Optimization of ventilation and its effect on the microclimate of a colombian multispan greenhouse Optimización de la ventilación y su efecto en el microclima de un invernadero multitúnel colombiano

RESUMEN In Colombia, greenhouse design optimization has not been a relevant topic and, as a consequence, the ventilation systems of current structures are not optimal, generating inadequate microclimates for the development of horticultural species. At the production level, management of the greenhouse climate is deficient, and this factor is not taken into account as a func tion of characteristics dependent on greenhouse design that cannot be modified during its lifespan. The aim of the present work was to study the efficiency of modifications applied to the ventilation system of a commercial greenhouse available on the Colombian market. This was accomplished by using numerical simulations through the application of the computational fluid dynamics method. Based on the commercial greenhouse design, two modified models were designed by applying structural modifications and changing the orientation of the fixed open ridges. Simulations with the three greenhouse models were carried out in order to maximize the air renovation rates and improve air movement within the entire greenhouse, striving for the highest degree of climate homogenization. The best greenhouse design was the one with the highest air renovation index, high enough to ensure adequate control of temperature and humidity extremes through natural ventilation. Additionally, this design generated the most homogenous microclimate within the cultivation zone En Colombia la optimizacion del diseno de los invernaderos no ha tenido mayor relevancia y en consecuencia las estructuras existentes presentan deficiencias en su ventilacion, generando asi microclimas inadecuados para los cultivos. A nivel productivo, el manejo climatico es deficiente, olvidando que el microclima interior es funcion de caracteristicas de diseno del invernadero. El objetivo del trabajo fue el de estudiar la eficiencia de variantes introducidas a la ventilacion de un invernadero multi-tunel mediante simulaciones numericas empleando el metodo de dinamica de fluidos computacional. A partir del modelo comercial se disenaron dos variantes experimentales realizando cambios estructurales y de orientacion de las ventanas cenitales fijas. Los tres disenos de invernade ros fueron sometidos a simulaciones por computador con el proposito de maximizar los indices de renovacion de aire, mejorar el movimiento del flujo de aire en toda la estructura y buscar una homogeneidad en el microclima. El diseno mas adecuado fue aquel que presento un indice de renovacion de aire suficiente para garantizar un adecuado control de la tem peratura y la humedad a traves de la ventilacion natural. Este diseno genero ademas el microclima mas homogeneo dentro de la zona de cultivo.