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| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| integer | :: | BaseboardNum | ||||
| real(kind=r64), | intent(out) | :: | LoadMet |
Nodes of different colours represent the following:
Solid arrows point from a procedure to one which it calls. Dashed arrows point from an interface to procedures which implement that interface. This could include the module procedures in a generic interface or the implementation in a submodule of an interface in a parent module. Where possible, edges connecting nodes are given different colours to make them easier to distinguish in large graphs.
Nodes of different colours represent the following:
Solid arrows point from a procedure to one which it calls. Dashed arrows point from an interface to procedures which implement that interface. This could include the module procedures in a generic interface or the implementation in a submodule of an interface in a parent module. Where possible, edges connecting nodes are given different colours to make them easier to distinguish in large graphs.
SUBROUTINE CalcSteamBaseboard(BaseboardNum, LoadMet)
! SUBROUTINE INFORMATION:
! AUTHOR Daeho Kang
! DATE WRITTEN September 2009
! MODIFIED Sep 2011 LKL/BG - resimulate only zones needing it for Radiant systems
! RE-ENGINEERED na
! PURPOSE OF THIS SUBROUTINE:
! This subroutine calculates both the convective and radiant heat transfer rate
! of steam baseboard heaters. The heater is assumed to be crossflow with
! both fluids unmixed. The air flow is bouyancy driven and a constant airflow.
! METHODOLOGY EMPLOYED:
! Equations that calculates heating capacity of steam coils and outlet air and water temperatures
! of the zone control steam coil in steam coil module in EnergyPlus are employed.
! REFERENCES:
! USE STATEMENTS:
USE ScheduleManager, ONLY: GetCurrentScheduleValue
USE DataZoneEnergyDemands, ONLY: ZoneSysEnergyDemand, CurDeadbandOrSetback
USE FluidProperties, ONLY: GetSatEnthalpyRefrig, GetSatDensityRefrig, GetSatSpecificHeatRefrig
USE DataInterfaces, ONLY: CalcHeatBalanceOutsideSurf, CalcHeatBalanceInsideSurf
USE DataHVACGlobals, ONLY: SmallLoad
USE DataBranchAirLoopPlant, ONLY : MassFlowTolerance
IMPLICIT NONE
! SUBROUTINE ARGUMENT DEFINITIONS:
INTEGER :: BaseboardNum
REAL(r64), INTENT(OUT) :: LoadMet
! SUBROUTINE PARAMETER DEFINITIONS:
! INTERFACE BLOCK SPECIFICATIONS
! na
! DERIVED TYPE DEFINITIONS
! na
! SUBROUTINE LOCAL VARIABLE DECLARATIONS:
INTEGER :: ZoneNum
REAL(r64) :: RadHeat
REAL(r64) :: SteamBBHeat
REAL(r64) :: SteamInletTemp
REAL(r64) :: SteamOutletTemp
REAL(r64) :: SteamMassFlowRate
REAL(r64) :: SubCoolDeltaT
REAL(r64) :: QZnReq
REAL(r64) :: EnthSteamInDry
REAL(r64) :: EnthSteamOutWet
REAL(r64) :: LatentHeatSteam
REAL(r64) :: Cp
ZoneNum = SteamBaseboard(BaseboardNum)%ZonePtr
QZnReq = ZoneSysEnergyDemand(ZoneNum)%RemainingOutputReqToHeatSP
SteamInletTemp = Node(SteamBaseboard(BaseboardNum)%SteamInletNode)%Temp
SteamOutletTemp = SteamInletTemp
SteamMassFlowRate = Node(SteamBaseboard(BaseboardNum)%SteamInletNode)%MassFlowRate
SubCoolDeltaT = SteamBaseboard(BaseboardNum)%DegOfSubCooling
IF (QZnReq > SmallLoad &
