Modeling And Simulation Of Temperature And Humidity In PC Board Greenhouse

Greenhouse technology is the typical representative of modern agricultural technology model, PC board covering material with its day lighting function, high strength, good resistance to blunt class damage performance is strong, long life and other advantages, is widely used in modern greenhouse. Green house uses mantle material to form a special microclimate environment form external environment.There are many Influence factors in greenhouse microclimate environment such as solar radiation, temperature, humidity, CO2concentration and ventilation etc. Temperature and humidity are the dominant factor. Greenhouse has the character of nonlinear, severe coupling, greatly disturbed by noise, time-varying, etc.Greenhouse microclimate control is the most important part for modern greenhouse control.modeling. Study of greenhouse microclimate is the foundation to establish a suitable automatically control for China’s national conditions. This paper aims to build a simple applicable temperature and humidity model for PC board greenhouse. In these models, indoor and outdoor environment and its impact on crop growth condition are considered. Some parameters in these models are determined by using iterative method.It firstly introduces the developing situation of modern greenhouse industry, and expounds the characteristics and greenhouse microclimate. Secondly it expounds the significance of the research field of greenhouse microclimate modeling research and progress, and put forward the current existence deficiency. Then the paper points out temperature and humidity has great effects on the greenhouse crop. So the research of the temperature and humidity in the development of modernized greenhouse industry in China has vital significance.Mechanism analysis is one of the basic methods of mathematical modeling. Through the analysis of greenhouse temperature and humidity conditions, according to the heat transfer theory, applied material and energy conservation principle, established and outdoor temperature, solar radiation intensity, wind speed and crop transpiration related dynamic model of temperature and humidity, a quantitative description of the solar radiation, long wave radiation, crop transpiration, ground evaporation and natural ventilation, and the model of process but difficult to determine parts have the parameters of the scope of using iterative method to estimate. Experimental results verify the farmers in Anhui Agricultural University PC board greenhouse. MATLAB is used to simulation verify the built model. The results showed that the model outputs is consistent with measured data and which have good tallied generality.In the end, this paper put forwards the study has research significance and points out the existing work must continue to improve.