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High-rise buildings because of the limitations of existing fire-fighting equipment, the fire safety design should be based on self-help, and should give priority to the indoor fire-fighting facilities. Water, as the main fire extinguishing agent has been widely adopted, especially automatic fire sprinkler system because of its high efficiency, small secondary water-related disasters have been favored by the majority of designers. In order to achieve the purpose of rapid fire, the relevant norms of the quantity and pressure indoor fire service are made specific provision. In the urban water supply, because most of the distribution network of dendritic, and life, fire use Combined, the occurrence of fire, municipal pipe network pressure and accident points out the water outlet difficult to meet the high-rise building design pressure and flow, and the other On the one hand, even if the municipal pipe network to meet their water requirements, under normal circumstances do not allow direct extraction of the pump from the pipe network, water supply pipes in order to avoid negative impact of around other users, therefore, are usually designed high-rise building fire water , or the use of wells, natural water sources, etc., by the water pumps and other pressurized equipment. Specification, features regulated pump, pressure tank, variable frequency pumps high pressure water equipment are temporary water supply system, and the provisional high-pressure system should be set fire water tank, in order to ensure the most negative point fire hydrant and sprinkler system put out the initial water and fire water pressure needed to achieve rapid initial fire fighting purposes. 1. The calculation of the volume of fire water tank The need to set fire water tank system, its water storage should first meet fire 10min (minutes) indoor water consumption. For ease of maintenance, management, customary practice is to life, fire combined tank design. For the combined water tank, the effective volume should meet: V = Vt + Vs + Vf + Vx, where Vt (m ^ 3) for a living water, Vs (m ^ 3) for a living regulation of water, Vf (m ^ 3) for the peak load reserve water, Vx (m ^ 3) for the fire water, where Vx = q600 / 1000, q a fire hydrant or sprinkler system design water (l / s). If the automatic sprinkler system and fire hydrant water tank provided separately, its capacity should meet their requirements. When sharing a fire hydrant fire water tank and sprinkler system, according to "automatic sprinkler system design specifications (GBJ84-85)" of specifications, which may not be less than 18 m3 fire water. Because in the same building when the fire broke out, the general is put into use before the fire hydrant, automatic sprinkler system, fire sprinklers started, if each nozzle by traffic 1.331 / s calculations, for 23 10min fire water sprinklers amount, or two 10min water gun nozzle 15, in line with the initial fire fighting requirements. Water supply system for the use of the partition, the use of parallel, each district fire water tank volume should be calculated on; For in-line water supply systems, water tanks at this time, except to ensure that the lower zone 10min fire water, mainly also acts on a pool area, which should meet the fire water storage area within the fire continue water that is Q = (q1t1 + q2t2) -q3t3, (q1, q2, q3 indoor fire hydrants, automatic sprinkler system design flow and water tanks flow, t1, t2, t3 for the specification of the fire duration and replenishment time), at the same time, the region should meet domestic water needs. To ensure fire water is not used for other purposes, the tank outlet pipe to take some technical measures, under normal circumstances, life, fire outlet pipe should be set separately and take damage to siphon water law and control on domestic water outlet pipe . as the picture shows. For the height of more than 50m building, indoor fire water system should be established in each district two tanks, and connect with a communication pipe. Doubles as a pool of water tanks should be divided into a grid, in order to keep water clean and overhaul. 2. Fire water tank piping According to specifications, should be set fire water tank inlet, outlet pipe, the overflow signal tube, snorkel, etc., in order to ensure that water is not contaminated and periodically discharged water sediment and impurities, fire water tank vent pipe should be provided. For the outlet pipe diameter, should be determined according to the design flow and velocity, ie d (m) = (4q / 3.14v) ^ (1/2) (q: m ^ 3 / sv: m / s). For fire hydrant system, water outlet pipe by pressurization (mean height of the tank does not meet the requirements of hydraulic calculation), you can connect directly to the hydrant pipe network, while the automatic sprinkler system, must be approved by wet alarm valve only after the sprinkler riser connected, and must not fail to be directly connected to the pipeline network through wet alarm valves, hydraulic alarm because the alarm valve on the water by the urge to alarm, if not through the alarm valve, in case of fire, water pressure the police can not enter the channel, resulting in pressure switch, hydraulic alarm does not operate, but not quickly sends an electrical signal to start spray pump, so that the water inside the pipe can not be fully guaranteed. After the fire pump to avoid open water through the water supply pipe network into the fire water tank, plus a check valve must fire water tank outlet pipe to prevent water from entering the tank fire and ensure the maintenance of the pipe network pressure fire pump is turned on. 3. The pressure measures According to specifications, high fire water tank set height should meet the system requirements needed to pressure the most negative point, most unfavorable point hydrant water column hydrostatic pressure of not less than 7m (over 100m when the hydrostatic pressure of not less than 15m of water), the most negative point operating pressure at the nozzle should not be less than 5m water column, if coupled with the local head loss along the way and the geometric height is the lowest point of the fire and tank level most negative point of at least not less than about 20m, which not only affects the appearance of the building, And the structure of the building design and construction also caused some difficulties, therefore, set up in high-rise building fire tank top is generally unable to meet the most unfavorable point hydrant or sprinkler equipment pressure requirements, pressurized facilities shall be provided. Commonly used equipment pressure tank or pump regulator. Design, if the individual is located on the tank outlet pipe pressure pump, since there is no regulation of water pipe network is available, once the pipe network leakage phenomenon, pressure inside the pipe network will rapidly decline, so that the pressure pump start closed frequently, affecting their life. For the design of water pressure alone, in the actual project, there are many. The city has put into use in engineering, designers often use the pump and pressure tank pressurization series manner, proven with good results, as shown in FIG. Under normal circumstances, is maintained by a small pressure tank pipe network pressure, the water storage capacity of the major role played trap, the pump to low flow, low head. After the pump is started, the roof of the water tank through the suction pipe, pump into the fire control network, at the same time, part of the water into the pressurized tank, the pressure gauge on the tank open and close to control the pump. Because the system has adjusted the amount of water to avoid pump frequent start. Its device structure is simple, small footprint, and in the case of no electricity, but also water fire. |
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Dongguan Zhuangyuan stainless steel water tower factory National service hotline:4008-3737-88 Address: Dongguan City, Da Lingshan Wan Long Road (large village) Dalingshan police brigade 200m E-mail:1651856382@qq.com No. QQ:1651856382 Tel:0769-81626031 Fax:0769-81626032 Phone:13326878298/13380111889 Contact:Mr. Chen Website:www.gdzystc.com |
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High-rise building fire water tank roof installation issues to consider
Source： Time：2015-04-08 09:40:25 views：
High-rise buildings because of the limitations of existing fire-fighting equipment, the fire safety design should be based on self-help, and should give priority to the indoor fire-fighting facilities. Water, as the main fire extinguishing agent has been widely adopted, especially automatic fire sprinkler system because of its high efficiency, small secondary water-related disasters have been favored by the majority of designers.