A novel study on enhanced temperature uniformity in a refrigerated container by optimizing inlet duct positions and their flow rates

This study investigates the impact of cold air inlet duct positions and their flow rates on the temperature distribution inside the refrigerated container. Computational fluid dynamics simulations are combined with response surface methodology to examine and optimize temperature uniformity in the container environment. Central composite design is applied to optimize the simulation samples with twenty-nine cases. A second-order temperature difference prediction model with four variables, including two inlet duct position parameters and two flow rate parameters, is developed and validated through analysis of variance, showing strong statistical significance with a coefficient of determination R² of 0.95. The results show that the identified optimal configuration has a container temperature difference of 2.09 K, substantially improving temperature uniformity by 40% compared to the conventional model. Ten optimal cases of temperature difference are selected based on the desirability functions to conduct simulations and compare with the predicted values ​​from the regression model, resulting in an average relative error of 3.37%. The current work contributes to more economical and environmentally friendly frozen transportation options by enhancing temperature uniformity within the container, thereby enabling the potential to reduce energy demand for refrigeration and lower CO 2 emissions. Additionally, the proposed approach maintains high prediction accuracy while improving overall optimization for refrigeration containers.