Predicting the Ultimate Performance of Advanced Power Cycles Based on Very High Temperature Gas Turbine Engines

1993 ◽  
Author(s):  
Paolo Chiesa ◽  
Stefano Consonni ◽  
Giovanni Lozza ◽  
Ennio Macchi
Keyword(s):  
Gas Turbine ◽  
Large Scale ◽  
Computer Code ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Gas Temperature ◽  
Clear Trend ◽  
Performance Improvements ◽  
Future Technology ◽  
The Impact

It is well known that the history of gas turbine engines has been characterized by a very clear trend toward higher and higher operating temperatures, a growth which in the past 40 years has progressed at the impressive pace of approximately 13°C/year. Expected improvements in blade cooling techniques and advancements in materials indicate that this tendency is going to last for long time, leading to firing temperatures of over 1500°C within the next two decades. This paper investigates the impact of such temperature increase on optimal cycle arrangements and on ultimate performance improvements achievable by future advanced gas/steam cycles for large-scale power generation. Performance predictions have been carried out by a modified, improved version of a computer code originally devised and calibrated for “1990 state-of-the-art” gas/steam cycles. The range of performances to be expected in the next decades has been delimited by considering various scenarios of cooling technology and materials, including the extreme situations of adiabatic expansion and stoichiometric combustion. The results of parametric thermodynamic analyses of several cycle configurations are presented for a number of technological scenarios, including cycles with intercooling and reheat. A specific section discusses how the optimum configuration of the bottoming steam cycle changes to keep up with exhaust gas temperature increases. Calculations show that, under plausible assumptions on future technology advancements, within two decades the proper selection of plant configuration and operating parameters can yield net efficiencies of over 60%.

Passive Absorption/Emission Spectroscopy for Gas Temperature Measurements in Gas Turbine Engines

2011 ◽  
Author(s):  
Hejie Li ◽  
Guanghua Wang ◽  
Nirm Nirmalan ◽  
Samhita Dasgupta ◽  
Edward R. Furlong
Keyword(s):  
Gas Turbine ◽  
Emission Spectroscopy ◽  
Gas Absorption ◽  
Temperature Measurements ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Gas Temperature ◽  
Measurement Results ◽  
Passive Absorption ◽  
Hot Surface

A novel technique is developed to simultaneously measure hot surface and gas temperatures based on passive absorption/emission spectroscopy (PAS). This non-intrusive, in situ technique is the extension of multi-wavelength pyrometry to also measure gas temperature. The PAS technique uses hot surface (e.g., turbine blade) as the radiation source, and measures radiation signals at multiple wavelengths. Radiation signals at wavelengths with minimum interference from gas (mostly from water vapor and CO2) can be used to determine the hot surface temperature, while signals at wavelengths with gas absorption/emission can be used to determine the gas temperature in the line-of-sight. The detection wavelengths are optimized for accuracy and sensitivity for gas temperature measurements. Simulation results also show the effect of non-uniform gas temperature profile on measurement results. High pressure/temperature tests are conducted in single nozzle combustor rig to demonstrate sensor proof-of-concept. Preliminary engine measurement results shows the potential of this measurement technique. The PAS technique only requires one optical port, e.g., existing pyrometer or borescope port, to collect the emission signal, and thus provide practical solution for gas temperature measurement in gas turbine engines.

Improved criteria for stall-free preliminary design of axial compressor of aero gas turbine engines

2018 ◽  
Vol 233 (9) ◽  
pp. 3286-3297 ◽  
Author(s):  
MR Aligoodarz ◽  
A Mehrpanahi ◽  
M Moshtaghzadeh ◽  
A Hashiehbaf
Keyword(s):  
Gas Turbine ◽  
Large Scale ◽  
Axial Compressor ◽  
Axial Flow ◽  
Design Criterion ◽  
Flow Coefficient ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Parameter Ranges ◽  
Axial Flow Compressors

A worldwide effort has been devoted to developing highly efficient and reliable gas turbine engines. There exist many prominent factors in the development of these engines. One of the most important features of the optimal design of axial flow compressors is satisfying the allowable range for various parameters such as flow coefficient, stage loading, the degree of reaction, De-Haller number, etc. But, there are some applicable cases that the mentioned criteria are exceeded. One of the most famous parameters is De-Haller number, which according to literature data should not be kept less than 0.72 in any stage of the axial compressor. A deep insight into the current small- or large-scale axial flow compressors shows that a discrepancy will occur among design criterion for De-Haller number and experimental measurements in which the De-Haller number is less than the design limit but no stall or surge is observed. In this paper, an improved formulation is derived based on one-dimensional modeling for predicting the stall-free design parameter ranges especially stage loading, flow coefficient, etc. for various combinations. It was found that the current criterion is much more accurate than the De-Haller criterion for design purposes.

