{"id":235,"date":"2024-06-27T10:45:24","date_gmt":"2024-06-27T10:45:24","guid":{"rendered":"https:\/\/study.madeeasy.in\/?p=235"},"modified":"2025-07-16T14:42:12","modified_gmt":"2025-07-16T09:12:12","slug":"what-are-the-characteristics-of-a-fan-curve","status":"publish","type":"post","link":"https:\/\/www.madeeasy.in\/study\/me\/power-plant\/what-are-the-characteristics-of-a-fan-curve","title":{"rendered":"What are the characteristics of a Fan Curve?"},"content":{"rendered":"\r\n<p style=\"text-align: justify;\">Fan characteristics can be represented in form of fan curve(s). The fan curve is a performance curve for the particular fan under a specific set of conditions. The fan curve is a graphical representation of a number of inter- related parameters. Typically a curve will be developed for a given set of conditions usually including: fan volume, system static pressure, fan speed, and brake horsepower required to drive the fan under the stated conditions. Some fan curves will also include an efficiency curve so that a system designer will know where on that curve the fan will be operating under the chosen conditions (see Figure). In the many curves shown in the Figure, the curve static pressure (SP) vs. flow is especially important.<\/p>\r\n<p style=\"text-align: justify;\">The intersection of the system curve and the static pressure curve defines the operating point. When the system resistance changes, the operating point also changes. Once the operating point is fixed, the power required could be found by following a vertical line that passes through the operating point to an intersection with the power (BHP) curve. A horizontal line drawn through the intersection with the power curve will lead to the required power on the right vertical axis. In the depicted curves, the fan efficiency curve is also presented.<\/p>\r\n<p style=\"text-align: justify;\">The required fan work can be calculated by knowing the flow rate and fan total pressure and including the fan efficiency in it. Thus<\/p>\r\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-163 size-full\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/fan-characterstics-curve.jpg\" alt=\"Fan Characteristics\" width=\"672\" height=\"508\" \/> <img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-165 size-full\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/fan.jpg\" alt=\"Fan Characteristics\" width=\"656\" height=\"240\" \/><\/p>\r\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_79_1 ez-toc-wrap-left counter-hierarchy ez-toc-counter ez-toc-light-blue ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.madeeasy.in\/study\/me\/power-plant\/what-are-the-characteristics-of-a-fan-curve\/#Classification-of-Boilers\" >Classification of Boilers<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.madeeasy.in\/study\/me\/power-plant\/what-are-the-characteristics-of-a-fan-curve\/#Boiler-Mounting\" >Boiler Mounting<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.madeeasy.in\/study\/me\/power-plant\/what-are-the-characteristics-of-a-fan-curve\/#Boiler-Accessories\" >Boiler Accessories<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.madeeasy.in\/study\/me\/power-plant\/what-are-the-characteristics-of-a-fan-curve\/#Analysis-of-SteamRankine-Cycle-with-Superheating\" >Analysis of Steam\/Rankine Cycle with Superheating<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.madeeasy.in\/study\/me\/power-plant\/what-are-the-characteristics-of-a-fan-curve\/#Mean-Temperature-of-Heat-Addition\" >Mean Temperature of Heat Addition<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.madeeasy.in\/study\/me\/power-plant\/what-are-the-characteristics-of-a-fan-curve\/#Regenerative-Feed-Water-Heating\" >Regenerative Feed Water Heating<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.madeeasy.in\/study\/me\/power-plant\/what-are-the-characteristics-of-a-fan-curve\/#Stagnation-Properties\" >Stagnation