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Mine disaster reduction measures and testing overview

Author: LiXiaoCong From: www.yourpaper.net Posted: 2010-06-14 23:19:00 Read:
Abstract: This article describes the background and current situation of the lightning, and gradually in-depth understanding of the lightning process and endanger the form of systematic analysis and study of the application and development of the mine disaster reduction management and mine disaster reduction technology, a clear direction and goals, to ensure the successful completion of the mine disaster reduction.
Keywords: lightning directly stroke; lightning; spherical mine; lightning electromagnetic pulse
Abstract: This text introduces the background of the thunder and lightning calamity and current situation, understand the thunder and lightning course and danger form in depth progressively, tie Interconnected system to defend thunder is it manage and defend thunder not to reduce natural disasters application and development of technology go on the analysis and research to reduce natural disasters, define developing direction sum Goal, is it defend thunder reduce natural disasters smooth completion that work to guarantee.
Key words: Attack the thunder directly; Reaction thunder; Spherical thunder; Electric magnetic pulse of thunder and lightning

1 Introduction

Lightning, is currently China's top ten natural disasters. Relevant departments, according to statistics, the world's average per minute thunderstorms 000 global casualties caused by lightning each year more than 10,000 people, caused by flood, explosion, etc., China has 21 provinces, autonomous regions and municipalities thunderstorm days more than 50 days, with a maximum of up to 134 days. Thunderstorm brings to a great security risk, especially in recent years, China's socio-economic, information technology, especially the rapid development of computer network technology, urban high-rise buildings increasing number of losses caused by this lightning hazards will also be increasingly bigger. Lightning is one of the many atmospheric phenomena in extremely destructive, but powerful lightning electromagnetic pulse (LEMP). It has a wide range of high frequency, intensity and other characteristics.
Mine disaster reduction as an important content of the national protection of life and property, by the governments at all levels attach great importance to. Meteorology Law of the People's Republic of China, "the implementation of, and promote the management of the mine disaster reduction in China industry, prosperity mine market, improve the scientific and technological content of the lightning protection work has played a powerful role in safeguarding national economic construction and social stability.

2 mine disaster mitigation technology foundation

Lightning is strong instantaneous discharge between clouds and the earth and the the thundercloud layer formed due to strong convection weather phenomenon. When lightning occurs, resulting in a powerful lightning current hot temperatures, violent shock waves, transients battery field and a strong electromagnetic radiation and other physical effects, cause harm to the building, electrical and electronic equipment and people, livestock, and is a kinds of severe weather natural disasters.
2.1 lightning directly stroke
Cloud-to-little clouds and the earth between a point on the rapid discharge phenomenon. Lightning current is current, it has has all the effects of the current, it is different in a short period of time in the form of pulses by a strong current; especially direct lightning stroke, it's tens of kA peak, as well as hundreds of kA. Peak time (counting from the peak value of the lightning current is increased to 1/2, until it drops to 1/2 the peak-to-time interval), only a few microseconds to tens of microseconds usually negative blitz blitz some longer, n It is this particular case, the lightning current has its special role in the destruction.
2.2 lightning
Lightning is charged clouds due to electrostatic induction and electromagnetic induction, ground to a range of belt opposite charge, after the occurrence of cloud-to-cloud electric charge quickly disappear, and some ground due to the bulk flow resistance, diffuser relatively slow, resulting in a partial high potential, or the cloud-to-discharge process, resulting in a strong electromagnetic pulse current to the electromagnetic induction phenomenon of high potential so as to cause lightning around the wire or metal objects.
2.3 spherical Ray
Ray Ball is an orange or red flame-like light-emitting sphere, occasionally yellow, blue or green. Most of the fireball diameter in 10 cm to 100 cm or so. Ball Ledo ordinary lightning most frequently in a severe thunderstorm spacetime. It may drift in the air a few seconds to a few minutes, often by the holes in the buildings, chimney or open the doors and windows into the room, sometimes through ungrounded doors and windows barbed wire into the interior.
2.4 LEMP
Lightning electromagnetic pulse, LEMP, the powerful lightning current and electromagnetic field is generated when the thunder of the sky as the source of interference. Its sensing range, buildings, personal and a variety of electrical equipment and pipelines will have varying degrees of harm.

