Real-Time Variable Geometry Triaxial Gas Turbine Model for Hardware-in-the-Loop Simulation Experiments

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Tao Wang ◽  
Yong-Sheng Tian ◽  
Zhao Yin ◽  
Da-Yue Zhang ◽  
Ming-Ze Ma ◽  
...  
Keyword(s):  
Real Time ◽  
Gas Turbine ◽  
Working Conditions ◽  
Gas Turbines ◽  
Neural Net ◽  
Hardware In The Loop ◽  
Gas Generator ◽  
Component Level ◽  
Simulation Experiments ◽  
Power Turbine

This paper proposes a hybrid method (HMRC) comprised of a radial basis function (RBF) neural net algorithm and component-level modeling method (CMM) as a real-time simulation model for triaxial gas turbines with variable power turbine guide vanes in matlab/simulink. The sample size is decreased substantially after analyzing the relationship between high and low pressure shaft rotational speeds under dynamic working conditions, which reduces the computational burden of the simulation. The effects of the power turbine rotational speed on overall performance are also properly accounted for in the model. The RBF neural net algorithm and CMM are used to simulate the gas generator and power turbine working conditions, respectively, in the HMRC. The reliability and accuracy of both the traditional single CMM model (SCMM) and HMRC model are verified using gas turbine experiment data. The simulation models serve as a controlled object to replace the real gas turbine in a hardware-in-the-loop simulation experiment. The HMRC model shows better real-time performance than the traditional SCMM model, suggesting that it can be readily applied to hardware-in-the-loop simulation experiments.

scholarly journals A Real-Time Degradation Model for Hardware in the Loop Simulation of Fuel Cell Gas Turbine Hybrid Systems

2015 ◽  
Author(s):  
Valentina Zaccaria ◽  
Alberto Traverso ◽  
David Tucker
Keyword(s):  
Fuel Cell ◽  
Real Time ◽  
Gas Turbine ◽  
Hybrid Systems ◽  
Current Density ◽  
Gas Turbines ◽  
Hardware In The Loop ◽  
Fuel Utilization ◽  
Time Operation ◽  
The Impact

The theoretical efficiencies of gas turbine fuel cell hybrid systems make them an ideal technology for the future. Hybrid systems focus on maximizing the utilization of existing energy technologies by combining them. However, one pervasive limitation that prevents the commercialization of such systems is the relatively short lifetime of fuel cells, which is due in part to several degradation mechanisms. In order to improve the lifetime of hybrid systems and to examine long-term stability, a study was conducted to analyze the effects of electrochemical degradation in a solid oxide fuel cell (SOFC) model. The SOFC model was developed for hardware-in-the-loop simulation with the constraint of real-time operation for coupling with turbomachinery and other system components. To minimize the computational burden, algebraic functions were fit to empirical relationships between degradation and key process variables: current density, fuel utilization, and temperature. Previous simulations showed that the coupling of gas turbines and SOFCs could reduce the impact of degradation as a result of lower fuel utilization and more flexible current demands. To improve the analytical capability of the model, degradation was incorporated on a distributed basis to identify localized effects and more accurately assess potential failure mechanisms. For syngas fueled systems, the results showed that current density shifted to underutilized sections of the fuel cell as degradation progressed. Over-all, the time to failure was increased, but the temperature difference along cell was increased to unacceptable levels, which could not be determined from the previous approach.

