{"id":17952,"date":"2018-06-03T08:16:54","date_gmt":"2018-06-03T08:16:54","guid":{"rendered":"http:\/\/sitepourvtc.com\/?page_id=17952"},"modified":"2022-11-19T17:01:18","modified_gmt":"2022-11-19T17:01:18","slug":"turbine-blades","status":"publish","type":"page","link":"https:\/\/sitepourvtc.com\/nuclear-power-plant\/turbine-generator-power-conversion-system\/what-is-steam-turbine-description-and-characteristics\/turbine-blades\/","title":{"rendered":"Turbine Blades"},"content":{"rendered":"<div   id="8n9s8rpp6h"    class=\"su-quote su-quote-style-default\"><div   id="8n9s8rpp6h"    class=\"su-quote-inner su-u-clearfix su-u-trim\"><b>Turbine blades<\/b> are the most important element of steam turbines. They are the principal elements that convert the pressure energy of working fluid into kinetic energy. Their dimensions and their shape determine the overall efficiency, reliability, and lifespan. Modern turbine blades often use <strong>nickel-based superalloys<\/strong>\u00a0that incorporate chromium, cobalt, and rhenium.<\/div><\/div>\n<p>The most important turbine elements are the <strong>turbine blades<\/strong>. They are the principal elements that convert the pressure energy of working fluid into kinetic energy. Turbine blades are of two basic types:<\/p>\n<ul>\n<li><strong>moving blades<\/strong><\/li>\n<li><strong>fixed blades<\/strong><\/li>\n<\/ul>\n<p><a href=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Steam-Turbine.png\"><img loading=\"lazy\" class=\"alignright size-medium wp-image-17900\" src=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Steam-Turbine-300x209.png\" alt=\"Steam Turbine\" width=\"300\" height=\"209\" srcset=\"https:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Steam-Turbine-300x209.png 300w, https:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Steam-Turbine.png 879w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a>In<strong> steam turbines<\/strong>, the steam expands through the fixed blade (nozzle), where the pressure potential energy is converted to kinetic energy. The high-velocity steam from fixed nozzles impacts the moving blades, then changes its direction and also expands (in the case of <strong>reaction type blades<\/strong>). The change in its direction and the steam acceleration (in the case of reaction type blades) applies a force. The resulting impulse drives the blades forward, causing the rotor to turn. Steam turbine types based on blade geometry and energy conversion process are:<\/p>\n<ul>\n<li><strong>impulse turbine<\/strong><\/li>\n<li><strong>reaction turbine<\/strong><\/li>\n<\/ul>\n<p>Modern steam turbines frequently employ both reaction and impulse in the same unit, varying the degree of reaction and impulse from the blade root to its periphery. The rotor blades are usually designed like an impulse blade at the rot and a reaction blade at the tip.<\/p>\n<p><a href=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Turbine-Blade-Impulse-and-Reaction.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-17883\" src=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Turbine-Blade-Impulse-and-Reaction.png\" alt=\"Turbine Blade - Impulse and Reaction\" width=\"446\" height=\"116\" srcset=\"https:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Turbine-Blade-Impulse-and-Reaction.png 446w, https:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Turbine-Blade-Impulse-and-Reaction-300x78.png 300w\" sizes=\"(max-width: 446px) 100vw, 446px\" \/><\/a><\/p>\n<p><a href=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/steam_turbine_blade_3.png\"><img loading=\"lazy\" class=\"alignright size-full wp-image-17892\" src=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/steam_turbine_blade_3.png\" alt=\"steam_turbine_blade_3\" width=\"330\" height=\"330\" srcset=\"https:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/steam_turbine_blade_3.png 