Clearance and Seals Design for New Heat™ Steam Turbine

2006 ◽  
Author(s):  
Bernard A. Couture ◽  
Leslie B. Keeling ◽  
Mark W. Kowalczyk
Keyword(s):  
Steam Turbine ◽  
High Speed ◽  
High Efficiency ◽  
Labyrinth Seal ◽  
Mechanical Analysis ◽  
Advanced Technology ◽  
Speed Test ◽  
Steady State Operation ◽  
Thermal Mechanical Analysis ◽  
Abradable Coatings

The HEAT™ (High Efficiency Advanced Technology) steam turbine utilizes high reaction technology [1], which is significantly influenced by the effectiveness of sealing between the stages. The thermal-mechanical analysis based clearance design and the combination of labyrinth sealing with abradable coatings offer an effective solution to minimize bucket and nozzle tip leakage through transient and steady state operation of the turbine. The aim of this paper is to describe the clearance design process and the development of abradable-labyrinth seal configurations. The paper describes extensive testing and detailed analysis conducted to evaluate seal properties and behaviors. Properties investigated included corrosion, erosion and in particular, rub characteristics. Rub behavior is investigated in a high temperature, high speed test apparatus designed to simulate clearance changes during transient periods of start-up, shutdown and hot re-start which often result in interference between the sealing components. This paper will discuss the method to predict differential rotor to stator movements and the resulting abradable incursion during the various operating transients. The seal tooth to coating contact is then simulated with component testing for multiple incursion modes (i.e. radial, axial and a combination of the two) and rates. The discussion will also include the application of the clearance design and sealing technology to a reaction type steam turbine.

Modern Reaction HP/IP Turbine Technology Advances and Experiences

2005 ◽  
Author(s):  
Paul Hurd ◽  
Frank Truckenmueller ◽  
Norbert Thamm ◽  
Helmut Pollak ◽  
Matthias Neef ◽  
...  
Keyword(s):  
Steam Turbine ◽  
High Efficiency ◽  
Combined Cycle ◽  
Advanced Technology ◽  
Advanced Materials ◽  
Operational Experience ◽  
Steam Turbines ◽  
Opposed Flow ◽  
Coal Market

Modern steam turbines of the author’s company are based on advanced technology such as high efficiency seals, 3D blading, single inner cylinders, and advanced materials. These technologies result in a compact opposed-flow HP/IP combined cylinder design with high long-term efficiency, reliability, and availability. This paper will illustrate the features, benefits, and operational experience of large steam turbines with advanced technologies using an opposed-flow HP/IP cylinder. The paper will also address the relative performance of this type of steam turbine against its predecessors. Specific examples will be examined: 350 MW fossil units in the Asian market, a typical 250 MW combined cycle steam turbine in the American market, a 700 MW three-cylinder class design for conventional steam plants developed for the global coal market, and a 600 MW steam turbine upgrade.

scholarly journals Controlled-Endwall-Flow Blading for Multistage Axial Compressor Rotor

1997 ◽  
Author(s):  
M. Inoue ◽  
M. Kuroumaru ◽  
M. Furukawa ◽  
Y. Kinoue ◽  
T. Tanino ◽  
...  
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
Axial Compressor ◽  
Internal Flow ◽  
Leading Edge ◽  
Rotor Blades ◽  
Advanced Technology ◽  
Low Flow ◽  
Surge Margin ◽  
Highly Loaded

This research aims to develop an advanced technology of highly loaded axial compressor stages with high efficiency and sufficient surge margin. To improve endwall boundary layer flows which lead to energy loss and instability at an operation of low flow rate, the Controlled-Endwall-Flow (CEF) rotor blades were designed and tested in the low speed rotating cascade facility of Kyushu University. The CEF rotor blades have three distinctive features: the leading-edge sweep near hub and casing wall, the leading-edge bend near the casing, and the same exit metal angle of blade evaluated by a conventional design method. Mechanical strength of the blade was verified by a numerical simulation at a high speed condition. The baseline rotor blades were designed under the same design condition and tested to compare with the CEF rotor. The results showed that the maximum stage efficiency of the CEF rotor was higher by 0.7 percent and the increase in surge margin was more than 20 percent in comparison with the baseline rotor. The results of both internal flow survey and 3D Navier-Stokes analysis showed that improvement of the overall stage performance resulted from activation of the endwall boundary layers, and suggested that further improvement might be expected by combination of end-bend stator blades and a highly loaded axial compressor stage could be developed by use of the CEF rotor.

scholarly journals Mechanical and Electromagnetic Analysis of High Speed Motor/Generator for Electric Turbo Compounding System

2018 ◽  
Vol 12 (1) ◽  
pp. 121-131
Author(s):  
Bongseok Choi ◽  
Donghoon Jung ◽  
Jaek wang Lee ◽  
Ju Lee
Keyword(s):  
Permanent Magnet ◽  
Safety Factor ◽  
High Speed ◽  
High Efficiency ◽  
Mechanical Analysis ◽  
Maximum Speed ◽  
Electromagnetic Analysis ◽  
Current Limit ◽  
Output Characteristics ◽  
Volume Current

