Flame stability of partially premixed combustion for PNG/LNG interchangeability

In this paper, the flame stability of partially premixed combustion for pipeline natural gas (PNG) and liquefied natural gas (LNG) interchangeability was investigated. A wide range of primary air ratio was considered and the characteristics of yellow flame and lifted flame were emphasized. The effect of gas flame speed (Sn), flame inner core height (h), gas flow rate (Lg), air flow rate (La), port thermal intensity (qp) and burner head temperature were discussed. Experiments showed that flame speed and flame inner cone height were mainly affected by gas components and lifted flame was influenced by flame speed and burner head temperature. When gases were interchanged, the flame speed and lifted flame could not be simply predicted by Wobbe index. When gas wobbe index increased, more chances yellow flame would appear and the gases with similar wobbe indexes have similar performance of yellow flame characteristics.