【 Weak current College 】 fire engineering construction, debugging is worth discussing issues---Power By 【 China power house network 】

Preface: in long been engaged in fire protection engineering construction and commissioning experience, with the architectural design of the new ideas and new technology of fire development in domestic and international fire sector advocacy performance-based fire protection technology of today, we believe that the fire engineering construction, testing should also be integrated into the scientific concepts, to abandon the current blind or Office way reproduced in construction and debugging process, the classic way of "Office" and "performance" science. To do this, put us in fire protection engineering they encountered in some of the issues to discuss and publish our views and our colleagues in the fire service to the cause of the fire in our country and make due contributions. 1. fire alarm system of wire and pipe laying problem
In fire protection engineering, distribution pipeline construction is the automatic fire alarm system engineering of the largest, most demanding a work, and broad, in order to guarantee system good running performance, must be scientific and reasonable.
In automatic fire alarm system design specifications, the transmission line cabling requirements stipulated: "should be used in metal tubes, flame treatment of hard plastic or closed Groove protection for wiring. "That is, wire and tube do not have to use a metal pipe. It's only considered to protect wire from mechanical damage, as well as fire-retardant, moisture, etc., but ignored the conduit should also have the shield and venting of strong electric, leakage, electrostatic and electromagnetic interference. So in the current construction, although using a metal wire and tube, pipe junction, takes plastic junction box, even with metal terminal box, the junction box interface Department does not lock the mother to join and retaining mouth protection, 2 wire tube junction or Groove junction not connected with a conductor, the pipeline does not form a whole. This construction method and wiring, and even access alarm controller entrance ground, also due to lightning and the role of resistance to electromagnetic interference, in the event of lightning or strong electric circuit leakage, wire and tube cannot effectively shielding and ground discharge will inevitably result in equipment damage or failure, particularly in the explosion protection area, this wiring methods will leave the severe consequences of risk. Work to ensure system reliability, into the fire control centre of metal wire and hose, cable shield must and controller enclosure joins, and to guarantee reliable earthing and grounding resistance must meet the fire code requirements. At the same time, in the construction of the terminal box must use metal terminal box, wire and tube into the box, outer side should set metal lock to be tube locking, junction box inside mouth guard should be installed. If using a metal wire wiring, online slot junction application of u-shaped galvanized metal trough, metal screws on either side. In short, the need to ensure that all metal pipe, in order to play the Unicom shield and venting of strong electric function. The average annual number of days in Shanghai is about 50 days of thunderstorm, fall within the area of thunderstorms, lightning burn alarm controller event occurred from time to time, this is a fire protection engineering construction company worthy of attention.
II. the automatic fire alarm system signal line selection problems
In the specification, only on automatic fire alarm system of the transmission lines of core minimum cross-sectional area, and on the wire line does not expressly require that equipment manufacturers on their products using wire specifications only recommendation made, such as a brand product design manual, the signal line "recommended BVR-twisted pair, ordinary parallel rows". A brand production factory on alarm bus "recommended ZBN-BV line." As guideline for confusing in fire protection engineering construction, selection of wire only consider flame requirements, as long as the price is cheap, convenient construction string line, resulting in the selection of the signal wire of arbitrariness, blindness, and some will use a single root (BV) copper conductors.
As the fire alarm the extensive application of advanced technology, intelligent fire alarm controller has access to extensive use, signal transmission been switch quantity into digital, the digital communication in bus transport (a bus for bus alarm), the requirements of second-line capacitance between the smaller the better. If a capacitance is, to transport the more serious the waveform distortion occurs, increase the probability of false positives occur, the system has an adverse impact on reliability. By the relevant departments of the test, the digital communication transmission wave in two parallel transmission of wire, its distortion-distortion 300m extent equivalent of twisted pair wires for distance 1000m. Therefore, in automatic fire alarm system construction, communication bus, detector alarm signal bus should use twisted pair copper wire with multiple corn. Particularly in large fire protection engineering, from centralized control machine and multiple alarm controller connected to a network, made up of multiple priority token ring no primary network or local area network, engineering and construction units on the signal lines of selection cannot be arbitrary, must meet the technical requirements to ensure system stability and reliability of work. 3. with regard to fire shutter of linkage problem
Fire shutter movement is determined by the fire alarm controller and linkage control equipment, design specification for the fire and the construction of the acceptance, on the fire prevention Division, evacuation channel Department of fire shutter action requests. However, the detector to provide signal, how to prepare the linkage program, this is the fire engineering common problem encountered. Due to the understanding of the specification, in the preparation of fire shutter linkage program, simply fire shutter nearby or both sides with smoke, temperature detector as an alarm signal, therefore, only after the action when these detectors, fire shutter only linkage. In this way, you lose the best fire prevention Division, in particular the closing time for the fire shutter Atrium, this control pattern, greatly undermined their fire safety features. Fire shutter correct linkage works, its action principles should be:
1. used for fire prevention Division of fire shutter, fire zones of fire detectors at any location confirmation after fire, all fire curtain should all fallen to the Earth.
