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Re: [EnergyPlus_Support] Re: sim. crashing, an all-glass building?





You might set your timesteps to 60 and widen your convergence limits to the max values in the building object and HVAC convergence object. (then lower them incrementally until your reaching convergence without error in as tight of range as possible) 


Jeremiah D. Crossett  | Senior Analyst  |  Phase Change Energy Solutions
120 E. Pritchard St.  | Asheboro, NC 27203  | Mobile 503-688-8951
www.phasechange.com 
  





On Wed, Apr 3, 2013 at 12:31 PM, ntraughpee <matthew.sverre.anderson@xxxxxxxxx> wrote:
 

As in under Simulation Parameters:Timestep what is the # of Timesteps per Hour? If your model isn't converging, iirc, the most likely reason is that the number of timesteps is not high enough.


--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "ntraughpee" <matthew.sverre.anderson@...> wrote:
>
> How many iterations/hour are you using?
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "thexenyth" <nick.novelli@> wrote:
> >
> > Hello all,
> >
> > long time listener, first time caller. My model consistently crashes when I run it, during June of the simulation. It used to crash in April, until I upped the warm-up days from 40 to 100. Errors that I get back are largely of the "oscillating across iterations" and "solutions not converging" varieties. There are two other consistent warnings: my heating coil load in my AHU is nil (even if I manually set the winterdesignday temperature very low) and the "Integrated Part Load Value" for my chillers cannot be calculated.
> >
> > I'm modeling a building that's fully double-skin curtain walled, with 1-meter cavities on all four sides, as well as the roof. There are six zones: north, south, east, west cavities, roof, and central occupied space. Using an HVACTemplate VAV, I've linked two of the zones to serve as input and output plenums for the roof zone. Interior walls are modeled as walls with large windows set into them.
> >
> > I've attached a cut-down section of the error output, for your perusal. Any suggestions on how to fix the crashing would be greatly appreciated! I'm learning a lot by working through the file objects, but so far, I haven't learned how to make it work;)
> >
> > Thanks,
> > Nick.
> >
> >
> > !||||||||||||||| *.err file: |||||||||||||||||||||||||||||||||||
> > Program Version,EnergyPlus-Windows-OMP-64 7.2.0.006, YMD=2013.04.03 13:46,IDD_Version 7.2.0.006
> > ************* Beginning Zone Sizing Calculations
> >
> > ...
> > ************* Beginning System Sizing Calculations
> > ************* Beginning Plant Sizing Calculations
> > ** Warning ** The design coil load is zero for Coil:Heating:Water AHU-1 HEATING COIL
> > ** ~~~ ** The autosize value for maximum water flow rate is zero
> > ** ~~~ ** To change this, input a value for UA, change the heating design day, or lower
> > ** ~~~ ** the system heating design supply air temperature
> > ** Warning ** The design coil load is zero for Coil:Heating:Water AHU-1 HEATING COIL
> > ** ~~~ ** The autosize value for maximum water flow rate is zero
> > ** ~~~ ** To change this, input a value for UA, change the heating design day, or lower
> > ** ~~~ ** the system heating design supply air temperature
> > ** Warning ** Chiller:Electric:EIR = CHILLER1: Integrated Part Load Value (IPLV) cannot be calculated.
> > ** ~~~ ** Check limits in Cooling Capacity Function of Temperature Curve , Curve Type = BIQUADRATIC, Curve Name = CHILLER1 CENTCAPFT
> > ** ~~~ ** Check limits in EIR Function of Temperature Curve, Curve Type = BIQUADRATIC, Curve Name = CHILLER1 CENTEIRFT
> > ...
> > ************* Testing Individual Branch Integrity
