"Turbulences caused by Waste Heat"

u&i receives subsidies within the framework of the "Lower Saxony Innovation Loan Program" funded by the economy sponsoring fund Lower Saxony, for a project dealing with the possibilities of increasing the efficiency of power plants.

The aim of this research project is to convert an additional part of the currently lost heat of condensation power stations into electrical energy. This research project has the working title "Turbulences caused by Waste Heat".

Project information "Turbulences caused by Waste Heat"

Thermal power plants show - depending on the utilized fuel, the used techniques and the design size - an efficiency factor of less than 25-60 % based on the pure electrification. The remaining waste heat is dissipated into the ambient air by air condensers or cooling towers. Generally, waste heat appears at comparatively low temperatures (< 50°C). At first sight, this energy seems to be lost for further use due to the low temperature level.

The aim of this project is the development of a technology that can use these amounts of waste heat at the so-called "cold end" of a power plant.

In this context, the German center for aerospace (Deutsche Zentrum für Luft- und Raumfahrt e.V. [DLR]) filed a patent in 2009. This patent targets a significant increase the efficiency factor of a classical power plant. An additional amount of the thermal energy which is dissipated into the environment by cooling devices will be converted into electrical energy.

u&i seizes this patent and will illustrate and optimize the idea of this patent with the help of a CFD simulation model in order to calculate its potential during the first project phase. In the second project phase these results shall be verified practically, and will be further optimized.

The patent document of the DLR picks up the principle of solar updraft towers. Therefore this principle should be modified to the effect that the heated air raises up inside the tower and is, meanwhile, set into rotation by adequate geometry. In the course of the way up, more air is sucked into the system by arranged feed stream notches and is also set into rotation. At the upper end of the tower, the rotating air is finally used to move an installed turbine in order to generate electrical power by a generator.

Considering the efforts that plant manufacturers and operating companies undertake to increase the efficiency of power plants, the above described technology presents a new approach to achieve an increase of the efficiency factor without complicated changes of the existing power plant peripheries and controls.

If u&i manages to develop this technology into marketability, it can influence the energy market significantly.

Also the strong growing market of solar thermal power plants, which shall be installed in deserts amongst others by the German Desertec-initiative, demonstrates a market for this technology, as these power plants depend on efficient cooling techniques in arid deserts. The achieved cooling effect can be increased in combination with the updraft technology.