Download or read book Autoignition Delay Time Measurements for Natural Gas Fuel Components and Their Mixtures written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Autoignition delay time measurements for natural gas fuel components and their mixtures.

Download or read book Autoignition Delay Time Measurements for Natural Gas Fuel Components and Their Mixtures written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Combustion Chemistry written by W. C. Jr. Gardiner and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 515 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detailed study of the rates and mechanisms of combustion reactions has not been in the mainstream of combustion research until the recent recognition that further progress in optimizing burner performance and reducing pollutant emission can only be done with fundamental understanding of combustion chemistry. This has become apparent at a time when our understanding of the chemistry, at least of small-molecule combustion, and our ability to model combustion processes on large computers have developed to the point that real confidence can be placed in the results. This book is an introduction for outsiders or beginners as well as a reference work for people already active in the field. Because the spectrum of combustion scientists ranges from chemists with little computing experience to engineers who have had only one college chemistry course, everything needed to bring all kinds of beginners up to the level of current practice in detailed combustion modeling is included. It was a temptation to include critical discussions of modeling results and computer programs that would enable outsiders to start quickly into problem solving. We elected not to do either, because we feel that the former are better put into the primary research literature and that people who are going to do combustion modeling should either write their own programs or collaborate with experts. The only exception to this is in the thermochemical area, where programs have been included to do routine fitting operations. For reference purposes there are tables of thermochemical, transport-property, and rate coefficient data.

Download or read book Effects of Natural Gas Composition on Ignition Delay Under Diesel Conditions written by and published by . This book was released on 1993 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effects of variations in natural gas composition on autoignition of natural gas under direct-injection (DI) diesel engine conditions were studied experimentally in a constant-volume combustion vessel and computationally using a chemical kinetic model. Four fuel blends were investigated: pure methane, a capacity weighted mean natural gas, a high ethane content natural gas, and a natural gas with added propane typical of peak shaving conditions. Experimentally measured ignition delays were longest for pure methane and became progressively shorter as ethane and propane concentrations increased. At conditions characteristic of a DI compression ignition natural gas engine at Top Dead Center (CR=23:1, p = 6.8 MPa, T = 1150K), measured ignition delays for the four fuels varied from 1.8 ms for the peak shaving and high ethane gases to 2.7 ms for pure methane. Numerically predicted variations in ignition delay as a function of natural gas composition agreed with these measurements.

Download or read book Autoignition Delay Time Measurments and Chemical Kinetic Modeling of Hydrogen ammonia natural Gas Mixtures written by Jessica Blue Baker and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In general, both models were able to capture the trend in autoignition delay times and CO time histories for natural gas and ammonia mixtures. However, for ammonia-hydrogen mixtures, GRI 3.0 failed to predict ignition delay times, whereas the UCF 2022 mechanism was able to capture the IDTs within the uncertainty limits of the experiments. A sensitivity analysis was conducted for different mixtures to understand the important reactions at the experimental conditions. Finally, a reaction pathway analysis was carried out to understand important ammonia decomposition pathways in the presence of hydrogen and natural gas.

Download or read book Ignition Delay Times of Natural Gas hydrogen Blends at Elevated Pressures written by Marissa Brower and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Applications of natural gases that contain high levels of hydrogen have become a primary interest in the gas turbine market. For reheat gas turbines, understanding of the ignition delay times of high-hydrogen natural gases is important for two reasons. First, if the ignition delay time is too short, autoignition can occur in the mixer before the primary combustor. Second, the flame in the secondary burner is stabilized by the ignition delay time of the fuel. While the ignition delay times of hydrogen and of the individual hydrocarbons in natural gases can be considered well known, there have been few previous experimental studies into the effects of different levels of hydrogen on the ignition delay times of natural gases at gas turbine conditions. In order to examine the effects of hydrogen content at gas turbine conditions, shock-tube experiments were performed on nine combinations of an L9 matrix. The L9 matrix was developed by varying four factors: natural gas higher-order hydrocarbon content of 0, 18.75, or 37.5%; hydrogen content of the total fuel mixture of 30, 60, or 80%; equivalence ratios of 0.3, 0.5, or 1; and pressures of 1, 10, or 30 atm. Temperatures ranged from 1092 K to 1722 K, and all mixtures were diluted in 90% Ar. Correlations for each combination were developed from the ignition delay times and, using these correlations, a factor sensitivity analysis was performed. It was found that hydrogen played the most significant role in ignition delay time. Pressure was almost as important as hydrogen content, especially as temperature increased. Equivalence ratio was slightly more important than hydrocarbon content of the natural gas, but both were less important than pressure or hydrogen content. Further analysis was performed using ignition delay time calculations for the full matrix of combinations (27 combinations for each natural gas) using a detailed chemical kinetics mechanism. Using these calculations, separate L9 matrices were developed for each natural gas. Correlations from the full matrix and the L9 matrix for each natural gas were found to be almost identical in each case, verifying that a thoughtfully prepared L9 matrix can indeed capture the major effects of an extended matrix.

