Tang Xueyang

Ankerui Electric Co., Ltd. Shanghai Jiading 201801

0. Introduction

Survey data shows that electrical fire monitoring systems play an important role in fire prevention and rescue in the early stages of a fire. China is vigorously promoting port transportation, which not only facilitates people's travel, but also poses a hidden danger of electrical fires during transportation. The demand for maritime transportation in our country is increasing day by day. Coal produced in northern China is transported to the south, mainly to the coastal areas of East and South China. Once an electrical fire accident occurs, the consequences will be unimaginable. So, the electrical fire monitoring system can play a significant role in the port enterprise system.

1. Monitoring system for electrical fires

The electrical fire monitoring system consists of residual current electrical fire monitors and residual current electrical fire monitoring. Composed of detectors and fire sound alarms. The electrical fire detector is installed at the output end of the distribution cabinet and connected to the electrical fire monitor through RS485 bus. The electrical fire monitor is installed in the duty control room of each substation and adopts a networked system to transmit all information to the fire brigade control room.

The detector can display the leakage current value in real time, and once the leakage current in the system reaches the set value of the electrical fire detector (300-500mA), the detector will issue an alarm signal. After receiving the alarm signal, the monitor will display the alarm information and activate the sound alarm, while transmitting the fault information to the central control room. At this point, the alarm information indicates that there is only a safety hazard in the relevant location. It is only necessary to dispatch relevant maintenance personnel to inspect the equipment and eliminate the hazard in a timely manner, without interrupting production, ensuring the safety of personnel and property in the factory area.

The electrical fire monitoring system not only monitors leakage current, but also has fault alarm function, self checking function, alarm information storage function, power supply function, etc., with high safety and convenience.

The electrical fire monitoring system can monitor the operation status of the power system in each district in real time, detect and eliminate hidden dangers in a timely manner. The operation data of the power system is saved in the electrical fire monitor and the central control room to identify the cause of the fire, formulate fire extinguishing plans, and reduce fire losses.

1. Characteristics of Electrical Fire Monitoring System

Operating standards. When a fire occurs, people or objects affected by the fire are usually classified, and whether to rescue them first is determined based on the degree of fire damage. The higher the classification, the stronger the corresponding rescue or assistance. Therefore, an electrical fire monitoring system must be installed near high-level rescue objects. On the one hand, it can prevent potential safety hazards, and on the other hand, it can ensure monitoring at any time. Once an electrical fire accident occurs, it can provide timely warning to ensure that personnel manually cut off or rescue the circuit equipment in a timely manner, avoiding damage to personnel or objects.

Operating mode. When equipping a monitoring system in a port enterprise system, its control system should be installed in a department that can centrally control the internal systems of the port enterprise system. After identifying important monitoring areas, the equipment that needs to be prevented and controlled and the safety hazard category to which the equipment should belong should be determined. The electrical fire monitoring system plays an important role in fire prevention, but not all electrical equipment in the entire port enterprise system needs to be equipped with this monitoring system. The number of monitoring systems will not have a significant impact on the overall monitoring system. Cost is also a factor to consider when investing in monitoring systems. It is important to control the cost and avoid wasting funds, so that the investment is proportional to the preventive effect achieved by the equipment.

Operating principles. In the current relevant documents in our country, there are clear regulations on the installation of monitoring electrical equipment. Under different electrodes, voltages, and currents, the installation and connection of monitoring electrical equipment systems should be replaced in a timely manner according to the differences in current, voltage, and electrodes. At the same time as equipping the electrical fire monitoring system, corresponding circuit monitoring equipment should be installed near other electrical equipment that is not connected to the electrical fire monitoring system, especially in areas where there are many intersections of power lines. Real time monitoring of the power lines in this area should be carried out through the installation of circuit monitoring equipment to prevent faults in the power lines during operation and to issue timely alarms in case of circuit leakage accidents, ensuring that all electrical equipment in the entire railway transportation system has corresponding monitoring and detection systems.

