The use of chemiluminescence for detection of ignition, temperature, and fuel-to-air ratio of flames

A fast response method for detection of ignition and extinction of liquid spray flames has been improved. Also, a method of determining fuel-to-air ratios and temperatures of pre-mixed, gaseous flames has been developed. Both methods utilize chemiluminescent signals from an OH system centered at 309 nm and a CH system centered at 431 nm. The ignition and extinction method was improved by replacing an optical system composed of lenses and a monochromator by a system composed of a fiber optic cable and band pass interference filters. The use of a solid-state photodiode instead of a photomultiplier tube was investigated. Transient histories of the OH and CH signals were recorded by performing light-off ignition and intermittent ignition flame tests. These signal histories were compared to histories obtained using the original apparatus. The fuel-to-air ratio and temperature detection method was investigated by recording the spectra of laminar, pre-mixed methane flames of known stoichiometry with a lens, monochromator, and photomultiplier tube set-up and measuring the flame temperatures with a high-temperature Pt-10%Rh thermocouple. Various combinations of signal characteristics were found to be functions of fuel-to-air ratio and temperature. Optimum signals for monitoring with a detector were determined. Recommendations for future work in this area are discussed.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Mechanical Engineering

Department dc:contributor.department

Mechanical Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1991

Author dc:creator

• Johnsson, Erik L.

Committee members dc:contributor.committeemember

• Roby, Richard J.
• O'Brien, Walter F. Jr.
• Roe, Larry A.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-05022009-040621

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/42410