When a load damage problem occurs in an air-cooled refrigeration unit, the primary task is to accurately identify the core of the fault - with a focus on confirming whether the compressor is burned out or its components are worn out. Once the compressor burns out or suffers severe wear, the refrigerant system is bound to be contaminated. For instance, the expired refrigeration oil will carbonize and remain inside the pipes, and the drying filter will also lose its effectiveness due to absorbing excessive moisture. Therefore, if it is confirmed that the compressor has burned out, a comprehensive analysis of the root cause of the fault must be conducted first. Specifically, the following aspects can be checked: whether there are quality defects in the temperature control components such as the contactor and overload device in the control box; Whether the relevant parameter setting values have been wrongly modified or improperly adjusted; Whether the supply voltage is in a stable state; Whether the operators strictly follow the standard procedures for operation, etc.
Air-cooled chillers are widely used in many industries such as chemical engineering, ink printing, large-scale energy equipment, mixing plants, food preservation, and central air conditioning. According to the differences in heat dissipation methods, it is mainly divided into two types: air-cooled screw type and water-cooled screw type. Even if the equipment is of high quality, it may still malfunction due to factors such as limited service life and improper operation. Among them, compressor damage is a common type of load-related failure. If it is confirmed through inspection that the compressor is damaged and cannot be repaired for use, a new compressor should be replaced according to the following steps:
1. Disassemble the original drying filter, connect the short-circuit parts with temporary detachable connecting pipes or copper pipe joints, and then purge the entire system with nitrogen at a pressure of 10kg/cm² until no cleaning agent remains.
2. Inject the cleaning agent into the pipeline system and let it circulate to complete the cleaning. If the cleaning effect is not satisfactory, the cleaning agent can be replaced multiple times to ensure the pipeline is clean.
3. Add refrigeration oil to the new compressor, observe the oil usage during operation, and then inject liquid refrigerant. After the refrigerant charge reaches 80% to 90% of the rated value, preheat the compressor for 2 hours and then start it for testing.
4. Install a new compressor and a drying filter, and simultaneously conduct a leak test using nitrogen at a pressure of 10kg/cm². After confirming there is no leakage, the remaining nitrogen in the system is discharged into the atmosphere through the high-pressure end Angle valve.
5. Perform vacuuming operations from both the high and low pressure ends until the vacuum degree reaches 1000micro. Finally, conduct a comprehensive inspection of the operating status of all power supplies and electronic control systems.
