Tyamo Okosun

Influence of conveyance methods for pulverised coal injection in a blast furnace

Pulverised coal injection (PCI) is a widely adopted industry practice for reducing blast furnace coke rates. The conditions under which pulverised coal (PC) is injected and combusted, including the co-injection of natural gas (NG), can lead to complex combustion phenomena inside the blast furnace, which must be understood to provide improved furnace performance. This research examines computational simulations of the co-injection phenomena, as well as the industrial drivers behind the project. A wide-ranging parametric study was conducted utilising numerous variations in furnace operating conditions, as well as a new technique for the conveyance of PC. It was found that utilising NG as the carrier gas for PCI could increase coal burnout across the raceway region from about 71% to approximately 87% without altering the design of the tuyere/blowpipe region, with an increase to 96% possible if a shift to a dual lance design for NG injection is considered.

CFD Analysis of Blast Furnace Operating Condition Impacts on Operational Efficiency

Blast furnaces are counter-current chemical reactors used to reduce iron ore into liquid iron. Hot reduction gases are blasted through a burden consisting of iron ore pellets, slag, flux, and coke. The chemical reactions that occur through the furnace reduce the iron ore pellets into liquid iron as they descend through the furnace. Experimental studies and live operation measurements can be extremely difficult to perform on a blast furnace due to the extremely harsh environment generated by the operational process. Computational Fluid Dynamics (CFD) modeling has been developed and applied to simulate the complex multiphase reacting flow inside a blast furnace shaft. The model is able to predict the burden distribution pattern, Cohesive Zone (CZ) shape, gas reduction utilization, coke rate, and other operational conditions. This paper details the application of this model to investigate the effects of coke size and porosity, iron ore pellet size, and burden descent speed on blast furnace efficiency.

Computational Examination of Utility Scale Wind Turbine Wake Interactions

Numerical simulations of small, utility scale wind turbine groupings were performed to determine how wakes generated by upstream turbines affect the performance of the small turbine group as a whole. Specifically, various wind turbine arrangements were simulated to better understand how turbine location influences small group wake interactions. The minimization of power losses due to wake interactions certainly plays a significant role in the optimization of wind farms. Since wind turbines extract kinetic energy from the wind, the air passing through a wind turbine decreases in velocity, and turbines downstream of the initial turbine experience flows of lower energy, resulting in reduced power output. This study proposes two arrangements of turbines that could generate more power by exploiting the momentum of the wind to increase velocity at downstream turbines, while maintaining low wake interactions at the same time. Simulations using Computational Fluid Dynamics are used to obtain results much more quickly than methods requiring wind tunnel models or a large scale experimental test.

CFD Simulation of a 6-Cylinder Diesel Engine Intake and Exhaust Manifold

Exhaust gas recirculation (EGR) is a nitrogen oxide (NOx) emissions reduction technique used in petrol/gasoline and diesel engines. By recirculating a portion of an engine’s exhaust, inert gas displaces combustible matter in the cylinder. Because NOx forms primarily when a mixture of nitrogen and oxygen is subjected to high temperature, the lower combustion chamber temperatures caused by EGR decrease the amount of NOx combustion generates. This project aims at optimizing the location of the EGR ports, which are crucial to the operation and efficiency of the EGR system. The Computational Fluid Dynamics (CFD) code ANSYS FLUENT was used to analyze the intake and exhaust manifold working processes. In order to conduct numerical optimization on determining the best EGR port location, a transient CFD model was developed. Real operational transient boundary conditions were applied to the model through user defined functions (UDF), and the results of flow characteristics and EGR distribution was analyzed in detail. The EGR mass flow rate mal-distribution was presented at the transient simulation. This model can be utilized for further optimization purposes.Copyright

A 3D Wind Turbine Simulator for Aerodynamics Education

The energy production and performance of wind turbines is heavily impacted by the aerodynamic properties of the turbine blades. Designing a wind turbine blade to take full advantage of the available wind resource is a complex task, and teaching students the aerodynamic aspects of blade design can be challenging. To address this educational challenge, a 3D software package was developed as part of the Mixed Reality Simulators for Wind Energy Education project, sponsored through the U.S. Department of Education’s FIPSE program. The software is suited for introductory wind energy courses and covers topics including blade aerodynamics, wind turbine components, and energy transfer.The simulator software combines a 3D model of a utility-scale Horizontal Axis Wind Turbine (HAWT) with animation, a set of interactive controls, and a series of computational fluid dynamics (CFD) simulations of an airfoil under a number of conditions. Students can fly around the wind turbine to view from any angle, adjust transparency layers to view components inside the nacelle, adjust a cross-section plane along the length of a blade to view the details of the blade design, and manipulate sliders to adjust variables such as angle of attack and Reynolds number and see contour plots in real-time. The application is available for download at www.windenergyeducation.org, and is planned for release as open source.Copyright