Facilities horticulture semiconductor lighting refers to using semiconductor lighting and its intelligent control equipment, according to the light environment demand rule of agricultural biological and agricultural production in all areas of production goals and objectives, creating artificial appropriate facilities or make up for the inadequacy of natural lighting light environment, regulation of agricultural biological growth and reproduction, in order to realize high quality, high yield, high efficiency, stable production targets a facility horticulture measure, it is the most important areas of agricultural semiconductor lighting, application progress and the most potential.
Various application fields have diverse biological forms and different requirements of the optical environment. The main applications are summarized as follows.
Make your greenhouse light up.
In order to increase photosynthetic yield, improve light intensity and prolong photoperiod, artificial light supplement should be carried out.
Edible fungus factory.
At present, the production of edible fungi is highly industrialized, and most of edible fungi don't have high requirements on light intensity, but they have harsh requirements on light quality, large output and quality effect, and the control of light environment is very important, with great application potential.
As the most advanced development stage of facility horticulture, plant factory can be used for large-scale production of vegetables, seedlings (vegetable seedlings, rice, tobacco, etc.), Chinese herbal medicine, etc.
Intelligent artificial light environment regulation plays a decisive role in its production efficiency.
Tissue culture of plants.
Plant tissue culture is an important method for rapid propagation and detoxification of seedlings. Artificial light is used in production completely, which has great demand for artificial light source, and it is very urgent to upgrade electric light source.
The application field of facility gardening semiconductor lighting is very complex, which requires systematic, multi-level and multi-scale research.
One of the reasons lies in the diversity and complexity of agricultural biological nutrition and growth and development rules. The response mechanism of agricultural organisms to the light environment is different, and the research methods are different. It needs to be systematically studied one by one to reveal the photobiological rules.
For example, plants use light energy, CO2 and water to form carbohydrates through chlorophyll photosynthesis and convert light energy into chemical energy.
Microorganisms (in the case of edible fungi) obtain the nutrients needed to produce mycelia and fruiting bodies by breaking down cultural substrates by extracellular enzymes.
The nutrition patterns of the three agricultural organisms are fundamentally different.
The second reason is that the field of agricultural production is vast and complex, with diverse types of agricultural organisms and their occurrence forms, and different demands on the space-time of the light environment.
The third reason is that there are more quantity attributes (light intensity and photoperiod), quality attributes (light quality and spectrum) and luminescence characteristics (duty ratio and frequency) of the electric light source, and the biological effects need to be studied one by one.
The complexity and systematicness of plant photobiology research are shown by the superposition of the above three factors.
Construction of facility garden LED lighting system equipment
The essential feature of facility horticulture semiconductor lighting is the accurate, dynamic and on-demand regulation of the light environment (light quality, light intensity and light cycle), and the implementation of efficient agricultural semiconductor lighting needs to establish different regulation strategies based on the space-time law of agricultural biological light environment demand.
The facility horticulture LED lighting system equipment includes LED light source and LED lamp, LED lamp suspension device and control system, and light environment intelligent control system.
The design and development of LED lighting system is aimed at maximizing the photoelectric conversion efficiency and the bioluminescence efficiency.
The efficiency enhancement of LED light sources and lamps, and the analysis of the biological rules of agricultural biophotobiology are the basis for the research and development of energy-saving LED lighting system equipment and the construction of high-light effect strategy.
The design and development of special LED light source and lamps for horticultural facilities focuses on the uniformity of irradiation, the rationality of the light quality combination, the reliability of heat dissipation, the suitability of LED chip power, the high efficiency of luminous surface design and sensory comfort.
The following principles should be followed.
(1) principle of utilization of high-light energy.
By making reasonable spectral components, the luminous efficiency of LED light source is increased to the greatest extent, and the biological distance between light source and irradiated light is reduced, and the light loss is reduced.
(2) low cost principle.
Cost is an important factor to determine the industrial development of horticulture semiconductor lighting.
(3) principle of ecological security.
On the basis of meeting the photosynthetic physiological needs of horticultural plants, it is appropriate to improve the composition of pure red and blue spectrum, add a little or a little green light, and increase the visual health.
(4) give priority to the development of LED light source and lamps for horticulture high-value agricultural products, which is conducive to the sales of lamps and the cultivation of leading enterprises.
(5) principle of universality.
Give priority to the development of LED lamps and related products in common with traditional T5 and T8 lamps.
LED lamp suspension device and control system include LED lamp suspension mode, spatial position control device, cultivation platform and control device, which determines the efficiency of plant canopy to intercept artificial light.
The establishment of intelligent control system of light environment and its intelligent control strategy of light environment is an important part of the facility horticulture LED lighting system.
Type semiconductor lighting large data involving facilities agriculture, agricultural biological species and varieties, the types of LED light source and lamps and lanterns, light formula and irradiation methods, production targets, control strategies, etc., need to establish the agricultural facilities and varieties of biological species, agricultural biological growth and development of light environment demand data, agricultural biological control data of high quality light environment, light environment in facilities dynamic data, the facility environmental elements daily variation and seasonal variation of data such as database.
