Features and Advantages

To analyze a piping system for hydraulic and thermal effects it is necessary to simulate its behavior on three scale levels: pipe cross section, pipe/branch run, and the whole piping network – and then link and solve these models together.

At the cross-sectional scale it is necessary to define the type of fluid flow (laminar, turbulent, choked, or subsonic, flow pattern for multiphase flow – stratified, annular, intermitted, etc.), and the specifics of heat exchange between fluid and environment through pipe wall and thermal insulation. This knowledge is then used when calculating integral parameters of the flow and heat exchange (pressure gradient, heat losses per length, etc.) and following up how all fluid parameters change along the pipe/branch and all over the network. This would be impossible without access to most reliable thermodynamic data provided by software.

PASS/HYDROSYSTEM provides a calculation engine for all necessary fluid properties and phase equilibrium on the base of fluid composition, for a wide spectrum of fluids and applications.

• The proprietary Properties library provides quick property calculation of ~150 most often used organic and non-organic components and their mixtures.
• The proprietary STARS library is focused on applications in the refining and petrochemical industry and allows for calculation of properties for individual fluid components, oil fractions and their mixtures in liquid and gas phases. This database contains more than 1600 components. STARS can also automatically compute gas-liquid phase equilibrium and check the validity of fluid phase entered.
• The GERG-2008 library allows calculation of natural gas thermodynamic properties and gas-liquid phase equilibrium based on the popular GERG-2008 equation of state.
• The WaterSteamPro module provides accurate calculations of water and steam fluid properties on the basis of IAPWS-IF97 equations.

For more advanced fluid properties and phase equilibrium calculations the program can use the Simulis Thermodynamics library by ProSim S.A.. This library covers Oil and Gas, Chemical, Biochemical, and other industries and provides a wide range of modern methods of physical properties, gas-liquid, and liquid-liquid phase equilibrium calculation for mixtures of more than 3000 compounds and oil fractions.

For hydrate formation prediction the program can use the Hydrate Open Structure module of the PVTSim library by Calsep, which can be purchased as a separate product.