Accuracy of the Heat Release Rate Measured in Microscale Combustion Calorimetry

Details

• Creators:
  Guo, Haiqing ; Lyon, Richard E. ; Safronava, Natallia
• Corporate Creators:
  C-FAR Services, LLC ; United States. Department of Transportation. Federal Aviation Administration. William J. Hughes Technical Center ; Technology & Management International
• Subject/TRT Terms:
  Bias Calorimeters Combustion Heat Heat Of Combustion Measurement Microscale Combustion Calorimeter Oxygen Consumption Calorimetry Polymers
• Publication/ Report Number:
  DOT/FAA/TC-TN17/45
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Corporate Publisher:
  United States. Department of Transportation. Federal Aviation Administration. William J. Hughes Technical Center
• Abstract:
  The ASTM standard method for measuring heats of combustion of plastics in microscale combustion calorimetry by the oxygen consumption principle uses only the volumetric flow rate and O2 volume fraction exiting a premixed combustor in the calculation. The carbon dioxide (CO2) generated by complete combustion replaces some or all of the O2 consumed from the dry gas stream, depending on the atomic composition of the fuel, so it can change the volumetric flow rate and affect the flow meter response, which is typically calibrated for pure nitrogen. Consequently, the presence of CO2 in the combustion stream causes a systematic error (bias) in the heat of combustion measurement that increases monotonically with the initial O2 concentration. Accounting for volume changes using the combustion stoichiometry is sensitive to the atomic composition of the fuel and is still subject to the CO2 bias in flow meter response, which can be up to 3%. Accounting for volume changes using both the initial and instantaneous flow rates measured at the terminal flow meter in the calculation and correcting the flow meter response for CO2 using an average combustion stoichiometry is more accurate and less sensitive to material composition. Heats of combustion computed by the new method are in quantitative agreement with theoretical values.
• Format:
  PDF
• Collection(s):
  FAA Fire Safety FAA William J. Hughes Technical Center for Advanced Aerospace
• Main Document Checksum:
  urn:sha-512:38b5a40cfccb25e41592bf3734318fdb3467196875590c284f0921123c479cdb3ae2456765d151cc3001253c2615536f587b9c012006365594af0725c53c96cb
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/57868/dot_57868_DS1.pdf
• File Type:
  [PDF - 562.51 KB ]