[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff





"you say radiators in this building have manual valve setting , a valve that opens or closes to control the hot water flow , but you said The zone thermostat will be use to simulate the manual valve setting. could you please desribe it more please?"

 

The capacity of the radiator is not known.  The heat sources are not specific, as it can be from the pipes or from the walls, etc.  Use the thermostat to control the room temperature as the measured temperature would give you the heat required as in the building model.  The heat is calculated from the flow rate and the temperture difference at the boiler.  It does not know the size of the radiator or the pipes.

 

If you turn the manual valve on the radiator, the room temperature would change.  The schedule of the setpoint for the room can then be adjusted to match the measured value.  The simulation will give you the heat supplied at the new radiator valve setting.

 

If you set the thermostat setpoint very low, it would turn off the radiator in simulation.

 

 

See my reply below for other points:

 Dr. Li  

 


To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: t.t111ir@xxxxxxxxx
Date: Sat, 4 Feb 2012 07:57:55 +0000
Subject: Re: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

 
Dear Dr.Li ,
 
ZoneControl:Thermostat,
    Block1:ROOME Thermostat, !- Name
    Block1:RoomE,            !- Zone or ZoneList Name
    Zone Control Type Sched1,!- Control Type Schedule Name
    ThermostatSetpoint:SingleHeating,  !- Control 1 Object Type
    THERMOSTAT1HALLE;        !- Control 1 Name
ZoneControl:Thermostat,
    Block2:HALLE Thermostat, !- Name
    Block2:HallE,            !- Zone or ZoneList Name
    Zone Control Type Sched1,!- Control Type Schedule Name
    ThermostatSetpoint:SingleHeating,  !- Control 1 Object Type
    THERMOSTAT2HALLE;        !- Control 1 Name
 
ThermostatSetpoint:SingleHeating,
    THERMOSTAT1HALLE,        !- Name
    Htg-SetP-Sch1HALLE;      !- Setpoint Temperature Schedule Name
 
ThermostatSetpoint:SingleHeating,
    THERMOSTAT2HALLE,        !- Name
    Htg-SetP-Sch2HALLE;      !- Setpoint Temperature Schedule Name
 
Dear Dr.Li , in zone control thermostat i use different  setpoint temperature schedule  for each zone .
Pick a cold day that you measured the room temperature and set these schedule temperature to match in each room.  In the simulation, the radiators will be controlled to provide you wit the heating load.
 
 --------------------------------CLASS: ZONEHVAC:EQUIPMENTCONNECTIONS----------------------------------
ZoneHVAC:EquipmentConnections,
    Block1:HallE,            !- Zone Name
    radiatorBLOCK1HALLE,     !- Zone Conditioning Equipment List Name
    ,                        !- Zone Air Inlet Node or NodeList Name
    ,                        !- Zone Air Exhaust Node or NodeList Name
    inlet air nodeBLOCK1HALLE,  !- Zone Air Node Name
    return air nodeBLOCK1HALLE;  !- Zone Return Air Node Name
and in ZoneHVAC:EquipmentConnections , i detemined zone name so the heater in this zone( radiatorBLOCK1HALLE) use
Htg-SetP-Sch1HALLE  i think heater in each zone linked to the zone thermostat ,    Yes.
 
in iran we first estimate that zone air temperature for winter should be 24C and then we estimate heating requirment , Input the building to IDF and so a sizing simulation with IdealLoadsAirSystm.
 
after estimating heating requirment we choose boiler with reasonable capacity , This is requested in the IDF I returned to you.  The heating comption is listed for every time step.
and then installed boiler ,
at this building we measured zone air temperature during winter , and see air temperature changes between 21-26 , 
If this is the range of temperature with the radiators turned off, your building does not require heating in Winter.  The hot water pipe for the DHW is sufficient to keep the building warm.
 i used the average  measured for each  zone air temperature  as heating setpoint , i dont know it is corect or not ?dont i use the  24C  as heating setpoint ?  You are still in the autosize mode.   The temperature schedule should be set to the desired room temperature.
 
The simulation helps you to determine the building heat demand in Winter on the coldest day (99.6% and cloudy)
 
 
 
 
 
 
You look up the  values in the .EIO file for the actual heat demand, temperature and flowrate used.   Look up the catalogue to match these values.
 
If you wanted to confirm that the equipment would work or wanted to save money by down sizing, you can then fill in the real numbers in all the autosize fields in the EPlus and run the annual simulation.  This is not easy to do, as you may get many warnings.
 