Background: Recently, environment friendly technologies are being introduced as global warming is rapidly progressing. One of the effective way to reduce the problem, Electric Turbo Compounding System has been researched globally. With this system, about 30% exhaust gas can be recycled as a power source. Therefore, this system is effective for engine systems with purposes such as downsizing and increasing efficiency of the system. Objective & Method: Surface mounted Permanent Magnet Motor is applied to this system due to its high efficiency, power density, small size, and low weight. However, during high speed operation, a retaining sleeve is essential in rotor such as Inconel 718 to satisfy a mechanical safety factor of the rotor. In this paper, through basic theory, the sleeve thickness is predicted according to the permanent magnet dimension and minimum sleeve thickness is determined satisfying mechanical safety factor by mechanical analysis. Furthermore, by electromagnetic analysis output characteristics according to the permanent magnet dimension having same constraints such as volume, current density, current and flux distribution are compared. Result & Conclusion: Based on the results of the electromagnetic analysis and mechanical analysis, the appropriate ratio of electric and magnetic loading is determined with equivalent constraint condition. Consequently, only model 2 satisfies the requirement at rated and maximum speed within the current limit.

Field Validation Testing of New HEAT™ Steam Turbine

2006 ◽  
Author(s):  
Richard J. Miller ◽  
Reginald D. Conner
Keyword(s):  
Steam Turbine ◽  
High Efficiency ◽  
Pressure Ratio ◽  
Performance Testing ◽  
Transient Behavior ◽  
Aerodynamic Characteristics ◽  
Advanced Technology ◽  
Field Validation ◽  
Code Type ◽  
Validation Testing

The field validation and launch unit performance testing of a new high efficiency steam turbine design is described. The HEAT™ (High Efficiency Advanced Technology) steam turbine utilizes a new line of high efficiency steam path components developed by the author’s company [1], [2]. The extensive field test program, executed at the customer’s plant, included all major aspects of steam turbine operation and performance. Data was gathered continuously using multiple automated systems. Careful indexing of this data provided a multi-faceted view of operating phenomena during the test period. Overall machine performance was tested using ASME PTC 6.2 protocol. HP and IP individual section thermodynamic performance was quantified with a series of enthalpy drop tests. In addition, all leakage flows were measured to confirm end seal performance. HP section pressure ratio tests and internal leakage blowdown tests were done to determine the HP steam path aerodynamic characteristics. Various pressure measurements were used to quantify LP bucket aerodynamics and overall LP hood/diffuser performance. Validation testing of thermal-mechanical transient behavior of major components during all normal operating modes was achieved using lasers, thermocouples and strain gauges. In addition, thermal imaging was used to increase understanding of these transients. The validation instrumentation had an additional benefit to this customer, as it assisted the site team to successfully commission this A14 code type turbine, which achieved world-class efficiency.

Static and Dynamic Analysis of 48″ Steel Last Stage Blade for Steam Turbine

2009 ◽  
Author(s):  
Tomas Misek ◽  
Zdenek Kubin ◽  
Karel Duchek
Keyword(s):  
Steam Turbine ◽  
Centrifugal Force ◽  
High Speed ◽  
Structural Damping ◽  
Static And Dynamic Analysis ◽  
Speed Test ◽  
Rotational Vibration ◽  
Eigen Frequencies ◽  
Last Stage ◽  
Vibration Tests

The 3000 rpm 48 inch blade for steam turbine has been developed with the application of new design features. The last stage moving blade was designed with integral cover, mid-span tie-boss connection, and fir-tree dovetail. Blades are continuously coupled by the blade untwist due to the centrifugal force, so vibration control and increased structural damping are provided. The last stage airfoil was optimized from view of minimization of its centrifugal force which helped to reach higher safety factors. The blade was well tuned in order to have eigen-frequencies safely away from possible excitation. Because of connection members, the number of the resonant vibration modes can be reduced by virtue of the vibration characteristics of the circumferentially continuous blades. In order to develop the 3000 rpm 48 inch blade, the latest analysis methods were applied to predict dynamic behavior of the bladed structure. Coupled rotor-blade analysis was also aim of the attention. To validate calculated results the verification measurement such as rotational vibration tests was carried out in the high-speed test rig. The test rotor was fitted with the actual full scale 48″ blades. Relation of the friction damping of the bladed structure on amount of excitation level was also monitored and evaluated.

scholarly journals An investigation into the role of specimen geometry when undertaking tribological testing on seal fin components

2021 ◽  
pp. 095440622110250
Author(s):  
Boxiu Zhang ◽  
Matthew Marshall ◽  
Roger Lewis
Keyword(s):  
Wear Mechanism ◽  
High Speed ◽  
Heat Removal ◽  
Labyrinth Seal ◽  
Specimen Geometry ◽  
Speed Test ◽  
Sealing Performance ◽  
Post Test ◽  
Surface Examination

