Development and Testing of the Upgraded High Pressure Turbine Section for an Industrial Gas Turbine

2008 ◽  
Author(s):  
E. Aschenbruck ◽  
D. Frank ◽  
T. Korte ◽  
R. Mu¨ller ◽  
U. Orth
Keyword(s):  
High Pressure ◽  
Gas Turbine ◽  
Cooling System ◽  
Mechanical Design ◽  
Development Program ◽  
Tip Clearance ◽  
Test Facility ◽  
High Pressure Turbine ◽  
Online Data ◽  
Clearance Control

As part of an ongoing development program to increase power output and efficiency of the THM 1304 gas turbine, modifications were made to the high pressure turbine. The modifications include but are not limited to blade and vane aerodynamics, cooling system and clearance control, mechanical design and materials. The development was to achieve the following goals: • Intensified blade and vane cooling to permit higher turbine inlet temperatures and to further extend service lifetime; • Improved aerodynamic performance; • Blades with pre-loaded tip shrouds to achieve low vibration amplitudes in a broad operating speed range; • Rotor design modifications to simplify assembly and disassembly; • Modified vane carrier and casing designs for optimal tip clearance control and turbine performance. The improved high pressure turbine was extensively tested in MAN TURBO’s full-load gas turbine test facility. Test results verified that component temperatures were within the expected range and design targets have been achieved. The first production gas turbine equipped with the upgraded high pressure turbine was installed in May 2004 as a gas compressor driver. To date a total of 11 units have gone into operation including units for power generation. Dry low emission technology is used on all engines. Every unit is monitored by an online data monitoring system and visually inspected in shorter intervals to verify the behavior in the field. Operation of the fleet is flawless at this time.

Innovative Measurement Techniques for a Cooled Turbine Casing Operating at Engine Representative Thermal Conditions

2014 ◽  
Author(s):  
Andrew G. Dann ◽  
Steve J. Thorpe ◽  
Leo V. Lewis ◽  
Peter Ireland
Keyword(s):  
Control System ◽  
Cooling System ◽  
Measurement Techniques ◽  
Axial Displacement ◽  
Tip Clearance ◽  
Test Facility ◽  
Uniform Heat Flux ◽  
Thermal Transients ◽  
Turbine Casing ◽  
Clearance Control

To optimize the efficiency of modern aero-gas turbine engines the turbine tip clearances must be tightly controlled so as to minimize leakage losses. In addition, the clearance control system must be able to respond with sufficient rapidity to engine thermal transients. One method of achieving turbine tip-clearance control is to manipulate the turbine casing temperature, and thereby radial growth, by convective cooling. The consequent clearance control system represents a particularly complex thermo-mechanical design problem. The current experimental study aims to simulate the heat loads to which the internal surfaces of the casing are typically exposed and to characterize the radial and axial displacement of the free-body casing under varying external cooling conditions. Importantly, the newly commissioned test facility allows a realistic assessment of the casing cooling impact on dimensional control, and also the rapid characterization and comparison of different concepts. The test facility comprises a model of a high-pressure/intermediate-pressure turbine casing with generic impingement cooling manifolds. A radiant heater is mounted within the casing model such that a near-uniform heat flux condition can be established on the casing wall inner surface. Extensive surface mounted thermocouples are welded to the casing wall to monitor variations in metal temperature. Radial and axial displacement of the casing is monitored using laser triangulation and linear variable differential transformer sensors. Experiments have been conducted over a range of heat load conditions and with engine representative levels of casing cooling applied. Importantly, the new test facility allows for the characterization of the casing cooling system as a whole.

scholarly journals The Aerodynamic and Mechanical Performance of a High-Pressure Turbine Stage in a Transient Wind Tunnel

1992 ◽  
Vol 114 (1) ◽  
pp. 132-140 ◽  
Author(s):  
A. G. Sheard ◽  
R. W. Ainsworth
Keyword(s):  
High Pressure ◽  
Mechanical Performance ◽  
Mechanical Design ◽  
Unsteady Aerodynamics ◽  
Operating Conditions ◽  
Test Facility ◽  
Operating Point ◽  
High Pressure Turbine ◽  
Transient Wind ◽  
Future Work

