4.5. In block 4.5, procedure 100 of FIG. 1 continues at block 1.9 where the maximum ring flame temperature boundary is determined for the A ring. After the maximum temperature boundary is determined for the A ring, procedure 250 continues to block 4.6 where the A ring flame temperature in the operating combustor is reduced by a predetermined number of degrees below its maximum boundary temperature (e.g. 50 degrees Fahrenheit). From block 4.6, procedure 250 continues to block 4.7, where the C ring flag is set to true, and then to block 1.9 of method 100, where mapping of the C ring is performed.
Returning to block 4.2, if the C ring flag is set to true, the procedure continues to block 4.3 where the A ring flag is set to true, and then to block 1.9 of method 100 where the mapping of the A ring begins. Returning to block 4.4, if the flag for either the ABC or BC+2A modes are set to false, procedure 250 ends and method 100 continues at block 1.9 where mapping of the ring is performed in the sequence indicated in the lookup table of block 4.1. ring flame temperaturering flame temperature.
FIG. 7 is a flow chart for a procedure, generally shown as 300, to determine the maximum ring temperature boundary for a given operating mode and bleed level, as is used in block 1.9 of method 100. After starting, emissions are stabilized in block 5.1. After emissions have been stabilized, a number of parameters are recorded using sensors 84-92 within the combustor 10 and an average of each parameter is determined in block 5.2. For example, the average of each parameter might be determined from sensor readings taken over a five second interval. The plurality of operational parameters may include ring flame temperature, various emissions levels (e.g. NOx and CO), bleed level and dynamic pressure level.
After the average of each parameter is determined in block 5.2, mapping device 13 instructs combustion controller 11 to increase the ring flame temperatures in the dome (ring) being mapped by a predetermined number of degrees in block 5.3. For example, the A ring flame temperature may be increased by 20 degrees Fahrenheit while the C ring flame temperature may be increased by 40 degrees Fahrenheit. After the ring flame temperatures are incremented in block 5.3, procedure 300 is delayed a predetermined amount of time (e.g., 5 seconds) in block 5.4 to allow the combustor sensor readings to stabilize. The procedure then continues to block 5.5, where it is determined whether or not the acoustics and blow out avoidance logic (e.g. ABAL) in the controller 11 has been activated in response to the increase in ring flame temperature