[an error occurred while processing this directive]
Posted by Boiler Guy on September 04, 2008 at 23:37:56:
In Reply to: Firebx volume posted by Kobe on September 04, 2008 at 22:48:46:
: How do you calculate The Firebox Volume in cubic feet and Furnace Heat Release Rate?
There are different types of heat release rates. I am assuming you are seeking the general volumetric and radiant heat release rates.
The volumetric heat release rate is simply the btu input divided by the volume of the furnace, typically the input is in millions BTU and volume in cubic feet providing a number with the units of btu's per cu ft.
For example if you have a boiler with an input of 10 mmbtu/hr and a volume of 1,000 cu ft the volumetric heat release rate would be 10,000 btu/cu ft.
The radiant hear release rate is the btu input divided by the flat projected heating surface of the furnace in square feet providing an answer in units of btu's per square foot. Depending on what you are trying to accomplish you may have to consider water-cooled areas and not refractory, brick, or other non-water-cooled surfaces in the furnace.
For this example lets say you have a completely water-cooled furnace with a flat-projected area of 1,000 square feet. At 10 mmbtu input the radiant heat release rate would be 10,000 btu/square foot. Consider however if the front, floor, and rear walls are not water-cooled reducing the actual heat transfer surface to 500 sq ft, the radiant heat release rate for this application is now 10 mmbtu / 500 sq ft or 20,000 btu/sq ft.
The above is just very generally speaking. Always contact the boiler manufacturer or your local rep for detailed assistance.
Boiler guy