How to Handle Blockages in Refrigeration Equipment
2024-07-26
What to do if ice blockage, dirt blockage or oil blockage occurs in refrigeration equipment?
How to solve the blocking failure in the refrigeration system is a concern for many users. The blocking in the refrigeration system is mainly caused by oil blockage, ice blockage or dirt blockage in the throttle valve, or dirt blockage in the drying filter.
- Oil Blockage Failure
The main reason for oil blockage is severe wear of the compressor cylinder or excessive clearance between the cylinders. The gasoline discharged from the compressor is discharged into the condenser and then enters the drying filter together with the refrigerant. Due to the high viscosity of the oil, it is blocked by the desiccant in the filter. When there is too much oil, a blockage is formed at the inlet of the filter, preventing the normal circulation of the refrigerant.
If there is too much refrigeration oil remaining in the refrigeration system, it will affect the refrigeration effect and even make refrigeration impossible. Therefore, the refrigeration oil in the system must be removed completely.
Treatment method for oil blockage:
When the filter is blocked by oil, a new filter should be replaced. 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.
When the filter is blocked by oil, a new filter should be replaced. 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.
Hazards of Oil Film:
If an oil film adheres to the surface of the heat exchanger, the condensation temperature will rise and the evaporation temperature will drop, resulting in increased energy consumption.
When a 0.1mm oil film adheres to the surface of the condenser, the refrigeration capacity of the refrigeration compressor drops by 16% and the power 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%.
If an oil film adheres to the surface of the heat exchanger, the condensation temperature will rise and the evaporation temperature will drop, resulting in increased energy consumption.
When a 0.1mm oil film adheres to the surface of the condenser, the refrigeration capacity of the refrigeration compressor drops by 16% and the power 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%.
Treatment method for oil film:
Using an efficient oil separator can greatly reduce the amount of oil entering the system pipeline.
If there is already an oil film in the system, it can be rinsed multiple times with nitrogen until there is no mist-like gas.
Using an efficient oil separator can greatly reduce the amount of oil entering the system pipeline.
If there is already an oil film in the system, it can be rinsed multiple times with nitrogen until there is no mist-like gas.
- Ice Blockage Failure
The occurrence of ice blockage failure is mainly due to the excessive moisture contained in the refrigeration system. With the continuous circulation of the refrigerant, the moisture in the refrigeration system gradually concentrates 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. When it reaches a certain extent, the capillary is completely blocked and the refrigerant cannot circulate.
Main sources of moisture:
Residual moisture in various components and connecting pipes of the refrigeration system due to insufficient drying.
The refrigeration oil and refrigerant contain more moisture than the allowable amount.
Installation and construction without vacuum pumping or improper installation lead to moisture.
The motor insulating paper in the compressor contains moisture.
Residual moisture in various components and connecting pipes of the refrigeration system due to insufficient drying.
The refrigeration oil and refrigerant contain more moisture than the allowable amount.
Installation and construction without vacuum pumping or improper installation lead to moisture.
The motor insulating paper in the compressor contains moisture.
Manifestations of ice blockage:
The airflow gradually weakens and is intermittent.
When the blockage is severe, the airflow sound disappears, the refrigerant circulation is interrupted, and the condenser gradually cools down.
Due to the blockage, the exhaust pressure rises and the operating sound of the machine increases.
No refrigerant flows into the evaporator, the frosting area gradually decreases, and the refrigeration effect worsens.
After the machine is shut down for a period of time, the refrigerant starts to refrigerate again (the ice begins to melt).
The formation of ice blockage is periodically repeated, sometimes blocked, sometimes unblocked, blocked again, and unblocked again.
The airflow gradually weakens and is intermittent.
When the blockage is severe, the airflow sound disappears, the refrigerant circulation is interrupted, and the condenser gradually cools down.
Due to the blockage, the exhaust pressure rises and the operating sound of the machine increases.
No refrigerant flows into the evaporator, the frosting area gradually decreases, and the refrigeration effect worsens.
After the machine is shut down for a period of time, the refrigerant starts to refrigerate again (the ice begins to melt).
The formation of ice blockage is periodically repeated, sometimes blocked, sometimes unblocked, blocked again, and unblocked again.
Treatment of ice blockage:
The ice blockage failure in the refrigeration system occurs because there is excessive moisture in the system. Therefore, the entire refrigeration system must be dried. The treatment methods are as follows:
Vacuum pumping, replace the drying filter. It is qualified when the moisture indicator in the sight glass of the refrigeration system turns green.
If a large amount of water enters the system, it is necessary to rinse the dirt in sections with nitrogen, replace the filter, replace the refrigeration oil, replace the refrigerant, vacuum pump until the moisture indicator in the sight glass turns green.
The ice blockage failure in the refrigeration system occurs because there is excessive moisture in the system. Therefore, the entire refrigeration system must be dried. The treatment methods are as follows:
Vacuum pumping, replace the drying filter. It is qualified when the moisture indicator in the sight glass of the refrigeration system turns green.
If a large amount of water enters the system, it is necessary to rinse the dirt in sections with nitrogen, replace the filter, replace the refrigeration oil, replace the refrigerant, vacuum pump until the moisture indicator in the sight glass turns green.
- Dirt Blockage Failure
After the dirt blockage occurs in the refrigeration system, because the refrigerant cannot circulate, the compressor operates continuously, the evaporator is not cold, the condenser is not hot, the compressor casing is not hot, and there is no airflow sound in the evaporator. If there are many impurities in the system, the drying filter and the filter screen of the throttling mechanism will be gradually blocked.
Main reasons for dirt blockage:
Dust and metal debris during the construction and installation process, and the oxide layer on the inner wall surface falling off during pipe welding.
During the processing of each component, the inner and outer surfaces are not cleaned thoroughly, and the pipeline is not sealed tightly, allowing dust to enter the pipe.
The refrigeration oil and refrigerant contain impurities, and the desiccant powder in the drying filter is of poor quality.
The too-close distance between the capillary and the filter screen in the drying filter is also prone to cause dirt blockage failure.
Dust and metal debris during the construction and installation process, and the oxide layer on the inner wall surface falling off during pipe welding.
During the processing of each component, the inner and outer surfaces are not cleaned thoroughly, and the pipeline is not sealed tightly, allowing dust to enter the pipe.
The refrigeration oil and refrigerant contain impurities, and the desiccant powder in the drying filter is of poor quality.
The too-close distance between the capillary and the filter screen in the drying filter is also prone to cause dirt blockage failure.
Manifestations after dirt blockage:
When partially blocked, the evaporator feels cool or icy, but does not frost.
When touching the outer surfaces of the drying filter and the throttle valve, it feels very cold and frosty, and even a layer of white frost may form.
The evaporator is not cold, the condenser is not hot, and the compressor casing is not hot.
When partially blocked, the evaporator feels cool or icy, but does not frost.
When touching the outer surfaces of the drying filter and the throttle valve, it feels very cold and frosty, and even a layer of white frost may form.
The evaporator is not cold, the condenser is not hot, and the compressor casing is not hot.
Treatment of dirt blockage failure: Dirt blockage is generally in the drying filter, the filter screen of the throttling mechanism, the suction filter screen, etc. The filter screen of the throttling mechanism and the suction filter screen can be removed and cleaned. The drying filter is generally replaced. After the replacement is completed, it is necessary to leak detect and vacuum the refrigeration system.
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