Reasonable Application Of Several High-Power Led Explosion-Proof Lighting Sources In Mines
Writer：Jane Time：2021-07-20 Browse：192 Reasonable application of several high-power LED light sources in mine explosion-proof lamps According to the layout and division of underground coal mine workplace, underground explosion-proof lamps are generally by mine lights, roadway lights, locomotive, support lights, emergency lights, signal lights, and some special places with floodlights and projectors.
From the structural characteristics of LED light source alone, the following solutions are more stable in application. Here is a detailed introduction of their application in mine explosion-proof lamps and lanterns:
The LED type of low-power bracket used in the early roadway lamp is mainly used in the underground explosion-proof signal lamp and the early roadway lamp. Generally, dozens of low-power Y5Y10 bracket tubes are used as the light source. Generally, dozens to hundreds of Y5Y10 white LED dot matrix arrangement is used, which is directly inserted on PCB board or welded on aluminum substrate. The power drive can be realized by capacitor buck. There is no need to consider too much in optical design, there is no heat dissipation problem, and the structure of the lamp is also easy to achieve; In particular, the degree of localization of this kind of pipe is very high, the cost of lamps is relatively low, and it is easy to design lamps. However, the production process is complex, the reliability of the lamp is poor, the fault efficiency is high, and the shell size is large, so the tunnel lamp is seldom used in this scheme, but it has a good effect in the explosion-proof signal lamp.
This light source is an improvement of the small-power stent-type LED, and the welding of aluminum base laminate can be reflow soldering, high process automation; Make the lamp strip after the overall thermal contact is full, good electrical conductivity, so the production efficiency is high, the rate of finished products is relatively high, as shown. LED patch is smaller in size, but the power is much larger than that of the bracket LED, so the number of tubes used in the lamp is less than that of the bracket LED type. The power of the lamps and lanterns generally has the specifications of 10W and 20W, and the driving circuit adopts the way of series and parallel combination. Due to the influence of its packaging process, the light source's translucent body is mostly made of silicon rubber, so the long-term stability and reliability of the light source is not ideal. At present, it is widely used in the roadway lamp of strip type fluorescent lamp and also in the explosion-proof support lamp. Because of the small current, it is also easy to realize the intrinsic safety.
The application of more mature high-power base (substrate) LED type is shown, which is the most widely used and the most mature scheme at present. Most of the 12 to 18W circular tunnel lamps are in this scheme, as shown. This kind of LED - generally has 1W and 3W specifications, single power is larger, widely used.
In general underground roadway, the height is about 3m and the width is 4 ~5m, and the installation spacing of lamps is generally 6~8m. In order to achieve the ideal lighting effect within the irradiation range, the light emitting Angle of lamps must be controlled through secondary optical design to make the light emitting Angle of lamps along the length of roadway as large as possible, generally 160 is appropriate. In the direction of the width of the roadway generally only 80~90°, so that the limited light emitted by the LED light source can all be reasonably used, so that the light emitted by the lamp forms an ellipse, so that the lamp is evenly distributed in the irradiation surface area. The secondary optical processing can generally be performed using a specially designed reflector or a special peanut shaped LED lens as shown.
This scheme can be used to drive the explosion-proof lamps power supply switch constant current drive circuit, high efficiency, up to more than 80%. When the power is large, two series drives can be used on the circuit, which can reduce the load of the total circuit and avoid the circuit instability caused by the damage of the LED pipe when the single drive, thus improving the reliability of the lamps and lanterns. At the same time, the lamp must have a good heat dissipation structure to reduce the light decline of the pipe itself as far as possible to ensure the service life of the lamp.
The explosion-proof lamps and lanterns that use base type high-power LED as light source are much higher than incandescent lamps, fluorescent lamps and energy-saving lamps, but its energy-saving effect and life are much higher than other lamps and lanterns. Its one-time investment is high, but the long-term electricity saving effect and economy are very considerable. Because it is easy to achieve secondary optical design, it can also be used in complex fixtures such as underground locomotive lights, explosion-proof floodlights (as shown) explosion-proof bracket lights and explosion-proof emergency lights.
Multi-chip integrated LED light source (as shown) has unique advantages: through different series and parallel combination, can achieve a variety of different rated voltage and current, better adapt to the design of the driving circuit, improve the overall luminous efficiency, reduce costs; The number of chips per unit area can be more or less, can be encapsulated into a variety of different point light source and surface light source.
The production process of the explosion-proof lamps is simple, and the secondary optical design is difficult because of the multi-point luminescence. Because the general single can do 10W or even to 100W, so the heat dissipation requirements of lamps and lanterns are also relatively harsh.
Limitations when lamps and lanterns design flexibility is not big, the chip is big, but the department of light pipe internal circuit complex (as shown) due to the chip inside with the method of 4 and 5 series power supply, if some one or a few pipe damage, along the way will inevitably cause the imbalance of the whole circuit driver, leading to circuit load increase, work is not stable, after internal pipe damage, The human eye is impossible to see from the outside; The second reason is that the VF value of the pipe itself is not balanced, either high or low, so it is difficult to guarantee the current balance of the four channels, and the real constant current drive can not be done, unless the internal adjustment circuit of the pipe is added to solve the problem.