I. Design Basis
The design of automatic fire alarm system is a highly professional technical work, and it also has a strong policy. Therefore, the following design basis should be defined first:
It is necessary to master the fire protection laws and regulations in five aspects: building design fire protection standards, system design standards, equipment manufacturing standards, installation and construction approval standards and administrative regulations, and understand the positive words: must, should, apply, can and negative words: forbidden, should not, not available and not applicable in the current national standards and norms in practice.
According to the function of high-rise civil buildings, the use and the fire rating of the protected objects, we should conscientiously implement the relevant national norms and standards and take seriously the examination and approval opinions of the public security fire supervision department.
Second, the automatic fire alarm system equipment settings
Fire detector facilities
The search scope of large seals or stairwells should be divided separately, and a fire detector should be set every 2 ~ 3.
The front room (including the front room of the smoke-proof stairwell, the fire elevator room and the front room where the smoke-proof stairwell for fire elevators comes in handy) and the walkway should be divided separately, especially the front room and the elevator shaft. The scattered stairwells are connected with the walkway, so the smoke is easier to gather or flow in case of fire, which is the target of personnel evacuation and fire fighting, so fire detectors should be installed. Although the front room of an ordinary elevator is not evacuated, it is connected with the elevator shaft, and smoke is easy to gather or flow in case of fire. It is advisable to divide the search range separately and install fire detectors.
Therefore, the cable shaft is easy to form a passage of smoke and fire; In case of fire, the fire is not easy to spread and burn along the cable. Therefore, the Code for Fire Protection Design of High-rise Civil Buildings and the Code for Electrical Design of Civil Buildings respectively put forward detailed and specific regulations on the modeling of buildings and wires or cables. However, considering the difficulty and present situation of concrete implementation, it is very necessary to install fire detectors in cable shafts, and to meet the requirements of fire fighting spacing of shafts, one detector should be installed every 2 ~ 3 floors or every floor.
Fire detectors should be installed in the elevator room, and the elevator is an important vertical transportation tool; The two elevator rooms are in danger of fire; There are necessary openings in its three elevator shafts, such as floor door openings, ventilation openings, permanent openings and elevator machine rooms or pulleys, etc. Fourth, when a fire breaks out, the elevator shaft often becomes the channel for the fire to spread, which is easy to threaten the facilities of the elevator machine room. Therefore, it is necessary to set fire detectors in the elevator machine room, and it is also suitable for elevator shafts with fire detectors.
Setting of manual fire alarm button
The front rooms of each floor (including the front rooms of smoke-proof stairwells, fire elevator rooms and smoke-proof stairwells for fire elevators) are the targets of evacuation and fire fighting in case of fire, and should be the first choice for setting manual fire alarm buttons. In addition, the room should also be equipped with a manual fire alarm button in front of the ordinary elevator.
In public activity places (including halls, auditoriums, restaurants, multi-function halls, etc.) and main passages, people are concentrated, and mainly evacuation passages. Therefore, manual alarm buttons should be set at the main entrances and exits of these public places; The manual fire alarm button set on the main road ensures that "the nearest manual fire alarm button to a fire zone should not be more than 30 meters away from any position".
Setting of fire emergency broadcast loudspeaker
People in corridors, halls, restaurants and other public places are very concentrated, and they are mainly evacuation passages. Therefore, fire emergency broadcast speakers should be installed in these public places according to the following principles: "The nearest speaker to any point in a fire zone is not more than 25m" and "The distance from the speaker on the aisle to the end of the aisle should not be more than12.5m"; Secondly, fire emergency loudspeakers should be set up in public bathrooms.
The front room (including the front room of the smoke-proof stairwell, the fire elevator room and the front room of the smoke-proof stairwell for the fire elevator) has the purpose of evacuation and fire fighting in case of fire, and there are also fire doors separated and noisy people, so fire emergency broadcast speakers should be set up. The room in front of the ordinary elevator should also be equipped with fire emergency broadcast speakers. The evacuation staircase hall is also used for evacuation and fire fighting in case of fire, and it is noisy. Therefore, fire emergency broadcasting speakers should be set up to facilitate fire emergency broadcasting evacuation instructions.
