Parabolic trough freeze protection

Hello!
I am currently modeling a parabolic trough system with molten salt as field and direct-storage HTF. Depending on salt choice, freeze protection must be used more or less frequently. In SAM this is modeled as an electric parasitic due to heat tracing, leading to the consumption of grid electricity at night. For an actual molten salt plant I would rather expect freeze protection to be run from thermal storage by some means, leading to a significantly better annual electric energy yield. Is there a way to simulate such a freeze protection in SAM or is there a plan to implement this feature at some point, e.g. by offering the choice between different means of freeze protection?
Thanks in advance!

Hello,

I am also facing the same questions, could somebody please give some suggestions.! Thanks:!!

SAM's CSP models in the current version (SAM 2012.5.11) do not model freeze protection using energy from the TES. We plan to add the capability in one of the 2013 versions of SAM.

Best regards,
Paul.

Hello,

I am trying to model the Molten Salt HTF in Parabolic Trough too, and I am trying to use Parametric Simulation to get optimum storage and solar multiple size. My simulation is faced with some errors and it cannot proceed ahead. All it says is Check your inputs. I am not sure how to go ahead with this error. If you can give me some inputs I will be grateful. Thanks.

Troubleshooting simulation errors with a parametric analysis can be tricky because it's hard to identify which of the several simulations is causing the error.

You might start by looking at the end points of your parametric inputs. For example, to see if the simulation fails with small solar multiple values. Try duplicating your case, and in the copy of the case, disable the parametric analysis option, and on the Solar Field page, set the solar multiple to the smallest value you included in the parametric values, and perhaps with the largest storage capacity. If the simulation crashes with those values, then the problem might be that the solar field at that solar multiple value is too small for the system you specified.

Best regards,
Paul.

Hello Paul,

I managed to get the simulation done. It gives me results but also displays an error which reads, "trnsys.dtr: WARNING: The property range for HitecXL has been exceeded more than 50 times. The value provided was 857.5, and the lower and upper limits are 393.0 and 773.0, respectively. (time: 187.0)"

This error is appearing many times in the simulation but it still gives result.

Any idea what it could mean.? (50 MW PT with Hitec XL)

Please share some suggestions.