U形管換熱器設(shè)計(jì)【含5張CAD圖紙】

資源目錄里展示的全都有，所見(jiàn)即所得。下載后全都有,請(qǐng)放心下載。原稿可自行編輯修改=【QQ：401339828 或11970985 有疑問(wèn)可加】 三 英文文獻(xiàn) Mechanical Design of Heat Exchangers The many configurations and types of heat exchangers necessary for the variety of fluids and widerange of temperature and pressure encountered inthe chemical industry make choice of design a complex problem in economics The WIDE RANGE of applications of heat exchangers in the chemical industry has led to a variety of constructions. Many types have been designed to accommodate the simple fluids, solutions, or slurries which must be cooled, condensed, or boiled. The extremes of temperatures and the pressures involved in these processes have also been considered. Standard Heat Exchangers To suit the majority of cases, standard shell-and-tube heat exchangers have developed. The essential parts are the tube sheets, tube bundle, the heads, the shell, shell baffles, and inlet and outlet nozzles. In general, these can be obtained for operating pressures up to 600 p.s.i. and for sizes up to 1200 square feet of heat transfer surface. Straight tube, straight shell, fixed-tube sheet heat exchanger Heat exchanger tube pattern These standards, developed by fabrica-tors, are primarily described by the “Standards of Tubular Exchanger Manufacturing Association.” The fourth edition of this booklet has just been published. A further effort at construction standardization is presently being undertaken by the American Standards Association, through the efforts of Sectional Committee B-78, Standardization of Heat Exchangers for Chemical Industry Use.” Standardization reduces first costs, speeds delivery, and permits interchange of parts. In the chemical industry, because of its dynamic technology, write-off time for process equipment is relatively rapid. First cost is of prime importance, but the first cost of a heat exchanger must be considered, together with many other factors, for the choice of a heat exchanger design is a very complex problem in economics. Important variables in this problem are the cost of outage time or the cost of operating at reduced efficiencies because of fouling, corrosion, leakage, or structural failure. The cost of some modifications can be justified, such as those that permit chemical cleaning or facilitate plugging tubes or replacing surface. Additional costs can be justified when they are necessary to accommodate severe cyclic conditions, or when the fluids involved are lethal. Shell expansion joint Straight tube, floating head heat exchanger Standard U-tube heat exchanger Special Heat Exchangers Sometimes these factors lead to exchanger requirements not covered by the standard tubular exchanger, and nonstandard shell-and-tube exchangers come into the picture, as well as miscellaneous special types, involving coiled tubes, plates, extended surface, and unusual construction materials, such as graphite or glass. Basically, heat exchangers must be designed