Application of Aero-Engine Technology to Heavy Duty Gas Turbines

Abstract

A description of an advanced version of a Siemens heavy duty gas turbine is presented which is based on a collaboration between Siemens Power Generation and United Technology Corporation. The main objective of this collaboration was to utilize the R&D capabilities of Siemens Power Generation and Pratt and Whitney to improve an existing heavy duty gas turbine (V84.3) by increasing compressor and turbine efficiency, refining the cycle and increasing turbine inlet temperature. This paper presents a description of the redesigned components, focusing on the features derived from aero engine technology. The main features of the advanced compressor are custom tailored blading to account for end wall boundary layer flow at the hub and casing wall, as advanced controlled diffusion airfoil (CDA) and a revised flowpath. These features result in both improvements in efficiency and surge margin over a wide operating range. The design features of the advanced turbine blading are 3D aerodynamics to reduce profile and secondary losses, aero-engine derived cooling configurations and use of single crystal materials to increase turbine durability. The performance improvement predicted for the redesign was demonstrated in a back-to-back test with the baseline engine, a 60 Hz Model V84.3. Testing was conducted at the Siemens Berlin facility which is capable of acquiring extensive performance and durability related data for full scale engines at design point and off-design conditions. Test results showed that over a 5 percent heat rate improvement was achieved by the application of aero-engine technology to the baseline machine.