The necessity and implied situation of lighting quality in the industry

1 The rapid development of China's economy and the acceleration of industrialization have provided favorable conditions for the development of the lighting industry. High-quality lighting systems play a pivotal role in industrial production, with features that increase productivity, reduce accidents, and protect worker health. However, from the current situation, the quality of lighting is often overlooked.

2 Lighting and lighting quality People get information from the outside world through organs such as the ear, nose and nose, and understand the world. 80% of the information comes from vision. Visible light is a necessary condition for the visual organs to start working. When there is no natural light or natural light in people's field of vision, the human eye must use the lighting to obtain information. Lighting is not only related to people's work and study, entertainment, health and safety, but also related to social economy, ecological environment, industry and construction (as shown in 1).

The quality of lighting directly affects people's work efficiency and physical and mental health. International Lighting Association (CIE) and the National Association of Lighting Engineers (IESNA) and other international lighting agencies have done a lot of research on visual function, glare and light color. Corresponding lighting quality indicators.

In addition to quantitative indicators such as illumination, uniformity, color rendering index, and glare, lighting quality also includes non-quantitative indicators that affect lighting quality, especially those that have psychological effects on people. Lighting designers can use lighting technology to use light, light, and light to modify architectural space, shape, virtual reality, bump, texture, surface color, etc. to meet people's aesthetic requirements and psychological comfort requirements.

Lighting quality is a complex indicator system. It not only contains physiological indicators, but also psychological indicators. There are still many controversies, but one thing is certain: lighting quality has received more and more attention in the world. Compared with the number of illuminations (illuminance, brightness, uniformity, etc.), if the quality of illumination cannot be the main role in the lighting system, it should at least be as important as the number of illuminations.

China's industrial lighting field has relatively simple considerations for lighting quality. The main reference to the CIE standard "Indoor Workplace Lighting" (S008/E-2001) is to establish a uniform glare value UGR standard and a general color rendering index Ra standard.

3 The importance of lighting quality in industrial production

3.1 Characteristics of industrial lighting

Industrial lighting is a kind of functional lighting, which has the characteristics of complicated working surface, important function and close correlation with production. It covers a wide range of locations, from fine processing in small workshops to heavy industrial production in tall plants, as well as production in harsh environments such as humidity, low temperatures, corrosion, dust, flammable and explosive atmospheres. activity. The working objects, operating methods, and working conditions vary widely, so different types of work place different requirements on lighting. A good industrial lighting system requires reasonable illumination, chooses the right luminaire, and handles the relationship between general lighting and local lighting to ensure the necessary color rendering index, with high efficiency, energy saving, low glare and so on.

3.2 Industrial lighting design and lighting quality elements

3.2.1 Fully meet the environmental requirements of process and working conditions

Industrial lighting design involves chemical, light industry, textile, metallurgy, mining, petroleum, paper, food, tobacco, thermal power, pharmaceutical, rubber, leather, wood, glass, cement, electronic processing and many other industries, production processes in different industries The environment is very different from the working conditions, and the lighting requirements are not the same. The lighting design should be targeted and closely related to the visual needs of the field staff, taking into account the special requirements of each production process and working environment.

In special occasions such as production, use, processing, storage of flammable liquids, dust, fibers, solids, etc., fires caused by lighting fixtures and fires caused by bulb heat sources should be prevented; open lamps should be used in normal production sites, but reliable The safety distance is strictly separated from the combustible materials; the underground oil pump room is sealed with lamps; in the case of flammable and explosive, the explosion-proof type lamps should be used.

If the humidity in the workshop is large, it is necessary to use lamps with good waterproof performance; in the cold storage environment, the insulation performance of lighting fixtures and wires is reduced, which is easy to cause short circuit. The lamps in such environments should use moisture-proof lamps or moisture-resistant waterproof porcelain. For the lamp holder, the lead of the lamp should be tightly sealed. It is possible that the metal parts of the leakage caused by the insulation are required to be reliably grounded. If the requirements are still not met, a neutral point ungrounded power supply system or a low voltage 36V supply may be used.

In dusty workshops, dust-proof luminaires must be used, and the degree of protection of the luminaires should be carefully selected; for those that can be touched by humans, there should be good protection against electric shock.

For the upper space of high temperature places (such as above the steel ladle, hot rolling stock storage, heating furnace, etc.), it is advisable to use a light-emitting luminaire with a long-range beam or a medium-narrow beam.

3.2.2 Illumination standard and uniformity

At present, China mainly adopts the national standard “Architectural Lighting Design Standard” (GB50034-2004) as the main basis for lighting design, but the working condition interface included in this standard is very limited, and many working conditions cannot find the required illuminance standard. The lighting design should be based on the specific working conditions and process requirements. The experience can be applied to the similar illumination standards and uniformity requirements, and the relevant standards of CIE and IESNA can also be used. When designing lighting, usually according to the combination of "general lighting" and "local lighting", general lighting is considered according to the total average illuminance of 5% to 15%, and the minimum illuminance should not be lower than 30lx.

