Oct 17 2005
Siemens is building the world’s most powerful and economical gas turbine, which is expected to set a new world record for efficiency.
Plans call for the combined cycle gas and steam power plant to have an efficiency of more than 60 percent. To achieve this kind of top performance, the turbine operates at extremely high temperatures and has a very efficient cooling system and an optimized water-steam cycle.
Near the city of Ingolstadt in Bavaria, the company is building a gas turbine plant with an output of 340 megawatts for the supplier E.ON Energy. The plant is scheduled to go into operation in late 2007. After the testing phase, this gas turbine will be expanded into a high-efficiency gas and steam (combined cycle) turbine power plant with an output of approximately 530 megawatts. That’s enough energy to meet the needs of the city of Hamburg, for example.
The two-percentage-point increase in efficiency — 58 percent has been the maximum to date — reduces CO2 emissions by about 40,000 tons per year. This volume of emissions is equivalent to the exhaust that would be produced by almost 10,000 VW Golfs if each vehicle were driven 20,000 kilometers annually. The key to the high efficiency is the extremely high combustion and stack gas temperatures. At the first turbine guide vane, these temperatures climb to well over 1,500 degrees Celsius, which is nearly hot enough to melt iron.
This is possible because the Siemens power plant specialists developed new, high-strength materials for turbine vanes that can also withstand high temperatures, as well as new burner and combustion chamber technologies. Each of the more than 250 turbine vanes has the same power output as ten sports cars and can withstand at high temperatures a centrifugal force that is 10,000 times its own weight. For this reason, the vanes are constructed using monocrystalline superalloys with ceramic coatings.
In addition, a newly developed compressor with a sophisticated vane design is combined with innovative sealing technology to reduce energy losses in the turbine. The new gas turbine is extremely flexible to operate. It has a shorter warmup time than previous models and makes faster power load changes possible, thanks to its air-based cooling technology. Air is always immediately available, by contrast to the much more complex steam cooling process. The gas turbine will be initially offered on the Asian and European markets, where the network frequency is 50 Hertz.
Plans call for a turbine operating on 60 Hertz to be available by 2010.