This article is a high level tutorial on shell & tube heat exchanger design procedure. We will mainly look at finalizing the process parameters of a new shell & tube exchanger and preparing theprocess specification sheetfor the new exchanger.
壳和管热交换器是过程行业中最受欢迎和最广泛使用的传热设备。这主要是因为壳和管交换机的多功能性，基于不同的外壳和管交换机的类型that can be easily created by changing the shell and tube arrangement.
Process and mechanical design
新热交换器工程设计的第一步是最终确定过程参数，例如 -
- Operating temperature and pressure
- Design temperature and pressure
- Heat duty, which is the total required heat transfer rate
- Inlet / Outlet temperature for hot fluid
- Inlet / Outlet temperature for cold fluid
- 最大允许的压力下降
- Maximum allowable pressure drop on cold side
- Type of heat exchangerto be used
- Shellside / tubeside fluid selection (i.e. whether hot / cold fluids should go to shell side or tube side)
基于此信息，机械工程师然后准备一个机械数据表，可以由热交换器制造商使用，以用于最终制造。机械数据表是基于由TEMA standardswhich are developed by Tubular Exchanger Manufacturer's Association (TEMA).
Iterative heat exchanger process design procedure
Process design of ashell and tube heat exchangeris an开放式的问题。与有约束相比，有更多的参数（或变量）。因此，我们有可能修复其中一些参数以获得具有成本效益和高效的热交换器设计。
But which parameters to fix and to what values?
That is why process design for a heat exchanger is often done in an iterative manner and the optimal design is found by trying out different heat exchanger design parameters.
考虑到这一点，让我们浏览壳和管热交换器设计过程中涉及的步骤。
Steps for heat exchanger design procedure
1. Define the essential process requirements
First and foremost, we must clearly define the primary objectives for the new heat exchanger equipment.
必须修复某些过程参数。例如，过程流体流量，入口 /出口温度，操作和设计压力值，最大允许压降等。这些参数是固定的输入到我们的heat exchanger design calculations它们也是约束。
2.选择合适的热交换器类型
Based on the nature of the process fluid (service), operating temperature and pressure, allowablepressure drop across the exchanger，可用的实用程序，流量等，您需要选择最合适的热交换器类型。
When you have selected a shell and tube heat exchanger, you also need to decide which fluid should go to the shell side and which one to the tube side. This is also decided based on the given process conditions and the nature of two hot and cold fluids.
在此阶段，还建议适当注意可以使用哪些公用事业和相应的公用事业进场温度值。Any required changes with respect to utility or heat exchanger type, should be made at this stage.
3. Fix some of the design parameters to create a heat exchanger model
由于热交换器设计将成为一个迭代过程，因此我们需要一个起点。我们需要修复一些设计参数，例如。管道通过，热交换器的长度，外壳ID，挡板间距等。
This is a starting point for out iterative model and these values will change as we examine the design against our process requirements. But it is important to select (guess) the initial parameters as close as possible to the final design. That way, we will need the minimum number of iterations to get to the final design.
You can also use these resources for manually doing theheat exchanger calculations, before going to a modeling software.
4.热交换器设计的评分
Next, create a model using a热交换器仿真软件。使用此模型检查是否满足了STEP1的所有过程要求。例如，检查壳和管侧的过程流体和压降值的出口温度。它们是否在我们的流程要求设定的约束之内？
If not, then check which process requirements are not met. Accordingly change the heat exchanger design parameters and go back to step3.
With the new design parameters, re-adjust your heat exchanger model and repeat the simulation calculations. Then you can again check the rating. This process will repeat till you find a heat exchanger model that can satisfy all your process requirements.
5.用最终的热交换器设计创建规格表
When the heat exchanger rating does satisfy your process requirements, you can capture all the details in a process datasheet. Send this data sheet to the mechanical equipment design engineer, so he can prepare theheat exchanger specification sheetas per TEMA standards.
热交换器周围的管道和仪器
除了设计热交换器设备本身之外，您还需要在热交换器周围设计管道和仪器，以进行适当的维护，安全和过程控制措施。
A process engineer creates a P&ID diagram to guide the piping and instrumentation engineers with their final design of surrounding piping and instrumentation.以下是创建P＆ID图的详细指南用于热交换器。
参考和资源
- Thisshell & tube heat exchanger diagram给一个详细的清单s parts with exact nomenclature as per TEMA standards.
- 流体分配指南on either sides of a shell & tube exchanger, i.e. to decide which fluid should go to the shell side and which to the tube side.
- 所有清单壳和管热交换器的重要方程式设计。
