scholarly journals Modeling and Control of the Starter Motor and Start-Up Phase for Gas Turbines

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 363
Author(s):  
Soheil Jafari ◽  
Seyed Miran Fashandi ◽  
Theoklis Nikolaidis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Numerical Solutions ◽  
Frequency Converter ◽  
Variable Structure ◽  
Transient Behavior ◽  
Intermediate Stage ◽  
Mechatronic System ◽  
Turbine Performance ◽  
Start Up

Improving the performance of industrial gas turbines has always been at the focus of attention of researchers and manufacturers. Nowadays, the operating environment of gas turbines has been transformed significantly respect to the very fast growth of renewable electricity generation where gas turbines should provide a safe, reliable, fast, and flexible transient operation to support their renewable partners. So, having a reliable tools to predict the transient behavior of the gas turbine is becoming more and more important. Regarding the response time and flexibility, improving the turbine performance during the start-up phase is an important issue that should be taken into account by the turbine manufacturers. To analyze the turbine performance during the start-up phase and to implement novel ideas so as to improve its performance, modeling, and simulation of an industrial gas turbine during cold start-up phase is investigated this article using an integrated modular approach. During this phase, a complex mechatronic system comprised of an asynchronous AC motor (electric starter), static frequency converter drive, and gas turbine exists. The start-up phase happens in this manner: first, the clutch transfers the torque generated by the electric starter to the gas turbine so that the turbine reaches a specific speed (cranking stage). Next, the turbine spends some time at this speed (purging stage), after which the turbine speed decreases, sparking stage begins, and the turbine enters the warm start-up phase. It is, however, possible that the start-up process fails at an intermediate stage. Such unsuccessful start-ups can be caused by turbine vibrations, the increase in the gradients of exhaust gases, or issues with fuel spray nozzles. If, for any reason, the turbine cannot reach the self-sustained speed and the speed falls below a certain threshold, the clutch engages once again with the turbine shaft and the start-up process is repeated. Consequently, when modeling the start-up phase, we face discontinuities in performance and a system with variable structure owing to the existence of clutch. Modeling the start-up phase, which happens to exist in many different fields including electric and mechanical application, brings about problems in numerical solutions (such as algebraic loop). Accordingly, this study attempts to benefit from the bond graph approach (as a powerful physical modeling approach) to model such a mechatronic system. The results confirm the effectiveness of the proposed approach in detailed performance prediction of the gas turbine in start-up phase.

Evolution of Gas Turbine Intake Air Filtration in a 420 MW Cogeneration Plant

2014 ◽  
Author(s):  
Steve Ingistov ◽  
Michael Milos ◽  
Rakesh K. Bhargava
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Economic Benefits ◽  
Cogeneration Plant ◽  
Air Filtration ◽  
Air Filter ◽  
Filter System ◽  
Turbine Performance ◽  
Filtration System ◽  
Operational Data

A suitable inlet air filter system is required for a gas turbine, depending on installation site and its environmental conditions, to minimize contaminants entering the compressor section in order to maintain gas turbine performance. This paper describes evolution of inlet air filter systems utilized at the 420 MW Watson Cogeneration Plant consisting of four GE 7EA gas turbines since commissioning of the plant in November 1987. Changes to the inlet air filtration system became necessary due to system limitations, a desire to reduce operational and maintenance costs, and enhance overall plant performance. Based on approximately 2 years of operational data with the latest filtration system combined with other operational experiences of more than 25 years, it is shown that implementation of the high efficiency particulate air filter system provides reduced number of crank washes, gas turbine performance improvement and significant economic benefits compared to the traditional synthetic media type filters. Reasons for improved gas turbine performance and associated economic benefits, observed via actual operational data, with use of the latest filter system are discussed in this paper.

