Transient flow combustion

NASA Technical Reports Server (NTRS)

Tacina, R. R.

1984-01-01

Non-steady combustion problems can result from engine sources such as accelerations, decelerations, nozzle adjustments, augmentor ignition, and air perturbations into and out of the compressor. Also non-steady combustion can be generated internally from combustion instability or self-induced oscillations. A premixed-prevaporized combustor would be particularly sensitive to flow transients because of its susceptability to flashback-autoignition and blowout. An experimental program, the Transient Flow Combustion Study is in progress to study the effects of air and fuel flow transients on a premixed-prevaporized combustor. Preliminary tests performed at an inlet air temperature of 600 K, a reference velocity of 30 m/s, and a pressure of 700 kPa. The airflow was reduced to 1/3 of its original value in a 40 ms ramp before flashback occurred. Ramping the airflow up has shown that blowout is more sensitive than flashback to flow transients. Blowout occurred with a 25 percent increase in airflow (at a constant fuel-air ratio) in a 20 ms ramp. Combustion resonance was found at some conditions and may be important in determining the effects of flow transients.

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

None

On behalf of the Department of Energy's Office of FreedomCAR and Vehicle Technologies, we are pleased to introduce the Fiscal Year (FY) 2004 Annual Progress Report for the Advanced Combustion Engine R&D Sub-Program. The mission of the FreedomCAR and Vehicle Technologies Program is to develop more energy efficient and environmentally friendly highway transportation technologies that enable Americans to use less petroleum for their vehicles. The Advanced Combustion Engine R&D Sub-Program supports this mission by removing the critical technical barriers to commercialization of advanced internal combustion engines for light-, medium-, and heavy-duty highway vehicles that meet future Federal and state emissionsmore » regulations. The primary objective of the Advanced Combustion Engine R&D Sub-Program is to improve the brake thermal efficiency of internal combustion engines from 30 to 45 percent for light-duty applications by 2010; and 40 to 55 percent for heavy-duty applications by 2012; while meeting cost, durability, and emissions constraints. R&D activities include work on combustion technologies that increase efficiency and minimize in-cylinder formation of emissions, as well as aftertreatment technologies that further reduce exhaust emissions. Work is also being conducted on ways to reduce parasitic and heat transfer losses through the development and application of thermoelectrics and turbochargers that include electricity generating capability, and conversion of mechanically driven engine components to be driven via electric motors. This introduction serves to outline the nature, current progress, and future directions of the Advanced Combustion Engine R&D Sub-Program. The research activities of this Sub-Program are planned in conjunction with the FreedomCAR Partnership and the 21st Century Truck Partnership and are carried out in collaboration with industry, national laboratories, and universities. Because of the importance of clean fuels in achieving low emissions, R&D activities are closely coordinated with the relevant activities of the Fuel Technologies Sub-Program, also within the Office of FreedomCAR and Vehicle Technologies. Research is also being undertaken on hydrogen-fueled internal combustion engines to provide an interim hydrogen-based powertrain technology that promotes the longer-range FreedomCAR Partnership goal of transitioning to a hydrogen-fueled transportation system. Hydrogen engine technologies being developed have the potential to provide diesel-like engine efficiencies with near-zero emissions.« less

Fluidized combustion of coal. [to limit SO2 and NOx emissions

NASA Technical Reports Server (NTRS)

Pope, M.

1978-01-01

A combustion technology that permits the burning of low quality coal, and other fuels, while maintaining stack emissions within State and Federal EPA limits is discussed. Low quality fuels can be burned directly in fluidized beds while taking advantage of low furnace temperatures and chemical activity within the bed to limit SO2 and NOx emissions. The excellent heat transfer characteristics of the fluidized beds also result in a reduction of total heat transfer surface requirements. Tests on beds operating at pressures of one to ten atmospheres, at temperatures as high as 1600 F, and with gas velocities in the vicinity of four to twelve feet per second, have proven the concept. The progress that has been made in the development of fluidized bed combustion technology and work currently underway are discussed.

Near-zero emissions combustor system for syngas and biofuels

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

Yongho, Kim; Rosocha, Louis

2010-01-01

A multi-institutional plasma combustion team was awarded a research project from the DOE/NNSA GIPP (Global Initiative for Prolifereation Prevention) office. The Institute of High Current Electronics (Tomsk, Russia); Leonardo Technologies, Inc. (an American-based industrial partner), in conjunction with the Los Alamos National Laboratory are participating in the project to develop novel plasma assisted combustion technologies. The purpose of this project is to develop prototypes of marketable systems for more stable and cleaner combustion of syngas/biofuels and to demonstrate that this technology can be used for a variety of combustion applications - with a major focus on contemporary gas turbines. Inmore » this paper, an overview of the project, along with descriptions of the plasma-based combustors and associated power supplies will be presented. Worldwide, it is recognized that a variety of combustion fuels will be required to meet the needs for supplying gas-turbine engines (electricity generation, propulsion), internal combustion engines (propulsion, transportation), and burners (heat and electricity generation) in the 21st Century. Biofuels and biofuel blends have already been applied to these needs, but experience difficulties in modifications to combustion processes and combustor design and the need for flame stabilization techniques to address current and future environmental and energy-efficiency challenges. In addition, municipal solid waste (MSW) has shown promise as a feedstock for heat and/or electricity-generating plants. However, current combustion techniques that use such fuels have problems with achieving environmentally-acceptable air/exhaust emissions and can also benefit from increased combustion efficiency. This project involves a novel technology (a form of plasma-assisted combustion) that can address the above issues. Plasma-assisted combustion (PAC) is a growing field that is receiving worldwide attention at present. The project is focused on research necessary to develop a novel, high-efficiency, low-emissions (near-zero, or as low as reasonably achievable), advanced combustion technology for electricity and heat production from biofuels and fuels derived from MSW. For any type of combustion technology, including the advanced technology of this project, two problems of special interest must be addressed: developing and optimizing the combustion chambers and the systems for igniting and sustaining the fuel-burning process. For MSW in particular, there are new challenges over gaseous or liquid fuels because solid fuels must be ground into fine particulates ({approx} 10 {micro}m diameter), fed into the advanced combustor, and combusted under plasma-assisted conditions that are quite different than gaseous or liquid fuels. The principal idea of the combustion chamber design is to use so-called reverse vortex gas flow, which allows efficient cooling of the chamber wall and flame stabilization in the central area of the combustor (Tornado chamber). Considerable progress has been made in design ing an advanced, reverse vortex flow combustion chamber for biofuels, although it was not tested on biofuels and a system that could be fully commercialized has never been completed.« less

Combustor nozzle for a fuel-flexible combustion system

DOEpatents

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

2011-03-22

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

Acoustic effects of sprays

NASA Technical Reports Server (NTRS)

Pindera, Maciej Z.; Przekwas, Andrzej J.

1994-01-01

Since the early 1960's, it has been known that realistic combustion models for liquid fuel rocket engines should contain at least a rudimentary treatment of atomization and spray physics. This is of particular importance in transient operations. It has long been recognized that spray characteristics and droplet vaporization physics play a fundamental role in determining the stability behavior of liquid fuel rocket motors. This paper gives an overview of work in progress on design of a numerical algorithm for practical studies of combustion instabilities in liquid rocket motors. For flexibility, the algorithm is composed of semi-independent solution modules, accounting for different physical processes. Current findings are report and future work is indicated. The main emphasis of this research is the development of an efficient treatment to interactions between acoustic fields and liquid fuel/oxidizer sprays.

Investigating the variability in brown carbon light-absorption properties

NASA Astrophysics Data System (ADS)

Saleh, R.; Cheng, Z.; Atwi, K.

2017-12-01

Combustion of biomass fuels contributes a significant portion of brown carbon (BrC), the light-absorbing fraction of organic aerosols. BrC exhibits highly variable light-absorption properties, with imaginary part of the refractive indices (k) reported in the literature varying over two orders of magnitude. This high variability in k is attributed to the chaotic nature of combustion; however, there is a major gap in the fundamental understanding of this variability. To address this gap, we hypothesize that BrC is comprised of black carbon (BC) precursors whose transformation to BC has not seen fruition. Depending on the combustion conditions, these BC precursors exhibit different maturity levels which dictate their light-absorption properties (k). The more mature are the precursors, the more absorptive (or BC-like) they are. Therefore, k of BrC obtained from a certain measurement depends on the specific combustion conditions associated with the measurement, leading to the aforementioned variability in the literature. To test this hypothesis, we performed controlled combustion experiments in which the combustion conditions (temperature and air/fuel ratio) were varied and k was retrieved from real-time multi-wavelength light-absorption measurements at each condition. We used benzene, the inception of which during combustion is the initial critical step leading to BC formation, as a model fuel. By varying the combustion conditions from relatively inefficient (low temperature and/or air/fuel ratio) to relatively efficient (high temperature and/or air/fuel ratio), we isolated BrC components with progressively increasing k, spanning the wide range reported in the literature. We also performed thermodenuder measurements to constrain the volatility of the BrC, as well as laser desorption ionization mass spectrometry analysis to constrain its molecular mass. We found that as the combustion conditions approached the BC-formation threshold, the increase in k was associated with an increase in molecular mass and decrease in volatility. This confirms our hypothesis, since the BC precursors are expected to grow in size and become less volatile as they mature. These results provide the first correlation between the BrC physical, chemical, and consequent light-absorption properties.

Method and system for low-NO.sub.x dual-fuel combustion of liquid and/or gaseous fuels

DOEpatents

Gard, Vincent; Chojnacki, Dennis A; Rabovitser, Ioseph K

2014-12-02

A method and apparatus for combustion in which a pressurized preheated liquid fuel is atomized and a portion thereof flash vaporized, creating a mixture of fuel vapor and liquid droplets. The mixture is mixed with primary combustion oxidant, producing a fuel/primary oxidant mixture which is then injected into a primary combustion chamber in which the fuel/primary oxidant mixture is partially combusted, producing a secondary gaseous fuel containing hydrogen and carbon oxides. The secondary gaseous fuel is mixed with a secondary combustion oxidant and injected into the second combustion chamber wherein complete combustion of the secondary gaseous fuel is carried out. The resulting second stage flue gas containing very low amounts of NO.sub.x is then vented from the second combustion chamber.

Combustion of liquid-fuel droplets in supercritical conditions

NASA Technical Reports Server (NTRS)

Shuen, J. S.; Yang, Vigor; Hsaio, C. C.

1992-01-01

A comprehensive analysis of liquid-fuel droplet combustion in both subcritical and supercritical environments has been conducted. The formulation is based on the complete conservation equations for both gas and liquid phases, and accommodates variable thermophysical properties, finite-rate chemical kinetics, and a full treatment of liquid-vapor phase equilibrium at the drop surface. The governing equations and associated interfacial boundary conditions are solved numerically using a fully coupled, implicit scheme with the dual time-stepping integration technique. The model is capable of treating the entire droplet history, including the transition from the subcritical to supercritical state. As a specific example, the combustion of n-pentane fuel droplets in air is studied for pressures in the range of 5-140 atm. Results indicate that the ambient gas pressure exerts significant control of droplet gasification and burning processes through its influence on fluid transport, gas-liquid interfacial thermodynamics, and chemical reactions. The droplet gasification rate increases progressively with pressure. However, the data for the overall burnout time exhibit a considerable change in the combustion mechanism at the critical pressure, mainly as a result of reduced mass diffusivity and latent heat of vaporization with increased pressure.

Genotoxic potential of diesel exhaust particles from the combustion of first- and second-generation biodiesel fuels-the FuelHealth project.

PubMed

Kowalska, Magdalena; Wegierek-Ciuk, Aneta; Brzoska, Kamil; Wojewodzka, Maria; Meczynska-Wielgosz, Sylwia; Gromadzka-Ostrowska, Joanna; Mruk, Remigiusz; Øvrevik, Johan; Kruszewski, Marcin; Lankoff, Anna

2017-11-01

Epidemiological data indicate that exposure to diesel exhaust particles (DEPs) from traffic emissions is associated with higher risk of morbidity and mortality related to cardiovascular and pulmonary diseases, accelerated progression of atherosclerotic plaques, and possible lung cancer. While the impact of DEPs from combustion of fossil diesel fuel on human health has been extensively studied, current knowledge of DEPs from combustion of biofuels provides limited and inconsistent information about its mutagenicity and genotoxicity, as well as possible adverse health risks. The objective of the present work was to compare the genotoxicity of DEPs from combustion of two first-generation fuels, 7% fatty acid methyl esters (FAME) (B7) and 20% FAME (B20), and a second-generation 20% FAME/hydrotreated vegetable oil (SHB: synthetic hydrocarbon biofuel) fuel. Our results revealed that particulate engine emissions from each type of biodiesel fuel induced genotoxic effects in BEAS-2B and A549 cells, manifested as the increased levels of single-strand breaks, the increased frequencies of micronuclei, or the deregulated expression of genes involved in DNA damage signaling pathways. We also found that none of the tested DEPs showed the induction of oxidative DNA damage and the gamma-H2AX-detectable double-strand breaks. The most pronounced differences concerning the tested particles were observed for the induction of single-strand breaks, with the greatest genotoxicity being associated with the B7-derived DEPs. The differences in other effects between DEPs from the different biodiesel blend percentage and biodiesel feedstock were also observed, but the magnitude of these variations was limited.

A Summary of Preliminary Investigations into the Characteristics of Combustion Screech in Ducted Burners

NASA Technical Reports Server (NTRS)

1958-01-01

Increasing demands for higher afterburner performance have required operation at progressively higher fuel-air ratios, which has increased the occurrence and intensity of screeching combustion. The onset of screech may be followed by rapid destruction of the combustor shell and other combustor parts. Because of its destructive characteristics, considerable effort has been expended to understand and eliminate screech. NACA work on the screeching combustion problem prior to 1954 is summarized herein. These studies showed that resonant acoustic oscillations are a primary component of the screech mechanism in the burners thus far investigated

Cleaner cooking solutions to achieve health, climate, and economic cobenefits.

PubMed

Anenberg, Susan C; Balakrishnan, Kalpana; Jetter, James; Masera, Omar; Mehta, Sumi; Moss, Jacob; Ramanathan, Veerabhadran

2013-05-07

Nearly half the world's population must rely on solid fuels such as biomass (wood, charcoal, agricultural residues, and animal dung) and coal for household energy, burning them in inefficient open fires and stoves with inadequate ventilation. Household solid fuel combustion is associated with four million premature deaths annually; contributes to forest degradation, loss of habitat and biodiversity, and climate change; and hinders social and economic progress as women and children spend hours every day collecting fuel. Several recent studies, as well as key emerging national and international efforts, are making progress toward enabling wide-scale household adoption of cleaner and more efficient stoves and fuels. While significant challenges remain, these efforts offer considerable promise to save lives, improve forest sustainability, slow climate change, and empower women around the world.

Reduction of gaseous pollutant emissions from gas turbine combustors using hydrogen-enriched jet fuel

NASA Technical Reports Server (NTRS)

Clayton, R. M.

1976-01-01

Recent progress in an evaluation of the applicability of the hydrogen enrichment concept to achieve ultralow gaseous pollutant emission from gas turbine combustion systems is described. The target emission indexes for the program are 1.0 for oxides of nitrogen and carbon monoxide, and 0.5 for unburned hydrocarbons. The basic concept utilizes premixed molecular hydrogen, conventional jet fuel, and air to depress the lean flammability limit of the mixed fuel. This is shown to permit very lean combustion with its low NOx production while simulataneously providing an increased flame stability margin with which to maintain low CO and HC emission. Experimental emission characteristics and selected analytical results are presented for a cylindrical research combustor designed for operation with inlet-air state conditions typical for a 30:1 compression ratio, high bypass ratio, turbofan commercial engine.

PROGRESS IN DETAILED KINETIC MODELING OF THE COMBUSTION OF OXYGENATED COMPONENTS OF BIOFUELS

PubMed Central

Sy Tran, Luc; Sirjean, Baptiste; Glaude, Pierre-Alexandre; Fournet, René; Battin-Leclerc, Frédérique

2013-01-01

Due to growing environmental concerns and diminishing petroleum reserves, a wide range of oxygenated species has been proposed as possible substitutes to fossil fuels: alcohols, methyl esters, acyclic and cyclic ethers. After a short review the major detailed kinetic models already proposed in the literature for the combustion of these molecules, the specific classes of reactions considered for modeling the oxidation of acyclic and cyclic oxygenated molecules respectively, are detailed. PMID:23700355

Progress in catalytic ignition fabrication, modeling and infrastructure : (part 1) catalytic ignition studies.

DOT National Transportation Integrated Search

2014-02-01

Platinum has been recognized as a viable combustion catalyst for use in transportation : engines operating at fuel-lean conditions. Its change in electrical resistance with temperature : has been used to measure light-off temperatures and rates of he...

Reduced Equations for Calculating the Combustion Rates of Jet-A and Methane Fuel

NASA Technical Reports Server (NTRS)

Molnar, Melissa; Marek, C. John

2003-01-01

Simplified kinetic schemes for Jet-A and methane fuels were developed to be used in numerical combustion codes, such as the National Combustor Code (NCC) that is being developed at Glenn. These kinetic schemes presented here result in a correlation that gives the chemical kinetic time as a function of initial overall cell fuel/air ratio, pressure, and temperature. The correlations would then be used with the turbulent mixing times to determine the limiting properties and progress of the reaction. A similar correlation was also developed using data from NASA's Chemical Equilibrium Applications (CEA) code to determine the equilibrium concentration of carbon monoxide as a function of fuel air ratio, pressure, and temperature. The NASA Glenn GLSENS kinetics code calculates the reaction rates and rate constants for each species in a kinetic scheme for finite kinetic rates. These reaction rates and the values obtained from the equilibrium correlations were then used to calculate the necessary chemical kinetic times. Chemical kinetic time equations for fuel, carbon monoxide, and NOx were obtained for both Jet-A fuel and methane.

Combustion Characterization and Model Fuel Development for Micro-tubular Flame-assisted Fuel Cells.

PubMed

Milcarek, Ryan J; Garrett, Michael J; Baskaran, Amrish; Ahn, Jeongmin

2016-10-02

Combustion based power generation has been accomplished for many years through a number of heat engine systems. Recently, a move towards small scale power generation and micro combustion as well as development in fuel cell research has created new means of power generation that combine solid oxide fuel cells with open flames and combustion exhaust. Instead of relying upon the heat of combustion, these solid oxide fuel cell systems rely on reforming of the fuel via combustion to generate syngas for electrochemical power generation. Procedures were developed to assess the combustion by-products under a wide range of conditions. While theoretical and computational procedures have been developed for assessing fuel-rich combustion exhaust in these applications, experimental techniques have also emerged. The experimental procedures often rely upon a gas chromatograph or mass spectrometer analysis of the flame and exhaust to assess the combustion process as a fuel reformer and means of heat generation. The experimental techniques developed in these areas have been applied anew for the development of the micro-tubular flame-assisted fuel cell. The protocol discussed in this work builds on past techniques to specify a procedure for characterizing fuel-rich combustion exhaust and developing a model fuel-rich combustion exhaust for use in flame-assisted fuel cell testing. The development of the procedure and its applications and limitations are discussed.

Real-time combustion controls and diagnostics sensors (CCADS)

DOEpatents

Thornton, Jimmy D.; Richards, George A.; Dodrill, Keith A.; Nutter, Jr., Roy S.; Straub, Douglas

2005-05-03

The present invention is directed to an apparatus for the monitoring of the combustion process within a combustion system. The apparatus comprises; a combustion system, a means for supplying fuel and an oxidizer, a device for igniting the fuel and oxidizer in order to initiate combustion, and a sensor for determining the current conducted by the combustion process. The combustion system comprises a fuel nozzle and an outer shell attached to the combustion nozzle. The outer shell defines a combustion chamber. Preferably the nozzle is a lean premix fuel nozzle (LPN). Fuel and an oxidizer are provided to the fuel nozzle at separate rates. The fuel and oxidizer are ignited. A sensor positioned within the combustion system comprising at least two electrodes in spaced-apart relationship from one another. At least a portion of the combustion process or flame is between the first and second electrodes. A voltage is applied between the first and second electrodes and the magnitude of resulting current between the first and second electrodes is determined.

Engine and method for operating an engine

DOEpatents

Lauper, Jr., John Christian; Willi, Martin Leo [Dunlap, IL; Thirunavukarasu, Balamurugesh [Peoria, IL; Gong, Weidong [Dunlap, IL

2008-12-23

A method of operating an engine is provided. The method may include supplying a combustible combination of reactants to a combustion chamber of the engine, which may include supplying a first hydrocarbon fuel, hydrogen fuel, and a second hydrocarbon fuel to the combustion chamber. Supplying the second hydrocarbon fuel to the combustion chamber may include at least one of supplying at least a portion of the second hydrocarbon fuel from an outlet port that discharges into an intake system of the engine and supplying at least a portion of the second hydrocarbon fuel from an outlet port that discharges into the combustion chamber. Additionally, the method may include combusting the combustible combination of reactants in the combustion chamber.

A spray flamelet/progress variable approach combined with a transported joint PDF model for turbulent spray flames

NASA Astrophysics Data System (ADS)

Hu, Yong; Olguin, Hernan; Gutheil, Eva

2017-05-01

A spray flamelet/progress variable approach is developed for use in spray combustion with partly pre-vaporised liquid fuel, where a laminar spray flamelet library accounts for evaporation within the laminar flame structures. For this purpose, the standard spray flamelet formulation for pure evaporating liquid fuel and oxidiser is extended by a chemical reaction progress variable in both the turbulent spray flame model and the laminar spray flame structures, in order to account for the effect of pre-vaporised liquid fuel for instance through use of a pilot flame. This new approach is combined with a transported joint probability density function (PDF) method for the simulation of a turbulent piloted ethanol/air spray flame, and the extension requires the formulation of a joint three-variate PDF depending on the gas phase mixture fraction, the chemical reaction progress variable, and gas enthalpy. The molecular mixing is modelled with the extended interaction-by-exchange-with-the-mean (IEM) model, where source terms account for spray evaporation and heat exchange due to evaporation as well as the chemical reaction rate for the chemical reaction progress variable. This is the first formulation using a spray flamelet model considering both evaporation and partly pre-vaporised liquid fuel within the laminar spray flamelets. Results with this new formulation show good agreement with the experimental data provided by A.R. Masri, Sydney, Australia. The analysis of the Lagrangian statistics of the gas temperature and the OH mass fraction indicates that partially premixed combustion prevails near the nozzle exit of the spray, whereas further downstream, the non-premixed flame is promoted towards the inner rich-side of the spray jet since the pilot flame heats up the premixed inner spray zone. In summary, the simulation with the new formulation considering the reaction progress variable shows good performance, greatly improving the standard formulation, and it provides new insight into the local structure of this complex spray flame.

Dry low NOx combustion system with pre-mixed direct-injection secondary fuel nozzle

DOEpatents

Zuo, Baifang; Johnson, Thomas; Ziminsky, Willy; Khan, Abdul

2013-12-17

A combustion system includes a first combustion chamber and a second combustion chamber. The second combustion chamber is positioned downstream of the first combustion chamber. The combustion system also includes a pre-mixed, direct-injection secondary fuel nozzle. The pre-mixed, direct-injection secondary fuel nozzle extends through the first combustion chamber into the second combustion chamber.

Lean direct wall fuel injection method and devices

NASA Technical Reports Server (NTRS)

Choi, Kyung J. (Inventor); Tacina, Robert (Inventor)

2000-01-01

A fuel combustion chamber, and a method of and a nozzle for mixing liquid fuel and air in the fuel combustion chamber in lean direct injection combustion for advanced gas turbine engines, including aircraft engines. Liquid fuel in a form of jet is injected directly into a cylindrical combustion chamber from the combustion chamber wall surface in a direction opposite to the direction of the swirling air at an angle of from about 50.degree. to about 60.degree. with respect to a tangential line of the cylindrical combustion chamber and at a fuel-lean condition, with a liquid droplet momentum to air momentum ratio in the range of from about 0.05 to about 0.12. Advanced gas turbines benefit from lean direct wall injection combustion. The lean direct wall injection technique of the present invention provides fast, uniform, well-stirred mixing of fuel and air. In addition, in order to further improve combustion, the fuel can be injected at a venturi located in the combustion chamber at a point adjacent the air swirler.

Experimental Investigation of Fuel-Reactivity Controlled Compression Ignition (RCCI) Combustion Mode in a Multi-Cylinder, Light-Duty Diesel Engine

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

Cho, Kukwon; Curran, Scott; Prikhodko, Vitaly Y

2011-01-01

An experimental study was performed to provide the combustion and emission characteristics resulting from fuel-reactivity controlled compression ignition (RCCI) combustion mode utilizing dual-fuel approach in a light-duty, multi-cylinder diesel engine. In-cylinder fuel blending using port fuel injection of gasoline before intake valve opening (IVO) and early-cycle, direct injection of diesel fuel was used as the charge preparation and fuel blending strategy. In order to achieve the desired auto-ignition quality through the stratification of the fuel-air equivalence ratio ( ), blends of commercially available gasoline and diesel fuel were used. Engine experiments were performed at an engine speed of 2300rpm andmore » an engine load of 4.3bar brake mean effective pressure (BMEP). It was found that significant reduction in both nitrogen oxide (NOx) and particulate matter (PM) was realized successfully through the RCCI combustion mode even without applying exhaust gas recirculation (EGR). However, high carbon monoxide (CO) and hydrocarbon (HC) emissions were observed. The low combustion gas temperature during the expansion and exhaust processes seemed to be the dominant source of high CO emissions in the RCCI combustion mode. The high HC emissions during the RCCI combustion mode could be due to the increased combustion quenching layer thickness as well as the -stratification at the periphery of the combustion chamber. The slightly higher brake thermal efficiency (BTE) of the RCCI combustion mode was observed than the other combustion modes, such as the conventional diesel combustion (CDC) mode, and single-fuel, premixed charge compression ignition (PCCI) combustion mode. The parametric study of the RCCI combustion mode revealed that the combustion phasing and/or the peak cylinder pressure rise rate of the RCCI combustion mode could be controlled by several physical parameters premixed ratio (rp), intake swirl intensity, and start of injection (SOI) timing of directly injected fuel unlike other low temperature combustion (LTC) strategies.« less

Research needs for finely resolved fossil carbon emissions

USGS Publications Warehouse

Gurney, K.; Ansley, W.; Mendoza, D.; Petron, G.; Frost, G.; Gregg, J.; Fischer, M.; Pataki, Diane E.; Ackerman, K.; Houweling, S.; Corbin, K.; Andres, R.; Blasing, T.J.

2007-01-01

Scientific research on the global carbon cycle has emerged as a high priority in biogeochemistry, climate studies, and global change policy. The emission of carbon dioxide (CO2) from fossil fuel combustion is a dominant driver of the current net carbon fluxes between the land, the oceans, and the atmosphere, and it is a key contributor to the rise in modern radiative forcing. Contrary to a commonly held perception, our quantitative knowledge about these emissions is insufficient to satisfy current scientific and policy needs. A more highly spatially and temporally resolved quantification of the social and economic drivers of fossil fuel combustion, and the resulting CO2 emissions, is essential to supporting scientific and policy progress. In this article, a new community of emissions researchers called the CO2 Fossil Fuel Emission Effort (CO2FFEE) outlines a research agenda to meet the need for improved fossil fuel CO2 emissions information and solicits comment from the scientific community and research agencies.

Combustor oscillation attenuation via the control of fuel-supply line dynamics

DOEpatents

Richards, George A.; Gemmen, Randall S.

1998-01-01

Combustion oscillation control in combustion systems using hydrocarbon fuels is provided by acoustically tuning a fuel-delivery line to a desired phase of the combustion oscillations for providing a pulse of a fuel-rich region at the oscillating flame front at each time when the oscillation produced pressure in the combustion chamber is in a low pressure phase. The additional heat release produced by burning such fuel-rich regions during low combustion chamber pressure effectively attenuates the combustion oscillations to a selected value.

PROGRESS REPORT: COFIRING PROJECTS FOR WILLOW ISLAND AND ALBRIGHT GENERATING STATIONS

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

K. Payette; D. Tillman

During the period April 1, 2001--June 30, 2001, Allegheny Energy Supply Co., LLC (Allegheny) accelerated construction of the Willow Island cofiring project, completed the installation of foundations for the fuel storage facility, the fuel receiving facility, and the processing building. Allegheny received all processing equipment to be installed at Willow Island. Allegheny completed the combustion modeling for the Willow Island project. During this time period construction of the Albright Generating Station cofiring facility was completed, with few items left for final action. The facility was dedicated at a ceremony on June 29. Initial testing of cofiring at the facility commenced.more » This report summarizes the activities associated with the Designer Opportunity Fuel program, and demonstrations at Willow Island and Albright Generating Stations. It details the construction activities at both sites along with the combustion modeling at the Willow Island site.« less

Method of combustion for dual fuel engine

DOEpatents

Hsu, Bertrand D.; Confer, Gregory L.; Shen, Zujing; Hapeman, Martin J.; Flynn, Paul L.

1993-12-21

Apparatus and a method of introducing a primary fuel, which may be a coal water slutty, and a high combustion auxiliary fuel, which may be a conventional diesel oil, into an internal combustion diesel engine comprises detecting the load conditions of the engine, determining the amount of time prior to the top dead center position of the piston to inject the main fuel into the combustion chamber, and determining the relationship of the timing of the injection of the auxiliary fuel into the combustion chamber to achieve a predetermined specific fuel consumption, a predetermined combustion efficiency, and a predetermined peak cylinder firing pressure.

Characteristics of American coals in relation to their conversion into clean energy fuels. Quarterly technical progress report, July--September 1977. [Coal-fuel oil-water slurries

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

Spackman, W.; Davis, A.; Walker, P. L.

1977-12-01

The Penn State/ERDA Coal Sample Bank was expanded to include 201 new coal samples. A total of 68 characterized coal samples and 115 selected printouts of coal data were supplied upon request to the coal research community. Selected chemical and petrographic properties were statistically analyzed for 119 coal channel samples chosen from the Penn State/ERDA Coal Data Base. Installation of the pressurized laminar flow isotherml reactor has begun. Experiments have continued on the combustion pot; the study of the reactivity of a Koppers Company coke is now complete. Studies show that weight changes associated with preoxidation can be precisely meausredmore » using a TGA apparatus. Water densities determined on 19 coals were lower when measured in the presence of a wetting agent. Study of the effect of reaction temperature on gasification of Saran carbon in air shows one percent platinum loading on Saran carbon increases gasification rates over the entire range of carbon burn-off. Study of the theoretical aspects of combustion of low volatile fuels was resumed. The computer model was expanded to include the effects of heat loss through the furnace walls and its effect on flame temperature profiles. Investigation of the combustion characteristics of coal-oil-water-air fuel mixtures was continued. Only through the use of non-equilibrium experiments can certain important combustion characteristics be studied, and computerized data acquisition is being developed to fully implement such methods.« less

Fuel governor for controlled autoignition engines

DOEpatents

Jade, Shyam; Hellstrom, Erik; Stefanopoulou, Anna; Jiang, Li

2016-06-28

Methods and systems for controlling combustion performance of an engine are provided. A desired fuel quantity for a first combustion cycle is determined. One or more engine actuator settings are identified that would be required during a subsequent combustion cycle to cause the engine to approach a target combustion phasing. If the identified actuator settings are within a defined acceptable operating range, the desired fuel quantity is injected during the first combustion cycle. If not, an attenuated fuel quantity is determined and the attenuated fuel quantity is injected during the first combustion cycle.

Combustor oscillation attenuation via the control of fuel-supply line dynamics

DOEpatents

Richards, G.A.; Gemmen, R.S.

1998-09-22

Combustion oscillation control in combustion systems using hydrocarbon fuels is provided by acoustically tuning a fuel-delivery line to a desired phase of the combustion oscillations for providing a pulse of a fuel-rich region at the oscillating flame front at each time when the oscillation produced pressure in the combustion chamber is in a low pressure phase. The additional heat release produced by burning such fuel-rich regions during low combustion chamber pressure effectively attenuates the combustion oscillations to a selected value. 9 figs.

Method of combustion for dual fuel engine

DOEpatents

Hsu, B.D.; Confer, G.L.; Zujing Shen; Hapeman, M.J.; Flynn, P.L.

1993-12-21

Apparatus and a method of introducing a primary fuel, which may be a coal water slurry, and a high combustion auxiliary fuel, which may be a conventional diesel oil, into an internal combustion diesel engine comprises detecting the load conditions of the engine, determining the amount of time prior to the top dead center position of the piston to inject the main fuel into the combustion chamber, and determining the relationship of the timing of the injection of the auxiliary fuel into the combustion chamber to achieve a predetermined specific fuel consumption, a predetermined combustion efficiency, and a predetermined peak cylinder firing pressure. 19 figures.

30 CFR 56.4103 - Fueling internal combustion engines.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Fueling internal combustion engines. 56.4103... Prevention and Control Prohibitions/precautions/housekeeping § 56.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts of...

30 CFR 56.4103 - Fueling internal combustion engines.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Fueling internal combustion engines. 56.4103... Prevention and Control Prohibitions/precautions/housekeeping § 56.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts of...

30 CFR 56.4103 - Fueling internal combustion engines.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Fueling internal combustion engines. 56.4103... Prevention and Control Prohibitions/precautions/housekeeping § 56.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts of...

30 CFR 56.4103 - Fueling internal combustion engines.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Fueling internal combustion engines. 56.4103... Prevention and Control Prohibitions/precautions/housekeeping § 56.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts of...

30 CFR 57.4103 - Fueling internal combustion engines.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Fueling internal combustion engines. 57.4103... Prevention and Control Prohibitions/precautions/housekeeping § 57.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts of...

30 CFR 57.4103 - Fueling internal combustion engines.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Fueling internal combustion engines. 57.4103... Prevention and Control Prohibitions/precautions/housekeeping § 57.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts of...

30 CFR 57.4103 - Fueling internal combustion engines.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Fueling internal combustion engines. 57.4103... Prevention and Control Prohibitions/precautions/housekeeping § 57.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts of...

30 CFR 57.4103 - Fueling internal combustion engines.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Fueling internal combustion engines. 57.4103... Prevention and Control Prohibitions/precautions/housekeeping § 57.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts of...

Gas turbine topping combustor

DOEpatents

Beer, Janos; Dowdy, Thomas E.; Bachovchin, Dennis M.

1997-01-01

A combustor for burning a mixture of fuel and air in a rich combustion zone, in which the fuel bound nitrogen in converted to molecular nitrogen. The fuel rich combustion is followed by lean combustion. The products of combustion from the lean combustion are rapidly quenched so as to convert the fuel bound nitrogen to molecular nitrogen without forming NOx. The combustor has an air radial swirler that directs the air radially inward while swirling it in the circumferential direction and a radial fuel swirler that directs the fuel radially outward while swirling it in the same circumferential direction, thereby promoting vigorous mixing of the fuel and air. The air inlet has a variable flow area that is responsive to variations in the heating value of the fuel, which may be a coal-derived fuel gas. A diverging passage in the combustor in front of a bluff body causes the fuel/air mixture to recirculate with the rich combustion zone.

40 CFR 62.15410 - What definitions must I know?

Code of Federal Regulations, 2014 CFR

2014-07-01

... period during which the municipal waste combustion unit combusts fossil fuel or other solid waste fuel... combusts municipal solid waste with nonmunicipal solid waste fuel (for example, coal, industrial process... permit that limits it to combusting a fuel feed stream which is 30 percent or less (by weight) municipal...

40 CFR 60.107a - Monitoring of emissions and operations for fuel gas combustion devices.

Code of Federal Regulations, 2011 CFR

2011-07-01

... for fuel gas combustion devices. 60.107a Section 60.107a Protection of Environment ENVIRONMENTAL... Commenced After May 14, 2007 § 60.107a Monitoring of emissions and operations for fuel gas combustion devices. (a) Fuel gas combustion devices subject to SO 2 or H 2 S limit. The owner or operator of a fuel...

40 CFR 60.107a - Monitoring of emissions and operations for fuel gas combustion devices.

Code of Federal Regulations, 2012 CFR

2012-07-01

... for fuel gas combustion devices. 60.107a Section 60.107a Protection of Environment ENVIRONMENTAL... Commenced After May 14, 2007 § 60.107a Monitoring of emissions and operations for fuel gas combustion devices. (a) Fuel gas combustion devices subject to SO 2 or H 2 S limit. The owner or operator of a fuel...

40 CFR 60.107a - Monitoring of emissions and operations for fuel gas combustion devices.

Code of Federal Regulations, 2010 CFR

2010-07-01

... for fuel gas combustion devices. 60.107a Section 60.107a Protection of Environment ENVIRONMENTAL... Commenced After May 14, 2007 § 60.107a Monitoring of emissions and operations for fuel gas combustion devices. (a) Fuel gas combustion devices subject to SO 2 or H 2 S limit. The owner or operator of a fuel...

40 CFR 60.107a - Monitoring of emissions and operations for fuel gas combustion devices and flares.

Code of Federal Regulations, 2013 CFR

2013-07-01

... for fuel gas combustion devices and flares. 60.107a Section 60.107a Protection of Environment... combustion devices and flares. (a) Fuel gas combustion devices subject to SO2 or H2S limit and flares subject to H2S concentration requirements. The owner or operator of a fuel gas combustion device that is...

40 CFR 60.107a - Monitoring of emissions and operations for fuel gas combustion devices and flares.

Code of Federal Regulations, 2014 CFR

2014-07-01

... for fuel gas combustion devices and flares. 60.107a Section 60.107a Protection of Environment... combustion devices and flares. (a) Fuel gas combustion devices subject to SO2 or H2S limit and flares subject to H2S concentration requirements. The owner or operator of a fuel gas combustion device that is...

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.

Low-Temperature Combustion of High Octane Fuels in a Gasoline Compression Ignition Engine

DOE PAGES

Cung, Khanh Duc; Ciatti, Stephen Anthony; Tanov, Slavey; ...

2017-12-21

Gasoline Compression Ignition (GCI) has been shown as one of the advanced combustion concepts that could potentially provide a pathway to achieve cleaner and more efficient combustion engines. Fuel and air in GCI are not fully premixed as compared to homogeneous charge compression ignition (HCCI) which is a completely kinetic-controlled combustion system. Therefore, the combustion phasing can be controlled by the time of injection, usually post injection in a multiple-injection scheme, to mitigate combustion noise. Gasoline fuels ignite more difficult than Diesel. The autoignition quality of gasoline can be indicated by research octane number (RON). Fuels with high octane tendmore » to have more resistance to auto-ignition, hence more time for fuel-air mixing. In this study, three fuels, namely, Aromatic, Alkylate, and E30, with similar RON value of 98 but different hydrocarbon compositions were tested in a multi-cylinder engine under GCI combustion mode. Considerations of EGR, start of injection (SOI), and boost were investigated to study the sensitivity of dilution, local stratification, and reactivity of the charge, respectively, for each fuel. Combustion phasing was kept constant during the experiments to the changes in ignition and combustion process before and after 50% of the fuel mass is burned. Emission characteristics at different levels of EGR and lambda were revealed for all fuels with E30 having the lowest filter smoke number (FSN) and was also most sensitive to the change in dilution. Reasonably low combustion noise (< 90 dB) and stable combustion (COVIMEP < 3%) were maintained during the experiments. The second part of this paper contains visualization of the combustion process obtained from endoscope imaging for each fuel at selected conditions. Soot radiation signal from GCI combustion were strong during late injection, and also more intense at low EGR conditions. Furthermore, soot/temperature profiles indicated only the high-temperature combustion period, while cylinder pressure-based heat release rate (HRR) showed a two-stage combustion phenomenon.« less

Low-Temperature Combustion of High Octane Fuels in a Gasoline Compression Ignition Engine

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

Cung, Khanh Duc; Ciatti, Stephen Anthony; Tanov, Slavey

Gasoline Compression Ignition (GCI) has been shown as one of the advanced combustion concepts that could potentially provide a pathway to achieve cleaner and more efficient combustion engines. Fuel and air in GCI are not fully premixed as compared to homogeneous charge compression ignition (HCCI) which is a completely kinetic-controlled combustion system. Therefore, the combustion phasing can be controlled by the time of injection, usually post injection in a multiple-injection scheme, to mitigate combustion noise. Gasoline fuels ignite more difficult than Diesel. The autoignition quality of gasoline can be indicated by research octane number (RON). Fuels with high octane tendmore » to have more resistance to auto-ignition, hence more time for fuel-air mixing. In this study, three fuels, namely, Aromatic, Alkylate, and E30, with similar RON value of 98 but different hydrocarbon compositions were tested in a multi-cylinder engine under GCI combustion mode. Considerations of EGR, start of injection (SOI), and boost were investigated to study the sensitivity of dilution, local stratification, and reactivity of the charge, respectively, for each fuel. Combustion phasing was kept constant during the experiments to the changes in ignition and combustion process before and after 50% of the fuel mass is burned. Emission characteristics at different levels of EGR and lambda were revealed for all fuels with E30 having the lowest filter smoke number (FSN) and was also most sensitive to the change in dilution. Reasonably low combustion noise (< 90 dB) and stable combustion (COVIMEP < 3%) were maintained during the experiments. The second part of this paper contains visualization of the combustion process obtained from endoscope imaging for each fuel at selected conditions. Soot radiation signal from GCI combustion were strong during late injection, and also more intense at low EGR conditions. Furthermore, soot/temperature profiles indicated only the high-temperature combustion period, while cylinder pressure-based heat release rate (HRR) showed a two-stage combustion phenomenon.« less

Combustion of liquid fuel droplets in supercritical conditions

NASA Technical Reports Server (NTRS)

Shuen, J. S.; Yang, Vigor

1991-01-01

A comprehensive analysis of liquid-fuel droplet combustion in both sub- and super-critical environments has been conducted. The formulation is based on the complete conservation equations for both gas and liquid phases, and accommodates finite-rate chemical kinetics and a full treatment of liquid-vapor phase equilibrium at the droplet surface. The governing equations and the associated interface boundary conditions are solved numerically using a fully coupled, implicit scheme with the dual time-stepping integration technique. The model is capable of treating the entire droplet history, including the transition from the subcritical to the supercritical state. As a specific example, the combustion of n-pentane fuel droplets in air is studied for pressures of 5-140 atm. Results indicate that the ambient gas pressure exerts significant control of droplet gasification and burning processes through its influences on the fluid transport, gas/liquid interface thermodynamics, and chemical reactions. The droplet gasification rate increases progressively with pressure. However, the data for the overall burnout time exhibits a significant variation near the critical burning pressure, mainly as a result of reduced mass-diffusion rate and latent heat of vaporization with increased pressure. The influence of droplet size on the burning characteristics is also noted.

Combustible structural composites and methods of forming combustible structural composites

DOEpatents

Daniels, Michael A [Idaho Falls, ID; Heaps, Ronald J [Idaho Falls, ID; Steffler, Eric D [Idaho Falls, ID; Swank, William D [Idaho Falls, ID

2011-08-30

Combustible structural composites and methods of forming same are disclosed. In an embodiment, a combustible structural composite includes combustible material comprising a fuel metal and a metal oxide. The fuel metal is present in the combustible material at a weight ratio from 1:9 to 1:1 of the fuel metal to the metal oxide. The fuel metal and the metal oxide are capable of exothermically reacting upon application of energy at or above a threshold value to support self-sustaining combustion of the combustible material within the combustible structural composite. Structural-reinforcing fibers are present in the composite at a weight ratio from 1:20 to 10:1 of the structural-reinforcing fibers to the combustible material. Other embodiments and aspects are disclosed.

Combustible structural composites and methods of forming combustible structural composites

DOEpatents

Daniels, Michael A.; Heaps, Ronald J.; Steffler, Eric D.; Swank, W. David

2013-04-02

Combustible structural composites and methods of forming same are disclosed. In an embodiment, a combustible structural composite includes combustible material comprising a fuel metal and a metal oxide. The fuel metal is present in the combustible material at a weight ratio from 1:9 to 1:1 of the fuel metal to the metal oxide. The fuel metal and the metal oxide are capable of exothermically reacting upon application of energy at or above a threshold value to support self-sustaining combustion of the combustible material within the combustible structural composite. Structural-reinforcing fibers are present in the composite at a weight ratio from 1:20 to 10:1 of the structural-reinforcing fibers to the combustible material. Other embodiments and aspects are disclosed.

Staged combustion with piston engine and turbine engine supercharger

DOEpatents

Fischer, Larry E [Los Gatos, CA; Anderson, Brian L [Lodi, CA; O'Brien, Kevin C [San Ramon, CA

2006-05-09

A combustion engine method and system provides increased fuel efficiency and reduces polluting exhaust emissions by burning fuel in a two-stage combustion system. Fuel is combusted in a piston engine in a first stage producing piston engine exhaust gases. Fuel contained in the piston engine exhaust gases is combusted in a second stage turbine engine. Turbine engine exhaust gases are used to supercharge the piston engine.

Staged combustion with piston engine and turbine engine supercharger

DOEpatents

Fischer, Larry E [Los Gatos, CA; Anderson, Brian L [Lodi, CA; O'Brien, Kevin C [San Ramon, CA

2011-11-01

A combustion engine method and system provides increased fuel efficiency and reduces polluting exhaust emissions by burning fuel in a two-stage combustion system. Fuel is combusted in a piston engine in a first stage producing piston engine exhaust gases. Fuel contained in the piston engine exhaust gases is combusted in a second stage turbine engine. Turbine engine exhaust gases are used to supercharge the piston engine.

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.

Fuel properties to enable lifted-flame combustion

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

Kurtz, Eric

The Fuel Properties to Enable Lifted-Flame Combustion project responded directly to solicitation DE-FOA-0000239 AOI 1A, Fuels and Lubricants for Advanced Combustion Regimes. This subtopic was intended to encompass clean and highly-efficient, liquid-fueled combustion engines to achieve extremely low engine-out nitrogen oxides (NOx) and particulate matter (PM) as a target and similar efficiency as state-of-the-art direct injection diesel engines. The intent of this project was to identify how fuel properties can be used to achieve controllable Leaner Lifted Flame Combustion (LLFC) with low NOx and PM emissions. Specifically, this project was expected to identify and test key fuel properties to enablemore » LLFC and their compatibility with current fuel systems and to enhance combustion models to capture the effect of fuel properties on advanced combustion. Successful demonstration of LLFC may reduce the need for after treatment devices, thereby reducing costs and improving thermal efficiency. The project team consisted of key technical personnel from Ford Motor Company (FMC), the University of Wisconsin-Madison (UW), Sandia National Laboratories (SNL) and Lawrence Livermore National Laboratories (LLNL). Each partner had key roles in achieving project objectives. FMC investigated fuel properties relating to LLFC and sooting tendency. Together, FMC and UW developed and integrated 3D combustion models to capture fuel property combustion effects. FMC used these modeling results to develop a combustion system and define fuel properties to support a single-cylinder demonstration of fuel-enabled LLFC. UW investigated modeling the flame characteristics and emissions behavior of different fuels, including those with different cetane number and oxygen content. SNL led spray combustion experiments to quantify the effect of key fuel properties on combustion characteristics critical for LLFC, as well as single cylinder optical engine experiments to improve fundamental understanding of flame lift-off, generate model validation data, and demonstrate LLFC concurrent with FMC efforts. Additionally, LLNL was added to the project during the second year to develop a detailed kinetic mechanism for a key oxygenate to support CFD modeling. Successful completion of this project allowed the team to enhance fundamental understanding of LLFC, improve the state of current combustion models and increase understanding of desired fuel properties. This knowledge also improves our knowledge of how cost effective and environmentally friendly renewable fuels can assist in helping meet future emission and greenhouse gas regulations.« less

Progress towards an Optimization Methodology for Combustion-Driven Portable Thermoelectric Power Generation Systems

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

Krishnan, Shankar; Karri, Naveen K.; Gogna, Pawan K.

2012-03-13

Enormous military and commercial interests exist in developing quiet, lightweight, and compact thermoelectric (TE) power generation systems. This paper investigates design integration and analysis of an advanced TE power generation system implementing JP-8 fueled combustion and thermal recuperation. Design and development of a portable TE power system using a JP-8 combustor as a high temperature heat source and optimal process flows depend on efficient heat generation, transfer, and recovery within the system are explored. Design optimization of the system required considering the combustion system efficiency and TE conversion efficiency simultaneously. The combustor performance and TE sub-system performance were coupled directlymore » through exhaust temperatures, fuel and air mass flow rates, heat exchanger performance, subsequent hot-side temperatures, and cold-side cooling techniques and temperatures. Systematic investigation of this system relied on accurate thermodynamic modeling of complex, high-temperature combustion processes concomitantly with detailed thermoelectric converter thermal/mechanical modeling. To this end, this work reports on design integration of systemlevel process flow simulations using commercial software CHEMCADTM with in-house thermoelectric converter and module optimization, and heat exchanger analyses using COMSOLTM software. High-performance, high-temperature TE materials and segmented TE element designs are incorporated in coupled design analyses to achieve predicted TE subsystem level conversion efficiencies exceeding 10%. These TE advances are integrated with a high performance microtechnology combustion reactor based on recent advances at the Pacific Northwest National Laboratory (PNNL). Predictions from this coupled simulation established a basis for optimal selection of fuel and air flow rates, thermoelectric module design and operating conditions, and microtechnology heat-exchanger design criteria. This paper will discuss this simulation process that leads directly to system efficiency power maps defining potentially available optimal system operating conditions and regimes. This coupled simulation approach enables pathways for integrated use of high-performance combustor components, high performance TE devices, and microtechnologies to produce a compact, lightweight, combustion driven TE power system prototype that operates on common fuels.« less

Method and apparatus for advanced staged combustion utilizing forced internal recirculation

DOEpatents

Rabovitser, Iosif K.; Knight, Richard A.; Cygan, David F.; Nester, Serguei; Abbasi, Hamid A.

