Pha Lai 2 Power Station
2 x 300 MW Pha Lai 2 Power Station is the largest coal fired station in Vietnam. Both units are equipped with FGD plants. 85 % of the gas flow is treated in the FGD absorber and the remaining 15 % is bypassed around the FGD, and mixed into the treated gas stream. After mixing, flue gas with an average temperature of 58 ˚C / 136 ˚F is released to the chimney. Pha Lai 2 Power Station has a new concrete chimney with 2 Pennguard® lined steel flues (5,400 m2 / 58,130 sqft).
The coal for Pha Lai 2 can be characterized as very difficult; it has an ash content of 27 % – 33 % and a volatile matter content of less than 5 %.
Fast and efficient installation process
The contractor decided to line the 7.2 m / 23.62 ft high steel cans on ground level in a specially designated work area. Then, the pre-lined cans were placed inside the chimney and welded to the flue. The chosen work method proved to be fast and efficient. The Pennguard® lined flues were installed within a period of 8 weeks.
The full installation process is explained and shown on page 2 and 3 of the Project Report PDF file.
Selection of the chimney flue lining
At 58 ˚C / 136 ˚F , the flue gas creates a very strong acidic environment in the chimney flues. Even though the gas temperature is slightly above the water dewpoint, it is far below the acid dewpoint, which is typically higher than 100˚C / 180 ˚F. Under these conditions, traces of SO3 and moisture combine to form sulfuric acid condensate on the internal surfaces of the chimney flues.
A Pennguard® chimney lining has:
- unlimited resistance to sulfuric acid condensate
- excellent thermal resistance, FGD bypass will not affect the lining
- an uncomplicated installation method, even in a tropical climate