Effi ciency

Two World Records

About to go commercial is the most powerful gas turbine ever, within the most effi cient combined cycle power plant ever. No wonder: The underlying technology is some of the most impressive – ever.

By Eric Johnson

Siemens’ Proven Combined Cycle Power Plant SCC5-8000H 1S

■ Location: Irsching near Munich, Germany ■ Performance (net)*: 578 MW ■ Efficiency (net)*: 60,75 % ■ Emissions at base load: NOx < 25 ppm / CO < 10 ppm ■ Fast hot start-up < 30 min

(*) Irsching 4 reference site conditions,

Photo: Siemens Siemens Photo: world record test run results, TÜV certified

16 Living Energy · Issue 1/November 2009 · www.siemens.com/energy/living-energy Living Energy · Issue 1/November 2009 · www.siemens.com/energy/living-energy 17 Effi ciency

Inside the Turbine Building

Components include: ■ Gas turbine SGT5-8000H ■ Steam turbine SST5-5000 ■ Water/hydrogen-cooled generator SGen5-3000W ■ Power plant automation system SPPA-T3000 ■ Siemens triple-pressure reheat heat recovery steam generator (HRSG) with BENSON HP evaporator ■ Advanced steam parameters and speed-controlled boiler feed pumps for highest combined cycle efficiency ■ Single-side condenser Photo: Siemens Siemens Photo: Effi ciency

“These developments constitute an advance to a completely new realm of technology.”

Klaus Hammer, Global Fleet Manager Combined Cycle Gas Turbines, E.ON Generation GmbH

ing arms race of size and efficiency, times.” During commissioning, a much more is at stake than mere start-up time of less than 30 minutes bragging rights for engineers. Larger, to full load was demonstrated in more efficient, and more operating addition to other world-class flexibili- flexibility pays off by cutting per-kWh ty features. investment, operating costs, emis- sions, and start-up times. Unlike con- Blades of More Than Steel ventional gas-fired power plants that In order to achieve such extraordinary run mainly at peak loads, Klaus performance, Irsching’s plant must Hammer from E.ON says, Irsching 4 is withstand operating conditions that economic enough to run a long peri- are, well, extraordinary. One is a natu- od of the year. And in contrast to an ral consequence of the unit’s record- average coal-fired plant with 36 per- size fins: The biggest blade wheel in cent efficiency in Europe, two of these the gas turbine sports a flow surface SCC5-8000H 1S will generate 4.2 mil- of 12.5 square meters. When spinning lion tonnes less of the number one at 50 revolutions per second, they are

greenhouse gas, CO2, per year. “This pulled by several hundred tonnes of plant,” says Lothar Balling, Vice Presi- centrifugal force; under these circum- dent of the GT Solution business in stances, each cubic centimeter of each Siemens Energy, “is a key milestone to blade weighs some 70 kilos.

Final stage of assembly: The rotor is inserted into the tight-fitting turbine shell. reduce CO2 emissions and allows re- Even when composed of specialized newable energy to be integrated more nickel alloys, blades made by conven- easily into the grid due to its out- tional casting – molten metal poured standing flexibility.” into a mould and cooled to a hard Although Irsching 4 is aimed at base- shape – are not capable of withstand- load service, its combined cycle ing this stress. So Siemens’ scientists Roger Bannister’s four-minute mile: Irsching, a small town 90 kilometers The breakthrough to over 60 percent ly new realm of technology,” accord- configuration (the SCC5-8000H 1S, created an alternative manufacturing , 1954. ’s eighth north of Munich. Date: May 9, 2011. efficiency was driven by a raft of ing to a statement by Klaus Hammer see sidebar page 23) can easily handle process. They engineered a proprie- gold medal: Beijing, 2008. Roger The performance: one world record technology tweaks pioneered by from E.ON, the utility that owns and 250 high-load start-ups and shut- tary chilling process that “grows” Federer’s 16th Grand Slam: Mel- for gas turbine power rating, at Siemens: reduced cooling air, torrid operates Irsching. Michael Suess, downs per year in 30 minutes, notes each blade as a so-called directional bourne, 2010. For sports cognoscenti, 375 MW; and another for combined turbine and cycle temperatures, tight- Siemens CEO of Sector Energy, agrees: Lothar Balling. “Especially in Europe, solidified crystal of metal, also mak- these are touchstones. Reminded of cycle efficiency, at 60.75 percent at er design tolerance; all done without “This plant is a trendsetter.” which is aiming for 20–30 percent re- ing sure that each crystal is aligned in them, fans nod knowingly, remem- a power output of 578 MW. As for effi- external cooling in the gas turbine Like most record breakers, E.ON and newable electricity by 2020, this kind the direction of the centrifugal force. bering the performer, the place, and ciency, Irsching 4 – which also incor- and using further innovation in the Siemens are clearly proud of what of flexibility will be critical to our sup- Because there are no longitudinal the date. The same is true for doyens porates a 600°C steam generator and steam-water cycle and heat recovery they have wrought. The official hand- ply security – notably at times when joins in the crystalline material, there of power production. Soon they will a 200-MW 600°C Siemens steam tur- steam generator. All are evolutionary, over of the plant is planned for end of the wind does not blow and the sun is no predetermined breaking point. be nodding in acknowledgement of bine – is first to crack the magical building on previous know-how, but July; after a final period of reliability does not shine. We will need gas-fired Then there is the matter of efficiency. two new outstanding achievements. barrier of 60 percent, verified by the taken together, these developments run, the ceremonies are scheduled units with maximum efficiency, mini- To get more bang from the burn,