2003-12-16

A method and apparatus for combustion of a fuel in which a first-stage fuel and a first-stage oxidant are introduced into a combustion chamber and ignited, forming a primary combustion zone. At least about 5% of the total heat output produced by combustion of the first-stage fuel and the first-stage oxidant is removed from the primary combustion zone, forming cooled first-stage combustion products. A portion of the cooled first-stage combustion products from a downstream region of the primary combustion zone is recirculated to an upstream region of primary combustion zone. A second-stage fuel is introduced into the combustion chamber downstream of the primary combustion zone and ignited, forming a secondary combustion zone. At least about 5% of the heat from the secondary combustion zone is removed. In accordance with one embodiment, a third-stage oxidant is introduced into the combustion chamber downstream of the secondary combustion zone, forming a tertiary combustion zone.

On-Line Measurement of Heat of Combustion of Gaseous Hydrocarbon Fuel Mixtures

NASA Technical Reports Server (NTRS)

Sprinkle, Danny R.; Chaturvedi, Sushil K.; Kheireddine, Ali

1996-01-01

A method for the on-line measurement of the heat of combustion of gaseous hydrocarbon fuel mixtures has been developed and tested. The method involves combustion of a test gas with a measured quantity of air to achieve a preset concentration of oxygen in the combustion products. This method involves using a controller which maintains the fuel (gas) volumetric flow rate at a level consistent with the desired oxygen concentration in the combustion products. The heat of combustion is determined form a known correlation with the fuel flow rate. An on-line computer accesses the fuel flow data and displays the heat of combustion measurement at desired time intervals. This technique appears to be especially applicable for measuring heats of combustion of hydrocarbon mixtures of unknown composition such as natural gas.

Evaluation of Liquid Fuel Field Space Heaters: Standard Military, Developmental and Foreign

DTIC Science & Technology

1978-10-01

least 15 kg/kg, (2) to react as much fuel as possible by the flameless combustion reaction, and (3) to maintain gas temperatures not higher than 1000...as there is enough oxygen there to support combustion . As the fuel flow increases, the flames move up until at maximum flow only flameless ...HEATING FIELD HEATING COMBUSTION COMBUSTION (LIQUID FUELS) HEATERS TENT HEATERS LIQUID FUELS FUELS LIQUIDS OXYGEN tS»TRACT rCoaltnu* an rmrormm

CFD propels NASP propulsion progress

NASA Technical Reports Server (NTRS)

Povinelli, Louis A.; Dwoyer, Douglas L.; Green, Michael J.

1990-01-01

The most complex aerothermodynamics encountered in the National Aerospace Plane (NASP) propulsion system are associated with the fuel-mixing and combustion-reaction flows of its combustor section; adequate CFD tools must be developed to model shock-wave systems, turbulent hydrogen/air mixing, flow separation, and combustion. Improvements to existing CFD codes have involved extension from two dimensions to three, as well as the addition of finite-rate hydrogen-air chemistry. A novel CFD code for the treatment of reacting flows throughout the NASP, designated GASP, uses the most advanced upwind-differencing technology.

CFD propels NASP propulsion progress

NASA Astrophysics Data System (ADS)

Povinelli, Louis A.; Dwoyer, Douglas L.; Green, Michael J.

1990-07-01

The most complex aerothermodynamics encountered in the National Aerospace Plane (NASP) propulsion system are associated with the fuel-mixing and combustion-reaction flows of its combustor section; adequate CFD tools must be developed to model shock-wave systems, turbulent hydrogen/air mixing, flow separation, and combustion. Improvements to existing CFD codes have involved extension from two dimensions to three, as well as the addition of finite-rate hydrogen-air chemistry. A novel CFD code for the treatment of reacting flows throughout the NASP, designated GASP, uses the most advanced upwind-differencing technology.

Combustion characteristics and air pollutant formation during oxy-fuel co-combustion of microalgae and lignite.

PubMed

Gao, Yuan; Tahmasebi, Arash; Dou, Jinxiao; Yu, Jianglong

2016-05-01

Oxy-fuel combustion of solid fuels is seen as one of the key technologies for carbon capture to reduce greenhouse gas emissions. The combustion characteristics of lignite coal, Chlorella vulgaris microalgae, and their blends under O2/N2 and O2/CO2 conditions were studied using a Thermogravimetric Analyzer-Mass Spectroscopy (TG-MS). During co-combustion of blends, three distinct peaks were observed and were attributed to C. vulgaris volatiles combustion, combustion of lignite, and combustion of microalgae char. Activation energy during combustion was calculated using iso-conventional method. Increasing the microalgae content in the blend resulted in an increase in activation energy for the blends combustion. The emissions of S- and N-species during blend fuel combustion were also investigated. The addition of microalgae to lignite during air combustion resulted in lower CO2, CO, and NO2 yields but enhanced NO, COS, and SO2 formation. During oxy-fuel co-combustion, the addition of microalgae to lignite enhanced the formation of gaseous species. Copyright © 2016 Elsevier Ltd. All rights reserved.

Combustion of Gaseous Mixtures

NASA Technical Reports Server (NTRS)

Duchene, R

1932-01-01

This report not only presents matters of practical importance in the classification of engine fuels, for which other means have proved inadequate, but also makes a few suggestions. It confirms the results of Withrow and Boyd which localize the explosive wave in the last portions of the mixture burned. This being the case, it may be assumed that the greater the normal combustion, the less the energy developed in the explosive form. In order to combat the detonation, it is therefore necessary to try to render the normal combustion swift and complete, as produced in carbureted mixtures containing benzene (benzol), in which the flame propagation, beginning at the spark, yields a progressive and pronounced darkening on the photographic film.

Fuel-rich catalytic combustion of Jet-A fuel-equivalence ratios 5.0 to 8.0

NASA Technical Reports Server (NTRS)

Brabbs, Theodore A.; Gracia-Salcedo, Carmen M.

1989-01-01

Fuel-rich catalytic combustion (E.R. greater than 5.0) is a unique technique for preheating a hydrocarbon fuel to temperatures much higher than those obtained by conventional heat exchangers. In addition to producing very reactive molecules, the process upgrades the structure of the fuel by the formation of hydrogen and smaller hydrocarbons and produces a cleaner burning fuel by removing some of the fuel carbon from the soot formation chain. With fuel-rich catalytic combustion as the first stage of a two stage combustion system, enhanced fuel properties can be utilized by both high speed engines, where time for ignition and complete combustion is limited, and engines where emission of thermal NO sub x is critical. Two-stage combustion (rich-lean) has been shown to be effective for NO sub x reduction in stationary burners where residence times are long enough to burn-up the soot formed in the first stage. Such residence times are not available in aircraft engines. Thus, the soot-free nature of the present process is critical for high speed engines. The successful application of fuel-rich catalytic combustion to Jet-A, a multicomponent fuel used in gas turbine combustors, is discusssed.

Gas turbine topping combustor

DOEpatents

Beer, J.; Dowdy, T.E.; Bachovchin, D.M.

1997-06-10

A combustor is described for burning a mixture of fuel and air in a rich combustion zone, in which the fuel bound nitrogen in converted to molecular nitrogen. The fuel rich combustion is followed by lean combustion. The products of combustion from the lean combustion are rapidly quenched so as to convert the fuel bound nitrogen to molecular nitrogen without forming NOx. The combustor has an air radial swirler that directs the air radially inward while swirling it in the circumferential direction and a radial fuel swirler that directs the fuel radially outward while swirling it in the same circumferential direction, thereby promoting vigorous mixing of the fuel and air. The air inlet has a variable flow area that is responsive to variations in the heating value of the fuel, which may be a coal-derived fuel gas. A diverging passage in the combustor in front of a bluff body causes the fuel/air mixture to recirculate with the rich combustion zone. 14 figs.

Propellant Chemistry for CFD Applications

NASA Technical Reports Server (NTRS)

Farmer, R. C.; Anderson, P. G.; Cheng, Gary C.

1996-01-01

Current concepts for reusable launch vehicle design have created renewed interest in the use of RP-1 fuels for high pressure and tri-propellant propulsion systems. Such designs require the use of an analytical technology that accurately accounts for the effects of real fluid properties, combustion of large hydrocarbon fuel modules, and the possibility of soot formation. These effects are inadequately treated in current computational fluid dynamic (CFD) codes used for propulsion system analyses. The objective of this investigation is to provide an accurate analytical description of hydrocarbon combustion thermodynamics and kinetics that is sufficiently computationally efficient to be a practical design tool when used with CFD codes such as the FDNS code. A rigorous description of real fluid properties for RP-1 and its combustion products will be derived from the literature and from experiments conducted in this investigation. Upon the establishment of such a description, the fluid description will be simplified by using the minimum of empiricism necessary to maintain accurate combustion analyses and including such empirical models into an appropriate CFD code. An additional benefit of this approach is that the real fluid properties analysis simplifies the introduction of the effects of droplet sprays into the combustion model. Typical species compositions of RP-1 have been identified, surrogate fuels have been established for analyses, and combustion and sooting reaction kinetics models have been developed. Methods for predicting the necessary real fluid properties have been developed and essential experiments have been designed. Verification studies are in progress, and preliminary results from these studies will be presented. The approach has been determined to be feasible, and upon its completion the required methodology for accurate performance and heat transfer CFD analyses for high pressure, tri-propellant propulsion systems will be available.

The history, genotoxicity and carcinogenicity of carbon-based fuels and their emissions: part 4 - alternative fuels.

PubMed

Claxton, Larry D

2015-01-01

Much progress has been made in reducing the pollutants emitted from various combustors (including diesel engines and power plants) by the use of alternative fuels; however, much more progress is needed. Not only must researchers improve fuels and combustors, but also there is a need to improve the toxicology testing and analytical chemistry methods associated with these complex mixtures. Emissions from many alternative carbonaceous fuels are mutagenic and carcinogenic. Depending on their source and derivation, alternative carbonaceous fuels before combustion may or may not be genotoxic; however, in order to know their genotoxicity, appropriate chemical analysis and/or bioassay must be performed. Newly developed fuels and combustors must be tested to determine if they provide a public health advantage over existing technologies - including what tradeoffs can be expected (e.g., decreasing levels of PAHs versus increasing levels of NOx and possibly nitroarenes in ambient air). Another need is to improve exposure estimations which presently are a weak link in doing risk analyses. Copyright © 2014 Elsevier B.V. All rights reserved.

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.

Fuel cells for hospitals

NASA Astrophysics Data System (ADS)

Damberger, Thomas A.

Traditionally, electrical and thermal energy is produced in a conventional combustion process. Coal, fuel oil, and natural gas are common fuels used for electrical generation, while nuclear, hydroelectric, and solar are non-combustion processes. All fossil fuels release their stored energy and air pollution simultaneously when burned in a contemporary combustion process. To reduce or eliminate air pollution, the combustion process must be shifted in some way to another type of process. Extracting pollution-free energy from fossil fuels can be accomplished through the electrochemical reaction of a fuel cell. A non-combustion process is a foundation from which pollution-free energy emerges, fulfilling our incessant need for energy without environmental compromise.

Analysis of long-time operation of micro-cogeneration unit with fuel cell

NASA Astrophysics Data System (ADS)

Patsch, Marek; Čaja, Alexander

2015-05-01

Micro-cogeneration is cogeneration with small performance, with maximal electric power up to 50 kWe. On the present, there are available small micro-cogeneration units with small electric performance, about 1 kWe, which are usable also in single family houses or flats. These micro-cogeneration units operate on principle of conventional combustion engine, Stirling engine, steam engine or fuel cell. Micro-cogeneration units with fuel cells are new progressive developing type of units for single family houses. Fuel cell is electrochemical device which by oxidation-reduction reaction turn directly chemical energy of fuel to electric power, secondary products are pure water and thermal energy. The aim of paper is measuring and evaluation of operation parameters of micro-cogeneration unit with fuel cell which uses natural gas as a fuel.

Mechanisms and kinetics of granulated sewage sludge combustion.

PubMed

Kijo-Kleczkowska, Agnieszka; Środa, Katarzyna; Kosowska-Golachowska, Monika; Musiał, Tomasz; Wolski, Krzysztof

2015-12-01

This paper investigates sewage sludge disposal methods with particular emphasis on combustion as the priority disposal method. Sewage sludge incineration is an attractive option because it minimizes odour, significantly reduces the volume of the starting material and thermally destroys organic and toxic components of the off pads. Additionally, it is possible that ashes could be used. Currently, as many as 11 plants use sewage sludge as fuel in Poland; thus, this technology must be further developed in Poland while considering the benefits of co-combustion with other fuels. This paper presents the results of experimental studies aimed at determining the mechanisms (defining the fuel combustion region by studying the effects of process parameters, including the size of the fuel sample, temperature in the combustion chamber and air velocity, on combustion) and kinetics (measurement of fuel temperature and mass changes) of fuel combustion in an air stream under different thermal conditions and flow rates. The combustion of the sludge samples during air flow between temperatures of 800 and 900°C is a kinetic-diffusion process. This process determines the sample size, temperature of its environment, and air velocity. The adopted process parameters, the time and ignition temperature of the fuel by volatiles, combustion time of the volatiles, time to reach the maximum temperature of the fuel surface, maximum temperature of the fuel surface, char combustion time, and the total process time, had significant impacts. Copyright © 2015 Elsevier Ltd. All rights reserved.

Gas turbine premixing systems

DOEpatents

Kraemer, Gilbert Otto; Varatharajan, Balachandar; Evulet, Andrei Tristan; Yilmaz, Ertan; Lacy, Benjamin Paul

2013-12-31

Methods and systems are provided for premixing combustion fuel and air within gas turbines. In one embodiment, a combustor includes an upstream mixing panel configured to direct compressed air and combustion fuel through premixing zone to form a fuel-air mixture. The combustor includes a downstream mixing panel configured to mix additional combustion fuel with the fule-air mixture to form a combustion mixture.

Numerical approaches to combustion modeling. Progress in Astronautics and Aeronautics. Vol. 135

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

Oran, E.S.; Boris, J.P.

1991-01-01

Various papers on numerical approaches to combustion modeling are presented. The topics addressed include; ab initio quantum chemistry for combustion; rate coefficient calculations for combustion modeling; numerical modeling of combustion of complex hydrocarbons; combustion kinetics and sensitivity analysis computations; reduction of chemical reaction models; length scales in laminar and turbulent flames; numerical modeling of laminar diffusion flames; laminar flames in premixed gases; spectral simulations of turbulent reacting flows; vortex simulation of reacting shear flow; combustion modeling using PDF methods. Also considered are: supersonic reacting internal flow fields; studies of detonation initiation, propagation, and quenching; numerical modeling of heterogeneous detonations, deflagration-to-detonationmore » transition to reactive granular materials; toward a microscopic theory of detonations in energetic crystals; overview of spray modeling; liquid drop behavior in dense and dilute clusters; spray combustion in idealized configurations: parallel drop streams; comparisons of deterministic and stochastic computations of drop collisions in dense sprays; ignition and flame spread across solid fuels; numerical study of pulse combustor dynamics; mathematical modeling of enclosure fires; nuclear systems.« less

Assessment of organic contaminants in emissions from refuse-derived fuel combustion

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

Chrostowski, J.; Wait, D.; Kwong, E.

1985-09-01

Organic contaminants in emissions from refuse-derived fuel combustion were investigated in a 20-inch-diameter atmospheric fluidized-bed combustor. Combinations of coal/EcoFuel/MSW/toluene were burned inthe combustor with temperatures ranging from 1250 to 1550 degrees F. A Source Assessment Sampling System (SASS) was used to sample the stack gas; Level 1 methodology was used to analyze the organic-contaminant levels. Combustion efficiencies of 93 to 98 percent were achieved in the test burns. Combustion of the EcoFuel generated fewer organic emissions than combustion of coal at similar combustion temperatures. The fine particulate collected by the SASS train filter contained higher concentrations of extractable organics thanmore » the reactor fly ash and the SASS cyclone samples. Combustion of a toluene/EcoFuel mix generated a large number of benzene derivatives not seen in the combustion of pure EcoFuel. Polycyclic aromatic hydrocarbons were the dominant organic compounds contained in the XAD-2 resin extract from coal combustion. A number of different priority pollutants were identified in the samples collected.« less

30 CFR 77.1105 - Internal combustion engines; fueling.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Internal combustion engines; fueling. 77.1105 Section 77.1105 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... COAL MINES Fire Protection § 77.1105 Internal combustion engines; fueling. Internal combustion engines...

30 CFR 77.1105 - Internal combustion engines; fueling.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Internal combustion engines; fueling. 77.1105 Section 77.1105 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... COAL MINES Fire Protection § 77.1105 Internal combustion engines; fueling. Internal combustion engines...

30 CFR 77.1105 - Internal combustion engines; fueling.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Internal combustion engines; fueling. 77.1105 Section 77.1105 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... COAL MINES Fire Protection § 77.1105 Internal combustion engines; fueling. Internal combustion engines...

30 CFR 77.1105 - Internal combustion engines; fueling.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Internal combustion engines; fueling. 77.1105 Section 77.1105 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... COAL MINES Fire Protection § 77.1105 Internal combustion engines; fueling. Internal combustion engines...

30 CFR 77.1105 - Internal combustion engines; fueling.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Internal combustion engines; fueling. 77.1105 Section 77.1105 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... COAL MINES Fire Protection § 77.1105 Internal combustion engines; fueling. Internal combustion engines...

Combustion of High Molecular Weight Hydrocarbon Fuels and JP-8 at Moderate Pressures

DTIC Science & Technology

2016-07-26

SECURITY CLASSIFICATION OF: The objective of this research is to characterize combustion of high molecular weight hydrocarbon fuels and jet- fuels (in...Unlimited UU UU UU UU 26-07-2016 1-May-2012 30-Apr-2016 Final Report: Combustion of High Molecular Weight Hydrocarbon Fuels and JP-8 at Moderate...Report: Combustion of High Molecular Weight Hydrocarbon Fuels and JP-8 at Moderate Pressures (Research Area 1: Mechanical Sciences) Report Title The

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

Jones, M.L.

This paper very briefly summarizes progress in the demonstration of a small (up to 6 MWe), environmentally acceptable electric generating system fueled by indigenous fuels and waste materials to serve power distribution systems typical of Alaskan Native communities. Two detailed appendices supplement the report. The project is focused on two primary technologies: (1) atmospheric fluidized bed combustion (AFBC), and (2) coalbed methane and coal-fired diesel technologies. Two sites have been selected as possible locations for an AFBC demonstration, and bid proposals are under review. The transfer of a coal-fired diesel clean coal demonstration project from Maryland to Fairbanks, Alaska wasmore » approved, and the environmental assessment has been initiated. Federal support for a fuel cell using coalbed methane is also being pursued. The appendices included in the report provide: (1) the status of the conceptual design study for a 600-kWe coal-fired cogeneration plant in McGrath, Alaska; and (2) a global market assessment of coalbed methane, fluidized-bed combustion, and coal-fired diesel technologies in remote applications.« less

Progress in hydrogen energy; Proceedings of the National Workshop on Hydrogen Energy, New Delhi, India, July 4-6, 1985

NASA Astrophysics Data System (ADS)

Dahiya, R. P.

1987-06-01

The present conference on the development status of hydrogen energy technologies considers electrolytic hydrogen production, photoelectrolytic hydrogen production, microorganic hydrogen production, OTEC hydrogen production, solid-state materials for hydrogen storage, and a thin-film hydrogen storage system. Also discussed are the cryogenic storage of hydrogen; liquid hydrogen fuel for ground, air, and naval vehicles; hydrogen-fuel internal combustion engines; the use of hydrogen for domestic, commercial, and industrial applications; hydrogen fuel-cell development; enzyme electrodes for the use of hydrogen-rich fuels in biochemical fuel cells; an analysis of H2-O2 MHD generators; and hydrogen energy technology characterization and evaluation on the basis of an input-output structure.

A perspective on the range of gasoline compression ignition combustion strategies for high engine efficiency and low NOx and soot emissions: Effects of in-cylinder fuel stratification

DOE PAGES

Dempsey, Adam B.; Curran, Scott J.; Wagner, Robert M.

2016-01-14

Many research studies have shown that low temperature combustion in compression ignition engines has the ability to yield ultra-low NOx and soot emissions while maintaining high thermal efficiency. To achieve low temperature combustion, sufficient mixing time between the fuel and air in a globally dilute environment is required, thereby avoiding fuel-rich regions and reducing peak combustion temperatures, which significantly reduces soot and NOx formation, respectively. It has been demonstrated that achieving low temperature combustion with diesel fuel over a wide range of conditions is difficult because of its properties, namely, low volatility and high chemical reactivity. On the contrary, gasolinemore » has a high volatility and low chemical reactivity, meaning it is easier to achieve the amount of premixing time required prior to autoignition to achieve low temperature combustion. In order to achieve low temperature combustion while meeting other constraints, such as low pressure rise rates and maintaining control over the timing of combustion, in-cylinder fuel stratification has been widely investigated for gasoline low temperature combustion engines. The level of fuel stratification is, in reality, a continuum ranging from fully premixed (i.e. homogeneous charge of fuel and air) to heavily stratified, heterogeneous operation, such as diesel combustion. However, to illustrate the impact of fuel stratification on gasoline compression ignition, the authors have identified three representative operating strategies: partial, moderate, and heavy fuel stratification. Thus, this article provides an overview and perspective of the current research efforts to develop engine operating strategies for achieving gasoline low temperature combustion in a compression ignition engine via fuel stratification. In this paper, computational fluid dynamics modeling of the in-cylinder processes during the closed valve portion of the cycle was used to illustrate the opportunities and challenges associated with the various fuel stratification levels.« less

A perspective on the range of gasoline compression ignition combustion strategies for high engine efficiency and low NOx and soot emissions: Effects of in-cylinder fuel stratification

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

Dempsey, Adam B.; Curran, Scott J.; Wagner, Robert M.

Many research studies have shown that low temperature combustion in compression ignition engines has the ability to yield ultra-low NOx and soot emissions while maintaining high thermal efficiency. To achieve low temperature combustion, sufficient mixing time between the fuel and air in a globally dilute environment is required, thereby avoiding fuel-rich regions and reducing peak combustion temperatures, which significantly reduces soot and NOx formation, respectively. It has been demonstrated that achieving low temperature combustion with diesel fuel over a wide range of conditions is difficult because of its properties, namely, low volatility and high chemical reactivity. On the contrary, gasolinemore » has a high volatility and low chemical reactivity, meaning it is easier to achieve the amount of premixing time required prior to autoignition to achieve low temperature combustion. In order to achieve low temperature combustion while meeting other constraints, such as low pressure rise rates and maintaining control over the timing of combustion, in-cylinder fuel stratification has been widely investigated for gasoline low temperature combustion engines. The level of fuel stratification is, in reality, a continuum ranging from fully premixed (i.e. homogeneous charge of fuel and air) to heavily stratified, heterogeneous operation, such as diesel combustion. However, to illustrate the impact of fuel stratification on gasoline compression ignition, the authors have identified three representative operating strategies: partial, moderate, and heavy fuel stratification. Thus, this article provides an overview and perspective of the current research efforts to develop engine operating strategies for achieving gasoline low temperature combustion in a compression ignition engine via fuel stratification. In this paper, computational fluid dynamics modeling of the in-cylinder processes during the closed valve portion of the cycle was used to illustrate the opportunities and challenges associated with the various fuel stratification levels.« less

Reduced No.sub.x combustion method

DOEpatents

Delano, Mark A.

1991-01-01

A combustion method enabling reduced NO.sub.x formation wherein fuel and oxidant are separately injected into a combustion zone in a defined velocity relation, combustion gases are aspirated into the oxidant stream prior to intermixture with the fuel, and the fuel is maintained free from contact with oxygen until the intermixture.

Analytical evaluation of effect of equivalence ratio inlet-air temperature and combustion pressure on performance of several possible ram-jet fuels

NASA Technical Reports Server (NTRS)

Tower, Leonard K; Gammon, Benson E

1953-01-01

The results of an analytical investigation of the theoretical air specific impulse performance and adiabatic combustion temperatures of several possible ram-jet fuels over a range of equivalence ratios, inlet-air temperatures, and combustion pressures, is presented herein. The fuels include octane-1, 50-percent-magnesium slurry, boron, pentaborane, diborane, hydrogen, carbon, and aluminum. Thermal effects from high combustion temperatures were found to effect considerably the combustion performance of all the fuels. An increase in combustion pressure was beneficial to air specific impulse at high combustion temperatures. The use of these theoretical data in engine operation and in the evaluation of experimental data is described.

Fuel processor for fuel cell power system

DOEpatents

Vanderborgh, Nicholas E.; Springer, Thomas E.; Huff, James R.

1987-01-01

A catalytic organic fuel processing apparatus, which can be used in a fuel cell power system, contains within a housing a catalyst chamber, a variable speed fan, and a combustion chamber. Vaporized organic fuel is circulated by the fan past the combustion chamber with which it is in indirect heat exchange relationship. The heated vaporized organic fuel enters a catalyst bed where it is converted into a desired product such as hydrogen needed to power the fuel cell. During periods of high demand, air is injected upstream of the combustion chamber and organic fuel injection means to burn with some of the organic fuel on the outside of the combustion chamber, and thus be in direct heat exchange relation with the organic fuel going into the catalyst bed.

Fuel combustion exhibiting low NO{sub x} and CO levels

DOEpatents

Keller, J.O.; Bramlette, T.T.; Barr, P.K.

1996-07-30

Method and apparatus are disclosed for safely combusting a fuel in such a manner that very low levels of NO{sub x} and CO are produced. The apparatus comprises an inlet line containing a fuel and an inlet line containing an oxidant. Coupled to the fuel line and to the oxidant line is a mixing means for thoroughly mixing the fuel and the oxidant without combusting them. Coupled to the mixing means is a means for injecting the mixed fuel and oxidant, in the form of a large-scale fluid dynamic structure, into a combustion region. Coupled to the combustion region is a means for producing a periodic flow field within the combustion region to mix the fuel and the oxidant with ambient gases in order to lower the temperature of combustion. The means for producing a periodic flow field can be a pulse combustor, a rotating band, or a rotating cylinder within an acoustic chamber positioned upstream or downstream of the region of combustion. The mixing means can be a one-way flapper valve; a rotating cylinder; a rotating band having slots that expose open ends of said fuel inlet line and said oxidant inlet line simultaneously; or a set of coaxial fuel annuli and oxidizer annuli. The means for producing a periodic flow field may or may not be in communication with an acoustic resonance. When employed, the acoustic resonance may be upstream or downstream of the region of combustion. 14 figs.

Investigation of critical burning of fuel droplets

NASA Technical Reports Server (NTRS)

Faeth, G. M.

1979-01-01

The general problem of spray combustion was investigated. The combustion of bipropellent droplets; combustion of hydrozine fuels; and combustion of sprays were studied. A model was developed to predict mean velocities and temperatures in a combusting gas jet.

Mitigating the effect of siloxanes on internal combustion engines using landfill gasses

DOEpatents

Besmann, Theodore M

2015-01-06

A waste gas combustion method that includes providing a combustible fuel source, in which the combustible fuel source is composed of at least methane and siloxane gas. A sodium source or magnesium source is mixed with the combustible fuel source. Combustion of the siloxane gas of the combustible fuel source produces a silicon containing product. The sodium source or magnesium source reacts with the silicon containing product to provide a sodium containing glass or sodium containing silicate, or a magnesium containing silicate. By producing the sodium containing glass or sodium containing silicate, or the magnesium containing silicate, or magnesium source for precipitating particulate silica instead of hard coating, the method may reduce or eliminate the formation of silica deposits within the combustion chamber and the exhaust components of the internal combustion engine.

Mitigating the effect of siloxanes on internal combustion engines using landfill gasses

DOEpatents

Besmann, Theodore M

2014-01-21

A waste gas combustion method that includes providing a combustible fuel source, in which the combustible fuel source is composed of at least methane and siloxane gas. A sodium source or magnesium source is mixed with the combustible fuel source. Combustion of the siloxane gas of the combustible fuel source produces a silicon containing product. The sodium source or magnesium source reacts with the silicon containing product to provide a sodium containing glass or sodium containing silicate, or a magnesium containing silicate. By producing the sodium containing glass or sodium containing silicate, or the magnesium containing silicate, or magnesium source for precipitating particulate silica instead of hard coating, the method may reduce or eliminate the formation of silica deposits within the combustion chamber and the exhaust components of the internal combustion engine.

The combustion properties analysis of various liquid fuels based on crude oil and renewables

NASA Astrophysics Data System (ADS)

Grab-Rogalinski, K.; Szwaja, S.

2016-09-01

The paper presents results of investigation on combustion properties analysis of hydrocarbon based liquid fuels commonly used in the CI engine. The analysis was performed with aid of the CRU (Combustion Research Unit). CRU is the machine consisted of a constant volume combustion chamber equipped with one or two fuel injectors and a pressure sensor. Fuel can be injected under various both injection pressure and injection duration, also with two injector versions two stage combustion with pilot injection can be simulated, that makes it possible to introduce and modify additional parameter which is injection delay (defined as the time between pilot and main injection). On a basis of this investigation such combustion parameters as pressure increase, rate of heat release, ignition delay and combustion duration can be determined. The research was performed for the four fuels as follows: LFO, HFO, Biofuel from rape seeds and Glycerol under various injection parameters as well as combustion chamber thermodynamic conditions. Under these tests the change in such injection parameters as injection pressure, use of pilot injection, injection delay and injection duration, for main injection, were made. Moreover, fuels were tested under different conditions of load, what was determined by initial conditions (pressure and temperature) in the combustion chamber. Stored data from research allows to compare combustion parameters for fuels applied to tests and show this comparison in diagrams.

Internal combustion engine using premixed combustion of stratified charges

DOEpatents

Marriott, Craig D [Rochester Hills, MI; Reitz, Rolf D [Madison, WI

2003-12-30

During a combustion cycle, a first stoichiometrically lean fuel charge is injected well prior to top dead center, preferably during the intake stroke. This first fuel charge is substantially mixed with the combustion chamber air during subsequent motion of the piston towards top dead center. A subsequent fuel charge is then injected prior to top dead center to create a stratified, locally richer mixture (but still leaner than stoichiometric) within the combustion chamber. The locally rich region within the combustion chamber has sufficient fuel density to autoignite, and its self-ignition serves to activate ignition for the lean mixture existing within the remainder of the combustion chamber. Because the mixture within the combustion chamber is overall premixed and relatively lean, NO.sub.x and soot production are significantly diminished.

40 CFR 97.504 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

... subpart: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine... paragraph (a)(1) of this section, is not a TR NOX Ozone Season unit begins to combust fossil fuel or to... date on which it both combusts fossil fuel and serves such generator. (b) Any unit in a State (and...

40 CFR 97.504 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

... subpart: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine... paragraph (a)(1) of this section, is not a TR NOX Ozone Season unit begins to combust fossil fuel or to... date on which it both combusts fossil fuel and serves such generator. (b) Any unit in a State (and...

40 CFR 97.204 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-07-01

...: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine serving... unit begins to combust fossil fuel or to serve a generator with nameplate capacity of more than 25 MWe... this section on the first date on which it both combusts fossil fuel and serves such generator. (b) The...

40 CFR 97.204 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

...: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine serving... unit begins to combust fossil fuel or to serve a generator with nameplate capacity of more than 25 MWe... this section on the first date on which it both combusts fossil fuel and serves such generator. (b) The...

40 CFR 97.104 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

...: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine serving... unit begins to combust fossil fuel or to serve a generator with nameplate capacity of more than 25 MWe... this section on the first date on which it both combusts fossil fuel and serves such generator. (b) The...

40 CFR 97.104 - Applicability

Code of Federal Regulations, 2012 CFR

2012-07-01

...: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine serving... unit begins to combust fossil fuel or to serve a generator with nameplate capacity of more than 25 MWe... this section on the first date on which it both combusts fossil fuel and serves such generator. (b) The...

40 CFR 97.404 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

... subpart: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine... paragraph (a)(1) of this section, is not a TR NOX Annual unit begins to combust fossil fuel or to serve a... both combusts fossil fuel and serves such generator. (b) Any unit in a State (and Indian country within...

40 CFR 97.204 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

...: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine serving... unit begins to combust fossil fuel or to serve a generator with nameplate capacity of more than 25 MWe... this section on the first date on which it both combusts fossil fuel and serves such generator. (b) The...

40 CFR 97.104 - Applicability

Code of Federal Regulations, 2010 CFR

2010-07-01

...: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine serving... unit begins to combust fossil fuel or to serve a generator with nameplate capacity of more than 25 MWe... this section on the first date on which it both combusts fossil fuel and serves such generator. (b) The...

40 CFR 97.204 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

...: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine serving... unit begins to combust fossil fuel or to serve a generator with nameplate capacity of more than 25 MWe... this section on the first date on which it both combusts fossil fuel and serves such generator. (b) The...

40 CFR 97.204 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-07-01

...: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine serving... unit begins to combust fossil fuel or to serve a generator with nameplate capacity of more than 25 MWe... this section on the first date on which it both combusts fossil fuel and serves such generator. (b) The...

40 CFR 97.404 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-07-01

... subpart: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine... paragraph (a)(1) of this section, is not a TR NOX Annual unit begins to combust fossil fuel or to serve a... both combusts fossil fuel and serves such generator. (b) Any unit in a State (and Indian country within...

40 CFR 97.104 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

...: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine serving... unit begins to combust fossil fuel or to serve a generator with nameplate capacity of more than 25 MWe... this section on the first date on which it both combusts fossil fuel and serves such generator. (b) The...

40 CFR 97.404 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

... subpart: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine... paragraph (a)(1) of this section, is not a TR NOX Annual unit begins to combust fossil fuel or to serve a... both combusts fossil fuel and serves such generator. (b) Any unit in a State (and Indian country within...

40 CFR 97.504 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-07-01

... subpart: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine... paragraph (a)(1) of this section, is not a TR NOX Ozone Season unit begins to combust fossil fuel or to... date on which it both combusts fossil fuel and serves such generator. (b) Any unit in a State (and...

40 CFR 97.104 - Applicability

Code of Federal Regulations, 2011 CFR

2011-07-01

...: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine serving... unit begins to combust fossil fuel or to serve a generator with nameplate capacity of more than 25 MWe... this section on the first date on which it both combusts fossil fuel and serves such generator. (b) The...

A Nonlinear Model for Fuel Atomization in Spray Combustion

NASA Technical Reports Server (NTRS)

Liu, Nan-Suey (Technical Monitor); Ibrahim, Essam A.; Sree, Dave

2003-01-01

Most gas turbine combustion codes rely on ad-hoc statistical assumptions regarding the outcome of fuel atomization processes. The modeling effort proposed in this project is aimed at developing a realistic model to produce accurate predictions of fuel atomization parameters. The model involves application of the nonlinear stability theory to analyze the instability and subsequent disintegration of the liquid fuel sheet that is produced by fuel injection nozzles in gas turbine combustors. The fuel sheet is atomized into a multiplicity of small drops of large surface area to volume ratio to enhance the evaporation rate and combustion performance. The proposed model will effect predictions of fuel sheet atomization parameters such as drop size, velocity, and orientation as well as sheet penetration depth, breakup time and thickness. These parameters are essential for combustion simulation codes to perform a controlled and optimized design of gas turbine fuel injectors. Optimizing fuel injection processes is crucial to improving combustion efficiency and hence reducing fuel consumption and pollutants emissions.

Research on the influence of ozone dissolved in the fuel-water emulsion on the parameters of the CI engine

NASA Astrophysics Data System (ADS)

Wojs, M. K.; Orliński, P.; Kamela, W.; Kruczyński, P.

2016-09-01

The article presents the results of empirical research on the impact of ozone dissolved in fuel-water emulsion on combustion process and concentration of toxic substances in CI engine. The effect of ozone presence in the emulsion and its influence on main engine characteristics (power, torque, fuel consumption) and selected parameters that characterize combustion process (levels of pressures and temperatures in combustion chamber, period of combustion delay, heat release rate, fuel burnt rate) is shown. The change in concentration of toxic components in exhausts gases when engine is fueled with ozonized emulsion was also identified. The empirical research and their analysis showed significant differences in the combustion process when fuel-water emulsion containing ozone was used. These differences include: increased power and efficiency of the engine that are accompanied by reduction in time of combustion delay and beneficial effects of ozone on HC, PM, CO and NOX emissions.

Fuel processor for fuel cell power system. [Conversion of methanol into hydrogen

DOEpatents

Vanderborgh, N.E.; Springer, T.E.; Huff, J.R.

1986-01-28

A catalytic organic fuel processing apparatus, which can be used in a fuel cell power system, contains within a housing a catalyst chamber, a variable speed fan, and a combustion chamber. Vaporized organic fuel is circulated by the fan past the combustion chamber with which it is in indirect heat exchange relationship. The heated vaporized organic fuel enters a catalyst bed where it is converted into a desired product such as hydrogen needed to power the fuel cell. During periods of high demand, air is injected upstream of the combustion chamber and organic fuel injection means to burn with some of the organic fuel on the outside of the combustion chamber, and thus be in direct heat exchange relation with the organic fuel going into the catalyst bed.

Flexible ceramic gasket for SOFC generator

DOEpatents

Zafred, Paolo [Murrysville, PA; Prevish, Thomas [Trafford, PA

2009-02-03

A solid oxide fuel cell generator (10) contains stacks of hollow axially elongated fuel cells (36) having an open top end (37), an oxidant inlet plenum (52), a feed fuel plenum (11), a combustion chamber (94) for combusting reacted oxidant/spent fuel; and, optionally, a fuel recirculation chamber (106) below the combustion chamber (94), where the fuel recirculation chamber (94) is in part defined by semi-porous fuel cell positioning gasket (108), all within an outer generator enclosure (8), wherein the fuel cell gasket (108) has a laminate structure comprising at least a compliant fibrous mat support layer and a strong, yet flexible woven layer, which may contain catalytic particles facing the combustion chamber, where the catalyst, if used, is effective to further oxidize exhaust fuel and protect the open top end (37) of the fuel cells.

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.

Computational Analysis of the Combustion Processes in an Axisymmetric, RBCC Flowpath

NASA Technical Reports Server (NTRS)

Steffen, Christopher J., Jr.; Yungster, Shaye

2001-01-01

Computational fluid dynamic simulations have been used to study the combustion processes within an axisymmetric, RBCC flowpath. Two distinct operating modes have been analyzed to date, including the independent ramjet stream (IRS) cycle and the supersonic combustion ramjet (scramJet) cycle. The IRS cycle investigation examined the influence of fuel-air ratio, fuel distribution, and rocket chamber pressure upon the combustion physics and thermal choke characteristics. Results indicate that adjustment of the amount and radial distribution of fuel can control the thermal choke point. The secondary massflow rate was very sensitive to the fuel-air ratio and the rocket chamber pressure. The scramjet investigation examined the influence of fuel-air ratio and fuel injection schedule upon combustion performance estimates. An analysis of the mesh-dependence of these calculations was presented. Jet penetration data was extracted from the three-dimensional simulations and compared favorably with experimental correlations of similar flows. Results indicate that combustion efficiency was very sensitive to the fuel schedule.

Advanced Chemical Modeling for Turbulent Combustion Simulations

DTIC Science & Technology

2012-05-03

premixed combustion. The chemistry work proposes a method for defining jet fuel surrogates, describes how different sub- mechanisms can be incorporated...Chemical Modeling For Turbulent Combustion Simulations Final Report submitted by: Heinz Pitsch (PI) Stanford University Mechanical Engineering Flow Physics...predict the combustion characteristics of fuel oxidation and pollutant emissions from engines . The relevant fuel chemistry must be accurately modeled

40 CFR 60.4360 - How do I determine the total sulfur content of the turbine's combustion fuel?

Code of Federal Regulations, 2011 CFR

2011-07-01

... content of the turbine's combustion fuel? 60.4360 Section 60.4360 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Monitoring § 60.4360 How do I determine the total sulfur content of the turbine's combustion fuel? You must monitor the total sulfur content of the...

40 CFR 60.4360 - How do I determine the total sulfur content of the turbine's combustion fuel?

Code of Federal Regulations, 2010 CFR

2010-07-01

... content of the turbine's combustion fuel? 60.4360 Section 60.4360 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Monitoring § 60.4360 How do I determine the total sulfur content of the turbine's combustion fuel? You must monitor the total sulfur content of the...

40 CFR 60.4360 - How do I determine the total sulfur content of the turbine's combustion fuel?

Code of Federal Regulations, 2013 CFR

2013-07-01

... content of the turbine's combustion fuel? 60.4360 Section 60.4360 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Monitoring § 60.4360 How do I determine the total sulfur content of the turbine's combustion fuel? You must monitor the total sulfur content of the...

40 CFR 60.4360 - How do I determine the total sulfur content of the turbine's combustion fuel?

Code of Federal Regulations, 2014 CFR

2014-07-01

... content of the turbine's combustion fuel? 60.4360 Section 60.4360 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Monitoring § 60.4360 How do I determine the total sulfur content of the turbine's combustion fuel? You must monitor the total sulfur content of the...

40 CFR 60.4360 - How do I determine the total sulfur content of the turbine's combustion fuel?

Code of Federal Regulations, 2012 CFR

2012-07-01

... content of the turbine's combustion fuel? 60.4360 Section 60.4360 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Monitoring § 60.4360 How do I determine the total sulfur content of the turbine's combustion fuel? You must monitor the total sulfur content of the...

Gravitational Influences on Flame Propagation through Non-Uniform, Premixed Gas Systems

NASA Technical Reports Server (NTRS)

Miller, Fletcher J.; Easton, John; Ross, Howard D.; Marchese, Anthony; Perry, David; Kulis, Michael

2001-01-01

Flame propagation through non-uniformly premixed (or layered) gases has importance both in useful combustion systems and in unintentional fires. As summarized previously, non-uniform premixed gas combustion receives scant attention compared to the more usual limiting cases of diffusion or uniformly premixed flames, especially regarding the role gravity plays. This paper summarizes our progress on furthering the knowledge of layered combustion, in which a fuel concentration gradient exists normal to the direction of flame spread. We present experimental and numerical results for flame spread through propanol-air layers formed near the flash point temperature (25 C) or near the stoichiometric temperature (33 C). Both the model and experimental results show that the removal of gravity results in a faster spreading flame, by as much as 80% depending on conditions. This is exactly the opposite effect as that predicted by an earlier model reported. We also found that having a gallery lid results in faster flame spread, an effect more pronounced at normal gravity, demonstrating the importance of enclosure geometry. Also reported here is the beginning of our spectroscopic measurements of fuel vapor.

Fuel Vapor Pressures and the Relation of Vapor Pressure to the Preparation of Fuel for Combustion in Fuel Injection Engines

NASA Technical Reports Server (NTRS)

Joachim, William F; Rothrock, A M

1930-01-01

This investigation on the vapor pressure of fuels was conducted in connection with the general research on combustion in fuel injection engines. The purpose of the investigation was to study the effects of high temperatures such as exist during the first stages of injection on the vapor pressures of several fuels and certain fuel mixtures, and the relation of these vapor pressures to the preparation of the fuel for combustion in high-speed fuel injection engines.

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2

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

George Rizeq; Janice West; Arnaldo Frydman

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the thermodynamic efficiency and environmental impact performance of fossil fuel utilization. General Electric Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Advanced Gasification-Combustion (AGC) concept to produce H{sub 2} and sequestration-ready CO{sub 2} from solid fuels. The AGC module offers potential for reduced cost and increased energy efficiency relative to conventional gasification and combustion systems. GE EER was awarded a Vision-21 program from U.S. DOE NETL tomore » develop the AGC technology. Work on this three-year program started on October 1, 2000. The project team includes GE EER, California Energy Commission, Southern Illinois University at Carbondale, and T. R. Miles, Technical Consultants, Inc. In the AGC technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on preliminary modeling work in the first quarter of this program, has an estimated process efficiency of approximately 67% based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal. The three-year R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the AGC concept. This is the fifth quarterly technical progress report for the Vision-21 AGC program supported by U.S. DOE NETL (Contract: DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting October 1, 2001 and ending December 31, 2001. The report includes an introduction summarizing the AGC concept, main program tasks, and program objectives; it also provides a summary of program activities covering program management and progress in tasks including lab- and bench-scale experimental testing, pilot-scale design, and economic studies.« less

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2

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

George Rizeq; Janice West; Arnaldo Frydman

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the thermodynamic efficiency and environmental impact performance of fossil fuel utilization. General Electric Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Advanced Gasification-Combustion (AGC) concept to produce H{sub 2} and sequestration-ready CO{sub 2} from solid fuels. The AGC module offers potential for reduced cost and increased energy efficiency relative to conventional gasification and combustion systems. GE EER was awarded a Vision-21 program from U.S. DOE NETL tomore » develop the AGC technology. Work on this three-year program started on October 1, 2000. The project team includes GE EER, California Energy Commission, Southern Illinois University at Carbondale, and T. R. Miles, Technical Consultants, Inc. In the AGC technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on preliminary modeling work in the first quarter of this program, has an estimated process efficiency of approximately 67% based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal. The three-year R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the AGC concept. This is the seventh quarterly technical progress report for the Vision-21 AGC program supported by U.S. DOE NETL (Contract: DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting April 1, 2002 and ending June 30, 2002. The report includes an introduction summarizing the AGC concept, main program tasks, and program objectives; it also provides a summary of program activities covering program management and progress in tasks including lab-/bench-scale experimental testing and pilot-scale design.« less

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2

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

George Rizeq; Janice West; Arnaldo Frydman

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the thermodynamic efficiency and environmental impact performance of fossil fuel utilization. GE Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Advanced Gasification-Combustion (AGC) concept to produce H{sub 2} and sequestration-ready CO{sub 2} from solid fuels. The AGC module offers potential for reduced cost and increased energy efficiency relative to conventional gasification and combustion systems. GE EER was awarded a Vision 21 program from U.S. DOE NETL tomore » develop the AGC technology. Work on this three-year program started on October 1, 2000. The project team includes GE EER, California Energy Commission, Southern Illinois University at Carbondale, and T. R. Miles, Technical Consultants, Inc. In the AGC technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on preliminary modeling work, has an estimated process efficiency of approximately 67% based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal. The three-year R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the AGC concept. This is the second annual technical progress report for the Vision 21 AGC program supported by U.S. DOE NETL (Contract No. DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting October 1, 2001 and ending September 30, 2002. The report includes an introduction summarizing the AGC concept, main program tasks, and program objectives; it also provides a summary of program activities and accomplishments covering progress in tasks including lab- and bench-scale experimental testing, pilot-scale design and assembly, and program management.« less

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2

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

George Rizeq; Janice West; Arnaldo Frydman

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the thermodynamic efficiency and environmental impact performance of fossil fuel utilization. General Electric Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Advanced Gasification-Combustion (AGC) concept to produce H{sub 2} and sequestration-ready CO{sub 2} from solid fuels. The AGC module offers potential for reduced cost and increased energy efficiency relative to conventional gasification and combustion systems. GE EER was awarded a Vision-21 program from U.S. DOE NETL tomore » develop the AGC technology. Work on this three-year program started on October 1, 2000. The project team includes GE EER, California Energy Commission, Southern Illinois University at Carbondale, and T. R. Miles, Technical Consultants, Inc. In the AGC technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on preliminary modeling work in the first quarter of this program, has an estimated process efficiency of approximately 67% based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal. The three-year R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the AGC concept. This is the third quarterly technical progress report for the Vision-21 AGC program supported by U.S. DOE NETL (Contract: DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting April 1, 2001 and ending June 30, 2001. The report includes an introduction summarizing the AGC concept, main program tasks, objectives of this program, and provides a summary of program activities covering program management and progress in first year tasks including lab- and bench-scale design, facilities preparation, and engineering studies.« less

Advanced Gas Turbine (AGT) powertrain system development for automotive applications

NASA Technical Reports Server (NTRS)

1980-01-01

Progress in the development of a gas turbine engine to improve fuel economy, reduce gaseous emissions and particulate levels, and compatible with a variety of alternate fuels is reported. The powertrain is designated AGT101 and consists of a regenerated single shaft gas turbine engine, a split differential gearbox and a Ford Automatic Overdrive production transmission. The powertrain is controlled by an electronic digital microprocessor and associated actuators, instrumentation, and sensors. Standard automotive accessories are driven by engine power provided by an accessory pad on the gearbox. Component/subsystem development progress is reported in the following areas: compressor, turbine, combustion system, regenerator, gearbox/transmission, structures, ceramic components, foil gas bearing, bearings and seals, rotor dynamics, and controls and accessories.