Setting of fire alarm device
To establish an automatic fire alarm system of fire emergency broadcast, the author thinks that a fire alarm device should also be installed, but its control procedure should be: the alarm should be confirmed after the fire occurs, and the alarm should be sent to the fire-related area by manual or automatic control, and the alarm should be stopped within the specified time, and the fire emergency broadcast should be quickly linked and evacuation instructions should be broadcast to people.
The setting position of the fire alarm device should be the same as that of the manual fire alarm button, and the installation height of the wall should be1.8m from the ground.
Special telephone facilities for fire fighting
The installation of special telephone extensions for fire fighting should be located in the computer room which is frequently linked with fire fighting and manned (including fire fighting water plant, standby generator room, distribution substation, air conditioning room for main ventilation, smoke exhaust room, fire elevator room and others), operating equipment room or control room of fire fighting control system, observation room for fire fighting personnel on duty, security management point and other public places. Both car fire elevator and ordinary elevator should be equipped with dedicated user telephone, which requires elevator machine room and elevator car, elevator machine room and fire control room, elevator car and fire control room to form a telephone system with reliable communication. Usually in the fire control room; Elevator monitoring display boards (including position indicator, direction indicator, intercom, fault light, etc.) shall be set up to control the elevator operation status in case of monitoring and emergency.
Manual fire alarm buttons shall be provided, and fire hydrant buttons shall also be equipped with special telephone sockets for fire fighting.
Third, the fire linkage control
The fire linkage control should include controlling the start and stop of the fire pump, and should also display the position of the pump start button and the work and fault of the fire pump. When the fire hydrant is equipped with a fire hydrant button, the electrical installation work point should also display the working mode and active state of the fire pump (that is, set the working indicator light of the fire pump).
The linkage control of fire fighting should include controlling the opening and closing of water spraying and water atomization fire fighting system, and also displaying the work and fault of fire pump and the working status of alarm valve and safety signal valve smoothly. In addition, the water level of basin and water tank should also be displayed and monitored; In order to prevent the maintenance signal valve from closing, the author thinks that the control signal valve with live signal should be used to show its open state.
Other control and display functions of fire linkage control shall be implemented in accordance with the specific provisions of existing national standards and norms.
Four, automatic fire alarm system wiring
In order to prevent the fire fighting, communication and warning line from being cut off when a fire breaks out, the fire fighting work cannot be carried out, resulting in great economic losses; In order to restrain the influence of electromagnetic interference (such as transformer, motor, cable, etc.) on the automatic fire alarm system. The transmission line, fire fighting, communication and alarm lines of the automatic fire alarm system shall be flame-retardant cables, and shall be protected by metal pipes or enclosed metal trunking. Fire-fighting manual positive control device lines should use fire-resistant cables, and their cables should also be protected by metal pipes or closed metal trunking. When the exposed type is used, fire protection measures should be taken for metal pipes or closed metal trunking. Fifth, the conclusion.
Based on the experience of specific engineering implementation, the author expounds the practical problems of automatic fire alarm design, such as design basis, system equipment setting, fire linkage control and wiring, and puts forward some superficial opinions, with the aim of improving the design quality of automatic fire alarm system, finding and reporting fires early, preventing and reducing fire hazards, and protecting personal and property safety.
With the rapid development of China's economy and the continuous improvement of people's living standards, urban use is in an emergency every day, urging the construction to face the direction of development. The materials and methods needed for the maintenance of this high-rise civil building are also more diversified and accelerated, and with the expansion of power load and gas consumption, higher and stricter requirements are put forward for the design of automatic fire alarm system. In order to ensure the safety of people's lives and property, the design of automatic fire alarm system has become the most important design content in the design of high-rise civil buildings. Based on the current experience in the design and supervision of automatic fire alarm system in high-rise civil buildings, this paper puts forward some unclear national codes and standards, discusses with peers and points out mistakes.
