Decision Support for Climate Dependent Greenhouse Production Planning and Climate Control by Modelling. I. Modelling Climate

摘要

In greenhouse production planning and control both, the greenhouse climate and cost of conditioning are of particular importance. To estimate greenhouse climate, respective plant growth and energy demand the external climatic conditions of the sites have to be processed. The suitability's of Long term normals (Ltn, long term means) and Reference years (BLUMEL et al. 1986) were tested. The Reference years are considered adequate to forecast the most probable climate for special periods. To derive seasonal trends Ltn are preferred. On the basis of these data and the advanced models of RATH (1992, 1994, 2004, 2007) greenhouse climate and energy demand for heating were estimated. The models of Rath enable to parameterise radiation and air as well as soil temperature in greenhouses as a function of the climate of sites, greenhouse size and type (Venlo block, Wide span greenhouse, height of side panel), energy saving installations (single and double glass, energy screens) and set point for heating. The energy demand for heating (RATH 1994) is calculated on hourly basis for the respective conditions considering ventilation, heat storage in the soil and wind speed.