A new transient facility for the study of time mean and unsteady aerodynamics and heat transfer in a high-pressure turbine has been commissioned and results are available. A detailed study has been made of aspects of the performance and behavior relevant to turbine mechanical design, and an understanding of the variation of the turbine operating point during the test, crucial to the process of valid data acquisition, has been obtained. In this this paper the outline concept and mode of operation of the turbine test facility are given, and the key aerodynamic and mechanical aspects of the facility’s performance are presented in detail. The variations of the those parameters used to define the turbine operating point during facility operation are examined, and the accuracy with which the turbine’s design point was achieved calculated. Aspects of the mechanical performance presented include the results of a finite element stress analysis of the loads in the turbine under operating conditions, and the performance of the rotor bearing system under these arduous load conditions. Both of these aspects present more information than has been available hitherto. Finally, the future work program and possible plans for further facility improvement are given.

scholarly journals The Aerodynamic and Mechanical Performance of a High Pressure Turbine Stage in a Transient Wind Tunnel

1990 ◽  
Author(s):  
A. G. Sheard ◽  
R. W. Ainsworth
Keyword(s):  
High Pressure ◽  
Mechanical Performance ◽  
Mechanical Design ◽  
Unsteady Aerodynamics ◽  
Operating Conditions ◽  
Test Facility ◽  
Operating Point ◽  
High Pressure Turbine ◽  
Transient Wind ◽  
Future Work

A new transient facility for the study of time mean and unsteady aerodynamics and heat transfer in a high pressure turbine has been commissioned and results are available. A detailed study has been made of aspects of the performance and behaviour relevant to turbine mechanical design, and an understanding of the variation of the turbine operating point during the test, crucial to the process of valid data acquisition, has been obtained. In this paper the outline concept and mode of operation of the tubine test facility are given, and the key aerodynamic and mechanical aspects of the facility’s performance are presented in detail. The variation of those parameters used to define the turbine operating point during facility operation are examined, and the accuracy with which the turbine’s design point was achieved calculated. Aspects of the mechanical performance which are presented include the results of a finite element stress analysis of the loads in the turbine under operating conditions, and the performance of the rotor bearing system under these arduous load conditions. Both of these aspects present more information than has been available hitherto. Finally, the future work programme and possible plans for further facility improvement are given.

Tip-Clearance Measurements on an Engine High Pressure Turbine Using an Eddy Current Sensor

2017 ◽  
Author(s):  
V. Sridhar ◽  
K. S. Chana
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Gas Turbine ◽  
Eddy Current ◽  
Health Monitoring ◽  
Tip Clearance ◽  
Current Sensor ◽  
High Pressure Turbine ◽  
Eddy Current Sensor ◽  
Health Monitoring Systems

Gas turbine health monitoring is an important area of research. As the performance of aircraft and power plants increase, they will require better sensors for health monitoring systems to prevent failures. Health monitoring systems help in preventive maintenance reducing unnecessary downtime and maintenance costs. Gas turbine blades are subjected to dynamic loads caused by rotor imbalances, distortions in the intake flows etc. These loads cause low or high cycle fatigues and the blades can fail over time. Tip-timing and tip-clearance systems makes it possible to assess turbomachinery blade vibration by using non-contact measurement systems such as optical, eddy current, hall effect, capacitve etc. The most widely used systems in industry are optical, however, these systems are still largely prone to contamination problems from dust, dirt, oil, water etc. Further development of these systems for in-service use is problematic because of the difficulty in eliminating contamination of the optics. Other systems, although immune to contamination, may not be able to measure both tip-clearance and tip-timing at the same time due to their operating principle. Another limitation is that they cannot be used in high temperature applications such as in a high pressure turbine where the temperatures can reach 1400°C. Eddy current sensors are found to be quite robust and can measure both tip-timing and tip-clearance. They are currently being used for gas turbine health monitoring applications at low temperatures such as in the compressor stage and last stage of a steam turbine. A new high temperature eddy current sensor has been developed in-house at the University of Oxford for application in gas turbine tip-timing and tip clearance measurements to assess blade vibrations. The current sensor is a modified version of the existing eddy current sensor that is able to operate at high temperatures of about 1400°C. The paper presents the development of the sensor and experimental results of tip clearance measurements in the high pressure turbine stage of a jet engine. In the engine tests, two blades were reduced in height to increase the tip-clearance and the measurements were taken at both idle and max operating speeds. The sensor was found to work in these harsh environments and was sufficiently sensitive to accurately determine the tip clearance at these elevated temperatures. Tests were carried out mainly to demonstrate the technique of obtaining good tip clearance measurements and the survivability of the sensors in the high temperature and pressure environment.