to be structurally sound for their intended service. Usually, pressure part thicknesses will be satisfactory if they meet the requirements of the ASME Code for Unfired Pressure Vessels. Beyond that, the TEMA Standards are used as a guide. The codes generally call for the use of materials conforming to the specifications of the ASTM. It is also the practice of many heat exchanger users to write their own more or less rigid specifications. Generally speaking, for the low pressure heat exchangers, fabrication requirements and corrosion allowances will be the governing factor in determining tube and shell thicknesses. Accommodating Mechanical and Chemical Cleaning An important consideration in most chemical plant applications is the fouling of the heat exchanger surface. Heat exchangers reflect this problem in a variety of construction details. Most head, channel, and cover plate designs permit ready access to tube ends so that the inside of tubes can be rodded clean. Where cleaning externally is important, the construction may permit removal of the entire tube bundle from the heat exchanger so that access to the outside of the tubes may be gained. While a tube pattern of triangular of space pitch is the most economical and materials, an in-line or square pitch tube pattern results in lanes for mechanical cleaning devices. Where chemical cleaning is possible, vents and drains are used as connections for circulating the solutions in and out. Reducing Stresses Due to Differential Expansion In the first heat exchanger drawing , a fixed-tube sheet arrangement is the simplest and least is shown. This expensive type of construction; but if the fluids on the tube side and shell side are of significantly different tem-peratures, so that the tubes and shell are at different temperatures, there will be a differential expansion between tubes and shell that might cause excessive stresses. The result: of these stresses may be fatigue failure, leaking tubes at the tube seats, or perhaps an acceleration of corrosion. To avoid these types of failures, construction modifications are introduced. One example is an expansion joint in the heat exchanger shell. Another common device is the floating tube sheet. While one end of the tube bundle is secured to the shell, the other end is permitted to float with packed seals to prevent leakage. The U-tube arrangement will accommodate differential expansion between tubes and shell and also different rates of expansion between adjacent tubes. ‘Note the flanged construcdon that permits disassembly and removal of the tube bundle. Bent tube heat exchanger Half-moon supports Disk-donut supports The use of bent tubes between fixed tube sheets is another ccepted means of accommodating differential expansions. An additional advantage claimed for this arrangement is the natural shedding of tube scale which accompanies tube flexing during heating and cooling. Directing Tube-Side and Shell-Side Flow Tube-side flow