Leakage is a common and prone failure of refrigerators and freezers. After the refrigerator has been used for a period of time, it can be as short as a few months or as long as a few years. There will be poor cooling effect, partial or no cooling, the compressor does not stop, the condenser does not heat enough or does not heat at all, and the compressor runs at a high temperature that is hot to the touch. When the process nozzle of the compressor is disconnected, little or no refrigerant is ejected. When these situations occur, it is enough to judge that there is a leakage fault in the system.
Most of the evaporators of refrigerators and freezers are made of aluminum tubes or "Bundy tubes"; refrigerator condensers are also more built-in, and like anti-dew tubes, they are basically made of iron. More than half of their area is buried in the insulating layer of foamed plastic. The condensed water from the evaporator and the water flowing from the bottom of the refrigerator cannot evaporate outwards, so they soak the pipeline for a long time, corroding the evaporation tube and the anti-dew respectively. Tube. Over time, it is very easy to be corroded and perforated. The material of the refrigerator freezer and the conditions in which it is used determine the root cause of the leakage failure.
When the refrigerator freezer is being repaired, first pay attention to whether there is refrigerant sprayed when the process port is disconnected? how many? The degree of system leakage can be judged.
If there is no refrigerant residual gas ejected at all, it means that the system has serious leakage, and the possibility of ice blockage during maintenance is high, especially the leakage of the low-pressure evaporator. Moisture or moisture is inhaled, so during maintenance, it should also be handled carefully according to the ice block treatment method, and strive for a success.
If there is still some or a small amount of residual gas discharged, it means that there is a slow leak or a slight leak in the system, and the possibility of ice blockage during maintenance is low.
As long as the fluorine gas released is less than the charging amount, the system must have different degrees of leakage. It is not advisable to only perform fluorination treatment for maintenance, and the refrigerant will eventually leak out. It is not enough to test the pressure for a few hours or dozens of hours, and it is difficult to prove the leakage. You must know that there are only dozens of grams or more than a hundred grams of refrigerant in the system of the refrigerator freezer, and it will take several months or even years to leak out. It is difficult to detect a leak for dozens of hours.
Under normal circumstances, if the refrigerator freezer leaks refrigerant, there is no doubt that there must be a leak in the system. If the evaporator, condenser, and anti-dew pipes are all copper pipes, there is generally no leakage. If it is a built-in (flat back) condenser, as long as it is an iron tube, it is the same as the evaporator and the anti-dew tube (except the copper anti-dew tube), and the possibility of leakage is high. The refrigerator freezer sent for repair, the evaporator, the condenser, and the anti-dew pipe inspection are made of iron pipes. Generally, there is no need for any gas pressure test, that is, re-coil or replace the condenser, disconnect the anti-dew pipe, and it will be successful once! As long as the compressor is good, you can promise that you will never need to enter the repair department again! If it is "headache, foot pain, foot pain" and the leakage problem is not completely eliminated, then even if the "head" is cured, it will not take long for the "foot" to hurt again, and a new leak point will appear. .
There is another point that should be paid attention to: when using compressed air to test the pressure, since the compressed air will condense the moisture in the air in the system after cooling, it is easy to cause ice blockage, so a safe inert gas (such as nitrogen) or It is better to test the compressed air after drying.