ROM: non-constant soil temperature

[PGorzalka]

What is the problem?

• ROM thermal zone currently only supports constant values for TSoil ("Outdoor surface temperature for floor plate")
• Validation of the model in a case study required using this value equivalent to weather data

How do we want to solve it? Describe the solution you'd like

• Conditional in ZoneBaseRecord that causes a switch between the (default) constant value and a new port for TSoil, which is passed through Multizone
• A time table of soil temperatures can be specified in the main model file

Additional context

This issue is related to a case-specific application of AixLib (ROM) and TEASER which also includes issue #679 in TEASER (others may follow after email consultations)

[LauraMaier]

@PGorzalka: Are you working or intend to work on this issue yourself? Otherwise, we will discuss it on hackday.

[PGorzalka]

@DaJansenGit already received some code from me that I intended to contribute here later this month. If he doesn't object, I think that would cover the issue.

[tobinfiedler]

@DaJansenGit @PGorzalka What is the current status of this issue?

[PGorzalka]

@tobinfiedler @DaJansenGit sorry I didn't come back to this; had other projects I was working on. However, as my PhD exam approaches it would be nice to have the code I wrote as part of the PhD project finally contributed here. That's the code mentioned in May last year. It covers several other topics, but this one could be a good starting point for the contribution. As it requires some extra work from my side (my fork of AixLib is pretty old): How urgently do you need it?

[DaJansenGit]

The long delay here is on me. I still need to give your models a detailed look @PGorzalka. But since the review is also a more comprehensive change, it's still on my list. Maybe we can schedule a meeting in December to discuss the next steps? I will then have a look at the changes beforehand. Hard deadlines usually help at least on my side 😆

[FelixStege]

Any updates on this? @DaJansenGit @PGorzalka

[PGorzalka]

@FelixStege not yet. @DaJansenGit didn't manage to schedule a meeting last year... If you're working on the topic, maybe we could arrange one together? My PhD thesis was delayed by RWTH-internal issues, but hopefully finish with the exam this year. So I still got the motivation mentioned above.

[DaJansenGit]

Discussion results

@PGorzalka and I had a discussion about the changes that makes sense. Following you can find the results.

Required changes

ThermalZone

• Move soilt temperature calculation into a submodel that is placed in ThermalZone
• We provide four options:
  • constant value (default and current state)
  • sinus curve
  • table
  • optional: EPW (energyplus) weather file which provides weekly? ground temperature data in header (these data might be removed from our weather conversion tool)
• Changes due to interzonal heat transfer like the average temperature of soil and neighborhood zones (currently named addNZsAndSoil will be not implemented in this issue

ZoneParams

• This requires additional parameters in zoneParam (not including weather file option)
  • amplitude for sinus curve
  • offset (but this might also be fixed)
  • table file reference

[PGorzalka]

Further notes on discussion results

• EPW files provides ground properties and monthly average ground temperatures in variable depths. A definition can be found here.
• additionally, envisaged contributions include
  • interzonal heat exchange (TEASER and AixLib)
  • custom template paths for Modelica output in TEASER (see issue 679 there)
  • a new possibility to estimate interior wall area

[DaJansenGit]

This was closed due a merge into IPBSA (https://github.com/ibpsa/modelica-ibpsa/pull/1790)

[DaJansenGit]

We will keep this open until the next IBPSA merge is done.