Abstract: After the refrigerator closed, due to the door opening of the refrigerator, the inflow of hot air and the decrease of indoor temperature are caused. Negative pressure will be formed in the chamber. As the core part of balancing the pressure inside the box, the drain pipe absorbs air to balance the air pressure inside and outside the box. If there exists water in the evaporating dish, it will generate water absorption noise. By studying the changes of indoor pressure and temperature, the influencing factors of water absorption noise were analyzed. Propose a drainage structure that can balance the negative pressure in the chamber and eliminate water absorption noise. At the same time, reduce the hot and humid air from the drain pipe into the room, improve the power consumption and temperature storage performance.

Key words: Negative pressure balance, Drainage structure, Water absorption noise, Power consumption performance, Temperature storage performance