Abstract: Extremely low temperature often occurs in energy-saving solar greenhouse in the winter of North China, which will lead to sharp decrease of greenhouse crop production or crop failures when the temperature is below lethal temperatures of corps. In order to control the greenhouse temperature accurately and reduce the loss caused by the low temperature, an intelligent heating control system has been designed, which is composed of sensing module, main control module, communication module, servo module and executive devices. The system can automatically collect temperature data, realize the automatic switch of temperature executive devices corresponding to heating control model in the main control module. In addition, the system can view data and perform device state control by remote client. Therefore, the system has initially realized the intelligent control of the greenhouse temperature environment. Application and verification of the system in second-generation brick wall solar greenhouse showed that, it needs running 4.9 hours to keep air temperature above 6-8℃ with the cost of 146￥. Accordingly, it needs running 6.1 hours to keep air temperature above 10-12℃ and costing 194￥. This study suggests the performance of system is very stable during application. The system realizes fine and unmanned intelligent control of temperature environment to ensure better heating at night time.

Key words: Solar greenhouse, Low temperature, Monitor, Intelligent control, Heating