Fire protection design of water supply and drainage for high-rise buildings?

Combined with practical experience, this paper introduces the concrete contents of water supply and drainage and fire protection design of high-rise commercial and residential buildings. According to the architectural characteristics of this project, a reasonable water supply and drainage system is adopted to ensure the reliability and economy of water supply and drainage and fire fighting system, and some opinions on some provisions of water supply and drainage and fire fighting laws and regulations are put forward.

With the vigorous development of real estate industry, high-rise residential buildings have become the main body of urban housing. Through the analysis of high-rise residential buildings, the water supply system and drainage system are established. Some views and solutions are put forward on the layout of fire-fighting facilities and the supply of fire-fighting water.

1. Characteristics and present situation of water supply and drainage in high-rise buildings

High-rise residence is the main building of urban life now and in the future. Its high plot ratio can solve the contradiction between the tight land supply and the enthusiasm for buying houses to a certain extent, but there are also many problems. The high population density has brought problems to the water supply of domestic water. There are few emergencies such as fire in the upper and lower passages, so it is difficult to evacuate and put out the fire, which puts forward a great test for the setting of fire-fighting facilities and the supply of fire-fighting water.

At present, the main ways of water supply for high-rise residential buildings in China are: direct water supply, which uses the pressure of municipal water supply to send water pressure directly to each floor; Water tank supply: firstly, the municipal water supply is sent to the roof storage tank, and then distributed to all floors by gravity river; There is also a combined water tank pipe network; Air pressure tank water supply; Secondary pressurized water supply and so on.

Sewage in high-rise drainage can be roughly divided into: fecal sewage, domestic sewage, domestic sewage, rainwater, kitchen sewage and other types of sewage; Different drainage systems should be set according to the nature of sewage.

2. Fire protection design of water supply and drainage in high-rise buildings

2. 1 Present situation of fire protection design technology

(1) The automatic fire extinguishing technology is diversified. There are wet system, dry system, pre-action system, circulating pre-action system, deluge system, water curtain system, water spray-foam composite system and so on.

(2) The function of automatic sprinkler system is gradually strengthened, and the function of fire hydrant system is gradually weakened. By the middle of this century, automatic sprinkler systems will completely replace fire hydrants. Practice has proved that the automatic sprinkler system is recognized as the most economical and effective fire extinguishing facility in the world today.

(3) The development of sprinkler technology. There are many types, such as standard nozzle, quick response nozzle, large droplet nozzle, extended cover side wall nozzle, repeated opening and closing nozzle, etc.

(4) The concept of "active fire fighting" came into being. There are nitrogen injection and oxygen control fire fighting system, large space intelligent fire fighting system, fixed fire monitor fire fighting system, etc.

(5) Variable flow and constant pressure pump, namely tangent pump, will be widely used in fire water supply, which will completely solve the problem of overpressure in the early stage of fire fighting, thus saving water for pumps.

Safety valve or safety valve on the pipeline. Multi-outlet fire pumps are used in high-rise buildings, which can save land occupation and investment.

2.2 Water supply and drainage and fire protection design steps

2.2. 1 determine the water supply and drainage scheme of high-rise residence according to the surrounding water supply and drainage conditions.

First of all, you should have a detailed understanding of the water supply and drainage system around you. Such as: pipe diameter and pressure of access point of municipal water supply network; The connection of external power supply and whether the external power supply can meet the first-class load standard of fire power supply provide data basis for pump selection.

2.2.2 Estimation of outdoor rainwater discharge and determination of drainage mode

For the drainage of roof rainwater, it is necessary to communicate with the architectural profession to clarify the drainage form of roof rainwater, whether it is internal drainage or external drainage. The internal drainage is designed according to the Code for Design of Water Supply and Drainage in Buildings, and the external drainage is completed by the architectural specialty.

2.2.3 Estimated water consumption and displacement

According to the relevant chapters of Code for Design of Water Supply and Drainage in Buildings, the maximum daily maximum hourly water consumption and average displacement are calculated. The rough algorithm is that the displacement is 80-90% of the water consumption. According to the preliminary calculation data, the later calculation is carried out.

2.3 Design of building water supply system

The selection of the most critical water supply mode in the design of high-rise building water supply system is directly related to the use quality and project cost of domestic water supply system. The vertical partition of water supply system should be reasonably determined to ensure the normal use of water supply equipment and sanitary ware, and avoid excessive pressure and unnecessary energy waste. When the water supply equipment is too strong, it is easy to produce water hammer when these equipment are closed, which will make the pipe network produce noise, vibration and even pipe fittings break, and make the water supply part of sanitary ware easy to be destroyed. Reasonable vertical partition of domestic water supply system is also an important factor for energy saving of household variable frequency speed regulation water supply equipment. The design flow of frequency conversion equipment will be increased when the number of floors in the partition is more, and the load of starting the pump will also increase when the water consumption is less. In addition, due to the high pressure of the zoning system, the number of layers of pressure reducing valves installed on residential pipelines increases, and the energy consumption also increases accordingly. According to the different fault buildings, the water supply modes mainly include the following:

2.3. 1 Pressure reducing valve decompression water supply mode.

