Discussion on fire protection of unattended substa

2022-08-09
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Talking about the fire protection of unattended substation

as a part of the whole power transmission and transformation system, substation plays an important role in connecting the preceding and the following, and the fire protection of substation directly affects its safe operation. For emergencies, whether the fire protection system can be put into operation normally, and it is very important to suppress and extinguish the initial fire. With the development of science and technology and the improvement of automation, as an important hub of power transmission and transformation, substations are developing in the direction of unattended. This puts forward higher requirements for the safety of substations

general substation is composed of main control communication building, 3.5kv distribution room, relay room and other buildings. The important equipment in each machine room and distribution room in these buildings are cabinets with various functions. As we all know, electrical fire is the biggest fire hazard for the safe work of cabinets. So, how can we ensure the safety of substations

I. fire prevention measures for existing substations

working principle: the smoke sensor installed in the substation detects a fire and sends an alarm signal. The alarm signal is transmitted to the command and dispatching center through the network. The command and dispatching center notifies relevant personnel to rush to the scene according to the situation and use the portable fire extinguisher equipped on the site to extinguish the fire

existing problems:

smoke detection or temperature detection need to reach a certain level to achieve alarm. Because smoke or temperature sensors are installed on the top of the room, when smoke or temperature sensors detect and send a fire alarm, it means that the fire has spread from the inside of the cabinet to the outside of the cabinet, which has caused great losses to the equipment

the fire fighting speed is slow. The fire alarm signal is transmitted to each dustpan in the control with a span of 1 mile (about 1.6 kilometers), and then the control center gives instructions, because the unattended substation is generally set in a relatively remote place. When the rescue workers arrive at the scene to put out the fire, the fire has spread. The fire extinguisher looked insignificant. Even if the fire brigade is called to put out the fire, the damage caused by water to electrical equipment may be more serious than the fire disaster. The losses caused by the operation of the equipment are irreparable

the current unattended substation has the function of emergency power supply switching. However, once a fire in a cabinet cannot be extinguished in time, it will immediately affect other cabinets. It leads to the shutdown of the whole substation and brings immeasurable losses

due to the low degree of automation of the equipment or some inherent deficiencies, the monitoring equipment often has problems, such as uploading some interference signals in large quantities instantaneously, which seriously interferes with the judgment of the monitoring personnel, and sometimes it is inevitable to miss part of a large amount of information. If there is a problem of poor communication, the fire alarm cannot be reported to the command center in time, which will interfere with the safe operation of the unattended substation, These disturbances will evolve into important factors causing accidents or accident expansion

II. Fire hazards

1. The buildings in the substation are brick concrete structures, with fire resistance rating of grade II, and the decoration materials have fire prevention requirements. The fire hazard is mainly electrical fire

2. Electrical fire generally refers to the fire caused by the thermal effect generated by electrical equipment, electrical lines, live conductors, lightning current, static electricity, arc, etc. If the surface temperature of electrical equipment rises, it may ignite the fire of surrounding substances; Electric arc or spark generated by electrical equipment during normal operation causes fire (or explosion) of adjacent substances; Electrostatic discharge arc, lightning discharge arc, insulation spontaneous combustion caused by wire short circuit, wire grounding arc, conductor joint is bad, heating temperature is too high, conductor insulation damage or aging causes short circuit, and the temperature is too high to ignite the fire of adjacent substances, etc

III. traditional solutions

in order to solve the fire caused by electrical equipment, we generally use the traditional fire extinguishing system to extinguish the fire, but there are the following problems

the traditional fire extinguishing system can only protect the whole room, and cannot carry out point-to-point fire extinguishing protection for the equipment. At the same time, the traditional solid fire extinguishing system can meet the needs of users in the traditional petrochemical industry to develop, develop and detect various medium and high-grade series of hydraulic oil, internal combustion engine oil and gear oil. The customized gas fire extinguishing system is when the protected object has a fire, and the fire has spread out from the equipment, After there is a large amount of smoke and high temperature in the room, the fire detector installed in the room will automatically start the fire extinguishing system after receiving two independent fire signals to extinguish the fire in the room where the protected object is located. At this time, the fire has been large, and the protected equipment has been greatly damaged. Therefore, for the equipment itself, this fire extinguishing method cannot solve the fire extinguishing problem of the equipment

whether it is a total flooding system or a local application system, whether it is automatic control, manual control or mechanical emergency operation, the traditional fixed gas fire extinguishing system sprays the extinguishing agent and spreads it into the protective area (a large enclosed space), without directly spraying the extinguishing agent into these electronic and electrical equipment in case of fire. Moreover, it is difficult for gaseous fire extinguishing agents to penetrate into these fire prone equipment with closed enclosures, so the pertinence of fire extinguishing is not strong, and the purpose of timely and effective fire extinguishing cannot be achieved

the fire extinguishing system is relatively expensive. Because after a fire in a small equipment, the extinguishing agent should be evenly filled into a larger space or room. The amount of fire extinguishing agent required is large, and the composition of the fire extinguishing system is also complex. The total consumption of these plastics in 2019 will exceed 13000 tons, and the cost of one-time fire extinguishing is large. Especially in the fast-growing industries such as electric power and telecommunications, in order to leave enough space for development, there is room for equipment expansion during project construction. At the initial stage of the project being put into use, only a few equipment are placed in the room with a large space. In order to protect these small equipment, the traditional fixed gas fire extinguishing system should be set up as a protective area according to the room with a large space

some extinguishing agents are toxic, and the amount of extinguishing agent is large. When spraying extinguishing agent into the room, it will bring harm to the personnel in the room and pollute the environment

