The Challenge
The wind farm about 100km north of Adelaide had 3 MW Vestas V90 turbines towers 80-metres above the ground each with a rotor diameter of 90 metres. With an investment on this scale, safety issues, and the environmental impact of fire-damaged or destroyed turbines, the windfarm was investigating options for effective fire detection and suppression. The windfarm operators were aware of the risk of sparks, embers or debris from a burning turbine fire falling to the ground and setting off a bushfire. Having conducted a detailed risk assessment, they turned to Delta Fire for a dependable fire safety solution.
The Solution
Several detection and suppression systems had been put forward as being suitable for the protection of wind turbines, but most are not designed for the particular fire challenges found in wind turbines.
The essential requirements are that the system needed to deliver around-the-clock detection and suppression reliability and provide 24/7 unsupervised protection, respond to a fire with 100 percent reliability, and offer the certainty of false alarm-free operation. Equally important was the need to stop a fire precisely where it breaks out and before it has an opportunity to take hold. At the same time, it has to contend with vibration, dust and debris, airflow through the nacelle and extreme temperature variations, be intrinsically safe and require no external electrical or other power that can fail and so put the system out of operation.
Following extensive field trials were undertaken in wind turbines at another windfarm, the decision was taken to entrust the Waterloo windfarm turbine fire safety to the Firetrace system that is available throughout Australia via Delta Fire.
Firetrace is a linear pneumatic, automatic fire detection and suppression system; one that provides both fire detection and suppression in a single self – contained package.
It comprises a cylinder that contained 3M Novec 1230 Fire Protection Fluid that is stored in containers as a low vapour pressure fluid. When discharged, it transmutes into a colourless and odourless gas. After discharge, the agent is dispersed through natural ventilation, leaving no residue to damage sensitive electrical equipment; it is also nonconductive and non-corrosive.
The Novec 1230-filled cylinder is attached to a purpose-designed, leak-resistant polymer tubing that is a heat and flame detector designed to deliver the desired temperature-sensitive detection and delivery characteristics. It is routed throughout the areas to be protected and, when the tubing is exposed to heat and radiant energy from a fire, it ruptures and instantly directs the suppression agent at the source of the fire.
The Outcome
The Danish-manufactured turbines were delivered to Port Adelaide, where Delta Fire fitted the Firetrace systems before the turbines were transported by road to Clare Valley. The Firetrace installation in each turbine took 24 man-hours to complete, and the final commissioning of the systems took place once the turbines were erected on site.