scholarly journals Assessment of degradation equivalent operating time for aircraft gas turbine engines

2020 ◽  
Vol 124 (1274) ◽  
pp. 549-580
Author(s):  
O. Alozie ◽  
Y.G. Li ◽  
M. Diakostefanis ◽  
X. Wu ◽  
X. Shong ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Operating Time ◽  
Environmental Parameters ◽  
Remaining Useful Life ◽  
Operating Conditions ◽  
Clock Time ◽  
Performance Simulation ◽  
Engine Model ◽  
Booster Compressor ◽  
Blade Tip

ABSTRACTThis paper presents a novel method for quantifying the effect of ambient, environmental and operating conditions on the progression of degradation in aircraft gas turbines based on the measured engine and environmental parameters. The proposed equivalent operating time (EOT) model considers the degradation modes of fouling, erosion, and blade-tip wear due to creep strain, and expresses the actual degradation rate over the engine clock time relative to a pre-defined reference condition. In this work, the effects of changing environmental and engine operating conditions on the EOT for the core engine booster compressor and the high-pressure turbine were assessed by performance simulation with an engine model. The application to a single and multiple flight scenarios showed that, compared to the actual engine clock time, the EOT provides a clear description of component degradation, prediction of remaining useful life, and sufficient margin for maintenance action to be planned and performed before functional failure.

The Degradation Simulation of Compressor Salt Fog Fouling for Marine Gas Turbine

2017 ◽  
Author(s):  
Yunpeng Cao ◽  
Lie Chen ◽  
Jianwei Du ◽  
Fang Yu ◽  
Qingcai Yang ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Cost Estimation ◽  
Gas Turbines ◽  
Operating Cost ◽  
Operating Time ◽  
Performance Degradation ◽  
Operating Conditions ◽  
Degradation Factor ◽  
Environment Temperature ◽  
Salt Fog

When a gas turbine operates in a marine environment, gradual performance degradation occurs due to salt fog in the compressor and turbine. Regular water washing of a gas turbine can effectively restore the performance loss caused by compressor salt fog fouling on the flow passage. However, inappropriate washing will increase maintenance costs, cause unnecessary down time and premature erosion of leaf surfaces. In this paper, a coefficient matching method for a three shaft marine gas turbine salt fog fouling degradation factor model is proposed, which can establish a model of salt fog fouling degradation factor according to a change in operating time and exhaust temperature in the washing cycle. The influences of load, environment temperature, inlet pressure loss and salt fog fouling rate on the performance degradation of the gas turbine are simulated and analyzed; then, the degradation regularity of the performance parameters of the gas turbine under different operating conditions and fouling degrees is obtained. Finally, a method of operating cost estimation for marine gas turbines is proposed that can estimate the cost of transient change and cumulative change in the cleaning cycle caused by the salt fog fouling, which can help the operator to determine the cleaning strategy and reduce the operation cost of the gas turbine.

A Comparative Analysis of Turbine Rotor Inlet Temperature Models

2011 ◽  
Author(s):  
Cristhian Maravilla Herrera ◽  
Sergiy Yepifanov ◽  
Igor Loboda
Keyword(s):  
Gas Turbines ◽  
Thermal State ◽  
Turbine Rotor ◽  
Remaining Useful Life ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Gas Temperature ◽  
Thermal Boundary Conditions ◽  
Power Setting ◽  
Stress Estimation

Life usage algorithms constitute one of the principal components of gas turbine engines monitoring systems. These algorithms aim to determine the remaining useful life of gas turbines based on temperature and stress estimation in critical hot part elements. Knowing temperatures around these elements is therefore very important. This paper deals with blades and disks of a high pressure turbine (HPT). In order to monitor their thermal state, it is necessary to set thermal boundary conditions. The main parameter to determine is the total gas temperature in relative motion at the inlet of HPT blades Tw*. We propose to calculate this unmeasured temperature as a function of measured gas path variables using gas path thermodynamics. Five models with different thermodynamic relations to calculate the temperature Tw* are proposed and compared. All temperature models include some unmeasured parameters that are presented as polynomial functions of a measured power setting variable. A nonlinear thermodynamic model is used to calculate the unknown coefficients included in the polynomials and to validate the models considering the influence of engine deterioration and operating conditions. In the validation stage, the polynomial’s inadequacy and the errors caused by the measurement inaccuracy are analyzed. Finally, the gas temperature models are compared using the criterion of total accuracy and the best model is selected.

