33.3.16 Macro Heat Exchanger Group Dialog Box

The Macro Heat Exchanger Group dialog box allows you to modify or define a heat exchanger core group.

Controls

Name   specifies the name of a new heat exchanger group.

Fluid Zones   contains a list of all the fluid zones.

HX Groups   contains list of the heat exchanger groups.

Model Data   contains all the parameters to be specified for the model.

Primary Fluid Flow Direction   gives you a choice of gas flow direction.

Width, Height, Depth   specifies the width, height and the depth of the gas flow direction.

Connectivity   allows you to define the upstream and downstream connections.

Upstream   specifies the upstream heat exchanger group.

Downstream   specifies the downstream heat exchanger group.

Heat Transfer Model   allows you to select either the simple-effectiveness-model or the ntu-model.

Core Porosity Model   specifies whether default values are chosen for the core porosity model.

Edit...   opens the Core Porosity Model dialog box (see Section  14.3.6) for the definition of a new core porosity model.

Heat Exchanger Performance Data   contains the parameters for heat transfer.

Heat Transfer Data...   opens the Heat Transfer Data Table dialog box (see Section  3e). This dialog box allows you to define the heat transfer for different primary and auxiliary fluid flow rates. This item will appear for the NTU model only.

Velocity Effectiveness Curve...   opens the Velocity Effectiveness Curve dialog box in which you can define the effectiveness of the heat exchanger core ( $\epsilon$ in this equation in the separate Theory Guide). This item will appear for simple effectiveness model only.

Auxiliary Fluid Temperature   specifies the auxiliary fluid temperature.This item will appear for the NTU model only.

Primary Fluid Temperature   specifies the gas stream fluid temperature.This item will appear for the NTU model only.

Geometry   contains parameters to define the macro grid.

Width, Height, Depth   specifies the width, height and the depth of the heat exchanger.

Number of Passes   specifies the number of passes.

Number of Rows/Pass   specifies the number of rows per pass.

Number of Columns/Pass   specifies the number of columns per pass.

View Passes   displays the macro grid. (This button becomes available after you click Set.) The path of the auxiliary fluid is color-coded in the display: macro $0$ is red and macro $n-1$ is blue.

Draw Mesh   toggles between displaying and not displaying the mesh when the macro mesh is displayed (using the View Passes button). The Mesh Display dialog box opens when Draw Mesh is selected.

Update from Plane Tool   updates the Auxiliary Fluid Inlet Direction and Pass-to-Pass Direction from the plane tool orientation. The Width, Height, and Depth will also be updated. See Section  28.6.1 for information about using the plane tool.

Auxiliary Fluid Inlet Direction   specifies the direction in which the auxiliary fluid enters the heat exchanger. See Figure  14.3.6.

Pass-to-Pass Direction   specifies the direction in which the auxiliary fluid moves at the end of each pass through the heat exchanger. See Figure  14.3.6.

Auxiliary Fluid   contains inputs to specify the properties of the auxiliary fluid.

Properties Method   specifies the method to specify the auxiliary fluid properties. You can choose from constant-specific-heat and user-defined-enthalpy.

Specific Heat   sets the specific heat of the auxiliary fluid ( $c_p$ in this equation in the separate Theory Guide). This option is available when you choose constant-specific-heat.

Enthalpy UDF   sets the enthalpy as defined by the UDF selected from the drop-down list.

Auxiliary Fluid Flow Rate   sets the flow rate of the auxiliary fluid ( $\dot{m}$ in this equation in the separate Theory Guide).

Initial Temperature   sets an initial guess for the inlet temperature ( $T_{_{\rm in}}$ in this equation and this equation in the separate Theory Guide). This value is specified only if Fixed Heat Rejection is selected.

Inlet Pressure   sets the auxiliary fluid inlet pressure. This value is specified only if user-defined-enthalpy is selected.

Inlet Quality   specifies the value of $x$ in this equation in the separate Theory Guide.

Pressure Drop   specifies the value of $p_{in}$ in this equation in the separate Theory Guide. This value is specified only if user-defined-enthalpy is selected.

Supplementary Auxiliary Fluid Stream   specifies properties of the supplementary auxiliary stream.

Supplementary Mass Flow Rate   specifies the supplementary fluid flow rate as constant, polynomial or piecewise-linear.

Supplementary Flow Temperature   specifies the supplementary fluid temperature as constant, polynomial or piecewise-linear.

Supplementary Flow Quality   specifies the supplementary fluid quality.

Create   saves all the settings in the dialog box.

Delete   deletes the group that is selected in the HX Groups list.

Replace   changes the parameters of the already existing group that is selected in the HX Groups list.

Set...   opens the Ungrouped Macro Heat Exchanger dialog box, in which you can define a new heat exchanger core model or read one from an external file.