Energy Plus LoadProfile:Plant from Schedule:File issues

asked 2018-12-18 15:06:12 -0500

sspielman's avatar

updated 2018-12-20 15:55:27 -0500

I am creating load profiles for a plant model using an 8760 csv file. The load profiles are the only objects on the demand side of the HHW and CHW loops. When I run the model, the loop demand rates do not match the load profile objects I specified. I have exported the Schedule:FIle object, and that seems to be importing ok, although there are no units associated with it. Does it need units? I didn't think so because as the load schedule it should automatically assume it is [W].

I am using a CentralHeatPumpSystem Object and have noticed when the flow-rates through the ChillerHeater:EIR are changed, the loop demands change (#weird).

Using EnergyPlus 9.0.1

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It's hard to tell what's going on without getting more information. Ideally the CSV file + the IDF model would make it easier to troubleshoot, but if you don't want to share this, could you at least give us the snippet of your LoadProfile:Plant object (which is defined by the load profile schedule, but also peak flow rate and flow rate schedule) and a table comparing what your inputs and outputs?

Julien Marrec's avatar Julien Marrec  ( 2018-12-19 02:46:19 -0500 )edit

@JulienMarrec I have placed the IDF and CSV in the link below. I had this model running with a smaller load. As soon as I increase chiller capacity, flow rates, and load profiles, it crashes. I flattened the chiller curves so they should operate at a constant COP throughout the year.

link text

Thanks for you help!

sspielman's avatar sspielman  ( 2018-12-20 16:31:16 -0500 )edit

How close are the profiles to the demand rates your seeing? Your pumps will be heating the loop and loading the plant beyond what the loadProfile is doing, for example. Give your pumps a very small head to eliminate this effect as a way to test.

Also, be sure that the plant loop delta temperature in your model matches the delta used in calculating your flow fractions (eg 11C?). If they don't match the loads won't be represented properly because the plant is not sized for that profile.

Matt Doiron's avatar Matt Doiron  ( 2019-05-15 00:37:41 -0500 )edit