scholarly journals Inter-Stage Dynamic Performance of an Axial Compressor of a Twin-Shaft Industrial Gas Turbine

Machines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 83
Author(s):  
Samuel Cruz-Manzo ◽  
Senthil Krishnababu ◽  
Vili Panov ◽  
Chris Bingham
Keyword(s):  
Gas Turbine ◽  
Dynamic Performance ◽  
Axial Compressor ◽  
Modeling Framework ◽  
Axial Compressors ◽  
Stage Performance ◽  
Compressor Map ◽  
Stage Characteristic ◽  
Industrial Gas Turbine ◽  
Semi Empirical

In this study, the inter-stage dynamic performance of a multistage axial compressor is simulated through a semi-empirical model constructed in the Matlab Simulink environment. A semi-empirical 1-D compressor model developed in a previous study has been integrated with a 0-D twin-shaft gas turbine model developed in the Simulink environment. Inter-stage performance data generated through a high-fidelity design tool and based on throughflow analysis are considered for the development of the inter-stage modeling framework. Inter-stage performance data comprise pressure ratio at various speeds with nominal variable stator guide vane (VGV) positions and with hypothetical offsets to them with respect to the gas generator speed (GGS). Compressor discharge pressure, fuel flow demand, GGS and power turbine speed measured during the operation of a twin-shaft industrial gas turbine are considered for the dynamic model validation. The dynamic performance of the axial-compressor, simulated by the developed modeling framework, is represented on the overall compressor map and individual stage characteristic maps. The effect of extracting air through the bleed port in the engine center-casing on transient performance represented on overall compressor map and stage performance maps is also presented. In addition, the dynamic performance of the axial-compressor with an offset in VGV position is represented on the overall compressor map and individual stage characteristic maps. The study couples the fundamental principles of axial compressors and a semi-empirical modeling architecture in a complementary manner. The developed modeling framework can provide a deeper understanding of the factors that affect the dynamic performance of axial compressors.

Transonic Axial Compressors Loss Correlations: Part I — Analysis and Update of Loss Models

2020 ◽  
Author(s):  
Marco Manfredi ◽  
Fabrizio Fontaneto
Keyword(s):  
Axial Compressor ◽  
Reduced Order ◽  
Axial Compressors ◽  
Analysis And Design ◽  
Main Driver ◽  
Validity Range ◽  
Loss Models ◽  
Generation Mechanisms ◽  
Semi Empirical ◽  
System Designs

Abstract The quest for greener, more efficient aircraft engines is the main driver for the development of innovative compression system designs. Reduced order design tools rely nevertheless on semi-empirical loss models, whose validity range is often not net or in general not verified. The present work aims at defining a set of loss correlations, which could readily be employed in the analysis and design process of modern transonic axial compressors. In part I, the main entropy generation mechanisms are described together with a review of the most commonly employed modelling approaches. Selected loss models are then deeper investigated and updated to increase both their range of validity and the accuracy of their predictions. In Part II, the effectiveness of the investigated models will be tested for one specific low aspect ratio axial compressor stage.

Improvement of the aerodynamic parameters of a 16-stage axial compressor for industrial gas turbine power unit

2021 ◽  
Author(s):  
Grigorii M. Popov ◽  
Maxim Miheev ◽  
Vasilii M. Zubanov ◽  
Oleg Baturin ◽  
Evgenii Goriachkin ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Power Unit ◽  
Axial Compressor ◽  
Aerodynamic Parameters ◽  
Industrial Gas Turbine

Quick Start of an Industrial Gas Turbine Engine Through the Development of “Silent Start” VGV Schedule

2020 ◽  
Author(s):  
Senthil Krishnababu ◽  
Vili Panov ◽  
Simon Jackson ◽  
Andrew Dawson
Keyword(s):  
Guide Vane ◽  
Pressure Ratio ◽  
Axial Compressor ◽  
Rotating Stall ◽  
Rotor Blades ◽  
Start Time ◽  
Turbine Engine ◽  
High Pressure Ratio ◽  
Compressor Map ◽  
Industrial Gas Turbine

Abstract In this paper, research that was carried out to optimise an initial variable guide vane schedule of a high-pressure ratio, multistage axial compressor is reported. The research was carried out on an extensively instrumented scaled compressor rig. The compressor rig tests carried out employing the initial schedule identified regions in the low speed area of the compressor map that developed rotating stall. Rotating stall regions that caused undesirable non-synchronous vibration of rotor blades were identified. The variable guide vane schedule optimisation carried out balancing the aerodynamic, aero-mechanical and blade dynamic characteristics gave the ‘Silent Start’ variable guide vane schedule, that prevented the development of rotating stall in the start regime and removed the non-synchronous vibration. Aerodynamic performance and aero-mechanical characteristics of the compressor when operated with the initial schedule and the optimised ‘Silent Start’ schedule are compared. The compressor with the ‘Silent Start’ variable guide vane schedule when used on a twin shaft engine reduced the start time to minimum load by a factor of four and significantly improved the operability of the engine compared to when the initial schedule was used.

