Numerical investigation of counter-flow diffusion flame of biogas–hydrogen blends: Effects of biogas composition, hydrogen enrichment and scalar dissipation rate on flame structure and emissions

Mameri, Abdelbaki; Tabet, Fouzi

doi:10.1016/j.ijhydene.2015.11.035

Cited by 51 publications

(12 citation statements)

References 40 publications

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“…The reference case was the combustion of natural gas (NG) since it is well known in the literature and used extensively in the industry. The rest of the biogas compositions were adopted from [20]. Even though the concentrations are fixed, it should be noted that the real-life application requires a well-controlled dilution to ensure constant combustion properties since the composition through anaerobic digestion might notably vary over the seasons.…”

Section: Methodsmentioning

confidence: 99%

Numerical analysis of biogas combustion in a lean premixed swirl burner

Füzesi

Józsa

2019

2019 7th International Youth Conference on Energy (IYCE)

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Modern combustion technology focuses on lean premixed burners to achieve high thermal efficiency, wide operating range, and low pollutant emissions for steady-state operation. The corresponding applications range from boilers to gas turbines. The present paper is a preliminary analysis of a turbulent laboratory test burner with 30 kW combustion power by using CFD. The reference fuel was natural gas and four biogases were tested which were modeled as a mixture of CH 4, CO2, and H2 in various compositions. Even though the combustion is steady, the steady solution was inappropriate due to the notable presence of unsteady flow structures. Since the combustion in the present case is dominated by volumetric reactions, a coarse boundary layer could be applied near the wall. However, the shear-dominated flow required the use of at least k-ω SST turbulent viscosity model. The transient cases were calculated by using Scale Adaptive Simulation. Among the fuels, natural gas combustion showed flashback due to the bluff body present at the center in the mixing tube inlet. Nevertheless, its extent was low and some central purge air in the real burner will solve this problem. All the flame shapes were V and W, meaning an optimal condition for combustion chamber loading. Even though the overall mass flow rates at the inlet are increasing with the decreasing heating value of the fuel, natural gas combustion showed the highest velocity and temperature in the flow field. Overall, a small hydrogen dilution of the CH 4-CO2 containing fuel acted as an excellent combustion stabilizer without flashback or too intense heat release rate. As a consequence, the presently analyzed burner can run on low calorific value fuels without design modifications or exposing locally high thermal load on the combustion chamber. Since it is an initial study, validation and the evaluation of practical relevance will be discussed in subsequent works.

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Section: Methodsmentioning

confidence: 99%

Numerical analysis of biogas combustion in a lean premixed swirl burner

Füzesi

Józsa

2019

2019 7th International Youth Conference on Energy (IYCE)

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“…The current numerical findings are supported by a prior study by Zheng et al, [21], which found that when CO2 and N2 were compared, CO2 exhibited greater combustion inhibition performance. CO2 has a larger heat capacity than CH4 [22]. As a result, CO2 could function as a diluent, absorbing some of the heat emitted during the reaction and therefore, lessening the combustion intensity [22].…”

Section: Predicted Flame Frontmentioning

confidence: 99%

Reacting Flow Characteristics and Multifuel Capabilities of a Multi-Nozzle Dry Low NOx Combustor: A Numerical Analysis

Rahman

Yasin

Aris

2021

CFDL

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The fluctuating quality of natural gas (NG) in Peninsular Malaysia (PM) makes it challenging for the gas turbine (GT) combustor to meet the combustion performance requirements from the Original Equipment Manufacturer (OEM). Moreover, the gas quality sensitivity is more apparent in modern dry low NOx (DLN) combustors. Many of the prior combustion investigations were conducted on a modest scale in the laboratory. In actuality, combustion characterizations in complicated DLN combustors are more valuable to the power generation sector. Hence, the current numerical analysis utilized the RANS formulation and a detailed chemistry to examine the impact of ethane (C2H6), carbon dioxide (CO2), and nitrogen (N2) proportions in NG on combustion characteristics in a multi-nozzle DLN (MN-DLN) combustor, with the support of Modified Wobbe Index (MWI) calculations. Validations were performed using the combustor outlet temperature (COT) from the power plant where the actual MN-DLN combustor is operated, which revealed less than 10 % discrepancy. Qualitative validations were carried out by comparing the burn trace from the actual combustor wall to the predicted results, revealing an adequate Structural Similarity Index (SSIM) of 0.43. From numerical results of flame fronts and COTs, the addition of 20 % diluents (CO2 and N2) to NG demonstrated the blowoff risk. When MWIs of Kerteh and the JDA (major NG resources) were used as baselines, MWI ranges of all NG compositions under study surpassed the OEM’s ± 5 % limit. The increase in CO2 proportion results in a wide MWI range, especially when Kerteh is used as the baseline. Therefore, any GTs in PM that have previously been calibrated to use Kerteh's NG are more likely to have combustion instabilities if CO2 levels in NG suddenly increase. The higher MWI range backs up the current numerical results that showed the deleterious effects of a high CO2 composition throughout the combustor firing process. However, increasing the amount of C2H6 by up to 20 % is predicted to have minor effects on combustion characteristics. Overall, the validated numerical model of the MN-DLN combustor provided critical information about combustion characteristics and multifuel capabilities in respect to the NG quality in PM.

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“…Moreover, the use of the biogas in lean combustion systems can also reduce NOx, unfortunately; its flame is weak and unstable, for that reason hydrogen is used to give more reactivity and to stabilize the flame. Many studies handled the case of hydrogen doped mixtures of biogas-air under several conditions Mameri et al (2016).…”

Section: Introductionmentioning

confidence: 99%

Effect of Replacement of Air N2 by H2O on Internal Structure and Pollutants Formation in an Opposed jet Diffusion Combustion of a Hydrogenated Biogas in Flameless Regime

2019

JAFM

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Nowadays, combustion intervenes in more than 80% of primary energy consumption, the control of the combustion process is essential. Fuel consumption, emissions reduction and energetic efficiency increasing are challenges to which researchers are faced. The most interesting invention that meets nearly all these prerequisites is the flameless combustion regime. This regime is based on the dilution and preheating of reactants by recirculated exhaust gases. This regime is well adapted for the low calorific fuels such as biofuels. In this context, this work presents a contribution to flameless combustion which differs from the conventional one by its low emissions and high efficiency. This numerical study considers the effects of air contained nitrogen substitution by water vapor, the oxygen volume concentration in the oxidizer stream and hydrogen doping of the fuel. To simplify analysis, the opposed jet configuration is adopted with a full diffusive transport approach. The MILD combustion is described by the well-known Gri 3.0 mechanism. It has been noticed that oxygen reduction within a range of 4% to 6%, which is a characteristic of flameless combustion, reduces significantly temperature and emissions whereas hydrogen addition to the fuel, which increases temperature and emissions, has a lower impact. Dilution by water vapor reduces temperature and emissions by thermal and chemical effects except OH radical.

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Numerical investigation of counter-flow diffusion flame of biogas–hydrogen blends: Effects of biogas composition, hydrogen enrichment and scalar dissipation rate on flame structure and emissions

Cited by 51 publications

References 40 publications

Numerical analysis of biogas combustion in a lean premixed swirl burner

Numerical analysis of biogas combustion in a lean premixed swirl burner

Reacting Flow Characteristics and Multifuel Capabilities of a Multi-Nozzle Dry Low NOx Combustor: A Numerical Analysis

Effect of Replacement of Air N2 by H2O on Internal Structure and Pollutants Formation in an Opposed jet Diffusion Combustion of a Hydrogenated Biogas in Flameless Regime

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