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Simple Heat Exchanger (G-G)

Simple model of a heat exchanger between two gas networks

  • Library:
  • Fluid Network Interfaces / Heat Exchangers

Description

The Simple Heat Exchanger (G-G) block models the heat transfer and fluid dynamics of a heat exchanger located between two gas networks. 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 networks are considered distinct. Each network must connect to a separate fluid properties block—Gas Properties (G) in each case. 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 networks. Two Simple Heat Exchanger Interface (G) blocks capture the pressure drop and temperature change between the gas inlets.

Component Block Diagram

Ports

Conserving

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Opening through which gas 1 can enter and exit the heat exchanger.

Opening through which gas 1 can enter and exit the heat exchanger.

Opening through which gas 2 can enter and exit the heat exchanger.

Opening through which gas 2 can enter and exit the heat exchanger.

Parameters

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Heat Transfer Tab

Array of mass flow rates at the inlet for gas 1. 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 inlet for gas 2. 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 two gases. 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|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 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 A and B are assumed to be identical in size for each gas.

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.

Introduced in R2017b

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