National Jet Fuels Combustion Program – Area #3 : Advanced Combustion Tests

DOT National Transportation Integrated Search

2017-12-31

The goal of this study is to develop, conduct, and analyze advanced laser and optical measurements in the experimental combustors developed under ASCENT National Fuel Combustion Program to measure sensitivity to fuel properties. We conducted advanced...

40 CFR 97.604 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

... subpart: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine... paragraph (a)(1) of this section, is not a TR SO2 Group 1 unit begins to combust fossil fuel or to serve a... both combusts fossil fuel and serves such generator. (b) Any unit in a State (and Indian country within...

40 CFR 97.604 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

... subpart: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine... paragraph (a)(1) of this section, is not a TR SO2 Group 1 unit begins to combust fossil fuel or to serve a... both combusts fossil fuel and serves such generator. (b) Any unit in a State (and Indian country within...

40 CFR 97.604 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-07-01

... subpart: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine... paragraph (a)(1) of this section, is not a TR SO2 Group 1 unit begins to combust fossil fuel or to serve a... both combusts fossil fuel and serves such generator. (b) Any unit in a State (and Indian country within...

40 CFR 97.704 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-07-01

... subpart: Any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine... paragraph (a)(1) of this section, is not a TR SO2 Group 2 unit begins to combust fossil fuel or to serve a... both combusts fossil fuel and serves such generator. (b) Any unit in a State (and Indian country within...

40 CFR 97.704 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

... subpart: Any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine... paragraph (a)(1) of this section, is not a TR SO2 Group 2 unit begins to combust fossil fuel or to serve a... both combusts fossil fuel and serves such generator. (b) Any unit in a State (and Indian country within...

40 CFR 97.704 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

... subpart: Any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine... paragraph (a)(1) of this section, is not a TR SO2 Group 2 unit begins to combust fossil fuel or to serve a... both combusts fossil fuel and serves such generator. (b) Any unit in a State (and Indian country within...

Progress Towards Environmentally Friendlier Automobiles

NASA Astrophysics Data System (ADS)

Culver, Robert

2002-03-01

The United States Council for Automotive Research (USCAR), the umbrella organization of DaimlerChrysler, Ford, and General Motors, has been conducting pre-competitive research in the areas of improving fuel efficiency and reducing tailpipe emissions. One of the major collaborations is with the U.S. Government in the Partnership for a New Generation of Vehicles (PNGV). The USCAR/PNGV technology portfolio includes lightweight materials, improved conventional internal combustion engine systems, electric traction and hybridization, and fuel cells. Significant progress has been made in developing these technologies and marketing them through today’s vehicles. New product announcements of hybrids demonstrate the commitment of the industry to bring the new technologies to market. Yet, breakthroughs and innovations will be required before many of the technologies can fully realize their promise. In addition, government policies and programs will be required to promote market acceptance and ensure an infrastructure to provide new fuels.

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

Kevin C. Galbreath; Donald L. Toman; Christopher J. Zygarlicke

Petroleum coke, a byproduct of the petroleum-refining process, is an attractive primary or supplemental fuel for power production primarily because of a progressive and predictable increase in the production volumes of petroleum coke (1, 2). Petroleum coke is most commonly blended with coal in proportions suitable to meet sulfur emission compliance. Petroleum coke is generally less reactive than coal; therefore, the cofiring of petroleum coke with coal typically improves ignition, flame stability, and carbon loss relative to the combustion of petroleum coke alone. Although petroleum coke is a desirable fuel for producing relatively inexpensive electrical power, concerns about the effectsmore » of petroleum coke blending on combustion and pollution control processes exist in the coal-fired utility industry (3). The Energy & Environmental Research Center (EERC) completed a 2-year technical assessment of petroleum coke as a supplemental fuel. A survey questionnaire was sent to seven electric utility companies that are currently cofiring coal and petroleum coke in an effort to solicit specific suggestions on research needs and fuel selections. An example of the letter and survey questionnaire is presented in Appendix A. Interest was expressed by most utilities in evaluating the effects of petroleum coke blending on grindability, combustion reactivity, fouling, slagging, and fly ash emissions control. Unexpectedly, concern over corrosion was not expressed by the utilities contacted. Although all seven utilities responded to the question, only two utilities, Northern States Power Company (NSP) and Ameren, sent fuels to the EERC for evaluation. Both utilities sent subbituminous coals from the Power River Basin and petroleum shot coke samples. Petroleum shot coke is produced unintentionally during operational upsets in the petroleum refining process. This report evaluates the effects of petroleum shot coke blending on grindability, fuel reactivity, fouling/slagging, and electrostatic precipitator (ESP) fly ash collection efficiency.« less

Experimental study of combustion in hydrogen peroxide hybrid rockets

NASA Astrophysics Data System (ADS)

Wernimont, Eric John

Combustion behavior in a hydrogen peroxide oxidized hybrid rocket motor is investigated with a series of experiments. Hybrid chemical rocket propulsion is presently of interest due to reduced system complexity compared to classical chemical propulsion systems. Reduced system complexity, by use of a storable oxidizer and a hybrid configuration, is expected to reduce propulsive costs. The fuel in this study is polyethylene which has the potential of continuous manufacture leading to further reduced system costs. The study investigated parameters of interest for nominal design of a full scale hydrogen peroxide oxidized hybrid rocket. Amongst these parameters is the influence of chamber pressure, mass flux, fuel molecular weight and fuel density on fuel regression rate. Effects of chamber pressure and aft combustion length on combustion efficiency and non-acoustic combustion oscillations are also examined. The fuel regression behavior is found to be strongly influenced by both chamber pressure and mass flux. Combustion efficiencies in the upper 90% range are attained by simple changes to the aft combustion chamber length as well as increased combustion pressure. Fuel burning surface is found to be influenced by the density of the polyethylene polymer as well as molecular weight. The combustion is observed to be exceptionally smooth (oscillations less than 5% zero-to-peak of mean) in all motors tested in this program. Tests using both a single port fuel gain and a novel radial flow hybrid are also performed.

Flame tube parametric studies for control of fuel bound nitrogen using rich-lean two-stage combustion

NASA Technical Reports Server (NTRS)

Schultz, D. F.; Wolfbrandt, G.

1980-01-01

An experimental parametric study of rich-lean two-stage combustion in a flame tube is described and approaches for minimizing the conversion of fuel-bound nitrogen to nitrogen oxides in a premixed, homogeneous combustion system are evaluated. Air at 672 K and 0.48 MPa was premixed with fuel blends of propane, toluene, and pyridine at primary equivalence ratios ranging from 0.5 to 2.0 and secondary equivalence ratios of 0.5 to 0.7. Distillates of SRC-II, a coal syncrude, were also tested. The blended fuels were proportioned to vary fuel hydrogen composition from 9.0 to 18.3 weight percent and fuel nitrogen composition from zero to 1.5 weight percent. Rich-lean combustion proved effective in reducing fuel nitrogen to NO sub x conversion; conversion rates up to 10 times lower than those normally produced by single-stage combustion were achieved. The optimum primary equivalence ratio, where the least NO sub x was produced and combustion efficiency was acceptable, shifted between 1.4 and 1.7 with changes in fuel nitrogen content and fuel hydrogen content. Increasing levels of fuel nitrogen content lowered the conversion rate, but not enough to avoid higher NO sub x emissions as fuel nitrogen increased.

Magnetic properties of Li0.5Fe2.5O4 nanoparticles synthesized by solution combustion method

NASA Astrophysics Data System (ADS)

Naderi, P.; Masoudpanah, S. M.; Alamolhoda, S.

2017-11-01

In this research, lithium ferrite (Li0.5Fe2.5O4) powders were prepared by solution combustion synthesis using glycine and citric acid fuels at various fuel to oxidant molar ratios ( ϕ = 0.5, 1 and 1.5). Phase evolution, microstructure and magnetic properties were characterized by thermal analysis, infrared spectroscopy, X-ray diffraction, electron microscopy and vibration sample magnetometry techniques. Single-phase lithium ferrite was formed using glycine fuel at all fuel to oxidant ratios, while some impurity α-Fe2O3 phase was appeared using citric acid fuel at ϕ ≥ 1. The phase and crystallite size mainly depended on the combustion rate through fuel type. Bulky microstructure observed for citric acid fuel was attributed to its slow combustion, while the fast exhausting of gaseous products led to spongy microstructure for glycine fuel. The highest saturation magnetization of 59.3 emu/g and coercivity of 157 Oe were achieved for the as-combusted powders using glycine fuel.

Solution combustion synthesis of strontium aluminate, SrAl2O4, powders: single-fuel versus fuel-mixture approach.

PubMed

Ianoş, Robert; Istratie, Roxana; Păcurariu, Cornelia; Lazău, Radu

2016-01-14

The solution combustion synthesis of strontium aluminate, SrAl2O4, via the classic single-fuel approach and the modern fuel-mixture approach was investigated in relation to the synthesis conditions, powder properties and thermodynamic aspects. The single-fuel approach (urea or glycine) did not yield SrAl2O4 directly from the combustion reaction. The absence of SrAl2O4 was explained by the low amount of energy released during the combustion process, in spite of the highly negative values of the standard enthalpy of reaction and standard Gibbs free energy. In the case of single-fuel recipes, the maximum combustion temperatures measured by thermal imaging (482 °C - urea, 941 °C - glycine) were much lower than the calculated adiabatic temperatures (1864 °C - urea, 2147 °C - glycine). The fuel-mixture approach (urea and glycine) clearly represented a better option, since (α,β)-SrAl2O4 resulted directly from the combustion reaction. The maximum combustion temperature measured in the case of a urea and glycine fuel mixture was the highest one (1559 °C), which was relatively close to the calculated adiabatic temperature (1930 °C). The addition of a small amount of flux, such as H3BO3, enabled the formation of pure α-SrAl2O4 directly from the combustion reaction.

Distributed ignition method and apparatus for a combustion engine

DOEpatents

Willi, Martin L.; Bailey, Brett M.; Fiveland, Scott B.; Gong, Weidong

2006-03-07

A method and apparatus for operating an internal combustion engine is provided. The method comprises the steps of introducing a primary fuel into a main combustion chamber of the engine, introducing a pilot fuel into the main combustion chamber of the engine, determining an operating load of the engine, determining a desired spark plug ignition timing based on the engine operating load, and igniting the primary fuel and pilot fuel with a spark plug at the desired spark plug ignition timing. The method is characterized in that the octane number of the pilot fuel is lower than the octane number of the primary fuel.

Numerical analysis of combustion characteristics of hybrid rocket motor with multi-section swirl injection

NASA Astrophysics Data System (ADS)

Li, Chengen; Cai, Guobiao; Tian, Hui

2016-06-01

This paper is aimed to analyse the combustion characteristics of hybrid rocket motor with multi-section swirl injection by simulating the combustion flow field. Numerical combustion flow field and combustion performance parameters are obtained through three-dimensional numerical simulations based on a steady numerical model proposed in this paper. The hybrid rocket motor adopts 98% hydrogen peroxide and polyethylene as the propellants. Multiple injection sections are set along the axis of the solid fuel grain, and the oxidizer enters the combustion chamber by means of tangential injection via the injector ports in the injection sections. Simulation results indicate that the combustion flow field structure of the hybrid rocket motor could be improved by multi-section swirl injection method. The transformation of the combustion flow field can greatly increase the fuel regression rate and the combustion efficiency. The average fuel regression rate of the motor with multi-section swirl injection is improved by 8.37 times compared with that of the motor with conventional head-end irrotational injection. The combustion efficiency is increased to 95.73%. Besides, the simulation results also indicate that (1) the additional injection sections can increase the fuel regression rate and the combustion efficiency; (2) the upstream offset of the injection sections reduces the combustion efficiency; and (3) the fuel regression rate and the combustion efficiency decrease with the reduction of the number of injector ports in each injection section.

Thermophysics Characterization of Kerosene Combustion

NASA Technical Reports Server (NTRS)

Wang, Ten-See

2001-01-01

A one-formula surrogate fuel formulation and its quasi-global combustion kinetics model are developed to support the design of injectors and thrust chambers of kerosene-fueled rocket engines. This surrogate fuel model depicts a fuel blend that properly represents the general physical and chemical properties of kerosene. The accompanying gaseous-phase thermodynamics of the surrogate fuel is anchored with the heat of formation of kerosene and verified by comparing a series of one-dimensional rocket thrust chamber calculations. The quasi-global combustion kinetics model consists of several global steps for parent fuel decomposition, soot formation, and soot oxidation and a detailed wet-CO mechanism to complete the combustion process. The final thermophysics formulations are incorporated with a computational fluid dynamics model for prediction of the combustion efficiency of an unielement, tripropellant combustor and the radiation of a kerosene-fueled thruster plume. The model predictions agreed reasonably well with those of the tests.

Spray combustion modeling

NASA Technical Reports Server (NTRS)

Bellan, J.

1997-01-01

Concern over the future availability of high quality liquid fuels or use in furnaces and boilers prompted the U. S. Department of Energy (DOE) to consider alternate fuels as replacements for the high grade liquid fuels used in the 1970's and 1980's. Alternate fuels were defined to be combinations of a large percentage of viscous, low volatility fuels resulting from the low end of distillation mixed with a small percentage of relatively low viscosity, high volatility fuels yielded by the high end of distillation. The addition of high volatility fuels was meant to promote desirable characteristics to a fuel that would otherwise be difficult to atomize and burn and whose combustion would yield a high amount of pollutants. Several questions thus needed to be answered before alternate fuels became commercially viable. These questions were related to fuel atomization, evaporation, ignition, combustion and pollutant formation. This final report describes the results of the most significant studies on ignition and combustion of alternative fuels.

Oxygen enhanced switching to combustion of lower rank fuels

DOEpatents

Kobayashi, Hisashi; Bool, III, Lawrence E.; Wu, Kuang Tsai

2004-03-02

A furnace that combusts fuel, such as coal, of a given minimum energy content to obtain a stated minimum amount of energy per unit of time is enabled to combust fuel having a lower energy content, while still obtaining at least the stated minimum energy generation rate, by replacing a small amount of the combustion air fed to the furnace by oxygen. The replacement of oxygen for combustion air also provides reduction in the generation of NOx.

40 CFR 98.192 - GHGs to report.

Code of Federal Regulations, 2011 CFR

2011-07-01

... emissions from lime kilns. (b) CO2 emissions from fuel combustion at lime kilns. (c) N2O and CH4 emissions... (General Stationary Fuel Combustion Sources). (d) CO2, N2O, and CH4 emissions from each stationary fuel... (General Stationary Fuel Combustion Sources). (e) CO2 collected and transferred off site under 40 CFR part...

40 CFR 98.192 - GHGs to report.

Code of Federal Regulations, 2014 CFR

2014-07-01

... emissions from lime kilns. (b) CO2 emissions from fuel combustion at lime kilns. (c) N2O and CH4 emissions... (General Stationary Fuel Combustion Sources). (d) CO2, N2O, and CH4 emissions from each stationary fuel... (General Stationary Fuel Combustion Sources). (e) CO2 collected and transferred off site under 40 CFR part...

40 CFR 98.192 - GHGs to report.

Code of Federal Regulations, 2012 CFR

2012-07-01

... emissions from lime kilns. (b) CO2 emissions from fuel combustion at lime kilns. (c) N2O and CH4 emissions... (General Stationary Fuel Combustion Sources). (d) CO2, N2O, and CH4 emissions from each stationary fuel... (General Stationary Fuel Combustion Sources). (e) CO2 collected and transferred off site under 40 CFR part...

40 CFR 98.192 - GHGs to report.

Code of Federal Regulations, 2013 CFR

2013-07-01

... emissions from lime kilns. (b) CO2 emissions from fuel combustion at lime kilns. (c) N2O and CH4 emissions... (General Stationary Fuel Combustion Sources). (d) CO2, N2O, and CH4 emissions from each stationary fuel... (General Stationary Fuel Combustion Sources). (e) CO2 collected and transferred off site under 40 CFR part...

Effects of fuel cetane number on the structure of diesel spray combustion: An accelerated Eulerian stochastic fields method

NASA Astrophysics Data System (ADS)

Jangi, Mehdi; Lucchini, Tommaso; Gong, Cheng; Bai, Xue-Song

2015-09-01

An Eulerian stochastic fields (ESF) method accelerated with the chemistry coordinate mapping (CCM) approach for modelling spray combustion is formulated, and applied to model diesel combustion in a constant volume vessel. In ESF-CCM, the thermodynamic states of the discretised stochastic fields are mapped into a low-dimensional phase space. Integration of the chemical stiff ODEs is performed in the phase space and the results are mapped back to the physical domain. After validating the ESF-CCM, the method is used to investigate the effects of fuel cetane number on the structure of diesel spray combustion. It is shown that, depending of the fuel cetane number, liftoff length is varied, which can lead to a change in combustion mode from classical diesel spray combustion to fuel-lean premixed burned combustion. Spray combustion with a shorter liftoff length exhibits the characteristics of the classical conceptual diesel combustion model proposed by Dec in 1997 (http://dx.doi.org/10.4271/970873), whereas in a case with a lower cetane number the liftoff length is much larger and the spray combustion probably occurs in a fuel-lean-premixed mode of combustion. Nevertheless, the transport budget at the liftoff location shows that stabilisation at all cetane numbers is governed primarily by the auto-ignition process.

Combustion performance and scale effect from N2O/HTPB hybrid rocket motor simulations

NASA Astrophysics Data System (ADS)

Shan, Fanli; Hou, Lingyun; Piao, Ying

2013-04-01

HRM code for the simulation of N2O/HTPB hybrid rocket motor operation and scale effect analysis has been developed. This code can be used to calculate motor thrust and distributions of physical properties inside the combustion chamber and nozzle during the operational phase by solving the unsteady Navier-Stokes equations using a corrected compressible difference scheme and a two-step, five species combustion model. A dynamic fuel surface regression technique and a two-step calculation method together with the gas-solid coupling are applied in the calculation of fuel regression and the determination of combustion chamber wall profile as fuel regresses. Both the calculated motor thrust from start-up to shut-down mode and the combustion chamber wall profile after motor operation are in good agreements with experimental data. The fuel regression rate equation and the relation between fuel regression rate and axial distance have been derived. Analysis of results suggests improvements in combustion performance to the current hybrid rocket motor design and explains scale effects in the variation of fuel regression rate with combustion chamber diameter.

Low-cost high-efficiency GDCI engines for low octane fuels

DOEpatents

Kolodziej, Christopher P.; Sellnau, Mark C.

2018-01-09

A GDCI engine has a piston arranged within a cylinder to provide a combustion chamber. According to one embodiment, the GDCI engine operates using a method that includes the steps of supplying a hydrocarbon fuel to the combustion chamber with a research octane number in the range of about 30-65. The hydrocarbon fuel is injected in completely stratified, multiple fuel injections before a start of combustion and supplying a naturally aspirated air charge to the combustion chamber.

DNS of High Pressure Supercritical Combustion

NASA Astrophysics Data System (ADS)

Chong, Shao Teng; Raman, Venkatramanan

2016-11-01

Supercritical flows have always been important to rocket motors, and more recently to aircraft engines and stationary gas turbines. The purpose of the present study is to understand effects of differential diffusion on reacting scalars using supercritical isotropic turbulence. Focus is on fuel and oxidant reacting in the transcritical region where density, heat capacity and transport properties are highly sensitive to variations in temperature and pressure. Reynolds and Damkohler number vary as a result and although it is common to neglect differential diffusion effects if Re is sufficiently large, this large variation in temperature with heat release can accentuate molecular transport differences. Direct numerical simulations (DNS) for one step chemistry reaction between fuel and oxidizer are used to examine the differential diffusion effects. A key issue investigated in this paper is if the flamelet progress variable approach, where the Lewis number is usually assumed to be unity and constant for all species, can be accurately applied to simulate supercritical combustion.

Fuel combustion exhibiting low NO.sub.x and CO levels

DOEpatents

Keller, Jay O.; Bramlette, T. Tazwell; Barr, Pamela K.

1996-01-01

Method and apparatus for safely combusting a fuel in such manner that very low levels of NO.sub.x and CO are produced. The apparatus comprises an inlet line (12) containing a fuel and an inlet line (18) containing an oxidant. Coupled to the fuel line (12) and to the oxidant line (18) is a mixing means (11,29,33,40) for thoroughly mixing the fuel and the oxidant without combusting them. Coupled to the mixing means (11,29,33,40) is a means for injecting the mixed fuel and oxidant, in the form of a large-scale fluid dynamic structure (8), into a combustion region (2). Coupled to the combustion region (2) is a means (1,29,33) for producing a periodic flow field within the combustion region (2) to mix the fuel and the oxidant with ambient gases in order to lower the temperature of combustion. The means for producing a periodic flow field can be a pulse combustor (1), a rotating band (29), or a rotating cylinder (33) within an acoustic chamber (32) positioned upstream or downstream of the region (2) of combustion. The mixing means can be a one-way flapper valve (11); a rotating cylinder (33); a rotating band (29) having slots (31) that expose open ends (20,21) of said fuel inlet line (12) and said oxidant inlet line (18) simultaneously; or a set of coaxial fuel annuli (43) and oxidizer annuli (42,44). The means for producing a periodic flow field (1, 29, 33) may or may not be in communication with an acoustic resonance. When employed, the acoustic resonance may be upstream or downstream of the region of combustion (2).

Flashback detection sensor for lean premix fuel nozzles

DOEpatents

Thornton, Jimmy Dean [Morgantown, WV; Richards, George Alan [Morgantown, WV; Straub, Douglas L [Morgantown, WV; Liese, Eric Arnold [Morgantown, WV; Trader, Jr., John Lee; Fasching, George Edward [Morgantown, WV

2002-08-06

A sensor for detecting the flame occurring during a flashback condition in the fuel nozzle of a lean premix combustion system is presented. The sensor comprises an electrically isolated flashback detection electrode and a guard electrode, both of which generate electrical fields extending to the walls of the combustion chamber and to the walls of the fuel nozzle. The sensor is positioned on the fuel nozzle center body at a location proximate the entrance to the combustion chamber of the gas turbine combustion system. The sensor provides 360.degree. detection of a flashback inside the fuel nozzle, by detecting the current conducted by the flame within a time frame that will prevent damage to the gas turbine combustion system caused by the flashback condition.

Diesel engine experiments with oxygen enrichment, water addition and lower-grade fuel

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

Sekar, R.R.; Marr, W.W.; Cole, R.L.

1990-01-01

The concept of oxygen enriched air applied to reciprocating engines is getting renewed attention in the context of the progress made in the enrichment methods and the tougher emissions regulations imposed on diesel and gasoline engines. An experimental project was completed in which a direct injection diesel engine was tested with intake oxygen levels of 21% -- 35%. Since an earlier study indicated that it is necessary to use a cheaper fuel to make the concept economically attractive, a less refined fuel was included in the test series. Since a major objection to the use of oxygen enriched combustion airmore » had been the increase in NO{sub x} emissions, a method must be found to reduce NO{sub x}. Introduction of water into the engine combustion process was included in the tests for this purpose. Fuel emulsification with water was the means used here even though other methods could also be used. The teat data indicated a large increase in engine power density, slight improvement in thermal efficiency, significant reductions in smoke and particulate emissions and NO{sub x} emissions controllable with the addition of water. 15 refs., 10 figs., 2 tabs.« less

Study on Combustion Oscillation of Premixed Flame with Pilot Fuel at Elevated Pressures

NASA Astrophysics Data System (ADS)

Ohtsuka, Masaya; Yoshida, Shohei; Hirata, Yoshitaka; Kobayashi, Nariyoshi

Acoustically-coupled combustion oscillation is studied for premixed flame with pilot fuel to be used in gas turbine combustors. Premixed gas is passed through swirl vanes and burnt with the centrally injected pilot fuel. The dependencies of pressure, fuel to air ratio, premixed fuel rate, inlet velocity and air temperature on the combustion oscillation are investigated. Two kinds of oscillation modes of ˜100Hz and ˜350Hz are activated according to inlet velocities. Fluctuating pressures are amplified when the premixed fuel rate is over ˜80% at elevated pressures. The fluctuating pressure peak moves to a higher premixed fuel ratio region with increased pressure or fuel to air ratio for the Helmholz type mode. Combustion oscillation occurs when the pilot fuel velocity is changed proportionally with the flame length.

Oxy-fuel combustion with integrated pollution control

DOEpatents

Patrick, Brian R [Chicago, IL; Ochs, Thomas Lilburn [Albany, OR; Summers, Cathy Ann [Albany, OR; Oryshchyn, Danylo B [Philomath, OR; Turner, Paul Chandler [Independence, OR

2012-01-03

An oxygen fueled integrated pollutant removal and combustion system includes a combustion system and an integrated pollutant removal system. The combustion system includes a furnace having at least one burner that is configured to substantially prevent the introduction of air. An oxygen supply supplies oxygen at a predetermine purity greater than 21 percent and a carbon based fuel supply supplies a carbon based fuel. Oxygen and fuel are fed into the furnace in controlled proportion to each other and combustion is controlled to produce a flame temperature in excess of 3000 degrees F. and a flue gas stream containing CO2 and other gases. The flue gas stream is substantially void of non-fuel borne nitrogen containing combustion produced gaseous compounds. The integrated pollutant removal system includes at least one direct contact heat exchanger for bringing the flue gas into intimated contact with a cooling liquid to produce a pollutant-laden liquid stream and a stripped flue gas stream and at least one compressor for receiving and compressing the stripped flue gas stream.

Oscillatory bursting of gel fuel droplets in a reacting environment.

PubMed

Miglani, Ankur; Nandagopalan, Purushothaman; John, Jerin; Baek, Seung Wook

2017-06-12

Understanding the combustion behavior of gel fuel droplets is pivotal for enhancing burn rates, lowering ignition delay and improving the operational performance of next-generation propulsion systems. Vapor jetting in burning gel fuel droplets is a crucial process that enables an effective transport (convectively) of unreacted fuel from the droplet domain to the flame zone and accelerates the gas-phase mixing process. Here, first we show that the combusting ethanol gel droplets (organic gellant laden) exhibit a new oscillatory jetting mode due to aperiodic bursting of the droplet shell. Second, we show how the initial gellant loading rate (GLR) leads to a distinct shell formation which self-tunes temporally to burst the droplet at different frequencies. Particularly, a weak-flexible shell is formed at low GLR that undergoes successive rupture cascades occurring in same region of the droplet. This region weakens due to repeated ruptures and causes droplet bursting at progressively higher frequencies. Contrarily, high GLRs facilitate a strong-rigid shell formation where consecutive cascades occur at scattered locations across the droplet surface. This leads to droplet bursting at random frequencies. This method of modulating jetting frequency would enable an effective control of droplet trajectory and local fuel-oxidizer ratio in any gel-spray based energy formulation.

Heat pipes to reduce engine exhaust emissions

NASA Technical Reports Server (NTRS)

Schultz, D. F. (Inventor)

1984-01-01

A fuel combustor is presented that consists of an elongated casing with an air inlet conduit portion at one end, and having an opposite exit end. An elongated heat pipe is mounted longitudinally in the casing and is offset from and extends alongside the combustion space. The heat pipe is in heat transmitting relationship with the air intake conduit for heating incoming air. A guide conduit structure is provided for conveying the heated air from the intake conduit into the combustion space. A fuel discharge nozzle is provided to inject fuel into the combustion space. A fuel conduit from a fuel supply source has a portion engaged in heat transfer relationship of the heat pipe for preheating the fuel. The downstream end of the heat pipe is in heat transfer relationship with the casing and is located adjacent to the downstream end of the combustion space. The offset position of the heat pipe relative to the combustion space minimizes the quenching effect of the heat pipe on the gaseous products of combustion, as well as reducing coking of the fuel on the heat pipe, thereby improving the efficiency of the combustor.

FY2015 Annual Report for Alternative Fuels DISI Engine Research.

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

Sjöberg, Carl-Magnus G.

2016-01-01

Climate change and the need to secure energy supplies are two reasons for a growing interest in engine efficiency and alternative fuels. This project contributes to the science-base needed by industry to develop highly efficient DISI engines that also beneficially exploit the different properties of alternative fuels. Our emphasis is on lean operation, which can provide higher efficiencies than traditional non-dilute stoichiometric operation. Since lean operation can lead to issues with ignition stability, slow flame propagation and low combustion efficiency, we focus on techniques that can overcome these challenges. Specifically, fuel stratification is used to ensure ignition and completeness ofmore » combustion but has soot- and NOx- emissions challenges. For ultralean well-mixed operation, turbulent deflagration can be combined with controlled end-gas auto-ignition to render mixed-mode combustion that facilitates high combustion efficiency. However, the response of both combustion and exhaust emissions to these techniques depends on the fuel properties. Therefore, to achieve optimal fuel-economy gains, the engine combustion-control strategies must be adapted to the fuel being utilized.« less

Enhanced air/fuel mixing for automotive stirling engine turbulator-type combustors

DOEpatents

Riecke, George T.; Stotts, Robert E.

1992-01-01

The invention relates to the improved combustion of fuel in a combustion chamber of a stirling engine and the like by dividing combustion into primary and secondary combustion zones through the use of a diverter plate.

Vertical feed stick wood fuel burning furnace system

DOEpatents

Hill, Richard C.

1984-01-01

A new and improved stove or furnace for efficient combustion of wood fuel including a vertical feed combustion chamber for receiving and supporting wood fuel in a vertical attitude or stack, a major upper portion of the combustion chamber column comprising a water jacket for coupling to a source of water or heat transfer fluid and for convection circulation of the fluid for confining the locus of wood fuel combustion to the bottom of the vertical gravity feed combustion chamber. A flue gas propagation delay channel extending from the laterally directed draft outlet affords delayed travel time in a high temperature environment to assure substantially complete combustion of the gaseous products of wood burning with forced air as an actively induced draft draws the fuel gas and air mixture laterally through the combustion and high temperature zone. Active sources of forced air and induced draft are included, multiple use and circuit couplings for the recovered heat, and construction features in the refractory material substructure and metal component superstructure.

Constant-Pressure Combustion Charts Including Effects of Diluent Addition

NASA Technical Reports Server (NTRS)

Turner, L Richard; Bogart, Donald

1949-01-01

Charts are presented for the calculation of (a) the final temperatures and the temperature changes involved in constant-pressure combustion processes of air and in products of combustion of air and hydrocarbon fuels, and (b) the quantity of hydrocarbon fuels required in order to attain a specified combustion temperature when water, alcohol, water-alcohol mixtures, liquid ammonia, liquid carbon dioxide, liquid nitrogen, liquid oxygen, or their mixtures are added to air as diluents or refrigerants. The ideal combustion process and combustion with incomplete heat release from the primary fuel and from combustible diluents are considered. The effect of preheating the mixture of air and diluents and the effect of an initial water-vapor content in the combustion air on the required fuel quantity are also included. The charts are applicable only to processes in which the final mixture is leaner than stoichiometric and at temperatures where dissociation is unimportant. A chart is also included to permit the calculation of the stoichiometric ratio of hydrocarbon fuel to air with diluent addition. The use of the charts is illustrated by numerical examples.

Mechanism of influence water vapor on combustion characteristics of propane-air mixture

NASA Astrophysics Data System (ADS)

Larionov, V. M.; Mitrofanov, G. A.; Sachovskii, A. V.; Kozar, N. K.

2016-01-01

The article discusses the results of an experimental study of the effect of water vapor at the flame temperature. Propane-butane mixture with air is burning on a modified Bunsen burner. Steam temperature was varied from 180 to 260 degrees. Combustion parameters changed by steam temperature and its proportion in the mixture with the fuel. The fuel-air mixture is burned in the excess air ratio of 0.1. It has been established that the injection of steam changes the characteristics of combustion fuel-air mixture and increase the combustion temperature. The concentration of CO in the combustion products is substantially reduced. Raising the temperature in the combustion zone is associated with increased enthalpy of the fuel by the added steam enthalpy. Reducing the concentration of CO is caused by decrease in the average temperature in the combustion zone by applying steam. Concentration of active hydrogen radicals and oxygen increases in the combustion zone. That has a positive effect on the process of combustion.

Some Factors Affecting Combustion in an Internal-Combustion Engine

NASA Technical Reports Server (NTRS)

Rothrock, A M; Cohn, Mildred

1936-01-01

An investigation of the combustion of gasoline, safety, and diesel fuels was made in the NACA combustion apparatus under conditions of temperature that permitted ignition by spark with direct fuel injection, in spite of the compression ratio of 12.7 employed. The influence of such variables as injection advance angle, jacket temperature, engine speed, and spark position was studied. The most pronounced effect was that an increase in the injection advance angle (beyond a certain minimum value) caused a decrease in the extent and rate of combustion. In almost all cases combustion improved with increased temperature. The results show that at low air temperatures the rates of combustion vary with the volatility of the fuel, but that at high temperatures this relationship does not exist and the rates depend to a greater extent on the chemical nature of the fuel.

Development of an instantaneous local fuel-concentration measurement probe: an engine application

NASA Astrophysics Data System (ADS)

Guibert, P.; Boutar, Z.; Lemoyne, L.

2003-11-01

This work presents a new tool which can deliver instantaneous local measurements of fuel concentration in an engine cylinder with a high temporal resolution, particularly during compression strokes. Fuel concentration is represented by means of equivalence fuel-air ratio, i.e. the real engine mass ratio of fuel to air divided by the same ratio in ideal stoichiometry conditions. Controlling the mixture configuration for any strategy in a spark ignition engine and for auto-ignition combustion has a dominant effect on the subsequent processes of ignition, flame propagation and auto-ignition combustion progression, pollutant formation under lean or even stoichiometric operating conditions. It is extremely difficult, under a transient operation, to control the equivalence air/fuel ratio precisely at a required value and at the right time. This requires the development of a highly accurate equivalence air/fuel ratio control system and a tool to measure using crank angle (CA) resolution. Although non-intrusive laser techniques have considerable advantages, they are most of the time inappropriate due to their optical inaccessibility or the complex experimental set-up involved. Therefore, as a response to the demand for a relatively simple fuel-concentration measurement system a probe is presented that replaces a spark plug and allows the engine to run completely normally. The probe is based on hot-wire like apparatus, but involves catalytic oxidation at the wire surface. The development, characteristics and calibration of the probe are presented followed by applications to in-cylinder engine measurements.

Review of alternative fuels data bases

NASA Technical Reports Server (NTRS)

Harsha, P. T.; Edelman, R. B.

1983-01-01

Based on an analysis of the interaction of fuel physical and chemical properties with combustion characteristics and indicators, a ranking of the importance of various fuel properties with respect to the combustion process was established. This ranking was used to define a suite of specific experiments whose objective is the development of an alternative fuels design data base. Combustion characteristics and indicators examined include droplet and spray formation, droplet vaporization and burning, ignition and flame stabilization, flame temperature, laminar flame speed, combustion completion, soot emissions, NOx and SOx emissions, and the fuels' thermal and oxidative stability and fouling and corrosion characteristics. Key fuel property data is found to include composition, thermochemical data, chemical kinetic rate information, and certain physical properties.

Greenhouse Impact Due to the Use of Combustible Fuels: Life Cycle Viewpoint and Relative Radiative Forcing Commitment

PubMed Central

Palosuo, Taru; Holmgren, Kristina; Savolainen, Ilkka

2008-01-01

Extensive information on the greenhouse impacts of various human actions is important in developing effective climate change mitigation strategies. The greenhouse impacts of combustible fuels consist not only of combustion emissions but also of emissions from the fuel production chain and possible effects on the ecosystem carbon storages. It is important to be able to assess the combined, total effect of these different emissions and to express the results in a comprehensive way. In this study, a new concept called relative radiative forcing commitment (RRFC) is presented and applied to depict the greenhouse impact of some combustible fuels currently used in Finland. RRFC is a ratio that accounts for the energy absorbed in the Earth system due to changes in greenhouse gas concentrations (production and combustion of fuel) compared to the energy released in the combustion of fuel. RRFC can also be expressed as a function of time in order to give a dynamic cumulative picture on the caused effect. Varying time horizons can be studied separately, as is the case when studying the effects of different climate policies on varying time scales. The RRFC for coal for 100 years is about 170, which means that in 100 years 170 times more energy is absorbed in the atmosphere due to the emissions of coal combustion activity than is released in combustion itself. RRFC values of the other studied fuel production chains varied from about 30 (forest residues fuel) to 190 (peat fuel) for the 100-year study period. The length of the studied time horizon had an impact on the RRFC values and, to some extent, on the relative positions of various fuels. PMID:18521657

Greenhouse impact due to the use of combustible fuels: life cycle viewpoint and relative radiative forcing commitment.

PubMed

Kirkinen, Johanna; Palosuo, Taru; Holmgren, Kristina; Savolainen, Ilkka

2008-09-01

Extensive information on the greenhouse impacts of various human actions is important in developing effective climate change mitigation strategies. The greenhouse impacts of combustible fuels consist not only of combustion emissions but also of emissions from the fuel production chain and possible effects on the ecosystem carbon storages. It is important to be able to assess the combined, total effect of these different emissions and to express the results in a comprehensive way. In this study, a new concept called relative radiative forcing commitment (RRFC) is presented and applied to depict the greenhouse impact of some combustible fuels currently used in Finland. RRFC is a ratio that accounts for the energy absorbed in the Earth system due to changes in greenhouse gas concentrations (production and combustion of fuel) compared to the energy released in the combustion of fuel. RRFC can also be expressed as a function of time in order to give a dynamic cumulative picture on the caused effect. Varying time horizons can be studied separately, as is the case when studying the effects of different climate policies on varying time scales. The RRFC for coal for 100 years is about 170, which means that in 100 years 170 times more energy is absorbed in the atmosphere due to the emissions of coal combustion activity than is released in combustion itself. RRFC values of the other studied fuel production chains varied from about 30 (forest residues fuel) to 190 (peat fuel) for the 100-year study period. The length of the studied time horizon had an impact on the RRFC values and, to some extent, on the relative positions of various fuels.

THE INFLUENCE OF CARBON BURNOUT ON SUBMICRON PARTICLE FORMATION FROM EMULSIFIED FUEL OIL COMBUSTION

EPA Science Inventory

The paper gives results of an examination of particle behavior and particle size distributions from the combustion of different fuel oils and emulsified fuels in three experimental combusators. Results indicate that improved carbon (C) burnout from fule oil combustion, either by...

Reducing mode circulating fluid bed combustion

DOEpatents

Lin, Yung-Yi; Sadhukhan, Pasupati; Fraley, Lowell D.; Hsiao, Keh-Hsien

1986-01-01

A method for combustion of sulfur-containing fuel in a circulating fluid bed combustion system wherein the fuel is burned in a primary combustion zone under reducing conditions and sulfur captured as alkaline sulfide. The reducing gas formed is oxidized to combustion gas which is then separated from solids containing alkaline sulfide. The separated solids are then oxidized and recycled to the primary combustion zone.

Stably operating pulse combustor and method

DOEpatents

Zinn, Ben T.; Reiner, David

1990-01-01

A pulse combustor apparatus adapted to burn either a liquid fuel or a pulverized solid fuel within a preselected volume of the combustion chamber. The combustion process is substantially restricted to an optimum combustion zone in order to attain effective pulse combustion operation.

Liquid fuel vaporizer and combustion chamber having an adjustable thermal conductor

DOEpatents

Powell, Michael R; Whyatt, Greg A; Howe, Daniel T; Fountain, Matthew S

2014-03-04

The efficiency and effectiveness of apparatuses for vaporizing and combusting liquid fuel can be improved using thermal conductors. For example, an apparatus having a liquid fuel vaporizer and a combustion chamber can be characterized by a thermal conductor that conducts heat from the combustion chamber to the vaporizer. The thermal conductor can be a movable member positioned at an insertion depth within the combustion chamber that corresponds to a rate of heat conduction from the combustion chamber to the vaporizer. The rate of heat conduction can, therefore, be adjusted by positioning the movable member at a different insertion depth.

Application of neural network in the study of combustion rate of natural gas/diesel dual fuel engine.

PubMed

Yan, Zhao-Da; Zhou, Chong-Guang; Su, Shi-Chuan; Liu, Zhen-Tao; Wang, Xi-Zhen

2003-01-01

In order to predict and improve the performance of natural gas/diesel dual fuel engine (DFE), a combustion rate model based on forward neural network was built to study the combustion process of the DFE. The effect of the operating parameters on combustion rate was also studied by means of this model. The study showed that the predicted results were good agreement with the experimental data. It was proved that the developed combustion rate model could be used to successfully predict and optimize the combustion process of dual fuel engine.

Combustion characteristics of gas turbine alternative fuels

NASA Technical Reports Server (NTRS)

Rollbuhler, R. James

1987-01-01

An experimental investigation was conducted to obtain combustion performance values for specific heavyend, synthetic hydrocarbon fuels. A flame tube combustor modified to duplicate an advanced gas turbine engine combustor was used for the tests. Each fuel was tested at steady-state operating conditions over a range of mass flow rates, fuel-to-air mass ratio, and inlet air temperatures. The combustion pressure, as well as the hardware, were kept nearly constant over the program test phase. Test results were obtained in regards to geometric temperature pattern factors as a function of combustor wall temperatures, the combustion gas temperature, and the combustion emissions, both as affected by the mass flow rate and fuel-to-air ratio. The synthetic fuels were reacted in the combustor such that for most tests their performance was as good, if not better, than the baseline gasoline or diesel fuel tests. The only detrimental effects were that at high inlet air temperature conditions, fuel decomposition occurred in the fuel atomizing nozzle passages resulting in blockage. And the nitrogen oxide emissions were above EPA limits at low flow rate and high operating temperature conditions.

[Spatial pattern of land surface dead combustible fuel load in Huzhong forest area in Great Xing'an Mountains].

PubMed

Liu, Zhi-Hua; Chang, Yu; Chen, Hong-Wei; Zhou, Rui; Jing, Guo-Zhi; Zhang, Hong-Xin; Zhang, Chang-Meng

2008-03-01

By using geo-statistics and based on time-lag classification standard, a comparative study was made on the land surface dead combustible fuels in Huzhong forest area in Great Xing'an Mountains. The results indicated that the first level land surface dead combustible fuel, i. e., 1 h time-lag dead fuel, presented stronger spatial auto-correlation, with an average of 762.35 g x m(-2) and contributing to 55.54% of the total load. Its determining factors were species composition and stand age. The second and third levels land surface dead combustible fuel, i. e., 10 h and 100 h time-lag dead fuels, had a sum of 610.26 g x m(-2), and presented weaker spatial auto-correlation than 1 h time-lag dead fuel. Their determining factor was the disturbance history of forest stand. The complexity and heterogeneity of the factors determining the quality and quantity of forest land surface dead combustible fuels were the main reasons for the relatively inaccurate interpolation. However, the utilization of field survey data coupled with geo-statistics could easily and accurately interpolate the spatial pattern of forest land surface dead combustible fuel loads, and indirectly provide a practical basis for forest management.

Coanda injection system for axially staged low emission combustors

DOEpatents

Evulet, Andrei Tristan [Clifton Park, NY; Varatharajan, Balachandar [Cincinnati, OH; Kraemer, Gilbert Otto [Greer, SC; ElKady, Ahmed Mostafa [Niskayuna, NY; Lacy, Benjamin Paul [Greer, SC

2012-05-15

The low emission combustor includes a combustor housing defining a combustion chamber having a plurality of combustion zones. A liner sleeve is disposed in the combustion housing with a gap formed between the liner sleeve and the combustor housing. A secondary nozzle is disposed along a centerline of the combustion chamber and configured to inject a first fluid comprising air, at least one diluent, fuel, or combinations thereof to a downstream side of a first combustion zone among the plurality of combustion zones. A plurality of primary fuel nozzles is disposed proximate to an upstream side of the combustion chamber and located around the secondary nozzle and configured to inject a second fluid comprising air and fuel to an upstream side of the first combustion zone. The combustor also includes a plurality of tertiary coanda nozzles. Each tertiary coanda nozzle is coupled to a respective dilution hole. The tertiary coanda nozzles are configured to inject a third fluid comprising air, at least one other diluent, fuel, or combinations thereof to one or more remaining combustion zones among the plurality of combustion zones.

Combustion studies of coal derived solid fuels by thermogravimetric analysis. III. Correlation between burnout temperature and carbon combustion efficiency

USGS Publications Warehouse

Rostam-Abadi, M.; DeBarr, J.A.; Chen, W.T.

1990-01-01

Burning profiles of 35-53 ??m size fractions of an Illinois coal and three partially devolatilized coals prepared from the original coal were obtained using a thermogravimetric analyzer. The burning profile burnout temperatures were higher for lower volatile fuels and correlated well with carbon combustion efficiencies of the fuels when burned in a laboratory-scale laminar flow reactor. Fuels with higher burnout temperatures had lower carbon combustion efficiencies under various time-temperature conditions in the laboratory-scale reactor. ?? 1990.

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.

Super low NO.sub.x, high efficiency, compact firetube boiler

DOEpatents

Chojnacki, Dennis A.; Rabovitser, Iosif K.; Knight, Richard A.; Cygan, David F.; Korenberg, Jacob

2005-12-06

A firetube boiler furnace having two combustion sections and an in-line intermediate tubular heat transfer section between the two combustion sections and integral to the pressure vessel. This design provides a staged oxidant combustion apparatus with separate in-line combustion chambers for fuel-rich primary combustion and fuel-lean secondary combustion and sufficient cooling of the combustion products from the primary combustion such that when the secondary combustion oxidant is added in the secondary combustion stage, the NO.sub.x formation is less than 5 ppmv at 3% O.sub.2.

Low emissions compression ignited engine technology

DOEpatents

Coleman, Gerald N [Dunlap, IL; Kilkenny, Jonathan P [Peoria, IL; Fluga, Eric C [Dunlap, IL; Duffy, Kevin P [East Peoria, IL

2007-04-03

A method and apparatus for operating a compression ignition engine having a cylinder wall, a piston, and a head defining a combustion chamber. The method and apparatus includes delivering fuel substantially uniformly into the combustion chamber, the fuel being dispersed throughout the combustion chamber and spaced from the cylinder wall, delivering an oxidant into the combustion chamber sufficient to support combustion at a first predetermined combustion duration, and delivering a diluent into the combustion chamber sufficient to change the first predetermined combustion duration to a second predetermined combustion duration different from the first predetermined combustion duration.

Indoor Spatial Monitoring of Combustion Generated Pollutants (TSP, CO, and BaP) by Indian Cookstoves

DTIC Science & Technology

1988-07-01

various building materials and consumer products, and combustion appliances. People and pets normally emit C02 , moisture, odors, and microbes. Tobacco ...fuels Group II. Sources both indoor and outdoor: Nitric oxide, nitrogen dioxide Fuel-burning, tobacco smoke Polycyclic hydrocarbons Fuel-burning, tobacco ...smoke Carbon monoxide Fuel-burning, tobacco smoke Carbon dioxide Metabolic activity, combustion Suspended particulate matter Resuspension

Fuel Composition Effects at Constant RON and MON in an HCCI Engine Operated with Negative Valve Overlap

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

Bunting, Bruce G; Farrell, John T

2006-01-01

The effects of fuel properties on gasoline HCCI operation have been investigated in a single cylinder, 500 cc, 11.3 CR port fuel injected research engine, operated at lambda=1 and equipped with hydraulic valve actuation. HCCI is promoted by early exhaust valve closing to retain hot exhaust in the cylinder, thereby increasing the cylinder gas temperature. Test fuels were formulated with pure components to have the same RON, MON, and octane sensitivity as an indolene reference fuel, but with a wide range of fuel composition differences. Experiments have been carried out to determine if fuel composition plays a role in HCCImore » combustion properties, independent of octane numbers. Fuel economy, emissions, and combustion parameters have been measured at several fixed speed/load conditions over a range of exhaust valve closing angles. When the data are compared at constant combustion phasing, fuel effects on emissions and other combustion properties are small. However, when compared at constant exhaust valve closing angle, fuel composition effects are more pronounced, specifically regarding ignition. Operability range differences are also related to fuel composition. An all-paraffinic (normal, iso, and cycloparaffins) fuel exhibited distinctly earlier combustion phasing, increased rate of cylinder pressure rise, and increased rate of maximum heat release compared to the indolene reference fuel. Conversely, olefin-containing fuels exhibited retarded combustion phasing. The fuels with the most advanced ignition showed a wider operating range in terms of engine speed and load, irrespective of exhaust closing angle. These ignition differences reflect contributions from both fuel and EGR kinetics, the effects of which are discussed. The fuel composition variables are somewhat inter-correlated, which makes the experimental separation their effects imprecise with this small set of fuels, though clear trends are evident. The overall effects of fuel composition on engine performance and emissions are small. However, the results suggest that the effects on combustion phasing and engine operability range may need to be considered in the practical implementation of HCCI for fuels with large compositional variations.« less

Penn State Multi-Discipline Tribology Group and Energy Institute Studies.