Alarm threshold. After the installation of the monitoring equipment is completed, the electrical fire monitoring system is set to trigger alarms based on the actual operation of the port enterprise system. In relevant documents in our country, alarm interval parameters are clearly defined for the triggering alarm values of monitoring equipment, which are divided into alarm low values and alarm high values. According to the alarm low value and alarm high value, the measurable current value of the electrical fire monitoring equipment can be set to the alarm low value. Once the circuit current that can be monitored is higher than the alarm low value, the electrical fire monitoring equipment will activate the alarm mode and electronically archive the changes in the monitored circuit current value. When the circuit current value returns to normal and is lower than the alarm low value, the electrical fire monitoring equipment will return to normal state. In addition to setting the alarm low value, it is also necessary to set a danger mode in the electrical fire monitoring equipment where the circuit current value exceeds the high value. Once the circuit current value reaches the high value, the electrical fire monitoring equipment will immediately sound an alarm and continue to provide light warnings. After on-site investigation and handling of electrical equipment leakage or other safety hazards, when the current value detected by the electrical fire monitoring drops below the alarm low value, the staff will manually turn it off, and the alarm sound and light warnings of the electrical fire monitoring system will stop.

Monitoring display. There are clear regulations in relevant documents of our country regarding the monitoring and display system in the fire control room. For the detection and display of fire protection facilities in the port enterprise system, they must be able to be displayed as a whole in the personnel controlled monitoring room or platform. As for the display monitoring system in the current port enterprise system, it can already achieve centralized display of all monitoring equipment in the control room and real-time transmission of monitored information. So after completing the installation of the fire monitoring system, the backend system of the electrical fire monitoring system can be connected to the fire control console to ensure that the fire monitoring system can be centrally displayed in the console.

1. Management Measures for Electrical Fire Monitoring System

When installing an electrical fire monitoring system, it is necessary to consider the installation area, installation cost, and installation quantity of the electrical fire monitoring system. For important power equipment or meter box areas, it is necessary to equip the electrical fire monitoring system to ensure that the installation cost of the monitoring system can be invested while monitoring the overall railway transportation system.

Due to the special nature of the fire monitoring system, a dedicated installation team must be responsible for on-site construction when installing the equipment or communicating with the control room display. They are responsible for the entire process of monitoring the system from installation to subsequent testing. Once problems are found with the installation or communication interface after testing, they can be adjusted in a timely manner to ensure the normal operation of the monitoring system.

During the installation process of the monitoring system, it involves the procurement of many parts and assembly equipment. In order to ensure the installation cost, it may be necessary to purchase different equipment from different suppliers during the procurement process. Therefore, during the installation of the monitoring system, it is necessary for various parts suppliers to dock with each other for parts or equipment. This process is prone to communication problems, and the subsequent maintenance services for the parts and equipment used are also quite troublesome. Therefore, when installing the monitoring system, the railway transportation party should directly connect with a construction team to establish clear standards for the required parts or equipment for the monitoring system. As for procurement, the construction team should conduct market research to ensure the timeliness of the monitoring system installation and to solve potential maintenance services that may be involved in the future.

4. System architecture

5. System functions

(1) The monitoring equipment can receive residual current and temperature information from multiple detectors, and emit sound and light alarm signals when an alarm is triggered. At the same time, the red "alarm" indicator light on the equipment is on, and the display screen indicates the alarm location and type. The alarm time is recorded, and the sound and light alarms are kept until the "reset" button on the equipment or touch screen is pressed to remotely reset the detector. The sound alarm signal can also be manually eliminated using the touch screen "mute" button.

(2) When the monitored circuit alarms, the control output relay is closed to control the protected circuit or other equipment. After the alarm is eliminated, the control output relay is released.

(3) Communication failure alarm: When there is a communication failure between the monitoring equipment and any connected detector or when the detector itself fails, the corresponding detector in the monitoring screen displays a fault prompt, and the yellow "fault" indicator light on the equipment lights up and emits a fault alarm sound. Power failure alarm: When the main or backup power supply fails, the monitoring equipment also emits sound and light alarm signals and displays fault information. You can enter the corresponding interface to view detailed information and cancel the alarm sound.

(4) When residual current, over temperature alarm or communication/power failure occurs, the alarm location, fault information, alarm time and other information are stored in the database. When the alarm is cleared and the fault is eliminated, it is also recorded. Historical data provides multiple convenient and fast query methods.

6. Configuration plan

7. Conclusion

The electrical fire monitoring system plays an important role in eliminating safety hazards in the port enterprise system. Only by introducing it into the substation can it play an effective role in enhancing the safety and stability of the substation. In addition to the port enterprise system, this monitoring system can also play a valuable role in other systems involving safety hazards such as circuit fires and leakage, and requires widespread promotion of monitoring technology.