POWER May 2021 - 32

COAL POWER
Coal-Fired Power Station Provides
Natural Ecological Environment
for Fireflies and Birds
In the 1980s, Taiwan's economy grew rapidly and its demand for electricity surged.
New power plants were urgently needed. In order to reduce transportation costs of
imported coal and to promote economic development in central Taiwan, a coal-fired
power plant was constructed in Taichung. With state-of-the-art emissions reduction
equipment, the site not only provides needed electricity, but has also proven to be
a haven for fireflies, terns, and many other birds.
Hsu ChiaHao and Liao ZiFeng
T
he Taichung Power Plant (TCPP) is located
in the south of Taichung Harbor
and in the north of Tatu River on land
reclaimed by dredging sand, totaling 277.5
hectares. The station was established on
July 18, 1989, and it was the first coal-fired
power plant in Taiwan to pass the country's
Environmental Impact Assessment. About
45% of the site is filled with trees to minimize
wind in the area.
The plant has eight GE and two Toshiba
tandem compound reheat steam turbines
with duplex flow at the low-pressure stage.
Each utilizes a Foxboro distributed control
system and a GE Mark VIe steam turbine
controller. The generators have a watercooled
stator and hydrogen-cooled rotor.
Each unit also has selective catalytic
reduction to reduce NOx
, an electrostatic
precipitator (EP) to remove particulate
matter, and a limestone/gypsum wet
scrubber flue gas desulfurization (FGD)
system to limit sulfur oxides (SOx
). The
use of a wet FGD was driven by the need
to conform to Taiwan's environmental regulations
and standards. At present, TCPP
is equipped with 10 coal-fired units of 550
MW, four gas turbine units of 70 MW, and
wind turbines with 22.2 MW of capacity.
There are plans to add two 1,300-MW
gas units by 2025.
Coal Management
In 1998, the spontaneous combustion
of sub-bituminous coal was a challenge.
However, TCPP learned to control the
problem by mastering various coal-blending
ratios, and continued to burn the fuel.
TCPP effectively reduces dust from the
coal and minimizes its escape, including
from gravity drops during loading/discharging,
mechanical power disturbance
in stacking coal, wind erosion on convey32
or
belts and surface coal piles, and coal
storage mainly in open air. The dust suppression
practices and facilities of the site
include 23-meter-high windproof grids
around the area, sprinkler equipment at a
certain distance, fixed hourly water sprinkling,
sealed coal conveyor belt and transfer
tower, and grab coal unloading.
The machine has been upgraded to a
continuous coal unloader, compacted coal
pile management, surrounding windbreak
forests, and other commonly used best
practices. The efficiency of dust suppression
and control measures of the plant
has reached 96.25%. TCPP is building a
shed-type coal bunker that is designed
with a windproof feature. In the future,
the efficiency of dust suppression and
control measures is expected to be as
high as 98%. Approximately 857 tons of
waste water produced per day in the reuse
plant is properly treated and meets
the standards announced by the Taiwan
Environmental Protection Agency for applicable
power plants, ensuring a better
dust suppression effect.
Plant Operation
The emission flue gas from the power
generation process enters the air preheater
through a primary air fan and forced
draft fan, then enters the boiler, and mixes
and burns the fuel to become fuel gas.
After the heat exchange of the furnace
tube in the furnace, it becomes flue gas
and enters the selective catalytic reduction
denitrification environmental protection
equipment and EP dust removal.
The booster fan and the gas-to-gas heat
exchanger cool down the flue gas before
it enters the FGD absorption tower.
Coal contains sulfur, and the flue gas
produced after combustion contains SOx
TCPP's wet FGD uses limestone powder
.
www.powermag.com
1. Taichung Power Plant uses fluidized-bed
crystallization water treatment technology
to effectively remove boron from wet flue
gas desulfurization wastewater. Courtesy:
Taipower
slurry to absorb SOx
in the flue gas. The
slurry is sprayed from the top of the spray
absorption tower, and the flue gas flows
upward from the bottom of the tower.
The FGD equipment can achieve a removal
rate of more than 90% of the SOx
in the flue gas, allowing the value of flue
gas pollutants to comply with environmental
protection regulations. It is finally
discharged to the atmosphere through a
250-meter-high chimney.
Wastewater Management
The wastewater produced by the wet
FGD process contains dissolved solids,
chloride ions, calcium ions, sulfates, and
nitrates, often in very high concentrations.
The substances contained in coal
POWER | May 2021
http://www.powermag.com
POWER May 2021

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