InitPipesHeatTransfer – EnergyPlusFortran

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private subroutine InitPipesHeatTransfer(PipeType, PipeHTNum, FirstHVACIteration)

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Arguments

Type	Intent		Name
integer		::	PipeType
integer,	intent(in)	::	PipeHTNum
logical,	intent(in)	::	FirstHVACIteration
Source Code

SUBROUTINE InitPipesHeatTransfer(PipeType,PipeHTNum,FirstHVACIteration)

          ! SUBROUTINE INFORMATION:
          !       AUTHOR         Simon Rees
          !       DATE WRITTEN   July 2007
          !       MODIFIED       L. Gu, 6/19/08, pipe wall heat capacity has metal layer only
          !       RE-ENGINEERED  na

          ! PURPOSE OF THIS SUBROUTINE:
          ! This subroutine Resets the elements of the data structure as necessary
          ! at the first step, and start of each call to simulated

          ! METHODOLOGY EMPLOYED:
          ! Check flags and update data structure

          ! REFERENCES:
          ! na

          ! USE STATEMENTS:

  USE DataGlobals,       ONLY : BeginSimFlag, BeginEnvrnFlag, PI, DayOfSim, HourOfDay,TimeStep, &
                                TimeStepZone, SecInHour, BeginTimeStepFlag
  USE DataHVACGlobals,   ONLY : SysTimeElapsed, TimeStepSys, ShortenTimeStepSys
  USE DataEnvironment,   ONLY : OutDryBulbTemp, GroundTemp, PubGroundTempSurface, PubGroundTempSurfFlag
  USE DataLoopNode,      ONLY : Node
  USE DataHeatBalance,   ONLY : TotConstructs, TotMaterials, Construct, Material
  USE DataHeatBalFanSys, ONLY : MAT !average (mean) zone air temperature [C]
  USE InputProcessor,    ONLY : SameString
  USE ScheduleManager,   ONLY : GetCurrentScheduleValue
  USE FluidProperties,   ONLY : GetSpecificHeatGlycol,GetDensityGlycol
  USE DataPlant,         ONLY : PlantLoop, DemandSide, ScanPlantLoopsForObject

  IMPLICIT NONE    ! Enforce explicit typing of all variables in this routine

          ! SUBROUTINE ARGUMENT DEFINITIONS:
  INTEGER :: PipeType
  INTEGER, INTENT(IN) :: PipeHTNum       ! component number
  LOGICAL, INTENT(IN) :: FirstHVACIteration       ! component number

          ! SUBROUTINE PARAMETER DEFINITIONS:
 INTEGER, PARAMETER   :: NumPipeSections    = 20     ! Number of length nodes in Hanby model
 INTEGER, PARAMETER   :: NumberOfDepthNodes = 8      ! Number of nodes in the cartesian grid
 INTEGER, PARAMETER   :: MonthsInYear       = 12     ! Number of months in the year
 INTEGER, PARAMETER   :: AvgDaysInMonth     = 30     ! Average days in a month
 INTEGER, PARAMETER   :: DemandLoopSide     = 1      ! Demand Loop side indicator
 REAL(r64), PARAMETER :: LargeNumber        = 9999.9d0 ! Large number (compared to temperature values)
 REAL(r64), PARAMETER :: SecondsInHour      = 3600.0d0 ! Number of seconds in hour
 REAL(r64), PARAMETER :: HoursInDay         = 24.0d0   ! Number of hours in day

          ! INTERFACE BLOCK SPECIFICATIONS
          ! na

          ! DERIVED TYPE DEFINITIONS
          ! na

          ! SUBROUTINE LOCAL VARIABLE DECLARATIONS:

  LOGICAL,SAVE        :: OneTimeInit = .TRUE.   ! one time flag
  REAL(r64)           :: FirstTemperatures      ! initial temperature of every node in pipe (set to inlet temp) [C]
  INTEGER             :: PipeNum                ! number of pipes
  INTEGER             :: MonthIndex
  INTEGER             :: TimeIndex
  INTEGER             :: LengthIndex
  INTEGER             :: DepthIndex
  INTEGER             :: WidthIndex
  REAL(r64)           :: CurrentDepth
  REAL(r64)           :: CurTemp
  REAL(r64)           :: CurSimDay
  INTEGER             :: PlantLoopCtr
  INTEGER             :: LoopSideCtr
  INTEGER             :: BranchCtr
  INTEGER             :: CompCtr
  LOGICAL             :: PushArrays
  LOGICAL             :: errFlag

