Mechanical Investigation of a Failed Lock-Pin

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
E. Poursaeidi ◽  
A. A. Pirmohammadi ◽  
M. R. Mohammadi Arhani
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Peak Stress ◽  
Element Model ◽  
Gas Turbine Engine ◽  
Time Service ◽  
Turbine Engine ◽  
Turbo Generator ◽  
Long Time ◽  
Mechanical Investigation

This paper presents the outcomes of computational mechanics applied in the root-cause investigation on hot section failure of a 25 MW gas turbo generator in the domestic power plant after 2228 start-stops and 52,586 h operation. The failure includes the complete damage of the first and the second stage of nozzles, blades, seals, shroud segments, and also a peripheral damage on the disk of first stage. Several reported cases from the different power plants with similar events evidenced that the failure is a serious common type in the mentioned gas turbine engine. A previous study on complete metallurgical analysis of disk, moving blades, and lock-pins, was done by Poursaeidi and Mohammadi (2008, “Failure Analysis of Lock-Pin in a Gas Turbine Engine,” Eng. Fail. Anal., 15(7), pp. 847–855), which concluded that the mechanical specification of applied materials had been satisfied. Nevertheless, some problems were found in the fractographic results of lock-pins: the typical fatigue fracture surfaces in the neck of failed lock-pins and frankly localized pitting signs near the head of lock-pin. The lock-pins are kinds of small devices that lock the buckets after inserting them into disk grooves. In this work, a 3D finite element model (FEM) of a blade, a disk, and a lock-pin are made and analyzed by the ANSYS software. The results of the FEM showed a reasonable agreement between the analysis and position of fracture on lock-pins. Also, the results showed that the second vibrational mode of the bucket is a possible cause of failure because in this mode the peak stress occurs on the head of the lock-pin. However, inadequate design and long time service reduced the performance of lock-pins for sustaining a severe hot condition in the first stage of the turbine section.

Direct Off-Design Performance Prediction of Micro Gas Turbine Engine for Distributed Power Generation

2017 ◽  
Author(s):  
Valentyn Barannik ◽  
Maksym Burlaka ◽  
Leonid Moroz ◽  
Abdul Nassar
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Power Plants ◽  
Gas Turbine Engine ◽  
Small Scale ◽  
Turbine Engine ◽  
Design Performance ◽  
Exhaust Heat ◽  
Electrical Generation ◽  
Central Station

Central-station power plants (CSPP) are the main provider of energy today. In the process of power generation at central-power stations, about 67% of primary energy is wasted. Distributed cogeneration or combined heat and power (CHP) systems are an alternative to central-station power plants. In these systems, an electrical generation system located in a residence or at a commercial site consumes natural gas to generate electricity locally and then the exhaust heat is utilized for local heating needs (in contrast to being wasted at central-stations). Microturbines offer a number of potential advantages compared to other technologies for small-scale power generation. For example, compact size and low-weight leading to reduced civil engineering costs, a small number of moving parts, lower noise and vibration, multi-fuel capabilities, low maintenance cost as well as opportunities for lower emissions. Inverter generators allow using micro-turbines of different shaft rotation speed that opens opportunities to unit optimization at off-design modes. The common approach to predict the off-design performance of gas turbine unit is the mapping of the compressor and the turbine separately and the consequent matching of common operation points. However, the above-mentioned approach might be rather inaccurate if the unit has some secondary flows. In this article an alternative approach for predicting off-design performance without using component maps is presented. Here the off-design performance is done by direct calculation of the components performances. On each off-design mode, the recalculation of the characteristic of all scheme components, including a compressor, gas turbine, combustor, recuperator and secondary flow system is performed. The different approaches for obtaining the performance at off-design modes considering the peculiarities of the gas turbine engine are presented in this paper.

scholarly journals ЕФЕКТИВНА ТЯГА ТА ЗОВНІШНІЙ ОПІР АВІАЦІЙНОЇ СИЛОВОЇ УСТАНОВКИ

2020 ◽  
pp. 61-67
Author(s):  
Юрий Юрьевич Терещенко ◽  
Иван Алексеевич Ластивка ◽  
Павел Владимирович Гуменюк ◽  
Су Хунсян
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Plants ◽  
Gas Turbine Engine ◽  
Turbine Engines ◽  
Gas Generator ◽  
External Resistance ◽  
Turbine Engine ◽  
Engine Thrust ◽  
Engine Nacelle

Increasing the efficiency and effectiveness of a gas turbine engine can be achieved through a comprehensive review of all tasks that determine the parameters and characteristics of an aircraft power plant and aircraft. An important place in this complex is occupied by the problem of obtaining the most efficient traction and power plant based on the integration of the parameters and characteristics of the nacelle and gas turbine engine, consisting of a universal gas generator module and a turbofan module. Reducing the negative impact of the engine nacelle module on effective traction and effective specific fuel consumption is an urgent problem that can be solved based on the results of studies of the integration parameters and characteristics of the engine nacelle of the gas generator module and the gas turbine engine with the turbine-fan extension module, namely, with the implementation of structurally layout diagram of a gas turbine engine with a modular design with a rear arrangement of a turbofan attachment. For modern power plants with bypass gas turbine engines with a large bypass ratio, the external resistance is 2-3 % of the engine thrust during cruising operation. The results of experimental studies have shown that the external resistance of power plants with bypass gas turbine engines of modern supersonic aircraft is 4-6 % of the engine thrust during cruising operation. The paper considers the issues of aerodynamic integration of a gas turbine engine and a nacelle of an aircraft power plant. Aerothermogasdynamic integration of a gas turbine engine and an aircraft provides for the coordination of the parameters of the working process and the characteristics of the gas turbine engine and the parameters and characteristics of the nacelle of the aircraft in order to obtain optimal parameters and characteristics of the aircraft in the design flight conditions. The dependences of the relative effective thrust on the flight velocity are obtained. The obtained dependencies show the influence of the external resistance of the engine nacelle on the effective thrust of the bypass engine at subsonic flight velocities. The calculations were performed to lengthen the nacelle in the range from 4 to 8.

