Design of fire protection system for super high-rise building
1. High-level fire-fighting water tank: Select according to GB50974-2014 5.2.1, residential residential buildings are selected according to section 2, public buildings take the larger value when section 1 is inconsistent with section 6. High-level of temporary high-pressure fire-fighting water supply system The effective volume of the fire fighting water tank shall meet the requirements of the initial fire fighting water consumption, and shall meet the following requirements: 1 Class 1 high-rise public buildings shall not be less than 36m3, but when the building height is greater than 100m, it shall not be less than 50m3. When the building height is greater than At 150m, it should not be less than 100m3; 2 Multi-story public buildings, second-class high-rise public buildings, and first-class high-rise residences should not be less than 18m3; when the height of first-class high-rise residential buildings exceeds 100m, it should not be less than 36m3; 6 Total construction area Store buildings larger than 10,000m2 and less than 30,000m2 shall not be less than 36m3, and stores with a total construction area of more than 30,000m2 shall not be less than 50m3, which shall be the larger value when inconsistent with the provisions of paragraph 1 of this article. 5.2.2 The installation position of the high-level fire water tank shall be higher than the water fire extinguishing facilities it serves, and the minimum effective water level shall meet the hydrostatic pressure at the most unfavorable point of the water fire extinguishing facilities, and shall be determined according to the following regulations: Class I high-rise public buildings , It should not be lower than 0.10MPa, but when the building height exceeds 100m, it should not be lower than 0.15MPa. When the water tank of some special buildings is set higher than the water fire extinguishing facilities they serve, effective measures shall be adopted and reported to the local fire department for approval.
2. Firefighting pump coupling: 5.4.6 When the firefighting water supply is vertical zone water supply, the pump coupling should be set in the zone within the water supply pressure range of the fire truck; when the building height exceeds the fire truck water supply height, the fire fighting water supply should be at Suction and pressurization interfaces for hand-pump or mobile pump relay water supply are provided at convenient places such as the equipment floor. This article specifies that the relay water supply measures for fire trucks to supply water through the fire pump adapter are to use hand pumps or mobile pumps. It is also required to consider the suction inlet and pressurized water connection of a hand-pump or mobile pump when designing a fire-fighting water supply system. The relay water supply for high-rise building fire water tankers shall be determined according to the model of the local fire brigade, and the plan for the relay water supply of fire pump couplings shall be determined according to the information provided by the local fire brigade. When the fire truck can run normally for a long time and can exert the fire truck’s greater efficiency, the flow rate is generally 10L / s to 15L / s. Therefore, the flow rate of each water pump adapter should also be determined by calculating from 10L / s to 15L / s. When the number of fire pump couplings is greater than 3, there may be difficulties in parking the fire truck, so it can be appropriately reduced according to the specific situation. The relay water supply facility consists of a relay water tank and a hand-pump. The intermediate transfer water tank can be used as a relay water tank. When the transfer pump water ring network is used as the relay water pipe of the pump adapter, water should be reserved before transferring the water tank. Lift or move the suction port of the pump. Fire brigades are generally equipped with hand pumps instead of electric pumps. The model of hand lift pump is as follows:
3. System partition: 6.1.13 When the building height exceeds 100m, the indoor fire water supply system should analyze and compare the reliability of a variety of systems, and adopt a safe and reliable fire water supply form; when using an ordinary high pressure fire water supply system, but high-level fire protection When the pool cannot meet the pressure and flow required by the upper floor, the upper floor shall adopt a temporary high-pressure fire-fighting water supply system. The effective volume of the high-level fire-fighting water tank of the system shall be determined according to the water supply height of the system in accordance with 5.2.1 of this code, It should not be less than 18m3. According to statistics, there are 220,000 high-rise buildings in cities in China, but there are fewer high-rise civil buildings with