【 Weak current College 】 electronic workshop of spray design---Power By 【 China power house network 】

Introduction: over the past few years with economic development, foreign investment projects in China is growing, engineering design demands on fire protection system is getting higher and higher. Especially when foreign investment projects in China will be insured in the insurance companies abroad, the fire protection design requirements more stringent, in addition to the implementation of national standards for the automatic sprinkler system design code GB50084-2001 (hereinafter "the regulation of spraying), consistent with United States plant joint insurance system standard (FM) and other foreign standards and specifications accordingly.
Keywords: head, minimum working pressure, flow, role area, alarm valve, spacing
The following specific projects as examples.

A, project profiles

A southern cities of electronic workshop, with a total construction area of about 31700M3, which contains a single storey building, a two-tier workforce Center, two-storey office building and a layer of equipment; production product is computer chips, in the case of r industrial architecture.

Second, the system design parameters

Regulation under the spray: employee centers, office buildings and equipment Center of storey are smaller than 8 meters, is the level of risk; where staff Center, Office building is a grade, sprinkling strength Ⅰ 6L/role area 160M2 min.m2, may use 68/74 ° c temperature level, 15mm, K = 80 closed sprinkler; equipment Center is ⅱ, sprinkling strength 8L/effects area 160M2 min.m2, may use 68/74 ° c temperature level, 20mm, K = 116 closed sprinkler.

Workshop includes in and out cargo warehouse, two manufacturing plants, equipment and Office area, architectural design for sloping roofs, roof height 13M, eaves height 10M, roof gradient of 5%. In the production and shipment warehouse has a two-tier device, in a corridor, 2 shipment warehouse and one, two, production workshop with Office area between. Because the Office area and the device layer in the layer are high or is less than 8 meters, also may use 68/74 ° c temperature level, 15mm, K = 80 closed sprinkler.

Warehouse is the powerhouse of the most dangerous place, part over the roof equipped with fire 12M smallpox, smallpox 12.2M off the ground. Under the regulation of law: This spray warehouse is dangerous-class Ⅱ-class warehouse, warehouse goods piled height greater than 3.5M considering sprayers for rapid response to early suppression (ESFR sprinkler), check the warehouse using rapid response early suppression nozzle system design parameters table, the minimum working pressure nozzles 0.50Mpa, role area open nozzle number 12 only; use of 68 ° c sprinkler temperature level, 20mm, K = 200 (inch 14) ESFR sprinkler. Flow is calculated as follows:

Most adverse nozzle flow: q = K (10P) 0.5 = 200 (10x0.5) 0.5 = 447l/min = 7.45l/s

Role in the area of flow nozzle 12 only: Q = 12q = 12x7.45 = 89.4l/s = 322M3/h

Taking into account the fact that the packaging is possible using foamed materials and goods of stacked height is over 7.5M, need to increase shelf life shower; there are wider than the fan following 0.6M additional nozzle. FM standard overlay this part of the nozzle flow.

To this effect within the nozzle flow area: Q = 322 + 218 = 540M3/H = 150l/s

Under the domestic standard, electronic workshop workshop not set spray, but this workshop area is big (over a fire partitions allow for a maximum area, but due to production needs and didn't set firewall separated), plus the line equipment and expensive, FM requirements workshop also need set spray system. Workshop roof height is smaller than the height of the eaves 10M 12M; in the case of danger-Ⅰ-in. You cannot use the normal 80 K = closed sprinkler fire-fighting, we do the following three types of analysis:

First: the regulation according to spray the 2 point 4.2.5 — Interior headroom than 8M of civil construction and industrial plants, rapid fire extinguishing initial deluge system should be used. While each shower valve control of spraying water area should not be greater than 160M2, according to one, two areas of the production plant, located four 15400M2 fire partitions; the total demand is set to 96 deluge valves, each fire partition 24 valve; deluge system flow press at the same time open the 24 valve flow calculation, the system flow, pipes and control complex, together with the plant's products is a computer chip, the shop does not belong to the burning speed. To do this using deluge system not economic.

