Monitoring System and Expert System For Prevention of Fire

Monitoring System and Expert System For Prevention Of Fire Points : Monitoring System and Expert System For Prevention Of Fire, Fire Detectors and Fire Detection System, Type of Detectors, Fire Detectors And Associated Water Spray System Expert System For Prevention of Fire These additional microprocessor based on-line systems are useful to plant control engineer, and safety engineer to have control on various dangerous parameters and take in advance a corrective action and prevent unsafe condition from developing. Temperature of windings in equipment of cooling media, status of detectors, loading of machines, etc. is monitored by periodic scanning of outputs by means of on line microprocessor based Monitoring System. The data is analyzed periodically by on line expert system. Any trend beyond safe trend is further analyzed and warning is given to control room engineer about impending danger along with suggested corrective actions in order of priority, e.g.,
- Transformer No.2 getting overheated rapidly.
- Cooling water flow low, check the water pipes.
- Load on transformer to be reduced by 20% within next 15 mm. Fire Detectors and Fire Detection System Detectors sense the fire/smoke and discriminate between normal condition and normal condition by sensing temperature / rate of rise temperature / presence of smoke / infrared or ultra violet radiation due to fire. Type of Detectors The following types of detectors are generally favoured in Plants and substations:
The operation of any one of the detectors is followed by one or more of following Actions:
- Alarm initiation
- Zone indication
- Initiation of Water Spray System
- Initiation of valves / Halon valves / Foam valves for releasing quenching medium.

1. Fusible Glass Bulb Detectors are Fixed Temperature Detector (e.g., Detectors which will detect 60°C, 80°C, 90°C). The glass of the bulb fuses at certain predetermined temperature. The breaking of glass initiates the desired action.

2. Rate of Rise Temperature Detectors (Detector which responds to Rate of rise of temperature at 5C/min).

3. Ionization Smoke Detector. Presence of smoke in ionization chamber in the detected.

4. Optical Smoke Detectors. The smoke operates the photo-electric device in the detector.

5. Flame Detector react to radiant energy in the infrare4 or ultraviolet radiation in the spectrum of light.

6. Fire Wire. It consists of a stainless steel capillary sensing element looped together and connected to a monitoring unit.

7. Fusible Links. Base of the link is soldered and the solder melts at certain temperature and thereby initiates protective equipment.

8. Temperature Sensitive Cabling. Change in temperature of cables is detected by connected analogue or digital electronic instruments.

9. Compressed Air Detection. System in conjunction with High Pressure Water Spray System. It is employed in some plants and substations, the. detecting elements are fitted on compressed air pipes distributed in various risk zones. Heat of fire operates the detectors and the pressure in compressed air system falls. Water from high pressure water system enters through sprinklers to extinguish the fire.

Fixed temperature detectors are distributed throughout the buildings and are connected with the manual push-button for fire alarm. The substation buildings (control room buildings, switchgear building, stores etc.) are divided into several fire-alarm zones. A fire — alarm control panel is installed in the control room. In case of fire, the window is lighted on corresponding alarm zone in the fire alarm control panel and als? a buzzer is sounded inside the fire alarm control panel. The fire-horns are sounded in respective zone. The a.c. supply is switched off area-wise by respective relays and contactors.

The 11 KV auxiliary a.c. switchgear, low voltage d.c. switchgear are provided with fixed temperature heat detector and response indictors. The response indicator sound an alarm and provide indication on the fire alarm control panel located in the control room. Fire Detectors And Associated Water Spray System