Thinking about Putting up Reservoir in High Rise Building

Chang Yuzhong* Gao Wei
Shanxi Province Institute of Architectural Design ＆ Research, Senior Engineer
Add:No.13 Str. Fudong Taiyuan Zip Code:030013
Fax: 0351-3073613 Tel:0153-3285422

　　ABSTRACT This paper discuss the viewpoint that It is inadvisable to put up a eservoir for a single high rise building in city.
　　KEYWORDS Reservoir The fire water flowrate Adjustable water

1 Introduction

　　In the last decade, more then 100 high rise buildings have set up in Taiyuan. All most every high rise building has a reservoir for itself. In roughly evaluate, the areas of these reservoirs reach 23000m2, the fee is high over 50 million RMB. So that if this case occur all over our country, the fee would be high over 6000 million RMB.
　　According to 《National Design Norm of High Rise Building Fire System》No.7.3.2.1, when the civil water supply or natural water sources can‘t supply fire water flowrate fully, It is necessary to put up a fire reservoir in high rise building. According to 《National Design Norm of Building Water Supply of adjustable water, reserving for fire water flowrate and water for accident in producing. The amount of water for accident in producing is no exist in common civil building, and the amount of adjustable water is the difference between amount of supplied water and maximum of used water . From that we can say waether putting up a reservoir for civil building is depend on either the civil water supply system can meet the needs of water of daily life of building is depend on either the civil water supply system can meet the meeds of water of daily life of building and fire water flowrate or can‘t, In general, the fire water flowrate of building always bigger than water of daily life. So that our opinion is that under the condition that civil water supply system can meet the need of the fire water flowrate we can don‘t putting up reservoirs for every high rise building.

