Discussion on the application of fire emergency lamps in buildings

Source: China Security World Network

Fire emergency lighting is an important part of building fire protection components and accessories, including fire emergency lighting and fire emergency sign lights, also known as fire emergency lighting and evacuation indication signs. Its main function is to ensure the safe evacuation of personnel, the persistence of work at special posts and fire fighting and rescue operations when the normal lighting system can no longer provide lighting in case of fire. The basic requirement is that people in the building can easily identify the location of the emergency exit and the specified evacuation route with the help of a certain illuminance regardless of any public part.

A large number of fire cases show that due to the unreasonable setting of safety evacuation facilities or poor evacuation in public buildings, personnel can not correctly find or identify the location of the emergency exit in the fire, which is one of the main causes of mass death and injury fire accidents. Therefore, we should attach great importance to whether the fire emergency lamps can play their due role in fire. Combined with the practice of many years of work and according to the relevant provisions of the code for fire protection design of buildings (GB50016-2006) (hereinafter referred to as the construction code), the author talks about his own views on the application of fire emergency lamps in buildings.

1、 Setting range of fire emergency lamps.

Article 11.3.1 of the construction regulations stipulates that the following parts of civil buildings, factories and class C warehouses except residential buildings shall be equipped with fire emergency lighting lamps:

1. Enclosed staircase, smoke proof staircase and its front room, front room of fire elevator room or shared front room;
2. Fire control room, fire pump room, self provided generator room, power distribution room, smoke control and smoke exhaust room and other rooms that still need to work normally in case of fire;
3. Auditorium, exhibition hall, business hall, multi-function hall and restaurant with a construction area of more than 400m2, and studio with a construction area of more than 200m2;
4. Underground and semi underground buildings or public activity rooms in basements and semi basements with a construction area of more than 300m2;
5. Evacuation walkways in public buildings.

Article 11.3.4 of the construction regulations stipulates that public buildings, high-rise plants (warehouses) and class A, B and C plants shall be equipped with light evacuation indication signs along the evacuation walkways and emergency exits and directly above the evacuation doors in densely populated places.

Article 11.3.5 of the construction regulations stipulates that the following buildings or places shall be provided with light evacuation indication signs or light storage evacuation indication signs that can maintain visual continuity on the ground of evacuation walkways and main evacuation routes:

1. Exhibition buildings with a total construction area of more than 8000m2;
2. Aboveground shops with a total construction area of more than 5000m2;
3. Underground and semi underground shops with a total construction area of more than 500m2;
4. Song and dance entertainment, screening and entertainment venues;
5. Cinemas and theatres with more than 1500 seats and gymnasiums, auditoriums or auditoriums with more than 3000 seats.

The building code lists the setting of fire emergency lamps as a separate chapter for comprehensive specification. Compared with the original code for fire protection design of buildings (gbj16-87), it significantly expands the setting scope of fire emergency lamps and highlights the mandatory setting of fire emergency marker lamps. For example, it is stipulated that fire emergency lamps should be set in the specified parts of ordinary civil buildings (except residential buildings) and plant (warehouse), public buildings, high-rise plant (warehouse) Except for class D and E, the evacuation walkways, emergency exits, evacuation doors and other parts of the plant shall be set with light evacuation indication signs, and the buildings with a certain scale such as public buildings, underground (semi underground) shops and song and dance entertainment and entertainment projection places shall be added with ground light or light storage evacuation indication signs.

However, at present, many design units do not understand the specification enough, implement the standard laxly, and reduce the standard design without authorization. They often only pay attention to the design of fire emergency lamps in densely populated places and large public buildings. For multi-storey industrial plants (warehouses) and ordinary public buildings, the fire emergency lamps are not designed, especially for the addition of ground lights or light storage evacuation indication signs, which can not be strictly implemented. They think it doesn't matter whether they are set or not. When reviewing the fire protection design, the construction and review personnel of some fire protection supervision institutions failed to strictly control due to the misunderstanding in understanding and the difference in understanding of the specification, resulting in the failure or inadequate setting of fire emergency lamps in many projects, resulting in the "congenital" fire hidden danger of the project.

