Emissions of Nitrogen Oxides from an Experimental Hydrogen-fueled Gas Turbine Combustor PDF Download

Author: Carl T. Norgren
Publisher:
ISBN:
Category : Aircraft gas-turbines
Languages : en
Pages : 28

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Author: David Nöel Anderson
Publisher:
ISBN:
Category : Aircraft gas-turbines
Languages : en
Pages : 24

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Author: Carl T. Norgren
Publisher:
ISBN:
Category : Aircraft gas-turbines
Languages : en
Pages : 28

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Book Description

Author: Timothy C. Lieuwen
Publisher: Cambridge University Press
ISBN: 052176405X
Category : Science
Languages : en
Pages : 385

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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.

Author:
Publisher: DIANE Publishing
ISBN: 1428902805
Category :
Languages : en
Pages : 57

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Author: Andrew North
Publisher:
ISBN:
Category :
Languages : en
Pages : 122

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The carbon dioxide emission prevention advantage of generating power with high hydrogen content fuels using gas turbines motivates an improved understanding of the ignition behavior of hydrogen in premixed and partially premixed environments. Hydrogen rich fueled flame stability is sensitive to operating conditions, including environment pressure, temperature, and jet velocity. Furthermore, when premixed or partially premixed operation is desired for nitric oxide emissions reduction, a diluent, such as nitrogen, is often added in allowing fuel/air mixing prior to combustion. Thus, the concentration of the diluent added is an additional independent variable on which flame stability dependence understanding is needed. The focus of this research is on characterizing the dependence of hydrogen jet flame stability on environment temperature, jet velocity, diluent concentration, and pressure by determining the dependence of the liftoff height of lifted flames on these 4 independent parameters. Nitrogen is used as the diluent due to its availability and effectiveness in promoting liftoff. Experiments are first conducted at atmospheric pressure in scoping subsequent research where the additional parameter of pressure is added. The stability and liftoff characteristics of a nitrogen diluted hydrogen jet flame at atmospheric pressure in a vitiated co-flow are investigated experimentally and numerically with particular attention focused on regimes where multiple stabilization mechanisms are active. Information gleaned from this research is instrumental for informing modeling approaches in flame transition situations when both autoignition and flame propagation influence combustion characteristics. Stability regime diagrams which outline the conditions under which the flame is attached, lifted, blown-out, and unsteady are experimentally developed and explored. The stability of the flame is investigated with a 1D Reynolds Averaged Navier Stokes parabolic numerical model which shows that under certain conditions, local turbulent flame speeds exceed the local velocity for the production of stable lifted hydrogen flames. These modeling results suggest that the dominant flame stabilization mechanism is flame propagation, and likely tribrachial flame propagation, consistent with the conclusions of prior studies for jet flames issuing into ambient environments such as the research of Muñiz and Mungal (1997). The lifted regime is further characterized at atmospheric pressure in determining liftoff height dependence on co-flow temperature, jet velocity, and nitrogen dilution. A strong sensitivity of liftoff height to co-flow temperature, jet velocity, and nitrogen dilution is observed. The numerical model results trend well with the experimentally developed stability regime diagrams. Liftoff heights predicted by Kalghatgi's correlation are unable to capture the effects of nitrogen dilution on liftoff height for the heated co-flow cases. A uniquely formulated Damköhler number was therefore developed which acceptably captures the effects of jet velocity, nitrogen dilution and environment temperature on liftoff height. Satisfactory agreement between the correlation results which relies on propagation parameters in its formulation further indicates that stabilization is indeed dominated by propagation. The unsteady regime is also investigated experimentally at atmospheric pressure. The unsteady regime is characterized by rapid ignition events of an initially unburned jet of fuel, and these events are always followed by subsequent blowout events. The frequency by which these ignition events occur are measured and insights are drawn regarding the impact of nitrogen dilution, jet velocity, and co-flow equivalence ratio on ignition frequency. Nitrogen addition to the fuel increases autoignition delay times which reduces ignition frequency, though it also reduces the speed of flame propagation which increases the frequency of blowoff. Consequently, when the level of nitrogen dilution added to the fuel is moderate, increases in dilution increase ignition frequency, and when high levels of nitrogen are added, further increases reduce ignition frequency because each ignition event is preceded by a blowoff event. Jet velocity increases lead to broader ranges of nitrogen dilution where unsteady behavior is observed. Finally, increases in co-flow equivalence ratio result in unsteady behavior for greater levels of nitrogen dilution Experiments are also conducted at elevated pressure with co-flow temperature, jet velocity, and nitrogen dilution still parameterized. Strong sensitivity of liftoff height on co-flow temperature and pressure is observed both when jet velocity and jet Reynolds number are held constant as pressure is varied. With confinement, which is required in achieving elevated pressure, liftoff height sensitivity on jet velocity is diminished. The Damköhler number is again utilized in assessing its utility in incorporating the pressure effect, and satisfactory correlation results are demonstrated. Elevated pressure results and atmospheric pressure results (without confinement) indicate that the Damköhler number can be used in scoping experimental lifted flame research at elevated pressures and temperatures and in informing numerical modeling approaches for research as well as in industry.

Author: David N. Anderson
Publisher:
ISBN:
Category : Combustion chambers
Languages : en
Pages : 28

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Hydrogen in quantities up to 5 percent by weight of the total fuel flow was injected into a premixed propane burner. The hydrogen was either premixed with the propane and air upstream of the burner or introduced as a torch at the flameholder. Emissions of total nitrogen oxides, carbon monoxide, and unburned hydrocarbon are reported as are combustion efficiencies and lean blowout limits. To maintain at least 99 percent combustion efficiency at a 700 K inlet mixture temperature with no hydrogen added, it was necessary to burn with a propane equivalence ratio of 0.525. When 4 percent hydrogen was premixed with the propane and air, a combustion efficiency greater than 99 percent was recorded at a propane equivalence ratio of 0.425. The total nitrogen oxides (NOx) emissions corresponding to these two conditions were 0.8 g NO2/kg equivalent propane and 0.44 g NO2/kg equivalent propane, respectively. The hydrogen torch did not reduce NOx emissions.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 20

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Author: Valerie J. Lyons
Publisher:
ISBN:
Category : Air-fuel ratio
Languages : en
Pages : 24

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Book Description

Author: Thomas Mikus
Publisher:
ISBN:
Category : Gas-turbines
Languages : en
Pages : 116

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Book Description