a height of more than 100m. Incomplete statistics include about 1,700 buildings and 1,254 buildings under construction. These buildings’ fire trucks are already powerless to fight the fire. Firefighters are on fire The location is relatively long. For this reason, it is determined that high-rise civil buildings should be completely self-rescue. The self-rescue mainly depends on the indoor fire water supply system, especially the sprinkler system, but the reliability of the fire water source is the core. Fire cannot be extinguished. In order to improve the self-rescue reliability of these high-rise civil buildings, this code stipulates that civil buildings with a building height of more than 100m should use reliable fire-fighting water supply. The reliability of fire-fighting water supply should be determined through reliability calculation analysis. 6.2.1 When the following conditions are met, the fire water supply system should supply water in zones: 1 The working pressure of the system is greater than 2.40 MPa; 2 The static pressure at the hydrant plug mouth is greater than 1.0 MPa; The working pressure is more than 1.20MPa. 6.2.2 The form of district water supply shall be determined according to system pressure, building characteristics, and comprehensive factors such as technical economy and safety and reliability. The form of fire pumps may be used in parallel or in series, and the pressure reduction tank and pressure reducing valve are used to reduce the pressure. When the working pressure is greater than 2.40MPa, the fire water pumps should be connected in series or the pressure-reducing water tanks should be divided into water supply forms. a.
4. Transfer water tanks and transfer pumps: When using fire pumps in series for district water supply, it is recommended to use fire pump transfers to tanks for series water supply, and it shall meet the following requirements: 6.2.3 When using fire pumps in series and district water supply, it shall be used The fire water pump transfer water tank is connected in series and shall meet the following requirements: 1. When the fire pump transfer water tank is connected in series, the effective water storage volume of the transfer water tank should not be less than 60m3, and the transfer water tank can be used as a high position. Fire-fighting water tank; 2. The overflow pipe of the series transfer water tank should be connected to the fire-fighting pool; 3. When the fire-fighting water pump is directly connected in series, measures should be taken to ensure the reliability of water supply, and the fire-fighting water pump should Start in order; 4. When the fire pump is directly connected in series, the water supply pressure of the system should be checked, and a pressure-reducing backflow preventer should be installed on the water pipe of the series fire pump. The effective volume of the transfer water tank should be determined by the sum of the water consumption of the indoor fire fighting water for 10 minutes and the effective water volume of the roof fire fighting water tank. The 60 square in the specification is determined by the sum of the water consumption of the indoor fire hydrant 40L / S and the spray of 30L / S for 10 minutes and the roof water tank 18T, that is: (40 + 30) X10X60 / 1000 + 18 = 60T. The drainage capacity of the overflow tank of the series water tank shall be calculated according to the transfer flow rate. If the transfer flow hydrant is 40L / S and the self-injection is 30L / S, the overflow drainage volume shall be considered as 70L / S. The overflow pipes of transfer water tanks on different floors should be connected directly to the bottom fire water tank. The transfer pump flow is the fire flow of the service system, and the head is the minimum water pressure required by the system.
5. Hose reel and apron: 7.4.4 For buildings with helipads on the roof, fire hydrants should be installed at the apron entrance or non-electrical equipment room, and the distance from the edge of the apron position should not be less than 5.0m. The purpose of helipad on the roof of public buildings is to provide fire rescue. Fire hydrants are installed at the entrance and exit of the helipad to facilitate self-protection against fire during a fire. Considering safety factors, the distance from the helipad is not less than 5m for safety. 7.4.11 The water consumption of fire hose reels and portable water hoses may not include the total fire water consumption of a person. Article 8.2.4 of the Code for Fire Protection of Building Design GB50016-2014: Personnel-intensive public buildings, buildings with a building height of more than 100m and commercial service outlets with a building area of more than 200m2 shall be equipped with fire hose reels or portable fire hoses. High-rise residential buildings should be equipped with portable fire hoses indoors.