The pressure valve decompression water supply mode is that the water consumption of the whole building is lifted from the water pump arranged on the ground floor (or basement) to the roof water tank, and then decompressed by the pressure reducing valves in each district for water supply in each district.

2.3.2 District series water supply mode.

Each area is provided with a water tank and a water pump, and the water pump in each area is located on the technical floor, pumping water from the water tank in the lower area for the upper area.

2.3.3 Partition water supply mode without water tank.

There is no water tank supply mode in each partition, and each partition is provided with a separate variable speed pump for water supply, without water tank. The water pumps are concentrated in the water pump room on the ground floor of the building, supplying water to the pipe network of each district respectively.

2.4 Water supply design of fire fighting system

2.4. 1 fire water supply

According to Code for Fire Protection Design of Buildings, Code for Fire Protection Design of High-rise Civil Buildings, Code for Design of Automatic Sprinkler Fire Extinguishing System and the categories and uses of various buildings, outdoor hydrant water supply system and indoor hydrant water supply system are set up. Automatic sprinkler system. Water consumption of outdoor hydrants, indoor hydrants, fire duration, water consumption of automatic sprinkler system and fire duration depend on specific conditions.

2.4.2 Fire hydrant water supply system

Outdoor fire hydrant pipe network is annular pipe network, and basement fire hydrants are set according to specification requirements. Indoor hydrant pipe network is annular pipe network. Because the hydrostatic pressure at the hydrant mouth does not exceed 1.00MPa, there is no need to partition the indoor hydrant system: when the outlet pressure of the hydrant mouth is 0.50MPa, the depressurized and stabilized hydrant is adopted. Indoor fire hydrant layout ensures that two full water columns reach any point indoors at the same time. Each hydrant box is equipped with a button to directly start the fire pump. At the same time, according to the water consumption of fire hydrants in each building, a water pump adapter is set.

2.5 building drainage system

The drainage system inside the building directly affects people's daily life and production. In the design process, first of all, we should ensure smooth drainage and good indoor living environment to avoid the infection of diseases. Especially for drainage risers in high-rise buildings, due to the large displacement and high building height, it is of great significance to reasonably set up drainage and ventilation systems and energy dissipators to increase the drainage flow of risers and ensure the smooth drainage system. Because of the long riser of the connecting pipe of the sanitary ware drainage system in high-rise buildings and the high drainage pressure at the bottom, it is easy to cause the drainage splash of the lower sanitary ware; Sanitary ware is intermittent drainage, which makes the forward pipeline system in the drainage direction generate positive pressure. In the process of water flow falling, the subsequent pipeline generates negative pressure to form suction, which may cause water splashing and water seal suction in the pipeline system.

If the drainage system of high-rise buildings is commercial, the following measures should be taken:

(1) The first and second floors of high-rise buildings are drained separately;

(2) Strengthen the ventilation of drainage pipeline system, keep the air pressure balance in the pipeline system, and adopt special ventilation pipeline or new drainage pipeline system;

(3) Sewage and wastewater should be discharged separately through vertical pipes to facilitate wastewater recovery and wastewater treatment.

Domestic wastewater is separated from domestic sewage, and the wastewater system is a reclaimed water raw water system; Domestic sewage system includes toilet flushing, laundry drainage, kitchen, dining room and underground garage drainage; Kitchen and restaurant drainage and underground garage drainage are discharged after being treated by grease trap.

3. Maintenance of fire water supply and drainage system

3. 1 Maintenance of indoor fire sprinkler water supply system

Indoor fire sprinklers should be maintained at least once every six months (or as required by the fire department). Maintenance items include: checking whether indoor fire hydrants, fire sprinklers, fire hoses and other fire-fighting facilities are in good condition; Check whether there is corrosion, whether the water stop ring is in good condition, and whether there is oil dripping and water leakage; Whether the fire pump can automatically start within 5 minutes of alarm and supply water normally; Whether the alarm button indicator light and indicator are in good condition; After the inspection, targeted drills can be conducted to check whether the equipment is running normally.

3.2 Maintenance of fire hydrant

Fire hydrants are generally installed outdoors or in public places, and need to be maintained due to man-made and natural hazards. The main maintenance tasks include: cleaning the garbage in fire hydrant box and near the water outlet, checking the compatibility between the wrench sleeve and the dryer, and lubricating the rotating rod; Removing rust spots on threads; Test run the fire hydrant, drain the rusty water in the pipeline at the same time, and check whether there is water leakage in the water stop ring; Remove the garbage in the underground fire hydrant well.

The quality of building water supply and drainage design directly affects people's quality of life and living environment. Therefore, in the design process, designers should not only meet the requirements of relevant specifications, but also carefully consider the use effect, constantly summarize and improve the design technology, and achieve the purpose of safety, rationality and economy.

References:

Cheng Yan. Design and discussion of water supply and drainage [J]. China Building Information 2007.

[2] Yuan Changbiao, Zhang Shaojie Zhai Ruihua. Reflections on several problems in water supply and drainage design of super high-rise buildings [J]. Water supply and drainage 2009.

[3] Jinjiang Liu. Summarize the detailed design of residential water supply and drainage [J]. Henan Building Materials 2009.

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