Efficiency or Outlet Temperature Specification
This is the second specification required to describe the operating conditions of the compressor, made after selecting the first specification (Pressure, Work or Head Specification). You can either select an efficiency parameter for the compressor or give the temperature of the product stream leaving the compressor.
The efficiency can be supplied either as a single value entry or as an efficiency curve. The efficiency choices available in the drop down list box depend on the first specification selected. For the actual basis, both adiabatic and polytropic efficiencies are listed, whereas, for the adiabatic and polytropic bases, only adiabatic or polytropic efficiencies are listed, respectively.
By default, compressor calculations assume 100% adiabatic efficiency for all first specification choices except for polytropic processes, where the default is 100% polytropic efficiency.
Select one of the following:
Adiabatic Efficiency : Adiabatic efficiency of the compressor.
Polytropic Efficiency : Polytropic efficiency of the compressor.
Outlet Temperature : The desired temperature of the product stream leaving the compressor.
Single Adiabatic Efficiency Curve : Relation between adiabatic efficiency and actual inlet volumetric flowrate.
Single Polytropic Efficiency Curve : Relation between polytropic efficiency and actual inlet volumetric flowrate.
Multiple Adiabatic Efficiency Curve : Multiple curves at different pressures, which define a relation between adiabatic efficiency and actual inlet volumetric flowrate.
Multiple Polytropic Efficiency Curve : Multiple curves at different pressures, which define a relation between polytropic efficiency and actual inlet volumetric flowrate.
The first three items are single value parameters and the others are efficiency curves.
Usage
Select your desired operating parameter from the drop down list box.
If you have selected a single value parameter, enter the value in the appropriate data entry field. Alternatively, instead of entering a value for these 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.
If you have selected an efficiency curve, push the appropriate Enter Curve button to enter the tabular values for the efficiency curve.
Related Topics
Referencing Data Using the Define System