The fireman's helmet camera takes you to the scene of the fire
Automatic fire alarm system is an important part of building equipment automation system (BAS) in intelligent building. The design of automatic fire alarm system in intelligent building must first meet the requirements of gb50116 code for design of automatic fire alarm system (the latest is gb50116-2013). At the same time, it is also necessary to adapt to the characteristics of intelligent building, reasonably select products, and achieve safety, applicability, advanced technology, economy and rationality.
Automatic fire alarm system is generally designed in three forms: regional automatic fire alarm system, centralized automatic fire alarm system and control center alarm system. According to the basic characteristics of intelligent building, the control center alarm system is the most suitable way.
The design points of automatic fire alarm system in intelligent building are: determine the fire type according to the combustion characteristics of the protected object in case of fire; According to the required protection area and position; Determine the total capacity of fire alarm controller according to the total number of fire detectors and the number of other alarm devices (such as manual alarm); Set regional alarm controller according to the divided alarm area; Determine the linkage control mode according to the fire-fighting equipment; Determine the logical relationship between alarm and linkage according to the requirements of fire prevention and extinguishing; Finally, the adaptability of automatic fire alarm system and intelligent building "3As" (construction equipment automation system, communication automation system and office automation system) should be considered.
Fire detector is the trigger device of automatic fire alarm system. According to the detected fire characteristic parameters, it can be divided into smoke fire detector, temperature fire detector, photosensitive fire smoke temperature composite fire detector and gas fire detector. According to its measurement and control range, it can be divided into point fire detector and linear fire detector. The point type fire detector can only control the temperature, smoke and other parameters around a certain point in the warning range, such as point type ion sensing, point type purple flame fire detector, point type temperature sensing fire detector, etc. the linear fire detector can detect the smoke and temperature around a certain line in the warning range, such as infrared beam linear fire detector, Laser linear fire detector, cable linear temperature sensing fire detector, etc.
The fire alarm controller is the center of the automatic fire alarm system. It receives the signal and makes analysis and judgment. In case of fire, it immediately sends out the fire alarm signal and starts the corresponding fire-fighting equipment. With the development of computer technology, the traditional switching multi wire automatic fire alarm system has been replaced by the analog bus automatic fire alarm system, The intelligent automatic fire alarm system based on technology is also widely used. Analog bus automatic fire alarm system and intelligent automatic fire alarm system are developed on the basis of computer technology, and can be used as the selected products of intelligent buildings.
The regional fire alarm controller is generally set according to the fire compartment, and the determination of its capacity mainly depends on the number of addressing detection equipment in the alarm area. The addressing detection equipment in the alarm area not only refers to the number of smoke and temperature detectors or other types of fire detectors, but also includes manual alarm buttons, fire hydrant alarm buttons in the alarm area, water flow indicators and water pressure switches that convert signals through the control module. For example, the capacity of a certain type of fire alarm controller is 4 circuits × 128 detection points, that is, each control loop can control 128 addressing detection points. If the total number of addressing equipment in an alarm area in the intelligent building is 400, the automatic fire alarm controller just meets the regional alarm requirements.
In case of fire, the fire alarm controller sends out alarm information, and the fire linkage controller outputs linkage signal according to the linkage relationship of the fire information management department, and starts relevant fire-fighting equipment to implement fire prevention and extinguishing.
Fire linkage must be realized in both "automatic" and "manual" states. Under the automatic condition, the automatic fire alarm system in the intelligent building outputs the automatic control command and starts the action of relevant equipment after the fire alarm according to the linkage logic relationship prepared in advance. In case of manual operation, corresponding control shall be realized according to manual operation.
System wiring and its adaptability to intelligent buildings
Due to the special status of automatic fire alarm system, it is different from other control systems in intelligent building in wiring and installation. First, the selection and wiring mode of cables should meet the technical conditions of automatic alarm device, such as twisted pair is required for most alarm transmission lines; Second, it is necessary to meet certain mechanical strength. Third, it is necessary to take pipe threading protection, concealed laying or flame retardant measures. Fourth, it is necessary to be arranged separately from other low-voltage system cable shafts in the daytime. Fifth, it is necessary to make its transmission network not shared with other transmission networks.
From the concept of intelligent building, the automatic fire alarm system and its linkage control should belong to the category of building equipment automation system (BAS). The automatic fire alarm system has special inventory management requirements, its alarm line and linkage line. The communication line is basically self-contained, which is quite different from the generic cabling system in intelligent buildings. However, with the development of intelligent buildings and the maturity of automatic fire alarm system, the combination of the two in application will be closer and closer. The key is that when designing and selecting the automatic fire alarm system in the intelligent building, the adaptability of the two on the connection interface must be considered. Make them combine in the best way in installation, use and operation.