Research on warming effect of water curtain system in Chinese solar greenhouse

In order to increasing air temperature at night in Chinese solar greenhouse which meet the need of crop growth, a water curtain system was designed to increase the air temperature in Chinese solar greenhouse at night. In this system north wall of Chinese solar greenhouse was regarded as a support, and water was used as media to store and release heat. In the day, when water circuited and passed water curtain, the solar radiation was absorbed in the system and stored the heat in a water tank simultaneously. At night, when water circuited and passed water curtain, the heat was released to the greenhouse and then the air temperature was increased in the Chinese solar greenhouse. The experiments had in last winter showed that the air temperature at night in greenhouse was increased by over 5.4℃ and the soil temperature at crop rhizosphere was increased by over 1.6℃, the heat release from water curtain at night in this system was 4.9-5.6MJ/m2, the increasing of the thermal storage and heat release of water curtain system in greenhouse made the tomatoes safely grow in winter and the time that cherry tomatoes was came into the market was put ahead by 20 days. It is significant to structure improvement and temperature control in Chinese solar greenhouse.