Design and calculation of water supply system for super high-rise buildings
Liu Ke Zhengzhou Architectural Design Institute
1. “Water Regulations” GB50015-2003 (2009 edition) Article 3.3.6: The living water supply system for buildings whose building height does not exceed 100m, should adopt the vertical partition parallel water supply or partition decompression water supply method; buildings with a building height exceeding 100m , Should adopt vertical tandem water supply. Let’s first understand the three water supply methods:
1.1. Vertical sub-zone parallel water supply: a. Middle and high districts are preferentially pressurized to the roof water tank (or sub-zone water tank), and then the self-flow sub-zone is decompressed to supply water. B. Each zone directly adopts a speed regulating pump unit to directly supply water, Local pressure regulation by pressure reducing valve. c. Each district directly supplies water by using air pressure water supply equipment, and then the regulator is used for local pressure regulation in the district.
1.2. District decompression water supply method: The building water is lifted from the pump to the roof water tank at one time, and then the water is supplied downward through the pressure reducing valve or the pressure water tank. In this water supply method, the roof water tank is large and the safety is poor. Rarely used, can be used in multi-storey buildings or with few partitions.
1.3. Vertically connected in series: a. There is a water tank: a water tank and a pump are set in each zone, and the water tank in the lower area doubles as the previous pool. This type of water supply test does not require the installation of high-pressure water pumps and high-pressure pipelines. The water supply is affected by the water supply from the lower pump. Once the equipment of the lower layer is faulty, the water supply of the upper layer cannot be used. This type of water supply requires a pressurized water supply pump room on the middle floor and a high-level water tank. The booster pump must also be equipped with a transfer pump that is parallel-locked with the lift pump in the upper zone. In addition to the water requirements in the zone, the water tanks in each zone must also store the starting pump water for the pump in the upper zone. b. No water tank: district water supply. Pumps are used to directly draw water from the external network or pool. Each district has its own system. The living pumps in each district match each other. When in use, the next district pump is started first, and then the upper stage pump is started. Small flow regulator pump or tank. 1.3.a is the water supply method commonly used in super high-rise buildings.
2. GB50015-2003 (2009 edition) 3.7.8 The transfer adjustment volume of the transfer water tank in the middle of domestic water should be taken from the flow of the transfer pump for 5 to 10 minutes. The transfer of the water tank halfway has two functions. One is to adjust the flow difference between the primary pump and the secondary pump. Generally, the flow of the primary pump is greater than or equal to the flow of the secondary pump. The volume of the transfer water tank should be 5min ~ 10min of the secondary pump. The second is to prevent the secondary pipe network from returning the water pressure when the secondary pump is stopped. The transfer water tank can transfer the return water. Pressure is eliminated to protect the primary pump from damage. This clause applies only to the case where there is no water supply to adjust the volume of the intermediate tank.
3. Calculation of lift pump flow:
3.1. The tankless water pump is connected in series with the life pumps in each zone. When using, start the next zone pump and then the upper pump. The pump flow rate is calculated according to the design second flow rate of the service object. The lift should be able to meet the most disadvantageous point of water supply pressure. Claim.
3.2 There is a water tank. When the lift pump supplies water to both the water point and the water tank (from the water tank to the remaining water points), the flow rate should be calculated separately and the maximum flow rate should be taken. Note that the adjustment volume of the high-level water tank should not be less than the service object. The maximum water consumption is 50%, and the pump water depth is half of the water depth. The pump head meets the water supply requirements of both superimposed.
3.3 There is a water tank. When using a water tank to supply water in series, the lift pump flow rate in this zone should be determined according to the maximum hourly flow rate in this zone. The lower zone should be equipped with a transfer pump that matches this zone (the flow rate is the same, and the lift is according to the requirements of each zone).
As above, the flow of the lift pump is determined according to the water supply range of the lift pump at the intermediate water tank. If the transfer pump and the water supply pump are separately set, the lift pump flow is determined according to the maximum hourly flow rate in the area, and the transfer pump is matched.
4. Calculation of living water tank (pool):
4.1 “Water Regulations” 220.127.116.11 The effective volume of the storage tank (tank) should be calculated and determined according to the curve of water intake and water consumption; when the information is insufficient, it should be based on 20% of the maximum daily water consumption of the building (pressurized part) -25% is determined; 18.104.22.168 The volume of domestic water for the high-level water tank that directly feeds water into the urban water supply network at night should be adjusted based on the number of water users and the maximum daily water quota; if it exceeds the bottom of high-rise buildings, the water tank or pool can be calculated according to this article.
The volume of domestic water adjustment of the water tank to be lifted by the water pump linkage should not be less than 50% of the maximum water consumption of the service object; the same as the above 3.2. This clause applies to 4.2 of the super high-rise intermediate tank calculation.
4.2 When vertical series connection is adopted, the volume V of the intermediate water tank for domestic water shall be calculated according to the sum of the water supply part of the water tank plus the water volume of the transfer part. V Intermediate water tank = Va + Vb a. The adjustment volume of the water supply is not less than 50% of the maximum hourly water consumption of the service water supply floor; b. The adjustment volume of the transfer water volume should be determined according to the 3-5min flow of the lift pump.
4.3 If the intermediate tank has no water supply part to adjust the volume, the transfer volume of the transfer water tank should take the flow of the transfer water pump for 5 to 10 minutes. V intermediate water tank = Vb.
As above, the middle water tank V of the super high-rise building can be selected and calculated according to different water supply forms.
5. According to the building design fire protection code GB50016-2014 (2018 edition), public buildings and residential buildings with a building height of more than 100 meters should be provided with refuge floors. Intermediate water tanks (transferring or relay water tanks) can be installed on the refuge floors, but “Water Regulations” Article 3.8.11: The domestic water supply pump house installed in the building should not be adjacent to or above or below the residential house. The pump unit should be located on the side and below the pool. A single pump can be located in the pool. Or within the pipeline, its operating noise should comply with the current national standard “Code for Design of Sound Insulation of Civil Buildings” GB 10070. For residential buildings below 200 meters, the impact of noise and water leakage on the residents upstairs and downstairs needs to be considered, and a vertical parallel water supply method with a series roof water tank can be considered. Or consider the possibility that the upper and lower floors are not sold as a commercial house.