The Effect of Fuel Types and Admission Method Upon Combustion Efficiency

1959 ◽  
Vol 81 (4) ◽  
pp. 423-426
Author(s):  
H. N. McManus ◽  
W. E. Ibele ◽  
T. E. Murphy
Keyword(s):  
Combustion Chamber ◽  
Air Flow ◽  
Flow Patterns ◽  
Combustion Efficiency ◽  
Spray Nozzle ◽  
Optimum Size ◽  
Fuel Type ◽  
Chamber Length ◽  
Different Types ◽  
Improved Performance

A series of tests to determine the effect of combustion-chamber length for three different types of fuel admission (gaseous, spray, and vaporized) upon combustion efficiency was performed in identical combustor geometries and with similar air-flow patterns. The effects of fuel-air ratio and full-section velocity were examined for individual methods of admission. The effect of fuel volatility also was examined. It was found that the vaporized fuel type of admission was superior in efficiency to the spray-fuel admission in all comparable cases. Increased fuel volatility improved performance in the case of the vaporizer but did not affect the performance of the spray nozzle. The performance of vaporising tubes was found to vary inversely with size. An optimum size was exhibited.

Study on the Technology of Increasing Combustion Efficiency and Decreasing NOx Emission of Blending Coals

2012 ◽  
Vol 614-615 ◽  
pp. 41-44 ◽  
Author(s):  
Chun Zhi Wei ◽  
Yi Cong Wang
Keyword(s):  
Combustion Chamber ◽  
Flue Gas ◽  
Coal Combustion ◽  
Thermal Load ◽  
Load Distribution ◽  
Combustion Efficiency ◽  
Pollutant Emission ◽  
Gas Temperature ◽  
Emission Properties ◽  
Different Types

Study on the combustion behavior and pollutant emission properties of the different types and different ratio of blending coal have been done. The influence of the ratio of brown-blending coal on the combustion efficiency and NOx emission have been researched and concentrated ratio and method of pulverized coal have been get. The thermal-load distribution along the height of furnace and the control of the flue gas temperature at the exit of the combustion chamber have been discussed and the retrofit schema has been put forward. By reasonably blending coal, combustion efficiency increases and NOx emission goes down.

Experience of Low-Emission Combustion of Aviation and Bio Fuels in Individual Flames After Front Mini-Modules of a Combustion Chamber

2018 ◽  
Author(s):  
A. Vasilyev ◽  
V. Zakharov ◽  
V. Lyashenko ◽  
R. Medvedev ◽  
O. Chelebyan ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Combustion Chamber ◽  
Air Flow ◽  
Combustion Efficiency ◽  
Fuel Combustion ◽  
Flame Tube ◽  
Nitric Oxide Emission ◽  
Low Emission ◽  
Harmful Substances ◽  
Emission Index

In the world economy more and more attention is paid to the environment protection. This has brought a requirement for reduction of harmful substances emission from the gas turbine engine combustors to the foreground scene. Several concepts of low-emission combustion of liquid fuels have been suggested to solve the problem of nitric oxide emission reduction. The authors consider combustion of lean homogenized (quick-mixed) fuel-air mixtures to be the most promising concept for a multi-mode combustion chamber. Based on the accumulated experience, the authors have formed some notion with respect to design peculiarities of low-emission combustors. Based on such general notions, an attempt has been made to create a model combustion chamber for decreasing harmful substances emission. A design for compact mixing modules has been worked out, as well as for a perforated flame tube. 3D computations have been carried out for the flow in the combustor compartment with 3 mini-modules, so to compare design and experimental data. In calculations the air entered the flame tube through a channel with a rectangular cross-section and, further, through swirlers of three burners (60% of air flow). Besides, the air came into the gap between the flame tube and casing through two side channels and, further, it got inside the flame tube through cooling system holes (40% of air flow). In parallel, tests have been carried out in similar combustor compartment, using standard fuels, measuring harmful substances emission at gas temperature (T4) up to 1700 K. Data obtained testifies to essential reduction of nitric oxides in the experimental combustor being considered. Emission index NOx does not exceed value of 1 g/kg f in all the conditions investigated. Fuel efficiency is ≥ 99% for all the measurement regimes, except one, where it is 98%. Additionally, tests have been conducted, using bio fuel obtained from plant raw material. Research results have revealed problems of changeover to such type of fuel mixtures. Comparing test data with 3D simulation results, it can be noted that there, where computed value of the fuel combustion efficiency coincides with the measured one, NOx value also coincides. However, the emission index value is higher there, where the fuel combustion efficiency value obtained in computation is higher, i.e. where there are zones with higher temperature. The experimental results obtained have confirmed possibility of organizing low-emission combustion, as well as possibility of achieving the nitric oxide emission index level equal to 1 g/kg f at the combustor inlet temperature of 682K. It is evident that more detailed design study is required for transfer of the experimental technology to the working compartment of the combustion chamber. The achieved level of harmful substances emission, after improvement and implementation of technology, may allow meeting the strictest ICAO requirements and reducing the airport fees significantly.

