{"id":17951,"date":"2018-06-03T08:01:58","date_gmt":"2018-06-03T08:01:58","guid":{"rendered":"http:\/\/sitepourvtc.com\/?page_id=17951"},"modified":"2022-11-19T16:25:32","modified_gmt":"2022-11-19T16:25:32","slug":"governing-of-steam-turbine-2","status":"publish","type":"page","link":"https:\/\/sitepourvtc.com\/nuclear-power-plant\/turbine-generator-power-conversion-system\/what-is-steam-turbine-description-and-characteristics\/governing-of-steam-turbine-2\/","title":{"rendered":"Governing of Steam Turbine"},"content":{"rendered":"<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\"><div   id="8n9s8rpp6h"    class=\"su-spacer\" style=\"height:10px\"><\/div>\n<div   id="8n9s8rpp6h"    class=\"su-quote su-quote-style-default\"><div   id="8n9s8rpp6h"    class=\"su-quote-inner su-u-clearfix su-u-trim\"> <strong>Governing of steam turbine<\/strong> is the procedure of controlling the flow rate of steam to a steam turbine so as to maintain the speed of the turbine fairly constant irrespective of load on the turbine. <\/div><\/div>\n<p>The typical main turbine in nuclear power plants, in which steam expands from pressures about 6 MPa to pressures about 0.008 MPa, operates at speeds about:<\/p>\n<ul>\n<li>3000 RPM for 50 Hz systems for 2-pole generator (or 1500RPM for 4-pole generator),<\/li>\n<li>1800 RPM for 60 Hz systems for 4-pole generator (or 3600 RPM for 2-pole generator).<\/li>\n<\/ul>\n<p>The variation in load (power output) during the operation of a steam turbine can significantly impact its performance and efficiency. Traditionally, nuclear power plants (NPPs) have been considered as <strong>baseload sources<\/strong> of electricity as they rely on technology with high fixed costs and low variable costs. \u00a0However, this simple state of affairs no longer applies in all countries. The share of nuclear power in the national electricity mix of some countries has become so large that the utilities have had to implement or improve the maneuverability capabilities of their power plants to adapt the electricity supply to daily, seasonal, or other variations in power demand. For example, this is the case in France, where NPPs generate more than 75% of electricity and some nuclear reactors operate in <strong>load-following mode<\/strong>.<\/p>\n<p>The primary objective in the steam turbine operation is to maintain a constant speed of rotation irrespective of the varying load. This can be achieved through governing of the steam turbine. The principal methods of governing which are used in steam turbines are:<\/p>\n<ol>\n<li>\n<figure id=\"attachment_17913\" aria-describedby=\"caption-attachment-17913\" style=\"width: 290px\" class=\"wp-caption alignright\"><a href=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Governing-of-Steam-Turbine.png\"><img loading=\"lazy\" class=\"size-medium wp-image-17913\" src=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Governing-of-Steam-Turbine-300x233.png\" alt=\"Nozzle Governing\" width=\"300\" height=\"233\" srcset=\"https:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Governing-of-Steam-Turbine-300x233.png 300w, https:\/\/sitepourvtc.com\/wp-content\/uploads\/2017\/05\/Governing-of-Steam-Turbine.png 615w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-17913\" class=\"wp-caption-text\">Nozzle Governing. Source: wikipedia.org License: CC BY-SA 3.0<\/figcaption><\/figure>\n<p><strong>Throttle governing<\/strong>. The main parts of a simple throttle governing system are the throttle-stop valves and especially control valves between steam generators and the main turbine. The primary aim of control valves is to reduce the steam flow rate. Incidental to reducing the mass rate of flow, the steam experiences an increasing pressure drop across the control valve, which is, in fact, an isenthalpic process. Although throttling is an isenthalpic process, the enthalpy drop available for work in the turbine is reduced because this causes an <strong>increase in the <a title=\"Vapor Quality \u2013 Dryness Fraction\" href=\"http:\/\/sitepourvtc.com\/nuclear-engineering\/materials-nuclear-engineering\/properties-steam-what-is-steam\/vapor-quality-dryness-fraction\/\">vapor quality <\/a><\/strong>of outlet steam.<\/p><\/li>\n<li><strong>Nozzle governing<\/strong>. In the nozzle control governing, the steam supply from the main valve is divided into two, three, or more lines. The flow rate of steam is regulated by the opening and shutting of sets of nozzles rather than regulating its pressure.<\/li>\n<li><strong>Bypass governing<\/strong>. This is generally used for the overload valve, which passes the steam directly into the latter stages of a steam turbine. During such operation, bypass valves are opened, and live steam is introduced into the later stages of the turbine. This generates more energy to satisfy the increased load.<\/li>\n<li><strong> Combination of 2 and 3<\/strong>.<\/li>\n<\/ol>\n<\/div><\/div><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, AND FLUID FLOW. DOE Fundamentals Handbook, Volume 1, 2, and 3. June 1992.<\/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":"","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\/17951"}],"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=17951"}],"version-history":[{"count":3,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages\/17951\/revisions"}],"predecessor-version":[{"id":35343,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages\/17951\/revisions\/35343"}],"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=17951"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}