Ventilation optimization of solar greenhouse with removable back walls based on CFD

He, Xin; Wang, Jian; Guo, Shirong; Zhang, Jian; Wei, Bin; Sun, Jian; Shu, Sheng

doi:10.1016/j.compag.2017.10.001

Cited by 94 publications

(66 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…To obtain a high quality CFD model, the grid should be refined to get a grid-independent solution [38]. In order to identify the independence of the results from mesh dimension, a grid-convergence study was performed by comparing three unstructured mesh decreased by a factor respectively equal to 1, 1.1, and 1.2.…”

Section: Mesh Sensitivitymentioning

confidence: 99%

“…The results show that the solutions corresponding to decreases equal to 1, 1.1, and 1.2 are similar ( Figure 7). By following the methodology reported in [38], where indoor average temperature and average velocity were compared for eight meshes, the indoor average velocity was compared for the three chosen meshes. The results are showed in Figure 8.…”

Section: Mesh Sensitivitymentioning

confidence: 99%

See 1 more Smart Citation

Development of a CFD Model to Simulate Natural Ventilation in a Semi-Open Free-Stall Barn for Dairy Cows

et al. 2019

View full text Add to dashboard Cite

Natural ventilation is the most common passive cooling system in livestock buildings. The aim of this research is to assess airflow distribution inside a free-stall barn for dairy cows by computational fluid dynamics (CFD) modelling and simulation. The model is validated by using the average values of experimental data acquired in a free-stall barn, which is considered relevant because it is located in a region characterised by hot climate conditions during the summer that could induce animal heat stress. Simulations are carried out in steady-state conditions, and simulated data are validated by the average values of air velocity measurements. Since the modelled air velocity distribution in the barn fits the real one well, the CFD model is considered reliable to simulate other conditions. The application of the proposed CFD model in the simulation of specific building design alternatives could be aimed at studying the related airflow distribution in order to find the best configuration.

show abstract

Section: Mesh Sensitivitymentioning

confidence: 99%

Section: Mesh Sensitivitymentioning

confidence: 99%

Development of a CFD Model to Simulate Natural Ventilation in a Semi-Open Free-Stall Barn for Dairy Cows

et al. 2019

View full text Add to dashboard Cite

show abstract

“…CFD modeling of different parameters in greenhouses has been used to examine various features such as vent configuration [4]; natural and mechanical ventilation [5,6]; ventilation in screenhouses [7]; condensation, transpiration, and heat and mass transfer [8][9][10]; and, more recently, calefaction and HCVA [11] and their interactions [12,13]. The analyses of these systems allow for climate control, thereby offering the possibility to provide large numbers of high-quality crops with greater predictability.…”

Section: Computational Fluid Dynamics (Cfd) In a Greenhouse Simulationmentioning

confidence: 99%

“…Traditional solar greenhouse ( Figure 1) uses radiation to store energy and get advantages of its use naturally. Some studies [10] showed that it is possible to reduce averaged air temperature by approximately 1.7°C and the highest temperature drop by approximately 5.8°C, in comparison to a traditional solar greenhouse with brick back wall (TG). These authors also suggest that a back-wall vent of 1.4 m increased internal ventilation efficiency in a solar greenhouse by installing removable back walls [10].…”

Section: Computational Fluid Dynamics (Cfd) In a Greenhouse Simulationmentioning

confidence: 99%

“…Furthermore, new complementary devices have been adapted to enhance the efficiency of air renewal rates. For instance, the use of the back-wall vent dimension on solar greenhouse cooling was investigated by He et al [10] using CFD. In this study, the average air temperature in a solar greenhouse with removable back walls (RG) was reduced by approximately 1.7°C with a back-wall vent of 1.4 m, thereby increasing ventilation efficiency.…”

Section: Cfd Simulations In Greenhouses 41 Natural and Mechanical Vementioning

confidence: 99%

See 1 more Smart Citation

CFD Simulation of Heat and Mass Transfer for Climate Control in Greenhouses

Rodriguez¹,

Velázquez²

2019

Heat and Mass Transfer - Advances in Science and Technology Applications

View full text Add to dashboard Cite

Greenhouse plant production involves a number of processes such as transpiration, condensation, photosynthesis, and climate control. Such processes, in turn, set off mass and heat transfer phenomena that influence not only the quality and quantity of crop production but also its environmental cost. While these processes have considerably been analyzed in separate, they strongly interact with one another. For instance, increased radiation (mainly thermal infrared) increases temperature, reduces humidity, consequently increases transpiration, and affects CO 2 exchange as well as other reaction rates. Computational fluid dynamics (CFD) is a numerical tool with a solid physical basis which allows, through the construction of a computational model, to simulate the fluid flow environment. Heating, ventilation, and condensation have been analyzed in the greenhouse environment with CFD techniques. The current challenge is the interaction of these processes and their impact on the production system. The present work summarizes some CFD investigations carried out in this topic, in order to analyze the processes of heat and mass transfer in a greenhouse for agronomic purposes.In greenhouse crop production, climate has peculiar considerations, because the most important data is the impact of the environmental factors on the crop cycle. The cultivation of plants requires a sufficient amount of light, a specific range of temperature, humidity, and CO 2 , among other requirements. These requirements are primarily influenced by the greenhouse design and size and vary according to the local climate conditions. For instance, the radiation quantity inside the greenhouse depends on whether greenhouses are built with PVC or glass, because the surface material is the element to optimally use solar radiation for the required lighting [1].Recently, heating, ventilation, and air conditioning (HVAC) systems have been extensively used in urban spaces, such as offices or stores, at agriculture area, and specifically in greenhouses. For instance, HVAC has been used in buildings in order to analyze the optimization and comfort inner Officine's and several uses. In greenhouses, the concept is incipient, even though the application of the ventilation and calefaction systems as a method to climate control in cold and warm regions is nothing new.The climate produced in a greenhouse is the result of complex mechanisms involving the processes of heat and mass exchange. The internal climate is strongly dependent on the outside conditions, especially in unheated greenhouses. In greenhouse climate models, the parameters of the internal climate such as air, soil, and crop temperatures as well as air humidity are calculated using energy and water vapor balances for the various components of the system [2].Climate in the greenhouse is a consequence of radiation crossing the cover material, usually plastic. After that, climate condition is a strong relationship between several factors, temperature, humidity, wind velocity, and the solar radiation. Environ...

show abstract