Turbine nozzle with cavity insert having impingement and convection cooling regions

摘要

A turbine vane segment is provided that has inner and outer walls (14, 12) spaced from one another, a vane (10) extending between the inner and outer walls (14, 12) and having leading and trailing edges (18, 20) and pressure and suction sides, the vane (10) including discrete leading edge, intermediate, aft and trailing edge cavities (42, 44, 46, 48, 50, 52) between the leading and trailing edges and extending lengthwise of the vane (10) for flowing a cooling medium; and an insert sleeve (58, 60, 62, 64, 66, 68, 70) within at least one of the cavities (42, 44, 46, 48, 50, 52) and spaced from interior wall surfaces thereof. The insert sleeve (58, 60, 62, 64, 66, 68, 70) has an inlet for flowing the cooling medium into the insert sleeve and has impingement holes (86, 88) defined in first and second walls (82, 84) thereof that respectively face the pressure and suction sides of the vane. The impingement holes (86, 88) of at least one of those first and second walls (82, 84) are defined along substantially only a first, upstream portion (87, 89) thereof, whereby the cooling flow is predominantly impingement cooling along a first region of the insert wall corresponding to the first, upstream portion (87, 89)) and the cooling flow is predominantly convective cooling along a second region corresponding to a second, downstream portion (90, 92) of the at least one wall 82, 84) of the insert sleeve (64).