Reliability Research On Fire Control Systems Of High-Rise Buildings

The high-rise buildings are integrations of economy, technology and culture in modern society. For their high stories, large spatial spans and complex functions, once fires occur, the extinguishments are difficult and may cause heavy losses and disastrous consequences. Therefore, the concerned standards in China have made clear the principle of the automatic fire-fighting in high-rise buildings, and its reliability of techniques in fighting fires have drawn more and more attentions in recent years.The automatic sprinkler system can effectively control the fires at initial stage in high-rise buildings; it's the generally established reliable automatic fire-fighting facility and should be generalized in China. But the advantages of automatic sprinkler system have not been fully recognized. So the actual application of the system in fire fighting is not ideal.There are few documents about the optimal design of the water supply system in China, the current studies only analyze the reliability of water supply system and the pipe network for water distribution respectively, and there have been no comprehensive analysis researches and no complete design models for the automatic sprinkler system. The dissertation applies mathematical theory to the establishment of reliable model of the system and studies the mathamaticalized problems, providing the theoretical background to assure the reliability of the system in actual design and construction. There lie many latent troubles in fire-fighting of routine high-rise buildings, for example, there are many steps in starting the water pumps, the control circuit is complex, the system maintenance difficult and thus the system reliability is low. The dissertation has analyzed and compared the initiation mode of the water pump in routine system, proposed that the control mode of double pressure switches is much more reliable, and provided the setting mode of the switch. The automatic sprinkler system that adopts lateral pressure or standard high-pressure water supply has fewer control sections, lightens maintenance and management, but can ensure the reliability of water supply system remarkably.The automatic alarming system can forecast the fires at early stages in time and control the corresponding linkage facilities. It has been extensively applied to high-rise buildings. But in practical use, the false alarm and the breakdown often occur and the persons in charge are often forced to cut the system off. The property of the detectordetermines its application places; the pursuing of new product and technology does not mean the improvement of the system's reliability. The two-wire mode that integrates linkage and control with alarm can further improve the reliability between alarm and linkage.The water pump is an important fire-fighting facility and it is the heart of the water supply system; its reliability is directly related to the successful prevention of fire, thus it is crucial to get a reliable control of the pump. The adoption of PLC to realize control of the pump not only cancels all the intermediate sections and the second-time wire connection but also adds the function of regular exchange between primary pump and stand-by one and automatic testing function which cannot be realized by relay control system. Therefore, it is very important to the operation reliability of control system.