Study On Artificial Lighting Used In The Closed Plant Factory

The closed plant factory, which is the advanced stage of protected agriculture, has the advantages of energy saving, environmental protective, high precision control and low productive cost and it can be developed greatly.According to the present situation of plant factory of the world and the problems such as low level of environmental control, low yield, poor quality, high cost et al., a closed plant factory using artificial lighting was constructed by the opaque thermal insulated materials. A real-time dynamic supervisory environmental control system was developed, controlling the environmental factors precisely; to improve the lighting for the plant to growth and the efficiency utilization of light, a LED lighting environmental control device and the lighting distance adjustable fluorescent board were designed. Air condition drived by different heat loads and air circular system were used to control the material and energy flow; Circulating nutrient solution system can achieve circular reuse. Experimental studies of environmental control system and biology were taken to supply information to the closed plant factory and the research on LED used in the seedling production area.1. Experiment results showed that the temperature, relative humidity, CO₂ concentration and the lighting can be controlled synthetically. The temperature can be changed periodically from 15℃～29℃with±0.5℃control precision; the humidity was controlled in 50%～85%; the CO₂ concentration was controlled in 1000±30μmol·mol^-1; the lighting intensity of fluorescent lamp was controlled in 67～200μmol·m^-2·s^-1.2. The wavelength of the LED lighting environmental control device were 660±5nm and 450±5nm, which can be adjusted to discretionary spectrum proportion and adapt to many breeds.3. The compare experiments between fluorescent lamp and sunlight showed the environment control in the closed plant factory greatly accelerated the growth, mainly augmenting the leaves area, leaves number, fresh weight.4. The cucumber seedling compare experiments under LED, fluorescent lamp and the sunlight showed LED lighting was superior to other treatments, which has more advantages. The photosynthesis rate reached 5.02μmol·m^-2·s^-1, was 1.8, 2.0 and 3.6 times of the LF15, LF20 and LF30.5. Weak point and optimized project were put forward by analyzing the effect of the system synthetically.