Triaxial Gas Turbine Performance Analysis for Variable Power Turbine Inlet Guide Vane Control Law Optimization

2018 ◽  
Author(s):  
Tao Wang ◽  
Yong-sheng Tian ◽  
Zhao Yin ◽  
Qing Gao ◽  
Chun-qing Tan
Keyword(s):  
Gas Turbine ◽  
Working Conditions ◽  
Guide Vane ◽  
Inlet Guide Vane ◽  
Control Law ◽  
Inlet Guide Vanes ◽  
Turbine Performance ◽  
Turbine Inlet ◽  
Power Turbine ◽  
Vane Angle

This paper proposes an inlet guide vane control law optimization technique for improving the off-design working condition thermal efficiency of triaxial gas turbine. Gas turbine dynamic and steady component-level simulation models are established in MATLAB/SIMULINK via Newton-Raphson algorithm based on component characteristic maps. After validating the models against experimental data and Gasturb software, they are applied to determine the effects of guide vane angle on gas turbine performance parameters. High Efficiency Mode (HEM) is utilized to adjust the power turbine inlet guide vanes to enhance the gas turbine efficiency and decrease the specific fuel consumption under off-design working conditions on account of the above gas turbine overall performance analysis results. The optimal angles of power turbine inlet guide vanes for various working conditions are acquired based on the steady gas turbine model as-established. HEM enhances the gas turbine’s thermal efficiency without exceeding its temperature or rotational speed constraints. The Radial Basis Function (RBF), a three-layer, feedforward neural network, is employed to fit the optimal guide vane angles and establish the corresponding relationship between the angles and various working conditions by system identification. The control strategy and gas turbine dynamic simulation model are tested in MATLAB/SIMULINK to verify their effects on gas turbine performance. The guide vane angle is found to significantly influence the gas turbine operating parameters, and HEM to effectively optimize gas turbine performance even within unpredictable atmospheric environment and working conditions.

Off-design performance improvement of twin-shaft gas turbine by variable geometry turbine and compressor besides fuel control

2019 ◽  
Vol 234 (7) ◽  
pp. 957-980
Author(s):  
Sepehr Sanaye ◽  
Salahadin Hosseini
Keyword(s):  
Life Cycle ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Guide Vane ◽  
Design Parameters ◽  
Inlet Guide Vane ◽  
Inlet Temperature ◽  
Gas Generator ◽  
Turbine Inlet ◽  
Exit Temperature

A novel procedure for finding the optimum values of design parameters of industrial twin-shaft gas turbines at various ambient temperatures is presented here. This paper focuses on being off design due to various ambient temperatures. The gas turbine modeling is performed by applying compressor and turbine characteristic maps and using thermodynamic matching method. The gas turbine power output is selected as an objective function in optimization procedure with genetic algorithm. Design parameters are compressor inlet guide vane angle, turbine exit temperature, and power turbine inlet nozzle guide vane angle. The novel constrains in optimization are compressor surge margin and turbine blade life cycle. A trained neural network is used for life cycle estimation of high pressure (gas generator) turbine blades. Results for optimum values for nozzle guide vane/inlet guide vane (23°/27°–27°/6°) in ambient temperature range of 25–45 ℃ provided higher net power output (3–4.3%) and more secured compressor surge margin in comparison with that for gas turbines control by turbine exit temperature. Gas turbines thermal efficiency also increased from 0.09 to 0.34% (while the gas generator turbine first rotor blade creep life cycle was kept almost constant about 40,000 h). Meanwhile, the averaged values for turbine exit temperature/turbine inlet temperature changed from 831.2/1475 to 823/1471°K, respectively, which shows about 1% decrease in turbine exit temperature and 0.3% decrease in turbine inlet temperature.

scholarly journals Identifying a Dynamic Model for a GE Frame 7 Gas Turbine

1994 ◽  
Author(s):  
Howard Kaufman ◽  
R. Ravi
Keyword(s):  
Gas Turbine ◽  
Linear Models ◽  
Controller Design ◽  
Guide Vane ◽  
Selection Criterion ◽  
Inlet Guide Vane ◽  
Data Sets ◽  
Similar Work ◽  
Identification Techniques ◽  
Vane Angle

Several tests were conducted on a GE Frame 7 gas turbine to determine its dynamic characteristics. The objective is to obtain a model that can be used for controller design. The tests consisted of adding sequences of square waves to the two inputs — the fuel reference and the inlet guide vane angle reference — and recording the inputs and the outputs. This method of exciting the system afforded us with a way of separating the data sets into two categories, the first, in which the fuel reference was changed, and the second, in which the guide vane angle reference was changed. Least-squares system identification techniques were used to obtain linear models using a selection criterion that was a measure of how well a model fit both the sets of data. This brought in a measure of robustness to the models thus making them ideal for use in controller design. This paper summarizes the results from these tests, contains plots that show how well the linear models are able to fit the recorded data, and finally, provides some recommendations for others doing similar work.

