High-Temperature Turbine-Technology Program. Phase II. Technology Test and Support Studies. Design and Development of a Regeneratively Fuel Cooled High Temperature Gas Turbine Combustor for Operation on Low Btu Gas

摘要

The fuel-air requirements for low Btu gas combustors result in a paucity of cooling air which results in low Btu gas-fueled air cooled combustor designs with annular configurations with complex flow path schemes to maximize cooling efficiency. These design trends are in the direction of reduced maintainability and reliability. Alternatively, if the low Btu gas can be utilized as a cooling medium before it is combusted, conventional multiple can arrangements with simple convection-cooled liner can be developed. This report describes the design, fabrication and test of a full scale industrial gas turbine burner can with convective cooling of the liner wall by 150 Btu/scf gaseous fuel typical of air-blown gasification of coal. The entire primary combustion zone burner wall surface area was cooled with 375 exp 0 F LBG fuel, which after cooling the wall was reinjected for combustion. The fuel gas cooling passage is a concentric annulus of nominal .140'' height, designed to limit linear temperature to a maximum of 1200 exp 0 F at approximately 4% gas supply pressure loss. The 10-in. internal diameter combustor can was successfully operated up to 6 atmospheres pressure, burning 150 Btu/scf gaseous fuel up to 3000 exp 0 F average exit temperature. The fuel cooling effect and combustor exit emissions levels were determined for gas supply temperatures of 150 and 375 exp 0 F. All liner temperature measurements were well below the average 1200 exp 0 F estimated for the 3000 exp 0 F design point. This was confirmed by post-test visual inspection of all components which were found in excellent condition. In addition, the NO/sub x/ emissions level at the nominal 3000 exp 0 F combustor exit temperature was substantially below the EPA regulatory level of 75 ppM when adjusted for pressure level effect of 15 atm and 15% oxggen. (ERA citation 08:020246)