Fire/blowdown helper capabilities

This note summarizes the current fire, heat-transfer, and structural integrity helpers available in NeqSim and how to apply them in process simulations.

Fire heat-load modelling

• API 521 pool fire: FireHeatLoadCalculator.api521PoolFireHeatLoad(wettedArea, F) returns the classic total heat input (W) using wetted area and environment factor.
• Generalized Stefan–Boltzmann radiation: FireHeatLoadCalculator.generalizedStefanBoltzmannHeatFlux(...) calculates radiative heat flux (W/m²) from emissivity, view/configuration factor, and flame temperature so callers can compose pool or jet fire scenarios and include shielding/angle effects.

Heat-transfer / wall-temperature treatment

• FireHeatTransferCalculator solves a steady 1-D wall model for wetted and unwetted regions using caller-supplied internal/external film coefficients.
• SurfaceTemperatureResult reports inner/outer metal temperatures and heat flux for each region so process models can track thermal response during depressurization.

Structural integrity / rupture logic

• VesselRuptureCalculator provides thin-wall von-Mises stress plus helpers to compute rupture margin or boolean likelihood when allowable tensile strength is supplied (optionally temperature-dependent when paired with wall temperatures from the heat-transfer step).

Integration with process equipment

• Separators expose wetted and dry surface areas (getWettedArea(), getUnwettedArea()), allowing fire heat loads to follow liquid level during blowdown.
• SeparatorFireExposure.evaluate(...) (also available via separator.evaluateFireExposure(...)) wraps area lookup, heat-load estimation, wall temperatures, and rupture checks into a single call to simplify use inside dynamic process simulations.
• Fire heat input is based on the separator’s geometry and process temperature, not on how much gas is flowing to the flare; flare-rate changes will not alter the radiative or pool-fire heat loads unless they change level/area or temperature.
• Apply fire heat as a separator duty via separator.setDuty(fireResult.totalFireHeat()); the separator’s runTransient call will consume that duty in its energy balance so the process temperature responds to fire loading without manual temperature edits.
• The runnable SeparatorFireDepressurizationExample demonstrates end-to-end use by routing a separator blowdown to a flare while evaluating fire loads, wall temperatures, and rupture margin over time.