The infiltration of warm and humid air from the outside into a freezer results in frost accumulation around the evaporator in household refrigerators. This can significantly reduce the cooling capacity of refrigerators. In this study, the pressure, temperature, and frost around a proposed drain tube were monitored through in-situ measurements until the first defrost process (about 54 h). The proposed drain tube has 220 times higher hydraulic resistance and shows 55 times lower inflow in computational fluid dynamics (CFD) analysis. Once the door of the freezer compartment is opened and closed, external warm air replaces the cold air in the freezer. Negative pressure is produced by the shrinkage of this external air under low-temperature conditions. The other role of the drain tube is to vent air between the outside and inside of the refrigerator under negative pressure. To release the negative pressure, the proposed drain tube has a movable shutter. In the CFD results, the secondary inlet increases the inflow by 3.2 times compared to the inflow in an I-type tube. To determine the design, the weight and inner diameter of the drain tube were changed. The performance of the proposed tube was validated by the lack of blockage of discharge until the first defrost process. The movable shutter did not allow the negative pressure to exceed -100 Pa by facilitating air venting after opening the door for 10 seconds and then closing it.

温暖和潮湿的空气从外面渗入冰箱，导致家用冰箱蒸发器周围结霜。这会显着降低冰箱的冷却能力。在这项研究中，在第一次除霜过程（约 54 小时）之前，通过原位测量监测了拟议排水管周围的压力、温度和霜冻。拟议的排水管具有高 220 倍的液压阻力，并在计算流体动力学 (CFD) 分析中显示出低 55 倍的流入量。一旦冷冻室的门打开和关闭，外部热空气就会取代冷冻室中的冷空气。这种外部空气在低温条件下收缩会产生负压。排水管的另一个作用是在负压下排出冰箱内外之间的空气。为了释放负压，建议的排水管有一个可移动的百叶窗。在 CFD 结果中，与 I 型管中的流入量相比，辅助入口使流入量增加了 3.2 倍。为了确定设计，改变了排水管的重量和内径。通过在第一次除霜过程之前没有堵塞排放，验证了建议管的性能。活动百叶窗通过在打开门10秒然后关闭门后促进排气使负压不超过-100 Pa。与 I 型管中的流入量相比是 2 倍。为了确定设计，改变了排水管的重量和内径。通过在第一次除霜过程之前没有堵塞排放，验证了建议管的性能。活动百叶窗通过在打开门10秒然后关闭门后促进排气使负压不超过-100 Pa。与 I 型管中的流入量相比是 2 倍。为了确定设计，改变了排水管的重量和内径。通过在第一次除霜过程之前没有堵塞排放，验证了建议管的性能。活动百叶窗通过在打开门10秒然后关闭门后促进排气使负压不超过-100 Pa。