Abstract
Regenerative combustion is an effective measure for fuel saving in practical combustion technology. Nitric oxide emission can be deduced even in highly preheated air combustion if combustion air and fuel are diluted by large amount of flue gas in the furnace. Influences of preheat temperature and oxygen concentration of diluted air on flame characteristics are not clear. Lifted height and flame length of coaxial-flow diffusion flames in highly preheated air were observed, and found that they have great influence on formation of flame and following combustion regime.
