Power station monitoring: for testing we even enter some tubes!
Entering pipes that are 5-7 meters in diameter? No problem for the testing experts at Applus+ IMA Dresden. In coal-fired power plants, gas is discharged during the combustion of the raw material. This then arrives in the large natural draft cooling towers, which are often a visible feature of a power plant in the landscape. So-called clean gas ducts are used to transport the gas as a reaction product. In the past, these pipes were typically made of metal. But the glass-fiber-reinforced plastic (GRP) now used has a major advantage: it is more resistant to corrosion. This is because the high temperatures and the media (chemicals, water) cause the pipes to corrode quite quickly. Since the construction of the clean gas ducts, the experts at Applus+ IMA Dresden have been supervising the ducts in central Germany by carrying out approval tests for obtaining approval in individual cases, or ZiE for short. This ZiE from the responsible building authority is required because the GRP ducts are a non-regulated construction product. Since commissioning, the engineers of the Dresden-based testing service provider have been carrying out regular visual inspections and material tests. Of course, this only works when there is no gas flowing through the ducts. When inspecting the ducts, colleagues evaluate the condition of the duct surface through a visual inspection and look for surface damage, delamination or cracking. To check the material, a piece is removed from the GRP duct and examined in the laboratory for the mechanical properties of the pipe’s supporting laminate. The resulting gap in the pipe is then sealed by specialist companies so that the power plant can continue to operate. And if the colleagues take the wrong turn during the test, they end up at the very top of the cooling tower – 40 meters up – and briefly enjoy the view.