Repair method of screw refrigeration compressor wear
The application of screw refrigeration compressors is becoming more and more common, and some of them have entered a period of frequent failures. When the abrasion of the female and male rotors, body, and exhaust end seat of the refrigeration compressor reaches above 0.65rnm, vibration will occur when the refrigeration compressor is running, the sound is abnormal, the cooling capacity is reduced, and the compressor cannot work normally.
1. Reasons for wear of screw refrigeration compressor
1. Compressor components were not replaced in time after they were worn
Analyze the force of the screw refrigeration compressor. During the meshing process of the male and female rotors, a V-shaped working volume is formed to complete the suction, compression and exhaust of the gas. At the same time, it produces force on the female and male rotors and the body. The reaction force is transmitted to sliding bearings, radial thrust balls and other bearings. In this way, although there is abrasion between the female and male rotors and other components, they are more durable due to oil lubrication and special surface treatment. However, if the bearing bearing the force is damaged, the position of the yin and yang rotors will be moved, causing the yin and yang rotors to wear in a short time, and at the same time wear the body and end seats.
2. Insufficient oil supply due to operating errors, etc., makes the refrigeration compressor in a dry grinding state.
3. The oil and the inhaled gas contain impurities, which cause large scratches on the female and yang rotors, body, and exhaust end seat of the refrigeration compressor, causing internal leakage and unable to work normally.
2. Repair methods for screw refrigeration compressor wear
1. The electroplating method is used to plate a layer of chromium on the surface of the parts to be repaired. After plating a layer of chrome (plating) on the surface of the parts to be repaired, they are processed to the specified size and then assembled. This method is expensive.
2. On the premise that the yin and yang rotors are not bent and deformed, use polymer adhesive to repair the worn parts, the steps are as follows:
(1) Degreasing, that is, removing oil in the pores of the repair parts to enhance the bonding effect. The parts to be repaired can be sprayed, beaten, roasted to remove the oil in the pores of the repaired parts.
(2) Make the surface of the parts to be repaired pitted.
(3) Use acetone to treat the surface.
(4) Brush the Beijing-made strong polymer adhesive on the surface of the part with a brush.
(5) It can be treated with whetstone, emery paper, or polished on a machine tool to make the clearance meet the assembly requirements of the screw refrigeration compressor.
A maintenance master once repaired an LG12.5 twin-screw refrigeration compressor, the refrigerant is R22, the refrigeration capacity is 200kw under standard conditions, and the transmission mode between the rotors: Yin with Yang. The LG12.5 twin-screw refrigeration compressor has abnormal sound after being used for a period of time, which has not attracted attention. Until the unit cannot work normally. After disassembly, it was found that the wear and tear of the yin and yang rotor, the body, and the exhaust end seat were above 0.65 nm. The manufacturer considered it to be of no repair value. After repairing by this method, it has been in operation for two years and the effect is good. In short, we must pay attention to the repair and maintenance of screw refrigeration compressors. For example, the compressor must be disassembled after 2 years of operation. During maintenance, the rolling bearings and the "O" ring are replaced at the same time to prevent the screw refrigeration compressor from failing to work due to wear.