Marine Gas Turbine Performance Model for More Electric Ships

2011 ◽  
Author(s):  
George M. Koutsothanasis ◽  
Anestis I. Kalfas ◽  
Georgios Doulgeris
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Diesel Engines ◽  
Gas Turbines ◽  
Electric Propulsion ◽  
Operating Conditions ◽  
Prime Mover ◽  
Creep Life ◽  
Hull Fouling ◽  
Turbine Performance

This paper presents the benefits of the more electric vessels powered by hybrid engines and investigates the suitability of a particular prime-mover for a specific ship type using a simulation environment which can approach the actual operating conditions. The performance of a mega yacht (70m), powered by two 4.5MW recuperated gas turbines is examined in different voyage scenarios. The analysis is accomplished for a variety of weather and hull fouling conditions using a marine gas turbine performance software which is constituted by six modules based on analytical methods. In the present study, the marine simulation model is used to predict the fuel consumption and emission levels for various conditions of sea state, ambient and sea temperatures and hull fouling profiles. In addition, using the aforementioned parameters, the variation of engine and propeller efficiency can be estimated. Finally, the software is coupled to a creep life prediction tool, able to calculate the consumption of creep life of the high pressure turbine blading for the predefined missions. The results of the performance analysis show that a mega yacht powered by gas turbines can have comparable fuel consumption with the same vessel powered by high speed Diesel engines in the range of 10MW. In such Integrated Full Electric Propulsion (IFEP) environment the gas turbine provides a comprehensive candidate as a prime mover, mainly due to its compactness being highly valued in such application and its eco-friendly operation. The simulation of different voyage cases shows that cleaning the hull of the vessel, the fuel consumption reduces up to 16%. The benefit of the clean hull becomes even greater when adverse weather condition is considered. Additionally, the specific mega yacht when powered by two 4.2MW Diesel engines has a cruising speed of 15 knots with an average fuel consumption of 10.5 [tonne/day]. The same ship powered by two 4.5MW gas turbines has a cruising speed of 22 knots which means that a journey can be completed 31.8% faster, which reduces impressively the total steaming time. However the gas turbine powered yacht consumes 9 [tonne/day] more fuel. Considering the above, Gas Turbine looks to be the only solution which fulfills the next generation sophisticated high powered ship engine requirements.

scholarly journals Comparison of Coriolis and Turbine Type Flow Meters for Fuel Measurement in Gas Turbine Testing

1993 ◽  
Author(s):  
J. D. MacLeod ◽  
W. Grabe
Keyword(s):  
Steady State ◽  
Gas Turbine ◽  
Mass Flow ◽  
Gas Turbines ◽  
Gas Turbine Engine ◽  
Turbine Engine ◽  
Turbine Flowmeter ◽  
Turbine Performance ◽  
Coriolis Flowmeter ◽  
Project Objectives

The Machinery and Engine Technology (MET) Program of the National Research Council of Canada (NRCC) has established a program for the evaluation of sensors to measure gas turbine engine performance accurately. The precise measurement of fuel flow is an essential part of steady-state gas turbine performance assessment. Prompted by an international engine testing and information exchange program, and a mandate to improve all aspects of gas turbine performance evaluation, the MET Laboratory has critically examined two types of fuel flowmeters, Coriolis and turbine. The two flowmeter types are different in that the Coriolis flowmeter measures mass flow directly, while the turbine flowmeter measures volumetric flow, which must be converted to mass flow for conventional performance analysis. The direct measurement of mass flow, using a Coriolis flowmeter, has many advantages in field testing of gas turbines, because it reduces the risk of errors resulting from the conversion process. Turbine flowmeters, on the other hand, have been regarded as an industry standard because they are compact, rugged, reliable, and relatively inexpensive. This paper describes the project objectives, the experimental installation, and the results of the comparison of the Coriolis and turbine type flowmeters in steady-state performance testing. Discussed are variations between the two types of flowmeters due to fuel characteristics, fuel handling equipment, acoustic and vibration interference and installation effects. Also included in this paper are estimations of measurement uncertainties for both types of flowmeters. Results indicate that the agreement between Coriolis and turbine type flowmeters is good over the entire steady-state operating range of a typical gas turbine engine. In some cases the repeatability of the Coriolis flowmeter is better than the manufacturers specification. Even a significant variation in fuel density (10%), and viscosity (300%), did not appear to compromise the ability of the Coriolis flowmeter to match the performance of the turbine flowmeter.