330w, https:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/steam_turbine_blade_3-150x150.png 150w, https:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/steam_turbine_blade_3-300x300.png 300w, https:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/steam_turbine_blade_3-66x66.png 66w\" sizes=\"(max-width: 330px) 100vw, 330px\" \/><\/a>The efficiency and reliability of a turbine depend on the proper design of the blades. It is, therefore, necessary for all engineers involved in turbines engineering to have an overview of the importance and the basic design aspects of the steam turbine blades. <b>The engineering<\/b>\u00a0of turbine blades is a <strong>multi-disciplinary task<\/strong>. It involves <a title=\"Thermodynamics\" href=\"http:\/\/sitepourvtc.com\/nuclear-engineering\/thermodynamics\/\">thermodynamics<\/a>, aerodynamics, mechanical and <a title=\"Materials for Nuclear Engineering\" href=\"http:\/\/sitepourvtc.com\/nuclear-engineering\/materials-nuclear-engineering\/\">material engineering<\/a>.<\/p>\n<p><strong>For gas turbines<\/strong>, the turbine blades are often the limiting component. \u00a0The highest temperature in the cycle occurs at the end of the combustion process, and it is limited by the <strong>maximum temperature<\/strong> that the <strong>turbine blades<\/strong> can withstand. As usual, metallurgical considerations (about 1700 K) place upper limits on thermal efficiency. Therefore turbine blades often use exotic materials like <strong>superalloys<\/strong> and different cooling methods, such as internal air channels, boundary layer cooling, and thermal barrier coatings. The development of superalloys in the 1940s and new processing methods such as vacuum induction melting in the 1950s greatly increased the temperature capability of turbine blades. Modern turbine blades often use <strong>nickel-based superalloys<\/strong> that incorporate chromium, cobalt, and rhenium.<\/p>\n<p><strong>Steam turbine blades<\/strong> are not exposed to such high temperatures, but they must withstand an operation with <a title=\"Two-phase Fluid Flow\" href=\"http:\/\/sitepourvtc.com\/nuclear-engineering\/fluid-dynamics\/two-phase-fluid-flow\/\">two-phase fluid<\/a>. A high content of water droplets can cause rapid impingement and erosion of the blades, which occurs when condensed water is blasted onto the blades. For example, condensate drains are installed in the steam piping leading to the turbine to prevent this. Another challenge for engineers is the design of blades of the last stage of the LP turbine. These blades must be (due to high <a title=\"What is Specific Volume\" href=\"http:\/\/sitepourvtc.com\/nuclear-engineering\/thermodynamics\/thermodynamic-properties\/what-is-specific-volume\/\">specific volume<\/a> of steam) very long, which induces <strong>enormous centrifugal forces<\/strong> during operation. Therefore, turbine blades are subjected to stress from centrifugal force (turbine stages can rotate at tens of thousands of revolutions per minute (RPM), but usually at 1800 RPM) and fluid forces that can cause a fracture, yielding, or creep failures.<\/p>\n<p>See also: <a href=\"http:\/\/sitepourvtc.com\/nuclear-power-plant\/reactor-and-power-plant-materials\/materials-for-steam-turbines\/\">Materials for Steam Turbines<\/a><\/p>\n<div   id="8n9s8rpp6h"    class=\"collapsible-container\">\n<h2>Turbine Blades &#8211; Root, Profile, Shroud<\/h2>\n<p>Turbine blades are usually divided into three parts:<\/p>\n<ul>\n<li><strong>Root.<\/strong> The root is a constructional feature of turbine blades, which fixes the blade into the turbine rotor.