2. for evacuation channels or the first floor of fire curtain, you must ensure that fire prevention Division and the evacuation of the function, the second step down respectively by the smoke, temperature detector control. Fire in any place of smoke detectors, fire shutter achieve first step down. Temperature detector installation location should be based on the actual situation of the evacuation channel on-site, in fire zones and evacuation channels from shutter certain distance are installed to a certain number of temperature detector, control the shutter of the second step in the action, can play an effectiveFunction.
In short, the control of fire shutter detectors, in particular temperature detector installation location, should be based on the nature and situation of buildings, jumped classic Office construction concept, introduced in the way of performance-based design concepts so that fire shutter play function. 4. elevator landing linkage problem "automatic fire alarm system design specifications" in: fire control rooms in confirmation after fire, should be able to control all of the stops on the first elevator, and receive their feedback signal. Also in the acceptance, after confirmation when the fire, the fire in all elevators should force the landing of the first floor. However, how to control how to control has not expressly, and this is also the encounter in fire protection engineering construction. In the current fire protection engineering, accustomed to using alarm area any second smoke detector signals as linkage instruction (commonly known as the second point linkage), this approach is confirmed by the fire did not correctly understand the concept. Confirm that the concept, generally refers to the artificial confirmation (also available TV monitor), or two or more after the confirmation of the detector, with two of the same type of detector (in most places is smoke) signal as confirmation is not in line with regulatory requirements. In addition, with the second smoke action signal as elevator landing of linkage directive will cause malfunction, particularly in rooms such as smoking or easy to produce smog smoke detectors, places greater potential for false positives, and the elevator is personnel safety lifting of important tools, in the absence of fire, if the elevator because of smoke detector false positives but suddenly forced landing, but will result in personal injury (which has happened), therefore, on the elevator landing is worth discussing. According to design specifications, the following recommendations:
1. take the elevator control device (or a wired remote control) is set to fire in wired, confirm that the fire, the watch personnel manual lift landing.
2. If the use of automatic control, available in front of the room and elevator leading to the elevator channel within the detector signal as linkage, confirm the automatic landing after fire. 5. with regard to the non-fire-fighting power of cutting issues in the design specification and acceptance of the principle of "cutting off the non-fire power" requirements, provides for the "fire control rooms in confirmation after fire, should be able to cut off the parts of the non-fire power, ...". This is fire construction and debugging of problems they encountered in that way, when the construction of wiring, wiring, and also how to consider is how to determine the working interface. Non-fire power including air conditioning, water pump, normal elevator, escalator and lighting power supply, etc. Especially for lighting power supply cut off is worth discussing, in large supermarkets, personnel are crowded places, if not installed emergency lighting power supply (EPS), because false positives as well as human as the detector operation manual alarm button, so that the fire alarm linkage controller actions, automatically cut off lighting power supply will cause panic, confusion and personal injury. Due to various architectural, conditions vary greatly, so cut off the non-fire power linkage function of the construction program and linkage methods, should be based on the nature of the building, use the function of different and differently, if you use the classic way to handle fire concept, the fire will not reach the practical requirements. 6. with regard to the fire hydrant system boot issues are universal use and effective means of fire fighting, fire pumps and ensure fire water key equipment, when the fire quickly start the fire pump and fire hydrant boxes of extinguishing fire hose. This is the fire water system construction and debugging must be the quality and quantity completed an important component. During construction, fire hydrant system encountered mainly to temporary high pressure system located in the fire box within the cycle pump button starts the fire pumps, fire protection control center or by joint control cabinet artificial starts fire pump. In the design of the description or the tender documents, often made of linkage function requirements, rather than direct cycle pump's functional requirements. Therefore during construction, the general practice is implemented through linkage module cycle pump function in the debug or fire detection, automatic fire alarm controller located in automated files can only be achieved within the fire box Kai Kai pump button function, in peacetime, many organizations are often the alarm controller located in manual transmission, so when the fire is out of control and fight the best time of the initial fire. The current domestic production of fire alarm controller almost no press "GB-16806-1997" configure a direct output contact. National Fire electronic product quality supervision Center for direct output contacts have clearly defined: "export contacts directly on the action button should not fire control equipment is not normal and lose their function," and provides for direct output contact of the test method and requirements. Shanghai Municipal Fire Department issuing the Shanghai building fire facilities commissioning technology requirements "in the indoor hydrant system there is one stipulation:" start the fire hydrant box remote reboot the pump button or the system pressure is lower than the set value, the main pump operation and stable pressure ". This is to guarantee the correct and timely Kai pump, due to the automatic fire alarm system linkage control cabinet is essentially bus system linkage type product, according to China's national