管壳式换热器设计说明书.docx

1、管壳式换热器设计说明书第三章 换热器设计一、例子已知混合气体的流量为227801kg/h，压力为6.9Mpa，循环冷却水的压力为0.4Mpa，循环水入口温度29，出口温度39，试设计一台列管式换热器，完成该任务。混合气体在85下有如下物性：热容cp1=3.297kJ/kg，导热系数=0.0279w/m，粘度=0.000015Pas，密度=90kg/m3。循环冷却水在34下有如下物性：热容cp1=4.174kJ/kg，导热系数=0.624w/m，粘度=0.000742Pas，密度=994.3kg/m3。 二、Input输入模块1、problem definition问题定义模块1.1、descr

2、iption基本描写（1）标题(Heading)公司（pany）地址（location）服务对象（Service of Unit）、本单位联系人（our Reference）项目编号（item No）、对方单位联系人（Your Reference）日期（date）等。 （2）物流名称热流（Hot side） 冷流（Cold side）（3）备注(Remarks)2、 application options（程序运行环境选择）2.1、Hot side application（热流运行环境）（1）Liquid，no phase change（液体，无相变化）（2）Gas，no phase chan

3、ge（气体，无相变化）（3）Narrow range condensation: Application covers the cases where the condensing side filmcoefficient does not change significantly over the temperature range. Therefore, thecalculations can be based on an assumed linear condensation profile. This class isremended for cases of isothermal c

4、ondensation and cases of multiple condensableswithout noncondensables where the condensing range is less than 6C (10F).狭窄围的冷凝：用于冷凝液膜系数不随温度改变的情况。因此，该计算认为冷凝呈线性曲线。该方法推荐用于等温冷凝和在6 C下不冷凝的多组分冷凝。（4）Multi-ponent condensation: Application covers the other cases of condensation wherethe condensing side film co

5、efficient changes significantly over the condensing range.Therefore, the condensing range must be divided into several zones where the properties andconditions must be calculated for each zone. This class is remended for all cases wherenoncondensables are present or where there are multiple condensa

6、bles with a condensingrange of more than 6C (10F).多组分冷凝：用于冷凝液膜系数随温度改变的情况。因此，根据特性和环境，将冷凝温度围分成几个区间，然后对每一个区间进行计算。该方法推荐用于不凝液和在高于6 C下冷凝的多组分冷凝。Saturated steam condensation（饱和蒸气冷凝）Falling film liquid cooler（降膜液体冷却器）2.2、Condensation curve冷凝曲线You can input a vapor/liquid equilibrium curve or have the program

7、 calculate the curve usingideal gas laws or several other non-ideal methods.你可以输入一个汽/液平衡曲线或使用理想气体定律或其他一些非理想的计算方法计算曲线的程序2.3、Condenser type冷凝器类型Most condensers have the vapor and condensate flow in the same direction. However, forsome special applications where you want to minimize the amount of subco

8、oling you canselect a knockback reflux condenser type. The condensate formed flows back towards thevapor inlet. With this type of condenser, you should consider using the differentialcondensation option if the program calculates the condensation curve.2.4、Cod side application（冷流运行环境）（1）Liquid，no pha

9、se change（液体，无相变化）（2）Gas，no phase change（气体，无相变化）（3）Narrow range vaporization: 狭窄围的蒸发（4）Multi-ponent vaporization多组分蒸发2.5、Location of hot fluid流程安排（热流位置）Tube side（管程）、shell side（壳程），（1）较脏和易结垢的物流应走易于清洗的一侧。对于固定管板式、浮头式换热器，一般应使易结垢流体流经管程，而对于U型管换热器，易结垢流体应走壳程。如冷却水为易结垢流体。若必须走壳程，则应采用正方形管子排列，并采用可拆式换热器（浮头式、填料函

10、式、U形管式）。（2）有时在设计上需要提高流体的流速，以提高其传热膜系数，在这种情况下，应将需要提高流速的流体放在管程。这是因为管程流通截面积一般较小，且易于采用多管程结构以提高流速，（3）具有腐蚀性的流体应走管程，这样可以节约耐腐蚀材料，降低换热器成本。（4）压力高的流体应走管程。这是因为管子直径小，承压能力强，能够避免采用耐压的壳体和密封措施。（5）具有饱和蒸汽冷凝的换热器，应使饱和蒸汽走壳程，便于排出冷凝器。（6）粘度大的流体应走壳程，因为壳体的流体在折流板的作用下，流通截面和方向都不断变化，在较低的雷诺数下就可达湍流状态。（7）为了节省保温层和减少壳体厚度，高温物流一般走管程，有时为了

