Fire emergency lighting design research

Key words: fire emergency lighting; power supply; reliability; lighting; installation position control method; evacuation indication;

1 Introduction

At present, China has not issued special standards or specifications for fire emergency lighting design. The terms, terms, standards and practices prescribed by the existing regulations are not uniform, which will inevitably bring some confusion to the designers. The author has a deep understanding of this. Starting from the relevant specifications, combined with the situation encountered in the design, talk about some issues that should be paid attention to in the design of fire emergency lighting.

2, fire emergency lighting power supply building fire emergency lighting power load level should be the same as the building fire power load level, its power supply reliability requirements should also be consistent.

The fire emergency lighting of a type of high-rise building shall be powered according to the primary load requirement. The fire emergency lighting of the second-class high-rise building shall be powered according to the secondary load requirement, and an automatic switching device shall be set at the last-level distribution box. The time shall meet the requirements of Appendix C.3.1 of the “People's Regulations”. The following two examples are described in conjunction with the design.

(1) The emergency lighting of the fire pump room inside the building is a fire standby lighting. The continuous power supply time should meet the time requirement for the fire pump to work in the fire. GB 50016-2006 11.3.2.4 "Strong strip" requirements: "Fire emergency lighting of fire pump room, should still ensure the illumination of normal lighting", that is, the reliability of its power supply is the same as the fire equipment. If the lighting of the fire pump room is connected to the general lighting circuit, only the emergency light of the self-contained battery is used for the lamp, and the "continuous power supply time should not be less than 30 minutes", the requirements cannot be met, and the "strong bar" is violated. Because the working time of the fire pump is more than or equal to 2min in most cases, the standard for emergency lighting is generally specified as continuous power supply for 90min. If the continuous working time of the emergency light is changed to 120min, since the luminaire is a standard product, if the power supply time is increased, It is necessary to increase the volume and weight of the lamp to make a non-standard product, which is not convenient to operate, and thus is not the best choice. In the project without emergency lighting box, a small micro-break can be added to the fire pump distribution box to supply lighting.

(2) In the emergency lighting design of the diesel generator room, if the lighting power of the generator room is taken from the emergency lighting box of the power supply and the generator switching power supply, and the lamps adopt ordinary fluorescent lamps, once the fire occurs at night, the utility power suddenly fails. In the event of a power outage, it is urgent to start the input of the diesel generator. At this time, since the diesel-electric power supply has not been established yet, the dual power supply switching box has no power supply, and the generator room will lose the most basic illumination for starting operation. Even if it is a self-starting unit, it may fail to start from the start, and manual assistance is required. Just because the standby lighting of the generator room is set up to establish the special requirements of the backup power supply, it is necessary to set the lamp with its own power supply. As the transitional lighting, according to the provisions of the “People's Regulations” 6.1.9.5, the continuous power supply time should be met. Or greater than 1, the illuminance should be equal to or higher than 50% of the general illumination.

3 The selection of fire emergency lighting conductors and the distribution of fire emergency lighting must meet the requirements for continuous power supply during fire.

“High Regulation”, “Low Regulation” and “Fire Automatic Alarm System Design Specification” did not make specific provisions on the matching of cable selection and laying methods, and only emphasized “fire protection measures”. In combination with the relevant requirements in the "People's Regulations", the author believes that wearing a dark tube is a reliable and economical way of laying, and should be used as far as practicable. However, because the lighting arrangement of fire emergency lighting often changes with the decoration, the method of dark coating is often difficult to adapt to the scene, so the pipe or the wire slot is still the more common laying method. To ensure the reliability of the line power supply, it is difficult to achieve the fire protection measures of the externally fireproof coating on the metal pipe or the metal wire trough. The reason is mainly due to the complicated painting process, which needs to be repeated and repeated, and is also susceptible to the influence of the site, weather and human factors. The quality is difficult to guarantee, and it needs to be re-brushed after several years, which is difficult to implement, so most of them do not To the effect it deserves. The author believes that it should focus on the refractory and flame-retardant properties of the cable itself and the laying method. When using the metal pipe, wear the fire-resistant cable. When wearing the metal wire trough and the metal bridge, use the fire-retardant fire-resistant cable. Only then can the problem be solved fundamentally.

For a lamp with its own battery, it seems to have nothing to do with the external power supply line. In fact, it should be reliable if the external power supply is in case of fire. It should still be based on external power supply, because the reliability of the battery is closely related to the usual management. If it is not frequently checked and maintained, once the external power supply is lost, the lighting and its brightness cannot be guaranteed, so the reliability of the external power supply line. can not be ignored. For the lighting system with EPS as the emergency power supply, since the lamp with its own battery is not set, the distribution line of EPS is like the “lifeline” of emergency lighting, and its selection and laying should be foolproof.

4. Selection of fire emergency lighting fixtures The choice of fire emergency lighting fixtures is often a problem that designers tend to overlook. The author below talks about the problems that arise in the design and talks about his own understanding.

(1) Fire emergency lighting, especially the light source of evacuation instructions, must be able to light up instantly, such as incandescent lamps, fast-starting fluorescent lamps, high-frequency fluorescent lamps, and low-power tungsten halogen lamps. In some high-space spaces, such as theaters, shopping malls, warehouses, etc., individual designers choose to use metal halide lamps as fire emergency in order to use fire emergency lighting as part of the backup lighting. Lighting source, this is actually wrong. Because the metal halide lamp is a high-intensity gas discharge lamp, the filament needs 4~8min from the cold state to the full brightness. When the power is suddenly turned off, it takes 4~5 minutes to cool down before it can be started again, so it can not meet the requirement of instant lighting. .

(2) Evacuation indicator lights should be selected for special lamps, but the design often fails to indicate the capacity and size of the light source. In the case of fire, the visibility and clarity of the evacuation indicator in the smoke is closely related to the selection of the lamp. We often see this phenomenon in public places: large shopping malls are equipped with small-sized evacuation lights and safety exit lights, which will inevitably affect the evacuation effect. The scheme for the selection of evacuation indicators is given in Appendix C.3.11 and c.3.13 of the “People's Regulations” and should be used in the design.

(3) Article 24.7.6 of the “People's Regulations” stipulates that “the emergency lighting shall be provided with a protective cover made of glass or other non-combustible materials”. The evacuation indicator light is made of special lamps, and its manufacturing standards have met the requirements. However, when the emergency lighting is used as part of normal lighting, in order to achieve the decoration effect, the same lighting as the normal lighting, such as downlights, ceiling lamps, grille lamps, etc., is often used, and the protective cover materials of these lamps are often not non-combustible materials. If the design is not stated, the legend is no different from the normal luminaire, which violates the specification.