US 12,305,853 B2
Integrated flare combustion control
Daniel Robert Johnson, Methuen, MA (US); Chong Tao, Winchester, MA (US); Joshua Daniel Brooks, Houston, TX (US); Randy Scott Pfenninger, Groton, MA (US); and Lei Sui, Winchester, MA (US)
Assigned to Baker Hughes Holdings LLC, Houston, TX (US)
Filed by Baker Hughes Holdings LLC, Houston, TX (US)
Filed on Aug. 17, 2020, as Appl. No. 16/995,056.
Application 16/995,056 is a continuation of application No. 15/633,204, filed on Jun. 26, 2017, granted, now 10,746,400.
Claims priority of provisional application 62/355,744, filed on Jun. 28, 2016.
Prior Publication US 2021/0071865 A1, Mar. 11, 2021
Int. Cl. G05B 21/00 (2006.01); F23G 5/50 (2006.01); F23G 7/06 (2006.01); F23G 7/08 (2006.01); F23N 1/00 (2006.01); F23N 5/00 (2006.01); G05B 19/418 (2006.01)
CPC F23G 5/50 (2013.01) [F23G 7/065 (2013.01); F23G 7/085 (2013.01); F23N 1/002 (2013.01); F23N 5/003 (2013.01); G05B 19/418 (2013.01); F23G 2207/10 (2013.01); F23G 2207/112 (2013.01); F23N 2225/00 (2020.01); G05B 2219/41108 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A flare combustion control system comprising:
an ultrasonic flowmeter configured to measure a sound speed of a flare vent gas flowing within a flare gas conduit;
a pressure sensor and a temperature sensor, configured to measure a pressure and temperature of the flare vent gas, respectively;
a fuel gas control valve configured to control a flow rate of a supplemental fuel gas flow delivered from a supplemental fuel gas conduit to the flare gas conduit upstream from the ultrasonic flowmeter; and
a flare combustion controller communicatively coupled to the ultrasonic flowmeter, the pressure sensor, the temperature sensor and the fuel gas control valve, and comprising at least one processor programmed to perform operations including:
receive the measured sound speed, the pressure, and the temperature from the ultrasonic flowmeter, the pressure sensor, and the temperature sensor, respectively;
determine, based on the measured sound speed, the pressure, and the temperature, an estimated molecular weight of the flare vent gas;
determine, based on the measured sound speed, the pressure, the temperature, and the estimated molecular weight, a predicted sound speed;
compare the measured sound speed to the predicted sound speed;
update the estimated molecular weight based on the comparing;
repeat the steps of determining the estimated sound speed, comparing the measured sound speed to the predicted sound speed, and updating the estimated molecular weight until the predicted sound speed is approximately equal to the measured sound speed;
determine, based on the estimated molecular weight, a net heating value of the flare vent gas; and
adjust a valve position of the fuel gas control valve based on the net heating value of the flare vent gas.