Fire Load Calculation - CPWD(2).pptx

fire load

1. FIRE AND LIFE SAFETY IN NBC G C MISRA [email protected] 9868022790

2. WHAT DO WE DESIGN FOR? THE CORE OBJECTIVE IS TO PROTECT AGAINST THE HAZARD THAT MAY EXIST IN ANY BUILDING DUE TO PRESENCE OF VARIOUS LOADS AND ACCORDINGLY NAMED.

3. DESIGNING FOR FIRE & LIFE SAFETY

4. How the hazards come into play? DUE TO ACCIDENTAL FIRE THREAT TO LIFE DUE TO HEAT & SMOKE DAMAGE TO PROPERTY DUE TO BURNING DAMAGE TO STRUCTURE INCLUDING COLLAPSE WHAT TO WORRY FOR? HEAT ENERGY

5. CAN WE CREATE ENERGY? NO WHERE TO GET ENERGY FROM? CONVERT SOME OTHER FORM OF ENERGY WHAT IS THAT OTHER FORM? CHEMICAL ENERGY

6. WHAT IS FIRE? FIRE IS AN EXOTHERMIC REACTION THAT TAKES PLACE IN THE PRESENCE OF HEAT AND OXYGEN TO CONVERT CHEMICAL ENERGY OF FUEL INTO HEAT ENERGY.

7. WHY DO WE IGNITE A FUEL? TO GET HEAT WHAT IS HEAT? HEAT IS A FORM OF ENERGY HOW TO GET HEAT ENERGY? CONVERT SOME OTHER FORM OF ENERGY WHAT ARE OTHER FORMS OF ENERGY? CHEMICAL/ELECTRICAL/MECHANICAL/NUCLEAR

8. WHAT IS THE SOURCE CHEMICAL ENERGY? THEY ARE CHEMICALS HOW CHEMICALS GIVE HEAT ENERGY? THROUGH A CHEMICAL REACTION DOES ALL REACTIONS GIVE HEAT? NO WHICH REACTIONS GIVE HEAT? EXOTHERMIC REACTIONS

9. WHAT IS A FUEL? FUEL IS A SOURCE OF CHEMICAL ENERGY EXAMPLES? WOOD, PAPER, CLOTH,OILS, GAS ETC. CAN WE BURN STEEL? NO IS STEEL A FUEL? ANY MATERIAL THAT CAN NOT BURN IS NOT A FUEL?

10. WHAT IS A LOAD? LOAD IS THE WEIGHT OF FUEL HOW MUCH IS THE FUEL LOAD IN A ROOM IF IT HAS THE FOLLOWING: 10 KG OF STEEL 20 KG OF WOOD 5 KG OF CLOTH 2 LITERS OF PETROL 3 KG OF PLASTICS

11. DO FUELS RELEASE SAME HEAT ENERGY WHEN BURNED? NO, DIFFERENT FUELS RELEASE DIFFERENT AMOUNT OF HEAT ENERGY. WHAT IS THIS HEAT ENERGY CALLED? CALORIFIC VALUE OF FUELS HOW IS THAT HEAT ENERGY MEASURED? IT IS MEASURED IN JOULES PER UNIT MASS [J/g]

12. CALORIFIC VALUE Calorific value is  the amount of heat energy present in fuel and which is determined by the complete combustion of specified quantity at constant pressure and in normal conditions . It is also called calorific power. The unit of calorific value is kilo joule per kilogram i.e. KJ/Kg.

13. CALORIFIC VALUE OF WOOD THE CALORIFIC VALUE OF WOOD IS 17600 kJ/kg WHAT DOES THIS MEANS? THIS MEANS THAT IF ONE KG OF WOOD IS BURNED COMPLETELY THEN 17600 kJ HEAT ENERGY IS PRODUCED.