Properties\u00a0<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.madeeasy.in\/study\/me\/power-plant\/what-are-the-characteristics-of-a-fan-curve\/#Pressure-compounding\" >Pressure compounding<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.madeeasy.in\/study\/me\/power-plant\/what-are-the-characteristics-of-a-fan-curve\/#Velocity-compounding-Nozzle\" >Velocity compounding Nozzle<\/a><\/li><\/ul><\/nav><\/div>\n<h4><span class=\"ez-toc-section\" id=\"Classification-of-Boilers\"><\/span>Classification of Boilers<span class=\"ez-toc-section-end\"><\/span><\/h4>\r\n<ul>\r\n<li><strong>Fire tube boiler<\/strong> : In the fire tube boilers; the hot <strong>gases are inside<\/strong> the tubes and water surrounds the Example <strong>Cochran, Lancashire, Locomotive<\/strong> etc.<\/li>\r\n<li><strong>Water tube boiler<\/strong>: In the water tube boilers, the <strong>water is inside<\/strong> the tubes and hot gas surrounds them. Example <strong>Babcock and Wilcox, Stirling, Yarrow boiler<\/strong> etc.<\/li>\r\n<li><strong>Externally fired boiler<\/strong>: In the externally fired boiler fire is outside the shell. Example Babcock and Wilcox boiler, Stirling boiler etc.<\/li>\r\n<li><strong>Internally fired boiler<\/strong>: In case of internally fired boilers, the furnace is located inside the boiler shell Example <strong>Cochran<\/strong>, Lancashire boiler etc.<\/li>\r\n<li><strong>Forced circulation boiler<\/strong>: In forced circulation, circulation of water is done by <strong>a pump<\/strong>. Example Velox, Lamont, Benson etc.<\/li>\r\n<li><strong>Natural circulation boiler<\/strong>: In natural circulation type of boiler water in boilers takes place due to natural convection currents. Example Lancashire, Babcock &amp; Wilcox etc.<\/li>\r\n<li><strong>Super critical boiler<\/strong>: The boiler which operating parameter is above critical point which is <em>p <\/em>= 221.2 bar and <em>T <\/em>= 373\u00b0C, is called super-critical boiler.<\/li>\r\n<\/ul>\r\n<h4><span class=\"ez-toc-section\" id=\"Boiler-Mounting\"><\/span>Boiler Mounting<span class=\"ez-toc-section-end\"><\/span><\/h4>\r\n<ul>\r\n<li>The item which is used for safety of boiler is called boiler mounting.<\/li>\r\n<li>The items such as stop valve, safety valves, fusible plug, blow off cock, pressure gauges, water level indicator.<\/li>\r\n<\/ul>\r\n<h4><span class=\"ez-toc-section\" id=\"Boiler-Accessories\"><\/span>Boiler Accessories<span class=\"ez-toc-section-end\"><\/span><\/h4>\r\n<ul>\r\n<li>The item which is used to increase the efficiency of boiler is called boiler accessories.<\/li>\r\n<li>The items such as superheaters, economizers, feed pumps etc. are termed as accessories, they form integral part of boiler.<\/li>\r\n<\/ul>\r\n<h4><span class=\"ez-toc-section\" id=\"Analysis-of-SteamRankine-Cycle-with-Superheating\"><\/span>Analysis of Steam\/Rankine Cycle with Superheating<span class=\"ez-toc-section-end\"><\/span><\/h4>\r\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-152 aligncenter\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/analysis-steam.jpg\" alt=\"Analysis of Steam\" width=\"459\" height=\"129\" \/><\/p>\r\n<table class=\"table table-striped table-bordered table-condensed\" style=\"margin: 0 auto; width: 99%;\">\r\n<tbody>\r\n<tr>\r\n<td width=\"90\">\r\n<p style=\"text-align: center;\">Process 4s-1 :<\/p>\r\n<\/td>\r\n<td style=\"text-align: center;\" width=\"340\">Reversible constant pressure heating of water (Q<sub>1<\/sub>) in boiler<\/td>\r\n<\/tr>\r\n<tr>\r\n<td width=\"90\">\r\n<p style=\"text-align: center;\">Process 1-2s :<\/p>\r\n<\/td>\r\n<td style=\"text-align: center;\" width=\"340\">Reversible adiabatic expansion of steam in turbine (W<sub>T<\/sub>)<\/td>\r\n<\/tr>\r\n<tr>\r\n<td width=\"90\">\r\n<p style=\"text-align: center;\">Process 2s-3 :<\/p>\r\n<\/td>\r\n<td width=\"340\">\r\n<p style=\"text-align: center;\">Reversible constant pressure heat rejection (Q<sub>2<\/sub>) in condenser<\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"text-align: center;\" width=\"90\">Process 3-4s :<\/td>\r\n<td width=\"340\">\r\n<p style=\"text-align: center;\">Reversible adiabatic input work (W<sub>P<\/sub>) in pump.