Effects of Fuel Type on the Performance of Aero Gas Turbine Combustion Chambers, and the Influence of Design Features

1954 ◽  
Vol 58 (528) ◽  
pp. 813-825
Author(s):  
J. G. Sharp
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Combustion Efficiency ◽  
Combustion Stability ◽  
Fuel Type ◽  
Combustion Chambers ◽  
Exhaust Temperature ◽  
Design Changes ◽  
Fuel Characteristics ◽  
Gas Turbine Combustion

SummaryThe performance of aero gas turbine combustion chambers is discussed under the following headings : Combustion efficiency, combustion stability, ease of ignition, deposits, exhaust temperature variation, and smooth combustion. It is shown that, as assessed by these criteria, combustion chamber performance can be significantly affected by fuel characteristics; also that the effects of fuel type can be greatly modified by equipment design changes. The conclusion is that most of the problems- aggravated by fuel characteristics are better solved by modifications to equipment, if fuel availability and cost are not to be adversely affected.

scholarly journals ANALISIS KEBUTUHAN UDARA PEMBAKARAN UNTUK MENGOPTIMALKAN PROSES PEMBAKARAN BOILER PT. PLN (PERSERO) SEKTOR PEMBANGKITAN ASAM ASAM UNIT 3 & UNIT 4

INFO-TEKNIK ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 85
Author(s):  
Akhmad Syarief ◽  
Yudistira Bayu Setiambodo ◽  
Muhammad Nizar Ramadhan ◽  
A'yan Sabitah
Keyword(s):  
Power Plant ◽  
Combustion Chamber ◽  
Air Flow ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Efficient Operation ◽  
Actual Amount ◽  
The Right ◽  
The Ideal

The performance of a power plant unit is strongly influenced by various aspects, one of which is very determined by how the combustion process occurs in the combustion chamber, because it can affect the efficiency of the power plant itself, especially in the efficiency aspects of the boiler combustion process. To find out the efficient operation of the boiler, the operator as the holder of the power plant must understand what the combustion process is like in it. Good combustion will always require the right combination of fuel and air (oxygen). From the results of the research that has been done, it can be seen that if the actual amount of air flow needed for the combustion process is closer to the ideal air flow value it will indirectly increase the combustion efficiency value of the boiler.

Modeling and Experiment on Combustion Characteristics for Biomass Rotary Burner

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.

scholarly journals Combustion Thermodynamics of Ethanol, n-Heptane, and n-Butanol in a Rapid Compression Machine with a Dual Direct Injection (DDI) Supply System

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2729
Author(s):  
Ireneusz Pielecha ◽  
Sławomir Wierzbicki ◽  
Maciej Sidorowicz ◽  
Dariusz Pietras
Keyword(s):  
Heat Release ◽  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Direct Injection ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Injection System ◽  
Rapid Compression Machine ◽  
Process Indicators ◽  
Rapid Compression

The development of internal combustion engines involves various new solutions, one of which is the use of dual-fuel systems. The diversity of technological solutions being developed determines the efficiency of such systems, as well as the possibility of reducing the emission of carbon dioxide and exhaust components into the atmosphere. An innovative double direct injection system was used as a method for forming a mixture in the combustion chamber. The tests were carried out with the use of gasoline, ethanol, n-heptane, and n-butanol during combustion in a model test engine—the rapid compression machine (RCM). The analyzed combustion process indicators included the cylinder pressure, pressure increase rate, heat release rate, and heat release value. Optical tests of the combustion process made it possible to analyze the flame development in the observed area of the combustion chamber. The conducted research and analyses resulted in the observation that it is possible to control the excess air ratio in the direct vicinity of the spark plug just before ignition. Such possibilities occur as a result of the properties of the injected fuels, which include different amounts of air required for their stoichiometric combustion. The studies of the combustion process have shown that the combustible mixtures consisting of gasoline with another fuel are characterized by greater combustion efficiency than the mixtures composed of only a single fuel type, and that the influence of the type of fuel used is significant for the combustion process and its indicator values.

Study on flow patterns in different types of direct coal liquefaction reactors

2009 ◽  
Vol 4 (5) ◽  
pp. 563-567 ◽  
Author(s):  
Xiangkun Ren ◽  
Dingye Fang ◽  
Jialu Jin ◽  
Jinsheng Gao
Keyword(s):  
Flow Patterns ◽  
Coal Liquefaction ◽  
Different Types ◽  
Direct Coal Liquefaction

scholarly journals Contribution to the Sustainability of Agricultural Production in Greenhouses Built on Slope Soils: A Numerical Study of the Microclimatic Behavior of a Typical Colombian Structure

2021 ◽  
Vol 13 (9) ◽  
pp. 4748
Author(s):  
Edwin Villagran ◽  
Carlos Bojacá ◽  
Mohammad Akrami
Keyword(s):  
Latin American ◽  
Crop Yields ◽  
Numerical Study ◽  
Air Flow ◽  
Research Work ◽  
Flow Patterns ◽  
Soil Conditions ◽  
Air Velocity ◽  
The Hours ◽  
Microclimatic Conditions

