Application of LED light sources and lamps in industrial lighting

In recent years, the application scope of semiconductor lighting has become wider and wider. LED lamps have moved from outdoor to indoor, from landscape lighting and road lighting to indoor decorative lighting and functional lighting of civil buildings, and are now moving towards the field of industrial lighting.

　　1. Emphasis on functionality

　　Compared with other lighting, industrial lighting emphasizes functionality and has higher requirements for various technical indicators of lighting; it has higher requirements for environmental adaptability and visual effects. In lighting design, the most basic indicator is illumination. The illumination requirements for some industrial sites are as follows:

　　It can be seen that the illumination requirements of industrial buildings range widely, from tens, hundreds, or even thousands of lux. The illuminated space is also very complex: outdoor lighting for reaction pots and pipelines in the petrochemical and pharmaceutical industries, raw material yards in processing enterprises, and indoor lighting for tall factories in the steel industry and assembly workshops in electronics factories. LED lighting needs to select different light source power combinations and lamp types according to the above different illumination and space.

　　2. Complex environment and diverse lighting selection

　　Another characteristic of industrial buildings: complex environment and harsh conditions. Therefore, different types of lamps should be selected according to the various environmental conditions of the lighting venue:

　　1. In humid places, waterproof lamps with corresponding protection levels or open lamps with waterproof lamp holders should be used;

　　2. In places with corrosive gases or steam, anti-corrosion enclosed lamps should be used. If open lamps are used, each part should have anti-corrosion or waterproof measures;

　　3. In dusty places, appropriate lamps should be selected according to the corresponding dust protection level;

　　4. In places where clean space is required, clean lamps that are not easy to accumulate dust and are easy to wipe should be used;

　　5. In high temperature places, it is advisable to use lamps with good heat dissipation performance and high temperature resistance;　　

6. Lamps used in places that are susceptible to mechanical damage or where the light source may fall off and cause personal injury or property loss should have protective measures;

　　7. Lamps used in places with large vibrations such as forging hammers and large bridge cranes should have anti-vibration and anti-falling measures;

　　8. In places where ultraviolet radiation must be prevented, ultraviolet-blocking lamps or ultraviolet-free light sources should be used.

　　The IP (INGRESS PROTECTION) protection level system was drafted by IEC, which classifies electrical appliances according to their dust and moisture resistance characteristics. The IP protection level is composed of two numbers. The first number indicates the level of dust isolation and foreign body intrusion prevention of the lamp, and the second number indicates the degree of moisture and water intrusion of the lamp. The larger the number, the higher the protection level (for details, please refer to the corresponding electrical manual).

　　3. LED products used in industrial lighting

　　LED light sources and lamps have the characteristics of low voltage power supply, small size, light weight, and fully enclosed installation. Therefore, they can be widely used in many of the above-mentioned places.

　　The lighting source of tri-proof lamps used to be compact fluorescent lamps (now LEDs are also available). The lamp body is made of ABS material, and the lamp body and lampshade are tightly combined, which has waterproof, dustproof, anti-corrosion and other functions. It is suitable for lighting in high-precision places, such as pharmaceutical factories, food processing plants, and other places that require purification and harsh environments (see Table 3, Figure 1).

Figure 1 Appearance and installation dimensions of tri-proof lamp

　　There is also a special case in industrial lighting: places with explosion and fire hazards. The lamps used in such places should comply with the relevant provisions of the current national relevant standard "Design Specifications for Electrical Installations in Explosive and Fire Hazardous Environments" (GB50058-92) (see Figure 2). LED lamps are low-voltage powered, and the probability and degree of sparks in the event of a fault are relatively small. Therefore, their application in the field of explosion-proof lamps will have great advantages.

Figure 2 Technical indicators and dimensions of explosion-proof energy-saving fluorescent lamps

　　When selecting light sources for factory lighting, in addition to meeting the requirements of illumination and environment, they should also meet conditions such as color rendering, color temperature, and start-up time. They should be determined after a comprehensive economic and technical analysis and comparison based on the efficiency, lifespan, and price of light sources, lamps, and ballasts.

　　The color rendering requirements for industrial sites can refer to Table 5.3.1 in the "Architectural Lighting Design Standard" (GB50034-2004). For ordinary sites, the color rendering index is generally required to be greater than 80. However, some assembly workshop lighting or key lighting areas for product inspection have relatively higher requirements for the color rendering index of the light source. At present, the color rendering index of LED light sources needs to be further improved.

　　Color temperature is also an issue that needs to be paid attention to in factory lighting. Different workshops require different color temperatures: the high-temperature workshops of metallurgical enterprises will use cold white light sources with high color temperature, while the cold storage of food factories can use warm white light sources with low color temperature. This is also an issue that should be paid attention to when designing LED factory lamps.

　　Glare is a problem that should be paid special attention to in industrial lighting. Since workers in industrial buildings work long hours in production sites and their positions are relatively fixed, the light in the production sites has a considerable impact on workers' vision. Therefore, preventing glare is something that should be paid special attention to in industrial building design. LED lamps are directional light sources, so more attention should be paid to the occurrence of light problems than traditional lamps.

　　Factories and enterprises not only have a harsh space environment, but also the power supply may be unstable. The start and stop of large machinery will cause voltage fluctuations, and the large-scale use of electronic products such as thyristors for industrial control will lead to the generation of a large number of harmonics. Therefore, the power supply and control part of LED lamps need to have considerable anti-interference capabilities in order to be well applied in the industrial field.

　　In some factory workshops, rotating motors, reciprocating devices, polishing workshops, etc., under the stroboscopic effect of gas discharge lamps, will have some impact on visual operations, causing adverse consequences and even the risk of personal injury. Therefore, in the lighting of these occasions, the non-stroboscopic effect of LED light sources is more suitable than gas discharge lamps.

　　In addition, in local lighting and equipment maintenance lighting for mechanical equipment such as lathes, LED low-voltage lighting has the absolute advantage of replacing traditional light sources. The control flexibility of LED lamps makes it very convenient to implement group control of work sections or processes in production workshop lighting. This also fully reflects the advantages of LED lighting in energy saving and can greatly reduce the risk of electric shock. In addition, the long life of LED lamps is also a guarantee for long-term safe production of industrial enterprises.

　　Although factory lighting has a wide range, complex functions and high requirements, the application of LED light sources and lamps has begun to enter the field of industrial lighting, and the prospects are very broad. In the future, if LED light sources and lamps are to have a larger and broader development space in the field of industrial lighting, the technical personnel of the lighting industry need to study hard, overcome difficulties, and invent more, better, and more practical LED lamps that meet various industrial lighting application segments.