Thermo Special Interest Group met on May 30, 2023 from 10 am till noon (Central European Summer Time).
- Progress the errata and clarifications on Thermodynamic and Physical Properties interface specification v1.1
Highlights
Thermo SIG reviewed the modifications brought to section 5.2.4 of version 1.1 of the Thermodynamic and Physical Properties interface specification. Section 5.2.4 details the behavourial requirements set on a Material Object. The review was conducted to ensure that the wording used does not leave space to several different interpretations.
This review led to a heated discussion on the responsabilities assumed by the Material Object.
A consensus was found to express that a Material Object assumes sole responsibility for providing values of Physical Properties to its client, for example to a Unit Operation.
While the CAPE-OPEN standard expects a thermodynamic source, such as a Property Package, to be as complete as possible regarding the Physical Properties it is capable to deliver values for, it may happen that a Physical Property, requested by a Unit Operation, is not available from the Property Package. Rather than raising an exception on being requested to provide such a Physical Property missing on the Property Package, the Material Object is definitely allowed to jump in, and to provide the corresponding value to the Unit Operation.
While this provision may lead to thermodynamic inconsistencies if not completely properly handled, it may also, for example, permit a temperature derivative of a Physical Property to be calculated numerically, through perturbations, by a Material Object and provided to the Material Object client (typically a Unit Operation, but not only), if the Property Package does not support such derivative, but is just capable to deliver values of this Physical Property. This is the role of a “clever” Material Object.
The part in section 5.2.4 about which Physical Properties are mandatorily or optionnally supported by a Material Object, was also reworded for the purpose of making it clearer. The introduction to section 5.2.4 was modified as well, taking off it the necessity to assure consistency of data handled through CAPE-OPEN interfaces. The CAPE-OPEN standard is delivering interoperability between software applications while not systematically verifying how sound and consistent data transferred through CAPE-OPEN interfaces is.
Next conference call is scheduled for June 6, 2023.
