Discussion on Application of LED Light Source in Mine Lighting

Mine lighting source is an important part of the mining machinery industry. Old-fashioned miner's lamps, such as incandescent lamps, fluorescent lamps and high-pressure sodium lamps, not only consume large amounts of electricity, but also have short lamp life, small light-emitting area and uneven illumination. Especially the old miner's lamp is mostly a heat source. Improper use will cause mine gas explosion and seriously endanger the safe production of the mine. A fourth-generation new light source semiconductor light-emitting diode (LED) light source with energy saving, environmental protection, harmlessness, long life, low heat, shock resistance and high color purity came into being. It is now widely used in life, such as landscape. Lamps, traffic lights, car lights, etc., will also have broad application prospects in mine lighting.

1 LED light source illumination mechanism and advantages

1.1 LED light source illumination mechanism

A light-emitting diode (LED) is an injecting electroluminescent device made of a III-IV compound such as gallium arsenide, gallium phosphide, and gallium arsenide, the core of which is a PN junction. It has the characteristics of a general PN junction: forward conduction, reverse cutoff, breakdown, and, in addition, it has luminescent properties under certain conditions. When the PN junction is in equilibrium, there is a certain barrier zone, and its energy band is shown in Figure 1.

When a positive bias is applied to both ends of the PN junction, the barrier of the PN junction region is lowered, and a large number of unbalanced carriers are injected from the diffusion N region to the P region, and the holes diffused from the P region to the N region are continuously recombined. . The composite process is a process in which electrons fall from a high energy level to a low energy level, releasing energy in the form of light radiation to emit light. Since the diffusion speed of holes is much smaller than the diffusion speed of electrons, luminescence mainly occurs in the P region [1].

1.2 LED light source advantages analysis

Compared with old miner's lamps, LED lights have many advantages, mainly the following:

(1) The high-energy-saving LED light source is a primary light source. In the process of illuminating, the electric energy directly becomes light energy, and the LED light is used as a new light source, and the power consumption is maintained under the same brightness as the ordinary incandescent lamp (secondary light source). It is only 1/10 of the ordinary incandescent lamp, so the energy consumption is small.

(2) Long life and fast response LED light source is called long life light, and its service life can reach 50,000 to 100,000 hours, which is more than 10 times longer than that of old light sources. LEDs respond quickly, with a response time of nanoseconds, 0.1 ms for fluorescent lights, and milliseconds for fluorescent lamps.

(3) Environmentally friendly LED light source has no ultraviolet, infrared, low heat and no stroboscopic light. It is a cold light source, can be safely touched, does not contain lead and mercury, and is a non-polluting light source.

(4) High luminous efficiency and high luminous brightness The incandescent lamp and tungsten halogen light effect are 12 ~ 24 lm / W, and the fluorescent lamp is 50 ~ 70 lm / W. The sodium lamp is
90 to 140 lm / W, most of the power consumption becomes heat loss. The improved LED light efficiency will reach 150-200 lm/W, and its light has good monochromaticity and narrow spectrum. It can directly emit colored visible light without filtering.

(5) Safety lighting LED power supply can use 24 V low-voltage line, easy to drive, which provides a safe and stable power supply environment for the mine. Because LED light source has good shock resistance, good sealing performance, low heat radiation, small size and easy to carry, it can be widely used in special working places such as explosion-proof, field operations, mines, military operations or harsh working environments, such as miner's lamp and explosion-proof lamp. , emergency lights, safety indicator lights.

2 LED light source application in mine lighting

At present, mine lighting is mainly divided into factory floor lighting and mine downhole lighting. Factory floor lighting is the same as lighting in everyday life. Underground mine lighting can be divided into roadway lighting, working head-on lighting and other working point lighting. The choice of LED light source should be selected according to different environments and usage requirements [2, 3].

2.1 Lane lighting

Mine roadway lighting is mainly used to provide illumination for transportation or pedestrian access. At present, most of the roadway explosion-proof lamps widely used at home and abroad use ordinary straight tube fluorescent lamps as the light source, which has the disadvantages of large power consumption, short lamp life and difficult maintenance, and the voltage loss is especially obvious if the power supply distance is long. The use of LED light source not only has low energy consumption, saves energy, but also has a long life, which can effectively reduce the maintenance of roadway lamps. At present, China's mines have begun to promote the use of LED light source roadway explosion-proof lamps, although there are still some problems in the initial stage, but with the advancement of LED light source technology, its application in roadway lighting will become more and more extensive.