scholarly journals A Comparison of Single-Entry and Multiple-Entry Casing Impingement Manifolds for Active Thermal Tip Clearance Control

2021 ◽  
Vol 6 (2) ◽  
pp. 10
Author(s):  
Priyanka Dhopade ◽  
Benjamin Kirollos ◽  
Peter Ireland ◽  
Leo Lewis
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Heat Transfer Coefficient ◽  
Control System ◽  
Tip Clearance ◽  
Feed System ◽  
High Pressure Turbine ◽  
Aero Engine ◽  
Single Entry ◽  
Clearance Control

In this paper, we compare using computational fluid dynamics the aero-thermal performance of two candidate casing manifolds for supplying an impingement-actuated active tip clearance control system for an aero-engine high-pressure turbine. The two geometries are (a) single-entry: an annular manifold fed at one circumferential location; (b) multiple-entry: a casing manifold split into four annular sectors, with each sector supplied separately from an annular ring main. Both the single-entry and multiple-entry systems analysed in this paper are idealised versions of active clearance control systems in current production engines. Aero-thermal performance is quantitatively assessed on the basis of the heat transfer coefficient distribution, driving temperature difference for heat transfer between the jet and casing wall and total pressure loss within the high-pressure turbine active clearance control system. We predict that the mean heat transfer coefficient (defined with respect to the inlet temperature and local wall temperature) of the single-entry active clearance control system is 77% greater than the multiple-entry system, primarily because the coolant in the multiple-entry case picks up approximately 40 K of temperature from the ring main walls, and secondarily because the average jet Reynolds number of impingement holes in the single-entry system is 1.2 times greater than in the multiple-entry system. The multiple-entry system exhibits many local hot and cold spots, depending on the position of the transfer boxes, while the single-entry case has a more predictable aero-thermal field across the system. The multiple-entry feed system uses an average of 20% of the total available pressure drop, while the feed system for the single-entry geometry uses only 2% of the total available pressure drop. From the aero-thermal results of this computational study, and in consideration of holistic aero-engine design factors, we conclude that a single-entry system is closer to an optimal solution than a multiple-entry system.

Tip Clearance Control Concept in Gas Turbine H.P. Compressors

2012 ◽  
Author(s):  
G. I. Ekong ◽  
C. A. Long ◽  
P. R. N. Childs
Keyword(s):  
Gas Turbine ◽  
Tip Clearance ◽  
Test Facility ◽  
Turbine Engines ◽  
Thermodynamic Efficiency ◽  
Gas Turbine Engines ◽  
Critical Importance ◽  
Operating Cycle ◽  
Expansion Time ◽  
Clearance Control

