CFD Simulation Study on the Cooling Characteristics of Shading and Natural Ventilation in Greenhouse of a Botanical Garden in Shanghai

Abstract

Botanical garden greenhouses typically use solar radiation as an important heat source and meanwhile provide light for plants to survive. However, in the summertime, when the solar radiation is too strong, overheating will occur in the greenhouse and natural ventilation assisted with shading is used to cool it down. The modulation strategy of shading is very important not only to indoor temperature but also to the growth of plants. In order to determine the control strategy of the shading area in the design and installation stage, a CFD model of an exhibition greenhouse in Shanghai is established. During summer conditions, under the worst-case scenario of a windless day, the minimum shading area needed under different outdoor comprehensive temperatures is studied, and the correlation curve is fitted to guide the control of the shading to maintain appropriate thermal conditions. The decrease in indoor temperature under different shading areas is also explored when the outdoor comprehensive temperature is 34 °C. The annual carbon emission reduction of the greenhouse is about 500 t CO2, by adopting shading and natural ventilation. This study provides a reference value for shading control and energy saving and emission reduction of a botanical garden greenhouse.

Numerical simulation study on drifts and salt deposition in the huge salt water cooling tower group

“…It is proved that the two have good consistency. Shi Xuefeng et al [15] compared and analyzed the CFD model and SACTI model of oating droplets and salt deposition in cooling tower, and believed that CFD considered evaporation and condensation of fog plume, which was closer to the actual weather, and also considered the in uence of local circulation and buildings, resulting in that the peak value of salt deposition predicted by SACTI was about 3 times that of CFD. By comparing the simulation results of fog plume trajectory with the eld observation results, CFD is more reliable in ow eld prediction, so it is more suitable for calculating oating droplets and salt deposition problems.…”