  ! Assign variable
  CurSimDay      = REAL(DayOfSim,r64)

  ! some useful module variables
  InletNodeNum  = PipeHT(PipeHTNum)%InletNodeNum
  OutletNodeNum = PipeHT(PipeHTNum)%OutletNodeNum
  MassFlowRate  = Node(InletNodeNum)%MassFlowRate
  InletTemp = Node(InletNodeNum)%Temp

  ! get some data only once
  IF(OneTimeInit)THEN

    errFlag=.false.
    Do PipeNum =1,NumOfPipeHT

      CALL ScanPlantLoopsForObject(PipeHT(PipeNum)%Name, &
                                 PipeHT(PipeNum)%TypeOf, &
                                 PipeHT(PipeNum)%LoopNum, &
                                 PipeHT(PipeNum)%LoopSideNum, &
                                 PipeHT(PipeNum)%BranchNum, &
                                 PipeHT(PipeNum)%CompNum,  &
                                 errFlag=errFlag)

    ! 2010-03-15 ESL:
    ! The following code was in place because during the first implementation stage, bizarre MaxIters were found when
    !  heat transfer pipes were placed on demand sides
    ! Since then, a large number of plant and component upgrades were performed.  As such, heat transfer pipes were
    !  re-tested on several locations of the demand side
    ! No problems were encountered placing the pipes on the demand side.  This restriction is removed unless there are any
    !  problems encountered.  If problems are encountered, it is expected that this restriction will still be avoided, and
    !  the proper fix implemented to allow the pipes to be placed on the demand side
    !
    !  IF (PipeHT(PipeNum)%LoopSideNum == DemandSide) THEN
    !    CALL ShowSevereError('InitPipesHeatTransfer: Heat Transfer Pipe='//TRIM(PipeHT(PipeNum)%Name)//&
    !                      ' was encountered on the demand side of loop: '//TRIM(PlantLoop(PipeHT(PipeNum)%LoopNum)%Name)//'.')
    !    CALL ShowContinueError('Due to simulation restrictions, heat transfer pipes are only allowed on supply sides.')
    !    CALL ShowFatalError('Preceding errors cause termination')
    !  END IF

      IF (errFlag) CYCLE

      !If there are any underground buried pipes, we must bring in data
      IF(PipeHT(PipeNum)%EnvironmentPtr .EQ. GroundEnv)THEN

        !If ground temp data was not brought in manually in GETINPUT,
        ! then we must get it from the surface ground temperatures
        IF (PipeHT(PipeNum)%AvgAnnualManualInput .EQ. 0)THEN

          IF (.NOT. PubGroundTempSurfFlag) THEN
            CALL ShowFatalError('No Site:GroundTemperature:Shallow object found.  This is required for a Pipe:Underground object.')
          END IF

          !Calculate Average Ground Temperature for all 12 months of the year:
          PipeHT(PipeNum)%AvgGroundTemp = 0.0d0
          Do MonthIndex = 1, MonthsInYear
            PipeHT(PipeNum)%AvgGroundTemp = PipeHT(PipeNum)%AvgGroundTemp + PubGroundTempSurface(MonthIndex)
          END Do
          PipeHT(PipeNum)%AvgGroundTemp = PipeHT(PipeNum)%AvgGroundTemp / MonthsInYear

          !Calculate Average Amplitude from Average:
          PipeHT(PipeNum)%AvgGndTempAmp = 0.0d0
          Do MonthIndex = 1, MonthsInYear
            PipeHT(PipeNum)%AvgGndTempAmp = PipeHT(PipeNum)%AvgGndTempAmp + &
                                               ABS(PubGroundTempSurface(MonthIndex) - PipeHT(PipeNum)%AvgGroundTemp)
          END Do
          PipeHT(PipeNum)%AvgGndTempAmp = PipeHT(PipeNum)%AvgGndTempAmp / MonthsInYear

