POWER October 2012 - 38

TOP PLANTS
Northside Generating Station,
Jacksonville, Florida
Owner/operator: JEA
Courtesy: JEA
Since the Northside Generating Station's two repowered units were placed into service
in 2002, a series of modifications and repairs have been undertaken to make
its two circulating fluidized bed boiler plants reliable. The two chief problems were
ash agglomeration on heat transfer surfaces and poor Intrex heat exchanger performance.
JEA reports these problems have been permanently resolved, and data
shows the two units have joined the top tier of reliable fossil plants.
By Dr. Robert Peltier, PE
T
he original Northside Generating Station
(NGS) consisted of three oil/gas-fired
thermal plants: Units 1 and 2 were 275MW
designs; Unit 3 was 618 MW. Unit 1 began
service in 1966, Unit 2 was built in 1972
but was idled in 1983, and Unit 3 was completed
in 1977. The need for additional baseload
generation prompted a 1997 study that
concluded Units 1 and 2 were good candidates
for repowering: removing the old boilers and
replacing them with new ones. Negotiations
with Foster Wheeler and the U.S. Department
of Energy (DOE) produced a contract under
the DOE's Clean Coal Technology Program
for the construction of two circulating fluidized
bed (CFB) boilers nominally rated at 300
MW each. Unit 3 continues to operate today,
principally on natural gas with oil backup.
The official project title was the JEA LargeScale
CFB Demonstration Project. The DOE
cost-shared about 25% in the first unit (Unit 2),
and JEA paid the remaining cost of Unit 2 and
38
the total cost of Unit 1. At the time of construction,
the two CFBs were among the world's
largest. Foster Wheeler supplied the extended
boiler island scope, which included the CFB
boilers and air quality control system, as well
as engineering, procurement, and construction
management services. Black & Veatch provided
supplemental engineering services to JEA.
Construction began on the two units in July
1999. Initial synchronization of Unit 2 occurred
on Feb. 19, 2002, followed by Unit 1
on May 29, 2002. As part of the cooperative
agreement, the DOE cost-shared two years of
demonstration test runs, during which both
coal and coal/petroleum coke (petcoke) blends
were to be fired. Other specific details of the
project design can be found in the final technical
report issued in June 2005.
In 2002, POWER named NGS its Plant of
the Year Award (then called the Powerplant
Award) winner. In the September 2002 issue,
the editors noted the justification for the
www.powermag.com
award: " The development of a successful repowering
strategy for converting existing oil/
gas-fired steam plants to solid fuels to increase
efficiency while reducing both emissions and
the cost of electricity. "
Operational Realities
JEA CFB boilers were designed to burn 100%
coal or 100% petcoke or a mixture of both.
The desired fuel at the time of commissioning
was 100% petcoke, as it was the lowest cost
fuel. JEA successfully burned petcoke/coal
blends in both units, although higher ratios of
petcoke and 100% petcoke quickly produced
agglomeration of ash in the integrated recycle
heat exchanger (Intrex) and furnace heat transfer
surfaces within weeks. Unable to maintain
steam temperatures, the plant was forced to
shut down to remove the excessive ash buildup.
Further testing found that a maximum blend of
70% petcoke produced minimally acceptable
plant reliability.
POWER | October 2012
http://www.powermag.com
POWER October 2012

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