[2024]Digital Global Overview Report 2024 Meltwater.pdf
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Operation and Modeling of Turbogenerators - Hsing-pang Liu - June 2010
1. 2010 ESRDC Team Meeting Operation and Modeling of Turbogenerators Hsing-Pang Liu Center for Electromechanics, University of Texas at Austin Ruixian Fang Department of Mechanical Engineering, University of South Carolina June 3, 2010
2. Operation Basis and Modeling Goal Gas turbines are primarily used for jet aircraft propulsion and power generation. Operation of gas turbines is based on thermodynamics principles and constitutive relations of heat transfer and fluid mechanics. The goal of ESRDC gas turbine modeling effort is to perform transient dynamic modeling and simulation of generic gas turbines.
3. Initial Effort Contact various UT ESRDC team personnel to find out what has been done on the gas turbine modeling in the past Obtain technical information on gas turbine design, modeling, simulation, and testing through literature search Search existing gas turbine modeling/simulation software for potential use in electric ship power generation application Download several identified gas turbine modeling software for free trial and evaluation
17. Originally developed by NASA Glenn Research Center and its industrial/government partners for military jet engine applications and space transportation
18. A consortium was later created to ensure continued development and enhancement
19. Latest version of NPSS 2.2.1 has been released for commercial distribution
41. For āoff-designā modeling, deviation from the design point is calculated by solving a set of non-linear differential equations, which include conservation of mass, momentum, and energy for all components
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43. Another Thermodynamic Simulation Code (Cycle-Tempo) A thermodynamic simulation code developed by Delft University of Technology (Netherlands) A program for thermodynamic modeling and optimization of systems for production of electricity, heat, and refrigeration Capable of modeling steady-state behavior of generic gas turbine engines (NOT transient dynamic gas turbine simulation) Well-documented and relatively simple Used to build a gas turbine engine model to predict the steady-state performance at the engineās design point Compare the steady-state results, at engineās design point, predicted by āCycle-Tempoā with those predicted by other commercial software
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45. Selected by US Navy to power IPS EDM, DDG 1000, and Littoral Combat Ship (LCS)
46. Selected by UK MOD to power Royal Navyās future all-electric aircraft carrier
47. A multi-spool engine and is composed of intermediate-pressure and high-pressure compressors (IPC and HPC) and high-pressure, intermediate-pressure, and free-power turbines (HPT, IPT, FPT)
82. Three map input parameters are used to define the map operating point
83. Both steady state and transient simulation results can be plotted in component maps to assess component performance, such as compressor stall margin
84. For small differences (<25%), scaling usually does not add large errors; however, scaling for large difference will introduce large error margins
90. constantbeta lines are virtually perpendicular to the constant corrected speed curves in themaps
91. are equidistant, ranging between 0 and 1Two input parameters (i.e. beta parameter and speed parameter) can be used to find three output parameters (i.e., efficiency, pressure ratio, and corrected mass flow).
99. A testing steady-state series off-design simulation was performed by investigating the relation between engine performance and fuel flow.
100. A manual fuel flow control was applied over a wide operating range by sweeping the fuel flow rate from the design-point value of 2.07 kg/s to a value of 0.6 kg/s.
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102. MT30 Operating Lines in Scaled Free-Power Turbine Map (during An Off-Design Decreasing Fuel Flow Sweep)
103. A Transient Off-Design Simulation Input parameters are specified as functions of time, and the engine response to that input changes is then calculated. A testing transient simulation was carried out by using a manual fuel flow control to input an assumed time-dependent fuel flow rate (shown in the following figure).
104. Predicted MT30 Engine Transient Parameters Specific Fuel Consumption Airflow Rate High-Pressure Turbine Inlet Temperature Free-Power Turbine Output
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107. Allows rapid adaptation to various configurations, rather than being dedicated to a specific engine
108. Implemented in Matlab-Simulink by using graphical user interface to reflect component-based architecture of the gas turbine model
109. Input is provided in files listing input variables, off-design component maps, control schedules, etc, and these files are accessed by any text file editor
110. Uses scalable maps, control functions and dimensionless parameters, for generic component models
111. Calculations performed on component level, using relations between component entry and exit gas properties based on component maps and thermodynamic equations
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114. 29 Component-wise Gas Turbine VTB Model Gas Turbine Gas Turbine Simple-cycle 2-shaft 2 Stage compressor Intercooler Combustor Power Turbine Power turbine shaft speed feedback regulates fuel flow Six-phase Synchronous Generator Fuel Supply Heat Exchanger Combustor Low Pressure Compressor High Pressure Compressor Thermal Sink Note : compressors and turbines are characteristic curve based model. Power Turbine Gas Generator Turbine Intercooler Inlet Air Controllable resistive Load Starter Motor
115. Validation of VTB Gas Turbine Model Compare a single shaft VTB model results with GasTurb commercial simulation software Boundary conditions for the VTB model match those for GasTurb Compressor inlet conditions Air bleed Design point of shaft speed Etc. Results were compared Pressures and temperatures at the compressor exit port Turbine inlet/outlet ports Shaft power Compressor Map Turbine Map VTB Gasturb Fuel Combustor Component maps employed by GasTurb Bleeding design point (N = 11427rpm, Mass flow rate 21.018 kg/s). compressor Turbine inlet Note : Characteristic curves near design point were extracted and put into VTB model
116. Validation Results Comparison Design Point Compressor Outlet pressure error 2%, Outlet temperature error 9% Error caused by the assumption of ideal compression. Turbine Outlet pressure error 4% Outlet temperature error 8% Shaft power error 4% Note: GasTurb uses Generic fuel, while VTB assumes methane for these comparisons, we adjust the methane flow rate to match the compressor exhaust temperature. Off-Design Point Off-design validation Same engine settings. Different operating point. N = 9999 rpm - 10% below design point. Compressor Outlet temperature consistent with GasTurb Outlet pressure error 42% Error caused by the modeling method of the characteristic curve Turbine Outlet temperature error 15% Outlet pressure error 9% Shaft power error 8%
