International Journal of Research and Innovation (IJRI)
International Journal of Research and Innovation (IJRI) 1401-1402
DESIGN AND ANALYSIS OF MULTI- STAGE STEAM TURBINE BLADE AND SHAFT ASSEMBLY
K.Khishor Kumar 1, D.Gopichand2, 1 Research Scholar, Department Of Mechanical Engineering, Mother Theresa Institute of Technology(mist) Khammam,India 2 Assistant professor , Department Of Mechanical Engineering, Mother Theresa Institute of Technology(mist) Khammam,India
Abstract A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. A system of angled and shaped blades arranged on a rotor through which steam is passed to generate rotational energy. The blades are designed in such a way as to produce maximum rotational energy by directing the flow of the steam along its surface. The blades are made at specific angles in order to incorporate the net flow of steam over it in its favor. The blades may be of stationary or fixed and rotary or moving or types, and Shaft designed to work in extreme conditions, hear it has to bear the temperature which is coming from the steam and loads(weight and centrifugal force) of the blades assembly and other assembly parts. The aim of the project is to reduce maintenance, product cost and improving quality / life. Initially literature survey will be done to understand rectification methodology and approach. 3D models of blades set’s shaft will be prepared according to C.M.M data. Assembly of shaft and blades will be prepared and exported into IGES (inertial graphical exchanging specifications) format to conduct further work in ANSYS. Structural analysis will be carried out on assembly to evaluate structural characteristics. Model analysis will be carried out on same to find natural frequency’s (for comparison with other results) Thermal analysis will be carried out on to find thermal characteristic. Various materials and ceramic coating will be implemented on ANSYS for evaluation. Comparison tables will be prepared according to the obtained results from Ansys; Conclusion will be made according to the above. Key words: Multi Stage, Ceramic Coating’s, Thermal *Corresponding Author: K.Khishor Kumar, Research Scholar, Department Of Mechanical Engineering, Mother Theresa Institute of Technology(mist) Khammam,India Published: Sep 22, 2014 Review Type: peer reviewed Volume: I, Issue : III
Citation: K.Khishor Kumar, Research Scholar (2014)
DESIGN AND ANALYSIS OF MULTI- STAGE STEAM TURBINE BLADE AND SHAFT ASSEMBLY Problem Description
Steam turbines are generally used for power generation by using thermal energy (steam pressure) to produce rotary motion which in turn converted to electric power. In this process a set of turbine blades and shaft are used to convert steam pressure in to mechanical energy. Generally in turbine the blades and shafts are subjected to high amount of pressurized steam with
high temperature. This causes thermal and static stresses which leads to effect daily maintenance and replacement of blades rapidly. The rapid replacement of blades causes less power generation and expensive. Solution Methodology As per the directions and requirements of R&D department, analysis has to be done on entire assembly of shaft and group of blades with variant materials to suggest the best material and coatings which can withstand the thermal and static loads. Regular material EN24 stainless steel material and new materials such as zinc aluminum alloy (zamak) and cast iron C70 along with partially stabilized zirconium coating for surface protection for the materials are used. Static, modal and thermal analysis is to be done on above three materials to analyze the structural, vibrational and thermal characteristics.
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International Journal of Research and Innovation (IJRI)
Steam Turbine Introduction A turbine is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. A turbine is a turbomachine with at least one moving part called a rotor assembly, which is a shaft or drum with blades attached. Moving fluid acts on the blades so that they move and impart rotational energy to the rotor. Early turbine examples are windmills and waterwheels. The word "turbine" was coined in 1822 by the French mining engineer Claude Burdin from the Latin turbo.Gas, steam, and water turbines usually have a casing around the blades that contains and controls the working fluid. Credit for invention of the steam turbine is given both to the British engineer Sir Charles Parsons (1854–1931), for invention of the reaction turbine and to Swedish engineer Gustaf de Laval (1845–1913), for invention of the impulse turbine. Modern steam turbines frequently employ both reaction and impulse in the same unit, typically varying the degree of reaction and impulse from the blade root to its periphery.