Performance Simulation of 3-Stage Gas Turbine CHP Plant for Marine Applications

2016 ◽  
Author(s):  
Zhitao Wang ◽  
Yi-Guang Li ◽  
Shuying Li
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Propulsion System ◽  
Operating Conditions ◽  
Intermediate Water ◽  
Performance Simulation ◽  
Marine Applications ◽  
Chp System

Energy saving and environment become important issues in power and propulsion generation industry. One of such examples is the marine transportation where a lot of energy from consumed fuel is wasted in exhaust and emissions are produced in vessel propulsion systems. The focus of this research is to look at a typical marine propulsion system where gas turbines are the prime movers and to investigate the potentials of a novel 3-stage gas turbine combined heat and power (CHP) system for marine applications. Such a CHP system may include a topping gas turbine Brayton cycle, an intermediate water Rankine cycle (WRC), and a bottoming organic Rankine cycle (ORC). In the system, gas turbine is connected with a generator to produce electricity, water Rankine cycle produces superheated steam driving steam turbine for electricity generation and/or for heating, and organic Rankine cycle is used to produce electricity by recycling low temperature energy. A thermodynamic model for the 3-stage CHP system is established to simulate the performance of the system at different power demand operating conditions. The developed performance simulation system has been applied to a typical model vessel propulsion system application. Based on the simulated results, it is evident that compared with a conventional 2-stage CHP cycle where only gas turbine topping cycle and water Rankine bottoming cycle are included, the introduction of the organic Rankine cycle can increase the power output by about 7% and improve the cycle thermal efficiency by about 3.52%.

A Gas Turbine Performance Simulation Program and Its Application to an IGCC Gas Turbine

2010 ◽  
Author(s):  
Jong Jun Lee ◽  
Young Sik Kim ◽  
Tong Seop Kim ◽  
Jeong Lak Sohn ◽  
Yong Jin Joo
Keyword(s):  
Gas Turbine ◽  
System Integration ◽  
Gas Turbines ◽  
Engine Performance ◽  
Operating Conditions ◽  
Simulation Program ◽  
Component Level ◽  
Performance Simulation ◽  
Blade Cooling ◽  
Variable Stator

This paper explains a performance simulation program for power generation gas turbines and its application to an IGCC gas turbine. The program has a modular structure and both the stage-level and entire component-level models were adopted. Stage-by-stage calculations were used in the compressor and the turbine. In particular, the compressor module is based on a stage-stacking method and is capable of simulating the effect of variable stator vanes. The combustor model has the capability of dealing with various fuels including syngas. The turbine module is capable of estimating blade cooling performance. The program can be easily extended to other applied cycles such as recuperated and reheated cycles because the program structure is fully modular. The program was verified for simple cycle commercial engines. In addition, the program was applied to the gas turbine in an IGCC plant. Influences of major system integration parameters on the operating conditions of the compressor and turbine as well as on engine performance were analyzed.

Dynamic Performance Simulation of an Aeroderivative Gas Turbine Using the Matlab Simulink Environment

2013 ◽  
Author(s):  
Elias Tsoutsanis ◽  
Nader Meskin ◽  
Mohieddine Benammar ◽  
Khashayar Khorasani
Keyword(s):  
Power Generation ◽  
Real Time ◽  
Gas Turbine ◽  
Dynamic Behavior ◽  
Gas Turbines ◽  
Simulation Software ◽  
Performance Simulation ◽  
Matlab Simulink ◽  
Engine Model ◽  
Turbine Performance

In fossil fuel applications, such as air transportation and power generation systems, gas turbine is the prime mover which governs the aircraft’s propulsive and the plant’s thermal efficiency, respectively. Therefore, an accurate engine performance simulation has a significant impact on the operation and maintenance of gas turbines as far as reliability and availability considerations are concerned. Current trends in achieving stable engine operation, reliable fault diagnosis and prognosis requirements do motivate the development and implementation of real-time dynamic simulators for gas turbines that are sufficiently complex, highly nonlinear, have high fidelity and include fast response modules. This paper presents a gas turbine performance model for predicting the transient dynamic behavior of an aeroderivative engine that is suitable for both mechanical drive and power generation applications. The engine model has been developed in the Matlab/Simulink environment and combines both the inter-component volume and the constant mass flow methods. Dynamic equations of the mass momentum and the energy balance are incorporated into the steady state thermodynamic equations. This allows one to represent the engine model by a set of first order differential and algebraic equations. The developed Simulink model in an object oriented environment, can be easily adapted to any kind of gas turbine configuration. The model consists of a number of subsystems for representing the gas turbine’s components and the thermodynamic relationships among them. The components are represented by a set of suitable performance maps that are available from the open literature. The engine model has been validated with an established gas turbine performance simulation software. Time responses of the main variables that describe the gas turbine dynamic behavior are also included. The proposed gas turbine model with its dynamic simulation characteristics is a useful tool for development of real-time model-based diagnostics and prognostics technologies.

