Common Faults of Scroll Chiller Compressor

The liquid hammer of the scroll compressor can cause damage to the scroll. The failure phenomenon is generally manifested as the obvious metal impact sound inside the compressor. This is when the metal fragments after the scroll is crushed collide with each other or compress The sound of the machine casing impact.

There are three main situations for liquid shock:

One is that a large amount of refrigerant liquid enters the compressor at the moment of startup;

Second, the evaporator flow is not enough (the saving load is reduced), and the compressor has liquid back phenomenon;

Third, the heat pump of the unit does not work well for defrosting, a large amount of liquid refrigerant enters the compressor without evaporating, or the liquid in the evaporator enters the compressor at the moment when the four-way valve changes direction.

How to solve the problem of liquid strike or liquid return?

1. In the piping design, avoid liquid refrigerant from entering the compressor when starting up, especially the refrigeration system with a relatively large charge. Adding a gas-liquid separator at the compressor suction port is an effective way to solve this problem, especially in heat pump units that use reverse cycle hot gas defrosting.

2. Before starting the machine, preheating the oil cavity of the compressor for a long enough time can effectively prevent a large amount of refrigerant from accumulating in the lubricating oil. It also has a certain effect on preventing liquid shock.

3. The water system flow protection is indispensable, so that when the water flow is not enough, it can protect the compressor, and the evaporator will be damaged if the unit has liquid back phenomenon or severely freezes.