scholarly journals The EPRI Gas Turbine Digital Twin – a Platform for Operator Focused Integrated Diagnostics and Performance Forecasting

2021 ◽  
Author(s):  
Jamie Lim ◽  
Christopher A. Perullo ◽  
Joe Milton ◽  
Rachel Whitacre ◽  
Chris Jackson ◽  
...  

Abstract EPRI has been developing a digital twin of simple and combined cycle gas turbines over the last 5+ years to provide owners and operators with improved capabilities that typically reside in the expert domain of OEMs and 3rd party service providers. The digital twin is a digital model, a physics-based representation of the actual asset. The model is thermodynamic and is created with the intent to support 5 M&D areas: • Integrate with existing M&D tools such as advanced pattern recognition (APR) • Power plant performance prediction and trending such as day, week, and month ahead performance prediction for capacity and generation planning • Health Monitoring and Fault Diagnostics to support asset management with additional health scores and virtual instrumentation enabled by the digital twin model • Monitoring and prediction of both base and part-load performance. Many gas turbine tools have been simplified to work only at full load conditions. To be useful and to improve utilization of collected data, part-load conditions should also be considered. • Outage and repair impacts, including “what-if” capability to understand and quantify potential root causes of less than expected performance improvement or recovery after outage and repairs. This paper presents current progress in creating an EPRI Digital Twin applicable to gas turbines. The formulation, methodology, and real-world use cases are presented. To date, digital twins have been created and tested for both E and F class frames. This paper describes the process of generating closed-form equations capable of transforming existing, measured historian data into the health parameters and virtual sensors needed to better track unit health and monitor faulted performance. These equations encapsulate the digital twin physical model and provide end-users with a methodology to calibrate to their specific unit and efficiently use their choice of monitoring software. Tests have been performed using operator data and have shown good accuracy at detecting anomalous operation and predicting week ahead performance with excellent accuracy. Post-outage impact analysis is also assessed. Real-world application cases for the digital twin are also presented. Examples include using the digital twin to identify causes of post-outage emissions and performance issues, expected impact of degradation and fault conditions, and simulating improvements to operation through part repair and upgrades.

Author(s):  
G. Barigozzi ◽  
G. Bonetti ◽  
G. Franchini ◽  
A. Perdichizzi ◽  
S. Ravelli

A modeling procedure was developed to simulate design and off-design operation of Hybrid Solar Gas Turbines in a combined cycle (CC) configuration. The system includes an heliostat field, a receiver and a commercial gas turbine interfaced with a conventional steam Rankine cycle. Solar power input is integrated in the GT combustor by natural gas. Advanced commercial software tools were combined together to get design and off-design performance prediction: TRNSYS® was used to model the solar field and the receiver while the gas turbine and steam cycle simulations were performed by means of Thermoflex®. Three GT models were considered, in the 35–45 MWe range: a single shaft engine (Siemens SGT800) and two two-shaft engines (the heavy-duty GT Siemens SGT750 and the aero derivative GE LM6000 PF). This in order to assess the influence of different GT spool arrangements and control strategies on GT solarization. The simulation method provided an accurate modeling of the daily solar hybrid CC behavior to be compared against the standard CC. The effects of solarization were estimated in terms of electric power and efficiency reduction, fossil fuel saving and solar energy to electricity conversion efficiency.


Author(s):  
Thomas P. Schmitt ◽  
Herve Clement

Current trends in usage patterns of gas turbines in combined cycle applications indicate a substantial proportion of part load operation. Commensurate with the change in operating profile, there has been an increase in the propensity for part load performance guarantees. When a project is structured such that gas turbines are procured as equipment-only from the manufacturer, there is occasionally a gas turbine part load performance guarantee that coincides with the net plant combined cycle part load performance guarantee. There are several methods by which to accomplish part load gas turbine performance testing. One of the more common methods is to operate the gas turbine at the specified load value and construct correction curves at constant load. Another common method is to operate the gas turbine at a specified load percentage and construct correction curves at constant percent load. A third method is to operate the gas turbine at a selected load level that corresponds to a predetermined compressor inlet guide vane (IGV) angle. The IGV angle for this third method is the IGV angle that is needed to achieve the guaranteed load at the guaranteed boundary conditions. The third method requires correction curves constructed at constant IGV, just like base load correction curves. Each method of test and correction embodies a particular set of advantages and disadvantages. The results of an exploration into the advantages and disadvantages of the various performance testing and correction methods for part load performance testing of gas turbines are presented. Particular attention is given to estimates of the relative uncertainty for each method.


