Electrical Static Discharge in Turbo Machinery

2012 ◽  
Author(s):  
David A. Ross
Keyword(s):  
Gas Turbine ◽  
Gear Tooth ◽  
Vibration Level ◽  
Turbo Machinery ◽  
A Site ◽  
Industrial Gas Turbine ◽  
Static Discharge

An industrial gas turbine had a reoccurring failure with its accessory gearbox. The gearbox would run for a few days and then begin to show increased vibrations. The vibration level would gradually increase until the turbine alarm and trip signals operated. Studies at the time suggested alignment and accessory coupling issues were the cause. After many realignments and gears being changed the problem persisted. Eventually the gearbox replaced as it was suspected the original had internal alignment issues. This proved to be unsuccessful and the problem continued. At the time of the unit’s last overhaul it was discovered the generator’s non-drive-end bearings insulation had failed and could not be rectified in time for its return to operation. It was then decided to install a second rotor earthing brush to the non-drive-end of the generator. The writer reviewed all the historical and current date including a site inspection of the plant. Initial inspection of the gear damage indicated excessive misalignment and gear tooth overload. Finally, examination of the shell bearing liners had indications consistent with Electrical Static Discharge [ESD]. This had been overlooked; interpretation of the marking was due to unusual misalignment and the gear shaft.

Development of L1-norm sliding mode observer for sensor fault diagnosis of an industrial gas turbine

2021 ◽  
pp. 095965182199617
Author(s):  
Mahyar Akbari ◽  
Abdol Majid Khoshnood ◽  
Saied Irani
Keyword(s):  
Fault Detection ◽  
State Space ◽  
Gas Turbine ◽  
Sliding Mode ◽  
State Space Model ◽  
Sensor Fault ◽  
Space Model ◽  
Decision Logic ◽  
Sensor Fault Detection ◽  
Industrial Gas Turbine

In this article, a novel approach for model-based sensor fault detection and estimation of gas turbine is presented. The proposed method includes driving a state-space model of gas turbine, designing a novel L1-norm Lyapunov-based observer, and a decision logic which is based on bank of observers. The novel observer is designed using multiple Lyapunov functions based on L1-norm, reducing the estimation noise while increasing the accuracy. The L1-norm observer is similar to sliding mode observer in switching time. The proposed observer also acts as a low-pass filter, subsequently reducing estimation chattering. Since a bank of observers is required in model-based sensor fault detection, a bank of L1-norm observers is designed in this article. Corresponding to the use of the bank of observers, a two-step fault detection decision logic is developed. Furthermore, the proposed state-space model is a hybrid data-driven model which is divided into two models for steady-state and transient conditions, according to the nature of the gas turbine. The model is developed by applying a subspace algorithm to the real field data of SGT-600 (an industrial gas turbine). The proposed model was validated by applying to two other similar gas turbines with different ambient and operational conditions. The results of the proposed approach implementation demonstrate precise gas turbine sensor fault detection and estimation.

Performance Prediction of Gas Turbine Under Different Strategies Using Low Heating Value Fuel

2013 ◽  
Author(s):  
Edson Batista da Silva ◽  
Marcelo Assato ◽  
Rosiane Cristina de Lima
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Equivalence Ratio ◽  
Safe Operation ◽  
Engine Operation ◽  
Heating Value ◽  
Gasification Process ◽  
Surge Margin ◽  
And Performance ◽  
Industrial Gas Turbine

Usually, the turbogenerators are designed to fire a specific fuel, depending on the project of these engines may be allowed the operation with other kinds of fuel compositions. However, it is necessary a careful evaluation of the operational behavior and performance of them due to conversion, for example, from natural gas to different low heating value fuels. Thus, this work describes strategies used to simulate the performance of a single shaft industrial gas turbine designed to operate with natural gas when firing low heating value fuel, such as biomass fuel from gasification process or blast furnace gas (BFG). Air bled from the compressor and variable compressor geometry have been used as key strategies by this paper. Off-design performance simulations at a variety of ambient temperature conditions are described. It was observed the necessity for recovering the surge margin; both techniques showed good solutions to achieve the same level of safe operation in relation to the original engine. Finally, a flammability limit analysis in terms of the equivalence ratio was done. This analysis has the objective of verifying if the combustor will operate using the low heating value fuel. For the most engine operation cases investigated, the values were inside from minimum and maximum equivalence ratio range.

