According to the national "Several Opinions on Accelerating the Development of Sports Industry to Promote Sports Consumption" and the spirit of "Developing National Fitness, Athletic Sports and Sports Industry" proposed by the two government work reports, the sports industry will become an important force to promote sustained economic growth. By the end of 2013, there were more than 1.69 million sports venues and more than 6,000 large-scale sports venues in the country [1]. The number of sports venues in China will continue to increase in the next few years, which indicates that the construction of sports stadiums in China is still at a high-speed development stage. For the stadiums to be built in the future, the planning should be more scientific, the design should be more reasonable, and the functions must first meet the requirements of sports and sports events. In particular, China has initially formed a sports professional competition system, and has taken on more and more Many international major events have more stringent requirements for sports venues.
The functional requirements of sports lighting are very high, especially in sports venues with TV broadcasts, which have higher functional requirements for lighting. High illumination, high uniformity, high light source color rendering in stadiums, etc. require good lighting. In addition to the product, reasonable horse setting and high level of lighting design, there is also a high power consumption. A large number of actual surveys have shown that because the position of the horseway, that is, the installation height of the lamp is not reasonable, it not only directly affects various lighting technical indicators, but also causes a large amount of waste of electrical energy. This paper will analyze the technical indicators of lighting design and the main factors affecting the lighting power density through the actual survey of a large number of stadiums, in order to provide reference for lighting designers in the design of stadium lighting. At the same time, it is a hot issue in the current lighting applications - whether LED can be used for sports lighting for further discussion.
1 Stadium lighting survey survey
The Construction Quality Inspection Center of China Academy of Building Research has conducted lighting inspections on hundreds of stadiums across the country for many years, and has undertaken lighting inspection, commissioning and acceptance of all venues of the Olympic Games, Asian Games, Universiade and National Games. A large number of lighting engineering on-site inspection data. In the revision process of "Sports Lighting Design and Testing Standards", the member groups and lighting companies of the compilation team have designed a large number of important sports venues at home and abroad, occupying a very important position in lighting design, and have rich design experience. Provides a lot of valuable data. Analysis and summarization of this valuable information laid the foundation for our completion of the revision of the standard.
1.1 Overview of the survey of stadiums
The collected data includes more than 300 venues for the actual measurement and statistics of important sports venues in the country, all of which are competition venues, including a large number of high-level competition venues (V or VI), and domestic and foreign sources provided by various lighting design units. The lighting design data of major sports venues has collected more than 1,000 venues, including outdoor stadiums, comprehensive gymnasiums, tennis halls, swimming pools, competition venues and training venues. In more than 1000 cases of data, due to incomplete project content, or the test data can not meet the standard requirements, this part of the venue has been removed from the statistics, the number of stadiums that can participate in statistical analysis is more than 900, including 462 competition venues and training. There are about 440 venues. The survey contents include lighting methods, fixture installation height, lighting power, illumination, illumination uniformity, illumination ratio, color rendering index, color temperature, glare, and so on.
1.2 Number and functional level of the venue
In the competition venues of the survey, there are many outdoor stadiums and comprehensive gymnasiums. The number of venues with functional level V is slightly higher than Grade IV and VI, as shown in Table 1.
1.3 luminaire installation height and functional level
According to the statistics of the installation height of the luminaire, the following conclusions can be drawn:
1) The installation height of the stadium lamps is between 40≤h<50(m), accounting for 45.7% of the total heights, which means that almost half of the installation height of the existing stadiums is between 40-50m; The installation height of the stadium, tennis hall and swimming pool is between 15≤h<25(m), which is more than 60% of the total height, which means that the installation height of the stadium is generally between 15 and 25m. .
2) In general, when the height of the lamps is low, the probability of occurrence of low-level (IV) competition venues is too large; when the height of the lamps is too high, the probability of occurrence of high-level (VI) competition venues is too large, because high-level refers to major The event, high-definition television broadcast, the stadium has more seats in the auditorium, the volume is large, and the position of the horse track (the height of the installation of the lamp) will also increase accordingly. The installation height range of the luminaire and the relationship with the movement level are shown in Table 2 - Table 3:
2 Statistical data error analysis and data selection
In the data of more than 900 venues surveyed and surveyed, due to various reasons, such as unreasonable position setting of the horse track, improper lighting distribution of the lamps, and serious occlusion of the building structure, some data dispersion is large. According to the statistical principle, according to the statistical principle, The theory makes a trade-off between the data.