Capacity Matching of Aeroderivative Gas Generator With Free Power Turbine: Challenges, Uncertainties, and Opportunities

2019 ◽  
Author(s):  
Deepak Thirumurthy ◽  
Jose Carlos Casado Coca ◽  
Kanishka Suraweera
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Systems Approach ◽  
Gas Generator ◽  
Performance Guarantees ◽  
Design Variables ◽  
Performance Trends ◽  
Power Turbine ◽  
Parameter Matching ◽  
Turbine Capacity

Abstract For gas turbines with free power turbines, the capacity or flow parameter matching is of prime importance. Accurately matched capacity enables the gas turbine to run at its optimum conditions. This ensures maximum component efficiencies, and optimum shaft speeds within mechanical limits. This paper presents the challenges, uncertainties, and opportunities associated with an accurate matching of a generic two-shaft aeroderivative HP-LP gas generator with the free power turbine. Additionally, generic performance trends, uncertainty quantification, and results from the verification program are also discussed. These results are necessary to ensure that the final free power turbine capacity is within the allowable range and hence the product meets the performance guarantees. The sensitivity of free power turbine capacity to various design variables such as the vane throat area, vane trailing edge size, and manufacturing tolerance is presented. In addition, issues that may arise due to not meeting the target capacity are also discussed. To conclude, in addition to design, analysis, and statistical studies, a system-of-systems approach is mandatory to meet the allowed variation in the free power turbine capacity and hence the desired gas turbine performance.

Design and Analysis of a Real-Time Hot Gas Temperature Estimator for Heavy-Duty Gas Turbines

2015 ◽  
Author(s):  
Eric A. Müller ◽  
Adrian Ticǎ
Keyword(s):  
Real Time ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Gas Temperature ◽  
Heavy Duty ◽  
Component Level ◽  
Load Range ◽  
Hot Gas ◽  
Dynamic Tracking ◽  
Heavy Duty Gas Turbine

The knowledge about a relevant process and lifetime indicative quantity, such as the hot gas temperature, is crucial for the control of a gas turbine. Since this indicative process quantity usually cannot be directly measured, it has to be estimated. The paper describes a model-based method to accurately estimate in real-time the hot gas temperature of a heavy-duty gas turbine. The method follows a well-balanced trade-off between resulting prediction accuracy and involved computational complexity. It takes advantage of the capability of a component-level dynamic model to predict the system behaviour and of the capacity of a dynamic tracking filter to adapt to the current gas turbine conditions. In a simulation study, it is shown that the proposed design can provide an accurate hot gas temperature estimation over the entire gas turbine load range, along the gas turbine lifecycle, and during fast transient manoeuvres.

Service Exchange or Major Overhaul. Which Philosophy to Implement for Gas Turbine

2021 ◽  
Author(s):  
Karim Mamdouh Youssef
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Gas Generator ◽  
Major Overhaul ◽  
Maintenance Program ◽  
Direct Benefits ◽  
Equipment Availability ◽  
Power Turbine ◽  
Service Exchange ◽  
Correct Implementation

Abstract Maintenance costs and machine availability are two of the most important concerns to gas turbine equipment owner. Therefore, a well thought out maintenance program that reduces costs while increasing equipment availability should be instituted. The correct implementation of planned maintenance relying on preventive maintenance optimization through perfect inspection frequency and scope provides direct benefits in the avoidance of forced outages, unscheduled repairs, and downtime. Major overhaul is carried out for each gas turbine every 48,000 firing hours which costs around 1 M USD for each engine and with more than 8 months unavailability for the unit. To increase equipment availability and enhance cost and time efficiency, alternatives approaches were evaluated including Service Exchange of gas turbines. It is found that service exchange is the best option for optimizing time and cost of overhaul of such engines. This paper is written to improve Major Overhaul practice for existing Gas Turbines from ongoing practice of routine major overhaul including engine strip down, inspection and repair to Service Exchange of Gas Generator and Power Turbine every 48,000 firing hours.

scholarly journals Development and Field Experience of a 27,400 HP Aeroderivative Gas Turbine

1983 ◽  
Author(s):  
J. K. Hubbard ◽  
R. Tillinger
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Field Experience ◽  
Performance Test ◽  
Gas Generator ◽  
Successful Operation ◽  
Field Development ◽  
Design Concepts ◽  
Power Turbine ◽  
Field Unit

The paper describes the development and field experience of the model DJ270G Gas Turbine, the second of the manufacturer’s “second generation” gas turbines. By combining the merits of a proven aero-derivative gas generator with an advanced power turbine, the DJ270G has been developed to provide a reliable and efficient dual shaft gas turbine. Previously established power turbine design concepts were uniquely modified to maximize the overall efficiency of the unit. The introduction rate was advanced by running the development and manufacturing programs simultaneously. Field development was minimized by completing a full load performance test program in the factory prior to start-up of the first field unit. The completed machine has achieved an output of 27,400 horsepower with a thermal efficiency of 36.3%. Four units are now in operation and have logged over 33,000 hours of successful operation.

