How to solve the problem of blockage in the refrigeration system is a concern of many users. Blockage in the refrigeration system is mainly caused by oil blockage, ice blockage or dirty blockage in the throttle valve, or dirty blockage in the drying filter. Today I will give you a detailed introduction to the causes and solutions of system congestion.
1. Oil blockage failure
The main reason for oil blockage is that the compressor cylinder is severely worn or the cylinder fitting clearance is too large. The gasoline discharged from the compressor is discharged into the condenser, and then enters the drying filter along 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, it forms a blockage at the filter inlet, causing Refrigerant cannot circulate properly.
Excessive refrigeration oil remains in the refrigeration system, which affects the refrigeration effect or even prevents refrigeration. Therefore, the refrigeration oil in the system must be removed.
How to deal with oil blockage: When the filter is blocked, replace it with a new one, and use high-pressure nitrogen to blow out part of the refrigeration oil accumulated in the condenser. It is best to use a hair dryer to heat the condenser when nitrogen is introduced.
By the way, the refrigeration network will talk about the oil film here. The main reason for the oil film is that the lubricating oil that has not been separated by the oil separator will enter the system and flow with the refrigerant in the tube, forming an oil cycle. There is still a fundamental difference between oil film and oil plugging.
Dangers 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 is attached to the surface of the condenser, the cooling capacity of the refrigeration compressor decreases 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%.
Oil film treatment method:
The use of high-efficiency oil can greatly reduce the amount of oil entering the system pipeline;
If an oil film already exists in the system, it can be flushed with nitrogen several times until there is no mist-like gas.
2. Ice blockage failure
The occurrence of ice blockage failure is mainly due to the excessive moisture in the refrigeration system. With the continuous circulation of refrigerant, the moisture in the refrigeration system gradually concentrates at the outlet of the throttle valve. Since the temperature at the outlet of the throttle valve is the lowest, water forms. The ice builds up and gradually increases. To a certain extent, the capillary tube is completely blocked and the refrigerant cannot circulate.
Main sources of moisture:
The remaining moisture in the various components and connecting pipes of the refrigeration system due to insufficient drying;
Refrigeration oil and refrigerant contain more than the allowable amount of moisture;
Failure to vacuum during installation or improper installation results in moisture;
The insulation paper of the motor in the compressor contains moisture.
Symptoms of ice blockage:
The air flow gradually becomes weaker and intermittent;
When the blockage is serious, the air flow sound disappears, the refrigerant circulation is interrupted, and the condenser gradually becomes cooler;
Due to blockage, the exhaust pressure increases and the operating sound of the machine increases;
There is no refrigerant flowing into the evaporator, the frosting area gradually becomes smaller, and the cooling effect becomes worse;
After a period of shutdown, the refrigerant begins to be regenerated (the cold ice cubes begin to melt)
The ice blockage forms a periodic repetition of being cleared for a while, blocked for a while, blocked and then cleared, and cleared and blocked again.
Ice blockage treatment:
Ice blockage occurs in the refrigeration system because there is excess moisture in the system, so the entire refrigeration system must be dried. The processing methods are as follows:
Evacuate and replace the drying filter. When the moisture indicator in the sight glass of the refrigeration system turns green, it is considered qualified;
If a large amount of water enters the system, flush it with nitrogen in stages, replace the filter, replace the refrigeration oil, replace the refrigerant, and vacuum until the moisture indicator in the sight glass turns green.
3. Dirty blockage fault
After the refrigeration system is clogged, the refrigerant cannot circulate, causing the compressor to run continuously. The evaporator is not cold, the condenser is not hot, the compressor shell is not hot, and there is no sound of air flow in the evaporator. If there are too many impurities in the system, the filter dryer will gradually be clogged and the filter screen of the throttling mechanism will be clogged.
The main reasons for dirty blockage:
Dust and metal shavings from 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 internal and external surfaces were not cleaned, and the pipelines were not tightly sealed and dust entered the pipes;
The refrigeration oil and refrigerant contain impurities, and the desiccant powder in the drying filter is of poor quality;
Performance after dirty blockage:
If it is partially blocked, the evaporator will feel cold or cold, but there will be no frost;
When you touch the outer surface of the filter dryer and throttle valve, it will feel cool to the touch, and there will be frost, or even a layer of white frost;
The evaporator is not cold, the condenser is not hot, and the compressor shell is not hot.
Dealing with dirty blockage problems: Dirty blockage usually occurs in the drying filter, throttling mechanism mesh filter, suction filter, etc. The throttling mechanism filter and the suction filter can be removed and cleaned, and the drying filter is usually replaced. After the replacement is completed, the refrigeration system needs to be checked for leaks and vacuumed.
Guangxi Cooler Refrigeration Equipment Co.,Ltd.
Tel/Whatsapp:+8613367611012
Email:karen@coolerfreezerunit.com
If the distance between the capillary tube and the filter screen in the filter dryer is too close, it can easily cause dirty blockage.
Post time: Jan-13-2024