Turbulent flame speed for syngas at gas turbine relevant conditions

Daniele, Salvatore; Jansohn, P.; Mantzaras, John; Boulouchos, Konstantinos

doi:10.1016/j.proci.2010.05.057

Cited by 135 publications

(105 citation statements)

References 24 publications

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“…Studies on turbulent syngas flames have focused on the determination of turbulent flame speeds (S T ); (Daniele et al 2011;Venkateswaran et al 2011;Monteiro et al 2011). Venkateswaran et al (2011) reported measurements of global turbulent flame speeds using a Bunsen burner and examined the effects of ϕ, syngas composition, mean flow velocity, and turbulence intensity.…”

Section: Syngas Combustion and Emission Characteristicsmentioning

confidence: 99%

Using Petroleum and Biomass-Derived Fuels in Duel-fuel Diesel Engines

Xiao

2014

Novel Combustion Concepts for Sustainable Energy Development

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There is worldwide interest in developing renewable energy sources in a sustainable manner. Syngas and biogas offer significant potential in this context, as these fuels offer great flexibility with regard to their production and utilization. This chapter provides an overview of research dealing with the combustion and emission characteristics of these fuels, both as stand-alone fuels or by blending with petroleum fuels. Conversion methods for producing these fuels from different biomass sources are also briefly reviewed. While the syngas composition can vary widely, it generally has lower heating value, lower density, higher mass diffusivity, higher flame speeds, and wider flammability limits compared to hydrocarbon fuels. Moreover, its combustion leads to almost zero soot emission, although NO x emission may be a concern depending upon its composition and operating temperatures. Similarly, biogas has lower heating value compared to hydrocarbon fuels, and its ignition and combustion characteristics can vary noticeably depending upon its composition. While there have been few studies focusing directly on biogas combustion, there is extensive literature on methane combustion, including ignition, extinction, flammability limits, flame speeds, cellular instabilities, and emissions. Fundamental combustion aspects requiring further research include cellular instabilities, flame stabilization and blowout behavior, turbulent flames, and emission characteristics. Such efforts would lead to the development of optimized systems for producing these fuels and provide guidelines for optimizing their composition for a given set of operating conditions. The use of syngas and biogas in dual-fuel diesel engines has been a subject of numerous experimental and computational studies. A general observation is that the engine performance and emission characteristics are significantly modified by the presence of gaseous fuel. While the heat release in a diesel engine generally occurs through a hybrid combustion mode, involving rich premixed combustion and diffusion combustion, that in a dual-fuel engine also involves a lean combustion mode with a propagating flame. The dualfuel operation at high-load conditions can provide significant reduction in soot and CO soot emissions, while maintaining the engine efficiency, provided the injection characteristics including the amount of pilot fuel can be optimized. However, the NO x emission may increase, requiring a suitable strategy for lowering the temperatures. The dual-fuel strategy may be less effective at low load, resulting in lower thermal efficiency and higher UHC and CO emissions. Future work should be directed at optimizing the various parameters, such as injection timing, amount of pilot fuel injected, EGR, and multiple injections.

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Section: Syngas Combustion and Emission Characteristicsmentioning

confidence: 99%

Using Petroleum and Biomass-Derived Fuels in Duel-fuel Diesel Engines

Xiao

2014

Novel Combustion Concepts for Sustainable Energy Development

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“…A statistical expression generated from the data is shown in Figure 91 for the 20 mm diameter which calculates for FB in the annular combustor. The correlation developed by Daniele et al (2011) will be used to calculate S T .…”

Section: Flashback Correlation Via Turbulent Propagation Ratementioning

confidence: 99%

“…is considered to be 10% of 2) Integral length scale is equal to the one determined by Daniele et al (2011) 3) Burner diameter effect between 20 mm for Venkateswaran et al (2011) and 25 mm for Capstone OEM injector is negligible With these assumptions, the turbulent premixed combustion regime the flame resides in can be determined to evaluate whether the correlations coincide with the regime in which the FB data exist. FB for H 2 /CO two injector varied configuration is characterized by strongly wrinkled flames in the Borghi diagram depicted in Figure 92.…”

Section: )mentioning

confidence: 99%

“…According to E-31, the magnitude of A is around 10. To estimate the turbulent flame speed, the ratio of turbulent flame speed and laminar flame speed presented in the previous publications are employed (Daniele, Jansohn et al 2011;Venkateswaran, Marshall et al 2011). The magnitude of velocity fluctuation is estimated to be 5 m/s according to CFD simulation ( Figure 113).…”

Section: Quenching and Critical Distance Comparisonsmentioning

confidence: 99%

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Fuel Flexible Turbine System (FFTS) Program

None¹

2012

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“…urms/SL, and that of the length scales, i.e. Lo/δL [13,[15][16][17]. Here, SL and δL denote the flame speed and flame thickness of an unstrained laminar flame, respectively, while urms and Lo represents the root-mean-square of turbulent velocity fluctuations and the integral length scale, respectively.…”

Section: Introductionmentioning

confidence: 99%

Effects of equivalence ratio variations on turbulent flame speed in lean methane/air mixtures under lean-burn natural gas engine operating conditions

Wang

Motheau

Abraham

2017

Proceedings of the Combustion Institute

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Direct numerical simulations (DNS) of turbulent premixed methane/air flames are carried out to investigate the effects of equivalence ratio on the turbulent flame speed in lean mixtures. Turbulent flames are simulated as statistically stationary following a Lagrangian framework using an inflowoutflow configuration. The inflow velocity is dynamically adjusted at run-time to stabilize the flame brush location within the computational domain. Linear forcing is applied inside the unburned mixtures to maintain the turbulent intensities at desired levels. For the same turbulence properties, several equivalence ratios near the lean limit are selected and it is shown that the normalized turbulent flame speed is a function of the equivalence ratio. Velocity and length scales of the imposed turbulence are then selected in such a way that the Karlovitz and Damköhler numbers remain constant for flames of different equivalence ratios. Simulations are run for more than 80 eddy turnover times and the turbulent flame speed is derived by averaging the inflow velocity. The results show that equivalence ratio does not have an explicit effect on the normalized turbulent flame speed above the lean limit. Examining the flame surface statistics, it is shown that the flame surface normal is preferentially parallel to the most compressive strain rate direction for all equivalence ratios. KeywordsDNS of turbulent premixed flames, premixed flame speed, lean-burn, natural gas engines

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Turbulent flame speed for syngas at gas turbine relevant conditions

Cited by 135 publications

References 24 publications

Using Petroleum and Biomass-Derived Fuels in Duel-fuel Diesel Engines

Using Petroleum and Biomass-Derived Fuels in Duel-fuel Diesel Engines

Fuel Flexible Turbine System (FFTS) Program

Effects of equivalence ratio variations on turbulent flame speed in lean methane/air mixtures under lean-burn natural gas engine operating conditions

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