Abstract

VIEGAS, Graciela Melisa; JODRA, Juan Ignacio; DISCOLI, Carlos Alberto  and  SAN JUAN, Gustavo Alberto. Agro production spaces thermal stabilization from a modular passive solar system with thermal mass variations. Ing. invest. y tecnol. [online]. 2020, vol.21, n.3, 00004.  Epub Dec 02, 2020. ISSN 2594-0732.  https://doi.org/10.22201/fi.25940732e.2020.21.3.024.

Agro production areas are often solved with light structures. Inside them there are temperature peak conditions that affect the crops by producing cooling or overheating. In this context, this work presents the comparison of the internal thermal behavior of an empty light greenhouse with the incorporation of a passive accumulator system, a versatile, and possible to be industrialized, modular thermal buffer which can set up different thermal load conditions and stabilize its temperature. The system is presented in two versions, one only with solid materiality, and the other combining it with encapsulated water, thus showing the benefits for its incorporation. The present work aims to deepen the assessment of a passive solar technological solution for air conditioning in agro production spaces, by comparing the thermal response, the load and the thermal contribution in the use of only solid mass variants with that of mixed solid and liquid mass (concrete and water). The methodology develops the manufacturing, installation and laboratory testing of a greenhouse with the incorporation of cultivation tables built with thermal accumulator/buffer systems for comparison. The results show that the maximum thermal contributions of the systems were quantified in 17 MJ, 32 MJ and 36 MJ for the 864 kg solid system, the 1968 kg solid one and the 864 kg mixed one respectively. The thermal contribution achieved approximately doubles that of the lighter system either by increasing solid mass or by replacing the same solid mass by mixed mass. The costs of the systems are recorded as 17.1 USD/MJ; 20.7 USD/MJ and 9 USD/MJ for the 864 kg solid system, the 1968 kg solid one and the 864 kg mixed one respectively, showing in this way the cost reduction in the mixed system when compared to the others.

Keywords : Renewable energy; passive solar systems; thermal buffer; heat storage system; agro-production spaces.