Gas Turbine Operation Offshore: On-Line Compressor Wash at Peak Load

2003 ◽  
Author(s):  
Elisabet Syverud ◽  
Lars E. Bakken ◽  
Kyrre Langnes ◽  
Frode Bjo̸rna˚s
Keyword(s):  
Gas Turbine ◽  
Field Test ◽  
Power Output ◽  
Peak Load ◽  
Economic Factors ◽  
Absolute Accuracy ◽  
Key Factors ◽  
Turbine Performance ◽  
Performance Deterioration ◽  
On Line

On-line compressor wash is discussed for a RB211 compressor driver running at peak load at the Statoil Heidrun offshore platform. The oil field’s economy is directly linked to oil production; however, the production rate is limited by driver and gas compressor capacity. From this perspective, the power output and gas turbine uptime become decisive economic factors. The economic potentials related to successful on-line washing are given. This work is based on a series of trials with on-line compressor washing over a two-year period. Results include effect of different on-line washing procedures and washing fluids. The field test campaign has shown no significant improvements with on-line compressor washing at peak load. Understanding the gas turbine performance deterioration is of vital importance. Trending of its deviation from the engine baseline (datum maps) facilitates load-independent monitoring of the gas turbine’s condition. Peak load turbine response to compressor deterioration is analyzed. Instrument resolution and repeatability are key factors that sometimes are more important than absolute accuracy in condition trending. As a result of these analyses, a set of monitoring parameters is suggested for effective diagnostics of compressor degradation in peak load operation. Avenues for further research and development are suggested as our understanding of the deterioration mechanisms at peak load remains incomplete.

Gas Turbine Fouling Offshore: Correction Methodology Compressor Efficiency

2017 ◽  
Author(s):  
Stian Madsen ◽  
Lars E. Bakken
Keyword(s):  
Gas Turbine ◽  
Peak Load ◽  
Operational Experience ◽  
Air Filtration ◽  
Ambient Conditions ◽  
Key Factors ◽  
Turbine Performance ◽  
Main Challenge ◽  
Filtration System ◽  
Compressor Efficiency

Gas turbine performance has been analyzed for a fleet of GE LM2500 engines at two Statoil offshore fields in the North Sea. Both generator drive engines and compressor driver engines have been analyzed, covering both the LM2500 base and plus configurations, as well as the SAC and DLE combustor configurations. Several of the compressor drive engines are running at peak load (T5.4 control), and the production rate is thus limited to the available power from these engines. The majority of the engines discussed run continuously without redundancy, implying that gas turbine uptime is critical for the field’s production and economy. Previous studies and operational experience have emphasized that the two key factors to minimize compressor fouling are the optimum designs of the inlet air filtration system and the water wash system. An optimized inlet air filtration system, in combination with daily online water wash (at high water-to-air ratio), are the key factors to achieve successful operation at longer intervals between offline washes and higher average engine performance. Operational experience has documented that the main gas turbine recoverable deterioration is linked to the compressor section. The main performance parameter when monitoring compressor fouling is the gas turbine compressor efficiency. Previous studies have indicated that inlet depression (air mass flow at compressor inlet) is a better parameter when monitoring compressor fouling, whereas instrumentation for inlet depression is very seldom implemented on offshore gas turbine applications. The main challenge when analyzing compressor efficiency (uncorrected) is the large variation in efficiency during the periods between offline washes, mainly due to operation at various engine loads and ambient conditions. Understanding the gas turbine performance deterioration is of vital importance. Trending of the deviation from the engine baseline facilitates load-independent monitoring of the gas turbine’s condition. Instrument resolution and repeatability are key factors for attaining reliable results in the performance analysis. A correction methodology for compressor efficiency has been developed, which improves the long term trend data for effective diagnostics of compressor degradation. Avenues for further research and development are proposed in order to further increase the understanding of the deterioration mechanisms, as well as gas turbine performance and response.

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.

Gas Turbine Operation Offshore: On-Line Compressor Wash Operational Experience

2014 ◽  
Author(s):  
Stian Madsen ◽  
Lars E. Bakken
Keyword(s):  
Gas Turbine ◽  
Performance Monitoring ◽  
Water Injection ◽  
Peak Load ◽  
Engine Performance ◽  
Operational Experience ◽  
Term Operation ◽  
Turbine Performance ◽  
On Line ◽  
Effective Diagnosis