Labyrinth seal systems are used in aeroengines to seal the clearance, the understanding of the wear mechanism of labyrinth seal system is necessary to achieve better sealing performance. In this work a series of tests are conducted on a high-speed test rig capable of fin tip speeds of 100 m/s. With force and temperature measurements recorded in each case, the influence of specimen geometry is investigated. Surface examination and debris analysis is also performed using microscopy post-test. The wear mechanism was found to be influenced by fin geometry. A discrete fin was observed to trigger a more efficient material removal mechanism at both incursion conditions. Where the fin segment and ring-shaped fin leading to increased temperatures and material smearing. The heat dissipate role of fin was also observed during test where longer contact time of fin and abradable gives better heat removal performance.

Thermal-mechanical analysis on the mass loss of high-speed projectiles penetrating concrete targets

2017 ◽  
Vol 65 ◽  
pp. 159-177 ◽  
Author(s):  
Lei Guo ◽  
Yong He ◽  
Xianfeng Zhang ◽  
Yuan He ◽  
Jiajie Deng ◽  
...  
Keyword(s):  
Mass Loss ◽  
High Speed ◽  
Mechanical Analysis ◽  
Thermal Mechanical Analysis

Comparison of Blade Tip Timing With Strain Gauge Data for Evaluation of Dynamic Characterization of Last Stage Blade With Interlocked Shroud for Steam Turbine

2018 ◽  
Author(s):  
Jiamin Zhang ◽  
Peng Shan ◽  
Kai Cheng ◽  
Dechao Ye
Keyword(s):  
Steam Turbine ◽  
Strain Gauge ◽  
High Speed ◽  
Aircraft Engine ◽  
Dynamic Strain ◽  
Dynamic Characterization ◽  
Speed Test ◽  
Gauge Data ◽  
Last Stage

The tip-timing technology has been widely developed and has become an industry standard in aircraft engine and gas turbine over past decade. The main application of the tip-timing method is to verify safe operation of blades and monitor the health of blades. But tip-timing technology gets rarely used to the last stage blade of steam turbine. Particularly the blade is designed with an integral shroud, snubber and fir-tree root. The article mainly describes the process of identifying the dynamic characterization of last stage blade with an integral shroud and snubber by contactless measurements provided by tip-timing technology. Attention is focused on the comparison of tip-timing results with the results from strain gauge data. Firstly, the frequency response of the bladed blisk is calculated by using Computer-Aided-Engineering (CAE) technologies. Secondly, according to the results of finite element modal calculation, the location of strain gauge is confirmed. The dynamic strain of blade is measured by utilizing telemetry technology. Finally, according to the design features of integral shroud, the tip-timing probe locations must be accurately confirmed in order to acquire the valid data. All probes are positioned along the radial direction of blades. The rotating vibration test of the bladed blisk has been carried out in the high-speed test rig. In order to validate the tip-timing measurement, all the results from the tip-timing, especially the resonant frequencies and damping ratios, are compared with results from the strain gauges with which only a few blades were equipped.

Experimental Study on the Cavitation Characteristics of an Oil Jet Pump With Multiple Nozzles for the Lubrication System in a Steam Turbine

2014 ◽  
Vol 136 (12) ◽  
Author(s):  
Jun Zhang ◽  
Jing-ru Mao ◽  
Shun-sen Wang ◽  
Bin Wu ◽  
Hao Yuan ◽  
...  
Keyword(s):  
Steam Turbine ◽  
High Speed ◽  
High Efficiency ◽  
Pressure Ratio ◽  
Area Ratio ◽  
Quantitative Relation ◽  
Lubrication System ◽  
Jet Pump ◽  
Relative Safety ◽  
Oil Jet

Cavitation characteristics of oil jet pumps with multiple nozzles were studied using high frequency response pressure transducers with Mobile DTE Light Oil in experiment, which has an environment the same as that in the lubrication system of the steam turbine in a power plant. The influence of working oil pressure, pressure ratio, and area ratio on cavitation characteristics were studied with the area ratio ranging from 4 to 9, and the working oil pressure ranging from 1.8 to 2.8 MPa. Results show that the cavitation erosion on the throat surface is caused by the intense shear layer of high-speed jet in the throat, which leads to the collapse of vortex cavitation bubbles near the throat surface in an oil jet pump with multiple nozzles. What is more, the vortex cavitation is difficult to eradicate in an oil jet pump with multiple nozzles for the lubrication system of a steam turbine. However, there is a working point with low cavitation intensity, which is also the high efficiency point that ensures both relative safety and high efficiency. This study provides quantitative relation for the determination of working oil pressure, area ratio, and pressure ratio of an oil jet pump with multiple nozzles, which is significant for engineering.

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