A Control System for a High-Quality Generating Set Equipped With a Two-Shaft Gas Turbine

1991 ◽  
Vol 113 (2) ◽  
pp. 290-295 ◽  
Author(s):  
H. Kumakura ◽  
T. Matsumura ◽  
E. Tsuruta ◽  
A. Watanabe
Keyword(s):  
Control System ◽  
Gas Turbine ◽  
Gas Turbines ◽  
High Quality ◽  
Constant Frequency ◽  
Generating Set ◽  
Generating Sets ◽  
Power Turbine ◽  
Computer Centers ◽  
Supply Systems

A control system has been developed for a high-quality generating set (150-kW) equipped with a two-shaft gas turbine featuring a variable power turbine nozzle. Because this generating set satisfies stringent frequency stability requirements, it can be employed as the direct electric power source for computer centers without using constant-voltage, constant-frequency power supply systems. Conventional generating sets of this kind have normally been powered by single-shaft gas turbines, which have a larger output shaft inertia than the two-shaft version. Good frequency characteristics have also been realized with the two-shaft gas turbine, which provides superior quick start ability and lower fuel consumption under partial loads.

Development and Fabrication of Silicon Nitride Components for Ceramic Gas Turbine

1997 ◽  
Author(s):  
Keisuke Makino ◽  
Ken-Ichi Mizuno ◽  
Toru Shimamori
Keyword(s):  
High Temperature ◽  
Silicon Nitride ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Turbine Blades ◽  
High Strength ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Spark Plug ◽  
Power Turbine

NGK Spark Plug Co., Ltd. has been developing various silicon nitride materials, and the technology for fabricating components for ceramic gas turbines (CGT) using theses materials. We are supplying silicon nitride material components for the project to develop 300 kW class CGT for co-generation in Japan. EC-152 was developed for components that require high strength at high temperature, such as turbine blades and turbine nozzles. In order to adapt the increasing of the turbine inlet temperature (TIT) up to 1,350 °C in accordance with the project goals, we developed two silicon nitride materials with further unproved properties: ST-1 and ST-2. ST-1 has a higher strength than EC-152 and is suitable for first stage turbine blades and power turbine blades. ST-2 has higher oxidation resistance than EC-152 and is suitable for power turbine nozzles. In this paper, we report on the properties of these materials, and present the results of evaluations of these materials when they are actually used for CGT components such as first stage turbine blades and power turbine nozzles.

Advanced Control System Considerations for Small Shaft-Type Aircraft Gas Turbines

1970 ◽  
Author(s):  
D. A. Prue ◽  
T. L. Soule
Keyword(s):  
Control System ◽  
Gas Turbines ◽  
Evaluation Criteria ◽  
Open Loop ◽  
Engine Control ◽  
Gas Generator ◽  
Engine Control System ◽  
Power Turbine ◽  
Advanced Control ◽  
Temperature Load

The next generation of free-turbine engines in the 2 to 5-lb/sec airflow class will undergo vast improvements in performance and efficiency. The improvements will be achieved concurrent with overall reductions in size and weight. Effort is required at optimization and miniaturization of the engine control system to keep pace with these improvements. This paper describes a conceptual design of an advanced engine control system for this class of engine. It provides gas generator and power turbine control with torque, temperature, load sharing and overspeed limiting functions. The control system was concepted to accommodate, with minimum hardware changes, such variants as regenerative cycle and/or variable power turbine geometry. In addition, considerations for closed and open loop modes of control and fluidic, electronic and hydromechanical technologies were studied to best meet a defined specification and a weighted set of evaluation criteria.

