Menu > SETTINGS > Fluids > REFPROP library

If a fluid from the REFPROP library is to be added the following windows will appear. Precondition for that is that REFPROP is installed properly on the same computer as CFturbo.

Incompressible fluid [ for pumps, fans only ]

The constant data needed for the design process will be derived at a temperature T1. CFturbo considers the liquid state only. Therefore, p1 > pv and Ttriple < T1 < Tcrit. Triple point temperature as well as critical temperature are used as range limits for the vapor pressure curve, see picture below.

If pressure and temperature are not above the vapor pressure curve, the fluid is not valid and cannot be added to the list of the fluids to be used in a project. In this case the OK-button is deactivated. In the diagram below the pressure-temperature state is OK.

Compressible fluid [ for compressors, turbines only ]

Constant data as well as pressure and temperature dependent properties are displayed in a table. The heat capacity coefficients cpi (at zero pressure) are derived at temperatures T1 and T2. A least square fitting algorithm is used for this purpose.

The gaseous state exists in a certain scope, i.e. p1 < pv and p1 < ptriple and Ttriple < T1. Triple point temperature as well as critical temperature are used as range limits for the vapor pressure curve, see picture below. Additionally the heat capacity at zero pressure is given as function of T1 and T2 both based on REFPROP as well as on the polynomial with the coefficients cpi.