【 Weak current College 】 fire curtain of water protection measures

【 Summary 】: this article describes the civil building fire shutter types, applications, and spray cooling protection measures proposed fire shutter cooling protection practices and the method of calculating the cooling water consumption.

【 Keywords 】: fire shutter protection measures for cooling water

0. preface

In the modernization of large buildings such as shopping malls, exhibition hall, terminal building, bus station, public building Atrium, a large underground garage, etc., the use of fire shutter as fireproofing and more popular.

The tall buildings design fire protection standard "GB50045-95 (2001 Edition) (hereinafter referred to as" the regulations ") section 5.4.4:" in the settings for firewall do have difficulty, you can use fire shutter for fire compartmentation separated. When using the included back fire surface temperature rise for fire resistance determinant conditions of fire shutter, the fire resistance rating of not less than 3.00h; when using do not include back fire surface temperature rise for fire resistance determinant conditions of fire shutter, shutter should be set on both sides of the independent closed sprinkler system protection systems sprinkling duration should not be less than 3.00h. "Control" the regulations "(95) article: 5.4.4 fire shutter" used in place of the firewall, its fire shutter should be consistent with the fire resistance of firewall conditions or supposes closed on both sides of the sprinkler system, its nozzle spacing should not be less than 2.0m. "The old and new versions of the" doctrine of "fire shutter requirements, while new specifications for cooling protection system is made more explicit requirements. The automatic sprinkler system design code (GB50084-2001) on the protection of the design parameters of cooling water curtain provides as follows: when the water point height ≤ 4m, sprinkling strength requirements for 0.5L/s · m. (Note: the protection of water spray water cooling point height, each enhanced 1m should increase waterjet strength 0.1L/s · m, but over time sprinkling 9m intensity is still using 1.0L/s · m. ）

In engineering practice, fire shutter selection and set belongs to the building professional design category, but fire shutter cooling protection system belongs to the design of water supply and Drainage Professional. But existing drainage design manual or handbook on fire safety design fire curtain of water conservation practices were not clearly defined. In practical engineering designers typically have the following practices: 1, from the automatic sprinkler system received a water pipe, in both sides set fire curtain wall type nozzle, spacing 2.0 ~ 2.5m; 2, setting up an independent cooling protection system, on both sides of the curtain; 3 installed encryption nozzle, received from the fire hydrant system out of the pipeline, curtain side mounting encrypted nozzle.

In addition, on fire shutter of cooling water requirement calculations, there are some differences. If there is a large project, a fire shutter total length exceeds the height exceeds 8m 50m. According to the specification for the "flowing" calculation of the cooling water is greater than 40L/S, exceeding the hydrant water consumption. If a fire compartment has two road length 50m of fire shutter, the calculation of the cooling water consumption exceeds indoor hydrant and closed water sprinkler system. A large amount of water used for indirect fire-extinguishing system design, it is economical and reasonable? on these questions the need for in-depth analysis and discussion.

⒈ fire shutter of concepts and categories

1.1 fire shutter concept

Fire shutter is a special type of shutter, usually installed in buildings require fireproofing site above or to the side. Usually rolled up, when a fire, the fire alarm system or manual control expand, play the next fire, smoke and heat-insulating features to prevent fire spread and smoke dispersion.

1.2 fire shutter structure shown in the figure a

1.3 fire shutter type

Fire shutter under fire and anti-heat property can be divided into ordinary fire shutter and Super fire shutter. Common fire shutter is in accordance with the national product standards GB14102 the steel fire shutter General technical conditions ", only the margin back fire surface at a distance of radiant heat intensity and curtain surface is wearing fire to determine its fire resistance of shutter, can achieve non-insulated fire separation requirements. Including back fire surface temperature rise as judging criteria, fire resistance and fire resistance rating of not less than 3.0h fire shutter for special fire shutter. As a result of normal fire shutter does not meet the requirements of the fire separation, you should set the shutter curtain protection on both sides of cooling.

From fire shutter opening direction can be divided into: vertical open fire shutter and standard open fire shutter. The latter are commonly used in the atrium and the opening of the escalator. This shutter of reel for vertical installation, slat usually rolled up in a small room.

Under fire shutter structure forms of different can be divided into single layer slat steel fire shutter, composite fire shutter, VAP-steel fire shutter, dual-track double curtain inorganic composite fire shutter, evaporative steam mist fire shutter, after three of them belong to the special fire shutter.

⒉ fire curtain of water spray cooling protection measures

Ordinary steel fire shutter requires installation of the cooling water protection, protection to meet the requirements of the fire separation. Protection should be used in the cooling water separate systems, the effect of time of not less than 3h. Specific practices in fire curtain sides (both sides may be affected by the fire situation) or one side (unilateral under fire conditions, such as escalators openings or patio), ceiling-mounted wall, closed sprinkler nozzle spacing of 2 ~ 2.5m, toward the shutter. Water jet strength in accordance with the norms of "flowing" first subparagraphs. 5.0.10

Common fire shutter of cooling water consumption. If the total length of the roller shutter 30m, height calculation of cooling water consumption 8m, about 27L/S, corresponding to the risk level in ⅱ sprinkler system for water consumption. In a large project with a total length of dozens of meters fire compartment or even hundreds of metres of fire shutter often encountered. Protection of water in the cooling water and fire water in very large. To solve this problem, in recent years developed a water consumption of smaller steam fog-steel fire shutter, evaporative air mist fire volumeCurtain, and does not need to water protection-track double curtain inorganic composite fire shutter, Super fire shutter.

