Hi everyone,
I tried to be brave and take on the task of vetting DOE 2.3 - It has come with a few headaches. I thought I was getting the hang of it until eQUEST started throwing errors at me. Being less familiar with the DOE 2.3, I'm not finding success trouble shooting the issue either. I have attached the file for everyone's reference.
I tried rebuilding the model from scratch in case the file got corrupted somehow - no luck. That effort pointed me to the CHW loop/equipment, but nothing jumps out at me when I review the inputs. The water-side model tries to take advantage of an 'UPSTREAM' water-side economizer in series with two chiller which operate in parallel. DOE 2.3 is supposed to explicitly model this scenario if I'm correct.
The air-side systems include VAVs w/ reheat for the office spaces, 2-pipe fan coils for the communication rooms, and water cooled CRAC units with humidification for the Labs/Data Center - server by an MAU. The equipment loads for these spaces are considerably higher than what one might see in a typical office building.
I'm curious to see if we can figure out the error as a group. Additionally, I'm always open to learning from my mistakes, so if you see anything unusual in the model that might not be directly related to the issue at hand, I'm open to the criticism.
Thanks in advance!
[ARCH | NEXUS]
DAVID W. GRIFFIN II
BEMP
ENERGY ANALYST
2505 E Parleys Way
Salt Lake City, UT 84109
Office 801.924.5028
archnexus.com
[Twitter]
I don't have a lot of answers, but took a shallow dive that may be a little insightful:
I thought to look first at your chillers in the INP and something caught my eye by omission:
[cid:image001.png at 01D2304A.4C616490]
With the new, optional, series/parallel arrangement inputs I think we should be seeing something here along those lines for inputs. Looks like if you don't add anything the default through the interface is to assume everything on the loop is in a parallel configuration.
Look for the large-ish article occurring here in the doe2.3 reference manual (help files) to see what I'm not seeing, if that isn't totally clear:
Volume 2: Dictionary > HVAC Components > CIRCULATION-LOOP > Series vs. Parallel Equipment > Series/Parallel Configuration
I haven't tackled a series + parallel setup yet, but it seems at least implicit that you would need an equip-ctrl defined to land on that particular arrangement. Also looks like you're missing the "mandatory" DOWNSTREAM-SPLIT input at the loop for parallel/series configuration (as worded by the doe23 reference article).
It wouldn't surprise me, btw, to learn the waterside economizer chiller is a special case to consider with series/parallel inputs... WSE chillers have always been a headache in my experience so I have a procedure to "roll my own" (it's been alluded to/posted here a few times).
Anecdotally: On my machine after trying to open & simulate with build v7173 & in doe2.3 mode, my simulation seemed to completely hang up and eQUEST was non-responsive here:
[cid:image002.png at 01D2304A.4C616490]
... but then it completed with errors. On trying to open the SIM via eQUEST I get this:
[cid:image005.png at 01D2304D.11A0C690]
And... haha... you set a new record for the biggest SIM I've ever seen... notepad++ tells me it's too large to even peek inside:
[cid:image006.png at 01D2304D.11A0C690]
All this leads me to consider: it's possible there's something specific to eQUEST getting hung up - you may after reviewing your series/parallel inputs want to try simulating this with doe2.3 command line?
Hope that offers a few new perspectives!
~Nick
[cid:image003.png at 01D2304A.4C616490]
Nick Caton, P.E., BEMP
Senior Energy Engineer
Energy and Sustainability Services
Schneider Electric
D 913.564.6361
M 785.410.3317
E nicholas.caton at schneider-electric.com
F 913.564.6380
15200 Santa Fe Trail Drive
Suite 204
Lenexa, KS 66219
United States
[cid:image001.png at 01D189AB.58634A10]
Nick,
As always, thank you for the time you put into reviewing and responding to the forum questions/comments.
Apparently, there are some convergence issues within the model which the SIM file documents - hence the large size. Do I get some sort of plaque or medal for the largest SIM file record?
