【 Weak current College 】 fire linkage in need clarification of

In order to fire occurs can achieve oneselk purpose, modern building set in a variety of fire-fighting facilities, such as: fire in the early detection of automatic fire alarm system, able to disperse smoke as soon as possible, give people an escape environmental smoke control system and positive pressure ventilation system to help people fight early fire water fire suppression system, which includes fire hydrant systems, automatic sprinkler systems and water spray systems, and most commonly used most convenient fire-fighting equipment, fire extinguisher, as well as setting-in key protected room or area of the fixed fire extinguishing systems (gas, foam, dry powder fire extinguishing system and so on), to prevent the spread of fire and smoke and fire doors, fire curtain, curtain and smoke vertical wall, in the fire emergency transportation of fire fighters and rescue personnel by the fire in the elevator, fire lighting power supply is cut off, illuminating the surrounding environment and guided ways of escape in case of emergency lighting and evacuation instructions, in addition to this, there is also a guide to an orderly evacuation of fire emergency broadcast system, to keep abreast of fire region fire dedicated phone, and help-social forces of 119 alarm calls, and so on. According to the nature of the building, the fire danger, evacuation and rescue difficulty, select set the above part or all of the fire-fighting facilities.


However, to make these fire facilities truly in fire occurs, maximize their effectiveness, truly achieve oneselk purposes, it is necessary to enable them at all stages of the fire accurately action, that is, we often speak of the fire.

In the years of fire prevention practice, found a lot of fire, including fire designers, fire inspectors, fire fighting supervisory staff and fire service personnel, or even fire equipment manufacturers of technical personnel in fire protection engineering design, construction, commissioning and acceptance of each link on the fire also exist many vague awareness and confusion of concepts, there is a need to be clarified, to the benefit of our future work.

1. inappropriate linkage time.

We all know that the fire development is its inherent characteristics and law, General civil architecture in A class of mostly (solid fuel) fire, and such fires are first generated a lot of smoke, with the burning intensifies, then produce a lot of heat. Therefore, countries in the formulation of standards would explicitly require a fire alarm, fire control equipment on smoke, smoke extraction facilities linkage: stop position of the ⒈ empty air supply, shut down the electric fire dampers, and receive their feedback signal; the relevant parts of the ⒉ start for smoke and exhaust fans, exhaust valve, etc., and receive their feedback signal; ⒊ control vertical wall, etc. smoke smoke facilities. (See "automatic fire alarm system design specifications" 6.3.9) this is because the air conditioning system for the development of high-impact, fire and smoke control equipment to prevent the spread of fire and evacuation.

Automatic fire alarm system in operation, due to environmental factors and the device itself anti-jamming performance, and so on, are inevitably occur in case of false alarms, fire alarm, you must have a fire confirmation process, after the fire to confirm that you want to cut off the parts of the ⒈ non-fire power, and receiving alarms and ⒉ ⒊ fire emergency lighting and evacuation signs lamp; all stop ⒋ controlled elevator on the first floor, and receive their feedback signal (see "specifications 6.3.1.8 and 6.3.1.9"). Obviously, alarm linkage to fall into the "alarm" and "after" this fire to confirm the two time periods.

However in practice, many people ignore the linkage of the concept of time, when the host alarm, you will be recognized should be in the fire before they occur, all of the content of linked, for example, would have been no fire, the false alarm (or malfunction or manually detector alarm button is pressed in error), the alarm will sound, and even the lighting power cut, the elevator landing to the first floor, the result is often resulted in a lot of unnecessary panic, affecting people's normal work and life, for unexpected panic sometimes cause great loss, especially in the personnel-intensive public places this potential danger. Therefore, master the correct response time is very important.

Second, not appropriate linkage.