Steam turbine showing blade and shaft assembly
Experimental Procedure Generation of Pressure Distribution Data on the Blade Surface: Last stage blade of steam turbine, which is being analyzed, for stress and vibration is a highly twisted blade due to the variation if the blade speeds across the height of the blade. The deflection in the blade passage also reduces from hub to tip to vary the loading on each section. Thus the pressure distribution on the suction & pressure surface of the blade changes considerably from hub to tip to match the loading at that suction .It is known fact that the area of pressure distribution curve representing the blade loading. Hence it has been decided to generate the pressure distribution at all the ‘17’ blade sections. The following procedure is allows to get the blade surface pressure distribution with the help of Blade Gen&Blade Gen plus package. From the blade coordinate input data file for suction/pressure surface x, y, z, coordinate of surface was generated as a loop with the following notations. X-along the height of the blade. Y- Meridional direction. Z-along blade to blade 2. Profile curve is generated with above coordinates of all sections placed one below the other is sequence from section (1) to section (5 along the height of the blade. The coordinates between two section separated by ‘#’. 3. Hub & Shroud boundary is generated at the appropriate heights with –Y negative Meridional axis corresponded from LE (Leading edge). And positive distance from Meridional distance from TE (Tailing Edge). 4. Hub. Curve file is generated as follows X, Y, Z 283.450000 0.000000000 -100.000000 283.450000 0.000000000 0.000000000 283.450000 0.000000000 100.000000 In between the values Comma is compulsory. (X, Y, Z)
working of impulse and reaction turbine
A profile contains total 60 points for all ‘5’ sections. 38
International Journal of Research and Innovation (IJRI)
5. Profile. Curve file is generated as follows X, Y, Z # 283.45,-5.74,-22.92 283.45,-5.23,-23.25 283.45,-4.46,-23.36 283.45,-3.43,-23.22 283.45,-2.15,-22.82 283.45,-0.66,-22.12 283.45, 1.03,-21.11 283.45, 2.85,-19.72 283.45, 4.74,-17.91 283.45, 6.61,-15.62 283.45, 8.32,-12.78 283.45, 9.66,-9.39 283.45, 10.4,-5.53 283.45, 10.35,-1.43 #442.65, 15.21,-15.51 442.65, 15.64,-15.21 442.65, 15.81,-14.69 442.65, 15.74,-13.95 442.65, 15.44,-12.99 442.65, 14.91,-11.83 442.65, 14.19,-10.49 442.65, 13.26,-8.99 442.65, 12.14,-7.36 442.65, 10.79,-5.66 442.65, 9.23,-3.95
The above image shows blades pattern model
The above image shows final shaft
Introduction To Cad Computer-aided design (CAD), also known as computer-aided design and drafting (CADD), is the use of computer technology for the process of design and design-documentation. Computer Aided Drafting describes the process of drafting with a computer. CADD software, or environments, provide the user with input-tools for the purpose of streamlining design processes; drafting, documentation, and manufacturing processes. CADD output is often in the form of electronic files for print or machining operations. The development of CADD-based software is in direct correlation with the processes it seeks to economize; industry-based software (construction, manufacturing, etc.) typically uses vector-based (linear) environments whereas graphic-based software utilizes raster-based (pixelated) environments. Modeling of Turbine Blade and Shaft
The above image shows blade profile
The above image shows assembly of blades and shaft pressure Specified Initial Steam Pressure (s)
36
ata
Permissible deviation without Limitation (1)
39
ata
Permissible deviation (2)
39
ata
Permissible deviation Instantaneously For A Total Duration Of 12 Hours Per Annam(2)
46.8
ata
Specified initial Steam Temperature (%)
360
˚C
Permissible Deviation without Limitation (1)
380
˚C
Permissible Deviation for Longer Periods (2)
388
˚C
Permissible Deviation for 400 hours per annum (2)
394
˚C
Permissible Deviation for 80 hours per annum (2)
408
˚C
Maximum Output
3769
KW
Design Rating (Economical Rating)
3426
KW