VAP-fire shutter is in conventional steel fire curtain of retrofitted a spray cooling device, as shown in Figure 2. Control valve of water cooling system consists of the roller shutter box temperature sensing device control. When the shutter of temperature detector action, namely the open curtain spray water supply pipe on valve on the fire-fighting water spray system, cooling in the Netherlands is atomised spray to slat surface. Because of the slat is crafted, surface regularity to suppress the "X"-notch. Therefore, throughout the slat surface forms a layer of uniform, continuous flow of water, heat, and effectively control the slat temperature, so as to achieve fire, heat, smoke, the amount of cooling water needed by the average cloth curtain Panel $ water strength 2.2L/m2 · min. [1] to a long, worth mentioning 8m 4m high fire shutter for comparison, VAP-fire curtain of water consumption is about ordinary fire shutter water consumption by 30%, you can significantly save cooling water consumption.

3. calculation of the cooling water

3.1 ordinary steel fire shutter of cooling water

3.1.1 when shutter height less than when 4m

Q=0.5·L

Type: Q for cooling water volume L/S.

L is the length of the fire curtain

3.1.2 when shutter height when 4 ~ 9m

Q=[0.5+（H-4）·0.1]·L

Type: H-fire shutter height (m)

3.1.3 when shutter height ≥ 9m time

Q=1.0·L

3.2 VAP-fire shutter of cooling water

Q=q·A

Type: q-for steam mist fire shutter unit area determination of cooling water flow (L/S.m2), provided by the product manufacturer.

A to fire shutter's surface area (m2)

3.3 fire shutter calculation of length of

Building a fire, while the burning point generally assumed to be a Department. The fire from spreading around the ignition point, when protected by a firewall or fire shutter and other obstacles, the fire was confined to a certain range. When the building of the sprinkler system startup and firemen arrives with indoor hydrant sprinkler, fire has been suppressed, the last fight. Therefore, the area of fire in buildings is not a free extension. In the "flowing specification", in the light of dangerous and hazardous levels of civil construction, sprinkler systems of range as 160m2 about 10m×16m range, installation of about 14 closed sprinkler. According to statistics 【 2 】 display, when participating in fire extinguishing nozzle reaching 14. On the success rate of high-rise building fire 99.4%. Taking into account the randomness of the fire burning area and further increase the safety factor, the fire area to enlarge a times, the scene of the long side of about 16 × √ 2 = 22.6m, short edge about 10 × √ 2 = 14m. When the fire region is located in the Middle when fire compartment, fire threat, need to open the spray cooling protection fire shutter length about 22.6m. If using VAP-Super fire shutter, shutter height 6m, the amount of cooling water unit area to 2.2L/m2 · min, you need to turn on cooling system with shutter 3 is worth mentioning that the length of each worth mentioning as 8m, cooling water, 5.3L/S, corresponding to a fire hydrant water.

Because fire shutter cooling protection system time is equal to the fire hydrant 3.0h, of time. If using VAP-Super fire shutter, a fire compartment fire shutter of cooling water consumption is equivalent to a fire hydrant water. So the VAP-fire shutter of cooling water system should be combined with the fire hydrant system.

⒋ project example

Guangzhou International Convention and Exhibition Center (first phase) building area 39.5 million m2, is currently the largest exhibition center in Asia. Photo 3, Photo 4 to Guangzhou Convention Center 1st floor exhibition hall floor plan and profiles locally. Guangzhou Exhibition Center is adjacent to the South side of 1st floor of five exhibition halls, each exhibition hall of the plane dimensions under clear height ceiling 126.6m×86m, 13 meters. According to the needs of different scale exhibition, five exhibition halls which can be used free-standing and joint use. Hence, uses the stainless steel material with special steam mist fire shutter. When you use the Independence Hall, the curtain fell, the partition function. There are two exhibition rooms, the channel 4m column spacing is the width of the column as 10m 1.5m. Each is worth mentioning is the length of the shutter, height for 8.5m 6m. When the fire hall, exhibition hall at the sides of the fire curtain by the fire alarm system control lowered. Each is worth mentioning is fire shutter are equipped with a spray cooling. When the temperature near the curtain rises significantly, the roller shutter box temperature sensing device signals, open spray system of solenoid valve, nozzle spray, cooling shutter. According to the generality of the foregoing analysis, the length of the fire by 23m meter, you need to spray protection shutter 3 worth mentioning. After calculation, spray cooling system using water as 5.6l/s, corresponding to a hydrant water. Therefore, after consultation with the local fire department, in the design of the showrooms curtain into the fire hydrant system cooling system. From the nearby indoor hydrant hose online, received a pipeline for shutter cooling water, while increasing the amount of water hydrant system. It should be noted that the shutter cooling system water pressure is low (about 0.10MPa), therefore, in the solenoid valve with pressure relief valve before and to avoid water pressure and spray water, consumption of water for fire fighting. This practice, in Guangzhou Exhibition Center fire safety review meeting was "the regulations" and "flowing" specification Editorial Board, fire-fighting sector celebrities.

The "doctrine of ⒌" section 5.4.4 record of discussion

"The regulations" section 5.4.4 article "... When using do not include back fire surface temperature rise for fire resistance determinant conditions of fire shutter, shutter should be set on both sides of the independentClosed sprinkler system protection systems sprinkling duration should not be less than 3.00h. "In my view, when the fire shutter is only one side of the fire, as the Atrium, escalator opening area, just on one side of it is water protection system. As for "should be set independent of the closed type of automatic sprinkler protection system", the author believes the specification is intended to sprinkler protection system and automatic sprinkler system independent. Because automatic sprinkler system time 1.0h. When fire duration exceeding 1.0h due to fire spread, the fire area is over automatically off water fire extinguishing system role area, blasting the number of closed head too large, the result of insufficient water spray system useless. But as fireproofing fire shutter, the fire resistance is greater than 3.0h. Therefore, the role of the cooling system should be greater than 3.0h time, it is not possible and closed sprinkler system and network.