GAS TURBINE & RECIPROCATING ENGINE
DECISIONS UPDATE
November 2017
Table of Contents
Industry News
HRSG Users Group News
Crane Pacific Forged Pressure Seal Valves used in a Variety of GTCC Applications
Mogas contends that Ball Valves have advantages for GTCC Applications
______________________________________________________________________________
Industry
News
FERCo
has Tools to optimize GTCC NOx Reduction
FERCo has developed tools for optimization and diagnostic purposes, including
instrumentation and methodologies for 1) tuning the ammonia injection grid
(AIG), 2) measuring the NH3/NOx and velocity distribution at the
catalyst face, 3) identifying flue gas bypass, and 4) monitoring catalyst
activity in situ. These tools are applicable to SCR systems ranging from
gas turbines to coal-fired power plants.
One of the most important SCR operating parameters is the NH3/NOx
distribution across the catalyst surface. For overall NOx
reductions of 90% or
more, the NH3/NOx
distribution becomes extremely important. The maldistribution is characterized the RMS. If lower NOx reductions are required,
a much larger NH3/NOx maldistribution (RMS) can be tolerated.
The emphasis on achieving uniform NH3/NOx
ratios across the catalyst
points to the importance of the ammonia injection grid (AIG) as part of the SCR
system. AIGs should be designed with the flexibility to bias ammonia flow
in multiple zones across both dimensions of the duct even when static mixers are
utilized. Although ductwork design is optimized to achieve a uniform
velocity distribution at the AIG inlet, the actual NOx
distribution may not be
uniform due to the unit’s boiler and combustion system design and overall
operating characteristics.
FERCo has been actively involved in tuning SCR systems and has developed an
approach using instrumentation and
techniques that allow the NH3/NOx
distribution to be measured by
making only NOx
measurements at the catalyst exit.
AMP
Cherokee combines CEMS with PEMS to provide Unique Combinations of Predictions
and Measurements
CEMS/PEMS Hybrid systems feature the DAS ProLogix software and an HMI
interface. Monitor multiple sources through CEMS and/or PEMS systems via DAS
ProLogix for analysis and reporting.
Emerson
to retrofit Gas Turbine Controls at Engie Plant
Emerson has won a contract to retrofit controls on two Alstom turbines at
Engie’s DK6 combined-cycle power
plant (pictured) in Dunkirk, France.
The existing controls on the GT13 turbines at
the 800 MW plant are obsolete and no longer supported by Alstom, Emerson said,
adding that the project marks the first time a vendor other than the turbine OEM
has been selected to retrofit GT13 combustion turbine controls. The scope of work includes dismantling the existing
controls, engineering and installing the new controls, and assisting with
commissioning and startup.
The new controls are planned to be installed at each
unit during a 13-day outage, a compressed timeframe for a turbine controls
replacement project according to Emerson.
The first retrofitted power
block is expected to be back online in September 2018, and the second in July
2019.
The technology “uses the same
hardware and software platform for turbine control as it uses for other plant
controls, such as heat recovery steam generators (HRSGs), burner management
systems, generator excitation and high-fidelity embedded simulation. This single
platform architecture significantly reduces O&M automation-related expenses and
simplifies lifecycle management and planning.
Pre–cleaning
of HRSG Tubes often not sufficient
When Startup teams conduct
overall-plant efficiency testing of new combined-cycle projects, they often
overlook one of the necessary correction factors.
When they’re looking within the system boundary of the overall plant, the
Startup team typically does a thorough job—closely monitoring, and correcting
for such gas-turbine variables as firing temperature, ambient temperature,
ambient humidity and elevation.
When they’re looking within the system boundary of the GT, however, some Startup
teams don’t do as thorough of a job. Specifically, they don’t always monitor,
and correct for tube fouling in the heat-recovery steam generator (HRSG),
because they assume that a brand-new HRSG isn’t going to have any significant
fouling.
But experience in the HRSG User’s Group—the combined-cycle industry’s original
and longest-running user group—proves otherwise.