3 modern mine technology

The 3.1 lightning protection
Speaking of lightning, people only think of the lightning rod, lightning network, deflectors and ground network, this does not mean your device safe, this is only resolve the lightning powerful lightning directly hit a higher position in the surface facilities and equipment. Lightning directly stroke not only equipped with a lightning rod, lightning network above, where the projections in the surface of the surface, such as high and low voltage power lines, telephone lines, TV antenna, poles, flagpoles, trees, bamboo and so on are a good conductor lead directly into the earth mine, cloud-to-the deflectors strong current around induced magnetic electric field.
Protective measures against direct lightning stroke, the first should be based on the importance of the need to protect buildings or device, the use of nature, likelihood and consequences of an electrical accident, in accordance with the relevant norms make a correct assessment; Secondly, according to the specifications of the various types of The lightning protection of buildings or the different requirements of the apparatus, a reasonable choice of air terminals (pin, net, band) type and height of the cross-sectional area of ??the deflectors, the spacing and number of grounding apparatus structure and meet the design requirements of the grounding resistor, the equalizing ring set and distance, equipotential bonding, anti-high potential counterattack distance measures, so that the formation of a comprehensive lightning protection measures.
The 3.2 lightning protection
Lightning sensors due to electrostatic induction caused by lightning and the lightning electromagnetic pulse through the power supply line, indoor and outdoor signal data transmission lines, Antenna into the engine room of a variety of pipes, cables into the electronic information system, destroying all types of electrical equipment and micro-chip, the device was a permanent loss. Defense electrostatic induction and electromagnetic pulse caused by lightning interference ideal for lightning protection design is a cage lightning network, which use the principle of the Faraday cage. Metal buildings throughout the entire structure without a lot of steel and can be easily connected together to form a Faraday cage, and thus good shielding electronic equipment within the building. Ignore well, not only defense space electromagnetic radiation, but also to enable the diversion of the inside of the building and the pressure to achieve the best results.
3.3 ball lightning protection
Protective ball Lei measures best cage lightning network, less than cage lightning network conditions, installation of metal gauze on the doors and windows of the building and ground; blocking unnecessary holes in the wall of the building; chimney particularly important buildings in the tall trees and the trachea catchy to install barbed wire and grounding; storage or injury flammable objects warehouse and factory chimneys and discharge pipe should be retrofitted with flame arrester and ground to take protective measures of ball Lei.
3.4 equipotential connection
Other potential connection lightning invasion "road" cut off, making it the internal facilities is not damaged. Equipotential bonding is the potential of the various types of electrical, electronic information equipment and separate conductive devices connecting conductor connection, in order to reduce the potential difference between the metal components and devices of the device where the building or between the device and the device caused by lightning strikes. Multiple connections to take advantage of all the metal components of the reinforced concrete structure of the building, to create a three-dimensional network connection is the best choice to achieve equipotential bonding. Equilibrium to the extent that they can accept the potential difference between any device, is never electrical breakdown damage.

4 lightning protection measures

Lightning activity is a natural phenomenon of the discharge thunderclouds, lightning phenomenon mechanism is very complicated, there has not been an unassailable theory, the mine project necessarily involves a wide range of technology. Therefore, from the perspective of administrative, technical standards, engineering practice, lightning is a systems engineering.
4.1 Strengthening lightning detection industry management
Lightning protection device safety testing, different from the general business related to all walks of life, safety testing and technical services in accordance with the law, there must be a perfect organization, standardized management. Lightning protection departments gathered lightning protection technology, human resources and other advantages, in particular, have a strong strength and foundation of a considerable part of the Ministry, the Committee system lightning protection technology strength, device configuration, and some years in this work, These departments and systems are self-contained, their own way, did not form a complete system, the lack of standardized management. So, how to make good use of the advantages of various aspects, performance of good government entrusted to us by management functions, without creating a monopoly situation in the industry. Lightning protection device safety testing network should be established to better play to their functions and roles. If you rely only on the meteorological department bear the detection task, it is difficult to achieve the intended purpose, and some departments, special industry is not within our reach. Mobilize all the positive factors, in order to better fulfill Meteorology Law of the functions entrusted to us. To enhance detection and management work to develop testing qualification examination and approval system, the annual qualification examination system, detection system, the re-examination system, the information submitted to the system, a major accident reporting system, testing equipment annual inspection calibration system certificates, so that the management of more standardized.
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