.Buildings.DHC.BaseClasses.Steam.PartialTwoPortTwoMedium

Information

This partial model defines an interface for components with two ports and separate medium definitions at each port. The component transports fluid between two ports without storing mass or energy. The treatment of the design flow direction and of flow reversal are predefined based on the parameter allowFlowReversal.

This model is intended for steam heating applications, where phase change is inherently present. The split-medium approach enables a numerically-efficient liquid water model (i.e., Buildings.Media.Specialized.Water.TemperatureDependentDensity) to be implemented alongside various water/steam models for other phases. For most applications, an efficient model (i.e., Modelica.Media.Water.StandardWater is suitable as it covers the largest range of pressure-temperature conditions through its implementation of the IAPWS-IF97 water/steam formulation. If a reduce pressure-temperature range is applicable, Buildings.Media.Steam) provides a more efficient implementation. Through the split-medium approach, pressure and density calculations are decoupled, eliminating costly nonlinear systems of equations. This interface model also includes parameters for mass and energy dynamics as well as initialization.

Reference

Hinkelman, Kathryn, Saranya Anbarasu, Michael Wetter, Antoine Gautier, and Wangda Zuo. 2022. “A Fast and Accurate Modeling Approach for Water and Steam Thermodynamics with Practical Applications in District Heating System Simulation.” Preprint. February 24. doi:10.13140/RG.2.2.20710.29762.

Contents

Name	Description
Medium_a	Medium model for port_a (inlet)
Medium_b	Medium model for port_b (outlet)

Revisions

• July 22, 2021 by Kathryn Hinkelman:
• First implementation.