11、物料的冷却，也可使高温物流走壳程。（8）若两流体温差较大，对于刚性结构的换热器，易将传热膜系数大的流体通入壳程，以减小温差应力。（9）流量小的液体一般走壳程，因为壳体的流体在折流板的作用下，流通截面和方向都不断变化，在较低的雷诺数下就可达湍流状态。（10）对压力降有特定要求的工艺物流走管程，因管程的传热系数和压降计算误差小。（11）传热膜系数较小的物流（如气体）应走壳程，易于提高传热膜系数。（12）有毒性的流体走管程，以减少泄露机会。注意：采用Aspen进行计算是，可以采用试的方法，首先让其热流体走管程，计算传热系数及换热面积；然后再假设走壳程，计算传热系数及换热面积。最后取传热系数最大，换热

12、面积最小的情况。2.6、Program mode（程序模式选择：设计、优化、模拟） Design（设计）、Rating（优化）、Simulatin（模拟）、Selest from standard file(从标准文件中选择），3、process data物流参数输入3.1、Fluid name（流体名称）3.2、Fluid quantity, total（热或冷流体总流速）选择单位、依据条件输入冷、热流体流量，3.3、Temperature冷热流体进出口温度3.4、Operating Pressure(absolute) 绝对操作压力选择单位、依据条件输入冷、热流体进出口压力3.5、Heat

13、 exchanged交换热量若交换热量没有直接给出，不输。3.6、allowable pressure drop允许的压力降一般情况下，流体流过换热器的阻力或压力降为10000100000Pa，气体为100010000Pa。允许的压力降往往与换热器的操作压力有关、操作压力越大，允许流体阻力可相应大一些。如操作压力为P200000Pa，P50000。3.7、fouling resistance污垢热阻4、热平衡计算环境This input allows you to specify whether you want the total flow rate or the outlet temper

14、atureto be adjusted to balance the heat load against the specified heat load or the heat loadcalculated from the opposite side. The program will calculate the required adjustment.There is also an option to not balance the heat loads, in which case the program will designthe exchanger with the specif

15、ied flows and temperatures but with the highest of the specifiedor calculated heat loads.输入允许您指定是否总流量和出口温度，要调整到平衡的热负荷与指定的热负荷和热负荷从对面的计算。该程序将计算所需的调整。还有一个选择是不平衡的热负荷，在这种情况下，程序设计换热器与指定的流动和温度而指定的最高或计算热负荷。5、 Physical Property Data物理特性数据（1）Property Option（特性程序选择一般默认）（2） Hot Side position热物质组成（若未知可不输）（3）Hot

16、Side Properties（热物流特性）（1）Temperature（温度），（2）Specific heat（热容）cp1=3.297kJ/kg（3）Thermal cond（导热系数）=0.0279w/m（4）Viscosity（粘度）=0.000015Pas（5）Density（密度）=90kg/m3（6）Molecular weight（分子量）（7）Diffusivity（扩散率）（4）cold side position（冷物流组成与前热物流组成一样）（5） cold side properties（冷物流特性）（1）Temperature（温度），（2）Specific he

17、at（热容）cp1=4.174kJ/kg（3）Thermal cond（导热系数）=0.624w/m（4）Viscosity（粘度）=0.000742Pas（5）Density（密度）=994.3kg/m3（6）Surface tension（表面力）（7）Critical pressure（临界压力）（8）Latent heat（潜热）温度、热容、导热系数、粘度、密度、分子量、扩散率6、 Exchanger Geometry（结构参数）6.1 exchanger Type（换热器类型）（1）Front head type（换热器前端管箱）A-channel & B-bonnet bolted

18、 C-integral tubesheet bundleremovable cover or integral with tubesheet & removeable （平盖管箱） 封头管箱 ( 选择) 用于可拆管束与管板制成一体的管箱N-integral tubesheet & nonremovable bundle D-high pressure enclosure与管板制成一体的固定管板管箱 特殊高压管箱A full access cover provided in the A, C, （A，C提供了一个完整的检修盖） N type heads may be needed if the

19、tube side of the exchanger must be cleaned frequently. （如果换热器的管程必须经常清洗时，则需N型）The B type is generally the most economical type head. （B型通常是最经济型的）Default: B Type（默认值：B型）（2）Shell type（壳体结构）E-one pass shell F-two pass shell with long baffle单壳程 （选择） 具有常隔板的双壳程 G-Split flow H-double split flow分流 双分流J-divid

