Download or read book Effects of Fuel Split Ratio on NOx Emissions of a Lean burn Staged Combustor written by Yang Chen (Researcher in aeronautics and astronautics) and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aviation NO[subscript x] emissions are a significant factor in causing air quality deterioration, leading to potentially 16,000 annual premature deaths globally. To cope with the expected increase in air traffic demand in the near future, aircraft-based lean-burn staged combustion becomes a promising solution in reducing NO[subscript x] emissions. This thesis investigates the effects of a lean-burn staged combustor's fuel split ratio and staging threshold on the NO[subscript x] emissions for both a sea-level static scenario and a representative flight mission. NO[subscript x] reduction benefits from optimizing the fuel split ratio are studied, and the EINO[subscript NOx] performance between an RQL and a lean-burn staged combustor are compared. Chemical reactor networks, NPSS engine cycle models, and a TASOPT flight mission model are utilized. In comparison to previous studies, a wider range of pilot fuel fraction, from 16% to 100%, are tested over more refined thrust cases, from 0% to 100% rated thrust. A wider range of phases, including the cruise conditions in addition to the LTO cycle, is employed in this thesis. This thesis illustrates how a pilot fuel fraction below 30% is infeasible through the calibration of the combustor model. It is found that staging should occur as early as allowed by combustion stability to minimize NO[subscript x] emissions, and the optimal fuel split ratio is roughly constant across different throttle conditions. Moreover, reducing the air distributed to the pilot zone decreases the overall EINO[subscript NOx] level, and the lean-burn staged combustor is observed to outperform an RQL combustor in terms of NO[subscript x] emissions.
Download or read book Effects of Fuel Split Ratio on NO3 Emissions of a Lean burn Staged Combustor written by Yang Chen (Researcher in aeronautics) and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aviation NOx emissions are a significant factor in causing air quality deterioration, leading to potentially 16,000 annual premature deaths globally. To cope with the expected increase in air traffic demand in the near future, aircraft-based lean-burn staged combustion becomes a promising solution in reducing NOx emissions. This thesis investigates the effects of a lean-burn staged combustor's fuel split ratio and staging threshold on the NOx emissions for both a sea-level static scenario and a representative flight mission. NOx reduction benefits from optimizing the fuel split ratio are studied, and the EINOx performance between an RQL and a lean-burn staged combustor are compared. Chemical reactor networks, NPSS engine cycle models, and a TASOPT flight mission model are utilized. In comparison to previous studies, a wider range of pilot fuel fraction, from 16% to 100%, are tested over more refined thrust cases, from 0% to 100% rated thrust. A wider range of phases, including the cruise conditions in addition to the LTO cycle, is employed in this thesis. This thesis illustrates how a pilot fuel fraction below 30% is infeasible through the calibration of the combustor model. It is found that staging should occur as early as allowed by combustion stability to minimize NOx emissions, and the optimal fuel split ratio is roughly constant across different throttle conditions. Moreover, reducing the air distributed to the pilot zone decreases the overall EINOx level, and the lean-burn staged combustor is observed to outperform an RQL combustor in terms of NOx emissions.
Download or read book Effect of Variable Fuel Composition on Emissions and Lean Blowoff Stability Performance written by Andrés Colorado and published by . This book was released on 2017 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Combustion Instabilities in Gas Turbine Engines written by Timothy C. Lieuwen and published by AIAA (American Institute of Aeronautics & Astronautics). This book was released on 2005 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers gas turbine users and manufacturers a valuable resource to help them sort through issues associated with combustion instabilities. In the last ten years, substantial efforts have been made in the industrial, governmental, and academic communities to understand the unique issues associated with combustion instabilities in low-emission gas turbines. The objective of this book is to compile these results into a series of chapters that address the various facets of the problem. The Case Studies section speaks to specific manufacturer and user experiences with combustion instabilities in the development stage and in fielded turbine engines. The book then goes on to examine The Fundamental Mechanisms, The Combustor Modeling, and Control Approaches.