Fire alarm and fire, the object should be coordinated in the specification of ranges is available on the site of "this" four-word boundaries, and not very specific, but in the practical application is based on linkage object functionality, in fire-fighting and evacuation procedure played a role, both to meet specifications, and truly serve to the facility in fire-fighting role should be played, not because it's actions cause a fire spread or other adverse effects to be determined and cannot be expanded at will.

The following classification in accordance with the system.

⒈ smoke control system: when alarm to turn on the alarm level and the exhaust valve pressure supply outlet valve and turn off the layer air duct fire valve, start the exhaust fan and positive-pressure blowers, stop the layer of air conditioning blowers, this was done to prevent fire spreading (stop air conditioning, fire valves) and evacuation (smoke, air). But for a long time, many people are not in accordance with the scope for joint action, but rather in accordance with the "rolling layer" linkage methods, like alarms and fire emergency broadcast of linkage in the same manner as that fire its lower level together. Doing so can easily lead to fire along the duct to the adjacent layer diffusion, it is not advisable;

⒉ water fire suppression system: the system in the fire protection system is relatively independent of location, for example, fire hydrant system of action is to require fire hydrant for fire protection design valve open, pressing the fire hydrant alarm cycle pump button, or fire control room press cycle pump button, or directly at the pump house, which Kai pump water fire extinguishing. The automatic sprinkler system startup almost no human intervention, it is against the fires hot smoke makes on the sprinkler glass bulb fixed boiling point of liquid glass bubble bursting of boiling, so that a certain pressure of the water in the pipe from the nozzle churning out, when the pressure in the pipeline, where the film down pipeline root wet alarm valve pressure switch in action, take advantage ofPressure switch action signals as Kai pump command, start spraying pump, to supply water pressure continued in order to ensure the fire-fighting water. Located in fire control room linkage controller pump start button, in order to prevent some due to equipment failure or system failure automatically restart pump failure, can not be timely to network within water remediation facilities.

To sum up, the action of water extinguishing systems and fire alarm system of an action are mutually independent. However in practice, some people have both linked together, or in alarm occurs, even when the host alarm to the water pump starts up, so that the pressure in water pipe network in the absence of pressure relief oral rise quickly, for the dilapidated pipe pressure failure or poor-quality system that can easily run water accidents, it is not necessary;

⒊ electric fire doors and fire shutter in "automatic" State closed or drop actions, only managed to install it on either side of the detector, which is in the "specification" 6.3.7 and 6.3.8 two provisions have already been very clearly. But some people feel free to expand the scope of its managed, the most common is any one of the region in fire detector action raises the fire doors or fire shutter is closed and downward, it is very dangerous, because in the burning area it was time to get out of it was put in there, the consequences can be imagined.

⒋ other, such as cutting off the non-fire power, the sound alarm devices, and so there was also free to expand the scope of the joint, causing widespread panic among the crowd, against organized orderly evacuation, as well.

Third, the "automatic" and "manual" conceptual confusion.

Specification mentioned on the fire control centre "automatic" to control facilities have the fire pump, smoke exhaust fan, fire doors, fire shutter automatically closes or declined, and in particular the fire pump, blower start not only automatic control, you should be able to manually direct control, evacuation channels on both sides of the fire shutter should be set manually control button, this is because these facilities to fight early fire, prevent the spread of fire, evacuation has a crucial role. Other such as alarms and fire emergency broadcast of "rolling layer" connected, Elevator landing, non-fire-fighting power of removal, fire valves close, exhaust valve air valve open, uniform supply of emergency lighting, evacuation instructions on, and so on fire facilities only requires a control function, did not mention the word "automatically", at the same time, building sets of fixed fire-extinguishing systems: gas fire extinguishing systems, foam extinguishing systems and fire extinguishing system control, it provides only the latter two (foam and dry chemical extinguishing systems) with start-stop function rather than automatically, for pipeline gas extinguishing system specification is not required in the control center control its commitment, the only requirement to display the system manually or automatically for operation, monitoring system alerts, injection phases of feedback signal, only requests in delay phase automatically shut off the fire doors and Windows, fire dampers, stop ventilation and air-conditioning system (see "specifications" 6.3.4, 6.3.5 and 6.3.6).

