MultiComponentMultiPhase - A Framework for Thermodynamic Properties in Modelica

Optimization-friendly thermodynamic properties of water and steam

“…(Parini, 2015) approximates the subcooled liquid as incompressible fluid and describe the superheated vapor using a cubic equation of state but does not describe any accuracy or region of validity. (Windahl, et al, 2014) investigate requirements for a new media interface, mentioning the benefit of an interface that supports analytic calculations of the Hessian but don't go any further. (Schulze, 2014) focuses on numerically efficient implementation but does so from a simulation perspective.…”

“…The availability of a Modelica implementation of the industry standard of water and steam properties IF97 (Wagner, et al, 2000) helped to spread the usage of the Modelica technology to the energy and power sector (Windahl, et al, 2014  limited support of first order and no support of second order partial derivatives of thermodynamic properties  discontinuous first order partial derivatives at the phase borders between liquid and steam  discontinuous first order partial derivatives at the region boundaries. IF97 is divided into 5 regions that have their own implementation (Wagner, et al, 2000) Figure 1 Density (upper) and its partial derivative with respect to specific enthalpy at constant pressure as a function of specific enthalpy.…”

Implementation of a Property Database and Thermodynamic Calculations in OpenModelica for Chemical Process Simulation

“…Sandrock and de Vaal were the early authors who attempted to provide thermodynamic capability in OpenModelica. A method to connect to external thermodynamic calculations from Modelica was demonstrated by Windahl et al…”

“…Windahl et al indicated that it would be desirable to perform the thermodynamic calculations inside Modelica itself, from a calculation efficiency point of view. This is an important observation, as thermodynamic calculations are known to form a major portion of the simulation time.…”

“…Sandrock and de Vaal 13 were the early authors who attempted to provide thermodynamic capability in OpenModelica. A method to connect to external thermodynamic calculations from Modelica was demonstrated by Windahl et al 14 Windahl et al 14 indicated that it would be desirable to perform the thermodynamic calculations inside Modelica itself, from a calculation efficiency point of view. This is an important observation, as thermodynamic calculations are known to form a major portion of the simulation time.…”