VGB Technical Committee Power Plant Concepts, Berlin, 5-6 October 2015

For this, I arrived on Sunday afternoon so had time to have a good walk before dark. The bus from Tegel airport takes 20 minutes and only €2.70 so I was delighted to maintain my boycott of taxis. The hotel was a very new and very no-frills place and entirely adequate. Although close to the station at the zoological gardens, the hotel had double double-glazing, and the electric trains, though only a few metres away, were virtually unnoticeable.

This was my first visit to Berlin, and I planned to see the Brandenburg Gate, 3-4 km away, as a realistic objective. Once you leave the immediate area around the station, everything is pleasant and, after ten minutes walking northwards, you pass the Technical University (hosts for the meeting) and then reach the parkland forming the Tiergarten, with multiple paths, canals and lakes. It was absolutely idyllic, and there were hundreds of Berliners out enjoying the unseasonably warm weather. There was a lovely atmosphere about the whole area.

There was music coming from further west which I found came from an event at the Brandenburg Gate, with repeater loudspeakers at intervals along the Strasse des 17 Juni leading from the Grosser Stern monument towards the Gate. There was a pop concert in full flow with quite a crowd listening. It was part of the festivities for the anniversary of Germany’s reunification; in fact the 25th anniversary fell the previous day (3 October). The stage blocked access to the Gate, but it was possible to walk around, by the Reichstag, and get to the far side and view it from there.

Brandenburg Gate


VGB Meeting

The VGB Technical Committee Power Plant Concepts meeting was informative and enjoyable. It looks at future technologies, as its name suggests. About 15 people attended. After the first day, there was a dinner at a nice bar/restaurant near the Tiergarten. The Festbier was strong and good!

There was first a short tour of facilities for measuring the acoustics to correct imbalances in gas turbine (GT) combustors and for humidification of GT combustors to raise output. Oxygen firing is also being contemplated, as Dr Stathopoulos, of the Thermal Engineering Departments told us. We also saw a wind tunnel for wind turbine evaluations using models.

In the meeting itself, Dr Stathopoulos gave a presentation on using a hydrogen/oxygen combination system for adding (its product) steam to the hot reheat steam path of coal-fired plants to provide very rapid output changes for frequency control duty, and especially valuable for CHP plants. They are looking for an industrial partner. Another speaker from MESY GmbH presented on a very similar system (Project THOR), saying it was practical and available to install now.

Dr Stathopoulos also described a modified combustion system for GTs, exploiting the Humphrey process, which causes multiple minor detonations in the combusting streams, so operating combustion effectively locally at constant volume but elevated pressure, without overall increased pressure. This could raise the GT efficiency without needing ever higher turbine entry temperatures. The combustion system has been shown to work, but not yet been connected to a GT expander.

Dr Hendricksen, of DONG, presented on the biomass conversion of the gas-fired Skaerbaek 3 plant in Denmark. New wood chip boilers will provide hot reheat grade steam to the existing turbine, and the VHP turbine will be kept under vacuum. The LP stages will also not be used. The 29 MPa/580°C/580°C USC steam generator will be kept in case it is needed but is not expected to be used. Commissioning is expected in 2017. Speaking with Dr Hendricksen, I found that a full conversion to biomass appears also to be a possibility for the Nordjyllands 3 USC coal unit, which was a twin of the Skaerbaek gas-fired  unit, and which is now owned by a local heat supply company.