Real-Fluid Property Workbench
Equation-of-state property evaluation for a fixed list of pure and pseudo-pure working fluids. Solve a single state, generate saturation tables, sweep along an isobar or isotherm and plot the actual computed points. Every result carries its model, residual checks and provenance.
Process
Sign convention: work done by the system and heat into the system are positive; ΔU = Q − W is checked by the engine.
Exergy
Physical (thermo-mechanical) exergy only, same fluid at the dead state; no chemical exergy or kinetic/potential terms. Flow exergy applies to streams, non-flow exergy to closed-system mass.
Total cells (pressures × rows) are limited to 2400 and validated before any computation. Compressed-liquid rows also show the textbook approximation v ≈ vf(T), h ≈ hf(T) + vf(P − Psat(T)) and its error against the full model.
Ranges outside the EOS temperature limits are refused, not extrapolated. Reference T uses the same unit as the range.
HEOS — Helmholtz-energy equations of state as implemented by the property engine (for water: IAPWS-95). IF97 — IAPWS Industrial Formulation 1997, offered for water only; it is a distinct region-based formulation and agrees with IAPWS-95 to within its documented tolerances, not exactly.
Fluids: Water, R134a, R1234yf, R32, R410A (pseudo-pure mixture model — not a true multi-component VLE; glide is not represented), Ammonia, CO2, Propane. Reference states are the engine defaults per fluid and cannot be changed here; absolute h, u, s values differ between textbooks, but differences between states do not.
- Input pairs: P-T, P-h, P-s, P-quality, T-quality, T-density. P-T inside the dome is ambiguous and rejected.
- Advanced outputs: kinematic viscosity, compressibility factor Z, isothermal compressibility, volumetric thermal expansion, (∂h/∂T)P and (∂ρ/∂P)T — single-phase only.
- Process paths: isobaric, isochoric, isothermal, isentropic, polytropic (closed system, reversible). Exergy: physical only.
- Two-phase cp, cv, speed of sound and transport values are reported as unavailable with a reason, never as single-phase numbers.
- Transport properties (viscosity, conductivity, Prandtl) have their own validity ranges and may be unavailable where thermodynamic properties exist.
- Near-critical states converge slowly and carry larger uncertainty; solid, metastable and mixture-composition inputs are not supported.
- Ideal-gas tables use the ideal-gas Helmholtz part of: Air — Lemmon et al., J. Phys. Chem. Ref. Data 29 (2000), pseudo-pure dry air of fixed composition; N2 — Span et al. (2000); O2 — Schmidt & Wagner (1985); CO2 — Span & Wagner (1996); H2O — Wagner & Pruss (2002, IAPWS-95); Ar — Tegeler et al. (1999); H2 — Leachman et al. (2009, normal hydrogen); CH4 — Setzmann & Wagner (1991). Entropy is evaluated at ρ = Pref/(RT), never at a real-fluid flash density. No JANAF/NASA polynomial tables are bundled, so there is no second independent ideal-gas source on this page.
- Not implemented: open-system (flow) process paths with irreversibility, gauge pressure input, arbitrary mixtures or user-defined reference states.
Provenance (library, version, formulation citation) is reported by the engine with every result and included in all exports.
Engine: CoolProp 8.0.0 (pinned) — I. H. Bell, J. Wronski, S. Quoilin, V. Lemort, "Pure and Pseudo-pure Fluid Thermophysical Property Evaluation and the Open-Source Thermophysical Property Library CoolProp", Ind. Eng. Chem. Res. 53(6), 2498–2508 (2014), doi:10.1021/ie4033999. Distributed under the MIT licence. Water: IAPWS-95 (HEOS) and IAPWS-IF97 (industrial formulation) as implemented in CoolProp. Remaining limitations are listed above.