Tianjin explosion caused thinking: warehouse lighting safety transformation

LED (Light Emitting Diode) illumination is LED illumination. The technology utilizes carrier electrons and valence band holes in a semiconductor material to perform energy conversion and combine to emit photons of a certain frequency under the action of an electric field. Different semiconductor materials have different band gaps and can emit light of various colors. LED lighting products are lighting products made with LED light sources, which will gradually replace various traditional light sources and become the green lighting products of the 21st century. It is imperative that warehouses in the port area use LED lamps instead of traditional lighting sources.

First, the status quo of warehouse lighting in the port area

Warehouse lighting in the port area is generally opened in the case of weak night and cloudy sights, so that production in the warehouse can proceed as usual. Generally, warehouse lighting in the port area uses metal halide lamps or high-pressure sodium lamps as the light source. The disadvantage of metal halide lamp is that it has no long-term high-pressure sodium lamp, high light-effect sodium lamp, poor ability to transmit rain, but good color rendering; high-pressure sodium lamp has poor color rendering, but high light efficiency and ability to transmit rain. Strong. The common disadvantage of both is that the earthquake resistance is poor and the energy consumption is large. See Table 1 for details of the advantages and disadvantages of both.

Second, the advantages and development status of LED lamps

Light-emitting diode (LED) is a kind of light-emitting device that directly converts electrical energy into light energy. Compared with traditional light sources, it has the advantages of green environmental protection, energy saving and high efficiency, long life, rich color, good monochromaticity and shock resistance. LED types and uses are numerous, such as LED indoor lighting, LED outdoor lighting, headlights or handheld lighting, various indicators, display backlighting, camera flash, laser equipment, etc. LED lighting as a green light source has received more and more attention and has been greatly developed. Traditional lighting sources are difficult to improve due to the principle and technical bottlenecks. LEDs enable direct conversion of electrical energy to light energy for higher light efficiency. Now, the white LEDs that have been mass-produced have a luminous efficacy of more than 130 lm/W, which exceeds the traditional high-pressure sodium lamps and metal halide lamps. At present, with the development of technology, LED light efficiency is still improving, and the advantages of LED lighting fixtures are becoming more and more efficient. In addition, LEDs have the advantages of low voltage, small size, long life, low maintenance cost, and environmental protection.

Third, the application of LED lamps in warehouse lighting in the port area

1. Warehouse overview

A warehouse covers an area of ​​36,548 square meters, with a building area of ​​35,770 square meters, a building area of ​​71,540 square meters, and a building height of 11.65 meters. It is mainly used to store auto parts such as engines. The warehouse lighting design uses 534 sets of 250W deep-illuminated metal halide lamps. The distance between the light sources is 10.5m×8m and the height from the ground is 6m. According to the requirements of the warehouse user, it is necessary to achieve an average illumination of more than 100lx. At the same time, in order to ensure that the long-term working environment of the operator is good, the light source must meet the requirements of no glare, no glare, no stroboscopic.

Highlights: As the mind is concerned, the illuminance is particularly high directly below the light source, which is significantly higher than the surrounding area. It is a kind of light source agglomeration effect, and the presence of bright spots indicates that the illumination uniformity is poor.

Shadow: When the light source is projected onto the ground to form an aperture, the diameter of the aperture is related to the diameter of the lamp cover and the height of the installation. The larger the diameter of the lamp cover, the larger the installation height, and the larger the aperture diameter, and vice versa. If the aperture and the aperture are not crossed, shadows will be generated, resulting in poor illumination uniformity and easy visual blind spots.

Glare: Glare refers to visual conditions in the field of view that result from undesired brightness distribution, or extreme brightness contrast in space or time, causing visual discomfort and reducing object visibility. A bright feeling that the human eye cannot adapt to in the field of view may cause disgust, discomfort, or even loss of visibility, such as excessive brightness in a certain place in the field of view or excessive brightness change before and after. Glare is one of the important causes of visual fatigue. If the height of the lampshade becomes smaller, the aperture diameter will become larger, and the effect of eliminating the shadow is obvious. However, if the height of the lampshade is too small and the light source is exposed, looking up in the warehouse will see a particularly bright light source, which is easy to cause glare. It will affect the visual perception of drivers driving vehicles such as forklifts in warehouses.

2. Lighting layout plan and lighting test situation

Under the designed power and luminaire layout conditions, four different lighting fixtures were selected depending on the size of the lampshade and the material of the reflective surface. The schematic diagram and physical map of the luminaire are shown in Figure 1.

After the construction of the typical construction area (21 m × 16 m), a total of 9 lamps were installed, and the actual illuminance of the site was tested in a completely dark environment. The results are shown in Table 2.

Through the lighting test, it is found that the illumination of the first three schemes can basically meet the design requirements, but the lighting effects are not ideal. There are bright spots, shadows or glare, which affects the normal operation of the production operations in the warehouse, and there are potential safety hazards. Only the fourth scheme can meet the illumination requirements, and there are no hidden dangers such as bright spots, shadows and glare that affect safety production, and basically meet the lighting requirements of production operations.

3, the application of LED lamps

At present, there are many types of LED lamps that can be used in warehouse lighting on the market, such as "corn lamps, mining lamps, high-bay lamps" and so on. One of the LED warehouse lights breaks through the design concept of traditional luminaires. Based on the lightweight and versatile design goals, it can realize flexible angle adjustment and meet the lighting requirements of many occasions. At the same time, the LED warehouse light fixture is designed with a mounting bracket on the back, which can be adjusted according to actual needs, so as to be convenient for installation and adjustment in different occasions. The LED warehouse light has the following advantages:

1) The illumination angle of the luminaire can be adjusted according to the needs.

2) Lightweight design, compared with the weight of traditional warehouse lamps, the advantages are very obvious, and the installation is simple and easy to maintain.

3) Energy saving and environmental protection. In order to achieve energy saving and emission reduction in the port area, the warehouse lighting is optimized. The new LED lighting fixture with a power of 90W is selected to replace the 250 W metal halide lamp at the same position. After the typical construction, the lighting test is carried out, and the average illumination reaches 105 lx. Bad phenomena such as shadows, highlights and glare satisfy all the lighting requirements of warehouse production operations.

Fourth, energy saving and economic situation comparison

Through the comparison of the two warehouse lighting schemes, it is found that the functions can meet the lighting requirements of the production operation, but the LED lamps have obvious advantages in terms of economy and energy saving. See Table 3.

Calculated according to 365 days per year and working 10 hours a day, it can save 312,000 kWh of electricity and save 64% of energy every year. If the electricity bill is calculated at 1.0 yuan/kWh of industrial electricity, the annual electricity cost can be saved by about 300,000 yuan. Although the cost of purchasing LED lamps is about 3 to 5 times higher than that of metal halide lamps, the cost of use can be fully recovered in one year.

V. Conclusion

LED lamps are a new type of lighting fixtures that are energy efficient, environmentally friendly, and green and healthy. At present, the promotion of domestic LED lighting applications is lagging behind in developed countries. Except for outdoor lighting such as street lights and tunnel lights, the level and scale of indoor lighting applications with the greatest market potential are still quite limited. The lighting of warehouses in the port area began to be tested with LEDs. In the future, the port yards and terminal lighting can also try to use LED lights to further promote the construction and development of green ports. Therefore, there is still a lot of room for the development of LED lamps in the port area.