Lean Blowout Detection Techniques for Partially Premixed Flames in a Dump Combustor - Novel Combustion Concepts for Sustainable Energy Development - page 220

Fig. 15 Variation of anomaly measure with for air fl ow Q air = 85 LPM, L fuel = 35 cm (port 1)

Ф

for different nominal conditions taken: a = 0.82, b = 0.81, c = 0.8, and d = 0.79

Ф Ф Ф Ф

The range of operating condition where the combustor exhibits stable fl flame is

long; it is preferable to select the nominal condition nearer to LBO where ame

shows stable operation. We explore the technique by varying the nominal condition
with different equivalence ratios, which is shown in Fig. 15 a

fl

d, and the results
obtained are quite satisfactory and a chosen value of threshold can be used for
sensing LBO.
As noted earlier, Φ LBO is observed to be dependent on L fuel , i.e., the degree of
premixing. In order to explore the applicability of anomaly measure LBO predictor
for various degrees of premixing permitted by our setup (characterized by L fuel ),we
present the variation of anomaly measure with

-

Φ LBO calculated with simple
partitioning and ASSP for different L fuel with nominal condition close to

Φ /

= 0.80

Ф

for different flow conditions shown in Figs. 16 and 17 . The implication of this

observation is that the anomaly measure calculated with simple partition acquires a
value in the range 0.9

fl

1.1 in all the cases irrespective of the premixing length used

-