conditions, and the user's current management and usage levels, to remote reboot control line of the pump button, direct access to the pump control cabinet start loop, and water pump installed on total outlet pressure switches, electrical contacts and then halt boot loop join, depending on the system design of work pressure requirements set starting pressure value, the realization of the water pressure control linkage control function, in order to ensure the normal operation of the fire hydrant system. VII. stable high-pressure system regulators pumps restart/shutdown pressure setting of automatic sprinkler system is generally use fixed automatic fire extinguishing system, and also the world's most efficient and cheapest 24/7 automatic fire extinguishing system. According to the statistics show that the success rate of more than 96% of the fire, the casualties and property loss reduction rate 1/2 above. Voltage pump is in fire water supply system is used to stabilize the usual most unfavourable point pressure of pump, in stable high-pressure systems, and fire pump installed in the same water pump-room; the temporary high pressure water supply system, regulators pumps can also be installed on the roof. Water in fire protection engineering system design description, often only provide fire pumps, regulators pumps, flow rate, head, no voltage pump pressure requires reboot/shutdown. And fire protection engineering constructionEnterprises of construction and commissioning staff, on the fire water system working pressure and voltage pump function, the function does not make a specific analysis, and some had misunderstood. Therefore, when you debug the system opened, regulators pumps restart/shutdown pressure setting values appear arbitrary voltage pump start pressure value, lower than the system working pressure, there's a lot better than the pump pressure value is also high, this is the fire protection engineering and a common fault. While testing, acceptance unit, only attach importance to regulators pumps of restart/shutdown or reboot/shutdown interval time, ignore the restart/shutdown pressure value meets design and system functional requirements, it is necessary to pay attention. If the supply pressure, usually not maintained in the normal minimum pressure values (such as the most negative point the nozzle of the minimum working pressure is 0.05Mpa), when the fire, significantly reducing the effect of initial firefighting and will result in serious consequences. In the civil construction design specifications for fire-extinguishing system of the stable high-pressure fire water system, fire regulators pumps start-up pressure value, fire regulators pump stop pressure value and linkage fire pump start pressure value difference should not be .05mpa. United States NFPA20 specification requirements, regulators pumps of restart/shutdown pressure should be based on the system of work pressure and the fire pump pressure of agitation, be determined by the calculation, after the more stringent requirements. Although the specification on regulators pumps operating pressure not expressly provided for, but based on our extensive project experience in the practice of, voltage pump rated working pressure than the main pump, high 0.1 ~ 0.2Mpa its cycle pump pressure higher than the rated pressure, low pressure pump 0.05Mpa than the rated pressure high 0.05Mpa, this is more reasonable and practicable. In short, in the installation and commissioning of fire water system, regulators pumps of the restart/shutdown pressure set, do not blindly, I want to ensure that the system is in good working order, in the event of a fire when normal running, improving the efficiency of the fire. VIII. fire-extinguishing system controller installation location problem set gas extinguishing system of protected areas, often expensive equipment or critical places. In the "gas extinguishing system construction and acceptance", in the local development of various types of technical specifications for gas fire extinguishing systems, getting ready for the construction, pipeline and installation of fire-extinguishing agent storage containers, select the valve and collecting pipe installation, water pressure strength test, air tightness test, and debug, acceptance requirements, have detailed provisions, but not on fire alarm and fire extinguishing controller installation requirements. Therefore, in the construction process, especially some of the individual to protect small area, no network of gas fire suppression systems, fire extinguishing controller installation location, consider only from the easy installation, blindness, randomness. The installation in the basement, there is an installation within the storage bottles, installed in the protection zone of the aisle, for installation in the protection zone (usually unmanned), this non-canonical, is a gas fire extinguishing system construction of universal phenomenon.
Gas extinguishing controller, in receiving the signal fire detector and confirm that the action will be issued after the fire. Many builders are often the second probe of the same type (usually a second smoke detector) as a confirmation signal, if fire occurs false positives, since the controller installation in unattended, system error injection occurs, causing unnecessary losses, in addition, many units on the system of maintenance of the lack of professional and technical personnel, fire controller fails or discover the gas fire extinguishing system useless. In order to ensure that the gas fire extinguishing system is in a normal working condition, timely processing failures or fires, gas fire extinguishing controller should be installed in the fire control room or someone on duty. Acceptance and inspection in fire, should be strictly controlled to ensure gas fire extinguishing system is in good working condition, and in the event of a fire-fighting capabilities when you play in a timely manner. Reference documents:
1. GB50116-98 the automatic fire alarm system design specifications "
2. GB50263-97 the gas fire extinguishing system construction and acceptance of
3. GBJ16-87 the architectural design of the fire code
4. GB50045-95 tall buildings design fire protection standard "
5. automatic sprinkler system design manual
6. Shanghai City fire station the Shanghai building fire equipment debugging technical regulations
7. Weng lijian the automatic fire alarm system construction problems and solutions "