scholarly journals Investigation of the Combined Effect of Variable Inlet Guide Vane Drift, Fouling, and Inlet Air Cooling on Gas Turbine Performance

Entropy ◽  
2019 ◽  
Vol 21 (12) ◽  
pp. 1186 ◽  
Author(s):  
Muhammad Baqir Hashmi ◽  
Tamiru Alemu Lemma ◽  
Zainal Ambri Abdul Karim
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Thermal Efficiency ◽  
Guide Vane ◽  
Inlet Guide Vane ◽  
Air Cooling ◽  
Turbine Performance ◽  
Surge Margin ◽  
Performance Deterioration ◽  
Variable Inlet Guide Vane

Variable geometry gas turbines are susceptible to various malfunctions and performance deterioration phenomena, such as variable inlet guide vane (VIGV) drift, compressor fouling, and high inlet air temperatures. The present study investigates the combined effect of these performance deterioration phenomena on the health and overall performance of a three-shaft gas turbine engine (GE LM1600). For this purpose, a steady-state simulation model of the turbine was developed using a commercial software named GasTurb 12. In addition, the effect of an inlet air cooling (IAC) technique on the gas turbine performance was examined. The design point results were validated using literature results and data from the manufacturer’s catalog. The gas turbine exhibited significant deterioration in power output and thermal efficiency by 21.09% and 7.92%, respectively, due to the augmented high inlet air temperature and fouling. However, the integration of the inlet air cooling technique helped in improving the power output, thermal efficiency, and surge margin by 29.67%, 7.38%, 32.84%, respectively. Additionally, the specific fuel consumption (SFC) was reduced by 6.88%. The VIGV down-drift schedule has also resulted in improved power output, thermal efficiency, and the surge margin by 14.53%, 5.55%, and 32.08%, respectively, while the SFC decreased by 5.23%. The current model can assist in troubleshooting the root cause of performance degradation and surging in an engine faced with VIGV drift and fouling simultaneously. Moreover, the combined study also indicated the optimum schedule during VIGV drift and fouling for performance improvement via the IAC technique.

Experimental Investigation of Forced Response Impeller Blade Vibration in a Centrifugal Compressor With Variable Inlet Guide Vanes: Part 2—Forcing Function and FSI Computations

2011 ◽  
Author(s):  
Armin Zemp ◽  
Reza S. Abhari ◽  
Matthias Schleer
Keyword(s):  
Experimental Investigation ◽  
Centrifugal Compressor ◽  
Guide Vane ◽  
Forced Response ◽  
Inlet Guide Vane ◽  
Compressor Stage ◽  
Blade Vibration ◽  
Impeller Blade ◽  
Inlet Guide Vanes ◽  
Vane Angle

As the second part of a two-part paper, this paper presents an experimental investigation of forced response impeller blade vibrations in a centrifugal compressor stage caused by variable inlet guide vanes. Although it is common practice to experimentally test the forced response blade vibration behavior of new impeller designs in terms of strain gauge or tip-timing measurements, the impact of the unsteady blade pressure distribution acting as an unsteady load on the blade surfaces is still not known. A centrifugal compressor impeller was therefore instrumented with dynamic strain gauges and fast-response pressure transducers to measure the forcing of the impeller blades for different compressor operating points and various inlet guide vane angle settings. The results showed a decrease in the excitation amplitudes for reduced mass flow rates of the compressor stage. The inlet guide vane angle setting affected the convection speed of the distortion pattern along the blade surface. An increase in the negative inlet guide vane angle caused higher excitation amplitudes especially in the inducer part of the blade. However, the largest negative inlet guide vane setting caused the smallest excitation amplitudes as this setup introduced the smallest amount of inlet distortion to the inlet flow field. A series of unidirectional fluid structure interaction calculations was performed to show the limitations and requirements of today’s numerical tools.

Influence of Variable Geometry Transients on the Gas Turbine Performance

2011 ◽  
Author(s):  
Joa˜o Roberto Barbosa ◽  
Franco Jefferds dos Santos Silva ◽  
Jesuino Takachi Tomita ◽  
Cleverson Bringhenti
Keyword(s):  
Gas Turbine ◽  
Guide Vane ◽  
Pressure Ratio ◽  
Research Work ◽  
Combined Cycle ◽  
Inlet Guide Vane ◽  
Variable Geometry ◽  
Gas Generator ◽  
Turbine Performance ◽  
Blade Geometry

