【 Weak current College 】 on fire systems engineering approach to the problem of fire

In order to improve the fire safety of building works to ensure that buildings in fire occurs can achieve oneselk purposes, depending on the nature of the building, the fire danger, evacuation and rescue such factors as the degree of difficulty, in modern architecture set better automatic fire-fighting facilities. However, how these fire-fighting facilities able to fire occurs to maximize its effect, really oneselk aims to implement the correct fire linkage is a very important link. This article will automatically fire facilities engineering fire linkage on the issues.

First, understand the automatic fire-fighting facilities of linkage time

Fire development have their inherent characteristics and laws, and general civil construction of fire are A class of (solid fuel) fire, and such fires are generally is to produce a lot of smoke, with the burning intensifies, then produce a lot of heat. Therefore, countries in the formulation of standards when building automatic fire-fighting facilities at a different time to the linkage of the automatic fire-fighting capabilities, alarm linkage is divided into the "alarm" and "fire confirmed" two time periods. "Fire alarm" is defined as a trigger action that alarm beep signal process. And whether there is a fire, you need to shift quickly and field staff contact, or distribution, or in person on the spot, be sure that this is confirmation of the "fire."

In practice, many units have ignored the linkage of the concept of time, when the fire alarm system host alarm, you will be recognized should be in the fire before they occur, all of the content in the fire alarm linkage afterwards. As a result, after the false alarm in the system (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 storey, improper operation, often resulted in a lot of unnecessary panic, affecting people's normal work and life. In setting up automatic fire-fighting facilities linkage time, automatic fire-fighting facilities need to fire alarm, automatic fire-fighting facilities implement linkage. Such as fire control equipment on smoke, smoke extraction facilities linkage, receiving the fire alarm, stop the relevant parts of the air conditioning, close the electric fire dampers, and receive their feedback signal; start the parts of the smoke and exhaust fans, exhaust valve, etc., and receive their feedback signal; control of vertical wall, etc. smoke smoke facilities. This is because the air conditioning system for the fire development impact, vulnerable to the spread of fires, smoke control equipment is very conducive to evacuate. While there are automatic fire-fighting facilities need to fire upon confirmation, the automatic fire-fighting facilities implement linkage. As part of non-cut off the power and reach of fire alarm and fire emergency lighting and evacuation signs lamp, control all stop at the first elevator, and receive their feedback signal. This is because the automatic fire alarm system in operation, due to environmental factors and the device itself anti-jamming performance, and other reasons, it is difficult to avoid false alarms, to prevent false alarms cause unnecessary losses or panic, on some automatic fire-fighting facilities of linkage, fire alarm, you must have a fire confirmation process.

Second, reasonable determination of automatic fire extinguishing facilities of linkage range

Fire alarm and fire upon confirmation, the scope of the object should be coordinated in the specification are used on the site, "" two words, not very specific. The "related sites" how to determine the linkage between objects, in fire-fighting and evacuation procedure played a role in identifying, achieving both meet specifications, and should make the facilities in the fire-fighting has played its role, while at the same time not because it's actions cause a fire or other adverse effects. That is, cannot expand, also cannot shrink.

At present, in particular the construction of the automatic fire-fighting facilities and the use of the process, there are many linkage scope inappropriate behavior. Some of the smoke extraction system, not in accordance with the provisions on the scope chain, but rather in accordance with the "rolling layer" linkage methods, like alarms and fire emergency broadcast in the same way as the linkage, received the alarm, the fire in its lower level actions together, exceeding the scope of application of the linkage, it is easy to result smoke along the duct to the adjacent layer. But the way its correct linkage should be opened when the alarm to the alarm of exhaust valve and positive pressure air 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 will help to prevent the spread of fire (stop air conditioning, fire valves) and evacuation (smoke, air).

