流通环境对液氮充注蓄冷配送箱保温性能的影响

目的 为了提高液氮充注蓄冷配送箱在流通过程中的保温性能，保证配送品质。方法 搭建配送箱流通环境模拟试验平台，研究不同外界风速、外界温度和振动频率对蓄冷配送箱内空气温度变化和温度场分布的影响。结果 试验结果表明，当外界风速增大时，箱体内部环境的升温速度也会增大;外界温度对液氮充注完毕后箱内最低温度产生较大影响，箱体内部空气最低温度随外界温度降低而降低，同时始终在运输过程中维持较低的温度，箱体内温度场均匀性先提高后降低;振动对箱体内部环境的升温速度影响较大，而随着振动频率增大，箱体内部的温度场均匀性变差。结论 该研究可为蓄冷运输配送设备的设计与优化提供参考。

Effect of Circulation Environment on Thermal Insulation Performance of Cold Storage Distribution Box Based on Liquid Nitrogen Injection

The work aims to improve the thermal insulation performance of cold storage distribution box based on liquid nitrogen injection during circulation and ensure the distribution quality. A simulation test platform of distribution box circulation environment was established to investigate the effect of different external air velocity, external temperature and vibration frequency on the air temperature variation and temperature field distribution in the cold storage distribution box. According to the test results, when the external air velocity increased, the temperature rising speed of the internal environment in the box also increased. The external temperature had a great effect on the minimum air temperature inside the box after injection of liquid nitrogen, and the minimum air temperature decreased as the external temperature lowered. At the same time, a lower temperature was always kept during transportation. The homogeneity of temperature field rose firstly and then decreased. The vibration frequency had a great effect on the air temperature rising speed inside the box, and the homogeneity of temperature field decreased with the increase of vibration frequency. The results can provide a reference for the design and optimization of cold storage distribution equipment.