Effect of burner geometry on the blowout limits of jet diffusion flames in a co-flowing oxidizing stream

Journal Article · Sat Jun 01 04:00:00 EDT 1996 · Journal of Energy Resources Technology

DOI:https://doi.org/10.1115/1.2792704· OSTI ID:253694

Papanikolaou, N; Wierzba, I ^[1]

---

1. Univ. of Calgary, Alberta (Canada). Dept. of Mechanical Engineering

In many industrial thermal applications, such as gas turbines and furnaces, a fuel jet is burned in the presence of a co-flowing oxidizing stream. This not only enhances the efficiency of the process by maintaining an uninterrupted supply of thermal energy, but it reduces the flame length and NO{sub x} emissions. The effects of changes in the jet nozzle geometry, i.e., nozzle shape and lip thickness, on the blowout limits of jet diffusion flames in a co-flowing air stream were experimentally investigated for a range of co-flow air stream velocities. Circular and elongated nozzles of different axes ratios were employed. Preliminary results showed that nozzles with low major-to-minor axes ratios improved, while high ratios reduced the blowout limit of attached flames compared with that for an equivalent circular nozzle. The nozzle shape had no apparent influence on the blowout limits lifted flames and the limiting stream velocity. The experimental blowout limits of lifted flames were found to be a function of the co-flowing stream velocity and jet discharge area. On the other hand, the stability of attached flames was a function of the co-flowing stream velocity, jet discharge area as well as the nozzle shape. The effect of premixing a fuel with the surrounding air was also studied. Generally, the introduction of auxiliary fuel into the surrounding stream either increased or decreased the blowout limit depending on the type of flame stabilization mechanism prior to blowout. The stability mechanism of the flame was found to be a function of the co-flow stream velocity and the auxiliary fuel employed. Methane was employed as the jet fuel, while methane, propane, ethylene, and hydrogen were used as auxiliary fuels in the co-flowing stream.

• Sponsoring Organization: USDOE
• OSTI ID: 253694
• Journal Information: Journal of Energy Resources Technology, Journal Name: Journal of Energy Resources Technology Journal Issue: 2 Vol. 118; ISSN 0195-0738; ISSN JERTD2
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
08 HYDROGEN
10 SYNTHETIC FUELS
40 CHEMISTRY
BLOWOUTS
COCOMBUSTION
COMBUSTION INSTABILITY
DESIGN
ETHYLENE
EXPERIMENTAL DATA
FLAMES
FLOW RATE
FUEL-AIR RATIO
GAS BURNERS
HYDROGEN FUELS
INHIBITION
METHANE
NOZZLES
PROPANE