Nominal Size Selection, Heat Loss & Hydraulic Calculation of Pipeline Systems
||The List of Changes
- A bug in fluid components search and input has been fixed;
- The calculation of the fluids containing petroleum fractions with a boiling point below 0Ñ using the "STARS" library has been improved;
- The error in calculation of two-phase flow in pipelines containing closed ending branches has been fixed;
- An error leading to improper use of the pressure drop on the equipment at two-phase flow calculation has been fixed;
- The use of computer RAM in two-phase flow calculation using the "STARS" library has been optimized;
- Added support of the "START" files 4.82 R2 and later versions.
- Ñalculation of two-phase gas-liquid flows with boiling and condensation in branched pipelines (without recycles) is implemented.
- Group pipeline elements selection, group copy/cut/delete operations for both tree and graphic windows are added.
- Waterhammer calculation has been improved:
- Speed of waterhammer calculation has been dramatically increased;
- Column separation (cavitation) effect is now considered;
- Several consecutive pipeline components can now be calculated;
- Viewpoints are now checked to be not too close to the reflecting node or an element with a changing statein order to accurately calculate the magnitude of the pressure and velocity peaks;
- Waterhammer caused by the opening/closing of the butterfly valve is now more accurately calculated;
- Corrections has been made in the waterhammer calculation for pipelines with manually entered inflows/outflows in nodes;
- A bug has been fixed that deals with invalid reducer length at calculation.,.
- Significant changes have been made to the two-phase flow calculation module:
- Severe slugging flow in pipelines with gas-liquid flow is now predicted.
- Phase change calculation algorithm has been improved - phase transitions points are now determined more accuratey.
- Calculation of Mach numbers for water-steam mixtures using the WaterSteamPro library now is more precise.
- Some corrections have been made to the calculation of pipelines containing branches with negative flowrates.
- The inaccuracy in two-phase flow calculation of temperature and enthalpy after the orifice has been corrected.
- The inaccuracy of hydraulic resistance calculation for two-phase flow on vertical pipes is fixed.
- The error in the two-phase calculation settings files causing frictional losses on bends, elbows and reducers to be considered differently than on straight pipes has been fixed.
- Refinements and improvements to other calculation functions of the program have been made:
- Internal heat transfer coefficient (from the fluid to the pipe wall) at heat analysis was corrected, thus improving the accuracy of calculations of uninsulated pipelines with strong cooling/warming during flow.
- Normalization algorithm of the fluid compounds compositions has been improved.
- A bug causing static pressure differences in the closed branches of the pipeline to be inaccurately considered has been fixed.
- A rare bug of the incorrect Mach numbers and velocities calculation and output before the pipe enter and after pipe exit has been fixed.
- Significant improvements have been made to the user interface of the program:
- Flow distribution calculation convergence criteria can be now defined by the end user that enables analysis of complex pipelines with convergence problems and speeds up the calculation by reducing its accuracy.
- The modeling of pipelines with looped circuits is optimized.
- Design of the output forms has been improved – their structure is now adapted to export to editable formats (.docx and .rtf).
- A rare bug causing problems with the printing of the pipeline input data on has been fixed.
- Some other minor bugs and typos have been fixed.
- Parameter selection feature has been introduced that allows maintaining specified flow parameters at any pipeline location:
- Waterhammer module has been upgraded:
- It is now possible to consider cavitation during waterhammer analysis (in beta-mode)
- Dampers (waterhammer arrestors) now may be simulated
- Customizable reports are added with waterhammer calculation results and charts
- A list has been added to view elements with changed state, boundary conditions in nodes and dampers characteristics
- Hydraulic friction at waterhammer is now calculated more precisely.
- Topological pipeline analysis has been added that allows viewing both unconnected and computationally independent pipeline parts.
- Algorithm of heat and hydraulic analysis of long gas/steam pipelines with big pressure loss has been optimized to achieve better convergence.
- Joule-Tomson effect for gas is now considered more precisely that has refined heat and hydraulic analysis of long steam pipelines and also improved its convergence.
- A number of improvements of hydrate calculation via PVTSim have been made:
- Equation of state used in phase equilibria calculations via PVTSim can now be selected by user,
- Database of components and reference constants has been upgraded to that of the latest PVTSim version;
- Program warning and error messages during analysis have been optimized, including:
- Messages of aggregate state changing and wrong aggregate state during heat and hydraulic analysis of pipelines with single-phase fluids;
- Messages at calculating pipelines with pumps having invalid pump head curve definition;
- A bug in heat analysis of gas pipelines containing control valves has been fixed.
- Analysis of two-phase flows in pipelines with big hydrostatic pressure differences and low pressure has been refined.
- Liquid flow with negligibly small velocities are now calculated more precisely.
- “Recalc on Graphics” command now more accurately calculates projections of closing loop pipes.
- Input data report has been modified:
- Thermal insulation is now displayed more correctly;
- Fluid data display is now optimized.
- A number of heat and hydraulic pipeline analysis bugs have been fixed, including that of pipelines:
- having closed branches,
- having branches with upstream flows.
- A bug on removing pump NPSHR curve points has been fixed.
- “Insert node” command has been optimized to refine the location of new node for very long pipes.
- A rare bug on calculating phase equilibria of fluid containing one oil fraction has been fixed.
- A bug has been fixed that deals with considering roughness at hydraulic analysis of two-phase flow by TUFFP Unified model.
- Some other minor bugs and typos have been fixed.
- Two-phase flow calculation using “Unified model” by TUFFP (Tulsa University Fluid Flow Project) has been significantly improved:
- automatic selection of closure relations for “Unified model” has been implemented – it’s based on newest data of TUFFP experimental database which allows to improve the convergence of calculation results to the experimental data;
- new option of closure relations manual selection for “Unified model” has been implemented (for more precise adjustment of two-phase flow calculation methods);
- latest version of TUFFP ”Unified model” has been plugged to Hydrosystem (including newest experimental database).
- Integration with Hydrate Open Structure of PVTSim thermodynamic package (by Calsep) has been developed – it allows to call PVTSim for hydrates calculation in pipeline straight from Hydrosystem.
- Hydrosystem interface with “START” software has been improved:
- the checking of pipeline structure at ctp-files import has been added – it allowed to prevent the import of incorrect pipelines containing the connections of 4 or more pipes in one single node;
- the bug of incorrect displaying of the pipelines with zero-length pipes (imported from START) has been fixed.
- The range of the viscosities at which automatic pump head curve correction is turned on (for liquids with high viscosities) has been revised.
- Slight improvements in calculation diagnostics for pipelines with control valves has been made:
- incorrect message at negative pressure drop on control valve has been excluded;
- nodes inflow/outflow displaying in calculation results window has been fixed.
- Gas pipelines heat calculation algorithm has been significantly optimized for extended pipelines with very high pressure drop values.
- The algorithm of calculation for pipelines with “dangling” circuits (connected with the rest of the pipeline with only one branch) has been improved.
- Flow pattern map drawing for two-phase flow has been improved.
- Some minor bugs have been fixed.