<\/li>\n<li><strong>Profile. <\/strong>The profile converts the kinetic energy of steam into the mechanical energy of the blade.<\/li>\n<li><strong>Shroud. <\/strong>\u00a0The shroud reduces the blade&#8217;s vibration, which can be induced by the flowing of high pressure steam through the blades.<\/li>\n<\/ul>\n<h2>Types of Steam Turbines<\/h2>\n<p><strong><span style=\"font-weight: 400;\"><strong><a href=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Steam-Turbine-types.png\"><img loading=\"lazy\" class=\"alignright size-medium wp-image-17901\" src=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Steam-Turbine-types-300x194.png\" alt=\"Steam Turbine - types\" width=\"300\" height=\"194\" srcset=\"https:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Steam-Turbine-types-300x194.png 300w, https:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Steam-Turbine-types.png 614w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a><\/strong><\/span><\/strong><\/p>\n<p><strong><span style=\"font-weight: 400;\"><strong>Steam turbines<\/strong> may be classified into different categories depending on their construction, working pressures, size, and other parameters. But there are two basic types of steam turbines: <\/span><\/strong><\/p>\n<ul>\n<li><strong>impulse turbines<\/strong><\/li>\n<li><strong><span style=\"font-weight: 400;\"><strong>reaction turbines<\/strong>.<\/span><\/strong><\/li>\n<\/ul>\n<p><strong><span style=\"font-weight: 400;\">The main distinction is how the steam is expanded as it passes through the turbine.<\/span><\/strong><\/p>\n<p><strong>Impulse Turbine and Reaction Turbine<\/strong><\/p>\n<p>Steam turbine types based on blade geometry and energy conversion process are impulse turbine and reaction turbine.<\/p>\n<p><a href=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Steam-Turbine-Types-of-Turbine.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-17891\" src=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Steam-Turbine-Types-of-Turbine.png\" alt=\"Steam Turbine - Types of Turbine\" width=\"909\" height=\"281\" srcset=\"https:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Steam-Turbine-Types-of-Turbine.png 909w, https:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Steam-Turbine-Types-of-Turbine-300x93.png 300w\" sizes=\"(max-width: 909px) 100vw, 909px\" \/><\/a><\/p>\n<\/div>\n<div   id="8n9s8rpp6h"    class=\"su-divider su-divider-style-dotted\" style=\"margin:20px 0;border-width:2px;border-color:#999999\"><\/div>\n<div   id="8n9s8rpp6h"     class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights \"><div   id="8n9s8rpp6h"     class=\"inside-grid-column\">\u00a0 <div   id="8n9s8rpp6h"    class=\"su-accordion su-u-trim\"><div   id="8n9s8rpp6h"    class=\"su-spoiler su-spoiler-style-default su-spoiler-icon-plus su-spoiler-closed\" data-scroll-offset=\"0\"><div   id="8n9s8rpp6h"    class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\"><span class=\"su-spoiler-icon\"><\/span>References:<\/div><div   id="8n9s8rpp6h"    class=\"su-spoiler-content su-u-clearfix su-u-trim\"><strong>Reactor Physics and Thermal Hydraulics:<\/strong>\n<ol>\n<li>J. R. Lamarsh, Introduction to Nuclear Reactor Theory, 2nd ed., Addison-Wesley, Reading,\u00a0MA (1983).<\/li>\n<li>J. R. Lamarsh, A. J. Baratta, Introduction to Nuclear Engineering, 3d ed., Prentice-Hall, 2001, ISBN: 0-201-82498-1.<\/li>\n<li>W. M. Stacey, Nuclear Reactor Physics, John Wiley &amp; Sons, 2001, ISBN: 0- 471-39127-1.