Rosenbauer Brandschutz equips ten substations of the Austrian Power Grid (APG) with modern water spray extinguishing systems.
They have already been installed and commissioned in Villach Süd, Lienz, Bisamberg, Nauders, Vienna South/East, and Salzburg/Elixhausen, while installation work is currently underway in St. Johann/Pongau, Hessenberg, Ybbsfeld and Dürnrohr, or will commence in spring 2024.
ÖVE/ÖNORM EN 61936
Water spray extinguishing systems primarily protect the transformers installed in the switchgear, which are used to switch between the individual voltage levels and relay them to the grid partners. The extinguishing systems are equipped with infrared detection to detect a hotspot or fire hazard at an early stage and react immediately.
The aim is to fight or extinguish a transformer fire and to protect the surrounding facilities and equipment (operating buildings, switchgear, etc.) in accordance with the requirements of ÖVE/ÖNORM EN 61936. However, the systems are not only used for fire protection but also as a preventative measure to cool the transformer before it has to be removed from the grid due to overheating.
Planning and installation
Rosenbauer is responsible for the complete planning and implementation of the fire protection systems
Rosenbauer is responsible for the complete planning and implementation of the fire protection systems and is therefore responsible for the electrical engineering and cabling as well as the firefighting equipment. The most important component is the Rosenbauer nozzle, through which the transformers are supplied with water for extinguishing, but also for cooling, or with a water-foam mixture if required.
Each nozzle is manually aligned according to the structural and spatial conditions on site and is set to spray jet. On the one hand, this achieves a very even and large-area application of water and, on the other hand, causes rapid cooling of the overheated parts due to the finely distributed water droplets. Water damage can also be avoided due to the spray effect.
Water spray extinguishing systems
The capacity of the water spray extinguishing systems depends on the size of the transformer. The largest ones, which are ten meters long and weigh several hundred tons, can discharge up to 6,000 liters of extinguishing agent or water/foam mixture per minute.
The capacity of the water spray extinguishing systems depends on the size of the transformer
The systems are supplied with water via powerful underwater pumps from underground extinguishing water tanks (capacity 300-600 m3); the foam proportioning system including the foam compound tank, the alarm valves and the control cabinets are installed in separate, external containers. In addition, each system has a feed-in point for the fire department. The infrared fire detectors automatically sound the alarm in the monitoring center, but the extinguishing attack is always triggered manually in order to be able to control the extinguishing operation on site.
APG grids
APG operates the supra-regional transmission grid at the 110, 220, and 380 kV voltage levels. This grid consists of around 7,000 km of power lines, 65 substations, 92 transformers, and ten directly connected distribution grids in the federal states. The substations form the nodes of the Austrian transmission grid.
They are used to transform electrical energy, i.e., to change the electrical voltage between two or more voltage levels. In 2022, energy transport via the APG grids amounted to a total of 46,592 GWh with a supply reliability of 99.99%.