Impacts of the Heating Value and CO/H2 Ratio on Syngas Diffusion Flame Structure

Syngas with CO/H2/N2 as the primary ingredients is the main fuel for the gas turbine in the IGCC system, but changes of the heating value and CO/H2 ratio frequently cause great impacts on the normal operation of the combustor, which is a challenge to the design of the syngas combustor. In this paper based on the Sandia/ETH-Zurich CO/H2/N2. Flame A, numerical simulations and predictions of the impacts of these two factors on the flame structure and diffusion combustion characteristics are carried out, and the main results are as follows. The heating value and CO/H2 ratio both have important impacts on the diffusion combustion characteristics. Most of the impacts have regularity such as changes of the axis velocity and temperature distribution, the highest temperature of the whole temperature field, the combustion efficiency and the NO formation with the heating value and CO/H2 ratio. However, the most important one is that the relationship between the flame size and the Wobbe Index is linear, for it has established connections between the structure size of the combustor and the characteristics of the fuel and the linear relationship can be used to provide reference for the combustor design. So the Wobbe Index is not only an important parameter to judge whether different fuels can be exchanged or not under the same initial pressure and heat load of a combustion equipment, but also an important parameter for syngas combustor design.

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Combustion Characteristics of a Can Combustor With a Rotating Casing for an Innovative Micro Gas Turbine

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.3043807 ◽

2009 ◽

Vol 131 (4) ◽

Cited By ~ 5

Author(s):

Hsin-Yi Shih ◽

Chi-Rong Liu

Keyword(s):

Gas Turbine ◽

Flame Structure ◽

Three Dimensional ◽

Combustion Efficiency ◽

Swirling Flows ◽

Combustion Characteristics ◽

Maximum Speed ◽

Flow Angle ◽

Rotating Speed ◽

Micro Gas Turbine

A can type combustor with a rotating casing for an innovative micro gas turbine has been modeled, and the combustion characteristics were investigated. The simulations were performed using commercial code STAR-CD, in which a three-dimensional compressible k-ε turbulent flow model and a one-step overall chemical reaction between methane/air were used. The results include the detailed flame structure at different rotation speeds of outside casing, ranging from stationary to the maximum speed of 58,000 rpm of the design point. The airflows are baffled when entering the combustor through the linear holes due to the centrifugal force caused by the rotating casing, and the inlet flow angle is inclined. When the rotation is in the opposite direction of the swirling flows driven by the designed swirler, a shorter but broader recirculation zone and a concave shape flame are found at a higher rotating speed. At maximum rotating speed, the swirling flows are dominated by the rotating flows caused by the casing, especially downstream of the combustor. The combustor performance was also analyzed, indicating a higher combustion efficiency and higher exit temperature when the casing rotates, which benefits the performance of the gas turbine, but the cooling and possible hot spots for turbines are the primary concerns.

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Effects of Bio-Syngas Blends on Combustion Characteristics of Coal: Kinetic Analysis

Journal of Biobased Materials and Bioenergy ◽

10.1166/jbmb.2021.2053 ◽

2021 ◽

Vol 15 (3) ◽

pp. 269-277

Author(s):

Ailing He ◽

Zaifeng Li ◽

Jingping Li ◽

Xin Wang ◽

Liya Zhang ◽

...

Keyword(s):

Coal Combustion ◽

Combustion Process ◽

Combustion Efficiency ◽

Combustion Characteristics ◽

Combustion Mechanism ◽

Exponential Factor ◽

Maximum Reaction Rate ◽

Heating Value ◽

Renewable Biomass ◽

Reasonable Description

The coupled combustion of biomass and coal can utilize large amounts of renewable biomass and reduce the emission of pollutants during power generation. In this study, the coal combustion characteristics were analyzed at different heating value-based biomass blending ratios and temperatures in the coupled combustion of bio-syngas and coal. The kinetic reaction mechanism of coal combustion was investigated by Micro-fluidized Bed Reaction Analyzer (MFBRA). The results indicated that the reaction time decreased with increasing the heating value-based biomass blending ratio and temperature in the coupled combustion process of bio-syngas and coal. The major conversion process of coal combustion usually took 15 s at 1273 K and the maximum reaction rate was usually below 0.14 at 873 K to 1273 K and decreased with increasing reaction temperature. The nucleation and growth model offered a most reasonable description of the coal combustion process. The activation energy was about 121.04 kJ/mol and the pre-exponential factor was of the order of 5.01 × 104 s−1 in the combustion of coal. These data are important to the understanding of the coupled combustion mechanism of bio-syngas and coal, which is beneficial for improving combustion efficiency as well as operating a combustion furnace.