Download or read book Effects of the Fuel Air Mixing on Combustion Instabilities and NOx Emissions in Lean Premixed Combustion written by Wessam Estefanos and published by . This book was released on 2016 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental study was conducted to investigate the effects of the fuel-air mixing on combustion instabilities and NO x emissions in lean premixed combustion. High speed PIV measurements in water were conducted to capture the mean and dynamic behavior of the cold flow generated by a 3X model of the tested premixer. High speed PLIF in water measurements were conducted to quantify the mean and unsteady fuel-air mixing at different momentum flux ratios. Atmospheric combustion tests using the original premixer, were conducted using natural gas and propane at the same momentum flux ratios of the PLIF mixing tests. An emissions analyzer was used to measure the emissions from combustion tests. Dynamic pressure transducers were used to measure the amplitude and the frequency of the dynamic pressure oscillations associated with the combustion instabilities. CHEMKIN-PRO was used to model the atmospheric combustion and predict NO x emissions at different conditions. Results showed that unsteady fuel-air mixing was concentrated at the center and near the outer edges of the premixer. These regions were characterized by high fuel concentration gradients. With the increase in the momentum flux ratio, the concentration gradient and the level of unsteady mixing increased, indicating that the fuel-air spatial unmixedness was the source of the unsteady mixing. It was found that local flow turbulence tended to decrease the concentration gradient through enhancing the fuel-air mixing, which resulted in decreasing the level of unsteady mixing. NO x emissions from atmospheric combustion increased with the increase in the momentum flux ratio due to the increase in the flame temperature and the fuel-air spatial and temporal unmixedness. The intensity of the combustion dynamics increased with the increase in the level of unsteady mixing. Axial injection of the fuel into the regions of strong unsteady mixing eliminated the combustion dynamics through damping the unsteady mixing. Results of CHEMKIN-PRO agreed very well with the experimental results and showed that the spatial and temporal unmixedness have a significant effect on NO x emissions for very lean combustion (F = 0.4). With the increase in the equivalence ratio, their relative contribution decreased.
Download or read book NOx Emission Control Technologies in Stationary and Automotive Internal Combustion Engines written by B. Ashok and published by Elsevier. This book was released on 2021-11-09 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: NOx Emission Control Technologies in Stationary and Automotive Internal Combustion Engines: Approaches Toward NOx Free Automobiles presents the fundamental theory of emission formation, particularly the oxides of nitrogen (NOx) and its chemical reactions and control techniques. The book provides a simplified framework for technical literature on NOx reduction strategies in IC engines, highlighting thermodynamics, combustion science, automotive emissions and environmental pollution control. Sections cover the toxicity and roots of emissions for both SI and CI engines and the formation of various emissions such as CO, SO2, HC, NOx, soot, and PM from internal combustion engines, along with various methods of NOx formation. Topics cover the combustion process, engine design parameters, and the application of exhaust gas recirculation for NOx reduction, making this book ideal for researchers and students in automotive, mechanical, mechatronics and chemical engineering students working in the field of emission control techniques. Covers advanced and recent technologies and emerging new trends in NOx reduction for emission control Highlights the effects of exhaust gas recirculation (EGR) on engine performance parameters Discusses emission norms such as EURO VI and Bharat stage VI in reducing global air pollution due to engine emissions
Download or read book Experimental Study of the Effect of Cycle Pressure on Lean Combustion Emission written by Gerald Roffe and published by . This book was released on 1978 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nitrogen oxides NOx why and how they are controlled written by and published by DIANE Publishing. This book was released on 1999 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Paper written by and published by . This book was released on 2001 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure Stability and Emissions of Lean Direct Injection Combustion Including a Novel Multi point Ldi System for Nox Reduction written by Rodrigo Villalva Gómez and published by . This book was released on 2013 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental research on lean direct injection (LDI) combustors for gas turbine applications is presented. LDI combustion is an alternative to lean premixed combustion which has the potential of equivalent reduction of oxides of nitrogen (NOx) emissions and of peak combustor exit temperatures, but without some drawbacks of premixed combustors, such as flashback and autoignition. Simultaneous observations of the velocity field and reaction zone of an LDI swirl-stabilized combustor with a mixing tube at atmospheric conditions, with the goal of studying the flame stabilization mechanism, are shown. The flame was consistently anchored at the shear layer formed by the high-speed reactants exiting the mixing tube and the low speed recirculation region. Individual image analysis of the location of the tip of the recirculation zone and tip of the reaction region confirmed previously observed trends, but showed that calculation of the distance between these two points for corresponding image pairs yields results no different than when calculated from random image pairs. This most likely indicates a lag in the anchoring of the flame to changes in the recirculation zone, coupled with significant stochastic variation. An alternate LDI approach, multi-point LDI (MLDI), is also tested experimentally. A single large fuel nozzle is replaced by multiple small fuel nozzles to improve atomization and reduce the total volume of the high-temperature, low velocity recirculation zones, reducing NOx formation. The combustor researched employs a novel staged approach to allow good performance across a wide range of conditions by using a combination of nozzle types optimized to various power settings. The combustor has three independent fuel circuits referenced as pilot, intermediate, and outer. Emissions measurements, OH* chemiluminescence imaging, and thermoacoustic instability studies were run in a pressurized combustion facility at pressures from 2.0 to 5.3 bar.Combustor performance was analyzed for three fuel staging configurations, using local equivalence ratio of the individual circuits as a predictive parameter. Pilot-only mode enabled combustor operation at very low overall equivalence ratios while limiting NOx formation in idle power settings due to its configuration approximating a rich-quench-lean combustor. Pilot and intermediate staging tests demonstrated the range of equivalence ratios that are effective in reducing NOx formation while keeping other pollutants in check; very low equivalence ratio results in high unburned hydrocarbon and carbon monoxide, while very high equivalence ratios result in a detrimental effect as more fuel is routed through the intermediate fuel circuit. Using all three fuel circuits simultaneously in high power operation resulted in very low NOx levels (emissions index at or below 0.5 g/kg), particularly when fuel distribution was such that local equivalence ratio was equal among all circuits. The observed NOx levels compared favorably with other MLDI designs which do not have the operational flexibility of the combustor tested. Thermoacoustic instabilities occurred in the MLDI combustor for some test conditions. The local equivalence ratio of the intermediate fuel circuit was found to be one of the major predictor of the onset of instabilities. Detailed analysis of a two-circuit instability (pilot and intermediate) is presented.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1993 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Diesel Engine written by Saiful Bari and published by BoD – Books on Demand. This book was released on 2013-04-30 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diesel engines, also known as CI engines, possess a wide field of applications as energy converters because of their higher efficiency. However, diesel engines are a major source of NOX and particulate matter (PM) emissions. Because of its importance, five chapters in this book have been devoted to the formulation and control of these pollutants. The world is currently experiencing an oil crisis. Gaseous fuels like natural gas, pure hydrogen gas, biomass-based and coke-based syngas can be considered as alternative fuels for diesel engines. Their combustion and exhaust emissions characteristics are described in this book. Reliable early detection of malfunction and failure of any parts in diesel engines can save the engine from failing completely and save high repair cost. Tools are discussed in this book to detect common failure modes of diesel engine that can detect early signs of failure.