To improve the thermodynamic efficiency of aircraft engine and other gas turbine engines, higher and higher pressure ratios are desired in conjunction with more refined engine cycles. In the high pressure compressor, higher pressure ratios result in lower aspect blades and enhanced sensitivity of the engine design to radial clearance effects. The tip clearance in the axial flow compressor of modern commercial civil aero-engines is of critical importance in terms of both mechanical integrity and performance. Typically as the clearance between the compressor blade tips and the casing increases, the aerodynamic efficiency will decrease and therefore the specific fuel consumption and operating costs will increase, and the clearance is therefore of critical importance to civil airline operators and their customers alike. A design exercise was performed and a series of conceptual solutions were developed using the theory of inventive problem solving (TRIZ) process and their potential viability in clearance control was investigated with thermal modelling. TRIZ was selected as an appropriate tool as the issue was long-standing having been the focus of previous projects, and robust design solutions were being sought. In order to validate the concepts, use was made of a test facility developed at the University of Sussex, incorporating a rotor and an inner shaft scaled down from a Rolls Royce Trent aeroengine to a ratio of 0.7:1. The mechanical design of the test facility allows the simulation of flow conditions in the HP compressor cavity equivalent to the Trent 1000 aero-engine, with a rotational speed of up to 10000 rpm. The idle and maximum take-off conditions in the square cycle correspond to in-cavity rotational Reynolds numbers of 3.1×106 ≤ Reφ ≤ 1.0×107. The finite element thermomechanical model has been built to validate the engine measurements. This paper describes the use of TRIZ and the development of a selected concept and the detailed evaluation for reduction and control of tip clearance in HP compressors. This was achieved through the reduction in the compressor disc heat expansion time constant by improving drum heat transfer using bleed air from the compressor core flow. This paper explores the trade-offs between clearance and efficiency and develops and explores concepts to control the compressor tip clearance throughout the engine operating cycle. The project involved modelling of potential solutions and use of experimental facilities, a rotating compressor cavity rig, in order to explore the physical principles and demonstrate proof of concept for controlling tip clearance in HP compressors of gas turbine engines.

MS5002C and D “Power Crystal™ Kit” Heavy Duty Gas Turbine Development and Operating Experience

2012 ◽  
Author(s):  
Paolo Del Turco ◽  
Michele D’Ercole ◽  
Ahmed Ossama Fouad ◽  
Riccardo Carta ◽  
Alessandro Russo ◽  
...  
Keyword(s):  
High Pressure ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Energy Demand ◽  
Operating Experience ◽  
Development Program ◽  
Heavy Duty ◽  
High Pressure Turbine ◽  
Initial Field ◽  
Turbine Wheel

Given the constant increase in world energy demand, gas turbine operators are continuously looking for turbo-machinery improvements, both in terms of increased power and extended maintenance intervals, limiting, as much as possible, the downtime for upgrading. In 2006, GE Oil & Gas engineers launched the Power Crystal™ development program to enhance the output power or extend the maintenance interval of the MS5002C and D heavy duty gas turbines. This effort resulted in an upgrade kit potentially to be installed during a standard major inspection, which include a single crystal material 1st stage high pressure turbine blade and additional improvements, such as new coatings for combustor hardware and improved cooling of the 1st stage high pressure turbine nozzle and 1st stage high pressure turbine wheel. The upgrade kit was validated through an extensive test campaign, which included test-rig component tests in advance of the First Engine to Test (FETT). All critical-to-quality parameters of the gas turbine were investigated, such as turbine gas path component temperatures and stresses, performance and operability. This paper describes the background for the upgrade, discusses the new kit features, how the test program was built and conducted, and reports the experience accumulated on the gas turbine during the initial field operation.

scholarly journals A Comparison of Single-Entry and Multiple-Entry Casing Impingement Manifolds for Active Thermal Tip Clearance Control

2021 ◽  
Author(s):  
Priyanka Dhopade ◽  
Benjamin Kirollos ◽  
Peter Ireland ◽  
Leo Lewis
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Heat Transfer Coefficient ◽  
Control System ◽  
Tip Clearance ◽  
Feed System ◽  
High Pressure Turbine ◽  
Aero Engine ◽  
Single Entry ◽  
Clearance Control

