scholarly journals Detailed Derivations of Formulas for Heat Release Rate Calculations Revisited: A Pedagogical and Systematic Approach

2019 ◽  
Vol 124 ◽  
Author(s):  
Jiann C. Yang
Keyword(s):  
Oxygen Consumption ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Chemical Engineering ◽  
Chemical Species ◽  
Flow Process ◽  
Generalized Framework ◽  
Oxygen Consumption Calorimetry ◽  
Engineering Practices

The derivations of the formulas for heat release rate calculations are revisited based on the oxygen consumption principle. A systematic, structured, and pedagogical approach to formulate the problem and derive the generalized formulas with fewer assumptions is used. The operation of oxygen consumption calorimetry is treated as a chemical flow process, the problem is formulated in matrix notation, and the associated material balances using the tie component concept commonly used in chemical engineering practices are solved. The derivation procedure described is intuitive and easy to follow. Inclusion of other chemical species in the measurements and calculations can be easily implemented using the generalized framework developed here.

Calculations of the Heat Release Rate by Oxygen Consumption for Various Applications

1984 ◽  
Vol 2 (5) ◽  
pp. 380-395 ◽  
Author(s):  
W.J. Parker
Keyword(s):  
Oxygen Consumption ◽  
High Temperature ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Fire Tests ◽  
Total Heat Release ◽  
Exhaust Duct ◽  
Closed Systems ◽  
Gas Burner

The calculation of heat release rate by oxygen consumption is based on the assumption that all materials release approximately the same amount of heat per unit mass of oxygen consumed. This technique is now being employed to determine the heat release rate of materials in various heat release rate cal orimeters. Other uses include the heat release rate of assemblies in the fire en durance furnaces and the total heat release rate in room fire tests. These dif ferent applications lead to different experimental procedures which require dif ferent formulas. The experimental choices or constraints include open or closed systems, paramagnetic or high temperature oxygen analyzers, CO2 analyzers or CO2 traps, and the use of a gas burner whose heat release rate must be deducted from the total. Various assumptions about CO levels in the exhaust duct and vitiation and humidity in the incoming air are made. General formulas for the heat release rate by oxygen consumption are developed in this paper from which the formulas for specific applications can easily be derived.

scholarly journals INVESTIGATION THE FIRE HAZARD OF PLYWOODS USING A CONE CALORIMETER

Wood Research ◽  
2021 ◽  
Vol 66 (6) ◽  
pp. 933-942
Author(s):  
ZHIGANG WU ◽  
XUE DENG ◽  
LIFEN LI ◽  
LIPING YU ◽  
JIE CHEN ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Cone Calorimeter ◽  
High Efficiency ◽  
Fire Hazard ◽  
Mass Loss Rate ◽  
Fire Retardant ◽  
Safety Level

A high-efficiency fire retardant composition was prepared with dicyandiamide, phosphoric acid, boric acid, borax, urea and magnesium sulfate and it was used to process veneers which were then to prepare the plywood. Meanwhile, heat release and smoke release from combustion of plywood were tested by a cone calorimeter, including heat release rate, mass loss rate, CO yield, CO2 yield and oxygen consumption. Results showed that the plywood with this fire retardant treatment had the better flame-retardant performance and smoke suppression effect as well as the stronger char-forming capability compared to plywood without fire retardant treatment. The average heat release rate, total heat release, average effective heat of combustion, total smoke release, CO yield and oxygen consumption of the plywood with fire retardant treatment were decreased by 63.72%, 91.94%, 53.70%, 76.81%, 84.99% and 91.86%, respectively. Moreover, the fire growth index of plywood treated by fire retardant was relatively low (3.454 kW·m-2·s-1) and it took longer time to reach the peak heat release rate, accompanied with slow fire spreading. The fire performance index was relatively high (0.136 s·m2·kW-1) and it took longer time to be ignited, thus leaving a long time for escaping at fire accidents. The fire hazard of plywood with fire retardant treatment was low, and its safety level was high.

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