WSrZUgl2YY/V2uDwBToIRI/AAAAAAAACZY/5eTw9X0LAwwo4mdlkUCd_w6_SwGj0khOgCLcB/s640/one-piece-450x270.jpg' alt='9Th Edition Tema Standards' title='9Th Edition Tema Standards' />Shell and tube heat exchanger. Fluid flow simulation for a shell and tube style exchanger The shell inlet is at the top rear and outlet in the foreground at the bottom. A shell and tube heat exchanger is a class of heat exchanger designs. It is the most common type of heat exchanger in oil refineries and other large chemical processes, and is suited for higher pressure applications. As its name implies, this type of heat exchanger consists of a shell a large pressure vessel with a bundle of tubes inside it. One fluid runs through the tubes, and another fluid flows over the tubes through the shell to transfer heat between the two fluids. Th Edition Tema Standards' title='9Th Edition Tema Standards' />The set of tubes is called a tube bundle, and may be composed of several types of tubes plain, longitudinally finned, etc. Theory and applicationeditTwo fluids, of different starting temperatures, flow through the heat exchanger. One flows through the tubes the tube side and the other flows outside the tubes but inside the shell the shell side. Heat is transferred from one fluid to the other through the tube walls, either from tube side to shell side or vice versa. TEMArLogo2.gif' alt='9Th Edition Tema Standards' title='9Th Edition Tema Standards' />The fluids can be either liquids or gases on either the shell or the tube side. In order to transfer heat efficiently, a large heat transfer area should be used, leading to the use of many tubes. In this way, waste heat can be put to use. This is an efficient way to conserve energy. Heat exchangers with only one phase liquid or gas on each side can be called one phase or single phase heat exchangers. Two phase heat exchangers can be used to heat a liquid to boil it into a gas vapor, sometimes called boilers, or cool a vapor to condense it into a liquid called condensers, with the phase change usually occurring on the shell side. Boilers in steam engine locomotives are typically large, usually cylindrically shaped shell and tube heat exchangers. In large power plants with steam driven turbines, shell and tube surface condensers are used to condense the exhaust steam exiting the turbine into condensate water which is recycled back to be turned into steam in the steam generator. Shell and tube heat exchanger designeditThere can be many variations on the shell and tube design. Typically, the ends of each tube are connected to plenums sometimes called water boxes through holes in tubesheets. The tubes may be straight or bent in the shape of a U, called U tubes. In nuclear power plants called pressurized water reactors, large heat exchangers called steam generators are two phase, shell and tube heat exchangers which typically have U tubes. When it comes to bedding down in one of our favourite cities, we love the hip and the new, but we also value the timehonoured classic. We asked Time Outs. I celebrate myself, and sing myself, And what I assume you shall assume, For every atom belonging to me as good belongs to you. I loafe and invite my soul. The 296 page Ninth Edition of the Standards of the Tubular Exchanger Manufacturers Association begins shipping on November 20, 2007. The 9th Edition retains the. Standard Edition Section Inquiry Question Reply API 510 Pressure Vessel Inspection Code Last update June 28, 2007 510 9th Edition, June 2006. They are used to boil water recycled from a surface condenser into steam to drive a turbine to produce power. Most shell and tube heat exchangers are either 1, 2, or 4 pass designs on the tube side. Th Marksheet 2013. This refers to the number of times the fluid in the tubes passes through the fluid in the shell. In a single pass heat exchanger, the fluid goes in one end of each tube and out the other. Free Trial Adobe Indesign Cc 2015. Th Edition Tema Standards' title='9Th Edition Tema Standards' />Surface condensers in power plants are often 1 pass straight tube heat exchangers see surface condenser for diagram. Two and four pass designs are common because the fluid can enter and exit on the same side. This makes construction much simpler. There are often baffles directing flow through the shell side so the fluid does not take a short cut through the shell side leaving ineffective low flow volumes. These are generally attached to the tube bundle rather than the shell in order that the bundle is still removable for maintenance. Counter current heat exchangers are most efficient because they allow the highest log mean temperature difference between the hot and cold streams. Many companies however do not use two pass heat exchangers with a u tube because they can break easily in addition to being more expensive to build. Often multiple heat exchangers can be used to simulate the counter current flow of a single large exchanger. Selection of tube materialeditTo be able to transfer heat well, the tube material should have good thermal conductivity. Because heat is transferred from a hot to a cold side through the tubes, there is a temperature difference through the width of the tubes. Because of the tendency of the tube material to thermally expand differently at various temperatures, thermal stresses occur during operation. This is in addition to any stress from high pressures from the fluids themselves. The tube material also should be compatible with both the shell and tube side fluids for long periods under the operating conditions temperatures, pressures, p. H, etc. to minimize deterioration such as corrosion. All of these requirements call for careful selection of strong, thermally conductive, corrosion resistant, high quality tube materials, typically metals, including aluminium, copper alloy, stainless steel, carbon steel, non ferrous copper alloy, Inconel, nickel, Hastelloy and titanium. Fluoropolymers such as Perfluoroalkoxy alkane PFA and Fluorinated ethylene propylene FEP are also used to produce the tubing material due to their high resistance to extreme temperatures. Poor choice of tube material could result in a leak through a tube between the shell and tube sides causing fluid cross contamination and possibly loss of pressure. Applications and useseditThe simple design of a shell and tube heat exchanger makes it an ideal cooling solution for a wide variety of applications. One of the most common applications is the cooling of hydraulic fluid and oil in engines, transmissions and hydraulic power packs. With the right choice of materials they can also be used to cool or heat other mediums, such as swimming pool water or charge air. One of the big advantages of using a shell and tube heat exchanger is that they are often easy to service, particularly with models where a floating tube bundle where the tube plates are not welded to the outer shell is available. Design and construction standardseditStandards of the Tubular Exchange Manufacturers Association TEMA, 9th edition, 2. EN 1. 34. 45 3 Unfired Pressure Vessels Part 3 Design, Section 1. ASME Boiler and Pressure Vessel Code, Section VIII, Division 1, Part UHXSee alsoeditReferenceseditExternal linksedit.