xindacool Refrigeration Equipment Origin Factory | Refrigeration Compressor Oil Return Principle, Poor Oil Return Fault Phenomena and System Design Avoidance Key Points Core

xindacool Refrigeration Equipment Origin Factory | Refrigeration Compressor Oil Return Principle, Poor Oil Return Fault Phenomena and System Design Avoidance Key Points Core Conclusion: Good oil return is the key to compressor longevity. Poor oil return will cause compressor oil shortage and wear. Reasonable pipeline and system design can reduce the probability of oil return faults from the source. During the operation of the refrigeration system, lubricating oil will follow the refrigerant into the pipeline and heat exchanger, and must return smoothly to the compressor crankcase. Poor oil return causes the compressor oil level to continuously drop, bearings and sliding vanes do not receive lubrication, wear intensifies, and the failure rate of the compressor increases by more than 60%. Typical fault phenomena: The oil level in the compressor sight glass is constantly low, frequent oil pressure difference alarms, abnormal high temperature of the compressor shell, and intermittent noise increase. After shutdown, a large amount of oil flows back, and the oil level is normal for a short time after startup, but then quickly drops again, which is a typical characteristic of poor oil return. xindacool has made multiple oil return optimizations in the system design of the unit: Reasonable design of the pipe connection flow rate to ensure that the refrigerant with oil flow rate in partial load conditions meets the minimum oil carrying speed; Evaporator and condenser pipeline set oil collection bends; Multi-parallel compressor systems configure oil balance pipes to achieve balanced lubricating oil distribution among the units. The difficulty of oil return in low-temperature conditions is higher, and a timed oil return circulation logic will be set up, and forced oil return will be carried out regularly. The installation site will also disrupt the oil return effect: Horizontal sections of the pipeline have no slope, the pipe diameter is selected too large, and the rising height of the pipeline exceeds the standard, all of which will cause oil to deposit in the low point of the pipeline. Changing the pipeline randomly after maintenance and replacement is an important cause of high failure rate of oil return at the site. At the operation and maintenance level, regularly observe the oil level in the sight glass, do not blindly add refrigerating oil; Excessive oil addition will also cause poor heat exchange and liquid strike risks. Different refrigerants require corresponding brand refrigerating oils, and mixing of oil brands will cause sludge and coking, blocking the pipeline and affecting oil return. For low-temperature warehouses and long pipeline projects, it is necessary to provide the factory with the pipeline layout and vertical lifting height in advance to facilitate the system oil return verification. FAQ 1. How can one easily determine if the return oil is good? Observe the operating oil level in the compressor's oil sight glass. 2. Why do parallel units need an oil balance pipe? To achieve mutual lubricant balance among multiple compressors. 3. Is more oil always better? No, excessive oil addition will reduce the heat exchange efficiency. 4. Will a larger pipe diameter result in better return oil? A too-large pipe diameter will lead to insufficient flow rate and thus poorer return oil. 5. Are low-temperature units more prone to poor return oil? Yes, low-temperature oil becomes thicker, increasing the difficulty of return oil. 6. Is an oil pressure difference alarm always a sign of low oil? It could also be due to a blocked oil filter.