During the design of a gas turbine it is required the analysis of all possible operating points in the gas turbine operational envelope, for the sake of verification of whether or not the established performance might be achieved. In order to achieve the design requirements and to improve the engine off-design operation, a number of specific analyses must be carried out. This paper deals with the characterization of a small gas turbine under development with assistance from ITA (Technological Institute of Aeronautics), concerning the compressor variable geometry and its transient operation during accelerations and decelerations. The gas turbine is being prepared for the transient tests with the gas generator, whose results will be used for the final specification of the turboshaft power section. The gas turbine design has been carried out using indigenous software, developed specially to fulfill the requirements of the design of engines, as well as the support for validation of research work. The engine under construction is a small gas turbine in the range of 5 kN thrust / 1.2 MW shaft power, aiming at distributed power generation using combined cycle. The work reported in this paper deals with the variable inlet guide vane (VIGV) transients and the engine transients. A five stage 5:1 pressure ratio axial-flow compressor, delivering 8.1 kg/s air mass flow at design-point, is the basis for the study. The compressor was designed using computer programs developed at ITA for the preliminary design (meanline), for the axisymmetric analysis to calculate the full blade geometry (streamline curvature) and for the final compressor geometry definition (3-D RANS and turbulence models). The programs have been used interatively. After the final channel and blade geometry definition, the compressor map was generated and fed to the gas turbine performance simulation program. The transient study was carried out for a number of blade settings, using different VIGV geometry scheduling, giving indication that simulations needed to study the control strategy can be easily achieved. The results could not be validated yet, but are in agreement with the expected engine response when such configuration is used.

Experimental Investigation of Forced Response Impeller Blade Vibration in a Centrifugal Compressor With Variable Inlet Guide Vanes: Part 1—Blade Damping

2011 ◽  
Author(s):  
Armin Zemp ◽  
Reza S. Abhari ◽  
Beat Ribi
Keyword(s):  
Centrifugal Compressor ◽  
Guide Vane ◽  
Operating Conditions ◽  
Inlet Pressure ◽  
Dynamic Strain ◽  
Inlet Guide Vane ◽  
Guide Vanes ◽  
Aerodynamic Damping ◽  
Inlet Guide Vanes ◽  
Vane Angle

Forming the first part of a two-part paper, the quantification of the resonant response levels and the damping quantities for a centrifugal compressor impeller with variable inlet guide vanes under engine representative operating conditions is detailed in this work. The motivation for the investigation is the lack of experimental data that are needed to improve and validate computational tools used during the design phase. Measurements were performed during resonant blade vibrations with the inlet pressure, the inlet guide vane angle and the operating point as the varying parameters. The flow non-uniformity introduced into the inlet flow field was measured with an aerodynamic probe. These measurements showed an increase in flow distortion for increased guide vane angles. The response amplitudes were acquired with dynamic strain gauges. A curve-fit method was applied to estimate the critical damping ratios. The results showed a linear correlation of the aerodynamic damping with the inlet pressure. The mode dependent material damping was therefore derived using a linear extrapolation to vacuum conditions of the inlet pressure dependent overall damping. The resonant blade dynamics could be captured with a single degree of freedom model. The aerodynamic damping and the maximum strain response were found to significantly depend on the inlet guide vane angle setting and on the throttle setting of the compressor.

Optimal Gas Turbine Power Plant Operation Regarding Fuel and Maintenance Cost

2017 ◽  
Author(s):  
Phillip Waniczek ◽  
Dirk Therkorn ◽  
Darrel Lilley
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Guide Vane ◽  
Maintenance Cost ◽  
Inlet Guide Vane ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Plant Operation ◽  
Turbine Inlet ◽  
Power Plant Operation

This paper describes a method that optimizes the commercial benefit by modifying gas turbine control parameters like turbine inlet temperature and variable inlet guide vane position for any dispatched power plant load. The method is a trade-off between best efficiency in the component characteristic together with higher efficiency due to increased turbine inlet temperature and lifetime. With commercial data, both effects are transferred into costs and an optimization routine identifies controller settings for minimum power plant operation cost. Test cases demonstrate the advantage of the operational cost optimization. Costs are calculated based on historic plant data with the original and the optimized operation concept. Although savings per operating hour are small, the accumulated savings over years or major inspection intervals are significant. It could be demonstrated that in regions with high fuel prices the commercial benefit of the optimized gas turbine operating concept sums up to “several million dollars” of savings. Parametric and sensitivity studies show the effect of the main parameters. Dispatch power optimization is not subject of the presented model, but can be implemented on top of the proposed concept. All in all, this work demonstrates and quantifies the commercial benefits when todays and future digital industrial capabilities are applied to gas turbine operation concepts and strategies. The proposed digital approach has the advantage of minimum investment and is attractive for gas turbine operators to generate electricity at lower costs and fuel consumption, increasing revenues and minimizing environmental impact.