2 Putting up reservoirs for every building in city is unsuitable

　　To single building in city design of its outdoor water supply system should depend on civil water supply system. However, about design of city civil water supply system, the amount of adjustable water of city and the fire water flowrate are considered fully. Although city is changing with economic development, the needs of water increase continually. We should see that civil construction has developing with the civic development . To meet all kinds of need, the state of civil water supply and the needs of water is remain balance. Since the design of civil water supply system alr%ady consider the amount of adjustable water of city and the fire water flowrate, putting up a reservoir for single building to save this part of water is unnecessary. Although there is the difference between the maximum of hourly using water in design of civil water supply system and the flowrate per second in building design, we can consider this problem in wide scope, events of using water take place in different time and different places. So that the difference would be very small, we could not care of it. For the more, the design of civil fire fighting demand once using amount of water for putting out a fire in anywhere and at anytime is over than 100L/s. As we know, the design of city water supply consistent of water source,pressurize station and pipe-network. Doing these designs depend on making the maximum of hourly usingwater in city as essential parameter, And designs are checked by sum of maximum of hourly using water in city and the fire water flowrate. According to our analyses anyone system of civil water supply could meet the needs of water for daily life of buildin and the fire water flowrater in city. As a designer of building water supply and drainage, his design of building water supply should be based on design of city water supply, and he also should consider the actual conditions about location of building.He must make a decision either put up a water tank or not carefully. At present, because of lack of water source, some cities supply the water by the method to different region in different time. In this case, some high rise buildings lack of water supply sometimes. For this special case, we can solve the problem by a temporary small water tank. Inforward view, this case is not the property of city and foundation of building water supply ,it well be changed with the civic development al last, We say so because that:(1)this case is just a adjustment of civic water source distribute by unit of city water supply. (2)human being can change this state in anytime.(3)the ability of water supply that be designed in design of city water supply still exist.(4)civil construction has developing with the civic development. In sum, putting up a water tank for single building repeat the total design of city water supply. Such repeat is unsuitable and unnecessary.
　　There are some branch offices of city waterworks or region booster-pumping stations in medium or big cities, the branch offices and booster-pumping stations are distribute uniformly. There are some boosters and adjusting devices in the branch offices and booster-pumping stations. The adjustable water of daily life, the water dribbled as usual and must prepared the fire water flowrate of this region have saved in the adjusting devices. Another hand, there are some boosters and adjusting devices in the small residential quarters of city. Because of reasons just we taking above, it is assured that the pressure reach over0.15MPa under condition of maximum of hourly using water and the pressure reach over 0.10 MPa under condition adding together maximum of hourly using water and fire water flowrate. In the same time, there is a high-level water tank on the high rise building usually,in which the initial fire water flowrate and part water of daily life are stored. Considering the conditions just we taking above, we think it is unnecessary that putting up a water tank for single high rise building.
　　We should iliustrate tha when for ru at anyWhe the unit of dty water suPPly ho acts for important. When the fire department receives the report of fire taking place at somewhere, he should tell the unit of tw water supply in the region at once, switching on the pumps set to work immediately and the the amount of water of civil water supply pipe-network meets the demand of design of the system rapidly. The cooperation in different departments is essential condition to accomplish fire protection tasks perfectly
　　Putting up a reservoir for high rise building has two purposes, the first it is a device saving water for fire system, the second it is a device saving adjustable water for daily life. But in our discussing just taken, generally,civil water supply could meet the need of single building in city, so that we needn‘t to put up a reservoir. On the one hand putting up a reservoir for high rise building is unnecessary and on the other hand it has some defects. There are 5 main defects in our thinking.(1)Reservoir will occupy using area.At present usable land is limited in city. So that the building functions have developed forward space, just as we put up the water tank, water pump, air-condition station, distrbutung substation,parking and so on in underground room as usually. Therefor the underground room is very crowd. However the most volume of reservoir is occupied by water for fire system,it is of no use for a long time, even forever. It is regretful.(2)Putting up a reservoir for one high rise building is every expensive.(3)The energy losing is too big. Using a reservoir couldn‘t use the pressure of civil water supply system fully, this is very wasteful of energy.(4)The quality of water is polluted again. While water save in a reservoir for a long time, it is possible to cause water to deteriorate.(5)The water for fire system no use for a long time, that means reservoir is no use, but the daily maintain of the device needs fee.
　　Don‘t put up a reservoir for high rise building, we can do that.(1)for water of daily life,put up a boost pump in pipe line of civil water supply directly. Putting up a boost pressure pump can choose different size in different region, just as having a reservoir.(2)for water of fire system, we should put up two pipe line of civil water supply from different directions. The diameter of pipeline can be increased properly, the pipe line can form independent system, and putting up a fire pump in pipe line. Putting up fire pump can choose different size in different region, just as having a reservoir.(2)for water of fire system, we should put up two pipe line of civil water supply from different directions . The diameter of pipeline can be in creased properly, the pipe line can form independent system, and putting up a fire pump in pipe line. Putting up fire pump can choose different size in different region, the design of the other fire devices and control methods is the same just as having reservoirs. Fire departments are set up in different regions of city. The fire departments distribute depent on the distance the fire department could reach the fire spot no more then ten minutes. When fire occurs, building manager should switch on fire pump and other fire fighting devices, at the same time, report to fire department and unit of civil water supply. They can do these works in short time. Therefor we needn‘t put up a reservoir for a building.
　　Under special cases,(1)The high rise buildings are constructed at suburb, the state of civil water supply is bad indeed or the character of buildings is important especially. We can consider put up a reservoir for a building,(2)At the area that high rise buildings are very crowd, we can set up a reservoir and booster-pumping station for the region. It is efficient.

3 Conclusion

　　It is unnecessary that putting up a water tank for single high rise building in city. Doing not put up water tank is no affect to water of daily life and the fire water flowrate. Doing not put up water tank we can make good use of environment and limited energy.

References

　　[1]People‘s Republic of China Public Security Ministry《The National Design Norm of High Rise Civil Building Fire System》GB50045-95 1995.11.