Numerical Simulation of Temperature Decrease in Greenhouses with Summer Water-Sprinkling Roof

Abstract

Decreasing the temperature of a greenhouse in summer is very important for the growth of plants. To investigate the effects of a roof sprinkler on the heat environment of a greenhouse, a three-dimensional symmetrical model was built, in which a k-ε (k-epsilon) turbulent model, a DO (Discrete Ordinates) irrational model, a Semi-Implicit Method for Pressure-Linked Equations (SIMPLE) algorithm, and a multiphase model were used to simulate the effects of the roof sprinkler, at different flow rates. Based on the simulation results, it was found that the temperature could be further reduced under a proper sprinkle rate, and the temperature distribution in the film on the roof was more uniform. A test was conducted to verify the accuracy of the model, which proved the validity of the numerical results. The simulation results of this study will be helpful for controlling and optimizing the heat environment of a greenhouse.

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].…”

Research on the Microclimate of Protected Agriculture Structures Using Numerical Simulation Tools: A Technical and Bibliometric Analysis as a Contribution to the Sustainability of Under-Cover Cropping in Tropical and Subtropical Countries

“…Within these studies, we have also found research where the objective was the study of anti-insect screen establishment in the ventilation areas of passive greenhouses and their effect on natural ventilation [44][45][46][47]. There have also been more recent studies evaluating the microclimate and its variation due to the presence of different types of crops and at different phenological stages or the effect on the microclimate due to the implementation of active climate control equipment, such as heating, cooling, and CO 2 injection systems [48][49][50][51][52].…”

Modeling and Simulation of Temperature and Relative Humidity Inside a Growth Chamber

“…For example, in [6], the authors obtained lower coefficients of determination than ours, or the research reported in [40], who obtained slightly higher coefficients than ours. It is so complex to model humidity conditions, that there are even authors who, in their work, only model and simulate temperature, or perhaps they do not show interest in this [11,15,28,30,38].…”

“…Due to the complex interactions carried out among the variables, such as temperature, humidity, radiation, carbon dioxide, water, nutrients, pests, diseases, and weeds, among others, it is necessary to identify and analyze them in subsystems. Several authors [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] have characterized the subsystems from different perspectives-for example, climate, nutrition, and irrigation. Models are used to achieve detailed knowledge of all interactions and processes.…”

“…Other research projects predict the behavior of one or more variables and provide an appropriate response to keep these variables within the desired limits [3][4][5]. Most of the research on modeling and simulations has mainly been developed for greenhouses [6][7][8][9][10][11] to predict the internal environmental conditions of enclosures utilized for cultivation and plant growth. Several studies from the perspective of different environments of models have also been pursued, with the objective of knowing the behavior of the internal variables, such as temperature and relative humidity, that will serve as support to later define an adequate strategy for controlling the growth conditions within an enclosure.…”