Unfortunately, in practice, some people do not go to the research specifications "is like" is the intention, but is not an indiscriminate, all specifications asked to request control of objects, both to add automatic features, for example, the sound alarm devices, would have to fire upon confirmation by the control centre press "scroll layer" linkage of manual issued is very reliable, but also with automatic features, host an alarm alerts automatically, and some want to allow automatic more "reliable" some, or put the alarm device and manual alarm button linkage, or Manual alarm button plus a probe or with two or more simultaneous actions linked with photodetector, Elevator landing and non-removal of fire power is also linked to these conditions, as stated earlier, is extremely easy to cause a lot of unnecessary panic.

Water extinguishing systems, fire hydrant system startup, is affected by the fire hydrant button, the control centre of the linkage controller on the Start button and the pumping of water pump control box on the restart button to control of the pump. These three conditions are phase "or" relationship, i.e. the system regardless of the installation where a cycle pump button is pressed, the fire hydrant pump should start, but these actions are implemented, there is no automatic manually, usually in water pumping station control cabinet status switch often marked with a "manual" and "automatic", "manual" refers to the "in-place start" and "automatic" refers to the start of the "remote control". In the automatic sprinkler system, the pump room spray pump control cabinet of "manual" and "automatic" status switch on "manual" refers to the "in-place start" and "automatic" refers to the control center to manually restart the pump or wet alarm valve pressure switch action linkage kai, and the entire pump spray system, the "automatic" refers to the pressure switch to manually start the linkage, "" refers to the control centre of the remote control to start. These concepts must ascertain the straightened out.

For pipeline gas fire extinguishing systems, fire extinguishing gas release must be signed by people to make a fire scene. Automatic status confirmation of fire, is a device to confirm that the general practice is two sets of detector beep at the same time, it is a fire starting signal. When the first group of detector beep, watchkeeping personnel should be immediately to the scene to scene of artificial confirmation in deciding whether to start the fixed fire extinguishing systems. Although the design is both automatic and manual start, should someone on duty to manual startup. Therefore, in the control center only display system manual and automatic operation, the monitoring system alerts, injection phases of feedback signal, the linkage to other objects such as fire protection doors and Windows, air conditioning and fire safety valve to control, and does not have to control fire-fighting system of emergency boot, this is to ensure the system is secure and accurate and reliable.

However, many systems still starts the control button located in the control center, which was likely to miss the eruption of the risk.

In addition, the sides of the fire curtain must install manual control button, and you want to manually first. A system to control the shutter detector action, its descent instruction cannot be removed, so that the manual control button losesRole, the priority is not guaranteed to do so manually, it is possible to put people off in the fire area is very dangerous.

4. linkage function implementation.

In how to implement a linkage function, there are a lot of fuzzy knowledge, we cite here a few examples.

⒈ Tuyere valve open.

In the system alarm to turn on the alarm level exhaust valve and positive pressure air valve and turn off the layer air duct fire valve. Building area, set the number of air inlet valve is also different in large buildings, some with as many as a dozen, this occurs is "both" or "order," open issues, whether what is open, depending on your system. General mechanical valves open, by the action of DC solenoid valve, release spring tension, valve plate rotation of 90 degrees. And solenoid action current generally 0.7A above, multiple valve while connected, you will be instantly to power a big load, if somewhat less power quality, the solenoid valve will be not enough current to the action. We did an experiment: use standard called 24V3A of regulated power supply to the 4 solenoid power supply, the power of instantaneous power supply voltage is pulled down to 15 Volts, air one to open it. To add the order to open with, and the problem is resolved. Order to open the connection is opened the first valve, valve plate rotation of 90 degrees, fixed in its hinge on cam oppression micro switch, through to the second power outlet, so one by one, in order to open with, and for power, a moment of maximum load of only one solenoid action current, it will not cause overload, but it also requires each outlet opened must be in place, otherwise, would leave because of a power not threaded, not all open, this requires the strengthening of maintenance, prevent mechanical failure fault caused the linkage.