scholarly journals Single-Coil Eddy Current Sensors and Their Application for Monitoring the Dangerous States of Gas-Turbine Engines

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2107 ◽  
Author(s):  
Sergey Borovik ◽  
Yuriy Sekisov
Keyword(s):  
Gas Turbine ◽  
Eddy Current ◽  
Natural Aging ◽  
Turbine Engines ◽  
Radial Clearance ◽  
Gas Turbine Engines ◽  
Structural Elements ◽  
Single Coil ◽  
The Impact ◽  
Blade Tips

The creation and exploitation of gas turbine engines (GTE) often involve two mutually exclusive tasks related to ensuring the highest reliability while achieving a good economic and environmental performance of the power plant. The value of the radial clearance between the blade tips of the compressor or turbine and the stator is a parameter that has a significant impact on the efficiency and safety of the GTE. However, the radial displacements that form tip clearances are only one of the components of the displacements made by GTE elements due to the action of power loads and thermal deformations during engines’ operation. The impact of loads in conjunction with natural aging is also the reason for the wear of the GTE’s structural elements (for example, bearing assemblies) and the loss of their mechanical strength. The article provides an overview of the methods and tools for monitoring the dangerous states of the GTE (blade tips clearances, impellers and shafts displacements, debris detecting in lubrication system) based on the single-coil eddy current sensor, which remains operational at the temperatures above 1200 °C. The examples of practical application of the systems with such sensors in bench tests of the GTE are given.

The Potential Impact of Future Fuels on Small Gas Turbine Engines

1982 ◽  
Author(s):  
J. A. Saintsbury ◽  
P. Sampath
Keyword(s):  
Gas Turbine ◽  
Operating Experience ◽  
Gas Turbine Engine ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Turbine Engine ◽  
The Future ◽  
Potential Impact ◽  
The Impact ◽  
Whitney Aircraft

The impact of potential aviation gas turbine fuels available in the near to midterm, is reviewed with particular reference to the small aviation gas turbine engine. The future course of gas turbine combustion R&D, and the probable need for compromise in fuels and engine technology, is also discussed. Operating experience to date on Pratt & Whitney Aircraft of Canada PT6 engines, with fuels not currently considered of aviation quality, is reported.

The Interaction Between Mistuning and Friction in the Forced Response of Bladed Disk Assemblies

1985 ◽  
Vol 107 (1) ◽  
pp. 205-211 ◽  
Author(s):  
J. H. Griffin ◽  
A. Sinha
Keyword(s):  
Gas Turbine ◽  
Turbine Blades ◽  
Forced Response ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Resonant Response ◽  
Friction Dampers ◽  
Bladed Disk ◽  
The Impact ◽  
Slip Force

This paper summarizes the results of an investigation to establish the impact of mistuning on the performance and design of blade-to-blade friction dampers of the type used to control the resonant response of turbine blades in gas turbine engines. In addition, it discusses the importance of friction slip force variations on the dynamic response of shrouded fan blades.

Component Integration and Loss Sources in 3 – 5 kW Gas Turbines

2005 ◽  
Author(s):  
M. A. Monroe ◽  
A. H. Epstein ◽  
H. Kumakura ◽  
K. Isomura
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Large Scale ◽  
Engine Performance ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Flow Distortion ◽  
Thermal Isolation ◽  
Component Integration ◽  
Measured Efficiency

The performance of a regenerated gas turbine generator in the 3–5 kW power range has been analyzed to understand why its measured efficiency was on the order of 6% rather than the 20% suggested by consideration of its components’ efficiencies as measured on rigs. This research suggests that this discrepancy can be primarily attributed to heat and fluid leaks not normally considered in the analysis of large gas turbine engines because they are not as important at large scale. In particular, fluid leaks among the components and heat leakage from the hot section into the compressor flow path contributed the largest debits to the engine performance. Such factors can become more important as the engine size is reduced. Other non-ideal effects reducing engine performance include temperature flow distortion at the entrance to both the compressor and turbine. A cycle calculation including all of the above effects matched measured engine data. It suggests that relatively simple changes such as thermal isolation and leak sealing can increase both power output and efficiency of this engine, over 225% in the latter case. The validity of this analysis was demonstrated on an engine in which partial thermal isolation and improved sealing resulted in a more than 40% increase in engine output power.