20、ed flow(nozzles:1 in,2 out) K-kettle无隔板分流（或冷凝器壳体） 釡式重沸器X-crossflow V-vapor belt交错流 蒸汽机J-divided flow(nozzles:2 in,1 out)无隔板分流（或冷凝器壳体）E type: Generally provides the best heat transfer but also the highest shell side pressure drop. Used for temperature cross applications where pure counter current flo

21、w is needed.F type: This two pass shell can enhance shell side heat transfer and also maintain counter current flow if needed for temperature cross applications. G type: Will enhance the shell side film coefficient for a given exchanger size. H type: A good choice for low shell side operating pressu

22、re applications. Pressure drop can be minimized. Used for shell side thermosiphons. J type: Used often for shell side condensers. With two inlet vapor nozzles on top and the single condensate nozzle on bottom, vibration problems can be avoided.K type: Used for kettle type shell side reboilers.X type

23、: Good for low shell side pressure applications. Units is provided with support plates which provides pure cross flow through the bundle. Multiple inlet and outlet nozzles or flow distributors are remended to assure full distribution of the flow along the bundle. V type shell: This type is not curre

24、ntly part of the TEMA standards. It is used for very low shell side pressure drops. It is especially well suited for vacuum condensers. The vapor belt is an enlarged shell over part of the bundle length. Default: E type (except K type shell side pool boilers)（3）Rear head type（后端结构）L-removable channe

25、l with flat cover M-bonnet与A相似的固定管板结构 与B相似的固定管板结构N-integral channel with flat cover P-outside packed floating heat与C相似的固定管板结构 填料函式浮头S-floating head with backing device T-pull through floating head钩圈式浮头（选择） 可抽式浮头U-U-tube bundle W-floating head with lantem ringU型管束 带套环填料函式浮头固定管板式、浮头式、U型管式、填料函式浮头式换热器（冷

26、热流体进口温度29，出口温度39，该换热器用循环冷却水冷却，冬季操作时，其进口温度会降低，考虑到这一因素，估计该换热器的管壁温之差较大，因此初步确定为选用浮头式换热器）The rear head type affects the thermal design, because it determines the outer tube limits and therefore the number of tubes and the required number of tube passes. Default: U type for kettle shells, M type for all o

27、thers（4）exchanger position（换热器水平还是垂直安装）Horizontal（水平）、Vertical（垂直）Default: vertical for tube side thermosiphon; horizontal for all others默认：热虹吸换热器垂直安装，其他都水平安装）（5）cover密封（盖子）面类型（工艺计算没必要提供）（6）Tubesheet type管板形式管板类型对热计算和投资预算来说起着一个非常重要的作用。为了避免管侧和壳侧流体漏液，则往往选择双管板。双管板在固定管板换热器中最常用，同样也可用于U形管式换热器和外包装的浮动式换热器。双

28、管板缩短了壳侧流体流动的长度，因此，降低了有效面积。也影响壳体接管的位置与挡板间距。间隙式双管板有一个空间，通常约150毫米（6in）。整体式双管板是由加工出一个蜂巢图案板单块厚使任何泄漏流体穿过管板的漏，这种类型是罕见的，因为它需要特殊的制作工具和经验。默认值：单板The tubesheet type has a very significant effect on both the thermal design and the cost.Double tubesheets are used when it is extremely important to avoid any leakag

29、e between theshell and tube side fluids. Double tubesheets are most often used with fixed tubesheetexchangers, although they can also be used with U-tubes and outside packed floating heads.Double tubesheets shorten the length of the tube which is in contact with the shell side fluidand therefore red

30、uce the effective surface area. They also affect the location of the shell sidenozzles and the possible baffle spacings.The gap type double tubesheet has a space, usually about 150 mm (6 in.), between the inner(shell side) and outer (tube side) tubesheets. The integral type double tubesheet is made

31、bymachining out a honeyb pattern inside a single thick piece of plate so that any leakingfluid can flow down through the inside of the tubesheet to a drain. This type is rare, since itrequires special fabrication tools and experience.Default: normal single tubesheet(s)（7）Tube to tubesheet joint管子与管板的连接（工艺不关键）6.2 Tubes（换热管）（1）Tube type（管子类型）（a）Plain光管（b）finned tube翅片管（c）默认值：光管当壳程膜传热系数远比管程膜传热系数小时，常使用外翅片管。然而在一