Dear list,
My company NRGsim Inc., and NREL have finished a preliminary version of an enhanced PCM model for Energy Plus. This new version includes the effects of hysteresis when modeling PCM's.
History: As a modeler, working with products such as Phase Change Enegry BioPCM, DuPont Energain, BASF Micronol, and Insolcorp Infinite R; I found that when modeling PCM's in the previous versions of Enegry Plus a key factor was omitted, namely the effects of hysteresis from the fitting of the melting and freezing curves into a single linear temperature enthalpy profile did not produce results that matched manufacturers experiences. After outfitting several occupancy types, construction types and locations with sensors my findings have confirmed manufacturers experiences. In 2012 I began work on finding the problem and solution to the discrepancy. In 2013, I met with NREL to discuss the issue and we determined that the single curve method would drop heat back into the zone as soon as temperatures dropped, while actual PCM products would result in some amount of sub-cooling where the PCM would need to reach a critical temperature to freeze the PCM and release stored heat. I was directed to a student group at Oklahoma state university who had code in FORTRAN/Energy Plus 6.0 that modeled PCM's using two curves. I modified their code to work in Energy Plus 8.1 and attempted a new feature proposal to the Energy Plus team, but fell short on timelines and wound up with a custom version of Energy Plus, but the code was not included in public versions of Energy plus. From 2013 to 2016 I used this custom version on roughly 1,000 buildings and most globally commercially viable PCM products. In 2016, NRGsim Inc. was awarded a small business voucher to work with DOE labs to implement the new code into the Energy Plus program. As of yesterday the beta test release has been published to the NREL github. More info here:Â
https://www.energy.gov/eere/buildings/downloads/energyplus-hysteresis-pcm-model
Please feel free to message me personally (this list does not accept attachments) for a product database of the Infinite R product fromÂ
http://www.insolcorp.com/.Â
Feel free to contact me through the E+ list or directly for support and/pr questions.Â
Kind regardsÂ