Fire Commander Fire Extinguishing Water Calculation

News Related Keywords: No tags.

I. Fire water consumption calculation: Q=Aq

Note: A is the burning area of ​​the fire, q---the intensity of the fire extinguishing water supply, generally 0.15 L / (S · m 2 ) , the high-rise building is 0.2 L / (S · m 2 ) , the underground confined space and the cotton fiber products are taken 0.3 L / (S · m 2 )

Example: A fire occurred in a residential building of 100 square meters . Try to calculate the amount of fire water used.

Solution: The fire extinguishing water supply intensity of residential buildings takes 0.15 L / (S · m 2 ) ,

The fire water quantity of the fire site Q , according to the formula Q=Aq=100 m 2 *0.15 L/(S · m 2 )=15L/S

Second, the water pressure loss calculation: hd = SQ2

Note: HD --- Pressure loss per 20 m of hose, each hose impedance is S ---, --- the water with a flow Q, Φ 65mm impedance factor S = 0.035, Φ 80mm impedance factor S = 0.015

Example: One hand lifts the pump to absorb water from the natural water source, and uses 10 Φ 65mm plastic hoses to supply water for 1 Φ 19mm water gun. The water column of the water gun is required to be not less than 15m . Calculate the pressure loss of the water supply mains.

Solution: It is known that the impedance coefficient of the Φ 65mm rubber hose is 0.035 .

When the Φ 19mm water gun is filled with a water column of 15m , the flow rate at the nozzle of the water gun is 6.5L /s .

The pressure loss of the hose is Hd=nSQ2=10 × 0.035 × 6.52=14.8 ( 104Pa )

Third, the fire truck water supply calculation:

( 1 ) Known water guns and hose lines for the export pressure of fire engines: Hb=hq+hd+h1-2

Note: Hb --- Fire pump outlet pressure, hq --- pressure at the nozzle

HD --- water mains with a pressure loss, h1-2 --- elevation difference

Example: a fire engine from a natural water source, water absorption, using 10 enrich the water column in the water Φ 65mm plastic strip is a water gun Φ 19mm, outdoor fire fighting, gun requires not less than 15m, flat water to the fire. Try to calculate the pump outlet pressure.

Solution: If the water source is flat to the fire, H1-2=0.

When the water pressure of the Φ 19mm water gun is 15m and the pressure and flow at the nozzle of the water gun are 27 × 104Pa and 6.5L /s respectively, the pressure loss of each hose is 1.48 × 104Pa . The pressure loss of the 10 hoses is: Hd =10 × 1.48=14.8 ( 104Pa ) or the impedance coefficient of the hose in Φ 65mm is 0.035 .

When the Φ 19mm water gun is filled with a water column of 15m , the flow rate at the nozzle of the water gun is 6.5L /s .

Then Hd=nSQ2=10 × 0.035 × 6.52=14.8 ( 104Pa )

The pressure loss calculated by the above two methods was 14.8 × 104Pa .

Fire truck water pump outlet pressure: Hb=hq+hd+H1-2=27+14.8+0=41.8 ( 104Pa )

( 2 ) Calculation of maximum water supply distance for fire engines: Sn= ( r Hb-hq-H1-2 ) /hd

Note: Sn --- the maximum water supply distance of the fire truck (how many lengths of the hose), r --- the coefficient of use of the pump lift pump, generally take 0.6 ~ 0.8 , Hb --- fire pump pump head (outlet pressure), --- gun nozzle pressure at HQ, H1-2 is --- elevation difference, the pressure loss of each hose. HD ---

Example: CG36/40 fire truck, pump head is 120 × 104Pa , with Φ 90mm rubber hose in single trunk water supply, the supply of 2 Φ 19mm water gun is 15m , and the water source is flat to the fire site. Calculate the maximum water supply distance for the fire truck relay.

Solution: When the Φ 19mm water gun is filled with a water column of 15m , the outlet pressure is 10 × 104Pa , and the flow rate of each water gun is 6.5L /s . The flow rate of the two water guns is 13L /s .

