风冷冰箱的湿度场动态仿真通用模型及湿度均匀性改善

To address the critical challenge of accurately and dynamically forecasting the humidity distribution in frost-free refrigerators equipped with active humidification capabilities, a general model integrating commercial simulation software and self-programming was proposed in this paper for dynamic simulation of humidity distribution in frost-free refrigerator and humidity uniformity improvement. Initially, a physical model was constructed, focusing on a specific frost-free refrigerating chamber as the subject of investigation. Subsequently, a mathematical model of the evaporator was developed based on the distribution parameter method and the porous media model to calculate pressure drop, heat exchange, and frost accumulation as wet air flows through the evaporator. Additionally, simulation models for the humidifier, fan, and other components were established, reflecting the actual operational conditions of the frost-free refrigerator. Finally, a control program was crafted based on the control strategy of refrigerating chamber to couple the mathematical models of various components with the physical model of the refrigerating chamber. This enabled dynamic simulation of the humidity distribution, and the experimental data was used to verify models. The results show that the general model proposed could precisely forecast the dynamic changes in temperature and humidity in the refrigerating chamber of a frost-free refrigerator. Compared with experimental data, the average temperature deviation was below 0.7 ℃, while the average relative humidity deviation was less than 5.1% during a start-stop cycle. Moreover, by using the new design of relocating the humidifier to the middle of the door, the humidity uniformity in the refrigerating chamber was significantly improved with a reduction of the coefficient of variation for humidity from 0.55 to 0.41. The study results are of significance for the forecast of temperature and humidity distribution in the pre-design stage of frost-free refrigerators and the improvement of design efficiency.