modelStorageSimple

Simplified multi-layer storage model with volumes as heat exchangers without pressure losses
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Information

Overview

Simple multi-layer thermal energy storage model with volumes as heat exchangers (no pressure losses).

Concept

The water volume of the thermal energy storage can be discretised in several layers.

The following physical processes are modelled

  • heat exchange with the environment
  • heat exchange over the heat exchanger
  • a bouyancy model for the heat transfer between the layers


In contrast to the StorageDetailed model, the following simplifications are taken as a basis:

  • Only indirect charging and discharging using a heat exchanger is possible. Thus, there are two separated hydraulic circuits.
  • The heat exchanger is an array of volumes without any pressure losses
  • There is no optional heating coil and no second heating coil. Hence, the StorageSimple model is limited to a two-circuit application.


Example Results

AixLib.Fluid.Storage.Examples.StorageSimpleExample

  • November 2022 by Laura Maier:
    Rename model and specify difference compared to detailed thermal energy storage model
  • November 2014  by Marcus Fuchs:
    Changed model to use Annex 60 base class
  • 13.12.2013 by Sebastian Stinner:
    implemented

Parameters

TypeNameDefaultDescription
Integernnumber of layers
Modelica.Units.SI.Lengthdstorage diameter
Modelica.Units.SI.Lengthhstorage height
Modelica.Units.SI.MassFlowRatem_flow_nominal_layerNominal mass flow rate in layers
Modelica.Units.SI.MassFlowRatem_flow_nominal_HENominal mass flow rate of heat exchanger layers
Booleanuse_TOuttrueUse temperature real outputs
Modelica.Fluid.Types.DynamicsenergyDynamicsModelica.Fluid.Types.Dynamics.DynamicFreeInitialType of energy balance: dynamic (3 initialization options) or steady state in layers and layers_HE
Heat losses
Modelica.Units.SI.ThermalConductivitylambda_insthermal conductivity of insulation
Modelica.Units.SI.Lengths_insthickness of insulation
Modelica.Units.SI.CoefficientOfHeatTransferhConInIinternal heat transfer coefficient
Modelica.Units.SI.CoefficientOfHeatTransferhConOutExternal heat transfer coefficient
Heat exchanger
Modelica.Units.SI.VolumeV_HEheat exchanger volume
Modelica.Units.SI.CoefficientOfHeatTransferk_HEheat exchanger heat transfer coefficient
Modelica.Units.SI.AreaA_HEheat exchanger area
Bouyancy
Modelica.Units.SI.RelativePressureCoefficientbeta350e-6
Realkappa0.4
Initialization
Modelica.Units.SI.Temperature[n]T_startStart value of temperature of each layer, e.g. for 3 layers: {20, 20, 20}
Modelica.Media.Interfaces.Types.AbsolutePressurep_startMedium.p_defaultStart value of pressure
Advanced
Modelica.Units.SI.MassFlowRatem_flow_small_layer1E-4*abs(m_flow_nominal_layer)Small mass flow rate for regularization of zero flow
Modelica.Units.SI.MassFlowRatem_flow_small_layer_HE1E-4*abs(m_flow_nominal_HE)Small mass flow rate for regularization of zero flow

Connectors

TypeNameDefaultDescription
Modelica.Fluid.Interfaces.FluidPort_aport_a_consumer
Modelica.Fluid.Interfaces.FluidPort_bport_b_consumer
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_aheatPortconnect to ambient temperature around the storage
Modelica.Fluid.Interfaces.FluidPort_bport_b_heatGenerator
Modelica.Fluid.Interfaces.FluidPort_aport_a_heatGenerator
Modelica.Blocks.Interfaces.RealOutput[n]TLayerTemperature in the top layer
Modelica.Blocks.Interfaces.RealOutput[n]TLayer_HETemperature in the top layer

Components

TypeNameDefaultDescription
Fluid.MixingVolumes.MixingVolume[n]layer
Fluid.MixingVolumes.MixingVolume[n]layer_HE
Modelica.Thermal.HeatTransfer.Components.ThermalConductor[n]heatTransfer_HE
Modelica.Thermal.HeatTransfer.Components.ThermalConductor[n]heatTransfer
BaseClasses.Bouyancy[n - 1]bouyancy

Contents

NameDescription
Medium