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Modeling a building with heavy electrical component gains [closed]

I need to model a building (31 x 18 x 4 m) with no windows. The building is made of polyurethanic panels that should assure the insulation during hot months. Inside the building I have a very high electric load (50MW) that can dissipate up to 5% of this power as thermal contribution. Obviously this electrical load is not working at full capacity all the time. How can I simulate this kind of load? I have tryed with both "electric equipment" and "other equipment" loads but the simulation stops with this error:

Temperature (high) out of bounds (209.38] for zone="THERMAL ZONE 1", for surface="SURFACE 5" * ~~~ * During Warmup & Sizing, Environment=BIRMINGHAM ANN CLG .4% CONDNS DB=>MWB, at Simulation time=07/21 12:20 - 12:30 * ~~~ * Zone="THERMAL ZONE 1", Diagnostic Details: * ~~~ * ...Internal Heat Gain [4480.287] W/m2 * ~~~ * ...Infiltration/Ventilation [0.000] m3/s * ~~~ * ...Mixing/Cross Mixing [0.000] m3/s * ~~~ * ...Zone is part of HVAC controlled system.

I assumed that the temeprature rises too much also because I have not well defined the materials, infact I have simulated a hot day (15 august) and the temperature inside the building with NO gains in it rises up to 34 °C. This should not happen since the panels are supposed to insulate the building.

I have tryed to turn on ideal loads to have an idea of the size of the HVAC system that have to be installed there.

For the polyurethane panels I have defined a new material with these specifics:

The load schedule is a fractional set to be 0 except for an hour a day, in which I have the maximum thermal dispersion from the electical load.

edit: I have set the radiant fraction to 0 and rerun the simulation that unfortunately stops with the following error:

* Severe * Temperature (high) out of bounds (212.96] for zone="THERMAL ZONE 1", for surface="SURFACE 1" * ~~~ * During Warmup & Sizing, Environment=BIRMINGHAM ANN CLG .4% CONDNS DB=>MWB, at Simulation time=07/21 12:40 - 12:41 * ~~~ * Zone="THERMAL ZONE 1", Diagnostic Details: * ~~~ * ...Internal Heat Gain [448.029] W/m2 * ~~~ * ...Infiltration/Ventilation [0.000] m3/s * ~~~ * ...Mixing/Cross Mixing [0.000] m3/s * ~~~ * ...Zone is part of HVAC controlled system.

* Severe * Temperature (high) out of bounds (221.06] for zone="THERMAL ZONE 1", for surface="SURFACE 5" * ~~~ * During Warmup & Sizing, Environment=BIRMINGHAM ANN CLG .4% CONDNS DB=>MWB, at Simulation time=07/21 12:40 - 12:41

* Severe * Temperature (low) out of bounds [-127.12] for zone="THERMAL ZONE 1", for surface="SURFACE 1" * ~~~ * During Warmup & Sizing, Environment=BIRMINGHAM ANN CLG .4% CONDNS DB=>MWB, at Simulation time=07/21 12:40 - 12:41

* Severe * Temperature (low) out of bounds [-126.17] for zone="THERMAL ZONE 1", for surface="SURFACE 5" * ~~~ * During Warmup & Sizing, Environment=BIRMINGHAM ANN CLG .4% CONDNS DB=>MWB, at Simulation time=07/21 12:40 - 12:41

* Severe * Temperature (high) out of bounds (221.80] for zone="THERMAL ZONE 1", for surface="SURFACE 2 ...

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Closed for the following reason question is not relevant or outdated by FSilenzi close date 2016-06-10 02:39:46.996537

Hmm, the temps look worse. Try setting the fraction lost to 1 and see if that works. 50MW of electric equipment is a lot!

( 2016-04-29 11:22:41 -0500 )edit

They are indeed a lot, but it is a high power electric conversion building that needs to be cooled out, the equipment is 50MW in size and dissipates up to 5% when it is working at full power. Howerver, setting the fraction lost to 1 allows the simulation to run, but it turns out that there is no need for cooling, even if the Zone air temperature reported in result viewer rises up to 40 °C, and the thermostat is set to 30° for cooling.

( 2016-05-02 02:08:51 -0500 )edit

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OutputDiagnostics,ReportDuringWarmup;

OutputVariable,*Surface Inside Face Temperature.detailed;


Then look at the simulation results to see what is happening.

What did you use for "Fraction Radiant" when you tried using the ElectricEquipment object?

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I have used 30% for fraction radiant, when using both other equipment and electrical equipment. What about the space heating during summer even if the walls are supposed to be insulating?

( 2016-04-27 01:58:59 -0500 )edit

Set the radiant fraction to 0 to see if the simulation runs. If it does, raise the fraction gradually while watching inside surface temperatures to see the radiant impact.

( 2016-04-28 10:18:39 -0500 )edit

When I've encountered this error I've been able to fix it by increasing the Fraction Lost. If only 5% the electric equipment load is converted to waste heat, then I would set the fraction lost to 0.95 and the remaining heat fractions to 0, which will result in a convective fraction of 0.05 to the zone.

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Asked: 2016-04-20 05:05:22 -0500

Seen: 775 times

Last updated: Apr 29 '16