Rich-lean gas turbine combustor

Synthetic Fuel Character Effects on a Rich—Lean Gas Turbine Combustor... 

The first of these approaches uses controlled air addition to provide a fuel rich primary zone followed by fuel lean intermediate and dilution zones within the gas turbine combustor. The fuel rich primary zone, with an equivalence ratio of about 1,4, promotes the conversion of the ammonia contained in the fuel to nitrogen rather than to NO, The intermediate zone conqiletes the combustion of the fuel to achieve low CO emissions at an equivalence ratio near unity, whilst the dilution zone provides the correct temperature profile to suit the inlet to the gas turbine. The primary zone of the combustor is fully iti ingement cooled. This ensures that the local equivalence ratio... 

Although gas turbine combustion systems operate with overall air/fuel ratios which are quite fuel-lean, perhaps three times stoichiometric, stabilization of the combustion process requires that a portion of the combustor, the primary zone, operate stoichiometric or fuel-rich. Under fuel-lean conditions, fuel-bound nitrogen can be converted directly to N0X. Under fuel-rich conditions, fuel-bound nitrogen can be converted to HCN and NH3 in addition to N0X. Of course, in either case, the most desirable product of converted fuel nitrogen would be molecular nitrogen,... 

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