FIELD: machine building.
SUBSTANCE: gas turbine connected with secondary combustion chamber contains a set of guide vanes of LP turbine installed downstream of the specified combustion chamber. Radially the external border of the secondary combustion chamber is made by the external wall segment secured on the supporting component radially installed outside. The hot gases flow is limited radially from outside, inside the guide vanes by the external platform secured on the support of the guide vane. Between the wall segment and the external platform there is radially continuing cavity with width from 1 to 25 mm in axial direction in the inlet area. The cavity inlet area has step element reducing the cavity width by 10% per step, and continuing in the cavity at right angle to the direction of the hot gas flow. Relatively to the step element the cavity width radially outside again increases to width of the inlet area by means of the step continuing in the cavity at right angle to the direction of the hot gas flow.
EFFECT: invention reduces ingress of the hot gas in the cavity between the wall segment and external platform of the guide vanes.
16 cl, 9 dwg
