Fire presents a significant and ever-present danger in power plants of all types. Regardless of whether you are dealing with a fossil fuel, nuclear, or hydro plant, it is essential to have the right kind of fire protection in place. Depending on the area of the plant in question, fire protection systems for power plants may incorporate a number of tactics, including both passive (building features such as firewalls) and active (suppression) fire protection measures.
Deluge valves play a key role in active fire protection system design for power plants and can be used to protect many different types of power plant equipment and infrastructure. Some of these include control rooms, operating floors, fuel tanks, coal conveyor belts, and cooling towers. However, one of the most critical places to install a deluge fire protection system in a power plant is around the transformers.
Why Deluge Valves are Ideal for Transformer Fire Protection
Power plant transformers pose a high fire risk. Due to human error or inefficient maintenance, transformer fires have increased in the past years. These oil-filled high voltage units—some contain 500 gallons of oil or more—are susceptible to failure due to lightning, faulty insulation, or short circuits in the plant’s electrical system. Studies show that one out of ten transformer failures results in a fire. All it takes is a single spark to ignite a fire in the transformelighr area. When this happens, the results can be devastating. It is common for transformers to rupture in the event of a fire, releasing hundreds of gallons of oil. This can cause the fire to spread rapidly to other transformers and/or other parts of the power generating facility. Any oil that is not burned, carries the risk of environmental contamination should it find its way into the groundwater.
In a situation like this, it is imperative that the fire protection system be designed to operate very quickly at the first onset of a fire event. Deluge valves are the perfect solution because they open immediately when triggered, compared to other types of valves, such as gate valves, that are sometimes used to protect transformers.
How to Use Deluge Valves to Protect Power Plant Transformers
The transformer area is best protected by an automatic high velocity water spray system (HVWS). This requires a special nozzle capable of handling fast delivery of fire water at high pressures (typically not less than 3.5 bars for outdoor transformers.) Care should be taken to place the nozzles, so that the spray patterns overlap each other, thus providing continuous coverage of the entire area with no gaps in protection.
Some transformers are now being manufactured with relatively high design temperatures. This can result in large amounts of heat being discharged from the unit by the cooling fans, which in turn, might inadvertently trigger the deluge system if rate-of-rise heat detection units are used in the system; Therefore, it is best to use fixed temperature heat detection systems to activate deluge fire protection systems in the transformer area.
Designing a Power Plant Fire Protection System?
Fire protection system design for power plants requires a great deal of expertise. It is critical for designers to maintain rigid adherence to stringent fire protection guidelines and regulations (including NFPA, government, and insurance requirements), as well as to optimize the system for the most efficient delivery. BERMAD engineers are available to provide you with expert guidance in fire protection applications and systems. To learn more, click here to contact a BERMAD representative in your region.