IV. equipment fire extinguishing solution - fire detection tube automatic fire detection and extinguishing device

electrical fire, as a major problem that has plagued the fire industry and users for a long time, especially with the development of science and technology, the protection of more and more electrical equipment has become an urgent problem to be solved. The emergence of fire detection tube type automatic fire detection device is a good medicine to truly solve the problem of equipment fire extinguishing, and it is also the only best way to solve the problem of equipment fire extinguishing at present. Next, we will analyze its characteristics and advantages

1. Working principle

the fire detection and extinguishing device is to directly arrange the fire detection tube in the electronic and electrical equipment prone to fire, and directly use it as the fire detection and extinguishing agent spraying element. Using the sensitivity of the fire detection tube to temperature, in case of fire, under the temperature environment of 160 ℃ ± ℃ (within 1 meter from the protected equipment), within a few seconds to more than ten seconds, depending on the pressure in the tube, The fire detection tube automatically explodes to form a spray hole, and the extinguishing agent is sprayed directly to the fire source to extinguish the fire

2. Fire extinguishing efficiency

because it is directly arranged in the protected equipment, its response is fast and accurate, the release of extinguishing agent is timely and symptomatic, the pertinence and effectiveness of fire extinguishing are stronger, and it can quickly and effectively detect and extinguish the initial fire. It is an early fire extinguishing system. This is a major progress compared with the principle that the traditional fixed gas fire extinguishing system only extinguishes the fire in the whole room or large space when the fire is already large

3. System setup and cost comparison

the fire detection and fire extinguishing device does not need to set up a special bottle storage room, and the floor area is small. No power supply, complex electric control equipment and pipelines, and no special smoke and temperature detectors. The system only relies on a fire detection pipe and a set of fire extinguishing agent bottles and valves, and can extinguish the fire in the initial stage by using its own pressure storage. The system is greatly simplified, the construction is simple, the construction area is saved, and the project cost is greatly reduced

4. Comparison of fire-extinguishing costs

the traditional fixed gas fire-extinguishing system takes the room with a large enclosed space as the protective area, while the fire detection fire-extinguishing system only takes the protected electronic and electrical equipment such as power transformation and distribution cabinets, communication cabinets, cable trays and boxes in the room with a large enclosed space as the protective area. The amount of extinguishing agent is greatly reduced, reducing the cost of a fire

5. Safety and environmental protection

since this fire extinguishing system releases the extinguishing agent in the cabinet with a closed shell, no matter which kind of extinguishing agent is allowed by the specification, even if it is slightly toxic, it will have little impact on site personnel, and the harm will be minimized, so there is no need for personnel to disperse urgently; At the same time, because the amount of extinguishing agent is greatly reduced, the pollution to the environment is reduced

6. Advantages

fast response time, quickly extinguish the fire in the bud, and effectively reduce the economic losses caused by the fire

passive operation. The device does not need power supply, which will not make the device unable to operate due to power supply problems, and eliminates the interference that may be generated by the electronic system and affect the operation function

the fire detection tube is a soft object, which is not affected by any position, and can extend into all kinds of narrow and complex flammable spaces or equipment

close to the protected object, high fire extinguishing efficiency and good reliability

simple design, simple installation and low cost

v. specifications and standards of fire detection devices

as a new fire detection and fire extinguishing device, the fire detection device solves the fire prevention problem of electrical equipment, control boxes, distribution boards and other spaces prone to fire that has plagued the fire industry for a long time. It has been widely used in power plants, communications, radio and television, petrochemical, railway and other systems in China. The application of fire detection devices is also described in the latest revised code for fire protection design of buildings and code for fire protection of thermal power plants. Moreover, the code for design, construction and acceptance of fire detection tube automatic fire detection and extinguishing device has also been formulated for this device in our province, which provides standards and basis for the application and promotion of fire detection devices. "People oriented, safety first. The primary task is to ensure the life safety and health of the people, and to prevent and reduce casualties caused by work safety accidents and disasters to the greatest extent." It is our common goal

VI. service commitment

as the general agent of the fire detection device in China, Shanghai xinfu'an Industrial Co., Ltd. has the patent, trademark and the only test report of the product in China, and is the drafting and editing unit of all standards of the device in China. Shanghai xinfu'an Industrial Co., Ltd. has a strong after-sales service center to provide customers with the best one-stop service of design, installation and commissioning. (end)

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