GREENHOUSE SIMULATION MODEL "ARCEL" APPLIED TO A DOUBLE-LAYER INFLATED POLYETHYLENE TUNNEL USING LOW TEMPERATURE WASTE HEAT
The tunnel was designed to be supported by low enthalpy heat in agriculture. The water temperature levels, in effect, corresponds to the temperatures levels discharged by ENEL (Italian National Board of Electricity) closed cycle wet tower thermoelectric power plant. The numerical model includes a set of energy balance equations, by means of implicit finite difference method, in order to represent simultaneous heat and mass transfer. Fortran 77 computer programming language was selected. The code includes also evapotranspiration and latent heat transfer processes. At the present validation step, only the sensible heat transfer is considered. A consistency analysis was carried out, on hourly time-series basis, to verify the performance of the model applied to some italian test reference years. The model validation stage is concerned with establishing the verisimilitude of the responses from the verified model and comparable observations taken on the modeled system. Several periods of continuous hourly performance data were selected to validate the mathematical model. Comparisons between model calculation and measured results show a good agreement for both the temperature field and the energy exchange rate. Some results on hourly and daily performance of the system are presented.