With the rapid development of modern communication technology in China, the communication industry has become a significant symbol of the progress of modern society. As the hub of the communication center, the fire safety of large communication rooms and other places is also particularly important. If there is a fire accident, the communication network of the whole city may be paralyzed in an instant, which will bring great inconvenience to people's production and life, and the resulting social impact and property losses are immeasurable.
A, room gas fire extinguishing system, mainly including the equipment parts are:
Smoke sense, temperature sense, sound and light alarm, emergency start and stop, deflation indicator light, IO module, gas fire extinguishing controller, heptafluoropropane fire extinguishing device in cabinet.
2. What gas fire extinguishing system is the best for the computer room?
Heptafluoropropane (HFC-227ea/FM200) is a clean gas fire extinguishing agent, which has both chemical and physical fire extinguishing functions. Colorless, tasteless, low toxic, non-conductive, not polluting the protected object, and not causing damage to property and precision facilities; Can reliably extinguish class B and C fires and electrical fires with low extinguishing concentration; Small storage space, high critical temperature and low critical pressure, which can be liquefied and stored at room temperature; After release, it contains no particulate matter and oily residue, and has no destructive effect on the atmospheric ozone layer (ODP value is zero). The residence time in the atmosphere is 3 1~42 years, which meets the requirements of environmental protection.
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1, main equipment
The equipment of heptafluoropropane (FM200) gas fire extinguishing system can be divided into two parts, namely, chemical storage and spraying equipment, and alarm and control equipment. Drug storage and spraying equipment mainly includes heptafluoropropane (FM200) gas cylinder, gas cylinder fixing bracket, electromagnetic starter of bottle head valve, manual starter of bottle head valve, high-pressure hose, pneumatic hose and nozzle. The alarm and control equipment mainly includes the following contents: gas control panel, smoke fire detector, emergency start-stop button, alarm bell, buzzer and flash, gas release indicator light, pressure switch, etc.
2. The general situation and design of protected areas
This system is used to protect the information room on the second floor. According to the principle of economic rationality and optimized design, on the premise of ensuring the safety and reliability of system performance, the protected areas are divided as follows: * * Use a set of system: information room, with an area of 65m2, clear height h=3.5m, volume V= 140m3, and required heptafluoropropane (FM200) gas 165438. The cylinder chamber in this scheme is located on the second floor. The system uses nitrogen to convey under pressure, the pressure is 4.2MPa, and a certain concentration of FM200 fire extinguishing agent is sprayed within 7 seconds to make it evenly fill the whole protected area, and the soaking time is not less than 3 minutes to put out the fire in the protected area.
3. System design performance
1. Basic design parameters
(1) Related parameters of nature reserves
(2) The reserve is an independent closed space.
(3) The reserve is equipped with ventilation equipment.
(4) The design ambient temperature of the reserve is 20℃
(5) The altitude correction coefficient is 1. The minimum designed fire extinguishing concentration of heptafluoropropane (FM200) gas fire extinguishing system is 8% (at 20℃), and a certain concentration of FM200 fire extinguishing agent is sprayed within 7 seconds to make it evenly fill the whole protected area, and the immersion time is not less than 3 minutes.
(3), the requirements of the reserve:
(1) The reserve should be an independent area.
(2) The fire resistance limit of the enclosure structure and doors and windows of the reserve is not less than 0.5h, and the allowable pressure of the enclosure structure and doors and windows is not less than 1200Pa.
(3) Before spraying FM200, stop all the equipment that affects the fire extinguishing effect.
(4) Before spraying FM200 fire extinguishing agent, the ventilation system of the reserve should be closed. And set fire damper to close the vent.
(5) The door of the reserve should be opened outwards and can be closed by itself; Make sure it can be opened from the protected area under any circumstances.
(7) Requirements between gas cylinders
According to the requirements of domestic codes, the room (gas cylinder room) for storing gas cylinder groups should be an independent room, located outside each protected area, with an exit directly leading to the evacuation walkway and a closable door. The fire resistance rating between steel cylinders shall not be lower than Grade II, and the room temperature shall be-10℃ ~ 55℃. Ventilation devices should be installed between cylinders to keep them dry and ventilated. FM200 bottles should be protected from direct sunlight. Flammable, combustible and corrosive substances are not allowed to be stored in the bottle station, and shaking and impact are not allowed. The area between cylinders is about 8m2.
