Chapter-I: Introduction To Fire Detection Protection & Alarm System
Fire: Definition & Classes:
Fire is caused due to rapid oxidation of a substance in the process of combustion, thus releasing heat, light and other bye-products.
Fire has been used by human beings from ages mainly for cooking, generating heat and propulsion purposes. Fire is also the commonest form that has the potential to cause physical damage and its negative effects include atmospheric pollution, contamination of water and damage to life and property.
Fire conditions may be broadly classified into the following classes:-
- Ordinary Combustibles.
- Flammable Liquids.
- Flammable Gases.
- Electrical Equipments Fire.
- Combustible Metals.
- Cooking Oils & Fats.
Basics of Fire fighting
In this present day world, where the strength of a nation is determined by its production of energy, Fire Fighting systems plays an important role in safeguarding the economic needs of a nation.
In this segment, I will be discussing mainly on the Fire protection system employed in Thermal Power plants. As you all might be somewhat aware of Power plant fundamentals, lets us discuss the basic aspects of a Fire Fighting Systems. Fire suppression ( or, Fire fighting system) is a combination of the following systems:
- Alarm, &
As already mentioned above, various fire conditions are caused due to burning of different classes of combustibles. So, fire suppression system must employ different methodology for suppressing fire caused by different combustibles.
In this comprehensive discussion about Fire Fighting System, we will be dealing with the following Fire suppression systems:-
1. Fire Alarm System
A Common concern is shared by all automatic fire detection methods to detect a hostile fire early enough to allow for effective counter actions i.e. evacuation of persons or extinguishing of Fire through Gas Flooding System, Medium & High Velocity Protection Systems and Foam systems.
The Fire Detection and Alarm System provides instantaneous audio alarm when fire is detected in order to prevent loss of life, property and valuables etc., by warning inhabitants in the affected premises immediately, so as to obtain necessary help from Fire Fighting and Salvage Staff.
The Fire Alarm System may be activated by automatic detection devices or by manual operation. Fire Detection and Alarm System performs the function of monitoring the areas from fire continuously and giving an audible alarm in case of sensing of “Fire”. The sensing of the Fire is accomplished through various types of Detectors, Linear heat Sensing Cables, etc.
2. Fire Water System
The Fire Water System includes all equipment, which supplies water to the following pressurized systems:-
- Hydrant system that consists of internal and external hydrant valves, water monitors and piping network for hydrant system around and inside the plants.
- High Velocity Water Spray System for transformers, shunt reactors, Boiler feed pumps/Lube oil consoles, Boiler Burner fronts, Steam turbine oil tanks & Purifier units, Oil canals, Clean & Dirty oil tank and Generator Seal oil units & pumps.
- Medium Velocity Water Spray System for cable galleries at various levels and buildings, coal conveyors, crusher houses, conveyor transfer points, F.O. Pressurizing Pump House, HFO/ LDO tanks and D.G set oil tanks.
- Sprinkler System for Comprehensive Pump House and Diesel Generator Buildings.
- Fixed Foam System for HFO/ LDO Storage Tanks and HFO/ LDO Day Oil Tanks.
The next chapter 'Fire Suppression Methodology' will immensely discuss about the methodology used in a thermal power plant.