14. WHAT IS THE FIRE LOAD? FIRE LOAD IS DEFINED AS THE TOTAL AMOUNT OF HEAT ENERGY PRODUCED BY BURNING THE ENTIRE FUEL PRESENT IN AN AREA. THIS IS EXPRESSED IN kJ/m 2 [1 kJ= 0.24 k Cal = 0.95 x 10 -3 BTU]

15. FIRE LOAD OF MATERIALS FIRE LOAD OF MATERIALS : CELLULOSIC (E.G. PAPER, CARDBOARD, WOOD), PLASTIC, TEXTILE/FABRIC); Wood 18.6 MJ/kg Paper 17.0 MJ/kg Plastic 22.1 MJ/kg Textile 19.0 MJ/kg

16. WOOD EQUIVALENT [WE] THIS MEANS THAT ALL FUELS ARE EQUATED TO WOOD AND DETERMINED BY DIVIDING THE CV OF FUEL BY CV OF WOOD. EXAMPLE: THE CV OF WOOD IS 17.6 kJ/Kg AND CV OF POLYSTER IS 22 kJ/Kg. THUS, 1 Kg OF POLYSTER IS EQUIVALENT TO 1.25 Kg OF WOOD IN TERMS OF HEAT ENERGY.

17. HOW TO CALCULATE FIRE LOAD? SELECT A ROOM MEASURE THE LENGTH (m) MEASURE THE WIDTH (m) LIST THE NAMES OF ALL FUELS IN THE ROOM MEASURE THE WEIGHT OF EACH FUEL NOTE THE CALORIFIC VALUE OF EACH FUEL

18. PREPARE A TABLE WRITE SR. NO. IN COLUMN 1 WRITE NAME OF FUEL IN COLUMN 2 WRITE CALORIFIC VALUE IN COLUMN 3 WRITE TOTAL WEIGHT OF FUEL IN COLUMN 4 WRITE TOTAL CALORIFIC VALUE OF FUEL BY MULTIPLYING THE WEIGHT OF FUEL [Kg] x CV SUM TOTAL OF TOTAL CV OF ALL FUELS DIVIDE SUM TOTAL OF CV OF ALL FUELS BY ARE OF ROOM TO GET FIRE LOAD OF THE ROOM IN kJ/SQUARE METER

19. FIRE LOAD CLASSIFICATION 1. LOW  FIRE LOAD (up to 2,75,000. Kcal/m 2 ) 2. MODERATE FIRE LOAD  (above 2,75,000 Kcal/m 2  to 5,50,000 kcal/m 2 ) 3. HIGH FIRE LOAD  (above 5, 50, 000 kcal/m 2  to 11,00, 000 kcal/m 2 )

20. WHERE DO WE USE FL INFORMATION? CLASSIFICATION OF OCCUPANCY ESTIMATING THE FIRE GROWTH POTENTIAL ESTIMATING FIRE RESISTANCE REQUIREMENTS ESTIMATING WATER DEMANDS

21. OCCUPANCY CLASSIFICATION WRT FIRE LOAD DENSITY (WE) [NBC 2005] RESIDENTIAL [A1 & A2]: 25 kg/m 2 RESIDENTIAL [A3 TO A5]: 25 kg/m 2 EDUCATIONAL & INSTITUTIONAL: 25 kg/m 2 ASSEMBLY & BUSINESS: 25-50 kg/m 2 MERCANTILE: UPTO 250 kg/m 2 INDUSTRIAL: UPTO 150 kg/m 2 STORAGE & HAZARDOUS : UPTO 500 kg/m 2

22. CLASSIFICATION OF STRUCTURES TYPE I STRUCTURAL COMPONENTS: 4 Hrs TYPE II STRUCTURAL COMPONENTS: 3 Hrs TYPE III STRUCTURAL COMPONENTS : 2 Hrs TYPE IV STRUCTURAL COMPONENTS:  1 Hrs THE FIRE RESISTANCE CAN BE CALCULATED WRT FOLLOWING FACTORS :- a) STABILITY b) INTEGRITY c) THERMAL INSULATION

23. FIRE RESISTANCE WRT FIRE LOAD Wood and Fiber, 9(1), 1977, pp. 73-85, by the Society of Wood Science and Technology

24. FIRE TEMPERATURE The time-equivalence method creates a relation between the effects of heating in structural members caused by natural fires and those caused by the ISO fire curve (BS ISO834, 2014).