<\/p>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<p>&nbsp;<\/p>\r\n<p>For 1 kg of fluid, the steady flow energy equation to each processes:<\/p>\r\n<p>&nbsp;<\/p>\r\n<table class=\"table table-striped table-bordered table-condensed\" style=\"margin: 0 auto; width: 99%;\">\r\n<tbody>\r\n<tr>\r\n<td width=\"53\">\r\n<p style=\"text-align: center;\"><strong>Process<\/strong><\/p>\r\n<\/td>\r\n<td style=\"text-align: center;\" width=\"73\"><strong>Component<\/strong><\/td>\r\n<td style=\"text-align: center;\" width=\"85\"><strong>Reduced SFEE<\/strong><\/td>\r\n<\/tr>\r\n<tr>\r\n<td width=\"53\">\r\n<p style=\"text-align: center;\">1 &#8211; 2s<\/p>\r\n<\/td>\r\n<td style=\"text-align: center;\" width=\"73\">Turbine<\/td>\r\n<td style=\"text-align: center;\" width=\"85\"><em>W<\/em><em><sub>T<\/sub> <\/em>= <em>h<\/em><sub>1<\/sub> \u2013 <em>h<\/em>2<sub>s<\/sub><\/td>\r\n<\/tr>\r\n<tr>\r\n<td width=\"53\">\r\n<p style=\"text-align: center;\">2s &#8211; 3<\/p>\r\n<\/td>\r\n<td style=\"text-align: center;\" width=\"73\">Condenser<\/td>\r\n<td width=\"85\">\r\n<p style=\"text-align: center;\"><em>Q<\/em><sub>2<\/sub> = <em>h<\/em><sub>2s<\/sub> \u2013 <em>h<\/em><sub>3<\/sub><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td width=\"53\">\r\n<p style=\"text-align: center;\">3 &#8211; 4s<\/p>\r\n<\/td>\r\n<td width=\"73\">\r\n<p style=\"text-align: center;\">Pump<\/p>\r\n<\/td>\r\n<td width=\"85\">\r\n<p style=\"text-align: center;\"><em>W<\/em><em><sub>P<\/sub> <\/em>= <em>h<\/em><sub>4s<\/sub> \u2013 <em>h<\/em><sub>3<\/sub><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"text-align: center;\" width=\"53\">4s &#8211; 1<\/td>\r\n<td style=\"text-align: center;\" width=\"73\">Boiler<\/td>\r\n<td width=\"85\">\r\n<p style=\"text-align: center;\"><em>Q<\/em><sub>1<\/sub> = <em>h<\/em><sub>1<\/sub> \u2013 <em>h<\/em><sub>4s<\/sub><\/p>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<p>&nbsp;<\/p>\r\n<ul>\r\n<li>Efficiency of Rankine cycle (Ideal)<\/li>\r\n<\/ul>\r\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-166 size-full\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/mean-temperature.jpg\" alt=\"Mean Temperature\" width=\"261\" height=\"45\" \/><\/p>\r\n<h4><span class=\"ez-toc-section\" id=\"Mean-Temperature-of-Heat-Addition\"><\/span>Mean Temperature of Heat Addition<span class=\"ez-toc-section-end\"><\/span><\/h4>\r\n<p>In the Rankine cycle, heat is added reversible at a constant pressure but at infinite temperatures. If <strong><em>T<\/em><em><sub>m<\/sub><\/em><\/strong> is the <strong>mean temperature of heat addition<\/strong> then <img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-157 aligncenter\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/heat-addition.jpg\" alt=\"Mean Temperature of Heat Addition\" width=\"694\" height=\"177\" \/><\/p>\r\n<h4><span class=\"ez-toc-section\" id=\"Regenerative-Feed-Water-Heating\"><\/span>Regenerative Feed Water Heating<span class=\"ez-toc-section-end\"><\/span><\/h4>\r\n<p>In practical regenerative cycle the feed water enters the boiler at high temperature as compared to the corresponding temperature in case of simple Rankine cycle and it is heated by steam extracted or bled from intermediate stages of the turbine. <br \/><br \/><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-158\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/regenerative-feed-water-heating.jpg\" alt=\"Regenerative Feed Water Heating\" width=\"361\" height=\"105\" \/> <br \/><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-159 aligncenter\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/regenerative-feed.jpg\" alt=\"Regenerative Feed Water Heating \" width=\"257\" height=\"169\" \/> \u00a0<\/p>\r\n<h4><span