Application of Corrugated Tubes in Power Plant Heat Exchangers (Field Test)

Project Number 325

So far only plain tubes are used at the so-called "cold end" of power plant condensers although tubes with surface structure (corrugated tubes) increase heat transfer and correspondingly condenser performance.

Smaller design considerably reduces investment of condenser tubes, i.e. higher output is possible at unchanged condenser size. This can be of importance in retrofit projects, because improved turbines can be retrofitted at a given condenser space.

Promising experience with corrugated tubes has been made by the sugar industry in large-scale applications. However, measuring results documenting performance improvements through the application of corrugated tubes under real conditions are not yet available for power plants. Besides, knowledge has to be gathered about the corrosion behaviour in open and closed power plant cooling cycles. Finally, systematic experience has to be collected with the application of tube cleaning devices for corrugated tubes.

Thus, the project is aiming at proving the every-day suitability of corrugated tubes in turbine condensers and coolers in order to pave their way for application in power plants.

The focus is on a field test to be carried out in the Schwarze Pumpe power plant, i.e. over a period of two years on an intermediate cooler of 17 MW that is equipped with corrugated tubes. The field tests, which are to be prepared in the lab and to be accompanied, are to concentrate on the following targets:

  • Determination of the real heat transfer capacity,
  • Determination of the corrosion behaviour,
  • Optimisation of the flow behaviour,
  • Adoption of tube cleaning systems to be applied in corrugated tubes.

The project is being carried out from 2009 until 2013 by MPG Wärmetechnik GmbH, headed by Dr Andreas Gahl. Vattenfall Europe Generation AG & Co. KG, the Institute for Energy- and Process Engineering of Paderborn University, the Laboratory for Corrosion Protection Engineering of Fachhochschule Südwestfalen, Taprogge Gesellschaft mbH and Ohl Technologies GmbH are also participating in this project. The Technical Committee Machines is looking after project realisation.