When the flow rate of the hose in the Φ 90mm adhesive is 13L /s , the pressure loss of each hose is 1.35 × 104Pa (also calculated by the hose pressure loss formula hd = SQ2 ).   If the water source reaches the fire site with a flat potential , the elevation H1-2=0 . The maximum relay water supply distance for CG36/40 fire engines is:

Sn = ( r Hb-hq-H1-2 ) /hd = ( 120-10-0 ) /1.35 = 81.48 (Articles) 81 items are actually used .

The water supply distance is 81X20=1620 meters .

Answer: The maximum water supply distance for the fire truck relay is 81 hose lengths, 1620 meters .

( 3 ) Calculation of maximum water supply height for fire engines: H1-2=Hb-hq-hd

Note: H1-2---The height of water supply for fire engines, Hb---The pump lift for fire engines,

Hq --- nozzle pressure at the water gun, hd--- pressure loss in the hose system

Example: A fire broke out in a high-rise building. The fire truck was parked at a fire hydrant 20 meters away from the building . The fire truck was a CG36/40 type fire truck with a pump head of 120 × 104Pa . The hose was supplied with a Φ 90mm rubber hose in a single trunk line. , The supply of 2 Φ 19mm water guns is 15m . Calculate the maximum water supply for the fire truck.

Solution: When the Φ 19mm water gun is filled with a water column of 15m , the outlet pressure is 10 × 104Pa , and the flow rate of each water gun is 6.5L /s . The flow rate of the two water guns is 13L /s .

When the flow rate of the hose in the Φ 90mm adhesive is 13L /s , the pressure loss of each hose is 1.35 × 104Pa (also calculated by the hose pressure loss formula hd = SQ2 ). If the fire truck is 20 meters away from the fire , the pressure loss on the horizontal laying of the water belt is a loss of one belt, hd is 1.35 x 104Pa . The maximum height of CG36/40 fire engines is:

H1-2=Hb-hq-hd=120×104Pa-10×104Pa-1.35×104Pa

=108.65×104Pa=1.0865×106Pa=1.0865M Pa

According to pressure formula: P= ρ gh

A standard atmospheric pressure of about 1.01 × 105Pa or 10.3 m of water,

H1-2 = 1.0865 × 106Pa / 1.01 × 105Pa = height of 10.7 atmospheres, about 110 m high water column.

Answer: The maximum water supply for the fire truck is 110 meters .

(4) the estimated water height: â‘  H = 100 (Hb- Hq) ( MPa when the pressure is uniform units)

Note: H is the water supply height in m , Hb is the pressure at the pump outlet, Hq is the pressure at the water gun outlet, and 10 m is the estimated water supply height at 0.1 MPa .

Example: A fire truck with a water pump head of 120 × 104Pa is supplying water to a high-rise building. The pressure at the water gun mouth is not less than 10 × 104 Pa . Estimate the maximum water supply of the fire truck.

Solution: fire pump head Hb is 120 × 104Pa = 1.2 × 106Pa (i.e. we are talking about 12 kilograms or pressure 1.2MPa), Hq gun outlet pressure is 10 × 104Pa = 0.1 × 106Pa (i.e. we are talking about 0.1MPa Or 1 kg pressure )

H=100 (Hb-Hq) =100 (1.2MPa-0.1MPa)=10X1.1=110 meters

Answer: The maximum water supply for the fire truck is about 110 meters .

2 P= Hq +0.04* (N-2)MPa

Note: Hq is the pressure at the outlet of the water gun, N is the number of floors, and 0.04 is the coefficient.

Fourth, the fire field transport vehicle calculation

N=(t1+t2+t3)/T+I(3)

Note: N---The number of water trucks required to ensure uninterrupted water supply for 1 vehicle at the fire site , t 1--- water truck time, t 2--- transport time for water on fire, t 3- - Return time on the way to the water truck, T---1 time when pot water is used on the fire

Example: A fire site is far away from the source of water and it needs a water truck to carry water from a water source. If the tanker watering time is 2 minutes, the transfer time of the water on the fire site is 1 minute, the return time of the water tanker is 12 minutes, and the use time of 1 pot of water on the fire site is 3 minutes, so as to ensure uninterrupted water supply to the fire site. The number of water trucks needed.

