Calculations of the Heat Release Rate by Oxygen Consumption for Various Applications.
Calculations of the Heat Release Rate by Oxygen
Consumption for Various Applications.
Parker, W. J.
NBSIR 81-2427-1; 41 p. March 1982.
Journal of Fire Sciences, Vol. 2, No. 5, 380-395,
Available from: National Technical Information Service
(NTIS), Technology Administration, U.S. Department of
Commerce, Springfield, VA 22161.
1-800-553-6847 or 703-605-6000;
Fax: 703-605-6900; Rush
Service (Telephone Orders Only) 800-553-6847;
Order number: PB82-192956
calorimeters; fire tests; heat release rate; oxygen
consumption; room fires; tunnel tests; oxygen analyzers;
The oxygen consumption technique is emerging as a
powerful tool for determing the heat release rate in a
number of diverse fire test applications, including room
fire tests, fire endurance tests, the ASTM E 84 tunnel
test, and vaious heat release rate calorimeters.
Depending upon the constraints of the test, the accuracy
required, the availability of instrumentation and
computational facilities, and the willingness to put up
with experimental inconveniences, a number of
instrumentation options have been considered--each of
which require different calculational procedures. The
purpose of this report is to develop the equations in a
general way and show how to adapt them to various
applications such as: closed systems versus open
systems; trapping carbon dioxide before it reaches the
oxygen analyzer, measuring it, or assuming that it is
equal to the reduction in oxygen concentration; ignoring
carbon monoxide or measuring it; accounting for the
density of the exhaust gases or assuming that it is the
same as for air; using a high temperature oxygen cell
which measures the oxygen concentration in the exhaust
duct directly or a paramagnetic analyzer for which
corrections must be made for eater vapor trapping;
taking into account or ignoring the ambient
concentration of water vapor and carbon dioxide; and,
improving the accuracy for open systems by monitoring
the water vapor in the exhaust duct. The equation
developed here should be useful to anyone setting up a
new system and will provide a means of calculating the
errors which might be expected when simplified
procedures are used.