ENCIT2012-257 GAS TURBINE PERFORMANCE ANALYSIS OPERATING WITH LOW HEATING VALUE FUELS - PDF
Edson Batista da Silva, Cleverson Bringhenti, CTA, Brazil
Marcelo Assato, Rosiane C. Lima, Vale Soluções em Energia, Brazil
Abstract: Usually, power plants work with gas turbine designed to fire natural gas; however, there are possibilities to use other types of gaseous fuels with different calorific values that may be available close to the power plant site. These fuels can be gases obtained from steel (from blast furnaces and coking plants), from gasification processes of coal or biomass, among others. In this work, a gas turbine performance was evaluated at different operational conditions in order to verify the technical feasibility of burning low calorific value fuels. A gas turbine designed to operate with natural gas was used as a reference, the model was built and the performance evaluated at design and off-design conditions using a commercial computer program, GasTurb 11®. A good agreement was obtained between the model operating with natural gas and the available data from open literature, at design and off-design conditions. The model was simulated using low heating value fuels under the same conditions established for natural gas. A reduction in compressor's surge margin was identified when using low heating value fuels as well as an increase in power output. Therefore, for safe operation a strategy for recovering the surge margin was adopted. In this study the control strategy adopted was bleed air at the compressor discharge. This control strategy presents a technical viability and ensures that the gas turbine operates with the same surge margin level as when using natural gas
Keywords:emb312; Low Heating Value Fuels, Gas Turbine, Performance, Simulation.
Presentation Schedule: NO PRESENTATION.
ENCIT2012-378 COMPARATIVE ANALYSIS OF TURBINE BLADE TRAILING EDGE COOLING CONFIGURATIONS - PDF
Grazieli Luiza Costa Carosio, Márcio T. Mendonca, IAE, Brazil
Abstract: In the present investigation, numerical simulations are used to compare two turbine blade trailing edge cooling configurations. The classic circular pin fin configuration is compared to a configuration composed with short plates. In the first configuration increased heat transfer is achieved through higher turbulence levels, which also increases pressure drop along the passage. In the second configuration increased heat transfer is achieved on the plates due to the thin developing boundary layer. The results show that a higher number of plates are necessary for achieve the same or higher cooling rates, but even with a grater number of plate fins a lower pressure drop is achieved. The proposed configuration allows a higher cooling with a smaller pumping power, therefore lower losses through the cooling system.
Keywords:gas turbine; convective cooling; computational fluid dynamics; compact heat exchangers; pin fin.
Presentation Schedule: Tuesday, 17:20-17:40. Session: AES3-2/AES2. Presenter: Marcio Teixeira de Mendonça.
ENCIT2012-322 NUMERICAL SIMULATION OF CENTRIFUGAL PUMP OF LIQUID PROPELLANT ROCKET ENGINE - PDF
Marcel Vieira Duarte, Wladimyr Mattos da Costa Dourado, IAE, Brazil
Abstract: High-speed pumps, i.e., pumps with angular speed are widely used in aeronautics, missiles, naval, petrochemical industry and power plants. Because of high angular speed, they can be used without the application of gearboxes in Liquid Propellant Rocket Engines. The use of pumps of high rotational speed take into account the requirements to get high pressures with small dimensions, reduced mass and few stages. The goal of this work is study the performance characteristics of a Liquid Oxygen pump applied to Liquid Propellant Rocket Engine. From the dimensions and the energy characteristics of the centrifugal pump, it is determined the performance parameters through the Computational Fluid Dynamics. From the numerical results generated by the simulation, improvements in the similar design are considered to optimize the efficiency of the pump through the analysis of the flow field inside the centrifugal pump. For volume mesh generation the software Gambit was used. To simulate the flow in centrifugal pump, the equations of Navier-Stokes with adequate boundary conditions are applied for three-dimensional geometry with the commercial software of finite volumes Fluent, assuming steady-state, incompressible flow conditions and without free gas dissolved in liquid. The model kappa-epsilon is used to simulate the turbulent flow. Based in the results obtained, flow field and pressure distribution for different flow rates were analyzed. The characteristics curves of head, power and efficiency of centrifugal pump was ploted. The flow presented high instability due to probably presence of rotating stall in blades channels, as strong secondary flow and internal recirculation at suction and discharge of impeller for low flow rates (part load regime), affecting considerably its operation
Keywords:Computational Fluid Dynamics; Propulsion; Liquid Propellant Rocket Engine; Turbopump; Pumps; Turbomachines.
Presentation Schedule: Tuesday, 17:00-17:20. Session: AES3-2/AES2. Presenter: Marcel Vieira Duarte.