Enthalpy balance of PFR

[hiren]

Dear Jasper,
The attached flowsheet is simulation of PFR for methanol synthesis from CO,CO2 and H2O. The wall heat transfer coefficient is set to zero and tube heat transfer coefficient have been set to 500 W/m2.K . On running the simulation, it is found that the enthalpyF balance is not zero. Can you explain this? I thinl it should be zero.

[jasper]

Aplogies for the delay - somehow the RSS feed stopped working and I missed your post.

You seem to have cooling / heating tubes enabled.

Annotation 2019-04-08 151958.png (6.47 KiB) Viewed 15985 times

[jasper]

EnthalpyF duty is zero (within tolerance) if you either set the number of tubes to zero or the heat transfer coefficient to the tubes to zero.