Analysis of light source advantages Incandescent lamp is a common light source to create long sunshine, but its low electrical efficiency and low red to far red light ratio cannot improve stem elongation, so it is gradually prohibited from being sold and used. Compact fluorescent lamps and HPS have higher energy efficiency and higher R: FR ratio. There are three types of HPS: 400W, 600W and 1000W. Traditional light sources such as HPS cannot launch low-power products, and their applications are limited. 1000W is more popular because the number of such lamps required to achieve the same light intensity is small. In greenhouse lighting practice, reducing the number of lamps can effectively reduce the degree of shielding natural light due to the reflector of lamps. Energy efficient regulation of natural light requires an intelligent control system, which adjusts the amount of artificial light according to the intensity of natural light.
In comparison, the photoelectric conversion efficiency of HPS is 30%, while that of incandescent lamp is only 6%, and that of LED lamp is 40%. Other electric energy is converted into heat energy to heat the ambient temperature of the greenhouse. In fact, electric heating is not economical, and in mild weather conditions, high temperature is adverse to production, so it is necessary to turn on fans and other equipment to cool down. HPS spectrum includes yellow light, orange light and red light, and blue light is more effective. Plants need a certain amount of blue light to obtain normal plant development and morphology. In addition, far red light is also important to form building, and the proportion between red light, blue light and far red light needs to be adjusted.
LED lights or modules need to be screened for light quality, waterproof, solid and compact, and reduce the area of light blocking surface. The heat dissipation methods include water-cooled LED, passive gas cooled LED, and active gas cooled LED. LED heat dissipation has always been a problem to be seriously solved. HPS heat dissipation and heating can warm plants and increase respiration. In turn, respiration reduces leaf temperature.
In 2007, some companies in the Netherlands introduced special LED modules for the greenhouse industry. From 2008 to 2009, some large-scale LED lighting experiments were conducted on roses, tomatoes, sweet peppers, cucumbers and medicinal plants. The results were different. LEDs have the potential to regulate greenhouse photoperiod and supplement light, but there is relatively little research on horticultural crops, Due to the high price, its application may be limited to the field of special plant production (Runkle et al., 2011). LED greenhouse light supplement is a very promising technology, which can effectively capture better plant photosynthesis (red LED is higher than HPS), start special plant reaction or guide plant process and balance through LED special light quality modulation (Nederhoff, 2010).
Analysis on the Advantages of Semiconductor Light Compensation in Greenhouse（一）
Analysis of light source advantages Incandescent lamp is a common light source to create long sunshine, but its low electrical efficiency and low red to far red light ratio cannot improve stem elongation, so it is gradually prohibited from being sold and used. Compact fluorescent lamps and HPS have higher energy efficiency and higher R: FR ratio. There are three types of HPS: 400W, 600W and 1000W. Traditional light sources such as HPS cannot launch low-power products, and their applications are limited. 1000W is more popular because the number of such lamps required to achieve the same light intensity is small. In greenhouse lighting practice, reducing the number of lamps can effectively reduce the degree of shielding natural light due to the reflector of lamps. Energy efficient regulation of natural light requires an intelligent control system, which adjusts the amount of artificial light according to the intensity of natural light.
In comparison, the photoelectric conversion efficiency of HPS is 30%, while that of incandescent lamp is only 6%, and that of LED lamp is 40%. Other electric energy is converted into heat energy to heat the ambient temperature of the greenhouse. In fact, electric heating is not economical, and in mild weather conditions, high temperature is adverse to production, so it is necessary to turn on fans and other equipment to cool down. HPS spectrum includes yellow light, orange light and red light, and blue light is more effective. Plants need a certain amount of blue light to obtain normal plant development and morphology. In addition, far red light is also important to form building, and the proportion between red light, blue light and far red light needs to be adjusted.
LED lights or modules need to be screened for light quality, waterproof, solid and compact, and reduce the area of light blocking surface. The heat dissipation methods include water-cooled LED, passive gas cooled LED, and active gas cooled LED. LED heat dissipation has always been a problem to be seriously solved. HPS heat dissipation and heating can warm plants and increase respiration. In turn, respiration reduces leaf temperature.
In 2007, some companies in the Netherlands introduced special LED modules for the greenhouse industry. From 2008 to 2009, some large-scale LED lighting experiments were conducted on roses, tomatoes, sweet peppers, cucumbers and medicinal plants. The results were different. LEDs have the potential to regulate greenhouse photoperiod and supplement light, but there is relatively little research on horticultural crops, Due to the high price, its application may be limited to the field of special plant production (Runkle et al., 2011). LED greenhouse light supplement is a very promising technology, which can effectively capture better plant photosynthesis (red LED is higher than HPS), start special plant reaction or guide plant process and balance through LED special light quality modulation (Nederhoff, 2010).