Hydrogen Systems (`hydrogen-systems`)

Hydrogen Systems

Hydrogen storage, pipe flow, leak and vent screening

Standards catalog

Validation: indicative · Method band: formula

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Indicative method: Ideal gas storage, thin-wall stress and incompressible orifice screening

Assumptions

Linear elastic material behavior unless noted otherwise.
User is responsible for load combinations and load factors per the selected design code.
Design standard (US/EU/ISO) sets unit defaults and screening check labels — not a full code worksheet.

Limitations

High-pressure hydrogen may require real-gas compressibility, material compatibility and code vessel checks.
Leak flow is a first-pass screen and not a relief-device sizing calculation.

Engineering checks

Check	IND	US	EU	ISO
Stored hydrogen mass	implemented	—	—	—
Thin-wall hoop stress	implemented	—	—	—
Leak/vent flow screening	implemented	—	—	—

Purpose

Screen gaseous hydrogen storage mass, energy content, vessel hoop stress, leak mass flow, and vent area using ideal gas relations. Supports preliminary H₂ storage and vent line sizing with code awareness notes.

Physics & theory

Ideal gas storage: $m = P V M / (R T)$ for pressure $P$ , volume $V$ , molar mass $M$ , gas constant $R$ , temperature $T$ . Lower heating value energy $E \approx m \times 120$ MJ/kg for screening. Thin-wall hoop stress $σ_{h} = P r / t$ .

Leak through orifice approximated by $\overset{m}{˙} = C_{d} A 2 ρ Δ P$ with discharge coefficient $C_{d}$ and gas density $ρ = m / V$ . High-pressure hydrogen deviates from ideal gas — compressibility factor $Z$ needed above ~10 MPa for accurate mass.

Advanced systems calculators use lumped-parameter screening models suitable for concept trade studies. Each calculator returns explicit assumptions and warnings arrays documenting model limits. Constants such as ( sigma ) (Stefan–Boltzmann), ( mu_0 ), and ( R ) (gas constant) use SI definitions from the solver source.

Results are not certified for regulatory submission without independent verification against detailed analysis or test data.

Governing equations

m = \frac{P V M}{R T}

σ_{h} = \frac{P r}{t}

\overset{m}{˙} = C_{d} A 2 ρ Δ P

Numerical method

Ideal gas and thin-wall stress (advanced-systems/calculators). Warning when pressure > 10 MPa recommends real-gas and code vessel checks. Vent area back-calculated from leak flow relation.

Inputs

Parameter	Description
`pressure`, `volume`, `temperature`	Storage conditions
`vesselRadius`, `wallThickness`	Vessel geometry
`dischargeCoefficient`, `orificeArea`	Leak path
`ventDeltaP`	Vent differential pressure

Outputs

Stored mass (kg), energy content (J), hoop stress (Pa), gas density, leak mass flow, vent area.

Design codes & checks

Indicative: Storage mass, hoop stress, leak/vent screening
ISO: ISO 19880 hydrogen fueling (context)
US: ASME B31.12 hydrogen piping; NFPA 2 hydrogen technologies

Assumptions & limitations

Ideal gas; high-P requires compressibility correction.
Thin-wall vessel; composite Type IV tanks need specialized rules.
Leak flow is orifice model — not relief valve certified sizing.
Material compatibility (hydrogen embrittlement) not evaluated.

References

NFPA 2:2020. Hydrogen Technologies Code.
ASME B31.12:2019. Hydrogen Piping and Pipelines.
ISO 19880-1:2020. Gaseous hydrogen — Fuelling stations.
SAE J2579. Technical Information Report on Fuel Systems in Fuel Cell Vehicles.
PhyCalcPro verification benchmarks in src/data/verification/ where available for this module.
Beer, F. P., et al. Mechanics of Materials, 8th ed. McGraw-Hill — foundational stress and deformation theory.

Maintainer note: Ideal gas hydrogen storage and vent screening.

Hydrogen Systems

Assumptions

Limitations

Engineering checks

Hydrogen Systems (hydrogen-systems)

Hydrogen Systems (`hydrogen-systems`)