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

Perez, Joseph

This presentation is a summary of the current research activities on fuels and lubricants in the Multi-discipline Tribology group and the engine test group in the Combustion Laboratory of the Pennsylvania State University. The progress areas discussed in this summary include those found in Table 1. Table 1. RESEARCH AREAS: Diesel Engine Emission Reduction; Oxygenated Fuels; Improved Friction Fuels; Vegetable Oil Lubricants; Extended Drain Lubricants; Effect of Chemical Structure on Friction and Wear. The research is of interest either directly or indirectly to the goal of this workshop, diesel engine emissions reduction. The current projects at Penn State in themore » areas listed above will be discussed.« less

FUEL EFFECTS ON COMBUSTION WITH EGR DILUTION IN SPARK IGNITED ENGINES

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

Szybist, James P

The use of EGR as a diluent allows operation with an overall stoichiometric charge composition, and the addition of cooled EGR results in well-understood thermodynamic benefits for improved fuel consumption. This study investigates the effect of fuel on the combustion and emission response of EGR dilution in spark ignited engines. A 2.0 L GM Ecotec LNF engine equipped with the production side-mounted direct injection (DI) fueling system is used in this study. Ethanol, isooctane and certified gasoline are investigated with EGR from 0% to the EGR dilution tolerance. Constant BMEP at 2000 rpm was operated with varying CA50 from 8more » CAD to 16 CAD aTDCf. The results show that ethanol gives the largest EGR tolerance at a given combustion phasing, engine load and speed. The improved EGR dilution tolerance with ethanol is attributed to a faster flame speed, which manifests itself as shorter combustion duration. Data shows that the combustion stability limit occurs at a critical combustion duration that is fuel independent. Due to different flame speeds, this critical combustion duration occurs at different EGR levels for the different fuels.« less

Ultra-lean combustion at high inlet temperatures

NASA Technical Reports Server (NTRS)

Anderson, D. N.

1981-01-01

Combustion at inlet air temperatures of 1100 to 1250 K was studied for application to advanced automotive gas turbine engines. Combustion was initiated by the hot environment, and therefore no external ignition source was used. Combustion was stabilized without a flameholder. The tests were performed in a 12 cm diameter test section at a pressure of 2.5 x 10 to the 5th power Pa, with reference velocities of 32 to 60 m/sec and at maximum combustion temperatures of 1350 to 1850 K. Number 2 diesel fuel was injected by means of a multiple source fuel injector. Unburned hydrocarbons emissions were negligible for all test conditions. Nitrogen oxides emissions were less than 1.9 g NO2/kg fuel for combustion temperatures below 1680 K. Carbon monoxide emissions were less than 16 g CO/kg fuel for combustion temperatures greater than 1600 K, inlet air temperatures higher than 1150 K, and residence times greater than 4.3 microseconds.

Exhaust after-treatment system with in-cylinder addition of unburnt hydrocarbons

DOEpatents

Coleman, Gerald N.; Kesse, Mary L.

2007-10-30

Certain exhaust after-treatment devices, at least periodically, require the addition of unburnt hydrocarbons in order to create reductant-rich exhaust conditions. The present disclosure adds unburnt hydrocarbons to exhaust from at least one combustion chamber by positioning, at least partially within a combustion chamber, a mixed-mode fuel injector operable to inject fuel into the combustion chamber in a first spray pattern with a small average angle relative to a centerline of the combustion chamber and a second spray pattern with a large average angle relative to the centerline of the combustion chamber. An amount of fuel is injected in the first spray pattern into a non-combustible environment within the at least one combustion chamber during at least one of an expansion stroke and exhaust stroke. The exhaust with the unburnt amount of fuel is moved into an exhaust passage via an exhaust valve.

Multi-stage combustion using nitrogen-enriched air

DOEpatents

Fischer, Larry E.; Anderson, Brian L.

2004-09-14

Multi-stage combustion technology combined with nitrogen-enriched air technology for controlling the combustion temperature and products to extend the maintenance and lifetime cycles of materials in contact with combustion products and to reduce pollutants while maintaining relatively high combustion and thermal cycle efficiencies. The first stage of combustion operates fuel rich where most of the heat of combustion is released by burning it with nitrogen-enriched air. Part of the energy in the combustion gases is used to perform work or to provide heat. The cooled combustion gases are reheated by additional stages of combustion until the last stage is at or near stoichiometric conditions. Additional energy is extracted from each stage to result in relatively high thermal cycle efficiency. The air is enriched with nitrogen using air separation technologies such as diffusion, permeable membrane, absorption, and cryogenics. The combustion method is applicable to many types of combustion equipment, including: boilers, burners, turbines, internal combustion engines, and many types of fuel including hydrogen and carbon-based fuels including methane and coal.

Two-stage coal gasification and desulfurization apparatus

DOEpatents

Bissett, Larry A.; Strickland, Larry D.

1991-01-01

The present invention is directed to a system which effectively integrates a two-stage, fixed-bed coal gasification arrangement with hot fuel gas desulfurization of a first stream of fuel gas from a lower stage of the two-stage gasifier and the removal of sulfur from the sulfur sorbent regeneration gas utilized in the fuel-gas desulfurization process by burning a second stream of fuel gas from the upper stage of the gasifier in a combustion device in the presence of calcium-containing material. The second stream of fuel gas is taken from above the fixed bed in the coal gasifier and is laden with ammonia, tar and sulfur values. This second stream of fuel gas is burned in the presence of excess air to provide heat energy sufficient to effect a calcium-sulfur compound forming reaction between the calcium-containing material and sulfur values carried by the regeneration gas and the second stream of fuel gas. Any ammonia values present in the fuel gas are decomposed during the combustion of the fuel gas in the combustion chamber. The substantially sulfur-free products of combustion may then be combined with the desulfurized fuel gas for providing a combustible fluid utilized for driving a prime mover.

The effect of azeotropism on combustion characteristics of blended fuel pool fire.

PubMed

Ding, Yanming; Wang, Changjian; Lu, Shouxiang

2014-04-30

The effect of azeotropism on combustion characteristics of blended fuel pool fire was experimentally studied in an open fire test space of State Key Laboratory of Fire Science. A 30 cm × 30 cm square pool filled with n-heptane and ethanol blended fuel was employed. Flame images, burning rate and temperature distribution were collected and recorded in the whole combustion process. Results show that azeotropism obviously dominates the combustion behavior of n-heptane/ethanol blended fuel pool fire. The combustion process after ignition exhibits four typical stages: initial development, azeotropic burning, single-component burning and decay stage. Azeotropism appears when temperature of fuel surface reaches azeotropic point and blended fuel burns at azeotropic ratio. Compared with individual pure fuel, the effect of azeotropism on main fire parameters, such as flame height, burning rate, flame puffing frequency and centerline temperature were analyzed. Burning rate and centerline temperature of blended fuel are higher than that of individual pure fuel respectively at azeotropic burning stage, and flame puffing frequency follows the empirical formula between Strouhal and Froude number for pure fuel. Copyright © 2014 Elsevier B.V. All rights reserved.

Flex-flame burner and combustion method

DOEpatents

Soupos, Vasilios; Zelepouga, Serguei; Rue, David M.; Abbasi, Hamid A.

2010-08-24

A combustion method and apparatus which produce a hybrid flame for heating metals and metal alloys, which hybrid flame has the characteristic of having an oxidant-lean portion proximate the metal or metal alloy and having an oxidant-rich portion disposed above the oxidant lean portion. This hybrid flame is produced by introducing fuel and primary combustion oxidant into the furnace chamber containing the metal or metal alloy in a substoichiometric ratio to produce a fuel-rich flame and by introducing a secondary combustion oxidant into the furnace chamber above the fuel-rich flame in a manner whereby mixing of the secondary combustion oxidant with the fuel-rich flame is delayed for a portion of the length of the flame.

Internal combustion engines for alcohol motor fuels: a compilation of background technical information

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

Blaser, Richard

1980-11-01

This compilation, a draft training manual containing technical background information on internal combustion engines and alcohol motor fuel technologies, is presented in 3 parts. The first is a compilation of facts from the state of the art on internal combustion engine fuels and their characteristics and requisites and provides an overview of fuel sources, fuels technology and future projections for availability and alternatives. Part two compiles facts about alcohol chemistry, alcohol identification, production, and use, examines ethanol as spirit and as fuel, and provides an overview of modern evaluation of alcohols as motor fuels and of the characteristics of alcoholmore » fuels. The final section compiles cross references on the handling and combustion of fuels for I.C. engines, presents basic evaluations of events leading to the use of alcohols as motor fuels, reviews current applications of alcohols as motor fuels, describes the formulation of alcohol fuels for engines and engine and fuel handling hardware modifications for using alcohol fuels, and introduces the multifuel engines concept. (LCL)« less

Combustion chamber and thermal vapor stream producing apparatus and method

DOEpatents

Sperry, John S.; Krajicek, Richard W.; Cradeur, Robert R.

1978-01-01

A new and improved method and apparatus for burning a hydrocarbon fuel for producing a high pressure thermal vapor stream comprising steam and combustion gases for injecting into a subterranean formation for the recovery of liquefiable minerals therefrom, wherein a high pressure combustion chamber having multiple refractory lined combustion zones of varying diameters is provided for burning a hydrocarbon fuel and pressurized air in predetermined ratios injected into the chamber for producing hot combustion gases essentially free of oxidizing components and solid carbonaceous particles. The combustion zones are formed by zones of increasing diameters up a final zone of decreasing diameter to provide expansion zones which cause turbulence through controlled thorough mixing of the air and fuel to facilitate complete combustion. The high pressure air and fuel is injected into the first of the multiple zones where ignition occurs with a portion of the air injected at or near the point of ignition to further provide turbulence and more complete combustion.

Hybrid two fuel system nozzle with a bypass connecting the two fuel systems

DOEpatents

Varatharajan, Balachandar [Cincinnati, OH; Ziminsky, Willy Steve [Simpsonville, SC; Yilmaz, Ertan [Albany, NY; Lacy, Benjamin [Greer, SC; Zuo, Baifang [Simpsonville, SC; York, William David [Greer, SC

2012-05-29

A hybrid fuel combustion nozzle for use with natural gas, syngas, or other types of fuels. The hybrid fuel combustion nozzle may include a natural gas system with a number of swozzle vanes and a syngas system with a number of co-annular fuel tubes.

Effects of fuel nozzle design on performance of an experimental annular combustor using natural gas fuel

NASA Technical Reports Server (NTRS)

Wear, J. D.; Schultz, D. F.

1972-01-01

Tests of various fuel nozzles were conducted with natural gas fuel in a full-annulus combustor. The nozzles were designed to provide either axial, angled, or radial fuel injection. Each fuel nozzle was evaluated by measuring combustion efficiency at relatively severe combustor operating conditions. Combustor blowout and altitude ignition tests were also used to evaluate nozzle designs. Results indicate that angled injection gave higher combustion efficiency, less tendency toward combustion instability, and altitude relight characteristics equal to or superior to those of the other fuel nozzles that were tested.

Simultaneous identification of multi-combustion-intermediates of alkanol-air flames by femtosecond filament excitation for combustion sensing.

PubMed

Li, Helong; Chu, Wei; Xu, Huailiang; Cheng, Ya; Chin, See-Leang; Yamanouchi, Kaoru; Sun, Hong-Bo

2016-06-02

Laser filamentation produced by the propagation of intense laser pulses in flames is opening up new possibility in application to combustion diagnostics that can provide useful information on understanding combustion processes, enhancing combustion efficiency and reducing pollutant products. Here we present simultaneous identification of multiple combustion intermediates by femtosecond filament excitation for five alkanol-air flames fueled by methanol, ethanol, n-propanol, n-butanol, and n-pentanol. We experimentally demonstrate that the intensities of filament-induced photoemission signals from the combustion intermediates C, C2, CH, CN increase with the increasing number of carbons in the fuel molecules, and the signal ratios between the intermediates (CH/C, CH/C2, CN/C, CH/C2, CN/CH) are different for different alkanol combustion flames. Our observation provides a way for sensing multiple combustion components by femtosecond filament excitation in various combustion conditions that strongly depend on the fuel species.

Nitrogen oxides, sulfur trioxide, and mercury emissions during oxy-fuel fluidized bed combustion of Victorian brown coal.

PubMed

Roy, Bithi; Chen, Luguang; Bhattacharya, Sankar

2014-12-16

This study investigates, for the first time, the NOx, N2O, SO3, and Hg emissions from combustion of a Victorian brown coal in a 10 kWth fluidized bed unit under oxy-fuel combustion conditions. Compared to air combustion, lower NOx emissions and higher N2O formation were observed in the oxy-fuel atmosphere. These NOx reduction and N2O formations were further enhanced with steam in the combustion environment. The NOx concentration level in the flue gas was within the permissible limit in coal-fired power plants in Victoria. Therefore, an additional NOx removal system will not be required using this coal. In contrast, both SO3 and gaseous mercury concentrations were considerably higher under oxy-fuel combustion compared to that in the air combustion. Around 83% of total gaseous mercury released was Hg(0), with the rest emitted as Hg(2+). Therefore, to control harmful Hg(0), a mercury removal system may need to be considered to avoid corrosion in the boiler and CO2 separation units during the oxy-fuel fluidized-bed combustion using this coal.

Key challenges and recent progress in batteries, fuel cells, and hydrogen storage for clean energy systems

NASA Astrophysics Data System (ADS)

Chalk, Steven G.; Miller, James F.

Reducing or eliminating the dependency on petroleum of transportation systems is a major element of US energy research activities. Batteries are a key enabling technology for the development of clean, fuel-efficient vehicles and are key to making today's hybrid electric vehicles a success. Fuel cells are the key enabling technology for a future hydrogen economy and have the potential to revolutionize the way we power our nations, offering cleaner, more efficient alternatives to today's technology. Additionally fuel cells are significantly more energy efficient than combustion-based power generation technologies. Fuel cells are projected to have energy efficiency twice that of internal combustion engines. However before fuel cells can realize their potential, significant challenges remain. The two most important are cost and durability for both automotive and stationary applications. Recent electrocatalyst developments have shown that Pt alloy catalysts have increased activity and greater durability than Pt catalysts. The durability of conventional fluorocarbon membranes is improving, and hydrocarbon-based membranes have also shown promise of equaling the performance of fluorocarbon membranes at lower cost. Recent announcements have also provided indications that fuel cells can start from freezing conditions without significant deterioration. Hydrogen storage systems for vehicles are inadequate to meet customer driving range expectations (>300 miles or 500 km) without intrusion into vehicle cargo or passenger space. The United States Department of Energy has established three centers of Excellence for hydrogen storage materials development. The centers are focused on complex metal hydrides that can be regenerated onboard a vehicle, chemical hydrides that require off-board reprocessing, and carbon-based storage materials. Recent developments have shown progress toward the 2010 DOE targets. In addition DOE has established an independent storage material testing center to verify storage capacity of promising materials. These developments point to a viable path to achieving the DOE/FreedomCAR cost and performance goals. The transition to hydrogen-powered fuel cell vehicles will occur over the next 10-15 years. In the interim, fossil fuel consumption will be reduced by increased penetration of battery/gasoline hybrid cars.

40 CFR 60.49b - Reporting and recordkeeping requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... into the oxidation zone. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted, the NOX emission limit for fossil fuel in § 60.44b(a) applies. (ii) When natural gas and chemical by... back into the combustion air. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted...

40 CFR 60.49b - Reporting and recordkeeping requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... into the oxidation zone. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted, the NOX emission limit for fossil fuel in § 60.44b(a) applies. (ii) When natural gas and chemical by... back into the combustion air. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted...

40 CFR 60.49b - Reporting and recordkeeping requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... into the oxidation zone. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted, the NOX emission limit for fossil fuel in § 60.44b(a) applies. (ii) When natural gas and chemical by... back into the combustion air. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted...

40 CFR 60.49b - Reporting and recordkeeping requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... into the oxidation zone. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted, the NOX emission limit for fossil fuel in § 60.44b(a) applies. (ii) When natural gas and chemical by... back into the combustion air. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted...

40 CFR 60.49b - Reporting and recordkeeping requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... into the oxidation zone. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted, the NOX emission limit for fossil fuel in § 60.44b(a) applies. (ii) When natural gas and chemical by... back into the combustion air. (2) Standard for nitrogen oxides. (i) When fossil fuel alone is combusted...

Vertical feed stick wood fuel burning furnace system

DOEpatents

Hill, Richard C.

1982-01-01

A stove or furnace for efficient combustion of wood fuel includes a vertical feed combustion chamber (15) for receiving and supporting wood fuel in a vertical attitude or stack. A major upper portion of the combustion chamber column comprises a water jacket (14) for coupling to a source of water or heat transfer fluid for convection circulation of the fluid. The locus (31) of wood fuel combustion is thereby confined to the refractory base of the combustion chamber. A flue gas propagation delay channel (34) extending laterally from the base of the chamber affords delayed travel time in a high temperature refractory environment sufficient to assure substantially complete combustion of the gaseous products of wood burning with forced air prior to extraction of heat in heat exchanger (16). Induced draft draws the fuel gas and air mixture laterally through the combustion chamber and refractory high temperature zone to the heat exchanger and flue. Also included are active sources of forced air and induced draft, multiple circuit couplings for the recovered heat, and construction features in the refractory material substructure and metal component superstructure.

The NACA Apparatus for Studying the Formation and Combustion of Fuel Sprays and the Results from Preliminary Tests

NASA Technical Reports Server (NTRS)

Rothrock, A M

1933-01-01

This report describes the apparatus as designed and constructed at the Langley Memorial Aeronautical Laboratory, for studying the formation and combustion of fuel sprays under conditions closely simulating those occurring in a high-speed compression-ignition engine. The apparatus consists of a single-cylinder modified test engine, a fuel-injection system so designed that a single charge of fuel can be injected into the combustion chamber of the engine, an electric driving motor, and a high-speed photographic apparatus. The cylinder head of the engine has a vertical-disk form of combustion chamber whose sides are glass windows. When the fuel is injected into the combustion chamber, motion pictures at the rate of 2,000 per second are taken of the spray formation by means of spark discharges. When combustion takes place the light of the combustion is recorded on the same photographic film as the spray photographs. The report includes the results of some tests to determine the effect of air temperature, air flow, and nozzle design on the spray formation.

NOx reduction in combustion with concentrated coal streams and oxygen injection

DOEpatents

Kobayashi, Hisashi; Bool, III, Lawrence E.; Snyder, William J.

2004-03-02

NOx formation in the combustion of solid hydrocarbonaceous fuel such as coal is reduced by obtaining, from the incoming feed stream of fuel solids and air, a stream having a ratio of fuel solids to air that is higher than that of the feed steam, and injecting the thus obtained stream and a small amount of oxygen to a burner where the fuel solids are combusted.

An innovative system for supplying air and fuel mixture to a combustion chamber of an engine

NASA Astrophysics Data System (ADS)

Saikumar, G. R. Bharath

2018-04-01

Conventional carburetors are being used since decades to ensure that the desired ratio of air and fuel enters the combustion chamber for combustion for the purpose of generating power in an Spark Ignition(SI) internal combustion engine. However to increase the efficiency, the carburetor system is gradually being replaced by fuel injection systems. Fuel injection systems use injectors to supply pressurized fuel into the combustion chamber. Owing to the high initial and maintenance cost, carburetors are still ruling in the low cost vehicle domain. An innovative concept is conceived, which is an alternative method to the carburetor system to supply the air and fuel mixture to a combustion chamber of an engine. This system comprises of an inner hollow cylinder with minute holes drilled along its length with an outer cylinder capable of sliding along its length or its longitudinal axis. This system is placed in the venturi instead of the conventional carburetor system. Fuel enters from the bottom inlet of the inner cylinder and flows out through the holes provided along its length. The fuel flow from the inner cylinder is dependent on the size and the number of holes exposed at that instance by the sliding outer cylinder which in turn is connected to the throttle or accelerator.

An extinction/reignition dynamic method for turbulent combustion

NASA Astrophysics Data System (ADS)

Knaus, Robert; Pantano, Carlos

2011-11-01

Quasi-randomly distributed locations of high strain in turbulent combustion can cause a nonpremixed or partially premixed flame to develop local regions of extinction called ``flame holes''. The presence and extent of these holes can increase certain pollutants and reduce the amount of fuel burned. Accurately modeling the dynamics of these interacting regions can improve the accuracy of combustion simulations by effectively incorporating finite-rate chemistry effects. In the proposed method, the flame hole state is characterized by a progress variable that nominally exists on the stoichiometric surface. The evolution of this field is governed by a partial-differential equation embedded in the time-dependent two-manifold of the flame surface. This equation includes advection, propagation, and flame hole formation (flame hole healing or collapse is accounted by propagation naturally). We present a computational algorithm that solves this equation by embedding it in the usual three-dimensional space. A piece-wise parabolic WENO scheme combined with a compression algorithm are used to evolve the flame hole progress variable. A key aspect of the method is the extension of the surface data to the three-dimensional space in an efficient manner. We present results of this method applied to canonical turbulent combusting flows where the flame holes interact and describe their statistics.

Stably operating pulse combustor and method

DOEpatents

Zinn, B.T.; Reiner, D.

1990-05-29

A pulse combustor apparatus is described which is adapted to burn either a liquid fuel or a pulverized solid fuel within a preselected volume of the combustion chamber. The combustion process is substantially restricted to an optimum combustion zone in order to attain effective pulse combustion operation. 4 figs.

40 CFR 98.143 - Calculating GHG emissions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Fuel Combustion Sources). (2) Calculate and report the process and combustion CO2 emissions separately... Fuel Combustion Sources) the combustion CO2 emissions in the glass furnace according to the applicable... calculate and report the annual process CO2 emissions from each continuous glass melting furnace using the...

40 CFR 98.193 - Calculating GHG emissions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Stationary Fuel Combustion Sources). (2) Calculate and report process and combustion CO2 emissions separately... Stationary Fuel Combustion Sources) the combustion CO2 emissions from each lime kiln according to the... must calculate and report the annual process CO2 emissions from all lime kilns combined using the...

40 CFR 98.193 - Calculating GHG emissions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Stationary Fuel Combustion Sources). (2) Calculate and report process and combustion CO2 emissions separately... Stationary Fuel Combustion Sources) the combustion CO2 emissions from each lime kiln according to the... must calculate and report the annual process CO2 emissions from all lime kilns combined using the...

40 CFR 98.143 - Calculating GHG emissions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Fuel Combustion Sources). (2) Calculate and report the process and combustion CO2 emissions separately... Fuel Combustion Sources) the combustion CO2 emissions in the glass furnace according to the applicable... calculate and report the annual process CO2 emissions from each continuous glass melting furnace using the...

Study of soot production for double injections of n-dodecane in CI engine-like conditions

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

Moiz, Ahmed Abdul; Ameen, Muhsin M.; Lee, Seong-Young

Soot production mechanism in multiple injections is complex since it involves its dependence on turbulent interactions of constituting injections and their combustion progress. A concise study was performed in a constant-volume combustion vessel by considering a double injection scheme of 0.3 ms pilot injection, 0.5 ms dwell time and 1.2 ms main injection (nomenclature: 0.3/0.5/12 ms) with n-dodecane as fuel and replicating the thermodynamic operating condition of a compression ignition (CI) engine. Experimental ambient temperature variations of 900 K and 800 K were performed at 15% ambient oxygen level. Simultaneous planar laser-induced fluorescence (PUP) of formaldehyde and schlieren imaging techniquesmore » were employed to analyze the ignition and flame characteristics experimentally. These studies revealed almost similar heat release rates for a double injection at 900 K and 800 K ambient gas temperatures due to combustion of a longer main injection which is enhanced by pilot combustion event A lower soot production for 800 K ambient condition over 900 K case was observed, which was concluded to be due to its higher lift-off length which would allow for a leaner combustion of fuel-air mixtures. Numerical simulations were performed using a Large Eddy Simulation (LES) approach by extensively validating the 900 K double injection condition with respect to non-reacting vapor penetration profiles of both injections, reacting jet heat release rate and spatial as well as temporal (qualitative) soot production. As part of LES work, a dwell time variation of 0.65 ms (0.3/0.65/1.2 ms) was performed to reveal the sensitivity of soot production to variations in dwell time. It was observed numerically that marginally higher quasi steady lift-off length of the 0.3/0.65/1.2 ms injection causes increased entrainment of surrounding oxygen into the flame region. This leads to combustion of slightly leaner fuel-air mixture and hence relatively less soot when compared to a 0.3/0.5/1.2 ms injection. (C) 2016 The Combustion Institute. Published by Elsevier Inc All rights reserved.« less

State and prospects of solid propellant rocket development

NASA Astrophysics Data System (ADS)

Kukushkin, V. Kh.

1992-07-01

An overview is presented of aspects of solid-propellant rocket engine (SPRE) development with individual treatment given to sustainer and spacecraft SPRE technologies. The paper focuses on low-modulus fuels of composite solid propellant, requirements for adhesion stability, and enhancement of the power characteristics of solid propellants. R&D activities are described that relate to the use of SPREs with extending nozzles and to the design of ultradimensional nozzles for upper-stage engines. Other developments for the SPREs include engines with separate loading and pasty fuel applications, and progress is reported in the direction of detonation SPREs. The SPREs using pasty propellants provide good control over thrust characteristics and fuel qualities. A device is incorporated that assures fuel burning in the combustion region and reliable ignition during restarting of these engines.

Engine combustion control at low loads via fuel reactivity stratification

DOEpatents

Reitz, Rolf Deneys; Hanson, Reed M; Splitter, Derek A; Kokjohn, Sage L

2014-10-07

A compression ignition (diesel) engine uses two or more fuel charges during a combustion cycle, with the fuel charges having two or more reactivities (e.g., different cetane numbers), in order to control the timing and duration of combustion. By appropriately choosing the reactivities of the charges, their relative amounts, and their timing, combustion can be tailored to achieve optimal power output (and thus fuel efficiency), at controlled temperatures (and thus controlled NOx), and with controlled equivalence ratios (and thus controlled soot). At low load and no load (idling) conditions, the aforementioned results are attained by restricting airflow to the combustion chamber during the intake stroke (as by throttling the incoming air at or prior to the combustion chamber's intake port) so that the cylinder air pressure is below ambient pressure at the start of the compression stroke.

Gaseous emissions during concurrent combustion of biomass and non-recyclable municipal solid waste

PubMed Central

2011-01-01

Background Biomass and municipal solid waste offer sustainable sources of energy; for example to meet heat and electricity demand in the form of combined cooling, heat and power. Combustion of biomass has a lesser impact than solid fossil fuels (e.g. coal) upon gas pollutant emissions, whilst energy recovery from municipal solid waste is a beneficial component of an integrated, sustainable waste management programme. Concurrent combustion of these fuels using a fluidised bed combustor may be a successful method of overcoming some of the disadvantages of biomass (high fuel supply and distribution costs, combustion characteristics) and characteristics of municipal solid waste (heterogeneous content, conflict with materials recycling). It should be considered that combustion of municipal solid waste may be a financially attractive disposal route if a 'gate fee' value exists for accepting waste for combustion, which will reduce the net cost of utilising relatively more expensive biomass fuels. Results Emissions of nitrogen monoxide and sulphur dioxide for combustion of biomass are suppressed after substitution of biomass for municipal solid waste materials as the input fuel mixture. Interactions between these and other pollutants such as hydrogen chloride, nitrous oxide and carbon monoxide indicate complex, competing reactions occur between intermediates of these compounds to determine final resultant emissions. Conclusions Fluidised bed concurrent combustion is an appropriate technique to exploit biomass and municipal solid waste resources, without the use of fossil fuels. The addition of municipal solid waste to biomass combustion has the effect of reducing emissions of some gaseous pollutants. PMID:21284885

Effects of Fuel and Nozzle Characteristics on Micro Gas Turbine System: A Review

NASA Astrophysics Data System (ADS)

Akasha Hashim, Muhammad; Khalid, Amir; Salleh, Hamidon; Sunar, Norshuhaila Mohamed

2017-08-01

For many decades, gas turbines have been used widely in the internal combustion engine industry. Due to the deficiency of fossil fuel and the concern of global warming, the used of bio-gas have been recognized as one of most clean fuels in the application of engine to improve performance of lean combustion and minimize the production of NOX and PM. This review paper is to understand the combustion performance using dual-fuel nozzle for a micro gas turbine that was basically designed as a natural gas fuelled engine, the nozzle characteristics of the micro gas turbine has been modelled and the effect of multi-fuel used were investigated. The used of biogas (hydrogen) as substitute for liquid fuel (methane) at constant fuel injection velocity, the flame temperature is increased, but the fuel low rate reduced. Applying the blended fuel at constant fuel rate will increased the flame temperature as the hydrogen percentages increased. Micro gas turbines which shows the uniformity of the flow distribution that can be improved without the increase of the pressure drop by applying the variable nozzle diameters into the fuel supply nozzle design. It also identifies the combustion efficiency, better fuel mixing in combustion chamber using duel fuel nozzle with the largest potential for the future. This paper can also be used as a reference source that summarizes the research and development activities on micro gas turbines.

Final Report - Low Temperature Combustion Chemistry And Fuel Component Interactions

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

Wooldridge, Margaret

Recent research into combustion chemistry has shown that reactions at “low temperatures” (700 – 1100 K) have a dramatic influence on ignition and combustion of fuels in virtually every practical combustion system. A powerful class of laboratory-scale experimental facilities that can focus on fuel chemistry in this temperature range is the rapid compression facility (RCF), which has proven to be a versatile tool to examine the details of fuel chemistry in this important regime. An RCF was used in this project to advance our understanding of low temperature chemistry of important fuel compounds. We show how factors including fuel molecularmore » structure, the presence of unsaturated C=C bonds, and the presence of alkyl ester groups influence fuel auto-ignition and produce variable amounts of negative temperature coefficient behavior of fuel ignition. We report new discoveries of synergistic ignition interactions between alkane and alcohol fuels, with both experimental and kinetic modeling studies of these complex interactions. The results of this project quantify the effects of molecular structure on combustion chemistry including carbon bond saturation, through low temperature experimental studies of esters, alkanes, alkenes, and alcohols.« less

Evaluation and Improvement of Liquid Propellant Rocket Chugging Analysis Techniques. Part 2: a Study of Low Frequency Combustion Instability in Rocket Engine Preburners Using a Heterogeneous Stirred Tank Reactor Model. Final Report M.S. Thesis - Aug. 1987

NASA Technical Reports Server (NTRS)

Bartrand, Timothy A.

1988-01-01

During the shutdown of the space shuttle main engine, oxygen flow is shut off from the fuel preburner and helium is used to push the residual oxygen into the combustion chamber. During this process a low frequency combustion instability, or chug, occurs. This chug has resulted in damage to the engine's augmented spark igniter due to backflow of the contents of the preburner combustion chamber into the oxidizer feed system. To determine possible causes and fixes for the chug, the fuel preburner was modeled as a heterogeneous stirred tank combustion chamber, a variable mass flow rate oxidizer feed system, a constant mass flow rate fuel feed system and an exit turbine. Within the combustion chamber gases were assumed perfectly mixed. To account for liquid in the combustion chamber, a uniform droplet distribution was assumed to exist in the chamber, with mean droplet diameter determined from an empirical relation. A computer program was written to integrate the resulting differential equations. Because chamber contents were assumed perfectly mixed, the fuel preburner model erroneously predicted that combustion would not take place during shutdown. The combustion rate model was modified to assume that all liquid oxygen that vaporized instantaneously combusted with fuel. Using this combustion model, the effect of engine parameters on chamber pressure oscillations during the SSME shutdown was calculated.

40 CFR 97.302 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., petroleum, coal, or any form of solid, liquid, or gaseous fuel derived from such material. Fossil-fuel-fired... right-of-way tree trimmings. Boiler means an enclosed fossil-or other-fuel-fired combustion device used... means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine: (1...

40 CFR 97.102 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., petroleum, coal, or any form of solid, liquid, or gaseous fuel derived from such material. Fossil-fuel-fired... enclosed fossil- or other-fuel-fired combustion device used to produce heat and to transfer heat to... means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine: (1...

40 CFR 96.102 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., petroleum, coal, or any form of solid, liquid, or gaseous fuel derived from such material. Fossil-fuel-fired... right-of-way tree trimmings. Boiler means an enclosed fossil- or other-fuel-fired combustion device used..., fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine: (1) Having equipment used...

40 CFR 96.102 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., petroleum, coal, or any form of solid, liquid, or gaseous fuel derived from such material. Fossil-fuel-fired... right-of-way tree trimmings. Boiler means an enclosed fossil- or other-fuel-fired combustion device used..., fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine: (1) Having equipment used...

40 CFR 97.102 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., petroleum, coal, or any form of solid, liquid, or gaseous fuel derived from such material. Fossil-fuel-fired... enclosed fossil- or other-fuel-fired combustion device used to produce heat and to transfer heat to... means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine: (1...

40 CFR 96.102 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., petroleum, coal, or any form of solid, liquid, or gaseous fuel derived from such material. Fossil-fuel-fired... right-of-way tree trimmings. Boiler means an enclosed fossil- or other-fuel-fired combustion device used..., fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine: (1) Having equipment used...

40 CFR 97.102 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., petroleum, coal, or any form of solid, liquid, or gaseous fuel derived from such material. Fossil-fuel-fired... enclosed fossil- or other-fuel-fired combustion device used to produce heat and to transfer heat to... means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine: (1...

40 CFR 97.302 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., petroleum, coal, or any form of solid, liquid, or gaseous fuel derived from such material. Fossil-fuel-fired... right-of-way tree trimmings. Boiler means an enclosed fossil-or other-fuel-fired combustion device used... means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine: (1...

40 CFR 97.302 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., petroleum, coal, or any form of solid, liquid, or gaseous fuel derived from such material. Fossil-fuel-fired... right-of-way tree trimmings. Boiler means an enclosed fossil-or other-fuel-fired combustion device used... means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine: (1...

40 CFR 96.102 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., petroleum, coal, or any form of solid, liquid, or gaseous fuel derived from such material. Fossil-fuel-fired... right-of-way tree trimmings. Boiler means an enclosed fossil- or other-fuel-fired combustion device used..., fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine: (1) Having equipment used...

40 CFR 97.102 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., petroleum, coal, or any form of solid, liquid, or gaseous fuel derived from such material. Fossil-fuel-fired... enclosed fossil- or other-fuel-fired combustion device used to produce heat and to transfer heat to... means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine: (1...

40 CFR 96.102 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., petroleum, coal, or any form of solid, liquid, or gaseous fuel derived from such material. Fossil-fuel-fired... right-of-way tree trimmings. Boiler means an enclosed fossil- or other-fuel-fired combustion device used..., fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine: (1) Having equipment used...

40 CFR 97.302 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., petroleum, coal, or any form of solid, liquid, or gaseous fuel derived from such material. Fossil-fuel-fired... right-of-way tree trimmings. Boiler means an enclosed fossil-or other-fuel-fired combustion device used... means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine: (1...

40 CFR 97.302 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., petroleum, coal, or any form of solid, liquid, or gaseous fuel derived from such material. Fossil-fuel-fired... right-of-way tree trimmings. Boiler means an enclosed fossil-or other-fuel-fired combustion device used... means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine: (1...

40 CFR 97.102 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., petroleum, coal, or any form of solid, liquid, or gaseous fuel derived from such material. Fossil-fuel-fired... enclosed fossil- or other-fuel-fired combustion device used to produce heat and to transfer heat to... means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine: (1...

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.

Emissions from laboratory combustion of wildland fuels: Emission factors and source profiles

Treesearch

L.-W. Anthony Chen; Hans Moosmuller; W. Patrick Arnott; Judith C. Chow; John G. Watson; Ronald A. Susott; Ronald E. Babbitt; Cyle E. Wold; Emily N. Lincoln; Wei Min Hao

2007-01-01

Combustion of wildland fuels represents a major source of particulate matter (PM) and light-absorbing elemental carbon (EC) on a national and global scale, but the emission factors and source profiles have not been well characterized with respect to different fuels and combustion phases. These uncertainties limit the accuracy of current emission inventories, smoke...

40 CFR 98.36 - Data reporting requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... measured by the CEMS consists entirely of non-biogenic CO2 (i.e., CO2 from fossil fuel combustion plus, if... tons of CO2e. If any of the units burn both fossil fuels and biomass, report also the annual CO2 emissions from combustion of all fossil fuels combined and annual CO2 emissions from combustion of all...

Fuel injection device and method

DOEpatents

Carlson, L.W.

1983-12-21

A fuel injection system and method provide for shaping a combustion plume within a combustion chamber to effectively recirculate hot combustion gases for stable combustion conditions while providing symmetrical combustion conditions. Char and molten slag are passed to the outer boundary layer to complete combustion of char while permitting initial substoichiometric combustion in a reductive atmosphere for reducing discharge of nitrogen oxides. Shaping of the plume is accomplished by an axially adjustable pintle which permits apportionment of driving pressure between elements which contribute tangential and those which contribute radial directional components to oxidant flow entering the combustion chamber.

Fuel injection device and method

DOEpatents

Carlson, Larry W.

1986-01-01

A fuel injection system and method provide for shaping a combustion plume within a combustion chamber to effectively recirculate hot combustion gases for stable combustion conditions while providing symmetrical combustion conditions. Char and molten slag are passed to the outer boundary layer to complete combustion of char while permitting initial substoichiometric combustion in a reductive atmosphere for reducing discharge of nitrogen oxides. Shaping of the plume is accomplished by an axially adjustable pintle which permits apportionment of driving pressure between elements which contribute tangential and those which contribute radial directional components to oxidant flow entering the combustion chamber.

Fuel injection device and method

DOEpatents

Carlson, Larry W.

1986-02-04

A fuel injection system and method provide for shaping a combustion plume within a combustion chamber to effectively recirculate hot combustion gases for stable combustion conditions while providing symmetrical combustion conditions. Char and molten slag are passed to the outer boundary layer to complete combustion of char while permitting initial substoichiometric combustion in a reductive atmosphere for reducing discharge of nitrogen oxides. Shaping of the plume is accomplished by an axially adjustable pintle which permits apportionment of driving pressure between elements which contribute tangential and those which contribute radial directional components to oxidant flow entering the combustion chamber.

Compression-ignition engine tests of several fuels

NASA Technical Reports Server (NTRS)

Spanogle, J A

1932-01-01

The tests reported in this paper were made to devise simple engine tests which would rate fuels as to their comparative value and their suitability for the operating conditions of the individual engine on which the tests are made. Three commercial fuels were used in two test engines having combustion chambers with and without effective air flow. Strictly comparative performance tests gave almost identical results for the three fuels. Analysis of indicator cards allowed a differentiation between fuels on a basis of rates of combustion. The same comparative ratings were obtained by determining the consistent operating range of injection advance angle for the three fuels. The difference in fuels is more pronounced in a quiescent combustion chamber than in one with high-velocity air flow. A fuel is considered suitable for the operating conditions of an engine with a quiescent combustion chamber if it permits the injection of the fuel to be advanced beyond the optimum without exceeding allowable knock or allowable maximum cylinder pressures.

Engine combustion control via fuel reactivity stratification

DOEpatents

Reitz, Rolf Deneys; Hanson, Reed M.; Splitter, Derek A.; Kokjohn, Sage L.

2015-07-14

A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a preferred implementation, a lower-reactivity fuel charge is injected or otherwise introduced into the combustion chamber, preferably sufficiently early that it becomes at least substantially homogeneously dispersed within the chamber before a subsequent injection is made. One or more subsequent injections of higher-reactivity fuel charges are then made, and these preferably distribute the higher-reactivity matter within the lower-reactivity chamber space such that combustion begins in the higher-reactivity regions, and with the lower-reactivity regions following thereafter. By appropriately choosing the reactivities of the charges, their relative amounts, and their timing, combustion can be tailored to achieve optimal power output (and thus fuel efficiency), at controlled temperatures (and thus controlled NOx), and with controlled equivalence ratios (and thus controlled soot).

Engine combustion control via fuel reactivity stratification

DOEpatents

Reitz, Rolf Deneys; Hanson, Reed M.; Splitter, Derek A.; Kokjohn, Sage L.

2016-06-28

A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a preferred implementation, a lower-reactivity fuel charge is injected or otherwise introduced into the combustion chamber, preferably sufficiently early that it becomes at least substantially homogeneously dispersed within the chamber before a subsequent injection is made. One or more subsequent injections of higher-reactivity fuel charges are then made, and these preferably distribute the higher-reactivity matter within the lower-reactivity chamber space such that combustion begins in the higher-reactivity regions, and with the lower-reactivity regions following thereafter. By appropriately choosing the reactivities of the charges, their relative amounts, and their timing, combustion can be tailored to achieve optimal power output (and thus fuel efficiency), at controlled temperatures (and thus controlled NOx), and with controlled equivalence ratios (and thus controlled soot).

Engine combustion control via fuel reactivity stratification

DOEpatents

Reitz, Rolf Deneys; Hanson, Reed M; Splitter, Derek A; Kokjohn, Sage L

2013-12-31

A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a preferred implementation, a lower-reactivity fuel charge is injected or otherwise introduced into the combustion chamber, preferably sufficiently early that it becomes at least substantially homogeneously dispersed within the chamber before a subsequent injection is made. One or more subsequent injections of higher-reactivity fuel charges are then made, and these preferably distribute the higher-reactivity matter within the lower-reactivity chamber space such that combustion begins in the higher-reactivity regions, and with the lower-reactivity regions following thereafter. By appropriately choose the reactivities of the charges, their relative amounts, and their timing, combustion can be tailored to achieve optimal power output (and thus fuel efficiency), at controlled temperatures (and thus controlled NOx), and with controlled equivalence ratios (and thus controlled soot).

Large eddy simulation of soot evolution in an aircraft combustor

NASA Astrophysics Data System (ADS)

Mueller, Michael E.; Pitsch, Heinz

2013-11-01

An integrated kinetics-based Large Eddy Simulation (LES) approach for soot evolution in turbulent reacting flows is applied to the simulation of a Pratt & Whitney aircraft gas turbine combustor, and the results are analyzed to provide insights into the complex interactions of the hydrodynamics, mixing, chemistry, and soot. The integrated approach includes detailed models for soot, combustion, and the unresolved interactions between soot, chemistry, and turbulence. The soot model is based on the Hybrid Method of Moments and detailed descriptions of soot aggregates and the various physical and chemical processes governing their evolution. The detailed kinetics of jet fuel oxidation and soot precursor formation is described with the Radiation Flamelet/Progress Variable model, which has been modified to account for the removal of soot precursors from the gas-phase. The unclosed filtered quantities in the soot and combustion models, such as source terms, are closed with a novel presumed subfilter PDF approach that accounts for the high subfilter spatial intermittency of soot. For the combustor simulation, the integrated approach is combined with a Lagrangian parcel method for the liquid spray and state-of-the-art unstructured LES technology for complex geometries. Two overall fuel-to-air ratios are simulated to evaluate the ability of the model to make not only absolute predictions but also quantitative predictions of trends. The Pratt & Whitney combustor is a Rich-Quench-Lean combustor in which combustion first occurs in a fuel-rich primary zone characterized by a large recirculation zone. Dilution air is then added downstream of the recirculation zone, and combustion continues in a fuel-lean secondary zone. The simulations show that large quantities of soot are formed in the fuel-rich recirculation zone, and, furthermore, the overall fuel-to-air ratio dictates both the dominant soot growth process and the location of maximum soot volume fraction. At the higher fuel-to-air ratio, the maximum soot volume fraction is found inside the recirculation zone; at the lower fuel-to-air ratio, turbulent fluctuations in the mixture fraction promote the oxidation of soot inside the recirculation zone and suppress the accumulation of a large soot volume fraction. Downstream, soot exits the combustor in intermittent fuel-rich pockets that are not mixed during the injection of dilution air and subsequent secondary fuel-lean combustion. At the higher fuel-to-air ratio, the frequency of these fuel-rich pockets is increased, leading to higher soot emissions from the combustor. Quantitatively, the soot emissions from the combustor are overpredicted by about 50%, which is a substantial improvement over previous works utilizing RANS to predict such emissions. In addition, the ratio between the two fuel-to-air ratios predicted by LES compares very favorably with the experimental measurements. Furthermore, soot growth is dominated by an acetylene-based pathway rather than an aromatic-based pathway, which is usually the dominant mechanism in nonpremixed flames. This finding is the result of the interactions between the hydrodynamics, mixing, chemistry, and soot in the recirculation zone and the resulting residence times of soot at various mixture fractions (compositions), which are not the same in this complex recirculating flow as in nonpremixed jet flames.

Basic Considerations in the Combustion of Hydrocarbon Fuels with Air

NASA Technical Reports Server (NTRS)

Barnett, Henry C; Hibbard, Robert R

1957-01-01

Basic combustion research is collected, collated, and interpreted as it applies to flight propulsion. The following fundamental processes are treated in separate chapters: atomization and evaporation of liquid fuels, flow and mixing processes in combustion chambers, ignition and flammability of hydrocarbon fuels, laminar flame propagation, turbulent flames, flame stabilization, diffusion flames, oscillations in combustors, and smoke and coke formation in the combustion of hydrocarbon-air mixtures. Theoretical background, basic experimental data, and practical significance to flight propulsion are presented.

Downhole steam generator using low pressure fuel and air supply

DOEpatents

Fox, Ronald L.

1983-01-01

An apparatus for generation of steam in a borehole for penetration into an earth formation wherein a spiral, tubular heat exchanger is used in the combustion chamber to isolate the combustion process from the water being superheated for conversion into steam. The isolation allows combustion of a relatively low pressure oxidant and fuel mixture for generating high enthalpy steam. The fuel is preheated by feedback of combustion gases from the top of the combustion chamber through a fuel preheater chamber. The hot exhaust gases of combustion at the bottom of the combustion chamber, after flowing over the heat exchanger enter an exhaust passage and pipe. The exhaust pipe is mounted inside the water supply line heating the water flowing into the heat exchanger. After being superheated in the heat exchanger, the water is ejected through an expansion nozzle and converts into steam prior to penetration into the earth formation. Pressure responsive doors are provided at a steam outlet downstream of the nozzle and close when the steam pressure is lost due to flameout.

Cavity Coupled Aeroramp Injector Combustion Study

DTIC Science & Technology

2009-08-01

Lin 5 Taitech Inc., Beavercreek, OH, 45430 The difficulties with fueling of supersonic combustion ramjet engines with hydrocarbon based fuels...combustor to not force the pre- combustion shock train out of the isolator and, in a full engine with inlet, cause an inlet unstart and likely...metric used to quantify engine performance is the combustion efficiency. Figure 9 shows the comparison of the combustion efficiency as a function of

Ducted combustion chamber for direct injection engines and method

DOEpatents

Mueller, Charles

2015-03-03

An internal combustion engine includes an engine block having a cylinder bore and a cylinder head having a flame deck surface disposed at one end of the cylinder bore. A piston connected to a rotatable crankshaft and configured to reciprocate within the cylinder bore has a piston crown portion facing the flame deck surface such that a combustion chamber is defined within the cylinder bore and between the piston crown and the flame deck surface. A fuel injector having a nozzle tip disposed in fluid communication with the combustion chamber has at least one nozzle opening configured to inject a fuel jet into the combustion chamber along a fuel jet centerline. At least one duct defined in the combustion chamber between the piston crown and the flame deck surface has a generally rectangular cross section and extends in a radial direction relative to the cylinder bore substantially along the fuel jet centerline.

Cassidy conducts MDCA Fuel Reservoir Remove and Replace OPS

NASA Image and Video Library

2013-04-10

ISS035-E-017699 (10 April 2013) --- This is one of several photos documenting the Multi-user Droplet Combustion Apparatus (MDCA) Fuel Reservoir replacement. Here, Expedition 35 Flight Engineer Chris Cassidy removes and replaces one of the Fuel Reservoirs with the MDCA Chamber Insert Assembly (CIA) pulled partially out of the Combustion Chamber. The MDCA Fuel Reservoirs contain the liquid fuel used during droplet combustion experiments. This reservoir change-out was in support of the FLame EXtinguishment (FLEX)-2 experiment, scheduled to be executed by ground controllers.