2.1 Reasonable error range allowed by statistics
Error probability distribution: When the error of the statistical value is within the range of ±0.6745σ (standard error), the probability is 50%; when the error is within the range of ±2σ, the probability is 95%; when the error is within the range of ±3σ, the probability is 99.7 %; the probability that the error appears outside the ±3σ range is only 0.3%.
In the limited statistical data, the probability error 3σ to 5σ is generally selected as the reasonable error range or the statistically allowed maximum probability error.
2.2 The method of selecting suspicious statistical values
Usually, a set of statistical values ​​will find that a certain statistical value is very different from the remaining statistical values. If this value is retained, it will have a great influence on the average value and the contingency error. If there is no sufficient reason, only According to the error theory, the choice of the value is correct. The steps to determine the data trade-off are as follows:
1) Find the arithmetic mean and the probability error of the single value, and the suspicious data should be included in the calculation;
2) Calculate the ratio d/γ of the suspicious large deviation to the probability error;
3) According to the ratio of the number of statistics (n) listed in the table and the corresponding deviation d and the probability error γ (d / γ), determine the trade-off;
4) If the d/γ of the statistical value is greater than d/γ in the table, this statistical value can be discarded.
The above numerical discarding rule is simplified based on the Chauvenet value discarding standard.
According to the above principles, the data of the actual survey was processed, and the suspicious values ​​with large discrete values ​​were discarded.
3 analysis of actual survey results
The survey results show that: for most stadiums, due to the use of high-performance light sources, lighting products, with high efficiency, environmental protection, energy saving, long life and other characteristics, coupled with high-level lighting design, the technical indicators are basically Can achieve the technical indicators specified in JGJ 153 "Sports Hall Lighting Design and Testing Standards". This paper only further analyzes the relationship between lighting indicators and lighting energy savings to determine reasonable lighting power density values.
3.1 Lighting indicators and lighting energy saving
1) Illuminance and illuminance uniformity: This is an important indicator in lighting design, and also the main content in lighting detection, especially the vertical illumination of the camera direction and the illumination uniformity of the camera. This indicator is difficult to achieve when the horse's path is too short or too close to the venue or other conditions (the athlete can't light the front of the athlete). It is proved that the position of the pole and the horseway is particularly important for the implementation of the lighting scheme, so in the architectural design Should pay attention to it;
2) Illumination ratio: It refers to the ratio of the average horizontal illuminance to the average vertical illuminance. When there is no TV broadcast, the horizontal illuminance value has specific provisions. When there is a TV broadcast request, the standard only specifies a range for the horizontal illuminance value, that is, the average horizontal illuminance. For the average vertical illuminance of 0.75 ~ 1.5 times, the value of vertical illuminance is mainly determined by the camera type and TV broadcast requirements. The ratio of horizontal illuminance to vertical illuminance is mainly to ensure the overall lighting effect and lighting stereoscopic sense. It is sometimes difficult to control this indicator, especially when it is limited by the conditions of the site and the horse course. It is often necessary to increase the vertical illumination value by increasing the horizontal illumination, which makes the ratio too large, which not only affects the quality of the illumination, but also Greatly increase the lighting power, resulting in energy waste. Through reasonable lighting design, effectively controlling this index within the specified range is of great significance for improving lighting quality and saving energy. The illuminance ratios obtained from the survey results are shown in Table 5.
The International Commission on Illumination (CIE) and the International Sports Federation (GAISF) stipulate that the ratio of average illuminance to average illuminance is between 0.5 and 2.0. The International Broadcasting Service (OBS) stipulates that the ratio of the main division (PA) is 0.75~ 1.5, the ratio of the total competition area (TA) is 0.5 to 2.0. According to the actual survey results of the stadiums in China, the ratio of the horizontal illumination to the vertical illumination of the stadium is set at 0.75 to 1.8; the stadium is set between 1.0 and 2.0. More reasonable, this is more conducive to energy saving.