Therefore, the design unit and fire supervision organization should attach great importance to the design of fire emergency lamps, organize personnel to strengthen the study and understanding of the specifications, strengthen the publicity and implementation of the specifications, and improve the theoretical level. Only when the design is in place and the audit is strictly controlled can we ensure that the fire emergency lamps play their due role in the fire.

2、 Power supply mode of fire emergency lamps.
Article 11.1.4 of the construction regulations stipulates that * * power supply circuit shall be adopted for fire-fighting electrical equipment. When production and domestic electricity are cut off, fire-fighting electricity shall still be guaranteed.

At present, fire emergency lamps generally adopt two power supply modes: one is the independent control type with its own power supply. That is, the normal power supply is connected from the ordinary 220V lighting power supply circuit, and the emergency lamp battery is charged at ordinary times.

When the normal power supply is cut off, the standby power supply (battery) will supply power automatically. This kind of lamp has the advantages of small investment and convenient installation; The other is centralized power supply and centralized control type. That is, there is no independent power supply in the emergency lamps. When the normal lighting power supply is cut off, it will be powered by the centralized power supply system. This kind of lamp is convenient for centralized management and has good system reliability. When selecting the power supply mode of emergency lighting lamps, it shall be reasonably selected according to the specific situation.

Generally speaking, for small places and secondary decoration projects, the independent control type with its own power supply can be selected. For new projects or projects with fire control room, centralized power supply and centralized control type shall be selected as far as possible.

In the daily supervision and inspection, it is found that  is commonly used in self-contained power independent control fire emergency lamps. Each lamp in this form has a large number of electronic components such as voltage transformation, voltage stabilization, charging, inverter and battery. The battery needs to be charged and discharged when the emergency lamp is in use, maintenance and failure. For example, the common lighting and fire emergency lamps adopt the same circuit, so that the fire emergency lamps are often in the state of charge and discharge, It causes great loss to the battery, accelerates the scrapping of the emergency lamp battery, and seriously affects the service life of the lamp. During the inspection of some places, fire supervisors often found "habitual" fire-fighting violations that the emergency lighting system can not work normally, most of which are caused by the failure of power supply circuit for fire emergency lamps.

Therefore, when reviewing the electrical diagram, the fire supervision organization should pay great attention to whether the power supply circuit is adopted for the fire emergency lamps.

3、 Line laying and wire selection of fire emergency lamps.

Article 11.1.6 of the construction regulations stipulates that the distribution line of fire-fighting electrical equipment shall meet the needs of continuous power supply in case of fire, and its laying shall comply with the following provisions:

1. In case of concealed laying, it shall be laid through the pipe and in the non combustible structure, and the thickness of the protective layer shall not be less than 3cm. In case of open laying (including laying in the ceiling), it shall pass through metal pipe or closed metal trunking, and fire protection measures shall be taken;
2. When flame-retardant or fire-resistant cables are used, fire protection measures may not be taken for laying in cable wells and cable trenches;
3. When mineral insulated incombustible cables are used, they can be directly laid in the open;
4. It should be laid separately from other distribution lines; When laid in the same well trench, it should be arranged on both sides of the well trench respectively.

Fire emergency lamps are widely used in building layout, which basically involves all public parts of the building. If the pipeline is not laid in place, it is very easy to cause open circuit, short circuit and leakage of electrical lines in fire, which will not only make the emergency lamps play their due role, but also lead to other disasters and accidents. The emergency lamps with centralized power supply have higher requirements on the line, because the power supply of such emergency lamps is connected from the main line of the distribution board. As long as one part of the main line is damaged or the lamps are short circuited, all the emergency lamps on the whole line will be damaged.

In the fire inspection and acceptance of some projects, it is often found that when the lines of fire emergency lamps are concealed, the thickness of the protective layer can not meet the requirements, no fire prevention measures are taken when they are exposed, the wires use ordinary sheathed wires or aluminum core wires, and there is no pipe threading or closed metal trunking for protection. Even if the specified fire protection measures are taken, the hoses, junction boxes and connectors introduced into the lamps can not be effectively protected, or even exposed to the outside. Some fire emergency lamps are directly connected to the socket and the ordinary lighting lamp line behind the switch. These non-standard line laying and lamp installation methods are common in the decoration and reconstruction projects of some small public places, and the harm caused by them is also extremely bad.

