Adiabatic burning velocity and cellular flame characteristics of H2–CO–CO2–air mixtures

Velamati, Ratna Kishore; Ravi, M.R.; Ray, Anjan

doi:10.1016/j.combustflame.2011.03.018

Cited by 69 publications

(58 citation statements)

References 42 publications

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“…Adding to this uncertainty is the modeling of the associated collisional efficiency of the three body molecules H 2 O and CO 2 . Reducing this uncertainty has driven recent studies with wet H 2 flames (e.g., [33][34][35][36][37][38][39] …”

Section: Introductionmentioning

confidence: 99%

Studies of premixed and non-premixed hydrogen flames

Park

Veloo

Burbano

et al. 2015

Combustion and Flame

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a b s t r a c tThe hydrogen oxidation chemistry constitutes the foundation of the kinetics of all carbon-and hydrogencontaining fuels. The validation of rate constants of hydrogen-related reactions can be complicated by uncertainties associated with experimental data caused by the high reactivity and diffusivity of hydrogen. In the present investigation accurate experimental data on flame propagation and extinction were determined for premixed and non-premixed hydrogen flames at pressures between p = 1 and 7 atm. The experiments were designed to sensitize the three-body H + O 2 + M ? HO 2 + M reaction, whose rate is subject to notable uncertainty. This was achieved by increasing the pressure and by adding to the reactants H 2 O and CO 2 whose collision efficiencies are high compared to other species. In the present study, directly measured flame properties were compared against computed ones, in order to eliminate uncertainties associated with extrapolations, as is the case for laminar flame speeds. The measured extinction strain rates exhibit both a positive and negative dependence on pressure with and without weighting with the density, and this non-monotonic behavior is caused by the competition between the H + O 2 ? O + OH and H + O 2 + M ? HO 2 + M reactions as well as HO 2 kinetic pathways as pressure increases. The various kinetic models considered in this investigation did not reproduce equally well the non-premixed flame extinction data with added H 2 O. On the other hand, the predicted extinction strain rates were consistent between the various models in the case of added CO 2 . Finally, it was shown that the formulation of binary diffusion coefficient pairs including H-N 2 and H 2 -N 2 has a first order effect on the prediction of extinction strain rates of non-premixed H 2 flames.

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Section: Introductionmentioning

confidence: 99%

Studies of premixed and non-premixed hydrogen flames

Park

Veloo

Burbano

et al. 2015

Combustion and Flame

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“…In recent literature, flat flame burners are used for many experimental purposes in fundamental research, for example, determining fuel characteristics like laminar burning velocity (Bosschaart and de Goey, 2004), studying flame structure (Ratna Kishore et al, 2011), and flame stabilization and blowoff studies (Kedia and Ghoniem, 2011). Many applications like gas turbines operate at elevated pressures and temperatures.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulations of Flat Laminar Premixed Methane-Air Flames at Elevated Pressure

Goswami

Coumans

Bastiaans

et al. 2014

Combustion Science and Technology

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“…Moreover, dilution is often used to lower the flame temperature and thereby limit NO x emissions. Several researchers have examined the effects of diluents on laminar flame speed, stability, and emissions (McLean et al 1994;Natarajan et al 2009;Kishore et al 2011;Burke et al 2007;Burbano et al 2011;Das et al 2011). It is important to note that only NO x emission is relevant in syngas flames, while both soot and NO x emissions are important for hydrocarbon flames.…”

Section: Syngas Combustion and Emission Characteristicsmentioning

confidence: 98%

“…It is of critical importance with regard to burning rate, flame stabilization, flashback, and blowout in practical systems. Laminar burning velocities for H 2 -CO mixtures have been measured using different systems, including flat-flame burner (Yan et al 2001), Bunsen burner (Natarajan et al 2007(Natarajan et al , 2009, and expanding spherical flames (McLean et al 1994;Prathap et al 2008;Kishore et al 2011). Figure 3 presents measured and predicted laminar flame speeds versus equivalence ratio and pressure, respectively.…”

Section: Syngas Combustion and Emission Characteristicsmentioning

confidence: 99%

“…The flame response to stretch is characterized in terms of the Markstein length or nondimensional parameter, Markstein number. Spherically expanding flames have been commonly used to determine this parameter, and details can be found in Aggarwal (2013) and Kishore et al (2011). Since syngas generally contains other species in addition to CO 2 and H 2 O, it is important to examine the effects of various diluents on syngas combustion and emissions.…”

Section: Syngas Combustion and Emission Characteristicsmentioning

confidence: 99%

See 1 more Smart Citation

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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Adiabatic burning velocity and cellular flame characteristics of H2–CO–CO2–air mixtures

Cited by 69 publications

References 42 publications

Studies of premixed and non-premixed hydrogen flames

Studies of premixed and non-premixed hydrogen flames

Numerical Simulations of Flat Laminar Premixed Methane-Air Flames at Elevated Pressure

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

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