Number of tubes per shellRigorous Heat Exchanger - Main Window
The Rigorous Heat Exchanger unit operation carries out a performance rating of an existing shell and tube heat exchanger. The exchanger may have one or more shells, arranged in series and/or parallel. All shells have identical geometries.
The shell geometry has to be defined. Other parameters can be set to allow you to match the model with measured plant operating data.
The rigorous heat transfer calculations performed in this unit need Transport Properties. Be sure to declare methods for these in the Thermodynamic Data Window.
Usage
Simulation Model
Select the desired simulation model: either PRO/II or HTRI.
The PRO/II option solves heat exchanger cases using the PRO/II HXRIG algorithms. Enter all data using the data entry fields and push button in the main data entry window.
Alternatively, an interface to HTRI’s XIST model allows solving the heat exchanger cases using HTRI algorithms. Choosing the HTRI option disables almost all data entry push buttons and data entry fields in the main HXRIG data entry window. Instead, an HTRI Setup button is activated. When activated, the HTRI Setup button must be used to enter data required by the HTRI model.
The following data entry fields, groups, and buttons are available only when the Use PRO/II Simulation Model is active. This is the default mode of calculation.
Calculation Type
Select the desired mode for the unit to be calculated. Depending on the selection, the unit calculates different parameters, as described in Calculation Type
Overall Configuration
At least one of the following must be entered by the user:
Number of tubes per shell
Area per shell
Shell Inside Diameter
See Overall Configuration for further information.
Products/Thermo
Push this button to display the Feeds and Products Data Window to specify product stream data and thermodynamics. If there is only one product from each side of the exchanger, all the data items in this window have default values.
Configuration
Press this button to display the Configuration Data Window. Use this window to specify the type, number, configuration and orientation of the shells in the exchanger. All the data items in this window have default values, so data entry is optional.
Tubes
Pressing this button displays the Tube Data Window Use this window to enter details for the exchanger tubes. All the data items in this window have default values.
Baffles
Push this button to display the Baffle Data Window. Go here to enter configuration data for exchanger baffle geometry. All the data items in this window have default values.
Film Coefficients
Pushing this button displays the Film Coefficient Data Window. This window allows data entry for shell-side, tube-side and overall film heat transfer coefficients. These data provide adjustment factors and override values for the heat transfer coefficients. All the data items in this window have default values, so they all are optional.
Pressure Drop
When pressed, this button displays the Pressure Drop Data Window. In this window, enter shell-side and tube-side pressure drops on either a per shell or per unit basis. Each side also supports a "DP Scale Factor", which may be used to "fine tune" the rigorously-calculated pressure drops to match actual plant data. Additionally, the calculation method for shell-side pressure drop may be chosen. The Bell and Stream methods are available. All entries in this window are optional, since defaults satisfy the minimum data requirements.
Materials
Push this button to display the Material Data Window. By default the shell and tubes are assumed to be constructed from carbon steel. Visit this window to change the materials of construction, or to modify the material properties (density, thermal conductivity).
Print Options
Push this button to display the Print Options Window. Use this window to include additional data with the standard output reports. An extended TEMA data sheet and a zones analysis report are available.
Nozzles
This button opens the Nozzle Data Window to specify nozzle type and sizes. All the data items in this window have default values.
The following buttons are the only data entry mechanisms available when the Use HTRI Simulation Model chosen.
Setup
Press this button to open the HTRI Setup Window where the user can specify process and data initialization details for HTRI option. This button will be enabled only when HTRI option is selected.
HTRI GUI
Push this button to display HTRI input and output files in the HTRI GUI. This button is enabled only when "Intilialize HTRI Data" button in "HTRI Setup" DEW is in satisfied state.
How to get to this window
The Rigorous Heat Exchanger Window is accessed by double clicking on the Rigorous Heat Exchanger icon laid down on the Process Flow Diagram.
Complete technical details may be found in topics under Heat Exchangers in the PRO/II Reference Manual.
Standard Heat Curves option
When the Standard Heat Curves option is selected, three standard heating/cooling curves are generated on shell and tube sides of the heat exchanger. These curves are generated at three isobar points: starting pressure, midpoint pressure, and ending pressure. For each curve, 11 evaluation points are considered. Also, for each curve, the transport and critical properties are calculated.