Cassidy conducts MDCA Fuel Reservoir Remove and Replace OPS

NASA Image and Video Library

2013-04-10

ISS035-E-017712 (10 April 2013)?-- This is one of several photos documenting the Multi-user Droplet Combustion Apparatus (MDCA) Fuel Reservoir replacement in the U.S. lab Destiny. Here, Expedition 35 Flight Engineer Chris Cassidy removes and replaces one of the Fuel Reservoirs with the MDCA Chamber Insert Assembly (CIA) pulled partially out of the Combustion Chamber. The MDCA Fuel Reservoirs contain the liquid fuel used during droplet combustion experiments. This reservoir change-out was in support of the FLame EXtinguishment (FLEX)-2 experiment, scheduled to be executed by ground controllers.

Effects of fuel-injector design on ultra-lean combustion performance

NASA Technical Reports Server (NTRS)

Anderson, D. N.

1981-01-01

Emissions data were obtained for six fuel injector configurations tested with ultra lean combustion. Fuel injectors included three multiple source designs and three configurations using a single air assist injector. Only the multiple source fuel injectors provided acceptable emissions. Values of 16g CO/kg fuel, 1.9g HC/kg fuel, and 19.g NO2/kg fuel were obtained for the combustion temperature range of 1450 to 1700 K for both a high blockage 19 source injector and a low blockage 41 source injector. It was shown that high fuel injector pressure drop may not be required to achieve low emissions performance at high inlet air temperature when the fuel is well dispersed in the airstream.

Millwright Apprenticeship. Related Training Modules. 10.1-10.5 Combustion.

ERIC Educational Resources Information Center

Lane Community Coll., Eugene, OR.

This packet, part of the instructional materials for the Oregon apprenticeship program for millwright training, contains five modules covering combustion. The modules provide information on the following topics: the combustion process, types of fuel, air and fuel gases, heat transfer, and combustion in wood. Each module consists of a goal,…

Superheated fuel injection for combustion of liquid-solid slurries

DOEpatents

Robben, Franklin A.

1985-01-01

A method and device for obtaining, upon injection, flash evaporation of a liquid in a slurry fuel to aid in ignition and combustion. The device is particularly beneficial for use of coal-water slurry fuels in internal combustion engines such as diesel engines and gas turbines, and in external combustion devices such as boilers and furnaces. The slurry fuel is heated under pressure to near critical temperature in an injector accumulator, where the pressure is sufficiently high to prevent boiling. After injection into a combustion chamber, the water temperature will be well above boiling point at a reduced pressure in the combustion chamber, and flash boiling will preferentially take place at solid-liquid surfaces, resulting in the shattering of water droplets and the subsequent separation of the water from coal particles. This prevents the agglomeration of the coal particles during the subsequent ignition and combustion process, and reduces the energy required to evaporate the water and to heat the coal particles to ignition temperature. The overall effect will be to accelerate the ignition and combustion rates, and to reduce the size of the ash particles formed from the coal.

Increasing Operational Stability in Low NOX GT Combustor Using Fuel Rich Concentric Pilot Combustor

NASA Astrophysics Data System (ADS)

Levy, Yeshayahou; Erenburg, Vladimir; Sherbaum, Valery; Ovcharenko, Vitali; Rosentsvit, Leonid; Chudnovsky, Boris; Herszage, Amiel; Talanker, Alexander

2012-03-01

Lean combustion is a method in which combustion takes place under low equivalence ratio and relatively low combustion temperatures. As such, it has the potential to lower the effect of the relatively high activation energy nitrogen-oxygen reactions which are responsible for substantial NOX formation during combustion processes. However, lowering temperature reduces the reaction rate and deteriorates combustion stability. The objective of the present study is to reduce the lower equivalence ratio limit of the stable combustion operational boundary in lean Gas Turbine (GT) combustors while still maintaining combustion stability. A lean premixed gaseous combustor was equipped with a surrounding concentric pilot flame operating under rich conditions, thus generating a hot stream of combustion products with significant amount of reactive radicals. The main combustor's fuel-air composition was varied from stoichiometric to lean mixtures. The pilot's mixture composition was also varied by changing the air flow rate, within a limited rich mixtures range. The pilot fuel flow rate was always lower than five percent of the total fuel supply at the specific stage of the experiments.

Pulsed jet combustion generator for premixed charge engines

DOEpatents

Oppenheim, A. K.; Stewart, H. E.; Hom, K.

1990-01-01

A method and device for generating pulsed jets which will form plumes comprising eddie structures, which will entrain a fuel/air mixture from the head space of an internal combustion engine, and mixing this fuel/air mixture with a pre-ignited fuel/air mixture of the plumes thereby causing combustion of the reactants to occur within the interior of the eddie structures.

40 CFR Appendix G to Part 75 - Determination of CO2 Emissions

Code of Federal Regulations, 2014 CFR

2014-07-01

... following procedures to estimate daily CO2 mass emissions from the combustion of fossil fuels. The optional... tons/day) from the combustion of fossil fuels. Where fuel flow is measured in a common pipe header (i.e... discharged to the atmosphere (in tons/day) as the sum of CO2 emissions from combustion and, if applicable...

40 CFR Appendix G to Part 75 - Determination of CO2 Emissions

Code of Federal Regulations, 2011 CFR

2011-07-01

... following procedures to estimate daily CO2 mass emissions from the combustion of fossil fuels. The optional... tons/day) from the combustion of fossil fuels. Where fuel flow is measured in a common pipe header (i.e... discharged to the atmosphere (in tons/day) as the sum of CO2 emissions from combustion and, if applicable...

40 CFR Appendix G to Part 75 - Determination of CO2 Emissions

Code of Federal Regulations, 2013 CFR

2013-07-01

... following procedures to estimate daily CO2 mass emissions from the combustion of fossil fuels. The optional... tons/day) from the combustion of fossil fuels. Where fuel flow is measured in a common pipe header (i.e... discharged to the atmosphere (in tons/day) as the sum of CO2 emissions from combustion and, if applicable...

40 CFR Appendix G to Part 75 - Determination of CO2 Emissions

Code of Federal Regulations, 2012 CFR

2012-07-01

... following procedures to estimate daily CO2 mass emissions from the combustion of fossil fuels. The optional... tons/day) from the combustion of fossil fuels. Where fuel flow is measured in a common pipe header (i.e... discharged to the atmosphere (in tons/day) as the sum of CO2 emissions from combustion and, if applicable...

Performance Evaluation of a High Bandwidth Liquid Fuel Modulation Valve for Active Combustion Control

NASA Technical Reports Server (NTRS)

Saus, Joseph R.; DeLaat, John C.; Chang, Clarence T.; Vrnak, Daniel R.

2012-01-01

At the NASA Glenn Research Center, a characterization rig was designed and constructed for the purpose of evaluating high bandwidth liquid fuel modulation devices to determine their suitability for active combustion control research. Incorporated into the rig s design are features that approximate conditions similar to those that would be encountered by a candidate device if it were installed on an actual combustion research rig. The characterized dynamic performance measures obtained through testing in the rig are planned to be accurate indicators of expected performance in an actual combustion testing environment. To evaluate how well the characterization rig predicts fuel modulator dynamic performance, characterization rig data was compared with performance data for a fuel modulator candidate when the candidate was in operation during combustion testing. Specifically, the nominal and off-nominal performance data for a magnetostrictive-actuated proportional fuel modulation valve is described. Valve performance data were collected with the characterization rig configured to emulate two different combustion rig fuel feed systems. Fuel mass flows and pressures, fuel feed line lengths, and fuel injector orifice size was approximated in the characterization rig. Valve performance data were also collected with the valve modulating the fuel into the two combustor rigs. Comparison of the predicted and actual valve performance data show that when the valve is operated near its design condition the characterization rig can appropriately predict the installed performance of the valve. Improvements to the characterization rig and accompanying modeling activities are underway to more accurately predict performance, especially for the devices under development to modulate fuel into the much smaller fuel injectors anticipated in future lean-burning low-emissions aircraft engine combustors.

Simultaneous identification of multi-combustion-intermediates of alkanol-air flames by femtosecond filament excitation for combustion sensing

PubMed Central

Li, Helong; Chu, Wei; Xu, Huailiang; Cheng, Ya; Chin, See-Leang; Yamanouchi, Kaoru; Sun, Hong-Bo

2016-01-01

Laser filamentation produced by the propagation of intense laser pulses in flames is opening up new possibility in application to combustion diagnostics that can provide useful information on understanding combustion processes, enhancing combustion efficiency and reducing pollutant products. Here we present simultaneous identification of multiple combustion intermediates by femtosecond filament excitation for five alkanol-air flames fueled by methanol, ethanol, n-propanol, n-butanol, and n-pentanol. We experimentally demonstrate that the intensities of filament-induced photoemission signals from the combustion intermediates C, C2, CH, CN increase with the increasing number of carbons in the fuel molecules, and the signal ratios between the intermediates (CH/C, CH/C2, CN/C, CH/C2, CN/CH) are different for different alkanol combustion flames. Our observation provides a way for sensing multiple combustion components by femtosecond filament excitation in various combustion conditions that strongly depend on the fuel species. PMID:27250021

Solid fuel combustion system for gas turbine engine

DOEpatents

Wilkes, Colin; Mongia, Hukam C.

1993-01-01

A solid fuel, pressurized fluidized bed combustion system for a gas turbine engine includes a carbonizer outside of the engine for gasifying coal to a low Btu fuel gas in a first fraction of compressor discharge, a pressurized fluidized bed outside of the engine for combusting the char residue from the carbonizer in a second fraction of compressor discharge to produce low temperature vitiated air, and a fuel-rich, fuel-lean staged topping combustor inside the engine in a compressed air plenum thereof. Diversion of less than 100% of compressor discharge outside the engine minimizes the expense of fabricating and maintaining conduits for transferring high pressure and high temperature gas and incorporation of the topping combustor in the compressed air plenum of the engine minimizes the expense of modifying otherwise conventional gas turbine engines for solid fuel, pressurized fluidized bed combustion.

Investigation of methyl decanoate combustion in an optical direct-injection diesel engine

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

Cheng, A. S.; Dumitrescu, Cosmin E.; Mueller, Charles J.

In this study, an optically accessible heavy-duty diesel engine was used to investigate the impact of methyl decanoate (MD) on combustion and emissions. A specific goal of the study was to determine if MD could enable soot-free leaner-lifted flame combustion (LLFC) – a mode of mixing-controlled combustion associated with fuel-air equivalence ratios below approximately two. An ultra-low sulfur diesel certification fuel (CF) was used as the baseline fuel, and experiments were conducted at two fuel-injection pressures with three levels of charge-gas dilution. In addition to conventional pressure-based and engine-out emissions measurements, exhaust laser-induced incandescence, in-cylinder natural luminosity (NL), and in-cylindermore » chemiluminescence (CL) diagnostics were used to provide detailed insight into combustion processes.« less

Investigation of methyl decanoate combustion in an optical direct-injection diesel engine

DOE PAGES

Cheng, A. S.; Dumitrescu, Cosmin E.; Mueller, Charles J.

2014-11-24

In this study, an optically accessible heavy-duty diesel engine was used to investigate the impact of methyl decanoate (MD) on combustion and emissions. A specific goal of the study was to determine if MD could enable soot-free leaner-lifted flame combustion (LLFC) – a mode of mixing-controlled combustion associated with fuel-air equivalence ratios below approximately two. An ultra-low sulfur diesel certification fuel (CF) was used as the baseline fuel, and experiments were conducted at two fuel-injection pressures with three levels of charge-gas dilution. In addition to conventional pressure-based and engine-out emissions measurements, exhaust laser-induced incandescence, in-cylinder natural luminosity (NL), and in-cylindermore » chemiluminescence (CL) diagnostics were used to provide detailed insight into combustion processes.« less

Construction of combustion models for rapeseed methyl ester bio-diesel fuel for internal combustion engine applications.

PubMed

Golovitchev, Valeri I; Yang, Junfeng

2009-01-01

Bio-diesel fuels are non-petroleum-based diesel fuels consisting of long chain alkyl esters produced by the transesterification of vegetable oils, that are intended for use (neat or blended with conventional fuels) in unmodified diesel engines. There have been few reports of studies proposing theoretical models for bio-diesel combustion simulations. In this study, we developed combustion models based on ones developed previously. We compiled the liquid fuel properties, and the existing detailed mechanism of methyl butanoate ester (MB, C(5)H(10)O(2)) oxidation was supplemented by sub-mechanisms for two proposed fuel constituent components, C(7)H(16) and C(7)H(8)O (and then, by mp2d, C(4)H(6)O(2) and propyne, C(3)H(4)) to represent the combustion model for rapeseed methyl ester described by the chemical formula, C(19)H(34)O(2) (or C(19)H(36)O(2)). The main fuel vapor thermal properties were taken as those of methyl palmitate C(19)H(36)O(2) in the NASA polynomial form of the Burcat database. The special global reaction was introduced to "crack" the main fuel into its constituent components. This general reaction included 309 species and 1472 reactions, including soot and NO(x) formation processes. The detailed combustion mechanism was validated using shock-tube ignition-delay data under diesel engine conditions. For constant volume and diesel engine (Volvo D12C) combustion modeling, this mechanism could be reduced to 88 species participating in 363 reactions.

Relationship of fuel size and spacing to combustion characteristics of laboratory fuel cribs

Treesearch

Hal E. Anderson

1990-01-01

Flaming combustion in cribs of large woody fuels, thickness 5 cm or greater, is not sustained when fuel spacing ratio, fuel edge-to-edge separation distance to fuel thickness, is greater than 3:1. The flame length associated with the large-fuel burning rate was found to drop rapidly when the large-fuel spacing ratio increases beyond 2.23:1. This supports the critical...

40 CFR 98.36 - Data reporting requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... fossil fuels only, the annual CO2 emissions for all fuels combined. Reporting CO2 emissions by type of fuel is not required. (ii) For units that burn both fossil fuels and biomass, the annual CO2 emissions from combustion of all fossil fuels combined and the annual CO2 emissions from combustion of all...

Fuel Injector With Shear Atomizer

NASA Technical Reports Server (NTRS)

Beal, George W.; Mills, Virgil L.; Smith, Durward B., II; Beacom, William F.

1995-01-01

Atomizer for injecting liquid fuel into combustion chamber uses impact and swirl to break incoming stream of fuel into small, more combustible droplets. Slanted holes direct flow of liquid fuel to stepped cylindrical wall. Impact on wall atomizes liquid. Air flowing past vanes entrains droplets of liquid in swirling flow. Fuel injected at pressure lower than customarily needed.

Fuel-rich catalytic combustion: A fuel processor for high-speed propulsion

NASA Technical Reports Server (NTRS)

Brabbs, Theodore A.; Rollbuhler, R. James; Lezberg, Erwin A.

1990-01-01

Fuel-rich catalytic combustion of Jet-A fuel was studied over the equivalence ratio range 4.7 to 7.8, which yielded combustion temperatures of 1250 to 1060 K. The process was soot-free and the gaseous products were similar to those obtained in the iso-octane study. A carbon atom balance across the catalyst bed calculated for the gaseous products accounted for about 70 to 90 percent of the fuel carbon; the balance was condensed as a liquid in the cold trap. It was shown that 52 to 77 percent of the fuel carbon was C1, C2, and C3 molecules. The viability of using fuel-rich catalytic combustion as a technique for preheating a practical fuel to very high temperatures was demonstrated. Preliminary results from the scaled up version of the catalytic combustor produced a high-temperature fuel containing large amounts of hydrogen and carbon monoxide. The balance of the fuel was completely vaporized and in various stages of pyrolysis and oxidation. Visual observations indicate that there was no soot present.

Injector with integrated resonator

DOEpatents

Johnson, Thomas Edward; Ziminsky, Willy Steve; York, William David; Stevenson, Christian Xavier

2014-07-29

The system may include a turbine engine. The turbine engine may include a fuel nozzle. The fuel nozzle may include an air path. The fuel nozzle may also include a fuel path such that the fuel nozzle is in communication with a combustion zone of the turbine engine. Furthermore, the fuel nozzle may include a resonator. The resonator may be disposed in the fuel nozzle directly adjacent to the combustion zone.

Active suppression of vortex-driven combustion instability using controlled liquid-fuel injection

NASA Astrophysics Data System (ADS)

Pang, Bin

Combustion instabilities remain one of the most challenging problems encountered in developing propulsion and power systems. Large amplitude pressure oscillations, driven by unsteady heat release, can produce numerous detrimental effects. Most previous active control studies utilized gaseous fuels to suppress combustion instabilities. However, using liquid fuel to suppress combustion instabilities is more realistic for propulsion applications. Active instability suppression in vortex-driven combustors using a direct liquid fuel injection strategy was theoretically established and experimentally demonstrated in this dissertation work. Droplet size measurements revealed that with pulsed fuel injection management, fuel droplet size could be modulated periodically. Consequently, desired heat release fluctuation could be created. If this oscillatory heat release is coupled with the natural pressure oscillation in an out of phase manner, combustion instabilities can be suppressed. To identify proper locations of supplying additional liquid fuel for the purpose of achieving control, the natural heat release pattern in a vortex-driven combustor was characterized in this study. It was found that at high Damkohler number oscillatory heat release pattern closely followed the evolving vortex front. However, when Damkohler number became close to unity, heat release fluctuation wave no longer coincided with the coherent structures. A heat release deficit area was found near the dump plane when combustor was operated in lean premixed conditions. Active combustion instability suppression experiments were performed in a dump combustor using a controlled liquid fuel injection strategy. High-speed Schlieren results illustrated that vortex shedding plays an important role in maintaining self-sustained combustion instabilities. Complete combustion instability control requires total suppression of these large-scale coherent structures. The sound pressure level at the excited dominant frequency was reduced by more than 20 dB with controlled liquid fuel injection method. Scaling issues were also investigated in this dump combustor to test the effectiveness of using pulsed liquid fuel injection strategies to suppress instabilities at higher power output conditions. With the liquid fuel injection control method, it was possible to suppress strong instabilities with initial amplitude of +/-5 psi down to the background noise level. The stable combustor operating range was also expanded from equivalence ratio of 0.75 to beyond 0.9.

Performance gains by using heated natural-gas fuel in an annular turbojet combustor

NASA Technical Reports Server (NTRS)

Marchionna, N. R.

1973-01-01

A full-scale annular turbojet combustor was tested with natural gas fuel heated from ambient temperature to 800 K (980 F). In all tests, heating the fuel improved combustion efficiency. Two sets of gaseous fuel nozzles were tested. Combustion instabilities occurred with one set of nozzles at two conditions: one where the efficiency approached 100 percent with the heated fuel; the other where the efficiency was very poor with the unheated fuel. The second set of nozzles exhibited no combustion instability. Altitude relight tests with the second set showed that relight was improved and was achievable at essentially the same condition as blowout when the fuel temperature was 800 K (980 F).

Apparatus and method for combusting low quality fuel

DOEpatents

Brushwood, John Samuel; Pillsbury, Paul; Foote, John; Heilos, Andreas

2003-11-04

A gas turbine (12) capable of combusting a low quality gaseous fuel having a ratio of flammability limits less than 2, or a heat value below 100 BTU/SCF. A high quality fuel is burned simultaneously with the low quality fuel to eliminate instability in the combustion flame. A sensor (46) is used to monitor at least one parameter of the flame indicative of instability. A controller (50) having the sensor signal (48) as input is programmed to control the relative flow rates of the low quality and high quality fuels. When instability is detected, the flow rate of high quality fuel is automatically increased in relation to the flow rate of low quality fuel to restore stability.

Assessment of future natural gas vehicle concepts

NASA Astrophysics Data System (ADS)

Groten, B.; Arrigotti, S.

1992-10-01

The development of Natural Gas Vehicles is progressing rapidly under the stimulus of recent vehicle emission regulations. The development is following what can be viewed as a three step progression. In the first step, contemporary gasoline or diesel fueled automobiles are retrofitted with equipment enabling the vehicle to operate on either natural gas or standard liquid fuels. The second step is the development of vehicles which utilize traditional internal combustion engines that have been modified to operate exclusively on natural gas. These dedicated natural gas vehicles operate more efficiently and have lower emissions than the dual fueled vehicles. The third step is the redesigning, from the ground up, of a vehicle aimed at exploiting the advantages of natural gas as an automotive fuel while minimizing its disadvantages. The current report is aimed at identifying the R&D needs in various fuel storage and engine combinations which have potential for providing increased efficiency, reduced emissions, and reductions in vehicle weight and size. Fuel suppliers, automobile and engine manufacturers, many segments of the natural gas and other industries, and regulatory authorities will influence or be affected by the development of such a third generation vehicle, and it is recommended that GRI act to bring these groups together in the near future to begin, developing the focus on a 'designed-for-natural-gas' vehicle.

FY 2014 Annual Progress Report - Advanced Combustion Engine Research and Development (Book)

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

Not Available

In the past year, the DOE Hydrogen Program (the Program) made substantial progress toward its goals and objectives. The Program has conducted comprehensive and focused efforts to enable the widespread commercialization of hydrogen and fuel cell technologies in diverse sectors of the economy. With emphasis on applications that will effectively strengthen our nation's energy security and improve our stewardship of the environment, the Program engages in research, development, and demonstration of critical improvements in the technologies. Highlights of the Program's accomplishments can be found in the sub-program chapters of this report.

Method of regulating the amount of underfire air for combustion of wood fuels in spreader-stroke boilers

DOEpatents

Tuttle, Kenneth L.

1980-01-01

A method of metering underfire air for increasing efficiency and reducing particulate emissions from wood-fire, spreader-stoker boilers is disclosed. A portion of the combustion air, approximately one pound of air per pound of wood, is fed through the grate into the fuel bed, while the remainder of the combustion air is distributed above the fuel in the furnace, and the fuel bed is maintained at a depth sufficient to consume all oxygen admitted under fire and to insure a continuous layer of fresh fuel thereover to entrap charred particles inside the fuel bed.

Low NOx combustion using cogenerated oxygen and nitrogen streams

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

Kobayashi, Hisashi; Bool, Lawrence E; Snyder, William J

Combustion of hydrocarbon fuel is achieved with less formation of NOx by feeding the fuel into a slightly oxygen-enriched atmosphere, and separating air into oxygen-rich and nitrogen-rich streams which are fed separately into the combustion device.

40 CFR 49.125 - Rule for limiting the emissions of particulate matter.

Code of Federal Regulations, 2011 CFR

2011-07-01

... pollution sources? (1) Particulate matter emissions from a combustion source stack (except for wood-fired..., British thermal unit (Btu), coal, combustion source, distillate fuel oil, emission, fuel, fuel oil, gaseous fuel, heat input, incinerator, marine vessel, mobile sources, motor vehicle, nonroad engine...

40 CFR 60.4207 - What fuel requirements must I meet if I am an owner or operator of a stationary CI internal...

Code of Federal Regulations, 2011 CFR

2011-07-01

... am an owner or operator of a stationary CI internal combustion engine subject to this subpart? 60... Compression Ignition Internal Combustion Engines Fuel Requirements for Owners and Operators § 60.4207 What fuel requirements must I meet if I am an owner or operator of a stationary CI internal combustion...

40 CFR 60.4207 - What fuel requirements must I meet if I am an owner or operator of a stationary CI internal...

Code of Federal Regulations, 2010 CFR

2010-07-01

... am an owner or operator of a stationary CI internal combustion engine subject to this subpart? 60... Compression Ignition Internal Combustion Engines Fuel Requirements for Owners and Operators § 60.4207 What fuel requirements must I meet if I am an owner or operator of a stationary CI internal combustion...

40 CFR 60.4207 - What fuel requirements must I meet if I am an owner or operator of a stationary CI internal...

Code of Federal Regulations, 2012 CFR

2012-07-01

... am an owner or operator of a stationary CI internal combustion engine subject to this subpart? 60... Compression Ignition Internal Combustion Engines Fuel Requirements for Owners and Operators § 60.4207 What fuel requirements must I meet if I am an owner or operator of a stationary CI internal combustion...

40 CFR 60.4207 - What fuel requirements must I meet if I am an owner or operator of a stationary CI internal...

Code of Federal Regulations, 2013 CFR

2013-07-01

... am an owner or operator of a stationary CI internal combustion engine subject to this subpart? 60... Compression Ignition Internal Combustion Engines Fuel Requirements for Owners and Operators § 60.4207 What fuel requirements must I meet if I am an owner or operator of a stationary CI internal combustion...

40 CFR 60.4207 - What fuel requirements must I meet if I am an owner or operator of a stationary CI internal...

Code of Federal Regulations, 2014 CFR

2014-07-01

... am an owner or operator of a stationary CI internal combustion engine subject to this subpart? 60... Compression Ignition Internal Combustion Engines Fuel Requirements for Owners and Operators § 60.4207 What fuel requirements must I meet if I am an owner or operator of a stationary CI internal combustion...

Investigation of combustion characteristics of methane-hydrogen fuels

NASA Astrophysics Data System (ADS)

Vetkin, A. V.; Suris, A. L.; Litvinova, O. A.

2015-01-01

Numerical investigations of combustion characteristics of methane-hydrogen fuel used at present in tube furnaces of some petroleum refineries are carried out and possible problems related to change-over of existing furnaces from natural gas to methane-hydrogen fuel are analyzed. The effect of the composition of the blended fuel, associated temperature and emissivity of combustion products, temperature of combustion chamber walls, mean beam length, and heat release on variation in the radiation heat flux is investigated. The methane concentration varied from 0 to 100%. The investigations were carried out both at arbitrary given gas temperatures and at effective temperatures determined based on solving a set of equations at various heat-release rates of the combustion chamber and depended on the adiabatic combustion temperature and the temperature at the chamber output. The approximation dependence for estimation of the radiation heat exchange rate in the radiant chamber of the furnace at change-over to fuel with a greater hydrogen content is obtained. Hottel data were applied in the present work in connection with the impossibility to use approximated formulas recommended by the normative method for heat calculation of boilers to determine the gas emissivity, which are limited by the relationship of partial pressures of water steam and carbon dioxide in combustion products . The effect of the methane-hydrogen fuel on the equilibrium concentration of nitrogen oxides is also investigated.

Study on Characteristics of Co-firing Ammonia/Methane Fuels under Oxygen Enriched Combustion Conditions

NASA Astrophysics Data System (ADS)

Xiao, Hua; Wang, Zhaolin; Valera-Medina, Agustin; Bowen, Philip J.

2018-06-01

Having a background of utilising ammonia as an alternative fuel for power generation, exploring the feasibility of co-firing ammonia with methane is proposed to use ammonia to substitute conventional natural gas. However, improvement of the combustion of such fuels can be achieved using conditions that enable an increase of oxygenation, thus fomenting the combustion process of a slower reactive molecule as ammonia. Therefore, the present study looks at oxygen enriched combustion technologies, a proposed concept to improve the performance of ammonia/methane combustion. To investigate the characteristics of ammonia/methane combustion under oxygen enriched conditions, adiabatic burning velocity and burner stabilized laminar flame emissions were studied. Simulation results show that the oxygen enriched method can help to significantly enhance the propagation of ammonia/methane combustion without changing the emission level, which would be quite promising for the design of systems using this fuel for practical applications. Furthermore, to produce low computational-cost flame chemistry for detailed numerical analyses for future combustion studies, three reduced combustion mechanisms of the well-known Konnov's mechanism were compared in ammonia/methane flame simulations under practical gas turbine combustor conditions. Results show that the reduced reaction mechanisms can provide good results for further analyses of oxygen enriched combustion of ammonia/methane. The results obtained in this study also allow gas turbine designers and modellers to choose the most suitable mechanism for further combustion studies and development.

Internal combustion engine fuel controls. (Latest citations from the US Patent database). Published Search

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

Not Available

1992-12-01

The bibliography contains citations of selected patents concerning fuel control devices and methods for use in internal combustion engines. Patents describe air-fuel ratio control, fuel injection systems, evaporative fuel control, and surge-corrected fuel control. Citations also discuss electronic and feedback control, methods for engine protection, and fuel conservation. (Contains a minimum of 232 citations and includes a subject term index and title list.)

Real-time combustion control and diagnostics sensor-pressure oscillation monitor

DOEpatents

Chorpening, Benjamin T [Morgantown, WV; Thornton, Jimmy [Morgantown, WV; Huckaby, E David [Morgantown, WV; Richards, George A [Morgantown, WV

2009-07-14

An apparatus and method for monitoring and controlling the combustion process in a combustion system to determine the amplitude and/or frequencies of dynamic pressure oscillations during combustion. An electrode in communication with the combustion system senses hydrocarbon ions and/or electrons produced by the combustion process and calibration apparatus calibrates the relationship between the standard deviation of the current in the electrode and the amplitudes of the dynamic pressure oscillations by applying a substantially constant voltage between the electrode and ground resulting in a current in the electrode and by varying one or more of (1) the flow rate of the fuel, (2) the flow rate of the oxidant, (3) the equivalence ratio, (4) the acoustic tuning of the combustion system, and (5) the fuel distribution in the combustion chamber such that the amplitudes of the dynamic pressure oscillations in the combustion chamber are calculated as a function of the standard deviation of the electrode current. Thereafter, the supply of fuel and/or oxidant is varied to modify the dynamic pressure oscillations.

Molecular Structure of Photosynthetic Microbial Biofuels for Improved Engine Combustion and Emissions Characteristics

PubMed Central

Hellier, Paul; Purton, Saul; Ladommatos, Nicos

2015-01-01

The metabolic engineering of photosynthetic microbes for production of novel hydrocarbons presents an opportunity for development of advanced designer biofuels. These can be significantly more sustainable, throughout the production-to-consumption lifecycle, than the fossil fuels and crop-based biofuels they might replace. Current biofuels, such as bioethanol and fatty acid methyl esters, have been developed primarily as drop-in replacements for existing fossil fuels, based on their physical properties and autoignition characteristics under specific combustion regimes. However, advances in the genetic engineering of microalgae and cyanobacteria, and the application of synthetic biology approaches offer the potential of designer strains capable of producing hydrocarbons and oxygenates with specific molecular structures. Furthermore, these fuel molecules can be designed for higher efficiency of energy release and lower exhaust emissions during combustion. This paper presents a review of potential fuel molecules from photosynthetic microbes and the performance of these possible fuels in modern internal combustion engines, highlighting which modifications to the molecular structure of such fuels may enhance their suitability for specific combustion regimes. PMID:25941673

Molecular structure of photosynthetic microbial biofuels for improved engine combustion and emissions characteristics.

PubMed

Hellier, Paul; Purton, Saul; Ladommatos, Nicos

2015-01-01

The metabolic engineering of photosynthetic microbes for production of novel hydrocarbons presents an opportunity for development of advanced designer biofuels. These can be significantly more sustainable, throughout the production-to-consumption lifecycle, than the fossil fuels and crop-based biofuels they might replace. Current biofuels, such as bioethanol and fatty acid methyl esters, have been developed primarily as drop-in replacements for existing fossil fuels, based on their physical properties and autoignition characteristics under specific combustion regimes. However, advances in the genetic engineering of microalgae and cyanobacteria, and the application of synthetic biology approaches offer the potential of designer strains capable of producing hydrocarbons and oxygenates with specific molecular structures. Furthermore, these fuel molecules can be designed for higher efficiency of energy release and lower exhaust emissions during combustion. This paper presents a review of potential fuel molecules from photosynthetic microbes and the performance of these possible fuels in modern internal combustion engines, highlighting which modifications to the molecular structure of such fuels may enhance their suitability for specific combustion regimes.

Effects of Air-Fuel Spray and Flame Formation in a Compression-Ignition Engine

NASA Technical Reports Server (NTRS)

Rothrock, A M; Waldron, C D

1937-01-01

High-speed motion pictures were taken at the rate of 2,500 frames per second of the fuel spray and flame formation in the combustion chamber of the NACA combustion apparatus. The compression ratio was 13.2 and the speed 1,500 revolutions per minute. An optical indicator was used to record the time-pressure relationship in the combustion chamber. The air-fuel ratio was varied from 10.4 to 365. The results showed that as the air-fuel ratio was increased definite stratification of the charge occurred in the combustion chamber even though moderate air flow existed. The results also showed the rate of vapor diffusion to be relatively slow.

Development of Air Supply System for Gas Turbine Combustor Test Rig

NASA Astrophysics Data System (ADS)

Kamarudin, Norhaimi Izlan; Hanafi, Muhammad; Mantari, Asril Rajo; Jaafar, Mohammad Nazri Mohd

2010-06-01

Complete combustion process occurs when the air and fuel burns at their stoichiometric ratio, which determines the appropriate amount of air needed to be supplied to the combustion chamber. Thus, designing an appropriate air supply system is important, especially for multi-fuel combustion. Each type of fuel has different molecular properties and structures which influence the stoichiometric ratio. Therefore, the designed air supply system must be operable for different types of fuels. Basically, the design of the air supply system is at atmospheric pressure. It is important that the air which enters the combustion chamber is stable and straight. From the calculation, the maximum required mass flow rate of air is 0.1468kg/s.

40 CFR 98.273 - Calculating GHG emissions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... fossil fuels and combustion of biomass in spent liquor solids. (1) Calculate fossil fuel-based CO2 emissions from direct measurement of fossil fuels consumed and default emissions factors according to the Tier 1 methodology for stationary combustion sources in § 98.33(a)(1). (2) Calculate fossil fuel-based...

Performance of a flameless combustion furnace using biogas and natural gas.

PubMed

Colorado, A F; Herrera, B A; Amell, A A

2010-04-01

Flameless combustion technology has proved to be flexible regarding the utilization of conventional fuels. This flexibility is associated with the main characteristic of the combustion regime, which is the mixing of the reactants above the autoignition temperature of the fuel. Flameless combustion advantages when using conventional fuels are a proven fact. However, it is necessary to assess thermal equipments performance when utilizing bio-fuels, which usually are obtained from biomass gasification and the excreta of animals in bio-digesters. The effect of using biogas on the performance of an experimental furnace equipped with a self-regenerative Flameless burner is reported in this paper. All the results were compared to the performance of the system fueled with natural gas. Results showed that temperature field and uniformity are similar for both fuels; although biogas temperatures were slightly lower due to the larger amount of inert gases (CO(2)) in its composition that cool down the reactions. Species patterns and pollutant emissions showed similar trends and values for both fuels, and the energy balance for biogas showed a minor reduction of the efficiency of the furnace; this confirms that Flameless combustion is highly flexible to burn conventional and diluted fuels. Important modifications on the burner were not necessary to run the system using biogas. Additionally, in order to highlight the advantages of the Flameless combustion regime, some comparisons of the burner performance working in Flameless mode and working in conventional mode are presented. Copyright 2009 Elsevier Ltd. All rights reserved.

Drive cycle simulation of high efficiency combustions on fuel economy and exhaust properties in light-duty vehicles

DOE PAGES

Gao, Zhiming; Curran, Scott J.; Parks, James E.; ...

2015-04-06

We present fuel economy and engine-out emissions for light-duty (LD) conventional and hybrid vehicles powered by conventional and high-efficiency combustion engines. Engine technologies include port fuel-injected (PFI), direct gasoline injection (GDI), reactivity controlled compression ignition (RCCI) and conventional diesel combustion (CDC). In the case of RCCI, the engine utilized CDC combustion at speed/load points not feasible with RCCI. The results, without emissions considered, show that the best fuel economies can be achieved with CDC/RCCI, with CDC/RCCI, CDC-only, and lean GDI all surpassing PFI fuel economy significantly. In all cases, hybridization significantly improved fuel economy. The engine-out hydrocarbon (HC), carbon monoxidemore » (CO), nitrogen oxides (NOx), and particulate matter (PM) emissions varied remarkably with combustion mode. The simulated engine-out CO and HC emissions from RCCI are significantly higher than CDC, but RCCI makes less NOx and PM emissions. Hybridization can improve lean GDI and RCCI cases by increasing time percentage for these more fuel efficient modes. Moreover, hybridization can dramatically decreases the lean GDI and RCCI engine out emissions. Importantly, lean GDI and RCCI combustion modes decrease exhaust temperatures, especially for RCCI, which limits aftertreatment performance to control tailpipe emissions. Overall, the combination of engine and hybrid drivetrain selected greatly affects the emissions challenges required to meet emission regulations.« less

On the combustion mechanisms of ZrH2 in double-base propellant.

PubMed

Yang, Yanjing; Zhao, Fengqi; Yuan, Zhifeng; Wang, Ying; An, Ting; Chen, Xueli; Xuan, Chunlei; Zhang, Jiankan

2017-12-13

Metal hydrides are regarded as a series of promising hydrogen-supplying fuel for solid rocket propellants. Their effects on the energetic and combustion performances of propellants are closely related to their reaction mechanisms. Here we report a first attempt to determine the reaction mechanism of ZrH 2 , a high-density metal hydride, in the combustion of a double-base propellant to evaluate its potential as a fuel. ZrH 2 is determined to possess good resistance to oxidation by nitrocellulose and nitroglycerine. Thus its combustion starts with dehydrogenation to generate H 2 and metallic Zr. Subsequently, the newly formed Zr and H 2 participate in the combustion and, especially, Zr melts and then combusts on the burning surface which favors the heat feedback to the propellant. This phenomenon is completely different from the combustion behavior of the traditional fuel Al, where the Al particles are ejected off the burning surface of the propellant to get into the luminous flame zone to burn. The findings in this work validate the potential of ZrH 2 as a hydrogen-supplying fuel for double-base propellants.

An experimental investigation of concentrated slop combustion characteristics in cyclone furnace

NASA Astrophysics Data System (ADS)

Panpokha, Suphaopich; Wongwuttanasatian, Tanakorn; Tangchaichit, Kiatfa

2018-02-01

Slop is a by-product in alcoholic industries requiring costly waste management. An idea of using slop as a fuel in a boiler for the industries was proposed. Due to high content of ash, a cyclone furnace was designed to combust the slop. This study aims to examine the concentrated slop combustion in a designed cyclone furnace, consisting of combustion temperature and exhaust gases. The tests were carried out under 4 different air-fuel ratios. Fuels injected into the furnace were 3 g/s of concentrated slop and 1 g/s of diesel. The air-fuel ratios were corresponding to 100, 120, 140 and 160 percent theoretical air. The results demonstrated that combustion of concentrated slop can gave temperature of 800-1000°C and a suitable theoretical air was 100%-120%, because the combustion temperature was higher than that of other cases. In cyclone combustion, excess air is not recommended because it affects a reduction in overall temperature inside the cyclone furnace. It is expected that utilization of the concentrated slop (by-product) will be beneficial in the development of green and zero waste factory.

Shock Tube Measurements for Liquid Fuels Combustion

DTIC Science & Technology

2006-06-01

UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP023631 TITLE: Shock Tube Measurements for Liquid Fuels Combustion ... COMBUSTION ARO Contract Number DAAD 19-01-1-0597 Principal Investigator: Ronald K. Hanson Mechanical Engineering Department Stanford University, Stanford CA...94305-3032 SUMMARY/OVERVIEW: We report results of basic research aimed at improving knowledge of the combustion behavior of diesel and jet-related

Superheated fuel injection for combustion of liquid-solid slurries

DOEpatents

Robben, F.A.

1984-10-19

A method and device are claimed for obtaining, upon injection, flash evaporation of a liquid in a slurry fuel to aid in ignition and combustion. The device is particularly beneficial for use of coal-water slurry fuels in internal combustion engines such as diesel engines and gas turbines, and in external combustion devices such as boilers and furnaces. The slurry fuel is heated under pressure to near critical temperature in an injector accumulator, where the pressure is sufficiently high to prevent boiling. After injection into a combustion chamber, the water temperature will be well above boiling point at a reduced pressure in the combustion chamber, and flash boiling will preferentially take place at solid-liquid surfaces, resulting in the shattering of water droplets and the subsequent separation of the water from coal particles. This prevents the agglomeration of the coal particles during the subsequent ignition and combustion process, and reduces the energy required to evaporate the water and to heat the coal particles to ignition temperature. The overall effect will be to accelerate the ignition and combustion rates, and to reduce the size of the ash particles formed from the coal. 2 figs., 2 tabs.

Potential Occupational Exposures and Health Risks Associated with Biomass-Based Power Generation.

PubMed

Rohr, Annette C; Campleman, Sharan L; Long, Christopher M; Peterson, Michael K; Weatherstone, Susan; Quick, Will; Lewis, Ari

2015-07-22

Biomass is increasingly being used for power generation; however, assessment of potential occupational health and safety (OH&S) concerns related to usage of biomass fuels in combustion-based generation remains limited. We reviewed the available literature on known and potential OH&S issues associated with biomass-based fuel usage for electricity generation at the utility scale. We considered three potential exposure scenarios--pre-combustion exposure to material associated with the fuel, exposure to combustion products, and post-combustion exposure to ash and residues. Testing of dust, fungal and bacterial levels at two power stations was also undertaken. Results indicated that dust concentrations within biomass plants can be extremely variable, with peak levels in some areas exceeding occupational exposure limits for wood dust and general inhalable dust. Fungal spore types, identified as common environmental species, were higher than in outdoor air. Our review suggests that pre-combustion risks, including bioaerosols and biogenic organics, should be considered further. Combustion and post-combustion risks appear similar to current fossil-based combustion. In light of limited available information, additional studies at power plants utilizing a variety of technologies and biomass fuels are recommended.

Potential Occupational Exposures and Health Risks Associated with Biomass-Based Power Generation

PubMed Central

Rohr, Annette C.; Campleman, Sharan L.; Long, Christopher M.; Peterson, Michael K.; Weatherstone, Susan; Quick, Will; Lewis, Ari

2015-01-01

Biomass is increasingly being used for power generation; however, assessment of potential occupational health and safety (OH&S) concerns related to usage of biomass fuels in combustion-based generation remains limited. We reviewed the available literature on known and potential OH&S issues associated with biomass-based fuel usage for electricity generation at the utility scale. We considered three potential exposure scenarios—pre-combustion exposure to material associated with the fuel, exposure to combustion products, and post-combustion exposure to ash and residues. Testing of dust, fungal and bacterial levels at two power stations was also undertaken. Results indicated that dust concentrations within biomass plants can be extremely variable, with peak levels in some areas exceeding occupational exposure limits for wood dust and general inhalable dust. Fungal spore types, identified as common environmental species, were higher than in outdoor air. Our review suggests that pre-combustion risks, including bioaerosols and biogenic organics, should be considered further. Combustion and post-combustion risks appear similar to current fossil-based combustion. In light of limited available information, additional studies at power plants utilizing a variety of technologies and biomass fuels are recommended. PMID:26206568

Fireside corrosion in oxy-fuel combustion of coal

DOE PAGES

Holcomb, Gordon R.; Tylczak, Joseph; Meier, Gerald H.; ...

2011-08-01

Oxy-fuel combustion is based on burning fossil fuels in a mixture of recirculated flue gas and oxygen, rather than in air. An optimized oxy-combustion power plant will have ultra-low emissions since the flue gas that results from oxy-fuel combustion consists almost entirely of CO2 and water vapor. Once the water vapor is condensed, it is relatively easy to sequester the CO2 so that it does not escape into the atmosphere. A variety of laboratory tests comparing air-firing to oxy-firing conditions, and tests examining specific simpler combinations of oxidants, were conducted at 650-700 C. Alloys studied included model Fe-Cr and Ni-Crmore » alloys, commercial ferritic steels, austenitic steels, and nickel base superalloys. Furthermore, the observed corrosion behavior shows accelerated corrosion even with sulfate additions that remain solid at the tested temperatures, encapsulation of ash components in outer iron oxide scales, and a differentiation between oxy-fuel combustion flue gas recirculation choices.« less

Multiple Threats to Child Health from Fossil Fuel Combustion: Impacts of Air Pollution and Climate Change.

PubMed

Perera, Frederica P

2017-02-01

Approaches to estimating and addressing the risk to children from fossil fuel combustion have been fragmented, tending to focus either on the toxic air emissions or on climate change. Yet developing children, and especially poor children, now bear a disproportionate burden of disease from both environmental pollution and climate change due to fossil fuel combustion. This commentary summarizes the robust scientific evidence regarding the multiple current and projected health impacts of fossil fuel combustion on the young to make the case for a holistic, child-centered energy and climate policy that addresses the full array of physical and psychosocial stressors resulting from fossil fuel pollution. The data summarized here show that by sharply reducing our dependence on fossil fuels we would achieve highly significant health and economic benefits for our children and their future. These benefits would occur immediately and also play out over the life course and potentially across generations. Going beyond the powerful scientific and economic arguments for urgent action to reduce the burning of fossil fuels is the strong moral imperative to protect our most vulnerable populations. Citation: Perera FP. 2017. Multiple threats to child health from fossil fuel combustion: impacts of air pollution and climate change. Environ Health Perspect 125:141-148; http://dx.doi.org/10.1289/EHP299.

Soybean and Coconut Biodiesel Fuel Effects on Combustion Characteristics in a Light-Duty Diesel Engine

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

Han, Manbae; Cho, Kukwon; Sluder, Scott

This study investigated the effects of soybean- and coconut-derived biodiesel fuels on combustion characteristics in a 1.7-liter direct injection, common rail diesel engine. Five sets of fuels were studied: 2007 ultra-low sulfur diesel (ULSD), 5% and 20% volumetric blends of soybean biodiesel with ULSD (soybean B5 and B20), and 5% and 20% volumetric blends of coconut biodiesel with ULSD (coconut B5 and B20). In conventional diesel combustion mode, particulate matter (PM) and nitrogen oxides (NO/dx) emissions were similar for all fuels studied except soybean B20. Soybean B20 produced the lowest PM but the highest NO/dx emissions. Compared with conventional dieselmore » combustion mode, high efficiency clean combustion (HECC) mode, achieved by increased EGR and combustion phasing, significantly reduced both PM and NO/dx emissions for all fuels studied at the expense of higher hydrocarbon (HC) and carbon monoxide (CO) emissions and an increase in fuel consumption (less than 4%). ULSD, soybean B5, and coconut B5 showed no difference in exhaust emissions. However, PM emissions increased slightly for soybean B20 and coconut B20. NO/dx emissions increased significantly for soybean B20, while those for coconut B20 were comparable to ULSD. Differences in the chemical and physical properties of soybean and coconut biodiesel fuels compared with ULSD, such as higher fuel-borne oxygen, greater viscosity, and higher boiling temperatures, play a key role in combustion processes and, therefore, exhaust emissions. Furthermore, the highly unsaturated ester composition in soybean biodiesel can be another factor in the increase of NO/dx emissions.« less

Method for control of NOx emission from combustors using fuel dilution

DOEpatents

Schefer, Robert W [Alamo, CA; Keller, Jay O [Oakland, CA

2007-01-16

A method of controlling NOx emission from combustors. The method involves the controlled addition of a diluent such as nitrogen or water vapor, to a base fuel to reduce the flame temperature, thereby reducing NOx production. At the same time, a gas capable of enhancing flame stability and improving low temperature combustion characteristics, such as hydrogen, is added to the fuel mixture. The base fuel can be natural gas for use in industrial and power generation gas turbines and other burners. However, the method described herein is equally applicable to other common fuels such as coal gas, biomass-derived fuels and other common hydrocarbon fuels. The unique combustion characteristics associated with the use of hydrogen, particularly faster flame speed, higher reaction rates, and increased resistance to fluid-mechanical strain, alter the burner combustion characteristics sufficiently to allow operation at the desired lower temperature conditions resulting from diluent addition, without the onset of unstable combustion that can arise at lower combustor operating temperatures.

Fuel-rich, catalytic reaction experimental results

NASA Technical Reports Server (NTRS)

Rollbuhler, R. James

1991-01-01

Future aeropropulsion gas turbine combustion requirements call for operating at very high inlet temperatures, pressures, and large temperature rises. At the same time, the combustion process is to have minimum pollution effects on the environment. Aircraft gas turbine engines utilize liquid hydrocarbon fuels which are difficult to uniformly atomize and mix with combustion air. An approach for minimizing fuel related problems is to transform the liquid fuel into gaseous form prior to the completion of the combustion process. Experimentally obtained results are presented for vaporizing and partially oxidizing a liquid hydrocarbon fuel into burnable gaseous components. The presented experimental data show that 1200 to 1300 K reaction product gas, rich in hydrogen, carbon monoxide, and light-end hydrocarbons, is formed when flowing 0.3 to 0.6 fuel to air mixes through a catalyst reactor. The reaction temperatures are kept low enough that nitrogen oxides and carbon particles (soot) do not form. Results are reported for tests using different catalyst types and configurations, mass flowrates, input temperatures, and fuel to air ratios.

Use of petroleum-based correlations and estimation methods for synthetic fuels

NASA Technical Reports Server (NTRS)

Antoine, A. C.

1980-01-01

Correlations of hydrogen content with aromatics content, heat of combustion, and smoke point are derived for some synthetic fuels prepared from oil and coal syncrudes. Comparing the results of the aromatics content with correlations derived for petroleum fuels shows that the shale-derived fuels fit the petroleum-based correlations, but the coal-derived fuels do not. The correlations derived for heat of combustion and smoke point are comparable to some found for petroleum-based correlations. Calculated values of hydrogen content and of heat of combustion are obtained for the synthetic fuels by use of ASTM estimation methods. Comparisons of the measured and calculated values show biases in the equations that exceed the critical statistics values. Comparison of the measured hydrogen content by the standard ASTM combustion method with that by a nuclear magnetic resonance (NMR) method shows a decided bias. The comparison of the calculated and measured NMR hydrogen contents shows a difference similar to that found with petroleum fuels.