(8), system control mode
The control of gas fire extinguishing system should have three control modes: automatic control, electric manual control and manual operation of emergency manipulator. The operating procedures of three control modes of heptafluoropropane (FM200) gas fire extinguishing system are as follows:
A) Automatic control: the smoke detector is set in the protected area and divided into two independent alarm combinations. In case of fire, after any group of detectors give an alarm, the gas control panel will receive the fire alarm signal and display it. At the same time, the control panel will output the following linkage control signals: ring an alarm bell in the protected area to inform people to evacuate; Output the following linkage control signals: stop the ventilation equipment within the protection range and close the room; Close the fire damper of the vent in the protected area and close the room. Output the dry node alarm signal to the master control panel of the fire alarm system; At this point, the fire personnel on duty should immediately go to the scene to deal with and confirm the fire. When another group of detectors also alarm, the acousto-optic alarm signal appears again on the gas control panel, and this group of alarm signals is displayed. At the same time, the control panel outputs the following linkage control signals again: the alarm bell in the protected area stops ringing; Sound a buzzer and light a flash outside the protected area to warn all personnel not to enter the protected area until it is confirmed that the fire has been put out.
After a delay of 30 seconds, start the electromagnetic starter (electromagnetic valve) of the release valve on the heptafluoropropane (FM200) gas cylinder group and the area selection valve of the corresponding protection area through the control panel, and the heptafluoropropane (FM200) gas will be transported to the corresponding designated protection area along the pipeline and nozzle for fire extinguishing; Once the heptafluoropropane (FM200) gas is released, the pressure switch on the pipeline will send back the dry node signal that the drug has been released to the gas control panel and the general control panel of the fire alarm system. And light the gas release lamp in the protected area to warn all personnel not to enter the protected area until it is confirmed that the fire has been extinguished. When the control panel of heptafluoropropane (FM200) gas fire extinguishing system starts all the alarm bells, buzzers and flashlights, if it is found that the system is in the delay stage, or if there is a fire, only portable fire extinguishers and other mobile fire extinguishing equipment can be used to extinguish the fire, and the manual/automatic changeover switch on the gas control panel can be turned to the manual state (until the reset switch on the gas control panel is pressed), so that the system can temporarily stop releasing chemicals.
If it is necessary to continue to turn on the heptafluoropropane (FM200) gas fire extinguishing system, just put the manual/automatic changeover switch on the gas control cabinet in the automatic state. Gas release indicator light, buzzer and flashing light will be set above the door outside each entrance and exit in the protected area, and alarm bells will be set inside each entrance and exit. Similarly, an emergency start-stop button will be set outside each entrance and exit in the protected area, but the manual/automatic transfer switch of the system is only set on the air control cabinet.
B) Electrical manual control: that is, manual control by electrical means. After pressing the emergency start button, the system will start immediately, releasing heptafluoropropane (FM200) gas.
C) Emergency mechanical operation: Emergency operation is actually an all-mechanical operation without any power supply. Only when both automatic control and electric manual control fail, emergency operation is needed. At this time, the whole gas fire extinguishing system can be started by operating the mechanical hand starter on the heptafluoropropane (FM200) gas cylinder and the mechanical hand starter on the area selection valve, and at the same time, the dry node signal is output to the gas control panel, causing the following linkage: an audible and visual alarm signal appears on the control panel to show whether the pressure switch has acted; Ring buzzers and flashing lights inside and outside the protected area; Output the dry node blowout signal to the general control panel of the fire alarm system;
(9) Requirements of fire alarm system
Two smoke detectors should be installed in the protected area of heptafluoropropane (FM200) gas fire extinguishing system, which are connected in two different alarm combinations to ensure the secondary alarm requirements of the fire extinguishing system. Smoke detectors in the protected area should be arranged at intervals, and the protection area of each detector should be calculated as 50 ~ 60m2. There are raised floors, suspended ceilings and fire detectors in the reserve. In order to meet the requirements of linkage control between the heptafluoropropane (FM200) gas fire extinguishing system and the automatic fire alarm system, the automatic fire alarm system should be able to receive the heptafluoropropane (FM200) gas blowout action signal sent by the pressure switch and the detector first-class alarm signal and system fault signal sent by the gas control panel, that is, the fire alarm system should be equipped with modules that can send or receive the above signals near the gas control panel in the protected area.