A new approach to the design of adaptive automatic control systems for a short-range gas turbine engine

2011 ◽  
Vol 8 (1) ◽  
pp. 239-248
Author(s):  
E.V. Denisova ◽  
E.Sh. Nasibullaeva ◽  
M.A. Chernikova
Keyword(s):  
Automatic Control ◽  
Unmanned Aerial Vehicles ◽  
Control Systems ◽  
Gas Turbine ◽  
Short Range ◽  
Power Plants ◽  
Gas Turbine Engine ◽  
New Approach ◽  
Turbine Engine ◽  
Automatic Control Systems

The paper presents a new approach to the management of power plants by unmanned aerial vehicles, provides a structural diagram of the proposed automatic control systems of a gas turbine engine, presents preliminary results of modeling.

Probabilistic Assessment of Thermodynamic Output of an Intercooled-Reheated-Regenerative Brayton Cycle Coupled to Variable Temperature Heat Reservoirs

2013 ◽  
Author(s):  
Vishal Anand ◽  
Krishna Nelanti
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Variable Temperature ◽  
Gas Turbine Engine ◽  
Design Parameters ◽  
Probabilistic Assessment ◽  
Brayton Cycle ◽  
Turbine Engine ◽  
Temperature Heat

The gas turbine engine works on the principle of Brayton cycle. One of the ways to improve the thermal efficiency of gas turbine engine is to make changes in the Brayton cycle. These changes may include intercooling, reheating, regeneration etc. The aim of the present study is to do a probabilistic assessment of the thermal efficiency and the dimensionless power of an intercooled, reheated, regenerative Brayton cycle coupled to variable temperature heat reservoirs. The Spearman’s rank coefficient has been used to find the design parameters which most affect the thermal efficiency and the dimensionless power. The design parameters, such as the effectiveness of the different heat exchangers, the efficiency of turbines and compressors and the heat capacitance rates of the external and the working fluids; have been listed with their relative impact on the thermal efficiency and the dimensionless power. The probabilistic assessment gives us a new insight into the sensitivity of the thermal efficiency and the dimensionless power of the Brayton Cycle with respect to these parameters. It will help the designers/decision makers to allocate the limited resources in a better way with the ultimate aim of making more efficient power plants.

Impact of Air Quality and Site Selection on Gas Turbine Engine Performance

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
David W. MacPhee ◽  
Asfaw Beyene
Keyword(s):  
Air Quality ◽  
Gas Turbine ◽  
Site Selection ◽  
Power Plants ◽  
Cfd Simulation ◽  
Gas Turbine Engine ◽  
Simple Assumption ◽  
Turbine Engine ◽  
Aerodynamic Properties ◽  
The Impact

Air pollution can have detrimental effects on gas turbine performance leading to blade fouling, which reduces power output and requires frequent cleanings. This issue is a fairly well-known phenomenon in the power industry. However, site selection for gas turbine installation on the basis of air quality is rarely part of the decision-making process, mainly due to lack of geographical options especially in an urban environment or perhaps due to a simple assumption that air quality at a local micro-level has no impact on the performance of the engine. In this paper, we perform a computational fluid dynamics (CFD) study on an area surrounding a combined heat and power (CHP) facility to assess the impact of local wind distribution on air quality and the performance of a gas turbine engine. Several aerodynamic properties are suggested as possible indicators of air quality and/or high airborne particulate concentration. These indicators are then compared to data collected at various points in and around the site. The results suggest that through post-processing of a simplified CFD simulation analyzing the adjacent terrain, a continuous map of field variables can be obtained and help designers locate future CHP or gas turbine power plants in regions of lower particulate concentrations. This, in turn, would greatly increase efficiency and cost-effectiveness of the proposed power plant.

Gas Turbine Engine Off-Design Performance Simulation Using Syngas From Biomass Derived Gas as Fuel

2007 ◽  
Author(s):  
Sandro B. Ferreira ◽  
Marco Antoˆnio R. do Nascimento
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Gas Turbine Engine ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Performance Simulation ◽  
Turbine Engine ◽  
Design Performance ◽  
Surge Line ◽  
And Performance

The use of syngas from gasified biomass as fuel for electric power generation based on gas turbine engines has been seriously studied over the past last two decades. Few experimental power plants have been built around the world. A small review of the use of syngas from gasified biomass and a cleaning system for gas turbine engines are presented. In this paper a computational program was presented and validated to simulate the design and off-design performance analysis of simple cycle gas turbine engines with one and two shafts. The aim was to assess the behavior and performance of the gas turbine engine without accounting for auxiliary syngas fuel compressor when the gasifier is atmospheric. It shows the behavior and performance at the off design condition of these two types of hypothetic gas turbine engines. The two engines were designed to use kerosene as fuel and at off-design conditions, and they were run using syngas from gasified biomass. The results show that the running line in the compressor characteristic moves towards the surge line and that the performance changes when the engine runs with the syngas.

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