Documentation

Simple Heat Exchanger (G-TL)

Simple model of a heat exchanger between a gas circuit and a thermal liquid network

  • Library:
  • Fluid Network Interfaces / Heat Exchangers

Description

The Simple Heat Exchanger (G-TL) block models the heat transfer and fluid dynamics of a heat exchanger located between a gas network and a thermal liquid network. The model is based on tabulated data relating the operating conditions inside the heat exchanger—the mass flow rate, pressure drop, and specific dissipation factor, a measure of heat exchange effectiveness.

The gas and thermal liquid networks are considered distinct. Each network must connect to a separate fluid properties block—Gas Properties (G) or Thermal Liquid Settings (TL). The fluids do not mix nor do they change phase. Their only interaction is heat transfer across a common boundary. The rate of heat transfer is computed using the specific dissipation method.

Component Structure

This block is a composite component assembled from simpler components found in the Fundamental Components library. A Specific Dissipation Heat Transfer block captures the heat transfer between the gas and thermal liquid networks. A Simple Heat Exchanger Interface (G) block and a Simple Heat Exchanger Interface (TL) block capture the pressure drop and temperature change between the inlets.

Component Block Diagram

Ports

Conserving

expand all

Opening through which gas can enter and exit the heat exchanger.

Opening through which gas can enter and exit the heat exchanger.

Opening through which thermal liquid can enter and exit the heat exchanger.

Opening through which thermal liquid can enter and exit the heat exchanger.

Parameters

expand all

Heat Transfer Tab

Array of mass flow rates at the gas inlet. Each value corresponds to a row in the specific dissipation lookup table. Positive values indicate flow into the heat exchanger and negative values indicate flow out of the heat exchanger.

Array of mass flow rates at the thermal liquid inlet. Each value corresponds to a row in the specific dissipation lookup table. Positive values indicate flow into the heat exchanger and negative values indicate flow out of the heat exchanger.

Matrix of specific dissipation values corresponding to the specified mass flow rate arrays for the gas and controlled fluid. The block uses the tabulated data to calculate the heat transfer at the simulated operating conditions.

Option to warn if the specific dissipation falls outside the bounds of the specified tabulated data.

Gas 1 Tab

Array of mass flow rates at which to specify the pressure drop tabulated data.

Array of pressure drops from inlet to outlet corresponding to the tabulated mass flow rate data.

Temperature at which the tabulated pressure-drop data is specified.

Pressure at which the tabulated pressure-drop data is specified.

Mass flow rate below which to initiate a smooth flow reversal to prevent discontinuities in the simulation data.

Volume of gas occupying the heat exchanger at any given time. The initial conditions specified in the Effects and Initial Conditions tab apply to this volume. The volume is constant during simulation.

Flow area at the gas inlets. Inlets A1 and B1 are assumed to be identical in size.

Thermal Liquid 2 Tab

Array of mass flow rates at which to specify the pressure drop tabulated data.

Array of pressure drops from inlet to outlet corresponding to the tabulated mass flow rate data.

Temperature at which the tabulated pressure-drop data is specified.

Pressure at which the tabulated pressure-drop data is specified.

Mass flow rate below which to initiate a smooth flow reversal to prevent discontinuities in the simulation data.

Volume of thermal liquid occupying the heat exchanger at any given time. The initial conditions specified in the Effects and Initial Conditions tab apply to this volume. The volume is constant during simulation.

Flow area at the thermal liquid inlets. Inlets A2 and B2 are assumed to be identical in size.

Effects and Initial Conditions Tab

Temperature of the internal volume of gas at the start of simulation.

Pressure of the internal volume of gas at the start of simulation.

Option to model the pressure dynamics inside the heat exchanger. Setting this parameter to Off removes the pressure derivative terms from the component energy and mass conservation equations. The pressure inside the heat exchanger is then reduced to the weighted average of the two port pressures.

Temperature of the internal volume of thermal liquid at the start of simulation.

Pressure of the internal volume of thermal liquid at the start of simulation.

Introduced in R2017b

Was this topic helpful?