a cylindrical chamber, under conditions relevant to a wide range of engineering applications, including the technology of a Hybrid Solar Receiver Combustor (HSRC). The HSRC geometry is simplified here to a cylindrical cavity with four inlet jets (representing four burners) which are configured in an annular arrangement and aligned at an inclination angle to the axis with a tangential component (azimuthal angle) to generate a swirl in the chamber. In this study, the jet inclination angle (αj) was varied over the range of 25°-45°, while the jet azimuthal angle (θj) was varied from 5° to 15°. The inlet Reynolds number for each injected jet and the number of jets were fixed at ReD = 10 500 and 4, respectively. Measurements obtained with Particle Image Velocimetry were used to characterise the large-scale flow field within selected configurations. The results reveal a significant dependence of the mean and root-mean-square flow-fields on the jet azimuthal angle (θj) and the jet inclination angle (αj). Three different flow regimes with distinctive flow characteristics were identified within the configurations investigated here. It was also found that θj can significantly influence (a) the position and strength of an external recirculation zone and a central recirculation zone, (b) the extent of turbulence fluctuation, and (c) the flow unsteadiness. Importantly, the effect of αj on the flow characteristics was found to depend strongly on the value of θj.

Premixed Flames Under Microgravity and Normal Gravity Conditions

NASA Astrophysics Data System (ADS)

Krikunova, Anastasia I.; Son, Eduard E.

2018-03-01

Premixed conical CH4-air flames were studied experimentally and numerically under normal straight, reversed gravity conditions and microgravity. Low-gravity experiments were performed in Drop tower. Classical Bunsen-type burner was used to find out features of gravity influence on the combustion processes. Mixture equivalence ratio was varied from 0.8 to 1.3. Wide range of flow velocity allows to study both laminar and weakly turbulized flames. High-speed flame chemoluminescence video-recording was used as diagnostic. The investigations were performed at atmospheric pressure. As results normalized flame height, laminar flame speed were measured, also features of flame instabilities were shown. Low- and high-frequency flame-instabilities (oscillations) have a various nature as velocity fluctuations, preferential diffusion instability, hydrodynamic and Rayleigh-Taylor ones etc., that was explored and demonstrated.

Determination of combustion gas temperatures by infrared radiometry in sooting and nonsooting flames

NASA Technical Reports Server (NTRS)

Lyons, Valerie J.; Gracia-Salcedo, Carmen M.

1989-01-01

Flame temperatures in nonsooting and sooting environments were successfully measured by radiometry for pre-mixed propane-oxygen laminar flames stabilized on a water-cooled, porous sintered-bronze burner. The measured temperatures in the nonsooting flames were compared with fine-wire thermocouple measurements. The results show excellent agreement below 1700 K, and when the thermocouple measurements were corrected for radiation effects, the agreement was good for even higher temperatures. The benefits of radiometry are: (1) the flow is not disturbed by an intruding probe, (2) calibration is easily done using a blackbody source, and (3) measurements can be made even with soot present. The theory involved in the radiometry measurements and the energy balance calculations used to correct the thermocouple temperature measurements are discussed.

Simultaneous CARS and Interferometric Rayleigh Scattering

NASA Technical Reports Server (NTRS)

Bivolaru, Daniel; Danehy, Paul M.; Grinstead, Keith D., Jr.; Tedder, Sarah; Cutler, Andrew D.

2006-01-01

This paper reports for the first time the combination of a dual-pump coherent anti-Stokes Raman scattering system with an interferometric Rayleigh scattering system (CARS - IRS) to provide time-resolved simultaneous measurement of multiple properties in combustion flows. The system uses spectrally narrow green (seeded Nd:YAG at 532 nm) and yellow (552.9 nm) pump beams and a spectrally-broad red (607 nm) beam as the Stokes beam. A spectrometer and a planar Fabry-Perot interferometer used in the imaging mode are used to record the spectrally broad CARS spectra and the spontaneous Rayleigh scattering spectra, respectively. Time-resolved simultaneous measurement of temperature, absolute mole fractions of N2, O2, and H2, and two components of velocity in a Hencken burner flame were performed to demonstrate the technique.

Turbine gas temperature measurement and control system

NASA Technical Reports Server (NTRS)

Webb, W. L.

1973-01-01

A fluidic Turbine Inlet Gas Temperature (TIGIT) Measurement and Control System was developed for use on a Pratt and Whitney Aircraft J58 engine. Based on engine operating requirements, criteria for high temperature materials selection, system design, and system performance were established. To minimize development and operational risk, the TIGT control system was designed to interface with an existing Exhaust Gas Temperature (EGT) Trim System and thereby modulate steady-state fuel flow to maintain a desired TIGT level. Extensive component and system testing was conducted including heated (2300F) vibration tests for the fluidic sensor and gas sampling probe, temperature and vibration tests on the system electronics, burner rig testing of the TIGT measurement system, and in excess of 100 hours of system testing on a J58 engine. (Modified author abstract)

NASA powered lift facility internally generated noise and its transmission to the acoustic far field

NASA Technical Reports Server (NTRS)

Huff, Ronald G.

1988-01-01

Noise tests of NASA Lewis Research Center's Powered Lift Facility (PLF) were performed to determine the frequency content of the internally generated noise that reaches the far field. The sources of the internally generated noise are the burner, elbows, valves, and flow turbulence. Tests over a range of nozzle pressure ratios from 1.2 to 3.5 using coherence analysis revealed that low frequency noise below 1200 Hz is transmitted through the nozzle. Broad banded peaks at 240 and 640 Hz were found in the transmitted noise. Aeroacoustic excitation effects are possible in this frequency range. The internal noise creates a noise floor that limits the amount of jet noise suppression that can be measured on the PLF and similar facilities.