Combustion Analysis of Biomass Based Slurry Fuels in Oil Fired Furnace Using CFD-Tool

Solar Energy ◽  
2005 ◽  
Author(s):  
S. V. Prakash ◽  
S. R. Shankapal
Keyword(s):  
Constant Velocity ◽  
Research Work ◽  
Combustion Efficiency ◽  
Initial Position ◽  
Premixed Combustion ◽  
Combustion Model ◽  
Combustion Analysis ◽  
Swirl Burner ◽  
Post Process ◽  
Inlet Angle

An existing oil fired furnace was modeled to obtain the maximum swirling of biomass based slurry fuel and air to achieve better combustion of the biomass fuel present in the slurry. For analysis a computational model of the furnace was constructed with a swirl burner placed at the bottom of the furnace using commercially available CFD preprocessing software (GAMBIT). The boundary conditions were set so as to allow biomass slurry and air with different swirl angles with respect to horizontal and vertical planes, with constant velocities of the mixtures. This research work focuses on the effect of different inlet angles of the fuel supply at constant velocity into the furnace for maximum combustion efficiency. Using Fluent, the post process results shows the increase in residence time by 40% with inlet angle of 45 deg with respect to the x and z-axis, 75 deg from positive y-axis and top partially opened, compared to the initial position of the swirl burner placed directly at zero deg. Using non-premixed combustion model the combustion efficiency of the fuel was increased.

scholarly journals Modelling of Combustion Characteristics of a Single Curved-Cylinder Spark-Ignition Crank-Rocker Engine

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3313
Author(s):  
Salah E. Mohammed ◽  
M. B. Baharom ◽  
A. Rashid A. Aziz ◽  
Ezrann Z. Zainal A.
Keyword(s):  
Research Work ◽  
Experimental Tests ◽  
Spark Ignition ◽  
Combustion Efficiency ◽  
Combustion Characteristics ◽  
Operating Conditions ◽  
Combustion Characteristic ◽  
Combustion Model ◽  
Fuel Burn ◽  
Spark Timing

A crank-rocker engine is a new invention used to convert oscillating motion from the curve-piston into the rotary motion of the crankshaft. The configuration of this new engine is different from the normal slider-crank engine, so the existing model used to calculate the combustion characteristic is not appropriate for this new engine. A fundamental thermodynamic model of a single curved-cylinder spark-ignition crank-rocker engine is presented. The model was simulated in MATLAB to predict the combustion characteristics at different operating conditions. The friction losses, residual gas fraction and combustion efficiency were introduced into the combustion model to improve the overall accuracy of the model. The developed model was used to analyze and evaluate the in-cylinder pressure, fuel burn rate, and heat release under various crank angle positions. To validate the predictions of the model, experimental tests were conducted on a single-cylinder crank-rocker engine at an engine speed of 2000 rpm, spark timing of 8.60 CA BTDC, full load and wide-open throttle (WOT) condition. Finally, the results were plotted and compared with the simulation results. The findings obtained from the current study have shown the ability of the simulation model to predict the combustion characteristics under different operating conditions. The agreement between the results of the present model and experimental data was reasonably good. This research work proposes a new model which can predict the behavior of the crank-rocker engine. The information gained from this study will aid in the tuning process and future development of this engine.

scholarly journals Numerical Investigation of Turbulent Premixed Combustion of Methane / Air in Low Swirl Burner under Elevated Pressures and Temperatures

2021 ◽  
Vol 39 (1) ◽  
pp. 155-160
Author(s):  
Akram Ben Ali ◽  
Mansour Karkoub ◽  
Mouldi Chrigui
Keyword(s):  
Flame Structure ◽  
Elevated Pressure ◽  
Operating Conditions ◽  
Premixed Combustion ◽  
Combustion Model ◽  
Swirl Burner ◽  
Combustion Modeling ◽  
Eddy Simulation ◽  
Elevated Pressures ◽  
First Case

