Methodology Objectives Greehouse Analysis for Strawberry Crops Fernando De Howitt (200053) Gabriel Gómez (204438) Nicolás Herrera (201713) Mateo Ormaza (204684) Heat Transfer (NRC: 3371) Simulations Results Parameters used in the simulations General : • Design a greenhouse capable of maintaining ideal conditions for planting strawberries Specific : • Research the methods used in greenhouses to control the climate • Develop mathematical models to understand the different conditions present inside a greenhouse • Utilize the knowledge acquired in class Figure 1: dimensions of the greenhouse Figure 2: Energy balance of the greenhouse • The air flow velocity is found to be 11 85 [m/s], which corresponds to a fresh breeze • To supply the required ventilation, a rectangular duct is designed with a cross - sectional area of 0 28 [m^ 2 ], with a length of 36 [m] placed in the center of the roof of the green house • The fan that distributes the air flow through the greenhouse needs a power of 12 17 [kW] • The simulation performed confirms the theoretical results, as temperature conditions remain adequate inside the greenhouse • At night, the air velocity inside the greenhouse is found to be nearly zero to maintain the optimal conditions, which is why the ventilation system is turned off at night • With the designed greenhouse, the sustainable growth of quality strawberries is possible in Cumbaya Figure 3: Radiation energy balance of the greenhouse Table 4: Extracted parameters Figure 6: streamlines of the air at the exit of the AC pipe system Figure 4: Simulation results for the temperature at the walls of the greenhouse Figure 5: Internal temperature in the midplane along the greenhouse To design the greenhouse first we needed to find the parameters that the strawberries need to grow efficiently After that we found that the greenhouse experiments convection heat transfer in and outside and radiation from the sun and the earth To modify the conditions inside we used an AC system to lower de humidity and increase the temperature during the day Parameter Values Units 𝑞 𝑐𝑜𝑛𝑣 , 𝑜𝑢𝑡 1523.06 [W] 𝑞 𝑐𝑜𝑛𝑣 , 𝑖𝑛 33518.11 [W] 𝑞 𝑟𝑎𝑑 35041.17 [W] Inner flow velocity 11.85 [m/s] Duct volume flow rate 7129.09 [CFM] Number of diffusers 6 - Power of fan 12.17 [kW] Conclusions Greenhouse Cumbaya % Relative humidity 70% 80% Temperature [ ° C] 20 16 Radiation [kWh/dia] - 5.736 Figure 1: Energy balance equations Table 3: environmental parameters inside and outside the greenhouse adaptive sizing Yes Resolution 5 Nodes 20800 Elements 87977 Energy On Viscous k-epsilon Radiation S2S Gravity On Fuild Air Solid mdpe Inlet velocity 11,85 [m/s] outlet Pressure 0 Simulation parameters Mesh Set Up Table 1: mesh and set up parameters References thermal conditions mixed heat transfer coeff [W/m2*K] 3 free Stream temperature [K] 289,15 External emissivity 0,3 External Radiation temperature [K] 289,15 Wall thickness [m] 0,01 Type Semi-transparent absortivity (all) 0,21 Transmissivity (all) 0,72 walls Simulation parameters Table 2: wall parameters Figure 6: streamlines of the air at the exit of the AC pipe system Cengel , Y., Boles, M., & Kanoglu , M. (2019). Termodinámica. México D.F.: McGraw - Hill. Gerhart , P., Gerhart, A., & Hochstein, J. (2016). Munson, Young and Okiishi's Fundamentals of Fluid Mechanics. Hoboken: John Wiley & Sons Inc. . Global Solar Atlas. (n.d.). Retrieved from Global Solar Atlas: https://globalsolaratlas.info/map?c= - 0.211354, - 78.442805,11&s= - 0.211354, - 78.442805&m=site Incopera , F., Dewitt , D., Bergman, T., & Lavine, A. (2011). Fundamentals of Heat and Mass Transfer. Jefferson City: John Wiley & Sons Inc.