Objective As a key device in agricultural research and environmental ecological assessment, plant growth chambers need to precisely control environmental factors such as light and temperature. However, the high-power light sources introduced in high-light-intensity plant growth chambers significantly affect the stability and uniformity of the temperature inside the chamber due to the heat they generate. Therefore, this study aims to systematically explore the influence mechanism of chamber structure and working parameters on the temperature field based on computational fluid dynamics (CFD) technology, and to seek the optimal parameter combination to achieve uniform temperature control under high light intensity.
Method Firstly, a physical model of the plant growth chamber with high-power LED light sources was constructed, and a CFD numerical simulation model was established based on the ANSYS Workbench platform. The standard k-ε turbulence model and Gaussian heat source model were adopted to accurately describe the airflow and heat dissipation characteristics of the light sources inside the chamber. Through temperature control experiments on a physical prototype, the reliability of the model was verified by comparing the measured data with the simulation results. On this basis, 128 parameter combination schemes were designed, and 13 representative schemes were selected for qualitative analysis. Further, fine-grained traversal simulation were conducted on key parameters such as the air inlet angle, number of structural layers, air inlet temperature, air inlet velocity, and internal circulation velocity. A comprehensive distribution index including the mean and standard deviation of temperature and wind speed was introduced, and combined with weight sensitivity analysis, the optimal working parameter combination was quantitatively evaluated and determined.
Result The model validation results showed that the temperature distribution characteristics of the simulation and experiments were highly consistent, proving the accuracy of the CFD model. The parameter optimization results indicated that in terms of the air inlet angle, horizontal air inlet was more effective in optimizing the airflow path than upward or downward inclined air inlets. Regarding structure and heat load, multi-layer structures had increased heat dissipation pressure due to higher heat load and required higher air inlet velocity compared to single-layer structures. In terms of temperature control mechanism, the air inlet temperature mainly determined the overall temperature inside the chamber, and its impact on the uniformity of the temperature field was negligible. The optimal parameter combination was that a single-layer structure performed best with an air inlet velocity of 3 m/s and no internal circulation. For a double-layer structure, internal circulation needed to be activated, and the optimal combination was an air inlet velocity of 3.5 m/s and an internal circulation velocity of 1 m/s. Under this combination, even with a significant increase in the heat load of the light sources, the chamber could still maintain a good uniformity of the temperature field.
Conclusion This study provides a theoretical basis and technical guidance for the development of high-light-intensity plant growth chambers.
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