Turbulent combustion modeling of lean premixed methane/air gas mixture in a low swirl burner is carried out using Large Eddy Simulation (LES). The operating conditions of the experiment as well as simulation are carried out at elevated pressure and temperature. The first case-simulation is a premixed combustion model based on C-equation formulation, the second one is based on species transport – Eddy Dissipation Concept (EDC) model. Numerical results for axial velocity and turbulence intensity along the centerline showed a good agreement against the experimental data. Quantitative results of OH mass fraction contour showing the flame structure are in a plausible agreement compared to the experimental measurement.

scholarly journals Combustion Optimization for Coal Fired Power Plant Boilers Based on Improved Distributed ELM and Distributed PSO

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1036 ◽  
Author(s):  
Xinying Xu ◽  
Qi Chen ◽  
Mifeng Ren ◽  
Lan Cheng ◽  
Jun Xie
Keyword(s):  
Power Plant ◽  
Combustion Process ◽  
Optimization Method ◽  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Combustion Model ◽  
Nox Emissions ◽  
Coupling Characteristics ◽  
Learning Machine ◽  
Combustion Optimization

Increasing the combustion efficiency of power plant boilers and reducing pollutant emissions are important for energy conservation and environmental protection. The power plant boiler combustion process is a complex multi-input/multi-output system, with a high degree of nonlinearity and strong coupling characteristics. It is necessary to optimize the boiler combustion model by means of artificial intelligence methods. However, the traditional intelligent algorithms cannot deal effectively with the massive and high dimensional power station data. In this paper, a distributed combustion optimization method for boilers is proposed. The MapReduce programming framework is used to parallelize the proposed algorithm model and improve its ability to deal with big data. An improved distributed extreme learning machine is used to establish the combustion system model aiming at boiler combustion efficiency and NOx emission. The distributed particle swarm optimization algorithm based on MapReduce is used to optimize the input parameters of boiler combustion model, and weighted coefficient method is used to solve the multi-objective optimization problem (boiler combustion efficiency and NOx emissions). According to the experimental analysis, the results show that the method can optimize the boiler combustion efficiency and NOx emissions by combining different weight coefficients as needed.

scholarly journals Using Kalman Filters to Reduce Noise from RFID Location System

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Pedro Henriques Abreu ◽  
José Xavier ◽  
Daniel Castro Silva ◽  
Luís Paulo Reis ◽  
Marcelo Petry
Keyword(s):  
Kalman Filter ◽  
Kalman Filters ◽  
Constant Velocity ◽  
Research Work ◽  
The Other ◽  
Full Potential ◽  
Comparison Study ◽  
Location System ◽  
Oval Shape ◽  
Location Systems

Nowadays, there are many technologies that support location systems involving intrusive and nonintrusive equipment and also varying in terms of precision, range, and cost. However, the developers some time neglect the noise introduced by these systems, which prevents these systems from reaching their full potential. Focused on this problem, in this research work a comparison study between three different filters was performed in order to reduce the noise introduced by a location system based on RFID UWB technology with an associated error of approximately 18 cm. To achieve this goal, a set of experiments was devised and executed using a miniature train moving at constant velocity in a scenario with two distinct shapes—linear and oval. Also, this train was equipped with a varying number of active tags. The obtained results proved that the Kalman Filter achieved better results when compared to the other two filters. Also, this filter increases the performance of the location system by 15% and 12% for the linear and oval paths respectively, when using one tag. For a multiple tags and oval shape similar results were obtained (11–13% of improvement).