3.2.3 Illumination stability

Due to fluctuations in the supply voltage of the lighting system, vibration and sway of the luminaire, the illuminance of the working surface changes, the quality of the lighting is reduced, and the production is affected. In the process of industrial production, the stability of the contrast is relatively high. In the lighting design, the following measures can be taken to improve the illumination stability: a. Improve the quality of the power supply and reduce the voltage fluctuation. If there is a high-power device in the power supply system, the lighting system should be powered by a separate circuit; if the harmonic content of the power supply system is high, the isolation transformer should be used to improve the stability and reliability of the lighting.

b. In the vicinity of the strong airflow area of ​​the air inlet and outlet, the luminaire should be avoided as much as possible. If it cannot be avoided, the fixture should be installed with reliable fixing measures.

c. When using a gas discharge lamp in a high-speed operation equipment area, the stroboscopic effect of the lighting system should be improved. Generally, the capacitive phase shifting method can be used or the lamps can be respectively connected to different phases, and the operating frequency of the gas discharge lamp source can be increased to reduce the stroboscopic effect.

d. When installing the luminaire in a vibrating place, shock absorbing measures must be taken to improve the illuminance stability.

3.2.4 Color rendering and color temperature

When it comes to the color of light, it is necessary to distinguish the appearance of light from the appearance of the color of the object it produces, the former being represented by color temperature and the latter by color rendering. The color temperature of light has a certain relationship with the ideal illuminance (as shown in 2). Warm light at low color temperature is easily accepted at low illumination levels, and cold light at high color temperature is more popular at higher illumination levels. .

When people need to identify the appearance of mechanical equipment, processed parts, safety signs, etc. (such as paint shop, food processing workshop, etc.), or when color inspection is required, the position of color temperature and color rendering in the evaluation of lighting quality is extremely important. It is necessary to select a light source with good color rendering and suitable color temperature. For example, in the meat workshop, a light source with good warm color and good color rendering should be selected; in the canning workshop, the light source should have good color rendering in order to ensure the freshness of the observed food.

3.2.5 glare limit

Glare is the high-intensity interference light that enters the field of view and affects people's vision. In severe cases, it can temporarily or even permanently lose the visual function of the human eye. Glare is mainly caused by the type of lamp and light source, installation method, aiming direction, reflective material, ambient brightness and working position. In industrial lighting design, it is necessary to avoid high-intensity reflected glare and direct glare in the field of view. The lamp can be properly adjusted by properly selecting the light distribution of the lamp, limiting the minimum protection angle of the lamp, rationally arranging the position of the lamp, and combining the vision of the worker. A method such as aiming angle reduces glare.

3.2.6 Utilization of natural light

In today's energy and environmental problems, how to make full use of natural light and save electricity for lighting has attracted the attention of the international architecture and lighting industry. In order to effectively utilize the inexhaustible natural light and green energy, CIE organized the investigation and observation of the global natural light resources, namely the IDMP program, and will release the natural lighting of the building and the performance of natural light in the building. Publications such as natural lighting design for buildings.

In the field of domestic industrial lighting, architectural lighting design and lighting design often have insufficient communication. Coupled with the irrationality of lighting control, many lamps are still turned on for a long time without lighting during the day, and energy waste is quite serious.

3.2.7 Lighting control and energy saving

In the field of industrial lighting, there are generally phenomena such as single control mode, too concentrated control box, few control loops, inconvenient operation, and waste of energy. A high-quality lighting system requires both a suitable lighting environment and lighting energy-saving purposes, which often needs to be achieved through a lighting control system. At present, the main lighting control systems are: low-voltage circuit breaker or manual switch direct control mode, relay contactor control mode, computer control system. Computer control systems used in lighting engineering include direct digital control systems (DDC), distributed control systems (DCS), and fieldbus control systems (FCS).

In the past ten years, the intelligent lighting control system has been successfully applied in practical engineering and has developed rapidly. Its development direction has shifted from intelligent function development to more human-oriented behavior. Based on the research of visual effects, visual physiology and psychology, and human behavior, it develops intelligent lighting with more scientific and technological content, people-oriented, high efficiency, comfort and health.

The introduction of intelligent lighting control system has effectively improved lighting quality, lighting system efficiency, power grid quality, and light source life, greatly reducing system energy consumption, operating costs, management and maintenance costs. Intelligent lighting systems have been widely used in sports venues, office buildings, parking lots, park squares, hotel restaurants, and comprehensive buildings. It is believed that in the near future, intelligent lighting will gradually penetrate into the field of industrial lighting.

3.2.8 Reliability and security

The quality of lighting is also reflected in the reliability and safety of lighting systems. In some industrial production sites, serious safety accidents may occur when the lighting system is suddenly interrupted. Therefore, the reliability and safety of the lighting system must be improved. The following aspects:

a. Provide reliable power supply conditions, use high-quality switchgear in the power supply circuit, and use separate loop power supply, dual-loop power supply, backup power supply or uninterruptible power supply (UPS) for the lighting system, and the lamps are interlaced. Form the distribution circuit.

b. Accident lighting and evacuation lighting are required in densely populated workshops or in more important workshops.

c. Choose high-quality lamps, configure high-quality electrical accessories and light sources.

d. Moving and rotating production machinery requires good illumination and avoids stroboscopic effects.

e. For tall and complex pipelines, the luminaires should be installed in appropriate positions and heights to avoid shadows on the work surface.

f. In the places of humidity, dust, corrosion, explosion hazard, etc., appropriate lamps, switches and distribution lines should be selected according to the regulations.

