Because the SGT5-8000H was only
offered after validation, guarantees for
even the first customer were supported
by real base-load engine data. Prior to
operation at the first customer site, the
SGT6-8000H was also thoroughly tested in the Siemens test facility.
There are now sixteen SGT5-8000H
units in commercial operation, and
every unit has met given guarantees as
demonstrated by performance test results. The units not only satisfy new and
clean performance tests, which are often used for evaluation, but also satisfy
actual degraded real-time performance
Additionally, Siemens recently commissioned a burner test center in Lud-wigsfelde, Germany. Here the company
independently conducts intensive research of burner technology using contaminated gases, low-calorific process
gases, or liquid fuels such as crude-oil,
naphtha, heavy fuel-oil, and other condensates.
Seven years after its first fire, and four
years into commercial operation, the
SGT-8000 fleet is growing fast.
To date, the SGT-8000H series is the
only commercially proven air-cooled
technology in its class, with over
100,000 hours of operation and high
starting reliability and availability. In
the United States, there are now six
SGT6-8000H turbines in commercial
operation, with another nine units under construction.
Historically, the introduction of new gas turbines to the market has resulted in unforeseen problems during early operation. The risks of these problems can
exist irrespective of developmental
know-how, especially when technologies are rolled out directly to customer sites. To combat this problem, the
industry has now developed a much
greater awareness of risks than it had in
To reduce onsite problems, Siemens
performed full in-house validation on
its SGT-8000H series turbines, applying
a rigid “keep the risk inside” approach
to the SGT6-8000H. In addition to test-bed testing, the SGT5-8000H was validated for simple- and combined-cycle
functionality via real world operation.
The SGT5-8000H was the first and
only gas turbine to exceed 60 percent
net plant efficiency, demonstrating a
still unmatched, independently-veri-fied world record since 2011. Since this
time, the SG T-8000H series has reached
proven combined-cycle efficiency levels
of nearly 61 percent in commercial applications all over the world.
The “infant mortality” issues of new
turbine designs present a high risk to
early adopters of these new technologies. Although in the long term, problems can always be solved, in the short
term losses due to handover delays or
unscheduled outages can have a negative impact on a plant’s bottom line.
Working from this knowledge, Siemens endeavored to design the SGT-
8000H within the existing design
experience range. This reduced owner
risks by incorporating specific features
to aid in the reduction of downtime.
Siemens also conducted a rigid pre-val-
idation of new features and complet-
ed full in-house validation tests on a
complete engine. This ensured that the
very first customer would get a mature
product into which short-term improve-
ments had already been incorporated.
The SGT-8000H tests confirmed the
anticipated robustness of the turbine’s
design. Still, in order to reduce the risk
of an unplanned standstill before or after the commercial operation date, the
SG T-8000H design incorporated several
features to minimize downtimes.
The compressor’s rotating blades,
as well as all turbine vanes, were engineered to be replaceable without a ro-tor-lift. A Hydraulic Clearance Optimization (HCO) system was also installed
in order to avoid rubbing of the turbine
blades. Furthermore, in an effort to concentrate on the highest risk areas in the
hot gas path, stage-one and last-stage
turbine blades were designed to be replaced without a cover lift.
Before building and testing the SGT5-
8000H, Siemens performed a full-scale test of the compressor, including
off-frequency testing, on a modified
SGT-5000F gas turbine in its Berlin Test
In order to draw on the knowledge
gained from the 24 G-class units already in operation (which have a combined total of 1. 2 million fired hours),
Siemens decided to stay within the firing temperature of its G-class engines.
Validating New Technologies
is the Key to Lasting
BY FRANCISCO DOVALI-SOLIS, SIEMENS POWER AND GAS