<\/li>\n<li>Glasstone, Sesonske. Nuclear Reactor Engineering: Reactor Systems Engineering,\u00a0Springer; 4th edition, 1994, ISBN:\u00a0978-0412985317<\/li>\n<li>Todreas Neil E., Kazimi Mujid S. Nuclear Systems Volume I: Thermal Hydraulic Fundamentals, Second Edition. CRC\u00a0Press; 2\u00a0edition, 2012, ISBN:\u00a0978-0415802871<\/li>\n<li>Zohuri B., McDaniel P. Thermodynamics in Nuclear Power Plant Systems. Springer; 2015, ISBN:\u00a0978-3-319-13419-2<\/li>\n<li>Moran Michal J., Shapiro Howard N. Fundamentals of Engineering Thermodynamics, Fifth Edition,\u00a0John Wiley &amp; Sons, 2006, ISBN:\u00a0978-0-470-03037-0<\/li>\n<li>Kleinstreuer C. Modern Fluid Dynamics. Springer, 2010,\u00a0ISBN 978-1-4020-8670-0.<\/li>\n<li>U.S. Department of Energy, THERMODYNAMICS, HEAT TRANSFER,\u00a0AND FLUID FLOW.\u00a0DOE Fundamentals Handbook,\u00a0Volume 1, 2 and 3. June\u00a01992.<\/li>\n<li>U.S. NRC. NUREG-0800,\u00a0Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR Edition<\/li>\n<\/ol>\n<\/div><\/div><\/div><div   id="8n9s8rpp6h"    class=\"su-divider su-divider-style-dotted\" style=\"margin:15px 0;border-width:2px;border-color:#999999\"><\/div><\/div><\/div><div   id="8n9s8rpp6h"    class=\"su-divider su-divider-style-default\" style=\"margin:15px 0;border-width:2px;border-color:#999999\"><\/div><div   id="8n9s8rpp6h"     class=\"lgc-column lgc-grid-parent lgc-grid-33 lgc-tablet-grid-33 lgc-mobile-grid-100 lgc-equal-heights \"><div   id="8n9s8rpp6h"     class=\"inside-grid-column\"><\/div><\/div><div   id="8n9s8rpp6h"     class=\"lgc-column lgc-grid-parent lgc-grid-33 lgc-tablet-grid-33 lgc-mobile-grid-100 lgc-equal-heights \"><div   id="8n9s8rpp6h"     class=\"inside-grid-column\">\n<h2>See above:<\/h2>\n<p>Steam Turbine<a href=\"http:\/\/sitepourvtc.com\/nuclear-power-plant\/turbine-generator-power-conversion-system\/what-is-steam-turbine-description-and-characteristics\/\" class=\"su-button su-button-style-flat\" style=\"color:#606060;background-color:#ffffff;border-color:#cccccc;border-radius:10px;-moz-border-radius:10px;-webkit-border-radius:10px\" target=\"_self\"><span style=\"color:#606060;padding:7px 20px;font-size:16px;line-height:24px;border-color:#ffffff;border-radius:10px;-moz-border-radius:10px;-webkit-border-radius:10px;text-shadow:0px 0px 0px #000000;-moz-text-shadow:0px 0px 0px #000000;-webkit-text-shadow:0px 0px 0px #000000\"><i class=\"sui sui-link\" style=\"font-size:16px;color:#5d5d5d\"><\/i> <\/span><\/a><\/p><\/div><\/div><div   id="8n9s8rpp6h"     class=\"lgc-column lgc-grid-parent lgc-grid-33 lgc-tablet-grid-33 lgc-mobile-grid-100 lgc-equal-heights \"><div   id="8n9s8rpp6h"     class=\"inside-grid-column\"><\/div><\/div>\n","protected":false},"excerpt":{"rendered":"<p>The most important turbine elements are the turbine blades. They are the principal elements that convert the pressure energy of working fluid into kinetic energy. Turbine blades are of two basic types: moving blades fixed blades In steam turbines, the steam expands through the fixed blade (nozzle), where the pressure potential energy is converted to &#8230; <a title=\"Turbine Blades\" class=\"read-more\" href=\"https:\/\/sitepourvtc.com\/nuclear-power-plant\/turbine-generator-power-conversion-system\/what-is-steam-turbine-description-and-characteristics\/turbine-blades\/\" aria-label=\"More on Turbine Blades\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":17859,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"generate_page_header":""},"_links":{"self":[{"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages\/17952"}],"collection":[{"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/comments?post=17952"}],"version-history":[{"count":4,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages\/17952\/revisions"}],"predecessor-version":[{"id":35348,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages\/17952\/revisions\/35348"}],"up":[{"embeddable":true,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages\/17859"}],"wp:attachment":[{"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/media?parent=17952"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}