.AND. .NOT. CurDeadbandOrSetback(ZoneNum) &
.AND. SteamMassFlowRate > 0.0d0 &
.AND. GetCurrentScheduleValue(SteamBaseboard(BaseboardNum)%SchedPtr) > 0) THEN
! Unit is on
EnthSteamInDry = GetSatEnthalpyRefrig('STEAM',SteamInletTemp,1.0d0, &
SteamBaseboard(BaseboardNum)%FluidIndex,'CalcSteamBaseboard')
EnthSteamOutWet = GetSatEnthalpyRefrig('STEAM',SteamInletTemp,0.0d0, &
SteamBaseboard(BaseboardNum)%FluidIndex,'CalcSteamBaseboard')
LatentHeatSteam = EnthSteamInDry-EnthSteamOutWet
Cp = GetSatSpecificHeatRefrig('STEAM',SteamInletTemp,0.0d0,SteamBaseboard(BaseboardNum)%FluidIndex, &
'CalcSteamBaseboard')
SteamBBHeat = SteamMassFlowRate*(LatentHeatSteam+SubCoolDeltaT*Cp) ! Baseboard heating rate
SteamOutletTemp = SteamInletTemp - SubCoolDeltaT ! Outlet temperature of steam
! Estimate radiant heat addition
RadHeat = SteamBBHeat * SteamBaseboard(BaseboardNum)%FracRadiant ! Radiant heating rate
QBBSteamRadSource(BaseboardNum) = RadHeat ! Radiant heat source which will be distributed to surfaces and people
! Now, distribute the radiant energy of all systems to the appropriate surfaces, to people, and the air
CALL DistributeBBSteamRadGains
! Now "simulate" the system by recalculating the heat balances
CALL CalcHeatBalanceOutsideSurf(ZoneNum)
CALL CalcHeatBalanceInsideSurf(ZoneNum)
! Here an assumption is made regarding radiant heat transfer to people.
! While the radiant heat transfer to people array will be used by the thermal comfort
! routines, the energy transfer to people would get lost from the perspective
! of the heat balance. So, to avoid this net loss of energy which clearly
! gets added to the zones, we must account for it somehow. This assumption
! that all energy radiated to people is converted to convective energy is
! not very precise, but at least it conserves energy. The system impact to heat balance
! should include this.
! Actual system load that the unit should meet
LoadMet = (SumHATsurf(ZoneNum) - ZeroSourceSumHATsurf(ZoneNum)) &
+ (SteamBBHeat * SteamBaseboard(BaseboardNum)%FracConvect) &
+ (RadHeat * SteamBaseboard(BaseboardNum)%FracDistribPerson)
SteamBaseboard(BaseboardNum)%SteamOutletEnthalpy = SteamBaseboard(BaseboardNum)%SteamInletEnthalpy &
- SteamBBHeat / SteamMassFlowRate
SteamBaseboard(BaseboardNum)%SteamOutletQuality = 0.0d0
ELSE
SteamOutletTemp = SteamInletTemp
SteamBBHeat = 0.0d0
LoadMet = 0.0d0
RadHeat = 0.0d0
SteamMassFlowRate = 0.0d0
QBBSteamRadSource(BaseboardNum) = 0.0d0
SteamBaseboard(BaseboardNum)%SteamOutletQuality = 0.0d0
SteamBaseboard(BaseboardNum)%SteamOutletEnthalpy = SteamBaseboard(BaseboardNum)%SteamInletEnthalpy
END IF
SteamBaseboard(BaseboardNum)%SteamOutletTemp = SteamOutletTemp
SteamBaseboard(BaseboardNum)%SteamMassFlowRate = SteamMassFlowRate
SteamBaseboard(BaseboardNum)%SteamOutletEnthalpy = SteamBaseboard(BaseboardNum)%SteamOutletEnthalpy
SteamBaseboard(BaseboardNum)%SteamOutletQuality = SteamBaseboard(BaseboardNum)%SteamOutletQuality
SteamBaseboard(BaseboardNum)%TotPower = LoadMet
SteamBaseboard(BaseboardNum)%Power = SteamBBHeat
SteamBaseboard(BaseboardNum)%ConvPower = SteamBBHeat - RadHeat
SteamBaseboard(BaseboardNum)%RadPower = RadHeat
RETURN
END SUBROUTINE CalcSteamBaseboard