Download or read book Ignition Delay Time Measurements for Distillate and Synthetic Jet Fuels written by Yi Cao and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As alternatives to traditional petroleum-based fuels are increasingly sought after, the National Jet Fuel Combustion Program (NJFCP) was established to streamline the evaluation and certification of these fuels. The current mandate is for the replacements of traditional fuels to be equally safe and to provide better environmental performance [1]. These so-called "drop-in" jet fuels refer to hydrocarbon fuels that deliver identical combustion performance and are produced from non-petroleum sources [2]. Following the mandate delivered by the NJFCP for alternative fuels, this study aims to improve the traditionally phenomenological understanding of combustion performance by making connections between fuel properties and the chemical composition of fuels. The ignition delay time is an important measure of the combustion performance of fuels, as it is an integrated measure of the fuels' physical and chemical properties, such as volatility, diffusivity, and chemical reactivity. Consequently, it is a very useful validation target in chemical kinetic modeling and has implications in practical aviation phenomena such as, among others, lean blowout, cold-start ignition and altitude relight. Shock tubes are well-suited for ignition delay time measurements, as they provide a well-defined time zero and a quasi-constant temperature and pressure test region behind the reflected shocks. All experiments in this thesis were performed on the Stanford Flexible Application Shock Tube (FAST). Reactive gas mixtures were prepared with equivalence ratios of 1 ± 0.05, and mixed in the shock tube driven section to avoid fuel loss attributed to non-idealities in the jet fuel vapor. Changes in the fuel mole fraction during mixing and ignition were monitored using laser absorption diagnosis at 3.39 μm. The ignition delay time is defined in this study by the onset of emission from electronically excited OH radicals at 306 nm. Ignition delay times were measured in the temperature range of 1200-1500 K and at 4 atm pressure for five distillate jet fuels from refineries around the US (termed geographical fuels), and for six synthetic jet fuels with varying cetane numbers ranging from 30-55 (termed CN fuels). The ignition delay times for A1-3 and C1-9 jet fuels were also measured at 1300 K and at 4 atm. The dependence of combustion properties on fuel chemical composition were investigated using the ignition delay times for these fuels. In particular, the key role that the degree of branching in the jet fuel molecular structure plays in the combustion kinetics and performance is discussed.

Download or read book Development and Evaluation of Gas Fuel Interchangeability Criteria and Methodologies written by Vincent G. McDonell and published by . This book was released on 2014 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Gas Turbines written by Claire Soares and published by Elsevier. This book was released on 2011-04-01 with total page 773 pages. Available in PDF, EPUB and Kindle. Book excerpt: This major reference book offers the professional engineer - and technician - a wealth of useful guidance on nearly every aspect of gas turbine design, installation, operation, maintenance and repair. The author is a noted industry expert, with experience in both civilian and military gas turbines, including close work as a technical consultant for GE and Rolls Royce. • Guidance on installation, control, instrumentation/calibration, and maintenance, including lubrication, air seals, bearings, and filters• Unique compendium of manufacturer’s specifications and performance criteria, including GE, and Rolls-Royce engines• Hard-to-find help on the economics and business-management aspect of turbine selection, life-cycle costs, and the future trends of gas turbine development and applications in aero, marine, power generation and beyond