6. Pipe material selection: 8.2.5 When the system working pressure is not more than 1.20MPa for buried pipelines, ductile iron pipe or steel wire mesh plastic composite pipe water supply pipeline should be used; when the system working pressure is greater than 1.20MPa and less than 1.60MPa, it should be used Steel wire mesh plastic composite pipe, thickened steel pipe and seamless steel pipe; when the system working pressure is greater than 1.60MPa, seamless steel pipe should be used. The steel pipe connection should use grooved connectors (clamps) and flanges. When connected with grooved connectors, the working pressure of the grooved pipe joint system with a nominal diameter of DN250 or less should not be greater than 2.50MPa, and the nominal diameter is greater than or equal to The working pressure of the grooved pipe joint system of DN300 should not be greater than 1.60MPa. 8.2.8 When the system working pressure is less than or equal to 1.20MPa, hot-dip galvanized steel pipe can be used; when the system working pressure is greater than 1.20MPa, hot-dip galvanized thick steel pipe or hot-dip galvanized seamless steel pipe should be used ; When the system working pressure is greater than 1.60MPa, hot-dip galvanized seamless steel pipe should be used.
7. Test drainage: 9.3.1 Special drainage facilities shall be provided at the test installations of fire water supply systems, and the diameter of drainage pipes shall comply with the following rules: 1 Drain riser pipes at the end of automatic water extinguishing systems such as sprinkler systems The diameter should be determined according to the discharge flow of the terminal water test device and should not be less than DN75; 2 The drainage riser at the alarm valve should be DN100; 3 The pressure test drainage pipe diameter at the pressure reducing valve should be determined according to the pressure reducing valve flow, but It should not be less than DN100. 9.3.2 The recyclable part of the test drainage should be discharged into a dedicated fire water tank for recycling.
8. Hydraulic calculation: 10.1.9 The hydraulic calculation of the hydrant system pipe network should meet the following requirements: 1 The pipe network of the outdoor hydrant system should not be simplified in the hydraulic calculation, and the hydraulic calculation should be based on the annular pipe network in the branch or accident state. ; 2 The indoor fire hydrant system pipe network can be simplified into a branch pipe network in hydraulic calculation. The vertical pipe flow of the indoor fire hydrant system shall be in accordance with Article 8.1.6, paragraph 1 of this code. When the maximum number of vertical pipes that can be closed, the remaining group of the most unfavorable vertical pipes determines that each vertical pipe in the group of vertical pipes distributes the indoor fire hydrant equally. The design flow rate shall not be less than the riser flow rate specified in Table 3.5.2 of this code. The flow rate of the indoor fire hydrant system water supply main pipe shall be the designed flow rate of the indoor fire hydrant. This article stipulates the principle of hydraulic calculation of fire water supply. China’s previous codes and manuals did not provide calculation principles for indoor fire hydrant systems for fire extinguishing and water supply systems. According to the summary of engineering practice, the standardization group proposed the calculation principles of the indoor fire hydrant system ring pipe network simplified to branch pipe network. The reason is that the domestic fire hydrant system Both have the problems of the minimum riser flow rate and the transfer flow rate, so the conventional calculation method of the water supply pipe network is inappropriate, so it is comprehensively simplified into a branch pipe network.
9. Spray pipeline: 8.0.1 The working pressure of the water distribution pipeline should not be greater than 1.20MPa, and no other water facilities should be set up. To ensure the water consumption of the system, no other water facilities can be set on the pipeline after the exit of the alarm valve. According to the minimum pressure division required by the specification, the alarm valves are scattered.
10. Excerpts: “Technical Specifications for Fire Water Supply and Fire Hydrant System” GB50974-2014
Code for Fire Protection of Building Design GB50016-2014 (2018 Edition)
“National Civil Construction Engineering Design Technical Measures Water Supply and Drainage” 2009 Edition
(Revised Edition) Implementation Guide for Technical Specifications for Fire Water Supply and Fire Hydrant Systems