Neqsim Flare Radiation Screening

Flare Radiation Screening

Use this skill for public, educational flare thermal-radiation screening. It estimates radiant heat flux at a distance from a flare using the open API 521 / API 537 point-source model and compares it to common allowable limits so an agent can decide whether a detailed flare-radiation study is needed.

When to Use

• When a user asks how far personnel or equipment must be from a flare for a given relief rate.
• When an agent needs a quick radiation triage to scope a flare or relief study.
• When examples must run without confidential flare designs, vendor tip data, or company radiation criteria.

Inputs

• mass_flow: flared mass flow in kg/s.
• heat_of_combustion: lower heating value of the flared gas in MJ/kg.
• distance: distance from the flame center to the receptor in m.
• fraction_radiated: fraction of heat radiated F, default 0.2.
• transmissivity: atmospheric transmissivity, default 1.0.
• allowable_flux: allowable radiant flux in kW/m2, default 6.31 (API 521 limit for a few seconds of exposure).

Outputs

• total_heat_release_kw: total combustion heat release Q.
• radiant_heat_flux_kw_m2: radiant flux at the receptor.
• allowable_flux_kw_m2: the supplied allowable flux.
• flux_ratio: ratio of computed flux to allowable flux.
• radiation_warning: ok, watch, or high.
• assumptions: public assumptions used by the placeholder model.

Engineering Method

The Python class FlareRadiationModel uses the open API 521 / API 537 point-source equation only:

• the total heat release uses Q = mass_flow * heat_of_combustion.
• the radiant flux uses q = tau * F * Q / (4 pi r^2), treating the flame as a single point source.
• the warning compares the flux to the allowable limit using simple rule-based thresholds.

Common public allowable radiation limits from API 521 are about 4.73 kW/m2 (continuous exposure), 6.31 kW/m2 (a few seconds for escape), and 9.46 kW/m2 (equipment and structures). This is educational and screening-only logic. It does not include flame length and tilt, wind, multi-point flame models, view factors, solar radiation, or shielding. It is not a vendor flare method or a replacement for validated flare-radiation design and a qualified safety review.

Python Usage Pattern

from flare_radiation_screening import FlareRadiationModel

model = FlareRadiationModel()
result = model.evaluate(
    mass_flow=50.0,
    heat_of_combustion=46.0,
    distance=60.0,
)

print(result.radiation_warning)
print(result.radiant_heat_flux_kw_m2)
print(result.flux_ratio)

Related NeqSim Functionality

For validated flare-radiation calculations, redirect to existing NeqSim classes:

• neqsim.process.equipment.flare.Flare — flare model with estimateRadiationHeatFlux for radiant flux at distance.
• neqsim.process.equipment.flare.FlareStack — flare stack sizing and tip selection.
• neqsim.mcp.runners.FlareRadiationRunner — runner that drives flare radiation calculations.

This skill is a public point-source triage layer that decides when to invoke those validated flare classes.

Validation Checklist

• Mass flow, heating value, and distance are positive and in the stated units.
• Example inputs are public and synthetic.
• Tests cover ok, watch, high, and invalid-input cases.
• Results are described as educational screening indicators.
• Real design is redirected to validated methods, API 521, API 537, and qualified review.

Common Mistakes

Limitations

• No proprietary flare designs, vendor tip data, or company radiation criteria are included.
• No flame length, tilt, wind, view factor, or solar radiation is modeled.
• No shielding, dispersion, or multi-flame interaction is considered.

References

• NeqSim repository: https://github.com/equinor/neqsim
• NeqSim Skills Guide: https://github.com/equinor/neqsim/blob/master/docs/integration/skills_guide.md