On-line compressor wash for six GE LM2500PE engines at a Statoil North Sea offshore field is analyzed. Three engines are generator drivers whilst three engines are compressor drivers. Two of the compressor drive engines are running at peak load (T5.4 control), hence production rate is limited by the available power from these engines. All the six engines analyzed run continuously without redundancy, hence gas turbine uptime is critical for the field’s production and economy. The performance and operational experience with online wash at different water-to-air ratios and engine loads, as well as economy potentials related to successful on-line washing are given. This work is based on long-term operation with on-line washing, where operational data is collected and performance analyzed, over a 4–5 year period. All engines are operated with four month intervals between maintenance stops, where off-line crank-wash is performed as well as other necessary maintenance and repairs. On-line wash is performed daily between the maintenance stops at full load (i.e. normal operating load for the subject engine). To keep the engine as clean as possible and reduce degradation between maintenance stops, both an effective on-line water wash system as well as effective air intake filter system, are critical factors. The overall target is to maintain high engine performance, and extend the interval between maintenance stops through effective on-line washing. It is of vital importance to understand the gas turbine performance deterioration. The trending of its deviation from the engine baseline facilitates load-independent monitoring of the gas turbine’s condition. Engine response to water injection at different loads and water-to-air ratios, as well as engine response to compressor deterioration is documented and analyzed. Instrument resolution and repeatability are key factors required in order to obtain reliable performance analysis results. Offshore instrumentation on older installations is often limited to the necessary instruments for machine control/protection, and additional instruments for effective performance monitoring and analysis are often missing or, if installed, have less accuracy. As a result of these analyses, a set of monitoring parameters is proposed for effective diagnosis of compressor degradation. Avenues for further research and development are proposed in order to further increase the understanding of the deterioration mechanisms and of the gas turbine performance and response.

Prediction Reliability of a Statistical Methodology for Gas Turbine Prognostics

2012 ◽  
Vol 134 (10) ◽  
Author(s):  
Mauro Venturini ◽  
Nicola Puggina
Keyword(s):  
Gas Turbine ◽  
Correction Factor ◽  
Gas Turbines ◽  
Threshold Value ◽  
False Alarms ◽  
Prediction Errors ◽  
Past Behavior ◽  
Turbine Performance ◽  
Performance Deterioration ◽  
Prediction Reliability

The performance of gas turbines degrades over time and, as a consequence, a decrease in gas turbine performance parameters also occurs, so that they may fall below a given threshold value. Therefore, corrective maintenance actions are required to bring the system back to an acceptable operating condition. In today’s competitive market, the prognosis of the time evolution of system performance is also recommended, in such a manner as to take appropriate action before any serious malfunctioning has occurred and, as a consequence, to improve system reliability and availability. Successful prognostics should be as accurate as possible, because false alarms cause unnecessary maintenance and nonprofitable stops. For these reasons, a prognostic methodology, developed by the authors, is applied in this paper to assess its prediction reliability for several degradation scenarios typical of gas turbine performance deterioration. The methodology makes use of the Monte Carlo statistical method to provide, on the basis of the recordings of past behavior, a prediction of future availability, i.e., the probability that the considered machine or component can be found in the operational state at a given time in the future. The analyses carried out in this paper aim to assess the influence of the degradation scenario on methodology prediction reliability, as a function of a user-defined threshold and minimum value allowed for the parameter under consideration. A technique is also presented and discussed, in order to improve methodology prediction reliability by means a correction factor applied to the time points used for methodology calibration. The results presented in this paper show that, for all the considered degradation scenarios, the prediction error is lower than 4% (in most cases, it is even lower than 2%), if the availability is estimated for the next trend, while it is not higher than 12%, if the availability is estimated five trends ahead. The application of a proper correction factor allows the prediction errors after five trends to be reduced to approximately 5%.

Crude Oil Burning Experience in MS5001P Gas Turbines

1984 ◽  
Vol 106 (4) ◽  
pp. 812-818 ◽  
Author(s):  
W. J. Bunz ◽  
G. N. Ziady ◽  
H. vonE. Doering ◽  
R. J. Radice
Keyword(s):  
Crude Oil ◽  
Gas Turbines ◽  
Peak Load ◽  
Wash Water ◽  
Eastern Province ◽  
Turbine Performance ◽  
Purification System ◽  
On Line ◽  
Cleaning Methods ◽  
The Impact

At Qaisumah, Saudi Arabia, there are four GE MS5001P Gas Turbines operated by the Saudi Consolidated Electric Company in the Eastern Province (SCECO East). The Power Plant is not connected to the main SCECO grid and experiences near-capacity peak load demands in the summer months. Its remoteness and proximity to the Trans-Arabian Pipeline (TAPLINE) dictates the burning of Light Saudi Arabian Crude Oil which is desalted by centrifugal purification without the addition of wash water. Eliminating the need for wash water is important because of the scarcity of water at this site. Power loss is controlled and shutdowns minimized during the critical summer months by removing the ash accumulation on the turbine components by on-line nutshell cleaning. This paper describes the first application of this waterless (dry centrifuge) fuel purification system and the impact of various turbine cleaning methods (particularly on-line nutshelling) on turbine performance, availability, and maintenance.

scholarly journals Industrial Gas Turbine Performance: Compressor Fouling and On-Line Washing

2014 ◽  
Vol 136 (10) ◽  
Author(s):  
Uyioghosa Igie ◽  
Pericles Pilidis ◽  
Dimitrios Fouflias ◽  
Kenneth Ramsden ◽  
Panagiotis Laskaridis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Engine Performance ◽  
Operating Conditions ◽  
Compressor Cascade ◽  
Compressor Blades ◽  
Turbine Performance ◽  
Industrial Gas Turbines ◽  
On Line ◽  
The Impact