Experimental and Modeling Studies of the Combustion Characteristics of Conventional and Alternative Jet Fuels. Final Report

NASA Technical Reports Server (NTRS)

Meeks, Ellen; Naik, Chitral V.; Puduppakkam, Karthik V.; Modak, Abhijit; Egolfopoulos, Fokion N.; Tsotsis, Theo; Westbrook, Charles K.

2011-01-01

The objectives of this project have been to develop a comprehensive set of fundamental data regarding the combustion behavior of jet fuels and appropriately associated model fuels. Based on the fundamental study results, an auxiliary objective was to identify differentiating characteristics of molecular fuel components that can be used to explain different fuel behavior and that may ultimately be used in the planning and design of optimal fuel-production processes. The fuels studied in this project were Fischer-Tropsch (F-T) fuels and biomass-derived jet fuels that meet certain specifications of currently used jet propulsion applications. Prior to this project, there were no systematic experimental flame data available for such fuels. One of the key goals has been to generate such data, and to use this data in developing and verifying effective kinetic models. The models have then been reduced through automated means to enable multidimensional simulation of the combustion characteristics of such fuels in real combustors. Such reliable kinetic models, validated against fundamental data derived from laminar flames using idealized flow models, are key to the development and design of optimal combustors and fuels. The models provide direct information about the relative contribution of different molecular constituents to the fuel performance and can be used to assess both combustion and emissions characteristics.

Chemistry and Transport Properties for Jet Fuel Combustion

DTIC Science & Technology

2013-04-01

AFRL-OSR-VA-TR-2013-0168 Chemistry and Transport Properties for Jet Fuel Combustion Angela Violi University of Michigan...5a. CONTRACT NUMBER (U) Chemistry and Transport Properties for Jet Fuel Combustion 5b. GRANT NUMBER FA9550-09-1-0021 5c...combustors.   Although,  chemical  kinetic  mechanisms  of  hydrocarbons  have  been  widely  studied,  molecular   transport

Fuel combustion adds to anxiety over CO/sub 2/ buildup

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

Sleeper, D.

1979-08-01

In the past 20 y, the annual rate of increase of atmosphreic carbon dioxide has grown sharply because of increased fossil fuel combustion. Most scientists agree that CO/sub 2/ buildup in the atmosphere is causing a greenhouse effect, slowly warming the earth's climate. Large-scale production of synthetic fuels that could be combusted without releasing CO/sub 2/ is examined as a possible solution. 31 references, 1 figure.

76 FR 70352 - Approval and Promulgation of Implementation Plans; Reasonably Available Control Technology for...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-14

... controlling oxides of nitrogen from the stationary reciprocating, diesel fuel fired, internal combustion... County. The facility contains two stationary reciprocating, diesel fuel fired, internal combustion... Conditions of Approval specify the NO X emissions limits, combustion process adjustments mentioned above...

Liquid fuel injection elements for rocket engines

NASA Technical Reports Server (NTRS)

Cox, George B., Jr. (Inventor)

1993-01-01

Thrust chambers for liquid propellant rocket engines include three principal components. One of these components is an injector which contains a plurality of injection elements to meter the flow of propellants at a predetermined rate, and fuel to oxidizer mixture ratio, to introduce the mixture into the combustion chamber, and to cause them to be atomized within the combustion chamber so that even combustion takes place. Evolving from these injectors are tube injectors. These tube injectors have injection elements for injecting the oxidizer into the combustion chamber. The oxidizer and fuel must be metered at predetermined rates and mixture ratios in order to mix them within the combustion chamber so that combustion takes place smoothly and completely. Hence tube injectors are subject to improvement. An injection element for a liquid propellant rocket engine of the bipropellant type is provided which includes tangential fuel metering orifices, and a plurality of oxidizer tube injection elements whose injection tubes are also provided with tangential oxidizer entry slots and internal reed valves.

Influence of carbonation under oxy-fuel combustion flue gas on the leachability of heavy metals in MSWI fly ash.

PubMed

Ni, Peng; Xiong, Zhuo; Tian, Chong; Li, Hailong; Zhao, Yongchun; Zhang, Junying; Zheng, Chuguang

2017-09-01

Due to the high cost of pure CO 2 , carbonation of MSWI fly ash has not been fully developed. It is essential to select a kind of reaction gas with rich CO 2 instead of pure CO 2 . The CO 2 uptake and leaching toxicity of heavy metals in three typical types of municipal solid waste incinerator (MSWI) fly ash were investigated with simulated oxy-fuel combustion flue gas under different reaction temperatures, which was compared with both pure CO 2 and simulated air combustion flue gas. The CO 2 uptake under simulated oxy-fuel combustion flue gas were similar to that of pure CO 2 . The leaching concentration of heavy metals in all MSWI fly ash samples, especially in ash from Changzhou, China (CZ), decreased after carbonation. Specifically, the leached Pb concentration of the CZ MSWI fly ash decreased 92% under oxy-fuel combustion flue gas, 95% under pure CO 2 atmosphere and 84% under the air combustion flue gas. After carbonation, the leaching concentration of Pb was below the Chinese legal limit. The leaching concentration of Zn from CZ sample decreased 69% under oxy-fuel combustion flue gas, which of Cu, As, Cr and Hg decreased 25%, 33%, 11% and 21%, respectively. In the other two samples of Xuzhou, China (XZ) and Wuhan, China (WH), the leaching characteristics of heavy metals were similar to the CZ sample. The speciation of heavy metals was largely changed from the exchangeable to carbonated fraction because of the carbonation reaction under simulated oxy-fuel combustion flue gas. After carbonation reaction, most of heavy metals bound in carbonates became more stable and leached less. Therefore, oxy-fuel combustion flue gas could be a low-cost source for carbonation of MSWI fly ash. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

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.

Combustion characteristics of various fuels during research octane number testing on an instrumented CFR F1/F2 engine

DOE PAGES

Kolodziej, Christopher P.; Wallner, Thomas

2017-04-01

The Cooperative Fuels Research (CFR) engine is the long-established standard for characterization of fuel knock resistance in spark-ignition internal combustion engines. Despite its measurements of RON and MON being widely used, there is little understanding of what governs the CFR octane rating for fuels of various chemical compositions compared to primary reference fuels (iso-octane and n-heptane). Some detailed combustion characteristics were measured on a highly instrumented CFR F1/F2 engine during RON testing of fuels with significantly different chemical composition. Our results revealed differences in the cylinder pressure and temperature conditions, as well as knocking characteristics.

Combustion characteristics of various fuels during research octane number testing on an instrumented CFR F1/F2 engine

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

Kolodziej, Christopher P.; Wallner, Thomas

The Cooperative Fuels Research (CFR) engine is the long-established standard for characterization of fuel knock resistance in spark-ignition internal combustion engines. Despite its measurements of RON and MON being widely used, there is little understanding of what governs the CFR octane rating for fuels of various chemical compositions compared to primary reference fuels (iso-octane and n-heptane). Some detailed combustion characteristics were measured on a highly instrumented CFR F1/F2 engine during RON testing of fuels with significantly different chemical composition. Our results revealed differences in the cylinder pressure and temperature conditions, as well as knocking characteristics.

Fossil energy program

NASA Astrophysics Data System (ADS)

McNeese, L. E.

1981-12-01

The progress made during the period from July 1 through September 30 for the Oak Ridge National Laboratory research and development projects in support of the increased utilization of coal and other fossil fuels as sources of clean energy is reported. The following topics are discussed: coal conversion development, chemical research and development, materials technology, fossil energy materials program, liquefaction projects, component development, process analysis, environmental control technology, atmospheric fluidized bed combustion, underground coal gasification, coal preparation and waste utilization.

The challenges and opportunities of supersonic transport propulsion technology

NASA Technical Reports Server (NTRS)

Strack, William C.; Morris, Shelby J., Jr.

1988-01-01

The major challenges confronting the propulsion community for civil supersonic transport applications are identified: high propulsion system efficiency at both supersonic and subsonic cruise conditions, low-cost fuel with adequate thermal stability at high temperatures, low noise cycles and exhaust systems, low emission combustion systems, and low drag installations. Both past progress and future opportunities are discussed in relation to perceived technology shortfalls for an economically successful airplane that satisfies environmental constraints.

Lump wood combustion process

NASA Astrophysics Data System (ADS)

Kubesa, Petr; Horák, Jiří; Branc, Michal; Krpec, Kamil; Hopan, František; Koloničný, Jan; Ochodek, Tadeáš; Drastichová, Vendula; Martiník, Lubomír; Malcho, Milan

2014-08-01

The article deals with the combustion process for lump wood in low-power fireplaces (units to dozens of kW). Such a combustion process is cyclical in its nature, and what combustion facility users are most interested in is the frequency, at which fuel needs to be stoked to the fireplace. The paper defines the basic terms such as burnout curve and burning rate curve, which are closely related to the stocking frequency. The fuel burning rate is directly dependent on the immediate thermal power of the fireplace. This is also related to the temperature achieved in the fireplace, magnitude of flue gas losses and the ability to generate conditions favouring the full burnout of the fuel's combustible component, which, at once ensures the minimum production of combustible pollutants. Another part of the paper describes experiments conducted in traditional fireplaces with a grate, at which well-dried lump wood was combusted.

The influence of fuel type to combustion characteristic in diffusion flame drying by computational fluid dynamics simulation

NASA Astrophysics Data System (ADS)

Septiani, Eka Lutfi; Widiyastuti, W.; Machmudah, Siti; Nurtono, Tantular; Winardi, Sugeng

2017-05-01

Diffusion flame spray drying has become promising method in nanoparticles synthesis giving several advantages and low operation cost. In order to scale up the process which needs high experimentation time and cost, Computational Fluid Dynamics (CFD) by Ansys Fluent 15.0 software has been used. Combustion characteristic in diffusion flame reactor may affects particle size distribution. This study aims to observe influence of fuel type to combustion characteristic in the reactor. Large Eddy Simulation (LES) and non-premixed combustion model are selected for the turbulence and combustion model respectively. Methane, propane, and LPG in 0.5 L/min were used as type of fuel. While the oxidizer is air with 200% excess of O2. Simulation result shown that the maximum temperature was obtained from propane-air combustion in 2268 K. However, the stable temperature contour was achieved by methane-air combustion.

Analysis of Turbulent Combustion in Simplified Stratified Charge Conditions

NASA Astrophysics Data System (ADS)

Moriyoshi, Yasuo; Morikawa, Hideaki; Komatsu, Eiji

The stratified charge combustion system has been widely studied due to the significant potentials for low fuel consumption rate and low exhaust gas emissions. The fuel-air mixture formation process in a direct-injection stratified charge engine is influenced by various parameters, such as atomization, evaporation, and in-cylinder gas motion at high temperature and high pressure conditions. It is difficult to observe the in-cylinder phenomena in such conditions and also challenging to analyze the following stratified charge combustion. Therefore, the combustion phenomena in simplified stratified charge conditions aiming to analyze the fundamental stratified charge combustion are examined. That is, an experimental apparatus which can control the mixture distribution and the gas motion at ignition timing was developed, and the effects of turbulence intensity, mixture concentration distribution, and mixture composition on stratified charge combustion were examined. As a result, the effects of fuel, charge stratification, and turbulence on combustion characteristics were clarified.

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

DOEpatents

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

2012-11-20

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

Vortex combustor for low NOx emissions when burning lean premixed high hydrogen content fuel

DOEpatents

Steele, Robert C [Woodinville, WA; Edmonds, Ryan G [Renton, WA; Williams, Joseph T [Kirkland, WA; Baldwin, Stephen P [Winchester, MA

2009-10-20

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

Los Alamos National Security, LLC Request for Information on how industry may partner with the Laboratory on KIVA software.

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

Mcdonald, Kathleen Herrera

2016-02-29

KIVA is a family of Fortran-based computational fluid dynamics software developed by LANL. The software predicts complex fuel and air flows as well as ignition, combustion, and pollutant-formation processes in engines. The KIVA models have been used to understand combustion chemistry processes, such as auto-ignition of fuels, and to optimize diesel engines for high efficiency and low emissions. Fuel economy is heavily dependent upon engine efficiency, which in turn depends to a large degree on how fuel is burned within the cylinders of the engine. Higher in-cylinder pressures and temperatures lead to increased fuel economy, but they also create moremore » difficulty in controlling the combustion process. Poorly controlled and incomplete combustion can cause higher levels of emissions and lower engine efficiencies.« less

On the formulation and assessment of flamelet-generated manifolds applied to two-phase turbulent combustion

NASA Astrophysics Data System (ADS)

Bojko, Brian T.

Accounting for the effects of finite rate chemistry in reacting flows is intractable when considering the number of species and reactions to be solved for during a large scale flow simulation. This is especially complicated when solid/liquid fuels are also considered. While modeling the reacting boundary layer with the use of finite-rate chemistry may allow for a highly accurate description of the coupling between the flame and fuel surface, it is not tractable in large scale simulations when considering detailed chemical kinetics. It is the goal of this research to investigate a Flamelet-Generated Manifold (FGM) method in order to reduce the finite rate chemistry to a lookup table cataloged by progress variables and queried during runtime. In this study, simplified unsteady 1D flames with mass blowing are considered for a solid biomass fuel where the FGM method is employed as a model reduction strategy for potential application to multidimensional calculations. Two types of FGM are considered. The first are a set of steady-state flames differentiated by their scalar dissipation rate. Results show the use of steady flames produce unacceptable errors compared to the finite-rate chemistry solution, with temperature errors in excess of 45%. To avoid these errors, a new methodology for developing an unsteady FGM (UFGM) is presented that accounts for unsteady diffusion effects and greatly reduces errors in temperature with differences that are under 10%. The FGM modeling is then extended to individual droplet combustion with the development of a Droplet Flamelet-Generated Manifold (DFGM) to account for the effects of finite-rate chemistry of individual droplets. A spherically symmetric droplet model is developed for methanol and aluminum. The inclusion of finite-rate chemistry allows the capturing of the transition from diffusion to kinetically controlled combustion as the droplet diameter decreases. The droplet model is then used to create a DFGM by successively solving the 1D flame equations at varying drop sizes, where the source terms for energy, mixture fraction, and progress variable are cataloged as a function of normalized diameter. A unique coupling of the DFGM and planar UFGM is developed and is used to account for individual and gas phase combustion processes in turbulent combustion situations, such as spray flames, particle laden blasts, etc. The DFGM for the methanol and aluminum droplets are used in mixed Eulerian and Eulerian-Lagrangian formulations of compressible multiphase flows. System level simulations are conducted and compared experimental data for a methanol spray flame and an aluminized blast studied at the Explosives Components Facility (ECF) at Sandia National Laboratories.

COMBUSTION OF HEAVY LIQUID FUELS

DTIC Science & Technology

characteristics of individual fuel droplets, as functions of the external conditions and fuel properties, the droplet combustion process in a flame ... length and the quality of atomization are examined. In addition, atomization quality is covered, and nozzle systems and the construction of nozzles are

Applying Thermodynamics to Fossil Fuels: Heats of Combustion from Elemental Compositions.

ERIC Educational Resources Information Center

Lloyd, William G.; Davenport, Derek A.

1980-01-01

Discussed are the calculations of heats of combustions of some selected fossil fuel compounds such as some foreign shale oils and United States coals. Heating values for coal- and petroleum-derived fuel oils are also presented. (HM)

40 CFR 96.104 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

... through HH of this part: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired... section, is not a CAIR NOX unit begins to combust fossil fuel or to serve a generator with nameplate... provided in paragraph (a)(1) of this section on the first date on which it both combusts fossil fuel and...

40 CFR 96.104 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

... through HH of this part: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired... section, is not a CAIR NOX unit begins to combust fossil fuel or to serve a generator with nameplate... provided in paragraph (a)(1) of this section on the first date on which it both combusts fossil fuel and...

40 CFR 96.204 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

... through HHH of this part: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired... section, is not a CAIR SO2 unit begins to combust fossil fuel or to serve a generator with nameplate... provided in paragraph (a)(1) of this section on the first date on which it both combusts fossil fuel and...

40 CFR 96.104 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... through HH of this part: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired... section, is not a CAIR NOX unit begins to combust fossil fuel or to serve a generator with nameplate... provided in paragraph (a)(1) of this section on the first date on which it both combusts fossil fuel and...

40 CFR 96.204 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

... through HHH of this part: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired... section, is not a CAIR SO2 unit begins to combust fossil fuel or to serve a generator with nameplate... provided in paragraph (a)(1) of this section on the first date on which it both combusts fossil fuel and...

40 CFR 96.204 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-07-01

... through HHH of this part: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired... section, is not a CAIR SO2 unit begins to combust fossil fuel or to serve a generator with nameplate... provided in paragraph (a)(1) of this section on the first date on which it both combusts fossil fuel and...

40 CFR 96.104 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-07-01

... through HH of this part: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired... section, is not a CAIR NOX unit begins to combust fossil fuel or to serve a generator with nameplate... provided in paragraph (a)(1) of this section on the first date on which it both combusts fossil fuel and...

40 CFR 96.204 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-07-01

... through HHH of this part: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired... section, is not a CAIR SO2 unit begins to combust fossil fuel or to serve a generator with nameplate... provided in paragraph (a)(1) of this section on the first date on which it both combusts fossil fuel and...

40 CFR 96.104 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-07-01

... through HH of this part: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired... section, is not a CAIR NOX unit begins to combust fossil fuel or to serve a generator with nameplate... provided in paragraph (a)(1) of this section on the first date on which it both combusts fossil fuel and...

40 CFR 96.204 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... through HHH of this part: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired... section, is not a CAIR SO2 unit begins to combust fossil fuel or to serve a generator with nameplate... provided in paragraph (a)(1) of this section on the first date on which it both combusts fossil fuel and...

40 CFR 63.14 - Incorporations by reference.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., Heat of Combustion of Hydrocarbon Fuels by Bomb Calorimeter (High-Precision Method), IBR approved for... for Heat of Combustion of Liquid Hydrocarbon Fuels by Bomb Calorimeter (Precision Method), IBR... Oxygen Bomb Combustion/Atomic Absorption Method,1 IBR approved for table 6 to subpart DDDDD of this part...

Atomization and combustion performance of antimisting kerosene and jet fuel

NASA Technical Reports Server (NTRS)

Fleeter, R.; Parikh, P.; Sarohia, V.

1983-01-01

Combustion performance of antimisting kerosene (AMK) containing FM-9 polymer was investigated at various levels of degradation (restoration of AMK for normal use in a gas turbine engine). To establish the relationship of degradation and atomization to performance in an aircraft gas turbine combustor, sprays formed by the nozzle of a JT8-D combustor with Jet A and AMK at 1 atmosphere (atm) (14.1 lb/square in absolute) pressure and 22 C at several degradation levels were analyzed. A new spray characterization technique based on digital image analysis of high resolution, wide field spray images formed under pulsed ruby laser sheet illumination was developed. Combustion tests were performed for these fuels in a JT8-D single can combustor facility to measure combustion efficiency and the lean extinction limit. Correlation of combustion performance under simulated engine operating conditions with nozzle spray Sauter mean diameter (SMD) measured at 1 atm and 22 C were observed. Fuel spray SMD and hence the combustion efficiency are strongly influenced by fuel degradation level. Use of even the most highly degraded AMK tested (filter ratio = 1.2) resulted in an increase in fuel consumption of 0.08% to 0.20% at engine cruise conditions.

A numerical study on combustion process in a small compression ignition engine run dual-fuel mode (diesel-biogas)

NASA Astrophysics Data System (ADS)

Ambarita, H.; Widodo, T. I.; Nasution, D. M.

2017-01-01

In order to reduce the consumption of fossil fuel of a compression ignition (CI) engines which is usually used in transportation and heavy machineries, it can be operated in dual-fuel mode (diesel-biogas). However, the literature reviews show that the thermal efficiency is lower due to incomplete combustion process. In order to increase the efficiency, the combustion process in the combustion chamber need to be explored. Here, a commercial CFD code is used to explore the combustion process of a small CI engine run on dual fuel mode (diesel-biogas). The turbulent governing equations are solved based on finite volume method. A simulation of compression and expansions strokes at an engine speed and load of 1000 rpm and 2500W, respectively has been carried out. The pressure and temperature distributions and streamlines are plotted. The simulation results show that at engine power of 732.27 Watt the thermal efficiency is 9.05%. The experiment and simulation results show a good agreement. The method developed in this study can be used to investigate the combustion process of CI engine run on dual-fuel mode.

Engine combustion control at low loads via fuel reactivity stratification

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

Reitz, Rolf Deneys; Hanson, Reed M.; Splitter, Derek A.

A compression ignition (diesel) engine uses two or more fuel charges during a combustion cycle, with the fuel charges having two or more reactivities (e.g., different cetane numbers), in order to control the timing and duration of combustion. By appropriately choosing the reactivities of the charges, their relative amounts, and their timing, combustion can be tailored to achieve optimal power output (and thus fuel efficiency), at controlled temperatures (and thus controlled NOx), and with controlled equivalence ratios (and thus controlled soot). At low load and no load (idling) conditions, the aforementioned results are attained by restricting airflow to the combustionmore » chamber during the intake stroke (as by throttling the incoming air at or prior to the combustion chamber's intake port) so that the cylinder air pressure is below ambient pressure at the start of the compression stroke.« less

The investigation of critical burning of fuel droplets

NASA Technical Reports Server (NTRS)

Allison, C. B.; Canada, G. S.; Faeth, G. M.

1973-01-01

The combustion and evaporation of liquid fuels at high pressures were investigated. Particular emphasis was placed on conditions where the liquid surface approaches the thermodynamic critical point during combustion. The influence of transient effects on a burning liquid fuel was also investigated through both analysis and measurements of the response of liquid monopropellant combustion to imposed pressure oscillations. Work was divided into four phases (1) Droplet combustion at high pressures, which consider both measurement and analysis of the porous sphere burning rate of liquids in a natural convection environment at elevated pressure. (2) High pressure droplet burning in combustion gases, which involved steady burning and evaporation of liquids from porous spheres in a high pressure environment that simulates actual combustion chamber conditions. (3) Liquid strand combustion, which considered the burning rate, the state of the liquid surface and the liquid phase temperature distribution of a burning liquid monopropellant column over a range of pressures. (4) Oscillatory combustion, which was a theoretical and experimental investigation of the response of a burning liquid monopropellant to pressure oscillations.

Experiments on Nitrogen Oxide Production of Droplet Arrays Burning under Microgravity Conditions

NASA Astrophysics Data System (ADS)

Moesl, Klaus; Sattelmayer, Thomas; Kikuchi, Masao; Yamamoto, Shin; Yoda, Shinichi

The optimization of the combustion process is top priority in current aero-engine and aircraft development, particularly from the perspectives of high efficiency, minimized fuel consumption, and a sustainable exhaust gas production. Aero-engines are exclusively liquid-fueled with a strong correlation between the combustion temperature and the emissions of nitric oxide (NOX ). Due to safety concerns, the progress in NOX reduction has been much slower than in stationary gas turbines. In the past, the mixing intensity in the primary zone of aero-engine combustors was improved and air staging implemented. An important question for future aero-engine combustors, consequently, is how partial vaporization influences the NOX emissions of spray flames? In order to address this question, the combustion of partially vaporized, linear droplet arrays was studied experimentally under microgravity conditions. The influence of fuel pre-vaporization on the NOX emissions was assessed in a wide range. The experiments were performed in a drop tower and a sounding rocket campaign. The microgravity environment provided ideal experiment conditions without the disturbing ef-fect of natural convection. This allowed the study of the interacting phenomena of multi-phase flow, thermodynamics, and chemical kinetics. This way the understanding of the physical and chemical processes related to droplet and spray combustion could be improved. The Bremen drop tower (ZARM) was utilized for the precursor campaign in July 2008, which was com-prised of 30 drops. The sounding rocket experiments, which totaled a microgravity duration of 6 minutes, were finally performed on the flight of TEXUS-46 in November 2009. On both campaigns the "Japanese Combustion Module" (JCM) was used. It is a cooperative experi-ment on droplet array combustion between the Japan Aerospace Exploration Agency (JAXA) and ESA's (European Space Agency) research team, working on the combustion properties of partially premixed sprays. One droplet array consisted of five droplets (for sounding rocket) and 9 -17 droplets (for drop tower) of the hydrocarbon n-decane (C10 H22 ). While keeping the pressure at 1.0 bar (+/-20 mbar), the combustion chamber temperature and the fuel vaporization time were varied in the range of 300 -500 K and 0.5 -18 s, respectively. Consequently, the total amount of fuel, the local equivalence ratio Φ along the droplet array, and the dimensionless droplet spacing S/d0 , with d0 being the initial droplet diameter, were adapted. Ignition was initiated by a hot-wire igniter from one end of the droplet array. Representative gas samples were collected from every single combustion sequence after flame extinction and stored in specially treated gas sampling cylinders for their succeeding analysis on ground. Visual observation of the combustion process, as well as temperature and pressure logging, supported the scientific interpretation of the gas analysis. With an increase of the preheating temperature, NOX emissions increase due to a higher effec-tive flame temperatures. However, with an increasing pre-vaporization, NOX emissions become lower due to the dropping number and the dropping size of burning droplets, acting as hot spots. A correction for the effect of the preheating temperature was developed. It reveals the effect of pre-vaporization and shows that the NOX emissions are almost independent of it for near-stoichiometric operation. At overall lean conditions the NOX emissions drop non-linearly with the degree of vaporization. Up to now, this leads to the conclusion that a high degree of vaporization is required in order to achieve substantial NOX abatement.

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

Thermal Loss Determination for a Small Internal Combustion Engine

DTIC Science & Technology

2014-03-27

calibration temperature rc Compression ratio S̄ p Mean piston speed T Temperature Vc Combustion chamber volume Vd Displacement volume Wc,i Indicated work...are typically fueled by gasoline, ignited by a spark, and operate on either a two or four-stroke cycle. Compression-ignition diesel engines as seen in...engine, the fuel is usually withheld from the cylinder until the combustion event is desired as in diesel engines. Similarly, the fuel in a gas

Biofuels combustion.

PubMed

Westbrook, Charles K

2013-01-01

This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. Research efforts on so-called second- and third-generation biofuels are discussed briefly.

Methodology for Formulating Diesel Surrogate Fuels with Accurate Compositional, Ignition-Quality, and Volatility Characteristics

DOE PAGES

Mueller, Charles J.; Cannella, William J.; Bruno, Thomas J.; ...

2012-05-22

In this study, a novel approach was developed to formulate surrogate fuels having characteristics that are representative of diesel fuels produced from real-world refinery streams. Because diesel fuels typically consist of hundreds of compounds, it is difficult to conclusively determine the effects of fuel composition on combustion properties. Surrogate fuels, being simpler representations of these practical fuels, are of interest because they can provide a better understanding of fundamental fuel-composition and property effects on combustion and emissions-formation processes in internal-combustion engines. In addition, the application of surrogate fuels in numerical simulations with accurate vaporization, mixing, and combustion models could revolutionizemore » future engine designs by enabling computational optimization for evolving real fuels. Dependable computational design would not only improve engine function, it would do so at significant cost savings relative to current optimization strategies that rely on physical testing of hardware prototypes. The approach in this study utilized the state-of-the-art techniques of 13C and 1H nuclear magnetic resonance spectroscopy and the advanced distillation curve to characterize fuel composition and volatility, respectively. The ignition quality was quantified by the derived cetane number. Two well-characterized, ultra-low-sulfur #2 diesel reference fuels produced from refinery streams were used as target fuels: a 2007 emissions certification fuel and a Coordinating Research Council (CRC) Fuels for Advanced Combustion Engines (FACE) diesel fuel. A surrogate was created for each target fuel by blending eight pure compounds. The known carbon bond types within the pure compounds, as well as models for the ignition qualities and volatilities of their mixtures, were used in a multiproperty regression algorithm to determine optimal surrogate formulations. The predicted and measured surrogate-fuel properties were quantitatively compared to the measured target-fuel properties, and good agreement was found.« less

Estimating soot emissions from an elevated flare

NASA Astrophysics Data System (ADS)

Almanza, Victor; Sosa, Gustavo

2009-11-01

Combustion aerosols are one of the major concerns in flaring operations, due to both health and environmental hazards. Preliminary results are presented for a 2D transient simulation of soot formation in a reacting jet with exit velocity of 130 m/s under a 5 m/s crossflow released from a 50 m high elevated flare and a 50 cm nozzle. Combustion dynamics was simulated with OpenFOAM. Gas-phase non-premixed combustion was modeled with the Chalmers PaSR approach and a κ-ɛ turbulence model. For soot formation, Moss model was used and the ISAT algorithm for solving the chemistry. Sulfur chemistry was considered to account for the sourness of the fuel. Gas composition is 10 % H2S and 90 % C2H4. A simplified Glassman reaction mechanism was used for this purpose. Results show that soot levels are sensitive to the sulfur present in the fuel, since it was observed a slight decrease in the soot volume fraction. NSC is the current oxidation model for soot formation. Predicted temperature is high (about 2390 K), perhaps due to soot-radiation interaction is not considered yet, but a radiation model implementation is on progress, as well as an oxidation mechanism that accounts for OH radical. Flame length is about 50 m.

Theoretical Investigation For The Effect of Fuel Quality on Gas Turbine Power Plants

NASA Astrophysics Data System (ADS)

AbdulRazzak khudair, Omar; Alwan Abass, Khetam; Saadi Abed, Noor; Hussain Ali, Khalid; AbdulAziz, Saad; Chlaib Shaboot, Ali

2018-05-01

Gas turbine engine power generation is declined dramatically because of the reduction in thermodynamic parameters as a work of turbine, compressor ratio, compressor work, and air mass flow rate and fuel consumption. There are two main objectives of this work, the first is related with the effect of fuel kinds and their quality on the operation of fuel flow divider and its performance specifically gear pump displacement and fuel flow rate to the combustion chambers of gas power plant. AL-DORA gas turbine power plant 35MW was chosen to predict these effects on its performance MATLAB Software program is used to perform thermodynamic calculations. Fuel distribution stage before the process of combustion and as a result of the kind and its quality, chemical reaction will occur between the fuel and the parts of the gear system of each pump of the flow divider, which causes the erosion of the internal pump wall and the teeth of the gear system, thus hampering the pump operation in terms of fuel discharge. The discharge of fuel form the eight external gates of flow divider is decreased and varied when going to the combustion chambers, so that, flow divider does not give reliable mass flow rate due to absence of accurate pressure in each of eight exit pipes. The second objective deals with the stage of fuel combustion process inside the combustion chamber. A comparative study based upon performance parameters, such as specific fuel consumption for gas and gasoil and power generation. Fuel poor quality causes incomplete combustion and increased its consumption, so that combustion products are interacted with the surface of the turbine blades, causing the erosion and create surface roughness of the blade and disruption of gas flow. As a result of this situation, turbulence flow of these gases will increase causing the separation of gas boundary layers over the suction surface of the blade. Therefore the amount of extracted gas will decrease causing retreat work done by turbine, as a result decline of power and gas turbine power plant efficiency causing the drop in the level of electric generation. The fuel quality is found to be a strong function of specific fuel consumption and its effects on the power generation and the efficiency of the gas turbine power plants and hence, the cycle performance shifts towards favorable conditions.

An Experimental Examination of Combustion of Isolated Liquid Fuel Droplets with Polymeric and Nanoparticle Additives

NASA Astrophysics Data System (ADS)

Ghamari, Mohsen

In spite of recent attention to renewable sources of energy, liquid hydrocarbon fuels are still the main source of energy for industrial and transportation systems. Manufactures and consumers are consistently looking for ways to optimize the efficiency of fuel combustion in terms of cost, emissions and consumer safety. In this regard, increasing burning rate of liquid fuels has been of special interest in both industrial and transportation systems. Recent studies have shown that adding combustible nano-particles could have promising effects on improving combustion performance of liquid fuels. Combustible nano-particles could enhance radiative and conductive heat transfer and also mixing within the droplet. Polymeric additive have also shown promising effect on improving fire safety by suppressing spreading behavior and splatter formation in case of crash scenario. Polymers are also known to have higher burning rate than regular hydrocarbon fuels. Therefore adding polymeric additive could have the potential to increase the burning rate. In this work, combustion dynamics of liquid fuel droplets with both polymeric and nanoparticle additives is studied in normal gravity. High speed photography is employed and the effect of additive concentration on droplet burning rate, burning time, extinction and soot morphology is investigated. Polymer added fuel was found to have a volatility controlled combustion with four distinct regimes. The first three zones are associated with combustion of base fuel while the polymer burns last and after a heating zone because of its higher boiling point. Polymer addition reduces the burning rate of the base fuel in the first zone by means of increasing viscosity and results in nucleate boiling and increased burning rates in the second and third stages. Overall, polymer addition resulted in a higher burning rate and shorter burning time in most of the scenarios. Colloidal suspensions of carbon-based nanomaterials in liquid fuels were also tested at different particle loadings. It was found that dispersing nanoparticles results in higher burning rate by means of enhanced radiative heat absorption and thermal conductivity. An optimum particle loading was found for each particle type at which the maximum burning rate was achieved. It was observed that the burning rate again starts to reduce after this optimum point most likely due to the formation of large aggregates that reduce thermal conductivity and suppress the diffusion of species.

Shock Tunnel Studies of Scramjet Phenomena

NASA Technical Reports Server (NTRS)

Stalker, R. J.

1996-01-01

Work focussed on a large number of preliminary studies of supersonic combustion in a simple combustion duct - thrust nozzle combination, investigating effects of Mach number, equivalence ratio, combustor divergence, fuel injecting angle and other parameters with an influence on the combustion process. This phase lasted for some three or four years, during which strongest emphasis was placed on responding to the request for preliminary experimental information on high enthalpy effects, to support the technology maturation activities of the NASP program. As the need for preliminary data became less urgent, it was possible to conduct more systematic studies of high enthalpy combustion phenomena, and to initiate other projects aimed at improving the facilities and instrumentation used for studying scramjet phenomena at high enthalpies. The combustion studies were particularly directed towards hypersonic combustion, and to the effects of injecting fuel along the combustion chamber wall. A substantial effort was directed towards a study of the effect of scale on the supersonic combustion process. The influence of wave phenomena (both compression waves and expansion waves) on the realization of thrust from a supersonic combustion process was also investigated. The effect of chemical kinetics was looked into, particularly as it affected the composition of the test flow provided by a ground facility. The effect of injection of the fuel through wall orifices was compared with injection from a strut spanning the stream, and the effect of heating the fuel prior to injection was investigated. Studies of fuel-air mixing by shock impingement were also done, as well as mass spectrometer surveys of a combustion wake. The use of hypersonic nozzles with an expansion tube was investigated. A new method was developed for measuring the forces acting of a model in less than one millisecond. Also included in this report are listings of published journal papers and conference presentations.

FINE PARTICLE EMISSIONS FROM RESIDUAL FUEL OIL COMBUSTION: CHARACTERIZATION AND MECHANISMS OF FORMATION

EPA Science Inventory

The paper gives results of a comparison of the characteristics of particulate matter (PM) emitted from residual fuel oil combustion in two types of combustion equipment. A small commercial 732-kW fire-tube boiler yielded a weakly bi-modal particulate size distribution (PSD) with...

FINE PARTICLE EMISSIONS FROM RESIDUAL FUEL OIL COMBUSTION: CHARACTERIZATION AND MECHANISMS OF FORMATION

EPA Science Inventory

The paper gives results of a comparison of the characteristics of particulate matter (PM) emitted from residual fuel oil combustion in two types of combustion equipment. A small commercial 732-kW-rated fire-tube boiler yielded a weakly bimodal PM size distribution (PSD) with over...

76 FR 47092 - Approval and Promulgation of Implementation Plans; Reasonably Available Control Technology for...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-04

... oxides of nitrogen from the stationary reciprocating, diesel fuel fired, internal combustion engines..., diesel fuel fired, internal combustion engines--one existing and one new engine. B. Why is EPA proposing... both engines. In addition, the Conditions of Approval specify the NO X emissions limits, combustion...

40 CFR 63.1326 - Batch process vents-recordkeeping provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

...): (i) For an incinerator or non-combustion control device, the percent reduction of organic HAP or TOC... introduced with combustion air or used as a secondary fuel and is not mixed with the primary fuel, the... scrubber or other halogen reduction device following a combustion device to control halogenated batch...

Combustor for fine particulate coal

DOEpatents

Carlson, L.W.

1988-01-26

A particulate coal combustor with two combustion chambers is provided. The first combustion chamber is toroidal; air and fuel are injected, mixed, circulated and partially combusted. The air to fuel ratio is controlled to avoid production of soot or nitrogen oxides. The mixture is then moved to a second combustion chamber by injection of additional air where combustion is completed and ash removed. Temperature in the second chamber is controlled by cooling and gas mixing. The clean stream of hot gas is then delivered to a prime mover. 4 figs.

Combustor for fine particulate coal

DOEpatents

Carlson, Larry W.

1988-01-01

A particulate coal combustor with two combustion chambers is provided. The first combustion chamber is toroidal; air and fuel are injected, mixed, circulated and partially combusted. The air to fuel ratio is controlled to avoid production of soot or nitrogen oxides. The mixture is then moved to a second combustion chamber by injection of additional air where combustion is completed and ash removed. Temperature in the second chamber is controlled by cooling and gas mixing. The clean stream of hot gas is then delivered to a prime mover.

Combustor for fine particulate coal

DOEpatents

Carlson, L.W.

1988-11-08

A particulate coal combustor with two combustion chambers is provided. The first combustion chamber is toroidal; air and fuel are injected, mixed, circulated and partially combusted. The air to fuel ratio is controlled to avoid production of soot or nitrogen oxides. The mixture is then moved to a second combustion chamber by injection of additional air where combustion is completed and ash removed. Temperature in the second chamber is controlled by cooling and gas mixing. The clean stream of hot gas is then delivered to a prime mover. 4 figs.

Recovery Act: Novel Oxygen Carriers for Coal-fueled Chemical Looping

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

Pan, Wei-Ping; Cao, Yan

2012-11-30

Chemical Looping Combustion (CLC) could totally negate the necessity of pure oxygen by using oxygen carriers for purification of CO{sub 2} stream during combustion. It splits the single fuel combustion reaction into two linked reactions using oxygen carriers. The two linked reactions are the oxidation of oxygen carriers in the air reactor using air, and the reduction of oxygen carriers in the fuel reactor using fuels (i.e. coal). Generally metal/metal oxides are used as oxygen carriers and operated in a cyclic mode. Chemical looping combustion significantly improves the energy conversion efficiency, in terms of the electricity generation, because it improvesmore » the reversibility of the fuel combustion process through two linked parallel processes, compared to the conventional combustion process, which is operated far away from its thermo-equilibrium. Under the current carbon-constraint environment, it has been a promising carbon capture technology in terms of fuel combustion for power generation. Its disadvantage is that it is less mature in terms of technological commercialization. In this DOE-funded project, accomplishment is made by developing a series of advanced copper-based oxygen carriers, with properties of the higher oxygen-transfer capability, a favorable thermodynamics to generate high purity of CO{sub 2}, the higher reactivity, the attrition-resistance, the thermal stability in red-ox cycles and the achievement of the auto-thermal heat balance. This will be achieved into three phases in three consecutive years. The selected oxygen carriers with final-determined formula were tested in a scaled-up 10kW coal-fueled chemical looping combustion facility. This scaled-up evaluation tests (2-day, 8-hour per day) indicated that, there was no tendency of agglomeration of copper-based oxygen carriers. Only trace-amount of coke or carbon deposits on the copper-based oxygen carriers in the fuel reactor. There was also no evidence to show the sulphidization of oxygen carriers in the system by using the high-sulfur-laden asphalt fuels. In all, the scaled-up test in 10 kW CLC facility demonstrated that the preparation method of copper-based oxygen carrier not only help to maintain its good reactivity, also largely minimize its agglomeration tendency.« less

Use of Adaptive Injection Strategies to Increase the Full Load Limit of RCCI Operation

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

Hanson, Reed; Ickes, Andrew; Wallner, Thomas

2015-01-01

Dual-fuel combustion using port-injection of low reactivity fuel combined with direct injection of a higher reactivity fuel, otherwise known as Reactivity Controlled Compression Ignition (RCCI), has been shown as a method to achieve low-temperature combustion with moderate peak pressure rise rates, low engine-out soot and NOx emissions, and high indicated thermal efficiency. A key requirement for extending to high-load operation is moderating the reactivity of the premixed charge prior to the diesel injection. One way to accomplish this is to use a very low reactivity fuel such as natural gas. In this work, experimental testing was conducted on a 13Lmore » multi-cylinder heavy-duty diesel engine modified to operate using RCCI combustion with port injection of natural gas and direct injection of diesel fuel. Engine testing was conducted at an engine speed of 1200 RPM over a wide variety of loads and injection conditions. The impact on dual-fuel engine performance and emissions with respect to varying the fuel injection parameters is quantified within this study. The injection strategies used in the work were found to affect the combustion process in similar ways to both conventional diesel combustion and RCCI combustion for phasing control and emissions performance. As the load is increased, the port fuel injection quantity was reduced to keep peak cylinder pressure and maximum pressure rise rate under the imposed limits. Overall, the peak load using the new injection strategy was shown to reach 22 bar BMEP with a peak brake thermal efficiency of 47.6%.« less

Plasma torch for ignition, flameholding and enhancement of combustion in high speed flows

NASA Technical Reports Server (NTRS)

O'Brien, Walter F. (Inventor); Billingsley, Matthew C. (Inventor); Sanders, Darius D. (Inventor); Schetz, Joseph A. (Inventor)

2009-01-01

Preheating of fuel and injection into a plasma torch plume fro adjacent the plasma torch plume provides for only ignition with reduced delay but improved fuel-air mixing and fuel atomization as well as combustion reaction enhancement. Heat exchange also reduced erosion of the anode of the plasma torch. Fuel mixing atomization, fuel mixture distribution enhancement and combustion reaction enhancement are improved by unsteady plasma torch energization, integral formation of the heat exchanger, fuel injection nozzle and plasma torch anode in a more compact, low-profile arrangement which is not intrusive on a highspeed air flow with which the invention is particularly effective and further enhanced by use of nitrogen as a feedstock material and inclusion of high pressure gases in the fuel to cause effervescence during injection.

Laser controlled flame stabilization

DOEpatents

Early, James W.; Thomas, Matthew E.

2001-01-01

A method and apparatus is provided for initiating and stabilizing fuel combustion in applications such as gas turbine electrical power generating engines and jet turbine engines where it is desired to burn lean fuel/air mixtures which produce lower amounts of NO.sub.x. A laser induced spark is propagated at a distance from the fuel nozzle with the laser ignitor being remotely located from the high temperature environment of the combustion chamber. A laser initiating spark generated by focusing high peak power laser light to a sufficiently tight laser spot within the fuel to cause the ionization of air and fuel into a plasma is unobtrusive to the flow dynamics of the combustion chamber of a fuel injector, thereby facilitating whatever advantage can be taken of flow dynamics in the design of the fuel injector.

Global mercury emissions from combustion in light of international fuel trading.

PubMed

Chen, Yilin; Wang, Rong; Shen, Huizhong; Li, Wei; Chen, Han; Huang, Ye; Zhang, Yanyan; Chen, Yuanchen; Su, Shu; Lin, Nan; Liu, Junfeng; Li, Bengang; Wang, Xilong; Liu, Wenxin; Coveney, Raymond M; Tao, Shu

2014-01-01

The spatially resolved emission inventory is essential for understanding the fate of mercury. Previous global mercury emission inventories for fuel combustion sources overlooked the influence of fuel trading on local emission estimates of many countries, mostly developing countries, for which national emission data are not available. This study demonstrates that in many countries, the mercury content of coal and petroleum locally consumed differ significantly from those locally produced. If the mercury content in locally produced fuels were used to estimate emission, then the resulting global mercury emissions from coal and petroleum would be overestimated by 4.7 and 72%, respectively. Even higher misestimations would exist in individual countries, leading to strong spatial bias. On the basis of the available data on fuel trading and an updated global fuel consumption database, a new mercury emission inventory for 64 combustion sources has been developed. The emissions were mapped at 0.1° × 0.1° resolution for 2007 and at country resolution for a period from 1960 to 2006. The estimated global total mercury emission from all combustion sources (fossil fuel, biomass fuel, solid waste, and wildfires) in 2007 was 1454 Mg (1232-1691 Mg as interquartile range from Monte Carlo simulation), among which elementary mercury (Hg(0)), divalent gaseous mercury (Hg(2+)), and particulate mercury (Hg(p)) were 725, 548, and 181 Mg, respectively. The total emission from anthropogenic sources, excluding wildfires, was 1040 Mg (886-1248 Mg), with coal combustion contributing more than half. Globally, total annual anthropogenic mercury emission from combustion sources increased from 285 Mg (263-358 Mg) in 1960 to 1040 Mg (886-1248 Mg) in 2007, owing to an increased fuel consumption in developing countries. However, mercury emissions from developed countries have decreased since 2000.

Fuel/oxidizer-rich high-pressure preburners. [staged-combustion rocket engine

NASA Technical Reports Server (NTRS)

Schoenman, L.

1981-01-01

The analyses, designs, fabrication, and cold-flow acceptance testing of LOX/RP-1 preburner components required for a high-pressure staged-combustion rocket engine are discussed. Separate designs of injectors, combustion chambers, turbine simulators, and hot-gas mixing devices are provided for fuel-rich and oxidizer-rich operation. The fuel-rich design addresses the problem of non-equilibrium LOX/RP-1 combustion. The development and use of a pseudo-kinetic combustion model for predicting operating efficiency, physical properties of the combustion products, and the potential for generating solid carbon is presented. The oxygen-rich design addresses the design criteria for the prevention of metal ignition. This is accomplished by the selection of materials and the generation of well-mixed gases. The combining of unique propellant injector element designs with secondary mixing devices is predicted to be the best approach.

Comparison of emissions and toxicological properties of fine particles from wood and oil boilers in small (20-25 kW) and medium (5-10 MW) scale

NASA Astrophysics Data System (ADS)

Kaivosoja, T.; Jalava, P. I.; Lamberg, H.; Virén, A.; Tapanainen, M.; Torvela, T.; Tapper, U.; Sippula, O.; Tissari, J.; Hillamo, R.; Hirvonen, M.-R.; Jokiniemi, J.

2013-10-01

The aim of this study was to compare four alternatives for providing decentralized energy production in small communities in terms of their flue gas emissions and toxicological properties of the emissions. In this study, two different size classes of boilers were examined and the use of fossil fuel oils was compared against wood fuels. The lowest PM1 emission, 0.1 mg MJ-1, was observed from small-scale light fuel oil combustion. In medium-scale wood combustion, PM1 emission values from a grate fired wood combustion boiler (10 MW) without particulate filtration were the highest (264 mg MJ-1) but were substantially reduced down to 0.6 mg MJ-1 due to the usage of an electrostatic precipitator (ESP). The wood combustion particles were mainly formed of potassium salts. In light fuel oil combustion, one of the main components in the particles was sulphate whereas in heavy fuel oil combustion also significant amounts of V and Ni were emitted. Pellet combustion produced the lowest PAH emissions. Overall, oil combustion produced higher amount of PAHs than wood combustion. This was indicated also as a higher cytotoxicity of the oil combustion samples when compared to those from wood combustion in the corresponding scale of boilers. However, when calculated on an equal mass basis, the particles collected after ESP were even more cytotoxic which can be explained by the altered chemical characteristics of the emissions in the ESP. Due to the variation in the emissions and in the toxicity of the emissions, we propose that in the long term, not only the emission levels but also the toxicity of the emissions should be taken into account in the regulations of the emission limits of the combustion plants.

Nanotechnology Investigated for Future Gelled and Metallized Gelled Fuels

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan A.

2003-01-01

The objective of this research is to create combustion data for gelled and metallized gelled fuels using unique nanometer-sized gellant particles and/or nanometer-sized aluminum particles. Researchers at the NASA Glenn Research Center are formulating the fuels for both gas turbine and pulsed detonation engines. We intend to demonstrate metallized gelled fuel ignition characteristics for pulse detonation engines with JP/aluminum fuel and for gas turbine engines with gelled JP, propane, and methane fuel. The fuels to be created are revolutionary as they will deliver the highest theoretically maximum performance of gelled and metallized gelled fuels. Past combustion work has used micrometer-sized particles, which have limited the combustion performance of gelled and metallized gelled fuels. The new fuel used nanometer-sized aluminum oxide particles, which reduce the losses due to mismatch in the gas and solid phases in the exhaust. Gelled fuels provide higher density, added safety, reduced fuel slosh, reduced leakage, and increased exhaust velocity. Altogether, these benefits reduce the overall size and mass of the vehicle, increasing its flexibility.