An Analysis of Axial Compressor Fouling and a Blade Cleaning Method

1998 ◽  
Vol 120 (2) ◽  
pp. 256-261 ◽  
Author(s):  
A. P. Tarabrin ◽  
V. A. Schurovsky ◽  
A. I. Bodrov ◽  
J.-P. Stalder
Keyword(s):  
Mathematical Model ◽  
Axial Compressor ◽  
Axial Compressors ◽  
Cleaning Method ◽  
Engine Efficiency ◽  
Calculation Results ◽  
On Line ◽  
Compressor Performance ◽  
High Level ◽  
Industrial Gas Turbine

The paper describes the phenomenon of axial compressor fouling due to aerosols contained in the air. Key parameters having effect on the level of fouling are determined. A mathematical model of a progressive compressor fouling using the stage-by-stage calculation method is developed. Calculation results on the influence of fouling on the compressor performance are presented. A new index of sensitivity of axial compressors to fouling is suggested. The paper gives information about Turbotect’s deposit cleaning method of compressor blading and the results of its application on an operating industrial gas turbine. Regular on-line and off-line washings of the compressor flow path make it possible to maintain a high level of engine efficiency and output.

An Analysis of Axial Compressors Fouling and a Cleaning Method of Their Blading

1996 ◽  
Author(s):  
A. P. Tarabrin ◽  
V. A. Schurovsky ◽  
A. I. Bodrov ◽  
J.-P. Stalder
Keyword(s):  
Mathematical Model ◽  
Axial Compressor ◽  
Axial Compressors ◽  
Cleaning Method ◽  
Engine Efficiency ◽  
Calculation Results ◽  
On Line ◽  
Compressor Performance ◽  
High Level ◽  
Industrial Gas Turbine

The paper describes the phenomenon of axial compressor fouling due to aerosols contained in the air. Key parameters having effect on the level of fouling are determined. A mathematical model of a progressive compressor fouling using the stage-by-stage calculation method is developed. Calculation results on the influence of fouling on the compressor performance are presented. A new index of sensitivity of axial compressors to fouling is suggested. The paper gives information about the Turbotect’s deposit cleaning method of compressor blading and the results of its application on an operating industrial gas turbine. Regular on line and off line washings of compressor flow path make it possible to maintain a high level of engine efficiency and output.

scholarly journals EFFECT OF HYSTERESIS IN AXIAL COMPRESSORS OF GAS-TURBINE ENGINES

Aviation ◽  
2012 ◽  
Vol 16 (4) ◽  
pp. 97-102 ◽  
Author(s):  
Mykola Kulyk ◽  
Ivan Lastivka ◽  
Yuri Tereshchenko
Keyword(s):  
Gas Turbine ◽  
Axial Compressor ◽  
Separated Flow ◽  
Aerodynamic Performance ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Bladed Disks ◽  
Axial Compressors

The phenomenon of separated flow hysteresis in the process of the streamlining the axial compressor of gas-turbine engines is considered. Generalised results of research on the occurrence of hysteresis in the aerodynamic performance of compressor grids and its influence on the performance of the bladed disks of compressors that operate in real conditions of periodic circular non-uniformity are demonstrated.

scholarly journals Axial compressor fouling detection for gas turbine driven gas compression unit

2019 ◽  
Vol 15 (3) ◽  
pp. 1257
Author(s):  
Nurlan Batayev
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Detection System ◽  
Axial Compressor ◽  
Compressor Blades ◽  
Exhaust Temperature ◽  
Gas Compression ◽  
Compressor Power ◽  
Industrial Gas Turbine

<span>One of the main reasons of the performance degradation of gas turbines is the axial compressor fouling due to air pollutants. Considering the fact that the fouling leads to high consumption of fuel, reducing of the axial compressor’s discharge air pressure and increasing of the exhaust temperature, thus designing a compressor degradation detection system will allow prevent such issues. Many gas turbine plants lose power due to dirty axial compressor blades, which can add up to 4% loss of power. In case of power plants, the power loosing could be observed by less megawatts produced by generator. But in case of gas compression stations the effect of power loosing could not be quickly detected, because there is not direct measurement of the discharge power produced by gas turbine. This article represents technique for detection of gas turbine axial compressor degradation in case of gas turbine driven natural gas compression units. Calculation of the centrifugal gas compressor power performed using proven methodology. Approach for evaluation of the gas turbine performance based on machine learning prediction model is shown.  Adequacy of the model has been made to three weeks’ operation data of the 10 Megawatt class industrial gas turbine.</span>

scholarly journals Loss in Axial Compressor Bleed Systems

2019 ◽  
Author(s):  
S. D. Grimshaw ◽  
J. Brind ◽  
G. Pullan ◽  
R. Seki
Keyword(s):  
Gas Turbine ◽  
Control Volume ◽  
Axial Compressor ◽  
Thermodynamic Cycle ◽  
Loss Coefficient ◽  
Dynamic Head ◽  
Definition Of ◽  
Gas Turbine Compressor ◽  
Industrial Gas Turbine ◽  
Loss Mechanisms

