IGTC-144 ABB's Advanced Gas Turbines GT24/GT26 : Testing and Validation Program(ADVANCED GAS TURBINE SYSTEMS FOR THE NEXT GENERATION: EFFICIENCY, USABILITY AND ENVIRONMENTAL COMPATIBILITY)

The 60Hz, 165MW gas turbine GT24 and its up-scale, the 50Hz, 240MW gas turbine GT26 are the first two members of ABB's Advanced Cycle System gas turbine family. During combined cycle operation with a triple pressure reheat process, gross efficiencies of up to 58.5% can be realized. Due to the sequential combustion system and the annular combustor technology, known already from ABB's successful gas turbines GT10 and GT13E2, a very compact design is resulting, which makes the GT24/GT26 the gas turbines with the highest power density available on the market today. The compactness achieved, amongst many other advantages, leads to shorter blade lengths compared to other gas turbines of the respective output class which means lower tip speeds and, thus, lower mechanical stresses. Together with the very even temperature profile typical for the annular combustor arrangement the GT24/GT26 gas turbines offer a higher safety by design benefiting their reliability and availability. When a manufacturer introduces a breakthrough in technology, time and again one point of great interest to the industry is: how has the manufacturer tested its developments and what has the manufacturer done to secure the high reliability and availability which is often promised these days. What is the "pedigree" of a development. Key components in ABB's Advanced Cycle System gas turbine family are the compressor and the two annular combustors. The design of high performance gas turbines requires the reliable prediction of the performance and the characteristics of these key components. ABB has conducted an extensive compressor testing program, where flow, pressure ratio, efficiency, start-up characteristics, fullspeed surge margin, and the mechanical integrity of the design have been established. The annular combustors which are based on ABB's proven dry Low-NO_x EV burner technology which ensures lowest NO_x emissions have also been very intensively tested in a five stage testing program including segment tests under full engine operating conditions using real engine parts. This testing program was performed in the same way as already done during the development of the GT13E2 annular combustor which was later tested and validated in the first GT13E2 operating in Japan. This paper describes the development approach of ABB and how it differentiates from other manufacturer's approaches. It provides a detailed overview on the testing program and the validation of the GT24/GT26 gas turbine family. Additionally the paper demonstrates how ABB has based this development on proven key components such as the single welded rotor, ABB's EV-burner and ABB's annular combustor technology. Finally the paper summarizes some conclusions in regards to RAM-Reliability Availability Maintainability. The first GT24 has been ordered by Jersey Central Power & Light Company, a utility power producer located in New Jersey, USA. The unit will be installed at Gilbert Station in Hunterdon County to start operation in 1995 and will later be used to repower an existing steam turbine. The first GT26 has been ordered by a German public utility to repower an existing 120MW steam turbine, thus boosting the plant efficiency to 58.2% when firing natural gas. This unit will start operation in late 1996.