neqsim-process-modeling

name	neqsim-process-modeling
description	Process modeling and flowsheet construction patterns for NeqSim. USE WHEN: building executable NeqSim process simulations, ProcessSystem flowsheets, or runnable process models with streams, separators, compressors, heat exchangers, valves, pumps, distillation columns, recycles, adjusters, topology checks, result extraction, and engineering validation.
last_verified	2026-05-31

NeqSim Process Modeling Skill

Build executable NeqSim process simulations from engineering descriptions. This skill is the process-flowsheet layer between thermodynamic fluid setup and downstream specialists such as mechanical design, safety, plant data, and reporting.

Use When

• Building a ProcessSystem or ProcessModel flowsheet from a process description.
• Connecting equipment such as streams, separators, compressors, coolers, heaters, heat exchangers, pumps, valves, pipes, mixers, splitters, recycles, adjusters, and distillation columns.
• Extracting process results with units, compositions, duties, powers, phase splits, mass balances, energy balances, or equipment profiles.
• Preparing a steady-state process base case for mechanical design, relief sizing, flow assurance, dynamic simulation, plant-data comparison, or optimization.

Core Workflow

1. Define the fluid using the EOS and component sequence from neqsim-api-patterns.
2. Create feed streams with explicit temperature, pressure, and flow units.
3. Add equipment in topological order to a ProcessSystem.
4. Connect by outlet stream objects, for example separator gas outlet to compressor inlet or valve outlet to downstream separator.
5. Run once after assembly unless recycle initialization requires a staged solve.
6. Validate results using conservation checks, phase sanity checks, equipment limits, and applicable standards.
7. Report outputs with units and include assumptions for missing design data.

Modeling Choices

Situation	Recommended Pattern
Single train, linear or branched flowsheet	One ProcessSystem
Multiple areas with cross-area streams	Multiple ProcessSystem objects in a ProcessModel
PFD/P&ID or unstructured text input	Use neqsim-process-extraction first
Distillation or fractionation	Load neqsim-distillation-design
Startup, shutdown, controllers, inventory dynamics	Load neqsim-dynamic-simulation
Turndown or control valve operability	Load neqsim-controllability-operability
Platform-scale separation/recompression	Load neqsim-platform-modeling

Required Checks

• Temperatures and pressures use explicit units in setters.
• Fluids have a mixing rule before simulation.
• Branching streams use cloned fluids or well-defined equipment outlet streams.
• Every equipment item has a unique name inside the process.
• Recycles and adjusters are added after their connected equipment.
• Results include mass balance, expected pressure ordering, and physically reasonable phase splits.
• Compressor, pump, heat exchanger, separator, and pipeline cases identify applicable standards through neqsim-standards-lookup.

Related Skills

• neqsim-api-patterns — fluid setup, equipment APIs, and result extraction.
• neqsim-input-validation — pre-simulation physical bounds and component checks.
• neqsim-troubleshooting — flash and process convergence recovery.
• neqsim-process-extraction — JSON builder and route extraction from documents.
• neqsim-notebook-patterns — executable notebook structure and devtools setup.