2021 04 21_meeting

SOEP Coordination meeting

Date: April 21, 2021, 8:15am-9am Pacific Times

The purpose of this meeting is to coordinate the Modelica integration for SOEP.

Meeting information

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Agenda

Previous action items
Modelon
Stuart: FMI-QSS
Modelica Conference paper
Kyle, Michael: EnergyPlus-Modelica coupling.
Kyle, Michael: EnergyPlus I/O variables.
Michael, Kyle: Support for radiant systems.
Other items

Participants

Kyle Benne

Hakan Lyngsjo

Baptiste Ravache

Hubertus Tummescheit

Michael Wetter

Minutes

Milestones

LBL AOP 9/30 (go/no-go): Release that can couple Modelica-based control to E+. OK to release in early 2021.

(https://github.com/lbl-srg/modelica-buildings/milestone/18)

LBL AOP 3/30: Implemented radiant slab coupling in Spawn.

LBL AOP 3/30: Release Buildings Library with radiant slab coupling.

LBL AOP 6/30 (go/no-go): Posted beta version of Spawn (jointly with NREL, Objexx and Modelon)

Modelon

Optimica license protection: Next week should be Modelon-side implementation of license protection.

OS X and Linux builds. FMI beta3 has a solution for where to place OS X binaries.

FMI Library should work on OS X. LBL to try to compile. OpenModelica seems to use it on OS X.

FMI-QSS

Stuart is working on analysis with Modelon.

Modelica Conference Paper

To be developed with Kyle and Baptiste as co-author.

Finish draft by March 29. Final revisions for last review by April 9. Deadline moved to May 10.

EnergyPlus-Modelica coupling

Binary code freeze by April 2.

Issues are at https://github.com/lbl-srg/modelica-buildings/issues?q=is%3Aissue+is%3Aopen+label%3Aspawn

Clarification on https://github.com/lbl-srg/modelica-buildings/issues/2223#issuecomment-788235569

Next, work on

Spawn FMUs are not yet self contained, https://github.com/lbl-srg/modelica-buildings/issues/2054

[For FY21, Q2] Kyle to fix schedule: https://github.com/lbl-srg/modelica-buildings/issues/2000

(Kyle either fixes it, or proposes new wording for https://lbl-srg.github.io/soep/softwareArchitecture.html#sending-input-to-energyplus)

[For FY21, Q2] Kyle to look into numerical instability (walls may be initialized to wrong temperature). See for example Experimental/EnergyPlus/Examples/VAVReheatRefBldgSmallOffice/FloorOpenLoop. The temperature in the attic should not raise in the first hour. (Pending since Nov. 2019)

Remove warnings issued by EnergyPlus, https://github.com/lbl-srg/modelica-buildings/issues/2220

Support negative start time in EnergyPlus, https://github.com/lbl-srg/modelica-buildings/issues/1938

Surface heat flux validation.

Test 1: Use 2 zones, separated by one surface. Set surface temperatures on both sides, and different room air temperatures. Difference in heat flux at surfaces must be the heat flux that goes through the wall at steady state.

Possible 2nd Test: Set the surface of an outside wall (room-side surface) and check heat conduction to outside. Maybe use steady-state heat conduction.

Tests to be implemented in EnergyPlus CI testing by Kyle.

LBL AOP 9/30 (go/no-go): Release that can couple Modelica-based control to E+. OK to release in early 2021.

Contract:

If there is a thermal zone in Modelica, then there need to be a Zone object in the idf file. Otherwise the simulation stops with an error. EnergyPlus reports a Fatal Error to its error file and to the FMI API call.
If there is an Zone object in the idf file but no thermal zone in Modelica for this EnergyPlus zone, then EnergyPlus simulates the zone using free floating temperature. There is no HVAC system, but may be internal gains. EnergyPlus reports an information message to its error file and to the FMI API call.
All HVAC objects in the idf file will be removed by the Spawn executable before it writes the idf file to the FMU.
For the EnergyPlus envelope, either the CTF transfer function or the finite difference method can be used.
Output variables and EMS actuators need not be present in the idf file.

Radiant systems

Specification at https://lbl-srg.github.io/soep/softwareArchitecture.html#coupling-of-a-zone-surface.

Implementation for both surfaces is at https://github.com/lbl-srg/modelica-buildings/tree/issue2358_spawn_surface_2_sided

Other items

None.

New action items