is channeled readily within the tubes, any number of passes using divider plates within the heat exchanger heads. On the shell side, a variety of devices are employed. Themost common is the half-moon baffling. These drilled plates, while directing the flow back and forth across the tubes, also act as tube supports or spacers. Another familiar baffle is the disk and donut. Longitudinal flow dividers may also be used and, if necessary, tubes may be supported with lattice arrangements which minimize flow obstruction. High pressure closure Tube rolled and seal-welded into tube sheet Preventing Erosion Erosion of heat exchangers in service is generally avoided by designing for low fluid velocities if the fluid is of an erosive nature. Two common mechanical devices are also employed in shell-and- tube exchangers to overcome this problem: the shell-side impingement baffle, and the tube-side bell-mouthed tube insert. Both are employed at fluid inlets. Seal-weld membranes Preventing leakage High pressure and leakage problems go together. A wide variety of standard gaskets are available to suit most applications. For very high pressures, a Bridgeman-type closure may be employed. This device takes advantage of the high pressure to effect the seal. For joining tubes to tube sheets, seal welding or strength welding may be necessary, besides the common tube roiling. For cover plates or closure heads, seal-welded membranes may be employed. These seals can be removed by using a cutter and then be rewelded. Constructions for Reducing Size and Cost When one of the fluids has a low heat transfer coefficient for a easonable pressure drop, the use of extended surface on the heat exchanger is often more economical, as for example, in the aircooled condenser used in the South- west. This surface takes on a number of different forms. Fins or studs may be welded on or mechanically attached to tubing. Some extended surface is produced by rolling or forming the fins from the base tube metal. In general, the least costly means involve mechanical attachment of extended surface, but the best thermal and mechanical bond required by severe service is obtained by welding, brazing, or rolling on the fins or studs. If the outside diameter of the finned surface is no greater than the outside diameter of expanded tube ends, the surface is termed "low fin," and the tubing may be used interchangeably with smooth tubing of the same diameter, thus lending itself well to standard constructions. Typical extended surface arrangements Extended surface may also be used inside tubes. This can be accomplished in cast tubes and also extruded tubes, and some special types of heat exchangers are available with this construction. Plate-type heat exchanger Spiral plate heat exchanger A compact and generally economical arrangement is sometimes achieved by employing plate-type heat exchangers. One such surface arrangement consists of an assembly of flat corrugated plates. Another