⒉ is placed at the entrance of the exhaust fan smoke fire dampers in peacetime must be open in order to ensure the early stage of fire smoke smooth discharge, when the fire continues to develop, exhaust fumes into the fire, this requires action to stop smoke to prevent fire spread along the duct, so called smoke fire dampers. And close the valve movement is controled by 280 ° c (280 ° c in the alloy melting temperature reaches the fuse is fuse, freeing the spring tension in advance, so that the valve plate rotates 90 degrees) closed by its linkage to fan stop feedback signal back to the control center, these linkage action all is done automatically, without human control, some people put the orifice of the closed control also in fire Centre plus the control button, this practice is very harmful, because doing so would undoubtedly increase the probability of false operation is extremely.

⒊ on fire pump start button "direct cycle pump".

Standard for fire pump on provisions ", smoke and exhaust blower control device when using the bus coding module control, it should also be in fire control room settings manually direct control devices" and we put the system settings in the fire box also considered direct fire hydrant button to cycle the pump button, Yes, but in practice, in order to be able to "direct cycle pump", from the Design Institute of plot on the adoption of a fire hydrant button in addition to connecting alarm bus, along with separate cloth directly leads to direct fire pump, and Kai pump line adopts the oldest direct control over 220 volts AC, that this is a direct cycle pump, but death is the direct control of AC!, in the system every hydrant button box has 220 VAC and 24 volt DC's lead at the same time there is such a dangerous thing, we actually work on the introduction of the AC experienced bus burned switchboard output Board and probe. Actually relevant national standards have been clearly stipulates the alarm linkage power should give priority to the use 24V DC power supply (the fire control equipment General technical conditions "of 4.1) so we should not hesitate to let direct cycle pump button control 24V DC, adopted at the end of the conversion methods (i.e. by Kai pump button control 24V DC relay, relay to control AC startup action current is switched on), so the risks of mixing with AC unlock, wiring through tubes are the same voltage level, eliminating the separate piping and wiring of the waste.

⒋ spray pump consists of a pressure switch Kai pump, at the same time, the signal sent to the control center, the pressure switch is only one contact person, has no choice but to switch signal through the module access bus, in the alarm linkage spraying pump within the programming cycle pump, which was around the corner "," near virtually pressure switch with a 24V DC relay for pressure switch-contact control their actions, the use of two groups of passive relay contact: a set of control pump start, another group by module access bus trip signal will be fed into the telephone exchange.

⒌ fire doors, fire shutter closes, Elevator landing action is completed to remove linked directives. This is in practice a lot of people to ignore it, as we've talked about is very dangerous. The correct approach is: in programming, when set on fire curtain sides of two groups of actions, at the same time the detector control fire curtain dropped, when the phone receives a shutter reach minimum position feedback signal, that is, the removal of the decline in orders, with this in mind, when programming should not be ignored.

6. emergency lighting and emergency evacuation led which should be connected to the power supply?

Emergency lighting and emergency evacuation led is on fire after confirmation, cut off power to the rear lights for lighting, and when we use a self-contained electric luminaires, light conditions is AC once cut off automatically, so it must be received in the lighting circuit, in order to achieve the correct action. However many people do not pay attention to the adoption of emergency lamp, in accordance with the fire-fighting facilities will consist of fire power, and fire power in fire after confirmation is not cut off, as a result, lighting power supply was cut off, and emergency lights on fire because of received power but not light, not the purpose of the emergency lighting. Of course, if theUse the unified power, unified control of emergency lamp, it must receive fire power, to cut off the lighting power control emergency lamp is lit.