          !Also need to get the month of minimum surface temperature to set phase shift for Kusuda and Achenbach:
          PipeHT(PipeNum)%MonthOfMinSurfTemp = 0
          PipeHT(PipeNum)%MinSurfTemp = LargeNumber !Set high so that the first months temp will be lower and actually get updated
          Do MonthIndex = 1, MonthsInYear
            If (PubGroundTempSurface(MonthIndex) <= PipeHT(PipeNum)%MinSurfTemp) THEN
              PipeHT(PipeNum)%MonthOfMinSurfTemp = MonthIndex
              PipeHT(PipeNum)%MinSurfTemp = PubGroundTempSurface(MonthIndex)
            END If
          END Do
          PipeHT(PipeNum)%PhaseShiftDays = PipeHT(PipeNum)%MonthOfMinSurfTemp * AvgDaysInMonth
        ENDIF !End manual ground data input structure

      ENDIF

    END DO
    IF (errFlag) THEN
      CALL ShowFatalError('InitPipesHeatTransfer: Program terminated due to previous condition(s).')
    ENDIF
    ! unset one-time flag
    OneTimeInit = .FALSE.

  END IF

  ! initialize temperatures by inlet node temp
  IF((BeginSimFlag.AND. PipeHT(PipeHTNum)%BeginSimInit) .OR. (BeginEnvrnFlag .AND. PipeHT(PipeHTNum)%BeginSimEnvrn)) THEN

    ! For underground pipes, we need to re-init the cartesian array each environment
    Do PipeNum =1,NumOfPipeHT
      IF(PipeHT(PipeNum)%EnvironmentPtr.EQ.GroundEnv)THEN
        Do TimeIndex = PreviousTimeIndex, TentativeTimeIndex
          !Loop through all length, depth, and width of pipe to init soil temperature
          Do LengthIndex = 1, PipeHT(PipeNum)%NumSections
            Do DepthIndex = 1, PipeHT(PipeNum)%NumDepthNodes
              Do WidthIndex = 1, PipeHT(PipeNum)%PipeNodeWidth
                CurrentDepth = (DepthIndex - 1) * PipeHT(PipeNum)%dSregular
                PipeHT(PipeNum)%T(TimeIndex, LengthIndex, DepthIndex, WidthIndex) = TBND(CurrentDepth, CurSimDay, PipeNum)
              EndDo
            EndDo
          EndDo
        EndDo
      ENDIF
    ENDDO

    ! We also need to re-init the Hanby arrays for all pipes, including buried
    FirstTemperatures = 21.0d0 !Node(InletNodeNum)%Temp
    PipeHT(PipeHTNum)%TentativeFluidTemp = FirstTemperatures
    PipeHT(PipeHTNum)%FluidTemp          = FirstTemperatures
    PipeHT(PipeHTNum)%PreviousFluidTemp  = FirstTemperatures
    PipeHT(PipeHTNum)%TentativePipeTemp  = FirstTemperatures
    PipeHT(PipeHTNum)%PipeTemp           = FirstTemperatures
    PipeHT(PipeHTNum)%PreviousPipeTemp   = FirstTemperatures
    PipeHT(PipeHTNum)%PreviousSimTime    = 0.0d0
    DeltaTime                            = 0.0d0
    OutletTemp                           = 0.0d0
    EnvironmentTemp                      = 0.0d0
    EnvHeatLossRate                      = 0.0d0
    FluidHeatLossRate                    = 0.0d0

    PipeHT(PipeHTNum)%BeginSimInit = .FALSE.
    PipeHT(PipeHTNum)%BeginSimEnvrn = .FALSE.

  END IF

  IF (.NOT. BeginSimFlag) PipeHT(PipeHTNum)%BeginSimInit = .TRUE.
  IF (.NOT. BeginEnvrnFlag) PipeHT(PipeHTNum)%BeginSimEnvrn = .TRUE.

