【 Weak current College 】 tall buildings fire summary and drainage design FAQ

As the senior civil building design fire protection standard (hereinafter referred to as the "regulations") updates and new sprinkler system design specifications "(hereinafter referred to as the" flowing specifications "), on the fire water system design requirements are becoming increasingly stringent. Especially the last two years, the provinces, municipalities have begun building works figure review system, its review of the main basis for 2000 was enacted in the engineering construction standard compulsory article law, the mandatory provision of the terms is the design which must follow the rigid requirements. Therefore, this article is the nearest one or two years of participation in the senior fire water system design, as well as design review, review the summary of a number of questions, hope to provide some reference along with the reference.

First, the design of high-rise building fire
1. the high-rise construction should control the use of double-valve double export instead of two sets of single-fire hydrant valve and hydrant.

The resistance of the law "on the floor of the adjacent two fire hydrant enrich the water reaches the nozzles are within the scope of protection of any part. "In some bars on tall buildings, its end can double double outlet fire hydrant valve, eliminating one set of settings for a single valve fire hydrant? while in the Chinese construction industry press and publication of the water supply and drainage Design Handbook (Second Edition)" in each floor of the end can be dual-valve double export fire hydrant, "the doctrine of" expressly provided "18 and 18 layers, each layer does not exceed 8 families, building area of not more than the Tower House, 650m2 when set two fire risers have difficulties, you can set a vertical tube, but must use the double-valve double export fire hydrant. "And in the form of the mandatory provisions provided for them. Therefore, in the design we should strive to avoid this situation.

2, the correct length to enrich the water hydrant, reasonable arrangement of the hydrant.

The doctrine of "the water gun enriched water hydrants shall be determined by calculations, and building height not exceeding 100m high-rise buildings should not be less than the height exceeds 10m; building 100m high-rise buildings should not be less than 13m. "For building height not exceeding 100m high-rise buildings, design we can under the water gun minimum flow 5L/s, water gun nozzle diameter 19mm, draw the design manual gun to replenish the water column length 11.3m; for building height exceeding 100m high-rise buildings, we can adjust the nozzle flow to meet specifications needed water gun full water column length. But in reality, high-rise building standard floor height to consider economic factors of general control in the following, if under 4.0m formula Sk = (H1-H2)/S I N α calculate water gun full water column, while the layer high on fetch 4m, water gun from 45 ° angle, the calculation of the Sk-4.24m, far specification requirements, i.e. layer high limits the length of the full water column. However, we can adjust the water gun on full tilt to achieve improved water column length, because the specifications and the relevant manuals proposed gun on angle should not be greater than 60 degrees, and does not provide its lower point value. I calculated that when the story still fetch water from 4m, equip, water gun 11.3m on 14.87 ° inclination angle. Moreover, the doctrine of law instructions explained, diameter of the full water column 19mm water gun is less than when, because of the fire 10m smoke, radiant heat, high difficulty that put out the fire, so the full water column length water gun should be calculated, and the need to meet the regulations of law provides a variety of enriching the high-rise building water gun fire hose lower bound value. In accordance with the water gun full water column length, we can determine the fire hydrant protection RADIUS, but in the design we cannot simply draw a circle with a RADIUS protection to lay out fire hydrant. Because of the tall building plane wall, in the aisle, door arrangement affect fire hydrant, design should use the hose length, replenish the water column of horizontal projection to check fire hydrant protection RADIUS furthest point.

3. fire the elevator room must be set before the fire hydrant.

The doctrine of "fire elevator room must be set before the fire hydrant", located in the front room of the hydrant can protect adjacent parts? "the provisions of the regulations does not describe specific instructions, but the architectural design fire protection standard for the" fire in the elevator room should be set to the provisions of indoor hydrant "clearly stated in the notes: fire hydrant elevator is used for the purpose of the firemen and to open up pathways fire hydrant, cannot be included in the total number of hydrants. Therefore in the design we are usually treated as the fire front, private elevator, not to protect the remaining parts of the body. At present, such as Shanghai and other parts of the local fire safety design of tall building, room smoke before the staircase also need to set the fire hydrant.

4, a fire water tank is set correctly and guarantee high building two water supply.

Usually in high-rise buildings, in the municipal water supply does not meet the requirements of the fire water consumption or municipal water for single, standard requires setting a fire water tank. Calculation of fire water tank volume, the duration will fire the fire water in the Interior and of minus the municipal water supply pipes. Water time can be the longest duration of fire. If you want to consider an outdoor fire water consumption or set living, fire water tank, you also need to add the appropriate water consumption. When you set the living, fire water tank, you cannot use the ontology structure buildings do pond pool wall and bottom, to prevent pollution of the water quality of life. To do this, the mandatory provisions of the Act has expressly prohibited. Similarly, if the high-rise building roof with living, fire water tank, should meet the requirements. Access from the fire water tank into the pipe between the pump should be guaranteed for a period of not less than two, if you access the pumping station before the introduction of a pipe, converging on fire water tank, only for single-supply, water supply security risk exists. At the same time, from the fire of fire pumps access network of water supply pipe should guarantee two road.

5, the fire pump outlet water valves and regulators return measures.

The doctrine of "fire pumps water supply pipe should be set on the water valve of DN65," which is aimed for easy drainage pump check test. Discharge hour, but directly to the pump house set pool; discharge large,Can drain back fire water tank. At the same time, the fire pump export also need to consider certain regulated drainage measures. Because in actual use, fire water is less than the value selected flow pump, pump lift appears much larger than the design value, in the absence of any return measures for the protection, fire fighting pipe pressure, easily lead to accidents. The simple way is to install the water supply pipe on steady voltage valve, safety in pipeline pressure, you can return pipe pressure relief, will return to fire-fighting water flowing; in unstable pipeline pressures, can also be regulated.

