[esp-r] Contamination modelling reveals multiple issues

[Christian Anker Hviid]

Dear ESP-r community

 

I am puzzled byt the contamination feature. Here are my findings:

 

I have a model of a building where I use a combined air flow network
(AFN) and plant system (PLANT) with a control law that acts on the air
flow network. I introduce a contamination model CONT with CO2. The
contamination model and the building have the same timestep /hour.

 

I have included an examplar file in the results: cellular_contam_bc
which contains AFN and CONT.

 

With timestep averaged output (hourly integration)

AFN + PLANT: Flow looks fine. Flow is controlled by the ctrl law and
shows high value in day and low at night.

AFN + CONT: Flow is wrong with jagged spikes and values beyond reality.
CO2 is also jagged.

AFN + PLANT + CONT: Flow is obviously wrong with jagged spikes. CO2
levels are also jagged spikes.

EXAMPLAR: CO2 is fine if plotted first, flow is oscillating.

 

Output saved at each timestep:

AFN + PLANT : Flow is not correct, shows almost constant value. Not
possible to plot results when a plant model is included here?

AFN + CONT: Flow is correct and CO2 is correct if I plot CO2 before
flow. Plotting flow first spoils the y-axis scale of CO2. Adjusting
scale does not bring CO2 curve back.

AFN + PLANT + CONT: Flow is not correct, almost constant value. CO2
seems ok if I consider the flow results.

EXAMPLAR: CO2 looks fine, Flow looks nice.

 

What am I doing wrong? Contamination works ok fine with AFN, but not
with a combined AFN+PLANT. Why does AFN+CONT only work when I save
output at each timestep? Anybody with experience in contamination
modelling? Thank you for your help.

 

 

Best regards

Christian Anker Hviid

 

Civ. ing., Erhvervsph.d.-studerende

DTU BYG / Alectia A/S

Brovej, bygning 118, lok. 213

2800 Kgs. Lyngby

E-mail: cah at byg.dtu.dk

Tlf. DTU: 45 251 886

Tlf. Alectia: 88 191 365

Mob. (privat): 40 879 749

 

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