3.3 The importance of lighting quality

In the contemporary society where industrialization is accelerating, lighting can no longer stay at the level of meeting basic illumination, and illumination standards are constantly improving, and the differences between countries' illumination standards are shrinking. Through investigation, it can be found that the illumination standard in the field of industrial lighting is generally not too high. Like commercial lighting, it is consciously close to the standards of developed countries in Europe and America. The situation exceeding the national standard rarely occurs in the field of industrial lighting. Generally, it is practically adopted to slightly exceed the national standard illumination value. The way. In the engineering case of functional lighting, it may be appropriate to appropriately increase the illuminance standard as one of the measures to effectively improve the quality of lighting.

Good industrial lighting has the functions of improving labor productivity, reducing production costs, improving product quality, protecting workers' vision, ensuring workers' physical and mental health, reducing fatigue, concentrating attention, and ensuring safe production. People are pursuing work efficiency while pursuing work. Comfortable, requiring the lighting environment to meet people's psychological and physiological comfort, it is necessary to re-recognize the lighting quality indicator system. If the assembly workshop provides good lighting conditions, the assembly speed and assembly quality can be directly improved, thereby reducing costs and achieving better economic benefits. In foreign countries, lighting designers and industry have agreed that productivity gains from high-quality lighting will benefit homeowners. Economic analysis shows that if workers' productivity is increased a little, the economic benefits obtained are far greater than the cost of a lighting system.

4 problems in industrial lighting

4.1 Industrial lighting is slower than other industries

Industrial lighting is the focus of lighting research. The earliest international lighting research is related to industrial lighting. The first lighting standard in China is mainly industrial lighting. However, due to the decline in the proportion of heavy industry in the period after the reform and opening up, the emphasis on lighting is not enough, which makes the research and development of industrial lighting fall into a low tide.

4.2 insufficient attention to industrial lighting

In the process of production of industrial and mining enterprises, each enterprise attaches great importance to the technology in its industry. It often introduces advanced production equipment and professional technicians periodically, but often ignores the lighting equipment updates closely related to them. Focus on technological progress and development in the lighting industry. Some owners, design institutes, supervisors, and construction units in the field of industrial lighting have problems in understanding the development of the lighting industry and keeping the concept old.

4.3 Insufficient investment in industrial lighting

Due to the lack of attention of the owners, the design of the design institute is traditionally old-fashioned. The initial investment control of the lighting design, lighting equipment bidding, and lighting engineering is strictly controlled throughout the industrial field, so that some low-quality lighting systems have emerged.

The author conducted a site inspection of an ironworks and communicated with field equipment maintenance personnel. It was found that more than 50% of the maintenance personnel used the lighting equipment maintenance, which greatly increased the maintenance cost and operating cost; the installation and maintenance of the lighting system It is a very cumbersome thing, the business leaders don't pay much attention to it, and they don't know the lighting environment and the closeness of the operators. The operators have a deep understanding. According to statistics, the cost of purchasing lamps only accounts for about 4% of the total cost, and 3 shows the relationship between the costs of the lamps.

4.4 Lighting design and user needs are very different

Industrial lighting has the characteristics of complicated working environment. It is difficult to consider every detail of the scene during lighting design. The drawings of the design institute often show incomplete phenomena. Therefore, during the construction process, the construction unit also during installation and commissioning. Can not take into account the real needs of the end user. After on-site inspection, the author found the following problems: a. Lighting design is not reasonable, lacks communication with operators, the designed solution is not close to the process requirements; lighting system is not energy-saving, does not have time-sharing, partitioning , the control method of the sub-process.

b. The lighting mode is single, the lighting of the lamps is not suitable for the site demand, resulting in glare and light waste.

c. The arrangement of the lamps is not reasonable. The design position is seriously different from the area where the lighting is actually needed. The installation position of the lamps is incorrect and the glare is serious. Many places have to reinstall the lamps and lay the lines after completion.

d. The maintenance cost of the luminaire is high, and the equipment and wiring of the lighting system are very cumbersome to maintain.

e. The lighting control mode is single, the number of lights in a single circuit is too much, the control box is too concentrated, the control is not flexible enough, the operation is very inconvenient, and the work efficiency is reduced.

f. The control loop does not take into account the weather, season, time period, function and other factors. Sometimes there is a phenomenon of maintenance lighting and normal lighting. Some areas need lighting during the day, but the lamps in these areas are connected with the lamps that do not need illumination during the day. .

5 Conclusion

Since the implementation of the green lighting plan, great achievements have been made in engineering demonstration and international exchange, and gradually affected the fields of commercial lighting, night lighting, industrial lighting, etc. Many industrial and mining enterprises have gradually recognized the importance of lighting. While industrial lighting design meets the basic lighting functions, it is more important to emphasize the quality of lighting, so that it is economical, safe, energy-saving, and has the characteristics of the times.