Simulación de flujos energéticos y requerimientos de calefacción auxiliar en invernaderos solares

The knowledge of thermal balance of a greenhouse including all components allows to determine the necessary energetic flow to maintain environmental conditions adequate to cultivation. In steady state it is easy to calculate the flow; but its determination in transient state is more difficult. In the present paper, a method to calculate these requirements is described treating the thermal problem as an electric one. An electric current generator is connected to a circuit node representing the air temperature in the greenhouse. The value of this electric current is determined according to the thermal losses. The model permits to show the solar energy contributions of all components. Results from April to September are analyzed and those showing the most unfavorable day of July in the last 20 years are described.