At the end of the SIM file (which I was able to open with some effort), the last error basically read like this - 'Whatever is happening is very unusual. Please send the file to the software development team,' so I sent the file to Mr. Hirsch. Jeff. His response came quickly, but without a definite answer - see below. I'm glad and thankful those horrible rumors of eQUEST not be supported or developed anymore are totally false.
We are looking into it. It seems to getting an error very early on in some cooling coil calculation during the initialization phase for the design day sizing calculations but rather than aborting with an error continuing on into the simulation and producing gigabytes of convergence errors (when it should have not continued). But this is preliminary and we are trying to see what it is in detail so as to get a workaround.
DOE-2.3 does an iterative design/sizing calculation stepping through all the components in a simulation mode with unspecified sizing to establish the required size for each component. This is very different from 2.2 that does a one pass simplified static sizing calculation. In the model there is an error occurring in a cooling coil model call we are trying to isolate.
Attached is the beginning of the .sim with the cautions (I added design days for heating and cooling, removed the "dummy zone and system - not sure what it was for, and stopped the simulation just after it was starting the initialization of the sizing calculations.
Here are the design routine warnings coming out before it goes on to try to perform the simulation and gets trapped into unending convergence problems that we need to trace down and fix.
**CAUTION**********************************************************************
Cooling Coil: Dummy Zone has a SENS-HEAT-RATIO
of 0.975, a RATED-EDB and EWB of 80.0 67.0F, and a rated
FLOW/CAPACITY of 252.1 cfm/ton. The SHR is too high, and
results in an outlet temperature of 53.30F; this is too
close to, or below, the apparatus dewpoint of 53.03F. The
coil bypass factor will be set to 0.01 and the SHR
decreased to 0.621
**CAUTION**********************************************************************
Cooling Coil: (CRAC) (1) has a SENS-HEAT-RATIO
of 0.932, a RATED-EDB and EWB of 75.0 61.0F, and a rated
FLOW/CAPACITY of 453.0 cfm/ton. The SHR is too high, and
results in an outlet temperature of 52.78F; this is too
close to, or below, the apparatus dewpoint of 52.55F. The
coil bypass factor will be set to 0.01 and the SHR
decreased to 0.923
**CAUTION**********************************************************************
Cooling Coil: (CRAC) (2) has a SENS-HEAT-RATIO
of 0.932, a RATED-EDB and EWB of 75.0 61.0F, and a rated
FLOW/CAPACITY of 453.0 cfm/ton. The SHR is too high, and
results in an outlet temperature of 52.78F; this is too
close to, or below, the apparatus dewpoint of 52.55F. The
coil bypass factor will be set to 0.01 and the SHR
decreased to 0.923
**CAUTION**********************************************************************
Cooling Coil: (CRAC) (3) has a SENS-HEAT-RATIO
of 0.932, a RATED-EDB and EWB of 75.0 61.0F, and a rated
FLOW/CAPACITY of 453.0 cfm/ton. The SHR is too high, and
results in an outlet temperature of 52.78F; this is too
close to, or below, the apparatus dewpoint of 52.55F. The
coil bypass factor will be set to 0.01 and the SHR
decreased to 0.923
**CAUTION**********************************************************************
Cooling Coil: (CRAC) (4) has a SENS-HEAT-RATIO
of 0.932, a RATED-EDB and EWB of 75.0 61.0F, and a rated
FLOW/CAPACITY of 453.0 cfm/ton. The SHR is too high, and
results in an outlet temperature of 52.78F; this is too
close to, or below, the apparatus dewpoint of 52.55F. The
coil bypass factor will be set to 0.01 and the SHR
decreased to 0.923
**CAUTION**********************************************************************
Cooling Coil: (CRAC) (5) has a SENS-HEAT-RATIO
of 0.932, a RATED-EDB and EWB of 75.0 61.0F, and a rated
FLOW/CAPACITY of 453.0 cfm/ton. The SHR is too high, and
results in an outlet temperature of 52.78F; this is too
close to, or below, the apparatus dewpoint of 52.55F. The
