LOW EMISSIONS PREVAPORIZATION TYPE COMBUSTOR ASSEMBLY

摘要

The invention comprises a prevaporization type combustor assembly for gas turbine engines particularly adapted to reduce exhaust emissions to meet automotive requirements Fuel is laid on a wall (68) of a cylindrical prechamber (36) and evaporated from the wall by combustion air which is introduced through a swirler (38) at the upstream end of the prechamber. The inner surface (66) of the prechamber is artificially roughened by a grid of grooves (78, 80) to improve fuel evaporation. The fuel is laid on the wall from an annular manifold (70) extending around the upstream end of the prechamber through tangential orifices (76) leading from the manifold into the interior of the prechamber. More air enters through entrance ports (84) distributed around the prechamber towards its downstream end. The resulting lean fuel-air mixture is delivered past an annular flow dam (64) at the outlet of the prechamber into a domed combustor chamber forming a reaction zone (28) which is abruptly enlarged from the prechamber. Still other air bypasses the prechamber and is directed through ports (104) formed in the dome of the combustor chamber where swirlers (106) direct the bypassed air into prevaporized fuel and air from the prechamber. The structure reduces pressure drop across the flow dam (64) while enhancing turbulent flow, recirculation, and good mixing in the reaction zone (28). A dilution zone (30) downstream of the reaction has a circumferential array of dilution air ports which are of such shape as to be varied non-linearly in area by a sliding ring valve (120). The sliding ring valve is coupled to a second sliding ring valve (118) which varies the area of the air entrance ports in the prechamber (36) in a reverse sense to the dilution air ports.