US 12,454,919 B2
Exhaust cooling injection for improved turndown
Hany Rizkalla, Stuart, FL (US)
Assigned to Power Systems Mfg., LLC, Jupiter, FL (US)
Filed by Power Systems Mfg., LLC, Jupiter, FL (US)
Filed on Aug. 1, 2024, as Appl. No. 18/791,552.
Claims priority of provisional application 63/516,917, filed on Aug. 1, 2023.
Prior Publication US 2025/0043735 A1, Feb. 6, 2025
Int. Cl. F02C 9/18 (2006.01); F01K 23/10 (2006.01); F02C 7/141 (2006.01); F02C 9/26 (2006.01)
CPC F02C 9/18 (2013.01) [F01K 23/10 (2013.01); F02C 7/141 (2013.01); F02C 9/26 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A method of operating a gas turbine engine during a period of turndown, the method comprising:
continuously decreasing a load of the gas turbine engine below a base load;
as the load is continually decreased, continuously determining a reference load for the gas turbine engine;
when the reference load reaches a first threshold value, operating an inlet bleed heat (IBH) system of the gas turbine engine according to a first schedule;
when the reference load reaches a second threshold value, operating the IBH system according to a second schedule;
when the reference load reaches a third threshold value, operating an exhaust bleed (ExB) system of the gas turbine engine according to a third schedule; and
when the reference load reaches a fourth threshold value:
continuously measuring an exhaust gas temperature of the gas turbine engine at an inlet of a heat recovery steam generator coupled in flow communication to the gas turbine engine, and
maintaining the measured exhaust gas temperature at a predetermined threshold temperature value by continuously adjusting an exhaust gas temperature setpoint of the gas turbine engine while the gas turbine engine continues operating at a reference load below the fourth threshold value.