The Automatic Control System For Temperature And Humidity Of Heat Exchange Type Greenhouse

Agriculture Greenhouse is mainly used to plant Anti season Vegetable and fruit,and other crops.In the environmental conditions affecting the growth and development ofvegetable and fruits, humidity and temperature are two important parameters, if notcontrolled properly, will greatly influence the growth and development of vegetableand fruits, increase the occurrence of pests and diseases, causing yield reduced,decline farmers ’ incomes. According to this problem, in this study designedtemperature and humidity controller, basing on lots of researches on humidity. Thiscontroller chooses heat exchanger and electronic heated apparatus as a desiccant,warming equipment, realized the automatic control of temperature and humidity inAgriculture Greenhouse.The control system consists of a heat exchanger, vent pipes, pipelines, axial-flowfan and temperature and humidity controller. Design of temperature and humiditycontroller includes design of hardware circuit and software into two parts. Hardwarecircuit design include single-chip control circuit, temperature and humidity dataacquisition circuit, clock circuits, LCD display, alarm circuit, strong current controland drive circuit。Software design developed a complete set of control procedures,used modular program structure and C language.In this control system, temperature and humidity controller choses STC89C52RCchip as control core, AM2303as senor, DS1307as clock chip. The controller candetect the humidity and temperature in real-time, and the humidity measurementaccuracy of±2%RH, temperature measurement accuracy of±0.5℃, the precision asdisplayed0.1℃。The main advantage in this control system is that, uses heat exchanger fordehumidification. Heat accumulated agricultural greenhouses were used efficiently,that to retaliate hot and cold air exchanging in the heat exchangers, making enteringagricultural greenhouses air temperature be promoted, reducing the temperaturechanges caused by wet reduction, causing the better energy-saving effect and loweconomic cost.