Hi all,
I am having problem with interpreting results of "Water Heater Source/Use Side Transfer Energy" in my E+ plant loop.
This plant loop is adapted from "SolarCollectorFlatPlateWater", which Low Temperature Radiant Floor heating is added in parallel to DHW demand.
The problem I am having is how to analyze the energy balance of the Storage Tank component connecting Collector Loop and Heating Loop:
1. Tank source side, which is expected to absorb heat, thus yield positive values only. But results show both positive and nagetive heat transfer.
2. Tank use side whish is expected to reject heat, thus yield nagitive values only. But results in winter yield positive value, meaning the tank is absorbing heat from use side (connecting to DHW, heating demands).
I also calculated the heat transfer manually with source/use side flow rate and Inlet/Outlet temperature differences. Use side heat transfer is pretty much the same as the energy plus heat transfer results, however, calculated Source side heat transfer is not entirelly following the energyplus results.
Attached are the description of my plant loop and the results I could not comprehence. It was run in 15 min timesteps.
It will be nice if anyone could explain how energy plus extract those values, at the end of each time step or calculating summations?
Thanks a lot!
Hsieh
Attachment not found: D:\Eudora\Attach\Energyplus_question.pdf