Hello everone,
I just developed a new primary-secondary chilled water system to provided the chilled water for multiple ZoneHVAC:FourPipeFanCoil
that are served as Zone Equipments
in thermal zones. I set all input parameters for the objects ofChiller:Electric EIR
, Pump:Constant Speed
,Pump:Variable Speed
and ZoneHVAC:FourPipeFanCoil
as autosized and ran the simulation. Based on the simulation results, i got some question to ask you guys. By the way, i also attche my osm file here for you to download for checking my problems:
Qustion 1: I opened the eplusout.sql
file to check the the sizing data of the Coil:Cooling:water
through the ComponentSizes table. I was confused that why the "Design Size Design Inlet Water Temperature" was 82oC. I tried to manually set the design inlet water temperature as 6oC, but the autosizing still used the value of 82oC. I have checked my osm file settings and did not find a reason.Here is a snapshot of component sizing results fom the database:
Question2: i am using multipleZoneHVAC:FourPipeFanCoil
to serve a single zone. but i did not find any object in openstudio to let me set the load distribution over the multiple ZoneHVAC:FourPipeFanCoil
objects. That is i have no idea about how the load is distributed over the several Coil:Cooling:water
objects for capacity sizing.
Question3: I am setting up the Common Pipe Simulation, but there are two options to let me choose: "CommonPipe" and "TwoWayCommonPipe". From the Energyplus documents i learned that the TwoWayCommonPipe soption can let me make adjustment on the temperature and flow compared to commonpipe setting, but i am still confused about the difference between these two options.
Question4: what is the purpose of using a bypass for the primary water loop? i noticed the flow rate through the bypass always remained zero and i thought the bypass was only used when the chiller was sheduled off so that the water from the pump can go though it. I am noy sure my understanding is right is not?