Computational Analysis of Non-Premixed Combustion in a Scramjet Combustor With a Wedge Shaped Strut Injector

2021 ◽  
Author(s):  
Sajal Katare ◽  
Nagendra P. Yadav
Keyword(s):  
Computational Analysis ◽  
Static Pressure ◽  
Computational Study ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Reaction Model ◽  
Premixed Combustion ◽  
Cold Flow ◽  
Flame Holder ◽  
Scramjet Combustor

Abstract This paper focuses the computational study of non-premixed combustion in a scramjet combustor. The wedge shaped strut injector was used in the combustion process. In order to investigate the flame holding mechanism of the wedge shaped strut in supersonic flow, the two-dimensional coupled implicit RANS equations, the standard k-ε turbulence model and the finite-rate/eddy-dissipation reaction model are introduced to simulate the flow field of the hydrogen fueled scramjet combustor with a strut flame holder under different conditions. The static pressure of the case under the engine ignition condition is much higher than that of the case under the cold flow condition. The reflection of shock waves improves the mixing of hydrogen with the stream of inlet air and thus increases combustion efficiency. The mass flow rate of air is optimized for the best performance of engine.

scholarly journals PRELIMINARY STUDY ON COMBUSTION AND OVERALL PARAMETERS OF SYNGAS FUEL MIXTURES FOR SPARK IGNITION COMBUSTION ENGINE

2017 ◽  
Vol 57 (1) ◽  
pp. 38-48 ◽  
Author(s):  
Rastislav Toman ◽  
Marián Polóni ◽  
Andrej Chríbik
Keyword(s):  
Combustion Engine ◽  
Spark Ignition ◽  
Full Scale ◽  
Inert Gases ◽  
Combustion Model ◽  
Closed Volume ◽  
Combustion Analysis ◽  
Gaseous Fuels ◽  
Fuel Mixtures ◽  
Burn Rate

This paper presents a numerical study on a group of alternative gaseous fuels – syngases, and their use in the spark-ignition internal combustion engine Lombardini LGW 702. These syngas fuel mixtures consist mainly of hydrogen and carbon monoxide, together with inert gases. An understanding of the impact of the syngas composition on the nature of the combustion process is essential for the improvement of the thermal efficiency of syngas-fuelled engines. The paper focuses on six different syngas mixtures with natural gas as a reference. The introduction of the paper goes through some recent trends in the field of the alternative gaseous fuels, followed by a discussion of the objectives of our work, together with the selection of mixtures. Important part of the paper is dedicated to the experimental and above all to the numerical methods. Two different simulation models are showcased: the single-cylinder ‘closed-volume’ combustion analysis model and the full-scale LGW 702 model; all prepared and tuned with the GT-Power software. Steady-state engine measurements are followed by the combustion analysis, which is undertaken to obtain the burn rate profiles. The burn rate profiles, in the form of the Vibe formula, are than inserted into the in-house developed empirical combustion model based on Csallner-Woschni recalculation formulas. Its development is described in the scope as well. The full-scale LGW 702 simulation model, together with this empirical combustion model, is used for the evaluation of engine overall performance parameters, running on gaseous fuel mixtures. The analysis was carried out only under the conditions of engine on full load and the stoichiometric mixture.

The Effects of Turbulent Burning Velocity Models in a Swirl-Stabilized Lean Premixed Combustor

2018 ◽  
Vol 35 (4) ◽  
pp. 365-372
Author(s):  
Jong-Chan Kim ◽  
Won-Chul Jung ◽  
Ji-Seok Hong ◽  
Hong-Gye Sung
Keyword(s):  
Burning Velocity ◽  
Premixed Combustion ◽  
Dynamic Mode Decomposition ◽  
Combustion Model ◽  
Dynamic Mode ◽  
Turbulent Premixed Combustion ◽  
Velocity Models ◽  
Flame Structures ◽  
Turbulent Burning Velocity ◽  
Turbulent Premixed

Abstract The effects of turbulent burning velocities in a turbulent premixed combustion simulation with a G-equation are investigated using the 3D LES technique. Two turbulent burning velocity models – Kobayashi model, which takes into account the burning velocity pressure effect, and the Pitsch model, which considers the flame regions on the premixed flame structure – are implemented. An LM6000 combustor is employed to validate the turbulent premixed combustion model. The results show that the flame structures in front of the injector have different shapes in each model because of the different turbulent burning velocities. These different flame structures induce changes in the entire combustor flow field, including in the recirculation zone. The dynamic mode decomposition (DMD) method and linear acoustic analysis provide the dominant acoustic mode.