First of all, the design basis
The design of automatic fire alarm system is a professional and technical work, and also has a strong policy. Therefore, the following design basis should be defined first:
First, we must firmly grasp the fire protection laws and regulations in five aspects: architectural design fire protection standards, system design standards, equipment manufacturing standards, installation and construction approval standards, and management regulations, and earnestly understand the positive words of national standards and norms: must, must bear, inappropriate, possible, and negative words: forbidden, shouldn't, and nothing.
Second, we should focus on the function of high-rise civil buildings, use and protect the fire rating of objects, conscientiously implement this standard and relevant national standards, and take seriously the examination and approval opinions of public security fire supervision departments.
Secondly, the automatic fire alarm system equipment is established.
Establish a fire detector
Whether it is a fully open seal or a staircase hall, it should be divided into separate search areas, each 2? 3 Establish a fire detector.
The first room (including front smoke prevention hall, front staircase, fire elevator room and fire elevator smoke prevention front staircase) and corridor should be distinguished, and the search scope should be divided respectively, especially the front room and elevator. The scattered staircase halls and corridors are interrelated, and the fire smoke that changes with time is easy to gather or flow, which is the goal of scattered preservation and fire prevention. Therefore, fire detectors should be installed. Although the people in the front room of the elevator are not scattered, and the space in this area is interrelated with a good elevator, with the passage of time, fire smoke can be easily collected or flowed, and properly divided into separate search coverage and installation of fire detectors.
Therefore, the cable shaft is easy to form an inflammatory passage of smoke, and the fire is not easy to spread and burn along the cable when a fire occurs. For this reason, the Standard for Fire Protection Design of High-rise Civil Buildings and the Standard for Electrical Design of Civil Buildings respectively put forward detailed and specific regulations on building and wire and cable forming. However, considering the difficulty and present situation of concrete implementation, it is considered that it is very necessary to install fire detectors in cable wells. The fireproof spacing of the coordinate axis is required to be every 2? 3 or each floor installation.
Fire detectors should be installed in the elevator room. Its elevator is an important vertical means of transportation, and its two elevator rooms are already in fire danger. There are three basic lifting and opening holes, such as the ball hole between the levels of the opening gate, the air hole, and the lasting relationship between the hole and the elevator room or pulley. At this time, there are four fires, elevators, which often become the transmission channels of fires, which easily endanger the facilities of elevator machine room. Therefore, it is necessary to set fire detectors in the elevator machine room, and it is also suitable for Huang Guan to set fire detectors in the elevator shaft.
2. Manual fire alarm button setting
(including the smoke-proof stairwell in front. Smoke-proof stairwells are used in front rooms of floors, fire elevators and rooms in front of fire elevators. ) is a button, when there is a fire, people should call the police immediately to save the target and prevent the fire, and set up a manual fire alarm in the preferred position. In addition, a fire prevention manual should be set up in the room, and there is an alarm button in front of the elevator.
In public places (including halls, auditoriums, restaurants, multi-function halls, etc.). ) and the main channel, which is a very centralized, mainly decentralized channel for all staff. So you should call the police immediately and set up artificial fire fighting in the main passages of these public places; The manual specifies the alarm buttons of the main passage in fire, so as to ensure that the nearest alarm button of manual fire alarm is not more than 30 meters away from any position in the fire zone. "
Third, set up a fire emergency broadcast horn.
The staff in public places such as walkways, halls and restaurants are very concentrated, mainly in scattered passages. Therefore, fire emergency broadcast loudspeakers should be set in these public places according to "the nearest loudspeaker distance at any position in the fire zone is not more than 25m" and "the loudspeaker distance at the end of the aisle is not more than 12.5m". The next step should be to set up emergency speakers for fire fighting in public toilets.