class=\"ez-toc-section\" id=\"Stagnation-Properties\"><\/span>Stagnation Properties\u00a0<span class=\"ez-toc-section-end\"><\/span><\/h4>\r\n<p>It is defined as the state a fluid in motion would reach if it is brought to rest <strong> isentropically <\/strong>in steady flow and zero work output device. <br \/><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-168\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/stagnation-properties.png\" alt=\"Stagnation Properties \" width=\"355\" height=\"115\" \/> <br \/><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-170\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/stagnation-pressure.png\" alt=\"Stagnation Pressure\" width=\"364\" height=\"59\" \/> <img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-169 aligncenter\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/stagnation-properties-ratio.jpg\" alt=\"Stagnation Properties \" width=\"196\" height=\"140\" \/><\/p>\r\n<h4><span class=\"ez-toc-section\" id=\"Pressure-compounding\"><\/span>Pressure compounding<span class=\"ez-toc-section-end\"><\/span><\/h4>\r\n<p>where, N = Nozzle,<br \/>MB = Moving blade<br \/>The pressure drop occur only in nozzle. There is no pressure drop while steam flows through the blades. <img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-171\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/pressure-compounding.jpg\" alt=\" Pressure compounding\" width=\"227\" height=\"131\" \/><\/p>\r\n<h4><span class=\"ez-toc-section\" id=\"Velocity-compounding-Nozzle\"><\/span>Velocity compounding Nozzle<span class=\"ez-toc-section-end\"><\/span><\/h4>\r\n<p>where, SB = Stationary blade<br \/>All the pressure drop and enthalpy drop of steam takes place in a single row of nozzles. <img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-172\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/velocity-compounding.jpg\" alt=\"Velocity compounding\" width=\"212\" height=\"157\" \/> <img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-182\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/total-number-of-stage.jpg\" alt=\"Total number of stage\" width=\"442\" height=\"80\" \/><\/p>\r\n\r\n\r\n\r\n<p style=\"text-align: center;\"><a class=\"btn btn-danger\" role=\"button\" href=\"https:\/\/study.madeeasy.in\/me\/power-plant\/what-is-axial-flow-compressor\/\" target=\"_blank\" rel=\"noopener\">&lt;&lt; Previous<\/a> | <a class=\"btn btn-success\" role=\"button\" href=\"https:\/\/study.madeeasy.in\/me\/power-plant\/what-is-gas-turbine-power-plant\/\" target=\"_blank\" rel=\"noopener\"> Next &gt;&gt;<\/a> <br \/><strong> Must Read: <\/strong> <a href=\"https:\/\/study.madeeasy.in\/subjects\/what-is-power-plant-engineering\/\" target=\"_blank\" rel=\"noopener\"><strong>What is Power Plant Engineering?<\/strong><\/a><\/p>\r\n<p>&nbsp;<\/p>\r\n","protected":false},"excerpt":{"rendered":"<p>Fan characteristics can be represented in form of fan curve(s). The fan curve is a performance curve for the particular<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[55,10],"tags":[78,79,80,81,77,82,83,84],"class_list":["post-235","post","type-post","status-publish","format-standard","hentry","category-power-plant","category-me","tag-analysis-of-steam","tag-boiler-accessories","tag-boiler-mounting","tag-classification-of-boilers","tag-fan-characteristics","tag-pressure-compounding","tag-rankine-cycle-with-superheating","tag-velocity-compounding"],"_links":{"self":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts\/235","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/comments?post=235"}],"version-history":[{"count":0,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts\/235\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/media?parent=235"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/categories?post=235"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/tags?post=235"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}