(3)Tube wall thickness(管子壁厚)
(4)Tube wall roughness(管子粗糙度)
(5)Tube wall Specification(管子壁厚计算指定)
有平均average、最小Minimum选项
Tube wall specification
In many countries, the tube wall thickness is specified as either average or minimum. Average means the average wall thickness will be at least the specified thickness; typically the
thickness may vary up to 12%. With minimum wall, all parts of the tube must be at least the specified thickness.
In the U.S., most heat exchanger tubes are specified as average wall thickness. In other countries, for example Germany, the standard requires minimum wall.
This item has a small effect on tube side pressure drop and a moderate effect on heat exchanger cost. Default: average
管壁厚度
在许多国家,管壁厚度指定为平均值。平均
方法的平均壁厚至少要指定的厚度;通常
厚度高达12%可能会有所不同。以最小的管壁,所有部件必须至少
指定的厚度。
在美国,大多数换热器管指定为平均壁厚。在其他
国家,例如德国,标准要求的最小壁。
这项对管侧压降和热适度影响小的影响
换热器的成本。
默认值:平均
(6)Tube pich管心距
(7)Tube material管子材质 (8)Tube pattem换热管的排列
Triangular正三角形、Rotated triangular选转45度的正三角形、Square正方形、Rotated square旋转45度的正方形。
一般来说,正三角形排列在相同的管板面积上可排列较多的管子,而且管外传热膜系数较大,有利于增强壳程物流的湍流,但正三角形排列时管外机械清洗较为困难,而且管外流体的流动阻力也较大。正方形排列在同样的管板面积上可配置的传热管最少,但管外易于进行机械清洗,所以当管子外壁需要机械清洗,常采用这种排列。为了弥补各自的缺点,产生了转过一定角度的正方形排布和留有清理通道的三角形排布两种形式。 (9)翅片管相关数据 (a)Fin density翅片密度
标准的翅片密度根据材料而定: 碳钢19
不锈钢16,28 铜19,26
铜镍90 / 10,16,19,26 铜镍70 / 30,19,26 镍基合金201 19
镍400合金(蒙乃尔)28 镍600合金(Inconel)28 镍合金800 28 哈氏合金30 钛30
海军19,26
铝黄铜合金687 19
The standard fin densities for various materials are: Carbon Steel 19
Stainless Steel 16, 28 Copper 19, 26
Copper-Nickel 90/10 16, 19, 26 Copper-Nickel 70/30 19, 26 Nickel Carbon Alloy 201 19 Nickel Alloy 400 (Monel) 28 Nickel Alloy 600 (Inconel) 28 Nickel Alloy 800 28 Hastelloy 30 Titanium 30 Admiralty 19, 26
Aluminum-Brass Alloy 687 19 (b)Fin height翅片高度
(c)Fin thickness翅片厚度
(d)Surface area per unit length每单位管长的表面积
Average outside surface area / Unit length: Tube O.D. 0.750 in 0.406-0.500 ft2/ft Tube O.D. 19.05 mm 0.124-0.152 m2/m Standard fin dimensions:
Fin Density 16-30 fins/in 630-1181 fins/m Fin Height 0.0625-0.032 in 1.59-0.81 mm Fin Thickness 0.011-0.012 in 0.28-0.31 mm
(e)Outside/Inside surface area ratio外内表面积比 (f)Twisted Tape Ratio扭带比
Provide the ratio of the length of tape required to make a 180 degree twist to the width of the tape. The smaller the ratio, the tighter the twist.
(g)Twisted Tape Width纽带宽
Specify the width of twisted tape insert.
(h)Tapered tube ends for knockback condensers
Select to have tapered tube ends at inlet tubesheet. Tapered tube ends promote better condensate drainage from the tubes and reduce the potential for flooding.
6.3 Bundle结构参数限定
(1)shell entrance/exit壳体入口/出口
Shell entrance construction壳体入口结构
(a)一般使用全管布置(full layout),即,尽可能多的将管子布在限管圆内侧,这使得一定壳体直径的换热面积使用最大,并最大限度地减少旁路。然而这将会导致流体高速流入壳体,这就要求在进口接管处的一些换热管需移走或加缓冲挡板或安装防冲带状物。
(b)拆除接管入口处换热管。在这种情况下,将不影响接管尺寸,但会影响壳体直径。 (c)接管阔嘴,不影响流体进入量,但是减小流速。 (d)分派带,减小流速,但价格高。
(e)拆除管子,使得壳体入口面积与接管入口面积一样大,这最为有效。
默认:如果无防冲板,则全管布置;如果采用扩径防冲板,则默认为扩径全管布置;如果设置防冲板,则默认为除去管子,使得壳体入口面积与接管进口面积相等。
(a)Normally, it is advantageous to use a full tube layout, i.e., to place as many tubes as possible within the outer tube limits. This maximizes the surface area within a given shell diameter and