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Combustion Characteristics of a Can Combustor With a Rotating Casing for an Innovative Micro Gas Turbine

Volume 3: Combustion, Fuels and Emissions, Parts A and B ◽

10.1115/gt2008-50116 ◽

2008 ◽

Author(s):

Hsin-Yi Shih ◽

Chih-Zong Liu

Keyword(s):

Gas Turbine ◽

Flame Structure ◽

Three Dimensional ◽

Combustion Efficiency ◽

Swirling Flows ◽

Combustion Characteristics ◽

Maximum Speed ◽

Flow Angle ◽

Rotating Speed ◽

Micro Gas Turbine

A can type combustor with rotating casing for the innovative micro gas turbine has been modeled, and the combustion characteristics were investigated. The simulations were performed using commercial code STAR-CD, in which three-dimensional compressible k-ε turbulent flow model and one-step overall chemical reaction between methane/air were used. The results include the detailed flame structure at different rotation speed of outside casing, ranging from stationary to the maximum speed of 58000 rpm of the design point. The airflows are baffled when entering the combustor through the linear holes due to the centrifugal force caused by the rotating casing and the inlet flow angle is inclined. When the rotation is in the opposite direction of the swirling flows driven by the designed swirler, a shorter but broader recirculation zone and a concave shape flame are found at higher rotating speed. At maximum rotating speed, the swirling flows are dominated by the rotating flows caused by the casing, especially downstream of the combustor. The combustor performance were also analyzed, indicating higher combustion efficiency and higher exit temperature when casing rotates, which benefits the performance of gas turbine, but the cooling and possible hot spots for turbines are the primary concerns.

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Modeling and Experiment on Combustion Characteristics for Biomass Rotary Burner

Current Alternative Energy ◽

10.2174/2405463104666200120113721 ◽

2020 ◽

Vol 04 ◽

Author(s):

Guohai Jia ◽

Lijun Li ◽

Li Dai ◽

Zicheng Gao ◽

Jiping Li

Keyword(s):

Combustion Chamber ◽

Combustion Temperature ◽

Combustion Efficiency ◽

Middle Part ◽

Combustion Characteristics ◽

Maximum Temperature ◽

Excess Air ◽

Element Simulation ◽

Excess Air Coefficient ◽

Secondary Air

Background: A biomass pellet rotary burner was chosen as the research object in order to study the influence of excess air coefficient on the combustion efficiency. The finite element simulation model of biomass rotary burner was established. Methods: The computational fluid dynamics software was applied to simulate the combustion characteristics of biomass rotary burner in steady condition and the effects of excess air ratio on pressure field, velocity field and temperature field was analyzed. Results: The results show that the flow velocity inside the burner gradually increases with the increase of inlet velocity and the maximum combustion temperature is also appeared in the middle part of the combustion chamber. Conclusion: When the excess air coefficient is 1.0 with the secondary air outlet velocity of 4.16 m/s, the maximum temperature of the rotary combustion chamber is 2730K with the secondary air outlet velocity of 6.66 m/s. When the excess air ratio is 1.6, the maximum temperature of the rotary combustion chamber is 2410K. When the air ratio is 2.4, the maximum temperature of the rotary combustion chamber is 2340K with the secondary air outlet velocity of 9.99 m/s. The best excess air coefficient is 1.0. The experimental value of combustion temperature of biomass rotary burner is in good agreement with the simulation results.

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Combustion Characteristics of Small Size Gas Turbine Combustor Fueled by Biomass Gas Employing Flameless Combustion

Volume 2: Turbo Expo 2007 ◽

10.1115/gt2007-27636 ◽

2007 ◽

Cited By ~ 3

Author(s):

Masato Hiramatsu ◽

Yoshifumi Nakashima ◽

Sadamasa Adachi ◽

Yudai Yamasaki ◽

Shigehiko Kaneko

Keyword(s):

Gas Turbine ◽

Combustion Efficiency ◽

Combustion Characteristics ◽

Operating Conditions ◽

Nox Emissions ◽

Gas Turbine Combustor ◽

Flameless Combustion ◽

Engine Exhaust ◽

Micro Gas Turbine

One approach to achieving 99% combustion efficiency (C.E.) and 10 ppmV or lower NOx (at 15%O2) in a micro gas turbine (MGT) combustor fueled by biomass gas at a variety of operating conditions is with the use of flameless combustion (FLC). This paper compares experimentally obtained results and CHEMKIN analysis conducted for the developed combustor. As a result, increase the number of stage of FLC combustion enlarges the MGT operation range with low-NOx emissions and high-C.E. The composition of fuel has a small effect on the characteristics of ignition in FLC. In addition, NOx in the engine exhaust is reduced by higher levels of CO2 in the fuel.