coil bypass factor will be set to 0.01 and the SHR
decreased to 0.923
**CAUTION**********************************************************************
Cooling Coil: (CRAC) (6) has a SENS-HEAT-RATIO
of 0.932, a RATED-EDB and EWB of 75.0 61.0F, and a rated
FLOW/CAPACITY of 453.0 cfm/ton. The SHR is too high, and
results in an outlet temperature of 52.78F; this is too
close to, or below, the apparatus dewpoint of 52.55F. The
coil bypass factor will be set to 0.01 and the SHR
decreased to 0.923
**CAUTION**********************************************************************
Cooling Coil: (CRAC) (7) has a SENS-HEAT-RATIO
of 0.932, a RATED-EDB and EWB of 75.0 61.0F, and a rated
FLOW/CAPACITY of 453.0 cfm/ton. The SHR is too high, and
results in an outlet temperature of 52.78F; this is too
close to, or below, the apparatus dewpoint of 52.55F. The
coil bypass factor will be set to 0.01 and the SHR
decreased to 0.923
**CAUTION**********************************************************************
Cooling Coil: (CRAC) (8) has a SENS-HEAT-RATIO
of 0.932, a RATED-EDB and EWB of 75.0 61.0F, and a rated
FLOW/CAPACITY of 453.0 cfm/ton. The SHR is too high, and
results in an outlet temperature of 52.78F; this is too
close to, or below, the apparatus dewpoint of 52.55F. The
coil bypass factor will be set to 0.01 and the SHR
decreased to 0.923
**WARNING**********************************************************************
Air Handler: EL1 Sys1 (VAV) (G.N1) has a supply flow,
either user-specified or set by FLOW/CAPACITY limits, that
is less than the sum of the minimum specified zone flow,
MIN-FLOW/AREA. Zone flows will be reduced below the minimum
See report SV-A.
**CAUTION**********************************************************************
Zone: EL1 Core Zn (G.C5) has a user-specified
minimum airflow ratio less than required by the peak
exhaust flow. The minimum will be reset to: 1.000. To
control to either the minimum flow, or the hourly exhaust
flow, whichever is greater, use AIRFLOW-TRACKING = EXHAUST.
**CAUTION**********************************************************************
Zone: EL1 Core Zn (G.C19) has a user-specified
minimum airflow ratio less than required by the peak
exhaust flow. The minimum will be reset to: 1.000. To
control to either the minimum flow, or the hourly exhaust
flow, whichever is greater, use AIRFLOW-TRACKING = EXHAUST.
**WARNING**********************************************************************
Air Handler: EL2 Sys1 (VAV) (G.N1) has a supply flow,
either user-specified or set by FLOW/CAPACITY limits, that
is less than the sum of the minimum specified zone flow,
MIN-FLOW/AREA. Zone flows will be reduced below the minimum
See report SV-A.
**CAUTION**********************************************************************
Zone: Dummy Zone has a design heating
temperature differential of only -0.0F. The result
may be an unusually large design airflow. Supply/Zone T: 74.0 73.9
**CAUTION**********************************************************************
Zone: EL1 Mechanical/Electrical T has a user-specified
minimum airflow ratio less than required by the peak
exhaust flow. The minimum will be reset to: 0.279. To
control to either the minimum flow, or the hourly exhaust
flow, whichever is greater, use AIRFLOW-TRACKING = EXHAUST.
There are a lot a lot of cautions related to plenum return with no plenum next to the zones with that return specified:
**CAUTION**********************************************************************
System: EL2 Sys1 (VAV) (G.N1) has return plenums defined,
but Zone: EL2 North Perim Zn (G.N1) is not attached to a plenum,
and no plenum shares an interior wall with the zone. The
zone will return its airflow via the first plenum found,
EL3 WNW Perim ML PlZn (ML.WNW2)
I'll try and post the solution once we find out what is going on, so everyone will be able to apply an temporary workarounds necessary to model systems similar to the one in this model.
Sincerely,
[ARCH | NEXUS][Facebook][Youtube][LinkedIn]
DAVID W. GRIFFIN II
BEMP
ENERGY ANALYST
2505 E Parleys Way
Salt Lake City, UT 84109
Office 801.924.5028
archnexus.com
[Twitter]