用于植物水培的智能控制LED照明装置
发布时间：2018-08-14 11:10
【摘要】：为了解决未来人口的粮食问题,植物工厂应运而生。而光照作为植物生长发育的重要因素,开发高效、无污染并且适宜植物生长的光源则成为重中之重。随着发光二极管(Light Emitting Diode,LED)的迅速发展,LED以其节能、环保、冷光源并且光谱可调逐渐成为植物工厂的主流光源。由于近些年红色荧光粉种类增多和稳定性不断提高,不同于传统将红蓝光LED芯片组合实现红蓝光的方式,本文提出一种新型红蓝光的实现方式:将红色荧光粉混合硅胶涂覆在蓝光LED芯片上,即荧光粉转化LED(phosphor converted LED,pc-LEDs),即可在单颗芯片实现植物所需红蓝光。(一)为了得到理想的植物照明效果pc-LEDs器件,本文分别采用传统荧光粉点胶技术、自适应涂层技术实现红蓝光,并对器件进行结温测试、脉冲宽度调制(Pulse-Width Modulation,PWM)调光测试、以及老化性能测试,结果显示:传统球形涂层结温为90℃,而自适应涂层结构结温在80℃左右;PWM调光下器件红蓝光量子数比基本不变;而随着时间的推移,红蓝光量子比从5.3衰减,在2000h后稳定于5.0。当粉胶比大于1:13时,传统球形荧光粉结构在空间红蓝光子比分布上呈现不均匀性,中心红蓝光子比偏小,边缘偏大;自适应涂层结构在-60~60°内呈现出比较高的均匀性,但由于杯碗的反射作用以及杯碗粘附的荧光粉,边缘区域呈现出不均匀性。为了改善传统球形结构的空间红蓝光子比分布均匀性,采用改进的双冠型荧光粉涂层技术,在一定程度上提高了中心红蓝光子比,但效果不明显,边缘红蓝光子比依旧很高。(二)为了得到空间红蓝光子比分布均匀的荧光粉层结构,本文采用蒙特卡洛思想借助matlab模拟该LED的光子传输过程:包括LED发光模型、吸收和散射模型、随机步长和随机波长的获得算法、荧光粉层离散化处理和出界判断算法。通过仿真和实验对比确立仿真各项参数,其中散射系数为2.0mm-1,吸收系数为1.0mm-1,并在仿真模型上验证了球形结构的缺陷。本文提出一种类似正态分布的新型红色荧光粉层结构,对于小角度前向散射机制的蓝光光子进行全反射和增加光程处理,对于边缘区域光子进行减少光程处理。将这种新型结构同与传统球形结构置于红蓝光子比为6.0区间对比,通过模拟确定该结构最大厚度为2.2mm以及该结构σ2值为0.25。相比于传统球形结构,该结构下不同角度对应红蓝光子比方差从0.445减少到0.0429,下降了90%。该结构下空间红蓝光分布具有非常高的均匀性。(三)为了验证pc-LEDs用于植物照明的可行性,本文采用自制不同红蓝光子比的pc-LEDs灯具照射豌豆苗,各组光量子通量密度(Photosynthetic Photon Flux Density,PPFD)均为70μmol·m-2·s-1。收获后,测量结果表明:当红蓝光子比为9.3时,豌豆苗的干重和茎长都达到最大值;红蓝光子比为7.2时,叶绿素的含量最高。
[Abstract]:In order to solve the food problem of future population, plant factory came into being. Light as an important factor in plant growth and development, the development of efficient, pollution-free and suitable for plant growth light source is the most important. With the rapid development of (Light Emitting diodes, LEDs have become the mainstream light source in plant factories because of their energy saving, environmental protection, cold light source and adjustable spectrum. Due to the increasing variety and stability of red phosphors in recent years, it is different from the traditional combination of red and blue LED chips to achieve red and blue light. In this paper, a new kind of red and blue light is proposed: the red phosphor mixed silica gel is coated on the blue LED chip, that is, the phosphor transforms the LED (phosphor converted LEDX pc-LEDs), which can realize the red and blue light needed by plant on a single chip. (1) in order to obtain the ideal plant lighting effect, the traditional phosphor dotting technique and the adaptive coating technology are used to realize the red and blue light, and the junction temperature and the Pulse-Width modulation dimming test are carried out. The results of aging test show that the junction temperature of conventional spherical coating is 90 鈩，
本文编号：2182662
[Abstract]:In order to solve the food problem of future population, plant factory came into being. Light as an important factor in plant growth and development, the development of efficient, pollution-free and suitable for plant growth light source is the most important. With the rapid development of (Light Emitting diodes, LEDs have become the mainstream light source in plant factories because of their energy saving, environmental protection, cold light source and adjustable spectrum. Due to the increasing variety and stability of red phosphors in recent years, it is different from the traditional combination of red and blue LED chips to achieve red and blue light. In this paper, a new kind of red and blue light is proposed: the red phosphor mixed silica gel is coated on the blue LED chip, that is, the phosphor transforms the LED (phosphor converted LEDX pc-LEDs), which can realize the red and blue light needed by plant on a single chip. (1) in order to obtain the ideal plant lighting effect, the traditional phosphor dotting technique and the adaptive coating technology are used to realize the red and blue light, and the junction temperature and the Pulse-Width modulation dimming test are carried out. The results of aging test show that the junction temperature of conventional spherical coating is 90 鈩，
本文编号：2182662
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