Hydrocarbon-fuel/combustion-chamber-liner materials compatibility

NASA Technical Reports Server (NTRS)

Gage, Mark L.

1990-01-01

Results of material compatibility experiments using hydrocarbon fuels in contact with copper-based combustion chamber liner materials are presented. Mil-Spec RP-1, n- dodecane, propane, and methane fuels were tested in contact with OFHC, NASA-Z, and ZrCu coppers. Two distinct test methods were employed. Static tests, in which copper coupons were exposed to fuel for long durations at constant temperature and pressure, provided compatibility data in a precisely controlled environment. Dynamic tests, using the Aerojet Carbothermal Test Facility, provided fuel and copper compatibility data under realistic booster engine service conditions. Tests were conducted using very pure grades of each fuel and fuels to which a contaminant, e.g., ethylene or methyl mercaptan, was added to define the role played by fuel impurities. Conclusions are reached as to degradation mechanisms and effects, methods for the elimination of these mechanisms, selection of copper alloy combustion chamber liners, and hydrocarbon fuel purchase specifications.

Elimination of Intermediate-Frequency Combustion Instability in the Fastrac Engine Thrust Chamber

NASA Technical Reports Server (NTRS)

Rocker, Marvin; Nesman, Tomas E.; Turner, Jim E. (Technical Monitor)

2001-01-01

A series of tests were conducted to measure the combustion performance of the Fastrac engine thrust chamber. The thrust chamber exhibited benign, yet marginally unstable combustion. The marginally unstable combustion was characterized by chamber pressure oscillations with large amplitudes and a frequency that was too low to be identified as acoustic or high-frequency combustion instability and too high to be identified as chug or low-frequency combustion instability. The source of the buzz or intermediate-frequency combustion instability was traced to the fuel venturi whose violently noisy cavitation caused resonance in the feedline downstream. Combustion was stabilized by increasing the throat diameter of the fuel venturi such that the cavitation would occur more quietly.

A study of the current group evaporation/combustion theories

NASA Technical Reports Server (NTRS)

Shen, Hayley H.

1990-01-01

Liquid fuel combustion can be greatly enhanced by disintegrating the liquid fuel into droplets, an effect achieved by various configurations. A number of experiments carried out in the seventies showed that combustion of droplet arrays and sprays do not form individual flames. Moreover, the rate of burning in spray combustion greatly deviates from that of the single combustion rate. Such observations naturally challenge its applicability to spray combustion. A number of mathematical models were developed to evaluate 'group combustion' and the related 'group evaporation' phenomena. This study investigates the similarity and difference of these models and their applicability to spray combustion. Future work that should be carried out in this area is indicated.

High pressure combustion of liquid fuels. [alcohol and n-paraffin fuels

NASA Technical Reports Server (NTRS)

Canada, G. S.

1974-01-01

Measurements were made of the burning rates and liquid surface temperatures for a number of alcohol and n-paraffin fuels under natural and forced convection conditions. Porous spheres ranging in size from 0.64-1.9 cm O.D. were emloyed to simulate the fuel droplets. The natural convection cold gas tests considered the combustion in air of methanol, ethanol, propanol-1, n-pentane, n-heptane, and n-decane droplets at pressures up to 78 atmospheres. The pressure levels of the natural convection tests were high enough so that near critical combustion was observed for methanol and ethanol vaporization rates and liquid surface temperature measurements were made of droplets burning in a simulated combustion chamber environment. Ambient oxygen molar concentrations included 13%, 9.5% and pure evaporation. Fuels used in the forced convection atmospheric tests included those listed above for the natural convection tests. The ambient gas temperature ranged from 600 to 1500 K and the Reynolds number varied from 30 to 300. The high pressure forced convection tests employed ethanol and n-heptane as fuels over a pressure range of one to 40 atmospheres. The ambient gas temperature was 1145 K for the two combustion cases and 1255 K for the evaporation case.

Characteristics of fundamental combustion and NOx emission using various rank coals.

PubMed

Kim, Sung Su; Kang, Youn Suk; Lee, Hyun Dong; Kim, Jae-Kwan; Hong, Sung Chang

2011-03-01

Eight types of coals of different rank were selected and their fundamental combustion characteristics were examined along with the conversion of volatile nitrogen (N) to nitrogen oxides (NOx)/fuel N to NOx. The activation energy, onset temperature, and burnout temperature were obtained from the differential thermogravimetry curve and Arrhenius plot, which were derived through thermo-gravimetric analysis. In addition, to derive the combustion of volatile N to NOx/fuel N to NOx, the coal sample, which was pretreated at various temperatures, was burned, and the results were compared with previously derived fundamental combustion characteristics. The authors' experimental results confirmed that coal rank was highly correlated with the combustion of volatile N to NOx/fuel N to NOx.

Evaporation And Ignition Of Dense Fuel Sprays

NASA Technical Reports Server (NTRS)

Bellan, Josette; Harstad, Kenneth G.

1988-01-01

Simple theoretical model makes useful predictions of trends. Pair of reports presents theoretical model of evaporation and ignition of sprayed liquid fuel. Developed as part of research in combustion of oil and liquid fuels derived from coal, tar sand, and shale in furnace. Work eventually contributes to increase efficiency of combustion and decrease pollution generated by burning of such fuels.

Multiple Threats to Child Health from Fossil Fuel Combustion: Impacts of Air Pollution and Climate Change

PubMed Central

Perera, Frederica P.

2016-01-01

Background: Approaches to estimating and addressing the risk to children from fossil fuel combustion have been fragmented, tending to focus either on the toxic air emissions or on climate change. Yet developing children, and especially poor children, now bear a disproportionate burden of disease from both environmental pollution and climate change due to fossil fuel combustion. Objective: This commentary summarizes the robust scientific evidence regarding the multiple current and projected health impacts of fossil fuel combustion on the young to make the case for a holistic, child-centered energy and climate policy that addresses the full array of physical and psychosocial stressors resulting from fossil fuel pollution. Discussion: The data summarized here show that by sharply reducing our dependence on fossil fuels we would achieve highly significant health and economic benefits for our children and their future. These benefits would occur immediately and also play out over the life course and potentially across generations. Conclusion: Going beyond the powerful scientific and economic arguments for urgent action to reduce the burning of fossil fuels is the strong moral imperative to protect our most vulnerable populations. Citation: Perera FP. 2017. Multiple threats to child health from fossil fuel combustion: impacts of air pollution and climate change. Environ Health Perspect 125:141–148; http://dx.doi.org/10.1289/EHP299 PMID:27323709

Expanding Robust HCCI Operation with Advanced Valve and Fuel Control Technologies

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

Szybist, J. P.; Confer, K.

2012-09-11

Delphi Automotive Systems and ORNL established this CRADA to advance the commercialization potential of the homogeneous charge compression ignition (HCCI) advanced combustion strategy for gasoline engine platforms. HCCI combustion has been shown by others to produce high diesel-like efficiency on a gasoline engine platform while simultaneously producing low NOX and particulate matter emissions. However, the commercialization barriers that face HCCI combustion are significant, with requirements for a more active engine control system, likely with next-cycle closed-loop feedback control, and with advanced valve train technologies to enable negative valve overlap conditions. In the partnership between Delphi and ORNL, each organization broughtmore » a unique and complementary set of skills to the project. Delphi has made a number of breakthroughs with production-intent valve train technologies and controls in recent years to make a part time production-intent HCCI engine plausible. ORNL has extensive knowledge and expertise with HCCI combustion, and also has a versatile research engine with hydraulic valve actuation (HVA) that is useful for guiding production of a cam-based HCCI system. Partnering these knowledge bases and capabilities was essential towards making progress to better understand HCCI combustion and the commercialization barriers that it faces. ORNL and Delphi maintained strong collaboration throughout the project. Meetings were held regularly, with additional reports, presentations, and meetings as necessary to maintain progress. Delphi provided guidance to ORNL regarding operational strategies to investigate on their single-cylinder research engine with HVA and data from their experimental multi-cylinder engine for modeling. ORNL provided single-cylinder engine data and modeling results.« less

Research in Supercritical Fuel Properties and Combustion Modeling

DTIC Science & Technology

2015-09-18

AFRL-AFOSR-VA-TR-2015-0296 RESEARCH IN SUPERCRITICAL FUEL PROPERTIES AND COMBUSTION MODELING Gregory Faris SRI INTERNATIONAL MENLO PARK CA Final...Properties and Combustion Modeling 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-13-1-0177 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Gregory W...carbon atom species for combustion modeling and optimization. On the stimulated scattering task, we have tested new methods for rapidly scanning

Smoke emissions due to burning of green waste in the Mediterranean area: Influence of fuel moisture content and fuel mass

NASA Astrophysics Data System (ADS)

Tihay-Felicelli, V.; Santoni, P. A.; Gerandi, G.; Barboni, T.

2017-06-01

The aim of this study was to investigate emission characteristics in relation to differences in fuel moisture content (FMC) and initial dry mass. For this purpose, branches and twigs with leaves of Cistus monspeliensis were burned in a Large Scale Heat Release apparatus coupled to a Fourier Transform Infrared Spectrometer. A smoke analysis was conducted and the results highlighted the presence of CO2, H2O, CO, CH4, NO, NO2, NH3, SO2, and non-methane organic compounds (NMOC). CO2, NO, and NO2 species are mainly released during flaming combustion, whereas CO, CH4, NH3, and NMOC are emitted during both flaming and smoldering combustion. The emission of these compounds during flaming combustion is due to a rich fuel to air mixture, leading to incomplete combustion. The fuel moisture content and initial dry mass influence the flame residence time, the duration of smoldering combustion, the combustion efficiency, and the emission factors. By increasing the initial dry mass, the emission factors of NO, NO2, and CO2 decrease, whereas those of CO and CH4 increase. The increase of FMC induces an increase of the emission factors of CO, CH4, NH3, NMOC, and aerosols, and a decrease of those of CO2, NO, and NO2. Increasing fuel moisture content reduces fuel consumption, duration of smoldering, and peak heat release rate, but simultaneously increases the duration of propagation within the packed bed, and the flame residence time. Increasing the initial dry mass, causes all the previous combustion parameters to increase. These findings have implications for modeling biomass burning emissions and impacts.

National Combustion Code Used To Study the Hydrogen Injector Design for Gas Turbines

NASA Technical Reports Server (NTRS)

Iannetti, Anthony C.; Norris, Andrew T.; Shih, Tsan-Hsing

2005-01-01

Hydrogen, in the gas state, has been proposed to replace Jet-A (the fuel used for commercial jet engines) as a fuel for gas turbine combustion. For the combustion of hydrogen and oxygen only, water is the only product and the main greenhouse gas, carbon dioxide, is not produced. This is an obvious benefit of using hydrogen as a fuel. The situation is not as simple when air replaces oxygen in the combustion process. (Air is mainly a mixture of oxygen, nitrogen, and argon. Other components comprise a very small part of air and will not be mentioned.) At the high temperatures found in the combustion process, oxygen reacts with nitrogen, and this produces nitrogen oxide compounds, or NOx--the main component of atmospheric smog. The production of NOx depends mainly on two variables: the temperature at which combustion occurs, and the length of time that the products of combustion stay, or reside, in the combustor. Starting from a lean (excess air) air-to-fuel ratio, the goal of this research was to minimize hot zones caused by incomplete premixing and to keep the residence time short while producing a stable flame. The minimization of these two parameters will result in low- NOx hydrogen combustion.

Predicted exhaust emissions from a methanol and jet fueled gas turbine combustor

NASA Technical Reports Server (NTRS)

Adelman, H. G.; Browning, L. H.; Pefley, R. K.

1975-01-01

A computer model of a gas turbine combustor has been used to predict the kinetic combustion and pollutant formation processes for methanol and simulated jet fuel. Use of the kinetic reaction mechanisms has also allowed a study of ignition delay and flammability limit of these two fuels. The NOX emissions for methanol were predicted to be from 69 to 92% lower than those for jet fuel at the same equivalence ratio which is in agreement with experimentally observed results. The high heat of vaporization of methanol lowers both the combustor inlet mixture temperatures and the final combustion temperatures. The lower combustion temperatures lead to low NOX emissions while the lower inlet mixture temperatures increase methanol's ignition delay. This increase in ignition delay dictates the lean flammability limit of methanol to be 0.8, while jet fuel is shown to combust at 0.4.

Secondary fuel delivery system

DOEpatents

Parker, David M.; Cai, Weidong; Garan, Daniel W.; Harris, Arthur J.

2010-02-23

A secondary fuel delivery system for delivering a secondary stream of fuel and/or diluent to a secondary combustion zone located in the transition piece of a combustion engine, downstream of the engine primary combustion region is disclosed. The system includes a manifold formed integral to, and surrounding a portion of, the transition piece, a manifold inlet port, and a collection of injection nozzles. A flowsleeve augments fuel/diluent flow velocity and improves the system cooling effectiveness. Passive cooling elements, including effusion cooling holes located within the transition boundary and thermal-stress-dissipating gaps that resist thermal stress accumulation, provide supplemental heat dissipation in key areas. The system delivers a secondary fuel/diluent mixture to a secondary combustion zone located along the length of the transition piece, while reducing the impact of elevated vibration levels found within the transition piece and avoiding the heat dissipation difficulties often associated with traditional vibration reduction methods.

Fuel nozzle assembly for use in turbine engines and methods of assembling same

DOEpatents

Uhm, Jong Ho; Johnson, Thomas Edward

2015-02-03

A fuel nozzle for use with a turbine engine is described herein. The fuel nozzle includes a housing that is coupled to a combustor liner defining a combustion chamber. The housing includes an endwall that at least partially defines the combustion chamber. A plurality of mixing tubes extends through the housing for channeling fuel to the combustion chamber. Each mixing tube of the plurality of mixing tubes includes an inner surface that extends between an inlet portion and an outlet portion. The outlet portion is oriented adjacent the housing endwall. At least one of the plurality of mixing tubes includes a plurality of projections that extend outwardly from the outlet portion. Adjacent projections are spaced a circumferential distance apart such that a groove is defined between each pair of circumferentially-apart projections to facilitate enhanced mixing of fuel in the combustion chamber.

40 CFR 60.4365 - How can I be exempted from monitoring the total sulfur content of the fuel?

Code of Federal Regulations, 2012 CFR

2012-07-01

... Standards of Performance for Stationary Combustion Turbines Monitoring § 60.4365 How can I be exempted from... fuel combusted in the turbine, if the fuel is demonstrated not to exceed potential sulfur emissions of...

Fuel Combustion and Engine Performance | Transportation Research | NREL

Science.gov Websites

. Through modeling, simulation, and experimental validation, researchers examine what happens to fuel inside combustion and engine research activities include: Developing experimental and simulation research platforms develop and refine accurate, efficient kinetic mechanisms for fuel ignition Investigating low-speed pre

Flame Characteristics and Fuel Entrainment Inside a Cavity Flame Holder in a Scramjet Combustor (Postprint)

DTIC Science & Technology

2007-07-01

RBL was observed to be higher than RIL, due to the presence of hot combustion products and the effect of cavity wall temperature. Table 1...Vol. 17, No. 4, 2001, pp. 869-877. 3. Yu, K., Wilson K., and Schadow, K., “ Effect of Flame-Holding Cavities on Supersonic- Combustion Performance... combustion products and is relatively rich with main fuel only. Consequently, additional fuel injection into the cavity increases the probability of

Effect of W/O Emulsion Fuel Properties on Spray Combustion

NASA Astrophysics Data System (ADS)

Ida, Tamio; Fuchihata, Manabu; Takeda, Shuuco

This study proposes a realizable technology for an emulsion combustion method that can reduce environmental loading. This paper discusses the effect on spray combustion for W/O emulsion fuel properties with an added agent, and the ratio between water and emulsifier added to a liquid fuel. The addition of water or emulsifier to a liquid fuel affected the spray combustion by causing micro-explosions in the flame due to geometric changes in the sprayed flame and changes to the temperature distribution. Experimental results revealed that the flame length shortened by almost 40% upon the addition of the water. Furthermore, it was found that water was effective in enhancing combustion due to its promoting micro-explosions. Results also showed that when the emulsifier was added to the spray flame, the additive burned in the flame's wake, producing a bright red flame. The flame length was observed to be long as a result. The micro-explosion phenomenon, caused by emulsifier dosage differences, was observed using time-dependent images at a generated frequency and an explosion scale with a high-speed photography method. Results indicated that the micro-explosion phenomenon in the W/O emulsion combustion method effectively promoted the combustion reaction and suppressed soot formation.

Diesel Fuel Property Effects on In-Cylinder Liquid Penetration Length: Impact on Smoke Emissions and Equivalence Ratio Estimates at the Flame Lift-Off Length

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

Dumitrescu, Cosmin E.; Polonowski, Christopher J.; Fisher, Brian T.

Here in this study, elastic scattering was employed to investigate diesel fuel property effects on the liquid length (i.e., the maximum extent of in-cylinder liquid-phase fuel penetration) using select research fuels: an ultralow-sulfur #2 diesel emissions-certification fuel (CF) and four of the Coordinating Research Council (CRC) Fuels for Advanced Combustion Engines (FACE) diesel fuels (F1, F2, F6, and F8). The experiments were performed in a single-cylinder heavy-duty optical compression-ignition engine under time-varying, noncombusting conditions to minimize the influence of chemical heat release on the liquid-length measurement. The FACE diesel fuel and CF liquid lengths under combusting conditions were also predicted using Siebers’ scaling law and pressure data from previous work using the same fuels at similar in-cylinder conditions. The objective was to observe if the liquid length under noncombusting or combusting conditions provides additional insights into the relationships among the main fuel properties (i.e., cetane number (CN), the 90 vol % distillation recovery temperature (T90), and aromatic content) and smoke emissions. Results suggest that liquid-length values are best correlated to fuel distillation characteristics measured with ASTM D2887 (simulated distillation method). This work also studied the relationship between liquid length and lift-off length, H (i.e., distance from the fuel-injector orifice exit to the position where the standing premixed autoignition zone stabilizes during mixing-controlled combustion). Two possible cases were identified based on the relative magnitudes of liquid length under combusting conditions (Lc) and H. The low-CN fuels are representative of the first case, L c < H, in which the fuel is always fully vaporized at H. The high-CN fuels are mostly representative of the second case, L c ≥ H, in which there is still liquid fuel at H. Lc ≥ H would suggest higher smoke emissions, but there is not enough evidence in this work to support a compounding effect of a longer liquid length on top of the aromatic-content effect on smoke emissions for fuels with similar CN, supporting previous findings in the literature that lift-off length plays a more important role than liquid-length on diesel combustion. At the same time, the experimental results suggest a decrease in the fuel-jet spreading angle, i.e., a decrease in the entrainment rate into the jet at and downstream of H, under combusting conditions, that is not accounted for in the model used to predict the values ofmore » $$\\phi$$(H). Lastly, as a result, L c may be of interest for accurate predictions of $$\\phi$$(H), especially for combustion strategies designed to lower in-cylinder soot by operating near or below the nonsooting $$\\phi$$(H)-value (i.e., $$\\phi$$(H) ≈ 2).« less

Diesel Fuel Property Effects on In-Cylinder Liquid Penetration Length: Impact on Smoke Emissions and Equivalence Ratio Estimates at the Flame Lift-Off Length

DOE PAGES

Dumitrescu, Cosmin E.; Polonowski, Christopher J.; Fisher, Brian T.; ...

2015-10-05

Here in this study, elastic scattering was employed to investigate diesel fuel property effects on the liquid length (i.e., the maximum extent of in-cylinder liquid-phase fuel penetration) using select research fuels: an ultralow-sulfur #2 diesel emissions-certification fuel (CF) and four of the Coordinating Research Council (CRC) Fuels for Advanced Combustion Engines (FACE) diesel fuels (F1, F2, F6, and F8). The experiments were performed in a single-cylinder heavy-duty optical compression-ignition engine under time-varying, noncombusting conditions to minimize the influence of chemical heat release on the liquid-length measurement. The FACE diesel fuel and CF liquid lengths under combusting conditions were also predicted using Siebers’ scaling law and pressure data from previous work using the same fuels at similar in-cylinder conditions. The objective was to observe if the liquid length under noncombusting or combusting conditions provides additional insights into the relationships among the main fuel properties (i.e., cetane number (CN), the 90 vol % distillation recovery temperature (T90), and aromatic content) and smoke emissions. Results suggest that liquid-length values are best correlated to fuel distillation characteristics measured with ASTM D2887 (simulated distillation method). This work also studied the relationship between liquid length and lift-off length, H (i.e., distance from the fuel-injector orifice exit to the position where the standing premixed autoignition zone stabilizes during mixing-controlled combustion). Two possible cases were identified based on the relative magnitudes of liquid length under combusting conditions (Lc) and H. The low-CN fuels are representative of the first case, L c < H, in which the fuel is always fully vaporized at H. The high-CN fuels are mostly representative of the second case, L c ≥ H, in which there is still liquid fuel at H. Lc ≥ H would suggest higher smoke emissions, but there is not enough evidence in this work to support a compounding effect of a longer liquid length on top of the aromatic-content effect on smoke emissions for fuels with similar CN, supporting previous findings in the literature that lift-off length plays a more important role than liquid-length on diesel combustion. At the same time, the experimental results suggest a decrease in the fuel-jet spreading angle, i.e., a decrease in the entrainment rate into the jet at and downstream of H, under combusting conditions, that is not accounted for in the model used to predict the values ofmore » $$\\phi$$(H). Lastly, as a result, L c may be of interest for accurate predictions of $$\\phi$$(H), especially for combustion strategies designed to lower in-cylinder soot by operating near or below the nonsooting $$\\phi$$(H)-value (i.e., $$\\phi$$(H) ≈ 2).« less

Supercritical fuel injection system

NASA Technical Reports Server (NTRS)

Marek, C. J.; Cooper, L. P. (Inventor)

1980-01-01

a fuel injection system for gas turbines is described including a pair of high pressure pumps. The pumps provide fuel and a carrier fluid such as air at pressures above the critical pressure of the fuel. A supercritical mixing chamber mixes the fuel and carrier fluid and the mixture is sprayed into a combustion chamber. The use of fuel and a carrier fluid at supercritical pressures promotes rapid mixing of the fuel in the combustion chamber so as to reduce the formation of pollutants and promote cleaner burning.

Development of Combustion Tube for Gaseous, Liquid, and Solid Fuels to Study Flame Acceleration and DDT

NASA Astrophysics Data System (ADS)

Graziano, Tyler J.

An experimental combustion tube of 20 ft. in length and 10.25 in. in internal diameter was designed and fabricated in order to perform combustion tests to study deflagration rates, flame acceleration, and the possibility of DDT. The experiment was designed to allow gaseous, liquid, or solid fuels, or any combination of the three to produce a homogenous fuel/air mixture within the tube. Combustion tests were initiated with a hydrogen/oxygen torch igniter and the resulting flame behavior was measured with high frequency ion probes and pressure transducers. Tests were performed with a variety of gaseous and liquid fuels in an unobstructed tube with a closed ignition end and open muzzle. The flame performance with the gaseous fuels is loosely correlated with the expansion ratio, while there is a stronger correlation with the laminar flame speed. The strongest correlation to flame performance is the run-up distance scaling factor. This trend was not observed with the liquid fuels. The reason for this is likely due to incomplete evaporation of the liquid fuel droplets resulting in a partially unburned mixture, effectively altering the intended equivalence ratio. Results suggest that the simple theory for run-up distance and flame acceleration must be modified to more accurately predict the behavior of gaseous fuels. Also, it is likely that more complex spray combustion modeling is required to accurately predict the flame behavior for liquid fuels.

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.

Intensification of the Process of Flame Combustion of a Pulverized Coal Fuel

NASA Astrophysics Data System (ADS)

Popov, V. I.

2017-11-01

Consideration is given to a method of mechanoactivation intensification of the flame combustion of a pulverized coal fuel through the formation of a stressed state for the microstructure of its particles; the method is based on the use of the regularities of their external (diffusion) and internal (relaxation) kinetics. A study has been made of mechanoactivation nonequilibrium processes that occur in fuel particles during the induced relaxation of their stressed state with a resumed mobility of the microstructure of the particles and intensify diffusion-controlled chemical reactions in them under the assumption that the time of these reactions is much shorter than the times of mechanical action on a particle and of stress relaxation in it. The influence of the diffusion and relaxation factors on the burnup time of a fuel particle and on the flame distance has been analyzed. Ranges of variation in the parameters of flame combustion have been singled out in which the flame distance is determined by the mechanisms of combustion of the fuel and of mixing of combustion products.

The comparative analysis of heat transfer efficiency in the conditions of formation of ash deposits in the boiler furnaces, with taking into account the crystallization of slag during combustion of coal and water-coal fuel

NASA Astrophysics Data System (ADS)

Salomatov, V. V.; Kuznetsov, G. V.; Syrodoy, S. V.

2017-11-01

The results of the numerical simulation of heat transfer from the combustion products of coal and coal-water fuels (CWF) to the internal environment. The mathematical simulation has been carried out on the sample of the pipe surfaces of the combustion chamber of the boiler unit. The change in the characteristics of heat transfer (change of thermochemical characteristics) in the conditions of formation of the ash deposits have been taken into account. According to the results of the numerical simulation, the comparative analysis of the efficiency of heat transfer has been carried out from the furnace environment to the inside pipe coolant (water, air, or water vapor) from the combustion of coal and coal-water fuels. It has been established that, in the initial period of the boiler unit operation during coal fuel combustion the efficiency of heat transfer from the combustion products of the internal environment is higher than when using CWF. The efficiency of heat transfer in CWF combustion conditions is more at large times (τ≥1.5 hours) of the boiler unit. A significant decrease in heat flux from the combustion products to the inside pipe coolant in the case of coal combustion compared to CWF has been found. It has been proved that this is due primarily to the fact that massive and strong ash deposits are formed during coal combustion.

Comparison of fuel value and combustion characteristics of two different RDF samples.

PubMed

Sever Akdağ, A; Atımtay, A; Sanin, F D

2016-01-01

Generation of Municipal Solid Waste (MSW) tends to increase with the growing population and economic development of the society; therefore, establishing environmentally sustainable waste management strategies is crucial. In this sense, waste to energy strategies have come into prominence since they increase the resource efficiency and replace the fossil fuels with renewable energy sources by enabling material and energy recovery instead of landfill disposal of the wastes. Refuse Derived Fuel (RDF), which is an alternative fuel produced from energy-rich Municipal Solid Waste (MSW) materials diverted from landfills, is one of the waste to energy strategies gaining more and more attention. This study aims to investigate the thermal characteristics and co-combustion efficiency of two RDF samples in Turkey. Proximate, ultimate and thermogravimetric analyses (TGA) were conducted on these samples. Furthermore, elemental compositions of ash from RDF samples were determined by X-Ray Fluorescence (XRF) analysis. The RDF samples were combusted alone and co-combusted in mixtures with coal and petroleum coke in a lab scale reactor at certain percentages on energy basis (3%, 5%, 10%, 20% and 30%) where co-combustion processes and efficiencies were investigated. It was found that the calorific values of RDF samples on dry basis were close to that of coal and a little lower compared to petroleum coke used in this study. Furthermore, the analysis indicated that when RDF in the mixture was higher than 10%, the CO concentration in the flue gas increased and so the combustion efficiency decreased; furthermore, the combustion characteristics changed from char combustion to volatile combustion. However, RDF addition to the fuel mixtures decreased the SO2 emission and did not change the NOx profiles. Also, XRF analysis showed that the slagging and fouling potential of RDF combustion was a function of RDF portion in fuel blend. When the RDF was combusted alone, the slagging and fouling indices of its ash were found to be higher than the limit values producing slagging and fouling. Copyright © 2015 Elsevier Ltd. All rights reserved.

Scramjet fuel injector design parameters and considerations: Development of a two-dimensional tangential fuel injector with constant pressure at the flame

NASA Technical Reports Server (NTRS)

Agnone, A. M.

1972-01-01

The factors affecting a tangential fuel injector design for scramjet operation are reviewed and their effect on the efficiency of the supersonic combustion process is evaluated using both experimental data and theoretical predictions. A description of the physical problem of supersonic combustion and method of analysis is followed by a presentation and evaluation of some standard and exotic types of fuel injectors. Engineering fuel injector design criteria and hydrogen ignition schemes are presented along with a cursory review of available experimental data. A two-dimensional tangential fuel injector design is developed using analyses as a guide in evaluating the effects on the combustion process of various initial and boundary conditions including splitter plate thickness, injector wall temperature, pressure gradients, etc. The fuel injector wall geometry is shaped so as to maintain approximately constant pressure at the flame as required by a cycle analysis. A viscous characteristics program which accounts for lateral as well as axial pressure variations due to the mixing and combustion process is used in determining the wall geometry.

Characterization and Mutagenicity of Biomass Smoke from Peat and Red Oak Fuel under Smolder and Flame Combustions

EPA Science Inventory

Although wildfire smoke is known to cause adverse health effects, less is known about the relative effects of wildfire smoke from different fuel types or combustion conditions. In this study, we describe a novel in-tandem application of controlled combustion and cryo-trapping tec...

Portland cement for SO/sub 2/ control in coal-fired power plants

DOEpatents

Steinberg, M.

1984-10-17

A method is described for removing oxides of sulfur from the emissions of fossil fuel combustion by injecting portland cement into the boiler with the fuel, the combustion air, or downstream with the combustion gases. The cement products that result from this method is also described. 1 tab.

40 CFR 241.3 - Standards and procedures for identification of non-hazardous secondary materials that are solid...

Code of Federal Regulations, 2013 CFR

2013-07-01

... combustion units. 241.3 Section 241.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES SOLID WASTES USED AS FUELS OR INGREDIENTS IN COMBUSTION UNITS Identification of Non-Hazardous Secondary Materials That Are Solid Wastes When Used as Fuels or Ingredients in Combustion Units...

40 CFR 241.3 - Standards and procedures for identification of non-hazardous secondary materials that are solid...

Code of Federal Regulations, 2012 CFR

2012-07-01

... combustion units. 241.3 Section 241.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES SOLID WASTES USED AS FUELS OR INGREDIENTS IN COMBUSTION UNITS Identification of Non-Hazardous Secondary Materials That Are Solid Wastes When Used as Fuels or Ingredients in Combustion Units...

40 CFR 241.3 - Standards and procedures for identification of non-hazardous secondary materials that are solid...

Code of Federal Regulations, 2014 CFR

2014-07-01

... combustion units. 241.3 Section 241.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES SOLID WASTES USED AS FUELS OR INGREDIENTS IN COMBUSTION UNITS Identification of Non-Hazardous Secondary Materials That Are Solid Wastes When Used as Fuels or Ingredients in Combustion Units...

Portland cement for SO.sub.2 control in coal-fired power plants

DOEpatents

Steinberg, Meyer

1985-01-01

There is described a method of removing oxides of sulfur from the emissions of fossil fuel combustion by injecting portland cement into the boiler with the fuel, the combustion air, or downstream with the combustion gases. There is also described the cement products that result from this method.

LOX/Hydrocarbon Combustion Instability Investigation

NASA Technical Reports Server (NTRS)

Jensen, R. J.; Dodson, H. C.; Claflin, S. E.

1989-01-01

The LOX/Hydrocarbon Combustion Instability Investigation Program was structured to determine if the use of light hydrocarbon combustion fuels with liquid oxygen (LOX) produces combustion performance and stability behavior similar to the LOX/hydrogen propellant combination. In particular methane was investigated to determine if that fuel can be rated for combustion instability using the same techniques as previously used for LOX/hydrogen. These techniques included fuel temperature ramping and stability bomb tests. The hot fire program probed the combustion behavior of methane from ambient to subambient temperatures. Very interesting results were obtained from this program that have potential importance to future LOX/methane development programs. A very thorough and carefully reasoned documentation of the experimental data obtained is contained. The hot fire test logic and the associated tests are discussed. Subscale performance and stability rating testing was accomplished using 40,000 lb. thrust class hardware. Stability rating tests used both bombs and fuel temperature ramping techniques. The test program was successful in generating data for the evaluation of the methane stability characteristics relative to hydrogen and to anchor stability models. Data correlations, performance analysis, stability analyses, and key stability margin enhancement parameters are discussed.

Energy and emission aspects of co-combustion solid recovered fuel with coal in a stoker boiler

NASA Astrophysics Data System (ADS)

Wasielewski, Ryszard; Głód, Krzysztof; Telenga-Kopyczyńska, Jolanta

2018-01-01

The results of industrial research on co-combustion of solid recovered fuel (SRF) with hard coal in a stoker boiler type WR-25 has been presented. The share of SRF in the fuel mixture was 10%. During the co-combustion of SRF, no technological disturbances or significant reduction in energy efficiency of the boiler were noted. Obtained SO2, NOx and CO emissions were comparable with coal combustion but dust emissions increased. During combustion of the coal mixture with a 10% share of SRF in the test boiler WR-25, the emission standards established for the combustion of the dedicated fuel were met. However, comparison of obtained emission results with the emission standards established for co-incineration of waste, revealed the exceedance of permissible levels of HCl, dust, heavy metals, dioxins and furans. Additionally, the residence time of flue gases in over 850°C conditions for the test boiler WR-25 was too short (1.3 seconds) in refer to the legislative requirements (2 seconds) for the thermal conversion of waste.

Biofuels combustion*

DOE PAGES

Westbrook, Charles K.

2013-01-04

This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acidsmore » and used primarily to replace or supplement conventional diesel fuels. As a result, research efforts on so-called second- and third-generation biofuels are discussed briefly.« less

Experimental Supersonic Combustion Research at NASA Langley

NASA Technical Reports Server (NTRS)

Rogers, R. Clayton; Capriotti, Diego P.; Guy, R. Wayne

1998-01-01

Experimental supersonic combustion research related to hypersonic airbreathing propulsion has been actively underway at NASA Langley Research Center (LaRC) since the mid-1960's. This research involved experimental investigations of fuel injection, mixing, and combustion in supersonic flows and numerous tests of scramjet engine flowpaths in LaRC test facilities simulating flight from Mach 4 to 8. Out of this research effort has come scramjet combustor design methodologies, ground test techniques, and data analysis procedures. These technologies have progressed steadily in support of the National Aero-Space Plane (NASP) program and the current Hyper-X flight demonstration program. During NASP nearly 2500 tests of 15 scramjet engine models were conducted in LaRC facilities. In addition, research supporting the engine flowpath design investigated ways to enhance mixing, improve and apply nonintrusive diagnostics, and address facility operation. Tests of scramjet combustor operation at conditions simulating hypersonic flight at Mach numbers up to 17 also have been performed in an expansion tube pulse facility. This paper presents a review of the LaRC experimental supersonic combustion research efforts since the late 1980's, during the NASP program, and into the Hyper-X Program.

Progress in Validation of Wind-US for Ramjet/Scramjet Combustion

NASA Technical Reports Server (NTRS)

Engblom, William A.; Frate, Franco C.; Nelson, Chris C.

2005-01-01

Validation of the Wind-US flow solver against two sets of experimental data involving high-speed combustion is attempted. First, the well-known Burrows- Kurkov supersonic hydrogen-air combustion test case is simulated, and the sensitively of ignition location and combustion performance to key parameters is explored. Second, a numerical model is developed for simulation of an X-43B candidate, full-scale, JP-7-fueled, internal flowpath operating in ramjet mode. Numerical results using an ethylene-air chemical kinetics model are directly compared against previously existing pressure-distribution data along the entire flowpath, obtained in direct-connect testing conducted at NASA Langley Research Center. Comparison to derived quantities such as burn efficiency and thermal throat location are also made. Reasonable to excellent agreement with experimental data is demonstrated for key parameters in both simulation efforts. Additional Wind-US feature needed to improve simulation efforts are described herein, including maintaining stagnation conditions at inflow boundaries for multi-species flow. An open issue regarding the sensitivity of isolator unstart to key model parameters is briefly discussed.

40 CFR 96.304 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

... requirements of this subpart and subparts BBBB through HHHH of this part: any stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine serving at any time, since the later of... combust fossil fuel or to serve a generator with nameplate capacity of more than 25 MWe producing...

40 CFR 97.602 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... trimmings. Boiler means an enclosed fossil- or other-fuel-fired combustion device used to produce heat and... electricity through the sequential use of energy. Cogeneration unit means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine that is a topping-cycle unit or a bottoming...

40 CFR 97.702 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... trimmings. Boiler means an enclosed fossil- or other-fuel-fired combustion device used to produce heat and... electricity through the sequential use of energy. Cogeneration unit means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine that is a topping-cycle unit or a bottoming...

40 CFR 97.702 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... trimmings. Boiler means an enclosed fossil- or other-fuel-fired combustion device used to produce heat and... electricity through the sequential use of energy. Cogeneration unit means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine that is a topping-cycle unit or a bottoming...

40 CFR 97.602 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... trimmings. Boiler means an enclosed fossil- or other-fuel-fired combustion device used to produce heat and... electricity through the sequential use of energy. Cogeneration unit means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine that is a topping-cycle unit or a bottoming...

40 CFR 97.402 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... fossil- or other-fuel-fired combustion device used to produce heat and to transfer heat to recirculating... the sequential use of energy. Cogeneration unit means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine that is a topping-cycle unit or a bottoming-cycle unit: (1...

40 CFR 97.602 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... trimmings. Boiler means an enclosed fossil- or other-fuel-fired combustion device used to produce heat and... electricity through the sequential use of energy. Cogeneration unit means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine that is a topping-cycle unit or a bottoming...

40 CFR 97.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... any form of solid, liquid, or gaseous fuel derived from such material. Fossil fuel fired means, with... subpart H of this part. Boiler means an enclosed fossil or other fuel-fired combustion device used to... efficiency of electricity generation or steam production. Combustion turbine means an enclosed fossil or...

40 CFR 97.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... any form of solid, liquid, or gaseous fuel derived from such material. Fossil fuel fired means, with... subpart H of this part. Boiler means an enclosed fossil or other fuel-fired combustion device used to... efficiency of electricity generation or steam production. Combustion turbine means an enclosed fossil or...

40 CFR 97.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... any form of solid, liquid, or gaseous fuel derived from such material. Fossil fuel fired means, with... subpart H of this part. Boiler means an enclosed fossil or other fuel-fired combustion device used to... efficiency of electricity generation or steam production. Combustion turbine means an enclosed fossil or...

40 CFR 97.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... any form of solid, liquid, or gaseous fuel derived from such material. Fossil fuel fired means, with... subpart H of this part. Boiler means an enclosed fossil or other fuel-fired combustion device used to... efficiency of electricity generation or steam production. Combustion turbine means an enclosed fossil or...

40 CFR 97.402 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... fossil- or other-fuel-fired combustion device used to produce heat and to transfer heat to recirculating... the sequential use of energy. Cogeneration unit means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine that is a topping-cycle unit or a bottoming-cycle unit: (1...

40 CFR 97.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... any form of solid, liquid, or gaseous fuel derived from such material. Fossil fuel fired means, with... subpart H of this part. Boiler means an enclosed fossil or other fuel-fired combustion device used to... efficiency of electricity generation or steam production. Combustion turbine means an enclosed fossil or...

40 CFR 97.402 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... fossil- or other-fuel-fired combustion device used to produce heat and to transfer heat to recirculating... the sequential use of energy. Cogeneration unit means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine that is a topping-cycle unit or a bottoming-cycle unit: (1...

40 CFR 97.702 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... trimmings. Boiler means an enclosed fossil- or other-fuel-fired combustion device used to produce heat and... electricity through the sequential use of energy. Cogeneration unit means a stationary, fossil-fuel-fired boiler or stationary, fossil-fuel-fired combustion turbine that is a topping-cycle unit or a bottoming...

FUEL RICH SULFUR CAPTURE IN A COMBUSTION ENVIRONMENT

EPA Science Inventory

A refractory-lined, natural gas furnace was used to study fuel rich sulfur capture reactions of calcium sorbents under typical combustion conditions. The fuel rich sulfur species H2S and COS were monitored in a near-continuous fashion using a gas chromatograph equipped with a fl...

Multiuser Droplet Combustion Apparatus Developed to Conduct Combustion Experiments

NASA Technical Reports Server (NTRS)

Myhre, Craig A.

2001-01-01

A major portion of the energy produced in the world today comes from the combustion or burning of liquid hydrocarbon fuels in the form of droplets. However, despite vigorous scientific examinations for over a century, researchers still lack a full understanding of many fundamental combustion processes of liquid fuels. Understanding how these fuel droplets ignite, spread, and extinguish themselves will help us develop more efficient ways of energy production and propulsion, as well as help us deal better with the problems of combustion-generated pollution and fire hazards associated with liquid combustibles. The ability to conduct more controlled experiments in space, without the complication of gravity, provides scientists with an opportunity to examine these complicated processes closely. The Multiuser Droplet Combustion Apparatus (MDCA) supports this continued research under microgravity conditions. The objectives are to improve understanding of fundamental droplet phenomena affected by gravity, to use research results to advance droplet combustion science and technology on Earth, and to address issues of fire hazards associated with liquid combustibles on Earth and in space. MDCA is a multiuser facility designed to accommodate different combustion science experiments. The modular approach permits the on-orbit replacement of droplet combustion principal investigator experiments such as different fuels, droplet-dispensing needles, and droplet-tethering mechanisms. Large components such as the avionics, diagnostics, and base-plate remain on the International Space Station to reduce the launch mass of new experiments. MDCA is also designed to operate in concert with ground systems on Earth to minimize the involvement of the crew during orbit.

Compression ignition engine having fuel system for non-sooting combustion and method

DOEpatents

Bazyn, Timothy; Gehrke, Christopher

2014-10-28

A direct injection compression ignition internal combustion engine includes a fuel system having a nozzle extending into a cylinder of the engine and a plurality of spray orifices formed in the nozzle. Each of the spray orifices has an inner diameter dimension of about 0.09 mm or less, and define inter-orifice angles between adjacent spray orifice center axes of about 36.degree. or greater such that spray plumes of injected fuel from each of the spray orifices combust within the cylinder according to a non-sooting lifted flame and gas entrainment combustion pattern. Related methodology is also disclosed.

Compression-ignition engine performance with undoped and doped fuel oils and alcohol mixtures

NASA Technical Reports Server (NTRS)

Moore, Charles S; Foster, Hampton H

1939-01-01

Several fuel oils, doped fuel oils, and mixtures of alcohol and fuel oil were tested in a high-speed, single-cylinder, compression-ignition engine to determine power output, fuel consumption, and ignition and combustion characteristics. Fuel oils or doped fuel oils of high octane number had shorter ignition lags, lower rates of pressure rise, and gave smoother engine operation than fuel oils or doped fuel oils of low octane number. Higher engine rotative speeds and boost pressures resulted in smoother engine operation and permitted the use of fuel oils of relatively low octane number. Although the addition of a dope to a fuel oil decreased the ignition lag and the rate of pressure rise, the ensuing rate of combustion was somewhat slower than for the undoped fuel oil so that the effectiveness of combustion was practically unchanged. Alcohol used as an auxiliary fuel, either as a mixture or by separate injection, increased the rates of pressure rise and induced roughness. In general, the power output decreased as the proportion of alcohol increased and, below maximum power, varied with the heating value of the total fuel charge.

Ducted fuel injection

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

Mueller, Charles J.

Various technologies presented herein relate to enhancing mixing inside a combustion chamber to form one or more locally premixed mixtures comprising fuel and charge-gas with low peak fuel to charge-gas ratios to enable minimal, or no, generation of soot and other undesired emissions during ignition and subsequent combustion of the locally premixed mixtures. To enable sufficient mixing of the fuel and charge-gas, a jet of fuel can be directed to pass through a bore of a duct causing charge-gas to be drawn into the bore creating turbulence to mix the fuel and the drawn charge-gas. The duct can be locatedmore » proximate to an opening in a tip of a fuel injector. The duct can comprise of one or more holes along its length to enable charge-gas to be drawn into the bore, and further, the duct can cool the fuel and/or charge-gas prior to combustion.« less

The effect of initial flow nonuniformity on second-stage fuel injection and combustion in a supersonic duct. [supersonic combustion ramjet engine

NASA Technical Reports Server (NTRS)

Russin, W. R.

1975-01-01

The effects of flow nonuniformity on second-stage hydrogen fuel injection and combustion in supersonic flow were evaluated. The first case, second-stage fuel injection into a uniform duct flow, produced data indicating that fuel mixing is considerably slower than estimates based on an empirical mixing correlation. The second-case, two-stage fuel injection (or second-stage fuel injection into a nonuniform duct flow), produced a large interaction between stages with extensive flow separation. For this case the measured wall pressure, heat transfer, and amount of reaction at the duct exit were significantly greater than estimates based on the mixing correlation. Substantially more second-stage fuel burned in the second case than in the first case. Overall effects of unmixedness/chemical kinetics were found not to be significant at the exit for stoichiometric fuel injection.

Fiber-Supported Droplet Combustion Experiment-2

NASA Technical Reports Server (NTRS)

Colantonio, Renato O.

1998-01-01

A major portion of the energy produced in the world today comes from the burning of liquid hydrocarbon fuels in the form of droplets. Understanding the fundamental physical processes involved in droplet combustion is not only important in energy production but also in propulsion, in the mitigation of combustion-generated pollution, and in the control of the fire hazards associated with handling liquid combustibles. Microgravity makes spherically symmetric combustion possible, allowing investigators to easily validate their droplet models without the complicating effects of gravity. The Fiber-Supported Droplet Combustion (FSDC-2) investigation was conducted in the Microgravity Glovebox facility of the shuttles' Spacelab during the reflight of the Microgravity Science Laboratory (MSL- 1R) on STS-94 in July 1997. FSDC-2 studied fundamental phenomena related to liquid fuel droplet combustion in air. Pure fuels and mixtures of fuels were burned as isolated single and duo droplets with and without forced air convection. FSDC-2 is sponsored by the NASA Lewis Research Center, whose researchers are working in cooperation with several investigators from industry and academia. The rate at which a droplet burns is important in many commercial applications. The classical theory of droplet burning assumes that, for an isolated, spherically symmetric, single-fuel droplet, the gas-phase combustion processes are much faster than the droplet surface regression rate and that the liquid phase is at a uniform temperature equal to the boiling point. Recent, more advanced models predict that both the liquid and gas phases are unsteady during a substantial portion of the droplet's burning history, thus affecting the instantaneous and average burning rates, and that flame radiation is a dominant mechanism that can extinguish flames in a microgravity environment. FSDC-2 has provided well-defined, symmetric droplet burning data including radiative emissions to validate these theoretical models for heptane, decane, ethanol, and methanol fuels. Since most commercial combustion systems burn droplets in a convective environment, data were obtained without and with convective flow over the burning droplet (see the following photos).

Assessment of Turbulence-Chemistry Interaction Models in the National Combustion Code (NCC) - Part I

NASA Technical Reports Server (NTRS)

Wey, Thomas Changju; Liu, Nan-suey

2011-01-01

This paper describes the implementations of the linear-eddy model (LEM) and an Eulerian FDF/PDF model in the National Combustion Code (NCC) for the simulation of turbulent combustion. The impacts of these two models, along with the so called laminar chemistry model, are then illustrated via the preliminary results from two combustion systems: a nine-element gas fueled combustor and a single-element liquid fueled combustor.

Effect of design changes and operating conditions on combustion and operational performance of a 28-inch diameter Ram-jet engine / T. B. Shillito and Shigeo Nakanishi

NASA Technical Reports Server (NTRS)

Shillito, T B; Nakanishi, Shigeo

1952-01-01

The results of an altitude test-chamber investigation of the effects of a number of design changes and operating conditions on altitude peformance of a 28-inch diameter ram jet engine are presented. Most of the investigation was for a simulated flight Mach number of 2.0 above the tropopause. Fuel-air distribution, gutter width, the presence of a pilot flame, cimbustion-chamber-inlet temperature, and exhaust-nozzle throat area were found to have significant effects on limits of combustion. Combustion efficiency increased with increasing combustion-chamber-inlet temperature and was adversely affected by an increase in the exhaust-nozzld area. Similiar lean limits of combustion were obtained for both Diesel fuel and normal heptane, but combustion efficiences obtained with Diesel fuel were lower than those obtained with normal heptane.

Environmental aspects of fossil fuels combustion in Poland

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

Sekula, R.

Combustion of fossil fuels is the main source of energy in Poland. Coal will probably remain the basic fuel for energy generation for many years. The principal problems connected with fuel utilization in Poland are presented in this study. The major pollutants and ways to reduce air pollution are also described. Data are based on the report of the Polish Academy of Sciences.

Combustion of coal gas fuels in a staged combustor

NASA Technical Reports Server (NTRS)

Rosfjord, T. J.; Mcvey, J. B.; Sederquist, R. A.; Schultz, D. F.