According to Rob Swanecamp experience shows that even newly erected HRSGs
without a single operating hour can have one to two inches, water column, of
tube fouling. That’s what Swanecamp calls “the missing link” in combined-cycle
efficiency calculations. Contamination starts
depositing on HRSG tubes starts all the way back during initial fabrication,
because the original equipment manufacturers (OEMs) aren’t meticulous enough in
their shop procedures. Even more contamination deposits on the HRSG tubes occurs
during their trek from the OEM’s shop to the project site.
Once it’s off-loaded at the project site, the HRSG gets stored outdoors and
exposed to the elements—often for as long as a year because of construction
delays or contractual conflicts.
Storing the HRSG anywhere other than in an indoor, climate-controlled facility
causes most of the tube fouling in a pre-operational HRSG—some 70 to 80 percent
of it.
The conclusion is that HRSG tube cleaning needs to be thorough.
HRSG
Users Group News
HRSG
Users Group 26th Conference slated for Feb 12-14, 2018
The HRSG User's Group Conference & Expo is the original and world's largest
gathering of HRSG users. Now in its 26th year, the conference draws over 1,500
attendees from across North America, Europe and Asia who work together to
discuss and solve the tougher problems in their plants.
For details, click on the link below, or if you have questions–contact Rob
Swanekamp at Rob@hrsgusers.org or call (406) 582-8655
https://www.hrsgusers.org/conference
The following articles are highlighting the activities of HRSG Users Group platinum sponsors.
EAI
will be discussing Specialized Cleaning
Environmental
Alternatives, Inc. (EAI) provides specialized cleaning services to the gas
turbine industry. EAI is credited with introducing the CO2
cleaning process to the gas turbine market in 1993. Over the past 20
years, EAI has cleaned hundreds of HRSGs and services customers all over the
United States and overseas in more than 10 countries around the globe.
For simple cycle and combined-cycle power plants, cleaning services allow plant
operators to maintain peak performance for heat recovery steam generators
(HRSGs), combustion turbine (CT) compressors, steam turbines, and selective
catalytic reduction (SCR) systems, and catalysts.
Haldor Topsoe’s stationary and mobile DeNOx business is being purchased by
Umicore. The closing date is currently set for November 30, 2017. Wayne Jones
Business Development Manager | SCR/DeNOx Catalyst and Technology is available
and reachable on his cell phone at 281-684-8811. His new email address
will be
wayne.jones@am.umicore.com
Umicore will acquire the heavy-duty diesel and stationary catalyst businesses of
Haldor Topsoe for an enterprise value of DKK 900 million (approx. EUR 120
million) plus an earn-out.
Haldor Topsoe is a leading producer of high performance catalysts for a wide
range of industries. Its automotive catalysts are used in emission systems for
on-road and non-road heavy-duty diesel applications and ensure compliance with
the most stringent emission norms, including Euro VI. Its stationary business
offers catalytic solutions to treat NOx emissions from industrial sources such
as gas-fired power plants as well as marine applications. The businesses
currently employ some 280 people, serve customers from production plants in
Frederikssund (Denmark), Houston (Texas), Tianjin (China) and Joinville (Brazil)
and has R&D facilities in Lyngby (Denmark).
Through this acquisition Umicore will gain access to an extended customer base,
particularly in Europe and China, a broader product portfolio for heavy-duty
diesel applications, as well as additional IP and technology in the field of
emission control catalysis. It also provides Umicore with an entry into the
stationary emission control segment. The combined businesses will continue to
focus on innovation to stay at the forefront of developing sustainable
technologies and products for its customers.
Pascal Reymondet, Executive Vice-President Catalysis, said: “The business is
highly complementary with Umicore, particularly through its focus on cutting
edge technology, operational excellence and sustainability. We are looking
forward to welcoming our new colleagues to Umicore. The combination of
expertise, talent and technology will enable us to further support our customers
with an even broader product and service offering.”
