Aerodynamic Design and Testing of an Axial Flow Compressor With Pressure Ratio of 23.3:1 for the LM2500+ Gas Turbine

Abstract

The LM2500ϩ gas turbine, rated between 39, 000-40,200 shaft horsepower (shp), was introduced for field service in 1998. This growth aero-derivative gas turbine is suitable for a variety of power generation applications, such as co-generation and combined cycle, as well as mechanical drive applications. At the heart of the LM2500ϩ 25% power increase is an up-rated derivative 17-stage axial compressor. This paper describes the aerodynamic design and development of this high-pressure ratio single-spool compressor for the LM2500ϩ gas turbine. The compressor is derived by zero-staging the highly efficient and reliable LM2500 compressor to increase the flow by 23% at a pressure ratio of 23.3:1. The aerodynamic efficiency of the compressor is further improved by using threedimensional, custom-tailored airfoil designs similar to those used in the CF6-80C2 highpressure compressor. The compressor achieved a peak polytropic efficiency above 91%, meeting all its operability objectives. The technical requirements and overall aerodynamic design features of the compressor are presented first. Next, the zero stage match point selection is described and the procedure used to set up the vector diagrams using a through-flow code with secondary flow and mixing is outlined. Detailed design results for the new transonic airfoils in the compressor using three-dimensional viscous analysis are presented. The compressor instrumentation and performance test results are discussed. The performance of the zero stage is separated from that of the baseline compressor with the CF6-80C2 airfoils to show the improvement in efficiency with the new airfoils.

Preliminary Optimization of Multi-Stage Axial-Flow Industrial Process Compressors Using Aero-Engine Compressor Design Strategy

“…In the past few decades, the high-efficiency and reliable aero-engine core compressor design strategy has been applied to the aerodynamic design of compressors used in other important fields, such as marine ship and natural gas pipeline median-duty [1], and electricity generation heavy-duty gas turbines [2]. The design of an advanced compressor is a time-consuming and highly experience-dependent process, requiring a variety of design and analysis phases ranging from the preliminary design to the full three-dimensional computational fluid dynamics (CFD) [3].…”

“…The work input and reaction per stage and annulus area per row were selected as key design parameters during the preliminary design phase. Subsequently, Wadia et al [1] developed the LM2500+ compressor by zero staging the LM2500 compressor to upgrade the flow and pressure ratio. Another successful engine core aero-derivative technology was reported by Novak et al [2], in which a series of aero-engine compressor design technologies were used to upgrade a high pressure ratio 22-stage compressor for applications in power-generation heavy-duty gas turbines.…”