EMISSIONS CHARACTERISTICS OF COMBUSTION OF LEAN SECONDARY PREMIXED GAS JETS INJECTED INTO BURNED GAS FROM PRIMARY STAGE BY LEAN PREMIXED COMBUSTION SUPPORTED BY REVERSE JET FLAME HOLDING

The emissions characteristics of a model gas turbine combustor characterized by the enhancement of the reactions of the secondary mixtures of lean to ultra-lean compositions by the burned gas from the primary stage were investigated at atmospheric pressure. A cylindrical quartz tube with the bottom end closed was used as the combustion chamber and the mixture injector was extending co-axially into the combustion chamber to the bottom wall. The stagnation point reverse flow combustion was used for the primary stage where the primary mixture was injected toward the end wall. The secondary mixture was injected radially from the multiple holes in the outer wall of the injector into the burned gas from the primary stage. The effects of the positions for injection of the primary and secondary mixtures as well as mixture temperatures on NOx, CO and HC emissions were investigated over a range of the primary and secondary mixture equivalence ratios at atmospheric pressure.