2 replies to this topic

[Marco78]

Dear all,

I have been asked to verify the behaviour of some exchangers (coolers and condensers) since we are going to change the service fluid (from chilled water at 5°C to industrial water at 15°C) for some months (the chillers are out of service). The exchangers are graphite block ones (20 m2 surface).
How can I proceed with the simulation? I have thought that I can use HTRI and a countercurrent S&T exchanger...is there any other software for blk heat exchangers?

[breizh]

Hi ,
Do you really need simulation? Why not trying to get the calculations sheets of existing equipment and redo the calculation ?

Breizh

[Padmakar Katre]

Dear all,

I have been asked to verify the behaviour of some exchangers (coolers and condensers) since we are going to change the service fluid (from chilled water at 5°C to industrial water at 15°C) for some months (the chillers are out of service). The exchangers are graphite block ones (20 m2 surface).
How can I proceed with the simulation? I have thought that I can use HTRI and a countercurrent S&T exchanger...is there any other software for blk heat exchangers?

Dear,
I understand from post that you are assigned to perform rating calculations for the existing heat exchangers for the revised conditions. It is so simple to rate the heat exchangers in a software like HTRI, HTFS but prior to that you need to have the revised parameters like the,
1.Flow,
2.Temperature (terminal i.e. available and expected)
3.Pressure (important in case of the phase change)
4.Heat capacities
5.Thermal conductivity
6.Surface tension in case of the liquids
7.Viscosity

and the most important the heat curves in case of the condensation or vaporization (critical pressure required here).
So you can get these parameters from your simulation and put in either of the above software (HTRI or HTFS).

If you are using Hysys then you have an interface with both HTRI and HTFS; and in case of Pro-II you have an interface with HTRI. The best way is to call the simulation case directly in these softwares in order to avoid the typing data mistakes.


Important: Keep a hard copy of the thermal datasheet of the existing exchanger to give the installed hardware inputs like Shell ID, Tube OD, No of tubes, Fluid side allocations and flow pattern (co-current or the counter current), Baffles if any and the spacing, Tube pitch, TEMA HE configuration, No of tubes, tube length.

I hope now you can start. The above data I have summarized may or may not be sufficient, though I have tried to list most of the parameters.