20 replies to this topic

[Jaldhipatel]

Hello, I'm have a task of design shell and tube heat exchanger for LNG service. So if anyone have excel sheet of shell and tube heat exchanger design then i will help me.

[Chemitofreak]

My two cents:

 

Use the software HTRI/Aspen or do hand calculation. 

 

If you don't have the softwares or do not want to do the hand calculation, then delegate this work of Thermal Design to the vendor. I am suggesting this because you cannot blindly rely on an unapproved, unvalidated excel sheet  

[Jaldhipatel]

Thank you i am trying using HTRI but i want to do hands on calculation also so if there any simple excelsheet which i can follow for that then it will help me.

Edited by Jaldhipatel, 19 June 2020 - 08:39 AM.

[breizh]

Hi,

 To get a proper answer you should supply more information about your application !

 You may use this calculator to support your work or any text book related to heat transfer ( Kern is a good one )

 http://www.engineeri...ng/thermal.html

 

Good luck

Breizh 

[Jaldhipatel]

So i'm working of Shell and tube vaporizer design calculation and i want basic excel sheet for shell and tube heat exchanger design which makes my task easy and consuming low time as i have to submit it as early as possible.
I just want some simple format of excelsheet to design shell and tube heat exchanger. I'm already aware with designing of s&t HEx but i want to do it with help of excel as i want to submit it.

[gegio1960]

I would suggest you to prepare an excel draft with your starting data/ideas and to submit us for comments, improvements, clarifications...

maybe we understand better... and you could learn something.

good luck!

[breizh]

Hi ,

As gegio was pointing out , we are here to support your work . Don't expect us to perform your task . Let us know your difficulties and for sure someone will review your work .

A bunch of literature are attached underneath . Another resource could be the search engine in this forum .

 

Engineering is always hard work .

Good luck

Breizh 

Edited by breizh, 20 June 2020 - 09:02 PM.

[Chemitofreak]

Thank you i am trying using HTRI but i want to do hands on calculation also so if there any simple excelsheet which i can follow for that then it will help me.

 

If you have HTRI then why do the hand calculations unless you are a fresher. The way you can alter the dimensions and get results in HTRI would be difficult by hand calculation.

 

Also, you need to check for the vibration analysis, that would be easier in HTRI. 

[Jaldhipatel]

Yes, I'm fresher and i'm not expert in HTRI i just started using it.

[Jaldhipatel]

Is there any documents which help me out to use HTRI for shell and tube HEx design ? If that are available to anyone please provide it so i will help me.

[breizh]

Hi,

Did you check for HTRI manual ? 

Another option , let you use your favorite search engine and key in : "HTRI tutorial " , you should find links and videos about HTRI .

 

https://www.google.c...chrome&ie=UTF-8

Good luck

Breizh 

Edited by breizh, 20 June 2020 - 06:36 PM.

[Chemitofreak]

Also, you can go through the TEMA Standard for heat exchangers. You will get all sorts of guidelines over there

[IGC]

Look up vendor datasheets for LNG Shell and Tube vaporisers to give you an indication of what sort of duty / size would be required. 

 

What is your heat source?  Water? Seawater? Steam? Mixed refrigerant? BOG?

 

Cryogenic shell and tubes have various unique conditions that need to be considered, e.g. ice growth, expansion/contraction etc.

 

To be blunt, if you want it to be easy and not time consuming, you need to know what you are doing on it.  

[Jaldhipatel]

Hi..anyone help me with what no of shell in parallel indicated in HTRI ? What it means ? It means my shell side fluid can be use up to that nos ? And how can i reduce that no in S&T designing using HTRI.

THANKS IN ADVANCE

[IGC]

It means you have that number of units operating in parallel - the total flow entered is divided equally between each unit.  

 

If you want to reduce the number of units in operation, you will probably need to make the exchangers larger.  it would depend on the impact that results from the increase of flowrate to each unit, the amount of surface area overdesign you had previously, etc.

[Jaldhipatel]

Hello, i have completed STV design using HTRI but i am facing one problem with it which i can't resolve till. If anyone help me, it will be great.

I got (0.95) vapor fraction in outlet not 1 so what's problem behind this anyone have idea. I done many trial and error to resolve it but it couldn't.

[IGC]

It's not completed then.
 

What are your process details?
What does your current design look like?

Is it below or above the critical pressure for the mixture?

Have you specified tube inserts?

 

https://www.htri.net...-critical-point

https://www.htri.net/stg-15

 

They will help you as well.

[Jaldhipatel]

Process details are as below :
Hot fluid cold fluid
In 90 C In -156 C
Out 12 C out 0 C
Op.pre 2.5 barg 90 barg

I got around 650 tubes with around 10 m lenth and 19.05 mm dia and 18.9 MW heat duty.

[Jaldhipatel]

No vibration or critical velocity violation.

[IGC]

18.9 MW - so around 100 tn/hr of LNG based on your inlet / outlet temps.

 

At this size, I would assume it is a straight pass BEM style unit. 

 

What is the shell ID?

What baffle type?

Shellside skin temperatures?

[Jaldhipatel]

There is another problem my horizontal orientation goes well but vertical orientation shows underdesign upto -25 % so what's the problem there anyone suggest ? Here i give some data if anyone can help me.

Hot fluid (GW 36% w/w)
In 90 C
Out 12 C
Flow 54.91 kg/s

Cold fluid (LNG)

In -156 C
Out 0 C
Flow 24.76 kg/s
Heat duty 16.5 MW