Gas turbine. Volume 1. Cycles and performance estimation

A new method for predicting performance of multistage axial flow compressors is proposed that utilizes stage performance curves. The method differs from the conventional sequential stage-stacking method in that it employs simultaneous calculation of all interstage variables (temperature, pressure and flow velocity). A consistent functional formulation of governing equations enables this simultaneous calculation. The method is found to be effective, i.e. fast and stable, in obtaining solutions for compressor inlet and outlet boundary conditions encountered in gas turbine analyses. Another advantage of the method is that the effect of changing the angles of movable stator vanes on the compressor's operating behaviour can be simulated easily. Accordingly, the proposed method is very suitable for complicated gas turbine system analysis. This paper presents the methodology and performance estimation results for various multistage compressors employing both fixed and variable vane setting angles. The effect of interstage air bleeding on compressor performance is also demonstrated.

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Effect of architecture configuration on software reliability and performance estimation

Proceedings. 1998 IEEE Workshop on Application-Specific Software Engineering and Technology. ASSET-98 (Cat. No.98EX183) ◽

10.1109/asset.1998.688240 ◽

2002 ◽

Cited By ~ 2

Author(s):

Mei-Hwa Chen ◽

Mei-Huei Tang ◽

Wen-Li Wang

Keyword(s):

Software Reliability ◽

Performance Estimation ◽

And Performance

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Comprehensive Thermodynamic Analysis of the Humphrey Cycle for Gas Turbines with Pressure Gain Combustion

Energies ◽

10.3390/en11123521 ◽

2018 ◽

Vol 11 (12) ◽

pp. 3521 ◽

Cited By ~ 5

Author(s):

Panagiotis Stathopoulos

Keyword(s):

Gas Turbine ◽

Gas Turbines ◽

Combustion Process ◽

Ideal Gas ◽

Point Of View ◽

Pressure Gain Combustion ◽

Combustion Technology ◽

Secondary Air ◽

And Performance ◽

The Impact

Conventional gas turbines are approaching their efficiency limits and performance gains are becoming increasingly difficult to achieve. Pressure Gain Combustion (PGC) has emerged as a very promising technology in this respect, due to the higher thermal efficiency of the respective ideal gas turbine thermodynamic cycles. Up to date, only very simplified models of open cycle gas turbines with pressure gain combustion have been considered. However, the integration of a fundamentally different combustion technology will be inherently connected with additional losses. Entropy generation in the combustion process, combustor inlet pressure loss (a central issue for pressure gain combustors), and the impact of PGC on the secondary air system (especially blade cooling) are all very important parameters that have been neglected. The current work uses the Humphrey cycle in an attempt to address all these issues in order to provide gas turbine component designers with benchmark efficiency values for individual components of gas turbines with PGC. The analysis concludes with some recommendations for the best strategy to integrate turbine expanders with PGC combustors. This is done from a purely thermodynamic point of view, again with the goal to deliver design benchmark values for a more realistic interpretation of the cycle.

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

Volume 4: Ceramics; Concentrating Solar Power Plants; Controls, Diagnostics and Instrumentation; Education; Electric Power; Fans and Blowers ◽

10.1115/gt2013-96013 ◽

2013 ◽

Cited By ~ 1

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.

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Characterization and Performance Estimation of a MEMS Spirometer

Procedia Engineering ◽

10.1016/j.proeng.2016.11.330 ◽

2016 ◽

Vol 168 ◽

pp. 1020-1023 ◽

Cited By ~ 4

Author(s):

Sahar Habibiabad ◽

Yeşim Serinağaoğlu Doğrusöz ◽

Mustafa İlker Beyaz

Keyword(s):

Performance Estimation ◽

And Performance

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Natural Gas Decarbonization to Reduce CO2 Emission From Combined Cycles—Part II: Steam-Methane Reforming

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.1395582 ◽

2000 ◽

Vol 124 (1) ◽

pp. 89-95 ◽

Cited By ~ 39

Author(s):

G. Lozza ◽

P. Chiesa

Keyword(s):

Natural Gas ◽

Gas Turbine ◽

Partial Oxidation ◽

Power Plants ◽

Combined Cycle ◽

Performance Estimation ◽

Thermodynamic Efficiency ◽

Methane Reforming ◽

Operating Pressure ◽

Carbon Conversion

This paper discusses novel schemes of combined cycle, where natural gas is chemically treated to remove carbon, rather than being directly used as fuel. Carbon conversion to CO2 is achieved before gas turbine combustion. The first part of the paper discussed plant configurations based on natural gas partial oxidation to produce carbon monoxide, converted to carbon dioxide by shift reaction and therefore separated from the fuel gas. The second part will address methane reforming as a starting reaction to achieve the same goal. Plant configuration and performance differs from the previous case because reforming is endothermic and requires high temperature heat and low operating pressure to obtain an elevated carbon conversion. The performance estimation shows that the reformer configuration has a lower efficiency and power output than the systems addressed in Part I. To improve the results, a reheat gas turbine can be used, with different characteristics from commercial machines. The thermodynamic efficiency of the systems of the two papers is compared by an exergetic analysis. The economic performance of natural gas fired power plants including CO2 sequestration is therefore addressed, finding a superiority of the partial oxidation system with chemical absorption. The additional cost of the kWh, due to the ability of CO2 capturing, can be estimated at about 13–14 mill$/kWh.

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A Comparative Study of Genetic Algorithms and Gradient Methods for RM12 Turbofan Engine Diagnostics and Performance Estimation

Volume 2: Turbo Expo 2004 ◽

10.1115/gt2004-53591 ◽

2004 ◽

Cited By ~ 7

Author(s):

Tomas Gro¨nstedt ◽

Markus Wallin

Keyword(s):

Gas Turbine ◽

Performance Test ◽

Gradient Methods ◽

Performance Testing ◽

Performance Estimation ◽

Data Sets ◽

Data Set ◽

Turbofan Engine ◽

Local Optima ◽

Bypass Ratio

Recent work on gas turbine diagnostics based on optimisation techniques advocates two different approaches: 1) Stochastic optimisation, including Genetic Algorithm techniques, for its robustness when optimising objective functions with many local optima and 2) Gradient based methods mainly for their computational efficiency. For smooth and single optimum functions, gradient methods are known to provide superior numerical performance. This paper addresses the key issue for method selection, i.e. whether multiple local optima may occur when the optimisation approach is applied to real engine testing. Two performance test data sets for the RM12 low bypass ratio turbofan engine, powering the Swedish Fighter Gripen, have been analysed. One set of data was recorded during performance testing of a highly degraded engine. This engine has been subjected to Accelerated Mission Testing (AMT) cycles corresponding to more than 4000 hours of run time. The other data set was recorded for a development engine with less than 200 hours of operation. The search for multiple optima was performed starting from more than 100 extreme points. Not a single case of multi-modality was encountered, i.e. one unique solution for each of the two data sets was consistently obtained. The RM12 engine cycle is typical for a modern fighter engine, implying that the obtained results can be transferred to, at least, most low bypass ratio turbofan engines. The paper goes on to describe the numerical difficulties that had to be resolved to obtain efficient and robust performance by the gradient solvers. Ill conditioning and noise may, as illustrated on a model problem, introduce local optima without a correspondence in the gas turbine physics. Numerical methods exploiting the special problem structure represented by a non-linear least squares formulation is given special attention. Finally, a mixed norm allowing for both robustness and numerical efficiency is suggested.

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