Semi-Closed Gas Turbine Cycles: An Ecological Solution

2001 ◽  
Author(s):  
A. L. Laganelli ◽  
C. Rodgers ◽  
W. E. Lear ◽  
P. L. Meitner
Keyword(s):  
Global Warming ◽  
Greenhouse Gases ◽  
Gas Turbine ◽  
Fossil Fuels ◽  
High Efficiency ◽  
Anthropogenic Heat ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Closed Cycle ◽  
The Impact

The impact on global warming of transportation and the infrastructure that supports it has been investigated over several decades. Anthropogenic heat and the generation of greenhouse gases from burning of fossil fuels and are major contributors to the warming process. An approach to mitigate these effects is discussed that considers semi-closed cycle gas turbine engines as a practical approach to slowing the release of greenhouse gases. Semi-closed cycle gas turbine engines have an inherent capability to reduce all regulated emissions while maintaining high efficiency, which in turn reduces CO2 emissions. With emerging technology development that includes higher component efficiencies, high temperature material development, improved control devices, and advanced combustor designs, aided by computational fluid dynamics, semi-closed cycle engines appear to have the potential to mitigate global warming with little economic or infrastructural impact. A specific semi-closed engine type is described, the high pressure recuperated turbine engine (HPRTE), along with the inherent mechanisms for control of NOx, CO, unburned hydrocarbons, and particulates. Results from a breadboard demonstration of the HPRTE are discussed, as well as emerging technologies which benefit this type of engine.

scholarly journals Exhaust gas temperature measurements in diagnostic examination of naval gas turbine engines: Part II Unsteady processes

2011 ◽  
Vol 18 (3) ◽  
pp. 37-42 ◽  
Author(s):  
Zbigniew Korczewski
Keyword(s):  
Gas Turbine ◽  
Temperature Measurements ◽  
Turbine Engines ◽  
Flow Section ◽  
Exhaust Gas ◽  
Gas Turbine Engines ◽  
Gas Temperature ◽  
Rate Of Increase ◽  
Exhaust Gas Temperature ◽  
Unsteady Processes

Exhaust gas temperature measurements in diagnostic examination of naval gas turbine engines: Part II Unsteady processes The second part of the article presents the results of operating diagnostic tests of a two- and three-shaft engine with a separate power turbine during the start-up and acceleration of the rotor units. Attention was paid to key importance of the correctness of operation of the automatic engine load control system, the input for which, among other signals, is the rate of increase of the exhaust gas flow temperature. The article presents sample damages of the engine flow section which resulted from disturbed functioning of this system. The unsteady operation of the compressor during engine acceleration was the source of excessive increase of the exhaust gas temperature behind the combustion chamber and partial burning of the turbine blade tips.

High Power Density Silicon Combustion Systems for Micro Gas Turbine Engines

2003 ◽  
Vol 125 (3) ◽  
pp. 709-719 ◽  
Author(s):  
C. M. Spadaccini ◽  
A. Mehra ◽  
J. Lee ◽  
X. Zhang ◽  
S. Lukachko ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Large Scale ◽  
Experimental Testing ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Deep Reactive Ion Etching ◽  
Turbine Engine ◽  
Micro Gas Turbine ◽  
Power Densities ◽  
Important Design

As part of an effort to develop a microscale gas turbine engine for power generation and micropropulsion applications, this paper presents the design, fabrication, experimental testing, and modeling of the combustion system. Two radial inflow combustor designs were examined; a single-zone arrangement and a primary and dilution-zone configuration. Both combustors were micromachined from silicon using deep reactive ion etching (DRIE) and aligned fusion wafer bonding. Hydrogen-air and hydrocarbon-air combustion were stabilized in both devices, each with chamber volumes of 191mm3. Exit gas temperatures as high as 1800 K and power densities in excess of 1100MW/m3 were achieved. For the same equivalence ratio and overall efficiency, the dual-zone combustor reached power densities nearly double that of the single-zone design. Because diagnostics in microscale devices are often highly intrusive, numerical simulations were used to gain insight into the fluid and combustion physics. Unlike large-scale combustors, the performance of the microcombustors was found to be more severely limited by heat transfer and chemical kinetics constraints. Important design trades are identified and recommendations for microcombustor design are presented.

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