3.2 Lighting power density value
China's "Architectural Lighting Design Standards", "Urban Road Lighting Design Standards" and "Urban Nightscape Design Codes" stipulate lighting power density values ​​for office buildings, commercial buildings, traffic buildings, industrial buildings and roads. The lighting power density of stadiums has not been specified in the "Architectural Lighting Design Standards" and "Sports Lighting Design and Testing Standards". Due to the complexity of sports building structure, the diversity of competition projects and the high requirements for lighting in sports competitions, it is difficult to determine the lighting power density. Relevant surveys show that different types of venues, including stadiums, gymnasiums, swimming pools, and tennis halls, can achieve more than five times the lighting power required to achieve the same illumination. Also, due to different building structures, the same venue, when the same illumination is reached. The lighting power density can also be several times different. It can be seen that the development of the stadium power density value is of great significance for lighting energy conservation [2].
In accordance with the above error theory, this paper analyzes and collates the data obtained from on-site inspection and lighting design, and obtains the lighting power density (LPD) value of TV broadcast training venues and TV broadcast competition venues, in order to develop stadium lighting power density values. Provide a reference basis.
The data of 462 competition venues in the survey were processed according to the error theory. Finally, a total of 448 competition venues were used to calculate the lighting power density (LPD) value. This paper mainly analyzes the illumination power density values ​​of the four types of venues (stadium, gymnasium, tennis hall, swimming pool) of commonly used metal halide lamps. Take the stadium and the gymnasium as an example. The statistical results are shown in Table 6 - Table 7.
In order to further explain the variation law of lighting power density in stadiums, the statistical results of the above surveys are taken as examples in the stadium, and the track and field and football projects are drawn into maps for analysis and understanding. The relationship between the installation height of the luminaire and the power density and the relationship between the competition level and the power density are shown in Fig. 1 to Fig. 4.
From the results of the actual survey, the following conclusions can be drawn:
1) Under the same functional level, the illumination power density value increases with the increase of the installation height of the lamp, and the regularity is strong;
2) The illumination power density is related to the function level. The higher the level, the greater the illumination power density and the nonlinear relationship;
3) The lighting power density of the outdoor stadium (soccer and track and field) football venue is higher than the lighting power density of the track and field venue, which is related to the size of the venue;
4) Different lighting modes should be designed for comprehensive sports venues.
4 outlook
The lighting of stadium venues mostly uses traditional light source high-intensity gas discharge lamps - metal halide lamps, and the power of lighting lamps is up to 1000W/2000W. The installation height of the luminaire can reach 50-60m. With the rapid development of LED lighting applications, the application of LEDs in stadium lighting has attracted more and more attention. So far, a number of newly built and rebuilt stadiums at home and abroad have adopted LED lighting, especially training venues, such as the National Sports General Administration Training Stadium, the Olympic Sports Center Training Stadium, the Workers Stadium Football Stadium, and the Shantou University Stadium. LED stadiums have been adopted in stadiums such as Michigan State University in the United States, and LED venues are also being used in competition venues, such as the NRG Stadium in the United States, the PNC Stadium, the Chelsea Football Stadium in the United Kingdom, and the Ekinox Stadium in France. LED lighting [3]. It is expected that more Olympic stadiums will use LED lighting by the 2022 Winter Olympics.
LED lighting is more suitable for sports lighting because of its unique characteristics such as low power consumption, adjustable color quality, flexible control, and instant ignition. Since the stadiums must balance the competition and television broadcasts, the requirements for lighting are very high. Further discussion on the stability, glare and strobe of LED lighting is needed.
The use of LEDs for stadium lighting must meet the corresponding requirements in terms of product performance and application technology:
1) LED product performance requirements:
a) LED lamp power and luminous efficiency value: the lighting illumination of the stadium venue is as high as 2000lx. Although the luminous efficiency of the LED light source is high, to achieve such high illumination, the single lamp power can reach several hundred watts (sports hall) or even kilowatts. (Stadium), such high-power lamp cooling is a big problem, and various companies are also working hard to solve this problem. At present, such products have been introduced to the market at home and abroad, forming a series of 1000W single lamps and used in sports venues. And the port terminal. According to the test results of the National Construction Quality Inspection Center for the stadium lighting fixtures of several major LED production enterprises in China in 2014, the efficacy of the lamps is above 90 lm/W. It can be seen that the LED light effect can meet the requirements.
