Summary:The article is based on the GB51309-2018 "Technical Standard for Fire Emergency Lighting and Evacuation Guidance System," and combines the design process of a steelmaking plant's converter project. It elaborates on the design concepts, principles, and methods of疏散照明 and backup lighting in the electrical room of a steelmaking workshop. By selecting a reasonable fire emergency evacuation lighting control system and lighting power supply and distribution scheme, it provides the necessary illumination and accurate evacuation information for personnel safety疏散，thereby ensuring the safe evacuation of personnel.
Keywords：Emergency Lighting; Emergency Power Supply; Centralized Control System
0 Introduction
Emergency lighting and evacuation signage systems refer to building fire protection systems designed to provide emergency lighting and evacuation guidance during emergencies, particularly in the event of fires, to facilitate personnel evacuation and emergency rescue. Emergency lighting and evacuation signage systems can be categorized by their purpose into emergency lighting and standby lighting. This article will discuss the design principles and methods for emergency lighting and standby lighting in the electrical room of a steelmaking workshop.
Project Overview
A new 180-ton converter has been constructed in the steelmaking workshop. In addition to setting up a main control building for the converter on the outside of the feeding span (constructed together with the 10KV switchgear station of the steelmaking workshop), a continuous casting substation, a cyclone well electrical room, and electrical rooms for circulating water pump houses, charging electrical rooms, and primary dedusting electrical rooms have also been established within the workshop. Outside the workshop, there are additional electrical rooms for these purposes. The main control building for the converter is a three-story reinforced concrete frame industrial building, classified as category C for fire hazard. The transformer room has a fire resistance grade of level 1, while the rest have a grade of level 2. The total floor area is 3,954.95 square meters, and the total height is 16.3 meters.
2. Emergency Egress Lighting
2.1 Control System Selection
Fire Emergency Evacuation Lighting Control Systems are categorized into centralized and decentralized control types. For locations with a fire control room, a centralized control system should be used; for those equipped with an automatic fire alarm system but without a fire control room, a centralized control system is also recommended. In this project, the selection of the control system considers the following factors:
(1) Although the fire control room is located within the fire pump house of the public and auxiliary project, it was constructed simultaneously with the converter. The converter workshop and all buildings fall under the jurisdiction of the fire control room.
(2) Each electrical room is equipped with an automatic fire alarm system.
(3) Personnel congestion in the main control building.
(4) A fine mist fire suppression system has been installed in the cable shaft of the main control building.
(5) The main control building is equipped with a fire hydrant system. In summary, the emergency evacuation lighting control systems in each electrical room of the converter steelmaking workshop adopt a centralized control type system. The centralized control type system typically includes emergency lighting controllers, centralized power supplies for emergency lighting, fire emergency lighting fixtures, and fire emergency sign fixtures.
2.2 Emergency Lighting Selection
Emergency lights can be categorized into Type A and Type B emergency lights based on their working voltage ratings and power supply methods. "Type A emergency lights" refer to those with a rated working voltage of no more than DC 36V. "Type B emergency lights" are those with a rated working voltage greater than AC 36V or DC 36V. Lights installed at a height of 8 meters or less from the ground should be Type A; buildings without a fire control room can opt for self-powered Type B lights.
Factors considered for the selection of emergency lighting in this project:
(1) Emergency疏散lights in the electrical room are mostly installed below 2.5 meters, with only a small number of lights designed according to door height, installed below 3.5 meters.
(2) Fire automatic alarm systems are installed in all electrical rooms; a fine water mist automatic fire extinguishing system is set up in the cable shaft of the main control building.
(3) The main control building is equipped with a fire hydrant system.
To prevent electric shock accidents caused by touching the housing during evacuation, this project utilizes Type A non-continuous emergency lighting fixtures with a safe voltage level. The emergency lighting fixtures and signage lights selected for this project are equipped with electronic coding, enabling wireless addressing of emergency lighting fixtures and signage lights via an infrared remote control encoder. The use of two-wire, non-polarized wiring method significantly enhances the construction efficiency of the project.
2.3 Emergency System Power Distribution
In this project, emergency lighting is powered by a centralized power supply. The emergency lighting centralized power supply uses AC220V input, with normal and emergency outputs at DC36V, and includes an integrated battery pack. Under normal conditions, the main power supply (mains electricity) powers the centralized supply, which in turn supplies the DC36V emergency lighting. Should the main power supply (mains electricity) that powers the centralized supply for the emergency lighting fail, the battery pack within the centralized supply will supply power to the DC36V emergency lighting.
