How to solve the problem if a blockage failure occurs in the refrigeration system

         If there is a blockage failure in the refrigeration system, how to solve it, is a problem that many users are concerned about, the blockage of the refrigeration system is mainly the throttle valve produces oil blockage, ice blockage or dirty blockage, or dirty filter drier. Today, I will introduce you in detail about the causes and solutions of system blockages.
　　1. Oil plug failure
　　The main cause of oil plug: it is caused by serious wear of the compressor cylinder block or excessive cylinder matching clearance. With the compressor exhaust gasoline is discharged into the condenser, and then with the refrigerant into the filter drier, due to the large viscosity of the oil, blocked by the desiccant in the filter, too much oil at the filter inlet to form a blockage, so that the refrigerant can not circulate normally.
　　There is too much refrigeration oil remaining in the refrigeration system, so that the refrigeration effect is affected, or even refrigeration cannot be refrigerated, so the refrigeration oil in the system must be removed.
　　Treatment method of oil plug: the filter oil plugging should be replaced with a new filter, and at the same time use high-pressure nitrogen to blow out part of the refrigeration oil accumulated in the condenser, it is best to heat the condenser with an electric hair dryer when nitrogen is introduced.
　　By the way, the main reason for the oil film is that the lubricating oil that has not been separated from the oil separator will enter the system and flow with the refrigerant in the pipe, forming an oil cycle. There is still a fundamental difference between oil film and oil plug.
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　　Hazards of oil film:
　　If an oil film is attached to the surface of the heat exchanger, the condensation temperature will rise, and the evaporation temperature will decrease, resulting in increased energy consumption;
　　When a 0.1mm oil film is attached to the surface of the condenser, the refrigeration capacity of the refrigeration compressor decreases by 16% and the electricity consumption increases by 12.4%; When the oil film in the evaporator reaches 0.1mm, the evaporation temperature will drop by 2.5°C and the power consumption will increase by 11%.
　　Oil film treatment method:
　　The use of high-efficiency oil can greatly reduce the amount of oil entering the system pipeline;
　　If the system already has an oil film, it can be washed several times with nitrogen until there is no mist gas.
　　2. Ice blocking failure
　　The occurrence of ice blocking failure is mainly due to the refrigeration system contains excessive moisture, with the continuous circulation of refrigerant, the water in the refrigeration system is gradually concentrated at the outlet of the throttle valve, because the temperature at the outlet of the throttle valve is the lowest, the water freezes and gradually increases, to a certain extent, the capillary tube is completely blocked, and the refrigerant can not circulate.
　　The main source of moisture: the moisture left by the components of the refrigeration system and the connecting pipes due to insufficient drying;
　　Refrigeration oil and refrigerant contain more than the permissible amount of moisture;
　　The installation is not vacuumed or improperly installed, resulting in moisture;
　　The motor insulation paper in the compressor contains moisture.
　　Manifestations of ice blockage:
　　The airflow gradually weakens and is intermittent;
　　When the blockage is serious, the air flow sound disappears, the refrigerant circulation is interrupted, and the condenser gradually cools;
　　Due to the blockage, the exhaust pressure rises and the machine running sound increases;
　　There is no refrigerant inflow in the evaporator, the frosting area gradually becomes smaller, and the refrigeration effect becomes worse;
　　After a period of downtime, the refrigerant is reproduced (the cold ice cubes begin to melt)
　　The ice jam forms a periodic repetition of one pass, one block, and another.
　　Treatment of ice blockage:
　　The ice blockage failure of the refrigeration system is due to the excessive moisture in the system, so the entire refrigeration system must be dried. It can be handled in the following ways:
　　Vacuum, replace the dry filter drier, and wait for the moisture indicator in the refrigeration system sight glass to turn green to qualify;
　　If the system has a lot of moisture, flush the dirt in sections with nitrogen, replace the filter, replace the refrigerant oil, replace the refrigerant, and vacuum until the moisture indicator in the sight glass turns green.
　　3. Dirty plugging fault
　　After the refrigeration system is dirty, because the refrigerant cannot be circulated, the compressor runs continuously, the evaporator is not cold, the condenser is not hot, the compressor shell is not hot, and there is no air flow sound in the evaporator. If there are more impurities in the system, the filter drier will gradually be blocked, and the filter screen of the throttle mechanism will be blocked.
　　The main causes of dirty blockage:
　　Dust, metal dust during construction and installation, and the oxide layer on the inner wall surface falling off during pipeline welding;
　　During the processing of each part, the inner and outer surfaces are not cleaned, and the pipeline is not tightly sealed and dust enters the pipe;
　　Refrigeration oil and refrigerant contain impurities, poor quality desiccant powder in the filter drier;
　　The distance between the capillary tube and the filter screen in the filter drier is too close and it is easy to cause dirt failure.
　　Manifestations after dirty blockage:
　　If it is partially blocked, the evaporator has a cold or cold feeling, but does not frost;
　　When touching the outer surface of the filter drier and throttle valve, it feels very cool, there is frost, and even a layer of white frost will form;
　　The evaporator is not cold, the condenser is not hot, and the compressor housing is not hot.
　　Treatment of dirty plugging faults: dirty plugs are generally in the filter drier, throttle mechanism screen, suction filter, etc. The throttle mechanism filter, the suction filter can be removed and cleaned, and the filter drier is generally replaced. After the replacement is completed, the refrigeration system needs to be leaked and vacuumed.