scholarly journals Effects of CO2, H2O and N2 Dilutions on Emission Characteristics and Partially Premixed Combustion of Shale Gas

2019 ◽  
Vol 8 (6) ◽  
pp. 4440-4446
Keyword(s):  
Shale Gas ◽  
Energy Production ◽  
Turbulent Flame ◽  
Emission Characteristics ◽  
Partially Premixed Combustion ◽  
Mass Fractions ◽  
Pressure Increment ◽  
Partially Premixed ◽  
Dilution Effects ◽  
Gas Fields

Environmental constraints of countries on hazardous emissions promote the usage of gas fuels in combustion systems for energy production. The shale gas recently shines out as one of the promising gas fuels of the future owing to its wide reserves discovered in the different gas fields of countries. This study numerically focuses on the emission characteristics and turbulent adiabatic combustion of partially premixed shale gas and humid air with dilution effects of CO2, H2O, and N2 under different pressures. Ansys codes are used for the numerical computations of computational fluid dynamics on 2D model of a co-axial type combustor to find out the emissions and flame speeds during the combustion of shale gas and air. Based on the results, the maximum NO mass fractions are obtained at 1.42, 1.44, and 1.4 equivalence ratios for Barnette, New Albany, and Haynesville. The increasing equivalence ratio raises the mass fractions of CO and turbulent flame speeds. The rising CO2 dilution into the additional air diminish the flame speeds, NO and CO fractions. The growing H2O addition decreases NO and CO mass fractions. On the contrary, it augments the flame speeds. The enhancing N2 dope decreases NO and rears CO mass fractions. The rising pressure with 15% CO2 dilution fades up the turbulent flame speeds, NO and CO fractions. The pressure increment with 15% H2O dope reduces CO and the flame speeds. But, it lightly relieves NO fractions. The growing pressure with 15% N2 addition abates the mass fractions of CO and turbulent flame speeds.

scholarly journals Identification of Flame Regimes in Partially Premixed Combustion from a Quasi-DNS Dataset

2020 ◽  
Author(s):  
Thorsten Zirwes ◽  
Feichi Zhang ◽  
Peter Habisreuther ◽  
Maximilian Hansinger ◽  
Henning Bockhorn ◽  
...  
Keyword(s):  
Turbulent Flame ◽  
Detailed Chemistry ◽  
Partially Premixed Combustion ◽  
Processing Step ◽  
Different Types ◽  
Partially Premixed ◽  
Definition Of ◽  
And Diffusion ◽  
Combustion Regimes ◽  
Term Analysis

Abstract Identifying combustion regimes in terms of premixed and non-premixed characteristics is an important task for understanding combustion phenomena and the structure of flames. A quasi-DNS database of the compositionally inhomogeneous partially premixed Sydney/Sandia flame in configuration FJ-5GP-Lr75-57 is used to directly compare different types of flame regime markers from literature. In the simulation of the flame, detailed chemistry and diffusion models are utilized and no turbulence and combustion models are used as the flame front and flow are fully resolved near the nozzle. This allows evaluating the regime markers as a post-processing step without modeling assumptions and directly comparing regime markers based on gradient alignment, drift term analysis and gradient free regime identification. The goal is not to find the correct regime marker, which might be impossible due to the different set of assumptions of every marker and the generally vague definition of the partially premixed regime itself, but to compare their behavior when applied to a resolved turbulent flame with partially premixed characteristics.

Dilution Effects on Partially-Premixed Combustion of an Ultra-Low Sulphur Diesel Fuel Under Low-Load Operation

2012 ◽  
Author(s):  
Cosmin E. Dumitrescu ◽  
W. Stuart Neill ◽  
Hongsheng Guo ◽  
Wallace L. Chippior
Keyword(s):  
Oxygen Concentration ◽  
Diesel Fuel ◽  
Fuel Injection ◽  
Premixed Combustion ◽  
Start Of Injection ◽  
Partially Premixed Combustion ◽  
Partially Premixed ◽  
Heavy Duty Diesel ◽  
Hc Emissions ◽  
Dilution Effects

Dilution of partially-premixed combustion (PPC) using different combinations of excess air (λ>1) and exhaust gas recirculation (EGR) was investigated in a single-cylinder, heavy-duty diesel engine equipped with common-rail fuel injection. The experiments were limited to a single fuel injection event using ultra-low sulphur diesel fuel at a low engine load (∼3 bar BMEP) and engine speeds of 900 and 1350 rpm. The start of injection was varied to optimize the combustion performance and emissions. The experimental results show that increasing air dilution at constant EGR reduced BSFC slightly. CO and HC emissions decreased significantly due to the increased oxygen concentration, but NOx and soot emissions increased. For a given level of charge dilution, there was an optimal EGR rate to minimize BSFC. NOx emissions decreased significantly as the proportion of dilution by EGR was increased, but CO and HC emissions increased due to the reduced in-cylinder temperature and oxygen concentration, which increased the combustion duration.

scholarly journals A Numerical Investigation on Emissions of Partially Premixed Shale Gas Combustion

2020 ◽  
Vol 38 (3) ◽  
pp. 745-751
Author(s):  
Suat Ozturk
Keyword(s):  
Shale Gas ◽  
Inlet Temperature ◽  
Ansys Software ◽  
Humidity Ratio ◽  
Gas Combustion ◽  
Flow Rates ◽  
Swirl Velocity ◽  
Mass Fractions ◽  
Partially Premixed ◽  
No Emissions

The adiabatic, turbulent, and partially premixed combustions of several shale gases and air in a co-axial type combustor are computationally examined under the effects of different equivalence ratios, inlet temperatures, flow rates, humidity ratios, pressure, oxid inlet temperatures and flow rates, and swirl velocities in this study. Shale gases are extracted from Barnette, New Albany, Fayetteville, and Haynesville areas of USA. ANSYS software is used for numerical calculations of combustion. Results show that the maximum NO emissions for Barnette, New Albany, Fayetteville, and Haynesville shale gas occur at the equivalence ratio of 1.42, 1.41, 1.4, and 1.39. The rising fuel inlet temperature increase NO and reduces CO emissions after 300 K. The increasing humidity ratio causes NO and CO mass fractions to decrease. The ascending pressure raises NO up to 4 bar and lowers CO emissions. The increasing oxid flow rate abates the mass fractions of both NO and CO. The rising swirl velocity escalates NO up to 15 m/s and decreases CO emissions for all the shale gas combustions.

Effects of porous media on partially premixed combustion and heat transfer in meso-scale burners fuelled with ethanol

Energy ◽  
2021 ◽  
pp. 120191
Author(s):  
Xinjian Chen ◽  
Junwei Li ◽  
Dan Zhao ◽  
Muhammad Tahir Rashid ◽  
Xinyuan Zhou ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Premixed Combustion ◽  
Partially Premixed Combustion ◽  
Partially Premixed ◽  
Meso Scale
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