Flare stack simulation

N relief inlets -> burned (terminal, no outlet)

Governing equations

The exact equations the solver works for a flare stack — the same math shown in the app's "Theory" panel, not a black box.

$W$

total simultaneous relief load [kg/s]

$A_{tip}$

flare tip area [m^2]

$\rho$

gas density at the tip [kg/m^3]

$\mathrm{Ma}$

tip exit Mach number

$q$

radiant flux at the receiver [W/m^2]

$Q$

heat release [W]

$D$

slant distance to the receiver [m]

$D_{excl}$

exclusion distance for a permissible flux level [m]

$\tau$

atmospheric transmissivity

$F$

fraction of heat radiated

$q_{perm}$

API 521 permissible flux (4730 personnel, 6310 equipment) [W/m^2]

Parameters

tip_diameter [m, required]; optional header_diameter [m] + header_length [m] (built-up back-pressure check), stack_height [m] and receiver_distance [m] (API 521 radiation), set_pressure [Pa, gauge — else the lowest relieving valve on the header is inferred from the inlet pressures], allowable_backpressure_fraction [default 0.10], friction_factor, fraction_radiated [default 0.2], transmissivity [default 0.8], heat_of_combustion [J/kg — else computed from the relief gas composition].

Example flowsheets that use it