Electrical studies for an industrial gas turbine cogeneration facility

1989 ◽  
Vol 25 (4) ◽  
pp. 750-765 ◽  
Author(s):  
R.L. Doughty ◽  
L. Gise ◽  
E.W. Kalkstein ◽  
R.D. Willoughby
Keyword(s):  
Gas Turbine ◽  
Electrical Studies ◽  
Industrial Gas Turbine

Effect of Geometric Uncertainty on a One Stage Transonic Compressor of an Industrial Gas Turbine

2021 ◽  
Author(s):  
Venkatesh Suriyanarayanan ◽  
Kentaro Suzuki ◽  
Mehdi Vahdati ◽  
Loic Salles ◽  
Quentin Rendu
Keyword(s):  
Gas Turbine ◽  
Transonic Compressor ◽  
One Stage ◽  
Geometric Uncertainty ◽  
Industrial Gas Turbine

scholarly journals Fluid Film Bearing Housing Design for a Hot Ambient Environment

1976 ◽  
Author(s):  
J. D. McHugh ◽  
W. O. Winer ◽  
G. D. Robson
Keyword(s):  
Gas Turbine ◽  
Journal Bearing ◽  
Test Facility ◽  
Experimental Program ◽  
Special Test ◽  
Housing Design ◽  
Full Size ◽  
Ambient Temperatures ◽  
Operating Field ◽  
Industrial Gas Turbine

Industrial gas turbine rotors sometimes require a journal bearing in a region of the machine surrounded by compressor discharge air. Ambient temperatures in this region may exceed 600 F (588 K), which poses a challenge to bearing designers. The present paper describes housing design approaches to meeting this challenge, an experimental program to evaluate them, and the application of results to operating field units. The experimental program was carried out in a special test facility on full-size housings for a 14-in. journal bearing in a hot, pressurized environment.

Predicting Thermoacoustic Instability in an Industrial Gas Turbine Combustor: Combining a Low Order Network Model With Flame LES

2017 ◽  
Author(s):  
Y. Xia ◽  
A. S. Morgans ◽  
W. P. Jones ◽  
J. Rogerson ◽  
G. Bulat ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Acoustic Waves ◽  
Gas Turbine Combustor ◽  
Network Modelling ◽  
Weakly Nonlinear ◽  
Thermoacoustic Instability ◽  
Reduced Chemistry ◽  
Flame Describing Function ◽  
Industrial Gas Turbine ◽  
Low Order

The thermoacoustic modes of a full scale industrial gas turbine combustor have been predicted numerically. The predictive approach combines low order network modelling of the acoustic waves in a simplified geometry, with a weakly nonlinear flame describing function, obtained from incompressible large eddy simulations of the flame region under upstream forced velocity perturbations, incorporating reduced chemistry mechanisms. Two incompressible solvers, each employing different numbers of reduced chemistry mechanism steps, are used to simulate the turbulent reacting flowfield to predict the flame describing functions. The predictions differ slightly between reduced chemistry approximations, indicating the need for more involved chemistry. These are then incorporated into a low order thermoacoustic solver to predict thermoacoustic modes. For the combustor operating at two different pressures, most thermoacoustic modes are predicted to be stable, in agreement with the experiments. The predicted modal frequencies are in good agreement with the measurements, although some mismatches in the predicted modal growth rates and hence modal stabilities are observed. Overall, these findings lend confidence in this coupled approach for real industrial gas turbine combustors.

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