Effects of Ambient Conditions and Fuel Composition on Combustion Stability


Book Description

Recent regulations on NO, emissions are promoting the use of lean premix (LPM) combustion for industrial gas turbines. LPM combustors avoid locally stoichiometric combustion by premixing fuel and the air upstream of the reaction region, thereby eliminating the high temperatures that produce thermal NO. Unfortunately, this style of combustor is prone to combustion oscillation. Significant pressure fluctuations can occur when variations in heat release periodically couple pressure to acoustic modes in the combustion chamber. These oscillations must be controlled because resulting vibration can shorten the life of engine hardware. Laboratory and engine field testing have shown that instability regimes can vary with environmental conditions. These observations prompted this study of the effects of ambient conditions and fuel composition on combustion stability. Tests are conducted on a sub-scale combustor burning natural gas, propane, and some hydrogen/hydrocarbon mixtures. A premix, swirl-stabilized fuel nozzle typical of industrial gas turbines is used. Experimental and numerical results describe how stability regions may shift as inlet air temperature, humidity, and fuel composition are altered. Results appear to indicate that shifting instability instability regimes are primarily caused by changes in reaction rate.




Emissions from Continuous Combustion Systems


Book Description

This volume documents the proceedings of the Symposium on Emissions from Continuous Combustion Systems that was held at the General Motors Research Laboratories, Warren, Michigan on September 27 and 28, 1971. This symposium was the fifteenth in an annual series presented by the Research Laboratories. Each symposium has covered a different technical discipline. To be selected as the theme of a symposium, the subject must be timely and of vital interest to General Motors as well as to the technical community at large. For each symposium, the practice is to solicit papers at the forefront of research from recognized authorities in the technical discipline of interest. Approximately sixty scientists and engineers from academic, government and industrial circles in this country and abroad are then invited to join about an equal number of General Motors technical personnel to discuss freely the commissioned papers. The technical portion of the meeting is supplemented by social functions at which ample time is afforded for informal exchanges of ideas amongst the participants. By such a direct interaction of a small and select group of informed participants, it is hoped to extend the boundaries of research in the selected technical field.




Gas Turbine Combustion


Book Description

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




Combustion Noise


Book Description

November, 2008 Anna Schwarz, Johannes Janicka In the last thirty years noise emission has developed into a topic of increasing importance to society and economy. In ?elds such as air, road and rail traf?c, the control of noise emissions and development of associated noise-reduction techno- gies is a central requirement for social acceptance and economical competitiveness. The noise emission of combustion systems is a major part of the task of noise - duction. The following aspects motivate research: • Modern combustion chambers in technical combustion systems with low pol- tion exhausts are 5 - 8 dB louder compared to their predecessors. In the ope- tional state the noise pressure levels achieved can even be 10-15 dB louder. • High capacity torches in the chemical industry are usually placed at ground level because of the reasons of noise emissions instead of being placed at a height suitable for safety and security. • For airplanes the combustion emissions become a more and more important topic. The combustion instability and noise issues are one major obstacle for the introduction of green technologies as lean fuel combustion and premixed burners in aero-engines. The direct and indirect contribution of combustion noise to the overall core noise is still under discussion. However, it is clear that the core noise besides the fan tone will become an important noise source in future aero-engine designs. To further reduce the jet noise, geared ultra high bypass ratio fans are driven by only a few highly loaded turbine stages.




Steam Generators and Waste Heat Boilers


Book Description

Incorporates Worked-Out Real-World Problems Steam Generators and Waste Heat Boilers: For Process and Plant Engineers focuses on the thermal design and performance aspects of steam generators, HRSGs and fire tube, water tube waste heat boilers including air heaters, and condensing economizers. Over 120 real-life problems are fully worked out which will help plant engineers in evaluating new boilers or making modifications to existing boiler components without assistance from boiler suppliers. The book examines recent trends and developments in boiler design and technology and presents novel ideas for improving boiler efficiency and lowering gas pressure drop. It helps plant engineers understand and evaluate the performance of steam generators and waste heat boilers at any load. Learn How to Independently Evaluate the Thermal Performance of Boilers and Their Components This book begins with basic combustion and boiler efficiency calculations. It then moves on to estimation of furnace exit gas temperature (FEGT), furnace duty, view factors, heat flux, and boiler circulation calculations. It also describes trends in large steam generator designs such as multiple-module; elevated drum design types of boilers such as D, O, and A; and forced circulation steam generators. It illustrates various options to improve boiler efficiency and lower operating costs. The author addresses the importance of flue gas analysis, fire tube versus water tube boilers used in chemical plants, and refineries. In addition, he describes cogeneration systems; heat recovery in sulfur plants, hydrogen plants, and cement plants; and the effect of fouling factor on performance. The book also explains HRSG simulation process and illustrates calculations for complete performance evaluation of boilers and their components. Helps plant engineers make independent evaluations of thermal performance of boilers before purchasing them Provides numerous examples on boiler thermal performance calculations that help plant engineers develop programming codes with ease Follows the metric and SI system, and British units are shown in parentheses wherever possible Includes calculation procedures for the basic sizing and performance evaluation of a complete steam generator or waste heat boiler system and their components with appendices outlining simplified procedures for estimation of heat transfer coefficients Steam Generators and Waste Heat Boilers: For Process and Plant Engineers serves as a source book for plant engineers, consultants, and boiler designers.




Scientific and Technical Aerospace Reports


Book Description

Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.




Gas Turbine Emissions


Book Description

The development of clean, sustainable energy systems is a preeminent issue in our time. Gas turbines will continue to be important combustion-based energy conversion devices for many decades to come, used for aircraft propulsion, ground-based power generation, and mechanical-drive applications. This book compiles the key scientific and technological knowledge associated with gas turbine emissions into a single authoritative source.




Gas Turbines for Electric Power Generation


Book Description

Everything you wanted to know about industrial gas turbines for electric power generation in one source with hard-to-find, hands-on technical information.