modelHeatStorageVariablePorts

Simple model of a heat storage

Extends from AixLib.Obsolete.BaseClasses.ObsoleteModel (Icon for classes that are obsolete and will be removed in later versions).

Information

Overview

Buffer storage model with support for heating rod and two heating coils. Model with variable connection pairs for loading and unlouding cycles which are defined by the associated storage layer number of the ports. Compared to the standard HeatStorage model, the position of the heating coils can also be defined in this model.

Concept

It represents a buffer storage stratified into n layers where 1 represents the bottom layer and n represents the top layer. The layers are connected to each other allowing heat and fluid transfer. The conductance, buoyancy and enthalpy flow represent the heat transfer between the layers.

The geometrical data for the storage is read by records in the DataBase package. In this model the number and the position of connection pairs for loading and unlouding cycles is variable. The position for each connection pair is defined by the associated storage layer number of input and output connection (compare connections tab).

The model also includes heat losses over the storage walls (wall, top and bottom).

Example Results

BufferStorage_variablePorts

Parameters

Type	Name	Default	Description
Integer	n	5	Model assumptions Number of Layers
Modelica.Units.SI.CoefficientOfHeatTransfer	hConIn	1500	Heat transfer coefficient at the inner wall
Modelica.Units.SI.CoefficientOfHeatTransfer	hConOut	15	Heat transder coefficient at the outer wall
AixLib.DataBase.Storage.BufferStorageBaseDataDefinition	data	AixLib.DataBase.Storage.Generic_New_2000l()	Storage data
Integer	dis_HC1	n_HC1_up - n_HC1_low + 1
Integer	dis_HC2	n_HC2_up - n_HC2_low + 1
Medium
FastHVAC.Media.BaseClasses.MediumSimple	medium	FastHVAC.Media.WaterSimple()	Mediums charastics (heat capacity, density, thermal conductivity)
FastHVAC.Media.BaseClasses.MediumSimple	mediumHC1	FastHVAC.Media.WaterSimple()	Mediums charastics for HC1 (heat capacity, density, thermal conductivity)
FastHVAC.Media.BaseClasses.MediumSimple	mediumHC2	FastHVAC.Media.WaterSimple()	Mediums charastics HC2 (heat capacity, density, thermal conductivity)
Initialisation
Modelica.Units.SI.Temperature	T_start	fill(293.15, n)	Start temperature of medium
Modelica.Units.SI.Temperature	T_start_wall	293.15	Starting Temperature of wall in K
Modelica.Units.SI.Temperature	T_start_ins	293.15	Starting Temperature of insulation in K
Connections
Integer	load_cycles	{{n, 1}, {n, 1}}	Loading cycle connection pairs (upper position first)
Integer	unload_cycles	{{1, n}, {1, n}}	Unloading cycle connection pairs (lower position first)
Integer	n_load_cycles	2	Number of loading cycle connection pairs
Integer	n_unload_cycles	2	Number of loading cycle connection pairs
Integer	n_HC1_up	n	Highest layer of Heating Coil 1
Integer	n_HC1_low	1	Lowest layer of Heating Coil 1
Integer	n_HC2_up	n	Highest layer of Heating Coil 2
Integer	n_HC2_low	1	Lowest layer of Heating Coil 2
Integer	n_HR	n	Layer of Heating Rod
Heating Coils and Rod
Boolean	use_heatingCoil1	true	Use Heating Coil1?
Boolean	use_heatingCoil2	true	Use Heating Coil2?
Boolean	use_heatingRod	true	Use Heating Rod?
Modelica.Units.SI.CoefficientOfHeatTransfer	hConHC1	20	Model assumptions heat transfer coefficient HC1 <-> Heating Water
Modelica.Units.SI.CoefficientOfHeatTransfer	hConHC2	400	Model assumptions heat transfer coefficient HC2 <-> Heating Water
Boolean	Up_to_down_HC1	true	Heating Coil 1 orientation from up to down?
Boolean	Up_to_down_HC2	true	Heating Coil 2 orientation from up to down?
Boolean	calcHCon	true	Use calculated value for inside heat transfer coefficient
Modelica.Units.SI.CoefficientOfHeatTransfer	hConIn_const	30	Fix value for heat transfer coefficient inside pipe

Connectors

Type	Name	Description
FastHVAC.Interfaces.EnthalpyPort_a[n_load_cycles]	LoadingCycle_In
FastHVAC.Interfaces.EnthalpyPort_b[n_load_cycles]	LoadingCycle_Out
FastHVAC.Interfaces.EnthalpyPort_b[n_unload_cycles]	UnloadingCycle_Out
FastHVAC.Interfaces.EnthalpyPort_a[n_unload_cycles]	UnloadingCycle_In
FastHVAC.Interfaces.EnthalpyPort_a	port_HC1_in	Fluid connector a (positive design flow direction is from port_a to port_b)
FastHVAC.Interfaces.EnthalpyPort_b	port_HC1_out	Fluid connector b (positive design flow direction is from port_a to port_b)
FastHVAC.Interfaces.EnthalpyPort_a	port_HC2_in	Fluid connector a (positive design flow direction is from port_a to port_b)
FastHVAC.Interfaces.EnthalpyPort_b	port_HC2_out	Fluid connector b (positive design flow direction is from port_a to port_b)
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a	heatingRod
Modelica.Blocks.Interfaces.RealOutput[n]	T_layers
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a	out

Components

Type	Name	Default	Description
Modelica.Units.SI.Energy	Heat_loss
Modelica.Thermal.HeatTransfer.Components.HeatCapacitor[n]	layer
FastHVAC.BaseClasses.EnergyBalance[n,n_load_cycles]	energyBalance_load
FastHVAC.BaseClasses.EnergyBalance[n,n_unload_cycles]	energyBalance_unload
Modelica.Thermal.HeatTransfer.Sources.PrescribedTemperature[n_load_cycles,2]	varTemp_load
Modelica.Thermal.HeatTransfer.Sources.FixedHeatFlow[n_load_cycles,2]	dummy_load
Modelica.Thermal.HeatTransfer.Sources.PrescribedTemperature[n_unload_cycles,2]	varTemp_unload
Modelica.Thermal.HeatTransfer.Sources.FixedHeatFlow[n_unload_cycles,2]	dummy_unload
BaseClasses.HeatingCoil	heatingCoil1
BaseClasses.HeatingCoil	heatingCoil2
Fluid.Storage.BaseClasses.StorageCover	top_cover
Fluid.Storage.BaseClasses.StorageMantle[n]	storage_mantle
Fluid.Storage.BaseClasses.StorageCover	bottom_cover
HeatTransfer	heatTransfer

Name	Description
HeatTransfer

Revisions

December 20, 2016 Tobias Blacha:
Moved into AixLib
January 27, 2015 by Konstantin Finkbeiner:
Added documentation.
December 16, 2014 by Sebastian Stinner:
Implemented.