The first room (including the front smoke prevention hall, the front staircase room, the fire elevator room and the front staircase room used by the fire elevator to prevent the smoke) is for people to evacuate and put out the fire in case of fire, and there are sounds of partitions and fire doors, which makes people confused and noisy. Therefore, a fire emergency broadcast horn should be set up. Fire emergency broadcast horn should also be set in front of the elevator room. Stairs in scattered halls have also been scattered by people in case of fire to save targets and prevent fires, which is also the confusion of people's voices and noises. Therefore, we should set up a fire emergency broadcast horn and advocate fire emergency broadcast to disperse instructions.
Fourth, establish a fire alarm device.
In order to establish an automatic fire alarm system for fire emergency broadcasting, the author thinks that a fire alarm device should also be set up, but its control program should be: after the fire alarm is confirmed, the alarm will be transmitted in the fire-related area by manual or automatic control, and the alarm will stop working time, so as to quickly contact the fire emergency broadcasting and TV programs and disperse personnel instructions.
The position of the fire alarm device is the button that should alarm. The manual fire alarm is the same, and its wall installation should be 1.8 meters off the ground.
Fifth, set up a dedicated fire telephone.
To install the special extension telephone, it is necessary to set up a computer room, which also involves some people who often control the fire in the workplace (including fire water supply equipment, spare parts generator room, match substation, main ventilation and air conditioning room, smoke exhaust wheel room, fire elevator room, etc.), the control room of fire control system business premises or equipment, the observation room of fire responsible personnel, on-site safety management and other public places. The fire elevator and ordinary elevator in the drive-in cinema should bear all the special telephones used. Please ensure that the elevator machine room and elevator car hall, elevator machine room and fire control room, elevator car hall square and fire control room are reliable communication telephone systems. Generally in the fire control room; Establish elevator monitoring demonstration board (including position indicator, display direction light, telephone, fault light, etc.). ), in order to carry out the necessary elevator monitoring and emergency control in the running state.
Equipped with buttons such as manual fire alarm position and fire hydrant button, and special telephone socket for fire control should be installed.
Third, fire linkage.
First, the fire linkage control should include the control of the start and stop of the fire pump, and should also display the button, the position of the pump and the work and failure of the fire pump. When the fire hydrant is equipped with a fire hydrant button, the effective working mode of the fire pump should also be displayed on the electrical installation site (that is, the working light of the fire pump should be established).
Second, the fire linkage control should include controlling the start and stop of automatic sprinkler system and water atomization fire extinguishing system, and should also display the working mode of fire pump, fault and smooth display, the positive position of alarm valve and safety signal valve. In addition, the water level of the water tank in the basin should be monitored through demonstration. In order to prevent the maintenance signal valve from closing, the author thinks that the signal valve should be controlled by live signal to prove its opening condition.
Thirdly, other control and demonstration functions of fire linkage control should be specified in this standard and relevant national standards.
Fourthly, the wiring of automatic fire alarm system.
In order to prevent the fire fighting, communication and warning line from being lifted when a fire breaks out, the fire fighting work cannot be carried out, resulting in greater economic losses, and also to suppress the influence of electromagnetic interference (such as transformers, motors, cables, etc.). ), the automatic fire alarm system is produced. The transmission lines, fire fighting, communication and early warning lines of the automatic fire alarm system shall be flame retardant cables, and shall be protected by metal pipes or closed metal trunking. Fire-fighting manual active director installation group should use fire-proof cables, and their cables should also be protected by metal pipes or closed metal trunking. When using open application, metal pipes or sealing metals with fire prevention measures should be adopted. Relay. Fifth, the conclusion.
Based on the specific project implementation experience, the author expounds the design basis, automatic fire alarm design and practical problems, so as to put forward some superficial views on the system equipment setting, fire control linkage control and its wiring. The purpose is to improve the design quality of automatic fire alarm system, find it as early as possible, and notify fire control, prevent and reduce fire hazards, and protect personal and property safety.