Flow Interactions Between Shrouded Power Turbine and Nonaxisymmetric Exhaust Volute for Marine Gas Turbines

2017 ◽  
Author(s):  
Jie Gao ◽  
Feng Lin ◽  
Xiying Niu ◽  
Qun Zheng ◽  
Guoqiang Yue ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Rotor Blade ◽  
Exhaust System ◽  
Computational Domain ◽  
Local Flow ◽  
Power Turbine ◽  
Flow Interactions ◽  
Shrouded Rotor ◽  
Turbine Exhaust

The marine gas turbine exhaust volute is an important component that connects a power turbine and an exhaust system, and it is of great importance to the overall performance of the gas turbine. Gases exhausted from the power turbine are expanded and deflected 90 degrees in the exhaust volute, and then discharge radially into the exhaust system. The flows in the power turbine and the nonaxisymmetric exhaust volute are closely coupled and inherently unsteady. The flow interactions between the power turbine and the exhaust volute have a significant influence on the shrouded rotor blade aerodynamic forces. However, the interactions have not been taken into account properly in current power turbine design approaches. The present study aims to investigate the flow interactions between the last stage of a shrouded power turbine and the nonaxisymmetric exhaust volute with struts. Special attention is given to the coupled aerodynamics and pressure response studies. This work was carried out using coupled computational fluid dynamics (CFD) simulations with the computational domain including a stator vane, 76 shrouded rotor blades, 9 struts and an exhaust volute. Three-dimensional (3D) unsteady and steady Reynolds-averaged Navier-Stokes (RANS) solutions in conjunction with a Spalart-Allmaras turbulence model are utilized to investigate the aerodynamic characteristics of shrouded rotors and an exhaust volute using a commercial CFD software ANSYS Fluent 14.0. The asymmetric flow fields are analyzed in detail; as are the unsteady pressures on the shrouded rotor blade. In addition, the unsteady total pressures at the volute outlet is also analyzed without consideration of the upstream turbine effects. Results show that the flows in the nonaxisymmetric exhaust volute are inherently unsteady; for the studied turbine-exhaust configuration the nonaxisymmetric back-pressure induced by the downstream volute leads to the local flow varying for each shrouded blade and low frequency fluctuations in the blade force. Detailed results from this investigation are presented and discussed in this paper.

A Modular Code for Real Time Dynamic Simulation of Gas Turbines in Simulink

2002 ◽  
Vol 128 (3) ◽  
pp. 506-517 ◽  
Author(s):  
S. M. Camporeale ◽  
B. Fortunato ◽  
M. Mastrovito
Keyword(s):  
Mathematical Model ◽  
Real Time ◽  
Gas Turbine ◽  
Dynamic Behavior ◽  
Gas Turbines ◽  
Simulation Software ◽  
Computational Time ◽  
High Fidelity ◽  
Time Step ◽  
The Mathematical Model

A high-fidelity real-time simulation code based on a lumped, nonlinear representation of gas turbine components is presented. The code is a general-purpose simulation software environment useful for setting up and testing control equipments. The mathematical model and the numerical procedure are specially developed in order to efficiently solve the set of algebraic and ordinary differential equations that describe the dynamic behavior of gas turbine engines. For high-fidelity purposes, the mathematical model takes into account the actual composition of the working gases and the variation of the specific heats with the temperature, including a stage-by-stage model of the air-cooled expansion. The paper presents the model and the adopted solver procedure. The code, developed in Matlab-Simulink using an object-oriented approach, is flexible and can be easily adapted to any kind of plant configuration. Simulation tests of the transients after load rejection have been carried out for a single-shaft heavy-duty gas turbine and a double-shaft aero-derivative industrial engine. Time plots of the main variables that describe the gas turbine dynamic behavior are shown and the results regarding the computational time per time step are discussed.

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