Abstract Loss in axial compressor bleed systems is quantified, and the loss mechanisms identified, in order to determine how efficiency can be improved. For a given bleed air pressure requirement, reducing bleed system loss allows air to be bled from further upstream in the compressor, with benefits for the thermodynamic cycle. A definition of isentropic efficiency which includes bleed flow is used to account for this. Two cases with similar bleed systems are studied: a low-speed, single-stage research compressor and a large industrial gas turbine high-pressure compressor. A new method for characterising bleed system loss is introduced, using research compressor test results as a demonstration case. A loss coefficient is defined for a control volume including only flow passing through the bleed system. The coefficient takes a measured value of 95% bleed system inlet dynamic head, and is shown to be a weak function of compressor operating point and bleed rate, varying by ±2.2% over all tested conditions. This loss coefficient is the correct non-dimensional metric for quantifying and comparing bleed system performance. Computations of the research compressor and industrial gas turbine compressor identify the loss mechanisms in the bleed system flow. In both cases, approximately two-thirds of total loss is due to shearing of a high-velocity jet at the rear face of the bleed slot, one quarter is due to mixing in the plenum chamber and the remainder occurs in the off-take duct. Therefore, the main objective of a designer should be to diffuse the flow within the bleed slot. A redesigned bleed slot geometry is presented that achieves this objective and reduces the loss coefficient by 31%.

Application of Smith Chart for Non-Repeating Stages in Axial Compressors

2013 ◽  
Author(s):  
Daniel Hernández ◽  
Antonio Antoranz ◽  
Raúl Vázquez
Keyword(s):  
Early Stage ◽  
Axial Compressor ◽  
Preliminary Design ◽  
The Novel ◽  
Flow Angle ◽  
Axial Compressors ◽  
Absolute Flow ◽  
Final Design ◽  
Semi Empirical ◽  
Smith Chart

The configuration of an axial compressor, including the mean radius, the annulus lines, stage loading or number of stages, flow parameter, work split and stage reactions, are all of them selected in the preliminary design phase. For the success of the final design, to attain the proper selection is mandatory. A representative geometry of the airfoils is not available at this early stage of the design process. Therefore the former parameters use to be selected based only on the designer prior experience and/or empirical correlations. Under these circumstances, the so called Smith Chart is a valuable tool that can provide simple guidelines to the designer and a preliminary assessment of the compressor efficiency. The use of this chart can be also extended to get the main features of the airfoils, like flow angles, turning, Mach and Reynolds number, diffusion factor, aspect ratio, etc. as well as to compare different design candidates. Several authors have produced their own diagrams by analytical or semi-empirical approach. The repeating stage hypothesis, which has been usually assumed, implies no change in inlet and outlet absolute flow angles and constant axial velocity throughout the stage. The density rise through the stage is compensated by reducing the annulus height and so the annulus wall slope along the compressor is directly obtained from the continuity equation, being in most of the cases not representative of real compressors. In order to have a more representative annulus, in the present work, the repeating stage hypothesis has not been assumed. The annulus shape (height and slope wall angle) is therefore defined by the designer and in order to close the equations of the problem, the absolute exit flow angle of every stage is required. The optimization of the compressor by the novel proposed method is more complicate because of the higher number of variables. However the method has the advantage to reduce the design iterations due to its more reliable results. The aim of this paper is to introduce the novel method of non-repeating stages and to show how this approach can be used in the preliminary design of an axial compressor.

An analytical approach to predicting particle deposit by fouling in the axial compressor of the industrial gas turbine

2005 ◽  
Vol 219 (3) ◽  
pp. 203-212 ◽  
Author(s):  
T W Song ◽  
J L Sohn ◽  
T S Kim ◽  
J H Kim ◽  
S T Ro
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Particle Deposition ◽  
Axial Compressor ◽  
Design Parameters ◽  
Compressor Blades ◽  
Particle Distributions ◽  
Industrial Gas Turbines ◽  
Industrial Gas Turbine ◽  
Physical Phenomena

The gas turbine performance deteriorates with increased operating hours. Fouling in the axial compressor is an important factor for the performance degradation of gas turbines. Airborne particles entering the compressor with the air adhere to the blade surface and result in the change of the blade shape, which directly influences the compressor performance. It is difficult to exactly understand the mechanism of compressor fouling because of its slow growth and different length scales of compressor blades. In this study, an analytical method to predict the particle motion in the axial compressor and the characteristics of particle deposition onto blade is proposed as an approach to investigating physical phenomena of fouling in the axial compressor of industrial gas turbines. Calculated results using the proposed method and comparison with measured data demonstrate the feasibility of the model. It was also found that design parameters of the axial compressor such as chord length, solidity, and number of stages are closely related to the fouling phenomena. Likewise, the particle size and patterns of particle distributions are also important factors related to fouling phenomena in the axial compressor.

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