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OpenFlowsheet

PyPI

OpenFlowsheet is an open, equation-oriented process simulator built for people and coding agents. Models, equations, numerical strategies, validity limits and evidence are explicit objects: a flowsheet is a validated document, a solve is a job with a typed result, and every converged run comes with a certificate from an independent verifier that says what it checked — and what it does not claim.

  • Equation-oriented, with process-specific numerics. Damped Newton on the whole flowsheet, tearing and Anderson acceleration for recycles, homotopy and restart recovery; CasADi supplies the exact derivatives.
  • Evidence, not just numbers. A run is VERIFIED, RELAXED, UNVERIFIED or FAILED, with every residual, balance and specification check listed. Numerical verification, empirical validation and optimality are kept apart, and only the first is claimed for a solve.
  • Refusals are results. An unsupported model, a state outside a property model's domain or an incomplete specification ends in a typed refusal, never in a quietly extrapolated answer.
  • One contract, four doors. Python (LocalApplication), the openflowsheet command line, HTTP and MCP all run the same operations with the same results.

What it can model

Area What is available
Property bases IAPWS-95 water; CoolProp Helmholtz equations of state for one pure fluid (optional extra); the Wilson activity model with an ideal-gas vapour for methanol–ethanol–water; Peng–Robinson for the ammonia-synthesis loop; the synthetic SYN-001 test system
Units Pumps, compressors, turbines, valves, heaters and coolers, mixers, splitters, flashes, heat exchangers, reactors, and countercurrent equilibrium-stage distillation columns — see the unit catalogue
Flowsheets Acyclic and recycle flowsheets, solved equation-oriented or by tearing, with specifications on streams or units
Studies Parametric sensitivities, sweeps and estimation on registered flowsheets; an optional NLP bridge (Pyomo/Ipopt)
Evidence Solution certificates, replay bundles that reproduce a run, and the complete project history

What is not supported is listed plainly in Limitations and support: anything not listed there as supported is unsupported.

Status

OpenFlowsheet is in early development. Released versions are on PyPI, and the changelog says what each release contains and what it does not claim. Comparisons with IDAES, DWSIM and BioSTEAM on shared cases agree to tight tolerances; because those tools share the equations, this is verification, not validation. Human numerical and process-modelling review of the project is still pending.

Where to go next