Download or read book Measurements of Ignition Times OH Time histories and Reaction Rates in Jet Fuel and Surrogate Oxidation Systems written by Subith Vasu Sumathi and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Fossil-based hydrocarbon fuels account for over 80% of the primary energy consumed in the world - it is still expected to be about 70% in year 2050 - and nearly 60% of that amount is used in the transport sector. The basis for globalization is transportation and a driving force has been the growth in global air traffic. The current climate crisis magnifies the need for improving the performance of jet engines by introducing scientific designs in which the use of chemical kinetics will be essential and critical for better performance and reducing pollutant emissions. Most aviation fuels are jet fuels originating from crude oil and there are major gaps in our knowledge of the high-temperature chemistry of real liquid carbon-based fuels. There is a critical need for experimental kinetic databases that can be used for the validation and refinement of jet fuel surrogate mechanisms. To fill this need, experiments were performed using shock tube and laser absorption methods to investigate jet fuel and surrogate oxidation systems under engine-relevant conditions. Ignition times and OH species time-histories were measured and low-uncertainty measurements of the reactions of OH with several stable intermediates were carried out. The work presented in this study can be broken into three categories: 1) jet fuel oxidation, 2) surrogate oxidation, and 3) OH radical reactions with several stable combustion intermediates. Ignition delay times were measured for gas-phase jet fuel oxidation (Jet-A and JP-8) in air behind reflected shock waves in a heated high-pressure shock tube. Initial reflected shock conditions were as follows: temperatures of 715-1229 K, pressures of 17-51 atm, equivalence ratios (phi) of 0.5 and 1, and oxygen concentrations of 10 and 21 % in synthetic air. Ignition delay times were measured using sidewall pressure and OH* emission at 306 nm. The new experimental results were modeled using several kinetic mechanisms using various jet fuel surrogate mixtures. Normal and cyclo alkanes are the two most important chemical classes found in jet fuels. Ignition delay time experiments were conducted during high-pressure oxidation of two commonly used representative components for normal and cyclo alkanes in jet fuel surrogates, i.e., n-dodecane and methylcyclohexane (MCH), respectively. Fuel/air ignition was studied for the following shock conditions: temperatures of 727-1177 K, pressures of 17-50 atm, phi's of 0.5 and 1. OH concentration time-histories during high-pressure n-dodecane, n-heptane and MCH oxidation were measured behind reflected shock waves in a heated, high-pressure shock tube. Experimental conditions covered temperatures of 1121 to 1422 K, pressures of 14.1-16.7 atm, and initial fuel concentrations of 500 to 1000 ppm (by volume), and an equivalence ratio of 0.5 with O2 as the oxidizer in argon as the bath gas. OH concentrations were measured using narrow-linewidth ring-dye laser absorption near the R-branchhead of the OH A-X (0,0) system at 306.47 nm. Detailed comparisons of these data with the predictions of various kinetic mechanisms were made. Sensitivity and pathway analyses for these reference fuel components were performed, leading to reaction rate recommendations with improved model performance. Reactions of OH radical with two alkenes (ethylene and propene) and a diene (1,3-butadiene) were studied behind reflected shock waves. Measurements were conducted in the range of temperatures from 890-1438 K and pressures from 1.99-10.18 atm for three initial concentrations of fuels (500ppm, 751.1ppm and 1000ppm). OH radicals were produced by shock-heating tert-butyl hydroperoxide, (CH3)3-CO-OH, and monitored by narrow-line width ring dye laser absorption of the well characterized R1(5) line of the OH A-X (0, 0) band near 306.7 nm. OH time-histories were modeled by using a modified oxidation mechanism and rate constants for the reactions of OH with ethylene, propene, and 1,3-butadiene were extracted by matching modeled and measured OH concentration time histories in the reflected shock region. Detailed error analyses yielded an uncertainty estimate of " 22.8% (OH+ethylene at 1201 K), "16.5% (OH+propene at 1136 K), and "13% (OH+1,3-butadiene at 1200K). Canonical and variational transition state theory calculations using recent ab initio results gave excellent agreement with our experimental measurements and data outside our range and hence the resulting expressions can be used directly in combustion models. In the current studies, a rate measurement for the decomposition of TBHP has been obtained in the range 745-1014 K using both incident and reflected OH data.

Download or read book Combustion Measurements written by Norman Chigier and published by CRC Press. This book was released on 1991-04-01 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book begins with an introduction to the general problems of making measurements in high temperature and a presentation of chemically reacting flow systems. It describes each instrument with the various diagnostic techniques and discusses measurements that have been made in furnaces, flames, and rocket engines. The detailed measurement techniques described in this book cover a wide spectrum of applications in combustion systems, including gas turbine, rocket measurement techniques that were developed in laboratories. Information obtained on detailed temperature, velocity, particle size, and gas concentration distribution is leading to improve understanding of the chemical combustion process and to design imporvements in combustors.

