An Experimental Study of the Effects of Waste-Gas Composition and Crosswind on Non-assisted Flares Using a Novel Indoor Testing Approach

Non-assisted
flares are a significant fraction of the flares in
use today, but there are few studies at real-world conditions. The
current work presents a novel indoor testing facility for characterizing
non-assisted flares including the effects of crosswind. Multiple flare
designs were tested using flare gas flow rates from 1.8 to 113 thousand
standard cubic feet per day (MSCFD) with natural gas and propane at
crosswind speeds from 0 to 13.1 miles per hour (MPH). Combustion efficiency
(CE) and destruction removal efficiency of methane (DRECH4) were determined for all operating conditions. CE >
98% was observed for low crosswind conditions for all flare geometries;
however, the 3-in. pipe flare underperformed (CE < 96.5%) for natural
gas at higher wind speeds and lower flare gas flow rates (e.g., 6.8
MSCFD and >4.6 MPH). Engineered burners significantly improved
performance.
The results are discussed in the context of EPA assumptions, prior
pipe flare wind-tunnel studies, and proposed scaling relations.