1982-01-01

Gaseous fuels produced from coal resources generally have heating values much lower than natural gas; the low heating value could result in unstable or inefficient combustion. Coal gas fuels may contain ammonia which if oxidized in an uncontrolled manner could result in unacceptable nitrogen oxide exhaust emission levels. Previous investigations indicate that staged, rich-lean combustion represents a desirable approach to achieve stable, efficient, low nitrogen oxide emission operation for coal-derived liquid fuels contaning up to 0.8-wt pct nitrogen. An experimental program was conducted to determine whether this fuel tolerance can be extended to include coal-derived gaseous fuels. The results of tests with three nitrogen-free fuels having heating values of 100, 250, and 350 Btu/scf and a 250 Btu/scf heating value doped to contain 0.7 pct ammonia are presented.

Partial oxidation power plant with reheating and method thereof

DOEpatents

Newby, Richard A.; Yang, Wen-Ching; Bannister, Ronald L.

1999-01-01

A system and method for generating power having an air compression/partial oxidation system, a turbine, and a primary combustion system. The air compression/partial oxidation system receives a first air stream and a fuel stream and produces a first partially oxidized fuel stream and a first compressed air stream therefrom. The turbine expands the first partially oxidized fuel stream while being cooled by the first compressed air stream to produce a heated air stream. The heated air stream is injected into the expanding first partially oxidized fuel stream, thereby reheating it in the turbine. A second partially oxidized fuel stream is emitted from the turbine. The primary combustion system receives said second partially oxidized fuel stream and a second air stream, combusts said second partially oxidized fuel stream, and produces rotating shaft power and an emission stream therefrom.

Investigation on the gaseous and particulate emissions of a compression ignition engine fueled with diesel-dimethyl carbonate blends.

PubMed

Cheung, C S; Zhu, Ruijun; Huang, Zuohua

2011-01-01

The effect of dimethyl carbonate (DMC) on the gaseous and particulate emissions of a diesel engine was investigated using Euro V diesel fuel blended with different proportions of DMC. Combustion analysis shows that, with the blended fuel, the ignition delay and the heat release rate in the premixed combustion phase increase, while the total combustion duration and the fuel consumed in the diffusion combustion phase decrease. Compared with diesel fuel, with an increase of DMC in the blended fuel, the brake thermal efficiency is slightly improved but the brake specific fuel consumption increases. On the emission side, CO increases significantly at low engine load but decreases at high engine load while HC decreases slightly. NO(x) reduces slightly but the reduction is not statistically significant, while NO(2) increases slightly. Particulate mass and number concentrations decrease upon using the blended fuel while the geometric mean diameter of the particles shifts towards smaller size. Overall speaking, diesel-DMC blends lead to significant improvement in particulate emissions while the impact on CO, HC and NO(x) emissions is small. Copyright © 2010 Elsevier B.V. All rights reserved.

Experimental investigation of wood combustion in a fixed bed with hot air

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

Markovic, Miladin, E-mail: m.markovic@utwente.nl; Bramer, Eddy A.; Brem, Gerrit

Highlights: • Upward combustion is a new combustion concept with ignition by hot primary air. • Upward combustion has three stages: short drying, rapid devolatilization and char combustion. • Variation of fuel moisture and inert content have little influence on the combustion. • Experimental comparison between conventional and upward combustion is presented. - Abstract: Waste combustion on a grate with energy recovery is an important pillar of municipal solid waste (MSW) management in the Netherlands. In MSW incinerators fresh waste stacked on a grate enters the combustion chamber, heats up by radiation from the flame above the layer and ignitionmore » occurs. Typically, the reaction zone starts at the top of the waste layer and propagates downwards, producing heat for drying and devolatilization of the fresh waste below it until the ignition front reaches the grate. The control of this process is mainly based on empiricism. MSW is a highly inhomogeneous fuel with continuous fluctuating moisture content, heating value and chemical composition. The resulting process fluctuations may cause process control difficulties, fouling and corrosion issues, extra maintenance, and unplanned stops. In the new concept the fuel layer is ignited by means of preheated air (T > 220 °C) from below without any external ignition source. As a result a combustion front will be formed close to the grate and will propagate upwards. That is why this approach is denoted by upward combustion. Experimental research has been carried out in a batch reactor with height of 4.55 m, an inner diameter of 200 mm and a fuel layer height up to 1 m. Due to a high quality two-layer insulation adiabatic conditions can be assumed. The primary air can be preheated up to 350 °C, and the secondary air is distributed via nozzles above the waste layer. During the experiments, temperatures along the height of the reactor, gas composition and total weight decrease are continuously monitored. The influence of the primary air speed, fuel moisture and inert content on the combustion characteristics (ignition rate, combustion rate, ignition front speed and temperature of the reaction zone) is evaluated. The upward combustion concept decouples the drying, devolatilization and burnout phase. In this way the moisture and inert content of the waste have almost no influence on the combustion process. In this paper an experimental comparison between conventional and reversed combustion is presented.« less

Dynamically balanced fuel nozzle and method of operation

DOEpatents

Richards, George A.; Janus, Michael C.; Robey, Edward H.

2000-01-01

An apparatus and method of operation designed to reduce undesirably high pressure oscillations in lean premix combustion systems burning hydrocarbon fuels are provided. Natural combustion and nozzle acoustics are employed to generate multiple fuel pockets which, when burned in the combustor, counteract the oscillations caused by variations in heat release in the combustor. A hybrid of active and passive control techniques, the apparatus and method eliminate combustion oscillations over a wide operating range, without the use of moving parts or electronics.

Fuel and Combustion Characteristics of Organic Wastes

NASA Astrophysics Data System (ADS)

Namba, Kunihiko; Ida, Tamio

From a viewpoint of environmental preservation and resource protection, the recycling of wastes has been promoting. Expectations to new energy resource are growing by decrease of fossil fuel. Biomass is one of new energies for prevent global warning. This study is an attempt to burn biomass lamps made from residues in order to thermally recycle waste products of drink industries. The pyrolytic properties of shochu dregs and used tea leaves were observed by thermo-gravimertic analysis (TG) to obtained fundamental data of drink waste pyrolysis. It observed that shochu dregs pyrolyze under lower temperature than used tea leaves. These wastes were compressed by hot press apparatus in the temperature range from 140 to 180 °C for use as Bio-fuel (BF). The combustion behavior of BF was observed in fall-type electric furnace, where video-recording was carried out at sequential steps, such as ignition, visible envelope flame combustion and char combustion to obtain combustion characteristics such as ignition delay, visible flame combustion time and char combustion time.

Jet plume injection and combustion system for internal combustion engines

DOEpatents

Oppenheim, A.K.; Maxson, J.A.; Hensinger, D.M.

1993-12-21

An improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure. 24 figures.

Jet plume injection and combustion system for internal combustion engines

DOEpatents

Oppenheim, Antoni K.; Maxson, James A.; Hensinger, David M.

1993-01-01

An improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure.

An experimental study of the combustion characteristics in SCCI and CAI based on direct-injection gasoline engine

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

Lee, C.H.; Lee, K.H.

2007-08-15

Emissions remain a critical issue affecting engine design and operation, while energy conservation is becoming increasingly important. One approach to favorably address these issues is to achieve homogeneous charge combustion and stratified charge combustion at lower peak temperatures with a variable compression ratio, a variable intake temperature and a trapped rate of the EGR using NVO (negative valve overlap). This experiment was attempted to investigate the origins of these lower temperature auto-ignition phenomena with SCCI and CAI using gasoline fuel. In case of SCCI, the combustion and emission characteristics of gasoline-fueled stratified-charge compression ignition (SCCI) engine according to intake temperaturemore » and compression ratio was examined. We investigated the effects of air-fuel ratio, residual EGR rate and injection timing on the CAI combustion area. In addition, the effect of injection timing on combustion factors such as the start of combustion, its duration and its heat release rate was also investigated. (author)« less

Chemical kinetic simulation of kerosene combustion in an individual flame tube.

PubMed

Zeng, Wen; Liang, Shuang; Li, Hai-Xia; Ma, Hong-An

2014-05-01

The use of detailed chemical reaction mechanisms of kerosene is still very limited in analyzing the combustion process in the combustion chamber of the aircraft engine. In this work, a new reduced chemical kinetic mechanism for fuel n-decane, which selected as a surrogate fuel for kerosene, containing 210 elemental reactions (including 92 reversible reactions and 26 irreversible reactions) and 50 species was developed, and the ignition and combustion characteristics of this fuel in both shock tube and flat-flame burner were kinetic simulated using this reduced reaction mechanism. Moreover, the computed results were validated by experimental data. The calculated values of ignition delay times at pressures of 12, 50 bar and equivalence ratio is 1.0, 2.0, respectively, and the main reactants and main products mole fractions using this reduced reaction mechanism agree well with experimental data. The combustion processes in the individual flame tube of a heavy duty gas turbine combustor were simulated by coupling this reduced reaction mechanism of surrogate fuel n-decane and one step reaction mechanism of surrogate fuel C12H23 into the computational fluid dynamics software. It was found that this reduced reaction mechanism is shown clear advantages in simulating the ignition and combustion processes in the individual flame tube over the one step reaction mechanism.

Chemical kinetic simulation of kerosene combustion in an individual flame tube

PubMed Central

Zeng, Wen; Liang, Shuang; Li, Hai-xia; Ma, Hong-an

2013-01-01

The use of detailed chemical reaction mechanisms of kerosene is still very limited in analyzing the combustion process in the combustion chamber of the aircraft engine. In this work, a new reduced chemical kinetic mechanism for fuel n-decane, which selected as a surrogate fuel for kerosene, containing 210 elemental reactions (including 92 reversible reactions and 26 irreversible reactions) and 50 species was developed, and the ignition and combustion characteristics of this fuel in both shock tube and flat-flame burner were kinetic simulated using this reduced reaction mechanism. Moreover, the computed results were validated by experimental data. The calculated values of ignition delay times at pressures of 12, 50 bar and equivalence ratio is 1.0, 2.0, respectively, and the main reactants and main products mole fractions using this reduced reaction mechanism agree well with experimental data. The combustion processes in the individual flame tube of a heavy duty gas turbine combustor were simulated by coupling this reduced reaction mechanism of surrogate fuel n-decane and one step reaction mechanism of surrogate fuel C12H23 into the computational fluid dynamics software. It was found that this reduced reaction mechanism is shown clear advantages in simulating the ignition and combustion processes in the individual flame tube over the one step reaction mechanism. PMID:25685503

Improve Your Boiler's Combustion Efficiency: Office of Industrial Technologies (OIT) Steam Energy Tips No.4

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

Not Available

2002-03-01

Operating your boiler with an optimum amount of excess air will minimize heat loss up the stack and improve combustion efficiency. Combustion efficiency is a measure of how effectively the heat content of a fuel is transferred into usable heat. The stack temperature and flue gas oxygen (or carbon dioxide) concentrations are primary indicators of combustion efficiency. Given complete mixing, a precise or stoichiometric amount of air is required to completely react with a given quantity of fuel. In practice, combustion conditions are never ideal, and additional or ''excess'' air must be supplied to completely burn the fuel. The correctmore » amount of excess air is determined from analyzing flue gas oxygen or carbon dioxide concentrations. Inadequate excess air results in unburned combustibles (fuel, soot, smoke, and carbon monoxide) while too much results in heat lost due to the increased flue gas flow--thus lowering the overall boiler fuel-to-steam efficiency. The table relates stack readings to boiler performance. On well-designed natural gas-fired systems, an excess air level of 10% is attainable. An often stated rule of thumb is that boiler efficiency can be increased by 1% for each 15% reduction in excess air or 40 F reduction in stack gas temperature.« less

Validated Numerical Models for the Convective Extinction of Fuel Droplets (CEFD)

NASA Technical Reports Server (NTRS)

Gogos, George; Bowen, Brent; Nickerson, Jocelyn S.

2002-01-01

The NASA Nebraska Space Grant (NSGC) & EPSCoR programs have continued their effort to support outstanding research endeavors by funding the Numerical Simulation of the Combustion of Fuel Droplets study at the University of Nebraska at Lincoln (UNL). This team of researchers has developed a transient numerical model to study the combustion of suspended and moving droplets. The engines that propel missiles, jets, and many other devices are dependent upon combustion. Therefore, data concerning the combustion of fuel droplets is of immediate relevance to aviation and aeronautical personnel, especially those involved in flight operations. The experiments being conducted by Dr. Gogos and Dr. Nayagam s research teams, allow investigators to gather data for comparison with theoretical predictions of burning rates, flame structures, and extinction conditions. The consequent improved fundamental understanding of droplet combustion may contribute to the clean and safe utilization of fossil fuels (Williams, Dryer, Haggard & Nayagam, 1997, f 2). The present state of knowledge on convective extinction of fuel droplets derives from experiments conducted under normal gravity conditions. However, any data obtained with suspended droplets under normal gravity are grossly affected by gravity. The need to obtain experimental data under microgravity conditions is therefore well justified and addresses one of the goals of NASA's Human Exploration and Development of Space (HEDS) microgravity combustion experiment.

The Influence of Fuel Properties on Combustion Efficiency and the Partitioning of Pyrogenic Carbon

NASA Astrophysics Data System (ADS)

Urbanski, S. P.; Baker, S. P.; Lincoln, E.; Richardson, M.

2016-12-01

The partitioning of volatized pyrogenic carbon into CO2, CO, CH4, non-methane organic carbon, and particulate organic carbon (POC) and elemental carbon (PEC) depends on the combustion characteristics of biomass fires which are influenced by the moisture content, structure and arrangement of the fuels. Flaming combustion is characterized by efficient conversion of volatized carbon into CO2. In contrast, smoldering is less efficient and produces incomplete combustion products like CH4 and carbonaceous particles. This paper presents a laboratory study that has examined the relationship between the partitioning of volatized pyrogenic carbon and specific fuel properties. The study focused on fuel beds composed of simple fuel particles — ponderosa pine needles. Ponderosa pine was selected because it contains a common wildland fuel component, conifer needles, which can be easily arranged into fuel beds of variable structure (bulk density and depth) and moisture contents that are both representative of natural conditions and are easily replicated. Modified combustion efficiency (MCE, ΔCO2/[ΔCO2+ ΔCO]) and emission factors (EF) for CO2, CO, CH4, POC, and PEC were measured over a range of needle moisture content and fuel bed bulk density and depth representative of naturally occurring fuel beds. We found that, as expected, MCE decreases as the fuel bed bulk density increases and emissions of CO, CH4, PM2.5, and POC increased. However, fuel bed depth did not appear to have an effect on how effect on MCE or emission factors. Surprisingly, a consistent relationship between the needle moisture content and emissions was not identified. At the high bulk densities, moisture content had a strong influence on MCE which explained variability in EFCH4. However, moisture content appeared to have an influence EFPOC and EFPEC that was independent of MCE. These findings may have significant implications since many models of biomass burning assume that litter fuels, such as ponderosa pine needles, burn almost exclusively via flaming combustion with a high efficiency. Our results indicate that for fuel bed properties typical of many conifer forests, pollutants generated from fires will be higher than that predicted using standard biomass burning models.

Combustion instability and active control: Alternative fuels, augmentors, and modeling heat release

NASA Astrophysics Data System (ADS)

Park, Sammy Ace

Experimental and analytical studies were conducted to explore thermo-acoustic coupling during the onset of combustion instability in various air-breathing combustor configurations. These include a laboratory-scale 200-kW dump combustor and a 100-kW augmentor featuring a v-gutter flame holder. They were used to simulate main combustion chambers and afterburners in aero engines, respectively. The three primary themes of this work includes: 1) modeling heat release fluctuations for stability analysis, 2) conducting active combustion control with alternative fuels, and 3) demonstrating practical active control for augmentor instability suppression. The phenomenon of combustion instabilities remains an unsolved problem in propulsion engines, mainly because of the difficulty in predicting the fluctuating component of heat release without extensive testing. A hybrid model was developed to describe both the temporal and spatial variations in dynamic heat release, using a separation of variables approach that requires only a limited amount of experimental data. The use of sinusoidal basis functions further reduced the amount of data required. When the mean heat release behavior is known, the only experimental data needed for detailed stability analysis is one instantaneous picture of heat release at the peak pressure phase. This model was successfully tested in the dump combustor experiments, reproducing the correct sign of the overall Rayleigh index as well as the remarkably accurate spatial distribution pattern of fluctuating heat release. Active combustion control was explored for fuel-flexible combustor operation using twelve different jet fuels including bio-synthetic and Fischer-Tropsch types. Analysis done using an actuated spray combustion model revealed that the combustion response times of these fuels were similar. Combined with experimental spray characterizations, this suggested that controller performance should remain effective with various alternative fuels. Active control experiments validated this analysis while demonstrating 50-70% reduction in the peak spectral amplitude. A new model augmentor was built and tested for combustion dynamics using schlieren and chemiluminescence techniques. Novel active control techniques including pulsed air injection were implemented and the results were compared with the pulsed fuel injection approach. The pulsed injection of secondary air worked just as effectively for suppressing the augmentor instability, setting up the possibility of more efficient actuation strategy.

High Efficiency, Low Emissions Homogeneous Charge Compression Ignition (HCCI) Engines

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

Gravel, Roland; Maronde, Carl; Gehrke, Chris

2010-10-30

This is the final report of the High Efficiency Clean Combustion (HECC) Research Program for the U.S. Department of Energy. Work under this co-funded program began in August 2005 and finished in July 2010. The objective of this program was to develop and demonstrate a low emission, high thermal efficiency engine system that met 2010 EPA heavy-duty on-highway truck emissions requirements (0.2g/bhp-hr NOx, 0.14g/bhp-hr HC and 0.01g/bhp-hr PM) with a thermal efficiency of 46%. To achieve this goal, development of diesel homogenous charge compression ignition (HCCI) combustion was the chosen approach. This report summarizes the development of diesel HCCI combustionmore » and associated enabling technologies that occurred during the HECC program between August 2005 and July 2010. This program showed that although diesel HCCI with conventional US diesel fuel was not a feasible means to achieve the program objectives, the HCCI load range could be increased with a higher volatility, lower cetane number fuel, such as gasoline, if the combustion rate could be moderated to avoid excessive cylinder pressure rise rates. Given the potential efficiency and emissions benefits, continued research of combustion with low cetane number fuels and the effects of fuel distillation are recommended. The operation of diesel HCCI was only feasible at part-load due to a limited fuel injection window. A 4% fuel consumption benefit versus conventional, low-temperature combustion was realized over the achievable operating range. Several enabling technologies were developed under this program that also benefited non-HCCI combustion. The development of a 300MPa fuel injector enabled the development of extended lifted flame combustion. A design methodology for minimizing the heat transfer to jacket water, known as precision cooling, will benefit conventional combustion engines, as well as HCCI engines. An advanced combustion control system based on cylinder pressure measurements was developed. A Well-to-wheels analysis of the energy flows in a mobile vehicle system and a 2nd Law thermodynamic analysis of the engine system were also completed under this program.« less

Global combustion: the connection between fossil fuel and biomass burning emissions (1997-2010).

PubMed

Balch, Jennifer K; Nagy, R Chelsea; Archibald, Sally; Bowman, David M J S; Moritz, Max A; Roos, Christopher I; Scott, Andrew C; Williamson, Grant J

2016-06-05

Humans use combustion for heating and cooking, managing lands, and, more recently, for fuelling the industrial economy. As a shift to fossil-fuel-based energy occurs, we expect that anthropogenic biomass burning in open landscapes will decline as it becomes less fundamental to energy acquisition and livelihoods. Using global data on both fossil fuel and biomass burning emissions, we tested this relationship over a 14 year period (1997-2010). The global average annual carbon emissions from biomass burning during this time were 2.2 Pg C per year (±0.3 s.d.), approximately one-third of fossil fuel emissions over the same period (7.3 Pg C, ±0.8 s.d.). There was a significant inverse relationship between average annual fossil fuel and biomass burning emissions. Fossil fuel emissions explained 8% of the variation in biomass burning emissions at a global scale, but this varied substantially by land cover. For example, fossil fuel burning explained 31% of the variation in biomass burning in woody savannas, but was a non-significant predictor for evergreen needleleaf forests. In the land covers most dominated by human use, croplands and urban areas, fossil fuel emissions were more than 30- and 500-fold greater than biomass burning emissions. This relationship suggests that combustion practices may be shifting from open landscape burning to contained combustion for industrial purposes, and highlights the need to take into account how humans appropriate combustion in global modelling of contemporary fire. Industrialized combustion is not only an important driver of atmospheric change, but also an important driver of landscape change through companion declines in human-started fires.This article is part of the themed issue 'The interaction of fire and mankind'. © 2016 The Author(s).

Use of Adaptive Injection Strategies to Increase the Full Load Limit of RCCI Operation

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

Hanson, Reed; Ickes, Andrew; Wallner, Thomas

Dual-fuel combustion using port-injection of low reactivity fuel combined with direct injection (DI) of a higher reactivity fuel, otherwise known as reactivity controlled compression ignition (RCCI), has been shown as a method to achieve low-temperature combustion with moderate peak pressure rise rates, low engine-out soot and NOx emissions, and high indicated thermal efficiency. A key requirement for extending to high-load operation is moderating the reactivity of the premixed charge prior to the diesel injection. One way to accomplish this is to use a very low reactivity fuel such as natural gas. In this work, experimental testing was conducted on amore » 13 l multicylinder heavy-duty diesel engine modified to operate using RCCI combustion with port injection of natural gas and DI of diesel fuel. Engine testing was conducted at an engine speed of 1200 rpm over a wide variety of loads and injection conditions. The impact on dual-fuel engine performance and emissions with respect to varying the fuel injection parameters is quantified within this study. The injection strategies used in the work were found to affect the combustion process in similar ways to both conventional diesel combustion (CDC) and RCCI combustion for phasing control and emissions performance. As the load is increased, the port fuel injection (PFI) quantity was reduced to keep peak cylinder pressure (PCP) and maximum pressure rise rate (MPRR) under the imposed limits. Overall, the peak load using the new injection strategy was shown to reach 22 bar brake mean effective pressure (BMEP) with a peak brake thermal efficiency (BTE) of 47.6%.« less

Global combustion: the connection between fossil fuel and biomass burning emissions (1997–2010)

PubMed Central

Balch, Jennifer K.; Nagy, R. Chelsea; Archibald, Sally; Moritz, Max A.; Williamson, Grant J.

2016-01-01

Humans use combustion for heating and cooking, managing lands, and, more recently, for fuelling the industrial economy. As a shift to fossil-fuel-based energy occurs, we expect that anthropogenic biomass burning in open landscapes will decline as it becomes less fundamental to energy acquisition and livelihoods. Using global data on both fossil fuel and biomass burning emissions, we tested this relationship over a 14 year period (1997–2010). The global average annual carbon emissions from biomass burning during this time were 2.2 Pg C per year (±0.3 s.d.), approximately one-third of fossil fuel emissions over the same period (7.3 Pg C, ±0.8 s.d.). There was a significant inverse relationship between average annual fossil fuel and biomass burning emissions. Fossil fuel emissions explained 8% of the variation in biomass burning emissions at a global scale, but this varied substantially by land cover. For example, fossil fuel burning explained 31% of the variation in biomass burning in woody savannas, but was a non-significant predictor for evergreen needleleaf forests. In the land covers most dominated by human use, croplands and urban areas, fossil fuel emissions were more than 30- and 500-fold greater than biomass burning emissions. This relationship suggests that combustion practices may be shifting from open landscape burning to contained combustion for industrial purposes, and highlights the need to take into account how humans appropriate combustion in global modelling of contemporary fire. Industrialized combustion is not only an important driver of atmospheric change, but also an important driver of landscape change through companion declines in human-started fires. This article is part of the themed issue ‘The interaction of fire and mankind’. PMID:27216509

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2

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

George Rizeq; Janice West; Arnaldo Frydman

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the process efficiency and environmental impact performance of fossil fuel utilization. GE Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Unmixed Fuel Processor (UFP) technology to produce H{sub 2}, power, and sequestration-ready CO{sub 2} from coal and other solid fuels. The UFP module offers the potential for reduced cost, increased process efficiency relative to conventional gasification and combustion systems, and near-zero pollutant emissions including NO{sub x}. GEmore » EER (prime contractor) was awarded a Vision 21 program from U.S. DOE NETL to develop the UFP technology. Work on this Phase I program started on October 1, 2000. The project team includes GE EER, Southern Illinois University at Carbondale (SIU-C), California Energy Commission (CEC), and T. R. Miles, Technical Consultants, Inc. In the UFP technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on process modeling work, has an estimated process efficiency of 68%, based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal, and an estimated equivalent electrical efficiency of 60%. The Phase I R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the UFP technology. This is the tenth quarterly technical progress report for the Vision 21 UFP program supported by U.S. DOE NETL (Contract No. DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting January 1, 2003 and ending March 31, 2003. The report includes an introduction summarizing the UFP technology, main program tasks, and program objectives; it also provides a summary of program activities and accomplishments covering progress in tasks including lab-scale experimental testing, pilot-scale assembly, and program management.« less

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2

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

George Rizeq; Janice West; Arnaldo Frydman

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the process efficiency and environmental impact performance of fossil fuel utilization. GE Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Unmixed Fuel Processor (UFP) technology to produce H{sub 2}, power, and sequestration-ready CO{sub 2} from coal and other solid fuels. The UFP module offers the potential for reduced cost, increased process efficiency relative to conventional gasification and combustion systems, and near-zero pollutant emissions including NO{sub x}. GEmore » EER was awarded a Vision 21 program from U.S. DOE NETL to develop the UFP technology. Work on this Phase I program started on October 1, 2000. The project team includes GE EER, California Energy Commission, Southern Illinois University at Carbondale, and T. R. Miles, Technical Consultants, Inc. In the UFP technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on process modeling work, has an estimated process efficiency of 68%, based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal, and an estimated equivalent electrical efficiency of 60%. The Phase I R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the UFP technology. This is the ninth quarterly technical progress report for the Vision 21 UFP program supported by U.S. DOE NETL (Contract No. DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting October 1, 2002 and ending December 31, 2002. The report includes an introduction summarizing the UFP technology, main program tasks, and program objectives; it also provides a summary of program activities and accomplishments covering progress in tasks including lab- and bench-scale experimental testing, pilot-scale design and assembly, and program management.« less

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2

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

George Rizeq; Janice West; Arnaldo Frydman

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the process efficiency and environmental impact performance of fossil fuel utilization. GE Global Research (GEGR) has developed an innovative fuel-flexible Unmixed Fuel Processor (UFP) technology to produce H{sub 2}, power, and sequestration-ready CO{sub 2} from coal and other solid fuels. The UFP module offers the potential for reduced cost, increased process efficiency relative to conventional gasification and combustion systems, and near-zero pollutant emissions including NO{sub x}. GEGR (prime contractor) was awardedmore » a Vision 21 program from U.S. DOE NETL to develop the UFP technology. Work on this Phase I program started on October 1, 2000. The project team includes GEGR, Southern Illinois University at Carbondale (SIU-C), California Energy Commission (CEC), and T. R. Miles, Technical Consultants, Inc. In the UFP technology, coal/opportunity fuels and air are simultaneously converted into separate streams of (1) pure hydrogen that can be utilized in fuel cells, (2) sequestration-ready CO{sub 2}, and (3) high temperature/pressure oxygen-depleted air to produce electricity in a gas turbine. The process produces near-zero emissions and, based on process modeling with best-case scenario assumptions, has an estimated process efficiency of 68%, based on electrical and H{sub 2} energy outputs relative to the higher heating value of coal, and an estimated equivalent electrical efficiency of 60%. The Phase I R&D program will determine the operating conditions that maximize separation of CO{sub 2} and pollutants from the vent gas, while simultaneously maximizing coal conversion efficiency and hydrogen production. The program integrates lab-, bench- and pilot-scale studies to demonstrate the UFP technology. This is the eleventh quarterly technical progress report for the Vision 21 UFP program supported by U.S. DOE NETL (Contract No. DE-FC26-00FT40974). This report summarizes program accomplishments for the period starting April 1, 2003 and ending June 30, 2003. The report includes an introduction summarizing the UFP technology, main program tasks, and program objectives; it also provides a summary of program activities and accomplishments covering progress in tasks including lab-scale experimental testing, pilot-scale assembly, and program management.« less

Fuel-Air Mixing and Combustion in Scramjets

NASA Technical Reports Server (NTRS)

Drummond, J. P.; Diskin, Glenn S.; Cutler, A. D.

2002-01-01

Activities in the area of scramjet fuel-air mixing and combustion associated with the Research and Technology Organization Working Group on Technologies for Propelled Hypersonic Flight are described. Work discussed in this paper has centered on the design of two basic experiments for studying the mixing and combustion of fuel and air in a scramjet. Simulations were conducted to aid in the design of these experiments. The experimental models were then constructed, and data were collected in the laboratory. Comparison of the data from a coaxial jet mixing experiment and a supersonic combustor experiment with a combustor code were then made and described. This work was conducted by NATO to validate combustion codes currently employed in scramjet design and to aid in the development of improved turbulence and combustion models employed by the codes.

Apparatus and method for controlling the secondary injection of fuel

DOEpatents

Martin, Scott M.; Cai, Weidong; Harris, Jr., Arthur J.

2013-03-05

A combustor (28) for a gas turbine engine is provided comprising a primary combustion chamber (30) for combusting a first fuel to form a combustion flow stream (50) and a transition piece (32) located downstream from the primary combustion chamber (30). The transition piece (32) comprises a plurality of injectors (66) located around a circumference of the transition piece (32) for injecting a second fuel into the combustion flow stream (50). The injectors (66) are effective to create a radial temperature profile (74) at an exit (58) of the transition piece (32) having a reduced coefficient of variation relative to a radial temperature profile (64) at an inlet (54) of the transition piece (32). Methods for controlling the temperature profile of a secondary injection are also provided.

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.

Simulated Altitude Investigation of Stewart-Warner Model 906-B Combustion Heater

NASA Technical Reports Server (NTRS)

Ebersbach, Frederick R.; Cervenka, Adolph J.

1947-01-01

An investigation has been conducted to determine thermal and pressure-drop performance and the operational characteristics of a Stewart-Warner model 906-B combustion heater. The performance tests covered a range of ventilating-air flows from 500 to 3185 pounds per hour, combustion-air pressure drops from 5 to 35 inches of water, and pressure altitudes from sea level to 41,000 feet. The operational characteristics investigated were the combustion-air flows for sustained combustion and for consistent ignition covering fuel-air ratios ranging from 0.033 to 0.10 and pressure altitudes from sea level to 45,000 feet. Rated heat output of 50,000 Btu per hour was obtained at pressure altitudes up to 27,000 feet for ventilating-air flows greater than 800 pounds per hour; rated output was not obtained at ventilating-air flow below 800 pounds per hour at any altitude. The maximum heater efficiency was found to be 60.7 percent at a fuel-air ratio of 0.050, a sea-level pressure altitude, a ventilating-air temperature of 0 F, combustion-air temperature of 14 F, a ventilating-air flow of 690 pounds per hour, and a combustion-air flow of 72.7 pounds per hour. The minimum combustion-air flow for sustained combustion at a pressure altitude of 25,000 feet was about 9 pounds per hour for fuel-air ratios between 0.037 and 0.099 and at a pressure altitude of 45,000 feet increased to 18 pounds per hour at a fuel-air ratio of 0.099 and 55 pounds per hour at a fuel-air ratio of 0.036. Combustion could be sustained at combustion-air flows above values of practical interest. The maximum flow was limited, however, by excessively high exhaust-gas temperature or high pressure drop. Both maximum and minimum combustion-air flows for consistent ignition decrease with increasing pressure altitude and the two curves intersect at a pressure altitude of approximately 25,000 feet and a combustion-air flow of approximately 28 pounds per hour.

Method of controlling cyclic variation in engine combustion

DOEpatents

Davis, L.I. Jr.; Daw, C.S.; Feldkamp, L.A.; Hoard, J.W.; Yuan, F.; Connolly, F.T.

1999-07-13

Cyclic variation in combustion of a lean burning engine is reduced by detecting an engine combustion event output such as torsional acceleration in a cylinder (i) at a combustion event (k), using the detected acceleration to predict a target acceleration for the cylinder at the next combustion event (k+1), modifying the target output by a correction term that is inversely proportional to the average phase of the combustion event output of cylinder (i) and calculating a control output such as fuel pulse width or spark timing necessary to achieve the target acceleration for cylinder (i) at combustion event (k+1) based on anti-correlation with the detected acceleration and spill-over effects from fueling. 27 figs.

Method of controlling cyclic variation in engine combustion

DOEpatents

Davis, Jr., Leighton Ira; Daw, Charles Stuart; Feldkamp, Lee Albert; Hoard, John William; Yuan, Fumin; Connolly, Francis Thomas

1999-01-01

Cyclic variation in combustion of a lean burning engine is reduced by detecting an engine combustion event output such as torsional acceleration in a cylinder (i) at a combustion event (k), using the detected acceleration to predict a target acceleration for the cylinder at the next combustion event (k+1), modifying the target output by a correction term that is inversely proportional to the average phase of the combustion event output of cylinder (i) and calculating a control output such as fuel pulse width or spark timing necessary to achieve the target acceleration for cylinder (i) at combustion event (k+1) based on anti-correlation with the detected acceleration and spill-over effects from fueling.

Advanced engine management of individual cylinders for control of exhaust species

DOEpatents

Graves, Ronald L [Knoxville, TN; West, Brian H [Knoxville, TN; Huff, Shean P [Knoxville, TN; Parks, II, James E

2008-12-30

A method and system controls engine-out exhaust species of a combustion engine having a plurality of cylinders. The method typically includes various combinations of steps such as controlling combustion parameters in individual cylinders, grouping the individual cylinders into a lean set and a rich set of one or more cylinders, combusting the lean set in a lean combustion parameter condition having a lean air:fuel equivalence ratio, combusting the rich set in a rich combustion parameter condition having a rich air:fuel equivalence ratio, and adjusting the lean set and the rich set of one or more cylinders to generate net-lean combustion. The exhaust species may have elevated concentrations of hydrogen and oxygen.

Hydrogen/Air Fuel Nozzle Emissions Experiments

NASA Technical Reports Server (NTRS)

Smith, Timothy D.

2001-01-01

The use of hydrogen combustion for aircraft gas turbine engines provides significant opportunities to reduce harmful exhaust emissions. Hydrogen has many advantages (no CO2 production, high reaction rates, high heating value, and future availability), along with some disadvantages (high current cost of production and storage, high volume per BTU, and an unknown safety profile when in wide use). One of the primary reasons for switching to hydrogen is the elimination of CO2 emissions. Also, with hydrogen, design challenges such as fuel coking in the fuel nozzle and particulate emissions are no longer an issue. However, because it takes place at high temperatures, hydrogen-air combustion can still produce significant levels of NOx emissions. Much of the current research into conventional hydrocarbon-fueled aircraft gas turbine combustors is focused on NOx reduction methods. The Zero CO2 Emission Technology (ZCET) hydrogen combustion project will focus on meeting the Office of Aerospace Technology goal 2 within pillar one for Global Civil Aviation reducing the emissions of future aircraft by a factor of 3 within 10 years and by a factor of 5 within 25 years. Recent advances in hydrocarbon-based gas turbine combustion components have expanded the horizons for fuel nozzle development. Both new fluid designs and manufacturing technologies have led to the development of fuel nozzles that significantly reduce aircraft emissions. The goal of the ZCET program is to mesh the current technology of Lean Direct Injection and rocket injectors to provide quick mixing, low emissions, and high-performance fuel nozzle designs. An experimental program is planned to investigate the fuel nozzle concepts in a flametube test rig. Currently, a hydrogen system is being installed in cell 23 at NASA Glenn Research Center's Research Combustion Laboratory. Testing will be conducted on a variety of fuel nozzle concepts up to combustion pressures of 350 psia and inlet air temperatures of 1200 F. Computational fluid dynamics calculations, with the Glenn developed National Combustor Code, are being performed to optimize the fuel nozzle designs.

An Assessment of Combustion Dynamics in a Low-Nox, Second-Generation Swirl-Venturi Lean Direct Injection Combustion Concept

NASA Technical Reports Server (NTRS)

Tacina, K. M.; Chang, C. T.; Lee, P.; Mongia, H.; Podboy, D. P.; Dam, B.

2015-01-01

Dynamic pressure measurements were taken during flame-tube emissions testing of three second-generation swirl-venturi lean direct injection (SV-LDI) combustor configurations. These measurements show that combustion dynamics were typically small. However, a small number of points showed high combustion dynamics, with peak-to-peak dynamic pressure fluctuations above 0.5 psi. High combustion dynamics occurred at low inlet temperatures in all three SV-LDI configurations, so combustion dynamics were explored further at low temperature conditions. A point with greater than 1.5 psi peak-to-peak dynamic pressure fluctuations was identified at an inlet temperature of 450!F, a pressure of 100 psia, an air pressure drop of 3%, and an overall equivalence ratio of 0.35. This is an off design condition: the temperature and pressure are typical of 7% power conditions, but the equivalence ratio is high. At this condition, the combustion dynamics depended strongly on the fuel staging. Combustion dynamics could be reduced significantly without changing the overall equivalence ratio by shifting the fuel distribution between stages. Shifting the fuel distribution also decreased NOx emissions.

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.

Broad specification fuels combustion technology program

NASA Technical Reports Server (NTRS)

Dodds, W. J.; Ekstedt, E. E.

1984-01-01

Design and development efforts to evolve promising aircraft gas turbine combustor configurations for burning broadened-properties fuels were discussed. Design and experimental evaluations of three different combustor concepts in sector combustor rig tests was conducted. The combustor concepts were a state of the art single-annular combustor, a staged double-annular combustor, and a short single-annular combustor with variable geometry to control primary zone stoichiometry. A total of 25 different configurations of the three combustor concepts were evaluated. Testing was conducted over the full range of CF6-80A engine combustor inlet conditions, using four fuels containing between 12% and 14% hydrogen by weight. Good progress was made toward meeting specific program emissions and performance goals with each of the three combustor concepts. The effects of reduced fuel hydrogen content, including increased flame radiation, liner metal temperature, smoke, and NOx emissions were documented. The most significant effect on the baseline combustor was a projected 33% life reduction, for a reduction from 14% to 13% fuel hydrogen content, due to increased liner temperatures.

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.

Sorbent control of trace metals in sewage sludge combustion and incineration

NASA Astrophysics Data System (ADS)

Naruse, I.; Yao, H.; Mkilaha, I. S. N.

2003-05-01

Coal and wastes combustion have become an important issue not only in terms of energy generation but also environmental conservation. The need for alternative fuels and wastes management has made the two energy sources of importance. However, the utilization of the two is faced with problems of impurity trace metals in the fuel. These metals usually speciate during combustion or incineration leading to generation of fumes and subsequently particles. This paper reports on the study aimed at understanding the speciation of trace metals and their emission from combustion systems as particulates. Experiments carried out using a down-flow furnace and theoretical study carried out using lead, chromium and cadmium as basic metals had shown that their speciation and subsequent emission is controlled by both chemical composition and physical properties of the fuel. The physical and chemical and physical properties of the fuel and their respective compounds and the operating conditions of the incineration and combustion system control the enrichment of the particles with trace metals.

SiC Recession Due to SiO2 Scale Volatility Under Combustion Conditions. Part 2; Thermodynamics and Gaseous Diffusion Model

NASA Technical Reports Server (NTRS)

Opila, Elizabeth J.; Smialek, James L.; Robinson, Raymond C.; Fox, Dennis S.; Jacobson, Nathan S.

1998-01-01

In combustion environments, volatilization of SiO2 to Si-O-H(g) species is a critical issue. Available thermochemical data for Si-O-H(g) species were used to calculate boundary layer controlled fluxes from SiO2. Calculated fluxes were compared to volatilization rates Of SiO2 scales grown on SiC which were measured in Part 1 of this paper. Calculated volatilization rates were also compared to those measured in synthetic combustion gas furnace tests. Probable vapor species were identified in both fuel-lean and fuel-rich combustion environments based on the observed pressure, temperature and velocity dependencies as well as the magnitude of the volatility rate. Water vapor is responsible for the degradation of SiO2 in the fuel-lean environment. Silica volatility in fuel-lean combustion environments is attributed primarily to the formation of Si(OH)4(g) with a small contribution of SiO(OH)2(g).

Periodic equivalence ratio modulation method and apparatus for controlling combustion instability

DOEpatents

Richards, George A.; Janus, Michael C.; Griffith, Richard A.

2000-01-01

The periodic equivalence ratio modulation (PERM) method and apparatus significantly reduces and/or eliminates unstable conditions within a combustion chamber. The method involves modulating the equivalence ratio for the combustion device, such that the combustion device periodically operates outside of an identified unstable oscillation region. The equivalence ratio is modulated between preselected reference points, according to the shape of the oscillation region and operating parameters of the system. Preferably, the equivalence ratio is modulated from a first stable condition to a second stable condition, and, alternatively, the equivalence ratio is modulated from a stable condition to an unstable condition. The method is further applicable to multi-nozzle combustor designs, whereby individual nozzles are alternately modulated from stable to unstable conditions. Periodic equivalence ratio modulation (PERM) is accomplished by active control involving periodic, low frequency fuel modulation, whereby low frequency fuel pulses are injected into the main fuel delivery. Importantly, the fuel pulses are injected at a rate so as not to affect the desired time-average equivalence ratio for the combustion device.

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.

Fuels Performance: Navigating the Intersection of Fuels and Combustion (Brochure)

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

Not Available

2014-12-01

Researchers at the National Renewable Energy Laboratory (NREL), the only national laboratory dedicated 100% to renewable energy and energy efficiency, recognize that engine and infrastructure compatibility can make or break the impact of even the most promising fuel. NREL and its industry partners navigate the intersection of fuel chemistry, ignition kinetics, combustion, and emissions, with innovative approaches to engines and fuels that meet drivers' expectations, while minimizing petroleum use and GHGs.

Coal-water slurry fuel internal combustion engine and method for operating same

DOEpatents

McMillian, Michael H.

1992-01-01

An internal combustion engine fueled with a coal-water slurry is described. About 90 percent of the coal-water slurry charge utilized in the power cycle of the engine is directly injected into the main combustion chamber where it is ignited by a hot stream of combustion gases discharged from a pilot combustion chamber of a size less than about 10 percent of the total clearance volume of main combustion chamber with the piston at top dead center. The stream of hot combustion gases is provided by injecting less than about 10 percent of the total coal-water slurry charge into the pilot combustion chamber and using a portion of the air from the main combustion chamber that has been heated by the walls defining the pilot combustion chamber as the ignition source for the coal-water slurry injected into the pilot combustion chamber.

Motor vehicle technology:Mobility for prosperity

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

Not Available

1985-01-01

This book presents the papers given at a conference on internal combustion engines for vehicles. Topics considered at the conference included combustion chambers, the lubrication of turbocharged engines, oil filters, fuel consumption, traffic control, crashworthiness, brakes, acceleration, unleaded gasoline, methanol fuels, pressure drop, safety regulations, tire vibration, detergents, fuel economy, ceramics in engines, steels, catalytic converters, fuel additives, heat exchangers, pump systems, emissions control, fuel injection systems, noise pollution control, natural gas fuels, assembly plant productivity, aerodynamics, torsion, electronics, and automatic transmissions.

Development of Kinetic Mechanisms for Next-Generation Fuels and CFD Simulation of Advanced Combustion Engines

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

Pitz, William J.; McNenly, Matt J.; Whitesides, Russell

Predictive chemical kinetic models are needed to represent next-generation fuel components and their mixtures with conventional gasoline and diesel fuels. These kinetic models will allow the prediction of the effect of alternative fuel blends in CFD simulations of advanced spark-ignition and compression-ignition engines. Enabled by kinetic models, CFD simulations can be used to optimize fuel formulations for advanced combustion engines so that maximum engine efficiency, fossil fuel displacement goals, and low pollutant emission goals can be achieved.

Legislative and Regulatory Timeline for Fossil Fuel Combustion Wastes

EPA Pesticide Factsheets

This timeline walks through the history of fossil fuel combustion waste regulation since 1976 and includes information such as regulations, proposals, notices, amendments, reports and meetings and site visits conducted.

Effect [of] co-combustion of sewage sludge and biomass on combustion behavior and emissions in pulverized fuel systems

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

Spliethoff, H.; Hein, K.R.G.

1999-07-01

Biomass not only has a considerable potential as an additional fuel source but also shows a reasonable cost level in comparison to other renewable energies. The practicable fuel types are both residual material from forestry and agriculture, such as wood or straw, and especially cultivated reproducible feedstock such as Miscanthus Sinensis, whole cereal plants, poplars, or willows. Besides as single fuel, it is also considered to be sensible to utilize biomass in co-combustion in existing firing systems, such as pc-fired power stations. Biomass or sewage sludge utilized as additional fuel in coal combustion systems has consequences on combustion behavior, emissions,more » corrosion and residual matter. The effects of burning sewage sludge and agricultural residuals such as straw and manure as well as specially grown energy plants in combination with coal were studied in a 0.5 MW pulverized fuel test facility and a 20 kW electrically heated combustor. A major aspect of the investigations had been the required preparation and milling of the additional fuels. The investigations showed that in co-combustion of straw with coal, a grinding of 6 mm and finer is sufficient. The definitely coarser milling degree of biomass delays combustion and is observable by in-flame measurements. The investigations reveal that biomass addition has a positive effect on emissions. Since biomass in most cases contains considerably less sulphur than coal, an increasing biomass share in the thermal output makes the SO{sub 2} emissions decrease proportionally. In addition, SO{sub 2} can partly be captured in the ash by the alkaline-earth fractions of the biomass ash. As for sewage sludge, the emissions of SO{sub 2} correlate with the sulphur content of the fuel and, hence, rise with an increasing share of this biomass. Independently from the type, biomass shows a considerably stronger release of volatile matter. This latter fact may have a positive impact on NOx emissions when NOx-reducing techniques are applied. Within the framework of these investigations the following configurations were used: (1) unstaged combustion with preblending of coal and biomass, (2) air-staged combustion with preblending of coal and biomass, (3) reburning with biomass as reduction fuel, and (4) various burner configurations. The results show that the burner design and operation mode have a great influence on the NOx emissions of combined flames. Air staging and reburning are effective measures to reduce the NOx emissions of combined fuels. NOx emissions smaller than 300 mg/m at 6% O{sub 2} can be reached with all fuels.« less

On the effect of injection timing on the ignition of lean PRF/air/EGR mixtures under direct dual fuel stratification conditions

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

Luong, Minh Bau; Sankaran, Ramanan; Yu, Gwang Hyeon

2017-06-09

The ignition characteristics of lean primary reference fuel (PRF)/air/exhaust gas recirculation (EGR) mixture under reactivity-controlled compression ignition (RCCI) and direct duel fuel stratification (DDFS) conditions are investigated in this paper by 2-D direct numerical simulations (DNSs) with a 116-species reduced chemistry of the PRF oxidation. The 2-D DNSs of the DDFS combustion are performed by varying the injection timing of iso-octane (i-C 8H 18) with a pseudo-iso-octane (PC 8H 18) model together with a novel compression heating model to account for the compression heating and expansion cooling effects of the piston motion in an engine cylinder. The PC 8H 18more » model is newly developed to mimic the timing, duration, and cooling effects of the direct injection of i-C 8H 18 onto a premixed background charge of PRF/air/EGR mixture with composition inhomogeneities. It is found that the RCCI combustion exhibits a very high peak heat release rate (HRR) with a short combustion duration due to the predominance of the spontaneous ignition mode of combustion. However, the DDFS combustion has much lower peak HRR and longer combustion duration regardless of the fuel injection timing compared to those of the RCCI combustion, which is primarily attributed to the sequential injection of i-C 8H 18. It is also found that the ignition delay of the DDFS combustion features a non-monotonic behavior with increasing fuel-injection timing due to the different effect of fuel evaporation on the low-, intermediate-, and high-temperature chemistry of the PRF oxidation. The budget and Damköhler number analyses verify that although a mixed combustion mode of deflagration and spontaneous ignition exists during the early phase of the DDFS combustion, the spontaneous ignition becomes predominant during the main combustion, and hence, the spread-out of heat release rate in the DDFS combustion is mainly governed by the direct injection process of i-C 8H 18. Finally, a misfire is observed for the DDFS combustion when the direct injection of i-C 8H 18 occurs during the intermediate-temperature chemistry (ITC) regime between the first- and second-stage ignition. Finally, this is because the temperature drop induced by the direct injection of i-C 8H 18 impedes the main ITC reactions, and hence, the main combustion fails to occur.« less

Estimating combustion of large downed woody debris from residual white ash

Treesearch

Alistair M. S. Smith; Andrew T. Hudak

2005-01-01

The production of residual white ash patches within wildfires represents near-complete combustion of the available fuel and releases a considerable quantity of gases to the atmosphere. These patches are generally produced from combustion of large downed woody debris (LDWD) such as fallen trees and snags. However, LDWD are generally ignored in calculations of fuel...