How to calculate radiation heat of emmision gas vs distance ?

[victor112]

How do you calculate the radiation heat of a emmision gas mixture as a function of distance?In other words is there a way to determine what the temperature will be at a distance?

 

[owg]

You may find that it is more use to calulate the received heat flux. There are good correlations showing the effect of various received heat flux levels on various receptors. AIChE CCPS has correlations for smoky and non smoky flames. These are in the form of spreadsheets accompanying "Guidelines for chemical Process Quantitative Risk Analysis".

HAZOP at

http://www.curryhydrocarbons.ca

 

[MortenA]

Temperature and heat radiation is not easily converted between - because a number of assumptions re. the body that the heat radiation hits are required.

A) Use e.g. API 521 to calculate the radiation at you required distance.

B)
If you know the heat radiation on a body then you _can_ use Planck to calculate the surface temperature corresponding to this heat flux 8assuming that the body reaches a equlibrium temperature where the heat radiated is equal to the the heat received.

This will however give a very high temperature.

Instead you should find an equation for energy loss from free conductivity for this specific body (e.g. horz. pipe, flat plat or whatever). Perry (sec 10= can help you here and so will many other textbooks. If you want to go the extra mile you can also set up a spreadshhet where you do the same for forced convection (wind) and assume different wind spped. free convection (no wind) is however conservative.

Again assume heat in=heat out(equlibrium is max temp).

Best regards

Morten