Author(s):  
Erwin Zauner ◽  
Yau-Pin Chyou ◽  
Frederic Walraven ◽  
Rolf Althaus

Power generation in gas turbines is facing three main challenges today: • Low pollution prescribed by legal requirements. • High efficiency to obtain low operating cost and low CO2 emissions. • High specific power output to obtain low product and installation cost. Unfortunately, some of these requirements are contradictory: high efficiency and specific power force the development towards higher temperatures and pressures which increase NOx emissions and intensify the cooling and material strength problems. A breakthrough can be achieved by applying an energy exchanger as a topping stage. Inherent advantages are the self-cooled cell-rotor which can be exposed to much higher gas temperature than a steady-flow turbine and a very short residence time at peak temperature which keeps NOx emissions under control. The basic idea has been proposed long time ago. Fundamental research has now led to a new energy exchanger concept. Key issues include symmetric pressure-wave processes, partial suppression of flow separation and fluid mixing, as well as quick afterburning in premixed mode. The concept has been proven in a laboratory-scale engine with very promising results. The application of an energy exchanger as a topping stage onto existing gas turbines would increase the efficiency by 17% (relative) and the power by 25%. Since the temperature level in the turbine remains unchanged, the performance improvement can also be fully utilized in combined cycle applications. This process indicates great potentials for developing advanced gas turbine systems as well as for retrofitting existing ones.


Author(s):  
David W. Donle ◽  
Robert C. Kiefer ◽  
Thomas C. Wright ◽  
Ugo A. Bertolami ◽  
Denis G. Hill

This paper describes the development, application, and performance verification of a new patented technology for cleaning and cooling combustion air to a gas turbine. A two (2) year in-depth research program at Dow Chemical Company in Freeport, Texas resulted in the development of this technology. At the conclusion of the research and development program, full-scale application of the hardware was made on a 100 MW combined cycle gas turbine, and its performance monitored for two (2) years. Application of the new technology resulted in increased power output, higher reliability, NOx emission reduction, reduced maintenance costs, and higher total system efficiency. Since the new technology has produced very large cost savings, Dow is using the new technology on three new combined cycle machines currently being installed, and further is exploring conversion of existing combined cycle gas turbines to this new technology.


2019 ◽  
Vol 200 ◽  
pp. 112063 ◽  
Author(s):  
Shucheng Wang ◽  
Zhitan Liu ◽  
Rasmus Cordtz ◽  
Muhammad Imran ◽  
Zhongguang Fu

Author(s):  
E. Tsoutsanis ◽  
Y. G. Li ◽  
P. Pilidis ◽  
M. Newby

Accurate gas turbine performance simulation is a vital aid to the operational and maintenance strategy of thermal plants having gas turbines as their prime mover. Prediction of the part load performance of a gas turbine depends on the quality of the engine’s component maps. Taking into consideration that compressor maps are proprietary information of the manufacturers, several methods have been developed to encounter the above limitation by scaling and adapting component maps. This part of the paper presents a new off-design performance adaptation approach with the use of a novel compressor map generation method and Genetic Algorithms (GA) optimization. A set of coefficients controlling a generic compressor performance map analytically is used in the optimization process for the adaptation of the gas turbine performance model to match available engine test data. The developed method has been tested with off-design performance simulations and applied to a GE LM2500+ aeroderivative gas turbine operating in Manx Electricity Authority’s combined cycle power plant in the Isle of Man. It has been also compared with an earlier off-design performance adaptation approach, and shown some advantages in the performance adaptation.