2.3.1 Main Control Building Emergency Power Distribution System
The main control building is an industrial structure with a three-story reinforced concrete frame, featuring a high-voltage power distribution room, high-voltage control room, low-voltage power distribution room (PCC), transformer room on the ground floor; a cable shaft and a meeting room on the second floor; and a low-voltage power distribution room (MCC), PLC room, main control room, dispatching room, and office on the third floor. According to GB50016-2014 "Code for Fire Prevention Design of Buildings" (2018 edition), for a Class B2 fire-resistant multi-story workshop in a Class C workshop, the maximum allowable floor area per fire compartment is 4,000 m². The floor area of the main control building in this project is 3,954.95 m², therefore, the upper and lower three floors of the main control building constitute a single fire compartment.
(1) Lighting Distribution Circuit Design Concept. The main control building evacuation unit can be divided into horizontal and vertical evacuation units. The main control building consists of three floors, which can be divided into three horizontal evacuation units by floor level. The enclosed stairwells at both ends are vertical evacuation units.疏散 paths are selected based on the division of evacuation units, lighting is arranged, circuits are configured, emergency lighting centralized power supplies are reasonably set, and evacuation guidance plans are determined according to the shortest path evacuation principle. In the event of a fire, the high-voltage power distribution room, PCC room, MCC room, main control room, dispatching room, etc., within the horizontal evacuation units still need to operate. The areas on duty and related evacuation passages should have separate distribution circuits. The enclosed stairwells in the vertical evacuation units should also have separate distribution circuits. This project has only one evacuation guidance plan for each floor, and all evacuation sign lights cannot use variable sign lights.
(2) Centralized Power Supply System. This project's emergency lighting centralized power supply utilizes the A-D-0.5KVA-A200L. According to the division of evacuation units and the different functional uses of each room, the main control building is equipped with two emergency lighting centralized power supplies. One is located in the third-floor MCC room, primarily providing power for emergency and evacuation lighting in the third-floor MCC room, main control room, dispatching room, and offices, etc. The other is situated in the first-floor PCC room, mainly serving the emergency and evacuation lighting in the first-floor high and low voltage distribution rooms and the second-floor cable shaft, etc. The A-D-0.5KVA-A200L features city power monitoring capabilities, promptly collecting the operational status of the incoming power to the lighting cabinets on the corresponding power supply floors. It ensures that the centralized power supply can quickly switch to battery operation when the lighting power is cut off during non-fire conditions, activating the emergency lighting into emergency illumination mode. Once the lighting power is restored, both the centralized power supply and the lighting equipment return to their original state. In a fire condition, the centralized power supply receives a start signal from the fire alarm controller or fire联动 controller, automatically switching to battery power output while illuminating the corresponding emergency lighting and evacuation signs. In a centralized control system, the centralized power supply is powered by a dedicated emergency circuit from the fire power supply.
Figure 1: Concentrated Power Topology Diagram
Image 1
2.3.2 Electrical Room Emergency Power Distribution System
Other electrical rooms are all single-story buildings, with the emergency lighting centralized power supply A-D-0.5KVA-A200L installed in each respective electrical room. The centralized power supply monitors the incoming power status of the lighting cabinets within the electrical rooms. In non-fire conditions, when the lighting power is interrupted, the centralized power supply switches to battery operation, and the emergency lights activate in emergency mode; upon the restoration of the lighting power supply, both the centralized power supply and the lights return to their original state. In a fire situation, upon receiving a start signal from the fire alarm controller or fire linkage controller, the centralized power supply automatically switches to battery power output and simultaneously illuminates the corresponding emergency lighting evacuation lights.
2.4 Centralized Control System's Control
2.4.1 Emergency Lighting Controller
This project features a single emergency lighting controller, which is installed in the main control building's dispatch room, alongside the converter steelmaking workshop's fire alarm controller. The emergency lighting controller is powered by the fire protection power supply, and it also comes with its own battery, ensuring operation for 3 hours in the event of a power outage. The A-C-A100 emergency lighting controller selected for this project is equipped with real-time inspection capabilities for the lighting fixtures, and it can transmit the status of the fixtures to the controller. Additionally, in case of a fault, it can alert the on-duty personnel through both audio and visual alarms.