Download or read book Homogeneous Charge Compression Ignition HCCI Engines written by Fuquan Zhao and published by SAE International. This book was released on 2003-01-01 with total page 658 pages. Available in PDF, EPUB and Kindle. Book excerpt: The homogeneous charge, compression-ignition (HCCI) combustion process has the potential to significantly reduce NOx and particulate emissions, while achieving high thermal efficiency and the capability of operating with a wide variety of fuels. This makes the HCCI engine an attractive technology that can ostensibly provide diesel-like fuel efficiency and very low emissions, which may allow emissions compliance to occur without relying on lean aftertreatment systems. A profound increase in the level of research and development of this technology has occurred in the last decade. This book gathers contributions from experts in both industry and academia, providing a basic introduction to the state-of-the-art of HCCI technology, a critical review of current HCCI research and development efforts, and perspective for the future. Chapters cover: Gasoline-Fueled HCCI Engines; Diesel-Fueled HCCI Engines; Alternative Fuels and Fuel Additives for HCCI Engines; HCCI Control and Operating Range Extension; Kinetics of HCCI Combustion; HCCI Engine Modeling Approaches.In addition to the extensive overview of terminology, physical processes, and future needs, each chapter also features select SAE papers (a total of 41 are included in the book), as well as a comprehensive list of references related to the subjects. Homogeneous Charge Compression Ignition (HCCI) Engines: Key Research and Development Issues provides a valuable base of information for those interested in learning about this rapidly-progressing technology which has the potential to enhance fuel economy and reduce emissions.

Download or read book Natural Gas Engines written by Kalyan Kumar Srinivasan and published by Springer. This book was released on 2018-11-03 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the various advanced reciprocating combustion engine technologies that utilize natural gas and alternative fuels for transportation and power generation applications. It is divided into three major sections consisting of both fundamental and applied technologies to identify (but not limited to) clean, high-efficiency opportunities with natural gas fueling that have been developed through experimental protocols, numerical and high-performance computational simulations, and zero-dimensional, multizone combustion simulations. Particular emphasis is placed on statutes to monitor fine particulate emissions from tailpipe of engines operating on natural gas and alternative fuels.

Download or read book Fundamentals of Combustion Processes written by Sara McAllister and published by Springer Science & Business Media. This book was released on 2011-05-10 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals of Combustion Processes is designed as a textbook for an upper-division undergraduate and graduate level combustion course in mechanical engineering. The authors focus on the fundamental theory of combustion and provide a simplified discussion of basic combustion parameters and processes such as thermodynamics, chemical kinetics, ignition, diffusion and pre-mixed flames. The text includes exploration of applications, example exercises, suggested homework problems and videos of laboratory demonstrations

Download or read book Gas Turbine Combustion written by Arthur H. Lefebvre and published by CRC Press. This book was released on 2010-04-26 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reflecting the developments in gas turbine combustion technology that have occurred in the last decade, Gas Turbine Combustion: Alternative Fuels and Emissions, Third Edition provides an up-to-date design manual and research reference on the design, manufacture, and operation of gas turbine combustors in applications ranging from aeronautical to po

Download or read book Ignitability and Explosibility of Gases and Vapors written by Tingguang Ma and published by Springer. This book was released on 2015-04-28 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book provides a systematic view on flammability and a collection of solved engineering problems in the fields of dilution and purge, mine gas safety, clean burning safety and gas suppression modeling. For the first time, fundamental principles of energy conservation are used to develop theoretical flammability diagrams and are then explored to understand various safety-related mixing problems. This provides the basis for a fully-analytical solution to any flammability problem. Instead of the traditional view that flammability is a fundamental material property, here flammability is discovered to be a result of the explosibility of air and the ignitability of fuel, or a process property. By exploring the more fundamental concepts of explosibility and ignitability, the safety targets of dilution and purge can be better defined and utilized for guiding safe operations in process safety. This book provides various engineering approaches to mixture flammability, benefiting not only the safety students, but also field operators, as a useful resource for the safe handling of flammable gases and liquids. It will be useful to anyone who worries about the ignition potential of a flammable mixture.

Download or read book Turbulent Premixed Flames written by Nedunchezhian Swaminathan and published by Cambridge University Press. This book was released on 2011-04-25 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: A work on turbulent premixed combustion is important because of increased concern about the environmental impact of combustion and the search for new combustion concepts and technologies. An improved understanding of lean fuel turbulent premixed flames must play a central role in the fundamental science of these new concepts. Lean premixed flames have the potential to offer ultra-low emission levels, but they are notoriously susceptible to combustion oscillations. Thus, sophisticated control measures are inevitably required. The editors' intent is to set out the modeling aspects in the field of turbulent premixed combustion. Good progress has been made on this topic, and this cohesive volume contains contributions from international experts on various subtopics of the lean premixed flame problem.