WOLFRAM SYSTEMMODELER

BasicHX

Simple heat exchanger model

Diagram

Wolfram Language

In[1]:=
SystemModel["Modelica.Fluid.Examples.HeatExchanger.BaseClasses.BasicHX"]
Out[1]:=

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

Simple model of a heat exchanger consisting of two pipes and one wall in between. For both fluids geometry parameters, such as heat transfer area and cross section as well as heat transfer and pressure drop correlations may be chosen. The flow scheme may be concurrent or counterflow, defined by the respective flow directions of the fluids entering the component. The design flow direction with positive m_flow variables is counterflow.

Parameters (38)

length

Value:

Type: Length (m)

Description: Length of flow path for both fluids

nNodes

Value: 2

Type: Integer

Description: Spatial segmentation

modelStructure_1

Value: Types.ModelStructure.av_vb

Type: ModelStructure

Description: Determines whether flow or volume models are present at the ports

modelStructure_2

Value: Types.ModelStructure.av_vb

Type: ModelStructure

Description: Determines whether flow or volume models are present at the ports

crossArea_1

Value:

Type: Area (m²)

Description: Cross sectional area

crossArea_2

Value:

Type: Area (m²)

Description: Cross sectional area

perimeter_1

Value:

Type: Length (m)

Description: Flow channel perimeter

perimeter_2

Value:

Type: Length (m)

Description: Flow channel perimeter

use_HeatTransfer

Value: true

Type: Boolean

Description: = true to use the HeatTransfer_1/_2 model

area_h_1

Value:

Type: Area (m²)

Description: Heat transfer area

area_h_2

Value:

Type: Area (m²)

Description: Heat transfer area

s_wall

Value:

Type: Length (m)

Description: Wall thickness

k_wall

Value:

Type: ThermalConductivity (W/(m·K))

Description: Thermal conductivity of wall material

c_wall

Value:

Type: SpecificHeatCapacity (J/(kg·K))

Description: Specific heat capacity of wall material

rho_wall

Value:

Type: Density (kg/m³)

Description: Density of wall material

area_h

Value: (area_h_1 + area_h_2) / 2

Type: Area (m²)

Description: Heat transfer area

m_wall

Value: rho_wall * area_h * s_wall

Type: Mass (kg)

Description: Wall mass

allowFlowReversal

Value: system.allowFlowReversal

Type: Boolean

Description: allow flow reversal, false restricts to design direction (port_a -> port_b)

energyDynamics

Value: system.energyDynamics

Type: Dynamics

Description: Formulation of energy balance

massDynamics

Value: system.massDynamics

Type: Dynamics

Description: Formulation of mass balance

momentumDynamics

Value: system.momentumDynamics

Type: Dynamics

Description: Formulation of momentum balance, if pressureLoss options available

Twall_start

Value:

Type: Temperature (K)

Description: Start value of wall temperature

dT

Value:

Type: Temperature (K)

Description: Start value for pipe_1.T - pipe_2.T

use_T_start

Value: true

Type: Boolean

Description: Use T_start if true, otherwise h_start

p_a_start1

Value: Medium_1.p_default

Type: AbsolutePressure (Pa)

Description: Start value of pressure

p_b_start1

Value: Medium_1.p_default

Type: AbsolutePressure (Pa)

Description: Start value of pressure

T_start_1

Value: if use_T_start then Medium_1.T_default else Medium_1.temperature_phX((p_a_start1 + p_b_start1) / 2, h_start_1, X_start_1)

Type: Temperature (K)

Description: Start value of temperature

h_start_1

Value: if use_T_start then Medium_1.specificEnthalpy_pTX((p_a_start1 + p_b_start1) / 2, T_start_1, X_start_1) else Medium_1.h_default

Type: SpecificEnthalpy (J/kg)

Description: Start value of specific enthalpy

X_start_1

Value: Medium_1.X_default

Type: MassFraction[Medium_1.nX] (kg/kg)

Description: Start value of mass fractions m_i/m

m_flow_start_1

Value: system.m_flow_start

Type: MassFlowRate (kg/s)

Description: Start value of mass flow rate

p_a_start2

Value: Medium_2.p_default

Type: AbsolutePressure (Pa)

Description: Start value of pressure

p_b_start2

Value: Medium_2.p_default

Type: AbsolutePressure (Pa)

Description: Start value of pressure

T_start_2

Value: if use_T_start then Medium_2.T_default else Medium_2.temperature_phX((p_a_start2 + p_b_start2) / 2, h_start_2, X_start_2)

Type: Temperature (K)

Description: Start value of temperature

h_start_2

Value: if use_T_start then Medium_2.specificEnthalpy_pTX((p_a_start2 + p_b_start2) / 2, T_start_2, X_start_2) else Medium_2.h_default

Type: SpecificEnthalpy (J/kg)

Description: Start value of specific enthalpy

X_start_2

Value: Medium_2.X_default

Type: MassFraction[Medium_2.nX] (kg/kg)

Description: Start value of mass fractions m_i/m

m_flow_start_2

Value: system.m_flow_start

Type: MassFlowRate (kg/s)

Description: Start value of mass flow rate

roughness_1

Value: 2.5e-5

Type: Roughness (m)

Description: Absolute roughness of pipe (default = smooth steel pipe)

roughness_2

Value: 2.5e-5

Type: Roughness (m)

Description: Absolute roughness of pipe (default = smooth steel pipe)

Connectors (4)

port_b1

Type: FluidPort_b

port_a1

Type: FluidPort_a

port_b2

Type: FluidPort_b

port_a2

Type: FluidPort_a

Components (4)

system

Type: System

Description: System properties

wall

Type: WallConstProps

pipe_1

Type: DynamicPipe

pipe_2

Type: DynamicPipe

Used in Examples (1)

HeatExchangerSimulation

Modelica.Fluid.Examples.HeatExchanger

simulation for the heat exchanger model