  ! time step in seconds
  DeltaTime = TimeStepSys*SecInHour
  NumInnerTimeSteps = INT(DeltaTime / InnerDeltaTime)


  ! previous temps are updated if necessary at start of timestep rather than end
  IF( (FirstHVACIteration .and. PipeHT(PipeHTNum)%FirstHVACupdateFlag) .or. &
      (BeginEnvrnFlag     .and. PipeHT(PipeHTNum)%BeginEnvrnupdateFlag)  )THEN

    !We need to update boundary conditions here, as well as updating the arrays
    IF(PipeHT(PipeHTNum)%EnvironmentPtr.EQ.GroundEnv)THEN

      ! And then update Ground Boundary Conditions
      Do TimeIndex = 1, TentativeTimeIndex
        Do LengthIndex = 1, PipeHT(PipeHTNum)%NumSections
          Do DepthIndex = 1, PipeHT(PipeHTNum)%NumDepthNodes
            !Farfield boundary
            CurrentDepth = (DepthIndex - 1) * PipeHT(PipeHTNum)%dSregular
            CurTemp = TBND(CurrentDepth, CurSimDay, PipeHTNum)
            PipeHT(PipeHTNum)%T(TimeIndex, LengthIndex, DepthIndex, 1) = CurTemp
          EndDo
          Do WidthIndex = 1, PipeHT(PipeHTNum)%PipeNodeWidth
            !Bottom side of boundary
            CurrentDepth = PipeHT(PipeHTNum)%DomainDepth
            CurTemp = TBND(CurrentDepth, CurSimDay, PipeHTNum)
            PipeHT(PipeHTNum)%T(TimeIndex, LengthIndex, PipeHT(PipeHTNum)%NumDepthNodes, WidthIndex) = CurTemp
          EndDo
        EndDo
      EndDo
    EndIf

  ! should next choose environment temperature according to coupled with air or ground
   SELECT CASE (PipeHT(PipeHTNum)%EnvironmentPtr)
      CASE(GroundEnv)
         !EnvironmentTemp = GroundTemp
      CASE(OutsideAirEnv)
         EnvironmentTemp = OutDryBulbTemp
      CASE(ZoneEnv)
         EnvironmentTemp = MAT(PipeHT(PipeHTNum)%EnvrZonePtr)
      CASE (ScheduleEnv)
         EnvironmentTemp = GetCurrentScheduleValue(PipeHT(PipeHTNum)%EnvrSchedPtr)
      CASE(None) !default to outside temp
         EnvironmentTemp = OutDryBulbTemp
   END SELECT

    PipeHT(PipeHTNum)%BeginEnvrnupdateFlag = .false.
    PipeHT(PipeHTNum)%FirstHVACupdateFlag = .false.

  END IF

  IF(.NOT. BeginEnvrnFlag) PipeHT(PipeHTNum)%BeginEnvrnupdateFlag = .true.
  IF(.NOT. FirstHVACIteration) PipeHT(PipeHTNum)%FirstHVACupdateFlag = .true.

  !Calculate the current sim time for this pipe (not necessarily structure variable, but it is ok for consistency)
  PipeHT(PipeHTNum)%CurrentSimTime = (dayofSim-1)*24 + hourofday-1 + (timestep-1)*timestepZone + SysTimeElapsed
  IF (ABS(PipeHT(PipeHTNum)%CurrentSimTime - PipeHT(PipeHTNum)%PreviousSimTime) > 1.0d-6) THEN
    PushArrays = .TRUE.
    PipeHT(PipeHTNum)%PreviousSimTime = PipeHT(PipeHTNum)%CurrentSimTime
  ELSE
    PushArrays = .FALSE.  !Time hasn't passed, don't accept the tentative values yet!
  END IF

  IF (PushArrays) THEN

     !If sim time has changed all values from previous runs should have been acceptable.
     ! Thus we will now shift the arrays from 2>1 and 3>2 so we can then begin
     ! to update 2 and 3 again.
     IF (PipeHT(PipeHTNum)%EnvironmentPtr .EQ. GroundEnv) THEN
       Do LengthIndex = 2, PipeHT(PipeHTNum)%NumSections
        Do DepthIndex = 1,  PipeHT(PipeHTNum)%NumDepthNodes
          Do WidthIndex = 2, PipeHT(PipeHTNum)%PipeNodeWidth
           !This will essentially 'accept' the tentative values that were calculated last iteration
           ! as the new officially 'current' values
           PipeHT(PipeHTNum)%T(CurrentTimeIndex, LengthIndex, DepthIndex, WidthIndex) = &
              PipeHT(PipeHTNum)%T(TentativeTimeIndex, LengthIndex, DepthIndex, WidthIndex)
          EndDo
        EndDo
      EndDo
    ENDIF