The use of covered structures is an alternative increasingly used by farmers to increase crop yields per unit area compared to open field production. In Latin American countries such as Colombia, productive areas are located in with predominantly hillside soil conditions. In the last two decades, farmers have introduced cover structures adapted to these soil conditions, structures for which the behavior of factors that directly affect plant growth and development, such as microclimate, are still unknown. Therefore, in this research work, a CFD-3D model successfully validated with experimental data of temperature and air velocity was implemented. The numerical model was used to determine the behavior of air flow patterns and temperature distribution inside a Colombian passive greenhouse during daytime hours. The results showed that the slope of the terrain affects the behavior of the air flow patterns, generating thermal gradients inside the greenhouse with values between 1.26 and 16.93 °C for the hours evaluated. It was also found that the highest indoor temperature values at the same time were located in the highest region of the terrain. Based on the results of this study, future researches on how to optimize the microclimatic conditions of this type of sustainable productive system can be carried out.

Enhancement of Propane Flame Stability by Dielectric Barrier Discharges

2005 ◽  
Vol 8 (2) ◽  
Author(s):  
Yongho Kim ◽  
Sy M. Stange ◽  
Louis A. Rosocha ◽  
Vincent W. Ferreri
Keyword(s):  
Barrier Discharge ◽  
Air Flow ◽  
Combustion Efficiency ◽  
Combustion Stability ◽  
Dielectric Barrier Discharges ◽  
Lean Burn ◽  
Decomposition Products ◽  
Dielectric Barrier ◽  
Novel Applications ◽  
Barrier Discharges

AbstractNon-thermal plasmas have recently found novel applications in improving fuel combustion. Typical electron temperatures in such plasmas are of order a few electron volts. Such electrons are sufficient to break down fuel molecules and to produce free radicals which may significantly affect combustion efficiency. In this work, we use a dielectric barrier discharge (DBD) to activate propane (C3H8) fuel before it is mixed with air and ignited. The use of activated propane enables us to operate combustion in very lean-burn conditions; for 0.2 lpm propane, air flow was 38 lpm, compared with an air flow of 26 lpm in the absence of a plasma. A residual gas analyzer (RGA) measures the decomposition products of the propane discharge, indicating that atomic and molecular hydrogen are produced in the plasma and that their concentrations depend on the DBD energy density. Based on the observations discussed in this work, we have shown that by activating propane, the DBD increases combustion stability.

On Numerical Simulation of Fuel Mixed With Steam or Air to Investigate Soot and Other Emissions

2015 ◽  
Author(s):  
Ajit Patki ◽  
Xianchang Li ◽  
Daniel Chen ◽  
Helen Lou ◽  
Vijaya Damodara
Keyword(s):  
Combustion Efficiency ◽  
Combustion Mechanism ◽  
Fuel Type ◽  
Ansys Fluent ◽  
Pm 2.5 ◽  
Combustion Gases ◽  
Numerical Studies ◽  
Baseline Case ◽  
Substantial Risk ◽  
Pdf Model

Soot emissions (PM 2.5) as well as CO and NOx from industrial flares and other industrial processes or sources pose a substantial risk to human being health and the environment, and now are subject to new and tougher EPA regulations. Flaring is used widely used in many industries to dispose unwanted combustion gases by burning them as a flame. However, flaring produces significant amount of particulate matter in the form of soot, along with other harmful gas emissions. Although many experimental and numerical studies have previously been done on flames burning in a controlled condition, relatively few studies have been conducted with fuel-steam mixture. In practice, air and steam are commonly used to assist the flaring processes — control the smoke and the combustion efficiency. This study aims to investigate soot, CO and NOx emissions of turbulent diffusion methane and propane flame mixed with air or superheated steam. To study such effect numerically, the computational fluid dynamics software ANSYS Fluent 14.5 is used with non-premixed probability density function (PDF) model. The laminar flamelet is generated with automated grid refinement. For the soot generation, the Moss-Brookes soot model with Lee sub-model is considered. The combustion mechanism is developed by the authors’ research group from the combined GRI and USC mechanisms. Two types of fuel, methane and propane, are used. The amount of super-heated steam varied from four percent to twenty percent (4%, 8 %, 12%, 16%, and 20%), and the behavior of the flame is analyzed. For the baseline case, the jet has a diameter of 50.8 mm or 2 inches, and the jet velocity is kept to 1.0 m/s. A co-flow air is supplied at a velocity of 0.2 m/s. The temperature distribution of methane and propane are compared with different contents of steam or air assists. The NOx, Soot and CO yields (kg/kg) varying with steam or air percentages are also presented. The results indicate that the soot yield is dependent on fuel type strongly and the percentage of steam or air affects the soot yield differently as the fuel type varies.

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