Gas Turbine Performance Improvement by Retrofit of Advanced Technology

1983 ◽  
Author(s):  
V. C. Tendon ◽  
A. Zabrodsky
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Advanced Technology ◽  
Inlet Temperature ◽  
Performance Improvements ◽  
Turbine Performance ◽  
Higher Power ◽  
Available Technology ◽  
Life Consumption ◽  
Implementation Technique

Development and operation of larger size gas turbines have demonstrated that higher turbine inlet temperature can be sustained due to advancement in material and cooling technology. After a feasibility study it was determined that modern available technology can be applied to existing previous generation of machines. These programs are identified as “The Performance Upgrade of Gas Turbine”. Amongst the significant benefits that can be realized by retrofitting state of art parts in existing machines are higher power and more durable parts. This paper discusses various programs that are currently offered and implementation technique of upgrading the machines. A recent example is also presented. These unique programs are particularly attractive at the time of overall life consumption of the initial set of hot parts. At that point in an operating gas turbine it will be beneficial to retrofit the latest configuration parts to realize the performance improvements.

Remote Condition Monitoring of a Peaking Gas Turbine

1991 ◽  
Author(s):  
Ralph E. Harris ◽  
Harold R. Simmons ◽  
Anthony J. Smalley ◽  
Richard M. Baldwin ◽  
George Quentin
Keyword(s):  
Gas Turbine ◽  
Condition Monitoring ◽  
Gas Turbines ◽  
Vibration Amplitude ◽  
Thermal Stabilization ◽  
Cost Effective ◽  
System Structure ◽  
Start Up ◽  
Data Content ◽  
Software And Hardware

This paper illustrates how software and hardware for telecommunications and data acquisition enable cost-effective monitoring of peaking gas turbines using personal computers. It describes the design and evaluation of a system which transmits data from each start-up and shutdown over 1,500 miles to a monitoring computer. It presents system structure, interfaces, data content, and management. The system captures transient sequences of acceleration, synchronization, loading, thermal stabilization, steady operation, shutdown and cooldown; it yields coherent sets of speed, load, temperature, journal eccentricity, vibration amplitude, and phase at intervals appropriately spaced in time and speed. The data may be used to characterize and identify operational problems.

Feasibility of an Isolated Reverse Turbine Concept for Marine Propulsion

1979 ◽  
Author(s):  
T. L. Bowen
Keyword(s):  
Gas Turbines ◽  
Axial Flow ◽  
Transient Behavior ◽  
Reduction Gear ◽  
Impulse Turbine ◽  
Stopping Distance ◽  
Turbine Performance ◽  
Marine Propulsion ◽  
Power Turbine ◽  
Performance Penalty

The feasibility of an isolated reverse turbine concept for marine propulsion was examined with emphasis on (1) the reverse turbine size needed to meet the stopping distance requirement of a particular ship during a crashback maneuver, and (2) the ahead turbine performance penalty due to reverse turbine windage losses. This particular reverse turbine system was made adaptable to the exhaust elbow and output shaft of an existing free-power-turbine gas turbine. The analysis was based on the application of this reverse turbine concept to a notational single-shaft frigate. The study-ship’s propulsion system includes two General Electric LM2500 gas turbines with reversing capability, a reduction gear, and a fixed-pitch propeller. A ship propulsion simulation was developed for the purpose of calculating steady-state ahead and backing performance data, as well as transient behavior of the ship during crashback maneuvers. The reverse turbine’s speed and torque required to stop the ship in five ship-lengths and 3.5 ship-lengths were determined from these calculations. Four reverse turbine designs were generated using a computer program for preliminary design of axial-flow turbines. The designs included a single-stage and a two-stage impulse turbine for both stopping distances. The penalty on ahead performance due to reverse turbine windage was estimated for each design, using existing experimental data found in the literature. The results obtained thus far tend to support the feasibility of this reverse turbine concept.

