Dynamic Simulation Modeling of Heat and Water Vapor Transfer in a Fluid-Roof Greenhouse

Abstract

A dynamic simulation model for heat and water vapor transfer in a fluid-roof greenhouse was developedto study the effects of the fluid-roof and plant density on the temperatures of the greenhouse components. Thegreenhouse components, consisting of hollow-channeled polycarbonate roof with 1.5% CuSO4-water solution as a liquid radiation filter, plant canopy, moist soil and the inside air, were described by a system of non-linear differential equations considering the possible modes of energy exchanges among these components. The Predictor Corrector technique was applied to solve the system of equations simultaneously to predict the temperatures of these components and the relative humidity of the greenhouse air. The simulated results show that the fluid-roof greenhouse can be used without ventilation during the hot summer daytime and that acceptable plant temperature can only be achieved at low plant density. However, the greenhouse with high plant density must be ventilated during the hot summer daytime to keep the relative humidity at a normal level and to keep the plant temperature lower than the outside temperature. © 2001, The Society of Agricultural Meteorology of Japan. All rights reserved.