How to control 3 chillder operation scheme for load ratio using ironbug?

grasshopper ironbug
1

This project has 3 same capacity chiller. The operation scheme is: 0-33% total load ,chiller 1 on. 33%-66% total load chiller 1 and 2 on. 66%-100% total load chiler 1\2\3 on. I tried to use IB_PlantEquipmentOperationCoolingLoad for this case, ironbug generated 3 chilled water loop.

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image1916Ă—823 237 KB

Then run Energyplus , here is the error.

Program Version,EnergyPlus, Version 23.1.0-87ed9199d4, YMD=2024.03.09 12:41,
   ** Severe  ** <root>[PlantEquipmentOperation:CoolingLoad][Plant Equipment Operation Cooling Load 1] - Missing required property 'load_range_1_lower_limit'.
   ** Severe  ** <root>[PlantEquipmentOperation:CoolingLoad][Plant Equipment Operation Cooling Load 1] - Missing required property 'load_range_1_upper_limit'.
   **  Fatal  ** Errors occurred on processing input file. Preceding condition(s) cause termination.
   ...Summary of Errors that led to program termination:
   ..... Reference severe error count=2
   ..... Last severe error=<root>[PlantEquipmentOperation:CoolingLoad][Plant Equipment Operation Cooling Load 1] - Missing required property 'load_range_1_upper_limit'.
   ************* Warning:  Node connection errors not checked - most system input has not been read (see previous warning).
   ************* Fatal error -- final processing.  Program exited before simulations began.  See previous error messages.
   ************* EnergyPlus Warmup Error Summary. During Warmup: 0 Warning; 0 Severe Errors.
   ************* EnergyPlus Sizing Error Summary. During Sizing: 0 Warning; 0 Severe Errors.
   ************* EnergyPlus Terminated--Fatal Error Detected. 0 Warning; 2 Severe Errors; Elapsed Time=00hr 00min  0.35sec

I used Ladybug Tools 1.7.26 verison.Please help me for right setting for this case. And is there a way to use EMS program for this operation?

2

Hi @minggangyin

You can set this “LoadDistributionScheme” of your plantloop to “SequentialLoad” and hard-size all your chillers.
Plant load scheme.gh (52.9 KB)

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image1378Ă—630 85.5 KB

This is what I get of each chiller’s electricity use rate to prove that three chillers are running sequentially.

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image951Ă—759 46.1 KB

3 Likes
3

Hi @MingboPeng
It is great. I will try this workflow today. Thanks for your reply

4

Hi Mingbo,

Is it possible to set multiple chilled water pumps, condenser water pumps, and cooling towers as well? In most of my projects, the quantity of pumps and cooling towers are the same as the chillers.