> > ************* All Branches passed integrity testing
> > ************* Testing Individual Supply Air Path Integrity
> > ************* All Supply Air Paths passed integrity testing
> > ************* Testing Individual Return Air Path Integrity
> > ************* All Return Air Paths passed integrity testing
> > ************* No node connection errors were found.
> > ************* Beginning Simulation
> > ** Warning ** SimHVAC: Maximum iterations (20) exceeded for all HVAC loops, at RUN PERIOD 1, 02/02 08:00 - 08:02
> > ** ~~~ ** The solution for one or more of the Air Loop HVAC systems did not appear to converge
> > ** ~~~ ** Air System Named = AHU-1 did not converge for mass flow rate
> > ** ~~~ ** Check values should be zero. Most Recent values listed first.
> > ** ~~~ ** Demand-to-Supply interface mass flow rate check value iteration history trace: 1.378248,0.295621,0.313831,0.333092,0.435704,1.378248,0.295621,0.313831,0.333092,0.435704,
> > ** ~~~ ** Supply-to-demand interface deck 1 mass flow rate check value iteration history trace: 0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,
> > ** ~~~ ** Air System Named = AHU-1 did not converge for temperature
> > ** ~~~ ** Check values should be zero. Most Recent values listed first.
> > ** ~~~ ** Demand-to-Supply interface temperature check value iteration history trace: 0.687609,2.743596E-002,3.274918E-002,0.121517,0.505907,0.687609,2.743596E-002,3.274918E-002,0.121517,0.505907,
> > ** ~~~ ** Supply-to-demand interface deck 1 temperature check value iteration history trace: 1.387004E-002,1.232698E-002,1.014035E-002,8.258505E-003,4.459587E-002,1.387004E-002,1.232698E-002,1.014035E-002,8.258505E-003,4.459587E-002,
> > ** ~~~ ** Air System Named = AHU-1 did not converge for energy
> > ** ~~~ ** Check values should be zero. Most Recent values listed first.
> > ** ~~~ ** Demand-to-Supply interface energy check value iteration history trace: 28638.101490,5671.270472,6020.707037,6767.800973,10178.323008,28638.101490,5671.270472,6020.707037,6767.800973,10178.323008,
> > ** ~~~ ** Supply-to-demand interface deck 1 energy check value iteration history trace: 77.112488,64.871886,50.166730,38.092643,-186.175304,77.112488,64.871886,50.166730,38.092643,-186.175304,
> > ** ~~~ ** Node named OCCUPIEDSPACE SUPPLY INLET shows oscillating humidity ratio across iterations with a repeated value of 7.842410E-003
> > ** ~~~ ** Node named OCCUPIEDSPACE SUPPLY INLET humidity ratio [kg-water/kg-dryair] iteration history trace (most recent first): 7.842410E-003,7.838653E-003,7.833785E-003,7.829630E-003,7.830275E-003,7.842410E-003,7.838653E-003,7.833785E-003,7.829630E-003,7.830275E-003,
> > ** ~~~ ** Node named OCCUPIEDSPACE SUPPLY INLET shows oscillating mass flow rate across iterations with a repeated value of 2.455383
> > ** ~~~ ** Node named OCCUPIEDSPACE SUPPLY INLET mass flow rate [kg/s] iteration history trace (most recent first): 2.455383,3.897430,3.664108,3.416400,3.092268,2.455383,3.897430,3.664108,3.416400,3.092268,
> > ** ~~~ ** Node named OCCUPIEDSPACE SUPPLY INLET shows oscillating temperatures across iterations with a repeated value of 38.090185
> > ** ~~~ ** Node named OCCUPIEDSPACE SUPPLY INLET temperature [C] iteration history trace (most recent first): 38.090185,32.246480,32.222890,32.231488,32.214365,38.090185,32.246480,32.222890,32.231488,32.214365,
> > ** ~~~ ** Node named ROOFZONE SUPPLY INLET shows oscillating mass flow rate across iterations with a repeated value of 1.098514
> > ...
> > ** Warning ** SimHVAC: Maximum iterations (20) exceeded for all HVAC loops, at RUN PERIOD 1, 02/02 08:02 - 08:04
> > ** ~~~ ** The solution for one or more of the Air Loop HVAC systems did not appear to converge
