{"id":569,"date":"2019-01-13T13:10:13","date_gmt":"2019-01-13T13:10:13","guid":{"rendered":"http:\/\/johnbrear-plantintegrity.com\/?page_id=569"},"modified":"2019-01-14T09:53:35","modified_gmt":"2019-01-14T09:53:35","slug":"temperature-imbalance-in-a-superheater-header","status":"publish","type":"page","link":"https:\/\/johnbrear-plantintegrity.com\/?page_id=569","title":{"rendered":"Temperature imbalance in a superheater header"},"content":{"rendered":"<p><strong><figure id=\"attachment_570\" aria-describedby=\"caption-attachment-570\" style=\"width: 340px\" class=\"wp-caption alignright\"><img fetchpriority=\"high\" decoding=\"async\" src=\"http:\/\/johnbrear-plantintegrity.com\/wp-content\/uploads\/2019\/01\/Imbheader.jpg\" alt=\"\" width=\"340\" height=\"230\" class=\"size-full wp-image-570\" srcset=\"https:\/\/johnbrear-plantintegrity.com\/wp-content\/uploads\/2019\/01\/Imbheader.jpg 508w, https:\/\/johnbrear-plantintegrity.com\/wp-content\/uploads\/2019\/01\/Imbheader-300x204.jpg 300w\" sizes=\"(max-width: 340px) 100vw, 340px\" \/><figcaption id=\"caption-attachment-570\" class=\"wp-caption-text\">Superheater outlet header<\/figcaption><\/figure>Component<\/strong>:<\/p>\r\n<p>Final superheater outlet header in a European coal-fired unit, fabricated from P22 and operating at 540\u00b0C, 15MPa<br \/>\r\n<br \/>\r\n<strong>Objectives:<\/strong><\/p>\r\n<ul>\r\n    <li>To determine the remaining life of this component<\/li>\r\n    <li>To demonstrate a consistent life assessment route, that might be applied company-wide to plant built to different design codes<\/li>\r\n    <li>To compare various temperature measurement and estimation methods<\/li>\r\n<\/ul>\r\n<p><strong>Approach:<\/strong><\/p>\r\n<p>Following the <a href=\"http:\/\/johnbrear-plantintegrity.com\/?page_id=432\">phased-approach<\/a>:<\/p>\r\n<ul>\r\n    <li>Phase 1: - Initial code-based calculations<\/li>\r\n    <li>Phase 2: - Visual inspection, conventional NDE and metallographic examination<\/li>\r\n    <li>Phase 3: - Installation of conventional thermocouples and off-line diffusion-couple sensors, application of hardness and oxide-thickness based temperature estimation method.&#160; Recalculation of header life using quantitative inspection results<\/li>\r\n<\/ul>\r\n<figure id=\"attachment_572\" aria-describedby=\"caption-attachment-572\" style=\"width: 373px\" class=\"wp-caption alignright\"><img decoding=\"async\" src=\"http:\/\/johnbrear-plantintegrity.com\/wp-content\/uploads\/2019\/01\/Imbalance.jpg\" alt=\"\" width=\"373\" height=\"211\" class=\"size-full wp-image-572\" srcset=\"https:\/\/johnbrear-plantintegrity.com\/wp-content\/uploads\/2019\/01\/Imbalance.jpg 373w, https:\/\/johnbrear-plantintegrity.com\/wp-content\/uploads\/2019\/01\/Imbalance-300x170.jpg 300w\" sizes=\"(max-width: 373px) 100vw, 373px\" \/><figcaption id=\"caption-attachment-572\" class=\"wp-caption-text\">Schematic cross-section of header showing measured \/ estimated metal temperatures and inferred steam temperature distribution.<\/figcaption><\/figure>\r\n<p><strong>Results:<\/strong><\/p>\r\n<ul>\r\n    <li>Header shown to be life-expired according to inverse-design calculations<\/li>\r\n    <li>Comparison of various code formulae and materials standards showed no significant variation in calculated stresses and lives<\/li>\r\n    <li>Adequate life demonstrated on the basis of initial inspection results<\/li>\r\n    <li>Apparent differences between temperature measurements reconciled through realisation that a temperature imbalance existed between the tube rows<\/li>\r\n<\/ul>\r\n<p><strong>Benefits:<\/strong><\/p>\r\n<ul>\r\n    <li>Consistent life assessment route established<\/li>\r\n    <li>Adequate header life demonstrated for continued operation<\/li>\r\n    <li>Thermal imbalance identified, leading to loss of unit efficiency and increased stresses in the header<\/li>\r\n    <li>Potential design modifications proposed to reduce this problem<\/li>\r\n    <li>Refined FE-based life assessment proposed to address effect of the additional thermal stresses<\/li>\r\n<\/ul>\r\n<p><strong>Published:<\/strong><\/p>\r\n<p>Jarvis, P., Jones, G.T., Batista, A. and Araujo, C.L.de, <br \/>\r\n\"Life assessment using codes and standard material properties in SP249 Carregado case study\"<br \/>\r\nSPRINT\/KBS Dissemination Workshops of MPA Seminar, Stuttgart, Germany, 6-7th October 1994<\/p>","protected":false},"excerpt":{"rendered":"<p>Component: Final superheater outlet header in a European coal-fired unit, fabricated from P22 and operating at 540\u00b0C, 15MPa Objectives: To determine the remaining life of this component To demonstrate a consistent life assessment route, that might be applied company-wide to plant built to different design codes To compare various temperature measurement and estimation methods Approach: &hellip; <a href=\"https:\/\/johnbrear-plantintegrity.com\/?page_id=569\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">Temperature imbalance in a superheater header<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":114,"menu_order":3,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-569","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/johnbrear-plantintegrity.com\/index.php?rest_route=\/wp\/v2\/pages\/569","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/johnbrear-plantintegrity.com\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/johnbrear-plantintegrity.com\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/johnbrear-plantintegrity.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/johnbrear-plantintegrity.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=569"}],"version-history":[{"count":6,"href":"https:\/\/johnbrear-plantintegrity.com\/index.php?rest_route=\/wp\/v2\/pages\/569\/revisions"}],"predecessor-version":[{"id":612,"href":"https:\/\/johnbrear-plantintegrity.com\/index.php?rest_route=\/wp\/v2\/pages\/569\/revisions\/612"}],"up":[{"embeddable":true,"href":"https:\/\/johnbrear-plantintegrity.com\/index.php?rest_route=\/wp\/v2\/pages\/114"}],"wp:attachment":[{"href":"https:\/\/johnbrear-plantintegrity.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=569"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}