Crane
Pacific Forged Pressure Seal Valves used in a Variety of GTCC Applications
Crane Pacific Forged Pressure Seal Valves were designed specifically to meet all
the challenges of the rapid cycling gas turbine combined cycle plants they were
specifically designed to last in the worst cyclic conditions of today’s, and
tomorrow’s, thermal power applications.
Key Applications
·
Drums (HP, IP, LP)
·
Superheater (HP, IP, LP)
·
Reheater
·
Steam Turbine
·
Feed Water Distribution
·
Economizers (HP, LP, IP)
What
is a pressure seal?
It is a valve that actually seals better the more pressure that is applied.
Pressure Seal bonnet design valves do this by utilizing system pressure
to force the bonnet into the gasket and sealing ring, creating a leak tight seal
– the higher the pressure, the tighter the seal.
This design makes Pressure Seal valves safer to operate at higher temperature
and pressures than bolted bonnet designs.
Pacific pressure seal valves are designed and
manufactured to strict requirements in order to prevent external leakage. The
stuffing box and stem surface finishes are tightly controlled, including strict
controls of concentricity of diametrical dimensions between stem and gland, stem
and backseat, and gland and stuffing box. Quality materials and strict Crane
assembly procedures assure consistent sealing in the stem packing area.
Standard packing set construction includes two high-density molded style
flexible graphite end rings with Inconel reinforcement, and three (center)
density-controlled die molded sealing rings.
Mogas
contends that Ball Valves have advantages for GTCC Applications
Gate and globe valves are multi-turn, torque seated valves that must seal
against line pressure. The MOGAS iRSVP is a quarter-turn, position seated ball
valve that utilizes pressure assisted sealing. Since drain valves remain open
during start-up and shut-down, gate and globe valves can experience rapid
erosion and wear due to primary sealing components being in the flow path of
high pressure steam. The MOGAS iRSVP offers a straight-through bore path and
protects the sealing components from the flow path. There are lots of GTCC
applications.
A – Feedwater System
Chemtreat
solves Corrosion Problem at Peaking Plant
A Northeastern power plant was experiencing difficulty determining the
effectiveness of their boiler treatment program. The 225 MW combined cycle power
plant only operates at peak times of the year, specifically when electricity
demands were high during the hot summers and cold winters. The boiler system
consisted of two gas turbines and two HRSG units. Each HRSG had an HP drum that
produced 240K#/hr. of stream at 1,450 psig. The condensate return was close to
90% when one unit was online, but dropped to 50-60% with both units online.
Intermittent operations posed a challenge for this system, because as the
boilers sat idle, they were subject to oxygen attack. To address this corrosion
issue, the plant fed a filming amine treatment to provide additional protection
during times of shut down. However, without a means to monitor and control feed,
performance of the treatment was difficult to determine without a physical
inspection. During one instance of a startup, a level transmitter was plugged up
with iron, which indicated that the treatment was not working very well.
TITAN360™ was a perfect candidate for this intermittently operating boiler with
a high condensate return of 50-60%. The superior filming amine in TITAN360™ was
expected to provide better corrosion inhibition, which would decrease iron throw
during times of startup. In addition, TITAN360™ would offer buffering action to
keep the pH of the system consistent. With the TITAN360™ test kit, proper dosage
could be measured and monitored with ease.
Within a few weeks, TITAN360™ began to dramatically decrease iron levels and
easily stabilize the pH of the system to 9.0 - 9.6 without additional
intervention. Additionally, with the simple test kit, the operators were able to
consistently maintain and measure a residual. This was a considerable
improvement over the previous treatment, which lacked the means of monitoring
the proper dosage. The presence of residual or “free” filming amine with
TITAN360™ indicated there was sufficient protection of the metal surface.
McIlvaine Company
Northfield, IL 60093-2743
Tel:
847-784-0012; Fax:
847-784-0061
E-mail:
editor@mcilvainecompany.com
Web site:
www.mcilvainecompany.com