    !Then update the Hanby near pipe model temperatures
    PipeHT(PipeHTNum)%FluidTemp         = PipeHT(PipeHTNum)%TentativeFluidTemp
    PipeHT(PipeHTNum)%PipeTemp          = PipeHT(PipeHTNum)%TentativePipeTemp

  ELSE !  IF(.NOT. FirstHVACIteration)THEN

     !If we don't have FirstHVAC, the last iteration values were not accepted, and we should
     ! not step through time.  Thus we will revert our T(3,:,:,:) array back to T(2,:,:,:) to
     ! start over with the same values as last time.
     Do LengthIndex = 2, PipeHT(PipeHTNum)%NumSections
      Do DepthIndex = 1,  PipeHT(PipeHTNum)%NumDepthNodes
        Do WidthIndex = 2, PipeHT(PipeHTNum)%PipeNodeWidth
         !This will essentially erase the past iterations and revert back to the correct values
         PipeHT(PipeHTNum)%T(TentativeTimeIndex, LengthIndex, DepthIndex, WidthIndex) = &
            PipeHT(PipeHTNum)%T(CurrentTimeIndex, LengthIndex, DepthIndex, WidthIndex)
        EndDo
      EndDo
    EndDo

    !Similarly for Hanby model arrays
    PipeHT(PipeHTNum)%TentativeFluidTemp = PipeHT(PipeHTNum)%FluidTemp
    PipeHT(PipeHTNum)%TentativePipeTemp = PipeHT(PipeHTNum)%PipeTemp

  ENDIF

  !This still catches even in winter design day
  !Even though the loop eventually has no flow rate, it appears it initializes to a value, then converges to OFF
  !Thus, this is called at the beginning of every time step once.

  PipeHT(PipeHTNum)%FluidSpecHeat = GetSpecificHeatGlycol(PlantLoop(PipeHT(PipeHTNum)%LoopNum)%FluidName,  &
                                                          InletTemp,                      &
                                                          PlantLoop(PipeHT(PipeHTNum)%LoopNum)%FluidIndex, &
                                                          'InitPipesHeatTransfer')
  PipeHT(PipeHTNum)%FluidDensity = GetDensityGlycol(PlantLoop(PipeHT(PipeHTNum)%LoopNum)%FluidName,  &
                                                    InletTemp, &
                                                    PlantLoop(PipeHT(PipeHTNum)%LoopNum)%FluidIndex,&
                                                    'InitPipesHeatTransfer')


  ! At this point, for all Pipe:Interior objects we should zero out the energy and rate arrays
  PipeHTReport(PipeHTNum)%FluidHeatLossRate       = 0.0d0
  PipeHTReport(PipeHTNum)%FluidHeatLossEnergy     = 0.0d0
  PipeHTReport(PipeHTNum)%EnvironmentHeatLossRate = 0.0d0
  PipeHTReport(PipeHTNum)%EnvHeatLossEnergy       = 0.0d0
  PipeHT(PipeHTNum)%ZoneHeatGainRate              = 0.d0
  FluidHeatLossRate                               = 0.0d0
  EnvHeatLossRate                                 = 0.0d0
  OutletTemp                                      = 0.0d0

  IF(PipeHT(PipeHTNum)%FluidDensity .GT. 0.0d0) THEN
    !The density will only be zero the first time through, which will be a warmup day, and not reported
    VolumeFlowRate= MassFlowRate / PipeHT(PipeHTNum)%FluidDensity
  ENDIF

 RETURN

END SUBROUTINE InitPipesHeatTransfer
InitPipesHeatTransfer Subroutine

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private subroutine InitPipesHeatTransfer(PipeType, PipeHTNum, FirstHVACIteration)

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