An Efficient Component Map Generation Method for Prediction of Gas Turbine Performance

2014 ◽  
Author(s):  
Elias Tsoutsanis ◽  
Nader Meskin ◽  
Mohieddine Benammar ◽  
Khashayar Khorasani
Keyword(s):  
Gas Turbine ◽  
Performance Prediction ◽  
Gas Turbines ◽  
Operating Conditions ◽  
Small Range ◽  
Engine Model ◽  
Turbine Performance ◽  
Map Generation ◽  
Compressor Map ◽  
Component Map

Improving efficiency, reliability and availability of gas turbines have become more than ever one of the main areas of interest in gas turbine research. This is mainly due to the stringent environmental regulations that have to be met in such a mature technology sector; and consequently new research challenges have been identified. One of these involves the establishment of high fidelity, accurate, and computationally efficient engine performance simulation, diagnosis and prognosis technology. Performance prediction of gas turbines is strongly dependent on detailed understanding of the engine component behaviour. Compressors are of special interest because they can generate all sorts of operability problems like surge, stall and flutter; and their operating line is determined by the turbine characteristic. Compressor performance maps, which are obtained in costly rig tests and remain manufacturers proprietary information, impose a stringent limitation that has been commonly resolved by scaling default generic maps in order to match the targeted off-design or engine degraded measurements. This approach is efficient in small range of operating conditions but becomes less accurate for a wider range of operations. In this paper, a novel compressor map generation method, with the primary objective of improving the accuracy and fidelity of the engine model performance prediction is developed and presented. A new compressor map fitting and modelling method is introduced to simultaneously determine the best elliptical curves to a set of compressor map data. The coefficients that determine the shape of compressor maps’ curves have been analyzed and tuned through a multi-objective optimization algorithm in order to meet the targeted set of measurements. The proposed component map generation method is developed in the object oriented Matlab/Simulink environment and is integrated in a dynamic gas turbine engine model. The accuracy of this method is evaluated for off-design steady state and transient engine conditions. The proposed compressor map generation method has the capability to refine current gas turbine performance prediction approaches and to improve model-based diagnostic techniques.

Viability of turbine blade material with a long service life

2019 ◽  
pp. 28-35
Author(s):  
O. B. Berdnik ◽  
I. N. Tsareva ◽  
M. K. Chegurov
Keyword(s):  
Heat Treatment ◽  
Service Life ◽  
Yield Strength ◽  
Mechanical Characteristics ◽  
Operating Time ◽  
Structural Features ◽  
Operating Conditions ◽  
Standard Methods ◽  
Experimental Values ◽  
Plasticity Coefficient

This article deals with structural features and characteristic changes that affect the mechanical characteristics after different service life in real conditions using the example of the blades of the 4th stage of turbine GTE-45-3 with an operating time of 13,000 to 100,000 hours. To study the change in the state of the material under different operating conditions, determine the degree of influence of heat treatment on the regeneration of the microstructure, and restore the mechanical characteristics of the alloy after different periods of operation, non-standard methods were used: relaxation tests on miniature samples to determine the physical yield strength and microplasticity limit and quantitative evaluation of the plasticity coefficient of the material from experimental values of hardness, which allow us to identify the changes occurring in the microvolumes of the material and predict the performance of the product as a whole.

scholarly journals Evaporator Optimization of Refrigerator Systems Using Quality Analysis

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 555
Author(s):  
Sangkyung Na ◽  
Sanghun Song ◽  
Seunghyuk Lee ◽  
Jehwan Lee ◽  
Hyun Kim ◽  
...  
Keyword(s):  
Power Consumption ◽  
Operating Time ◽  
Cooling Capacity ◽  
Operating Conditions ◽  
Quality Analysis ◽  
Lubricating Oil ◽  
Optimal Operating ◽  
Compressor Piston ◽  
Refrigerator Temperature ◽  
Visualization Experiments