Therefore, we should strictly abide by the relevant national specifications and regulations, strengthen the protection and wire selection of the distribution line of fire emergency lamps, strictly purchase and use products, wires and cables that meet the national standards, and do a good job in the fire protection of the distribution line.

4、 Efficacy and layout of fire emergency lamps.

Article 11.3.2 of the construction regulations stipulates that the illuminance of fire emergency lighting lamps in buildings shall meet the following requirements:
1. The ground low level illumination of evacuation walkway shall not be less than 0.5lx;
2. The ground low level illumination in densely populated places shall not be less than 1LX;
3. The ground low level illumination of the staircase shall not be less than 5lx;
4. The fire emergency lighting of fire control room, fire pump room, self provided generator room, power distribution room, smoke control and smoke exhaust room and other rooms that still need to work normally in case of fire shall still ensure the illumination of normal lighting.

Article 11.3.3 of the construction regulations stipulates that the fire emergency lamps should be set on the upper part of the wall, on the ceiling or on the top of the exit.

Article 11.3.4 of the construction regulations stipulates that the setting of light evacuation indication signs shall comply with the following provisions:
1. "Emergency exit" shall be used as an indication sign directly above the emergency exit and evacuation door;

2. The light evacuation indication signs set along the evacuation walkway shall be set on the wall below 1m from the ground at the evacuation walkway and its corner, and the spacing of light evacuation indication signs shall not be greater than 20m. For bag walkway, it shall not be greater than 10m, and in the corner area of walkway, it shall not be greater than 1m. The emergency sign lights set on the ground shall ensure continuous viewing angle and the spacing shall not be greater than 5m.

At present, the following five problems often appear in the efficiency and layout of fire emergency lamps: first, the fire emergency lamps should be set in relevant parts are not set; Second, the position of fire emergency lighting lamps is too low, the number is insufficient, and the illumination cannot meet the specification requirements; Third, the fire emergency sign lamps set at the evacuation walkway are not installed on the wall below 1m, the installation position is too high, and the spacing is too large, which exceeds the 20m spacing required by the specification, especially in the bag walkway and walkway corner area, the number of lamps is insufficient and the spacing is too large; Fourth, the fire emergency sign indicates the wrong direction and cannot correctly point to the evacuation direction; Fifth, the ground lighting or light storage evacuation indication signs should not be set, or although they are set, they can not ensure the visual continuity.

In order to avoid the existence of the above problems, the fire supervision organization must strengthen the supervision and inspection of the construction site, find problems in time and stop illegal construction. At the same time, it is necessary to strictly check the acceptance to ensure that the efficacy of fire emergency lamps meets the standard and are arranged in place.

5、 Product quality of fire emergency lamps.
In 2007, the province conducted supervision and random inspection on fire-fighting products. A total of 19 batches of fire-fighting emergency lighting products were selected, and only 4 batches of products were qualified, and the sampling qualified rate was only 21%. The spot check results show that the fire emergency lighting products mainly have the following problems: first, the use of batteries does not meet the standard requirements. For example: lead-acid battery, three no batteries or inconsistent with the certification inspection battery; Second, the battery capacity is low and the emergency time is not up to standard; Third, the over discharge and over charge protection circuits do not play their due role. This is mainly because some manufacturers modify the circuits of finalized products without permission in order to reduce costs, and simplify or do not set over discharge and over charge protection circuits; Fourth, the surface brightness in emergency state can not meet the standard requirements, the brightness is uneven, and the gap is too large.

The national standards fire safety signs gb13495 and fire emergency lamps GB17945 have made clear provisions on the technical parameters, component performance, specifications and models of fire emergency lamps. At present, some of the fire emergency lamps produced and sold on the market do not meet the market access requirements and have not obtained the corresponding national type inspection report. Some products do not meet the standards in terms of product consistency and some products fail to pass the performance test. Some illegal producers, sellers and even fake inspection reports produce and sell fake and shoddy products or shoddy products, seriously disrupting the fire product market.

Therefore, the fire supervision organization shall, in accordance with the relevant provisions of the fire protection law and the product quality law, strengthen the supervision and random inspection of the product quality of fire emergency lamps, seriously investigate and deal with illegal production and sales behaviors through market random inspection and on-site inspection, so as to purify the fire product market.