Measured Data Correction for Improved Fouling and Degradation Analysis of Offshore Gas Turbines

2004 ◽  
Author(s):  
Timot Veer ◽  
Klaus K. Haglero̸d ◽  
Olav Bolland
Keyword(s):  
Gas Turbines ◽  
Field Data ◽  
Measurement Data ◽  
Measured Data ◽  
Considerable Improvement ◽  
Data Correction ◽  
Performance Loss ◽  
Condition Evaluation ◽  
Degradation Analysis ◽  
Reliability And Availability

The authors suggest a straightforward methodology to correct measurement data in order to facilitate condition assessment of gas turbines. After data being prepared as such, a considerable improvement in accuracy is obtained in regard to condition evaluation of the machine. Such methodology brings proven benefits when regarding the fouling problem as well as washing scheduling at sites where the fouling process is relatively slow, e.g. offshore applications. Analyses of other relatively slow performance loss processes, like degradation, are also targeted. The usefulness of the methodology is validated against field data by employing advanced software tools and reliability and availability as well as condition and lifing prediction.

USE OF RIGID REFLECTORS FOR THE VIRTUAL INCREASE OF FIELD DATA IN THE NEAR-FIELD ACOUSTICAL HOLOGRAPHY

2007 ◽  
Vol 15 (01) ◽  
pp. 49-61 ◽  
Author(s):  
SUNG-IL KIM ◽  
JEONG-GUON IH ◽  
JI-HOON JEONG
Keyword(s):  
Boundary Element Method ◽  
Transfer Matrix ◽  
Field Data ◽  
Near Field ◽  
Measurement Data ◽  
Source Reconstruction ◽  
Matrix Equations ◽  
Inverse Boundary ◽  
Additional Information ◽  
Acoustical Holography

This paper suggests the use of rigid reflectors to provide additional information for source reconstruction in near-field acoustical holography based on the inverse boundary element method. The additional field pressure and transfer matrix equations introduced provide a virtual increase in the measurement data without increasing the number of sensors or altering their arrangement, which could cost more than using reflectors. In order to validate this method, we successfully reconstruct a vibrating ellipse.

Detection and Analysis of Rats’ Bioelectromagnetic Signal

2014 ◽  
Vol 536-537 ◽  
pp. 13-17
Author(s):  
Hong Long Cao ◽  
Fen Ju Qin ◽  
Xue Guan Liu ◽  
He Ming Zhao
Keyword(s):  
Standard Deviation ◽  
Automatic System ◽  
Measurement Method ◽  
Measurement Accuracy ◽  
Biological Activities ◽  
Measurement Data ◽  
Measured Data ◽  
The Mean ◽  
Frequency Window ◽  
Window Effects

In this paper, we designed an automatic system and automatic test software, and they can carry out Kunming rats bioelectromagnetic measurement in standard status and anesthesia automatically in anechoic chamber where the electromagnetic field outside is shielded, the reflection wave is absorbed, and the measurement accuracy will be improved. We get a great number of measurement data with frequency-sweep measurement method. The mean and standard deviation of amplitudes vs. frequencies is calculated and analyzed. The results show the measurement method is feasible. We have plotted the means of measured data as multiple sets of Y values in a series of bars with standard deviations bars included and distributed in the frequency axis of X. It is found that the fluctuation of the mean and standard deviation in some frequencies is not evident which may explain frequency window effects, while in other frequencies, such a fluctuation can be obviously observed, which may suggest that bioelectromagnetic signal is influenced by biological activities (standard and anaesthesia status) in these frequency points.

