POWER September 2014 - 39

TOP PLANTS
EWP's response to its regional power
shortages was to quickly begin development
of the 947.5-MW Ulsan 4 combined cycle
plant at its existing 8-acre coastal site in
Ulsan Metropolitan City, on the coast about
400 kilometers southeast of Seoul. The site
consists of 3 x 200-MW and 3 x 400-MW
heavy oil-fired conventional steam plants
built between 1970 and 1981-the last of the
large-scale oil-fired units built by KEPCO.
Oil currently accounts for less than 5% of the
country's generation mix.
Government approvals for the construction
of Ulsan 4 were quickly obtained. However,
EWP was under pressure to get additional capacity
constructed prior to the 2013 summer
peak period. In May 2012, EWP began constructing
the first phase of the project-the
simple cycle portion of the new 2 x 1 combined
cycle plant. The combustion turbines
entered commercial service on July 13, 2013,
18 days before the original targeted completion
date.
Construction of the steam bottoming plant
(heat-recovery steam generators [HRSGs] and
steam turbine) began on Aug. 15, 2013. The
project took only eight months for the planning
and permitting phase and 27 months for construction
of the entire project. The overall cost
of the project was approximately $800 million.
During the first year of operation, the
simple cycle combustions turbines (CTs) operated
in peaking mode. The completed combined
cycle plant finished full load testing on
June 15, 2014, and began commercial service
on July 31.
High-Efficiency Turbine
The consortium of Marubeni Corp., Daelim
Industrial, and Mitsubishi Heavy Industries
(MHI) received an order for engineering, procurement,
and delivery of the equipment as
well as the construction and installation work
for Ulsan 4. MHI supplied its 317.5-MW
M501J CTs, the single steam turbine, as well
as three Mitsubishi Electric 60-Hz generators.
Daelim Industrial delivered two triple-pressure
plus reheat HRSGs manufactured by Sedae
Enertech in addition to other balance-of-plant
equipment. The consortium delivered this
equipment to Daelim Industrial, which was responsible
for construction of the plant. KEPCO
E&C also provided engineering services, while
EWP provided project management of the entire
project.
The MHI M501J CTs are a 1,600C
(2,912F)-class design that produces (in a 2 x
1 combined cycle) 947.5 MW when burning
LNG, with an industry-leading 61.9% thermal
efficiency (lower heating value). MHI
claims this is " the world's highest level [efficiency]
in GTCC applications. "
The CTs are configured with a steamcooled,
can-annular, dry low-NOx combustion
system. A selective catalytic reduction
system located within the HRSG further reduces
the NOx emissions to 10 ppm or less,
five times lower than the Korean national
1. Two-phase project. The need for summer peaking capacity required the Ulsan Unit 4
project to be constructed in two phases. The first phase was completed with the commissioning
of the two combustion turbines (shown here) on July 13, 2013. The second phase added the
heat-recovery steam generators and single steam turbine to complete the 947.5-MW combined
cycle plant on July 31, 2014. Courtesy: Korea East-West Power Co., Ltd.
standard of 50 ppm. (For more information
on the test and development of the M501J,
see " The T-Point Plant: The Ultimate Validation
Test, " in the June 2011 issue).
Operation of the simple cycle CTs during
construction of the HRSG-steam turbine
system was made possible by inserting a
blanking plate in the ductwork and using a
temporary bypass stack. When the HRSGs
were commissioned, the bypass stack and
blanking plate were removed and the ductwork
to the HRSG was installed.
The two CTs and the steam turbine are
installed within an enclosed building for
weather protection and to be aesthetically
pleasing (Figure 1).
A total of 13 M501J CTs have been recently
purchased by South Korean utilities for
five different sites (including Ulsan) because
of the model's excellent performance, efficiency,
and positive customer reports. A total
of 30 units have been ordered worldwide
with 10 units now in service.
Keys to Success
The success of the Ulsan 4 project is due in
part to EWP's project management skills, according
to Soon Gu Doh, manager of EWP's
construction and engineering division. EWP
uses advanced computer-based tools to manage
every detail of the project, such as its
Integrated Management System of Design
Verification and its EWP Project Management
System (e-PMS). The former is used
for removing construction interferences with
the help of 3-D design data. The partnership
and EWP used e-PMS to share information
quickly and accurately.
EWP's project management team was responsible
for developing creative and costeffective
means to reduce the cost and risks
found in a project of this scale. For example,
a Construction Innovation Center was established
to " value engineer " the project. Also,
the " Preemptive Risk Management " (PreRM)
team was formed to identify ways to
reduce operational risks based on EWP's experience
with plant operations.
No safety incidents occurred during construction
of the plant, which is significant
given the short construction schedule and
very constrained site conditions. One safety
tool used by EWP was the Loughborough
University Safety Climate Assessment Toolkit
developed by the UK Health and Safety
Administration to gauge the safety climate of
a project and aid the promotion of a positive
safety culture. EWP also successfully used
safety awareness systems on the construction
site, such as " Keeper of the Construction
Site " and " 2 Strike Out System. " ■
-Dr. Robert Peltier, PE is POWER's
consulting editor.
September 2014 | POWER
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