In this paper we compare using computational fluid dynamics the aerothermal performance of two candidate casing manifolds for supplying an impingement-actuated active tip clearance control system for an aero-engine high-pressure turbine. The two geometries are (a) single-entry: an annular manifold fed at one circumferential location; (b) multiple-entry: a casing manifold split into four annular sectors, each sector supplied separately from an annular ring main. Both the single-entry and multiple-entry systems analysed in this paper are idealised version of active clearance control systems in current production engines. Aerothermal performance is quantitatively assessed on the basis of the heat transfer coefficient distribution, driving temperature difference for heat transfer between the jet and casing wall, and total pressure loss within the high-pressure turbine active clearance control system. We predict that the mean heat transfer coefficient (defined with respect to the inlet temperature and local wall temperature) of the single-entry active clearance control system is 77% greater than the multiple-entry system; primarily because the coolant in the multiple-entry case picks up approximately 40 K of temperature from the ring main walls, and secondarily because the average jet Reynolds number of impingement holes in the single entry system is 1.2 times greater than in the multiple entry system. The multiple-entry system exhibits many local hot and cold spots, depending on the position of the transfer boxes, while the single-entry case has a more predictable aerothermal field across the system. The multiple-entry feed system uses an average of 20% of the total available pressure drop, while the feed system for the single-entry geometry uses only 2% of the total available pressure drop. From the aerothermal results of this computational study, and in consideration of holistic aero-engine design factors, we conclude that a single-entry system is closer to an optimal solution than a multiple-entry system.

Heat Transfer Computations for High Pressure Turbines

2001 ◽  
Author(s):  
Graham C. Smith ◽  
Mary A. Hilditch ◽  
Nigel B. Wood
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Cooling System ◽  
Operating Temperature ◽  
Test Facility ◽  
Navier Stokes ◽  
Major Influence ◽  
High Pressure Turbine ◽  
Turbulent Transition ◽  
Very High

The life of a high pressure turbine blade is strongly dependent on the operating temperature of the blade material. The gas entering the turbine is at a very high temperature and the blades must be cooled. Accurate predictions of the heat transfer to an uncooled aerofoil are an important step in predicting the blade metal temperature and designing an efficient cooling system. 3D Navier-Stokes calculations of heat transfer are presented for the vanes of two modern high pressure, shroudless turbines. The results are compared with measurements taken in a short duration test facility at engine representative conditions. The experimental dataset includes repeat measurements made using different instrumentation. These data are shown to agree within the confidence limits of the experiment. In this experiment laminar-turbulent transition is known to be a major influence on the measured heat transfer levels. However, careful modelling of this parameter, through physical reasoning and published correlations, gives predictions in reasonable agreement with the measurements.

Heat Transfer and Aerodynamics of Over-Shroud Leakage Flows in a High-Pressure Turbine

2009 ◽  
Author(s):  
Knut Lehmann ◽  
Richard Thomas ◽  
Howard Hodson ◽  
Vassilis Stefanis
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Large Scale ◽  
Suction Side ◽  
Surface Flow ◽  
Tip Clearance ◽  
Flow Visualisation ◽  
Leakage Flow ◽  
High Pressure Turbine ◽  
High Heat Transfer

An experimental study has been conducted to investigate the distribution of the convective heat transfer on the shroud of a high pressure turbine blade in a large scale rotating rig. A continuous thin heater foil technique has been adapted and implemented on the turbine shroud. Thermochromic Liquid Crystals were employed for the surface temperature measurements to derive the experimental heat transfer data. The heat transfer is presented on the shroud top surfaces and the three fins. The experiments were conducted for a variety of Reynolds numbers and flow coefficients. The effects of different inter-shroud gap sizes and reduced fin tip clearance gaps were also investigated. Details of the shroud flow field were obtained using an advanced Ammonia-Diazo surface flow visualisation technique. CFD predictions are compared with the experimental data and used to aid interpretation. Contour maps of the Nusselt number reveal that regions of highest heat transfer are mostly confined to the suction side of the shroud. Peak values exceed the average by as much as 100 percent. It has been found that the interaction between leakage flow through the inter-shroud gaps and the fin tip leakage jets are responsible for this high heat transfer. The inter-shroud gap leakage flow causes a disruption of the boundary layer on the turbine shroud. Furthermore, the development of the large recirculating shroud cavity vortices is severely altered by this leakage flow.

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