Compressor Main Window

This window is used to enter the performance specifications for the compressor.

Product Phases Button

If there are two or more product streams leaving the compressor, this button becomes available. You must then specify the phase condition for each product stream using the Product Phases Window, which is displayed when this button is pushed.

Calculation Method Button

The ASME method is the default. You can change to the GPSA method if desired. See Compressor Calculation Methods for more details.

Aftercooler Button

Push this button if the compressor requires an aftercooler. The default is NO aftercooler. Enter the aftercooler data using Aftercooler Window which is displayed when this button is pushed.

Outlet Temperature Estimate

If you select an efficiency parameter, you have the option of entering a value for the estimated outlet temperature. A good estimate helps determine the correct outlet temperature faster.

Maximum Outlet Pressure

Supplying this value when work is specified allows PRO/II to reset the work specification, if the calculated outlet pressure exceeds this maximum value.

Alternatively, instead of entering a value for most of the above parameters, the numeric values may be referenced using the Define system relative to any available unit operation or stream parameter calculated elsewhere in the simulation. See Compressor Parameters Available for Cross Referencing for more details.

Single Molecular Weight Curves

This option enables user to enter performance data at input stream Molecular Weight. For more details, refer Single Molecular Weight Curves.

Multiple Molecular Weight Curves

This option enables user to enter performance data at different Molecular Weights. For more details, refer Multiple Molecular Weight Curves.

Machine Speed

Following entries are available in the list:

Not calculated
Input Machine Speed
From Shaft Work
From Outlet Pressure
From Pressure Ratio
From Outlet Temperature

When “Not calculated” is selected, single molecular weight performance data is entered at single RPM only and Multiple Molecular weight curves option is disabled. When other entries are selected, Single molecular weight performance data can be entered at multiple RPMs.

Outlet Temperature Estimate

You can supply the outlet temperature estimate to speed up the calculation of the actual outlet temperature for non-ideal gases.

Mechanical Efficiency

Mechanical efficiency is used to calculate shaft power. Shaft power is the ratio of shaft work to mechanical efficiency. The mechanical efficiency is 100% by default. You can change this value if desired.

Complete technical details may be found in topics under Isentropic Calculations in the PRO/II Reference Manual.

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