Linear Transfer Functions Extraction for a Power Generation Three-Shaft Gas Turbine Based on Actual Specifications

Author(s):  
Abdollah Mehrpanahi ◽  
Gholamhassan Payganeh ◽  
Mohammadreza Arbabtafti

The design and testing of various types of controllers require accurate and reliable transfer functions that are compatible with the performance condition of the system. In this paper, the linear and the nonlinear methods have been utilized for extracting the transfer functions for a three-shaft industrial gas turbine. The main variables are the fuel input and environment temperature, while the main outputs are the LPT exhaust gas temperature and the generated power. According to the nonlinear structure of the system and the input variation intervals, the quasi-amplitude-modulated pseudo random binary sequence signals have been utilized for generating input parameters. Finally, the results extracted from the selected methods were compared to the outputs of real performance data under loading and unloading conditions. Based on the comparison between the accuracies obtained by the results, the auto-regressive moving average with eXogenous, try and error transfer function and linearized Hammerstein model methods are proposed, respectively. The outcome of using the controller indicated higher compatibility from transfer functions as compared to the reference dynamic model.

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5950
Author(s):  
Jinfu Liu ◽  
Mingliang Bai ◽  
Zhenhua Long ◽  
Jiao Liu ◽  
Yujia Ma ◽  
...  

Failures of the gas turbine hot components often cause catastrophic consequences. Early fault detection can detect the sign of fault occurrence at an early stage, improve availability and prevent serious incidents of the plant. Monitoring the variation of exhaust gas temperature (EGT) is an effective early fault detection method. Thus, a new gas turbine hot components early fault detection method is developed in this paper. By introducing a priori knowledge and quantum particle swarm optimization (QPSO), the exhaust gas temperature profile continuous distribution model is established with finite EGT measuring data. The method eliminates influences of operating and ambient condition changes and especially the gas swirl effect. The experiment reveals the presented method has higher fault detection sensitivity.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Zhi-tao Wang ◽  
Ning-bo Zhao ◽  
Wei-ying Wang ◽  
Rui Tang ◽  
Shu-ying Li

As an important gas path performance parameter of gas turbine, exhaust gas temperature (EGT) can represent the thermal health condition of gas turbine. In order to monitor and diagnose the EGT effectively, a fusion approach based on fuzzy C-means (FCM) clustering algorithm and support vector machine (SVM) classification model is proposed in this paper. Considering the distribution characteristics of gas turbine EGT, FCM clustering algorithm is used to realize clustering analysis and obtain the state pattern, on the basis of which the preclassification of EGT is completed. Then, SVM multiclassification model is designed to carry out the state pattern recognition and fault diagnosis. As an example, the historical monitoring data of EGT from an industrial gas turbine is analyzed and used to verify the performance of the fusion fault diagnosis approach presented in this paper. The results show that this approach can make full use of the unsupervised feature extraction ability of FCM clustering algorithm and the sample classification generalization properties of SVM multiclassification model, which offers an effective way to realize the online condition recognition and fault diagnosis of gas turbine EGT.


Author(s):  
Giancarlo Chiatti ◽  
Ornella Chiavola

A comparative series of experimental tests has been performed on a 4-stroke multi cylinder indirect injection diesel engine fueled with diesel oil, pure gas-turbine fuel and gas-turbine fuel with additives. The engine has been equipped aimed at monitoring both the overall performances and the variation with time of the pressure in the pre-combustion chamber. Some key parameters have been investigated at different engine speeds and loads (ignition delay, pressure rise in the pre-combustion chamber, power output, specific fuel consumption, exhaust gas temperature) and discussed results are presented.


Author(s):  
T. Sugimoto ◽  
K. Ikesawa ◽  
S. Kajita ◽  
W. Karasawa ◽  
T. Kojima ◽  
...  

The M7A-01 gas turbine is a newly developed 6 MW class single-shaft machine. With its high simple-cycle efficiency and high exhaust gas temperature. it is particularly suited for use in electric power generation and co-generation applications. An advanced high efficiency axial-flow compressor, six can-type combustors, and a high inlet temperature turbine has been adopted. This results in a high thermal efficiency of 31.5% at the gas turbine output shaft and a high overall thermal efficiency of co-generation system. In addition, low NOx emissions from the combustors and a long service life permit long-term continuous operation under various environmental limitations. The results of the full load shop test, accelerated cyclic endurance test and extra severity tests verified that the performance, the mechanical characteristics and the emission have satisfied the initial design goals.


2019 ◽  
Vol 118 ◽  
pp. 03056
Author(s):  
Su Pan ◽  
Pengfeng Yu ◽  
Linbo Liu ◽  
Jing Han ◽  
Xiao Shen

In order to solve the problem of abnormal rise of the differential pressure of the revolving air preheater on 300MW unit, we analysed the causes of abnormal rise of the differential pressure of the air preheater and evaluated performances of control measures, through historical data mining and on-site inspection of the unit. The results show that, with the gradual decrease of environment temperature with the decrease of the exhaust gas temperature, the ashes in flue gas are bound by acid liquid produced by condensation of flue gas, and the adhesion areas of the ammonium bisulfate produced in the denitration process are enlarged. However the original set ash blowing pressure can no longer satisfy the requirements of the air preheater, giving rise to the differential pressure of the air preheater on both sides to rise. The reason of the higher differential pressure of the unilateral air preheater is that the large ammonia injection amount, leading to the increases of ammonia escape of the denitrification system. So the side of the air on preheater ammonium bisulfate type blockage is more serious. After the Measures of Adjusting distribution coefficient of ammonia supply valve on both sides, increasing the dust blowing frequency and pressure of the air preheater, the differential pressure of air preheater on both sides are close to the consistent. The decrease amplitude of the differential pressure of the air preheater on 280MW is about 300-500Pa.