Download or read book Experimental Study of the Effect of Cycle Pressure on Lean Combustion Emissions written by Gerald Roffe and published by . This book was released on 1978 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fuel air Mixing Effect on NOx Emissions for a Lean Pre mixed Pre vaporized Combustion System written by Chi-Ming Lee and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Investigation of Stability and Low NOx Potential of a Lean Direct Injection Combustor Concept written by Jacob Haseman and published by . This book was released on 2015 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current trends with swirler/combustor designs tend towards lower emissions in accordance with ICAO standards, with the main problems inherent in common lean-direct-injection (LDI) designs being poor stability and autoignition or flashback issues. The LDI design is meant to combine the good stability and performance of a traditional rich-burn quick-quench lean-burn (RQL) combustor with the ultra-low NOx emissions of a lean-premixed-prevaporized (LPP) combustor. The goal of this research is to investigate the feasibility of using swirlers with varying swirl strengths in an LDI combustor array by performing a series of combustion tests at atmospheric pressure. Three configurations were designed and tested which contained different arrangements of two counter-rotating radial-radial swirler designs with varying swirl strengths in a 3x3 array format. All nine swirlers contained a fuel nozzle with very similar flow numbers and were all set to the same insertion depth with respect to the swirlers' flare exits. Two nozzle insertion depths were investigated to see how the performance changes with changing insertion depth. Three fuel circuits supplied fuel to the nine fuel nozzles to the center, sides, and diagonal swirlers respectively. Testing was conducted by placing the hardware on a horizontally-oriented test rig connected to an air intake manifold, with the inlet air preheated to approximately 400°F and the pressure drop across the swirler set to 4% of atmospheric pressure. These tests investigated fuel staging configurations at various simulated engine throttle settings and flight conditions to gauge the steady-state combustion and LBO characteristics and low- NOx potential of this design. The results of this testing show that all three configurations tested were able to achieve stable-burning with low equivalence ratios for the three simulated flight conditions tested, as well as across a number of other investigated parameters. The two high-strength swirler configurations performed better than the baseline configuration in terms of LBO, stability, and flame uniformity, but all three configurations achieved stable combustion at comparable equivalence ratios to traditional combustor designs currently in use in industry. The low fuel flow rates required for ignition with the larger flow number fuel nozzles also demonstrates the practicality of this design in a real-world scenario. These tests also demonstrate that the deeper nozzle insertion depth performed better than the shallow insertion depth, and that future testing should focus on the high-strength swirler configurations.
Download or read book Fuel Systems for IC Engines written by Institution of Mechanical Engineers and published by Elsevier. This book was released on 2012-03-06 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the papers from the latest conference in this successful series on fuel injection systems for internal combustion engines. It is vital for the automotive industry to continue to meet the demands of the modern environmental agenda. In order to excel, manufacturers must research and develop fuel systems that guarantee the best engine performance, ensuring minimal emissions and maximum profit. The papers from this unique conference focus on the latest technology for state-of-the-art system design, characterisation, measurement, and modelling, addressing all technological aspects of diesel and gasoline fuel injection systems. Topics range from fundamental fuel spray theory, component design, to effects on engine performance, fuel economy and emissions. - Presents the papers from the IMechE conference on fuel injection systems for internal combustion engines - Papers focus on the latest technology for state-of-the-art system design, characterisation, measurement and modelling; addressing all technological aspects of diesel and gasoline fuel injection systems - Topics range from fundamental fuel spray theory and component design to effects on engine performance, fuel economy and emissions
Download or read book ASME COGEN TURBO written by and published by . This book was released on 1992 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:
