"Fire Fighting" Fire Base Water Supply Basic Ideas

Write in front

The purpose of water supply is to keep the water out of the fire field. To ensure that the combat vehicles have enough water to meet the needs of the fire, one, two, or even multiple water fire engines are needed to form a water supply system to supply water to the front fighting vehicles.

How to meet the amount of water in front of you, personally believe that the rear water supply system should be deployed from data such as the number, flow rate, and pressure of water outlet appliances.

Example: In front of the fire, two DC water guns are needed to extinguish the fire. The rear water supply needs to be greater than or equal to the flow of these two DC water guns. It can be estimated that: a DC water gun can be calculated at a flow rate of 6.5 L /s . Then two water guns are used. Needs ≥ 13L / s flow to meet the needs of the fire, usually our municipal fire hydrant pipe diameter is 100mm , the flow of municipal fire hydrant in the 10L / s-15L / s , that is, if only two guns, the fighting vehicle can be direct Connect a nearby hydrant for water supply, or the rear vehicle can be connected to a hydrant to supply water from a remote location to meet the requirements.

Watching

Usually, when there is a shortage of water in a fire field, the commander will order the water magistrate to expand the water source to find the scope, and even implement water supply from a long distance to the fire field. When the water magistrate discovers a water source at a long distance, the commander should also consider the actual situation of the vehicle on the spot. The long-distance water supply in series or the vehicle transport water, or continue to find multiple water sources.

★ Long distance water supply

Considerations:

1 Water source maximum capacity

The first thing to look for is how strong the supply of water in front of the fire site (as judged by the front fire extinguishing appliance) is to find what source of water (municipal fire hydrant, water tank, natural water source), and how to get water.

First of all, I talk about the method of municipal hydrant water intake. Usually there are two 65mm ports and a 100mm port on the outdoor fire hydrant on the ground . The 65mm port is used to supply water directly to the tank. The flow rate is between 10L /s-15L/s . If it is If water is supplied from a long distance, such a flow rate cannot satisfy the amount of water used in front of the fire.

Then you can consider using a suction pipe to connect the 100mm interface of the fire hydrant . At this time, the water supply flow depends on the performance of the fire pump. How much water is pumped is how much water is pumped, and other water sources are the same.

2 vehicles onboard water

Many commanders will entangle the distance of a fire engine when remote water supply. I think at this stage, most of the Chinese fire-fighting force's pump performance levels for the majority of fire engines are not at all a little problem. However, when water is supplied in long-distance series, it is not the vehicle pump that determines the water supply distance of each vehicle. The number of on-vehicle hoses in vehicles, even if the car pumps are stronger, there are only 5 plates of water, it is not only for 100 meters . Therefore, the distance of each water supply on the fire site should be determined by the number of vehicle hoses.

★ Some people still have two questions in this place:

1. How do I ensure the flow of water when a single trunk water supply?

Answer: According to the water source guarantee flow, if the water supply through the fire hydrant 65mm interface, then the maximum is 15L / s (actual generally reach less than 15L / s ), look at the distance, such as 10 trays of water, it can be estimated about the pump What is the pressure?

According to the formula: friction loss per disc = SQ 2

S is the coefficient of friction loss of the hose: The coefficient of the 80 hose is 0.015 65 The coefficient of the hose is 0.035

Q is the flow rate: According to the flow rate of 13L /s , the pressure loss of each belt is 2.535*104pa , which means 0.25 pressure, and the pressure loss of the 10 belts is 2.5 pressure ( 0.2Mpa ).

According to: pump pressure "outlet pressure" = pressure loss of the hose +10 * 104Pa , 0.35Mpa can ensure that the water flow in the water flow is the maximum flow, that is, the driver's water pressure can be 4 kg .

If the capacity for water absorption is greater, the water supply capacity of the water zone should be greater and the same pressure can be calculated as the pump pressure.

2. Since the single trunk can increase the flow of water, why should it be a double trunk?

If the single-line flow rate is 10L /s , 0.3Mpa pressure is needed. The double trunk line is one more water supply belt with a flow rate of 10L /s , but the pump pressure is still 0.3Mpa.