Author(s):  
K. Mathioudakis ◽  
E. Loukis ◽  
K. D. Papailiou

The results from an experimental investigation of the compressor casing vibration of an industrial Gas Turbine are presented. It is demonstrated that statistical properties of acceleration signals can be linked with engine operating conditions. The power content of such signals is dominated by contributions originating from the stages of the compressor, while the contribution of the shaft excitation is secondary. Using non-parametric identification methods, accelerometer outputs are correlated to unsteady pressure measurements taken by fast response transducers at the inner surface of the compressor casing. The transfer functions allow reconstruction of unsteady pressure signal features from the accelerometer readings. A possibility is thus provided, for “seeing” the unsteady pressure field of the rotor blades without actually penetrating through the casing, but by simply observing its external surface vibrations.


Author(s):  
Igor Loboda ◽  
Sergey Yepifanov ◽  
Yakov Feldshteyn

Monitoring algorithms analyzing measured gas path variables provide invaluable insight into gas turbine operating health. Some useful information about a gas turbine and its measurement system can be obtained from a direct analysis of raw measurements. To draw more comprehensive diagnostic information, deviations are usually calculated as discrepancies between the measured and baseline values of monitored variables. The deviations can serve as good indicators of different engine degradation mechanisms. However, there are many negative factors that tend to mask degradation effects. For a long period of time we have analyzed quality of gas path measurement data and a deviation accuracy problem of a gas turbine power plant driving a natural gas pipeline compressor. Possible error sources were examined and some methods were proposed to improve the accuracy of deviation calculations. This paper looks at maintenance data of another object, the General Electric LM2500 gas turbine used as a drive of an electric generator. The data cover prolonged periods of axial compressor fouling with washings between them, and provide valuable information for a deviation examination. In order to reduce deviation errors, the paper considers different cases of the abnormal functioning of the sensors and baseline model inadequacy and proposes measures to avoid them. As a result of these and previous efforts, the deviations have become good fouling indicators. They are capable to quantify the increase of exhaust gas temperature (EGT) and, consequently, to improve planning axial compressor washings.


2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Amir Mardani ◽  
Benyamin Asadi Rekabdarkolaei ◽  
Hamed Rezapour Rastaaghi

Abstract In this work, a double-high swirl gas turbine model combustor (GTMC) has been experimentally investigated to identify the effects of air partitioning and swirlers geometry on combustion characteristics in terms of flame stability, exhaust gas temperature, NOx generation, and combustion efficiency. This high swirl model combustor is originally developed in the German Aerospace Center (DLR) and known as GTMC and recently reconstructed at Sharif University's Combustion Laboratory (named as SGTMC). Here, SGTMC run for liquefied petroleum gas (LPG) fuel and air oxidizer at room temperature and atmospheric pressure. Eleven different burner geometries, M1–M11, are considered for the aims of this work. Furthermore, the effects of burner confinement are also investigated. The results show that under the confined state, the flame has a lower width and height than the unconfined one. Exchanging the swirlers of annular and central air inlets shows a more stable and lifted V type flame with almost zero levels of CO and CH4. In addition, measurement showed that the annular swirler removing leads to incomplete combustion. Moreover, an increment in discharged air velocity leads to more completed combustion and less pollutant exhaust gas but the attachment of flame to the burner hub. Strengthening the flow channeling is not reasonable in terms of emission aspects. Moreover, burner configuring to counterrotating swirlers leads to a more stable flame but with lower combustion efficiency. Among 11 test cases, the original configuration and the case of exchanging the swirlers of annular and central air inlets are the best choices in terms of combustion efficiency and stability. Measurements show the improvement of burner stability, 2–10%, due to inlet air preheating.


Author(s):  
J. H. Moore

Combined-cycle power plants have been built with the gas turbine, steam turbine, and generator connected end-to-end to form a machine having a single shaft. To date, these plants have utilized a nonreheat steam cycle and a single-casing steam turbine of conventional design, connected to the collector end of the generator through a flexible shaft coupling. A new design has been developed for application of an advanced gas turbine of higher rating and higher firing temperature and exhaust gas temperature with a reheat steam cycle. The gas turbine and steam turbine are fully integrated mechanically, with solid shaft couplings and a common thrust bearing. This paper describes the new machine, with emphasis on the steam turbine section where the elimination of the flexible coupling created a number of unusual design requirements. Significant benefits in reduced cost and reduced complexity of design, operation, and maintenance are achieved as a result of the integration of the machine and its control and auxiliary systems.


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