The refrigeration compressor is the core of the refrigeration system. The direct and effective way to improve the efficiency of the refrigeration system is to improve the efficiency of the compressor, so that the energy consumption of the system is significantly reduced.With the promotion of the concept of energy saving and emission reduction, refrigeration compressor plays a more and more critical role in medicine, refrigeration and other industries.
However, in the running process of refrigeration compressor, in addition to mastering the correct operation method, but also need to understand the common fault of refrigeration compressor, in order to find the corresponding solution when the fault occurs, to ensure the operation of production.So, what are the common failures of refrigeration compressors?
The suction temperature is too high or too low
Many users will find that the suction temperature is too high during the operation of refrigeration compressor.According to the industry, insufficient refrigerant charge in the system, the expansion valve is too small to open, the expansion valve screen is blocked, and other reasons may cause the suction temperature is too high.
However, if the suction temperature is too low, it is mainly caused by the large amount of evaporator liquid supply resulting in low suction superheat.In addition, too much refrigerant charge, expansion valve opened too large, etc., will also cause the suction temperature is too low.
The exhaust temperature is abnormal
The industry points out that the factors that affect the exhaust temperature include adiabatic index, compression ratio, suction temperature, etc.In general, the compressor exhaust temperature can be read from the exhaust line of the thermometer.The higher the suction temperature, the higher the compression ratio, the higher the exhaust temperature, and vice versa.
In addition, the condensation temperature and exhaust temperature is too high on the compressor operation is unfavorable, exhaust temperature is too high will make the lubricating oil dilute or even carbonization coking, thus making the compressor lubrication conditions deteriorated.
High exhaust pressure
The exhaust pressure generally corresponds to the condensation temperature.Normally, the exhaust pressure of the compressor is close to the condensing pressure.The high exhaust pressure will increase the compression work and reduce the gas transmission coefficient, thus reducing the refrigeration efficiency.
When the condensing pressure increases, the exhaust temperature of the compressor also increases.As the compression ratio of the compressor increases, the gas transmission coefficient decreases, thus the cooling capacity of the compressor decreases and the power consumption increases.If the exhaust temperature is too high, it will increase the consumption of compressor lubricating oil, making the oil dilute, affecting the lubrication;When the exhaust temperature and compressor oil flash point close, will also make part of the lubricating oil carbonization and accumulation in the suction, exhaust valve, affect the sealing of the valve.
According to the industry, lowering the temperature of the cooling medium can lower the condensing temperature and condensing pressure, but this is limited by environmental conditions.Increasing the flow of cooling media can reduce the condensation temperature a little, but not unilaterally increase the flow of cooling water or air, because this will increase the power of cooling pumps or fans and motors, should be considered comprehensively.
The lack of air displacement is related to the design of the compressor, which is one of the faults of the compressor.The main reasons include the following aspects.
First, the fouling of the inlet filter is blocked or the suction pipe of the compressor is too long, which increases the suction resistance and affects the suction volume, thus reducing the exhaust volume.
Second, the compressor speed reduction to reduce the volume of exhaust.If the compressor is used in an improper environment, the exhaust volume of the compressor is designed according to a certain suction temperature, humidity, power supply and other conditions. When it is used in an environment above the above standards, the exhaust volume will also be affected.