Emission prediction in conceptual design of the aircraft engines using augmented CRN

Saboohi, Zoheir; Ommi, Fathollah

doi:10.1017/aer.2017.40

Cited by 10 publications

(6 citation statements)

References 34 publications

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“…They conducted an experimental study in a gas turbine combustor and applied OH PLIF and POD to determine reasons for the frequency mode shift phenomenon (11) . Moreover, many researchers have studied the characteristics of combustion using experimental (12)(13)(14)(15)(16)(17)(18)(19)(20) , analytic (21,22) and computational (23)(24)(25) approaches.…”

Section: Past Research On H 2 /Ch 4 Combustion In Gas Turbinementioning

confidence: 99%

High-frequency transition characteristics of synthetic natural gas combustion in gas turbine

et al. 2019

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In this study, the combustion instability and emission characteristics of flames of different H2/CH4 compositions were investigated in a partially premixed model gas turbine combustor. A mode shift in the frequency of instability occurred under varying experimental conditions from the first to the seventh mode of longitudinal frequency in the combustor, and a parametric study was conducted to determine the reasons for this shift by using the length of the combustor, a factor that determines the mode frequency of longitudinal instability, as the main parameter. Furthermore, heat load and fuel composition (H2 ratio) were considered as parameters to compare the phenomenon under different conditions. The GRI-3.0 CANTERA code, OH chemiluminescence and the Abel inversion process were applied to analyse the frequency mode shift. NOx emissions, which occurred through the thermal NOx mechanism, increased with increasing heat load and H2 ratio. The instability frequency shifted from the first to the seventh mode as the H2 ratio increased in the H2/CH4 mixture. However, 100% H2 as fuel did not cause combustion instability because it has a higher burning velocity and extinction stretch rate than CH4. Furthermore, the laminar flame speed influenced the frequency mode shift. These phenomena were confirmed by the flame shapes. The Abel inversion process was applied to obtain the cross section of the flames from averaged OH chemiluminescence images. Stable and unstable flames were identified from the radial profile of OH concentration. The combustor length was found to not influence frequency mode shift, whereas the H2 ratio significantly influenced it as well as the flame shape. The results of this experimental study can help in the reliable operation of gas turbine systems in SNG plants.

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Section: Past Research On H 2 /Ch 4 Combustion In Gas Turbinementioning

confidence: 99%

High-frequency transition characteristics of synthetic natural gas combustion in gas turbine

et al. 2019

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“…_ m fuel is fuel flow rate, LHV fuel is fuel lower heating value, and Y is mass fraction. Note that in equation (24) we ignore the heat loss from the combustor and only take into account the heat absorbed by the flow (i.e. combustor is assumed adiabatic).…”

Section: Ammonia Addition Effectsmentioning

confidence: 99%

“…This method showed acceptable reliability and was used in later studies. 13,22,24–26 Xu et al 13 used this assumption to predict and validate NO x emission of a lean prevaporized premixed combustor. Saboohi and Ommi 24 predicted the CO and NO x emission of an annular combustor in different power settings using this assumption and showed relatively good agreement with the experimental results.…”

Section: Introductionmentioning

confidence: 99%

“…However, some studies have also been carried out without any auxiliary CFD simulations and solely dependent on the CRN simulations and showed acceptable results. 13,14,18,19,22–24 However, having an understanding of the flow field is vital for choosing appropriate reactors and their valid connections. Rizk et al 23 proposed an assumption regarding modeling air-fuel mixing in the primary zone of the combustor.…”

Section: Introductionmentioning

confidence: 99%

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Emission and performance of a micro gas turbine combustor fueled with ammonia-natural gas

