modelSimpleHeatTransfer

Model of a simple 1-dimensional heat transfer for compressor's inlet and outlet

Extends from AixLib.Fluid.Interfaces.PartialTwoPortTransport (Partial element transporting fluid between two ports without storage of mass or energy).

Information

This is a model of a simple one-directional heat transfer without storage of energy or mass. Therefore, some assumptions are made:

  • No storage of energy or mass.
  • No pressure losses.
  • Calculation of the heat flow between fluid and fictitious wall using a logarithmic temperature difference and time invariante effective thermal conductance.

Parameters

TypeNameDefaultDescription
General › Heat transfer
Types.HeatTransferModelsheaTraModTypes.HeatTransferModels.SimplifiedChoose heat transfer model
Modelica.Units.SI.ThermalConductancekAMea25Effective mean thermal conductance between medium and fictitious wall
Assumptions
BooleanallowFlowReversal (from PartialTwoPort)true= false to simplify equations, assuming, but not enforcing, no flow reversal
Advanced
Modelica.Units.SI.PressureDifferencedp_start (from PartialTwoPortTransport)0Guess value of dp = port_a.p - port_b.p
Medium.MassFlowRatem_flow_start (from PartialTwoPortTransport)0Guess value of m_flow = port_a.m_flow
Medium.MassFlowRatem_flow_small (from PartialTwoPortTransport)Small mass flow rate for regularization of zero flow
Modelica.Units.SI.MassFlowRatem_flow_nominal0.1Nominal mass flow rate
Advanced › Diagnostics
Booleanshow_T (from PartialTwoPortTransport)true= true, if temperatures at port_a and port_b are computed
Booleanshow_V_flow (from PartialTwoPortTransport)true= true, if volume flow rate at inflowing port is computed

Connectors

TypeNameDefaultDescription
Modelica.Fluid.Interfaces.FluidPort_aport_a (from PartialTwoPort)Fluid connector a (positive design flow direction is from port_a to port_b)
Modelica.Fluid.Interfaces.FluidPort_bport_b (from PartialTwoPort)Fluid connector b (positive design flow direction is from port_a to port_b)
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_bheatPortHeat port to calculate heat losses

Components

TypeNameDefaultDescription
Medium.MassFlowRatem_flow (from PartialTwoPortTransport)Mass flow rate in design flow direction
Modelica.Units.SI.PressureDifferencedp (from PartialTwoPortTransport)Pressure difference between port_a and port_b (= port_a.p - port_b.p)
Modelica.Units.SI.VolumeFlowRateV_flow (from PartialTwoPortTransport)m_flow/Modelica.Fluid.Utilities.regStep(m_flow, Medium.density(Medium.setState_phX(p = port_a.p, h = inStream(port_a.h_outflow), X = inStream(port_a.Xi_outflow))), Medium.density(Medium.setState_phX(p = port_b.p, h = inStream(port_b.h_outflow), X = inStream(port_b.Xi_outflow))), m_flow_small)Volume flow rate at inflowing port (positive when flow from port_a to port_b)
Medium.Temperatureport_a_T (from PartialTwoPortTransport)Modelica.Fluid.Utilities.regStep(port_a.m_flow, Medium.temperature(Medium.setState_phX(p = port_a.p, h = inStream(port_a.h_outflow), X = inStream(port_a.Xi_outflow))), Medium.temperature(Medium.setState_phX(port_a.p, port_a.h_outflow, port_a.Xi_outflow)), m_flow_small)Temperature close to port_a, if show_T = true
Medium.Temperatureport_b_T (from PartialTwoPortTransport)Modelica.Fluid.Utilities.regStep(port_b.m_flow, Medium.temperature(Medium.setState_phX(p = port_b.p, h = inStream(port_b.h_outflow), X = inStream(port_b.Xi_outflow))), Medium.temperature(Medium.setState_phX(port_b.p, port_b.h_outflow, port_b.Xi_outflow)), m_flow_small)Temperature close to port_b, if show_T = true

Revisions

  • October 28, 2017, by Mirko Engelpracht:
    First implementation (see issue 467).