In this study, evaporator optimization, via both experimental and simulation methods was conducted. To evaluate the evaporator performance, under the optimal system, the compressor operating time and the effects of oil on the refrigerator system were studied. If the temperature of the refrigerator chamber reaches the setting value, the compressor stops working and it leads to the temperature of the refrigerator chamber slowly increasing, due to the heat transfer to the ambient. When the refrigerator temperature is out of the setting range, the compressor works again, and the refrigerator repeats this process until the end of its life. These on/off period can be controlled through the compressor piston movement. To determine the optimal compressor operating conditions, experiments of monthly power consumption were conducted under various compressor working times and the lowest power consumption conditions was determined when the compressor worked continuously. Lubricating oil, the refrigerator system, using oil, also influenced the system performance. To evaluate the effect of oil, oil eliminated and oil systems were compared based on cooling capacity and power consumption. The cooling capacity of the oil eliminated system was 2.6% higher and the power consumption was 3.6% lower than that of the oil system. After determining the optimal operating conditions of the refrigerator system, visualization experiments and simulations were conducted to decide the optimal evaporator and the conventional evaporator size can be reduced by approximately 2.9%.

scholarly journals Engine Malfunctioning Conditions Identification through Instantaneous Crankshaft Torque Measurement Analysis

2021 ◽  
Vol 11 (8) ◽  
pp. 3522
Author(s):  
Konstantinos-Marios Tsitsilonis ◽  
Gerasimos Theotokatos
Keyword(s):  
Operating Conditions ◽  
Cylinder Pressure ◽  
Dynamics Model ◽  
Engine Model ◽  
Measurement Analysis ◽  
Start Of Injection ◽  
Rate Of Heat Release ◽  
Relationship Of ◽  
Diagnostic Measurement ◽  
The Relationship

In this study a coupled thermodynamics and crankshaft dynamics model of a large two-stroke diesel engine was utilised, to map the relationship of the engine Instantaneous Crankshaft Torque (ICT) with the following frequently occurring malfunctioning conditions: (a) change in Start of Injection (SOI), (b) change in Rate of Heat Release (RHR), (c) change in scavenge air pressure, and (d) blowby. This was performed using frequency analysis on the engine ICT, which was obtained through a series of parametric runs of the coupled engine model, under the various malfunctioning and healthy operating conditions. This process demonstrated that engine ICT can be successfully utilised to identify the distinct effects of malfunctions (c) or (d), as they occur individually in any cylinder. Furthermore by using the same process, malfunctions (a) and (b) can be identified as they occur individually for any cylinder, however there is no distinct effect on the engine ICT among these malfunctions, since their effect on the in-cylinder pressure is similar. As a result, this study demonstrates the usefulness of the engine ICT as a non-intrusive diagnostic measurement, as well as the benefits of malfunctioning conditions mapping, which allows for quick and less resource intensive identification of engine malfunctions.

scholarly journals A Comparative Study on Fault Detection Methods for Gas Turbine Combustion Systems

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 389
Author(s):  
Jinfu Liu ◽  
Zhenhua Long ◽  
Mingliang Bai ◽  
Linhai Zhu ◽  
Daren Yu
Keyword(s):  
Fault Detection ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Operating Conditions ◽  
Detection Methods ◽  
Distribution Model ◽  
Outlet Temperature ◽  
Combustion System ◽  
Comparison Results ◽  
Gas Turbine Combustion

As one of the core components of gas turbines, the combustion system operates in a high-temperature and high-pressure adverse environment, which makes it extremely prone to faults and catastrophic accidents. Therefore, it is necessary to monitor the combustion system to detect in a timely way whether its performance has deteriorated, to improve the safety and economy of gas turbine operation. However, the combustor outlet temperature is so high that conventional sensors cannot work in such a harsh environment for a long time. In practical application, temperature thermocouples distributed at the turbine outlet are used to monitor the exhaust gas temperature (EGT) to indirectly monitor the performance of the combustion system, but, the EGT is not only affected by faults but also influenced by many interference factors, such as ambient conditions, operating conditions, rotation and mixing of uneven hot gas, performance degradation of compressor, etc., which will reduce the sensitivity and reliability of fault detection. For this reason, many scholars have devoted themselves to the research of combustion system fault detection and proposed many excellent methods. However, few studies have compared these methods. This paper will introduce the main methods of combustion system fault detection and select current mainstream methods for analysis. And a circumferential temperature distribution model of gas turbine is established to simulate the EGT profile when a fault is coupled with interference factors, then use the simulation data to compare the detection results of selected methods. Besides, the comparison results are verified by the actual operation data of a gas turbine. Finally, through comparative research and mechanism analysis, the study points out a more suitable method for gas turbine combustion system fault detection and proposes possible development directions.

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