Watching

The problem of vertical water supply usually considers the supply height and supply method

★ Supply method:

1. Water supply using fixed fire-fighting facilities

2. Direct water supply

3. Coupling water supply

In high-rise building fires, the first thing that should be considered is the use of fixed fire-fighting facilities in the building itself. Fixed fire facilities refers to the indoor fire hydrant, building fire pipe network, fire pool, fire pump, pump adapter.

( 1 ) Start fire pump water supply for the first time

According to the fire pump performance parameters to determine the number of indoor fire hydrant that can be used, it is usually no problem to use 4-6 guns.

( 2 ) When the attackers go upstairs, they should bring along the water hoses, conversion interfaces, water guns and other equipment to prevent the indoor fire hydrant components from being damaged.

( 3 ) At the same time when the indoor fire hydrants are turned on, the pump adapter should be connected to the outside to prepare the water supply for the pump adapter.

( 4 ) In the use of water pump adapter water supply should distinguish between high and low areas (high-rise building pump adapter is partitioned), the pump adapter around the fire hydrant should be able to meet the fire truck to the pump adapter water supply, you can also choose to pass Other water supply channels provide water for the fire trucks.

( 5 ) Estimating water supply height and pressure

Height +40 = pump pressure

Such as: 60 meters building, how much pressure. It is 60+40=100 . That is, a pump pressure of 1.0 MPa is required . When connecting water, the hose connecting the pump adapter should be a pressure-resistant hose or a new hose.

Tips for estimating: Pressure loss 0.1Mpa for every 10 meters of altitude .

( 6 ) If the fire pump is damaged, the pump adapter is damaged, and the pipe network is in good condition, the fire hydrant on the first floor of the building can also be used for water supply.

However, attention should be paid to checking whether there is a decompression orifice in the mouth of the first floor fire hydrant. If there is a decompression orifice, the decompression orifice must be removed before supplying water.

If it is in a high district, water supplies should be provided from the first layer of fire hydrant at the junction of high and low areas.

( 7 ) When the water pump adapter and the fixed pump supply water at the same time, the pump adapter can not supply more than one times the flow of the fixed pump.

★ Direct water supply:

The direct water supply is a method of directly supplying water with a water hose without using indoor fixed fire facilities.

In the direct supply, the water is divided into vertical tape laying and laid serpentine fashion along the two kinds of floors, vertical laying of water may be used with disposable lifting water, layered cast concrete or the like can look of a combat training salon Shu Extinguishing fire hose laying technology for high-rise buildings (2).

Personally think that stratified casting is better. Regardless of which method is laid vertically, it is necessary to stratify and fix the water belt, slow down the action of water hammer, and fix the water hose, interface, and water separator. The pressure estimates for direct water supply are the same as those for the above-mentioned fixed fire-fighting facilities.

Estimated number of hoses:

a. Vertical laying: If 30 layers, 3 meters per layer , that is 90 meters , 5 layers of water tape are required for vertical laying.

b. laying along the stairs: height * 2.2 = distance   Distance / 20 = number of hoses   Of course, we must not forget the number of motorized water hoses.

★ Coupling water supply:

Coupled water supply is achieved through the superposition of the pressure between the pump and the pump to increase the pressure of the water supply. Coupling water supply means that the water behind the car (close to the water source) is directly added to the pump in the front car (close to the fire site) (using the water collector inserted in the suction port of the front car). The coupling water supply requires the best performance of the two car pump models. The rear vehicle pressure is smaller than the previous vehicle pump pressure (eg, the rear vehicle pump pressure is 0.8 and the front vehicle pump pressure is 1.0 ). In theory, the two vehicle pressures are superimposed, but the actual pressure increase cannot reach the theoretical superposition value.

When coupled water supply is difficult for single-vehicle water supply, water is supplied to high-rise buildings using the coupled water supply method. Coupling water supply has a dual-vehicle coupling and a single-vehicle and hand-lifting motor pump coupling.

Note: When coupled with a hand-lift motor pump, the rear vehicle should be pressurized with water before starting the motorized pump.

Coupling water supply can increase the head, and parallel water supply can increase the flow.

The author of this article, Xiao Xiong, was reorganized and edited by China Rescue Equipment Network.