Aberthaw Power Station

Aberthaw Power Station prepared for Flue Gas Desulfurization (FGD) operation by installing Pennguard® linings in existing chimney with 3 brick flues

Aberthaw Power Station is a 3 x 500 MW coal fired power station in Wales, UK. Its owner, RWE npower is one of the leading electricity generators in England and Wales. When the European Union created more stringent regulations, requiring all coal fired stations to limit their SO2 emissions by 2008, RWE npower decided to fit Sea Water Flue Gas Desulfurization at Aberthaw power station. Fitting Flue Gas Desulfurization to the power station would also have consequences for the existing, 40 year old chimney.

After investigation of the risks of Flue Gas Desulfurization operation for the existing chimney and its flues, the owner decided to modify the chimney by sealing all three brick flues with the Pennguard® Block Lining System. The three flues were lined with Pennguard® in 2004, 2005 and 2007.

Risk of Flue Gas Desulfurization operation for the existing 40 year old chimney

The frequent start ups and shut downs of the units at Aberthaw power station will lead to frequent formation of aggressive acidic condensate within the flues. If the flues were left unprotected, condensate would permeate through the brick joints and attack the structural integrity of the chimney.

Furthermore, the sudden thermal swings associated with switching from FGD operation to FGD bypass operation (or vice versa) would create damaging stresses in the brickwork.

The owner decided that the existing chimney should continue to be used after the Flue Gas Desulfurization (FGD) retrofit, provided that the flues could be protected against the much more aggressive Flue Gas Desulfurization (FGD) operating conditions.

It was decided to prepare the flues for Flue Gas Desulfurization (FGD) operation by installing the Pennguard® Block Lining System over the internal brickwork surfaces.

How Pennguard linings protect the 3 brick flues from thermal stress

The strong insulating effect of a Pennguard® lining will protect the flues against thermal cycling and thermal shock. In many FGD designs, the operation can change from FGD mode to FGD bypass mode within seconds, simply by the switch of a damper. The sudden exposure to a much hotter gas stream (or, cooler gas stream, when switching back to FGD operation) creates great stresses in a brick flue, which will result in damaging crack formation.

The Project Report explains in detail how a Pennguard® lining protects a brick flue from thermal stress (page 4) and how the installation of the Pennguard® lining in the Aberthaw brick flues was performed in a step-by-step process (page 2 and 3).