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Biodiesel Effects on Influencing Parameters of Brake Fuel Conversion Efficiency in a Medium Duty Diesel Engine

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4001086 ◽

2010 ◽

Vol 132 (12) ◽

Cited By ~ 6

Author(s):

Joshua A. Bittle ◽

Jesse K. Younger ◽

Timothy J. Jacobs

Keyword(s):

Conversion Efficiency ◽

Energy Content ◽

Combustion Efficiency ◽

Operating Conditions ◽

Biodiesel Fuel ◽

Mass Energy ◽

Fuel Conversion ◽

Heating Value ◽

Lower Heating Value ◽

Lower Heating

Biodiesel remains an alternative fuel of interest for use in diesel engines. A common characteristic of biodiesel, relative to petroleum diesel, is a lowered heating value (or per mass energy content of the fuel). For same torque engine comparisons, the lower heating value translates into a higher brake specific fuel consumption (amount of fuel consumed per unit of power produced). The efficiency at which fuel energy converts into work energy, however, may remain unchanged. In this experimental study, evaluating nine unique engine operating conditions, the brake fuel conversion efficiency (an assessor of fuel energy to work energy efficiency) remains unchanged between 100% petroleum diesel fuel and 100% biodiesel fuel (palm olein) at all conditions, except for high load conditions. Several parameters may affect the brake fuel conversion efficiency, including heat loss, mixture properties, pumping work, friction, combustion efficiency, and combustion timing. This article describes a study that evaluates how the aforementioned parameters may change with the use of biodiesel and petroleum diesel, and how these parameters may result in differences in the brake fuel conversion efficiency.

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Detailed Study of Front Module for Low-Emission Combustor

Volume 4A: Combustion, Fuels, and Emissions ◽

10.1115/gt2020-14820 ◽

2020 ◽

Author(s):

A. Vasilyev ◽

V. Zakharov ◽

O. Chelebyan ◽

O. Zubkova

Keyword(s):

Experimental Data ◽

Numerical Study ◽

Flame Structure ◽

Combustion Efficiency ◽

Liquid Fuels ◽

Pollutant Emission ◽

Additional Information ◽

Low Emission ◽

Wide Range ◽

To Receive

Abstract At the ASME Turbo Expo 2018 conference held in Oslo (Norway) on the 11th-15th of June 2018, the paper GT2018-75419 «Experience of Low-Emission Combustion of Aviation and Bio Fuels in Individual Flames after Front Mini-Modules of a Combustion Chamber» was published. This paper continues the studies devoted to the low-emission combustion of liquid fuels in GTE combustors. The paper presents a description of more detailed studies of the front module with a staged pneumatic fuel spray. The aerodynamic computations of the front module were conducted, and the disperse characteristics of the fuel-air spray were measured. The experimental research was carried out in two directions: 1) probing of the 3-burner sector flame tube at the distance of one third of its length (temperature field and gas sampling); 2) numerical study of the model combustor with actual arrangement of the modules in the dome within a wide range of fuel-air ratio. The calculated and experimental data of velocity field behind the front module were compared. And new data about the flame structure inside the test sector were obtained. Experimental data confirm the results of preliminary studies of the 3-burner sector: combustion efficiency is higher than 99.8%, EiNOx is at the level of 2–3 g/fuel kg at the combustor inlet air temperature of 680K and fuel-air ratio of 0.0225. The conducted research allowed to receive additional information on the influence of some design units on the pollutant emission and to estimate the different elements of computational methods for simulation of a low-emission combustor with a multi-atomizer dome.

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Co-combustion Characteristics and Kinetics Behavior of Torrefied Sugarcane Bagasse and Lignite

International Journal of Renewable Energy Development ◽

10.14710/ijred.2021.37249 ◽

2021 ◽

Vol 10 (4) ◽

pp. 737-746

Author(s):

Ukrit Samaksaman ◽

Kanit Manatura

Keyword(s):

Thermogravimetric Analysis ◽

Physicochemical Properties ◽

Burning Rate ◽

Sugarcane Bagasse ◽

Combustion Characteristics ◽

Firing Process ◽

Combustion System ◽

Heating Value ◽

Kinetics Of ◽

Derivative Thermogravimetry

The co-combustion characteristics and kinetics of torrefied sugarcane bagasse (TB), lignite (L), and their blended samples were experimentally investigated using thermogravimetric analysis (TGA) and derivative thermogravimetry (DTG)based on the Coats-Redfern method for kinetic estimation.Their physicochemical properties were also investigated.Raw bagasse was thermally treated in a laboratory-scale torrefactor at 275 °C with a torrefaction time of 60 min under an inert nitrogen environment.Then, the torrefied bagasse was blended with Thai lignite as a co-fuel at ratios of 50:50 (TB50L50), 70;30(TB70L30), and 90:10 (TB90L10), respectively. Torrefaction improved the fuel properties and heating value of the raw bagasse as well as reducing the O/C and H/C ratios.In addition, the blending of torrefied bagasse with lignite improved the combustion behavior.The TGA and DTG results indicated that the ignition and burnout temperatures stepped downwards with different increasing ratios of torrefied bagasse.The co-combustion behavior at the maximum burning rate showed that the burnout temperatures of TB50L50, TB70L30, and TB90L10 were 532, 529, and 528 °C, respectively, indicating a slight decrease with an increasing torrefied bagasse blending ratio.These results were sufficient to provide comprehensive guidelines in terms of the design and operation of the combustion system for adding torrefied bagasse into the co-firing process.

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