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Title: Periodic equivalence ratio modulation method and apparatus for controlling combustion instability

Abstract

The periodic equivalence ratio modulation (PERM) method and apparatus significantly reduces and/or eliminates unstable conditions within a combustion chamber. The method involves modulating the equivalence ratio for the combustion device, such that the combustion device periodically operates outside of an identified unstable oscillation region. The equivalence ratio is modulated between preselected reference points, according to the shape of the oscillation region and operating parameters of the system. Preferably, the equivalence ratio is modulated from a first stable condition to a second stable condition, and, alternatively, the equivalence ratio is modulated from a stable condition to an unstable condition. The method is further applicable to multi-nozzle combustor designs, whereby individual nozzles are alternately modulated from stable to unstable conditions. Periodic equivalence ratio modulation (PERM) is accomplished by active control involving periodic, low frequency fuel modulation, whereby low frequency fuel pulses are injected into the main fuel delivery. Importantly, the fuel pulses are injected at a rate so as not to affect the desired time-average equivalence ratio for the combustion device.

Inventors:
 [1];  [2];  [1]
  1. Morgantown, WV
  2. Baltimore, MD
Issue Date:
Research Org.:
National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV (United States)
OSTI Identifier:
872986
Patent Number(s):
6059560
Assignee:
United States of America as represented by United States (Washington, DC)
Patent Classifications (CPCs):
F - MECHANICAL ENGINEERING F23 - COMBUSTION APPARATUS F23C - METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  {A CARRIER GAS OR} AIR 
F - MECHANICAL ENGINEERING F23 - COMBUSTION APPARATUS F23D - BURNERS
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
periodic; equivalence; ratio; modulation; method; apparatus; controlling; combustion; instability; perm; significantly; reduces; eliminates; unstable; conditions; chamber; involves; modulating; device; periodically; operates; outside; identified; oscillation; region; modulated; preselected; reference; according; shape; operating; parameters; preferably; stable; condition; alternatively; applicable; multi-nozzle; combustor; designs; whereby; individual; nozzles; alternately; accomplished; active; control; involving; frequency; fuel; pulses; injected; main; delivery; importantly; rate; affect; desired; time-average; significantly reduce; main fuel; fuel delivery; equivalence ratio; method involves; combustion chamber; significantly reduces; operating parameters; ratio modulation; periodic equivalence; active control; combustion device; method involve; operating parameter; desired time; controlling combustion; /431/60/

Citation Formats

Richards, George A, Janus, Michael C, and Griffith, Richard A. Periodic equivalence ratio modulation method and apparatus for controlling combustion instability. United States: N. p., 2000. Web.
Richards, George A, Janus, Michael C, & Griffith, Richard A. Periodic equivalence ratio modulation method and apparatus for controlling combustion instability. United States.
Richards, George A, Janus, Michael C, and Griffith, Richard A. Sat . "Periodic equivalence ratio modulation method and apparatus for controlling combustion instability". United States. https://www.osti.gov/servlets/purl/872986.
@article{osti_872986,
title = {Periodic equivalence ratio modulation method and apparatus for controlling combustion instability},
author = {Richards, George A and Janus, Michael C and Griffith, Richard A},
abstractNote = {The periodic equivalence ratio modulation (PERM) method and apparatus significantly reduces and/or eliminates unstable conditions within a combustion chamber. The method involves modulating the equivalence ratio for the combustion device, such that the combustion device periodically operates outside of an identified unstable oscillation region. The equivalence ratio is modulated between preselected reference points, according to the shape of the oscillation region and operating parameters of the system. Preferably, the equivalence ratio is modulated from a first stable condition to a second stable condition, and, alternatively, the equivalence ratio is modulated from a stable condition to an unstable condition. The method is further applicable to multi-nozzle combustor designs, whereby individual nozzles are alternately modulated from stable to unstable conditions. Periodic equivalence ratio modulation (PERM) is accomplished by active control involving periodic, low frequency fuel modulation, whereby low frequency fuel pulses are injected into the main fuel delivery. Importantly, the fuel pulses are injected at a rate so as not to affect the desired time-average equivalence ratio for the combustion device.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2000},
month = {1}
}

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