Analysis of air-temperature profile in a solar-heated greenhouse with computational fluid dynamics
High-tech greenhouse crop-production systems usually require elevated energy inputs, mainly to the heating or cooling systems, to achieve the production levels required to be profitable. This, in turn, results in a high carbon footprint, which nowadays is a big concern worldwide. In order to reduce the usage of fossil fuels, a solar heating system has been integrated into a newly proposed single-span energy-neutral greenhouse for the climate conditions in central Mexico. Solar thermal collectors heat water during the day, which is stored in an insulated tank. During the coldest period, usually at night-time, the hot water is distributed through a grid of hoses buried into the greenhouse ground. A 3D computational fluid dynamics (CFD) simulation of the greenhouse environment was performed to estimate the vertical air-temperature profiles during the night-time. Results of the simulations were verified with what could be expected. Three scenarios were simulated for outside air temperature of 0, 5, and 10°C, for a minimum water temperature of 35°C (as a worst-case scenario on the solar thermal collectors) in the heating system, resulting in acceptable inside conditions for greenhouse crops, for these scenarios.
Fitz-Rodríguez, E., López-Cruz, I.L., Salazar-Moreno, R., Rojano-Aguilar, A., Rosales‑Vicelis, J.E. and López-Díaz, J.H. (2018). Analysis of air-temperature profile in a solar-heated greenhouse with computational fluid dynamics. Acta Hortic. 1227, 93-98
computational fluid dynamics, controlled environment agriculture, temperature gradients, energy balance, solar collectors