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International Journal of Research and Innovation (IJRI)
The above image shows meshed model Results :
Von Misses Stress The thermal readings are taken from the thermal images taken for the turbine Introduction to Fea Finite Element Analysis (FEA) was first developed in 1943 by R. Courant, who utilized the Ritz method of numerical analysis and minimization of variational calculus to obtain approximate solutions to vibration systems. Shortly thereafter, a paper published in 1956 by M. J. Turner, R. W. Clough, H. C. Martin, and L. J. Topp established a broader definition of numerical analysis. The paper centered on the "stiffness and deflection of complex structures". Displacement
Structural Analysis Steam Turbine
The above image shows imported Model from creo2.0 (Pro/Engineer)
Frequency Analysis on Steam Turbine
Displacement
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International Journal of Research and Innovation (IJRI)
Thermal Analysis on Steam Turbine
Nodal temperature
Conclusion
Thermal gradient
•A PT2001 turbo dine steam turbine is optimized for to reduce maintenance. Initially static and thermal conditions are evaluated using Infra-red thermometer and digital vibrometer. Those readings are taken for simulation inputs from ATICS •A FEA model is developed according to given drawing. •Static analysis is carried out on FE model using AISI steel (present material), cast-iron C70 with zirconia coating and zinc aluminum alloy (Zamak) with zirconia coating.
Thermal flux
Result Tables And Graphs s.no
Material
Stress
Strain
Displacement
1
Castiron C70with coating
308.6
0.0023
0.2036
2
AISI 4130 Steel
301.4
0.00078
0.765
3
Zamak
192.9
0.0012
0.123
•Modal analysis is carried out to determine the vibrations due to geometry and property of material. •Thermal analysis is carried out to determine the thermal behavior like thermal gradient and heat flux. •Partially stabilized zirconium is mainly used as a surface coating to prevent the thermal effect on surface and also it reduces the corrosive effect. •As per the analytical results ZAMAK material along with partially stabilized zirconia coating will improve reliability of turbine shaft and blades due to less stress, negligible displacement and strain values, also ZAMAK is having good level of thermal gradient(heat transfer rate) and sufficient heat flux rate which in turn improves the power generation rate by reducing the maintenance. 41
International Journal of Research and Innovation (IJRI)
References
Author
1) SPEED CONTROLLER DESIGN FOR STEAM TURBINE [1], Rekha Rajan, Muhammed Salih. P, N. Anilkumar, PG Students [I&C], Dept. of EEE, MES College of Engineering, Kuttippuram, Kerala, India 2) 3D Finite Element Structural Analysis of Attachments of Steam Turbine Last Stage Blades[2], Alexey I. Borovkov Alexander V. Gaev Computational Mechanics Laboratory, St.Petersburg State Polytechnic University, Russia 3) Design of a Constant Stress Steam Turbine Rotor Blade[3], Asst. Prof. Dr. Arkan Kh. Husain AlTai, Mechanical Engineering Department, University of Technology, Baghdad, Iraq 4) Simulation Modeling Practice and Theory[4], Ali Chaibakhsh, Ali Ghaffari * Department of Mechanical Engineering, K.N. Toosi University of Technology 5) Development of New High Efficiency Steam Turbine[5], EIICHIRO WATANABE, YOSHINORI TANAKA 6)Theoretical and Numerical Analysis of the Mechanical Erosion in Steam Turbine Blades[6], Fernando Rueda Martínez, Miguel Toledo Velázquez, Juan Abugaber Francis,
K.Khishor Kumar, Research Scholar, Department Of Mechanical Engineering, Mother Theresa Institute of Technology(mist) Khammam,India
D.Gopichand, Assistant professor, Department Of Mechanical Engineering , Mother Theresa Institute Of Technology(Mist) Khammam,India
7)DESIGN OPTIMIZATION AND STATIC & THERMAL ANALYSIS OF GAS TURBINE BLADE[7], Ganta Nagaraju , Venkata Ramesh Mamilla, M.V.Mallikarjun 8)ANALYSIS OF LIQUID DROPLET EROSIONFOR STEAM TURBINE BLADES OF COMPOSITE MATERIAL[8], Sandeep Soni
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