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[demank]

Dear ALL,

Anyone know how to make a hand calculation of radiation level?
Or any reference to make it?
Normally to calculate this we use such a software like PHAST or CFD.

regards
demank

[gvdlans]

Based on API Standard 521 (5th edition) section 6.4.2.3.3:

If you assume the flame to have a single radiant epicentre:

K = tau*F*Q/(4*pi*D^2)

with:

K = the radiant heat intensity at the object being considered in kW/m2
tau = the fraction of the radiated heat transmitted through atmosphere (use tau = 1 as a conservative approach)
F = the fraction of heat radiated (see table 10 in API std 521, values depend on flame size and fuel type and can range from ~0.1 to ~0.3)
Q = the heat release (based on Lower Heating Value), in kW
D = distance from the epicentre of the flame to the object being considered, in m

You can calculate Q based on fuel flowrate and LHV. For F you can use 0.3 as a conservative value. With values F=0.3 and tau = 1, the formula simplifies to:

K = 0.024*Q/D^2