In practice, we encounter different fires, which are, depending on their nature, the most manageable fire extinguishers compatible with it. In the master's thesis, we will present in detail the fires with an electrical source and functioning of Heptafluoropropane as a possible extinguisher. Heptafluoropropane (FM-200) was developed as a substitute for Halon 1301, which is harmful to health and the environment. It is more appropriate to use fire extinguishers containing Heptafluoropropane, as it is not harmful to the environment, people, or the equipment that is extinguished with this type of fire extinguishers.
Fires with electrical origin can occur in all environments or premises where electrical devices and installations are present, i.e., electrical cabinets, electrical wiring, computer, and other electrical devices. The priority of the master's thesis are fires with an electrical source in smaller rooms. A review and analysis of the literature show that the most convenient and the fastest way to extinguish such fires is with the pre-installed Heptafluoropropane (FM-200) tubes above the fire's potential source. When in contact with fire, or when the temperature exceeds 120 °C, Heptafluoropropane tubes are softened, triggered, and immediately extinguish the fire. Due to the cooling effect, the ambient temperature decreases.
The efficiency of Heptafluoropropane tubes was tested in the experimental part. We were interested in the trigger temperature of Heptafluoropropane tubes, the time required to extinguish the fire, and the temperature drop after triggering. By repeatedly simulating a fire in the experimental chamber, we found that Heptafluoropropane tubes, which should typically be placed above a potential combustion source, are on average triggered at a temperature of 131,1 °C (the result of thermocouple 1) and 181 ° C (the result of thermocouple 2). On average, 42.3 seconds elapsed between the start of space heating (test chamber) and the activation of the FM-200 tube. Heptafluoropropane tubes extinguished the combustion source immediately upon initiation, confirming the manufacturer's statement that the time required to extinguish the fire was less than 10 seconds. The fire was extinguished with Heptafluoropropane tubes according to the principle of quenching and cooling. Experiments have confirmed the effectiveness of Heptafluoropropane in extinguishing fires in a small space, e.g., electrical cabinets.
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