Emergency lighting controllers communicate with fire alarm controllers or fire linkage controllers via RS485 for network communication. In the event of a fire, the emergency lighting controller receives an activation signal from the fire alarm controller or fire linkage controller, simultaneously illuminating the corresponding emergency lighting evacuation fixtures to ensure that the evacuating crowd can疏散 and escape along the optimal evacuation route.
2.4.2 Communication Lines
Emergency lighting controllers are connected to centralized power supplies and emergency lighting fixtures via bus communication. The communication between emergency lighting controllers and centralized power supplies is done through a tree-shaped communication bus, while the communication bus of multiple centralized power supplies on-site is connected using a daisy-chain method. In the event of a communication failure between emergency lighting fixtures and centralized power supplies, emergency lighting fixtures will automatically illuminate during a fire. If there is a communication failure between the lighting controller and centralized power supply, the centralized power supply should initiate a chain reaction to control the emergency lighting fixtures to illuminate.
In this project, the emergency lighting controller is connected to the fire emergency lighting centralized power supply room via CAN communication cable WDZN-RYJSP-2X1.5mm²; the fire emergency lighting centralized power supply is connected to the emergency lighting and evacuation signage lighting through a two-wire system WDZN-RYJSP-2X2.5mm².
Figure 2: System topology diagram
Figure 2
3. Backup Lighting
In the event of a fire in high-voltage switchgear rooms, PCC rooms, MCC rooms, control rooms, and dispatch rooms, staff must continue to operate. All manned areas should be equipped with emergency lighting that matches the intensity of normal lighting. Emergency lighting is categorized into fire emergency lighting and non-fire emergency lighting for critical areas. The emergency lighting in electrical rooms (distribution rooms) should be fire emergency lighting. This project's electrical rooms are powered by a secondary load supply system, utilizing dual power circuits.
(1) Backup lighting in the master control building. The building is a three-story structure with dimensions of 95M in length and 16M in width. The first floor houses a high-voltage distribution room, high-voltage control room, PCC room, transformer room, etc.; the second floor contains a cable tray and a meeting room; and the third floor is equipped with an MCC room, PLC room, main control room, dispatching room, and office, among others. In accordance with the building's size and the functions of each room, there are four lighting distribution boxes on each of the first and third floors, while two are installed on the second floor. The cable tray on the second floor and the meeting room do not require backup lighting. On the first floor, all rooms except the transformer room must have backup lighting. On the third floor, all rooms except the office must have backup lighting as well. The lighting distribution boxes on the first and third floors are equipped with dual-power switching devices, with the two power circuits sourced from different bus segments of the upper power supply. Normal lighting serves as backup lighting, ensuring that during a fire, 100% of the normal lighting intensity is maintained, excluding the backup lighting circuit. Additional circuits (such as outlets) have circuit breakers with auxiliary release units in front, which, upon fire detection, are linked to the fire alarm controller's signals and the auxiliary release contactors, thus disconnecting non-fire load.
(2) Backup lighting for the electrical room. All other electrical rooms are equipped with a lighting distribution box, which utilizes a dual-power switching device for its incoming lines. The two power circuits of the dual-power switching device are sourced from different bus sections of the upstream power supply. Normal lighting also serves as backup lighting, ensuring 100% illumination during fires. Conclusion: The rational design of fire emergency evacuation and guidance systems, along with the electrical supply and distribution of lighting fixtures, plays a crucial role in providing necessary lighting and accurate evacuation guidance during emergencies, particularly fires, and is of significant importance for ensuring safe evacuation and rescue.
4. Ankelei Selects疏散Products for Selection
5. Closing Remarks
The rational design of fire emergency evacuation and signage systems, as well as electrical supply for lighting, plays a crucial role in providing necessary illumination and accurate evacuation guidance during emergencies, especially fires, ensuring the safety of personnel evacuation.
Reference
[1]. GB50016-2014 (2018 Edition) "Code for the Fire Prevention in Building Design" [S].
GB17945-2010 "Fire Emergency Lighting and Evacuation Guidance System" [Standard]
[3]. GB51309-2018 "Technical Standard for Fire Emergency Lighting and Evacuation Guidance System"[S].
[4]. GB51348-2019 "Standard for Electrical Design of Civil Buildings"[S].
[5]. GB50116-2013 "Code for Design of Automatic Fire Alarm Systems" [Standard]
Li Quanfeng. "Emergency Evacuation Lighting Design for the Electric Room in a Steelmaking Workshop"
[7] Ankorree Corporate Microgrid Design and Application Manual, 2022.05 Edition
