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For natural gas combustion, there is a large amount of experience in the gas turbine industry. However, much of the design work is based on costly combustion tests due to insufficient accuracy of existing prediction tools for data such as emissions and effects due to fuel composition. In the present work, Computational Fluid Dynamics (CFD) approach is used to study partially premixed combustion in the 3rd generation DLE (Dry Low Emission) burner that is used in SGT-700 and SGT-800 gas turbines. The fuels that are studied here are natural gas and enriched hydrogen fuel. The CFD models which are used in this work are an axisymmetric and a 3D model and the softwares are ANSYS CFX and ANSYS FLUENT. One of the main objectives of this thesis is the study of flame shape and NOx emission in hydrogen enriched combustion. In the first study of the present work, effect of adding hydrogen to non-preheated gas combustion was investigated and the results were compared with the available measurement data. Calculated laminar burning velocity with CANTERA showed a good agreement with the experimental and numerical references. Also, the accuracy of generated flamelet libraries in CFD tools to calculate adiabatic flame temperature was compared with different available tools. Results showed good agreement between available tools for the ranges of interest. In addition, flame shape and NOx prediction was studied in the gas turbine burner. Adding hydrogen to the fuel increased significantly turbulent burning velocity and OH distribution in the domain. The effect of hydrogen on the central stagnation point was studied and the simulation results did not show a significant effect on the stagnation point location. Beside the flame shape, this study showed that although the CFD NOx prediction tools in ANSYS CFX and ANSYS FLUENT predict the trend of NOx and the flame propagation in the right manner, in order to use as a reliable prediction tool in the gas turbine industry they need to be improved.

Flameless combustion technology has been developed over the past twenty years achieving low-NOx emissions and high energy efficiency for industrial applications. In the present work, three aspects of flameless combustion were examined based on a burner employing the Strong-Jet/Weak-Jet (SJ/WJ) configuration. In the first part of the work, a 3-D SJ/WJ physical model was developed in the Lagrangian perspective for an isothermal pair of free jets. The model was used to predict the WJ trajectory, identify important design/operation factors, and estimate the extent of mixing in the main combustion region (confluence region). The model was also validated with experimental data and showed excellent agreement over a wide range of flow conditions. In the second part of the work, a simplified chemical kinetic model was developed for the flameless combustion of natural gas. A detailed chemical reaction mechanism (GRI Mech 3.0) was successfully reduced to a skeletal chemical reaction mechanism under flameless combustion conditions by Principal Component Analysis, sensitivity analysis and reaction flow analysis. The skeletal mechanism was further simplified to a set of 2-D manifolds by Trajectory-Generated Low-Dimensional Manifolds (TGLDM) method. The set of 2-D manifolds was tested by the Batch Reactor (BR) and Perfect Stirred Reactor (PSR) models. From the BR model test, it was found that the chemical reaction rates were well represented by the 2-D manifolds. The effect of the physical perturbation, tested by PSR model, could be handled by the perpendicular projection instead of the orthogonal projection because both showed similar discrepancies with the skeletal mechanism. In the final part of the work, the steady-state Reynolds-Averaged Navier-Stokes (RANS) simulation was conducted for the turbulent flameless combustion in the SJ/WJ furnace, based on the Probability Density Function (PDF)/Mixing approach. The set of 2-D manifolds and Conditional Source-term Estimate (CSE) method were used for the combustion reaction and the estimation of the mean production/destruction rate, respectively. This CSE-TGLDM model provided good predictions of major species concentrations. However, the gas temperatures and CO concentrations were highly over-predicted. / Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2010-09-23 11:05:21.884

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This master's thesis talks about main burners of clinker rotary kiln. The first part is focused on the review of burners designed by main global producers. Description of the burners M.A.S.© and Turbu-Flex™ used in kiln system CEMMAC a.s. is in the next part. The influence of the replacement of M.A.S.© burner by Turbu-Flex™ burner is analysed in the last part of this thesis.

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The purpose of this study was to examine football neck collars and determine their effectiveness at preventing transient brachial plexopathy and other neck injuries due to football impacts. Transient brachial plexopathy, commonly called a stinger or burner, is an injury to the brachial plexus. As many as 65% of collegiate football players will receive suffer such an injury. Accessory neck collars are worn to mitigate the risk of stingers, although little research has been performed to test their effectiveness. In addition to the standard shoulder pad and helmet combination, three collars were tested: the McDavid Cowboy Collar, a collar designed by a Virginia Tech physician called the Bullock Collar, and a prototype device called the Kerr Collar. This study utilized a Hybrid-III 50th percentile male outfitted with a standard collegiate football helmet and shoulder pads, and impacted with a linear pneumatic impactor. Forty eight total impacts were performed; impacts were performed at side, front, and axial loading impact locations, with low and high speed impacts, and normal and raised shoulder pad configurations. Each collar was effective at some positions, but no collar was effective at all impact locations. The Cowboy Collar reduced lower neck bending moments in the front position, but raised upper neck bending moments. It also reduced lower neck bending moments in the side position, but only in the raised configuration. The Bullock Collar was effective at reducing lower neck bending moment in the side position. The Kerr Collar was effective at reducing lower neck bending moments in the side impact location, and provided a larger percent reduction in impactor force in the axial loading position, compared to the shoulder pads alone. Further testing is needed at lower impact velocities that more closely represent injurious impacts in the field. / Master of Science

The first part of this thesis intends to create a fuel processor model capable of generating 1kW power as output through the use of a solid oxide fuel cell system. The fuel processor system consists of a reformer, heat exchanger network, desulphurizer and an afterburner. Modelled in VMGSimTM, inlet diesel gas is provided at the mass flow rate of 0.2596kg/hour, with the oxygen to carbon ratio calculated at 0.31 and the steam to carbon ratio arbitrarily set to be 2.25. The diesel fuel is preheated and mixed with air and steam and then fed to the auto-thermal reformer. The higher hydrocarbons are broken down and converted into hydrogen. The outlet of the reformer is fed into the SOFC where H2 is converted to generate energy which, in this case is approximately 1200W. The off gas is fed to the afterburner; where the remaining H2 is burnt and the energy is used to provide for steam generation and pre-heating through the heat exchangers. The project also focuses upon performing basic sizing calculations on components of the system. The fuel cell efficiency was found to be 62% and the system efficiency was calculated to be approximately 41%, which falls within the range given in literature. For the second part of this work, a ceramic porous tail-gas burner using a non-premixed feed of anode exhaust and air was modeled using COMSOL™. The reaction kinetics were experimentally assessed on the basis of COMSOL™ limitations and accuracy of the comparative results. Three performance metrics were evaluated in the analysis: i) velocity profile, ii) temperature profile, and iii) concentration profile. These metrics confirm the combustion reaction at the outer boundary of the porous ceramic in the burner. The spike of temperature and decrease of mass fraction of hydrogen, carbon monoxide and methane to approximately zero in the outlet exhaust confirms this study. This study was further validated by comparing results with the experimental data collected at NRC-IFCI. The results of COMSOL™ model agreed with the experimental results of NRC-IFCI. / Thesis (Master, Chemical Engineering) -- Queen's University, 2013-10-29 17:49:32.266