Facilities horticulture LED lighting system light energy efficiency
From the production of light energy to the process of plant absorption and utilization, the light energy utilization efficiency of the facility garden LED lighting system refers to the efficiency of power conversion into light energy and utilization by plants, which is controlled by three links, namely LED light source and LED lamp, LED lamp suspension device and control system, and intelligent control system of light environment.
Therefore, in order to improve the efficiency of solar energy utilization, it is necessary to analyze the research and development from the above three aspects.
The way to improve the luminous efficiency of garden LED lighting system
3.1 LED light source and LED lamp luminous efficiency
The light efficiency of light source lamps is evaluated by the ratio of photosynthetic effective light quantum flux output to unit power consumption, namely photosynthetic effective light quantum efficiency (mol/W).
First of all, low cost, energy saving and efficient spectrum can be obtained through chip selection, spectrum construction, application of phosphor and packaging methods in the light quality construction of LED chips.
Secondly, appropriate light intensity distribution and uniformity in vertical direction can be obtained by selecting appropriate LED lamp bead luminescence Angle and LED array layout.
Thirdly, the maximum light energy capture rate of canopy can be obtained through the design of luminous surface of LED light source lamp, and the illumination benefit can be improved.
Finally, improve the heat dissipation system of the lamp, improve the service life, and obtain better input-output benefit.
At present, the common ways of heat dissipation include natural cooling, active air cooling, direct liquid cooling, and heat dissipation through heat conduction, heat convection and heat radiation.
3.2 efficiency of LED lamp suspension and control system
The suspension device and control system of LED lamp involve the relative spatial relationship between LED lamp and crop canopy, and the parameters such as beam irradiation direction, irradiation surface and light interception ratio of canopy.
The intelligent control system of optical environment is related to the spatial and temporal biological effectiveness, intensity suitability and yield quality benefit of illumination.
LED lamp suspension device and control system include the technical approaches of suspension mode, spatial position adjustment device, cultivation platform innovation and control, etc.
3.3 efficiency of intelligent control system of optical environment
Facilities horticulture semiconductor lighting light environment is the essential characteristic (light quality, light intensity and light cycle), accurate, dynamic, on-demand, the implementation of efficient agricultural semiconductor lighting needs to be based on the agricultural biological light environment demand space and time laws set up different control strategies, an urgent need to build agricultural semiconductor lighting large data and intelligent control system.
The control of light quality, light intensity and photoperiod corresponds to the requirements of plant optical environment from the perspective of both quality and quantity of light, so as to properly provide suitable optical environment conditions for plant growth, to maximize the potential of plant growth and development from the perspective of space and time, and to promote the rapid and high-quality growth of plants.
In order to build the agricultural semiconductor lighting big data, it is necessary to take the agricultural production field and agricultural biological species as the core, focus on optimizing the optical quality species and its quantitative attributes, and establish the dynamic data of high quality and high yield optical environment demand, control strategies and hardware and software equipment.
Technology status of LED lighting system in facility horticulture
4.1 greenhouse LED lighting system
Greenhouse light supplement facility semiconductor lighting is an important area.
In recent years, in order to improve the luminous efficiency level of the greenhouse LED supplementary lighting equipment, the innovation is mainly made in the light source lamps and the hanging mode.
In terms of light source lamp, double-sided LED light refill lamp, double-slope LED refill lamp, ground refill lamp and folding pin-shaped refill lamp have been developed.
In the aspect of lighting suspension, a variety of canopy proximity lighting technologies were developed, including the approach lighting technology on the top of the canopy, the inner lighting technology on the canopy and the three-dimensional lighting technology on the side of the canopy.
4.2 artificial light plant LED lighting system
Artificial light plant factory is an important area of facility gardening semiconductor lighting.
In recent years, technological breakthroughs have been achieved in such aspects as LED lamp suspension device and control system, cultivation platform innovation and regulation.
The LED light source space management technology is developed to realize the horizontal controllable movement technology device of LED light source lamps. The LED lighting system can be saved by 50% by means of the wrong lighting between different areas in plant factories, and the cost of light source lamps is reduced.
The vertical controlled mobile technology device of LED light source lamp was developed, and the vertical height of LED light source lamp was controlled dynamically according to the height of plant canopy, which can save energy by more than 18%.
Facility horticulture semiconductor lighting is an energy saving, efficient and accurate light environment control technology, which not only regulates the growth and development of plants, but also regulates the quality of agricultural products.
As the price of LED components continues to drop rapidly, the cost of the LED lighting system for facility gardening will decrease year by year, and the application potential and prospect are very big.
In order to achieve the best effect of photoenvironmental regulation, we must work on improving the performance of the facility gardening LED lighting system, and carry out technological innovation from the aspects of light source, lamps, suspension, cultivation platform, intelligent control, so as to comprehensively improve the photoefficiency level of the system and improve the efficiency of the facility gardening semiconductor lighting.