A NOx Reduction Project for a GT11 Type Gas Turbine

2005 ◽  
Author(s):  
Lars O. Nord ◽  
David R. Schoemaker ◽  
Helmer G. Andersen
Keyword(s):  
Power Plant ◽  
Distribution System ◽  
Gas Turbines ◽  
Nox Reduction ◽  
Measurement Data ◽  
Combustion Stability ◽  
Study Phase ◽  
Nox Emissions ◽  
Ambient Conditions ◽  
Exhaust Temperature

A study was initiated to investigate the possibility of significantly reducing the NOx emissions at a power plant utilizing, among other manufacturers, ALSTOM GT11 type gas turbines. This study is limited to one of the GT11 type gas turbines on the site. After the initial study phase, the project moved on to a mechanical implementation stage, followed by thorough testing and tuning. The NOx emissions were to be reduced at all ambient conditions, but particularly at cold conditions (below 0°C) where a NOx reduction of more than 70% was the goal. The geographical location of the power plant means cold ambient conditions for a large part of the year. The mechanical modifications included the addition of Helmholtz damper capacity with an approximately 30% increase in volume for passive thermo-acoustic instability control, significant piping changes to the fuel distribution system in order to change the burner configuration, and installation of manual valves for throttling of the fuel gas to individual burners. Subsequent to the mechanical modifications, significant time was spent on testing and tuning of the unit to achieve the wanted NOx emissions throughout a major part of the load range. The tuning was, in addition to the main focus of the NOx reduction, also focused on exhaust temperature spread, combustion stability, CO emissions, as well as other parameters. The measurement data was acquired through a combination of existing unit instrumentation and specific instrumentation added to aid in the tuning effort. The existing instrumentation readings were polled from the control system. The majority of the added instrumentation was acquired via the FieldPoint system from National Instruments. The ALSTOM AMODIS plant-monitoring system was used for acquisition and analysis of all the data from the various sources. The project was, in the end, a success with low NOx emissions at part load and full load. As a final stage of the project, the CO emissions were also optimized resulting in a nice compromise between the important parameters monitored, namely NOx emissions, CO emissions, combustion stability, and exhaust temperature distribution.

Aeroelastic Analysis of NREL Wind Turbine

2017 ◽  
Author(s):  
Yaozhi Lu ◽  
Fanzhou Zhao ◽  
Loic Salles ◽  
Mehdi Vahdati
Keyword(s):  
Numerical Model ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Gas Turbines ◽  
High Cycle Fatigue ◽  
Turbine Blades ◽  
Measured Data ◽  
Forced Response ◽  
Cycle Fatigue ◽  
Aeroelastic Analysis

The current development of wind turbines is moving toward larger and more flexible units, which can make them prone to fatigue damage induced by aeroelastic vibrations. The estimation of the total life of the composite components in a wind turbine requires the knowledge of both low and high cycle fatigue (LCF and HCF) data. The first aim of this study is to produce a validated numerical model, which can be used for aeroelastic analysis of wind turbines and is capable of estimating the LCF and HCF loads on the blade. The second aim of this work is to use the validated numerical model to assess the effects of extreme environmental conditions (such as high wind speeds) and rotor over-speed on low and high cycle fatigue. Numerical modelling of this project is carried out using the Computational Fluid Dynamics (CFD) & aeroelasticity code AU3D, which is written at Imperial College and developed over many years with the support from Rolls-Royce. This code has been validated extensively for unsteady aerodynamic and aeroelastic analysis of high-speed flows in gas turbines, yet, has not been used for low-speed flows around wind turbine blades. Therefore, in the first place the capability of this code for predicting steady and unsteady flows over wind turbines is studied. The test case used for this purpose is the Phase VI wind turbine from the National Renewable Energy Laboratory (NREL), which has extensive steady, unsteady and mechanical measured data. From the aerodynamic viewpoint of this study, AU3D results correlated well with the measured data for both steady and unsteady flow variables, which indicated that the code is capable of calculating the correct flow at low speeds for wind turbines. The aeroelastic results showed that increase in crosswind and shaft speed would result in an increase of unsteady loading on the blade which could decrease the lifespan of a wind turbine due to HCF. Shaft overspeed leads to significant increase in steady loading which affects the LCF behaviour. Moreover, the introduction of crosswind could result in significant dynamic vibration due to forced response at resonance.