b) LED color performance index: color rendering index CRI is an important indicator for evaluating color. The newly developed CQS is a new color rendering index evaluation system for traditional light sources and SSL light sources, which is the dominant position in the market. The CRI evaluation method can still be used to excite phosphors to produce white light. The emission spectrum of the yellow phosphor excited by blue light is mainly yellow-green light, and the red component R9 is absent. Therefore, the regulation of R9 should be added in the relevant standards. In addition, the evaluation of LED color performance indicators are also the color temperature, the color tolerance of the same kind of light source, the color deviation during the lifetime and the deviation of the lamps in different directions. Because the stadium has a TV broadcast, color performance is undoubtedly very important.
c) LED lighting: The installation height of the stadium's luminaires is usually between ten and tens of meters, and the uniformity of the contrast is extremely high (referring to the high-level competition), and the projection distance of the light reaches 100. A few tens of meters, the beam angle is only a few degrees, different projection distances need different light distribution, often a sports field needs a variety of light distribution, suitable for medium light distribution, narrow light distribution, and ultra narrow in sports venues Light distribution.
d) Weight requirements for LED lamps: Because the installation height of the lamps is relatively high, the weight of the control lamps can reduce the load on the building structure and greatly reduce the construction cost. LED lamps often increase the weight of the lamps because they need to solve the heat dissipation problem. Therefore, the weight of the lamps should be limited.
2) LED lighting application technical requirements:
a) LED color drift in the venue: in the color performance indicators of LED products, the color rendering index Ra, color temperature Tcp, color tolerance of the light source, color deviation can be quantitatively specified, but in practice With the influence of various factors, the on-site color rendering index Ra will increase, and the color temperature Tcp will decrease, which will make a big difference with the initial value, such as an Olympic venue, after several years of use, the scene The color rendering index Ra increased from 81 to 91, and the color temperature Tcp decreased from 5500K to 4400 K. The above is the field data of the metal halide lamp, and how much color drift the LED used in the stadium remains to be verified.
b) Glare problem of LED lighting: Glare in the stadium will not only affect the game, but also affect the athlete's mood. If the outgoing light directly hits the camera lens, it will also produce camera glare, which will affect the shooting. Solving the glare caused by LED lighting In addition to preventing glare in the design of the luminaire, the installation height and projection angle of the luminaire are also important factors in controlling glare.
c) The stroboscopic effect of LED lighting; there are two indicators for evaluating the stroboscopic effect: stroboscopic ratio and stroboscopic index. The stroboscopic effect of LED lamps is more prominent than other light sources. At the same frequency, the stroboscopic ratio of LED lamps is higher than that of metal halide lamps. In practical applications, stroboscopic is especially important for stadium lighting. When the broadcast game requires slow motion or super slow motion playback, the broadcast picture is prone to jitter. Therefore, the London Olympics put forward requirements for sports TV broadcast strobe, and some stadiums set the strobe ratio to less than 3%.
3) LED lighting control system:
LEDs are used in stadium lighting to have an absolute advantage in intelligent control systems. First, the stadium lighting needs to meet a variety of lighting modes, and second, TV emergency lighting requires the light source to be ignited instantaneously, etc., the metal halide lamp takes about 40 minutes from turning on the light to reaching the rated light, if the light is in the course of the game It is unlikely that it will go back to the competition for any reason. The Beijing Olympic venues have also added uninterruptible power supplies before they are put into use, which will not only greatly increase investment, but also bring a lot of inconvenience to the use; In the past, the safety lighting and evacuation lighting in the venues used tungsten halogen lamps, which have short life, low luminous efficiency and no energy saving. In addition, many games, such as tennis matches, are sometimes closed when the game is closed during the game. Only the lights on the athlete's seat are left. Previously, the switch was installed on the lamp. If the LED is used, it can be flexibly controlled. Also in the sports training venues, athletes can dim on demand and feel good. The LED intelligent control system can fully play its role in stadium applications.
4) Power density of LED lighting:
The stadium has high illumination intensity and large power consumption. LED lighting has greater energy saving potential than traditional metal halide lighting. According to the results of the "Semiconductor Lighting Products in the Training Field Application Research", the measured results of the sports training venues, under the premise of meeting the same illuminance indicators, the LED lamps have lower total power than the traditional metal halide lamps, and the average energy saving rate is about 40. %. It shows that the illumination power density value of the LED lamp is significantly lower than that of the traditional metal halide lamp. On the basis of the traditional illumination LPD limit, the corresponding correction coefficient can be multiplied. For the LED lighting power density value of the competition venue, further research is needed.
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