TY - JOUR
T1 - Nozzle effect on heat transfer and CO emission of impinging premixed flames
AU - Li, H. B.
AU - Zhen, H. S.
AU - Leung, C. W.
AU - Cheung, C. S.
N1 - Funding Information:
The Authors wish to thank for the fully financial support from the Research Grants Council of The Hong Kong SAR to the present project PolyU5217/06E (B-Q03R).
PY - 2011/1/15
Y1 - 2011/1/15
N2 - Experiments were carried out to investigate the heat transfer and CO emission characteristics of a premixed LPG/air circular flame jet impinging upwards normal to a flat plate. The effects of nozzle diameter and nozzle arrangement on the heat transfer and CO emission under different fuel/air mixture flow rates (Qmix), equivalence ratios () and normalized nozzle-to-plate distances (H/d) were examined. For the effect of nozzle diameter, burners of nozzle diameters of d = 7.9, 9 and 10 mm were used, and for the effect of nozzle arrangement, a twin-nozzle burner and a triple-nozzle burner, each with a cross-sectional area equal to that of the 9 mm diameter burner, were investigated under different normalized jet-to-jet spacing, S/d, of 3, 5 and 7. The heat transfer rate and CO emission index (EICO) are enhanced significantly with the decrease in the nozzle diameter for the single-nozzle flames. For the twin- and triple-nozzle flames, when the other operational conditions including Qmix, and H/d are invariant, the moderate S/d of 5 gives the highest heat transfer rate, whereas the EICO increases with increasing S/d. Comparison of the flames from all the burners shows that the highest heat transfer rate and EICO are obtained on the single-nozzle burner with the smallest nozzle diameter while the lowest heat transfer rate and EICO are obtained on the triple-nozzle burner with the smallest S/d.
AB - Experiments were carried out to investigate the heat transfer and CO emission characteristics of a premixed LPG/air circular flame jet impinging upwards normal to a flat plate. The effects of nozzle diameter and nozzle arrangement on the heat transfer and CO emission under different fuel/air mixture flow rates (Qmix), equivalence ratios () and normalized nozzle-to-plate distances (H/d) were examined. For the effect of nozzle diameter, burners of nozzle diameters of d = 7.9, 9 and 10 mm were used, and for the effect of nozzle arrangement, a twin-nozzle burner and a triple-nozzle burner, each with a cross-sectional area equal to that of the 9 mm diameter burner, were investigated under different normalized jet-to-jet spacing, S/d, of 3, 5 and 7. The heat transfer rate and CO emission index (EICO) are enhanced significantly with the decrease in the nozzle diameter for the single-nozzle flames. For the twin- and triple-nozzle flames, when the other operational conditions including Qmix, and H/d are invariant, the moderate S/d of 5 gives the highest heat transfer rate, whereas the EICO increases with increasing S/d. Comparison of the flames from all the burners shows that the highest heat transfer rate and EICO are obtained on the single-nozzle burner with the smallest nozzle diameter while the lowest heat transfer rate and EICO are obtained on the triple-nozzle burner with the smallest S/d.
KW - Emission index
KW - Heat flux distributions
KW - Impinging laminar flame
KW - LPG/air premixed combustion
UR - http://www.scopus.com/inward/record.url?scp=78449288651&partnerID=8YFLogxK
U2 - 10.1016/j.ijheatmasstransfer.2010.09.008
DO - 10.1016/j.ijheatmasstransfer.2010.09.008
M3 - Article
AN - SCOPUS:78449288651
SN - 0017-9310
VL - 54
SP - 625
EP - 635
JO - International Journal of Heat and Mass Transfer
JF - International Journal of Heat and Mass Transfer
IS - 1-3
ER -