form is the spiral plate exchanger. More recently, progress has been achieved in the design and fabrication of so-called “packed-surface” heat exchangers wherein extended surface is employed on both sides of the fluid-dividing plates. A variety of fabrication techniques has been developed to accomplish seal, manifolding, and general structural integrity of plate-type heat exchangers, although such exchangers are generally restricted to applications under 200 p.s.i. Provisions for Extreme Corrosion Resistance Where low volume and relatively low pressures and temperatures are in-volved, but highly corrosive conditions exist, impervious graphite and glass have been employed successfully as heat exchanger materials. Graphite can be formed in almost any shape and, thus, typical shell-and-tube heat exchanger designs can be used. The type may depend on whether the fluid on one side or on both sides of the heat exchanger is corrosive. One graphite exchanger arrangement consists of a block with passages in which the corrosive fluids are directed perpendicularly to one another. Glass is used to coat the inside or out side of metal tubes and to line the inside of shells in some heat exchanger constructions. Packed-surface heat exchanger Graphite block heat exchanger The structural strength of one material may be combined with the corrosive resistance of another by employing metallic cladding. A thin layer of stainless steel is often rolled or spot-welded to a less costly base material, such as carbon steel. Electrolytic or chemical plating is also employed to lay a corrosion-resistant film on a structural material. Sometimes fluids employed in a process may not be compatible with the same tubing material. In this case, it is possible to obtain a dual-metal tube, with one material, such as a nickel alloy, on one side and aluminum, for example, on the other. Such tubing is often produced by co-drawing in order to obtain a tight bond between the two materials. 四 英文翻譯 機(jī)械設(shè)計(jì)換熱器 許多配置和類型的換熱器所必需的各種液體和各種溫度,壓力的過(guò)程中所遇到的化學(xué)工業(yè)做出選擇設(shè)計(jì)得一個(gè)復(fù)雜的問(wèn)題 廣泛的應(yīng)用在換熱器的化學(xué)工業(yè)已經(jīng)成功建成了各種不同的建筑。參與這些進(jìn)程的許多類型的設(shè)計(jì)，以適應(yīng)簡(jiǎn)單的液體的解決方案：泥漿必須冷卻，濃縮等或極端的溫度和壓力的參與，也被認(rèn)可。 換熱器標(biāo)準(zhǔn) 標(biāo)準(zhǔn)的管殼式換熱器的開(kāi)發(fā)要滿足大多數(shù)情況下。其中重要組成部分是管板，管束的首長(zhǎng)，殼牌，殼牌擋板和進(jìn)風(fēng)口。一般而言，這些可經(jīng)營(yíng)壓力可達(dá)600防擴(kuò)散和規(guī)模高達(dá)1200平方英尺的傳熱表面。 直管，直殼固定管板換熱器 換熱管模式 左邊:三角間距 右邊:在行間距 這些標(biāo)準(zhǔn)，制定法布里卡-因子，主要是描述由“管式換熱器標(biāo)準(zhǔn)制造商協(xié)會(huì)?！?。目前正在建設(shè)的標(biāo)準(zhǔn)化正在進(jìn)行的美洲標(biāo)準(zhǔn)協(xié)會(huì)的努力下斷面委員會(huì)β - 78 ，“標(biāo)準(zhǔn)化的換熱器化學(xué)工業(yè)使用?！? 標(biāo)準(zhǔn)化減少了第一次的費(fèi)用，交付的速度，并允許交換的部分。在化學(xué)工業(yè)，由于其動(dòng)態(tài)技術(shù)，注銷時(shí)間，工藝設(shè)備相對(duì)迅速。首先成本是最重要的，但第一次成本換熱器都必須加以考慮和許多其他因素，選擇換熱器設(shè)計(jì)是一個(gè)非常復(fù)雜的問(wèn)題，經(jīng)濟(jì)學(xué)。成本停電時(shí)間或成本在降低經(jīng)營(yíng)效率是重要的變數(shù)。因?yàn)槲廴?，腐蝕，泄漏，或結(jié)構(gòu)上的失敗。一些費(fèi)用可以合理的修改，如那些允許或化學(xué)清洗便利堵管或更換表面。