(10) Overview of fire protection design scheme for computer room
In order to protect expensive electronic equipment and data resources, national standards stipulate that alarm and gas fire extinguishing systems must be used in a certain scale of computer rooms. With the progress of society and the increasing popularity of electronic equipment, various fire extinguishing agents have been launched. Due to the good environment of the computer room, there are not many special requirements for the alarm system. At present, all kinds of alarm systems are basically applicable. Computer is an important department of every enterprise and institution. Because of the special requirements of equipment and other related equipment for fire fighting, it is necessary to design a good fire fighting system for these important equipment, which is the key to the normal operation and protection of the equipment. It is forbidden to use water, foam and dry powder fire extinguishing agent in the fire fighting system of computer room, and gas fire extinguishing system should be used instead; The fire fighting system in the computer room should be a relatively independent system, but it must be linked with the fire fighting center. Generally speaking, in large and medium-sized computer rooms, in order to ensure safety, correctly grasp the abnormal state, and once a fire breaks out, it is necessary to install an automatic fire extinguishing system.
Traditional water, foam, dry powder and smoke systems are not suitable for fire fighting in computer rooms. It should be a non-conductive and non-corrosive gas fire extinguishing agent, which can evaporate quickly at room temperature without leaving evaporation residue. Gas fire extinguishing system is to store some gas compounds with fire extinguishing ability in high-pressure or low-temperature and low-pressure containers at room temperature, and release them to the fire area through automatic or manual control equipment when a fire occurs, so as to achieve the purpose of fire extinguishing. It has the advantages of cleanness, no stain, rapid fire extinguishing and so on, and is widely used in archives, electronic equipment rooms, expensive warehouses and so on. There are many kinds of gas fire fighting, but only halon (121,130 1), carbon dioxide and FM200 imported from abroad in recent years are widely used.
(2) Design process of gas fire extinguishing system
(1), according to the relevant design specifications, determine the room where gas fire extinguishing system is required, and select the type of gas fire extinguishing agent.
(2) Divide the protected area and the protected space, select the system form, and determine the location of the bottle storage room.
(3) According to the relevant design specifications, calculate the design consumption of fire extinguishing in the protected area and determine the number of storage bottles of fire extinguishing agent.
(4) Determine the layout of bottle groups in the bottle storage room and check whether the size of the bottle storage room is appropriate.
(5) Calculate the average flow of the main fire extinguishing agent conveying pipelines in the protected area, and preliminarily determine the diameter of the main pipeline and the number of nozzles.
(6) According to the actual spacing of the reserve, the nozzle and pipeline direction are evenly arranged, and the balance system is set as far as possible, and the pipe diameters of each section are preliminarily determined.
(7) According to the pipe network calculation method in the design specification, check and correct the pipe network layout and pipe diameter of each section until it meets the specification requirements, and determine the specifications of each nozzle.
(8), according to the design statistics system equipment materials. Comprehensively evaluate the design scheme and make optimization and adjustment when necessary.
(1 1), smoke exhaust system
The smoke produced by the fire is mainly carbon monoxide, which has a strong suffocating effect and poses a great threat to people's lives. The mortality rate of people can reach more than 50-70%. In other words, carbon monoxide is the chief culprit of casualties in the fire. In addition, the smoke from the fire blocked people's sight. People don't know the direction during evacuation, especially in high-rise buildings. Because of their own stack effect, the smoke rises very fast. If it is not eliminated in time and quickly, it will spread to all parts of the building quickly and vertically, and the harm is obvious. Therefore, the smoke control system should be operated immediately after the fire, and the smoke should be discharged as soon as possible. The computer room is a relatively closed environment. When gas injection occurs, it is not easy to eliminate the gas extinguishing agent. Installing smoke exhaust system is helpful to eliminate residual gas extinguishing agent.