Accommodation of Multi-Shaft Gas Turbine Switching Control Gain Tuning Problem to IGV Position

2021 ◽  
Author(s):  
Yujia Ma ◽  
Liu Jinfu ◽  
Linhai Zhu ◽  
Qi Li ◽  
Huanpeng Liu ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Guide Vane ◽  
Optimization Procedure ◽  
Switching Control ◽  
Inlet Guide Vane ◽  
Multi Objective ◽  
Control Gain ◽  
Controller Gain ◽  
Compressor Inlet ◽  
Comprehensive Indicator

Abstract This article aims to discuss the influence of compressor Inlet Guide Vane (IGV) position on gas turbine switching control system gain tuning problem. The distinction between IGV and normally reckoned working conditions is differentiated, and an improved double-layer LPV model is proposed to estimate the protected parameters under various IGV positions. Controller gain tuning is conducted with single and multi-objective intellectual optimization algorithms. Simulation results reveal that normally used multi-objective optimization procedure is unnecessary and time-consuming. While with the comprehensive indicator introduced in this paper, the calculation burden can be greatly eased. This improvement is especially advantageous when tuning work is carried out under multiple IGV positions.

Performance Study of a 1 MW Gas Turbine Using Variable Geometry Compressor and Turbine Blade Cooling

2010 ◽  
Author(s):  
Cleverson Bringhenti ◽  
Jesuino Takachi Tomita ◽  
Joa˜o Roberto Barbosa
Keyword(s):  
Gas Turbine ◽  
Guide Vane ◽  
Turbine Blades ◽  
Axial Flow ◽  
Operating Conditions ◽  
Inlet Guide Vane ◽  
Variable Geometry ◽  
Performance Study ◽  
Turbine Blade Cooling ◽  
Blade Cooling

This work presents the performance study of a 1 MW gas turbine including the effects of blade cooling and compressor variable geometry. The axial flow compressor, with Variable Inlet Guide Vane (VIGV), was designed for this application and its performance maps synthesized using own high technological contents computer programs. The performance study was performed using a specially developed computer program, which is able to numerically simulate gas turbine engines performance with high confidence, in all possible operating conditions. The effects of turbine blades cooling were calculated for different turbine inlet temperatures (TIT) and the influence of the amount of compressor-bled cooling air was studied, aiming at efficiency maximization, for a specified blade life and cooling technology. Details of compressor maps generation, cycle analysis and blade cooling are discussed.

Ice Crystal Icing Investigation on a Honeywell Uncertified Research Engine in an Altitude Simulation Icing Facility

2020 ◽  
Author(s):  
Ashlie B. Flegel
Keyword(s):  
Particle Size ◽  
Guide Vane ◽  
Leading Edge ◽  
Inlet Guide Vane ◽  
Inlet Temperature ◽  
Ice Crystal ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
The Core ◽  
Break Up

Abstract A Honeywell Uncertified Research Engine was exposed to various ice crystal conditions in the NASA Glenn Propulsion Systems Laboratory. Simulations using NASA’s 1D Icing Risk Analysis tool were used to determine potential inlet conditions that could lead to ice crystal accretion along the inlet of the core flowpath and into the high pressure compressor. These conditions were simulated in the facility to develop baseline conditions. Parameters were then varied to move or change accretion characteristics. Data were acquired at altitudes varying from 5 kft to 45 kft, at nominal ice particle Median Volumetric Diameters from 20 μm to 100 μm, and total water contents of 1 g/m3 to 12 g/m3. Engine and flight parameters such as fan speed, Mach number, and inlet temperature were also varied. The engine was instrumented with total temperature and pressure probes. Static pressure taps were installed at the leading edge of the fan stator, front frame hub, the shroud of the inlet guide vane, and first two rotors. Metal temperatures were acquired for the inlet guide vane and vane stators 1–2. In-situ measurements of the particle size distribution were acquired three meters upstream of the engine forward fan flange and one meter downstream of the fan in the bypass in order to study particle break-up behavior. Cameras were installed in the engine to capture ice accretions at the leading edge of the fan stator, splitter lip, and inlet guide vane. Additional measurements acquired but not discussed in this paper include: high speed pressure transducers installed at the trailing edge of the first stage rotor and light extinction probes used to acquire particle concentrations at the fan exit stator plane and at the inlet to the core and bypass. The goal of this study was to understand the key parameters of accretion, acquire particle break-up data aft of the fan, and generate a unique icing dataset for model and tool development. The work described in this paper focuses on the effect of particle break-up. It was found that there was significant particle break-up downstream of the fan in the bypass, especially with larger initial particle sizes. The metal temperatures on the inlet guide vanes and stators show a temperature increase with increasing particle size. Accretion behavior observed was very similar at the fan stator and splitter lip across all test cases. However at the inlet guide vanes, the accretion decreased with increasing particle size.

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