Development of a greenhouse simulation model to estimate energy and resources necessary for environmental controls under various climate conditions

摘要

From a global perspective, the number of countries that use greenhouses and cultivated areas are increasing. When applying environmental controls such as heating, cooling, ventilation, and CO2 enrichment in greenhouses under various climatic conditions, the estimation of energy consumption and other resources is important in both greenhouse design and the selection of a candidate crop. The objective of this study was to develop a new simulation model to predict greenhouse environments under given weather conditions. To achieve this objective, we developed an integrated model for greenhouse climates by using the transient system simulation program (TRNSYS). TRNSYS has a modular structure for use within the architectural design field. It includes manyof the components for thermal and electrical energy systems, and handles the input of weather data. We modified and added components that modeled ventilation, shading, heating, evaporation cooling, and evapotranspiration, and calculated the heat energybalance necessary for predicting inside air temperature and humidity. Environmental conditions inside the greenhouse were simulated using meteorological and plant data. We evaluated the developed model by using an experimental greenhouse with the above environmental controls installed. We applied the model to greenhouses under various climatic conditions in different countries, mainly Asia. We estimated the energy required for heating and/or cooling and CO2 and water in order to control the internal environmental conditions at the targeted values under given weather conditions. The study indicates that the model is an effective tool for making strategic decisions in the installation of greenhouses from the viewpoint of energy and resource application.