Computational Modelling of Self-Excited Combustion Instabilities

2000 ◽  
Author(s):  
Steve J. Brookes ◽  
R. Stewart Cant ◽  
Iain D. J. Dupere ◽  
Ann P. Dowling
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Heat Release ◽  
Large Scale ◽  
Computational Modelling ◽  
Combustion Efficiency ◽  
Design Tool ◽  
Premixed Combustion ◽  
Combustion Instabilities ◽  
Combustion Systems

It is well known that lean premixed combustion systems potentially offer better emissions performance than conventional non-premixed designs. However, premixed combustion systems are more susceptible to combustion instabilities than non-premixed systems. Combustion instabilities (large-scale oscillations in heat release and pressure) have a deleterious effect on equipment, and also tend to decrease combustion efficiency. Designing out combustion instabilities is a difficult process and, particularly if many large-scale experiments are required, also very costly. Computational fluid dynamics (CFD) is now an established design tool in many areas of gas turbine design. However, its accuracy in the prediction of combustion instabilities is not yet proven. Unsteady heat release will generally be coupled to unsteady flow conditions within the combustor. In principle, computational fluid dynamics should be capable of modelling this coupled process. The present work assesses the ability of CFD to model self-excited combustion instabilities occurring within a model combustor. The accuracy of CFD in predicting both the onset and the nature of the instability is reported.

Simulation of Char Dust Combustion Inside a Pyroscrubber Downstream of a Petroleum Coke Calcining Kiln

2010 ◽  
Author(s):  
Lei Zhao ◽  
Ting Wang
Keyword(s):  
Energy Saving ◽  
Petroleum Coke ◽  
Gas Flow ◽  
Flame Temperature ◽  
Combustion Efficiency ◽  
Energy Output ◽  
Combustion Model ◽  
Phase Flow ◽  
Two Phase ◽  
Particle Combustion

A pyroscrubber is a furnace used in the petroleum coke calcining industry to recover energy from the carbonaceous contents, including char dust and hydrocarbon volatiles of the exhaust gas from the calcination kiln. The combusted hot gases are used to generate steam and produce electricity, so it is important to optimize the pyroscrubber performance to produce high-grade combusted gases to generate steam but with minimal emissions. A previous study employed the locally-homogeneous flow (LHF) model to study rhe means to improve combustion efficiency and reduce emissions. In the LHF model, the inter-phase exchange rates of mass, momentum and energy are assumed to be infinitely fast, so the dispersed phase (char dust) can be simplified as the gas phase, and the complex two-phase flow is then treated as a single-phase flow. In this study, LHF model is replaced with a solid particle combustion model by incorporating both finite-rate heterogeneous and homogeneous combustion processes. Results reveal that the particle combustion model generates much higher local flame temperature (2200K) than in LHF model (1800K). All char particles are burned before or in the high-bay area. Total energy output of the case with particle combustion model is 92% of the LHF model. Furthermore, motivated by the potential energy saving from removing the air blower power supply, this study further investigates the possible benefit of running the pyroscrubber with the ventilation doors open. Three cases with different combinations of air injections and door opening have been studied. Results show that the gas flow is stably stratified with a large amount of the entrained cold air moving at the bottom of the chamber and the hot combusted gas moving through the top. With bottom doors completely open, sufficient air can be drawn into the pyroscrubber without the need of blowing air in, but the combustion gases will be overcooled making this practice unfavorable from the energy saving point of view.

Statistical Analysis and Verification of a New Premixed Combustion Model with DNS Data

2020 ◽  
Vol 192 (11) ◽  
pp. 2093-2114
Author(s):  
Maximilian Hansinger ◽  
Michael Pfitzner ◽  
Markus Klein
Keyword(s):  
Statistical Analysis ◽  
Premixed Combustion ◽  
Combustion Model
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