Industrial gas turbines are susceptible to compressor fouling, which is the deposition and accretion of airborne particles or contaminants on the compressor blades. This paper demonstrates the blade aerodynamic effects of fouling through experimental compressor cascade tests and the accompanied engine performance degradation using turbomatch, an in-house gas turbine performance software. Similarly, on-line compressor washing is implemented taking into account typical operating conditions comparable with industry high pressure washing. The fouling study shows the changes in the individual stage maps of the compressor in this condition, the impact of degradation during part-load, influence of control variables, and the identification of key parameters to ascertain fouling levels. Applying demineralized water for 10 min, with a liquid-to-air ratio of 0.2%, the aerodynamic performance of the blade is shown to improve, however most of the cleaning effect occurred in the first 5 min. The most effectively washed part of the blade was the pressure side, in which most of the particles deposited during the accelerated fouling. The simulation of fouled and washed engine conditions indicates 30% recovery of the lost power due to washing.

Impact of Blade Cooling on Gas Turbine Performance Under Different Operation Conditions and Design Aspects

2015 ◽  
Author(s):  
Maryam Besharati-Givi ◽  
Xianchang Li
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Combustion Process ◽  
Inlet Temperature ◽  
Blade Cooling ◽  
Operation Conditions ◽  
Turbine Performance ◽  
Cooling Air ◽  
The Impact ◽  
The Relationship

The increase of power need raises the awareness of producing energy more efficiently. Gas turbine has been one of the important workhorses for power generation. The effects of parameters in design and operation on the power output and efficiency have been extensively studied. It is well-known that the gas turbine inlet temperature (TIT) needs to be high for high efficiency as well as power production. However, there are some material restrictions with high-temperature gas especially for the first row of blades. As a result blade cooling is needed to help balance between the high TIT and the material limitations. The increase of TIT is also limited by restriction of emissions. While the blade cooling can allow a higher TIT and better turbine performance, there is also a penalty since the compressed air used for cooling is removed from the combustion process. Therefore, an optimal cooling flow may exist for the overall efficiency and net power output. In this paper the relationship between the TIT and amount of cooling air is studied. The TIT increase due to blade cooling is considered as a function of cooling air flow as well as cooling effectiveness. In another word, the increase of the TIT is limited while the cooling air can be increased continuously. Based on the relationship proposed the impact of blade cooling on the gas turbine performance is investigated. Compared to the simple cycle case without cooling, the blade cooling can increase the efficiency from 28.8 to 34.0% and the net power from 105 to 208 MW. Cases with different operation conditions such as pressure ratios as well as design aspects with regeneration are considered. Aspen plus software is used to simulate the cycles.

scholarly journals Diagnosing the Sources of Overall Performance Deterioration in CCGT Plants

1999 ◽  
Author(s):  
K. Mathioudakis ◽  
A. Stamatis ◽  
E. Bonataki
Keyword(s):  
Power Plant ◽  
Measurement Uncertainty ◽  
Gas Turbine ◽  
Power Output ◽  
Additional Data ◽  
Combined Cycle ◽  
Performance Deterioration ◽  
Overall Performance ◽  
Improve Reliability

A method for diagnosing which parts of a Combined Cycle Gas Turbine (CCGT) power plant are responsible for performance deviations is presented. When the overall power output and efficiency deviate from their baseline value, application of the method allows the determination of the component(s) of the plant, responsible for this deviation. The level of depth of this assessment depends on the number of quantities measured. It is demonstrated that a minimal number of measurements can be used to allocate differences between the gas turbine and the steam part of the plant. Additional data can then be used to identify deviating components in more detail. The influence of measurement uncertainty and the exploitation of different measurements in order to check consistency and improve reliability of the results are discussed.

Sensitivity Analysis on Brayton Cycle Gas Turbine Performance

1997 ◽  
Vol 119 (4) ◽  
pp. 910-916
Author(s):  
G. Negri di Montenegro ◽  
A. Peretto
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Numerical Procedure ◽  
Brayton Cycle ◽  
Or Efficiency ◽  
Analytical Functions ◽  
Turbine Performance ◽  
Numerical Performance ◽  
Gas Turbine Power Plant

This paper evaluates the performance of a Brayton cycle gas turbine, in terms of power output and conversion efficiency. Sensitivity of this performance to the realistic value of each input variable considered is analyzed. Sensitivity is evaluated by introducing a parameter, defined as the ratio between the logarithmic differential of the power output or efficiency functions and the logarithmic differential of each variable considered. These analytical functions and their derivatives correspond to a gas turbine model developed by the authors. The above-mentioned sensitivity parameter can be also evaluated by means of a numerical procedure utilizing a common gas turbine power plant computational model. The values calculated with the two procedures turn out to be substantially the same. Finally, the present analysis permits the determination of the weight of the input variable and of its value on the obtainable numerical performance. Such weights are found to be less important for some variables, while they are of marked significance for others, thus indicating those input parameters requiring a very precise verification of their numerical values.

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