Integrated Combustor and Vane Concept in Gas Turbines

Abstract

This paper numerically investigates the interaction between multiple can combustors and the first vane in an industrial gas turbine with 16 can combustors and 32 vanes in order to find ways of reducing the overall cooling requirements. Two promising concepts for the overall cooling reduction are presented. In the first, by minimizing the axial distance between the combustor wall and the vane, the stagnation region at the leading edge (LE) of every second vane can be effectively shielded from the hot mainstream gases. The LE shielding allows continuous cooling slots to be used (as an alternative to discrete cooling holes) to cool the downstream parts of the vane using a portion of the saved LE showerhead cooling air. The second concept proposes a full combustor and first vane integration. In this novel concept the number of vanes is halved and the combustor walls are used to assist the flow turning. All remaining vanes are fully integrated into the combustor walls. In this way the total wetted area of the integrated system is reduced, and by shielding the LEs of the remaining vanes the total amount of cooling air can be reduced. The proposed combustor and first vane integration does not detrimentally affect the aerodynamics of the combustor and vane system. The concept also simplifies the design and should lower the manufacturing costs.