> > ** ~~~ ** Air System Named = AHU-1 did not converge for mass flow rate
> > ** ~~~ ** Check values should be zero. Most Recent values listed first.
> > ** ~~~ ** Demand-to-Supply interface mass flow rate check value iteration history trace: 0.288483,0.306785,0.326184,0.428685,1.385090,0.286261,0.304430,0.323688,0.414083,1.568408,
> > ** ~~~ ** Supply-to-demand interface deck 1 mass flow rate check value iteration history trace: 0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,
> > ** ~~~ ** Air System Named = AHU-1 did not converge for temperature
> > ** ~~~ ** Check values should be zero. Most Recent values listed first.
> > ** ~~~ ** Demand-to-Supply interface temperature check value iteration history trace: 2.810574E-002,3.352814E-002,0.122844,0.512347,0.700030,2.751587E-002,3.276961E-002,0.109217,0.585956,0.771552,
> > ** ~~~ ** Supply-to-demand interface deck 1 temperature check value iteration history trace: 1.192168E-002,9.854747E-003,8.069472E-003,4.497397E-002,1.351934E-002,1.213345E-002,1.015172E-002,8.459500E-003,5.707929E-002,1.457109E-002,
> > ** ~~~ ** Air System Named = AHU-1 did not converge for energy
> > ** ~~~ ** Check values should be zero. Most Recent values listed first.
> > ** ~~~ ** Demand-to-Supply interface energy check value iteration history trace: 5561.680025,5914.619703,6667.671797,10105.986077,28923.808853,5518.849520,5869.195968,6564.285265,10182.948114,32732.919683,
> > ** ~~~ ** Supply-to-demand interface deck 1 energy check value iteration history trace: 62.507886,48.632584,37.177477,-187.829889,75.278576,64.071479,50.501386,39.331644,-241.634725,84.648170,
> > ** ~~~ ** Node named REARWALLCAVITY SUPPLY INLET shows oscillating mass flow rate across iterations with a repeated value of 0.202951
> > ** ~~~ ** Node named REARWALLCAVITY SUPPLY INLET mass flow rate [kg/s] iteration history trace (most recent first): 0.202951,0.202951,0.202951,0.202951,0.202951,0.202951,0.202951,0.216926,0.207935,0.206625,
> > ** Warning ** SimHVAC: Maximum iterations (20) exceeded for all HVAC loops, at RUN PERIOD 1, 02/02 08:04 - 08:06
> > ** ~~~ ** The solution for one or more of the Air Loop HVAC systems did not appear to converge
> > ** ~~~ ** Air System Named = AHU-1 did not converge for mass flow rate
> > ** ~~~ ** Check values should be zero. Most Recent values listed first.
> > ** ~~~ ** Demand-to-Supply interface mass flow rate check value iteration history trace: 0.273276,0.285308,0.303460,0.322706,0.411927,1.596677,0.273276,0.285308,0.303460,0.322706,
> > ** ~~~ ** Supply-to-demand interface deck 1 mass flow rate check value iteration history trace: 0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,0.000000,
> > ** ~~~ ** Air System Named = AHU-1 did not converge for temperature
> > ** ~~~ ** Check values should be zero. Most Recent values listed first.
> > ** ~~~ ** Demand-to-Supply interface temperature check value iteration history trace: 1.771386E-002,2.833045E-002,3.372917E-002,0.110092,0.605865,0.795730,1.771386E-002,2.833045E-002,3.372917E-002,0.110092,
> > ** ~~~ ** Supply-to-demand interface deck 1 temperature check value iteration history trace: 1.349728E-002,1.212849E-002,1.016772E-002,8.509408E-003,5.901931E-002,1.471642E-002,1.349728E-002,1.212849E-002,1.016772E-002,8.509408E-003,
> > ** ~~~ ** Air System Named = AHU-1 did not converge for energy
> > ** ~~~ ** Check values should be zero. Most Recent values listed first.
> > ** ~~~ ** Demand-to-Supply interface energy check value iteration history trace: 5276.603056,5550.515243,5903.749439,6601.117908,10296.044697,33628.030343,5276.603056,5550.515243,5903.749439,6601.117908,
> > ...
> >
>




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