Study of laser displacement measurement data abnormal correction algorithm

2017 ◽  
Vol 34 (1) ◽  
pp. 123-133 ◽  
Author(s):  
Zeguang Yi ◽  
Nan Pan ◽  
Yi Liu ◽  
Yu Guo
Keyword(s):  
Design Methodology ◽  
Euclidean Distance ◽  
Measurement Data ◽  
Correction Algorithm ◽  
Scatter Plot ◽  
Data Smoothing ◽  
Content Type ◽  
Data Correction ◽  
Noise Interference ◽  
Tool Mark

Purpose This paper aims to reduce and eliminate the abnormal peaks which, because of the reflection in the process of laser detection, make it easier to proceed with further analysis. Design/methodology/approach To solve the above problem, an abnormal data correction algorithm based on histogram, K-Means clustering and improved robust locally weighted scatter plot smoothing (LOWESS) is put forward. The proposed algorithm does section leveling for shear plant first and then applies histogram to define the abnormal fluctuation data between the neighboring points and utilizes a K-Means clustering to eliminate the abnormal data. After that, the improved robust LOWESS method, which is based on Euclidean distance, is used to remove the noise interference and finally obtain the waveform characteristics for next data processing. Findings The experiment result of liner tool mark laser test data correction demonstrates the accuracy and reliability of the proposed algorithm. Originality/value The study enables the following points: the detection signal automatic leveling; abnormal data identification and demarcation using K-Means clustering and histogram; and data smoothing using LOWESS.

Bayesian Estimation of Soil-Water Characteristic Curves

2021 ◽  
Author(s):  
Jie Zhang ◽  
Shuai Yang ◽  
Lulu Zhang ◽  
Mingliang Zhou
Keyword(s):  
Soil Water ◽  
Bayesian Model ◽  
Characteristic Curve ◽  
Measurement Data ◽  
Bayes Theorem ◽  
Empirical Method ◽  
Measured Data ◽  
Suggested Method ◽  
Empirical Methods ◽  
Soil Water Characteristic Curves

The soil-water characteristic curve (SWCC) is a significant prerequisite for studying the mechanical properties of unsaturated soil. As experimental measurement of the SWCC is time-consuming, empirical methods have been suggested to estimate the SWCC. However, the uncertainty associated with SWCC can be substantial. In this paper, a hybrid method based on Bayes’ theorem is suggested to estimate the SWCC, where an empirical method can be used to provide prior knowledge about the SWCC, and a limited quantity of measured data is used to update the SWCC. The Bayesian model is then solved with a Markov Chain Monte Carlo simulation. Through the suggested method, the valuable information provided by the empirical method can be combined with the measurement data. The suggested method can not only provide the best estimate about the SWCC, but also account for the associated uncertainty. Also, the effect of more measured points on the estimation of SWCC can be quantified. The suggested method provides a practical means to estimate the SWCC using a limited amount of data.

Maximizing MFL ILI Sizing Confidence and Accuracy Using High-Resolution Field Measurement Data

2012 ◽  
Author(s):  
Patrick Yeung ◽  
Ryan Sporns ◽  
Stuart Clouston ◽  
Grant A. Coleman ◽  
Scott Miller ◽  
...  
Keyword(s):  
High Resolution ◽  
Field Measurement ◽  
High Performance ◽  
Field Data ◽  
Oil And Gas ◽  
Measurement Techniques ◽  
Measurement Data ◽  
Industry Standards ◽  
Defect Profile ◽  
Wide Range

Magnetic Flux Leakage inspection tools are generally calibrated on a series of manufactured defects. This has been shown to give good results on a wide range of defects in varying wall thicknesses, velocities and pipeline conditions. Significant improvements in sizing performance can be achieved if sizing algorithms can be optimized on high resolution field data with low uncertainty that more closely reflects the actual line specific corrosion dimensions and profiles. The effects of defect profile can be significant to the MFL signal response. In order to achieve this goal, very high resolution and accurate field measurement techniques are needed to map the combined profile of a significant number of corrosion defects. This paper discusses a process for developing high performance sizing algorithms that consistently better industry standards for MFL sizing performance in areas of high density or complex corrosion in both oil and gas pipelines through the incorporation of high resolution laser scan technology. Complex corrosion may be considered as an area wherein individual corrosions interact together such that they no longer behave as a single corrosion and the MFL response experiences a superposition of leakage signals. A review of the methodology will be discussed and the results demonstrated through case studies from both Enbridge Pipelines Inc. and TransCanada Pipelines Ltd. where high-resolution field data was used as the basis for sizing model optimization.

