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.

scholarly journals Sensitivity Analysis on Brayton Cycle Gas Turbine Performance

1996 ◽  
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 on this performance due 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.

Determination of the optimum performance of gas turbines

2000 ◽  
Vol 214 (1) ◽  
pp. 243-255 ◽  
Author(s):  
J. H. Horlock ◽  
W. A. Woods
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Working Fluid ◽  
Optimum Conditions ◽  
Perfect Gas ◽  
Pressure Losses ◽  
Real Effects ◽  
Turbine Performance

Earlier analytical and graphical treatments of gas turbine performance, assuming the working fluid to be a perfect gas, are developed to allow for ‘non-perfect’ gas effects and pressure losses. The pressure ratios for maximum power and maximum thermal efficiency are determined analytically; the graphical presentations of performance based on the earlier approach are also modified. It is shown that the optimum conditions previously determined from the ‘air standard’ analyses may be changed quite substantially by the inclusion of the ‘real’ effects.

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 Thermodynamics performance optimization of a hybrid solar gas turbine power plant in Colombia

2022 ◽  
Vol 2163 (1) ◽  
pp. 012004
Author(s):  
F Moreno-Gamboa ◽  
J C Acevedo-Paez ◽  
D Sanin-Villa
Keyword(s):  
Power Plant ◽  
Solar Radiation ◽  
Gas Turbine ◽  
Power Output ◽  
Performance Optimization ◽  
Pressure Ratio ◽  
Direct Solar Radiation ◽  
Performance Point ◽  
Overall Efficiency ◽  
Gas Turbine Power Plant

Abstract A thermodynamic model is presented for evaluation of a solar hybrid gas-turbine power plant. The model uses variable ambient temperature and estimates direct solar radiation at different day times. The plant is evaluated in Barranquilla, Colombia, with a solar concentration system and a combustion chamber that burns natural gas. The hybrid system enables to maintain almost constant the power output throughout day. The model allows optimizing the different plant parameters and evaluating maximum performance point. This work presents pressure ratio ranges where the maximum values of overall efficiency, power output, thermal engine efficiency and fuel conversion rate are found. The study is based on the environmental conditions of Barranquilla, Colombia. The results obtained shows that optimum pressure ratio range for power output and overall efficiency is between 6.4 and 8.3, when direct solar radiation its maximum at noon. This thermodynamic analysis is necessary to design new generations of solar thermal power plants.

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.

Conceptual Recovery of Exhaust Heat From a Conventional Gas Turbine by an Inter-Cooled Inverted Brayton Cycle

1999 ◽  
Author(s):  
Y. Tsujikawa ◽  
K. Ohtani ◽  
K. Kaneko ◽  
T. Watanabe ◽  
S. Fujii
Keyword(s):  
Gas Turbine ◽  
Heat Recovery ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Brayton Cycle ◽  
Turbine Performance ◽  
Exhaust Heat ◽  
Manufacturing Techniques ◽  
Industrial Gas Turbine ◽  
Made In

Improvements in industrial gas turbine performance have been made in last decade. Advances in the gas turbine technologies such as higher turbine inlet temperature, materials, and manufacturing techniques justify the development of new combined or cogeneration cycle schemes, with more advance heat recovery capabilities. This paper describes the performance analysis of an Inverted Brayton Heat Recovery (IBHR) cycle, which is combined with conventional gas turbine and worked as a bottoming cycle. The optimum characteristics have been calculated and it is shown that this cycle is superior to the conventional combined cycle and cogeneration systems in terms of thermal efficiency and specific output. The main feature of this new concept is that the inverted Brayton cycle with inter-cooling is introduced. Further, a new estimating function, “the emission coefficient of carbon-dioxide” has been successfully introduced to assess the environmental compatibility.

scholarly journals Use of alternative fuels obtained from renewable sources in Brayton cycles

2013 ◽  
Vol 14 (2) ◽  
pp. 157-165
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Alternative Fuels ◽  
Alcoholic Fermentation ◽  
Combined Cycle ◽  
Brayton Cycle ◽  
Renewable Sources ◽  
Turbine Performance ◽  
Total Variability ◽  
Points Of View

Analysis and simulation of the behaviour of gas turbines for power generation using different nonconventional fuels obtained from different renewable sources are presented. Three biomass-tobiofuel processes are considered: anaerobic digestion of biomass (biogas), biomass gasification (synthesis gas) and alcoholic fermentation of biomass and dehydration (bioethanol), each of them with two different biomass substrates (energy crops and municipal solid waste) as input. The gas turbine behaviour in a Brayton cycle is simulated both in an isolated operation and in combined cycle. The differences in gas turbine performance when fired with the considered biofuels compared to natural gas are studied from different points of view related with the current complex energetic context: energetic and exergetic efficiency of the simple/combined cycle and CO2 emissions. Two different tools have been used for the simulations, each one with a different approach: while PATITUG (own software) analyses the behaviour of a generic gas turbine allowing a total variability of parameters, GT-PRO (commercial software) is more rigid, albeit more precise in the prediction of real gas turbine behaviour. Different potentially interesting configurations and its thermodynamic parameters have been simulated in order to obtain the optimal range for all of them and its variation for each fuel.

Analysis of Compressor On-Line Washing to Optimize Gas Turbine Power Plant Performance

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Ernst Schneider ◽  
Saba Demircioglu Bussjaeger ◽  
Susana Franco ◽  
Dirk Therkorn
Keyword(s):  
Gas Turbine ◽  
Performance Optimization ◽  
Gas Turbines ◽  
Compressor Blade ◽  
Plant Performance ◽  
Turbine Efficiency ◽  
Turbine Performance ◽  
On Line ◽  
Added Benefit ◽  
Gas Turbine Power Plant

Due to compressor fouling, gas turbine efficiency decreases over time, resulting in decreased power output of the plant. To counteract the effects of compressor fouling, compressor on-line and off-line washing procedures are used. The effectiveness of compressor off-line washing is enhanced if combined with the cleaning of the VIGVs and the first compressor blade row by hand. This paper presents a thorough analysis of the effects of compressor on-line washing on the gas turbine performance. The analysis is based on the measured data of six gas turbines operated at two different plants. Different washing schedules and washing fluids are analyzed and compared. Furthermore, the effects of compressor on-line washing on the load distribution within the compressor are analyzed. The performance benefit of daily compressor on-line washing compared with weekly compressor on-line washing is quantified. As expected, daily compressor on-line washing yields the lowest power degradation caused by compressor fouling. Also, the effect of washing additives is analyzed. It is shown with long term data that compressor on-line washing cleans up to the first 11 compressor stages, as can be detected well in the compressor. With a view to gas turbine performance optimization, the recommendation is to perform compressor off-line washing at regular intervals and to take advantage of occasions such as inspections, when the gas turbine is cooled down anyhow. Especially for gas turbines with a high fouling rate, a daily compressor on-line washing schedule should be considered to reduce the power loss. For gas turbines operating with high fogging, compressor on-line washing has no added benefit. To determine the optimal compressor washing schedule, compressor blade erosion also has to be considered. A reasonable balance between compressor on-line washing and off-line washing improves the gas turbine performance and optimizes the gas turbine availability.

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.

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.

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