CFD to analyze energy exchange by convection in a closed greenhouse with a pipe heating system

Abstract

In some locations with harsh winters, the heat stored in the soil may not be enough to heating a greenhouse, and so artificial heat must be supplied. The objective of this study was to evaluate a numerical model under local weather conditions, in Humboldt University of Berlin, Germany, during winter 2011 to analyze the air dynamics generated through a tube pipe heating system convection in a closed greenhouse, for it to be applicable in producing cold regions in Mexico. Results showed that 100 W m-2 of heat released from the soil kept the environment within acceptable ranges for plant growth from noon to evening. However, the energy lost by long-wave radiation during the night lowered the air temperature to minimal basal temperature. Heat from the pipes placed underneath the crop promoted air movement by convection, producing a uniform distribution of temperature and humidity within the plant canopy.

Contribution to the Sustainability of Agricultural Production in Greenhouses Built on Slope Soils: A Numerical Study of the Microclimatic Behavior of a Typical Colombian Structure

“…The CFD study has allowed the study of almost all existing passive greenhouse models worldwide, and has also been implemented as a tool for the optimization of climate management in greenhouses with active climate control [18][19][20]. There are currently a considerable number of studies applied to agricultural investors that have used CFD simulation to analyze thermal distribution [10,21,22], moisture distribution [5,21,23], efficiency of heating systems [24][25][26], the operation of cooling systems [27][28][29] and the microclimate generated as a function of different ventilation configurations [7,12,[30][31][32]. In the specific case of Colombia, the use of CFD and other modelling techniques to determine the behavior of the main greenhouse structures used has been carried out for the specific conditions of the Bogotá savannah and for a topography of flat soils, which is where the ornamental and cut flower industry is generally developed [33][34][35].…”

Análisis sobre la actividad científica referente a las estrategias de climatización pasiva usada en invernaderos: Parte 2: análisis técnico

“…Materiales de cubierta usados en los invernaderos. Por último, en menores proporciones, se encontraron estructuras donde se combina el vidrio con el plástico como material de cubierta y cerramiento (Tabla 2), esto quizás como una alternativa de reducir costos y de fabricación del invernadero, buscando además obtener los múltiples beneficios del vidrio, dentro de los que cabe mencionar, su foto estabilidad en el tiempo y su nula transmisión de la radiación térmica en las horas de la noche, lo que permite una mayor estanqueidad de la energía almacenada en el interior del invernadero durante el día o una mayor eficiencia energética de los sistema de calefacción implementados (Flores-Velazquez et al, 2019). Así mismo se identificaron 3 estudios donde se usan materiales de cubierta, como lo son las celdas fotovoltaicas policristalinas y las celdas fotovoltaicas estructuradas sobre los plásticos semitransparentes.…”

Valuation of the Energy Performance of a Greenhouse with an Electric Heater Using Numerical Simulations

“…In addition to the power, it was necessary to consider the distribution of electric heaters, since this type of system, compared to heating systems using pipe networks [34,42,43], was not the best option for homogenizing the The power supplied by the greenhouse heater used in this research was insufficient to mitigate the temperature drop that occurs mainly during the winter period. In addition to the power, it was necessary to consider the distribution of electric heaters, since this type of system, compared to heating systems using pipe networks [34,42,43], was not the best option for homogenizing the temperature in the greenhouse. Currently, there are many techniques used to heat the air in the greenhouse [10,27,44].…”