額外的費(fèi)用可當(dāng)他們的理由是必要的，以適應(yīng)嚴(yán)重循環(huán)條件時(shí)，或在流體參與，致命的。 殼牌伸縮縫 直管，浮頭式換熱器 標(biāo)準(zhǔn)U型管換熱器 特別式換熱器 有時(shí)，這些因素導(dǎo)致?lián)Q熱要求未涵蓋的管狀換熱器的標(biāo)準(zhǔn)，并非標(biāo)準(zhǔn)的管殼式換熱進(jìn)入，以及其他特殊類型，涉及卷曲管，板，延長(zhǎng)表面，和不尋常的施工材料，如石墨或玻璃。 基本上，熱交換器必須設(shè)計(jì)結(jié)構(gòu)要合理。通常情況下，如果他們符ASME規(guī)范的阻燃?jí)毫θ萜骶褪呛侠淼?，。除此之外，換熱標(biāo)準(zhǔn)有指導(dǎo)作用。這些守則一般要求使用的材料符合規(guī)格ASTM標(biāo)準(zhǔn)。這也是實(shí)踐中許多換熱器用戶寫(xiě)自己或多或少的規(guī)范。一般而言，為低壓換熱器，制作要求和腐蝕因素要確定管殼厚度。 容納機(jī)械和化學(xué)清洗 一個(gè)重要的考慮因素在大多數(shù)化工廠應(yīng)用上是污垢的換熱器表面。熱交換器反映這一問(wèn)題在不同的施工細(xì)節(jié)。渠道和蓋板設(shè)計(jì)允許隨時(shí)獲得管兩端，使管內(nèi)可柵干凈。清洗外部是重要的，建設(shè)可允許清除整個(gè)管束的換熱器，以便獲得外部的管可能上漲。 雖然管模式三角空間是最廉價(jià)和材料，一個(gè)在管模式清潔設(shè)備。凡化學(xué)清洗是可能的，噴口和水渠被用作循環(huán)連接的解決方案和退出。 由于脹差導(dǎo)致降低強(qiáng)度 固定管板安排是最簡(jiǎn)單和最不發(fā)達(dá)國(guó)家用的這個(gè)昂貴的建筑類型;但是，如果流體的管方和殼牌一邊是的顯著不同溫度下，使管和殼牌都在不同溫度下，將有差別擴(kuò)大管和外殼之間有可能產(chǎn)生過(guò)度的壓力。其結(jié)果是：這些壓力可能是疲勞破壞，泄漏管在管席位，或者加速腐蝕。為了避免這些類型的故障，介紹了建設(shè)修改。一個(gè)例子是一個(gè)伸縮縫在換熱器殼。另一種較常見(jiàn)的手段是浮動(dòng)管板。雖然一端管束擔(dān)保的外殼，另一端是允許的浮動(dòng)填料密封，以防止泄漏。那個(gè)U型管的安排，可容納管之間的差別擴(kuò)大和殼牌也有不同的利率和的擴(kuò)大相鄰管。 '注意：在法蘭建筑許可證拆卸和拆除管束。 彎曲管換熱器 半月支持 磁盤(pán)支持 使用彎曲管固定管板是另一種手段，可容納接受差別擴(kuò)大。另外一個(gè)優(yōu)點(diǎn)宣稱這一安是天然的脫落管規(guī)模伴隨管伸縮在加熱和冷卻。 導(dǎo)管方和殼側(cè)流 管端流動(dòng)渠道容易管內(nèi)，任何數(shù)量的通行證使用除法板換熱器內(nèi)的元首。殼體方面，在不同的設(shè)備被使用。那個(gè)最常見(jiàn)的是半月形。這些鉆鋼板，同時(shí)指導(dǎo)流動(dòng)來(lái)回跨越管，管也作為支持或間隔。另一個(gè)熟悉的擋板是磁盤(pán)?？v流分隔也可使用，如果有必要，管可支持格子安排盡量減少流通阻塞。 高壓封閉 軋管和密封焊接到管板 防腐蝕 換熱器腐蝕的服務(wù)一般是通過(guò)設(shè)計(jì)避免低流體的流動(dòng)速度，如果是一個(gè)糜爛的性質(zhì)。兩種常見(jiàn)的機(jī)械裝置還采用管殼式換熱為克服這個(gè)問(wèn)題：在殼側(cè)撞擊擋板和管端喇叭口的管插入。兩者都是受雇于流體入口。 密封焊膜 防止泄漏 高壓和滲漏問(wèn)題。各種各樣的標(biāo)準(zhǔn)墊圈，可滿足大多數(shù)應(yīng)用非常高的壓力，布里奇曼型關(guān)閉可能被應(yīng)用。這種裝置利用高壓力作用的印章。加入管子管板，密封焊或焊接強(qiáng)度，除了共同管攪動(dòng)。掩護(hù)板或關(guān)閉，密封焊接膜可被使用。這些可以使用切割機(jī)除去。 結(jié)構(gòu)化和降低成本 當(dāng)一個(gè)人的液體具有較低的傳熱系數(shù)在一個(gè)合理的壓降，使用延長(zhǎng)表面上的換熱器往往是更經(jīng)濟(jì)，例如，在空氣冷凝器用于西南。這表面上采取了一些不同的形式。鰭或螺栓可焊接或機(jī)械連接到油管。有些延長(zhǎng)表面生產(chǎn)滾動(dòng)或形成鰭從金屬管的基礎(chǔ)。一般情況下，最廉價(jià)的手段涉及機(jī)械表面附著的延長(zhǎng)，但最好的熱和機(jī)械債券所要求的嚴(yán)重的服務(wù)，得到了焊接，釬焊，或滾動(dòng)的鰭或螺栓。 如果外直徑的翅片表面不大于外直徑的擴(kuò)大管兩端，表面被稱為“低肋”并且油管可交替使用，光滑管的直徑相同，因此用于標(biāo)準(zhǔn)建設(shè) 擴(kuò)展表面也可使用內(nèi)部管。這可以鑄造管，也擠壓管，而一些特殊類型的換熱器，可與此建造。 典型表面狀延長(zhǎng) 契約和一般經(jīng)濟(jì)的安排，有時(shí)達(dá)到雇用板式換熱器。這樣一個(gè)表面安排平板瓦楞紙板， 沒(méi)有其他形式的螺旋板換熱器。最近，已取得很大進(jìn)展的設(shè)計(jì)和制造的所謂“包裝面” ，其中延長(zhǎng)熱交換器表面采用兩邊的流體劃分板塊。各種各樣的制造技術(shù)已經(jīng)開(kāi)發(fā)完成印章， 一般結(jié)構(gòu)完整性，板式換熱器，盡管這種熱交換器一般僅限于申請(qǐng)200磅。 板式換熱器 螺旋板換熱器 規(guī)定極耐腐蝕性 低量和相對(duì)較低的壓力和溫度有關(guān)，但高度腐蝕性的條件存在，不透水的石墨和玻璃 已成功地為換熱器的材料。石墨可以形成幾乎任何形狀，因此，典型的管殼式換熱器的設(shè)計(jì)都可以使用。該類型可取決于流體一方或雙方的換熱器具有腐蝕性。交換安排由一個(gè)塊通道構(gòu)成，其中腐蝕性的液體是針對(duì)垂直彼此的。玻璃是用于涂層的內(nèi)部或外部的金屬管，并線的內(nèi)側(cè)彈在一些換熱器結(jié)構(gòu)。 便攜表面換熱器 石墨塊換熱器 結(jié)構(gòu)強(qiáng)度的材料可以是一個(gè)抗侵蝕性的，另一種采用金屬包層。薄薄的一層不銹鋼往往推出或點(diǎn)焊一個(gè)成本較低的基礎(chǔ)材料，如碳素鋼。電解或化學(xué)鍍也雇用奠定耐腐蝕膜結(jié)構(gòu)材料。 有時(shí)流體就業(yè)過(guò)程中可能不符合同一油管材料。在這種情況下，有可能用上鋁管其中的材料，如鎳合金。這種管材生產(chǎn)的往往是制作，以便獲得最適合的材料。