Performer: Generating Plant 4. Place: German TÜV. constitute an advance “to a complete- Siemens Photo: for September 2011. But in this ongo- mal emissions, and fast start-up Siemens designers increased the

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airflow, the pressure, and the tempera- ture that flow through the gas turbine. This is a welcome effect to the extent Initiated in Irsching – that higher temperatures bring great- er efficiency. It may have adverse ef- Tomorrow’s Turbine Is Ready Today fects, however, in that metal compo- nents can withstand only so much First it set world records; now it is ready for commercial The 60-Hz version, dubbed the SGT6-8000H, has warmth. “It’s tricky when you send up operation. The SGT-8000H series comes at 50 Hz either already convinced two further buyers. At the South to 1,500°C gas across metal turbine as a 375-MW simple cycle gas turbine or as a 570-MW Korean site of Bugok, GS Electric Power & Services will blades,” says Willibald Fischer, Pro- combined cycle plant. In simple cycle operation, its effi- connect its SCC6-8000H 1S 400-MW combined cycle gram Director of the SGT-8000H series. ciency is 40 percent; in combined cycle mode, it is over power plant to the grid in mid-2013. CEO Lee Wan- “At 950°C, surfaces of conventional 60 percent under nominal rating. A 60-Hz version of Kyoung says the investment demonstrates GS’s great blades begin to glow red, and if things similar efficiency will also be ready commercially for all regard for efficiency and environmental-friendliness. get any hotter, the material begins to customers later this year, after completing testing Also on the books is Florida Power & Light, which dur- lose its stability and oxidize.” In lay- in Berlin. ing 2013–2014 will commission six 60-Hz version gas man’s speak: If it gets too hot, a con- turbines to refurbish existing power plants at Riviera ventional blade starts to disintegrate. “At Irsching, we’ve proven commercially the prototypes Beach and Cape Canaveral. Clearly, this retrofit will help To prevent this from happening, for the gas turbine, the 600°C Siemens Benson boiler, to reduce global warming. According to FPL Executive blades on the SGT-8000H series gas the 16-square-meter titanium steam turbine – all in com- Vice President Tony Rodriguez, the revamp will slash turbine are built with two special bination,” comments Wolfgang Winter, the Siemens the units’ carbon emissions in half. jackets. First comes a thin coating of General Project Manager who oversaw construction. exotic metals: a pinch of rhenium “They work together as we hoped; this really is a world added to a mixture of cobalt, nickel, record setter.” chromium, aluminum, and yttrium. Without it, the nickel alloy blade would survive less hours at maximum operating temperatures before suc- cumbing to oxidation. With it, by con- trast, the blade can spin on up to their headspace down to millimeters, which is now commercially available of CO2, but also of particles, nitrogen 25,000 hours without service. The waste is minimized. Almost all the gas (see sidebar), save serious amounts oxides, carbon monoxide, and green- exotic coating also acts as glue for passes across the blades and is con- of money. house gases nitrous oxide and the second jacket, a ceramic layer that verted to power. Having one 16-square-meter highly methane. insulates the underlying metal. Finally, Irsching performs a crowning innovative titanium turbine instead of All of these are details to be savored In addition to the jackets that resist efficiency. After the gas turbine ex- two 8-square-meter ones in the steam by electricity insiders. At commission- heat and wear, the blades are cooled tracts its mechanical power, heat is turbine exhaust means less capital ing time, the experts will be nodding. actively in two ways. The hollow in- wrung out of the over 620°C exhaust must be expended in terms of space, For the rest of us, there is a simpler sides of the blades are bathed with gas by a Benson boiler designed to piping, and infrastructure. High effi- way to summarize the exceptional lower-temperature air pumped by the generate high temperature, and high- ciency also means less gas must be nature of Irsching 4: When it comes to compressor, and at their very front pressure steam for the 600°C steam fed in to produce more power. “The power, economics, flexibility, and fuel (the hottest part), they have fine holes turbine. This finishing touch adds an- price per MW of output, and the effi- economy, it is a world record holder. from which air streams across the other 200 MW to the electrical output ciency, correlate to the size of the blades as a protective heat shield. All while also raising overall efficiency plant,” says Balling. “In other words, Eric Johnson writes about technology, told, the composite system reduces from 40 percent in simple cycle oper- the bigger it is, the more economical business, and the environment from Zurich. Formerly, he headed what is now a Thomson- surface temperature on the first row ation to the final mark above 60 per- it will be, as long as it is as flexible Reuters bureau and was a correspondent for of blades from more than 1,400°C to cent in combined cycle operation. as ours.” He notes that in 1990, the McGraw-Hill World News. around 950°C. largest gas turbine produced about Irsching’s second efficiency trick is to 150 MW, and, in conjunction with a fit the turbine in its shell like a hand Bigger Is Better, 75-MW steam turbine, had an efficien- Further Information in a glove. Thanks to three-dimen- and Better Is Better cy of only about 52 percent: “Since www.siemens.com/energy sional design and another innovation, Those who take a flip-the-switch-and- then, we have more than doubled the the so-called horizontal clearance op- forget-it attitude towards electri city unit output and increased the effi- timization, where the rotor is shifted might be bored or baffled by Irsching’s ciency by nearly 20 percent.” by hydraulics by some millimeters, high technology. Still, they have an- One final beneficiary is the environ- the blade edges nearly − but not quite The 16-square-meter titanium steam turbine blades of the SST5-5000 low-pressure other good reason to be interested: ment. Higher efficiency also means

− scrape the inner walls. By keeping rotor are assembled by Siemens engineers. Siemens Photo: Irsching and its SCC5-8000H 1S plant, fewer emissions per kWh, and not just

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