For water fire extinguishing system, should include the fire hydrant system and automatic sprinkler systems, fire protection system is relatively independent of location. Fire hydrant system of action is in the 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. Automatic sprinkler systems with started almost no human intervention, it is dependent on the fire with the heat that placed the nozzle glass bulb fixed boiling point of liquid glass bulb for boiling, bursting, so that a certain pressure of the water in the pipe from the nozzle churning out, when the pressure inside the pipe network, where the film down pipeline root wet alarm valve pressure switch in action, take advantage of pressure switch action signals as Kai pump command, start spraying pump, to supply water pressure continued in to ensure that the fire-fighting water. Located in the 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. However in practice, some units both linkage, or in alarm occurs, even when the host alarm directly start pump, resulting in pressure inside the pipe network in the absence of pressure relief vents and rise quickly, especially for the dilapidated, drain valve failure or poor-quality pipeline system is apt to cause leakage phenomenon, running, so that the system is damaged.

In the electric fire doors and fire shutter as fireproofing of electric fire doors and fire shutter in "automatic" State closed or drop actions, in the automatic fire alarm system design specifications "-MingIndeed, it only managed to install it on either side of the detector. But in the actual construction process, 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, which results in the burning area could escape from the locked inside, causing loss of life.

In addition, automatic fire fighting system linkage in the range of off power to the non-fire, alarm device for ringing and so there was also free to expand the scope of the joint, causing widespread panic among the crowd, against organized orderly evacuation to the masses, is not conducive to automatic fire-fighting role.

3. accurately differentiate between the "automatic" and "manual" action object

Specification on some automatic fire-fighting facilities provided for the "automatic" and "manual" two operation modes, but in fact the operation of the fire-fighting is not absolute, others by eliminating control center equipment achieve linkage control, this is typical of the "auto," but some are remote control of the "auto," but its essence remains the "manual".

The fire control centre "automatic" control facilities have fire pumps, smoke exhaust fan, fire doors, fire shutter automatically closes or decline. Particularly stressed the fire pumps, fan start not only automatic control, you should be able to manually direct control, fire hydrant and air should be set manually control buttons to facilitate early fire fighting, fire prevention, evacuation for personnel. And alarms and fire emergency broadcast of "rolling layer" connected, Elevator landing, non-fire power cut, 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, on whether the "automatic" control, there is no clear requirement. At the same time, building sets of fixed fire extinguishing systems, such as 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 the "automatic"; 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, simply asked to delay phase automatically close Windows and doors, fire prevention, fire safety valve to stop ventilation and air-conditioning system. In practice, the "manual" and "automatic" use more confusion, some in the specification requires the Elimination of central control of the object, are hard to add automatic function. If the ringing alarm devices, would have to fire upon confirmation by the control centre press "scroll layer" linkage of manually issued is very reliable and the specific operations that artificially with automated features, host an alarm alerts automatically; even the alert device and manual alarm button linkage, or Manual alarm button plus a probe or with two or more simultaneous actions linked with photodetector; some put elevator landing and non-removal of fire power is also linked to these conditions up; this is 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, the pumping of water pump control box on the restart button to control the pump, the three start way relatively independent, installed in the system no matter where you either restart the pump button is pressed, the fire hydrant pump should start, but these operations are manually, there is no automatic; 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" also 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 cycle pump; the joint action on the entire 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.

For pipeline gas fire extinguishing systems, fire extinguishing gas release must be confirmed by the site to make fire. Automatic status confirmation of fire, is a device to confirm, usually at the same time the two sets of detector beep, can be thought of as fire starting signal. When the first group of detector beep, watchkeeping personnel should be immediately to the scene to scene of artificial confirm that decide whether to start the fixed fire extinguishing systems. Although designed with both automatic and manual start, but when someone on duty should be to manually start the way. Therefore, in the control center only display system for 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 fire shutter control settings, it must be installed manually on both sides of the control button, and you want to manually first. If the system control shutter detector action, its descent instruction cannot be removed, so that the manual control button useless, not guaranteed priority, so easy to manually create the fire region staff cannot withdraw from the scene in a timely manner.

Automatic fire extinguishing system linkage control is to ensure that the fire-fighting role played by the important link, its role played by good ring is directly related to fire fighting, evacuation of persons. We in the fire protection design, construction, supervision and inspection process, should be carefully according to the law of development of fire occurrence, in strict accordance with the specifications, rigorous and careful, meticulous checks, automatic fire-fighting facilities linked control reasonable and orderly, ensure that the building oneselk played the largest role.