Author(s):  
T S Kim ◽  
S T Ro

This paper demonstrates a favourable influence of turbine coolant modulation on the part load performance of gas turbines. A general simulation programme is developed, which is capable of accurately estimating the design and part load performance of modern heavy-duty gas turbines characterized by intensive turbine blade cooling Investigations are made for a typical gas turbine and two distinct load control schemes are considered: the fuel-only control and the variable compressor geometry control. Maintaining blade temperatures as high as possible whose purpose is to minimize coolant consumption is simulated. It is found that the coolant modulation makes the part load characteristics deviate from usual behaviours and creates a considerable enhancement of part load thermal efficiency. For the fuel-only control with coolant modulation, it is predicted that efficiency can be higher than design efficiency over a wide range of part load operation.


2017 ◽  
Vol 32 (1) ◽  
pp. 625-645 ◽  
Author(s):  
Mijndert van der Spek ◽  
Davide Bonalumi ◽  
Giampaolo Manzolini ◽  
Andrea Ramirez ◽  
André Faaij

Author(s):  
Xiaomo Jiang ◽  
Craig Foster

Combined cycle gas turbine plants are built and operated with higher availability, reliability, and performance than simple cycle in order to help provide the customer with capabilities to generate operating revenues and reduce fuel costs while enhancing dispatch competitiveness. The availability of a power plant can be improved by increasing the reliability of individual assets through maintenance enhancement and performance degradation recovery through remote efficiency monitoring to provide timely corrective recommendations. This paper presents a comprehensive system and methodology to pursue this purpose by using instrumented data to automate performance modeling for real-time monitoring and anomaly detection of combined cycle gas turbine power plants. Through thermodynamic performance modeling of main assets in a power plant such as gas turbines, steam turbines, heat recovery steam generators, condensers and other auxiliaries, the system provides an intelligent platform and methodology to drive customer-specific, asset-driven performance improvements, mitigate outage risks, rationalize operational patterns, and enhance maintenance schedules and service offerings at total plant level via taking appropriate proactive actions. In addition, the paper presents the components in the automated remote monitoring system, including data instrumentation, performance modeling methodology, operational anomaly detection, and component-based degradation assessment. As demonstrated in two examples, this remote performance monitoring of a combined cycle power plant aims to improve equipment efficiency by converting data into knowledge and solutions in order to drive values for customers including shortening outage downtime, lowering operating fuel cost and increasing customer power sales and life cycle value of the power plant.


Author(s):  
H. H.-W. Funke ◽  
A. E. Robinson ◽  
U. Ro¨nna

There is a growing need for devices with small weight and large power density as a substitute for today’s accumulators widely used for electrical tools or as thrust application in the aerospace industry e.g. for small unmanned aerial vehicles (UAV). Systems burning liquid or gaseous fuels and working after the principle of the Brayton cycle became more and more interesting as a new field of research (powermems devices). This ongoing miniaturization of power devices such as ultra micro gas turbines requires a reliable and safe combustion of fuels. A new test rig for micro scale combustion chambers has been realized and tested with a new hydrogen prototype burner for a 600 W μ-scale gas turbine. By preheating and pressurizing the flow realistic combustion chamber inlet conditions for the design point and for μ-scale gas turbine part load conditions can be realized. Furthermore the quartz glass prototype burner offers visual access to the flame region during operation at atmospheric condition. Detailed investigations on the burning characteristics for different chamber configurations were carried out for an optimization of the burner concept and gas turbine integration. By changing air mass flow and thermal energy the results allow a mapping of the combustion chamber for setting the control laws of the μ-scale gas turbine. The test results prove a very good flame stability and burning efficiency for the micromix principle covering a wide range of power settings including the design point. Even at extreme part load conditions it was possible to handle all the operating points of the proposed μ-scale gas turbine. Based on the prototype burner results a realistic combustion chamber design for μ-scale gas turbine integration will be presented.


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