 
 
 
 
 
 
you say for simulating real system i shoul not use autosize ?yes ? so i must put the boiler capacity , flow rate ,...?
 
thank you very much
From: YuanLu Li <yli006@xxxxxxxxxxx>
To: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Sent: Saturday, February 4, 2012 1:39 AM
Subject: RE: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

 
 
 
" The baseboard heater should be linked to the zone thermostat" and " verify that they are controlling the baseboard heater "

When you place a zone equipment into a zone, it is automatically linked to the zone thermostat.  When you use a template or schedule, the same temperature may be set for all the heaters.  One heating setpoint for all the zones. In each zone or zone  equipment there is a feild for schedule name for temperature setpoint.  By adding a prefix to this type of schedule, then each zone will use its own schedule.
 
In a real system, there is heat loss in the pipes, etc.  Depending on how the pipes are installe, the resistance to water flow is also different.   These can be simulated in EPlus, by providing more details, and not to use autosize.
 
It is not simple to accurately to simulate a real system.  Right now, the simulation is using the heating requirement and converting it to the water flow rate and temperature between the inlet and outlet of the radiator, which is also the water tank temperature.  The tank is maintained at a fixed temperature, with large heating source capacity.
 
Real simulation should not use autosizing.
=================
The  (FTFFF) can be ignored for the time being.  After cleaning up the schedules they may disappear.
 
"i dont have any cooling equipment , but i dont use cooling setpoint i use heating setpoint ( in zonecontrol:thermostat and control type is 1-thermostatsetpoint:singleheating.)"
 
Type4 and type2 are still in the IDF, I think.
=====================
Type4 thermostate, economizer mode,  and zoneventilation:Designflowrate can be scheduled to different flow rate at different outdoor temprature or season.
 
 Dr. Li  

 
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: t.t111ir@xxxxxxxxx
Date: Fri, 3 Feb 2012 19:23:47 +0000
Subject: Re: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

 
Dear Dr.Li ,
 
Thank you from your kindness and replying to my questions
I  Changebuilding ground temperature to 18°C for Tehran , and the warning eror  ".Site:GroundTemperature:BuildingSurface: Some values fall outside the range of 15-25C " disappear .
 
You say,  i can add ventilation in Summer without adding air-conditioners.  Ventilation would remove moisture as well.
yes you r right but i just want to simulate it during winter , and aslo in idf file i put :zoneventilation:Designflowrate .
 
 
You say ,i  have 130 FTFFF warnings.  6 x 24 = 144 timesteps for one day.  I did not check whether you have by-pass branches installed in the plant loop or not.  Without the by-pass branch the flow quantity can goes to zero.  Since you only have zone equipment, it is passed.  The plant should pass as well, if the flow is not zero.
 
yes you r right i didnt have bypass branches intalled in the plant loop , now i put branch by-pass in my idef , but still there is FTFFF warnings.
You do not have any cooling equipment, the the cooling load for all the zones is zero.  The cool setpoint for the zone thermostat may have caused this warning
yes i dont have any cooling equipment , but i dont use cooling setpoint i use heating setpoint ( in zonecontrol:thermostat and control type is 1-thermostatsetpoint:singleheating.)
 
The heating setpoint is the zone thermostat value.  The baseboard heater should be linked to the zone thermostat.  You can provide different setpoint schedule for each zone to verify that they are controlling the baseboard heater.
how i could verify they are controlling the baseboard heater ?
 as you say:.
 
In a real system, the radiator temperature are all different, and the boiler temperature is also not constant.  You may leave the radiator valve rully open and adjust the boiler temperature, so that the occupants have no control of the system temperature.  This is the most practical way.
 ,i leave the radiator valve rully open and adjust the boiler temperature, so that the occupants have no control of the system temperature.
  so i set the avarage of data zone temperature that i measured for whole two month of january and febuary, as heating setpoint .  baseboard dont controll by this temperature ,  , i mean the heat of baseboard cause this temperature .
so why you say  " The baseboard heater should be linked to the zone thermostat" and "  verify that they are controlling the baseboard heater " ?
 
i attached  the picture of this building
thankyou very much

From: YuanLu Li <yli006@xxxxxxxxxxx>
To: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Sent: Friday, February 3, 2012 4:47 AM
Subject: RE: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

 
You have a large building to model.  On the whole the warning on non-convex surfaces may be ignored.
 
The error file and the edited IDF file is attached.  I removed about 300 of your meter variables.