A turbine is the opposite of a pump; it generates power from a pressure difference between the in- and the outlet. The turbine unit operation has a single inlet and a single outlet.
Pressure drop or outlet pressure needs to be specified.
Either energy generated, or adiabatic efficiency needs to be specified. Generated energy can be specified directly, or via an energy inlet stream.
If energy is not specified via an energy inlet stream, an energy outlet stream can be connected that will receive a value for the energy generated by the turbine.
The efficiency and power generation are related by:
where ΔP is the pressure drop, and L is the total volumetric liquid flow. The total volumetric flow is determined from the total molar flow multiplied by the average molar liquid volume; vapor phases are ignored in volume determination and the unit will fail in case the feed only contains vapor.
The total volumetric liquid flow is assumed equal to the total volumetric flow. If phases other than liquid are detected, a warning is reported. Volume is determined using the thermodynamic that apply to the inlet port.
For a vapor flow, use an expander unit operation.