Five common problems of refrigeration system, each is broken!

Five common problems of refrigeration system, each is broken!

1. Treatment of insufficient refrigerant:

　　1. Failure phenomenon:

The cooling effect of the whole machine is poor, the water outlet is only slightly cool, and the pressure on the high pressure side and the low pressure side are found to be low when checked with the manifold pressure gauge (at the normal speed of the compressor and the ambient temperature is about 35℃, the low pressure meter index is lower than 1kg /cm2, the high-pressure meter index is lower than 10kg/cm2), while the flow of bubbles can be seen in the sight glass.

　　2. Reason for failure:

　　 There are refrigerant leakage points in the refrigeration system, resulting in insufficient refrigerant.

　　 3. Treatment method:

　　1), use an electronic leak detector to find out the leak point and repair or replace parts.

2)If the parts are not replaced, only a proper amount of refrigerant can be added; if the parts are replaced, a proper amount of refrigerating oil should be added as required, and the system should be evacuated to add enough refrigerant.

2. Overcharge of refrigerant:

　　1. Failure phenomenon:

The refrigeration effect is poor. When checking with the manifold pressure gauge, it is found that the pressure on the high pressure side and the low pressure side are too high (when the compressor speed is normal and the ambient temperature is 35℃, the pressure of the high pressure gauge is about 19kg/cm2, and the pressure of the low pressure gauge is 2.3 kg/cm2, and no bubbles flow in the sight glass.

　　2. Reason for failure:

　　 The refrigeration system is filled with too much refrigerant, so that the refrigeration capacity cannot be fully utilized, resulting in poor refrigeration effect.

　　 3. Treatment method:

Connect the manifold pressure gauge to the system, and slowly loosen the manual valve on the low pressure side of the manifold pressure gauge to allow the refrigerant to be discharged slowly (it cannot be discharged from the high pressure side, because the refrigerant from the high pressure side will bring out a lot of refrigerant oil), Until the pressure on the high and low sides is normal, the refrigerant can be seen to flow clearly from the sight glass, and occasionally bubbles flow through.

　　 Three, the refrigeration system is mixed with air:

　　1. Failure phenomenon:

The refrigeration capacity of the whole machine is reduced; when checking with a manifold pressure gauge, it is found that the pressure on the high pressure side is high, and the pressure on the low pressure side is sometimes higher than the normal value. (When the compressor speed is normal and the ambient temperature is 35°C, the pressure on the high pressure side It is higher than 20kg/cm2; and the pointer of the high pressure meter is oscillating; on the other hand, many bubbles can be seen flowing in the sight glass.

　　2. Reason for failure:

　　 Air is mixed into the system. Mainly after assembly or overhaul, the vacuum is not complete; when charging refrigerant or adding refrigerating oil, air is brought into the system, or when the system is working under negative pressure, air is mixed in through improper places. When air enters the refrigerant, it has a certain pressure, and the refrigerant also has a certain pressure. In a closed container, the total gas pressure is equal to the sum of the partial pressures, so the high and low pressure gauges are higher than the normal value.

　　 3. Treatment method:

　　1) Release refrigerant (slowly release from the low pressure side with a pressure gauge).

　　 2) Check the cleanliness of the compressor oil.

　　3) Refill refrigerant after vacuuming.

　　 4. "Ice blockage" in the refrigeration system

　　1. Failure phenomenon:

　　 The refrigeration system periodically refrigerates suddenly and does not refrigerate. During operation, the pointer on the low pressure side of the manifold pressure gauge often fluctuates between the negative pressure and the normal value.

　　2. Reason for failure:

The refrigerant in the refrigeration system is mixed with moisture. Because moisture and the refrigerant are incompatible, when the refrigerant flows through the orifice of the expansion valve, the temperature drops suddenly, and the moisture mixed in the refrigerant is easily Small particles of ice formed around the orifice of the throttle valve or the valve needle hole are spherical or hemispherical. When the ice particles are condensed to a certain extent, they block the throttle channel and form an ice block failure. When ice is blocked due to icing, the refrigeration system cannot work normally, the cooling effect is obviously reduced, or even no cooling.

　　 At this time, the low pressure gauge has negative pressure, so the temperature at the ice block rises significantly, the ice particles in the ice block melt into water, the ice block phenomenon disappears, the refrigeration system resumes normal operation, the refrigeration is good, and the low pressure side pressure returns to normal. After a while, the system was blocked by ice again, and the system was not working properly.

　　 3. Treatment method:

　　1) Because the desiccant is in a supersaturated state, the reservoir with the desiccant must be replaced and 30ml of refrigerated oil must be added.

　　2) Vacuum the system and add a specified amount of refrigerant.

　　 5. Dirty blocking troubleshooting:

　　1. Failure phenomenon:

　　 The cooling effect is poor or no cooling. When the air-conditioning system is running, the readings of the high/low pressure gauges on the manifold pressure gauge are less than normal. (When the compressor speed is normal and the ambient temperature is about 35℃, the pressure on the high pressure gauge side is lower than 9kg/cm2, and the pressure on the low pressure side is at Negative pressure state), and there is frost or condensation on the filter and the pipes before and after the capillary tube.

　　2. Reason for failure:

　　 The dust in the refrigeration system sticks or adheres to the filter screen at the inlet end of the filter, or at the interface between the capillary tube and the filter screen, causing a local throttling phenomenon at this location, and the temperature drops rapidly, and condensation or frost occurs.

　　 3. Treatment method:

1) If there is frosting at the inlet of the filter and you hear the intermittent airflow sound, tap the filter body with a small wrench, the airflow sound will change, and the frost layer in front of the filter and the capillary will melt, and the filter can be judged The inlet filter is clogged.

　　 should now:

　　①Remove the capillary, clean the filter and blow dry, and reinstall it. Or replace the filter

　　②Evacuate and fill the refrigerant to the specified amount.