Nozari

EidiAttarZade

Tabejamaat

et al. 2021

International Journal of Engine Research

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Ammonia as a carbon-free fuel has great potentiality to be utilized in power generation sectors such as micro gas turbines (MGT) to mitigate carbon dioxide emission from combustion systems. It is also easy to store and transport at room temperature compared to hydrogen, and in liquid form has equal volumetric energy density to liquid hydrogen. However, some challenges regarding its NOx pollution and flame stabilization inhibit its usage in these areas which requires further studies. In the present study, thermal performance and NOx emission of an MGT combustor fueled with ammonia-natural gas blends has been analyzed numerically through chemical reactant networks (CRN). The combustor’s inlet conditions are at atmospheric conditions and diffusion flame is stabilized using air swirler. In the first part of the paper, the CRN model has been developed based on empirical and semi-empirical equations. Series of experiments have been carried out to find the required parameters for the CRN model. Also, the results of NOx emission and temperature distribution have been validated with the experimental results. In the second part, effects of ammonia addition to the natural gas fuel are studied for various ammonia percentages using the CRN. The results show that by increasing ammonia molar percentage in the fuel, NO emission rises dramatically and reaches up to 330 PPM, but after a certain threshold (about 12.5 molar percent of ammonia) further ammonia addition reduces NO emission. Moreover, the overall temperature of the combustor decreases with ammonia addition due to lower LHV (lower heating value) of ammonia relative to natural gas. However, the overall efficiency of the combustor does not change significantly. The results also reveal that most of the NO is produced in the primary and secondary zones of the combustor. NO2 is mostly created in the secondary zone of the combustor and comprises about 10% of total NOx emission.

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“…They concluded that the NOx emission index strongly depended on the used mechanism. Saboohi and Ommi (2017) compared the three mechanisms of Ranzi et al (2012), GRI-Mech.3.0 and Kollrack (Mattingly, 2002) based on temperature variations and NO and CO molar ratios in a PSR. They specified that the mechanism of Ranzi offered the best results, but due to the increase in the number of species and chemical reaction steps, the computation costs increased significantly.…”

Section: Kinetics In Chemical Reactor Networkmentioning

confidence: 99%

A review on the applications of the chemical reactor network approach on the prediction of pollutant emissions

Khodayari

Ommi

Saboohi

2020

AEAT

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Purpose The purpose of this paper is to review the applications of the chemical reactor network (CRN) approach for modeling the combustion in gas turbine combustors and classify the CRN construction methods that have been frequently used by researchers. Design/methodology/approach This paper initiates with introducing the CRN approach as a practical tool for precisely predicting the species concentrations in the combustion process with lower computational costs. The structure of the CRN and its elements as the ideal reactors are reviewed in recent studies. Flow field modeling has been identified as the most important input for constructing the CRNs; thus, the flow field modeling methods have been extensively reviewed in previous studies. Network approach, component modeling approach and computational fluid dynamics (CFD), as the main flow field modeling methods, are investigated with a focus on the CRN applications. Then, the CRN construction approaches are reviewed and categorized based on extracting the flow field required data. Finally, the most used kinetics and CRN solvers are reviewed and reported in this paper. Findings It is concluded that the CRN approach can be a useful tool in the entire process of combustion chamber design. One-dimensional and quasi-dimensional methods of flow field modeling are used in the construction of the simple CRNs without detailed geometry data. This approach requires fewer requirements and is used in the initial combustor designing process. In recent years, using the CFD approach in the construction of CRNs has been increased. The flow field results of the CFD codes processed to create the homogeneous regions based on construction criteria. Over the past years, several practical algorithms have been proposed to automatically extract reactor networks from CFD results. These algorithms have been developed to identify homogeneous regions with a high resolution based on the splitting criteria. Originality/value This paper reviews the various flow modeling methods used in the construction of the CRNs, along with an overview of the studies carried out in this field. Also, the usual approaches for creating a CRN and the most significant achievements in this field are addressed in detail.

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Emission prediction in conceptual design of the aircraft engines using augmented CRN

Cited by 10 publications

References 34 publications

High-frequency transition characteristics of synthetic natural gas combustion in gas turbine

High-frequency transition characteristics of synthetic natural gas combustion in gas turbine

Emission and performance of a micro gas turbine combustor fueled with ammonia-natural gas

A review on the applications of the chemical reactor network approach on the prediction of pollutant emissions

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