New version of ORC Library

Raúl Avezuela, EcosimPro/PROOSIS

A new version of the ORC library (1.2) is now available which palette of components is shown in the figure. It further facilitates the calculation of fluid properties and is compatible with the new versions of PROOSIS (3.6.14) and the TURBO library (4.0). We especially want to highlight the implementation of a new way of calculating the thermo-physical properties of the working fluid based on the interpolation in look-up tables. This new feature allows the use of the library without requiring a license for the external software REFPROP (REFerence fluid PROPerties). In addition, a number of minor modifications have also been implemented to correct bugs and improve component modelling.


The aim of the ORC library is to calculate the thermodynamic design and off-design of an ORC (Organic Rankine Cycle) and to study the overall performance of the aircraft engine when it is coupled to the ORC system.

The key features of the library are the following:

• Steady calculation and transient analyses can be performed
• The working fluid is selected from a list of coolants that are already defined in the library: R113; R245fa, R410a, R141b, R134a, water and ethanol. However users can use their own working fluid as well.
• The thermo-physical properties of the working fluids can be calculated either by means of external software REFPROP or by interpolating in fluid properties look-up tables
ORC library components are compatible with those of the TURBO library. This allows the user to create a combined model in which components from both libraries interact
• Components can be used in thermo-design mode or in off-design mode, just by switching an input parameter

The following figure shows an application example of an unmixed turbo-fan engine coupled to an ORC cycle heat recovery system.