POWER August 2012 - 29

2012 PLANT OF THE YEAR
tomers are BHP Billiton of Australia subsidiaries
Minera Escondida and Minera
Spence-both large copper mines. A longterm
power purchase agreement was essential
for obtaining long-term financing for
the project, which is discussed later.
South Korea's POSCO Engineering &
Construction Co., Ltd. (POSCO) was the
engineering, procurement, and construction
(EPC) contractor. Doosan Heavy Industries
2. Clean air was a priority. A full complement
of air quality control system (AQCS)
equipment-an electrostatic precipitator, fabric
filter, and spray dryer absorber for removing
SO2 from the stack gas-was included on
both units. It was the first use of this AQCS in
South America. Courtesy: AES
& Construction supplied the two coal-fired
steam boilers outfitted with low-NOx burners,
and Italian manufacturer Ansaldo Energia
provided the steam turbines and the
two 350-MVA air-cooled generators. (See
Table 2 for key performance characteristics
of the project.)
Other key components-such as the coaland
ash-handling systems and air quality
control system (AQCS), including electrostatic
precipitators (ESP) and fabric filter
(to remove particulates from the flue gas)
and spray dryer absorber flue gas scrubber
(to remove 95% of the SO2)-were supplied
by POSCO Plantec and other South
Korean manufacturers. The AQCS used
was the first of its kind in South America
and was designed to meet the latest emissions
standards, published in Chile in June
2010 (Figure 2).
POSCO received the notice to proceed for
construction of the plant on Apr. 7, 2008.
Earlier, on Oct. 17, 2007, AES Gener
had signed a turnkey EPC contract with
POSCO valued at $870 million. Although
POSCO started engineering the project
at contract signing, actual construction at
the site did not begin until June 2008. The
groundbreaking ceremony was held on August
27, 2008, with more than 150 participating,
including Energy Minister of Chile
Marcelo Tokman, Korean Ambassador to
Chile Lim Chang-Soon, POSCO E&C CEO
Han Soo-Yang, AES Gener Chairman An3.
Ocean cooling. The desert location of
the Angamos plant did not allow using potable
water for the cooling tower. Instead, a seawater
cooling tower was used, which runs at
about two cycles of concentration. Courtesy:
AES Corp.
dres Gluski, and President Felipe Creron.
" Angamos coal-fired power station with
a generation capacity of a large scale will
contribute to Chile's economic growth, "
said Soo-Yang in his congratulatory
speech.
Unit 1 was first synchronized to the
SING grid on Dec. 21, 2010, and entered
commercial service in April 2011, approximately
two weeks ahead of the scheduled
completion date. The second unit entered
commercial service in October 2011, also
several weeks ahead of schedule. This represents
a significant achievement, especially
given that a magnitude 8.8 on the Richter
scale earthquake hit southern Chile in February
2010 and delayed construction by
about a month because 70% of the workers
lived in the affected area. Even so, POSCO
completed both units early and earned a $7
million schedule bonus. In addition, unit
performance tests found that the net output
of both units was about 5% higher and the
heat rate about 6% lower than the contract
guarantee.
During the inauguration of Unit 1 in
August 2011, the subsecretary of energy
of Chile said, " This project meets the three
basic conditions of energy policies with
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which we work in our country since it is
competitive, it gives energy supply security
and meets the highest environmental standards.
Angamos complies with all environmental
standards promulgated by President
Sebastián Piñera last February and meets
the requirements of Latin-American and
are at the same level of the European Union
in terms of exigency. "
Unique Design Features
Fuel supply represented a special challenge
because coal deliveries for Angamos are
made by sea through a dry bulk terminal
that was constructed in Mejillones, north
of Angamos Port. Construction of the port
coal-handling facilities was completed in
January 2011. Bituminous and subbituminous
coal, purchased on the global market,
is transported to the plant's transfer tower,
from which it is distributed across the coal
pile. The port's solids-handling capacity is
1,500 metric tons (mt)/hour. It can receive
cargoes up to 80,000 mt and has unloading
rates between 17,000 and 20,000 mt/day.
Ash collected from the ESP hoppers is
conveyed to a silo, where it is stored. The
ash is then removed by truck and deposited
in a special landfill or used in the construction
industry as raw material for cement.
Although Angamos is located on the Pacific
coast of northern Chile, 55 km north
of Antofagasta and 1,300 km north of Santiago,
it is situated in the 1,000 km-long
Atacama Desert, the driest desert in the
world, according to NASA. Annual rainfall
in this desert is less than 0.004 inches, and
some areas have gone hundreds of years
with no rainfall. That makes water supply
a major concern.
The Angamos plant is the first of its kind
in South America to use seawater cooling
towers (Figure 3). About 6,000 cubic meters/hour
of seawater are supplied from a
seawater makeup pumping station with siphon
and submarine discharge pipe. This
pumping station also supplies seawater to
the thermal vapor compression (TVC) desalinization
plants to produce boiler makeup
water, firewater, potable water, service
water, and water for other facility uses.
Demineralized water is produced by a
multiple-effect distillation system as well
as with the TVC unit. Desalinated water
is next treated in a new demineralization
plant using electro-deionization units to
produce boiler-quality makeup water. Given
the arid location, this water system is
cost-effective and sustainable for a plant
located close to the ocean.
A containerized portable reverse osmosis
plant was shipped from South Korea to provide
potable water during construction.
POWER | August 2012
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POWER August 2012

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