Second: the use of large space automatically scans to locate fire suppression equipment, ZSDM-S03-Ⅲ A scan to locate in the automatic suspension sprinklers can fight RADIUS 10M, protect highly 13M, working pressure 0.8MPa, Jet flow 4.25L/S. This system flow is not big, small, control of pipeline is relatively simple. However, the analysis of knowledge production workshop while storey high, equipment pipes, large space; equipment pipe layer consumes 6M clearance, pipeline bottom ground only 3.8M; one of the largest pipeline is shop air tube, diameter ≤ 1.2M. These equipment piping has hampered the fire-fighting equipment detection accuracy, the impact of the fire. To do this in the workshop arrangement of large space automatically scans to locate fire extinguishing device nor feasible.

Third: the last representative with FM and the local fire department to discuss, decided to adopt the ELO system for large diameter nozzles, the nozzles of the minimum working pressure 0.17Mpa, role area 280M2; function area open nozzle number 25 only; use of 74 ° c sprinkler temperature level, 20mm, K = 160 (inch 11.2) ELO nozzle. Flow is calculated as follows:

Most adverse nozzle flow: q = K (10P) 0.5 = 160 (10x0.17) 0.5 = 209l/min = 3.48l/s

Function area 25 only nozzleFlow: Q = 25q = 25x3.48 = 87l/s = 313M3/H

3. wet alarm valve set

According to the standard FM, plant area of a single wet valve allows for maximum protection in an area of 3700M2 (40000 square feet), mainly to take into account after the network volume alarm valve and the pipe lengths.

Incoming goods warehouse area 5300M2, shipment warehouse area 2376M2, workshop area of 15400M2. Considering the future of maintenance management, and FM and local fire department communication, a final decision: in and out cargo warehouse respectively consists of a set of wet alarm valve control; one, two, the workshop consists of four groups of wet alarm valve control. In addition, in the alarm valve indoor DN300 ring on water pressure pipe set aside two DN250 interface for future additional control racks inside the nozzle of wet alarm valve.

IV. network layout

1, warehouse ESFR sprinkler layout: in and out of the shower warehouse DN200 respectively water distribution along the ring around the warehouse, to improve the security of ESFR sprinkler system. As a result of distribution mains into rings, each equipped with water pipes installed up to the nozzle can be appropriate for more than 6 only. Nozzle spacing is greater than, less than 3.3m 2.4m. (ESFP sprinkler installation as a)

　　

2, workshop of nozzles: 1 ELO, 2 workshop of low fire risk ratio, consider the warehouse are four DN200 of spray distribution mains branched water supply. Since the workshop roof truss structure is more complex, the workshop's column-horizontal and vertical spacing is separately and 6.0M 7.5M. Nozzle spacing used: horizontal, vertical 3.0m 2.5m. (ELO sprinkler installation following figure 2), this installation method is different from other conventional sprinkler installation. First, in order to keep the nozzle perimeter 300mm range does not have any obstructions; and secondly ensure pipeline washing process, debris from clogged nozzles.

　　

3. each spray water distribution pipe ends are located test water valve and the pipe wall DN65 to ground, so irrigation 1.2M branch network and convenient operation.

5. Summary

As the fire spread rapidly, the warehouse are not easy to fight, causing substantial property damage, especially fighting high stacking high rack warehouse fire, more difficult. To this end, the United States spent on development of the PCT successfully "rapid response early suppression nozzle," and "large" nozzle, used to fight high stacking, high-rack warehouse fire. While United States plant joint insurance system, also developed a quick response early suppressed nozzle (mainly ESFR sprinkler) system design, installation and operation standards, FM Global FM standard for short.

To sum up, in the design of foreign investment projects, automatic sprinkler system design measures, should take into account the requirements of domestic and international norms, reasonable design.

Reference documents:

[1] the automatic sprinkler system design code GB50084-2001

[2] FM Handbook (1998 Edition).

[3] the water supply and drainage design manual volume 2: construction of water supply and sewerage (Second Edition)