Numerical Simulation Analysis of Large-Scale Three-Dimensional Planting Greenhouse Based on Orthogonal Test Method

Maintaining optimal indoor environmental conditions for plant growth in greenhouse structures during hot summer periods presents a significant challenge in many regions. While natural and mechanical ventilation methods are commonly employed, there is a notable lack of theoretical simulation studies on greenhouse ventilation, particularly those incorporating light radiation and plant transpiration effects. This study employs Computational Fluid Dynamics (CFD) to simulate greenhouse environments, uniquely integrating both light radiation and plant transpiration factors in the analysis of mechanical ventilation characteristics. Through a combination of transient and steady-state calculations, temperature and humidity fields were comprehensively analyzed. Results indicate that positive pressure ventilation, symmetrical fan arrangement, and longitudinal airflow across plant shelves yield superior performance. Utilizing orthogonal experimental design and range analysis methodologies, a multi-factor variable analysis was conducted. Findings reveal that fan velocity exerts the most significant influence on the temperature field and the theoretical optimal combination was tested, and the most suitable combination scheme is selected according to the simulation results. This research provides valuable theoretical guidance for temperature and humidity control in greenhouses situated in subtropical monsoon climates.