UO: Heat Exchanger LMTD calc error
Simulate chemical processes using advanced thermodynamic models
Brought to you by:
danwbr
Upon closer examination of the NH3+H2O condensation simulation reported here:
https://sourceforge.net/p/dwsim/discussion/844529/thread/c89168de/?page=1
I found that the LMTD calculation seems to be incorrect by an order of magnitude. Note that I am using the 'CalcBothTemp UA' w/ 'CounterCurrent' method. I had supplied it with the exchanger geometry in an attempt a do a 'Shell&Tube Rating' calculation, therefore the values shown in the HeatExchanger table are remnants of that input data.
Ubuntu 12.04.5 64bit
Mono version 4.2.1 (Stable 4.2.1.102/6dd2d0d Thu Nov 12 09:52:44 UTC 2015)
DWSIM_bin_v36_b5859_beta.zip Build [git-9b6a447] (16/01/2016)
Can you attach the simulation file?
This "error" is a consequence of a bug which was corrected in Build 5876.
Hi JMB,
i created a new algorithm which is able to handle even very nasty cases like your example. This sample uses an extremely large heat exchanger surface compared to the small stream flows which created calculation problems.
Gregor
Hello Gregor,
Thank you for finding a fix! I am eager to try it out.
@Daniel: Am I correct in the assumption that Gregor's fix is not in Build 5876, because it is still not working as expected. If it is not in build 5876, would you kindly publish a new build?
Thank you!