Detection and Classification of Sensor Anomalies in Gas Turbine Field Data

2018 ◽  
Author(s):  
Giuseppe Fabio Ceschini ◽  
Lucrezia Manservigi ◽  
Giovanni Bechini ◽  
Mauro Venturini
Keyword(s):  
Anomaly Detection ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Field Data ◽  
Time Correlation ◽  
Detection Algorithm ◽  
Anomaly Classification ◽  
Monitoring And Diagnostics ◽  
Faulty Sensors

Anomaly detection and classification is a key challenge for gas turbine monitoring and diagnostics. To this purpose, a comprehensive approach for Detection, Classification and Integrated Diagnostics of Gas Turbine Sensors (named DCIDS) was developed by the authors in previous papers. The methodology consists of an Anomaly Detection Algorithm (ADA) and an Anomaly Classification Algorithm (ACA). The ADA identifies anomalies according to three different levels of filtering. Anomalies are subsequently analyzed by the ACA to perform their classification, according to time correlation, magnitude and number of sensors in which an anomaly is contemporarily identified. The performance of the DCIDS approach is assessed in this paper based on a significant amount of field data taken on several Siemens gas turbines in operation. The field data refer to six different physical quantities, i.e. vibration, pressure, temperature, VGV position, lube oil tank level and rotational speed. The analyses carried out in this paper allow the detection and classification of the anomalies and provide some rules of thumb for field operation, with the final aim of identifying time occurrence and magnitude of faulty sensors and measurements.

Evaluation of Car-Following Models Based on Measured Data from Real Traffic

2014 ◽  
Vol 701-702 ◽  
pp. 124-128
Author(s):  
Ji Qun Wu ◽  
Shuang Ke Li
Keyword(s):  
Traffic Simulation ◽  
Measurement Data ◽  
Measured Data ◽  
Velocity Change ◽  
Traffic Condition ◽  
Actual Measurement ◽  
The Real ◽  
Car Following ◽  
Xi’An City ◽  
Real Traffic

In this paper, we evaluate several typical car-following models based on actual measurement data from real traffic condition in Xi’an city by presenting a visual comparison between real and simulated value of the velocity for vehicles. We find that FVDM can depict the real velocity change accurately. Besides, some popular models such as OVM, GFM and OV-DM are not very suitable for real traffic simulation in Xi’an city, although they can represent some traffic phenomena under certain condition.

Unsteady Interaction Between Annulus and Turbine Rim Seal Flows

2012 ◽  
Author(s):  
Martin Chilla ◽  
Howard Hodson ◽  
David Newman
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Gas Turbines ◽  
Measurement Data ◽  
Design Flow ◽  
Flow Conditions ◽  
Disc Space ◽  
Flow Interaction ◽  
The Impact

In core gas turbines relatively cold air is purged through the hub gap between stator and rotor in order to seal the disc space against flow ingestion from the main annulus. Although the sealing mass flow rate is commonly very small compared to the main annulus mass flow rate, it can have significant effects on the development of the passage endwall flows and on the overall loss generation. In this paper, the interaction between annulus and rim sealing flows is investigated using numerical simulations of a generic high-pressure turbine. At first, the numerical approach is validated by comparing the results of calculations to measurement data at the design flow conditions. Following that, results from steady and unsteady calculations are used to describe in detail the aerodynamics in overlap-type rim seals and their effects on the blade passage flow. It is found that the flow interaction at the rim seal interface is strongly influenced by the velocity deficit of the rim sealing flow relative to the annulus flow as well as by the circumferentially non-uniform pressure field imposed by the rotor blades. At typical sealing flow conditions, the flow interaction is found to be naturally unsteady, with periodical vortex shedding into the rotor passage. Finally, the influence of the specific rim seal shape on the flow unsteadiness at the rim seal interface is investigated and the impact on turbine performance is assessed.

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