Fifth, the fire pipe network water supply capacity calculation :

( 1 ) Calculation of water flow in the pipe network: Q=0.0008D 2 v

Note: Q--- The flow of water in the ring pipe network, D---the diameter of the ring pipe, and v- the flow rate of the fire water supply pipe, generally 1.5m /s to 2.5m /s , and the branch shape to take 1m /s.

( 2 ) Calculation of water flow in the pipe network: Q=0.5 D 2 V

Note: Q--- The flow of water in the ring pipe network, D---the diameter of the ring pipe, the unit is inches, the diameter mm /25 converts the inch, v---the fire water supply pipe flow rate, generally take 1.5m /s ~ 2.5m /s , branch 1m /s .

( 3 ) Pipeline water supply capacity calculation: N=Q/Q car

Note: N--- The water supply capacity of the annular pipeline is the number of available fire engines; Q--- The flow of the annular pipeline water, Q truck --- The quantity of water supplied by each fire engine

Example 1: an annular duct fire Φ 300mm, the water pressure in the pipeline is not less than 0.2MPa. If the flow of a certain type of fire engine on the fire site is 40L /s , try to calculate the number of fire engines that can be parked on the pipeline.

Solution: The ring pipe v = 1.5m/s , then the flow of the pipe is:

Q=0.0008D2v=0.0008×3002×1.5=108L/s

N=Q/Q vehicle =108/40=2.7 (vehicle) Actual use to take 2 vehicles

Answer: The number of fire engines that the pipeline can park is 2 vehicles.

Estimation method: Q=1/2vD2=1/2 × 1.5 × (300/25) 2=108 L/s

N=Q/Q car =108/40=2.7 (vehicle)     Actual use of 2 vehicles

Sixth, the fire field water supply power calculation:

( 1 ) Calculation of control area for water gun: f=Q/q

Note: f --- the control area of each water gun , Q --- the flow rate of each water gun, q --- the water supply intensity of fire extinguishing water, which is generally 0.2 L / (S · m 2 ) , and 0.2 L / for high-rise buildings. (S · m 2 ) , underground confined space and cotton fiber products take 0.3 L / (S · m 2 ) Example : A

TORICH is specialized manufacturer and supplier of DOM STEEL TUBE, DOM STEEL TUBING,DOM Tubing, DOM STEEL PIPE.

DOM Steel Tubes, are produced with Cold Drawn Process based on ERW Steel Tubes, to achieve Good outside and inside surface,

the advantage of the production is better Concentricity and Ovality, to reduce deviation of Roundness of the steel tubes.

DOM Steel Tubing is also called Welded Cold Drawn Precision Steel Tubes.


Technical Standard:

ASTM A513 Type5, Type 6, SSID

EN10305-2

SAE J525


Products Application:
Oil Cylinders

Air Cylinder,
Automotive Cylinder Liners
Jack Lifting
Telescopic Systems
Pneumatic Cylinders
Gas Spring Cylinders

Race Car Frames

Roll Cages

Motorcycle Frames

Spindles

Rollers

Shafts

Bushings

Clinders, Bore Cylinders


Size range is:
O.D. 4-350mm,
W.T. 0.5-30mm,
Length: according to customer`s requirement and agreement


DOM Steel Tubing DOM Steel Tubes


DOM Steel Pipes Steel Tubing


DOM Round Steel Tube, is a ERW welded mechanical round steel tube with the internal weld seam removed achieving a smooth internal surface.

DOM round steel tube has been drawn over a mandrel and die to produce a tube having more accurate dimensional tolerances, and a very smooth inside and outside finish. DOM round steel tube is ideal for more stressful applications requiring higher quality, increased mechanical properties, uniformity, strength, and soundness.

Dom Tube

Dom Tube,Seamless Welded Pipes,Thin Wall Steel Tube,Drawn Over Mandrel Steel Tube

TORICH INTERNATIONAL LIMITED , https://www.steeltubepipechina.com

Posted on