6, fire fighting pipes arranged ring.

High-rise buildings generally require fire hydrant system layout into a pipe, in some large areas of the building, since the parties have arranged fire hydrants and fire standpipe, at this point we can back and front of the fire main pipe are a level loop, facade and formed risers connected vertical loops, this stereo system on the fire service is the most secure. But for some bar architecture, design and we will supply you with vertical loop, do not have to deliberately pursue this stereo system, if you force the fire main pipe around into loop, man-made complicate the system and do not make much sense.

Second, the skyscraper fire sprinkler system design
1, aisle nozzle.

In high-rise buildings, in order to have beautiful and often hidden structure beam ceiling, and various professional pipeline. While the sidewalk is usually the most various pipelines focused, in particular the setting up of central air conditioning of high-rise buildings, structures, beams, air duct, and hierarchical layout of drainage, electric power lines, etc. so that there are clearance lower ceiling of the aisle, to the ceiling for the bored: top, up: top of headroom most likely greater than 800mm. But the flowing code stipulates: "the clearance height is greater than the boring top and 800mm technology mezzanine with fuel, you should set the nozzle. "This is our design easy to ignore. Due to the large sidewalk in pipeline tend to appear in the design directly in flowing water distribution pipe upper and lower error received nozzle. First of all, the connection does not meet the distribution branch allows you to set the nozzle quantity (≤ 8), and secondly the aisle in flowing water distribution often pipe diameter is large, it lacks received small diameter nozzle pipe installation, there are drawbacks. Therefore, the aisle of the nozzle should be equipped with water pipes should be received out on, in the pipeline layout with HVAC, electrical professional closely.

2, high-rise buildings part layers flowing water distribution pipe entrance shall be required decompression.

New the flowing code stipulates: "the piping diameter hydraulic calculation shall be determined. Water distribution pipes for water distribution, should allow the entrance of the pressure equalization. Light hazard levels, risk levels in the water distribution in premises entrance pressure should not be greater than 0.4MPa. "Old" flowing code has no specific requirements. Tall buildings fire danger rating the risk level in General is, since the Jet pump is based on the top most adverse nozzle pressure after calculation and selection. The author in recent time the design calculation of the most vulnerable layer distribution mains inlet pressure is not required is greater than 0.3MPa (most negative nozzle pressure by 0.05MPa), due to the flowing water pump head to consider building height, water loss and other factors, it will make the bottom of the high-rise building several layers of water distribution pipe entrance pressure greater than 0.4MPa. Thus at design time, the sprinkler pump lift will not be able to determine just zoom in on the matter should be flowing layout after verification by calculation of hydraulic pump lift, and check the bottom of the layers of water distribution pipe entrance pressure.

3. correct settings flowing eqnipment, solve eqnipment drainage problems.

The flowing standard "requirements" each alarm valve group control of most disadvantageous nozzle, should set eqnipment, ... Eqnipment of water, should take the form of orifice flow discharged into the sewer. "In the design, we usually don't forget eqnipment in test water valve, pressure gauge, but tend to ignore the doctrine of joint settings, especially touching connectors outlet diameter without explanation. In fact, current market many fire equipment manufacturers, such as Shanghai jindun fire safety equipment co., Ltd, can produce complete eqnipment (ZSPP eqnipment with test water valves, pressure gauges, test water connector), we only need according to the design requirements, in accordance with the test water fittings outlet flow coefficient selection training products. In addition, test water connector cannot be used with a pipe or hose direct connect, affect the efficacy of orifice flow; flowing drainage pipe should also be designed as indirect emissions so as to avoid sewer gas drainage funnel effect of bulk into the Interior, indoor air quality.

4. alarm valve and export shall set signal valve.

New the flowing norms require "attach alarm valve import and export of control valve, the valve should be signal. "Generally flow indicator and alarm valve import settings signal valves are conventional design, very few left. But the specification requirements in alarm valve outlet must set signal valve or valves with locks to prevent accidental operation.

5, fire control pressurization pump set.

In order to guarantee the resistance or the flowing norms required by the most senior fire hydrant or the value of the static pressure nozzles, high water level difference is not enough, the design we usually set in the high-water-tank fire pump. First, a booster pump flow to meet 1 hydrant or water of a shower; Secondly, a booster pump head should not be too large. Due to high water tank fire hydrant or water-level and top-tier nozzle has a certain potential difference, specifications of static pressure value minus the level difference is the minimum pressure pump, booster pump lift head generally need only a few metres is sufficient to meet the requirements. If the pump head selection is too large, will result in lower supply network pressure too high, the fire hydrant outlet pressure or layers flowing water dry pipe entrance pressure increase is required to take measures so that the fire decompression system complexity. But only by a booster pump to meet fire protection requirements do not fit the static pressure, because the run by the boost pump pressure sensor signal control to fire system constantly kick to maintain pressure pumps require frequent, parts of perennial easily damaged. Since conditions permitting, andArchitectural consultation appropriate elevation water tank location, using the most secure high water tank regulator; building conditions do not allow the design choices with pressure tank pressurization facilities also.

6, flowing water supply should pass alarm valve.

The sprinkler system, since the Jet pump is alarm valve on the pressure switch action gives the signal to start the fire, the water flow indicator shows the location, so should be flowing water supply through alarm valve received to the network. Particularly from the high water tank or the supercharged facilities received flowing water supply pipe, cannot like fire hydrant system that directly access the fire pipe online, and must from alarm valve entrance access fire pipe network. Similarly, the sprinkler system of the pump adapter's introduction of pipe must be received by alarm valve into the pipeline network.