Danish Navy Experience With the KV-72 LM2500 CODOG Propulsion Plant

1983 ◽  
Author(s):  
Bent Hansen ◽  
Sloth Larsen ◽  
John W. Tenhundfeld
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Turbine Engines ◽  
Operational Experience ◽  
Gas Turbine Engines ◽  
Joint Effort ◽  
General Electric Company ◽  
Electric Company ◽  
Start Up ◽  
Selection Of

For more than twenty years the Royal Danish Navy (RDN) has been using gas turbine engines for propulsion of fast patrol vessels as well as frigates. This paper, which is the result of a joint effort by the Royal Danish Navy, Aalborg Vaerft Shipyard, and General Electric Company USA, describes how the propulsion system design was developed using previous RDN gas turbine system experience. A detailed description of the ship, the selection of machinery, and design of the propulsion configuration, including the LM2500 gas turbine module, is included. The three Royal Danish “KV-72” corvettes of the NIELS JUEL class have now been in operation for almost three years. Since the start-up of the NIELS JUEL machinery in November 1978 the CODOG propulsion plants aboard this class have accumulated more than 8,000 running hours, of which over 1,500 hours have been in the gas turbine or “sprint” drive mode. Operational experience with the GE LM2500 gas turbines is also described.

Prediction Reliability of a Statistical Methodology for Gas Turbine Prognostics

2012 ◽  
Vol 134 (10) ◽  
Author(s):  
Mauro Venturini ◽  
Nicola Puggina
Keyword(s):  
Gas Turbine ◽  
Correction Factor ◽  
Gas Turbines ◽  
Threshold Value ◽  
False Alarms ◽  
Prediction Errors ◽  
Past Behavior ◽  
Turbine Performance ◽  
Performance Deterioration ◽  
Prediction Reliability

The performance of gas turbines degrades over time and, as a consequence, a decrease in gas turbine performance parameters also occurs, so that they may fall below a given threshold value. Therefore, corrective maintenance actions are required to bring the system back to an acceptable operating condition. In today’s competitive market, the prognosis of the time evolution of system performance is also recommended, in such a manner as to take appropriate action before any serious malfunctioning has occurred and, as a consequence, to improve system reliability and availability. Successful prognostics should be as accurate as possible, because false alarms cause unnecessary maintenance and nonprofitable stops. For these reasons, a prognostic methodology, developed by the authors, is applied in this paper to assess its prediction reliability for several degradation scenarios typical of gas turbine performance deterioration. The methodology makes use of the Monte Carlo statistical method to provide, on the basis of the recordings of past behavior, a prediction of future availability, i.e., the probability that the considered machine or component can be found in the operational state at a given time in the future. The analyses carried out in this paper aim to assess the influence of the degradation scenario on methodology prediction reliability, as a function of a user-defined threshold and minimum value allowed for the parameter under consideration. A technique is also presented and discussed, in order to improve methodology prediction reliability by means a correction factor applied to the time points used for methodology calibration. The results presented in this paper show that, for all the considered degradation scenarios, the prediction error is lower than 4% (in most cases, it is even lower than 2%), if the availability is estimated for the next trend, while it is not higher than 12%, if the availability is estimated five trends ahead. The application of a proper correction factor allows the prediction errors after five trends to be reduced to approximately 5%.

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.

A Generalized Mathematical Model to Estimate Gas Turbine Starting Characteristics

1982 ◽  
Vol 104 (1) ◽  
pp. 194-201 ◽  
Author(s):  
R. K. Agrawal ◽  
M. Yunis
Keyword(s):  
Mathematical Model ◽  
Ambient Temperature ◽  
Gas Turbine ◽  
System Combination ◽  
Turbine Performance ◽  
Start Up ◽  
Starting Characteristics ◽  
Starting Torque

The paper describes a generalized mathematical model to estimate gas turbine performance in the starting regime of the engine. These estimates are then used to calculate the minimum engine starting torque requirements, thereby defining the specifications for the aircraft starting system. Alternatively, the model can also be used to estimate the start up time at any ambient temperature or altitude for a given engine/aircraft starting system combination.

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