3 replies to this topic

[andiez]

Hi,

Hope someone can help me with this.

When it comes to temperature profile, which program (HYSYS and PIPESIM) gives a better results? I have observed that for PIPESIM, regardless of the pipe length, the temperature tends to move quickly towards to the ambient temperature which i have specified compared to HYSYS. Is that a normal phenomena?

I believe PIPESIM gives a better results for pressure drop calcs, but the pressure drop however, is a function of temperature. If PIPESIM gives inaccurate temperature profile, will it not affect the pressure drop too?

Also, since we are entering the equivalent length into the program for pressure drop calculation, the temperature change too will take the longer equivalent length into the calculation instead of the actual length. Is this a correct approach?

Regards,
Andy

[ankur2061]

Hi,

Hope someone can help me with this.

When it comes to temperature profile, which program (HYSYS and PIPESIM) gives a better results? I have observed that for PIPESIM, regardless of the pipe length, the temperature tends to move quickly towards to the ambient temperature which i have specified compared to HYSYS. Is that a normal phenomena?

I believe PIPESIM gives a better results for pressure drop calcs, but the pressure drop however, is a function of temperature. If PIPESIM gives inaccurate temperature profile, will it not affect the pressure drop too?

Also, since we are entering the equivalent length into the program for pressure drop calculation, the temperature change too will take the longer equivalent length into the calculation instead of the actual length. Is this a correct approach?

Regards,
Andy

Andy,

Change in temperature profile is never considered based on equivalent length. It is only based on the straight length or more precisely on the surface area exposed to the temperature gradient. Hence, equivalent length does not play a role in determining the temperature profile.

Hope this make things clear.

Regards,
Ankur.

[djack77494]

Andy,
The temperature profile can be important since it impacts the fluid density, viscosity, and therefore velocities and hydraulic losses along the pipeline. Heat gains/losses depend on the surface area of the piping that is exposed to external conditions. That's approximately a function of the straight length of piping, but is not really a function of the equivalent length. I've used Hysys for modeling a long and complex pipeline network, and all were satisfied with the results. Really, for a long pipeline, the equivalent length tends not to be used since the straight length gets to be quite close to the equivalent length. If that's not true in your case, perhaps you could divide your piping into two segments. Allow heat transfer to occur in the one that represents straight pipe, and consider the second, representing added length due to fittings, etc. to be perfectly insulated.
Hope that helps,
Doug

[andiez]

hi

thanks for the suggestion i could try on that.
Hence, in your experience, does hysys gives much realistic temperature profile than pipesim?

Regards,
Andy